SCONS(1)SCONS(1)NAMEscons - a software construction tool
SYNOPSISscons [ options... ] [ name=val... ] [ targets... ]
DESCRIPTION
The scons utility builds software (or other files) by determining which
component pieces must be rebuilt and executing the necessary commands
to rebuild them.
By default, scons searches for a file named SConstruct, Sconstruct, or
sconstruct (in that order) in the current directory and reads its con‐
figuration from the first file found. An alternate file name may be
specified via the -f option.
The SConstruct file can specify subsidiary configuration files using
the SConscript() function. By convention, these subsidiary files are
named SConscript, although any name may be used. (Because of this nam‐
ing convention, the term "SConscript files" is sometimes used to refer
generically to all scons configuration files, regardless of actual file
name.)
The configuration files specify the target files to be built, and
(optionally) the rules to build those targets. Reasonable default
rules exist for building common software components (executable pro‐
grams, object files, libraries), so that for most software projects,
only the target and input files need be specified.
Before reading the SConstruct file, scons looks for a directory named
site_scons in various system directories (see below) and the directory
containing the SConstruct file; for each of those dirs which exists,
site_scons is prepended to sys.path, the file site_scons/site_init.py,
is evaluated if it exists, and the directory site_scons/site_tools is
prepended to the default toolpath if it exists. See the --no-site-dir
and --site-dir options for more details.
scons reads and executes the SConscript files as Python scripts, so you
may use normal Python scripting capabilities (such as flow control,
data manipulation, and imported Python libraries) to handle complicated
build situations. scons, however, reads and executes all of the SCon‐
script files before it begins building any targets. To make this obvi‐
ous, scons prints the following messages about what it is doing:
$ scons foo.out
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
cp foo.in foo.out
scons: done building targets.
$
The status messages (everything except the line that reads "cp foo.in
foo.out") may be suppressed using the -Q option.
scons does not automatically propagate the external environment used to
execute scons to the commands used to build target files. This is so
that builds will be guaranteed repeatable regardless of the environment
variables set at the time scons is invoked. This also means that if
the compiler or other commands that you want to use to build your tar‐
get files are not in standard system locations, scons will not find
them unless you explicitly set the PATH to include those locations.
Whenever you create an scons construction environment, you can propa‐
gate the value of PATH from your external environment as follows:
import os
env = Environment(ENV = {'PATH' : os.environ['PATH']})
Similarly, if the commands use external environment variables like
$PATH, $HOME, $JAVA_HOME, $LANG, $SHELL, $TERM, etc., these variables
can also be explicitly propagated:
import os
env = Environment(ENV = {'PATH' : os.environ['PATH'],
'HOME' : os.environ['HOME']})
Or you may explicitly propagate the invoking user's complete external
environment:
import os
env = Environment(ENV = os.environ)
This comes at the expense of making your build dependent on the user's
environment being set correctly, but it may be more convenient for many
configurations.
scons can scan known input files automatically for dependency informa‐
tion (for example, #include statements in C or C++ files) and will
rebuild dependent files appropriately whenever any "included" input
file changes. scons supports the ability to define new scanners for
unknown input file types.
scons knows how to fetch files automatically from SCCS or RCS subdirec‐
tories using SCCS, RCS or BitKeeper.
scons is normally executed in a top-level directory containing a SCon‐
struct file, optionally specifying as command-line arguments the target
file or files to be built.
By default, the command
scons
will build all target files in or below the current directory.
Explicit default targets (to be built when no targets are specified on
the command line) may be defined the SConscript file(s) using the
Default() function, described below.
Even when Default() targets are specified in the SConscript file(s),
all target files in or below the current directory may be built by
explicitly specifying the current directory (.) as a command-line tar‐
get:
scons .
Building all target files, including any files outside of the current
directory, may be specified by supplying a command-line target of the
root directory (on POSIX systems):
scons /
or the path name(s) of the volume(s) in which all the targets should be
built (on Windows systems):
scons C:\ D:\
To build only specific targets, supply them as command-line arguments:
scons foo bar
in which case only the specified targets will be built (along with any
derived files on which they depend).
Specifying "cleanup" targets in SConscript files is not usually neces‐
sary. The -c flag removes all files necessary to build the specified
target:
scons-c .
to remove all target files, or:
scons-c build export
to remove target files under build and export. Additional files or
directories to remove can be specified using the Clean() function.
Conversely, targets that would normally be removed by the -c invocation
can be prevented from being removed by using the NoClean() function.
A subset of a hierarchical tree may be built by remaining at the top-
level directory (where the SConstruct file lives) and specifying the
subdirectory as the target to be built:
scons src/subdir
or by changing directory and invoking scons with the -u option, which
traverses up the directory hierarchy until it finds the SConstruct
file, and then builds targets relatively to the current subdirectory:
cd src/subdir
scons-u .
scons supports building multiple targets in parallel via a -j option
that takes, as its argument, the number of simultaneous tasks that may
be spawned:
scons-j 4
builds four targets in parallel, for example.
scons can maintain a cache of target (derived) files that can be shared
between multiple builds. When caching is enabled in a SConscript file,
any target files built by scons will be copied to the cache. If an up-
to-date target file is found in the cache, it will be retrieved from
the cache instead of being rebuilt locally. Caching behavior may be
disabled and controlled in other ways by the --cache-force, --cache-
disable, and --cache-show command-line options. The --random option is
useful to prevent multiple builds from trying to update the cache
simultaneously.
Values of variables to be passed to the SConscript file(s) may be spec‐
ified on the command line:
scons debug=1 .
These variables are available in SConscript files through the ARGUMENTS
dictionary, and can be used in the SConscript file(s) to modify the
build in any way:
if ARGUMENTS.get('debug', 0):
env = Environment(CCFLAGS = '-g')
else:
env = Environment()
The command-line variable arguments are also available in the ARGLIST
list, indexed by their order on the command line. This allows you to
process them in order rather than by name, if necessary. ARGLIST[0]
returns a tuple containing (argname, argvalue). A Python exception is
thrown if you try to access a list member that does not exist.
scons requires Python version 2.4 or later. There should be no other
dependencies or requirements to run scons.
By default, scons knows how to search for available programming tools
on various systems. On Windows systems, scons searches in order for
the Microsoft Visual C++ tools, the MinGW tool chain, the Intel com‐
piler tools, and the PharLap ETS compiler. On OS/2 systems, scons
searches in order for the OS/2 compiler, the GCC tool chain, and the
Microsoft Visual C++ tools, On SGI IRIX, IBM AIX, Hewlett Packard HP-
UX, and Sun Solaris systems, scons searches for the native compiler
tools (MIPSpro, Visual Age, aCC, and Forte tools respectively) and the
GCC tool chain. On all other platforms, including POSIX (Linux and
UNIX) platforms, scons searches in order for the GCC tool chain, the
Microsoft Visual C++ tools, and the Intel compiler tools. You may, of
course, override these default values by appropriate configuration of
Environment construction variables.
OPTIONS
In general, scons supports the same command-line options as GNU make,
and many of those supported by cons.
-b Ignored for compatibility with non-GNU versions of make.
-c, --clean, --remove
Clean up by removing all target files for which a construction
command is specified. Also remove any files or directories
associated to the construction command using the Clean() func‐
tion. Will not remove any targets specified by the NoClean()
function.
--cache-debug=file
Print debug information about the CacheDir() derived-file
caching to the specified file. If file is - (a hyphen), the
debug information are printed to the standard output. The
printed messages describe what signature file names are being
looked for in, retrieved from, or written to the CacheDir()
directory tree.
--cache-disable, --no-cache
Disable the derived-file caching specified by CacheDir(). scons
will neither retrieve files from the cache nor copy files to the
cache.
--cache-force, --cache-populate
When using CacheDir(), populate a cache by copying any already-
existing, up-to-date derived files to the cache, in addition to
files built by this invocation. This is useful to populate a
new cache with all the current derived files, or to add to the
cache any derived files recently built with caching disabled via
the --cache-disable option.
--cache-show
When using CacheDir() and retrieving a derived file from the
cache, show the command that would have been executed to build
the file, instead of the usual report, "Retrieved `file' from
cache." This will produce consistent output for build logs,
regardless of whether a target file was rebuilt or retrieved
from the cache.
--config=mode
This specifies how the Configure call should use or generate the
results of configuration tests. The option should be specified
from among the following choices:
--config=auto
scons will use its normal dependency mechanisms to decide if a
test must be rebuilt or not. This saves time by not running the
same configuration tests every time you invoke scons, but will
overlook changes in system header files or external commands
(such as compilers) if you don't specify those dependecies
explicitly. This is the default behavior.
--config=force
If this option is specified, all configuration tests will be re-
run regardless of whether the cached results are out of date.
This can be used to explicitly force the configuration tests to
be updated in response to an otherwise unconfigured change in a
system header file or compiler.
--config=cache
If this option is specified, no configuration tests will be
rerun and all results will be taken from cache. Note that scons
will still consider it an error if --config=cache is specified
and a necessary test does not yet have any results in the cache.
-C directory, --directory=directory
Change to the specified directory before searching for the SCon‐
struct, Sconstruct, or sconstruct file, or doing anything else.
Multiple -C options are interpreted relative to the previous
one, and the right-most -C option wins. (This option is nearly
equivalent to -f directory/SConstruct, except that it will
search for SConstruct, Sconstruct, or sconstruct in the speci‐
fied directory.)
-D Works exactly the same way as the -u option except for the way
default targets are handled. When this option is used and no
targets are specified on the command line, all default targets
are built, whether or not they are below the current directory.
--debug=type
Debug the build process. type specifies what type of debugging:
--debug=count
Print how many objects are created of the various classes used
internally by SCons before and after reading the SConscript
files and before and after building targets. This is not sup‐
ported when SCons is executed with the Python -O (optimized)
option or when the SCons modules have been compiled with opti‐
mization (that is, when executing from *.pyo files).
--debug=duplicate
Print a line for each unlink/relink (or copy) of a variant file
from its source file. Includes debugging info for unlinking
stale variant files, as well as unlinking old targets before
building them.
--debug=dtree
A synonym for the newer --tree=derived option. This will be
deprecated in some future release and ultimately removed.
--debug=explain
Print an explanation of precisely why scons is deciding to
(re-)build any targets. (Note: this does not print anything
for targets that are not rebuilt.)
--debug=findlibs
Instruct the scanner that searches for libraries to print a mes‐
sage about each potential library name it is searching for, and
about the actual libraries it finds.
--debug=includes
Print the include tree after each top-level target is built.
This is generally used to find out what files are included by
the sources of a given derived file:
$ scons --debug=includes foo.o
--debug=memoizer
Prints a summary of hits and misses using the Memoizer, an
internal subsystem that counts how often SCons uses cached val‐
ues in memory instead of recomputing them each time they're
needed.
--debug=memory
Prints how much memory SCons uses before and after reading the
SConscript files and before and after building targets.
--debug=nomemoizer
A deprecated option preserved for backwards compatibility.
--debug=objects
Prints a list of the various objects of the various classes used
internally by SCons.
--debug=pdb
Re-run SCons under the control of the pdb Python debugger.
--debug=prepare
Print a line each time any target (internal or external) is pre‐
pared for building. scons prints this for each target it con‐
siders, even if that target is up to date (see also
--debug=explain). This can help debug problems with targets
that aren't being built; it shows whether scons is at least con‐
sidering them or not.
--debug=presub
Print the raw command line used to build each target before the
construction environment variables are substituted. Also shows
which targets are being built by this command. Output looks
something like this:
$ scons --debug=presub
Building myprog.o with action(s):
$SHCC $SHCFLAGS $SHCCFLAGS $CPPFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES
...
--debug=stacktrace
Prints an internal Python stack trace when encountering an oth‐
erwise unexplained error.
--debug=stree
A synonym for the newer --tree=all,status option. This will be
deprecated in some future release and ultimately removed.
--debug=time
Prints various time profiling information: the time spent exe‐
cuting each individual build command; the total build time (time
SCons ran from beginning to end); the total time spent reading
and executing SConscript files; the total time spent SCons
itself spend running (that is, not counting reading and execut‐
ing SConscript files); and both the total time spent executing
all build commands and the elapsed wall-clock time spent execut‐
ing those build commands. (When scons is executed without the
-j option, the elapsed wall-clock time will typically be
slightly longer than the total time spent executing all the
build commands, due to the SCons processing that takes place in
between executing each command. When scons is executed with the
-j option, and your build configuration allows good paralleliza‐
tion, the elapsed wall-clock time should be significantly
smaller than the total time spent executing all the build com‐
mands, since multiple build commands and intervening SCons pro‐
cessing should take place in parallel.)
--debug=tree
A synonym for the newer --tree=all option. This will be depre‐
cated in some future release and ultimately removed.
--diskcheck=types
Enable specific checks for whether or not there is a file on
disk where the SCons configuration expects a directory (or vice
versa), and whether or not RCS or SCCS sources exist when
searching for source and include files. The types argument can
be set to: all, to enable all checks explicitly (the default
behavior); none, to disable all such checks; match, to check
that files and directories on disk match SCons' expected config‐
uration; rcs, to check for the existence of an RCS source for
any missing source or include files; sccs, to check for the
existence of an SCCS source for any missing source or include
files. Multiple checks can be specified separated by commas;
for example, --diskcheck=sccs,rcs would still check for SCCS and
RCS sources, but disable the check for on-disk matches of files
and directories. Disabling some or all of these checks can pro‐
vide a performance boost for large configurations, or when the
configuration will check for files and/or directories across
networked or shared file systems, at the slight increased risk
of an incorrect build or of not handling errors gracefully (if
include files really should be found in SCCS or RCS, for exam‐
ple, or if a file really does exist where the SCons configura‐
tion expects a directory).
--duplicate=ORDER
There are three ways to duplicate files in a build tree: hard
links, soft (symbolic) links and copies. The default behaviour
of SCons is to prefer hard links to soft links to copies. You
can specify different behaviours with this option. ORDER must
be one of hard-soft-copy (the default), soft-hard-copy, hard-
copy, soft-copy or copy. SCons will attempt to duplicate files
using the mechanisms in the specified order.
-f file, --file=file, --makefile=file, --sconstruct=file
Use file as the initial SConscript file. Multiple -f options
may be specified, in which case scons will read all of the spec‐
ified files.
-h, --help
Print a local help message for this build, if one is defined in
the SConscript file(s), plus a line that describes the -H option
for command-line option help. If no local help message is
defined, prints the standard help message about command-line
options. Exits after displaying the appropriate message.
-H, --help-options
Print the standard help message about command-line options and
exit.
-i, --ignore-errors
Ignore all errors from commands executed to rebuild files.
-I directory, --include-dir=directory
Specifies a directory to search for imported Python modules. If
several -I options are used, the directories are searched in the
order specified.
--implicit-cache
Cache implicit dependencies. This causes scons to use the
implicit (scanned) dependencies from the last time it was run
instead of scanning the files for implicit dependencies. This
can significantly speed up SCons, but with the following limita‐
tions:
scons will not detect changes to implicit dependency search
paths (e.g. CPPPATH, LIBPATH) that would ordinarily cause dif‐
ferent versions of same-named files to be used.
scons will miss changes in the implicit dependencies in cases
where a new implicit dependency is added earlier in the implicit
dependency search path (e.g. CPPPATH, LIBPATH) than a current
implicit dependency with the same name.
--implicit-deps-changed
Forces SCons to ignore the cached implicit dependencies. This
causes the implicit dependencies to be rescanned and recached.
This implies --implicit-cache.
--implicit-deps-unchanged
Force SCons to ignore changes in the implicit dependencies.
This causes cached implicit dependencies to always be used.
This implies --implicit-cache.
--interactive
Starts SCons in interactive mode. The SConscript files are read
once and a scons>>> prompt is printed. Targets may now be
rebuilt by typing commands at interactive prompt without having
to re-read the SConscript files and re-initialize the dependency
graph from scratch.
SCons interactive mode supports the following commands:
build[OPTIONS] [TARGETS] ...
Builds the specified TARGETS (and their dependencies)
with the specified SCons command-line OPTIONS. b and
scons are synonyms.
The following SCons command-line options affect the
build command:
--cache-debug=FILE
--cache-disable, --no-cache
--cache-force, --cache-populate
--cache-show
--debug=TYPE
-i, --ignore-errors
-j N, --jobs=N
-k, --keep-going
-n, --no-exec, --just-print, --dry-run, --recon
-Q
-s, --silent, --quiet
--taskmastertrace=FILE
--tree=OPTIONS
Any other SCons command-line options that are specified
do not cause errors but have no effect on the build
command (mainly because they affect how the SConscript
files are read, which only happens once at the begin‐
ning of interactive mode).
clean[OPTIONS] [TARGETS] ...
Cleans the specified TARGETS (and their dependencies)
with the specified options. c is a synonym. This com‐
mand is itself a synonym for build --clean
exit Exits SCons interactive mode. You can also exit by
terminating input (CTRL+D on UNIX or Linux systems,
CTRL+Z on Windows systems).
help[COMMAND]
Provides a help message about the commands available in
SCons interactive mode. If COMMAND is specified, h and
? are synonyms.
shell[COMMANDLINE]
Executes the specified COMMANDLINE in a subshell. If
no COMMANDLINE is specified, executes the interactive
command interpreter specified in the SHELL environment
variable (on UNIX and Linux systems) or the COMSPEC
environment variable (on Windows systems). sh and !
are synonyms.
version
Prints SCons version information.
An empty line repeats the last typed command. Command-line
editing can be used if the readline module is available.
$ scons--interactive
scons: Reading SConscript files ...
scons: done reading SConscript files.
scons>>> build -n prog
scons>>> exit
-j N, --jobs=N
Specifies the number of jobs (commands) to run simultaneously.
If there is more than one -j option, the last one is effective.
-k, --keep-going
Continue as much as possible after an error. The target that
failed and those that depend on it will not be remade, but other
targets specified on the command line will still be processed.
-m Ignored for compatibility with non-GNU versions of make.
--max-drift=SECONDS
Set the maximum expected drift in the modification time of files
to SECONDS. This value determines how long a file must be
unmodified before its cached content signature will be used
instead of calculating a new content signature (MD5 checksum) of
the file's contents. The default value is 2 days, which means a
file must have a modification time of at least two days ago in
order to have its cached content signature used. A negative
value means to never cache the content signature and to ignore
the cached value if there already is one. A value of 0 means to
always use the cached signature, no matter how old the file is.
--md5-chunksize=KILOBYTES
Set the block size used to compute MD5 signatures to KILOBYTES.
This value determines the size of the chunks which are read in
at once when computing MD5 signatures. Files below that size
are fully stored in memory before performing the signature com‐
putation while bigger files are read in block-by-block. A huge
block-size leads to high memory consumption while a very small
block-size slows down the build considerably.
The default value is to use a chunk size of 64 kilobytes, which
should be appropriate for most uses.
-n, --just-print, --dry-run, --recon
No execute. Print the commands that would be executed to build
any out-of-date target files, but do not execute the commands.
--no-site-dir
Prevents the automatic addition of the standard site_scons dirs
to sys.path. Also prevents loading the site_scons/site_init.py
modules if they exist, and prevents adding their
site_scons/site_tools dirs to the toolpath.
--profile=file
Run SCons under the Python profiler and save the results in the
specified file. The results may be analyzed using the Python
pstats module.
-q, --question
Do not run any commands, or print anything. Just return an exit
status that is zero if the specified targets are already up to
date, non-zero otherwise.
-Q Quiets SCons status messages about reading SConscript files,
building targets and entering directories. Commands that are
executed to rebuild target files are still printed.
--random
Build dependencies in a random order. This is useful when
building multiple trees simultaneously with caching enabled, to
prevent multiple builds from simultaneously trying to build or
retrieve the same target files.
-s, --silent, --quiet
Silent. Do not print commands that are executed to rebuild tar‐
get files. Also suppresses SCons status messages.
-S, --no-keep-going, --stop
Ignored for compatibility with GNU make.
--site-dir=dir
Uses the named dir as the site dir rather than the default
site_scons dirs. This dir will get prepended to sys.path, the
module dir/site_init.py will get loaded if it exists, and
dir/site_tools will get added to the default toolpath.
The default set of site_scons dirs used when --site-dir is not
specified depends on the system platform, as follows. Note that
the directories are examined in the order given, from most
generic to most specific, so the last-executed site_init.py file
is the most specific one (which gives it the chance to override
everything else), and the dirs are prepended to the paths, again
so the last dir examined comes first in the resulting path.
Windows:
%ALLUSERSPROFILE/Application Data/scons/site_scons
%USERPROFILE%/Local Settings/Application Data/scons/site_scons
%APPDATA%/scons/site_scons
%HOME%/.scons/site_scons
./site_scons
Mac OS X:
/Library/Application Support/SCons/site_scons
/opt/local/share/scons/site_scons (for MacPorts)
/sw/share/scons/site_scons (for Fink)
$HOME/Library/Application Support/SCons/site_scons
$HOME/.scons/site_scons
./site_scons
Solaris:
/opt/sfw/scons/site_scons
/usr/share/scons/site_scons
$HOME/.scons/site_scons
./site_scons
Linux, HPUX, and other Posix-like systems:
/usr/share/scons/site_scons
$HOME/.scons/site_scons
./site_scons
--stack-size=KILOBYTES
Set the size stack used to run threads to KILOBYTES. This value
determines the stack size of the threads used to run jobs.
These are the threads that execute the actions of the builders
for the nodes that are out-of-date. Note that this option has
no effect unless the num_jobs option, which corresponds to -j
and --jobs, is larger than one. Using a stack size that is too
small may cause stack overflow errors. This usually shows up as
segmentation faults that cause scons to abort before building
anything. Using a stack size that is too large will cause scons
to use more memory than required and may slow down the entire
build process.
The default value is to use a stack size of 256 kilobytes, which
should be appropriate for most uses. You should not need to
increase this value unless you encounter stack overflow errors.
-t, --touch
Ignored for compatibility with GNU make. (Touching a file to
make it appear up-to-date is unnecessary when using scons.)
--taskmastertrace=file
Prints trace information to the specified file about how the
internal Taskmaster object evaluates and controls the order in
which Nodes are built. A file name of - may be used to specify
the standard output.
-tree=options
Prints a tree of the dependencies after each top-level target is
built. This prints out some or all of the tree, in various for‐
mats, depending on the options specified:
--tree=all
Print the entire dependency tree after each top-level target is
built. This prints out the complete dependency tree, including
implicit dependencies and ignored dependencies.
--tree=derived
Restricts the tree output to only derived (target) files, not
source files.
--tree=status
Prints status information for each displayed node.
--tree=prune
Prunes the tree to avoid repeating dependency information for
nodes that have already been displayed. Any node that has
already been displayed will have its name printed in [square
brackets], as an indication that the dependencies for that node
can be found by searching for the relevant output higher up in
the tree.
Multiple options may be specified, separated by commas:
# Prints only derived files, with status information:
scons --tree=derived,status
# Prints all dependencies of target, with status information
# and pruning dependencies of already-visited Nodes:
scons --tree=all,prune,status target
-u, --up, --search-up
Walks up the directory structure until an SConstruct , Scon‐
struct or sconstruct file is found, and uses that as the top of
the directory tree. If no targets are specified on the command
line, only targets at or below the current directory will be
built.
-U Works exactly the same way as the -u option except for the way
default targets are handled. When this option is used and no
targets are specified on the command line, all default targets
that are defined in the SConscript(s) in the current directory
are built, regardless of what directory the resultant targets
end up in.
-v, --version
Print the scons version, copyright information, list of authors,
and any other relevant information. Then exit.
-w, --print-directory
Print a message containing the working directory before and
after other processing.
--no-print-directory
Turn off -w, even if it was turned on implicitly.
--warn=type, --warn=no-type
Enable or disable warnings. type specifies the type of warnings
to be enabled or disabled:
--warn=all, --warn=no-all
Enables or disables all warnings.
--warn=cache-write-error, --warn=no-cache-write-error
Enables or disables warnings about errors trying to write a copy
of a built file to a specified CacheDir(). These warnings are
disabled by default.
--warn=corrupt-sconsign, --warn=no-corrupt-sconsign
Enables or disables warnings about unfamiliar signature data in
.sconsign files. These warnings are enabled by default.
--warn=dependency, --warn=no-dependency
Enables or disables warnings about dependencies. These warnings
are disabled by default.
--warn=deprecated, --warn=no-deprecated
Enables or disables all warnings about use of currently depre‐
cated features. These warnings are enabled by default. Note
that the --warn=no-deprecated option does not disable warnings
about absolutely all deprecated features. Warnings for some
deprecated features that have already been through several
releases with deprecation warnings may be mandatory for a
release or two before they are officially no longer supported by
SCons. Warnings for some specific deprecated features may be
enabled or disabled individually; see below.
--warn=deprecated-copy, --warn=no-deprecated-copy
Enables or disables warnings about use of the deprecated
env.Copy() method.
--warn=deprecated-source-signatures, --warn=no-deprecated-
source-signatures
Enables or disables warnings about use of the deprecated
SourceSignatures() function or env.SourceSignatures()
method.
--warn=deprecated-target-signatures, --warn=no-deprecated-tar‐
get-signatures
Enables or disables warnings about use of the deprecated
TargetSignatures() function or env.TargetSignatures()
method.
--warn=duplicate-environment, --warn=no-duplicate-environment
Enables or disables warnings about attempts to specify a build
of a target with two different construction environments that
use the same action. These warnings are enabled by default.
--warn=fortran-cxx-mix, --warn=no-fortran-cxx-mix
Enables or disables the specific warning about linking Fortran
and C++ object files in a single executable, which can yield
unpredictable behavior with some compilers.
--warn=future-deprecated, --warn=no-future-deprecated
Enables or disables warnings about features that will be depre‐
cated in the future. These warnings are disabled by default.
Enabling this warning is especially recommended for projects
that redistribute SCons configurations for other users to build,
so that the project can be warned as soon as possible about to-
be-deprecated features that may require changes to the configu‐
ration.
--warn=link, --warn=no-link
Enables or disables warnings about link steps.
--warn=misleading-keywords, --warn=no-misleading-keywords
Enables or disables warnings about use of the misspelled key‐
words targets and sources when calling Builders. (Note the last
s characters, the correct spellings are target and source.)
These warnings are enabled by default.
--warn=missing-sconscript, --warn=no-missing-sconscript
Enables or disables warnings about missing SConscript files.
These warnings are enabled by default.
--warn=no-md5-module, --warn=no-no-md5-module
Enables or disables warnings about the version of Python not
having an MD5 checksum module available. These warnings are
enabled by default.
--warn=no-metaclass-support, --warn=no-no-metaclass-support
Enables or disables warnings about the version of Python not
supporting metaclasses when the --debug=memoizer option is used.
These warnings are enabled by default.
--warn=no-object-count, --warn=no-no-object-count
Enables or disables warnings about the --debug=object feature
not working when scons is run with the python -O option or from
optimized Python (.pyo) modules.
--warn=no-parallel-support, --warn=no-no-parallel-support
Enables or disables warnings about the version of Python not
being able to support parallel builds when the -j option is
used. These warnings are enabled by default.
--warn=python-version, --warn=no-python-version
Enables or disables the warning about running SCons with a dep‐
recated version of Python. These warnings are enabled by
default.
--warn=reserved-variable, --warn=no-reserved-variable
Enables or disables warnings about attempts to set the reserved
construction variable names CHANGED_SOURCES, CHANGED_TARGETS,
TARGET, TARGETS, SOURCE, SOURCES, UNCHANGED_SOURCES or
UNCHANGED_TARGETS. These warnings are disabled by default.
--warn=stack-size, --warn=no-stack-size
Enables or disables warnings about requests to set the stack
size that could not be honored. These warnings are enabled by
default.
-Y repository, --repository=repository, --srcdir=repository
Search the specified repository for any input and target files
not found in the local directory hierarchy. Multiple -Y options
may be specified, in which case the repositories are searched in
the order specified.
CONFIGURATION FILE REFERENCE
Construction Environments
A construction environment is the basic means by which the SConscript
files communicate build information to scons. A new construction envi‐
ronment is created using the Environment function:
env = Environment()
Variables, called construction variables, may be set in a construction
environment either by specifying them as keywords when the object is
created or by assigning them a value after the object is created:
env = Environment(FOO = 'foo')
env['BAR'] = 'bar'
As a convenience, construction variables may also be set or modified by
the parse_flags keyword argument, which applies the ParseFlags method
(described below) to the argument value after all other processing is
completed. This is useful either if the exact content of the flags is
unknown (for example, read from a control file) or if the flags are
distributed to a number of construction variables.
env = Environment(parse_flags = '-Iinclude -DEBUG -lm')
This example adds 'include' to CPPPATH, 'EBUG' to CPPDEFINES, and 'm'
to LIBS.
By default, a new construction environment is initialized with a set of
builder methods and construction variables that are appropriate for the
current platform. An optional platform keyword argument may be used to
specify that an environment should be initialized for a different plat‐
form:
env = Environment(platform = 'cygwin')
env = Environment(platform = 'os2')
env = Environment(platform = 'posix')
env = Environment(platform = 'win32')
Specifying a platform initializes the appropriate construction vari‐
ables in the environment to use and generate file names with prefixes
and suffixes appropriate for the platform.
Note that the win32 platform adds the SystemDrive and SystemRoot vari‐
ables from the user's external environment to the construction environ‐
ment's ENV dictionary. This is so that any executed commands that use
sockets to connect with other systems (such as fetching source files
from external CVS repository specifications like :pserver:anony‐
mous@cvs.sourceforge.net:/cvsroot/scons) will work on Windows systems.
The platform argument may be function or callable object, in which case
the Environment() method will call the specified argument to update the
new construction environment:
def my_platform(env):
env['VAR'] = 'xyzzy'
env = Environment(platform = my_platform)
Additionally, a specific set of tools with which to initialize the
environment may be specified as an optional keyword argument:
env = Environment(tools = ['msvc', 'lex'])
Non-built-in tools may be specified using the toolpath argument:
env = Environment(tools = ['default', 'foo'], toolpath = ['tools'])
This looks for a tool specification in tools/foo.py (as well as using
the ordinary default tools for the platform). foo.py should have two
functions: generate(env, **kw) and exists(env). The generate() func‐
tion modifies the passed-in environment to set up variables so that the
tool can be executed; it may use any keyword arguments that the user
supplies (see below) to vary its initialization. The exists() function
should return a true value if the tool is available. Tools in the
toolpath are used before any of the built-in ones. For example, adding
gcc.py to the toolpath would override the built-in gcc tool. Also note
that the toolpath is stored in the environment for use by later calls
to Clone() and Tool() methods:
base = Environment(toolpath=['custom_path'])
derived = base.Clone(tools=['custom_tool'])
derived.CustomBuilder()
The elements of the tools list may also be functions or callable
objects, in which case the Environment() method will call the specified
elements to update the new construction environment:
def my_tool(env):
env['XYZZY'] = 'xyzzy'
env = Environment(tools = [my_tool])
The individual elements of the tools list may also themselves be two-
element lists of the form (toolname, kw_dict). SCons searches for the
toolname specification file as described above, and passes kw_dict,
which must be a dictionary, as keyword arguments to the tool's generate
function. The generate function can use the arguments to modify the
tool's behavior by setting up the environment in different ways or oth‐
erwise changing its initialization.
# in tools/my_tool.py:
def generate(env, **kw):
# Sets MY_TOOL to the value of keyword argument 'arg1' or 1.
env['MY_TOOL'] = kw.get('arg1', '1')
def exists(env):
return 1
# in SConstruct:
env = Environment(tools = ['default', ('my_tool', {'arg1': 'abc'})],
toolpath=['tools'])
The tool definition (i.e. my_tool()) can use the PLATFORM variable from
the environment it receives to customize the tool for different plat‐
forms.
If no tool list is specified, then SCons will auto-detect the installed
tools using the PATH variable in the ENV construction variable and the
platform name when the Environment is constructed. Changing the PATH
variable after the Environment is constructed will not cause the tools
to be redetected.
SCons supports the following tool specifications out of the box:
386asm
aixc++
aixcc
aixf77
aixlink
ar
as
bcc32
c++
cc
cvf
dmd
dvipdf
dvips
f77
f90
f95
fortran
g++
g77
gas
gcc
gfortran
gnulink
gs
hpc++
hpcc
hplink
icc
icl
ifl
ifort
ilink
ilink32
intelc
jar
javac
javah
latex
lex
link
linkloc
m4
masm
midl
mingw
mslib
mslink
mssdk
msvc
msvs
mwcc
mwld
nasm
pdflatex
pdftex
qt
rmic
rpcgen
sgiar
sgic++
sgicc
sgilink
sunar
sunc++
suncc
sunf77
sunf90
sunf95
sunlink
swig
tar
tex
textfile
tlib
yacc
zip
Additionally, there is a "tool" named default which configures the
environment with a default set of tools for the current platform.
On posix and cygwin platforms the GNU tools (e.g. gcc) are preferred by
SCons, on Windows the Microsoft tools (e.g. msvc) followed by MinGW are
preferred by SCons, and in OS/2 the IBM tools (e.g. icc) are preferred
by SCons.
Builder Methods
Build rules are specified by calling a construction environment's
builder methods. The arguments to the builder methods are target (a
list of targets to be built, usually file names) and source (a list of
sources to be built, usually file names).
Because long lists of file names can lead to a lot of quoting, scons
supplies a Split() global function and a same-named environment method
that split a single string into a list, separated on strings of white-
space characters. (These are similar to the split() member function of
Python strings but work even if the input isn't a string.)
Like all Python arguments, the target and source arguments to a builder
method can be specified either with or without the "target" and
"source" keywords. When the keywords are omitted, the target is first,
followed by the source. The following are equivalent examples of call‐
ing the Program builder method:
env.Program('bar', ['bar.c', 'foo.c'])
env.Program('bar', Split('bar.c foo.c'))
env.Program('bar', env.Split('bar.c foo.c'))
env.Program(source = ['bar.c', 'foo.c'], target = 'bar')
env.Program(target = 'bar', Split('bar.c foo.c'))
env.Program(target = 'bar', env.Split('bar.c foo.c'))
env.Program('bar', source = 'bar.c foo.c'.split())
Target and source file names that are not absolute path names (that is,
do not begin with / on POSIX systems or on Windows systems, with or
without an optional drive letter) are interpreted relative to the
directory containing the SConscript file being read. An initial #
(hash mark) on a path name means that the rest of the file name is
interpreted relative to the directory containing the top-level SCon‐
struct file, even if the # is followed by a directory separator charac‐
ter (slash or backslash).
Examples:
# The comments describing the targets that will be built
# assume these calls are in a SConscript file in the
# a subdirectory named "subdir".
# Builds the program "subdir/foo" from "subdir/foo.c":
env.Program('foo', 'foo.c')
# Builds the program "/tmp/bar" from "subdir/bar.c":
env.Program('/tmp/bar', 'bar.c')
# An initial '#' or '#/' are equivalent; the following
# calls build the programs "foo" and "bar" (in the
# top-level SConstruct directory) from "subdir/foo.c" and
# "subdir/bar.c", respectively:
env.Program('#foo', 'foo.c')
env.Program('#/bar', 'bar.c')
# Builds the program "other/foo" (relative to the top-level
# SConstruct directory) from "subdir/foo.c":
env.Program('#other/foo', 'foo.c')
When the target shares the same base name as the source and only the
suffix varies, and if the builder method has a suffix defined for the
target file type, then the target argument may be omitted completely,
and scons will deduce the target file name from the source file name.
The following examples all build the executable program bar (on POSIX
systems) or bar.exe (on Windows systems) from the bar.c source file:
env.Program(target = 'bar', source = 'bar.c')
env.Program('bar', source = 'bar.c')
env.Program(source = 'bar.c')
env.Program('bar.c')
As a convenience, a srcdir keyword argument may be specified when call‐
ing a Builder. When specified, all source file strings that are not
absolute paths will be interpreted relative to the specified srcdir.
The following example will build the build/prog (or build/prog.exe on
Windows) program from the files src/f1.c and src/f2.c:
env.Program('build/prog', ['f1.c', 'f2.c'], srcdir='src')
It is possible to override or add construction variables when calling a
builder method by passing additional keyword arguments. These overrid‐
den or added variables will only be in effect when building the target,
so they will not affect other parts of the build. For example, if you
want to add additional libraries for just one program:
env.Program('hello', 'hello.c', LIBS=['gl', 'glut'])
or generate a shared library with a non-standard suffix:
env.SharedLibrary('word', 'word.cpp',
SHLIBSUFFIX='.ocx',
LIBSUFFIXES=['.ocx'])
(Note that both the $SHLIBSUFFIX and $LIBSUFFIXES variables must be set
if you want SCons to search automatically for dependencies on the non-
standard library names; see the descriptions of these variables, below,
for more information.)
It is also possible to use the parse_flags keyword argument in an over‐
ride:
env = Program('hello', 'hello.c', parse_flags = '-Iinclude -DEBUG -lm')
This example adds 'include' to CPPPATH, 'EBUG' to CPPDEFINES, and 'm'
to LIBS.
Although the builder methods defined by scons are, in fact, methods of
a construction environment object, they may also be called without an
explicit environment:
Program('hello', 'hello.c')
SharedLibrary('word', 'word.cpp')
In this case, the methods are called internally using a default con‐
struction environment that consists of the tools and values that scons
has determined are appropriate for the local system.
Builder methods that can be called without an explicit environment may
be called from custom Python modules that you import into an SConscript
file by adding the following to the Python module:
from SCons.Script import *
All builder methods return a list-like object containing Nodes that
represent the target or targets that will be built. A Node is an
internal SCons object which represents build targets or sources.
The returned Node-list object can be passed to other builder methods as
source(s) or passed to any SCons function or method where a filename
would normally be accepted. For example, if it were necessary to add a
specific -D flag when compiling one specific object file:
bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR')
env.Program(source = ['foo.c', bar_obj_list, 'main.c'])
Using a Node in this way makes for a more portable build by avoiding
having to specify a platform-specific object suffix when calling the
Program() builder method.
Note that Builder calls will automatically "flatten" the source and
target file lists, so it's all right to have the bar_obj list return by
the StaticObject() call in the middle of the source file list. If you
need to manipulate a list of lists returned by Builders directly using
Python, you can either build the list by hand:
foo = Object('foo.c')
bar = Object('bar.c')
objects = ['begin.o'] + foo + ['middle.o'] + bar + ['end.o']
for object in objects:
print str(object)
Or you can use the Flatten() function supplied by scons to create a
list containing just the Nodes, which may be more convenient:
foo = Object('foo.c')
bar = Object('bar.c')
objects = Flatten(['begin.o', foo, 'middle.o', bar, 'end.o'])
for object in objects:
print str(object)
Note also that because Builder calls return a list-like object, not an
actual Python list, you should not use the Python += operator to append
Builder results to a Python list. Because the list and the object are
different types, Python will not update the original list in place, but
will instead create a new Node-list object containing the concatenation
of the list elements and the Builder results. This will cause problems
for any other Python variables in your SCons configuration that still
hold on to a reference to the original list. Instead, use the Python
.extend() method to make sure the list is updated in-place. Example:
object_files = []
# Do NOT use += as follows:
#
# object_files += Object('bar.c')
#
# It will not update the object_files list in place.
#
# Instead, use the .extend() method:
object_files.extend(Object('bar.c'))
The path name for a Node's file may be used by passing the Node to the
Python-builtin str() function:
bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR')
print "The path to bar_obj is:", str(bar_obj_list[0])
Note again that because the Builder call returns a list, we have to
access the first element in the list (bar_obj_list[0]) to get at the
Node that actually represents the object file.
Builder calls support a chdir keyword argument that specifies that the
Builder's action(s) should be executed after changing directory. If
the chdir argument is a string or a directory Node, scons will change
to the specified directory. If the chdir is not a string or Node and
is non-zero, then scons will change to the target file's directory.
# scons will change to the "sub" subdirectory
# before executing the "cp" command.
env.Command('sub/dir/foo.out', 'sub/dir/foo.in',
"cp dir/foo.in dir/foo.out",
chdir='sub')
# Because chdir is not a string, scons will change to the
# target's directory ("sub/dir") before executing the
# "cp" command.
env.Command('sub/dir/foo.out', 'sub/dir/foo.in',
"cp foo.in foo.out",
chdir=1)
Note that scons will not automatically modify its expansion of con‐
struction variables like $TARGET and $SOURCE when using the chdir key‐
word argument--that is, the expanded file names will still be relative
to the top-level SConstruct directory, and consequently incorrect rela‐
tive to the chdir directory. If you use the chdir keyword argument,
you will typically need to supply a different command line using expan‐
sions like ${TARGET.file} and ${SOURCE.file} to use just the filename
portion of the targets and source.
scons provides the following builder methods:
CFile()env.CFile()
Builds a C source file given a lex (.l) or yacc (.y) input file.
The suffix specified by the $CFILESUFFIX construction variable
(.c by default) is automatically added to the target if it is
not already present. Example:
# builds foo.c
env.CFile(target = 'foo.c', source = 'foo.l')
# builds bar.c
env.CFile(target = 'bar', source = 'bar.y')
Command()env.Command()
The Command() "Builder" is actually implemented as a function
that looks like a Builder, but actually takes an additional
argument of the action from which the Builder should be made.
See the Command() function description for the calling syntax
and details.
CXXFile()env.CXXFile()
Builds a C++ source file given a lex (.ll) or yacc (.yy) input
file. The suffix specified by the $CXXFILESUFFIX construction
variable (.cc by default) is automatically added to the target
if it is not already present. Example:
# builds foo.cc
env.CXXFile(target = 'foo.cc', source = 'foo.ll')
# builds bar.cc
env.CXXFile(target = 'bar', source = 'bar.yy')
DVI()env.DVI()
Builds a .dvi file from a .tex, .ltx or .latex input file. If
the source file suffix is .tex, scons will examine the contents
of the file; if the string ocumentclass or ocumentstyle is
found, the file is assumed to be a LaTeX file and the target is
built by invoking the $LATEXCOM command line; otherwise, the
$TEXCOM command line is used. If the file is a LaTeX file, the
DVI() builder method will also examine the contents of the .aux
file and invoke the $BIBTEX command line if the string bibdata
is found, start $MAKEINDEX to generate an index if a .ind file
is found and will examine the contents .log file and re-run the
$LATEXCOM command if the log file says it is necessary.
The suffix .dvi (hard-coded within TeX itself) is automatically
added to the target if it is not already present. Examples:
# builds from aaa.tex
env.DVI(target = 'aaa.dvi', source = 'aaa.tex')
# builds bbb.dvi
env.DVI(target = 'bbb', source = 'bbb.ltx')
# builds from ccc.latex
env.DVI(target = 'ccc.dvi', source = 'ccc.latex')
Install()env.Install()
Installs one or more source files or directories in the speci‐
fied target, which must be a directory. The names of the speci‐
fied source files or directories remain the same within the des‐
tination directory. The sources may be given as a string or as a
node returned by a builder.
env.Install('/usr/local/bin', source = ['foo', 'bar'])
InstallAs()env.InstallAs()
Installs one or more source files or directories to specific
names, allowing changing a file or directory name as part of the
installation. It is an error if the target and source arguments
list different numbers of files or directories.
InstallVersionedLib()env.InstallVersionedLib()
Installs a versioned shared library. The $SHLIBVERSION construc‐
tion variable should be defined in the environment to confirm
the version number in the library name. The symlinks appropri‐
ate to the architecture will be generated.
env.InstallAs(target = '/usr/local/bin/foo',
source = 'foo_debug')
env.InstallAs(target = ['../lib/libfoo.a', '../lib/libbar.a'],
source = ['libFOO.a', 'libBAR.a'])
Jar()env.Jar()
Builds a Java archive (.jar) file from the specified list of
sources. Any directories in the source list will be searched
for .class files). Any .java files in the source list will be
compiled to .class files by calling the Java() Builder.
If the $JARCHDIR value is set, the jar command will change to
the specified directory using the -C option. If $JARCHDIR is
not set explicitly, &SCons; will use the top of any subdirectory
tree in which Java .class were built by the Java() Builder.
If the contents any of the source files begin with the string
Manifest-Version, the file is assumed to be a manifest and is
passed to the jar command with the m option set.
env.Jar(target = 'foo.jar', source = 'classes')
env.Jar(target = 'bar.jar',
source = ['bar1.java', 'bar2.java'])
Java()env.Java()
Builds one or more Java class files. The sources may be any
combination of explicit .java files, or directory trees which
will be scanned for .java files.
SCons will parse each source .java file to find the classes
(including inner classes) defined within that file, and from
that figure out the target .class files that will be created.
The class files will be placed underneath the specified target
directory.
SCons will also search each Java file for the Java package name,
which it assumes can be found on a line beginning with the
string package in the first column; the resulting .class files
will be placed in a directory reflecting the specified package
name. For example, the file Foo.java defining a single public
Foo class and containing a package name of sub.dir will generate
a corresponding sub/dir/Foo.class class file.
Examples:
env.Java(target = 'classes', source = 'src')
env.Java(target = 'classes', source = ['src1', 'src2'])
env.Java(target = 'classes', source = ['File1.java', 'File2.java'])
Java source files can use the native encoding for the underlying
OS. Since SCons compiles in simple ASCII mode by default, the
compiler will generate warnings about unmappable characters,
which may lead to errors as the file is processed further. In
this case, the user must specify the LANG environment variable
to tell the compiler what encoding is used. For portibility,
it's best if the encoding is hard-coded so that the compile will
work if it is done on a system with a different encoding.
env = Environment()
env['ENV']['LANG'] = 'en_GB.UTF-8'
JavaH()env.JavaH()
Builds C header and source files for implementing Java native
methods. The target can be either a directory in which the
header files will be written, or a header file name which will
contain all of the definitions. The source can be the names of
.class files, the names of .java files to be compiled into
.class files by calling the Java() builder method, or the
objects returned from the Java() builder method.
If the construction variable $JAVACLASSDIR is set, either in the
environment or in the call to the JavaH() builder method itself,
then the value of the variable will be stripped from the begin‐
ning of any .class file names.
Examples:
# builds java_native.h
classes = env.Java(target = 'classdir', source = 'src')
env.JavaH(target = 'java_native.h', source = classes)
# builds include/package_foo.h and include/package_bar.h
env.JavaH(target = 'include',
source = ['package/foo.class', 'package/bar.class'])
# builds export/foo.h and export/bar.h
env.JavaH(target = 'export',
source = ['classes/foo.class', 'classes/bar.class'],
JAVACLASSDIR = 'classes')
Library()env.Library()
A synonym for the StaticLibrary() builder method.
LoadableModule()env.LoadableModule()
On most systems, this is the same as SharedLibrary(). On Mac OS
X (Darwin) platforms, this creates a loadable module bundle.
M4()env.M4()
Builds an output file from an M4 input file. This uses a
default $M4FLAGS value of -E, which considers all warnings to be
fatal and stops on the first warning when using the GNU version
of m4. Example:
env.M4(target = 'foo.c', source = 'foo.c.m4')
Moc()env.Moc()
Builds an output file from a moc input file. Moc input files are
either header files or cxx files. This builder is only available
after using the tool 'qt'. See the $QTDIR variable for more
information. Example:
env.Moc('foo.h') # generates moc_foo.cc
env.Moc('foo.cpp') # generates foo.moc
MOFiles()env.MOFiles()
This builder belongs to &t-link-msgfmt; tool. The builder com‐
piles PO files to MO files.
Example1. Create pl.mo and en.mo by compiling pl.poanden.po:
# ...
env.MOFiles(['pl', 'en'])
Example2. Compile files for languages defined in LINGUAS file:
# ...
env.MOFiles(LINGUAS_FILE = 1)
Example3. Create pl.mo and en.mo by compiling pl.po and en.po
plus files for languages defined in LINGUAS file:
# ...
env.MOFiles(['pl', 'en'], LINGUAS_FILE = 1)
Example4. Compile files for languages defined in LINGUAS file
(another version):
# ...
env['LINGUAS_FILE'] = 1
env.MOFiles()MSVSProject()env.MSVSProject()
Builds a Microsoft Visual Studio project file, and by default
builds a solution file as well.
This builds a Visual Studio project file, based on the version
of Visual Studio that is configured (either the latest installed
version, or the version specified by $MSVS_VERSION in the Envi‐
ronment constructor). For Visual Studio 6, it will generate a
.dsp file. For Visual Studio 7 (.NET) and later versions, it
will generate a .vcproj file.
By default, this also generates a solution file for the speci‐
fied project, a .dsw file for Visual Studio 6 or a .sln file for
Visual Studio 7 (.NET). This behavior may be disabled by speci‐
fying auto_build_solution=0 when you call MSVSProject(), in
which case you presumably want to build the solution file(s) by
calling the MSVSSolution() Builder (see below).
The MSVSProject() builder takes several lists of filenames to be
placed into the project file. These are currently limited to
srcs, incs, localincs, resources, and misc. These are pretty
self-explanatory, but it should be noted that these lists are
added to the $SOURCES construction variable as strings, NOT as
SCons File Nodes. This is because they represent file names to
be added to the project file, not the source files used to build
the project file.
The above filename lists are all optional, although at least one
must be specified for the resulting project file to be non-
empty.
In addition to the above lists of values, the following values
may be specified:
target: The name of the target .dsp or .vcproj file. The cor‐
rect suffix for the version of Visual Studio must be used, but
the $MSVSPROJECTSUFFIX construction variable will be defined to
the correct value (see example below).
variant: The name of this particular variant. For Visual Studio
7 projects, this can also be a list of variant names. These are
typically things like "Debug" or "Release", but really can be
anything you want. For Visual Studio 7 projects, they may also
specify a target platform separated from the variant name by a |
(vertical pipe) character: Debug|Xbox. The default target plat‐
form is Win32. Multiple calls to MSVSProject() with different
variants are allowed; all variants will be added to the project
file with their appropriate build targets and sources.
buildtarget: An optional string, node, or list of strings or
nodes (one per build variant), to tell the Visual Studio debug‐
ger what output target to use in what build variant. The number
of buildtarget entries must match the number of variant entries.
runfile: The name of the file that Visual Studio 7 and later
will run and debug. This appears as the value of the Output
field in the resutling Visual Studio project file. If this is
not specified, the default is the same as the specified build‐
target value.
Note that because &SCons; always executes its build commands
from the directory in which the SConstruct file is located, if
you generate a project file in a different directory than the
SConstruct directory, users will not be able to double-click on
the file name in compilation error messages displayed in the
Visual Studio console output window. This can be remedied by
adding the Visual C/C++ /FC compiler option to the $CCFLAGS
variable so that the compiler will print the full path name of
any files that cause compilation errors.
Example usage:
barsrcs = ['bar.cpp'],
barincs = ['bar.h'],
barlocalincs = ['StdAfx.h']
barresources = ['bar.rc','resource.h']
barmisc = ['bar_readme.txt']
dll = env.SharedLibrary(target = 'bar.dll',
source = barsrcs)
env.MSVSProject(target = 'Bar' + env['MSVSPROJECTSUFFIX'],
srcs = barsrcs,
incs = barincs,
localincs = barlocalincs,
resources = barresources,
misc = barmisc,
buildtarget = dll,
variant = 'Release')
MSVSSolution()env.MSVSSolution()
Builds a Microsoft Visual Studio solution file.
This builds a Visual Studio solution file, based on the version
of Visual Studio that is configured (either the latest installed
version, or the version specified by $MSVS_VERSION in the con‐
struction environment). For Visual Studio 6, it will generate a
.dsw file. For Visual Studio 7 (.NET), it will generate a .sln
file.
The following values must be specified:
target: The name of the target .dsw or .sln file. The correct
suffix for the version of Visual Studio must be used, but the
value $MSVSSOLUTIONSUFFIX will be defined to the correct value
(see example below).
variant: The name of this particular variant, or a list of vari‐
ant names (the latter is only supported for MSVS 7 solutions).
These are typically things like "Debug" or "Release", but really
can be anything you want. For MSVS 7 they may also specify tar‐
get platform, like this "Debug|Xbox". Default platform is Win32.
projects: A list of project file names, or Project nodes
returned by calls to the MSVSProject() Builder, to be placed
into the solution file. It should be noted that these file
names are NOT added to the $SOURCES environment variable in form
of files, but rather as strings. This is because they repre‐
sent file names to be added to the solution file, not the source
files used to build the solution file.
Example Usage:
env.MSVSSolution(target = 'Bar' + env['MSVSSOLUTIONSUFFIX'],
projects = ['bar' + env['MSVSPROJECTSUFFIX']],
variant = 'Release')
Object()env.Object()
A synonym for the StaticObject() builder method.
Package()env.Package()
Builds software distribution packages. Packages consist of
files to install and packaging information. The former may be
specified with the source parameter and may be left out, in
which case the &FindInstalledFiles; function will collect all
files that have an Install() or InstallAs() Builder attached.
If the target is not specified it will be deduced from addi‐
tional information given to this Builder.
The packaging information is specified with the help of con‐
struction variables documented below. This information is
called a tag to stress that some of them can also be attached to
files with the &Tag; function. The mandatory ones will complain
if they were not specified. They vary depending on chosen tar‐
get packager.
The target packager may be selected with the "PACKAGETYPE" com‐
mand line option or with the $PACKAGETYPE construction variable.
Currently the following packagers available:
* msi - Microsoft Installer
* rpm - Redhat Package Manger
* ipkg - Itsy Package Management System
* tarbz2 - compressed tar
* targz - compressed tar
* zip - zip file
* src_tarbz2 - compressed tar source
* src_targz - compressed tar source
* src_zip - zip file source
An updated list is always available under the "package_type"
option when running "scons --help" on a project that has packag‐
ing activated.
env = Environment(tools=['default', 'packaging'])
env.Install('/bin/', 'my_program')
env.Package( NAME = 'foo',
VERSION = '1.2.3',
PACKAGEVERSION = 0,
PACKAGETYPE = 'rpm',
LICENSE = 'gpl',
SUMMARY = 'balalalalal',
DESCRIPTION = 'this should be really really long',
X_RPM_GROUP = 'Application/fu',
SOURCE_URL = 'http://foo.org/foo-1.2.3.tar.gz'
)
PCH()env.PCH()
Builds a Microsoft Visual C++ precompiled header. Calling this
builder method returns a list of two targets: the PCH as the
first element, and the object file as the second element. Nor‐
mally the object file is ignored. This builder method is only
provided when Microsoft Visual C++ is being used as the com‐
piler. The PCH builder method is generally used in conjuction
with the PCH construction variable to force object files to use
the precompiled header:
env['PCH'] = env.PCH('StdAfx.cpp')[0]
PDF()env.PDF()
Builds a .pdf file from a .dvi input file (or, by extension, a
.tex, .ltx, or .latex input file). The suffix specified by the
$PDFSUFFIX construction variable (.pdf by default) is added
automatically to the target if it is not already present. Exam‐
ple:
# builds from aaa.tex
env.PDF(target = 'aaa.pdf', source = 'aaa.tex')
# builds bbb.pdf from bbb.dvi
env.PDF(target = 'bbb', source = 'bbb.dvi')
POInit()env.POInit()
This builder belongs to &t-link-msginit; tool. The builder ini‐
tializes missing PO file(s) if $POAUTOINIT is set. If $POAU‐
TOINIT is not set (default), POInit() prints instruction for
user (that is supposed to be a translator), telling how the PO
file should be initialized. In normal projects youshouldnotuse‐
POInit()andusePOUpdate() instead. POUpdate() chooses intelli‐
gently between msgmerge(1)andmsginit(1).POInit() always uses
msginit(1) and should be regarded as builder for special pur‐
poses or for temporary use (e.g. for quick, one time initializa‐
tion of a bunch of PO files) or for tests.
Target nodes defined through POInit() are not built by default
(they're Ignored from '.' node) but are added to special Alias
('po-create' by default). The alias name may be changed through
the $POCREATE_ALIAS construction variable. All PO files defined
through POInit()maybeeasilyinitializedbysconspo-create.
Example1. Initialize en.po and pl.po from messages.pot:
# ...
env.POInit(['en', 'pl']) # messages.pot --> [en.po, pl.po]
Example2. Initialize en.po and pl.po from foo.pot:
# ...
env.POInit(['en', 'pl'], ['foo']) # foo.pot --> [en.po, pl.po]
Example3. Initialize en.po and pl.po from foo.pot but using
$POTDOMAIN construction variable:
# ...
env.POInit(['en', 'pl'], POTDOMAIN='foo') # foo.pot --> [en.po, pl.po]
Example4. Initialize PO files for languages defined in LINGUAS
file. The files will be initialized from template messages.pot:
# ...
env.POInit(LINGUAS_FILE = 1) # needs 'LINGUAS' file
Example5. Initialize en.po and pl.pl PO files plus files for
languages defined in LINGUAS file. The files will be initialized
from template messages.pot:
# ...
env.POInit(['en', 'pl'], LINGUAS_FILE = 1)
Example6. You may preconfigure your environment first, and then
initialize PO files:
# ...
env['POAUTOINIT'] = 1
env['LINGUAS_FILE'] = 1
env['POTDOMAIN'] = 'foo'
env.POInit()
which has same efect as:
# ...
env.POInit(POAUTOINIT = 1, LINGUAS_FILE = 1, POTDOMAIN = 'foo')
PostScript()env.PostScript()
Builds a .ps file from a .dvi input file (or, by extension, a
.tex, .ltx, or .latex input file). The suffix specified by the
$PSSUFFIX construction variable (.ps by default) is added auto‐
matically to the target if it is not already present. Example:
# builds from aaa.tex
env.PostScript(target = 'aaa.ps', source = 'aaa.tex')
# builds bbb.ps from bbb.dvi
env.PostScript(target = 'bbb', source = 'bbb.dvi')
POTUpdate()env.POTUpdate()
The builder belongs to &t-link-xgettext; tool. The builder
updates target POT file if exists or creates one if it doesn't.
The node is not built by default (i.e. it is Ignored from '.'),
but only on demand (i.e. when given POT file is required or
when special alias is invoked). This builder adds its targe node
(messages.pot, say) to a special alias (pot-update by default,
see $POTUPDATE_ALIAS) so you can update/create them easily with
scons pot-update. The file is not written until there is no real
change in internationalized messages (or in comments that enter
POT file).
<note> You may see xgettext(1) being invoked by the &t-link-
xgettext; tool even if there is no real change in international‐
ized messages (so the POT file is not being updated). This hap‐
pens every time a source file has changed. In such case we
invoke xgettext(1) and compare its output with the content of
POT file to decide whether the file should be updated or
not.</para></note>
Example 1. Let's create po/ directory and place following SCon‐
struct script there:
# SConstruct in 'po/' subdir
env = Environment( tools = ['default', 'xgettext'] )
env.POTUpdate(['foo'], ['../a.cpp', '../b.cpp'])
env.POTUpdate(['bar'], ['../c.cpp', '../d.cpp'])
Then invoke scons few times:
user@host:$ scons # Does not create foo.pot nor bar.pot
user@host:$ scons foo.pot # Updates or creates foo.pot
user@host:$ scons pot-update # Updates or creates foo.pot and bar.pot
user@host:$ scons-c # Does not clean foo.pot nor bar.pot.
the results shall be as the comments above say.
Example 2. The POTUpdate() builder may be used with no target speci‐
fied, in which case default target messages.pot will be used. The
default target may also be overriden by setting $POTDOMAIN construction
variable or providing it as an override to POTUpdate() builder:
# SConstruct script
env = Environment( tools = ['default', 'xgettext'] )
env['POTDOMAIN'] = "foo"
env.POTUpdate(source = ["a.cpp", "b.cpp"]) # Creates foo.pot ...
env.POTUpdate(POTDOMAIN = "bar", source = ["c.cpp", "d.cpp"]) # and bar.pot
Example 3. The sources may be specified within separate file,
for example POTFILES.in:
# POTFILES.in in 'po/' subdirectory
../a.cpp
../b.cpp
# end of file
The name of the file (POTFILES.in) containing the list of
sources is provided via $XGETTEXTFROM:
# SConstruct file in 'po/' subdirectory
env = Environment( tools = ['default', 'xgettext'] )
env.POTUpdate(XGETTEXTFROM = 'POTFILES.in')
Example 4. You may use $XGETTEXTPATH to define source search
path. Assume, for example, that you have files a.cpp,
b.cpp,po/SConstruct, po/POTFILES.in.ThenyourPOT-related files
could look as below:
# POTFILES.in in 'po/' subdirectory
a.cpp
b.cpp
# end of file
# SConstruct file in 'po/' subdirectory
env = Environment( tools = ['default', 'xgettext'] )
env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH='../')
Example 5. Multiple search directories may be defined within a
list, i.e. XGETTEXTPATH = ['dir1', 'dir2', ...]. The order in
the list determines the search order of source files. The path
to the first file found is used.
Let's create 0/1/po/SConstruct script:
# SConstruct file in '0/1/po/' subdirectory
env = Environment( tools = ['default', 'xgettext'] )
env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../', '../../'])
and 0/1/po/POTFILES.in:
# POTFILES.in in '0/1/po/' subdirectory
a.cpp
# end of file
Write two *.cpp files, the first one is 0/a.cpp:
/* 0/a.cpp */
gettext("Hello from ../../a.cpp")
and the second is 0/1/a.cpp:
/* 0/1/a.cpp */
gettext("Hello from ../a.cpp")
then run scons. You'll obtain 0/1/po/messages.pot with the message
"Hello from ../a.cpp". When you reverse order in $XGETTEXTFOM, i.e.
when you write SConscript as
# SConstruct file in '0/1/po/' subdirectory
env = Environment( tools = ['default', 'xgettext'] )
env.POTUpdate(XGETTEXTFROM = 'POTFILES.in', XGETTEXTPATH=['../../', '../'])
then the messages.pot will contain msgid "Hello from
../../a.cpp" line and not msgidHello from ../a.cpp.
POUpdate()env.POUpdate()
The builder belongs to &t-link-msgmerge; tool. The builder
updates PO files with msgmerge(1), or initializes missing PO
files as described in documentation of &t-link-msginit; tool and
POInit() builder (see also $POAUTOINIT). Note, that POUpdate()
does not add its targets to po-create alias as POInit() does.
Target nodes defined through POUpdate() are not built by default
(they're Ignored from '.' node). Instead, they are added auto‐
matically to special Alias ('po-update' by default). The alias
name may be changed through the $POUPDATE_ALIAS construction
variable. You can easilly update PO files in your project by
scons po-update.
Example 1. Update en.po and pl.po from messages.pottem‐
plate(seealso$POTDOMAIN), assuming that the later one exists or
there is rule to build it (see POTUpdate()):
# ...
env.POUpdate(['en','pl']) # messages.pot --> [en.po, pl.po]
Example 2. Update en.po and pl.po from foo.pot template:
# ...
env.POUpdate(['en', 'pl'], ['foo']) # foo.pot --> [en.po, pl.pl]
Example 3. Update en.po and pl.po from foo.pot (another ver‐
sion):
# ...
env.POUpdate(['en', 'pl'], POTDOMAIN='foo') # foo.pot -- > [en.po, pl.pl]
Example 4. Update files for languages defined in LINGUAS file.
The files are updated from messages.pot template:
# ...
env.POUpdate(LINGUAS_FILE = 1) # needs 'LINGUAS' file
Example 5. Same as above, but update from foo.pot template:
# ...
env.POUpdate(LINGUAS_FILE = 1, source = ['foo'])
Example 6. Update en.po and pl.po plus files for languages
defined in LINGUAS file. The files are updated from messages.pot
template:
# produce 'en.po', 'pl.po' + files defined in 'LINGUAS':
env.POUpdate(['en', 'pl' ], LINGUAS_FILE = 1)
Example 7. Use $POAUTOINIT to automatically initialize PO file
if it doesn't exist:
# ...
env.POUpdate(LINGUAS_FILE = 1, POAUTOINIT = 1)
Example 8. Update PO files for languages defined in LINGUAS
file. The files are updated from foo.pot template. All necessary
settings are pre-configured via environment.
# ...
env['POAUTOINIT'] = 1
env['LINGUAS_FILE'] = 1
env['POTDOMAIN'] = 'foo'
env.POUpdate()Program()env.Program()
Builds an executable given one or more object files or C, C++,
D, or Fortran source files. If any C, C++, D or Fortran source
files are specified, then they will be automatically compiled to
object files using the Object() builder method; see that builder
method's description for a list of legal source file suffixes
and how they are interpreted. The target executable file prefix
(specified by the $PROGPREFIX construction variable; nothing by
default) and suffix (specified by the $PROGSUFFIX construction
variable; by default, .exe on Windows systems, nothing on POSIX
systems) are automatically added to the target if not already
present. Example:
env.Program(target = 'foo', source = ['foo.o', 'bar.c', 'baz.f'])
RES()env.RES()
Builds a Microsoft Visual C++ resource file. This builder
method is only provided when Microsoft Visual C++ or MinGW is
being used as the compiler. The .res (or .o for MinGW) suffix is
added to the target name if no other suffix is given. The
source file is scanned for implicit dependencies as though it
were a C file. Example:
env.RES('resource.rc')
RMIC()env.RMIC()
Builds stub and skeleton class files for remote objects from
Java .class files. The target is a directory relative to which
the stub and skeleton class files will be written. The source
can be the names of .class files, or the objects return from the
Java() builder method.
If the construction variable $JAVACLASSDIR is set, either in the
environment or in the call to the RMIC() builder method itself,
then the value of the variable will be stripped from the begin‐
ning of any .class file names.
classes = env.Java(target = 'classdir', source = 'src')
env.RMIC(target = 'outdir1', source = classes)
env.RMIC(target = 'outdir2',
source = ['package/foo.class', 'package/bar.class'])
env.RMIC(target = 'outdir3',
source = ['classes/foo.class', 'classes/bar.class'],
JAVACLASSDIR = 'classes')
RPCGenClient()env.RPCGenClient()
Generates an RPC client stub (_clnt.c) file from a specified RPC
(.x) source file. Because rpcgen only builds output files in
the local directory, the command will be executed in the source
file's directory by default.
# Builds src/rpcif_clnt.c
env.RPCGenClient('src/rpcif.x')
RPCGenHeader()env.RPCGenHeader()
Generates an RPC header (.h) file from a specified RPC (.x)
source file. Because rpcgen only builds output files in the
local directory, the command will be executed in the source
file's directory by default.
# Builds src/rpcif.h
env.RPCGenHeader('src/rpcif.x')
RPCGenService()env.RPCGenService()
Generates an RPC server-skeleton (_svc.c) file from a specified
RPC (.x) source file. Because rpcgen only builds output files
in the local directory, the command will be executed in the
source file's directory by default.
# Builds src/rpcif_svc.c
env.RPCGenClient('src/rpcif.x')
RPCGenXDR()env.RPCGenXDR()
Generates an RPC XDR routine (_xdr.c) file from a specified RPC
(.x) source file. Because rpcgen only builds output files in
the local directory, the command will be executed in the source
file's directory by default.
# Builds src/rpcif_xdr.c
env.RPCGenClient('src/rpcif.x')
SharedLibrary()env.SharedLibrary()
Builds a shared library (.so on a POSIX system, .dll on Windows)
given one or more object files or C, C++, D or Fortran source
files. If any source files are given, then they will be auto‐
matically compiled to object files. The static library prefix
and suffix (if any) are automatically added to the target. The
target library file prefix (specified by the $SHLIBPREFIX con‐
struction variable; by default, lib on POSIX systems, nothing on
Windows systems) and suffix (specified by the $SHLIBSUFFIX con‐
struction variable; by default, .dll on Windows systems, .so on
POSIX systems) are automatically added to the target if not
already present. Example:
env.SharedLibrary(target = 'bar', source = ['bar.c', 'foo.o'])
On Windows systems, the SharedLibrary() builder method will
always build an import (.lib) library in addition to the shared
(.dll) library, adding a .lib library with the same basename if
there is not already a .lib file explicitly listed in the tar‐
gets.
Any object files listed in the source must have been built for a
shared library (that is, using the SharedObject() builder
method). scons will raise an error if there is any mismatch.
On some platforms, there is a distinction between a shared
library (loaded automatically by the system to resolve external
references) and a loadable module (explicitly loaded by user
action). For maximum portability, use the LoadableModule()
builder for the latter.
When the $SHLIBVERSION construction variable is defined a ver‐
sioned shared library is created. This modifies the $SHLINKFLAGS
as required, adds the version number to the library name, and
creates the symlinks that are needed. $SHLIBVERSION needs to be
of the form X.Y.Z, where X and Y are numbers, and Z is a number
but can also contain letters to designate alpha, beta, or
release candidate patch levels.
This builder may create multiple links to the library. On a
POSIX system, for the shared library libbar.so.2.3.1, the links
created would be libbar.so, libbar.so.2, and libbar.so.2.3; on a
Darwin (OSX) system the library would be libbar.2.3.1.dylib and
the link would be libbar.dylib.
On Windows systems, specifying register=1 will cause the .dll to
be registered after it is built using REGSVR32. The command
that is run ("regsvr32" by default) is determined by $REGSVR
construction variable, and the flags passed are determined by
$REGSVRFLAGS. By default, $REGSVRFLAGS includes the /s option,
to prevent dialogs from popping up and requiring user attention
when it is run. If you change $REGSVRFLAGS, be sure to include
the /s option. For example,
env.SharedLibrary(target = 'bar',
source = ['bar.cxx', 'foo.obj'],
register=1)
will register bar.dll as a COM object when it is done linking
it.
SharedObject()env.SharedObject()
Builds an object file for inclusion in a shared library. Source
files must have one of the same set of extensions specified
above for the StaticObject() builder method. On some platforms
building a shared object requires additional compiler option
(e.g. -fPIC for gcc) in addition to those needed to build a nor‐
mal (static) object, but on some platforms there is no differ‐
ence between a shared object and a normal (static) one. When
there is a difference, SCons will only allow shared objects to
be linked into a shared library, and will use a different suffix
for shared objects. On platforms where there is no difference,
SCons will allow both normal (static) and shared objects to be
linked into a shared library, and will use the same suffix for
shared and normal (static) objects. The target object file pre‐
fix (specified by the $SHOBJPREFIX construction variable; by
default, the same as $OBJPREFIX) and suffix (specified by the
$SHOBJSUFFIX construction variable) are automatically added to
the target if not already present. Examples:
env.SharedObject(target = 'ddd', source = 'ddd.c')
env.SharedObject(target = 'eee.o', source = 'eee.cpp')
env.SharedObject(target = 'fff.obj', source = 'fff.for')
Note that the source files will be scanned according to the suf‐
fix mappings in the SourceFileScanner object. See the section
"Scanner Objects," below, for more information.
StaticLibrary()env.StaticLibrary()
Builds a static library given one or more object files or C,
C++, D or Fortran source files. If any source files are given,
then they will be automatically compiled to object files. The
static library prefix and suffix (if any) are automatically
added to the target. The target library file prefix (specified
by the $LIBPREFIX construction variable; by default, lib on
POSIX systems, nothing on Windows systems) and suffix (specified
by the $LIBSUFFIX construction variable; by default, .lib on
Windows systems, .a on POSIX systems) are automatically added to
the target if not already present. Example:
env.StaticLibrary(target = 'bar', source = ['bar.c', 'foo.o'])
Any object files listed in the source must have been built for a
static library (that is, using the StaticObject() builder
method). scons will raise an error if there is any mismatch.
StaticObject()env.StaticObject()
Builds a static object file from one or more C, C++, D, or For‐
tran source files. Source files must have one of the following
extensions:
.asm assembly language file
.ASM assembly language file
.c C file
.C Windows: C file
POSIX: C++ file
.cc C++ file
.cpp C++ file
.cxx C++ file
.cxx C++ file
.c++ C++ file
.C++ C++ file
.d D file
.f Fortran file
.F Windows: Fortran file
POSIX: Fortran file + C pre-processor
.for Fortran file
.FOR Fortran file
.fpp Fortran file + C pre-processor
.FPP Fortran file + C pre-processor
.m Object C file
.mm Object C++ file
.s assembly language file
.S Windows: assembly language file
ARM: CodeSourcery Sourcery Lite
.sx assembly language file + C pre-processor
POSIX: assembly language file + C pre-processor
.spp assembly language file + C pre-processor
.SPP assembly language file + C pre-processor
The target object file prefix (specified by the $OBJPREFIX con‐
struction variable; nothing by default) and suffix (specified by
the $OBJSUFFIX construction variable; .obj on Windows systems,
.o on POSIX systems) are automatically added to the target if
not already present. Examples:
env.StaticObject(target = 'aaa', source = 'aaa.c')
env.StaticObject(target = 'bbb.o', source = 'bbb.c++')
env.StaticObject(target = 'ccc.obj', source = 'ccc.f')
Note that the source files will be scanned according to the suf‐
fix mappings in SourceFileScanner object. See the section
"Scanner Objects," below, for more information.
Substfile()env.Substfile()
The Substfile() builder generates a single text file by concate‐
nating the source files. Nested lists of sources are flattened.
$LINESEPARATOR is used to separate the source files; see the
description of Textfile() for details.
If a single source file is present with an .in suffix, the suf‐
fix is stripped and the remainder is used as the default target
name.
The prefix and suffix specified by the $SUBSTFILEPREFIX and
$SUBSTFILESUFFIX construction variables (the null string by
default in both cases) are automatically added to the target if
they are not already present.
If a construction variable named $SUBST_DICT is present, it may
be either a Python dictionary or a sequence of (key,value)
tuples. If the former, the dictionary is converted into a list
of tuples in an arbitrary order, so if one key is a prefix of
another key or if one substitution could be further expanded by
another subsitition, it is unpredictible whether the expansion
will occur.
Any occurences in the source of a key are replaced by the corre‐
sponding value, which may be a Python callable function or a
string. If a value is a function, it is first called (with no
arguments) to produce a string. The string is subst-expanded
and the result replaces the key.
env = Environment(tools = ['default', 'textfile'])
env['prefix'] = '/usr/bin'
script_dict = {'@prefix@': '/bin', @exec_prefix@: '$prefix'}
env.Substfile('script.in', SUBST_DICT = script_dict)
conf_dict = {'%VERSION%': '1.2.3', '%BASE%': 'MyProg'}
env.Substfile('config.h.in', conf_dict, SUBST_DICT = conf_dict)
# UNPREDICTABLE - one key is a prefix of another
bad_foo = {'$foo': '$foo', '$foobar': '$foobar'}
env.Substfile('foo.in', SUBST_DICT = bad_foo)
# PREDICTABLE - keys are applied longest first
good_foo = [('$foobar', '$foobar'), ('$foo', '$foo')]
env.Substfile('foo.in', SUBST_DICT = good_foo)
# UNPREDICTABLE - one substitution could be futher expanded
bad_bar = {'@bar@': '@soap@', '@soap@': 'lye'}
env.Substfile('bar.in', SUBST_DICT = bad_bar)
# PREDICTABLE - substitutions are expanded in order
good_bar = (('@bar@', '@soap@'), ('@soap@', 'lye'))
env.Substfile('bar.in', SUBST_DICT = good_bar)
# the SUBST_DICT may be in common (and not an override)
substutions = {}
subst = Environment(tools = ['textfile'], SUBST_DICT = substitutions)
substitutions['@foo@'] = 'foo'
subst['SUBST_DICT']['@bar@'] = 'bar'
subst.Substfile('pgm1.c', [Value('#include "@foo@.h"'),
Value('#include "@bar@.h"'),
"common.in",
"pgm1.in"
])
subst.Substfile('pgm2.c', [Value('#include "@foo@.h"'),
Value('#include "@bar@.h"'),
"common.in",
"pgm2.in"
])
Tar()env.Tar()
Builds a tar archive of the specified files and/or directories.
Unlike most builder methods, the Tar() builder method may be
called multiple times for a given target; each additional call
adds to the list of entries that will be built into the archive.
Any source directories will be scanned for changes to any on-
disk files, regardless of whether or not scons knows about them
from other Builder or function calls.
env.Tar('src.tar', 'src')
# Create the stuff.tar file.
env.Tar('stuff', ['subdir1', 'subdir2'])
# Also add "another" to the stuff.tar file.
env.Tar('stuff', 'another')
# Set TARFLAGS to create a gzip-filtered archive.
env = Environment(TARFLAGS = '-c -z')
env.Tar('foo.tar.gz', 'foo')
# Also set the suffix to .tgz.
env = Environment(TARFLAGS = '-c -z',
TARSUFFIX = '.tgz')
env.Tar('foo')
Textfile()env.Textfile()
The Textfile() builder generates a single text file. The source
strings constitute the lines; nested lists of sources are flat‐
tened. $LINESEPARATOR is used to separate the strings.
If present, the $SUBST_DICT construction variable is used to
modify the strings before they are written; see the Substfile()
description for details.
The prefix and suffix specified by the $TEXTFILEPREFIX and
$TEXTFILESUFFIX construction variables (the null string and .txt
by default, respectively) are automatically added to the target
if they are not already present. Examples:
# builds/writes foo.txt
env.Textfile(target = 'foo.txt', source = ['Goethe', 42, 'Schiller'])
# builds/writes bar.txt
env.Textfile(target = 'bar',
source = ['lalala', 'tanteratei'],
LINESEPARATOR='|*')
# nested lists are flattened automatically
env.Textfile(target = 'blob',
source = ['lalala', ['Goethe', 42 'Schiller'], 'tanteratei'])
# files may be used as input by wraping them in File()
env.Textfile(target = 'concat', # concatenate files with a marker between
source = [File('concat1'), File('concat2')],
LINESEPARATOR = '====================\n')
Results are:
foo.txt
....8<----
Goethe
42
Schiller
....8<---- (no linefeed at the end)
bar.txt:
....8<----
lalala|*tanteratei
....8<---- (no linefeed at the end)
blob.txt
....8<----
lalala
Goethe
42
Schiller
tanteratei
....8<---- (no linefeed at the end)
Translate()env.Translate()
This pseudo-builder belongs to &t-link-gettext; toolset. The
builder extracts internationalized messages from source files,
updates POT template (if necessary) and then updates PO transla‐
tions (if necessary). If $POAUTOINIT is set, missing PO files
will be automatically created (i.e. without translator person
intervention). The variables $LINGUAS_FILE and $POTDOMAIN are
taken into acount too. All other construction variables used by
POTUpdate(), and POUpdate() work here too.
Example1. The simplest way is to specify input files and output
languages inline in a SCons script when invoking Translate()
# SConscript in 'po/' directory
env = Environment( tools = ["default", "gettext"] )
env['POAUTOINIT'] = 1
env.Translate(['en','pl'], ['../a.cpp','../b.cpp'])
Example2. If you wish, you may also stick to conventional style
known from <productname>autotools</productname>, i.e. using POT‐
FILES.in and LINGUAS files
# LINGUAS
en pl
#end
# POTFILES.in
a.cpp
b.cpp
# end
# SConscript
env = Environment( tools = ["default", "gettext"] )
env['POAUTOINIT'] = 1
env['XGETTEXTPATH'] = ['../']
env.Translate(LINGUAS_FILE = 1, XGETTEXTFROM = 'POTFILES.in')
The last approach is perhaps the recommended one. It allows eas‐
ily split internationalization/localization onto separate SCons
scripts, where a script in source tree is responsible for trans‐
lations (from sources to PO files) and script(s) under variant
directories are responsible for compilation of PO to MO files to
and for installation of MO files. The "gluing factor" synchro‐
nizing these two scripts is then the content of LINGUAS file.
Note, that the updated POT and PO files are usually going to be
committed back to the repository, so they must be updated within
the source directory (and not in variant directories). Addition‐
aly, the file listing of po/ directory contains LINGUAS file, so
the source tree looks familiar to translators, and they may work
with the project in their usual way.
Example3. Let's prepare a development tree as below
project/
+ SConstruct
+ build/
+ src/
+ po/
+ SConscript
+ SConscript.i18n
+ POTFILES.in
+ LINGUAS
with build being variant directory. Write the top-level SConstruct
script as follows
# SConstruct
env = Environment( tools = ["default", "gettext"] )
VariantDir('build', 'src', duplicate = 0)
env['POAUTOINIT'] = 1
SConscript('src/po/SConscript.i18n', exports = 'env')
SConscript('build/po/SConscript', exports = 'env')
the src/po/SConscript.i18n as
# src/po/SConscript.i18n
Import('env')
env.Translate(LINGUAS_FILE=1, XGETTEXTFROM='POTFILES.in', XGETTEXTPATH=['../'])
and the src/po/SConscript
# src/po/SConscript
Import('env')
env.MOFiles(LINGUAS_FILE = 1)
Such setup produces POT and PO files under source tree in src/po/ and
binary MO files under variant tree in build/po/. This way the POT and
PO files are separated from other output files, which must not be com‐
mitted back to source repositories (e.g. MO files).
<note> In above example, the PO files are not updated, nor created
automatically when you issue scons '.' command. The files must be
updated (created) by hand via scons po-update and then MO files can be
compiled by running scons '.'.</para></note>
TypeLibrary()env.TypeLibrary()
Builds a Windows type library (.tlb) file from an input IDL file
(.idl). In addition, it will build the associated inteface stub
and proxy source files, naming them according to the base name
of the .idl file. For example,
env.TypeLibrary(source="foo.idl")
Will create foo.tlb, foo.h, foo_i.c, foo_p.c and foo_data.c
files.
Uic()env.Uic()
Builds a header file, an implementation file and a moc file from
an ui file. and returns the corresponding nodes in the above
order. This builder is only available after using the tool
'qt'. Note: you can specify .ui files directly as source files
to the Program(), Library() and SharedLibrary() builders without
using this builder. Using this builder lets you override the
standard naming conventions (be careful: prefixes are always
prepended to names of built files; if you don't want prefixes,
you may set them to ``). See the $QTDIR variable for more
information. Example:
env.Uic('foo.ui') # -> ['foo.h', 'uic_foo.cc', 'moc_foo.cc']
env.Uic(target = Split('include/foo.h gen/uicfoo.cc gen/mocfoo.cc'),
source = 'foo.ui') # -> ['include/foo.h', 'gen/uicfoo.cc', 'gen/mocfoo.cc']
Zip()env.Zip()
Builds a zip archive of the specified files and/or directories.
Unlike most builder methods, the Zip() builder method may be
called multiple times for a given target; each additional call
adds to the list of entries that will be built into the archive.
Any source directories will be scanned for changes to any on-
disk files, regardless of whether or not scons knows about them
from other Builder or function calls.
env.Zip('src.zip', 'src')
# Create the stuff.zip file.
env.Zip('stuff', ['subdir1', 'subdir2'])
# Also add "another" to the stuff.tar file.
env.Zip('stuff', 'another')
All targets of builder methods automatically depend on their sources.
An explicit dependency can be specified using the Depends method of a
construction environment (see below).
In addition, scons automatically scans source files for various pro‐
gramming languages, so the dependencies do not need to be specified
explicitly. By default, SCons can C source files, C++ source files,
Fortran source files with .F (POSIX systems only), .fpp, or .FPP file
extensions, and assembly language files with .S (POSIX systems only),
.spp, or .SPP files extensions for C preprocessor dependencies. SCons
also has default support for scanning D source files, You can also
write your own Scanners to add support for additional source file
types. These can be added to the default Scanner object used by the
Object(), StaticObject(), and SharedObject() Builders by adding them to
the SourceFileScanner object. See the section "Scanner Objects" below,
for more information about defining your own Scanner objects and using
the SourceFileScanner object.
Methods and Functions to Do Things
In addition to Builder methods, scons provides a number of other con‐
struction environment methods and global functions to manipulate the
build configuration.
Usually, a construction environment method and global function with the
same name both exist so that you don't have to remember whether to a
specific bit of functionality must be called with or without a con‐
struction environment. In the following list, if you call something as
a global function it looks like:
Function(arguments)
and if you call something through a construction environment it looks
like:
env.Function(arguments)
If you can call the functionality in both ways, then both forms are
listed.
Global functions may be called from custom Python modules that you
import into an SConscript file by adding the following to the Python
module:
from SCons.Script import *
Except where otherwise noted, the same-named construction environment
method and global function provide the exact same functionality. The
only difference is that, where appropriate, calling the functionality
through a construction environment will substitute construction vari‐
ables into any supplied strings. For example:
env = Environment(FOO = 'foo')
Default('$FOO')
env.Default('$FOO')
In the above example, the first call to the global Default() function
will actually add a target named $FOO to the list of default targets,
while the second call to the env.Default() construction environment
method will expand the value and add a target named foo to the list of
default targets. For more on construction variable expansion, see the
next section on construction variables.
Construction environment methods and global functions supported by
scons include:
Action(action, [cmd/str/fun, [var, ...]] [option=value, ...])
env.Action(action, [cmd/str/fun, [var, ...]] [option=value, ...])
Creates an Action object for the specified action. See the sec‐
tion "Action Objects," below, for a complete explanation of the
arguments and behavior.
Note that the env.Action() form of the invocation will expand
construction variables in any argument strings, including the
action argument, at the time it is called using the construction
variables in the env construction environment through which
env.Action() was called. The Action() form delays all variable
expansion until the Action object is actually used.
AddMethod(object, function, [name])
env.AddMethod(function, [name])
When called with the AddMethod() form, adds the specified func‐
tion to the specified object as the specified method name. When
called with the env.AddMethod() form, adds the specified func‐
tion to the construction environment env as the specified method
name. In both cases, if name is omitted or None, the name of
the specified function itself is used for the method name.
Examples:
# Note that the first argument to the function to
# be attached as a method must be the object through
# which the method will be called; the Python
# convention is to call it 'self'.
def my_method(self, arg):
print "my_method() got", arg
# Use the global AddMethod() function to add a method
# to the Environment class. This
AddMethod(Environment, my_method)
env = Environment()
env.my_method('arg')
# Add the function as a method, using the function
# name for the method call.
env = Environment()
env.AddMethod(my_method, 'other_method_name')
env.other_method_name('another arg')
AddOption(arguments)
This function adds a new command-line option to be recognized.
The specified arguments are the same as supported by the stan‐
dard Python optparse.add_option() method (with a few additional
capabilities noted below); see the documentation for optparse
for a thorough discussion of its option-processing capabities.
In addition to the arguments and values supported by the opt‐
parse.add_option() method, the SCons AddOption() function allows
you to set the nargs keyword value to '?' (a string with just
the question mark) to indicate that the specified long option(s)take(s) an optional argument. When nargs = '?' is passed to
the AddOption() function, the const keyword argument may be used
to supply the "default" value that should be used when the
option is specified on the command line without an explicit
argument.
If no default= keyword argument is supplied when calling AddOp‐
tion(), the option will have a default value of None.
Once a new command-line option has been added with AddOption(),
the option value may be accessed using GetOption() or env.GetOp‐
tion(). The value may also be set, using SetOption() or
env.SetOption(), if conditions in a SConscript require overrid‐
ing any default value. Note, however, that a value specified on
the command line will always override a value set by any SCon‐
script file.
Any specified help= strings for the new option(s) will be dis‐
played by the -H or -h options (the latter only if no other help
text is specified in the SConscript files). The help text for
the local options specified by AddOption() will appear below the
SCons options themselves, under a separate Local Options head‐
ing. The options will appear in the help text in the order in
which the AddOption() calls occur.
Example:
AddOption('--prefix',
dest='prefix',
nargs=1, type='string',
action='store',
metavar='DIR',
help='installation prefix')
env = Environment(PREFIX = GetOption('prefix'))
AddPostAction(target, action)
env.AddPostAction(target, action)
Arranges for the specified action to be performed after the
specified target has been built. The specified action(s) may be
an Action object, or anything that can be converted into an
Action object (see below).
When multiple targets are supplied, the action may be called
multiple times, once after each action that generates one or
more targets in the list.
AddPreAction(target, action)
env.AddPreAction(target, action)
Arranges for the specified action to be performed before the
specified target is built. The specified action(s) may be an
Action object, or anything that can be converted into an Action
object (see below).
When multiple targets are specified, the action(s) may be called
multiple times, once before each action that generates one or
more targets in the list.
Note that if any of the targets are built in multiple steps, the
action will be invoked just before the "final" action that
specifically generates the specified target(s). For example,
when building an executable program from a specified source .c
file via an intermediate object file:
foo = Program('foo.c')
AddPreAction(foo, 'pre_action')
The specified pre_action would be executed before scons calls
the link command that actually generates the executable program
binary foo, not before compiling the foo.c file into an object
file.
Alias(alias, [targets, [action]])
env.Alias(alias, [targets, [action]])
Creates one or more phony targets that expand to one or more
other targets. An optional action (command) or list of actions
can be specified that will be executed whenever the any of the
alias targets are out-of-date. Returns the Node object repre‐
senting the alias, which exists outside of any file system.
This Node object, or the alias name, may be used as a dependency
of any other target, including another alias. Alias() can be
called multiple times for the same alias to add additional tar‐
gets to the alias, or additional actions to the list for this
alias.
Examples:
Alias('install')
Alias('install', '/usr/bin')
Alias(['install', 'install-lib'], '/usr/local/lib')
env.Alias('install', ['/usr/local/bin', '/usr/local/lib'])
env.Alias('install', ['/usr/local/man'])
env.Alias('update', ['file1', 'file2'], "update_database $SOURCES")
AllowSubstExceptions([exception, ...])
Specifies the exceptions that will be allowed when expanding
construction variables. By default, any construction variable
expansions that generate a NameError or IndexError exception
will expand to a '' (a null string) and not cause scons to fail.
All exceptions not in the specified list will generate an error
message and terminate processing.
If AllowSubstExceptions() is called multiple times, each call
completely overwrites the previous list of allowed exceptions.
Example:
# Requires that all construction variable names exist.
# (You may wish to do this if you want to enforce strictly
# that all construction variables must be defined before use.)
AllowSubstExceptions()
# Also allow a string containing a zero-division expansion
# like '${1 / 0}' to evalute to ''.
AllowSubstExceptions(IndexError, NameError, ZeroDivisionError)
AlwaysBuild(target, ...)
env.AlwaysBuild(target, ...)
Marks each given target so that it is always assumed to be out
of date, and will always be rebuilt if needed. Note, however,
that AlwaysBuild() does not add its target(s) to the default
target list, so the targets will only be built if they are spec‐
ified on the command line, or are a dependent of a target speci‐
fied on the command line--but they will always be built if so
specified. Multiple targets can be passed in to a single call
to AlwaysBuild().
env.Append(key=val, [...])
Appends the specified keyword arguments to the end of construc‐
tion variables in the environment. If the Environment does not
have the specified construction variable, it is simply added to
the environment. If the values of the construction variable and
the keyword argument are the same type, then the two values will
be simply added together. Otherwise, the construction variable
and the value of the keyword argument are both coerced to lists,
and the lists are added together. (See also the Prepend method,
below.)
Example:
env.Append(CCFLAGS = ' -g', FOO = ['foo.yyy'])
env.AppendENVPath(name, newpath, [envname, sep, delete_existing])
This appends new path elements to the given path in the speci‐
fied external environment (ENV by default). This will only add
any particular path once (leaving the last one it encounters and
ignoring the rest, to preserve path order), and to help assure
this, will normalize all paths (using os.path.normpath and
os.path.normcase). This can also handle the case where the
given old path variable is a list instead of a string, in which
case a list will be returned instead of a string.
If delete_existing is 0, then adding a path that already exists
will not move it to the end; it will stay where it is in the
list.
Example:
print 'before:',env['ENV']['INCLUDE']
include_path = '/foo/bar:/foo'
env.AppendENVPath('INCLUDE', include_path)
print 'after:',env['ENV']['INCLUDE']
yields:
before: /foo:/biz
after: /biz:/foo/bar:/foo
env.AppendUnique(key=val, [...], delete_existing=0)
Appends the specified keyword arguments to the end of construc‐
tion variables in the environment. If the Environment does not
have the specified construction variable, it is simply added to
the environment. If the construction variable being appended to
is a list, then any value(s) that already exist in the construc‐
tion variable will not be added again to the list. However, if
delete_existing is 1, existing matching values are removed
first, so existing values in the arg list move to the end of the
list.
Example:
env.AppendUnique(CCFLAGS = '-g', FOO = ['foo.yyy'])
env.BitKeeper()
A factory function that returns a Builder object to be used to
fetch source files using BitKeeper. The returned Builder is
intended to be passed to the SourceCode() function.
This function is deprecated. For details, see the entry for the
SourceCode() function.
Example:
env.SourceCode('.', env.BitKeeper())
BuildDir(build_dir, src_dir, [duplicate])
env.BuildDir(build_dir, src_dir, [duplicate])
Deprecated synonyms for VariantDir() and env.VariantDir(). The
build_dir argument becomes the variant_dir argument of Variant‐
Dir() or env.VariantDir().
Builder(action, [arguments])
env.Builder(action, [arguments])
Creates a Builder object for the specified action. See the sec‐
tion "Builder Objects," below, for a complete explanation of the
arguments and behavior.
Note that the env.Builder() form of the invocation will expand
construction variables in any arguments strings, including the
action argument, at the time it is called using the construction
variables in the env construction environment through which
env.Builder() was called. The Builder() form delays all vari‐
able expansion until after the Builder object is actually
called.
CacheDir(cache_dir)env.CacheDir(cache_dir)
Specifies that scons will maintain a cache of derived files in
cache_dir. The derived files in the cache will be shared among
all the builds using the same CacheDir() call. Specifying a
cache_dir of None disables derived file caching.
Calling env.CacheDir() will only affect targets built through
the specified construction environment. Calling CacheDir() sets
a global default that will be used by all targets built through
construction environments that do not have an env.CacheDir()
specified.
When a CacheDir() is being used and scons finds a derived file
that needs to be rebuilt, it will first look in the cache to see
if a derived file has already been built from identical input
files and an identical build action (as incorporated into the
MD5 build signature). If so, scons will retrieve the file from
the cache. If the derived file is not present in the cache,
scons will rebuild it and then place a copy of the built file in
the cache (identified by its MD5 build signature), so that it
may be retrieved by other builds that need to build the same
derived file from identical inputs.
Use of a specified CacheDir() may be disabled for any invocation
by using the --cache-disable option.
If the --cache-force option is used, scons will place a copy of
all derived files in the cache, even if they already existed and
were not built by this invocation. This is useful to populate a
cache the first time CacheDir() is added to a build, or after
using the --cache-disable option.
When using CacheDir(), scons will report, "Retrieved `file' from
cache," unless the --cache-show option is being used. When the
--cache-show option is used, scons will print the action that
would have been used to build the file, without any indication
that the file was actually retrieved from the cache. This is
useful to generate build logs that are equivalent regardless of
whether a given derived file has been built in-place or
retrieved from the cache.
The NoCache() method can be used to disable caching of specific
files. This can be useful if inputs and/or outputs of some tool
are impossible to predict or prohibitively large.
Clean(targets, files_or_dirs)
env.Clean(targets, files_or_dirs)
This specifies a list of files or directories which should be
removed whenever the targets are specified with the -c command
line option. The specified targets may be a list or an individ‐
ual target. Multiple calls to Clean() are legal, and create new
targets or add files and directories to the clean list for the
specified targets.
Multiple files or directories should be specified either as sep‐
arate arguments to the Clean() method, or as a list. Clean()
will also accept the return value of any of the construction
environment Builder methods. Examples:
The related NoClean() function overrides calling Clean() for the
same target, and any targets passed to both functions will not
be removed by the -c option.
Examples:
Clean('foo', ['bar', 'baz'])
Clean('dist', env.Program('hello', 'hello.c'))
Clean(['foo', 'bar'], 'something_else_to_clean')
In this example, installing the project creates a subdirectory
for the documentation. This statement causes the subdirectory
to be removed if the project is deinstalled.
Clean(docdir, os.path.join(docdir, projectname))
env.Clone([key=val, ...])
Returns a separate copy of a construction environment. If there
are any keyword arguments specified, they are added to the
returned copy, overwriting any existing values for the keywords.
Example:
env2 = env.Clone()
env3 = env.Clone(CCFLAGS = '-g')
Additionally, a list of tools and a toolpath may be specified,
as in the Environment constructor:
def MyTool(env): env['FOO'] = 'bar'
env4 = env.Clone(tools = ['msvc', MyTool])
The parse_flags keyword argument is also recognized:
# create an environment for compiling programs that use wxWidgets
wx_env = env.Clone(parse_flags = '!wx-config --cflags --cxxflags')
Command(target, source, action, [key=val, ...])
env.Command(target, source, action, [key=val, ...])
Executes a specific action (or list of actions) to build a tar‐
get file or files. This is more convenient than defining a sep‐
arate Builder object for a single special-case build.
As a special case, the source_scanner keyword argument can be
used to specify a Scanner object that will be used to scan the
sources. (The global DirScanner object can be used if any of
the sources will be directories that must be scanned on-disk for
changes to files that aren't already specified in other Builder
of function calls.)
Any other keyword arguments specified override any same-named
existing construction variables.
An action can be an external command, specified as a string, or
a callable Python object; see "Action Objects," below, for more
complete information. Also note that a string specifying an
external command may be preceded by an @ (at-sign) to suppress
printing the command in question, or by a - (hyphen) to ignore
the exit status of the external command.
Examples:
env.Command('foo.out', 'foo.in',
"$FOO_BUILD < $SOURCES > $TARGET")
env.Command('bar.out', 'bar.in',
["rm -f $TARGET",
"$BAR_BUILD < $SOURCES > $TARGET"],
ENV = {'PATH' : '/usr/local/bin/'})
def rename(env, target, source):
import os
os.rename('.tmp', str(target[0]))
env.Command('baz.out', 'baz.in',
["$BAZ_BUILD < $SOURCES > .tmp",
rename ])
Note that the Command() function will usually assume, by
default, that the specified targets and/or sources are Files, if
no other part of the configuration identifies what type of entry
it is. If necessary, you can explicitly specify that targets or
source nodes should be treated as directoriese by using the
Dir() or env.Dir() functions.
Examples:
env.Command('ddd.list', Dir('ddd'), 'ls -l $SOURCE > $TARGET')
env['DISTDIR'] = 'destination/directory'
env.Command(env.Dir('$DISTDIR')), None, make_distdir)
(Also note that SCons will usually automatically create any
directory necessary to hold a target file, so you normally don't
need to create directories by hand.)
Configure(env, [custom_tests, conf_dir, log_file, config_h])
env.Configure([custom_tests, conf_dir, log_file, config_h])
Creates a Configure object for integrated functionality similar
to GNU autoconf. See the section "Configure Contexts," below,
for a complete explanation of the arguments and behavior.
env.Copy([key=val, ...])
A now-deprecated synonym for env.Clone().
env.CVS(repository, module)
A factory function that returns a Builder object to be used to
fetch source files from the specified CVS repository. The
returned Builder is intended to be passed to the SourceCode()
function.
This function is deprecated. For details, see the entry for the
SourceCode() function.
The optional specified module will be added to the beginning of
all repository path names; this can be used, in essence, to
strip initial directory names from the repository path names, so
that you only have to replicate part of the repository directory
hierarchy in your local build directory.
Examples:
# Will fetch foo/bar/src.c
# from /usr/local/CVSROOT/foo/bar/src.c.
env.SourceCode('.', env.CVS('/usr/local/CVSROOT'))
# Will fetch bar/src.c
# from /usr/local/CVSROOT/foo/bar/src.c.
env.SourceCode('.', env.CVS('/usr/local/CVSROOT', 'foo'))
# Will fetch src.c
# from /usr/local/CVSROOT/foo/bar/src.c.
env.SourceCode('.', env.CVS('/usr/local/CVSROOT', 'foo/bar'))
Decider(function)env.Decider(function)
Specifies that all up-to-date decisions for targets built
through this construction environment will be handled by the
specified function. The function can be one of the following
strings that specify the type of decision function to be per‐
formed:
timestamp-newer
Specifies that a target shall be considered out of date
and rebuilt if the dependency's timestamp is newer than
the target file's timestamp. This is the behavior of
the classic Make utility, and make can be used a syn‐
onym for timestamp-newer.
timestamp-match
Specifies that a target shall be considered out of date
and rebuilt if the dependency's timestamp is different
than the timestamp recorded the last time the target
was built. This provides behavior very similar to the
classic Make utility (in particular, files are not
opened up so that their contents can be checksummed)
except that the target will also be rebuilt if a depen‐
dency file has been restored to a version with an ear‐
lier timestamp, such as can happen when restoring files
from backup archives.
MD5 Specifies that a target shall be considered out of date
and rebuilt if the dependency's content has changed
sine the last time the target was built, as determined
be performing an MD5 checksum on the dependency's con‐
tents and comparing it to the checksum recorded the
last time the target was built. content can be used as
a synonym for MD5.
MD5-timestamp
Specifies that a target shall be considered out of date
and rebuilt if the dependency's content has changed
sine the last time the target was built, except that
dependencies with a timestamp that matches the last
time the target was rebuilt will be assumed to be up-
to-date and not rebuilt. This provides behavior very
similar to the MD5 behavior of always checksumming file
contents, with an optimization of not checking the con‐
tents of files whose timestamps haven't changed. The
drawback is that SCons will not detect if a file's con‐
tent has changed but its timestamp is the same, as
might happen in an automated script that runs a build,
updates a file, and runs the build again, all within a
single second.
Examples:
# Use exact timestamp matches by default.
Decider('timestamp-match')
# Use MD5 content signatures for any targets built
# with the attached construction environment.
env.Decider('content')
In addition to the above already-available functions, the func‐
tion argument may be an actual Python function that takes the
following three arguments:
dependency
The Node (file) which should cause the target to be
rebuilt if it has "changed" since the last tme target
was built.
target The Node (file) being built. In the normal case, this
is what should get rebuilt if the dependency has
"changed."
prev_ni
Stored information about the state of the dependency
the last time the target was built. This can be con‐
sulted to match various file characteristics such as
the timestamp, size, or content signature.
The function should return a True (non-zero) value if the dependency
has "changed" since the last time the target was built (indicating that
the target should be rebuilt), and False (zero) otherwise (indicating
that the target should not be rebuilt). Note that the decision can be
made using whatever criteria are appopriate. Ignoring some or all of
the function arguments is perfectly normal.
Example:
def my_decider(dependency, target, prev_ni):
return not os.path.exists(str(target))
env.Decider(my_decider)Default(targets)env.Default(targets)
This specifies a list of default targets, which will be built by
scons if no explicit targets are given on the command line.
Multiple calls to Default() are legal, and add to the list of
default targets.
Multiple targets should be specified as separate arguments to
the Default() method, or as a list. Default() will also accept
the Node returned by any of a construction environment's builder
methods.
Examples:
Default('foo', 'bar', 'baz')
env.Default(['a', 'b', 'c'])
hello = env.Program('hello', 'hello.c')
env.Default(hello)
An argument to Default() of None will clear all default targets.
Later calls to Default() will add to the (now empty) default-
target list like normal.
The current list of targets added using the Default() function
or method is available in the DEFAULT_TARGETS list; see below.
DefaultEnvironment([args])
Creates and returns a default construction environment object.
This construction environment is used internally by SCons in
order to execute many of the global functions in this list, and
to fetch source files transparently from source code management
systems.
Depends(target, dependency)
env.Depends(target, dependency)
Specifies an explicit dependency; the target will be rebuilt
whenever the dependency has changed. Both the specified target
and dependency can be a string (usually the path name of a file
or directory) or Node objects, or a list of strings or Node
objects (such as returned by a Builder call). This should only
be necessary for cases where the dependency is not caught by a
Scanner for the file.
Example:
env.Depends('foo', 'other-input-file-for-foo')
mylib = env.Library('mylib.c')
installed_lib = env.Install('lib', mylib)
bar = env.Program('bar.c')
# Arrange for the library to be copied into the installation
# directory before trying to build the "bar" program.
# (Note that this is for example only. A "real" library
# dependency would normally be configured through the $LIBS
# and $LIBPATH variables, not using an env.Depends() call.)
env.Depends(bar, installed_lib)
env.Dictionary([vars])
Returns a dictionary object containing copies of all of the con‐
struction variables in the environment. If there are any vari‐
able names specified, only the specified construction variables
are returned in the dictionary.
Example:
dict = env.Dictionary()
cc_dict = env.Dictionary('CC', 'CCFLAGS', 'CCCOM')
Dir(name, [directory])
env.Dir(name, [directory])
This returns a Directory Node, an object that represents the
specified directory name. name can be a relative or absolute
path. directory is an optional directory that will be used as
the parent directory. If no directory is specified, the current
script's directory is used as the parent.
If name is a list, SCons returns a list of Dir nodes. Construc‐
tion variables are expanded in name.
Directory Nodes can be used anywhere you would supply a string
as a directory name to a Builder method or function. Directory
Nodes have attributes and methods that are useful in many situa‐
tions; see "File and Directory Nodes," below.
env.Dump([key])
Returns a pretty printable representation of the environment.
key, if not None, should be a string containing the name of the
variable of interest.
This SConstruct:
env=Environment()
print env.Dump('CCCOM')
will print:
While this SConstruct:
env=Environment()
print env.Dump()
will print:
{ 'AR': 'ar',
'ARCOM': '$AR $ARFLAGS $TARGET $SOURCES\n$RANLIB $RANLIBFLAGS $TARGET',
'ARFLAGS': ['r'],
'AS': 'as',
'ASCOM': '$AS $ASFLAGS -o $TARGET $SOURCES',
'ASFLAGS': [],
...
EnsurePythonVersion(major, minor)
env.EnsurePythonVersion(major, minor)
Ensure that the Python version is at least major.minor. This
function will print out an error message and exit SCons with a
non-zero exit code if the actual Python version is not late
enough.
Example:
EnsurePythonVersion(2,2)
EnsureSConsVersion(major, minor, [revision])
env.EnsureSConsVersion(major, minor, [revision])
Ensure that the SCons version is at least major.minor, or
major.minor.revision. if revision is specified. This function
will print out an error message and exit SCons with a non-zero
exit code if the actual SCons version is not late enough.
Examples:
EnsureSConsVersion(0,14)
EnsureSConsVersion(0,96,90)
Environment([key=value, ...])
env.Environment([key=value, ...])
Return a new construction environment initialized with the spec‐
ified key=value pairs.
Execute(action, [strfunction, varlist])
env.Execute(action, [strfunction, varlist])
Executes an Action object. The specified action may be an
Action object (see the section "Action Objects," below, for a
complete explanation of the arguments and behavior), or it may
be a command-line string, list of commands, or executable Python
function, each of which will be converted into an Action object
and then executed. The exit value of the command or return
value of the Python function will be returned.
Note that scons will print an error message if the executed
action fails--that is, exits with or returns a non-zero value.
scons will not, however, automatically terminate the build if
the specified action fails. If you want the build to stop in
response to a failed Execute() call, you must explicitly check
for a non-zero return value:
Execute(Copy('file.out', 'file.in'))
if Execute("mkdir sub/dir/ectory"):
# The mkdir failed, don't try to build.
Exit(1)
Exit([value])
env.Exit([value])
This tells scons to exit immediately with the specified value.
A default exit value of 0 (zero) is used if no value is speci‐
fied.
Export(vars)env.Export(vars)
This tells scons to export a list of variables from the current
SConscript file to all other SConscript files. The exported
variables are kept in a global collection, so subsequent calls
to Export() will over-write previous exports that have the same
name. Multiple variable names can be passed to Export() as sep‐
arate arguments or as a list. Keyword arguments can be used to
provide names and their values. A dictionary can be used to map
variables to a different name when exported. Both local vari‐
ables and global variables can be exported.
Examples:
env = Environment()
# Make env available for all SConscript files to Import().
Export("env")
package = 'my_name'
# Make env and package available for all SConscript files:.
Export("env", "package")
# Make env and package available for all SConscript files:
Export(["env", "package"])
# Make env available using the name debug:
Export(debug = env)
# Make env available using the name debug:
Export({"debug":env})
Note that the SConscript() function supports an exports argument
that makes it easier to to export a variable or set of variables
to a single SConscript file. See the description of the SCon‐
script() function, below.
File(name, [directory])
env.File(name, [directory])
This returns a File Node, an object that represents the speci‐
fied file name. name can be a relative or absolute path.
directory is an optional directory that will be used as the par‐
ent directory.
If name is a list, SCons returns a list of File nodes. Con‐
struction variables are expanded in name.
File Nodes can be used anywhere you would supply a string as a
file name to a Builder method or function. File Nodes have
attributes and methods that are useful in many situations; see
"File and Directory Nodes," below.
FindFile(file, dirs)
env.FindFile(file, dirs)
Search for file in the path specified by dirs. dirs may be a
list of directory names or a single directory name. In addition
to searching for files that exist in the filesystem, this func‐
tion also searches for derived files that have not yet been
built.
Example:
foo = env.FindFile('foo', ['dir1', 'dir2'])
FindInstalledFiles()env.FindInstalledFiles()
Returns the list of targets set up by the Install() or Instal‐
lAs() builders.
This function serves as a convenient method to select the con‐
tents of a binary package.
Example:
Install( '/bin', [ 'executable_a', 'executable_b' ] )
# will return the file node list
# [ '/bin/executable_a', '/bin/executable_b' ]
FindInstalledFiles()
Install( '/lib', [ 'some_library' ] )
# will return the file node list
# [ '/bin/executable_a', '/bin/executable_b', '/lib/some_library' ]
FindInstalledFiles()FindPathDirs(variable)
Returns a function (actually a callable Python object) intended
to be used as the path_function of a Scanner object. The
returned object will look up the specified variable in a con‐
struction environment and treat the construction variable's
value as a list of directory paths that should be searched (like
$CPPPATH, $LIBPATH, etc.).
Note that use of FindPathDirs() is generally preferable to writ‐
ing your own path_function for the following reasons: 1) The
returned list will contain all appropriate directories found in
source trees (when VariantDir() is used) or in code repositories
(when Repository() or the -Y option are used). 2) scons will
identify expansions of variable that evaluate to the same list
of directories as, in fact, the same list, and avoid re-scanning
the directories for files, when possible.
Example:
def my_scan(node, env, path, arg):
# Code to scan file contents goes here...
return include_files
scanner = Scanner(name = 'myscanner',
function = my_scan,
path_function = FindPathDirs('MYPATH'))
FindSourceFiles(node='"."')
env.FindSourceFiles(node='"."')
Returns the list of nodes which serve as the source of the built
files. It does so by inspecting the dependency tree starting at
the optional argument node which defaults to the '"."'-node. It
will then return all leaves of node. These are all children
which have no further children.
This function is a convenient method to select the contents of a
Source Package.
Example:
Program( 'src/main_a.c' )
Program( 'src/main_b.c' )
Program( 'main_c.c' )
# returns ['main_c.c', 'src/main_a.c', 'SConstruct', 'src/main_b.c']
FindSourceFiles()
# returns ['src/main_b.c', 'src/main_a.c' ]
FindSourceFiles( 'src' )
As you can see build support files (SConstruct in the above
example) will also be returned by this function.
Flatten(sequence)env.Flatten(sequence)
Takes a sequence (that is, a Python list or tuple) that may con‐
tain nested sequences and returns a flattened list containing
all of the individual elements in any sequence. This can be
helpful for collecting the lists returned by calls to Builders;
other Builders will automatically flatten lists specified as
input, but direct Python manipulation of these lists does not.
Examples:
foo = Object('foo.c')
bar = Object('bar.c')
# Because `foo' and `bar' are lists returned by the Object() Builder,
# `objects' will be a list containing nested lists:
objects = ['f1.o', foo, 'f2.o', bar, 'f3.o']
# Passing such a list to another Builder is all right because
# the Builder will flatten the list automatically:
Program(source = objects)
# If you need to manipulate the list directly using Python, you need to
# call Flatten() yourself, or otherwise handle nested lists:
for object in Flatten(objects):
print str(object)GetBuildFailures()
Returns a list of exceptions for the actions that failed while
attempting to build targets. Each element in the returned list
is a BuildError object with the following attributes that record
various aspects of the build failure:
.node The node that was being built when the build failure
occurred.
.status The numeric exit status returned by the command or
Python function that failed when trying to build the specified
Node.
.errstr The SCons error string describing the build failure.
(This is often a generic message like "Error 2" to indicate that
an executed command exited with a status of 2.)
.filename The name of the file or directory that actually caused
the failure. This may be different from the .node attribute.
For example, if an attempt to build a target named sub/dir/tar‐
get fails because the sub/dir directory could not be created,
then the .node attribute will be sub/dir/target but the .file‐
name attribute will be sub/dir.
.executor The SCons Executor object for the target Node being
built. This can be used to retrieve the construction environ‐
ment used for the failed action.
.action The actual SCons Action object that failed. This will
be one specific action out of the possible list of actions that
would have been executed to build the target.
.command The actual expanded command that was executed and
failed, after expansion of $TARGET, $SOURCE, and other construc‐
tion variables.
Note that the GetBuildFailures() function will always return an
empty list until any build failure has occurred, which means
that GetBuildFailures() will always return an empty list while
the SConscript files are being read. Its primary intended use
is for functions that will be executed before SCons exits by
passing them to the standard Python atexit.register() function.
Example:
import atexit
def print_build_failures():
from SCons.Script import GetBuildFailures
for bf in GetBuildFailures():
print "%s failed: %s" % (bf.node, bf.errstr)
atexit.register(print_build_failures)
GetBuildPath(file, [...])
env.GetBuildPath(file, [...])
Returns the scons path name (or names) for the specified file
(or files). The specified file or files may be scons Nodes or
strings representing path names.
GetLaunchDir()env.GetLaunchDir()
Returns the absolute path name of the directory from which scons
was initially invoked. This can be useful when using the -u, -U
or -D options, which internally change to the directory in which
the SConstruct file is found.
GetOption(name)env.GetOption(name)
This function provides a way to query the value of SCons options
set on scons command line (or set using the SetOption() func‐
tion). The options supported are:
cache_debug
which corresponds to --cache-debug;
cache_disable
which corresponds to --cache-disable;
cache_force
which corresponds to --cache-force;
cache_show
which corresponds to --cache-show;
clean which corresponds to -c, --clean and --remove;
config
which corresponds to --config;
directory
which corresponds to -C and --directory;
diskcheck
which corresponds to --diskcheck
duplicate
which corresponds to --duplicate;
file which corresponds to -f, --file, --makefile and --scon‐
struct;
help which corresponds to -h and --help;
ignore_errors
which corresponds to --ignore-errors;
implicit_cache
which corresponds to --implicit-cache;
implicit_deps_changed
which corresponds to --implicit-deps-changed;
implicit_deps_unchanged
which corresponds to --implicit-deps-unchanged;
interactive
which corresponds to --interact and --interactive;
keep_going
which corresponds to -k and --keep-going;
max_drift
which corresponds to --max-drift;
no_exec
which corresponds to -n, --no-exec, --just-print,
--dry-run and --recon;
no_site_dir
which corresponds to --no-site-dir;
num_jobs
which corresponds to -j and --jobs;
profile_file
which corresponds to --profile;
question
which corresponds to -q and --question;
random
which corresponds to --random;
repository
which corresponds to -Y, --repository and --srcdir;
silent
which corresponds to -s, --silent and --quiet;
site_dir
which corresponds to --site-dir;
stack_size
which corresponds to --stack-size;
taskmastertrace_file
which corresponds to --taskmastertrace; and
warn which corresponds to --warn and --warning.
See the documentation for the corresponding command line object for
information about each specific option.
Glob(pattern, [ondisk, source, strings])
env.Glob(pattern, [ondisk, source, strings])
Returns Nodes (or strings) that match the specified pattern,
relative to the directory of the current SConscript file. The
env.Glob() form performs string substition on pattern and
returns whatever matches the resulting expanded pattern.
The specified pattern uses Unix shell style metacharacters for
matching:
* matches everything
? matches any single character
[seq] matches any character in seq
[!seq] matches any char not in seq
If the first character of a filename is a dot, it must be
matched explicitly. Character matches do not span directory
separators.
The Glob() knows about repositories (see the Repository() func‐
tion) and source directories (see the VariantDir() function) and
returns a Node (or string, if so configured) in the local (SCon‐
script) directory if matching Node is found anywhere in a corre‐
sponding repository or source directory.
The ondisk argument may be set to False (or any other non-true
value) to disable the search for matches on disk, thereby only
returning matches among already-configured File or Dir Nodes.
The default behavior is to return corresponding Nodes for any
on-disk matches found.
The source argument may be set to True (or any equivalent value)
to specify that, when the local directory is a VariantDir(), the
returned Nodes should be from the corresponding source direc‐
tory, not the local directory.
The strings argument may be set to True (or any equivalent
value) to have the Glob() function return strings, not Nodes,
that represent the matched files or directories. The returned
strings will be relative to the local (SConscript) directory.
(Note that This may make it easier to perform arbitrary manipu‐
lation of file names, but if the returned strings are passed to
a different SConscript file, any Node translation will be rela‐
tive to the other SConscript directory, not the original SCon‐
script directory.)
Examples:
Program('foo', Glob('*.c'))
Zip('/tmp/everything', Glob('.??*') + Glob('*'))
Help(text)env.Help(text)
This specifies help text to be printed if the -h argument is
given to scons. If Help() is called multiple times, the text is
appended together in the order that Help() is called.
Ignore(target, dependency)
env.Ignore(target, dependency)
The specified dependency file(s) will be ignored when deciding
if the target file(s) need to be rebuilt.
You can also use Ignore() to remove a target from the default
build. In order to do this you must specify the directory the
target will be built in as the target, and the file you want to
skip building as the dependency.
Note that this will only remove the dependencies listed from the
files built by default. It will still be built if that depen‐
dency is needed by another object being built. See the third
and forth examples below.
Examples:
env.Ignore('foo', 'foo.c')
env.Ignore('bar', ['bar1.h', 'bar2.h'])
env.Ignore('.','foobar.obj')
env.Ignore('bar','bar/foobar.obj')
Import(vars)env.Import(vars)
This tells scons to import a list of variables into the current
SConscript file. This will import variables that were exported
with Export() or in the exports argument to SConscript(). Vari‐
ables exported by SConscript() have precedence. Multiple vari‐
able names can be passed to Import() as separate arguments or as
a list. The variable "*" can be used to import all variables.
Examples:
Import("env")
Import("env", "variable")
Import(["env", "variable"])
Import("*")
Literal(string)env.Literal(string)
The specified string will be preserved as-is and not have con‐
struction variables expanded.
Local(targets)env.Local(targets)
The specified targets will have copies made in the local tree,
even if an already up-to-date copy exists in a repository.
Returns a list of the target Node or Nodes.
env.MergeFlags(arg, [unique])
Merges the specified arg values to the construction environ‐
ment's construction variables. If the arg argument is not a
dictionary, it is converted to one by calling env.ParseFlags()
on the argument before the values are merged. Note that arg
must be a single value, so multiple strings must be passed in as
a list, not as separate arguments to env.MergeFlags().
By default, duplicate values are eliminated; you can, however,
specify unique=0 to allow duplicate values to be added. When
eliminating duplicate values, any construction variables that
end with the string PATH keep the left-most unique value. All
other construction variables keep the right-most unique value.
Examples:
# Add an optimization flag to $CCFLAGS.
env.MergeFlags('-O3')
# Combine the flags returned from running pkg-config with an optimization
# flag and merge the result into the construction variables.
env.MergeFlags(['!pkg-config gtk+-2.0 --cflags', '-O3'])
# Combine an optimization flag with the flags returned from running pkg-config
# twice and merge the result into the construction variables.
env.MergeFlags(['-O3',
'!pkg-config gtk+-2.0 --cflags --libs',
'!pkg-config libpng12 --cflags --libs'])
NoCache(target, ...)
env.NoCache(target, ...)
Specifies a list of files which should not be cached whenever
the CacheDir() method has been activated. The specified targets
may be a list or an individual target.
Multiple files should be specified either as separate arguments
to the NoCache() method, or as a list. NoCache() will also
accept the return value of any of the construction environment
Builder methods.
Calling NoCache() on directories and other non-File Node types
has no effect because only File Nodes are cached.
Examples:
NoCache('foo.elf')
NoCache(env.Program('hello', 'hello.c'))
NoClean(target, ...)
env.NoClean(target, ...)
Specifies a list of files or directories which should not be
removed whenever the targets (or their dependencies) are speci‐
fied with the -c command line option. The specified targets may
be a list or an individual target. Multiple calls to NoClean()
are legal, and prevent each specified target from being removed
by calls to the -c option.
Multiple files or directories should be specified either as sep‐
arate arguments to the NoClean() method, or as a list.
NoClean() will also accept the return value of any of the con‐
struction environment Builder methods.
Calling NoClean() for a target overrides calling Clean() for the
same target, and any targets passed to both functions will not
be removed by the -c option.
Examples:
NoClean('foo.elf')
NoClean(env.Program('hello', 'hello.c'))
env.ParseConfig(command, [function, unique])
Calls the specified function to modify the environment as speci‐
fied by the output of command. The default function is
env.MergeFlags(), which expects the output of a typical *-config
command (for example, gtk-config) and adds the options to the
appropriate construction variables. By default, duplicate val‐
ues are not added to any construction variables; you can specify
unique=0 to allow duplicate values to be added.
Interpreted options and the construction variables they affect
are as specified for the env.ParseFlags() method (which this
method calls). See that method's description, below, for a ta‐
ble of options and construction variables.
ParseDepends(filename, [must_exist, only_one])
env.ParseDepends(filename, [must_exist, only_one])
Parses the contents of the specified filename as a list of
dependencies in the style of Make or mkdep, and explicitly
establishes all of the listed dependencies.
By default, it is not an error if the specified filename does
not exist. The optional must_exist argument may be set to a
non-zero value to have scons throw an exception and generate an
error if the file does not exist, or is otherwise inaccessible.
The optional only_one argument may be set to a non-zero value to
have scons thrown an exception and generate an error if the file
contains dependency information for more than one target. This
can provide a small sanity check for files intended to be gener‐
ated by, for example, the gcc -M flag, which should typically
only write dependency information for one output file into a
corresponding .d file.
The filename and all of the files listed therein will be inter‐
preted relative to the directory of the SConscript file which
calls the ParseDepends() function.
env.ParseFlags(flags, ...)
Parses one or more strings containing typical command-line flags
for GCC tool chains and returns a dictionary with the flag val‐
ues separated into the appropriate SCons construction variables.
This is intended as a companion to the env.MergeFlags() method,
but allows for the values in the returned dictionary to be modi‐
fied, if necessary, before merging them into the construction
environment. (Note that env.MergeFlags() will call this method
if its argument is not a dictionary, so it is usually not neces‐
sary to call env.ParseFlags() directly unless you want to manip‐
ulate the values.)
If the first character in any string is an exclamation mark (!),
the rest of the string is executed as a command, and the output
from the command is parsed as GCC tool chain command-line flags
and added to the resulting dictionary.
Flag values are translated accordig to the prefix found, and
added to the following construction variables:
-arch CCFLAGS, LINKFLAGS
-D CPPDEFINES
-framework FRAMEWORKS
-frameworkdir= FRAMEWORKPATH
-include CCFLAGS
-isysroot CCFLAGS, LINKFLAGS
-I CPPPATH
-l LIBS
-L LIBPATH
-mno-cygwin CCFLAGS, LINKFLAGS
-mwindows LINKFLAGS
-pthread CCFLAGS, LINKFLAGS
-std= CFLAGS
-Wa, ASFLAGS, CCFLAGS
-Wl,-rpath= RPATH
-Wl,-R, RPATH
-Wl,-R RPATH
-Wl, LINKFLAGS
-Wp, CPPFLAGS
- CCFLAGS
+ CCFLAGS, LINKFLAGS
Any other strings not associated with options are assumed to be
the names of libraries and added to the $LIBS construction vari‐
able.
Examples (all of which produce the same result):
dict = env.ParseFlags('-O2 -Dfoo -Dbar=1')
dict = env.ParseFlags('-O2', '-Dfoo', '-Dbar=1')
dict = env.ParseFlags(['-O2', '-Dfoo -Dbar=1'])
dict = env.ParseFlags('-O2', '!echo -Dfoo -Dbar=1')
env.Perforce()
A factory function that returns a Builder object to be used to
fetch source files from the Perforce source code management sys‐
tem. The returned Builder is intended to be passed to the
SourceCode() function.
This function is deprecated. For details, see the entry for the
SourceCode() function.
Example:
env.SourceCode('.', env.Perforce())
Perforce uses a number of external environment variables for its
operation. Consequently, this function adds the following vari‐
ables from the user's external environment to the construction
environment's ENV dictionary: P4CHARSET, P4CLIENT, P4LANGUAGE,
P4PASSWD, P4PORT, P4USER, SystemRoot, USER, and USERNAME.
Platform(string)
The Platform() form returns a callable object that can be used
to initialize a construction environment using the platform key‐
word of the Environment() function.
Example:
env = Environment(platform = Platform('win32'))
The env.Platform() form applies the callable object for the
specified platform string to the environment through which the
method was called.
env.Platform('posix')
Note that the win32 platform adds the SystemDrive and SystemRoot
variables from the user's external environment to the construc‐
tion environment's $ENV dictionary. This is so that any exe‐
cuted commands that use sockets to connect with other systems
(such as fetching source files from external CVS repository
specifications like :pserver:anonymous@cvs.sourceforge.net:/cvs‐
root/scons) will work on Windows systems.
Precious(target, ...)
env.Precious(target, ...)
Marks each given target as precious so it is not deleted before
it is rebuilt. Normally scons deletes a target before building
it. Multiple targets can be passed in to a single call to Pre‐
cious().
env.Prepend(key=val, [...])
Appends the specified keyword arguments to the beginning of con‐
struction variables in the environment. If the Environment does
not have the specified construction variable, it is simply added
to the environment. If the values of the construction variable
and the keyword argument are the same type, then the two values
will be simply added together. Otherwise, the construction
variable and the value of the keyword argument are both coerced
to lists, and the lists are added together. (See also the
Append method, above.)
Example:
env.Prepend(CCFLAGS = '-g ', FOO = ['foo.yyy'])
env.PrependENVPath(name, newpath, [envname, sep, delete_existing])
This appends new path elements to the given path in the speci‐
fied external environment ($ENV by default). This will only add
any particular path once (leaving the first one it encounters
and ignoring the rest, to preserve path order), and to help
assure this, will normalize all paths (using os.path.normpath
and os.path.normcase). This can also handle the case where the
given old path variable is a list instead of a string, in which
case a list will be returned instead of a string.
If delete_existing is 0, then adding a path that already exists
will not move it to the beginning; it will stay where it is in
the list.
Example:
print 'before:',env['ENV']['INCLUDE']
include_path = '/foo/bar:/foo'
env.PrependENVPath('INCLUDE', include_path)
print 'after:',env['ENV']['INCLUDE']
The above example will print:
before: /biz:/foo
after: /foo/bar:/foo:/biz
env.PrependUnique(key=val, delete_existing=0, [...])
Appends the specified keyword arguments to the beginning of con‐
struction variables in the environment. If the Environment does
not have the specified construction variable, it is simply added
to the environment. If the construction variable being appended
to is a list, then any value(s) that already exist in the con‐
struction variable will not be added again to the list. How‐
ever, if delete_existing is 1, existing matching values are
removed first, so existing values in the arg list move to the
front of the list.
Example:
env.PrependUnique(CCFLAGS = '-g', FOO = ['foo.yyy'])
Progress(callable, [interval])
Progress(string, [interval, file, overwrite])
Progress(list_of_strings, [interval, file, overwrite])
Allows SCons to show progress made during the build by display‐
ing a string or calling a function while evaluating Nodes (e.g.
files).
If the first specified argument is a Python callable (a function
or an object that has a __call__() method), the function will be
called once every interval times a Node is evaluated. The
callable will be passed the evaluated Node as its only argument.
(For future compatibility, it's a good idea to also add *args
and **kw as arguments to your function or method. This will
prevent the code from breaking if SCons ever changes the inter‐
face to call the function with additional arguments in the
future.)
An example of a simple custom progress function that prints a
string containing the Node name every 10 Nodes:
def my_progress_function(node, *args, **kw):
print 'Evaluating node %s!' % node
Progress(my_progress_function, interval=10)
A more complicated example of a custom progress display object
that prints a string conta(aicarriageoreturn)eat the0endvsouthat
Nodes. Note the use of
the string will overwrite itself on a display:
import sys
class ProgressCounter(object):
count = 0
def __call__(self, node, *args, **kw):
self.count += 100
sys.stderr.write('Evaluated %s nodes\r' % self.count)
Progress(ProgressCounter(), interval=100)
If the first argument Progress() is a string, the string will be
displayed every interval evaluated Nodes. The default is to
print the string on standard output; an alternate output stream
may be specified with the file= argument. The following will
print a series of dots on the error output, one dot for every
100 evaluated Nodes:
import sys
Progress('.', interval=100, file=sys.stderr)
If the string contains the verbatim substring $TARGET, it will
be replaced with the Node. Note that, for performance reasons,
this is not a regular SCons variable substition, so you can not
use other variables or use curly braces. The following(carriage
will print the name of every evaluated Node, using a
return) to cause each line to overwritten by the next line, and
the overwrite= keyword argument to make sure the previously-
printed file name is overwritten with blank spaces:
import sys
Progress('$TARGET\r', overwrite=True)
If the first argument to Progress() is a list of strings, then
each string in the list will be displayed in rotating fashion
every interval evaluated Nodes. This can be used to implement a
"spinner" on the user's screen as follows:
Progress(['-\r', '\\\r', '|\r', '/\r'], interval=5)
env.RCS()
A factory function that returns a Builder object to be used to
fetch source files from RCS. The returned Builder is intended
to be passed to the SourceCode() function:
This function is deprecated. For details, see the entry for the
SourceCode() function.
Examples:
env.SourceCode('.', env.RCS())
Note that scons will fetch source files from RCS subdirectories
automatically, so configuring RCS as demonstrated in the above
example should only be necessary if you are fetching from RCS,v
files in the same directory as the source files, or if you need
to explicitly specify RCS for a specific subdirectory.
env.Replace(key=val, [...])
Replaces construction variables in the Environment with the
specified keyword arguments.
Example:
env.Replace(CCFLAGS = '-g', FOO = 'foo.xxx')
Repository(directory)env.Repository(directory)
Specifies that directory is a repository to be searched for
files. Multiple calls to Repository() are legal, and each one
adds to the list of repositories that will be searched.
To scons, a repository is a copy of the source tree, from the
top-level directory on down, which may contain both source files
and derived files that can be used to build targets in the local
source tree. The canonical example would be an official source
tree maintained by an integrator. If the repository contains
derived files, then the derived files should have been built
using scons, so that the repository contains the necessary sig‐
nature information to allow scons to figure out when it is
appropriate to use the repository copy of a derived file,
instead of building one locally.
Note that if an up-to-date derived file already exists in a
repository, scons will not make a copy in the local directory
tree. In order to guarantee that a local copy will be made, use
the Local() method.
Requires(target, prerequisite)
env.Requires(target, prerequisite)
Specifies an order-only relationship between the specified tar‐
get file(s) and the specified prerequisite file(s). The prereq‐
uisite file(s) will be (re)built, if necessary, before the tar‐
get file(s), but the target file(s) do not actually depend on
the prerequisites and will not be rebuilt simply because the
prerequisite file(s) change.
Example:
env.Requires('foo', 'file-that-must-be-built-before-foo')
Return([vars..., stop=])
By default, this stops processing the current SConscript file
and returns to the calling SConscript file the values of the
variables named in the vars string arguments. Multiple strings
contaning variable names may be passed to Return(). Any strings
that contain white space
The optional stop= keyword argument may be set to a false value
to continue processing the rest of the SConscript file after the
Return() call. This was the default behavior prior to SCons
0.98. However, the values returned are still the values of the
variables in the named vars at the point Return() is called.
Examples:
# Returns without returning a value.
Return()
# Returns the value of the 'foo' Python variable.
Return("foo")
# Returns the values of the Python variables 'foo' and 'bar'.
Return("foo", "bar")
# Returns the values of Python variables 'val1' and 'val2'.
Return('val1 val2')
Scanner(function, [argument, keys, path_function, node_class, node_fac‐
tory, scan_check, recursive])
env.Scanner(function, [argument, keys, path_function, node_class,
node_factory, scan_check, recursive])
Creates a Scanner object for the specified function. See the
section "Scanner Objects," below, for a complete explanation of
the arguments and behavior.
env.SCCS()
A factory function that returns a Builder object to be used to
fetch source files from SCCS. The returned Builder is intended
to be passed to the SourceCode() function.
Example:
env.SourceCode('.', env.SCCS())
Note that scons will fetch source files from SCCS subdirectories
automatically, so configuring SCCS as demonstrated in the above
example should only be necessary if you are fetching from s.SCCS
files in the same directory as the source files, or if you need
to explicitly specify SCCS for a specific subdirectory.
SConscript(scripts, [exports, variant_dir, duplicate])
env.SConscript(scripts, [exports, variant_dir, duplicate])
SConscript(dirs=subdirs, [name=script, exports, variant_dir, dupli‐
cate])
env.SConscript(dirs=subdirs, [name=script, exports, variant_dir, dupli‐
cate])
This tells scons to execute one or more subsidiary SConscript
(configuration) files. Any variables returned by a called
script using Return() will be returned by the call to SCon‐
script(). There are two ways to call the SConscript() function.
The first way you can call SConscript() is to explicitly specify
one or more scripts as the first argument. A single script may
be specified as a string; multiple scripts must be specified as
a list (either explicitly or as created by a function like
Split()). Examples:
SConscript('SConscript') # run SConscript in the current directory
SConscript('src/SConscript') # run SConscript in the src directory
SConscript(['src/SConscript', 'doc/SConscript'])
config = SConscript('MyConfig.py')
The second way you can call SConscript() is to specify a list of
(sub)directory names as a dirs=subdirs keyword argument. In
this case, scons will, by default, execute a subsidiary configu‐
ration file named SConscript in each of the specified directo‐
ries. You may specify a name other than SConscript by supplying
an optional name=script keyword argument. The first three exam‐
ples below have the same effect as the first three examples
above:
SConscript(dirs='.') # run SConscript in the current directory
SConscript(dirs='src') # run SConscript in the src directory
SConscript(dirs=['src', 'doc'])
SConscript(dirs=['sub1', 'sub2'], name='MySConscript')
The optional exports argument provides a list of variable names
or a dictionary of named values to export to the script(s).
These variables are locally exported only to the specified
script(s), and do not affect the global pool of variables used
by the Export() function. The subsidiary script(s) must use the
Import() function to import the variables. Examples:
foo = SConscript('sub/SConscript', exports='env')
SConscript('dir/SConscript', exports=['env', 'variable'])
SConscript(dirs='subdir', exports='env variable')
SConscript(dirs=['one', 'two', 'three'], exports='shared_info')
If the optional variant_dir argument is present, it causes an
effect equivalent to the VariantDir() method described below.
(If variant_dir is not present, the duplicate argument is
ignored.) The variant_dir argument is interpreted relative to
the directory of the calling SConscript file. See the descrip‐
tion of the VariantDir() function below for additional details
and restrictions.
If variant_dir is present, the source directory is the directory
in which the SConscript file resides and the SConscript file is
evaluated as if it were in the variant_dir directory:
SConscript('src/SConscript', variant_dir = 'build')
is equivalent to
VariantDir('build', 'src')
SConscript('build/SConscript')
This later paradigm is often used when the sources are in the
same directory as the SConstruct:
SConscript('SConscript', variant_dir = 'build')
is equivalent to
VariantDir('build', '.')
SConscript('build/SConscript')
Here are some composite examples:
# collect the configuration information and use it to build src and doc
shared_info = SConscript('MyConfig.py')
SConscript('src/SConscript', exports='shared_info')
SConscript('doc/SConscript', exports='shared_info')
# build debugging and production versions. SConscript
# can use Dir('.').path to determine variant.
SConscript('SConscript', variant_dir='debug', duplicate=0)
SConscript('SConscript', variant_dir='prod', duplicate=0)
# build debugging and production versions. SConscript
# is passed flags to use.
opts = { 'CPPDEFINES' : ['DEBUG'], 'CCFLAGS' : '-pgdb' }
SConscript('SConscript', variant_dir='debug', duplicate=0, exports=opts)
opts = { 'CPPDEFINES' : ['NODEBUG'], 'CCFLAGS' : '-O' }
SConscript('SConscript', variant_dir='prod', duplicate=0, exports=opts)
# build common documentation and compile for different architectures
SConscript('doc/SConscript', variant_dir='build/doc', duplicate=0)
SConscript('src/SConscript', variant_dir='build/x86', duplicate=0)
SConscript('src/SConscript', variant_dir='build/ppc', duplicate=0)
SConscriptChdir(value)env.SConscriptChdir(value)
By default, scons changes its working directory to the directory
in which each subsidiary SConscript file lives. This behavior
may be disabled by specifying either:
SConscriptChdir(0)env.SConscriptChdir(0)
in which case scons will stay in the top-level directory while
reading all SConscript files. (This may be necessary when
building from repositories, when all the directories in which
SConscript files may be found don't necessarily exist locally.)
You may enable and disable this ability by calling SCon‐
scriptChdir() multiple times.
Example:
env = Environment()SConscriptChdir(0)
SConscript('foo/SConscript') # will not chdir to foo
env.SConscriptChdir(1)
SConscript('bar/SConscript') # will chdir to bar
SConsignFile([file, dbm_module])
env.SConsignFile([file, dbm_module])
This tells scons to store all file signatures in the specified
database file. If the file name is omitted, .sconsign is used
by default. (The actual file name(s) stored on disk may have an
appropriated suffix appended by the dbm_module.) If file is not
an absolute path name, the file is placed in the same directory
as the top-level SConstruct file.
If file is None, then scons will store file signatures in a sep‐
arate .sconsign file in each directory, not in one global data‐
base file. (This was the default behavior prior to SCons
0.96.91 and 0.97.)
The optional dbm_module argument can be used to specify which
Python database module The default is to use a custom
SCons.dblite module that uses pickled Python data structures,
and which works on all Python versions.
Examples:
# Explicitly stores signatures in ".sconsign.dblite"
# in the top-level SConstruct directory (the
# default behavior).
SConsignFile()
# Stores signatures in the file "etc/scons-signatures"
# relative to the top-level SConstruct directory.
SConsignFile("etc/scons-signatures")
# Stores signatures in the specified absolute file name.
SConsignFile("/home/me/SCons/signatures")
# Stores signatures in a separate .sconsign file
# in each directory.
SConsignFile(None)
env.SetDefault(key=val, [...])
Sets construction variables to default values specified with the
keyword arguments if (and only if) the variables are not already
set. The following statements are equivalent:
env.SetDefault(FOO = 'foo')
if 'FOO' not in env: env['FOO'] = 'foo'
SetOption(name, value)
env.SetOption(name, value)
This function provides a way to set a select subset of the scons
command line options from a SConscript file. The options sup‐
ported are:
clean which corresponds to -c, --clean and --remove;
duplicate
which corresponds to --duplicate;
help which corresponds to -h and --help;
implicit_cache
which corresponds to --implicit-cache;
max_drift
which corresponds to --max-drift;
no_exec
which corresponds to -n, --no-exec, --just-print,
--dry-run and --recon;
num_jobs
which corresponds to -j and --jobs;
random
which corresponds to --random; and
stack_size
which corresponds to --stack-size.
See the documentation for the corresponding command line object for
information about each specific option.
Example:
SetOption('max_drift', 1)
SideEffect(side_effect, target)
env.SideEffect(side_effect, target)
Declares side_effect as a side effect of building target. Both
side_effect and target can be a list, a file name, or a node. A
side effect is a target file that is created or updated as a
side effect of building other targets. For example, a Windows
PDB file is created as a side effect of building the .obj files
for a static library, and various log files are created updated
as side effects of various TeX commands. If a target is a side
effect of multiple build commands, scons will ensure that only
one set of commands is executed at a time. Consequently, you
only need to use this method for side-effect targets that are
built as a result of multiple build commands.
Because multiple build commands may update the same side effect
file, by default the side_effect target is not automatically
removed when the target is removed by the -c option. (Note,
however, that the side_effect might be removed as part of clean‐
ing the directory in which it lives.) If you want to make sure
the side_effect is cleaned whenever a specific target is
cleaned, you must specify this explicitly with the Clean() or
env.Clean() function.
SourceCode(entries, builder)
env.SourceCode(entries, builder)
This function and its associate factory functions are depre‐
cated. There is no replacement. The intended use was to keep a
local tree in sync with an archive, but in actuality the func‐
tion only causes the archive to be fetched on the first run.
Synchronizing with the archive is best done external to &SCons;.
Arrange for non-existent source files to be fetched from a
source code management system using the specified builder. The
specified entries may be a Node, string or list of both, and may
represent either individual source files or directories in which
source files can be found.
For any non-existent source files, scons will search up the
directory tree and use the first SourceCode() builder it finds.
The specified builder may be None, in which case scons will not
use a builder to fetch source files for the specified entries,
even if a SourceCode() builder has been specified for a direc‐
tory higher up the tree.
scons will, by default, fetch files from SCCS or RCS subdirecto‐
ries without explicit configuration. This takes some extra pro‐
cessing time to search for the necessary source code management
files on disk. You can avoid these extra searches and speed up
your build a little by disabling these searches as follows:
env.SourceCode('.', None)
Note that if the specified builder is one you create by hand, it
must have an associated construction environment to use when
fetching a source file.
scons provides a set of canned factory functions that return
appropriate Builders for various popular source code management
systems. Canonical examples of invocation include:
env.SourceCode('.', env.BitKeeper('/usr/local/BKsources'))
env.SourceCode('src', env.CVS('/usr/local/CVSROOT'))
env.SourceCode('/', env.RCS())
env.SourceCode(['f1.c', 'f2.c'], env.SCCS())
env.SourceCode('no_source.c', None)
SourceSignatures(type)env.SourceSignatures(type)
Note: Although it is not yet officially deprecated, use of this
function is discouraged. See the Decider() function for a more
flexible and straightforward way to configure SCons' decision-
making.
The SourceSignatures() function tells scons how to decide if a
source file (a file that is not built from any other files) has
changed since the last time it was used to build a particular
target file. Legal values are MD5 or timestamp.
If the environment method is used, the specified type of source
signature is only used when deciding whether targets built with
that environment are up-to-date or must be rebuilt. If the
global function is used, the specified type of source signature
becomes the default used for all decisions about whether targets
are up-to-date.
MD5 means scons decides that a source file has changed if the
MD5 checksum of its contents has changed since the last time it
was used to rebuild a particular target file.
timestamp means scons decides that a source file has changed if
its timestamp (modification time) has changed since the last
time it was used to rebuild a particular target file. (Note
that although this is similar to the behavior of Make, by
default it will also rebuild if the dependency is older than the
last time it was used to rebuild the target file.)
There is no different between the two behaviors for Python
Value() node objects.
MD5 signatures take longer to compute, but are more accurate
than timestamp signatures. The default value is MD5.
Note that the default TargetSignatures() setting (see below) is
to use this SourceSignatures() setting for any target files that
are used to build other target files. Consequently, changing
the value of SourceSignatures() will, by default, affect the up-
to-date decision for all files in the build (or all files built
with a specific construction environment when env.SourceSigna‐
tures() is used).
Split(arg)env.Split(arg)
Returns a list of file names or other objects. If arg is a
string, it will be split on strings of white-space characters
within the string, making it easier to write long lists of file
names. If arg is already a list, the list will be returned
untouched. If arg is any other type of object, it will be
returned as a list containing just the object.
Example:
files = Split("f1.c f2.c f3.c")
files = env.Split("f4.c f5.c f6.c")
files = Split("""
f7.c
f8.c
f9.c
""")
env.subst(input, [raw, target, source, conv])
Performs construction variable interpolation on the specified
string or sequence argument input.
By default, leading or trailing white space will be removed from
the result. and all sequences of white space will be compressed
to a single space character. Additionally, any $( and $) char‐
acter sequences will be stripped from the returned string, The
optional raw argument may be set to 1 if you want to preserve
white space and $(-$) sequences. The raw argument may be set to
2 if you want to strip all characters between any $( and $)
pairs (as is done for signature calculation).
If the input is a sequence (list or tuple), the individual ele‐
ments of the sequence will be expanded, and the results will be
returned as a list.
The optional target and source keyword arguments must be set to
lists of target and source nodes, respectively, if you want the
$TARGET, $TARGETS, $SOURCE and $SOURCES to be available for
expansion. This is usually necessary if you are calling
env.subst() from within a Python function used as an SCons
action.
Returned string values or sequence elements are converted to
their string representation by default. The optional conv argu‐
ment may specify a conversion function that will be used in
place of the default. For example, if you want Python objects
(including SCons Nodes) to be returned as Python objects, you
can use the Python lambda idiom to pass in an unnamed function
that simply returns its unconverted argument.
Example:
print env.subst("The C compiler is: $CC")
def compile(target, source, env):
sourceDir = env.subst("${SOURCE.srcdir}",
target=target,
source=source)
source_nodes = env.subst('$EXPAND_TO_NODELIST',
conv=lambda x: x)
Tag(node, tags)
Annotates file or directory Nodes with information about how the
Package() Builder should package those files or directories.
All tags are optional.
Examples:
# makes sure the built library will be installed with 0644 file
# access mode
Tag( Library( 'lib.c' ), UNIX_ATTR="0644" )
# marks file2.txt to be a documentation file
Tag( 'file2.txt', DOC )
TargetSignatures(type)env.TargetSignatures(type)
Note: Although it is not yet officially deprecated, use of this
function is discouraged. See the Decider() function for a more
flexible and straightforward way to configure SCons' decision-
making.
The TargetSignatures() function tells scons how to decide if a
target file (a file that is built from any other files) has
changed since the last time it was used to build some other tar‐
get file. Legal values are build; content (or its synonym MD5);
timestamp; or source.
If the environment method is used, the specified type of target
signature is only used for targets built with that environment.
If the global function is used, the specified type of signature
becomes the default used for all target files that don't have an
explicit target signature type specified for their environments.
content (or its synonym MD5) means scons decides that a target
file has changed if the MD5 checksum of its contents has changed
since the last time it was used to rebuild some other target
file. This means scons will open up MD5 sum the contents of
target files after they're built, and may decide that it does
not need to rebuild "downstream" target files if a file was
rebuilt with exactly the same contents as the last time.
timestamp means scons decides that a target file has changed if
its timestamp (modification time) has changed since the last
time it was used to rebuild some other target file. (Note that
although this is similar to the behavior of Make, by default it
will also rebuild if the dependency is older than the last time
it was used to rebuild the target file.)
source means scons decides that a target file has changed as
specified by the corresponding SourceSignatures() setting (MD5
or timestamp). This means that scons will treat all input files
to a target the same way, regardless of whether they are source
files or have been built from other files.
build means scons decides that a target file has changed if it
has been rebuilt in this invocation or if its content or time‐
stamp have changed as specified by the corresponding SourceSig‐
natures() setting. This "propagates" the status of a rebuilt
file so that other "downstream" target files will always be
rebuilt, even if the contents or the timestamp have not changed.
build signatures are fastest because content (or MD5) signatures
take longer to compute, but are more accurate than timestamp
signatures, and can prevent unnecessary "downstream" rebuilds
when a target file is rebuilt to the exact same contents as the
previous build. The source setting provides the most consistent
behavior when other target files may be rebuilt from both source
and target input files. The default value is source.
Because the default setting is source, using SourceSignatures()
is generally preferable to TargetSignatures(), so that the up-
to-date decision will be consistent for all files (or all files
built with a specific construction environment). Use of Tar‐
getSignatures() provides specific control for how built target
files affect their "downstream" dependencies.
Tool(string, [toolpath, **kw])
env.Tool(string, [toolpath, **kw])
The Tool() form of the function returns a callable object that
can be used to initialize a construction environment using the
tools keyword of the Environment() method. The object may be
called with a construction environment as an argument, in which
case the object will add the necessary variables to the con‐
struction environment and the name of the tool will be added to
the $TOOLS construction variable.
Additional keyword arguments are passed to the tool's generate()
method.
Examples:
env = Environment(tools = [ Tool('msvc') ])
env = Environment()
t = Tool('msvc')
t(env) # adds 'msvc' to the TOOLS variable
u = Tool('opengl', toolpath = ['tools'])
u(env) # adds 'opengl' to the TOOLS variable
The env.Tool() form of the function applies the callable object
for the specified tool string to the environment through which
the method was called.
Additional keyword arguments are passed to the tool's generate()
method.
env.Tool('gcc')
env.Tool('opengl', toolpath = ['build/tools'])
Value(value, [built_value])
env.Value(value, [built_value])
Returns a Node object representing the specified Python value.
Value Nodes can be used as dependencies of targets. If the
result of calling str(value) changes between SCons runs, any
targets depending on Value(value) will be rebuilt. (This is
true even when using timestamps to decide if files are up-to-
date.) When using timestamp source signatures, Value Nodes'
timestamps are equal to the system time when the Node is cre‐
ated.
The returned Value Node object has a write() method that can be
used to "build" a Value Node by setting a new value. The
optional built_value argument can be specified when the Value
Node is created to indicate the Node should already be consid‐
ered "built." There is a corresponding read() method that will
return the built value of the Node.
Examples:
env = Environment()
def create(target, source, env):
# A function that will write a 'prefix=$SOURCE'
# string into the file name specified as the
# $TARGET.
f = open(str(target[0]), 'wb')
f.write('prefix=' + source[0].get_contents())
# Fetch the prefix= argument, if any, from the command
# line, and use /usr/local as the default.
prefix = ARGUMENTS.get('prefix', '/usr/local')
# Attach a .Config() builder for the above function action
# to the construction environment.
env['BUILDERS']['Config'] = Builder(action = create)
env.Config(target = 'package-config', source = Value(prefix))
def build_value(target, source, env):
# A function that "builds" a Python Value by updating
# the the Python value with the contents of the file
# specified as the source of the Builder call ($SOURCE).
target[0].write(source[0].get_contents())
output = env.Value('before')
input = env.Value('after')
# Attach a .UpdateValue() builder for the above function
# action to the construction environment.
env['BUILDERS']['UpdateValue'] = Builder(action = build_value)
env.UpdateValue(target = Value(output), source = Value(input))
VariantDir(variant_dir, src_dir, [duplicate])
env.VariantDir(variant_dir, src_dir, [duplicate])
Use the VariantDir() function to create a copy of your sources
in another location: if a name under variant_dir is not found
but exists under src_dir, the file or directory is copied to
variant_dir. Target files can be built in a different directory
than the original sources by simply refering to the sources (and
targets) within the variant tree.
VariantDir() can be called multiple times with the same src_dir
to set up multiple builds with different options (variants).
The src_dir location must be in or underneath the SConstruct
file's directory, and variant_dir may not be underneath src_dir.
The default behavior is for scons to physically duplicate the
source files in the variant tree. Thus, a build performed in
the variant tree is guaranteed to be identical to a build per‐
formed in the source tree even if intermediate source files are
generated during the build, or preprocessors or other scanners
search for included files relative to the source file, or indi‐
vidual compilers or other invoked tools are hard-coded to put
derived files in the same directory as source files.
If possible on the platform, the duplication is performed by
linking rather than copying; see also the --duplicate command-
line option. Moreover, only the files needed for the build are
duplicated; files and directories that are not used are not
present in variant_dir.
Duplicating the source tree may be disabled by setting the
duplicate argument to 0 (zero). This will cause scons to invoke
Builders using the path names of source files in src_dir and the
path names of derived files within variant_dir. This is always
more efficient than duplicate=1, and is usually safe for most
builds (but see above for cases that may cause problems).
Note that VariantDir() works most naturally with a subsidiary
SConscript file. However, you would then call the subsidiary
SConscript file not in the source directory, but in the vari‐
ant_dir, regardless of the value of duplicate. This is how you
tell scons which variant of a source tree to build:
# run src/SConscript in two variant directories
VariantDir('build/variant1', 'src')
SConscript('build/variant1/SConscript')
VariantDir('build/variant2', 'src')
SConscript('build/variant2/SConscript')
See also the SConscript() function, described above, for another
way to specify a variant directory in conjunction with calling a
subsidiary SConscript file.
Examples:
# use names in the build directory, not the source directory
VariantDir('build', 'src', duplicate=0)
Program('build/prog', 'build/source.c')
# this builds both the source and docs in a separate subtree
VariantDir('build', '.', duplicate=0)
SConscript(dirs=['build/src','build/doc'])
# same as previous example, but only uses SConscript
SConscript(dirs='src', variant_dir='build/src', duplicate=0)
SConscript(dirs='doc', variant_dir='build/doc', duplicate=0)
WhereIs(program, [path, pathext, reject])
env.WhereIs(program, [path, pathext, reject])
Searches for the specified executable program, returning the
full path name to the program if it is found, and returning None
if not. Searches the specified path, the value of the calling
environment's PATH (env['ENV']['PATH']), or the user's current
external PATH (os.environ['PATH']) by default. On Windows sys‐
tems, searches for executable programs with any of the file
extensions listed in the specified pathext, the calling environ‐
ment's PATHEXT (env['ENV']['PATHEXT']) or the user's current
PATHEXT (os.environ['PATHEXT']) by default. Will not select any
path name or names in the specified reject list, if any.
SConscript Variables
In addition to the global functions and methods, scons supports a num‐
ber of Python variables that can be used in SConscript files to affect
how you want the build to be performed. These variables may be
accessed from custom Python modules that you import into an SConscript
file by adding the following to the Python module:
from SCons.Script import *
ARGLIST
A list keyword=value arguments specified on the command line.
Each element in the list is a tuple containing the (key‐
word,value) of the argument. The separate keyword and value
elements of the tuple can be accessed by subscripting for ele‐
ment [0] and [1] of the tuple, respectively.
Example:
print "first keyword, value =", ARGLIST[0][0], ARGLIST[0][1]
print "second keyword, value =", ARGLIST[1][0], ARGLIST[1][1]
third_tuple = ARGLIST[2]
print "third keyword, value =", third_tuple[0], third_tuple[1]
for key, value in ARGLIST:
# process key and value
ARGUMENTS
A dictionary of all the keyword=value arguments specified on the
command line. The dictionary is not in order, and if a given
keyword has more than one value assigned to it on the command
line, the last (right-most) value is the one in the ARGUMENTS
dictionary.
Example:
if ARGUMENTS.get('debug', 0):
env = Environment(CCFLAGS = '-g')
else:
env = Environment()
BUILD_TARGETS
A list of the targets which scons will actually try to build,
regardless of whether they were specified on the command line or
via the Default() function or method. The elements of this list
may be strings or nodes, so you should run the list through the
Python str function to make sure any Node path names are con‐
verted to strings.
Because this list may be taken from the list of targets speci‐
fied using the Default() function or method, the contents of the
list may change on each successive call to Default(). See the
DEFAULT_TARGETS list, below, for additional information.
Example:
if 'foo' in BUILD_TARGETS:
print "Don't forget to test the `foo' program!"
if 'special/program' in BUILD_TARGETS:
SConscript('special')
Note that the BUILD_TARGETS list only contains targets expected
listed on the command line or via calls to the Default() func‐
tion or method. It does not contain all dependent targets that
will be built as a result of making the sure the explicitly-
specified targets are up to date.
COMMAND_LINE_TARGETS
A list of the targets explicitly specified on the command line.
If there are no targets specified on the command line, the list
is empty. This can be used, for example, to take specific
actions only when a certain target or targets is explicitly
being built.
Example:
if 'foo' in COMMAND_LINE_TARGETS:
print "Don't forget to test the `foo' program!"
if 'special/program' in COMMAND_LINE_TARGETS:
SConscript('special')
DEFAULT_TARGETS
A list of the target nodes that have been specified using the
Default() function or method. The elements of the list are
nodes, so you need to run them through the Python str function
to get at the path name for each Node.
Example:
print str(DEFAULT_TARGETS[0])
if 'foo' in map(str, DEFAULT_TARGETS):
print "Don't forget to test the `foo' program!"
The contents of the DEFAULT_TARGETS list change on on each suc‐
cessive call to the Default() function:
print map(str, DEFAULT_TARGETS) # originally []
Default('foo')
print map(str, DEFAULT_TARGETS) # now a node ['foo']
Default('bar')
print map(str, DEFAULT_TARGETS) # now a node ['foo', 'bar']
Default(None)
print map(str, DEFAULT_TARGETS) # back to []
Consequently, be sure to use DEFAULT_TARGETS only after you've
made all of your Default() calls, or else simply be careful of
the order of these statements in your SConscript files so that
you don't look for a specific default target before it's actu‐
ally been added to the list.
Construction Variables
A construction environment has an associated dictionary of construction
variables that are used by built-in or user-supplied build rules. Con‐
struction variables must follow the same rules for Python identifiers:
the initial character must be an underscore or letter, followed by any
number of underscores, letters, or digits.
A number of useful construction variables are automatically defined by
scons for each supported platform, and additional construction vari‐
ables can be defined by the user. The following is a list of the auto‐
matically defined construction variables:
AR The static library archiver.
ARCHITECTURE
Specifies the system architecture for which the package is being
built. The default is the system architecture of the machine on
which SCons is running. This is used to fill in the Architec‐
ture: field in an Ipkg control file, and as part of the name of
a generated RPM file.
ARCOM The command line used to generate a static library from object
files.
ARCOMSTR
The string displayed when an object file is generated from an
assembly-language source file. If this is not set, then $ARCOM
(the command line) is displayed.
env = Environment(ARCOMSTR = "Archiving $TARGET")
ARFLAGS
General options passed to the static library archiver.
AS The assembler.
ASCOM The command line used to generate an object file from an assem‐
bly-language source file.
ASCOMSTR
The string displayed when an object file is generated from an
assembly-language source file. If this is not set, then $ASCOM
(the command line) is displayed.
env = Environment(ASCOMSTR = "Assembling $TARGET")
ASFLAGS
General options passed to the assembler.
ASPPCOM
The command line used to assemble an assembly-language source
file into an object file after first running the file through
the C preprocessor. Any options specified in the $ASFLAGS and
$CPPFLAGS construction variables are included on this command
line.
ASPPCOMSTR
The string displayed when an object file is generated from an
assembly-language source file after first running the file
through the C preprocessor. If this is not set, then $ASPPCOM
(the command line) is displayed.
env = Environment(ASPPCOMSTR = "Assembling $TARGET")
ASPPFLAGS
General options when an assembling an assembly-language source
file into an object file after first running the file through
the C preprocessor. The default is to use the value of
$ASFLAGS.
BIBTEX The bibliography generator for the TeX formatter and typesetter
and the LaTeX structured formatter and typesetter.
BIBTEXCOM
The command line used to call the bibliography generator for the
TeX formatter and typesetter and the LaTeX structured formatter
and typesetter.
BIBTEXCOMSTR
The string displayed when generating a bibliography for TeX or
LaTeX. If this is not set, then $BIBTEXCOM (the command line)
is displayed.
env = Environment(BIBTEXCOMSTR = "Generating bibliography $TARGET")
BIBTEXFLAGS
General options passed to the bibliography generator for the TeX
formatter and typesetter and the LaTeX structured formatter and
typesetter.
BITKEEPER
The BitKeeper executable.
BITKEEPERCOM
The command line for fetching source files using BitKeeper.
BITKEEPERCOMSTR
The string displayed when fetching a source file using Bit‐
Keeper. If this is not set, then $BITKEEPERCOM (the command
line) is displayed.
BITKEEPERGET
The command ($BITKEEPER) and subcommand for fetching source
files using BitKeeper.
BITKEEPERGETFLAGS
Options that are passed to the BitKeeper get subcommand.
BUILDERS
A dictionary mapping the names of the builders available through
this environment to underlying Builder objects. Builders named
Alias, CFile, CXXFile, DVI, Library, Object, PDF, PostScript,
and Program are available by default. If you initialize this
variable when an Environment is created:
env = Environment(BUILDERS = {'NewBuilder' : foo})
the default Builders will no longer be available. To use a new
Builder object in addition to the default Builders, add your new
Builder object like this:
env = Environment()
env.Append(BUILDERS = {'NewBuilder' : foo})
or this:
env = Environment()
env['BUILDERS]['NewBuilder'] = foo
CC The C compiler.
CCCOM The command line used to compile a C source file to a (static)
object file. Any options specified in the $CFLAGS, $CCFLAGS and
$CPPFLAGS construction variables are included on this command
line.
CCCOMSTR
The string displayed when a C source file is compiled to a
(static) object file. If this is not set, then $CCCOM (the com‐
mand line) is displayed.
env = Environment(CCCOMSTR = "Compiling static object $TARGET")
CCFLAGS
General options that are passed to the C and C++ compilers.
CCPCHFLAGS
Options added to the compiler command line to support building
with precompiled headers. The default value expands expands to
the appropriate Microsoft Visual C++ command-line options when
the $PCH construction variable is set.
CCPDBFLAGS
Options added to the compiler command line to support storing
debugging information in a Microsoft Visual C++ PDB file. The
default value expands expands to appropriate Microsoft Visual
C++ command-line options when the $PDB construction variable is
set.
The Visual C++ compiler option that SCons uses by default to
generate PDB information is /Z7. This works correctly with par‐
allel (-j) builds because it embeds the debug information in the
intermediate object files, as opposed to sharing a single PDB
file between multiple object files. This is also the only way
to get debug information embedded into a static library. Using
the /Zi instead may yield improved link-time performance,
although parallel builds will no longer work.
You can generate PDB files with the /Zi switch by overriding the
default $CCPDBFLAGS variable as follows:
env['CCPDBFLAGS'] = ['${(PDB and "/Zi /Fd%s" % File(PDB)) or ""}']
An alternative would be to use the /Zi to put the debugging
information in a separate .pdb file for each object file by
overriding the $CCPDBFLAGS variable as follows:
env['CCPDBFLAGS'] = '/Zi /Fd${TARGET}.pdb'
CCVERSION
The version number of the C compiler. This may or may not be
set, depending on the specific C compiler being used.
CFILESUFFIX
The suffix for C source files. This is used by the internal
CFile builder when generating C files from Lex (.l) or YACC (.y)
input files. The default suffix, of course, is .c (lower case).
On case-insensitive systems (like Windows), SCons also treats .C
(upper case) files as C files.
CFLAGS General options that are passed to the C compiler (C only; not
C++).
CHANGE_SPECFILE
A hook for modifying the file that controls the packaging build
(the .spec for RPM, the control for Ipkg, the .wxs for MSI). If
set, the function will be called after the SCons template for
the file has been written. XXX
CHANGED_SOURCES
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
CHANGED_TARGETS
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
CHANGELOG
The name of a file containing the change log text to be included
in the package. This is included as the %changelog section of
the RPM .spec file.
_concat
A function used to produce variables like $_CPPINCFLAGS. It
takes four or five arguments: a prefix to concatenate onto each
element, a list of elements, a suffix to concatenate onto each
element, an environment for variable interpolation, and an
optional function that will be called to transform the list
before concatenation.
env['_CPPINCFLAGS'] = '$( ${_concat(INCPREFIX, CPPPATH, INCSUFFIX, __env__, RDirs)} $)',
CONFIGUREDIR
The name of the directory in which Configure context test files
are written. The default is .sconf_temp in the top-level direc‐
tory containing the SConstruct file.
CONFIGURELOG
The name of the Configure context log file. The default is con‐
fig.log in the top-level directory containing the SConstruct
file.
_CPPDEFFLAGS
An automatically-generated construction variable containing the
C preprocessor command-line options to define values. The value
of $_CPPDEFFLAGS is created by appending $CPPDEFPREFIX and
$CPPDEFSUFFIX to the beginning and end of each definition in
$CPPDEFINES.
CPPDEFINES
A platform independent specification of C preprocessor defini‐
tions. The definitions will be added to command lines through
the automatically-generated $_CPPDEFFLAGS construction variable
(see above), which is constructed according to the type of value
of $CPPDEFINES:
If $CPPDEFINES is a string, the values of the $CPPDEFPRE‐
FIXand$CPPDEFSUFFIX construction variables will be added to the
beginning and end.
# Will add -Dxyz to POSIX compiler command lines,
# and /Dxyz to Microsoft Visual C++ command lines.
env = Environment(CPPDEFINES='xyz')
If $CPPDEFINES is a list, the values of the $CPPDEFPRE‐
FIXand$CPPDEFSUFFIX construction variables will be appended to
the beginning and end of each element in the list. If any ele‐
ment is a list or tuple, then the first item is the name being
defined and the second item is its value:
# Will add -DB=2 -DA to POSIX compiler command lines,
# and /DB=2 /DA to Microsoft Visual C++ command lines.
env = Environment(CPPDEFINES=[('B', 2), 'A'])
If $CPPDEFINES is a dictionary, the values of the $CPPDEFPRE‐
FIXand$CPPDEFSUFFIX construction variables will be appended to
the beginning and end of each item from the dictionary. The key
of each dictionary item is a name being defined to the dictio‐
nary item's corresponding value; if the value is None, then the
name is defined without an explicit value. Note that the
resulting flags are sorted by keyword to ensure that the order
of the options on the command line is consistent each time scons
is run.
# Will add -DA -DB=2 to POSIX compiler command lines,
# and /DA /DB=2 to Microsoft Visual C++ command lines.
env = Environment(CPPDEFINES={'B':2, 'A':None})
CPPDEFPREFIX
The prefix used to specify preprocessor definitions on the C
compiler command line. This will be appended to the beginning
of each definition in the $CPPDEFINES construction variable when
the $_CPPDEFFLAGS variable is automatically generated.
CPPDEFSUFFIX
The suffix used to specify preprocessor definitions on the C
compiler command line. This will be appended to the end of each
definition in the $CPPDEFINES construction variable when the
$_CPPDEFFLAGS variable is automatically generated.
CPPFLAGS
User-specified C preprocessor options. These will be included
in any command that uses the C preprocessor, including not just
compilation of C and C++ source files via the $CCCOM, $SHCCCOM,
$CXXCOM and $SHCXXCOM command lines, but also the $FORTRANPPCOM,
$SHFORTRANPPCOM, $F77PPCOM and $SHF77PPCOM command lines used to
compile a Fortran source file, and the $ASPPCOM command line
used to assemble an assembly language source file, after first
running each file through the C preprocessor. Note that this
variable does not contain -I (or similar) include search path
options that scons generates automatically from $CPPPATH. See
$_CPPINCFLAGS, below, for the variable that expands to those
options.
_CPPINCFLAGS
An automatically-generated construction variable containing the
C preprocessor command-line options for specifying directories
to be searched for include files. The value of $_CPPINCFLAGS is
created by appending $INCPREFIX and $INCSUFFIX to the beginning
and end of each directory in $CPPPATH.
CPPPATH
The list of directories that the C preprocessor will search for
include directories. The C/C++ implicit dependency scanner will
search these directories for include files. Don't explicitly put
include directory arguments in CCFLAGS or CXXFLAGS because the
result will be non-portable and the directories will not be
searched by the dependency scanner. Note: directory names in
CPPPATH will be looked-up relative to the SConscript directory
when they are used in a command. To force scons to look-up a
directory relative to the root of the source tree use #:
env = Environment(CPPPATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(CPPPATH=include)
The directory list will be added to command lines through the
automatically-generated $_CPPINCFLAGS construction variable,
which is constructed by appending the values of the $INCPRE‐
FIXand$INCSUFFIX construction variables to the beginning and end
of each directory in $CPPPATH. Any command lines you define
that need the CPPPATH directory list should include
$_CPPINCFLAGS:
env = Environment(CCCOM="my_compiler $_CPPINCFLAGS -c -o $TARGET $SOURCE")
CPPSUFFIXES
The list of suffixes of files that will be scanned for C pre‐
processor implicit dependencies (#include lines). The default
list is:
[".c", ".C", ".cxx", ".cpp", ".c++", ".cc",
".h", ".H", ".hxx", ".hpp", ".hh",
".F", ".fpp", ".FPP",
".m", ".mm",
".S", ".spp", ".SPP"]
CVS The CVS executable.
CVSCOFLAGS
Options that are passed to the CVS checkout subcommand.
CVSCOM The command line used to fetch source files from a CVS reposi‐
tory.
CVSCOMSTR
The string displayed when fetching a source file from a CVS
repository. If this is not set, then $CVSCOM (the command line)
is displayed.
CVSFLAGS
General options that are passed to CVS. By default, this is set
to -d $CVSREPOSITORY to specify from where the files must be
fetched.
CVSREPOSITORY
The path to the CVS repository. This is referenced in the
default $CVSFLAGS value.
CXX The C++ compiler.
CXXCOM The command line used to compile a C++ source file to an object
file. Any options specified in the $CXXFLAGS and $CPPFLAGS con‐
struction variables are included on this command line.
CXXCOMSTR
The string displayed when a C++ source file is compiled to a
(static) object file. If this is not set, then $CXXCOM (the
command line) is displayed.
env = Environment(CXXCOMSTR = "Compiling static object $TARGET")
CXXFILESUFFIX
The suffix for C++ source files. This is used by the internal
CXXFile builder when generating C++ files from Lex (.ll) or YACC
(.yy) input files. The default suffix is .cc. SCons also
treats files with the suffixes .cpp, .cxx, .c++, and .C++ as C++
files, and files with .mm suffixes as Objective C++ files. On
case-sensitive systems (Linux, UNIX, and other POSIX-alikes),
SCons also treats .C (upper case) files as C++ files.
CXXFLAGS
General options that are passed to the C++ compiler. By
default, this includes the value of $CCFLAGS, so that setting
$CCFLAGS affects both C and C++ compilation. If you want to add
C++-specific flags, you must set or override the value of
$CXXFLAGS.
CXXVERSION
The version number of the C++ compiler. This may or may not be
set, depending on the specific C++ compiler being used.
DESCRIPTION
A long description of the project being packaged. This is
included in the relevant section of the file that controls the
packaging build.
DESCRIPTION_lang
A language-specific long description for the specified lang.
This is used to populate a %description -l section of an RPM
.spec file.
Dir A function that converts a string into a Dir instance relative
to the target being built.
Dirs A function that converts a list of strings into a list of Dir
instances relative to the target being built.
DSUFFIXES
The list of suffixes of files that will be scanned for imported
D package files. The default list is:
['.d']
DVIPDF The TeX DVI file to PDF file converter.
DVIPDFCOM
The command line used to convert TeX DVI files into a PDF file.
DVIPDFCOMSTR
The string displayed when a TeX DVI file is converted into a PDF
file. If this is not set, then $DVIPDFCOM (the command line) is
displayed.
DVIPDFFLAGS
General options passed to the TeX DVI file to PDF file con‐
verter.
DVIPS The TeX DVI file to PostScript converter.
DVIPSFLAGS
General options passed to the TeX DVI file to PostScript con‐
verter.
ENV A dictionary of environment variables to use when invoking com‐
mands. When $ENV is used in a command all list values will be
joined using the path separator and any other non-string values
will simply be coerced to a string. Note that, by default,
scons does not propagate the environment in force when you exe‐
cute scons to the commands used to build target files. This is
so that builds will be guaranteed repeatable regardless of the
environment variables set at the time scons is invoked.
If you want to propagate your environment variables to the com‐
mands executed to build target files, you must do so explicitly:
import os
env = Environment(ENV = os.environ)
Note that you can choose only to propagate certain environment
variables. A common example is the system PATH environment
variable, so that scons uses the same utilities as the invoking
shell (or other process):
import os
env = Environment(ENV = {'PATH' : os.environ['PATH']})
ESCAPE A function that will be called to escape shell special charac‐
ters in command lines. The function should take one argument:
the command line string to escape; and should return the escaped
command line.
F77 The Fortran 77 compiler. You should normally set the $FORTRAN
variable, which specifies the default Fortran compiler for all
Fortran versions. You only need to set $F77 if you need to use
a specific compiler or compiler version for Fortran 77 files.
F77COM The command line used to compile a Fortran 77 source file to an
object file. You only need to set $F77COM if you need to use a
specific command line for Fortran 77 files. You should normally
set the $FORTRANCOM variable, which specifies the default com‐
mand line for all Fortran versions.
F77COMSTR
The string displayed when a Fortran 77 source file is compiled
to an object file. If this is not set, then $F77COM or $FOR‐
TRANCOM (the command line) is displayed.
F77FILESUFFIXES
The list of file extensions for which the F77 dialect will be
used. By default, this is ['.f77']
F77FLAGS
General user-specified options that are passed to the Fortran 77
compiler. Note that this variable does not contain -I (or simi‐
lar) include search path options that scons generates automati‐
cally from $F77PATH. See $_F77INCFLAGS below, for the variable
that expands to those options. You only need to set $F77FLAGS
if you need to define specific user options for Fortran 77
files. You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options passed to the default
Fortran compiler for all Fortran versions.
_F77INCFLAGS
An automatically-generated construction variable containing the
Fortran 77 compiler command-line options for specifying directo‐
ries to be searched for include files. The value of
$_F77INCFLAGS is created by appending $INCPREFIX and $INCSUFFIX
to the beginning and end of each directory in $F77PATH.
F77PATH
The list of directories that the Fortran 77 compiler will search
for include directories. The implicit dependency scanner will
search these directories for include files. Don't explicitly put
include directory arguments in $F77FLAGS because the result will
be non-portable and the directories will not be searched by the
dependency scanner. Note: directory names in $F77PATH will be
looked-up relative to the SConscript directory when they are
used in a command. To force scons to look-up a directory rela‐
tive to the root of the source tree use #: You only need to set
$F77PATH if you need to define a specific include path for For‐
tran 77 files. You should normally set the $FORTRANPATH vari‐
able, which specifies the include path for the default Fortran
compiler for all Fortran versions.
env = Environment(F77PATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(F77PATH=include)
The directory list will be added to command lines through the
automatically-generated $_F77INCFLAGS construction variable,
which is constructed by appending the values of the $INCPRE‐
FIXand$INCSUFFIX construction variables to the beginning and end
of each directory in $F77PATH. Any command lines you define
that need the F77PATH directory list should include
$_F77INCFLAGS:
env = Environment(F77COM="my_compiler $_F77INCFLAGS -c -o $TARGET $SOURCE")
F77PPCOM
The command line used to compile a Fortran 77 source file to an
object file after first running the file through the C pre‐
processor. Any options specified in the $F77FLAGS and $CPPFLAGS
construction variables are included on this command line. You
only need to set $F77PPCOM if you need to use a specific C-pre‐
processor command line for Fortran 77 files. You should nor‐
mally set the $FORTRANPPCOM variable, which specifies the
default C-preprocessor command line for all Fortran versions.
F77PPCOMSTR
The string displayed when a Fortran 77 source file is compiled
to an object file after first running the file through the C
preprocessor. If this is not set, then $F77PPCOM or $FORTRANPP‐
COM (the command line) is displayed.
F77PPFILESUFFIXES
The list of file extensions for which the compilation + pre‐
processor pass for F77 dialect will be used. By default, this is
empty
F90 The Fortran 90 compiler. You should normally set the $FORTRAN
variable, which specifies the default Fortran compiler for all
Fortran versions. You only need to set $F90 if you need to use
a specific compiler or compiler version for Fortran 90 files.
F90COM The command line used to compile a Fortran 90 source file to an
object file. You only need to set $F90COM if you need to use a
specific command line for Fortran 90 files. You should normally
set the $FORTRANCOM variable, which specifies the default com‐
mand line for all Fortran versions.
F90COMSTR
The string displayed when a Fortran 90 source file is compiled
to an object file. If this is not set, then $F90COM or $FOR‐
TRANCOM (the command line) is displayed.
F90FILESUFFIXES
The list of file extensions for which the F90 dialect will be
used. By default, this is ['.f90']
F90FLAGS
General user-specified options that are passed to the Fortran 90
compiler. Note that this variable does not contain -I (or simi‐
lar) include search path options that scons generates automati‐
cally from $F90PATH. See $_F90INCFLAGS below, for the variable
that expands to those options. You only need to set $F90FLAGS
if you need to define specific user options for Fortran 90
files. You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options passed to the default
Fortran compiler for all Fortran versions.
_F90INCFLAGS
An automatically-generated construction variable containing the
Fortran 90 compiler command-line options for specifying directo‐
ries to be searched for include files. The value of
$_F90INCFLAGS is created by appending $INCPREFIX and $INCSUFFIX
to the beginning and end of each directory in $F90PATH.
F90PATH
The list of directories that the Fortran 90 compiler will search
for include directories. The implicit dependency scanner will
search these directories for include files. Don't explicitly put
include directory arguments in $F90FLAGS because the result will
be non-portable and the directories will not be searched by the
dependency scanner. Note: directory names in $F90PATH will be
looked-up relative to the SConscript directory when they are
used in a command. To force scons to look-up a directory rela‐
tive to the root of the source tree use #: You only need to set
$F90PATH if you need to define a specific include path for For‐
tran 90 files. You should normally set the $FORTRANPATH vari‐
able, which specifies the include path for the default Fortran
compiler for all Fortran versions.
env = Environment(F90PATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(F90PATH=include)
The directory list will be added to command lines through the
automatically-generated $_F90INCFLAGS construction variable,
which is constructed by appending the values of the $INCPRE‐
FIXand$INCSUFFIX construction variables to the beginning and end
of each directory in $F90PATH. Any command lines you define
that need the F90PATH directory list should include
$_F90INCFLAGS:
env = Environment(F90COM="my_compiler $_F90INCFLAGS -c -o $TARGET $SOURCE")
F90PPCOM
The command line used to compile a Fortran 90 source file to an
object file after first running the file through the C pre‐
processor. Any options specified in the $F90FLAGS and $CPPFLAGS
construction variables are included on this command line. You
only need to set $F90PPCOM if you need to use a specific C-pre‐
processor command line for Fortran 90 files. You should nor‐
mally set the $FORTRANPPCOM variable, which specifies the
default C-preprocessor command line for all Fortran versions.
F90PPCOMSTR
The string displayed when a Fortran 90 source file is compiled
after first running the file through the C preprocessor. If
this is not set, then $F90PPCOM or $FORTRANPPCOM (the command
line) is displayed.
F90PPFILESUFFIXES
The list of file extensions for which the compilation + pre‐
processor pass for F90 dialect will be used. By default, this is
empty
F95 The Fortran 95 compiler. You should normally set the $FORTRAN
variable, which specifies the default Fortran compiler for all
Fortran versions. You only need to set $F95 if you need to use
a specific compiler or compiler version for Fortran 95 files.
F95COM The command line used to compile a Fortran 95 source file to an
object file. You only need to set $F95COM if you need to use a
specific command line for Fortran 95 files. You should normally
set the $FORTRANCOM variable, which specifies the default com‐
mand line for all Fortran versions.
F95COMSTR
The string displayed when a Fortran 95 source file is compiled
to an object file. If this is not set, then $F95COM or $FOR‐
TRANCOM (the command line) is displayed.
F95FILESUFFIXES
The list of file extensions for which the F95 dialect will be
used. By default, this is ['.f95']
F95FLAGS
General user-specified options that are passed to the Fortran 95
compiler. Note that this variable does not contain -I (or simi‐
lar) include search path options that scons generates automati‐
cally from $F95PATH. See $_F95INCFLAGS below, for the variable
that expands to those options. You only need to set $F95FLAGS
if you need to define specific user options for Fortran 95
files. You should normally set the $FORTRANFLAGS variable,
which specifies the user-specified options passed to the default
Fortran compiler for all Fortran versions.
_F95INCFLAGS
An automatically-generated construction variable containing the
Fortran 95 compiler command-line options for specifying directo‐
ries to be searched for include files. The value of
$_F95INCFLAGS is created by appending $INCPREFIX and $INCSUFFIX
to the beginning and end of each directory in $F95PATH.
F95PATH
The list of directories that the Fortran 95 compiler will search
for include directories. The implicit dependency scanner will
search these directories for include files. Don't explicitly put
include directory arguments in $F95FLAGS because the result will
be non-portable and the directories will not be searched by the
dependency scanner. Note: directory names in $F95PATH will be
looked-up relative to the SConscript directory when they are
used in a command. To force scons to look-up a directory rela‐
tive to the root of the source tree use #: You only need to set
$F95PATH if you need to define a specific include path for For‐
tran 95 files. You should normally set the $FORTRANPATH vari‐
able, which specifies the include path for the default Fortran
compiler for all Fortran versions.
env = Environment(F95PATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(F95PATH=include)
The directory list will be added to command lines through the
automatically-generated $_F95INCFLAGS construction variable,
which is constructed by appending the values of the $INCPRE‐
FIXand$INCSUFFIX construction variables to the beginning and end
of each directory in $F95PATH. Any command lines you define
that need the F95PATH directory list should include
$_F95INCFLAGS:
env = Environment(F95COM="my_compiler $_F95INCFLAGS -c -o $TARGET $SOURCE")
F95PPCOM
The command line used to compile a Fortran 95 source file to an
object file after first running the file through the C pre‐
processor. Any options specified in the $F95FLAGS and $CPPFLAGS
construction variables are included on this command line. You
only need to set $F95PPCOM if you need to use a specific C-pre‐
processor command line for Fortran 95 files. You should nor‐
mally set the $FORTRANPPCOM variable, which specifies the
default C-preprocessor command line for all Fortran versions.
F95PPCOMSTR
The string displayed when a Fortran 95 source file is compiled
to an object file after first running the file through the C
preprocessor. If this is not set, then $F95PPCOM or $FORTRANPP‐
COM (the command line) is displayed.
F95PPFILESUFFIXES
The list of file extensions for which the compilation + pre‐
processor pass for F95 dialect will be used. By default, this is
empty
File A function that converts a string into a File instance relative
to the target being built.
FORTRAN
The default Fortran compiler for all versions of Fortran.
FORTRANCOM
The command line used to compile a Fortran source file to an
object file. By default, any options specified in the $FORTRAN‐
FLAGS, $CPPFLAGS, $_CPPDEFFLAGS, $_FORTRANMODFLAG, and $_FOR‐
TRANINCFLAGS construction variables are included on this command
line.
FORTRANCOMSTR
The string displayed when a Fortran source file is compiled to
an object file. If this is not set, then $FORTRANCOM (the com‐
mand line) is displayed.
FORTRANFILESUFFIXES
The list of file extensions for which the FORTRAN dialect will
be used. By default, this is ['.f', '.for', '.ftn']
FORTRANFLAGS
General user-specified options that are passed to the Fortran
compiler. Note that this variable does not contain -I (or simi‐
lar) include or module search path options that scons generates
automatically from $FORTRANPATH. See $_FORTRANINCFLAGSand$_FOR‐
TRANMODFLAG, below, for the variables that expand those options.
_FORTRANINCFLAGS
An automatically-generated construction variable containing the
Fortran compiler command-line options for specifying directories
to be searched for include files and module files. The value of
$_FORTRANINCFLAGS is created by prepending/appending $INCPREFIX
and $INCSUFFIX to the beginning and end of each directory in
$FORTRANPATH.
FORTRANMODDIR
Directory location where the Fortran compiler should place any
module files it generates. This variable is empty, by default.
Some Fortran compilers will internally append this directory in
the search path for module files, as well.
FORTRANMODDIRPREFIX
The prefix used to specify a module directory on the Fortran
compiler command line. This will be appended to the beginning
of the directory in the $FORTRANMODDIR construction variables
when the $_FORTRANMODFLAG variables is automatically generated.
FORTRANMODDIRSUFFIX
The suffix used to specify a module directory on the Fortran
compiler command line. This will be appended to the beginning
of the directory in the $FORTRANMODDIR construction variables
when the $_FORTRANMODFLAG variables is automatically generated.
_FORTRANMODFLAG
An automatically-generated construction variable containing the
Fortran compiler command-line option for specifying the direc‐
tory location where the Fortran compiler should place any module
files that happen to get generated during compilation. The
value of $_FORTRANMODFLAG is created by prepending/appending
$FORTRANMODDIRPREFIX and $FORTRANMODDIRSUFFIX to the beginning
and end of the directory in $FORTRANMODDIR.
FORTRANMODPREFIX
The module file prefix used by the Fortran compiler. SCons
assumes that the Fortran compiler follows the quasi-standard
naming convention for module files of module_name.mod. As a
result, this variable is left empty, by default. For situations
in which the compiler does not necessarily follow the normal
convention, the user may use this variable. Its value will be
appended to every module file name as scons attempts to resolve
dependencies.
FORTRANMODSUFFIX
The module file suffix used by the Fortran compiler. SCons
assumes that the Fortran compiler follows the quasi-standard
naming convention for module files of module_name.mod. As a
result, this variable is set to ".mod", by default. For situa‐
tions in which the compiler does not necessarily follow the nor‐
mal convention, the user may use this variable. Its value will
be appended to every module file name as scons attempts to
resolve dependencies.
FORTRANPATH
The list of directories that the Fortran compiler will search
for include files and (for some compilers) module files. The
Fortran implicit dependency scanner will search these directo‐
ries for include files (but not module files since they are
autogenerated and, as such, may not actually exist at the time
the scan takes place). Don't explicitly put include directory
arguments in FORTRANFLAGS because the result will be non-porta‐
ble and the directories will not be searched by the dependency
scanner. Note: directory names in FORTRANPATH will be looked-up
relative to the SConscript directory when they are used in a
command. To force scons to look-up a directory relative to the
root of the source tree use #:
env = Environment(FORTRANPATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(FORTRANPATH=include)
The directory list will be added to command lines through the
automatically-generated $_FORTRANINCFLAGS construction variable,
which is constructed by appending the values of the $INCPRE‐
FIXand$INCSUFFIX construction variables to the beginning and end
of each directory in $FORTRANPATH. Any command lines you define
that need the FORTRANPATH directory list should include $_FOR‐
TRANINCFLAGS:
env = Environment(FORTRANCOM="my_compiler $_FORTRANINCFLAGS -c -o $TARGET $SOURCE")
FORTRANPPCOM
The command line used to compile a Fortran source file to an
object file after first running the file through the C pre‐
processor. By default, any options specified in the $FORTRAN‐
FLAGS, $CPPFLAGS, $_CPPDEFFLAGS, $_FORTRANMODFLAG, and $_FOR‐
TRANINCFLAGS construction variables are included on this command
line.
FORTRANPPCOMSTR
The string displayed when a Fortran source file is compiled to
an object file after first running the file through the C pre‐
processor. If this is not set, then $FORTRANPPCOM (the command
line) is displayed.
FORTRANPPFILESUFFIXES
The list of file extensions for which the compilation + pre‐
processor pass for FORTRAN dialect will be used. By default,
this is ['.fpp', '.FPP']
FORTRANSUFFIXES
The list of suffixes of files that will be scanned for Fortran
implicit dependencies (INCLUDE lines and USE statements). The
default list is:
[".f", ".F", ".for", ".FOR", ".ftn", ".FTN", ".fpp", ".FPP",
".f77", ".F77", ".f90", ".F90", ".f95", ".F95"]
FRAMEWORKPATH
On Mac OS X with gcc, a list containing the paths to search for
frameworks. Used by the compiler to find framework-style
includes like #include <Fmwk/Header.h>. Used by the linker to
find user-specified frameworks when linking (see $FRAMEWORKS).
For example:
env.AppendUnique(FRAMEWORKPATH='#myframeworkdir')
will add
... -Fmyframeworkdir
to the compiler and linker command lines.
_FRAMEWORKPATH
On Mac OS X with gcc, an automatically-generated construction
variable containing the linker command-line options correspond‐
ing to $FRAMEWORKPATH.
FRAMEWORKPATHPREFIX
On Mac OS X with gcc, the prefix to be used for the FRAMEWORK‐
PATH entries. (see $FRAMEWORKPATH). The default value is -F.
FRAMEWORKPREFIX
On Mac OS X with gcc, the prefix to be used for linking in
frameworks (see $FRAMEWORKS). The default value is -framework.
_FRAMEWORKS
On Mac OS X with gcc, an automatically-generated construction
variable containing the linker command-line options for linking
with FRAMEWORKS.
FRAMEWORKS
On Mac OS X with gcc, a list of the framework names to be linked
into a program or shared library or bundle. The default value
is the empty list. For example:
env.AppendUnique(FRAMEWORKS=Split('System Cocoa SystemConfiguration'))
FRAMEWORKSFLAGS
On Mac OS X with gcc, general user-supplied frameworks options
to be added at the end of a command line building a loadable
module. (This has been largely superseded by the $FRAMEWORK‐
PATH, $FRAMEWORKPATHPREFIX, $FRAMEWORKPREFIX and $FRAMEWORKS
variables described above.)
GS The Ghostscript program used to convert PostScript to PDF files.
GSCOM The Ghostscript command line used to convert PostScript to PDF
files.
GSCOMSTR
The string displayed when Ghostscript is used to convert a Post‐
Script file to a PDF file. If this is not set, then $GSCOM (the
command line) is displayed.
GSFLAGS
General options passed to the Ghostscript program when convert‐
ing PostScript to PDF files.
HOST_ARCH
Sets the host architecture for Visual Studio compiler. If not
set, default to the detected host architecture: note that this
may depend on the python you are using. This variable must be
passed as an argument to the Environment() constructor; setting
it later has no effect.
Valid values are the same as for $TARGET_ARCH.
This is currently only used on Windows, but in the future it
will be used on other OSes as well.
HOST_OS
The name of the host operating system used to create the
Environment.
If a platform is specified when creating the Environ‐
ment, then
that Platform's logic will handle setting this value.
This value is immutable, and should not be changed by
the user after
the Environment is initialized.
Currently only set for Win32.
IDLSUFFIXES
The list of suffixes of files that will be scanned for IDL
implicit dependencies (#include or import lines). The default
list is:
[".idl", ".IDL"]
IMPLICIT_COMMAND_DEPENDENCIES
Controls whether or not SCons will add implicit dependencies for
the commands executed to build targets.
By default, SCons will add to each target an implicit dependency
on the command represented by the first argument on any command
line it executes. The specific file for the dependency is found
by searching the PATH variable in the ENV environment used to
execute the command.
If the construction variable $IMPLICIT_COMMAND_DEPENDENCIES is
set to a false value (None, False, 0, etc.), then the implicit
dependency will not be added to the targets built with that con‐
struction environment.
env = Environment(IMPLICIT_COMMAND_DEPENDENCIES = 0)
INCPREFIX
The prefix used to specify an include directory on the C com‐
piler command line. This will be appended to the beginning of
each directory in the $CPPPATH and $FORTRANPATH construction
variables when the $_CPPINCFLAGS and $_FORTRANINCFLAGS variables
are automatically generated.
INCSUFFIX
The suffix used to specify an include directory on the C com‐
piler command line. This will be appended to the end of each
directory in the $CPPPATH and $FORTRANPATH construction vari‐
ables when the $_CPPINCFLAGS and $_FORTRANINCFLAGS variables are
automatically generated.
INSTALL
A function to be called to install a file into a destination
file name. The default function copies the file into the desti‐
nation (and sets the destination file's mode and permission bits
to match the source file's). The function takes the following
arguments:
def install(dest, source, env):
dest is the path name of the destination file. source is the
path name of the source file. env is the construction environ‐
ment (a dictionary of construction values) in force for this
file installation.
INSTALLSTR
The string displayed when a file is installed into a destination
file name. The default is:
Install file: "$SOURCE" as "$TARGET"
INTEL_C_COMPILER_VERSION
Set by the "intelc" Tool to the major version number of the
Intel C compiler selected for use.
JAR The Java archive tool.
JARCHDIR
The directory to which the Java archive tool should change
(using the -C option).
JARCOM The command line used to call the Java archive tool.
JARCOMSTR
The string displayed when the Java archive tool is called If
this is not set, then $JARCOM (the command line) is displayed.
env = Environment(JARCOMSTR = "JARchiving $SOURCES into $TARGET")
JARFLAGS
General options passed to the Java archive tool. By default
this is set to cf to create the necessary jar file.
JARSUFFIX
The suffix for Java archives: .jar by default.
JAVABOOTCLASSPATH
Specifies the list of directories that will be added to the
&javac; command line via the -bootclasspath option. The indi‐
vidual directory names will be separated by the operating sys‐
tem's path separate character (: on UNIX/Linux/POSIX, ; on Win‐
dows).
JAVAC The Java compiler.
JAVACCOM
The command line used to compile a directory tree containing
Java source files to corresponding Java class files. Any
options specified in the $JAVACFLAGS construction variable are
included on this command line.
JAVACCOMSTR
The string displayed when compiling a directory tree of Java
source files to corresponding Java class files. If this is not
set, then $JAVACCOM (the command line) is displayed.
env = Environment(JAVACCOMSTR = "Compiling class files $TARGETS from $SOURCES")
JAVACFLAGS
General options that are passed to the Java compiler.
JAVACLASSDIR
The directory in which Java class files may be found. This is
stripped from the beginning of any Java .class file names sup‐
plied to the JavaH builder.
JAVACLASSPATH
Specifies the list of directories that will be searched for Java
.class file. The directories in this list will be added to the
&javac; and &javah; command lines via the -classpath option.
The individual directory names will be separated by the operat‐
ing system's path separate character (: on UNIX/Linux/POSIX, ;
on Windows).
Note that this currently just adds the specified directory via
the -classpath option. &SCons; does not currently search the
$JAVACLASSPATH directories for dependency .class files.
JAVACLASSSUFFIX
The suffix for Java class files; .class by default.
JAVAH The Java generator for C header and stub files.
JAVAHCOM
The command line used to generate C header and stub files from
Java classes. Any options specified in the $JAVAHFLAGS con‐
struction variable are included on this command line.
JAVAHCOMSTR
The string displayed when C header and stub files are generated
from Java classes. If this is not set, then $JAVAHCOM (the com‐
mand line) is displayed.
env = Environment(JAVAHCOMSTR = "Generating header/stub file(s) $TARGETS from $SOURCES")
JAVAHFLAGS
General options passed to the C header and stub file generator
for Java classes.
JAVASOURCEPATH
Specifies the list of directories that will be searched for
input .java file. The directories in this list will be added to
the &javac; command line via the -sourcepath option. The indi‐
vidual directory names will be separated by the operating sys‐
tem's path separate character (: on UNIX/Linux/POSIX, ; on Win‐
dows).
Note that this currently just adds the specified directory via
the -sourcepath option. &SCons; does not currently search the
$JAVASOURCEPATH directories for dependency .java files.
JAVASUFFIX
The suffix for Java files; .java by default.
JAVAVERSION
Specifies the Java version being used by the Java() builder.
This is not currently used to select one version of the Java
compiler vs. another. Instead, you should set this to specify
the version of Java supported by your &javac; compiler. The
default is 1.4.
This is sometimes necessary because Java 1.5 changed the file
names that are created for nested anonymous inner classes, which
can cause a mismatch with the files that &SCons; expects will be
generated by the &javac; compiler. Setting $JAVAVERSION to 1.5
(or 1.6, as appropriate) can make &SCons; realize that a Java
1.5 or 1.6 build is actually up to date.
LATEX The LaTeX structured formatter and typesetter.
LATEXCOM
The command line used to call the LaTeX structured formatter and
typesetter.
LATEXCOMSTR
The string displayed when calling the LaTeX structured formatter
and typesetter. If this is not set, then $LATEXCOM (the command
line) is displayed.
env = Environment(LATEXCOMSTR = "Building $TARGET from LaTeX input $SOURCES")
LATEXFLAGS
General options passed to the LaTeX structured formatter and
typesetter.
LATEXRETRIES
The maximum number of times that LaTeX will be re-run if the
.log generated by the $LATEXCOM command indicates that there are
undefined references. The default is to try to resolve unde‐
fined references by re-running LaTeX up to three times.
LATEXSUFFIXES
The list of suffixes of files that will be scanned for LaTeX
implicit dependencies (\include or \import files). The default
list is:
[".tex", ".ltx", ".latex"]
LDMODULE
The linker for building loadable modules. By default, this is
the same as $SHLINK.
LDMODULECOM
The command line for building loadable modules. On Mac OS X,
this uses the $LDMODULE, $LDMODULEFLAGS and $FRAMEWORKSFLAGS
variables. On other systems, this is the same as $SHLINK.
LDMODULECOMSTR
The string displayed when building loadable modules. If this is
not set, then $LDMODULECOM (the command line) is displayed.
LDMODULEFLAGS
General user options passed to the linker for building loadable
modules.
LDMODULEPREFIX
The prefix used for loadable module file names. On Mac OS X,
this is null; on other systems, this is the same as $SHLIBPRE‐
FIX.
LDMODULESUFFIX
The suffix used for loadable module file names. On Mac OS X,
this is null; on other systems, this is the same as $SHLIBSUF‐
FIX.
LEX The lexical analyzer generator.
LEXCOM The command line used to call the lexical analyzer generator to
generate a source file.
LEXCOMSTR
The string displayed when generating a source file using the
lexical analyzer generator. If this is not set, then $LEXCOM
(the command line) is displayed.
env = Environment(LEXCOMSTR = "Lex'ing $TARGET from $SOURCES")
LEXFLAGS
General options passed to the lexical analyzer generator.
_LIBDIRFLAGS
An automatically-generated construction variable containing the
linker command-line options for specifying directories to be
searched for library. The value of $_LIBDIRFLAGS is created by
appending $LIBDIRPREFIX and $LIBDIRSUFFIX to the beginning and
end of each directory in $LIBPATH.
LIBDIRPREFIX
The prefix used to specify a library directory on the linker
command line. This will be appended to the beginning of each
directory in the $LIBPATH construction variable when the $_LIB‐
DIRFLAGS variable is automatically generated.
LIBDIRSUFFIX
The suffix used to specify a library directory on the linker
command line. This will be appended to the end of each direc‐
tory in the $LIBPATH construction variable when the $_LIB‐
DIRFLAGS variable is automatically generated.
LIBEMITTER
TODO
_LIBFLAGS
An automatically-generated construction variable containing the
linker command-line options for specifying libraries to be
linked with the resulting target. The value of $_LIBFLAGS is
created by appending $LIBLINKPREFIX and $LIBLINKSUFFIX to the
beginning and end of each filename in $LIBS.
LIBLINKPREFIX
The prefix used to specify a library to link on the linker com‐
mand line. This will be appended to the beginning of each
library in the $LIBS construction variable when the $_LIBFLAGS
variable is automatically generated.
LIBLINKSUFFIX
The suffix used to specify a library to link on the linker com‐
mand line. This will be appended to the end of each library in
the $LIBS construction variable when the $_LIBFLAGS variable is
automatically generated.
LIBPATH
The list of directories that will be searched for libraries.
The implicit dependency scanner will search these directories
for include files. Don't explicitly put include directory argu‐
ments in $LINKFLAGS or $SHLINKFLAGS because the result will be
non-portable and the directories will not be searched by the
dependency scanner. Note: directory names in LIBPATH will be
looked-up relative to the SConscript directory when they are
used in a command. To force scons to look-up a directory rela‐
tive to the root of the source tree use #:
env = Environment(LIBPATH='#/libs')
The directory look-up can also be forced using the Dir() func‐
tion:
libs = Dir('libs')
env = Environment(LIBPATH=libs)
The directory list will be added to command lines through the
automatically-generated $_LIBDIRFLAGS construction variable,
which is constructed by appending the values of the $LIBDIRPRE‐
FIXand$LIBDIRSUFFIX construction variables to the beginning and
end of each directory in $LIBPATH. Any command lines you define
that need the LIBPATH directory list should include $_LIB‐
DIRFLAGS:
env = Environment(LINKCOM="my_linker $_LIBDIRFLAGS $_LIBFLAGS -o $TARGET $SOURCE")
LIBPREFIX
The prefix used for (static) library file names. A default
value is set for each platform (posix, win32, os2, etc.), but
the value is overridden by individual tools (ar, mslib, sgiar,
sunar, tlib, etc.) to reflect the names of the libraries they
create.
LIBPREFIXES
A list of all legal prefixes for library file names. When
searching for library dependencies, SCons will look for files
with these prefixes, the base library name, and suffixes in the
$LIBSUFFIXES list.
LIBS A list of one or more libraries that will be linked with any
executable programs created by this environment.
The library list will be added to command lines through the
automatically-generated $_LIBFLAGS construction variable, which
is constructed by appending the values of the $LIBLINKPRE‐
FIXand$LIBLINKSUFFIX construction variables to the beginning and
end of each filename in $LIBS. Any command lines you define
that need the LIBS library list should include $_LIBFLAGS:
env = Environment(LINKCOM="my_linker $_LIBDIRFLAGS $_LIBFLAGS -o $TARGET $SOURCE")
If you add a File object to the $LIBS list, the name of that
file will be added to $_LIBFLAGS, and thus the link line, as is,
without $LIBLINKPREFIX or $LIBLINKSUFFIX. For example:
env.Append(LIBS=File('/tmp/mylib.so'))
In all cases, scons will add dependencies from the executable
program to all the libraries in this list.
LIBSUFFIX
The suffix used for (static) library file names. A default
value is set for each platform (posix, win32, os2, etc.), but
the value is overridden by individual tools (ar, mslib, sgiar,
sunar, tlib, etc.) to reflect the names of the libraries they
create.
LIBSUFFIXES
A list of all legal suffixes for library file names. When
searching for library dependencies, SCons will look for files
with prefixes, in the $LIBPREFIXES list, the base library name,
and these suffixes.
LICENSE
The abbreviated name of the license under which this project is
released (gpl, lpgl, bsd etc.). See http://www.open‐
source.org/licenses/alphabetical for a list of license names.
LINESEPARATOR
The separator used by the Substfile() and Textfile() builders.
This value is used between sources when constructing the target.
It defaults to the current system line separator.
LINGUAS_FILE
The $LINGUAS_FILE defines file(s) containing list of additional
linguas to be processed by POInit(), POUpdate() or MOFiles()
builders. It also affects Translate() builder. If the variable
contains a string, it defines name of the list file. The $LIN‐
GUAS_FILE may be a list of file names as well. If $LINGUAS_FILE
is set to True (or non-zero numeric value), the list will be
read from default file named LINGUAS.
LINK The linker.
LINKCOM
The command line used to link object files into an executable.
LINKCOMSTR
The string displayed when object files are linked into an exe‐
cutable. If this is not set, then $LINKCOM (the command line)
is displayed.
env = Environment(LINKCOMSTR = "Linking $TARGET")
LINKFLAGS
General user options passed to the linker. Note that this vari‐
able should not contain -l (or similar) options for linking with
the libraries listed in $LIBS, nor -L (or similar) library
search path options that scons generates automatically from
$LIBPATH. See $_LIBFLAGS above, for the variable that expands
to library-link options, and $_LIBDIRFLAGS above, for the vari‐
able that expands to library search path options.
M4 The M4 macro preprocessor.
M4COM The command line used to pass files through the M4 macro pre‐
processor.
M4COMSTR
The string displayed when a file is passed through the M4 macro
preprocessor. If this is not set, then $M4COM (the command
line) is displayed.
M4FLAGS
General options passed to the M4 macro preprocessor.
MAKEINDEX
The makeindex generator for the TeX formatter and typesetter and
the LaTeX structured formatter and typesetter.
MAKEINDEXCOM
The command line used to call the makeindex generator for the
TeX formatter and typesetter and the LaTeX structured formatter
and typesetter.
MAKEINDEXCOMSTR
The string displayed when calling the makeindex generator for
the TeX formatter and typesetter and the LaTeX structured for‐
matter and typesetter. If this is not set, then $MAKEINDEXCOM
(the command line) is displayed.
MAKEINDEXFLAGS
General options passed to the makeindex generator for the TeX
formatter and typesetter and the LaTeX structured formatter and
typesetter.
MAXLINELENGTH
The maximum number of characters allowed on an external command
line. On Win32 systems, link lines longer than this many char‐
acters are linked via a temporary file name.
MIDL The Microsoft IDL compiler.
MIDLCOM
The command line used to pass files to the Microsoft IDL com‐
piler.
MIDLCOMSTR
The string displayed when the Microsoft IDL copmiler is called.
If this is not set, then $MIDLCOM (the command line) is dis‐
played.
MIDLFLAGS
General options passed to the Microsoft IDL compiler.
MOSUFFIX
Suffix used for MO files (default: '.mo'). See &t-link-msgfmt;
tool and MOFiles() builder.
MSGFMT Absolute path to msgfmt(1) binary, found by Detect(). See &t-
link-msgfmt; tool and MOFiles() builder.
MSGFMTCOM
Complete command line to run msgfmt(1) program. See &t-link-
msgfmt; tool and MOFiles() builder.
MSGFMTCOMSTR
String to display when msgfmt(1) is invoked (default: '', which
means ``print $MSGFMTCOM''). See &t-link-msgfmt; tool and
MOFiles() builder.
MSGFMTFLAGS
Additional flags to msgfmt(1). See &t-link-msgfmt; tool and
MOFiles() builder.
MSGINIT
Path to msginit(1) program (found via Detect()). See &t-link-
msginit; tool and POInit() builder.
MSGINITCOM
Complete command line to run msginit(1) program. See &t-link-
msginit; tool and POInit() builder.
MSGINITCOMSTR
String to display when msginit(1) is invoked (default: '', which
means ``print $MSGINITCOM''). See &t-link-msginit; tool and
POInit() builder.
MSGINITFLAGS
List of additional flags to msginit(1) (default: []). See &t-
link-msginit; tool and POInit() builder.
_MSGINITLOCALE
Internal ``macro''. Computes locale (language) name based on
target filename (default: '${TARGET.filebase}' ).
MSGMERGE
Absolute path to msgmerge(1) binary as found by Detect(). See
&t-link-msgmerge; tool and POUpdate() builder.
MSGMERGECOM
Complete command line to run msgmerge(1) command. See &t-link-
msgmerge; tool and POUpdate() builder.
MSGMERGECOMSTR
String to be displayed when msgmerge(1) is invoked (default: '',
which means ``print $MSGMERGECOM''). See &t-link-msgmerge; tool
and POUpdate() builder.
MSGMERGEFLAGS
Additional flags to msgmerge(1) command. See &t-link-msgmerge;
tool and POUpdate() builder.
MSSDK_DIR
The directory containing the Microsoft SDK (either Platform SDK
or Windows SDK) to be used for compilation.
MSSDK_VERSION
The version string of the Microsoft SDK (either Platform SDK or
Windows SDK) to be used for compilation. Supported versions
include 6.1, 6.0A, 6.0, 2003R2 and 2003R1.
MSVC_BATCH
When set to any true value, specifies that SCons should batch
compilation of object files when calling the Microsoft Visual
C/C++ compiler. All compilations of source files from the same
source directory that generate target files in a same output
directory and were configured in SCons using the same construc‐
tion environment will be built in a single call to the compiler.
Only source files that have changed since their object files
were built will be passed to each compiler invocation (via the
$CHANGED_SOURCES construction variable). Any compilations where
the object (target) file base name (minus the .obj) does not
match the source file base name will be compiled separately.
MSVC_USE_SCRIPT
Use a batch script to set up Microsoft Visual Studio compiler
$MSVC_USE_SCRIPToverrides$MSVC_VERSIONand$TARGET_ARCH. If set
to the name of a Visual Studio .bat file (e.g. vcvars.bat),
SCons will run that bat file and extract the relevant variables
from the result (typically %INCLUDE%, %LIB%, and %PATH%). Set‐
ting MSVC_USE_SCRIPT to None bypasses the Visual Studio autode‐
tection entirely; use this if you are running SCons in a Visual
Studio cmd window and importing the shell's environment vari‐
ables.
MSVC_VERSION
Sets the preferred version of Microsoft Visual C/C++ to use.
If $MSVC_VERSION is not set, SCons will (by default) select the
latest version of Visual C/C++ installed on your system. If the
specified version isn't installed, tool initialization will
fail. This variable must be passed as an argument to the Envi‐
ronment() constructor; setting it later has no effect. Set it
to an unexpected value (e.g. "XXX") to see the valid values on
your system.
MSVS When the Microsoft Visual Studio tools are initialized, they set
up this dictionary with the following keys:
VERSION: the version of MSVS being used (can be set via
$MSVS_VERSION)
VERSIONS: the available versions of MSVS installed
VCINSTALLDIR: installed directory of Visual C++
VSINSTALLDIR: installed directory of Visual Studio
FRAMEWORKDIR: installed directory of the .NET framework
FRAMEWORKVERSIONS: list of installed versions of the .NET frame‐
work, sorted latest to oldest.
FRAMEWORKVERSION: latest installed version of the .NET framework
FRAMEWORKSDKDIR: installed location of the .NET SDK.
PLATFORMSDKDIR: installed location of the Platform SDK.
PLATFORMSDK_MODULES: dictionary of installed Platform SDK mod‐
ules, where the dictionary keys are keywords for the various
modules, and the values are 2-tuples where the first is the
release date, and the second is the version number.
If a value isn't set, it wasn't available in the registry.
MSVS_ARCH
Sets the architecture for which the generated project(s) should
build.
The default value is x86. amd64 is also supported by &SCons;
for some Visual Studio versions. Trying to set $MSVS_ARCH to an
architecture that's not supported for a given Visual Studio ver‐
sion will generate an error.
MSVS_PROJECT_GUID
The string placed in a generated Microsoft Visual Studio project
file as the value of the ProjectGUID attribute. There is no
default value. If not defined, a new GUID is generated.
MSVS_SCC_AUX_PATH
The path name placed in a generated Microsoft Visual Studio
project file as the value of the SccAuxPath attribute if the
MSVS_SCC_PROVIDER construction variable is also set. There is
no default value.
MSVS_SCC_CONNECTION_ROOT
The root path of projects in your SCC workspace, i.e the path
under which all project and solution files will be generated. It
is used as a reference path from which the relative paths of the
generated Microsoft Visual Studio project and solution files are
computed. The relative project file path is placed as the value
of the SccLocalPath attribute of the project file and as the
values of the SccProjectFilePathRelativizedFromConnection[i]
(where [i] ranges from 0 to the number of projects in the solu‐
tion) attributes of the GlobalSection(SourceCodeControl) section
of the Microsoft Visual Studio solution file. Similarly the
relative solution file path is placed as the values of the
SccLocalPath[i] (where [i] ranges from 0 to the number of
projects in the solution) attributes of the GlobalSec‐
tion(SourceCodeControl) section of the Microsoft Visual Studio
solution file. This is used only if the MSVS_SCC_PROVIDER con‐
struction variable is also set. The default value is the cur‐
rent working directory.
MSVS_SCC_PROJECT_NAME
The project name placed in a generated Microsoft Visual Studio
project file as the value of the SccProjectName attribute if the
MSVS_SCC_PROVIDER construction variable is also set. In this
case the string is also placed in the SccProjectName0 attribute
of the GlobalSection(SourceCodeControl) section of the Microsoft
Visual Studio solution file. There is no default value.
MSVS_SCC_PROVIDER
The string placed in a generated Microsoft Visual Studio project
file as the value of the SccProvider attribute. The string is
also placed in the SccProvider0 attribute of the GlobalSec‐
tion(SourceCodeControl) section of the Microsoft Visual Studio
solution file. There is no default value.
MSVS_VERSION
Sets the preferred version of Microsoft Visual Studio to use.
If $MSVS_VERSION is not set, &SCons; will (by default) select
the latest version of Visual Studio installed on your system.
So, if you have version 6 and version 7 (MSVS .NET) installed,
it will prefer version 7. You can override this by specifying
the MSVS_VERSION variable in the Environment initialization,
setting it to the appropriate version ('6.0' or '7.0', for exam‐
ple). If the specified version isn't installed, tool initial‐
ization will fail.
This is obsolete: use $MSVC_VERSION instead. If $MSVS_VERSION is
set and $MSVC_VERSIONisnot,$MSVC_VERSIONwillbesetautomatical‐
lyto$MSVS_VERSION. If both are set to different values, scons
will raise an error.
MSVSBUILDCOM
The build command line placed in a generated Microsoft Visual
Studio project file. The default is to have Visual Studio
invoke SCons with any specified build targets.
MSVSCLEANCOM
The clean command line placed in a generated Microsoft Visual
Studio project file. The default is to have Visual Studio
invoke SCons with the -c option to remove any specified targets.
MSVSENCODING
The encoding string placed in a generated Microsoft Visual Stu‐
dio project file. The default is encoding Windows-1252.
MSVSPROJECTCOM
The action used to generate Microsoft Visual Studio project
files.
MSVSPROJECTSUFFIX
The suffix used for Microsoft Visual Studio project (DSP) files.
The default value is .vcproj when using Visual Studio version
7.x (.NET) or later version, and .dsp when using earlier ver‐
sions of Visual Studio.
MSVSREBUILDCOM
The rebuild command line placed in a generated Microsoft Visual
Studio project file. The default is to have Visual Studio
invoke SCons with any specified rebuild targets.
MSVSSCONS
The SCons used in generated Microsoft Visual Studio project
files. The default is the version of SCons being used to gener‐
ate the project file.
MSVSSCONSCOM
The default SCons command used in generated Microsoft Visual
Studio project files.
MSVSSCONSCRIPT
The sconscript file (that is, SConstruct or SConscript file)
that will be invoked by Visual Studio project files (through the
$MSVSSCONSCOM variable). The default is the same sconscript
file that contains the call to MSVSProject() to build the
project file.
MSVSSCONSFLAGS
The SCons flags used in generated Microsoft Visual Studio
project files.
MSVSSOLUTIONCOM
The action used to generate Microsoft Visual Studio solution
files.
MSVSSOLUTIONSUFFIX
The suffix used for Microsoft Visual Studio solution (DSW)
files. The default value is .sln when using Visual Studio ver‐
sion 7.x (.NET), and .dsw when using earlier versions of Visual
Studio.
MT The program used on Windows systems to embed manifests into DLLs
and EXEs. See also $WINDOWS_EMBED_MANIFEST.
MTEXECOM
The Windows command line used to embed manifests into executa‐
bles. See also $MTSHLIBCOM.
MTFLAGS
Flags passed to the $MT manifest embedding program (Windows
only).
MTSHLIBCOM
The Windows command line used to embed manifests into shared
libraries (DLLs). See also $MTEXECOM.
MWCW_VERSION
The version number of the MetroWerks CodeWarrior C compiler to
be used.
MWCW_VERSIONS
A list of installed versions of the MetroWerks CodeWarrior C
compiler on this system.
NAME Specfies the name of the project to package.
no_import_lib
When set to non-zero, suppresses creation of a corresponding
Windows static import lib by the SharedLibrary builder when used
with MinGW, Microsoft Visual Studio or Metrowerks. This also
suppresses creation of an export (.exp) file when using Micro‐
soft Visual Studio.
OBJPREFIX
The prefix used for (static) object file names.
OBJSUFFIX
The suffix used for (static) object file names.
P4 The Perforce executable.
P4COM The command line used to fetch source files from Perforce.
P4COMSTR
The string displayed when fetching a source file from Perforce.
If this is not set, then $P4COM (the command line) is displayed.
P4FLAGS
General options that are passed to Perforce.
PACKAGEROOT
Specifies the directory where all files in resulting archive
will be placed if applicable. The default value is "$NAME-$VER‐
SION".
PACKAGETYPE
Selects the package type to build. Currently these are avail‐
able:
* msi - Microsoft Installer
* rpm - Redhat Package Manger
* ipkg - Itsy Package Management System
* tarbz2 - compressed tar
* targz - compressed tar
* zip - zip file
* src_tarbz2 - compressed tar source
* src_targz - compressed tar source
* src_zip - zip file source
This may be overridden with the "package_type" command line
option.
PACKAGEVERSION
The version of the package (not the underlying project). This
is currently only used by the rpm packager and should reflect
changes in the packaging, not the underlying project code
itself.
PCH The Microsoft Visual C++ precompiled header that will be used
when compiling object files. This variable is ignored by tools
other than Microsoft Visual C++. When this variable is defined
SCons will add options to the compiler command line to cause it
to use the precompiled header, and will also set up the depen‐
dencies for the PCH file. Example:
env['PCH'] = 'StdAfx.pch'
PCHCOM The command line used by the PCH() builder to generated a pre‐
compiled header.
PCHCOMSTR
The string displayed when generating a precompiled header. If
this is not set, then $PCHCOM (the command line) is displayed.
PCHPDBFLAGS
A construction variable that, when expanded, adds the /yD flag
to the command line only if the $PDB construction variable is
set.
PCHSTOP
This variable specifies how much of a source file is precom‐
piled. This variable is ignored by tools other than Microsoft
Visual C++, or when the PCH variable is not being used. When
this variable is define it must be a string that is the name of
the header that is included at the end of the precompiled por‐
tion of the source files, or the empty string if the "#pragma
hrdstop" construct is being used:
env['PCHSTOP'] = 'StdAfx.h'
PDB The Microsoft Visual C++ PDB file that will store debugging
information for object files, shared libraries, and programs.
This variable is ignored by tools other than Microsoft Visual
C++. When this variable is defined SCons will add options to
the compiler and linker command line to cause them to generate
external debugging information, and will also set up the depen‐
dencies for the PDB file. Example:
env['PDB'] = 'hello.pdb'
The Visual C++ compiler switch that SCons uses by default to
generate PDB information is /Z7. This works correctly with par‐
allel (-j) builds because it embeds the debug information in the
intermediate object files, as opposed to sharing a single PDB
file between multiple object files. This is also the only way
to get debug information embedded into a static library. Using
the /Zi instead may yield improved link-time performance,
although parallel builds will no longer work. You can generate
PDB files with the /Zi switch by overriding the default
$CCPDBFLAGS variable; see the entry for that variable for spe‐
cific examples.
PDFCOM A deprecated synonym for $DVIPDFCOM.
PDFLATEX
The &pdflatex; utility.
PDFLATEXCOM
The command line used to call the &pdflatex; utility.
PDFLATEXCOMSTR
The string displayed when calling the &pdflatex; utility. If
this is not set, then $PDFLATEXCOM (the command line) is dis‐
played.
env = Environment(PDFLATEX;COMSTR = "Building $TARGET from LaTeX input $SOURCES")
PDFLATEXFLAGS
General options passed to the &pdflatex; utility.
PDFPREFIX
The prefix used for PDF file names.
PDFSUFFIX
The suffix used for PDF file names.
PDFTEX The &pdftex; utility.
PDFTEXCOM
The command line used to call the &pdftex; utility.
PDFTEXCOMSTR
The string displayed when calling the &pdftex; utility. If this
is not set, then $PDFTEXCOM (the command line) is displayed.
env = Environment(PDFTEXCOMSTR = "Building $TARGET from TeX input $SOURCES")
PDFTEXFLAGS
General options passed to the &pdftex; utility.
PKGCHK On Solaris systems, the package-checking program that will be
used (along with $PKGINFO) to look for installed versions of the
Sun PRO C++ compiler. The default is /usr/sbin/pgkchk.
PKGINFO
On Solaris systems, the package information program that will be
used (along with $PKGCHK) to look for installed versions of the
Sun PRO C++ compiler. The default is pkginfo.
PLATFORM
The name of the platform used to create the Environment. If no
platform is specified when the Environment is created, scons
autodetects the platform.
env = Environment(tools = [])
if env['PLATFORM'] == 'cygwin':
Tool('mingw')(env)
else:
Tool('msvc')(env)
POAUTOINIT
The $POAUTOINIT variable, if set to True (on non-zero numeric
value), let the &t-link-msginit; tool to automatically initial‐
ize missing PO files with msginit(1). This applies to both,
POInit() and POUpdate() builders (and others that use any of
them).
POCREATE_ALIAS
Common alias for all PO files created with POInit() builder
(default: 'po-create'). See &t-link-msginit; tool and POInit()
builder.
POSUFFIX
Suffix used for PO files (default: '.po') See &t-link-msginit;
tool and POInit() builder.
POTDOMAIN
The $POTDOMAIN defines default domain, used to generate POT
filename as $POTDOMAIN.pot when no POT file name is provided by
the user. This applies to POTUpdate(), POInit() and POUpdate()
builders (and builders, that use them, e.g. Translate()). Nor‐
mally (if $POTDOMAIN is not defined), the builders use mes‐
sages.pot as default POT file name.
POTSUFFIX
Suffix used for PO Template files (default: '.pot'). See &t-
link-xgettext; tool and POTUpdate() builder.
POTUPDATE_ALIAS
Name of the common phony target for all PO Templates created
with POUpdate()(default:'pot-update'). See &t-link-xgettext;
tool and POTUpdate() builder.
POUPDATE_ALIAS
Common alias for all PO files being defined with POUp‐
date()builder(default:'po-update'). See &t-link-msgmerge; tool
and POUpdate() builder.
PRINT_CMD_LINE_FUNC
A Python function used to print the command lines as they are
executed (assuming command printing is not disabled by the -q or
-s options or their equivalents). The function should take four
arguments: s, the command being executed (a string), target, the
target being built (file node, list, or string name(s)), source,
the source(s) used (file node, list, or string name(s)), and
env, the environment being used.
The function must do the printing itself. The default implemen‐
tation, used if this variable is not set or is None, is:
def print_cmd_line(s, target, source, env):
sys.stdout.write(s + "\n")
Here's an example of a more interesting function:
def print_cmd_line(s, target, source, env):
sys.stdout.write("Building %s -> %s...\n" %
(' and '.join([str(x) for x in source]),
' and '.join([str(x) for x in target])))
env=Environment(PRINT_CMD_LINE_FUNC=print_cmd_line)
env.Program('foo', 'foo.c')
This just prints "Building targetname from sourcename..."
instead of the actual commands. Such a function could also log
the actual commands to a log file, for example.
PROGEMITTER
TODO
PROGPREFIX
The prefix used for executable file names.
PROGSUFFIX
The suffix used for executable file names.
PSCOM The command line used to convert TeX DVI files into a PostScript
file.
PSCOMSTR
The string displayed when a TeX DVI file is converted into a
PostScript file. If this is not set, then $PSCOM (the command
line) is displayed.
PSPREFIX
The prefix used for PostScript file names.
PSSUFFIX
The prefix used for PostScript file names.
QT_AUTOSCAN
Turn off scanning for mocable files. Use the Moc Builder to
explicitly specify files to run moc on.
QT_BINPATH
The path where the qt binaries are installed. The default value
is '$QTDIR/bin'.
QT_CPPPATH
The path where the qt header files are installed. The default
value is '$QTDIR/include'. Note: If you set this variable to
None, the tool won't change the $CPPPATH construction variable.
QT_DEBUG
Prints lots of debugging information while scanning for moc
files.
QT_LIB Default value is 'qt'. You may want to set this to 'qt-mt'.
Note: If you set this variable to None, the tool won't change
the $LIBS variable.
QT_LIBPATH
The path where the qt libraries are installed. The default
value is '$QTDIR/lib'. Note: If you set this variable to None,
the tool won't change the $LIBPATH construction variable.
QT_MOC Default value is '$QT_BINPATH/moc'.
QT_MOCCXXPREFIX
Default value is ''. Prefix for moc output files, when source is
a cxx file.
QT_MOCCXXSUFFIX
Default value is '.moc'. Suffix for moc output files, when
source is a cxx file.
QT_MOCFROMCXXCOM
Command to generate a moc file from a cpp file.
QT_MOCFROMCXXCOMSTR
The string displayed when generating a moc file from a cpp file.
If this is not set, then $QT_MOCFROMCXXCOM (the command line) is
displayed.
QT_MOCFROMCXXFLAGS
Default value is '-i'. These flags are passed to moc, when mocc‐
ing a C++ file.
QT_MOCFROMHCOM
Command to generate a moc file from a header.
QT_MOCFROMHCOMSTR
The string displayed when generating a moc file from a cpp file.
If this is not set, then $QT_MOCFROMHCOM (the command line) is
displayed.
QT_MOCFROMHFLAGS
Default value is ''. These flags are passed to moc, when moccing
a header file.
QT_MOCHPREFIX
Default value is 'moc_'. Prefix for moc output files, when
source is a header.
QT_MOCHSUFFIX
Default value is '$CXXFILESUFFIX'. Suffix for moc output files,
when source is a header.
QT_UIC Default value is '$QT_BINPATH/uic'.
QT_UICCOM
Command to generate header files from .ui files.
QT_UICCOMSTR
The string displayed when generating header files from .ui
files. If this is not set, then $QT_UICCOM (the command line)
is displayed.
QT_UICDECLFLAGS
Default value is ''. These flags are passed to uic, when creat‐
ing a a h file from a .ui file.
QT_UICDECLPREFIX
Default value is ''. Prefix for uic generated header files.
QT_UICDECLSUFFIX
Default value is '.h'. Suffix for uic generated header files.
QT_UICIMPLFLAGS
Default value is ''. These flags are passed to uic, when creat‐
ing a cxx file from a .ui file.
QT_UICIMPLPREFIX
Default value is 'uic_'. Prefix for uic generated implementation
files.
QT_UICIMPLSUFFIX
Default value is '$CXXFILESUFFIX'. Suffix for uic generated
implementation files.
QT_UISUFFIX
Default value is '.ui'. Suffix of designer input files.
QTDIR The qt tool tries to take this from os.environ. It also ini‐
tializes all QT_* construction variables listed below. (Note
that all paths are constructed with python's os.path.join()
method, but are listed here with the '/' separator for easier
reading.) In addition, the construction environment variables
$CPPPATH, $LIBPATH and $LIBS may be modified and the variables
$PROGEMITTER,$SHLIBEMITTERand$LIBEMITTER are modified. Because
the build-performance is affected when using this tool, you have
to explicitly specify it at Environment creation:
Environment(tools=['default','qt'])
The qt tool supports the following operations:
Automatic moc file generation from header files. You do not
have to specify moc files explicitly, the tool does it for you.
However, there are a few preconditions to do so: Your header
file must have the same filebase as your implementation file and
must stay in the same directory. It must have one of the suf‐
fixes .h, .hpp, .H, .hxx, .hh. You can turn off automatic moc
file generation by setting QT_AUTOSCAN to 0. See also the cor‐
responding Moc()() builder method.
Automatic moc file generation from cxx files. As stated in the
qt documentation, include the moc file at the end of the cxx
file. Note that you have to include the file, which is generated
by the transformation ${QT_MOCCXXPREFIX}<basename>${QT_MOC‐
CXXSUFFIX}, by default <basename>.moc. A warning is generated
after building the moc file, if you do not include the correct
file. If you are using VariantDir, you may need to specify
duplicate=1. You can turn off automatic moc file generation by
setting QT_AUTOSCAN to 0. See also the corresponding Moc()
builder method.
Automatic handling of .ui files. The implementation files gen‐
erated from .ui files are handled much the same as yacc or lex
files. Each .ui file given as a source of Program, Library or
SharedLibrary will generate three files, the declaration file,
the implementation file and a moc file. Because there are also
generated headers, you may need to specify duplicate=1 in calls
to VariantDir. See also the corresponding Uic() builder method.
RANLIB The archive indexer.
RANLIBCOM
The command line used to index a static library archive.
RANLIBCOMSTR
The string displayed when a static library archive is indexed.
If this is not set, then $RANLIBCOM (the command line) is dis‐
played.
env = Environment(RANLIBCOMSTR = "Indexing $TARGET")
RANLIBFLAGS
General options passed to the archive indexer.
RC The resource compiler used to build a Microsoft Visual C++
resource file.
RCCOM The command line used to build a Microsoft Visual C++ resource
file.
RCCOMSTR
The string displayed when invoking the resource compiler to
build a Microsoft Visual C++ resource file. If this is not set,
then $RCCOM (the command line) is displayed.
RCFLAGS
The flags passed to the resource compiler by the RES builder.
RCINCFLAGS
An automatically-generated construction variable containing the
command-line options for specifying directories to be searched
by the resource compiler. The value of $RCINCFLAGS is created
by appending $RCINCPREFIX and $RCINCSUFFIX to the beginning and
end of each directory in $CPPPATH.
RCINCPREFIX
The prefix (flag) used to specify an include directory on the
resource compiler command line. This will be appended to the
beginning of each directory in the $CPPPATH construction vari‐
able when the $RCINCFLAGS variable is expanded.
RCINCSUFFIX
The suffix used to specify an include directory on the resource
compiler command line. This will be appended to the end of each
directory in the $CPPPATH construction variable when the
$RCINCFLAGS variable is expanded.
RCS The RCS executable. Note that this variable is not actually
used for the command to fetch source files from RCS; see the
$RCS_CO construction variable, below.
RCS_CO The RCS "checkout" executable, used to fetch source files from
RCS.
RCS_COCOM
The command line used to fetch (checkout) source files from RCS.
RCS_COCOMSTR
The string displayed when fetching a source file from RCS. If
this is not set, then $RCS_COCOM (the command line) is dis‐
played.
RCS_COFLAGS
Options that are passed to the $RCS_CO command.
RDirs A function that converts a string into a list of Dir instances
by searching the repositories.
REGSVR The program used on Windows systems to register a newly-built
DLL library whenever the SharedLibrary() builder is passed a
keyword argument of register=1.
REGSVRCOM
The command line used on Windows systems to register a newly-
built DLL library whenever the SharedLibrary() builder is passed
a keyword argument of register=1.
REGSVRCOMSTR
The string displayed when registering a newly-built DLL file.
If this is not set, then $REGSVRCOM (the command line) is dis‐
played.
REGSVRFLAGS
Flags passed to the DLL registration program on Windows systems
when a newly-built DLL library is registered. By default, this
includes the /s that prevents dialog boxes from popping up and
requiring user attention.
RMIC The Java RMI stub compiler.
RMICCOM
The command line used to compile stub and skeleton class files
from Java classes that contain RMI implementations. Any options
specified in the $RMICFLAGS construction variable are included
on this command line.
RMICCOMSTR
The string displayed when compiling stub and skeleton class
files from Java classes that contain RMI implementations. If
this is not set, then $RMICCOM (the command line) is displayed.
env = Environment(RMICCOMSTR = "Generating stub/skeleton class files $TARGETS from $SOURCES")
RMICFLAGS
General options passed to the Java RMI stub compiler.
_RPATH An automatically-generated construction variable containing the
rpath flags to be used when linking a program with shared
libraries. The value of $_RPATH is created by appending $RPATH‐
PREFIX and $RPATHSUFFIX to the beginning and end of each direc‐
tory in $RPATH.
RPATH A list of paths to search for shared libraries when running pro‐
grams. Currently only used in the GNU (gnulink), IRIX (sgilink)
and Sun (sunlink) linkers. Ignored on platforms and toolchains
that don't support it. Note that the paths added to RPATH are
not transformed by scons in any way: if you want an absolute
path, you must make it absolute yourself.
RPATHPREFIX
The prefix used to specify a directory to be searched for shared
libraries when running programs. This will be appended to the
beginning of each directory in the $RPATH construction variable
when the $_RPATH variable is automatically generated.
RPATHSUFFIX
The suffix used to specify a directory to be searched for shared
libraries when running programs. This will be appended to the
end of each directory in the $RPATH construction variable when
the $_RPATH variable is automatically generated.
RPCGEN The RPC protocol compiler.
RPCGENCLIENTFLAGS
Options passed to the RPC protocol compiler when generating
client side stubs. These are in addition to any flags specified
in the $RPCGENFLAGS construction variable.
RPCGENFLAGS
General options passed to the RPC protocol compiler.
RPCGENHEADERFLAGS
Options passed to the RPC protocol compiler when generating a
header file. These are in addition to any flags specified in
the $RPCGENFLAGS construction variable.
RPCGENSERVICEFLAGS
Options passed to the RPC protocol compiler when generating
server side stubs. These are in addition to any flags specified
in the $RPCGENFLAGS construction variable.
RPCGENXDRFLAGS
Options passed to the RPC protocol compiler when generating XDR
routines. These are in addition to any flags specified in the
$RPCGENFLAGS construction variable.
SCANNERS
A list of the available implicit dependency scanners. New file
scanners may be added by appending to this list, although the
more flexible approach is to associate scanners with a specific
Builder. See the sections "Builder Objects" and "Scanner
Objects," below, for more information.
SCCS The SCCS executable.
SCCSCOM
The command line used to fetch source files from SCCS.
SCCSCOMSTR
The string displayed when fetching a source file from a CVS
repository. If this is not set, then $SCCSCOM (the command
line) is displayed.
SCCSFLAGS
General options that are passed to SCCS.
SCCSGETFLAGS
Options that are passed specifically to the SCCS "get" subcom‐
mand. This can be set, for example, to -e to check out editable
files from SCCS.
SCONS_HOME
The (optional) path to the SCons library directory, initialized
from the external environment. If set, this is used to con‐
struct a shorter and more efficient search path in the $MSVSS‐
CONS command line executed from Microsoft Visual Studio project
files.
SHCC The C compiler used for generating shared-library objects.
SHCCCOM
The command line used to compile a C source file to a shared-
library object file. Any options specified in the $SHCFLAGS,
$SHCCFLAGS and $CPPFLAGS construction variables are included on
this command line.
SHCCCOMSTR
The string displayed when a C source file is compiled to a
shared object file. If this is not set, then $SHCCCOM (the com‐
mand line) is displayed.
env = Environment(SHCCCOMSTR = "Compiling shared object $TARGET")
SHCCFLAGS
Options that are passed to the C and C++ compilers to generate
shared-library objects.
SHCFLAGS
Options that are passed to the C compiler (only; not C++) to
generate shared-library objects.
SHCXX The C++ compiler used for generating shared-library objects.
SHCXXCOM
The command line used to compile a C++ source file to a shared-
library object file. Any options specified in the $SHCXXFLAGS
and $CPPFLAGS construction variables are included on this com‐
mand line.
SHCXXCOMSTR
The string displayed when a C++ source file is compiled to a
shared object file. If this is not set, then $SHCXXCOM (the
command line) is displayed.
env = Environment(SHCXXCOMSTR = "Compiling shared object $TARGET")
SHCXXFLAGS
Options that are passed to the C++ compiler to generate shared-
library objects.
SHELL A string naming the shell program that will be passed to the
$SPAWN function. See the $SPAWN construction variable for more
information.
SHF77 The Fortran 77 compiler used for generating shared-library
objects. You should normally set the $SHFORTRAN variable, which
specifies the default Fortran compiler for all Fortran versions.
You only need to set $SHF77 if you need to use a specific com‐
piler or compiler version for Fortran 77 files.
SHF77COM
The command line used to compile a Fortran 77 source file to a
shared-library object file. You only need to set $SHF77COM if
you need to use a specific command line for Fortran 77 files.
You should normally set the $SHFORTRANCOM variable, which speci‐
fies the default command line for all Fortran versions.
SHF77COMSTR
The string displayed when a Fortran 77 source file is compiled
to a shared-library object file. If this is not set, then
$SHF77COM or $SHFORTRANCOM (the command line) is displayed.
SHF77FLAGS
Options that are passed to the Fortran 77 compiler to generated
shared-library objects. You only need to set $SHF77FLAGS if you
need to define specific user options for Fortran 77 files. You
should normally set the $SHFORTRANFLAGS variable, which speci‐
fies the user-specified options passed to the default Fortran
compiler for all Fortran versions.
SHF77PPCOM
The command line used to compile a Fortran 77 source file to a
shared-library object file after first running the file through
the C preprocessor. Any options specified in the $SHF77FLAGS
and $CPPFLAGS construction variables are included on this com‐
mand line. You only need to set $SHF77PPCOM if you need to use
a specific C-preprocessor command line for Fortran 77 files.
You should normally set the $SHFORTRANPPCOM variable, which
specifies the default C-preprocessor command line for all For‐
tran versions.
SHF77PPCOMSTR
The string displayed when a Fortran 77 source file is compiled
to a shared-library object file after first running the file
through the C preprocessor. If this is not set, then
$SHF77PPCOM or $SHFORTRANPPCOM (the command line) is displayed.
SHF90 The Fortran 90 compiler used for generating shared-library
objects. You should normally set the $SHFORTRAN variable, which
specifies the default Fortran compiler for all Fortran versions.
You only need to set $SHF90 if you need to use a specific com‐
piler or compiler version for Fortran 90 files.
SHF90COM
The command line used to compile a Fortran 90 source file to a
shared-library object file. You only need to set $SHF90COM if
you need to use a specific command line for Fortran 90 files.
You should normally set the $SHFORTRANCOM variable, which speci‐
fies the default command line for all Fortran versions.
SHF90COMSTR
The string displayed when a Fortran 90 source file is compiled
to a shared-library object file. If this is not set, then
$SHF90COM or $SHFORTRANCOM (the command line) is displayed.
SHF90FLAGS
Options that are passed to the Fortran 90 compiler to generated
shared-library objects. You only need to set $SHF90FLAGS if you
need to define specific user options for Fortran 90 files. You
should normally set the $SHFORTRANFLAGS variable, which speci‐
fies the user-specified options passed to the default Fortran
compiler for all Fortran versions.
SHF90PPCOM
The command line used to compile a Fortran 90 source file to a
shared-library object file after first running the file through
the C preprocessor. Any options specified in the $SHF90FLAGS
and $CPPFLAGS construction variables are included on this com‐
mand line. You only need to set $SHF90PPCOM if you need to use
a specific C-preprocessor command line for Fortran 90 files.
You should normally set the $SHFORTRANPPCOM variable, which
specifies the default C-preprocessor command line for all For‐
tran versions.
SHF90PPCOMSTR
The string displayed when a Fortran 90 source file is compiled
to a shared-library object file after first running the file
through the C preprocessor. If this is not set, then
$SHF90PPCOM or $SHFORTRANPPCOM (the command line) is displayed.
SHF95 The Fortran 95 compiler used for generating shared-library
objects. You should normally set the $SHFORTRAN variable, which
specifies the default Fortran compiler for all Fortran versions.
You only need to set $SHF95 if you need to use a specific com‐
piler or compiler version for Fortran 95 files.
SHF95COM
The command line used to compile a Fortran 95 source file to a
shared-library object file. You only need to set $SHF95COM if
you need to use a specific command line for Fortran 95 files.
You should normally set the $SHFORTRANCOM variable, which speci‐
fies the default command line for all Fortran versions.
SHF95COMSTR
The string displayed when a Fortran 95 source file is compiled
to a shared-library object file. If this is not set, then
$SHF95COM or $SHFORTRANCOM (the command line) is displayed.
SHF95FLAGS
Options that are passed to the Fortran 95 compiler to generated
shared-library objects. You only need to set $SHF95FLAGS if you
need to define specific user options for Fortran 95 files. You
should normally set the $SHFORTRANFLAGS variable, which speci‐
fies the user-specified options passed to the default Fortran
compiler for all Fortran versions.
SHF95PPCOM
The command line used to compile a Fortran 95 source file to a
shared-library object file after first running the file through
the C preprocessor. Any options specified in the $SHF95FLAGS
and $CPPFLAGS construction variables are included on this com‐
mand line. You only need to set $SHF95PPCOM if you need to use
a specific C-preprocessor command line for Fortran 95 files.
You should normally set the $SHFORTRANPPCOM variable, which
specifies the default C-preprocessor command line for all For‐
tran versions.
SHF95PPCOMSTR
The string displayed when a Fortran 95 source file is compiled
to a shared-library object file after first running the file
through the C preprocessor. If this is not set, then
$SHF95PPCOM or $SHFORTRANPPCOM (the command line) is displayed.
SHFORTRAN
The default Fortran compiler used for generating shared-library
objects.
SHFORTRANCOM
The command line used to compile a Fortran source file to a
shared-library object file.
SHFORTRANCOMSTR
The string displayed when a Fortran source file is compiled to a
shared-library object file. If this is not set, then $SHFOR‐
TRANCOM (the command line) is displayed.
SHFORTRANFLAGS
Options that are passed to the Fortran compiler to generate
shared-library objects.
SHFORTRANPPCOM
The command line used to compile a Fortran source file to a
shared-library object file after first running the file through
the C preprocessor. Any options specified in the $SHFORTRAN‐
FLAGS and $CPPFLAGS construction variables are included on this
command line.
SHFORTRANPPCOMSTR
The string displayed when a Fortran source file is compiled to a
shared-library object file after first running the file through
the C preprocessor. If this is not set, then $SHFORTRANPPCOM
(the command line) is displayed.
SHLIBEMITTER
TODO
SHLIBPREFIX
The prefix used for shared library file names.
SHLIBSUFFIX
The suffix used for shared library file names.
SHLIBVERSION
When this construction variable is defined, a versioned shared
library is created. This modifies the $SHLINKFLAGS as required,
adds the version number to the library name, and creates the
symlinks that are needed. $SHLIBVERSION needs to be of the form
X.Y.Z, where X and Y are numbers, and Z is a number but can also
contain letters to designate alpha, beta, or release candidate
patch levels.
SHLINK The linker for programs that use shared libraries.
SHLINKCOM
The command line used to link programs using shared libraries.
SHLINKCOMSTR
The string displayed when programs using shared libraries are
linked. If this is not set, then $SHLINKCOM (the command line)
is displayed.
env = Environment(SHLINKCOMSTR = "Linking shared $TARGET")
SHLINKFLAGS
General user options passed to the linker for programs using
shared libraries. Note that this variable should not contain -l
(or similar) options for linking with the libraries listed in
$LIBS, nor -L (or similar) include search path options that
scons generates automatically from $LIBPATH. See $_LIBFLAGS
above, for the variable that expands to library-link options,
and $_LIBDIRFLAGS above, for the variable that expands to
library search path options.
SHOBJPREFIX
The prefix used for shared object file names.
SHOBJSUFFIX
The suffix used for shared object file names.
SOURCE A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
SOURCE_URL
The URL (web address) of the location from which the project was
retrieved. This is used to fill in the Source: field in the
controlling information for Ipkg and RPM packages.
SOURCES
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
SPAWN A command interpreter function that will be called to execute
command line strings. The function must expect the following
arguments:
def spawn(shell, escape, cmd, args, env):
sh is a string naming the shell program to use. escape is a
function that can be called to escape shell special characters
in the command line. cmd is the path to the command to be exe‐
cuted. args is the arguments to the command. env is a dictio‐
nary of the environment variables in which the command should be
executed.
SUBST_DICT
The dictionary used by the Substfile() or Textfile() builders
for substitution values. It can be anything acceptable to the
dict() constructor, so in addition to a dictionary, lists of
tuples are also acceptable.
SUBSTFILEPREFIX
The prefix used for Substfile() file names, the null string by
default.
SUBSTFILESUFFIX
The suffix used for Substfile() file names, the null string by
default.
SUMMARY
A short summary of what the project is about. This is used to
fill in the Summary: field in the controlling information for
Ipkg and RPM packages, and as the Description: field in MSI
packages.
SWIG The scripting language wrapper and interface generator.
SWIGCFILESUFFIX
The suffix that will be used for intermediate C source files
generated by the scripting language wrapper and interface gener‐
ator. The default value is _wrap$CFILESUFFIX. By default, this
value is used whenever the -c++ option is not specified as part
of the $SWIGFLAGS construction variable.
SWIGCOM
The command line used to call the scripting language wrapper and
interface generator.
SWIGCOMSTR
The string displayed when calling the scripting language wrapper
and interface generator. If this is not set, then $SWIGCOM (the
command line) is displayed.
SWIGCXXFILESUFFIX
The suffix that will be used for intermediate C++ source files
generated by the scripting language wrapper and interface gener‐
ator. The default value is _wrap$CFILESUFFIX. By default, this
value is used whenever the -c++ option is specified as part of
the $SWIGFLAGS construction variable.
SWIGDIRECTORSUFFIX
The suffix that will be used for intermediate C++ header files
generated by the scripting language wrapper and interface gener‐
ator. These are only generated for C++ code when the SWIG
'directors' feature is turned on. The default value is _wrap.h.
SWIGFLAGS
General options passed to the scripting language wrapper and
interface generator. This is where you should set -python,
-perl5, -tcl, or whatever other options you want to specify to
SWIG. If you set the -c++ option in this variable, scons will,
by default, generate a C++ intermediate source file with the
extension that is specified as the $CXXFILESUFFIX variable.
_SWIGINCFLAGS
An automatically-generated construction variable containing the
SWIG command-line options for specifying directories to be
searched for included files. The value of $_SWIGINCFLAGS is
created by appending $SWIGINCPREFIX and $SWIGINCSUFFIX to the
beginning and end of each directory in $SWIGPATH.
SWIGINCPREFIX
The prefix used to specify an include directory on the SWIG com‐
mand line. This will be appended to the beginning of each
directory in the $SWIGPATH construction variable when the
$_SWIGINCFLAGS variable is automatically generated.
SWIGINCSUFFIX
The suffix used to specify an include directory on the SWIG com‐
mand line. This will be appended to the end of each directory
in the $SWIGPATH construction variable when the $_SWIGINCFLAGS
variable is automatically generated.
SWIGOUTDIR
Specifies the output directory in which the scripting language
wrapper and interface generator should place generated language-
specific files. This will be used by SCons to identify the
files that will be generated by the &swig; call, and translated
into the swig -outdir option on the command line.
SWIGPATH
The list of directories that the scripting language wrapper and
interface generate will search for included files. The SWIG
implicit dependency scanner will search these directories for
include files. The default is to use the same path specified as
$CPPPATH.
Don't explicitly put include directory arguments in SWIGFLAGS;
the result will be non-portable and the directories will not be
searched by the dependency scanner. Note: directory names in
SWIGPATH will be looked-up relative to the SConscript directory
when they are used in a command. To force scons to look-up a
directory relative to the root of the source tree use #:
env = Environment(SWIGPATH='#/include')
The directory look-up can also be forced using the Dir() func‐
tion:
include = Dir('include')
env = Environment(SWIGPATH=include)
The directory list will be added to command lines through the
automatically-generated $_SWIGINCFLAGS construction variable,
which is constructed by appending the values of the $SWIGINCPRE‐
FIXand$SWIGINCSUFFIX construction variables to the beginning and
end of each directory in $SWIGPATH. Any command lines you
define that need the SWIGPATH directory list should include
$_SWIGINCFLAGS:
env = Environment(SWIGCOM="my_swig -o $TARGET $_SWIGINCFLAGS $SORUCES")
SWIGVERSION
The version number of the SWIG tool.
TAR The tar archiver.
TARCOM The command line used to call the tar archiver.
TARCOMSTR
The string displayed when archiving files using the tar
archiver. If this is not set, then $TARCOM (the command line)
is displayed.
env = Environment(TARCOMSTR = "Archiving $TARGET")
TARFLAGS
General options passed to the tar archiver.
TARGET A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
TARGET_ARCH
Sets the target architecture for Visual Studio compiler (i.e.
the arch of the binaries generated by the compiler). If not set,
default to $HOST_ARCH, or, if that is unset, to the architecture
of the running machine's OS (note that the python build or
architecture has no effect). This variable must be passed as an
argument to the Environment() constructor; setting it later has
no effect. This is currently only used on Windows, but in the
future it will be used on other OSes as well.
Valid values for Windows are x86, i386 (for 32 bits); amd64,
emt64, x86_64 (for 64 bits); and ia64 (Itanium). For example,
if you want to compile 64-bit binaries, you would set TAR‐
GET_ARCH='x86_64' in your SCons environment.
TARGET_OS
The name of the target operating system for the compiled
objects
created by this Environment.
This defaults to the value of HOST_OS, and the user can
override it.
Currently only set for Win32.
TARGETS
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
TARSUFFIX
The suffix used for tar file names.
TEMPFILEPREFIX
The prefix for a temporary file used to execute lines longer
than $MAXLINELENGTH. The default is '@'. This may be set for
toolchains that use other values, such as '-@' for the diab com‐
piler or '-via' for ARM toolchain.
TEX The TeX formatter and typesetter.
TEXCOM The command line used to call the TeX formatter and typesetter.
TEXCOMSTR
The string displayed when calling the TeX formatter and typeset‐
ter. If this is not set, then $TEXCOM (the command line) is
displayed.
env = Environment(TEXCOMSTR = "Building $TARGET from TeX input $SOURCES")
TEXFLAGS
General options passed to the TeX formatter and typesetter.
TEXINPUTS
List of directories that the LaTeX program will search for
include directories. The LaTeX implicit dependency scanner will
search these directories for \include and \import files.
TEXTFILEPREFIX
The prefix used for Textfile() file names, the null string by
default.
TEXTFILESUFFIX
The suffix used for Textfile() file names; .txt by default.
TOOLS A list of the names of the Tool specifications that are part of
this construction environment.
UNCHANGED_SOURCES
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
UNCHANGED_TARGETS
A reserved variable name that may not be set or used in a con‐
struction environment. (See "Variable Substitution," below.)
VENDOR The person or organization who supply the packaged software.
This is used to fill in the Vendor: field in the controlling
information for RPM packages, and the Manufacturer: field in the
controlling information for MSI packages.
VERSION
The version of the project, specified as a string.
WIN32_INSERT_DEF
A deprecated synonym for $WINDOWS_INSERT_DEF.
WIN32DEFPREFIX
A deprecated synonym for $WINDOWSDEFPREFIX.
WIN32DEFSUFFIX
A deprecated synonym for $WINDOWSDEFSUFFIX.
WIN32EXPPREFIX
A deprecated synonym for $WINDOWSEXPSUFFIX.
WIN32EXPSUFFIX
A deprecated synonym for $WINDOWSEXPSUFFIX.
WINDOWS_EMBED_MANIFEST
Set this variable to True or 1 to embed the compiler-generated
manifest (normally ${TARGET}.manifest) into all Windows exes and
DLLs built with this environment, as a resource during their
link step. This is done using $MT and $MTEXECOM and $MTSHLIB‐
COM.
WINDOWS_INSERT_DEF
When this is set to true, a library build of a Windows shared
library (.dll file) will also build a corresponding .def file at
the same time, if a .def file is not already listed as a build
target. The default is 0 (do not build a .def file).
WINDOWS_INSERT_MANIFEST
When this is set to true, scons will be aware of the .manifest
files generated by Microsoft Visua C/C++ 8.
WINDOWSDEFPREFIX
The prefix used for Windows .def file names.
WINDOWSDEFSUFFIX
The suffix used for Windows .def file names.
WINDOWSEXPPREFIX
The prefix used for Windows .exp file names.
WINDOWSEXPSUFFIX
The suffix used for Windows .exp file names.
WINDOWSPROGMANIFESTPREFIX
The prefix used for executable program .manifest files generated
by Microsoft Visual C/C++.
WINDOWSPROGMANIFESTSUFFIX
The suffix used for executable program .manifest files generated
by Microsoft Visual C/C++.
WINDOWSSHLIBMANIFESTPREFIX
The prefix used for shared library .manifest files generated by
Microsoft Visual C/C++.
WINDOWSSHLIBMANIFESTSUFFIX
The suffix used for shared library .manifest files generated by
Microsoft Visual C/C++.
X_IPK_DEPENDS
This is used to fill in the Depends: field in the controlling
information for Ipkg packages.
X_IPK_DESCRIPTION
This is used to fill in the Description: field in the control‐
ling information for Ipkg packages. The default value is $SUM‐
MARY0DESCRIPTION
X_IPK_MAINTAINER
This is used to fill in the Maintainer: field in the controlling
information for Ipkg packages.
X_IPK_PRIORITY
This is used to fill in the Priority: field in the controlling
information for Ipkg packages.
X_IPK_SECTION
This is used to fill in the Section: field in the controlling
information for Ipkg packages.
X_MSI_LANGUAGE
This is used to fill in the Language: attribute in the control‐
ling information for MSI packages.
X_MSI_LICENSE_TEXT
The text of the software license in RTF format. Carriage return
characters will be replaced with the RTF equivalent \\par.
X_MSI_UPGRADE_CODE
TODO
X_RPM_AUTOREQPROV
This is used to fill in the AutoReqProv: field in the RPM .spec
file.
X_RPM_BUILD
internal, but overridable
X_RPM_BUILDREQUIRES
This is used to fill in the BuildRequires: field in the RPM
.spec file.
X_RPM_BUILDROOT
internal, but overridable
X_RPM_CLEAN
internal, but overridable
X_RPM_CONFLICTS
This is used to fill in the Conflicts: field in the RPM .spec
file.
X_RPM_DEFATTR
This value is used as the default attributes for the files in
the RPM package. The default value is (-,root,root).
X_RPM_DISTRIBUTION
This is used to fill in the Distribution: field in the RPM .spec
file.
X_RPM_EPOCH
This is used to fill in the Epoch: field in the controlling
information for RPM packages.
X_RPM_EXCLUDEARCH
This is used to fill in the ExcludeArch: field in the RPM .spec
file.
X_RPM_EXLUSIVEARCH
This is used to fill in the ExclusiveArch: field in the RPM
.spec file.
X_RPM_GROUP
This is used to fill in the Group: field in the RPM .spec file.
X_RPM_GROUP_lang
This is used to fill in the Group(lang): field in the RPM .spec
file. Note that lang is not literal and should be replaced by
the appropriate language code.
X_RPM_ICON
This is used to fill in the Icon: field in the RPM .spec file.
X_RPM_INSTALL
internal, but overridable
X_RPM_PACKAGER
This is used to fill in the Packager: field in the RPM .spec
file.
X_RPM_POSTINSTALL
This is used to fill in the %post: section in the RPM .spec
file.
X_RPM_POSTUNINSTALL
This is used to fill in the %postun: section in the RPM .spec
file.
X_RPM_PREFIX
This is used to fill in the Prefix: field in the RPM .spec file.
X_RPM_PREINSTALL
This is used to fill in the %pre: section in the RPM .spec file.
X_RPM_PREP
internal, but overridable
X_RPM_PREUNINSTALL
This is used to fill in the %preun: section in the RPM .spec
file.
X_RPM_PROVIDES
This is used to fill in the Provides: field in the RPM .spec
file.
X_RPM_REQUIRES
This is used to fill in the Requires: field in the RPM .spec
file.
X_RPM_SERIAL
This is used to fill in the Serial: field in the RPM .spec file.
X_RPM_URL
This is used to fill in the Url: field in the RPM .spec file.
XGETTEXT
Path to xgettext(1) program (found via Detect()). See &t-link-
xgettext; tool and POTUpdate() builder.
XGETTEXTCOM
Complete xgettext command line. See &t-link-xgettext; tool and
POTUpdate() builder.
XGETTEXTCOMSTR
A string that is shown when xgettext(1) command is invoked
(default: '', which means "print $XGETTEXTCOM"). See &t-link-
xgettext; tool and POTUpdate() builder.
_XGETTEXTDOMAIN
Internal "macro". Generates xgettext domain name form source and
target (default: '${TARGET.filebase}').
XGETTEXTFLAGS
Additional flags to xgettext(1). See &t-link-xgettext; tool and
POTUpdate() builder.
XGETTEXTFROM
Name of file containing list of xgettext(1)'s source files.
Autotools' users know this as POTFILES.in so they will in most
cases set XGETTEXTFROM="POTFILES.in" here. The $XGETTEXTFROM
files have same syntax and semantics as the well known GNU POT‐
FILES.in. See &t-link-xgettext; tool and POTUpdate() builder.
_XGETTEXTFROMFLAGS
Internal "macro". Genrates list of -D<dir> flags from the $XGET‐
TEXTPATH list.
XGETTEXTFROMPREFIX
This flag is used to add single $XGETTEXTFROM file to xget‐
text(1)'s commandline (default: '-f').
XGETTEXTFROMSUFFIX
(default: '')
XGETTEXTPATH
List of directories, there xgettext(1) will look for source
files (default: []). <note>This variable works only together
with $XGETTEXTFROM </para></note> See also &t-link-xgettext;
tool and POTUpdate() builder.
_XGETTEXTPATHFLAGS
Internal "macro". Generates list of -f<file> flags from $XGET‐
TEXTFROM.
XGETTEXTPATHPREFIX
This flag is used to add single search path to xgettext(1)'s
commandline (default: '-D').
XGETTEXTPATHSUFFIX
(default: '')
YACC The parser generator.
YACCCOM
The command line used to call the parser generator to generate a
source file.
YACCCOMSTR
The string displayed when generating a source file using the
parser generator. If this is not set, then $YACCCOM (the com‐
mand line) is displayed.
env = Environment(YACCCOMSTR = "Yacc'ing $TARGET from $SOURCES")
YACCFLAGS
General options passed to the parser generator. If $YACCFLAGS
contains a -d option, SCons assumes that the call will also cre‐
ate a .h file (if the yacc source file ends in a .y suffix) or a
.hpp file (if the yacc source file ends in a .yy suffix)
YACCHFILESUFFIX
The suffix of the C header file generated by the parser genera‐
tor when the -d option is used. Note that setting this variable
does not cause the parser generator to generate a header file
with the specified suffix, it exists to allow you to specify
what suffix the parser generator will use of its own accord.
The default value is .h.
YACCHXXFILESUFFIX
The suffix of the C++ header file generated by the parser gener‐
ator when the -d option is used. Note that setting this vari‐
able does not cause the parser generator to generate a header
file with the specified suffix, it exists to allow you to spec‐
ify what suffix the parser generator will use of its own accord.
The default value is .hpp, except on Mac OS X, where the default
is ${TARGET.suffix}.h. because the default &bison; parser gen‐
erator just appends .h to the name of the generated C++ file.
YACCVCGFILESUFFIX
The suffix of the file containing the VCG grammar automaton def‐
inition when the --graph= option is used. Note that setting
this variable does not cause the parser generator to generate a
VCG file with the specified suffix, it exists to allow you to
specify what suffix the parser generator will use of its own
accord. The default value is .vcg.
ZIP The zip compression and file packaging utility.
ZIPCOM The command line used to call the zip utility, or the internal
Python function used to create a zip archive.
ZIPCOMPRESSION
The compression flag from the Python zipfile module used by the
internal Python function to control whether the zip archive is
compressed or not. The default value is zipfile.ZIP_DEFLATED,
which creates a compressed zip archive. This value has no
effect if the zipfile module is unavailable.
ZIPCOMSTR
The string displayed when archiving files using the zip utility.
If this is not set, then $ZIPCOM (the command line or internal
Python function) is displayed.
env = Environment(ZIPCOMSTR = "Zipping $TARGET")
ZIPFLAGS
General options passed to the zip utility.
ZIPSUFFIX
The suffix used for zip file names.
Construction variables can be retrieved and set using the Dictionary
method of the construction environment:
dict = env.Dictionary()
dict["CC"] = "cc"
or using the [] operator:
env["CC"] = "cc"
Construction variables can also be passed to the construction environ‐
ment constructor:
env = Environment(CC="cc")
or when copying a construction environment using the Clone method:
env2 = env.Clone(CC="cl.exe")
Configure Contexts
scons supports configure contexts, an integrated mechanism similar to
the various AC_CHECK macros in GNU autoconf for testing for the exis‐
tence of C header files, libraries, etc. In contrast to autoconf,
scons does not maintain an explicit cache of the tested values, but
uses its normal dependency tracking to keep the checked values up to
date. However, users may override this behaviour with the --config com‐
mand line option.
The following methods can be used to perform checks:
Configure(env, [custom_tests, conf_dir, log_file, config_h, clean,
help])
env.Configure([custom_tests, conf_dir, log_file, config_h, clean,
help])
This creates a configure context, which can be used to perform
checks. env specifies the environment for building the tests.
This environment may be modified when performing checks. cus‐
tom_tests is a dictionary containing custom tests. See also the
section about custom tests below. By default, no custom tests
are added to the configure context. conf_dir specifies a direc‐
tory where the test cases are built. Note that this directory
is not used for building normal targets. The default value is
the directory #/.sconf_temp. log_file specifies a file which
collects the output from commands that are executed to check for
the existence of header files, libraries, etc. The default is
the file #/config.log. If you are using the VariantDir()
method, you may want to specify a subdirectory under your vari‐
ant directory. config_h specifies a C header file where the
results of tests will be written, e.g. #define HAVE_STDIO_H,
#define HAVE_LIBM, etc. The default is to not write a config.h
file. You can specify the same config.h file in multiple calls
to Configure, in which case scons will concatenate all results
in the specified file. Note that SCons uses its normal depen‐
dency checking to decide if it's necessary to rebuild the speci‐
fied config_h file. This means that the file is not necessarily
re-built each time scons is run, but is only rebuilt if its con‐
tents will have changed and some target that depends on the con‐
fig_h file is being built.
The optional clean and help arguments can be used to suppress
execution of the configuration tests when the -c/--clean or
-H/-h/--help options are used, respectively. The default behav‐
ior is always to execute configure context tests, since the
results of the tests may affect the list of targets to be
cleaned or the help text. If the configure tests do not affect
these, then you may add the clean=False or help=False arguments
(or both) to avoid unnecessary test execution.
A created Configure instance has the following associated methods:
SConf.Finish(context)sconf.Finish()
This method should be called after configuration is done. It
returns the environment as modified by the configuration checks
performed. After this method is called, no further checks can
be performed with this configuration context. However, you can
create a new Configure context to perform additional checks.
Only one context should be active at a time.
The following Checks are predefined. (This list will likely
grow larger as time goes by and developers contribute new useful
tests.)
SConf.CheckHeader(context, header, [include_quotes, language])
sconf.CheckHeader(header, [include_quotes, language])
Checks if header is usable in the specified language. header
may be a list, in which case the last item in the list is the
header file to be checked, and the previous list items are
header files whose #include lines should precede the header line
being checked for. The optional argument include_quotes must be
a two character string, where the first character denotes the
opening quote and the second character denotes the closing
quote. By default, both characters are " (double quote). The
optional argument language should be either C or C++ and selects
the compiler to be used for the check. Returns 1 on success and
0 on failure.
SConf.CheckCHeader(context, header, [include_quotes])
sconf.CheckCHeader(header, [include_quotes])
This is a wrapper around SConf.CheckHeader which checks if
header is usable in the C language. header may be a list, in
which case the last item in the list is the header file to be
checked, and the previous list items are header files whose
#include lines should precede the header line being checked for.
The optional argument include_quotes must be a two character
string, where the first character denotes the opening quote and
the second character denotes the closing quote (both default to
"). Returns 1 on success and 0 on failure.
SConf.CheckCXXHeader(context, header, [include_quotes])
sconf.CheckCXXHeader(header, [include_quotes])
This is a wrapper around SConf.CheckHeader which checks if
header is usable in the C++ language. header may be a list, in
which case the last item in the list is the header file to be
checked, and the previous list items are header files whose
#include lines should precede the header line being checked for.
The optional argument include_quotes must be a two character
string, where the first character denotes the opening quote and
the second character denotes the closing quote (both default to
"). Returns 1 on success and 0 on failure.
SConf.CheckFunc(context,, function_name, [header, language])
sconf.CheckFunc(function_name, [header, language])
Checks if the specified C or C++ function is available. func‐
tion_name is the name of the function to check for. The
optional header argument is a string that will be placed at the
top of the test file that will be compiled to check if the func‐
tion exists; the default is:
#ifdef __cplusplus
extern "C"
#endif
char function_name();
The optional language argument should be C or C++ and selects the com‐
piler to be used for the check; the default is "C".
SConf.CheckLib(context, [library, symbol, header, language, autoadd=1])
sconf.CheckLib([library, symbol, header, language, autoadd=1])
Checks if library provides symbol. If the value of autoadd is 1
and the library provides the specified symbol, appends the
library to the LIBS construction environment variable. library
may also be None (the default), in which case symbol is checked
with the current LIBS variable, or a list of library names, in
which case each library in the list will be checked for symbol.
If symbol is not set or is None, then SConf.CheckLib() just
checks if you can link against the specified library. The
optional language argument should be C or C++ and selects the
compiler to be used for the check; the default is "C". The
default value for autoadd is 1. This method returns 1 on suc‐
cess and 0 on error.
SConf.CheckLibWithHeader(context, library, header, language, [call,
autoadd])
sconf.CheckLibWithHeader(library, header, language, [call, autoadd])
In contrast to the SConf.CheckLib call, this call provides a
more sophisticated way to check against libraries. Again,
library specifies the library or a list of libraries to check.
header specifies a header to check for. header may be a list,
in which case the last item in the list is the header file to be
checked, and the previous list items are header files whose
#include lines should precede the header line being checked for.
language may be one of 'C','c','CXX','cxx','C++' and 'c++'.
call can be any valid expression (with a trailing ';'). If call
is not set, the default simply checks that you can link against
the specified library. autoadd specifies whether to add the
library to the environment (only if the check succeeds). This
method returns 1 on success and 0 on error.
SConf.CheckType(context, type_name, [includes, language])
sconf.CheckType(type_name, [includes, language])
Checks for the existence of a type defined by typedef.
type_name specifies the typedef name to check for. includes is
a string containing one or more #include lines that will be
inserted into the program that will be run to test for the exis‐
tence of the type. The optional language argument should be C
or C++ and selects the compiler to be used for the check; the
default is "C". Example:
sconf.CheckType('foo_type', '#include "my_types.h"', 'C++')
Configure.CheckCC(self)
Checks whether the C compiler (as defined by the CC construction
variable) works by trying to compile a small source file.
By default, SCons only detects if there is a program with the
correct name, not if it is a functioning compiler.
This uses the exact same command than the one used by the object
builder for C source file, so it can be used to detect if a par‐
ticular compiler flag works or not.
Configure.CheckCXX(self)
Checks whether the C++ compiler (as defined by the CXX construc‐
tion variable) works by trying to compile a small source file.
By default, SCons only detects if there is a program with the
correct name, not if it is a functioning compiler.
This uses the exact same command than the one used by the object
builder for CXX source files, so it can be used to detect if a
particular compiler flag works or not.
Configure.CheckSHCC(self)
Checks whether the C compiler (as defined by the SHCC construc‐
tion variable) works by trying to compile a small source file.
By default, SCons only detects if there is a program with the
correct name, not if it is a functioning compiler.
This uses the exact same command than the one used by the object
builder for C source file, so it can be used to detect if a par‐
ticular compiler flag works or not. This does not check whether
the object code can be used to build a shared library, only that
the compilation (not link) succeeds.
Configure.CheckSHCXX(self)
Checks whether the C++ compiler (as defined by the SHCXX con‐
struction variable) works by trying to compile a small source
file. By default, SCons only detects if there is a program with
the correct name, not if it is a functioning compiler.
This uses the exact same command than the one used by the object
builder for CXX source files, so it can be used to detect if a
particular compiler flag works or not. This does not check
whether the object code can be used to build a shared library,
only that the compilation (not link) succeeds.
Example of a typical Configure usage:
env = Environment()
conf = Configure( env )
if not conf.CheckCHeader( 'math.h' ):
print 'We really need math.h!'
Exit(1)
if conf.CheckLibWithHeader( 'qt', 'qapp.h', 'c++',
'QApplication qapp(0,0);' ):
# do stuff for qt - usage, e.g.
conf.env.Append( CPPFLAGS = '-DWITH_QT' )
env = conf.Finish()
SConf.CheckTypeSize(context, type_name, [header, language, expect])
sconf.CheckTypeSize(type_name, [header, language, expect])
Checks for the size of a type defined by typedef. type_name
specifies the typedef name to check for. The optional header
argument is a string that will be placed at the top of the test
file that will be compiled to check if the function exists; the
default is empty. The optional language argument should be C or
C++ and selects the compiler to be used for the check; the
default is "C". The optional expect argument should be an inte‐
ger. If this argument is used, the function will only check
whether the type given in type_name has the expected size (in
bytes). For example, CheckTypeSize('short', expect = 2) will
return success only if short is two bytes.
SConf.CheckDeclaration(context, symbol, [includes, language])
sconf.CheckDeclaration(symbol, [includes, language])
Checks if the specified symbol is declared. includes is a
string containing one or more #include lines that will be
inserted into the program that will be run to test for the exis‐
tence of the type. The optional language argument should be C
or C++ and selects the compiler to be used for the check; the
default is "C".
SConf.Define(context, symbol, [value, comment])
sconf.Define(symbol, [value, comment])
This function does not check for anything, but defines a pre‐
processor symbol that will be added to the configuration header
file. It is the equivalent of AC_DEFINE, and defines the symbol
name with the optional value and the optional comment comment.
Examples:
env = Environment()
conf = Configure( env )
# Puts the following line in the config header file:
# #define A_SYMBOL
conf.Define('A_SYMBOL')
# Puts the following line in the config header file:
# #define A_SYMBOL 1
conf.Define('A_SYMBOL', 1)
Be careful about quoting string values, though:
env = Environment()
conf = Configure( env )
# Puts the following line in the config header file:
# #define A_SYMBOL YA
conf.Define('A_SYMBOL', "YA")
# Puts the following line in the config header file:
# #define A_SYMBOL "YA"
conf.Define('A_SYMBOL', '"YA"')
For comment:
env = Environment()
conf = Configure( env )
# Puts the following lines in the config header file:
# /* Set to 1 if you have a symbol */
# #define A_SYMBOL 1
conf.Define('A_SYMBOL', 1, 'Set to 1 if you have a symbol')
You can define your own custom checks. in addition to the predefined
checks. These are passed in a dictionary to the Configure function.
This dictionary maps the names of the checks to user defined Python
callables (either Python functions or class instances implementing the
__call__ method). The first argument of the call is always a CheckCon‐
text instance followed by the arguments, which must be supplied by the
user of the check. These CheckContext instances define the following
methods:
CheckContext.Message(self, text)
Usually called before the check is started. text will be dis‐
played to the user, e.g. 'Checking for library X...'
CheckContext.Result(self,, res)
Usually called after the check is done. res can be either an
integer or a string. In the former case, 'yes' (res != 0) or
'no' (res == 0) is displayed to the user, in the latter case the
given string is displayed.
CheckContext.TryCompile(self, text, extension)
Checks if a file with the specified extension (e.g. '.c') con‐
taining text can be compiled using the environment's Object
builder. Returns 1 on success and 0 on failure.
CheckContext.TryLink(self, text, extension)
Checks, if a file with the specified extension (e.g. '.c') con‐
taining text can be compiled using the environment's Program
builder. Returns 1 on success and 0 on failure.
CheckContext.TryRun(self, text, extension)
Checks, if a file with the specified extension (e.g. '.c') con‐
taining text can be compiled using the environment's Program
builder. On success, the program is run. If the program executes
successfully (that is, its return status is 0), a tuple (1, out‐
putStr) is returned, where outputStr is the standard output of
the program. If the program fails execution (its return status
is non-zero), then (0, '') is returned.
CheckContext.TryAction(self, action, [text, extension])
Checks if the specified action with an optional source file
(contents text , extension extension = '' ) can be executed.
action may be anything which can be converted to a scons Action.
On success, (1, outputStr) is returned, where outputStr is the
content of the target file. On failure (0, '') is returned.
CheckContext.TryBuild(self, builder, [text, extension])
Low level implementation for testing specific builds; the meth‐
ods above are based on this method. Given the Builder instance
builder and the optional text of a source file with optional
extension, this method returns 1 on success and 0 on failure. In
addition, self.lastTarget is set to the build target node, if
the build was successful.
Example for implementing and using custom tests:
def CheckQt(context, qtdir):
context.Message( 'Checking for qt ...' )
lastLIBS = context.env['LIBS']
lastLIBPATH = context.env['LIBPATH']
lastCPPPATH= context.env['CPPPATH']
context.env.Append(LIBS = 'qt', LIBPATH = qtdir + '/lib', CPPPATH = qtdir + '/include' )
ret = context.TryLink("""
#include <qapp.h>
int main(int argc, char **argv) {
QApplication qapp(argc, argv);
return 0;
}
""")
if not ret:
context.env.Replace(LIBS = lastLIBS, LIBPATH=lastLIBPATH, CPPPATH=lastCPPPATH)
context.Result( ret )
return ret
env = Environment()
conf = Configure( env, custom_tests = { 'CheckQt' : CheckQt } )
if not conf.CheckQt('/usr/lib/qt'):
print 'We really need qt!'
Exit(1)
env = conf.Finish()
Command-Line Construction Variables
Often when building software, some variables must be specified at build
time. For example, libraries needed for the build may be in non-stan‐
dard locations, or site-specific compiler options may need to be passed
to the compiler. scons provides a Variables object to support overrid‐
ing construction variables on the command line:
$ scons VARIABLE=foo
The variable values can also be specified in a text-based SConscript
file. To create a Variables object, call the Variables() function:
Variables([files], [args])
This creates a Variables object that will read construction
variables from the file or list of filenames specified in files.
If no files are specified, or the files argument is None, then
no files will be read. The optional argument args is a dictio‐
nary of values that will override anything read from the speci‐
fied files; it is primarily intended to be passed the ARGUMENTS
dictionary that holds variables specified on the command line.
Example:
vars = Variables('custom.py')
vars = Variables('overrides.py', ARGUMENTS)
vars = Variables(None, {FOO:'expansion', BAR:7})
Variables objects have the following methods:
Add(key, [help, default, validator, converter])
This adds a customizable construction variable to the Variables
object. key is the name of the variable. help is the help text
for the variable. default is the default value of the variable;
if the default value is None and there is no explicit value
specified, the construction variable will not be added to the
construction environment. validator is called to validate the
value of the variable, and should take three arguments: key,
value, and environment. The recommended way to handle an
invalid value is to raise an exception (see example below).
converter is called to convert the value before putting it in
the environment, and should take either a value, or the value
and environment, as parameters. The converter must return a
value, which will be converted into a string before being vali‐
dated by the validator (if any) and then added to the environ‐
ment.
Examples:
vars.Add('CC', 'The C compiler')
def validate_color(key, val, env):
if not val in ['red', 'blue', 'yellow']:
raise Exception("Invalid color value '%s'" % val)
vars.Add('COLOR', validator=valid_color)
AddVariables(list)
A wrapper script that adds multiple customizable construction
variables to a Variables object. list is a list of tuple or
list objects that contain the arguments for an individual call
to the Add method.
opt.AddVariables(
('debug', '', 0),
('CC', 'The C compiler'),
('VALIDATE', 'An option for testing validation',
'notset', validator, None),
)
Update(env, [args])
This updates a construction environment env with the customized
construction variables. Any specified variables that are not
configured for the Variables object will be saved and may be
retrieved with the UnknownVariables() method, below.
Normally this method is not called directly, but is called indi‐
rectly by passing the Variables object to the Environment()
function:
env = Environment(variables=vars)
The text file(s) that were specified when the Variables object
was created are executed as Python scripts, and the values of
(global) Python variables set in the file are added to the con‐
struction environment.
Example:
CC = 'my_cc'
UnknownVariables()
Returns a dictionary containing any variables that were speci‐
fied either in the files or the dictionary with which the Vari‐
ables object was initialized, but for which the Variables object
was not configured.
env = Environment(variables=vars)
for key, value in vars.UnknownVariables():
print "unknown variable: %s=%s" % (key, value)
Save(filename, env)
This saves the currently set variables into a script file named
filename that can be used on the next invocation to automati‐
cally load the current settings. This method combined with the
Variables method can be used to support caching of variables
between runs.
env = Environment()
vars = Variables(['variables.cache', 'custom.py'])
vars.Add(...)
vars.Update(env)
vars.Save('variables.cache', env)
GenerateHelpText(env, [sort])
This generates help text documenting the customizable construc‐
tion variables suitable to passing in to the Help() function.
env is the construction environment that will be used to get the
actual values of customizable variables. Calling with an
optional sort function will cause the output to be sorted by the
specified argument. The specific sort function should take two
arguments and return -1, 0 or 1 (like the standard Python cmp
function).
Help(vars.GenerateHelpText(env))
Help(vars.GenerateHelpText(env, sort=cmp))
FormatVariableHelpText(env, opt, help, default, actual)
This method returns a formatted string containing the printable
help text for one option. It is normally not called directly,
but is called by the GenerateHelpText() method to create the
returned help text. It may be overridden with your own function
that takes the arguments specified above and returns a string of
help text formatted to your liking. Note that the GenerateHelp‐
Text() will not put any blank lines or extra characters in
between the entries, so you must add those characters to the
returned string if you want the entries separated.
def my_format(env, opt, help, default, actual):
fmt = "120s: default=%s actual=%s (%s)0
return fmt % (opt, default. actual, help)
vars.FormatVariableHelpText = my_format
To make it more convenient to work with customizable Variables, scons
provides a number of functions that make it easy to set up various
types of Variables:
BoolVariable(key, help, default)
Return a tuple of arguments to set up a Boolean option. The
option will use the specified name key, have a default value of
default, and display the specified help text. The option will
interpret the values y, yes, t, true, 1, on and all as true, and
the values n, no, f, false, 0, off and none as false.
EnumVariable(key, help, default, allowed_values, [map, ignorecase])
Return a tuple of arguments to set up an option whose value may
be one of a specified list of legal enumerated values. The
option will use the specified name key, have a default value of
default, and display the specified help text. The option will
only support those values in the allowed_values list. The
optional map argument is a dictionary that can be used to con‐
vert input values into specific legal values in the allowed_val‐
ues list. If the value of ignore_case is 0 (the default), then
the values are case-sensitive. If the value of ignore_case is
1, then values will be matched case-insensitive. If the value
of ignore_case is 1, then values will be matched case-insensi‐
tive, and all input values will be converted to lower case.
ListVariable(key, help, default, names, [,map])
Return a tuple of arguments to set up an option whose value may
be one or more of a specified list of legal enumerated values.
The option will use the specified name key, have a default value
of default, and display the specified help text. The option
will only support the values all, none, or the values in the
names list. More than one value may be specified, with all val‐
ues separated by commas. The default may be a string of comma-
separated default values, or a list of the default values. The
optional map argument is a dictionary that can be used to con‐
vert input values into specific legal values in the names list.
PackageVariable(key, help, default)
Return a tuple of arguments to set up an option whose value is a
path name of a package that may be enabled, disabled or given an
explicit path name. The option will use the specified name key,
have a default value of default, and display the specified help
text. The option will support the values yes, true, on, enable
or search, in which case the specified default will be used, or
the option may be set to an arbitrary string (typically the path
name to a package that is being enabled). The option will also
support the values no, false, off or disable to disable use of
the specified option.
PathVariable(key, help, default, [validator])
Return a tuple of arguments to set up an option whose value is
expected to be a path name. The option will use the specified
name key, have a default value of default, and display the spec‐
ified help text. An additional validator may be specified that
will be called to verify that the specified path is acceptable.
SCons supplies the following ready-made validators: PathVari‐
able.PathExists (the default), which verifies that the specified
path exists; PathVariable.PathIsFile, which verifies that the
specified path is an existing file; PathVariable.PathIsDir,
which verifies that the specified path is an existing directory;
PathVariable.PathIsDirCreate, which verifies that the specified
path is a directory and will create the specified directory if
the path does not exist; and PathVariable.PathAccept, which sim‐
ply accepts the specific path name argument without validation,
and which is suitable if you want your users to be able to spec‐
ify a directory path that will be created as part of the build
process, for example. You may supply your own validator func‐
tion, which must take three arguments (key, the name of the
variable to be set; val, the specified value being checked; and
env, the construction environment) and should raise an exception
if the specified value is not acceptable.
These functions make it convenient to create a number of variables with
consistent behavior in a single call to the AddVariables method:
vars.AddVariables(
BoolVariable('warnings', 'compilation with -Wall and similiar', 1),
EnumVariable('debug', 'debug output and symbols', 'no'
allowed_values=('yes', 'no', 'full'),
map={}, ignorecase=0), # case sensitive
ListVariable('shared',
'libraries to build as shared libraries',
'all',
names = list_of_libs),
PackageVariable('x11',
'use X11 installed here (yes = search some places)',
'yes'),
PathVariable('qtdir', 'where the root of Qt is installed', qtdir),
PathVariable('foopath', 'where the foo library is installed', foopath,
PathVariable.PathIsDir),
)
File and Directory Nodes
The File() and Dir() functions return File and Dir Nodes, respectively.
python objects, respectively. Those objects have several user-visible
attributes and methods that are often useful:
path The build path of the given file or directory. This path is
relative to the top-level directory (where the SConstruct file
is found). The build path is the same as the source path if
variant_dir is not being used.
abspath
The absolute build path of the given file or directory.
srcnode()
The srcnode() method returns another File or Dir object repre‐
senting the source path of the given File or Dir. The
# Get the current build dir's path, relative to top.
Dir('.').path
# Current dir's absolute path
Dir('.').abspath
# Next line is always '.', because it is the top dir's path relative to itself.
Dir('#.').path
File('foo.c').srcnode().path # source path of the given source file.
# Builders also return File objects:
foo = env.Program('foo.c')
print "foo will be built in %s"%foo.path
A Dir Node or File Node can also be used to create file and subdirec‐
tory Nodes relative to the generating Node. A Dir Node will place the
new Nodes within the directory it represents. A File node will place
the new Nodes within its parent directory (that is, "beside" the file
in question). If d is a Dir (directory) Node and f is a File (file)
Node, then these methods are available:
d.Dir(name)
Returns a directory Node for a subdirectory of d named name.
d.File(name)
Returns a file Node for a file within d named name.
d.Entry(name)
Returns an unresolved Node within d named name.
f.Dir(name)
Returns a directory named name within the parent directory of f.
f.File(name)
Returns a file named name within the parent directory of f.
f.Entry(name)
Returns an unresolved Node named name within the parent direc‐
tory of f.
For example:
# Get a Node for a file within a directory
incl = Dir('include')
f = incl.File('header.h')
# Get a Node for a subdirectory within a directory
dist = Dir('project-3.2.1)
src = dist.Dir('src')
# Get a Node for a file in the same directory
cfile = File('sample.c')
hfile = cfile.File('sample.h')
# Combined example
docs = Dir('docs')
html = docs.Dir('html')
index = html.File('index.html')
css = index.File('app.css')
EXTENDING SCONS
Builder Objects
scons can be extended to build different types of targets by adding new
Builder objects to a construction environment. In general, you should
only need to add a new Builder object when you want to build a new type
of file or other external target. If you just want to invoke a differ‐
ent compiler or other tool to build a Program, Object, Library, or any
other type of output file for which scons already has an existing
Builder, it is generally much easier to use those existing Builders in
a construction environment that sets the appropriate construction vari‐
ables (CC, LINK, etc.).
Builder objects are created using the Builder function. The Builder
function accepts the following arguments:
action The command line string used to build the target from the
source. action can also be: a list of strings representing the
command to be executed and its arguments (suitable for enclosing
white space in an argument), a dictionary mapping source file
name suffixes to any combination of command line strings (if the
builder should accept multiple source file extensions), a Python
function; an Action object (see the next section); or a list of
any of the above.
An action function takes three arguments: source - a list of
source nodes, target - a list of target nodes, env - the con‐
struction environment.
prefix The prefix that will be prepended to the target file name. This
may be specified as a:
* string,
* callable object - a function or other callable that takes
two arguments (a construction environment and a list of
sources) and returns a prefix,
* dictionary - specifies a mapping from a specific source
suffix (of the first source specified) to a correspond‐
ing target prefix. Both the source suffix and target
prefix specifications may use environment variable sub‐
stitution, and the target prefix (the 'value' entries
in the dictionary) may also be a callable object. The
default target prefix may be indicated by a dictionary
entry with a key value of None.
b = Builder("build_it < $SOURCE > $TARGET",
prefix = "file-")
def gen_prefix(env, sources):
return "file-" + env['PLATFORM'] + '-'
b = Builder("build_it < $SOURCE > $TARGET",
prefix = gen_prefix)
b = Builder("build_it < $SOURCE > $TARGET",
suffix = { None: "file-",
"$SRC_SFX_A": gen_prefix })
suffix The suffix that will be appended to the target file name. This
may be specified in the same manner as the prefix above. If the
suffix is a string, then scons will append a '.' to the begin‐
ning of the suffix if it's not already there. The string
returned by callable object (or obtained from the dictionary) is
untouched and must append its own '.' to the beginning if one
is desired.
b = Builder("build_it < $SOURCE > $TARGET"
suffix = "-file")
def gen_suffix(env, sources):
return "." + env['PLATFORM'] + "-file"
b = Builder("build_it < $SOURCE > $TARGET",
suffix = gen_suffix)
b = Builder("build_it < $SOURCE > $TARGET",
suffix = { None: ".sfx1",
"$SRC_SFX_A": gen_suffix })
ensure_suffix
When set to any true value, causes scons to add the target suf‐
fix specified by the suffix keyword to any target strings that
have a different suffix. (The default behavior is to leave
untouched any target file name that looks like it already has
any suffix.)
b1 = Builder("build_it < $SOURCE > $TARGET"
suffix = ".out")
b2 = Builder("build_it < $SOURCE > $TARGET"
suffix = ".out",
ensure_suffix)
env = Environment()
env['BUILDERS']['B1'] = b1
env['BUILDERS']['B2'] = b2
# Builds "foo.txt" because ensure_suffix is not set.
env.B1('foo.txt', 'foo.in')
# Builds "bar.txt.out" because ensure_suffix is set.
env.B2('bar.txt', 'bar.in')
src_suffix
The expected source file name suffix. This may be a string or a
list of strings.
target_scanner
A Scanner object that will be invoked to find implicit dependen‐
cies for this target file. This keyword argument should be used
for Scanner objects that find implicit dependencies based only
on the target file and the construction environment, not for
implicit dependencies based on source files. (See the section
"Scanner Objects" below, for information about creating Scanner
objects.)
source_scanner
A Scanner object that will be invoked to find implicit dependen‐
cies in any source files used to build this target file. This
is where you would specify a scanner to find things like
#include lines in source files. The pre-built DirScanner Scan‐
ner object may be used to indicate that this Builder should scan
directory trees for on-disk changes to files that scons does not
know about from other Builder or function calls. (See the sec‐
tion "Scanner Objects" below, for information about creating
your own Scanner objects.)
target_factory
A factory function that the Builder will use to turn any targets
specified as strings into SCons Nodes. By default, SCons
assumes that all targets are files. Other useful target_factory
values include Dir, for when a Builder creates a directory tar‐
get, and Entry, for when a Builder can create either a file or
directory target.
Example:
MakeDirectoryBuilder = Builder(action=my_mkdir, target_factory=Dir)
env = Environment()
env.Append(BUILDERS = {'MakeDirectory':MakeDirectoryBuilder})
env.MakeDirectory('new_directory', [])
Note that the call to the MakeDirectory Builder needs to specify
an empty source list to make the string represent the builder's
target; without that, it would assume the argument is the
source, and would try to deduce the target name from it, which
in the absence of an automatically-added prefix or suffix would
lead to a matching target and source name and a circular depen‐
dency.
source_factory
A factory function that the Builder will use to turn any sources
specified as strings into SCons Nodes. By default, SCons
assumes that all source are files. Other useful source_factory
values include Dir, for when a Builder uses a directory as a
source, and Entry, for when a Builder can use files or directo‐
ries (or both) as sources.
Example:
CollectBuilder = Builder(action=my_mkdir, source_factory=Entry)
env = Environment()
env.Append(BUILDERS = {'Collect':CollectBuilder})
env.Collect('archive', ['directory_name', 'file_name'])
emitter
A function or list of functions to manipulate the target and
source lists before dependencies are established and the tar‐
get(s) are actually built. emitter can also be a string con‐
taining a construction variable to expand to an emitter function
or list of functions, or a dictionary mapping source file suf‐
fixes to emitter functions. (Only the suffix of the first
source file is used to select the actual emitter function from
an emitter dictionary.)
An emitter function takes three arguments: source - a list of
source nodes, target - a list of target nodes, env - the con‐
struction environment. An emitter must return a tuple contain‐
ing two lists, the list of targets to be built by this builder,
and the list of sources for this builder.
Example:
def e(target, source, env):
return (target + ['foo.foo'], source + ['foo.src'])
# Simple association of an emitter function with a Builder.
b = Builder("my_build < $TARGET > $SOURCE",
emitter = e)
def e2(target, source, env):
return (target + ['bar.foo'], source + ['bar.src'])
# Simple association of a list of emitter functions with a Builder.
b = Builder("my_build < $TARGET > $SOURCE",
emitter = [e, e2])
# Calling an emitter function through a construction variable.
env = Environment(MY_EMITTER = e)
b = Builder("my_build < $TARGET > $SOURCE",
emitter = '$MY_EMITTER')
# Calling a list of emitter functions through a construction variable.
env = Environment(EMITTER_LIST = [e, e2])
b = Builder("my_build < $TARGET > $SOURCE",
emitter = '$EMITTER_LIST')
# Associating multiple emitters with different file
# suffixes using a dictionary.
def e_suf1(target, source, env):
return (target + ['another_target_file'], source)
def e_suf2(target, source, env):
return (target, source + ['another_source_file'])
b = Builder("my_build < $TARGET > $SOURCE",
emitter = {'.suf1' : e_suf1,
'.suf2' : e_suf2})
multi Specifies whether this builder is allowed to be called multiple
times for the same target file(s). The default is 0, which means
the builder can not be called multiple times for the same target
file(s). Calling a builder multiple times for the same target
simply adds additional source files to the target; it is not
allowed to change the environment associated with the target,
specify addition environment overrides, or associate a different
builder with the target.
env A construction environment that can be used to fetch source code
using this Builder. (Note that this environment is not used for
normal builds of normal target files, which use the environment
that was used to call the Builder for the target file.)
generator
A function that returns a list of actions that will be executed
to build the target(s) from the source(s). The returned
action(s) may be an Action object, or anything that can be con‐
verted into an Action object (see the next section).
The generator function takes four arguments: source - a list of
source nodes, target - a list of target nodes, env - the con‐
struction environment, for_signature - a Boolean value that
specifies whether the generator is being called for generating a
build signature (as opposed to actually executing the command).
Example:
def g(source, target, env, for_signature):
return [["gcc", "-c", "-o"] + target + source]
b = Builder(generator=g)
The generator and action arguments must not both be used for the
same Builder.
src_builder
Specifies a builder to use when a source file name suffix does
not match any of the suffixes of the builder. Using this argu‐
ment produces a multi-stage builder.
single_source
Specifies that this builder expects exactly one source file per
call. Giving more than one source file without target files
results in implicitely calling the builder multiple times (once
for each source given). Giving multiple source files together
with target files results in a UserError exception.
The generator and action arguments must not both be used for the
same Builder.
source_ext_match
When the specified action argument is a dictionary, the default
behavior when a builder is passed multiple source files is to
make sure that the extensions of all the source files match. If
it is legal for this builder to be called with a list of source
files with different extensions, this check can be suppressed by
setting source_ext_match to None or some other non-true value.
When source_ext_match is disable, scons will use the suffix of
the first specified source file to select the appropriate action
from the action dictionary.
In the following example, the setting of source_ext_match pre‐
vents scons from exiting with an error due to the mismatched
suffixes of foo.in and foo.extra.
b = Builder(action={'.in' : 'build $SOURCES > $TARGET'},
source_ext_match = None)
env = Environment(BUILDERS = {'MyBuild':b})
env.MyBuild('foo.out', ['foo.in', 'foo.extra'])
env A construction environment that can be used to fetch source code
using this Builder. (Note that this environment is not used for
normal builds of normal target files, which use the environment
that was used to call the Builder for the target file.)
b = Builder(action="build < $SOURCE > $TARGET")
env = Environment(BUILDERS = {'MyBuild' : b})
env.MyBuild('foo.out', 'foo.in', my_arg = 'xyzzy')
chdir A directory from which scons will execute the action(s) speci‐
fied for this Builder. If the chdir argument is a string or a
directory Node, scons will change to the specified directory.
If the chdir is not a string or Node and is non-zero, then scons
will change to the target file's directory.
Note that scons will not automatically modify its expansion of
construction variables like $TARGET and $SOURCE when using the
chdir keyword argument--that is, the expanded file names will
still be relative to the top-level SConstruct directory, and
consequently incorrect relative to the chdir directory.
Builders created using chdir keyword argument, will need to use
construction variable expansions like ${TARGET.file} and
${SOURCE.file} to use just the filename portion of the targets
and source.
b = Builder(action="build < ${SOURCE.file} > ${TARGET.file}",
chdir=1)
env = Environment(BUILDERS = {'MyBuild' : b})
env.MyBuild('sub/dir/foo.out', 'sub/dir/foo.in')
WARNING: Python only keeps one current directory location for all of
the threads. This means that use of the chdir argument will not work
with the SCons -j option, because individual worker threads spawned by
SCons interfere with each other when they start changing directory.
Any additional keyword arguments supplied when a Builder object is cre‐
ated (that is, when the Builder() function is called) will be set in
the executing construction environment when the Builder object is
called. The canonical example here would be to set a construction
variable to the repository of a source code system.
Any additional keyword arguments supplied when a Builder object is
called will only be associated with the target created by that particu‐
lar Builder call (and any other files built as a result of the call).
These extra keyword arguments are passed to the following functions:
command generator functions, function Actions, and emitter functions.
Action Objects
The Builder() function will turn its action keyword argument into an
appropriate internal Action object. You can also explicity create
Action objects using the Action() global function, which can then be
passed to the Builder() function. This can be used to configure an
Action object more flexibly, or it may simply be more efficient than
letting each separate Builder object create a separate Action when mul‐
tiple Builder objects need to do the same thing.
The Action() global function returns an appropriate object for the
action represented by the type of the first argument:
Action If the first argument is already an Action object, the object is
simply returned.
String If the first argument is a string, a command-line Action is
returned. Note that the command-line string may be preceded by
an @ (at-sign) to suppress printing of the specified command
line, or by a - (hyphen) to ignore the exit status from the
specified command:
Action('$CC -c -o $TARGET $SOURCES')
# Doesn't print the line being executed.
Action('@build $TARGET $SOURCES')
# Ignores return value
Action('-build $TARGET $SOURCES')
List If the first argument is a list, then a list of Action objects
is returned. An Action object is created as necessary for each
element in the list. If an element within the list is itself a
list, the internal list is the command and arguments to be exe‐
cuted via the command line. This allows white space to be
enclosed in an argument by defining a command in a list within a
list:
Action([['cc', '-c', '-DWHITE SPACE', '-o', '$TARGET', '$SOURCES']])
Function
If the first argument is a Python function, a function Action is
returned. The Python function must take three keyword argu‐
ments, target (a Node object representing the target file),
source (a Node object representing the source file) and env (the
construction environment used for building the target file).
The target and source arguments may be lists of Node objects if
there is more than one target file or source file. The actual
target and source file name(s) may be retrieved from their Node
objects via the built-in Python str() function:
target_file_name = str(target)
source_file_names = map(lambda x: str(x), source)
The function should return 0 or None to indicate a successful
build of the target file(s). The function may raise an excep‐
tion or return a non-zero exit status to indicate an unsuccess‐
ful build.
def build_it(target = None, source = None, env = None):
# build the target from the source
return 0
a = Action(build_it)
If the action argument is not one of the above, None is returned.
The second argument is optional and is used to define the output which
is printed when the Action is actually performed. In the absence of
this parameter, or if it's an empty string, a default output depending
on the type of the action is used. For example, a command-line action
will print the executed command. The argument must be either a Python
function or a string.
In the first case, it's a function that returns a string to be printed
to describe the action being executed. The function may also be speci‐
fied by the strfunction= keyword argument. Like a function to build a
file, this function must take three keyword arguments: target (a Node
object representing the target file), source (a Node object represent‐
ing the source file) and env (a construction environment). The target
and source arguments may be lists of Node objects if there is more than
one target file or source file.
In the second case, you provide the string itself. The string may also
be specified by the cmdstr= keyword argument. The string typically
contains variables, notably $TARGET(S) and $SOURCE(S), or consists of
just a single variable, which is optionally defined somewhere else.
SCons itself heavily uses the latter variant.
Examples:
def build_it(target, source, env):
# build the target from the source
return 0
def string_it(target, source, env):
return "building '%s' from '%s'" % (target[0], source[0])
# Use a positional argument.
f = Action(build_it, string_it)
s = Action(build_it, "building '$TARGET' from '$SOURCE'")
# Alternatively, use a keyword argument.
f = Action(build_it, strfunction=string_it)
s = Action(build_it, cmdstr="building '$TARGET' from '$SOURCE'")
# You can provide a configurable variable.
l = Action(build_it, '$STRINGIT')
The third and succeeding arguments, if present, may either be a con‐
struction variable or a list of construction variables whose values
will be included in the signature of the Action when deciding whether a
target should be rebuilt because the action changed. The variables may
also be specified by a varlist= keyword parameter; if both are present,
they are combined. This is necessary whenever you want a target to be
rebuilt when a specific construction variable changes. This is not
often needed for a string action, as the expanded variables will nor‐
mally be part of the command line, but may be needed if a Python func‐
tion action uses the value of a construction variable when generating
the command line.
def build_it(target, source, env):
# build the target from the 'XXX' construction variable
open(target[0], 'w').write(env['XXX'])
return 0
# Use positional arguments.
a = Action(build_it, '$STRINGIT', ['XXX'])
# Alternatively, use a keyword argument.
a = Action(build_it, varlist=['XXX'])
The Action() global function can be passed the following optional key‐
word arguments to modify the Action object's behavior:
chdir The chdir keyword argument specifies that scons will exe‐
cute the action after changing to the specified directory. If
the chdir argument is a string or a directory Node, scons will
change to the specified directory. If the chdir argument is not
a string or Node and is non-zero, then scons will change to the
target file's directory.
Note that scons will not automatically modify its expansion of
construction variables like $TARGET and $SOURCE when using the
chdir keyword argument--that is, the expanded file names will
still be relative to the top-level SConstruct directory, and
consequently incorrect relative to the chdir directory.
Builders created using chdir keyword argument, will need to use
construction variable expansions like ${TARGET.file} and
${SOURCE.file} to use just the filename portion of the targets
and source.
a = Action("build < ${SOURCE.file} > ${TARGET.file}",
chdir=1)
exitstatfunc The Action() global function also takes an exit‐
statfunc keyword argument which specifies a function that is
passed the exit status (or return value) from the specified
action and can return an arbitrary or modified value. This can
be used, for example, to specify that an Action object's return
value should be ignored under special conditions and SCons
should, therefore, consider that the action always suceeds:
def always_succeed(s):
# Always return 0, which indicates success.
return 0
a = Action("build < ${SOURCE.file} > ${TARGET.file}",
exitstatfunc=always_succeed)
batch_key The batch_key keyword argument can be used to specify
that the Action can create multiple target files by processing
multiple independent source files simultaneously. (The canoni‐
cal example is "batch compilation" of multiple object files by
passing multiple source files to a single invocation of a com‐
piler such as Microsoft's Visual C / C++ compiler.) If the
batch_key argument is any non-False, non-callable Python value,
the configured Action object will cause scons to collect all
targets built with the Action object and configured with the
same construction environment into single invocations of the
Action object's command line or function. Command lines will
typically want to use the CHANGED_SOURCES construction variable
(and possibly CHANGED_TARGETS as well) to only pass to the com‐
mand line those sources that have actually changed since their
targets were built.
Example:
a = Action('build $CHANGED_SOURCES', batch_key=True)
The batch_key argument may also be a callable function that returns a
key that will be used to identify different "batches" of target files
to be collected for batch building. A batch_key function must take the
following arguments:
action The action object.
env The construction environment configured for the target.
target The list of targets for a particular configured action.
source The list of source for a particular configured action.
The returned key should typically be a tuple of values derived
from the arguments, using any appropriate logic to decide how
multiple invocations should be batched. For example, a
batch_key function may decide to return the value of a specific
construction variable from the env argument which will cause
scons to batch-build targets with matching values of that vari‐
able, or perhaps return the id() of the entire construction
environment, in which case scons will batch-build all targets
configured with the same construction environment. Returning
None indicates that the particular target should not be part of
any batched build, but instead will be built by a separate invo‐
cation of action's command or function. Example:
def batch_key(action, env, target, source):
tdir = target[0].dir
if tdir.name == 'special':
# Don't batch-build any target
# in the special/ subdirectory.
return None
return (id(action), id(env), tdir)
a = Action('build $CHANGED_SOURCES', batch_key=batch_key)
Miscellaneous Action Functions
scons supplies a number of functions that arrange for various common
file and directory manipulations to be performed. These are similar in
concept to "tasks" in the Ant build tool, although the implementation
is slightly different. These functions do not actually perform the
specified action at the time the function is called, but instead return
an Action object that can be executed at the appropriate time. (In
Object-Oriented terminology, these are actually Action Factory func‐
tions that return Action objects.)
In practice, there are two natural ways that these Action Functions are
intended to be used.
First, if you need to perform the action at the time the SConscript
file is being read, you can use the Execute global function to do so:
Execute(Touch('file'))
Second, you can use these functions to supply Actions in a list for use
by the Command method. This can allow you to perform more complicated
sequences of file manipulation without relying on platform-specific
external commands: that
env = Environment(TMPBUILD = '/tmp/builddir')
env.Command('foo.out', 'foo.in',
[Mkdir('$TMPBUILD'),
Copy('$TMPBUILD', '${SOURCE.dir}'),
"cd $TMPBUILD && make",
Delete('$TMPBUILD')])
Chmod(dest, mode)
Returns an Action object that changes the permissions on the
specified dest file or directory to the specified mode. Exam‐
ples:
Execute(Chmod('file', 0755))
env.Command('foo.out', 'foo.in',
[Copy('$TARGET', '$SOURCE'),
Chmod('$TARGET', 0755)])
Copy(dest, src)
Returns an Action object that will copy the src source file or
directory to the dest destination file or directory. Examples:
Execute(Copy('foo.output', 'foo.input'))
env.Command('bar.out', 'bar.in',
Copy('$TARGET', '$SOURCE'))
Delete(entry, [must_exist])
Returns an Action that deletes the specified entry, which may be
a file or a directory tree. If a directory is specified, the
entire directory tree will be removed. If the must_exist flag
is set, then a Python error will be thrown if the specified
entry does not exist; the default is must_exist=0, that is, the
Action will silently do nothing if the entry does not exist.
Examples:
Execute(Delete('/tmp/buildroot'))
env.Command('foo.out', 'foo.in',
[Delete('${TARGET.dir}'),
MyBuildAction])
Execute(Delete('file_that_must_exist', must_exist=1))
Mkdir(dir)
Returns an Action that creates the specified directory dir .
Examples:
Execute(Mkdir('/tmp/outputdir'))
env.Command('foo.out', 'foo.in',
[Mkdir('/tmp/builddir'),
Copy('/tmp/builddir/foo.in', '$SOURCE'),
"cd /tmp/builddir && make",
Copy('$TARGET', '/tmp/builddir/foo.out')])
Move(dest, src)
Returns an Action that moves the specified src file or directory
to the specified dest file or directory. Examples:
Execute(Move('file.destination', 'file.source'))
env.Command('output_file', 'input_file',
[MyBuildAction,
Move('$TARGET', 'file_created_by_MyBuildAction')])
Touch(file)
Returns an Action that updates the modification time on the
specified file. Examples:
Execute(Touch('file_to_be_touched'))
env.Command('marker', 'input_file',
[MyBuildAction,
Touch('$TARGET')])
Variable Substitution
Before executing a command, scons performs construction variable inter‐
polation on the strings that make up the command line of builders.
Variables are introduced by a $ prefix. Besides construction vari‐
ables, scons provides the following variables for each command execu‐
tion:
CHANGED_SOURCES
The file names of all sources of the build command that have
changed since the target was last built.
CHANGED_TARGETS
The file names of all targets that would be built from sources
that have changed since the target was last built.
SOURCE The file name of the source of the build command, or the file
name of the first source if multiple sources are being built.
SOURCES
The file names of the sources of the build command.
TARGET The file name of the target being built, or the file name of the
first target if multiple targets are being built.
TARGETS
The file names of all targets being built.
UNCHANGED_SOURCES
The file names of all sources of the build command that have not
changed since the target was last built.
UNCHANGED_TARGETS
The file names of all targets that would be built from sources
that have not changed since the target was last built.
(Note that the above variables are reserved and may not be set
in a construction environment.)
For example, given the construction variable CC='cc', targets=['foo'],
and sources=['foo.c', 'bar.c']:
action='$CC -c -o $TARGET $SOURCES'
would produce the command line:
cc -c -o foo foo.c bar.c
Variable names may be surrounded by curly braces ({}) to separate the
name from the trailing characters. Within the curly braces, a variable
name may have a Python slice subscript appended to select one or more
items from a list. In the previous example, the string:
${SOURCES[1]}
would produce:
bar.c
Additionally, a variable name may have the following special modifiers
appended within the enclosing curly braces to modify the interpolated
string:
base The base path of the file name, including the directory path but
excluding any suffix.
dir The name of the directory in which the file exists.
file The file name, minus any directory portion.
filebase
Just the basename of the file, minus any suffix and minus the
directory.
suffix Just the file suffix.
abspath
The absolute path name of the file.
posix The POSIX form of the path, with directories separated by /
(forward slashes) not backslashes. This is sometimes necessary
on Windows systems when a path references a file on other
(POSIX) systems.
srcpath
The directory and file name to the source file linked to this
file through VariantDir(). If this file isn't linked, it just
returns the directory and filename unchanged.
srcdir The directory containing the source file linked to this file
through VariantDir(). If this file isn't linked, it just
returns the directory part of the filename.
rsrcpath
The directory and file name to the source file linked to this
file through VariantDir(). If the file does not exist locally
but exists in a Repository, the path in the Repository is
returned. If this file isn't linked, it just returns the direc‐
tory and filename unchanged.
rsrcdir
The Repository directory containing the source file linked to
this file through VariantDir(). If this file isn't linked, it
just returns the directory part of the filename.
For example, the specified target will expand as follows for the corre‐
sponding modifiers:
$TARGET => sub/dir/file.x
${TARGET.base} => sub/dir/file
${TARGET.dir} => sub/dir
${TARGET.file} => file.x
${TARGET.filebase} => file
${TARGET.suffix} => .x
${TARGET.abspath} => /top/dir/sub/dir/file.x
SConscript('src/SConscript', variant_dir='sub/dir')
$SOURCE => sub/dir/file.x
${SOURCE.srcpath} => src/file.x
${SOURCE.srcdir} => src
Repository('/usr/repository')
$SOURCE => sub/dir/file.x
${SOURCE.rsrcpath} => /usr/repository/src/file.x
${SOURCE.rsrcdir} => /usr/repository/src
Note that curly braces braces may also be used to enclose arbitrary
Python code to be evaluated. (In fact, this is how the above modifiers
are substituted, they are simply attributes of the Python objects that
represent TARGET, SOURCES, etc.) See the section "Python Code Substi‐
tution" below, for more thorough examples of how this can be used.
Lastly, a variable name may be a callable Python function associated
with a construction variable in the environment. The function should
take four arguments: target - a list of target nodes, source - a list
of source nodes, env - the construction environment, for_signature - a
Boolean value that specifies whether the function is being called for
generating a build signature. SCons will insert whatever the called
function returns into the expanded string:
def foo(target, source, env, for_signature):
return "bar"
# Will expand $BAR to "bar baz"
env=Environment(FOO=foo, BAR="$FOO baz")
You can use this feature to pass arguments to a Python function by cre‐
ating a callable class that stores one or more arguments in an object,
and then uses them when the __call__() method is called. Note that in
this case, the entire variable expansion must be enclosed by curly
braces so that the arguments will be associated with the instantiation
of the class:
class foo(object):
def __init__(self, arg):
self.arg = arg
def __call__(self, target, source, env, for_signature):
return self.arg + " bar"
# Will expand $BAR to "my argument bar baz"
env=Environment(FOO=foo, BAR="${FOO('my argument')} baz")
The special pseudo-variables $( and $) may be used to surround parts of
a command line that may change without causing a rebuild--that is,
which are not included in the signature of target files built with this
command. All text between $( and $) will be removed from the command
line before it is added to file signatures, and the $( and $) will be
removed before the command is executed. For example, the command line:
echo Last build occurred $( $TODAY $). > $TARGET
would execute the command:
echo Last build occurred $TODAY. > $TARGET
but the command signature added to any target files would be:
echo Last build occurred . > $TARGET
Python Code Substitution
Any python code within ${-} pairs gets evaluated by python 'eval', with
the python globals set to the current environment's set of construction
variables. So in the following case:
env['COND'] = 0
env.Command('foo.out', 'foo.in',
'''echo ${COND==1 and 'FOO' or 'BAR'} > $TARGET''')
the command executed will be either
echo FOO > foo.out
or
echo BAR > foo.out
according to the current value of env['COND'] when the command is exe‐
cuted. The evaluation occurs when the target is being built, not when
the SConscript is being read. So if env['COND'] is changed later in
the SConscript, the final value will be used.
Here's a more interesting example. Note that all of COND, FOO, and BAR
are environment variables, and their values are substituted into the
final command. FOO is a list, so its elements are interpolated sepa‐
rated by spaces.
env=Environment()
env['COND'] = 0
env['FOO'] = ['foo1', 'foo2']
env['BAR'] = 'barbar'
env.Command('foo.out', 'foo.in',
'echo ${COND==1 and FOO or BAR} > $TARGET')
# Will execute this:
# echo foo1 foo2 > foo.out
SCons uses the following rules when converting construction variables
into command lines:
String When the value is a string it is interpreted as a space delim‐
ited list of command line arguments.
List When the value is a list it is interpreted as a list of command
line arguments. Each element of the list is converted to a
string.
Other Anything that is not a list or string is converted to a string
and interpreted as a single command line argument.
Newline
Newline characters (\n) delimit lines. The newline parsing is
done after all other parsing, so it is not possible for argu‐
ments (e.g. file names) to contain embedded newline characters.
This limitation will likely go away in a future version of
SCons.
Scanner Objects
You can use the Scanner function to define objects to scan new file
types for implicit dependencies. The Scanner function accepts the fol‐
lowing arguments:
function
This can be either: 1) a Python function that will process the
Node (file) and return a list of File Nodes representing the
implicit dependencies (file names) found in the contents; or: 2)
a dictionary that maps keys (typically the file suffix, but see
below for more discussion) to other Scanners that should be
called.
If the argument is actually a Python function, the function must
take three or four arguments:
def scanner_function(node, env, path):
def scanner_function(node, env, path, arg=None):
The node argument is the internal SCons node representing the
file. Use str(node) to fetch the name of the file, and
node.get_contents() to fetch contents of the file. Note that
the file is not guaranteed to exist before the scanner is
called, so the scanner function should check that if there's any
chance that the scanned file might not exist (for example, if
it's built from other files).
The env argument is the construction environment for the scan.
Fetch values from it using the env.Dictionary() method.
The path argument is a tuple (or list) of directories that can
be searched for files. This will usually be the tuple returned
by the path_function argument (see below).
The arg argument is the argument supplied when the scanner was
created, if any.
name The name of the Scanner. This is mainly used to identify the
Scanner internally.
argument
An optional argument that, if specified, will be passed to the
scanner function (described above) and the path function (speci‐
fied below).
skeys An optional list that can be used to determine which scanner
should be used for a given Node. In the usual case of scanning
for file names, this argument will be a list of suffixes for the
different file types that this Scanner knows how to scan. If
the argument is a string, then it will be expanded into a list
by the current environment.
path_function
A Python function that takes four or five arguments: a construc‐
tion environment, a Node for the directory containing the SCon‐
script file in which the first target was defined, a list of
target nodes, a list of source nodes, and an optional argument
supplied when the scanner was created. The path_function
returns a tuple of directories that can be searched for files to
be returned by this Scanner object. (Note that the Find‐
PathDirs() function can be used to return a ready-made
path_function for a given construction variable name, instead of
having to write your own function from scratch.)
node_class
The class of Node that should be returned by this Scanner
object. Any strings or other objects returned by the scanner
function that are not of this class will be run through the
node_factory function.
node_factory
A Python function that will take a string or other object and
turn it into the appropriate class of Node to be returned by
this Scanner object.
scan_check
An optional Python function that takes two arguments, a Node
(file) and a construction environment, and returns whether the
Node should, in fact, be scanned for dependencies. This check
can be used to eliminate unnecessary calls to the scanner func‐
tion when, for example, the underlying file represented by a
Node does not yet exist.
recursive
An optional flag that specifies whether this scanner should be
re-invoked on the dependency files returned by the scanner.
When this flag is not set, the Node subsystem will only invoke
the scanner on the file being scanned, and not (for example)
also on the files specified by the #include lines in the file
being scanned. recursive may be a callable function, in which
case it will be called with a list of Nodes found and should
return a list of Nodes that should be scanned recursively; this
can be used to select a specific subset of Nodes for additional
scanning.
Note that scons has a global SourceFileScanner object that is used by
the Object(), SharedObject(), and StaticObject() builders to decide
which scanner should be used for different file extensions. You can
using the SourceFileScanner.add_scanner() method to add your own Scan‐
ner object to the scons infrastructure that builds target programs or
libraries from a list of source files of different types:
def xyz_scan(node, env, path):
contents = node.get_text_contents()
# Scan the contents and return the included files.
XYZScanner = Scanner(xyz_scan)
SourceFileScanner.add_scanner('.xyz', XYZScanner)
env.Program('my_prog', ['file1.c', 'file2.f', 'file3.xyz'])
SYSTEM-SPECIFIC BEHAVIOR
SCons and its configuration files are very portable, due largely to its
implementation in Python. There are, however, a few portability issues
waiting to trap the unwary.
.C file suffix
SCons handles the upper-case .C file suffix differently, depending on
the capabilities of the underlying system. On a case-sensitive system
such as Linux or UNIX, SCons treats a file with a .C suffix as a C++
source file. On a case-insensitive system such as Windows, SCons
treats a file with a .C suffix as a C source file.
.F file suffix
SCons handles the upper-case .F file suffix differently, depending on
the capabilities of the underlying system. On a case-sensitive system
such as Linux or UNIX, SCons treats a file with a .F suffix as a For‐
tran source file that is to be first run through the standard C pre‐
processor. On a case-insensitive system such as Windows, SCons treats
a file with a .F suffix as a Fortran source file that should not be run
through the C preprocessor.
Windows: Cygwin Tools and Cygwin Python vs. Windows Pythons
Cygwin supplies a set of tools and utilities that let users work on a
Windows system using a more POSIX-like environment. The Cygwin tools,
including Cygwin Python, do this, in part, by sharing an ability to
interpret UNIX-like path names. For example, the Cygwin tools will
internally translate a Cygwin path name like /cygdrive/c/mydir to an
equivalent Windows pathname of C:/mydir (equivalent to C:\mydir).
Versions of Python that are built for native Windows execution, such as
the python.org and ActiveState versions, do not have the Cygwin path
name semantics. This means that using a native Windows version of
Python to build compiled programs using Cygwin tools (such as gcc,
bison, and flex) may yield unpredictable results. "Mixing and match‐
ing" in this way can be made to work, but it requires careful attention
to the use of path names in your SConscript files.
In practice, users can sidestep the issue by adopting the following
rules: When using gcc, use the Cygwin-supplied Python interpreter to
run SCons; when using Microsoft Visual C/C++ (or some other Windows
compiler) use the python.org or ActiveState version of Python to run
SCons.
Windows: scons.bat file
On Windows systems, SCons is executed via a wrapper scons.bat file.
This has (at least) two ramifications:
First, Windows command-line users that want to use variable assignment
on the command line may have to put double quotes around the assign‐
ments:
scons "FOO=BAR" "BAZ=BLEH"
Second, the Cygwin shell does not recognize this file as being the same
as an scons command issued at the command-line prompt. You can work
around this either by executing scons.bat from the Cygwin command line,
or by creating a wrapper shell script named scons .
MinGW
The MinGW bin directory must be in your PATH environment variable or
the PATH variable under the ENV construction variable for SCons to
detect and use the MinGW tools. When running under the native Windows
Python interpreter, SCons will prefer the MinGW tools over the Cygwin
tools, if they are both installed, regardless of the order of the bin
directories in the PATH variable. If you have both MSVC and MinGW
installed and you want to use MinGW instead of MSVC, then you must
explictly tell SCons to use MinGW by passing
tools=['mingw']
to the Environment() function, because SCons will prefer the MSVC tools
over the MinGW tools.
EXAMPLES
To help you get started using SCons, this section contains a brief
overview of some common tasks.
Basic Compilation From a Single Source File
env = Environment()
env.Program(target = 'foo', source = 'foo.c')
Note: Build the file by specifying the target as an argument ("scons
foo" or "scons foo.exe"). or by specifying a dot ("scons .").
Basic Compilation From Multiple Source Files
env = Environment()
env.Program(target = 'foo', source = Split('f1.c f2.c f3.c'))
Setting a Compilation Flag
env = Environment(CCFLAGS = '-g')
env.Program(target = 'foo', source = 'foo.c')
Search The Local Directory For .h Files
Note: You do not need to set CCFLAGS to specify -I options by hand.
SCons will construct the right -I options from CPPPATH.
env = Environment(CPPPATH = ['.'])
env.Program(target = 'foo', source = 'foo.c')
Search Multiple Directories For .h Files
env = Environment(CPPPATH = ['include1', 'include2'])
env.Program(target = 'foo', source = 'foo.c')
Building a Static Library
env = Environment()
env.StaticLibrary(target = 'foo', source = Split('l1.c l2.c'))
env.StaticLibrary(target = 'bar', source = ['l3.c', 'l4.c'])
Building a Shared Library
env = Environment()
env.SharedLibrary(target = 'foo', source = ['l5.c', 'l6.c'])
env.SharedLibrary(target = 'bar', source = Split('l7.c l8.c'))
Linking a Local Library Into a Program
env = Environment(LIBS = 'mylib', LIBPATH = ['.'])
env.Library(target = 'mylib', source = Split('l1.c l2.c'))
env.Program(target = 'prog', source = ['p1.c', 'p2.c'])
Defining Your Own Builder Object
Notice that when you invoke the Builder, you can leave off the target
file suffix, and SCons will add it automatically.
bld = Builder(action = 'pdftex < $SOURCES > $TARGET'
suffix = '.pdf',
src_suffix = '.tex')
env = Environment(BUILDERS = {'PDFBuilder' : bld})
env.PDFBuilder(target = 'foo.pdf', source = 'foo.tex')
# The following creates "bar.pdf" from "bar.tex"
env.PDFBuilder(target = 'bar', source = 'bar')
Note also that the above initialization overwrites the default Builder
objects, so the Environment created above can not be used call Builders
like env.Program(), env.Object(), env.StaticLibrary(), etc.
Adding Your Own Builder Object to an Environment
bld = Builder(action = 'pdftex < $SOURCES > $TARGET'
suffix = '.pdf',
src_suffix = '.tex')
env = Environment()
env.Append(BUILDERS = {'PDFBuilder' : bld})
env.PDFBuilder(target = 'foo.pdf', source = 'foo.tex')
env.Program(target = 'bar', source = 'bar.c')
You also can use other Pythonic techniques to add to the BUILDERS con‐
struction variable, such as:
env = Environment()
env['BUILDERS]['PDFBuilder'] = bld
Defining Your Own Scanner Object
The following example shows an extremely simple scanner (the
kfile_scan() function) that doesn't use a search path at all and simply
returns the file names present on any include lines in the scanned
file. This would implicitly assume that all included files live in the
top-level directory:
import re
include_re = re.compile(r'^include\s+(\S+)$', re.M)
def kfile_scan(node, env, path, arg):
contents = node.get_text_contents()
includes = include_re.findall(contents)
return env.File(includes)
kscan = Scanner(name = 'kfile',
function = kfile_scan,
argument = None,
skeys = ['.k'])
scanners = Environment().Dictionary('SCANNERS')
env = Environment(SCANNERS = scanners + [kscan])
env.Command('foo', 'foo.k', 'kprocess < $SOURCES > $TARGET')
bar_in = File('bar.in')
env.Command('bar', bar_in, 'kprocess $SOURCES > $TARGET')
bar_in.target_scanner = kscan
It is important to note that you have to return a list of File nodes
from the scan function, simple strings for the file names won't do. As
in the examples we are showing here, you can use the File() function of
your current Environment in order to create nodes on the fly from a
sequence of file names with relative paths.
Here is a similar but more complete example that searches a path of
directories (specified as the MYPATH construction variable) for files
that actually exist:
import re
import os
include_re = re.compile(r'^include\s+(\S+)$', re.M)
def my_scan(node, env, path, arg):
contents = node.get_text_contents()
includes = include_re.findall(contents)
if includes == []:
return []
results = []
for inc in includes:
for dir in path:
file = str(dir) + os.sep + inc
if os.path.exists(file):
results.append(file)
break
return env.File(results)
scanner = Scanner(name = 'myscanner',
function = my_scan,
argument = None,
skeys = ['.x'],
path_function = FindPathDirs('MYPATH')
)
scanners = Environment().Dictionary('SCANNERS')
env = Environment(SCANNERS = scanners + [scanner],
MYPATH = ['incs'])
env.Command('foo', 'foo.x', 'xprocess < $SOURCES > $TARGET')
The FindPathDirs() function used in the previous example returns a
function (actually a callable Python object) that will return a list of
directories specified in the $MYPATH construction variable. It lets
SCons detect the file incs/foo.inc , even if foo.x contains the line
include foo.inc only. If you need to customize how the search path is
derived, you would provide your own path_function argument when creat‐
ing the Scanner object, as follows:
# MYPATH is a list of directories to search for files in
def pf(env, dir, target, source, arg):
top_dir = Dir('#').abspath
results = []
if 'MYPATH' in env:
for p in env['MYPATH']:
results.append(top_dir + os.sep + p)
return results
scanner = Scanner(name = 'myscanner',
function = my_scan,
argument = None,
skeys = ['.x'],
path_function = pf
)
Creating a Hierarchical Build
Notice that the file names specified in a subdirectory's SConscript
file are relative to that subdirectory.
SConstruct:
env = Environment()
env.Program(target = 'foo', source = 'foo.c')
SConscript('sub/SConscript')
sub/SConscript:
env = Environment()
# Builds sub/foo from sub/foo.c
env.Program(target = 'foo', source = 'foo.c')
SConscript('dir/SConscript')
sub/dir/SConscript:
env = Environment()
# Builds sub/dir/foo from sub/dir/foo.c
env.Program(target = 'foo', source = 'foo.c')
Sharing Variables Between SConscript Files
You must explicitly Export() and Import() variables that you want to
share between SConscript files.
SConstruct:
env = Environment()
env.Program(target = 'foo', source = 'foo.c')
Export("env")
SConscript('subdirectory/SConscript')
subdirectory/SConscript:
Import("env")
env.Program(target = 'foo', source = 'foo.c')
Building Multiple Variants From the Same Source
Use the variant_dir keyword argument to the SConscript function to
establish one or more separate variant build directory trees for a
given source directory:
SConstruct:
cppdefines = ['FOO']
Export("cppdefines")
SConscript('src/SConscript', variant_dir='foo')
cppdefines = ['BAR']
Export("cppdefines")
SConscript('src/SConscript', variant_dir='bar')
src/SConscript:
Import("cppdefines")
env = Environment(CPPDEFINES = cppdefines)
env.Program(target = 'src', source = 'src.c')
Note the use of the Export() method to set the "cppdefines" variable to
a different value each time we call the SConscript function.
Hierarchical Build of Two Libraries Linked With a Program
SConstruct:
env = Environment(LIBPATH = ['#libA', '#libB'])
Export('env')
SConscript('libA/SConscript')
SConscript('libB/SConscript')
SConscript('Main/SConscript')
libA/SConscript:
Import('env')
env.Library('a', Split('a1.c a2.c a3.c'))
libB/SConscript:
Import('env')
env.Library('b', Split('b1.c b2.c b3.c'))
Main/SConscript:
Import('env')
e = env.Copy(LIBS = ['a', 'b'])
e.Program('foo', Split('m1.c m2.c m3.c'))
The '#' in the LIBPATH directories specify that they're relative to the
top-level directory, so they don't turn into "Main/libA" when they're
used in Main/SConscript.
Specifying only 'a' and 'b' for the library names allows SCons to
append the appropriate library prefix and suffix for the current plat‐
form (for example, 'liba.a' on POSIX systems, 'a.lib' on Windows).
Customizing construction variables from the command line.
The following would allow the C compiler to be specified on the command
line or in the file custom.py.
vars = Variables('custom.py')
vars.Add('CC', 'The C compiler.')
env = Environment(variables=vars)
Help(vars.GenerateHelpText(env))
The user could specify the C compiler on the command line:
scons "CC=my_cc"
or in the custom.py file:
CC = 'my_cc'
or get documentation on the options:
$ scons-h
CC: The C compiler.
default: None
actual: cc
Using Microsoft Visual C++ precompiled headers
Since windows.h includes everything and the kitchen sink, it can take
quite some time to compile it over and over again for a bunch of object
files, so Microsoft provides a mechanism to compile a set of headers
once and then include the previously compiled headers in any object
file. This technology is called precompiled headers. The general recipe
is to create a file named "StdAfx.cpp" that includes a single header
named "StdAfx.h", and then include every header you want to precompile
in "StdAfx.h", and finally include "StdAfx.h" as the first header in
all the source files you are compiling to object files. For example:
StdAfx.h:
#include <windows.h>
#include <my_big_header.h>
StdAfx.cpp:
#include <StdAfx.h>
Foo.cpp:
#include <StdAfx.h>
/* do some stuff */
Bar.cpp:
#include <StdAfx.h>
/* do some other stuff */
SConstruct:
env=Environment()
env['PCHSTOP'] = 'StdAfx.h'
env['PCH'] = env.PCH('StdAfx.cpp')[0]
env.Program('MyApp', ['Foo.cpp', 'Bar.cpp'])
For more information see the document for the PCH builder, and the PCH
and PCHSTOP construction variables. To learn about the details of pre‐
compiled headers consult the MSDN documention for /Yc, /Yu, and /Yp.
Using Microsoft Visual C++ external debugging information
Since including debugging information in programs and shared libraries
can cause their size to increase significantly, Microsoft provides a
mechanism for including the debugging information in an external file
called a PDB file. SCons supports PDB files through the PDB construc‐
tion variable.
SConstruct:
env=Environment()
env['PDB'] = 'MyApp.pdb'
env.Program('MyApp', ['Foo.cpp', 'Bar.cpp'])
For more information see the document for the PDB construction vari‐
able.
ENVIRONMENT
SCONS_LIB_DIR
Specifies the directory that contains the SCons Python module
directory (e.g. /home/aroach/scons-src-0.01/src/engine).
SCONSFLAGS
A string of options that will be used by scons in addition to
those passed on the command line.
SEE ALSOscons User Manual, scons Design Document, scons source code.
AUTHORS
Steven Knight <knight@baldmt.com>
Anthony Roach <aroach@electriceyeball.com>
March 2013 SCONS(1)
