BMAKE man page on SmartOS

BMAKE man page on SmartOS

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BMAKE(1) BSD General Commands Manual BMAKE(1)

NAME
bmake — maintain program dependencies

SYNOPSIS
bmake [-BeikNnqrstWX] [-C directory] [-D variable] [-d flags]
[-f makefile] [-I directory] [-J private] [-j max_jobs]
[-m directory] [-T file] [-V variable] [variable=value]
[target ...]

DESCRIPTION
bmake is a program designed to simplify the maintenance of other pro‐
grams. Its input is a list of specifications as to the files upon which
programs and other files depend. If no -f makefile makefile option is
given, bmake will try to open ‘makefile’ then ‘Makefile’ in order to find
the specifications. If the file ‘.depend’ exists, it is read (see
mkdep(1)).

This manual page is intended as a reference document only. For a more
thorough description of bmake and makefiles, please refer to Make - A
Tutorial.

bmake will prepend the contents of the MAKEFLAGS environment variable to
the command line arguments before parsing them.

The options are as follows:

-B Try to be backwards compatible by executing a single shell per
command and by executing the commands to make the sources of a
dependency line in sequence.

-C directory
Change to directory before reading the makefiles or doing any‐
thing else. If multiple -C options are specified, each is inter‐
preted relative to the previous one: -C / -C etc is equivalent to
-C /etc.

-D variable
Define variable to be 1, in the global context.

-d [-]flags
Turn on debugging, and specify which portions of bmake are to
print debugging information. Unless the flags are preceded by
‘-’ they are added to the MAKEFLAGS environment variable and will
be processed by any child make processes. By default, debugging
information is printed to standard error, but this can be changed
using the F debugging flag. The debugging output is always
unbuffered; in addition, if debugging is enabled but debugging
output is not directed to standard output, then the standard out‐
put is line buffered. Flags is one or more of the following:

A Print all possible debugging information; equivalent to
specifying all of the debugging flags.

a Print debugging information about archive searching and
caching.

C Print debugging information about current working direc‐
tory.

c Print debugging information about conditional evaluation.

d Print debugging information about directory searching and
caching.

e Print debugging information about failed commands and
targets.

F[+]filename
Specify where debugging output is written. This must be
the last flag, because it consumes the remainder of the
argument. If the character immediately after the ‘F’
flag is ‘+’, then the file will be opened in append mode;
otherwise the file will be overwritten. If the file name
is ‘stdout’ or ‘stderr’ then debugging output will be
written to the standard output or standard error output
file descriptors respectively (and the ‘+’ option has no
effect). Otherwise, the output will be written to the
named file. If the file name ends ‘.%d’ then the ‘%d’ is
replaced by the pid.

f Print debugging information about loop evaluation.

g1 Print the input graph before making anything.

g2 Print the input graph after making everything, or before
exiting on error.

g3 Print the input graph before exiting on error.

j Print debugging information about running multiple
shells.

l Print commands in Makefiles regardless of whether or not
they are prefixed by ‘@’ or other "quiet" flags. Also
known as "loud" behavior.

M Print debugging information about "meta" mode decisions
about targets.

m Print debugging information about making targets, includ‐
ing modification dates.

n Don't delete the temporary command scripts created when
running commands. These temporary scripts are created in
the directory referred to by the TMPDIR environment vari‐
able, or in /tmp if TMPDIR is unset or set to the empty
string. The temporary scripts are created by mkstemp(3),
and have names of the form makeXXXXXX. NOTE: This can
create many files in TMPDIR or /tmp, so use with care.

p Print debugging information about makefile parsing.

s Print debugging information about suffix-transformation
rules.

t Print debugging information about target list mainte‐
nance.

v Print debugging information about variable assignment.

x Run shell commands with -x so the actual commands are
printed as they are executed.

-e Specify that environment variables override macro assignments
within makefiles.

-f makefile
Specify a makefile to read instead of the default ‘makefile’. If
makefile is ‘-’, standard input is read. Multiple makefiles may
be specified, and are read in the order specified.

-I directory
Specify a directory in which to search for makefiles and included
makefiles. The system makefile directory (or directories, see
the -m option) is automatically included as part of this list.

-i Ignore non-zero exit of shell commands in the makefile. Equiva‐
lent to specifying ‘-’ before each command line in the makefile.

-J private
This option should not be specified by the user.

When the j option is in use in a recursive build, this option is
passed by a make to child makes to allow all the make processes
in the build to cooperate to avoid overloading the system.

-j max_jobs
Specify the maximum number of jobs that bmake may have running at
any one time. The value is saved in .MAKE.JOBS. Turns compati‐
bility mode off, unless the B flag is also specified. When com‐
patibility mode is off, all commands associated with a target are
executed in a single shell invocation as opposed to the tradi‐
tional one shell invocation per line. This can break traditional
scripts which change directories on each command invocation and
then expect to start with a fresh environment on the next line.
It is more efficient to correct the scripts rather than turn
backwards compatibility on.

-k Continue processing after errors are encountered, but only on
those targets that do not depend on the target whose creation
caused the error.

-m directory
Specify a directory in which to search for sys.mk and makefiles
included via the ⟨file⟩-style include statement. The -m option
can be used multiple times to form a search path. This path will
override the default system include path: /usr/share/mk. Fur‐
thermore the system include path will be appended to the search
path used for "file"-style include statements (see the -I
option).

If a file or directory name in the -m argument (or the
MAKESYSPATH environment variable) starts with the string ".../"
then bmake will search for the specified file or directory named
in the remaining part of the argument string. The search starts
with the current directory of the Makefile and then works upward
towards the root of the filesystem. If the search is successful,
then the resulting directory replaces the ".../" specification in
the -m argument. If used, this feature allows bmake to easily
search in the current source tree for customized sys.mk files
(e.g., by using ".../mk/sys.mk" as an argument).

-n Display the commands that would have been executed, but do not
actually execute them unless the target depends on the .MAKE spe‐
cial source (see below).

-N Display the commands which would have been executed, but do not
actually execute any of them; useful for debugging top-level
makefiles without descending into subdirectories.

-q Do not execute any commands, but exit 0 if the specified targets
are up-to-date and 1, otherwise.

-r Do not use the built-in rules specified in the system makefile.

-s Do not echo any commands as they are executed. Equivalent to
specifying ‘@’ before each command line in the makefile.

-T tracefile
When used with the -j flag, append a trace record to tracefile
for each job started and completed.

-t Rather than re-building a target as specified in the makefile,
create it or update its modification time to make it appear up-
to-date.

-V variable
Print bmake's idea of the value of variable, in the global con‐
text. Do not build any targets. Multiple instances of this
option may be specified; the variables will be printed one per
line, with a blank line for each null or undefined variable. If
variable contains a ‘$’ then the value will be expanded before
printing.

-W Treat any warnings during makefile parsing as errors.

-X Don't export variables passed on the command line to the environ‐
ment individually. Variables passed on the command line are
still exported via the MAKEFLAGS environment variable. This
option may be useful on systems which have a small limit on the
size of command arguments.

variable=value
Set the value of the variable variable to value. Normally, all
values passed on the command line are also exported to sub-makes
in the environment. The -X flag disables this behavior. Vari‐
able assignments should follow options for POSIX compatibility
but no ordering is enforced.

There are seven different types of lines in a makefile: file dependency
specifications, shell commands, variable assignments, include statements,
conditional directives, for loops, and comments.

In general, lines may be continued from one line to the next by ending
them with a backslash (‘\’). The trailing newline character and initial
whitespace on the following line are compressed into a single space.

FILE DEPENDENCY SPECIFICATIONS
Dependency lines consist of one or more targets, an operator, and zero or
more sources. This creates a relationship where the targets “depend” on
the sources and are usually created from them. The exact relationship
between the target and the source is determined by the operator that sep‐
arates them. The three operators are as follows:

: A target is considered out-of-date if its modification time is less
than those of any of its sources. Sources for a target accumulate
over dependency lines when this operator is used. The target is
removed if bmake is interrupted.

! Targets are always re-created, but not until all sources have been
examined and re-created as necessary. Sources for a target accumu‐
late over dependency lines when this operator is used. The target
is removed if bmake is interrupted.

:: If no sources are specified, the target is always re-created. Oth‐
erwise, a target is considered out-of-date if any of its sources
has been modified more recently than the target. Sources for a
target do not accumulate over dependency lines when this operator
is used. The target will not be removed if bmake is interrupted.

Targets and sources may contain the shell wildcard values ‘?’, ‘*’, ‘[]’,
and ‘{}’. The values ‘?’, ‘*’, and ‘[]’ may only be used as part of the
final component of the target or source, and must be used to describe
existing files. The value ‘{}’ need not necessarily be used to describe
existing files. Expansion is in directory order, not alphabetically as
done in the shell.

SHELL COMMANDS
Each target may have associated with it a series of shell commands, nor‐
mally used to create the target. Each of the commands in this script
must be preceded by a tab. While any target may appear on a dependency
line, only one of these dependencies may be followed by a creation
script, unless the ‘::’ operator is used.

If the first characters of the command line are any combination of ‘@’,
‘+’, or ‘-’, the command is treated specially. A ‘@’ causes the command
not to be echoed before it is executed. A ‘+’ causes the command to be
executed even when -n is given. This is similar to the effect of the
.MAKE special source, except that the effect can be limited to a single
line of a script. A ‘-’ causes any non-zero exit status of the command
line to be ignored.

VARIABLE ASSIGNMENTS
Variables in make are much like variables in the shell, and, by tradi‐
tion, consist of all upper-case letters.

Variable assignment modifiers
The five operators that can be used to assign values to variables are as
follows:

= Assign the value to the variable. Any previous value is overrid‐
den.

+= Append the value to the current value of the variable.

?= Assign the value to the variable if it is not already defined.

:= Assign with expansion, i.e. expand the value before assigning it
to the variable. Normally, expansion is not done until the vari‐
able is referenced. NOTE: References to undefined variables are
not expanded. This can cause problems when variable modifiers
are used.

!= Expand the value and pass it to the shell for execution and
assign the result to the variable. Any newlines in the result
are replaced with spaces.

Any white-space before the assigned value is removed; if the value is
being appended, a single space is inserted between the previous contents
of the variable and the appended value.

Variables are expanded by surrounding the variable name with either curly
braces (‘{}’) or parentheses (‘()’) and preceding it with a dollar sign
(‘$’). If the variable name contains only a single letter, the surround‐
ing braces or parentheses are not required. This shorter form is not
recommended.

If the variable name contains a dollar, then the name itself is expanded
first. This allows almost arbitrary variable names, however names con‐
taining dollar, braces, parenthesis, or whitespace are really best
avoided!

If the result of expanding a variable contains a dollar sign (‘$’) the
string is expanded again.

Variable substitution occurs at three distinct times, depending on where
the variable is being used.

1. Variables in dependency lines are expanded as the line is read.

2. Variables in shell commands are expanded when the shell command is
executed.

3. “.for” loop index variables are expanded on each loop iteration.
Note that other variables are not expanded inside loops so the fol‐
lowing example code:

.for i in 1 2 3
a+= ${i}
j= ${i}
b+= ${j}
.endfor

all:
@echo ${a}
@echo ${b}

will print:

1 2 3
3 3 3

Because while ${a} contains “1 2 3” after the loop is executed, ${b}
contains “${j} ${j} ${j}” which expands to “3 3 3” since after the
loop completes ${j} contains “3”.

Variable classes
The four different classes of variables (in order of increasing prece‐
dence) are:

Environment variables
Variables defined as part of bmake's environment.

Global variables
Variables defined in the makefile or in included makefiles.

Command line variables
Variables defined as part of the command line.

Local variables
Variables that are defined specific to a certain target. The
seven local variables are as follows:

.ALLSRC The list of all sources for this target; also known as
‘>’.

.ARCHIVE The name of the archive file.

.IMPSRC In suffix-transformation rules, the name/path of the
source from which the target is to be transformed (the
“implied” source); also known as ‘<’. It is not
defined in explicit rules.

.MEMBER The name of the archive member.

.OODATE The list of sources for this target that were deemed
out-of-date; also known as ‘?’.

.PREFIX The file prefix of the target, containing only the file
portion, no suffix or preceding directory components;
also known as ‘*’.

.TARGET The name of the target; also known as ‘@’.

The shorter forms ‘@’, ‘?’, ‘<’, ‘>’, and ‘*’ are permitted for
backward compatibility with historical makefiles and are not rec‐
ommended. The six variables ‘@F’, ‘@D’, ‘<F’, ‘<D’, ‘*F’, and
‘*D’ are permitted for compatibility with AT&T System V UNIX
makefiles and are not recommended.

Four of the local variables may be used in sources on dependency
lines because they expand to the proper value for each target on
the line. These variables are ‘.TARGET’, ‘.PREFIX’, ‘.ARCHIVE’,
and ‘.MEMBER’.

Additional built-in variables
In addition, bmake sets or knows about the following variables:

$ A single dollar sign ‘$’, i.e. ‘$$’ expands to a single
dollar sign.

.ALLTARGETS The list of all targets encountered in the Makefile. If
evaluated during Makefile parsing, lists only those tar‐
gets encountered thus far.

.CURDIR A path to the directory where bmake was executed. Refer
to the description of ‘PWD’ for more details.

MAKE The name that bmake was executed with (argv[0]). For
compatibility bmake also sets .MAKE with the same value.
The preferred variable to use is the environment variable
MAKE because it is more compatible with other versions of
bmake and cannot be confused with the special target with
the same name.

.MAKE.DEPENDFILE
Names the makefile (default ‘.depend’) from which gener‐
ated dependencies are read.

.MAKE.EXPORTED The list of variables exported by bmake.

.MAKE.JOBS The argument to the -j option.

.MAKE.JOB.PREFIX
If bmake is run with j then output for each target is
prefixed with a token ‘--- target ---’ the first part of
which can be controlled via .MAKE.JOB.PREFIX.
For example:
.MAKE.JOB.PREFIX=${.newline}---${.MAKE:T}[${.MAKE.PID}]
would produce tokens like ‘---make[1234] target ---’ mak‐
ing it easier to track the degree of parallelism being
achieved.

MAKEFLAGS The environment variable ‘MAKEFLAGS’ may contain anything
that may be specified on bmake's command line. Anything
specified on bmake's command line is appended to the
‘MAKEFLAGS’ variable which is then entered into the envi‐
ronment for all programs which bmake executes.

.MAKE.LEVEL The recursion depth of bmake. The initial instance of
bmake will be 0, and an incremented value is put into the
environment to be seen by the next generation. This
allows tests like: .if ${.MAKE.LEVEL} == 0 to protect
things which should only be evaluated in the initial
instance of bmake.

.MAKE.MAKEFILE_PREFERENCE
The ordered list of makefile names (default ‘makefile’,
‘Makefile’) that bmake will look for.

.MAKE.MAKEFILES
The list of makefiles read by bmake, which is useful for
tracking dependencies. Each makefile is recorded only
once, regardless of the number of times read.

.MAKE.MODE Processed after reading all makefiles. Can affect the
mode that bmake runs in. It can contain a number of key‐
words:

compat Like -B, puts bmake into "compat" mode.

meta Puts bmake into "meta" mode, where meta files
are created for each target to capture the
command run, the output generated and if
filemon(4) is available, the system calls
which are of interest to bmake. The captured
output can be very useful when diagnosing
errors.

curdirOk= bf Normally bmake will not create .meta files
in ‘.CURDIR’. This can be overridden by set‐
ting bf to a value which represents True.

verbose If in "meta" mode, print a clue about the
target being built. This is useful if the
build is otherwise running silently. The
message printed the value of:
.MAKE.META.PREFIX.

ignore-cmd Some makefiles have commands which are simply
not stable. This keyword causes them to be
ignored for determining whether a target is
out of date in "meta" mode. See also
.NOMETA_CMP.

.MAKE.META.BAILIWICK
In "meta" mode, provides a list of prefixes which match
the directories controlled by bmake. If a file that was
generated outside of .OBJDIR but within said bailiwick is
missing, the current target is considered out-of-date.

.MAKE.META.CREATED
In "meta" mode, this variable contains a list of all the
meta files updated. If not empty, it can be used to
trigger processing of .MAKE.META.FILES.

.MAKE.META.FILES
In "meta" mode, this variable contains a list of all the
meta files used (updated or not). This list can be used
to process the meta files to extract dependency informa‐
tion.

.MAKE.META.PREFIX
Defines the message printed for each meta file updated in
"meta verbose" mode. The default value is:
Building ${.TARGET:H:tA}/${.TARGET:T}

.MAKEOVERRIDES This variable is used to record the names of variables
assigned to on the command line, so that they may be
exported as part of ‘MAKEFLAGS’. This behaviour can be
disabled by assigning an empty value to ‘.MAKEOVERRIDES’
within a makefile. Extra variables can be exported from
a makefile by appending their names to ‘.MAKEOVERRIDES’.
‘MAKEFLAGS’ is re-exported whenever ‘.MAKEOVERRIDES’ is
modified.

.MAKE.PID The process-id of bmake.

.MAKE.PPID The parent process-id of bmake.

MAKE_PRINT_VAR_ON_ERROR
When bmake stops due to an error, it prints its name and
the value of ‘.CURDIR’ as well as the value of any vari‐
ables named in ‘MAKE_PRINT_VAR_ON_ERROR’.

.newline This variable is simply assigned a newline character as
its value. This allows expansions using the :@ modifier
to put a newline between iterations of the loop rather
than a space. For example, the printing of
‘MAKE_PRINT_VAR_ON_ERROR’ could be done as
${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'${.newline}@}.

.OBJDIR A path to the directory where the targets are built. Its
value is determined by trying to chdir(2) to the follow‐
ing directories in order and using the first match:

1. ${MAKEOBJDIRPREFIX}${.CURDIR}

(Only if ‘MAKEOBJDIRPREFIX’ is set in the environ‐
ment or on the command line.)

2. ${MAKEOBJDIR}

(Only if ‘MAKEOBJDIR’ is set in the environment or
on the command line.)

3. ${.CURDIR}/obj.${MACHINE}

4. ${.CURDIR}/obj

5. /usr/obj/${.CURDIR}

6. ${.CURDIR}

Variable expansion is performed on the value before it's
used, so expressions such as
${.CURDIR:S,^/usr/src,/var/obj,}
may be used. This is especially useful with
‘MAKEOBJDIR’.

‘.OBJDIR’ may be modified in the makefile as a global
variable. In all cases, bmake will chdir(2) to ‘.OBJDIR’
and set ‘PWD’ to that directory before executing any tar‐
gets.

.PARSEDIR A path to the directory of the current ‘Makefile’ being
parsed.

.PARSEFILE The basename of the current ‘Makefile’ being parsed.
This variable and ‘.PARSEDIR’ are both set only while the
‘Makefiles’ are being parsed.

.PATH A variable that represents the list of directories that
bmake will search for files. The search list should be
updated using the target ‘.PATH’ rather than the vari‐
able.

PWD Alternate path to the current directory. bmake normally
sets ‘.CURDIR’ to the canonical path given by getcwd(3).
However, if the environment variable ‘PWD’ is set and
gives a path to the current directory, then bmake sets
‘.CURDIR’ to the value of ‘PWD’ instead. This behaviour
is disabled if ‘MAKEOBJDIRPREFIX’ is set or ‘MAKEOBJDIR’
contains a variable transform. ‘PWD’ is set to the value
of ‘.OBJDIR’ for all programs which bmake executes.

.TARGETS The list of targets explicitly specified on the command
line, if any.

VPATH Colon-separated (“:”) lists of directories that bmake
will search for files. The variable is supported for
compatibility with old make programs only, use ‘.PATH’
instead.

Variable modifiers
Variable expansion may be modified to select or modify each word of the
variable (where a “word” is white-space delimited sequence of charac‐
ters). The general format of a variable expansion is as follows:

${variable[:modifier[:...]]}

Each modifier begins with a colon, which may be escaped with a backslash
(‘\’).

A set of modifiers can be specified via a variable, as follows:

modifier_variable=modifier[:...]
${variable:${modifier_variable}[:...]}

In this case the first modifier in the modifier_variable does not start
with a colon, since that must appear in the referencing variable. If any
of the modifiers in the modifier_variable contain a dollar sign (‘$’),
these must be doubled to avoid early expansion.

The supported modifiers are:

:E Replaces each word in the variable with its suffix.

:H Replaces each word in the variable with everything but the last com‐
ponent.

:Mpattern
Select only those words that match pattern. The standard shell
wildcard characters (‘*’, ‘?’, and ‘[]’) may be used. The wildcard
characters may be escaped with a backslash (‘\’).

:Npattern
This is identical to ‘:M’, but selects all words which do not match
pattern.

:O Order every word in variable alphabetically. To sort words in
reverse order use the ‘:O:[-1..1]’ combination of modifiers.

:Ox Randomize words in variable. The results will be different each
time you are referring to the modified variable; use the assignment
with expansion (‘:=’) to prevent such behaviour. For example,

LIST= uno due tre quattro
RANDOM_LIST= ${LIST:Ox}
STATIC_RANDOM_LIST:= ${LIST:Ox}

all:
@echo "${RANDOM_LIST}"
@echo "${RANDOM_LIST}"
@echo "${STATIC_RANDOM_LIST}"
@echo "${STATIC_RANDOM_LIST}"
may produce output similar to:

quattro due tre uno
tre due quattro uno
due uno quattro tre
due uno quattro tre

:Q Quotes every shell meta-character in the variable, so that it can be
passed safely through recursive invocations of bmake.

:R Replaces each word in the variable with everything but its suffix.

:gmtime
The value is a format string for strftime(3), using the current
gmtime(3).

:hash
Compute a 32bit hash of the value and encode it as hex digits.

:localtime
The value is a format string for strftime(3), using the current
localtime(3).

:tA Attempt to convert variable to an absolute path using realpath(3),
if that fails, the value is unchanged.

:tl Converts variable to lower-case letters.

:tsc
Words in the variable are normally separated by a space on expan‐
sion. This modifier sets the separator to the character c. If c is
omitted, then no separator is used. The common escapes (including
octal numeric codes), work as expected.

:tu Converts variable to upper-case letters.

:tW Causes the value to be treated as a single word (possibly containing
embedded white space). See also ‘:[*]’.

:tw Causes the value to be treated as a sequence of words delimited by
white space. See also ‘:[@]’.

:S/old_string/new_string/[1gW]
Modify the first occurrence of old_string in the variable's value,
replacing it with new_string. If a ‘g’ is appended to the last
slash of the pattern, all occurrences in each word are replaced. If
a ‘1’ is appended to the last slash of the pattern, only the first
word is affected. If a ‘W’ is appended to the last slash of the
pattern, then the value is treated as a single word (possibly con‐
taining embedded white space). If old_string begins with a caret
(‘^’), old_string is anchored at the beginning of each word. If
old_string ends with a dollar sign (‘$’), it is anchored at the end
of each word. Inside new_string, an ampersand (‘&’) is replaced by
old_string (without any ‘^’ or ‘$’). Any character may be used as a
delimiter for the parts of the modifier string. The anchoring,
ampersand and delimiter characters may be escaped with a backslash
(‘\’).

Variable expansion occurs in the normal fashion inside both
old_string and new_string with the single exception that a backslash
is used to prevent the expansion of a dollar sign (‘$’), not a pre‐
ceding dollar sign as is usual.

:C/pattern/replacement/[1gW]
The :C modifier is just like the :S modifier except that the old and
new strings, instead of being simple strings, are a regular expres‐
sion (see regex(3)) string pattern and an ed(1)-style string
replacement. Normally, the first occurrence of the pattern pattern
in each word of the value is substituted with replacement. The ‘1’
modifier causes the substitution to apply to at most one word; the
‘g’ modifier causes the substitution to apply to as many instances
of the search pattern pattern as occur in the word or words it is
found in; the ‘W’ modifier causes the value to be treated as a sin‐
gle word (possibly containing embedded white space). Note that ‘1’
and ‘g’ are orthogonal; the former specifies whether multiple words
are potentially affected, the latter whether multiple substitutions
can potentially occur within each affected word.

:T Replaces each word in the variable with its last component.

:u Remove adjacent duplicate words (like uniq(1)).

:?true_string:false_string
If the variable name (not its value), when parsed as a .if condi‐
tional expression, evaluates to true, return as its value the
true_string, otherwise return the false_string. Since the variable
name is used as the expression, :? must be the first modifier after
the variable name itself - which will, of course, usually contain
variable expansions. A common error is trying to use expressions
like
${NUMBERS:M42:?match:no}
which actually tests defined(NUMBERS), to determine is any words
match "42" you need to use something like:
${"${NUMBERS:M42}" != "":?match:no}.

:old_string=new_string
This is the AT&T System V UNIX style variable substitution. It must
be the last modifier specified. If old_string or new_string do not
contain the pattern matching character % then it is assumed that
they are anchored at the end of each word, so only suffixes or
entire words may be replaced. Otherwise % is the substring of
old_string to be replaced in new_string.

:@temp@string@
This is the loop expansion mechanism from the OSF Development Envi‐
ronment (ODE) make. Unlike .for loops expansion occurs at the time
of reference. Assign temp to each word in the variable and evaluate
string. The ODE convention is that temp should start and end with a
period. For example.
${LINKS:@.LINK.@${LN} ${TARGET} ${.LINK.}@}

:Unewval
If the variable is undefined newval is the value. If the variable
is defined, the existing value is returned. This is another ODE
make feature. It is handy for setting per-target CFLAGS for
instance:
${_${.TARGET:T}_CFLAGS:U${DEF_CFLAGS}}
If a value is only required if the variable is undefined, use:
${VAR:D:Unewval}

:Dnewval
If the variable is defined newval is the value.

:L The name of the variable is the value.

:P The path of the node which has the same name as the variable is the
value. If no such node exists or its path is null, then the name of
the variable is used.

:!cmd!
The output of running cmd is the value.

:sh If the variable is non-empty it is run as a command and the output
becomes the new value.

::=str
The variable is assigned the value str after substitution. This
modifier and its variations are useful in obscure situations such as
wanting to set a variable when shell commands are being parsed.
These assignment modifiers always expand to nothing, so if appearing
in a rule line by themselves should be preceded with something to
keep bmake happy.

The ‘::’ helps avoid false matches with the AT&T System V UNIX style
:= modifier and since substitution always occurs the ::= form is
vaguely appropriate.

::?=str
As for ::= but only if the variable does not already have a value.

::+=str
Append str to the variable.

::!=cmd
Assign the output of cmd to the variable.

:[range]
Selects one or more words from the value, or performs other opera‐
tions related to the way in which the value is divided into words.

Ordinarily, a value is treated as a sequence of words delimited by
white space. Some modifiers suppress this behaviour, causing a
value to be treated as a single word (possibly containing embedded
white space). An empty value, or a value that consists entirely of
white-space, is treated as a single word. For the purposes of the
‘:[]’ modifier, the words are indexed both forwards using positive
integers (where index 1 represents the first word), and backwards
using negative integers (where index -1 represents the last word).

The range is subjected to variable expansion, and the expanded
result is then interpreted as follows:

index Selects a single word from the value.

start..end
Selects all words from start to end, inclusive. For example,
‘:[2..-1]’ selects all words from the second word to the last
word. If start is greater than end, then the words are out‐
put in reverse order. For example, ‘:[-1..1]’ selects all
the words from last to first.

* Causes subsequent modifiers to treat the value as a single
word (possibly containing embedded white space). Analogous
to the effect of "$*" in Bourne shell.

0 Means the same as ‘:[*]’.

@ Causes subsequent modifiers to treat the value as a sequence
of words delimited by white space. Analogous to the effect
of "$@" in Bourne shell.

# Returns the number of words in the value.

INCLUDE STATEMENTS, CONDITIONALS AND FOR LOOPS
Makefile inclusion, conditional structures and for loops reminiscent of
the C programming language are provided in bmake. All such structures
are identified by a line beginning with a single dot (‘.’) character.
Files are included with either .include ⟨file⟩ or .include "file". Vari‐
ables between the angle brackets or double quotes are expanded to form
the file name. If angle brackets are used, the included makefile is
expected to be in the system makefile directory. If double quotes are
used, the including makefile's directory and any directories specified
using the -I option are searched before the system makefile directory.
For compatibility with other versions of bmake ‘include file ...’ is also
accepted. If the include statement is written as .-include or as
.sinclude then errors locating and/or opening include files are ignored.

Conditional expressions are also preceded by a single dot as the first
character of a line. The possible conditionals are as follows:

.error message
The message is printed along with the name of the makefile and
line number, then bmake will exit.

.export variable ...
Export the specified global variable. If no variable list is
provided, all globals are exported except for internal variables
(those that start with ‘.’). This is not affected by the -X
flag, so should be used with caution.

Appending a variable name to .MAKE.EXPORTED is equivalent to
exporting a variable.

.export-env variable ...
The same as ‘.export’, except that the variable is not appended
to .MAKE.EXPORTED. This allows exporting a value to the environ‐
ment which is different from that used by bmake internally.

.info message
The message is printed along with the name of the makefile and
line number.

.undef variable
Un-define the specified global variable. Only global variables
may be un-defined.

.unexport variable ...
The opposite of ‘.export’. The specified global variable will be
removed from .MAKE.EXPORTED. If no variable list is provided,
all globals are unexported, and .MAKE.EXPORTED deleted.

.unexport-env
Unexport all globals previously exported and clear the environ‐
ment inherited from the parent. This operation will cause a mem‐
ory leak of the original environment, so should be used spar‐
ingly. Testing for .MAKE.LEVEL being 0, would make sense. Also
note that any variables which originated in the parent environ‐
ment should be explicitly preserved if desired. For example:

.if ${.MAKE.LEVEL} == 0
PATH := ${PATH}
.unexport-env
.export PATH
.endif

Would result in an environment containing only ‘PATH’, which is
the minimal useful environment. Actually ‘.MAKE.LEVEL’ will also
be pushed into the new environment.

.warning message
The message prefixed by ‘warning:’ is printed along with the name
of the makefile and line number.

.if [!]expression [operator expression ...]
Test the value of an expression.

.ifdef [!]variable [operator variable ...]
Test the value of a variable.

.ifndef [!]variable [operator variable ...]
Test the value of a variable.

.ifmake [!]target [operator target ...]
Test the target being built.

.ifnmake [!] target [operator target ...]
Test the target being built.

.else Reverse the sense of the last conditional.

.elif [!] expression [operator expression ...]
A combination of ‘.else’ followed by ‘.if’.

.elifdef [!]variable [operator variable ...]
A combination of ‘.else’ followed by ‘.ifdef’.

.elifndef [!]variable [operator variable ...]
A combination of ‘.else’ followed by ‘.ifndef’.

.elifmake [!]target [operator target ...]
A combination of ‘.else’ followed by ‘.ifmake’.

.elifnmake [!]target [operator target ...]
A combination of ‘.else’ followed by ‘.ifnmake’.

.endif End the body of the conditional.

The operator may be any one of the following:

|| Logical OR.

&& Logical AND; of higher precedence than “||”.

As in C, bmake will only evaluate a conditional as far as is necessary to
determine its value. Parentheses may be used to change the order of
evaluation. The boolean operator ‘!’ may be used to logically negate an
entire conditional. It is of higher precedence than ‘&&’.

The value of expression may be any of the following:

defined Takes a variable name as an argument and evaluates to true if
the variable has been defined.

make Takes a target name as an argument and evaluates to true if the
target was specified as part of bmake's command line or was
declared the default target (either implicitly or explicitly,
see .MAIN) before the line containing the conditional.

empty Takes a variable, with possible modifiers, and evaluates to true
if the expansion of the variable would result in an empty
string.

exists Takes a file name as an argument and evaluates to true if the
file exists. The file is searched for on the system search path
(see .PATH).

target Takes a target name as an argument and evaluates to true if the
target has been defined.

commands
Takes a target name as an argument and evaluates to true if the
target has been defined and has commands associated with it.

Expression may also be an arithmetic or string comparison. Variable
expansion is performed on both sides of the comparison, after which the
integral values are compared. A value is interpreted as hexadecimal if
it is preceded by 0x, otherwise it is decimal; octal numbers are not sup‐
ported. The standard C relational operators are all supported. If after
variable expansion, either the left or right hand side of a ‘==’ or ‘!=’
operator is not an integral value, then string comparison is performed
between the expanded variables. If no relational operator is given, it
is assumed that the expanded variable is being compared against 0 or an
empty string in the case of a string comparison.

When bmake is evaluating one of these conditional expressions, and it
encounters a (white-space separated) word it doesn't recognize, either
the “make” or “defined” expression is applied to it, depending on the
form of the conditional. If the form is ‘.ifdef’, ‘.ifndef’, or ‘.if’
the “defined” expression is applied. Similarly, if the form is ‘.ifmake’
or ‘.ifnmake, the’ “make” expression is applied.

If the conditional evaluates to true the parsing of the makefile contin‐
ues as before. If it evaluates to false, the following lines are
skipped. In both cases this continues until a ‘.else’ or ‘.endif’ is
found.

For loops are typically used to apply a set of rules to a list of files.
The syntax of a for loop is:

.for variable [variable ...] in expression
⟨make-rules⟩
.endfor

After the for expression is evaluated, it is split into words. On each
iteration of the loop, one word is taken and assigned to each variable,
in order, and these variables are substituted into the make-rules inside
the body of the for loop. The number of words must come out even; that
is, if there are three iteration variables, the number of words provided
must be a multiple of three.

COMMENTS
Comments begin with a hash (‘#’) character, anywhere but in a shell com‐
mand line, and continue to the end of an unescaped new line.

SPECIAL SOURCES (ATTRIBUTES)
.EXEC Target is never out of date, but always execute commands any‐
way.

.IGNORE Ignore any errors from the commands associated with this tar‐
get, exactly as if they all were preceded by a dash (‘-’).

.MADE Mark all sources of this target as being up-to-date.

.MAKE Execute the commands associated with this target even if the -n
or -t options were specified. Normally used to mark recursive
bmake's.

.META Create a meta file for the target, even if it is flagged as
.PHONY, .MAKE, or .SPECIAL. Usage in conjunction with .MAKE is
the most likely case.

.NOMETA Do not create a meta file for the target. Meta files are also
not created for .PHONY, .MAKE, or .SPECIAL targets.

.NOMETA_CMP
Ignore differences in commands when deciding if target is out
of date. This is useful if the command contains a value which
always changes. If the number of commands change, though, the
target will still be out of date.

.NOPATH Do not search for the target in the directories specified by
.PATH.

.NOTMAIN Normally bmake selects the first target it encounters as the
default target to be built if no target was specified. This
source prevents this target from being selected.

.OPTIONAL
If a target is marked with this attribute and bmake can't fig‐
ure out how to create it, it will ignore this fact and assume
the file isn't needed or already exists.

.PHONY The target does not correspond to an actual file; it is always
considered to be out of date, and will not be created with the
-t option. Suffix-transformation rules are not applied to
.PHONY targets.

.PRECIOUS
When bmake is interrupted, it normally removes any partially
made targets. This source prevents the target from being
removed.

.RECURSIVE
Synonym for .MAKE.

.SILENT Do not echo any of the commands associated with this target,
exactly as if they all were preceded by an at sign (‘@’).

.USE Turn the target into bmake's version of a macro. When the tar‐
get is used as a source for another target, the other target
acquires the commands, sources, and attributes (except for
.USE) of the source. If the target already has commands, the
.USE target's commands are appended to them.

.USEBEFORE
Exactly like .USE, but prepend the .USEBEFORE target commands
to the target.

.WAIT If .WAIT appears in a dependency line, the sources that precede
it are made before the sources that succeed it in the line.
Since the dependents of files are not made until the file
itself could be made, this also stops the dependents being
built unless they are needed for another branch of the depen‐
dency tree. So given:

x: a .WAIT b
echo x
a:
echo a
b: b1
echo b
b1:
echo b1

the output is always ‘a’, ‘b1’, ‘b’, ‘x’.
The ordering imposed by .WAIT is only relevant for parallel
makes.

SPECIAL TARGETS
Special targets may not be included with other targets, i.e. they must be
the only target specified.

.BEGIN Any command lines attached to this target are executed before
anything else is done.

.DEFAULT
This is sort of a .USE rule for any target (that was used only
as a source) that bmake can't figure out any other way to cre‐
ate. Only the shell script is used. The .IMPSRC variable of a
target that inherits .DEFAULT's commands is set to the target's
own name.

.END Any command lines attached to this target are executed after
everything else is done.

.ERROR Any command lines attached to this target are executed when
another target fails. The .ERROR_TARGET variable is set to the
target that failed. See also MAKE_PRINT_VAR_ON_ERROR.

.IGNORE Mark each of the sources with the .IGNORE attribute. If no
sources are specified, this is the equivalent of specifying the
-i option.

.INTERRUPT
If bmake is interrupted, the commands for this target will be
executed.

.MAIN If no target is specified when bmake is invoked, this target
will be built.

.MAKEFLAGS
This target provides a way to specify flags for bmake when the
makefile is used. The flags are as if typed to the shell,
though the -f option will have no effect.

.NOPATH Apply the .NOPATH attribute to any specified sources.

.NOTPARALLEL
Disable parallel mode.

.NO_PARALLEL
Synonym for .NOTPARALLEL, for compatibility with other pmake
variants.

.ORDER The named targets are made in sequence. This ordering does not
add targets to the list of targets to be made. Since the depen‐
dents of a target do not get built until the target itself could
be built, unless ‘a’ is built by another part of the dependency
graph, the following is a dependency loop:

.ORDER: b a
b: a

The ordering imposed by .ORDER is only relevant for parallel
makes.

.PATH The sources are directories which are to be searched for files
not found in the current directory. If no sources are speci‐
fied, any previously specified directories are deleted. If the
source is the special .DOTLAST target, then the current working
directory is searched last.

.PHONY Apply the .PHONY attribute to any specified sources.

.PRECIOUS
Apply the .PRECIOUS attribute to any specified sources. If no
sources are specified, the .PRECIOUS attribute is applied to
every target in the file.

.SHELL Sets the shell that bmake will use to execute commands. The
sources are a set of field=value pairs.

name This is the minimal specification, used to select
one of the builtin shell specs; sh, ksh, and csh.

path Specifies the path to the shell.

hasErrCtl Indicates whether the shell supports exit on error.

check The command to turn on error checking.

ignore The command to disable error checking.

echo The command to turn on echoing of commands executed.

quiet The command to turn off echoing of commands exe‐
cuted.

filter The output to filter after issuing the quiet com‐
mand. It is typically identical to quiet.

errFlag The flag to pass the shell to enable error checking.

echoFlag The flag to pass the shell to enable command echo‐
ing.

newline The string literal to pass the shell that results in
a single newline character when used outside of any
quoting characters.
Example:

.SHELL: name=ksh path=/bin/ksh hasErrCtl=true \
check="set -e" ignore="set +e" \
echo="set -v" quiet="set +v" filter="set +v" \
echoFlag=v errFlag=e newline="'\n'"

.SILENT Apply the .SILENT attribute to any specified sources. If no
sources are specified, the .SILENT attribute is applied to every
command in the file.

.SUFFIXES
Each source specifies a suffix to bmake. If no sources are
specified, any previously specified suffixes are deleted. It
allows the creation of suffix-transformation rules.

Example:

.SUFFIXES: .o
.c.o:
cc -o ${.TARGET} -c ${.IMPSRC}

ENVIRONMENT
bmake uses the following environment variables, if they exist: MACHINE,
MACHINE_ARCH, MAKE, MAKEFLAGS, MAKEOBJDIR, MAKEOBJDIRPREFIX, MAKESYSPATH,
PWD, and TMPDIR.

MAKEOBJDIRPREFIX and MAKEOBJDIR may only be set in the environment or on
the command line to bmake and not as makefile variables; see the descrip‐
tion of ‘.OBJDIR’ for more details.

FILES
.depend list of dependencies
Makefile list of dependencies
makefile list of dependencies
sys.mk system makefile
/usr/share/mk system makefile directory

COMPATIBILITY
The basic make syntax is compatible between different versions of make,
however the special variables, variable modifiers and conditionals are
not.

The way that parallel makes are scheduled changed in NetBSD 4.0 so that
.ORDER and .WAIT apply recursively to the dependant nodes. The algo‐
rithms used may change again in the future.

The way that .for loop variables are substituted changed after NetBSD 5.0
so that they still appear to be variable expansions. In particular this
stops them being treated as syntax, and removes some obscure problems
using them in .if statements.

Unlike other bmake programs, this implementation by default executes all
commands for a given target using a single shell invocation. This is
done for both efficiency and to simplify error handling in remote command
invocations. Typically this is transparent to the user, unless the tar‐
get commands change the current working directory using “cd” or “chdir”.
To be compatible with Makefiles that do this, one can use -B to disable
this behavior.