scalac(1) USER COMMANDS scalac(1)NAMEscalac - Compiler for the Scala 2 language
SYNOPSISscalac [ <options> ] <source files>
PARAMETERS
<options>
Command line options. See OPTIONS below.
<source files>
One or more source files to be compiled (such as MyClass.scala).
DESCRIPTION
The scalac tool reads class and object definitions, written in the
Scala programming language, and compiles them into bytecode class
files.
By default, the compiler puts each class file in the same directory as
its source file. You can specify a separate destination directory with
-d (see OPTIONS, below).
OPTIONS
The compiler has a set of standard options that are supported on the
current development environment and will be supported in future
releases. An additional set of non-standard options are specific to the
current virtual machine implementation and are subject to change in the
future. Non-standard options begin with -X.
Standard Options
-Dproperty=value
Pass -Dproperty=value directly to the runtime system.
-J<flag>
Pass <flag> directly to the runtime system.
-P:<plugin:opt>
Pass an option to a plugin
-X Print a synopsis of advanced options.
-bootclasspath <path>
Override location of bootstrap class files (where to find the
standard built-in classes, such as "scala.List").
-classpath <path>
Specify where to find user class files (on Unix-based systems a
colon-separated list of paths, on Windows-based systems, a semi‐
colon-separate list of paths). This does not override the built-
in ("boot") search path.
The default class path is the current directory. Setting the
CLASSPATH variable or using the -classpath command-line option
overrides that default, so if you want to include the current
directory in the search path, you must include "." in the new
settings.
-d <directory|jar>
Specify where to place generated class files.
-deprecation
Emit warning and location for usages of deprecated APIs.
Available since Scala version 2.2.1
-encoding <encoding>
Specify character encoding used by source files.
The default value is platform-specific (Linux: "UTF8", Windows:
"Cp1252"). Executing the following code in the Scala interpreter
will return the default value on your system:
scala> new java.io.InputStreamReader(System.in).getEncoding
-explaintypes
Explain type errors in more detail.
-extdirs <dirs>
Override location of installed extensions.
-feature
Emit warning and location for usages of features that should be
imported explicitly.
-g:{none,source,line,vars,notailcalls}
"none" generates no debugging info,
"source" generates only the source file attribute,
"line" generates source and line number information,
"vars" generates source, line number and local variable informa‐
tion,
"notailcalls" generates all of the above and will not perform
tail call optimization.
-help Print a synopsis of standard options.
-javabootclasspath <path>
Override Java boot classpath.
-javaextdirs <path>
Override Java extdirs classpath.
-language:<feature>
Enable one or more language features.
-no-specialization
Ignore @specialize annotations.
-nobootcp
Do not use the boot classpath for the Scala jar files.
-nowarn
Generate no warnings
-optimise
Generates faster bytecode by applying optimisations to the pro‐
gram.
-print Print program with all Scala-specific features removed.
-sourcepath <path>
Specify location(s) of source files.
-target:{jvm-1.5,jvm-1.6,jvm-1.7,jvm-1.8}
"jvm-1.5" target JVM 1.5 (deprecated),
"jvm-1.6" target JVM 1.6 (default),
"jvm-1.7" target JVM 1.7,
"jvm-1.8" target JVM 1.8,
-toolcp <path>
Add to the runner classpath.
-unchecked
Enable detailed unchecked (erasure) warnings
Non variable type-arguments in type patterns are unchecked since
they are eliminated by erasure
Available since Scala version 2.3.0
-uniqid
Uniquely tag all identifiers in debugging output.
-usejavacp
Utilize the java.class.path in classpath resolution.
-usemanifestcp
Utilize the manifest in classpath resolution.
-verbose
Output messages about what the compiler is doing
-version
Print product version and exit.
@<file>
A text file containing compiler arguments (options and source
files)
Advanced Options
-Xcheckinit
Wrap field accessors to throw an exception on uninitialized
access.
-Xdev Enable warnings for developers working on the Scala compiler
-Xdisable-assertions
Generate no assertions and assumptions
-Xelide-below <n>
Calls to @elidable methods are omitted if method priority is
lower than argument.
-Xexperimental
Enable experimental extensions
-Xfatal-warnings
Fail the compilation if there are any warnings.
-Xfull-lubs
Retain pre 2.10 behavior of less aggressive truncation of least
upper bounds.
-Xfuture
Turn on future language features.
-Xgenerate-phase-graph <file>
Generate the phase graphs (outputs .dot files) to fileX.dot.
-Xlint Enable recommended additional warnings.
-Xlog-free-terms
Print a message when reification creates a free term.
-Xlog-free-types
Print a message when reification resorts to generating a free
type.
-Xlog-implicit-conversions
Print a message whenever an implicit conversion is inserted.
-Xlog-implicits
Show more detail on why some implicits are not applicable.
-Xlog-reflective-calls
Print a message when a reflective method call is generated.
-Xmacro-settings:<option>
Custom settings for macros.
-Xmain-class <path>
Class for manifest's Main-Class entry (only useful with -d
<jar>).
-Xmax-classfile-name <n>
Maximum filename length for generated classes.
-Xmigration:<version>
Warn about constructs whose behavior may have changed since<ver‐
sion>.
-Xno-forwarders
Do not generate static forwarders in mirror classes.
-Xno-patmat-analysis
Don't perform exhaustivity/unreachability analysis. Also, ignore
@switch annotation.
-Xno-uescape
Disable handling of \u unicode escapes
-Xnojline
Do not use JLine for editing.
-Xplugin:<paths>
Load a plugin from each classpath.
-Xplugin-disable:<plugin>
Disable plugins by name.
-Xplugin-list
Print a synopsis of loaded plugins.
-Xplugin-require:<plugin>
Abort if a named plugin is not loaded.
-Xpluginsdir <path>
Path to search for plugin archives.
-Xprint:<phases>
Print out program after <phases> (see below).
-Xprint-icode[:<phases>]
Log internal icode to *.icode files after<phases> (default:
icode).
-Xprint-pos
Print tree positions, as offsets.
-Xprint-types
Print tree types (debugging option).
-Xprompt
Display a prompt after each error (debugging option).
-Xresident
Compiler stays resident, files to compile are read from standard
input.
-Xscript <object>
Treat the source file as a script and wrap it in a main method.
-Xshow-class <class>
Show internal representation of class.
-Xshow-object <object>
Show internal representation of object.
-Xshow-phases
Print a synopsis of compiler phases.
-Xsource:<version>
Treat compiler input as Scala source for the specified version,
see SI-8126.
-Xsource-reader <classname>
Specify a custom method for reading source files.
-Xstrict-inference
Don't infer known-unsound types.
-Xverify
Verify generic signatures in generated bytecode (asm backend
only).
-Y Print a synopsis of private options.
Compilation Phases
parser parse source into ASTs, perform simple desugaring
namer resolve names, attach symbols to named trees
packageobjects
load package objects
typer the meat and potatoes: type the trees
patmat translate match expressions
superaccessors
add super accessors in traits and nested classes
extmethods
add extension methods for inline classes
pickler
serialize symbol tables
refchecks
reference/override checking, translate nested objects
selectiveanf
ANF pre-transform for @cps (CPS plugin)
selectivecps
@cps-driven transform of selectiveanf assignments (CPS plugin)
uncurry
uncurry, translate function values to anonymous classes
tailcalls
replace tail calls by jumps
specialize
@specialized-driven class and method specialization
explicitouter
this refs to outer pointers, translate patterns
erasure
erase types, add interfaces for traits
posterasure
clean up erased inline classes
lazyvals
allocate bitmaps, translate lazy vals into lazified defs
lambdalift
move nested functions to top level
constructors
move field definitions into constructors
flatten
eliminate inner classes
mixin mixin composition
cleanup
platform-specific cleanups, generate reflective calls
delambdafy
remove lambdas
icode generate portable intermediate code
inliner
optimization: do inlining
inlineHandlers
optimization: inline exception handlers
closelim
optimization: eliminate uncalled closures
constopt
optimization: optimize null and other constants
dce optimization: eliminate dead code
jvm generate JVM bytecode
terminal
the last phase in the compiler chain
all matches all phases
ENVIRONMENT
JAVACMD
Specify the java command to be used for running the Scala code.
Arguments may be specified as part of the environment variable;
spaces, quotation marks, etc., will be passed directly to the
shell for expansion.
JAVA_HOME
Specify JDK/JRE home directory. This directory is used to locate
the java command unless JAVACMD variable set.
JAVA_OPTS
Specify the options to be passed to the java command defined by
JAVACMD.
With Java 1.5 (or newer) one may for example configure the mem‐
ory usage of the JVM as follows: JAVA_OPTS="-Xmx512M -Xms16M
-Xss16M"
With GNU Java one may configure the memory usage of the GIJ as
follows: JAVA_OPTS="--mx512m --ms16m"
EXAMPLES
Compile a Scala program to the current directory
scalac HelloWorld
Compile a Scala program to the destination directory classes
scalac-d classes HelloWorld.scala
Compile a Scala program using a user-defined java command
env JAVACMD=/usr/local/bin/cacao scalac-d classes Hel‐
loWorld.scala
Compile all Scala files found in the source directory src to the desti‐
nation directory classes
scalac-d classes src/*.scala
EXIT STATUSscalac returns a zero exist status if it succeeds to compile the speci‐
fied input files. Non zero is returned in case of failure.
AUTHOR
Written by Martin Odersky and other members of the Scala team.
REPORTING BUGS
Report bugs to https://issues.scala-lang.org/.
COPYRIGHT
This is open-source software, available to you under a BSD-like
license. See accompanying "copyright" or "LICENSE" file for copying
conditions. There is NO warranty; not even for MERCHANTABILITY or FIT‐
NESS FOR A PARTICULAR PURPOSE.
SEE ALSOfsc(1), scala(1), scaladoc(1), scalap(1)version 1.0 March 2012 scalac(1)
