scalac man page

scalac — Compiler for the Scala 2 language

Synopsis

scalac  [ <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 semicolon-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.

-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 information,

"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.

-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 program.

-print

Print program with all Scala-specific features removed.

-sourcepath <path>

Specify location(s) of source files.

-target:<target>

Specify which backend to use (jvm-1.5,msil).

The default value is "jvm-1.5" (was "jvm-1.4" up to Scala version 2.6.1).

-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.

-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

-Xassem-extdirs <dirs>

(Requires -target:msil) List of directories containing assemblies.  default:lib.

-Xassem-name <file>

(Requires -target:msil) Name of the output assembly.

-Xassem-path <path>

(Requires -target:msil) List of assemblies referenced by the program.

-Xcheck-null

Warn upon selection of nullable reference

-Xcheckinit

Wrap field accessors to throw an exception on uninitialized access.

-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.

-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-implicits

Show more detail on why some implicits are not applicable.

-Xmax-classfile-name <n>

Maximum filename length for generated classes.

-Xmigration

Warn about constructs whose behavior may have changed between 2.7 and 2.8.

-Xno-forwarders

Do not generate static forwarders in mirror classes.

-Xno-uescape

Disable handling of \u unicode escapes

-Xnojline

Do not use JLine for editing.

-Xplugin:<file>

Load a plugin from a file

-Xplugin-disable:<plugin>

Disable a plugin

-Xplugin-list

Print a synopsis of loaded plugins

-Xplugin-require:<plugin>

Abort unless the given plugin(s) are available

-Xpluginsdir <path>

Path to search compiler plugins.

-Xprint:<phases>

Print out program after <phases> (see below).

-Xprint-icode

Log internal icode to *.icode files.

-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-reader <classname>

Specify a custom method for reading source files.

-Xsourcedir <path>

(Requires -target:msil) Mirror source folder structure in output directory..

-Xverify

Verify generic signatures in generated bytecode.

-Y

Print a synopsis of private options.

Compilation Phases

initial

initializing compiler

parse

parse source files

namer

create symbols

analyze

name and type analysis

refcheck

reference checking

uncurry

uncurry function types and applications

lambdalift

lambda lifter

typesasvalues

represent types as values

addaccessors

add accessors for constructor arguments

explicitouterclasses

make links from inner classes to enclosing one explicit

addconstructors

add explicit constructor for each class

tailcall

add tail-calls

wholeprog

perform whole program analysis

addinterfaces

add one interface per class

expandmixins

expand mixins by code copying

boxing

makes boxing explicit

erasure

type eraser

icode

generate icode

codegen

enable code generation

terminal

compilation terminated

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 memory 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 HelloWorld.scala

Compile all Scala files found in the source directory src to the destination directory classes

scalac -d classes src/*.scala

Exit Status

scalac returns a zero exist status if it succeeds to compile the specified 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/.

See Also

fsc(1), scala(1), scaladoc(1), scalap(1)

Referenced By

fsc(1), scala(1), scaladoc(1), scalap(1).

March 2012 version 1.0 USER COMMANDS