scalac(1)

NAME

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-separated 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 REPL 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 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.

-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 program.

-print
    Print program with all Scala-specific features removed.

-sourcepath <path>
    Specify location(s) of source files.

-target:{jvm-1.8}
    "jvm-1.8" target JVM 1.8 (default)

-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.

-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.

-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-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>).

-Xmigration:<version>
    Warn about constructs whose behavior may have changed since<version>.

-Xno-forwarders
    Do not generate static forwarders in mirror classes.

-Xno-patmat-analysis
    Don't perform exhaustivity/unreachability analysis. Also, ignore @switch annotation.

-Xjline
    The JLine keybindings to use: emacs/vi/off.

-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.

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

-Vprint-pos
    Print tree positions, as offsets.

-Vprint-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 scala/bug#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).

-Xxml:{coalescing}
    Configure XML parsing.

    "coalescing" convert PCData to Text and coalesce sibling nodes (default in 2.11).

-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

fields
    synthesize accessors and fields, including bitmaps for lazy vals

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

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.

    One might for example configure the memory usage of the JVM with: JAVA_OPTS="-Xmx2G -Xss16M"

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 exit 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://github.com/scala/bug/issues.

COPYRIGHT

This is open-source software, available to you under the Apache License 2.0. See accompanying "copyright" or "LICENSE" file for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

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