scalac man page
Author: Stephane Micheloud

scalac(1)
scalac(1)
USER COMMANDS

### 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-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/`.

### COPYRIGHT

This is open-source software, available to you under a BSD-like license. See accomponying "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)

version 1.0
scalac(1)
March 2012