1scalac(1) USER COMMANDS scalac(1)
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6 scalac - Compiler for the Scala 2 language
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9 scalac [ <options> ] <source files>
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12 <options>
13 Command line options. See OPTIONS below.
14 <source files>
16 One or more source files to be compiled (such as MyClass.scala).
17
19 The scalac tool reads class and object definitions, written in the
20 Scala programming language, and compiles them into bytecode class
21 files.
22 By default, the compiler puts each class file in the same directory as
24 its source file. You can specify a separate destination directory with
25 -d (see OPTIONS, below).
26
28 The compiler has a set of standard options that are supported on the
29 current development environment and will be supported in future
30 releases. An additional set of non-standard options are specific to the
31 current virtual machine implementation and are subject to change in the
32 future. Non-standard options begin with -X.
33 Standard Options
35 -Dproperty=value
36 Pass -Dproperty=value directly to the runtime system.
37 -J<flag>
39 Pass <flag> directly to the runtime system.
40 -P:<plugin:opt>
42 Pass an option to a plugin
43 -X Print a synopsis of advanced options.
45 -bootclasspath <path>
47 Override location of bootstrap class files (where to find the
48 standard built-in classes, such as "scala.List").
49 -classpath <path>
51 Specify where to find user class files (on Unix-based systems a
52 colon-separated list of paths, on Windows-based systems, a semi‐
53 colon-separated list of paths). This does not override the
54 built-in ("boot") search path.
55 The default class path is the current directory. Setting the
57 CLASSPATH variable or using the -classpath command-line option
58 overrides that default, so if you want to include the current
59 directory in the search path, you must include "." in the new
60 settings.
61 -d <directory|jar>
63 Specify where to place generated class files.
64 -deprecation
66 Emit warning and location for usages of deprecated APIs.
67 Available since Scala version 2.2.1
69 -encoding <encoding>
71 Specify character encoding used by source files.
72 The default value is platform-specific (Linux: "UTF8", Windows:
74 "Cp1252"). Executing the following code in the Scala interpreter
75 will return the default value on your system:
76 scala> new java.io.InputStreamReader(System.in).getEncoding
78 -explaintypes
80 Explain type errors in more detail.
81 -extdirs <dirs>
83 Override location of installed extensions.
84 -feature
86 Emit warning and location for usages of features that should be
87 imported explicitly.
88 -g:{none,source,line,vars,notailcalls}
90 "none" generates no debugging info,
91 "source" generates only the source file attribute,
93 "line" generates source and line number information,
95 "vars" generates source, line number and local variable informa‐
97 tion,
98 "notailcalls" generates all of the above and will not perform
100 tail call optimization.
101 -help Print a synopsis of standard options.
103 -javabootclasspath <path>
105 Override Java boot classpath.
106 -javaextdirs <path>
108 Override Java extdirs classpath.
109 -language:<feature>
111 Enable one or more language features.
112 -no-specialization
114 Ignore @specialize annotations.
115 -nobootcp
117 Do not use the boot classpath for the Scala jar files.
118 -nowarn
120 Generate no warnings
121 -optimise
123 Generates faster bytecode by applying optimisations to the pro‐
124 gram.
125 -print Print program with all Scala-specific features removed.
127 -sourcepath <path>
129 Specify location(s) of source files.
130 -target:{jvm-1.8}
132 "jvm-1.8" target JVM 1.8 (default)
133 -toolcp <path>
135 Add to the runner classpath.
136 -unchecked
138 Enable detailed unchecked (erasure) warnings
139 Non variable type-arguments in type patterns are unchecked since
141 they are eliminated by erasure
142 Available since Scala version 2.3.0
144 -uniqid
146 Uniquely tag all identifiers in debugging output.
147 -usejavacp
149 Utilize the java.class.path in classpath resolution.
150 -usemanifestcp
152 Utilize the manifest in classpath resolution.
153 -verbose
155 Output messages about what the compiler is doing
156 -version
158 Print product version and exit.
159 @<file>
161 A text file containing compiler arguments (options and source
162 files)
163 Advanced Options
165 -Xcheckinit
166 Wrap field accessors to throw an exception on uninitialized
167 access.
168 -Xdev Enable warnings for developers working on the Scala compiler
170 -Xdisable-assertions
172 Generate no assertions and assumptions
173 -Xelide-below <n>
175 Calls to @elidable methods are omitted if method priority is
176 lower than argument.
177 -Xexperimental
179 Enable experimental extensions
180 -Xfatal-warnings
182 Fail the compilation if there are any warnings.
183 -Xfull-lubs
185 Retain pre 2.10 behavior of less aggressive truncation of least
186 upper bounds.
187 -Xfuture
189 Turn on future language features.
190 -Xgenerate-phase-graph <file>
192 Generate the phase graphs (outputs .dot files) to fileX.dot.
193 -Xlint Enable recommended additional warnings.
195 -Xlog-free-terms
197 Print a message when reification creates a free term.
198 -Xlog-free-types
200 Print a message when reification resorts to generating a free
201 type.
202 -Xlog-implicit-conversions
204 Print a message whenever an implicit conversion is inserted.
205 -Xlog-implicits
207 Show more detail on why some implicits are not applicable.
208 -Xlog-reflective-calls
210 Print a message when a reflective method call is generated.
211 -Xmacro-settings:<option>
213 Custom settings for macros.
214 -Xmain-class <path>
216 Class for manifest's Main-Class entry (only useful with -d
217 <jar>).
218 -Xmax-classfile-name <n>
220 Maximum filename length for generated classes.
221 -Xmigration:<version>
223 Warn about constructs whose behavior may have changed since<ver‐
224 sion>.
225 -Xno-forwarders
227 Do not generate static forwarders in mirror classes.
228 -Xno-patmat-analysis
230 Don't perform exhaustivity/unreachability analysis. Also, ignore
231 @switch annotation.
232 -Xno-uescape
234 Disable handling of \u unicode escapes
235 -Xnojline
237 Do not use JLine for editing.
238 -Xplugin:<paths>
240 Load a plugin from each classpath.
241 -Xplugin-disable:<plugin>
243 Disable plugins by name.
244 -Xplugin-list
246 Print a synopsis of loaded plugins.
247 -Xplugin-require:<plugin>
249 Abort if a named plugin is not loaded.
250 -Xpluginsdir <path>
252 Path to search for plugin archives.
253 -Xprint:<phases>
255 Print out program after <phases> (see below).
256 -Xprint-icode[:<phases>]
258 Log internal icode to *.icode files after<phases> (default:
259 icode).
260 -Xprint-pos
262 Print tree positions, as offsets.
263 -Xprint-types
265 Print tree types (debugging option).
266 -Xprompt
268 Display a prompt after each error (debugging option).
269 -Xresident
271 Compiler stays resident, files to compile are read from standard
272 input.
273 -Xscript <object>
275 Treat the source file as a script and wrap it in a main method.
276 -Xshow-class <class>
278 Show internal representation of class.
279 -Xshow-object <object>
281 Show internal representation of object.
282 -Xshow-phases
284 Print a synopsis of compiler phases.
285 -Xsource:<version>
287 Treat compiler input as Scala source for the specified version,
288 see scala/bug#8126.
289 -Xsource-reader <classname>
291 Specify a custom method for reading source files.
292 -Xstrict-inference
294 Don't infer known-unsound types.
295 -Xverify
297 Verify generic signatures in generated bytecode (asm backend
298 only).
299 -Xxml:{coalescing}
301 Configure XML parsing.
302 "coalescing" convert PCData to Text and coalesce sibling nodes
304 (default in 2.11).
305 -Y Print a synopsis of private options.
307 Compilation Phases
309 parser parse source into ASTs, perform simple desugaring
310 namer resolve names, attach symbols to named trees
312 packageobjects
314 load package objects
315 typer the meat and potatoes: type the trees
317 patmat translate match expressions
319 superaccessors
321 add super accessors in traits and nested classes
322 extmethods
324 add extension methods for inline classes
325 pickler
327 serialize symbol tables
328 refchecks
330 reference/override checking, translate nested objects
331 selectiveanf
333 ANF pre-transform for @cps (CPS plugin)
334 selectivecps
336 @cps-driven transform of selectiveanf assignments (CPS plugin)
337 uncurry
339 uncurry, translate function values to anonymous classes
340 tailcalls
342 replace tail calls by jumps
343 specialize
345 @specialized-driven class and method specialization
346 explicitouter
348 this refs to outer pointers, translate patterns
349 erasure
351 erase types, add interfaces for traits
352 posterasure
354 clean up erased inline classes
355 fields synthesize accessors and fields, including bitmaps for lazy vals
357 lambdalift
359 move nested functions to top level
360 constructors
362 move field definitions into constructors
363 flatten
365 eliminate inner classes
366 mixin mixin composition
368 cleanup
370 platform-specific cleanups, generate reflective calls
371 delambdafy
373 remove lambdas
374 icode generate portable intermediate code
376 inliner
378 optimization: do inlining
379 inlineHandlers
381 optimization: inline exception handlers
382 closelim
384 optimization: eliminate uncalled closures
385 constopt
387 optimization: optimize null and other constants
388 dce optimization: eliminate dead code
390 jvm generate JVM bytecode
392 terminal
394 the last phase in the compiler chain
395 all matches all phases
397
399 JAVACMD
400 Specify the java command to be used for running the Scala code.
401 Arguments may be specified as part of the environment variable;
402 spaces, quotation marks, etc., will be passed directly to the
403 shell for expansion.
404 JAVA_HOME
406 Specify JDK/JRE home directory. This directory is used to locate
407 the java command unless JAVACMD variable set.
408 JAVA_OPTS
410 Specify the options to be passed to the java command defined by
411 JAVACMD.
412 With Java 1.5 (or newer) one may for example configure the mem‐
414 ory usage of the JVM as follows: JAVA_OPTS="-Xmx512M -Xms16M
415 -Xss16M"
416
418 Compile a Scala program to the current directory
419 scalac HelloWorld
420 Compile a Scala program to the destination directory classes
422 scalac -d classes HelloWorld.scala
423 Compile a Scala program using a user-defined java command
425 env JAVACMD=/usr/local/bin/cacao scalac -d classes Hel‐
426 loWorld.scala
427 Compile all Scala files found in the source directory src to the desti‐
429 nation directory classes
430 scalac -d classes src/*.scala
431
433 scalac returns a zero exit status if it succeeds to compile the speci‐
434 fied input files. Non zero is returned in case of failure.
435
437 Written by Martin Odersky and other members of the Scala team.
438
440 Report bugs to https://github.com/scala/bug/issues.
441
443 This is open-source software, available to you under the Apache License
444 2.0. See accompanying "copyright" or "LICENSE" file for copying condi‐
445 tions. There is NO warranty; not even for MERCHANTABILITY or FITNESS
446 FOR A PARTICULAR PURPOSE.
447
449 fsc(1), scala(1), scaladoc(1), scalap(1)
450version 1.0 March 2012 scalac(1)