xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/doc/sourcebuild.texi (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1@c Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
2@c Free Software Foundation, Inc.
3@c This is part of the GCC manual.
4@c For copying conditions, see the file gcc.texi.
5
6@node Source Tree
7@chapter Source Tree Structure and Build System
8
9This chapter describes the structure of the GCC source tree, and how
10GCC is built.  The user documentation for building and installing GCC
11is in a separate manual (@uref{http://gcc.gnu.org/install/}), with
12which it is presumed that you are familiar.
13
14@menu
15* Configure Terms:: Configuration terminology and history.
16* Top Level::       The top level source directory.
17* gcc Directory::   The @file{gcc} subdirectory.
18@end menu
19
20@include configterms.texi
21
22@node Top Level
23@section Top Level Source Directory
24
25The top level source directory in a GCC distribution contains several
26files and directories that are shared with other software
27distributions such as that of GNU Binutils.  It also contains several
28subdirectories that contain parts of GCC and its runtime libraries:
29
30@table @file
31@item boehm-gc
32The Boehm conservative garbage collector, used as part of the Java
33runtime library.
34
35@item config
36Autoconf macros and Makefile fragments used throughout the tree.
37
38@item contrib
39Contributed scripts that may be found useful in conjunction with GCC@.
40One of these, @file{contrib/texi2pod.pl}, is used to generate man
41pages from Texinfo manuals as part of the GCC build process.
42
43@item fixincludes
44The support for fixing system headers to work with GCC@.  See
45@file{fixincludes/README} for more information.  The headers fixed by
46this mechanism are installed in @file{@var{libsubdir}/include-fixed}.
47Along with those headers, @file{README-fixinc} is also installed, as
48@file{@var{libsubdir}/include-fixed/README}.
49
50@item gcc
51The main sources of GCC itself (except for runtime libraries),
52including optimizers, support for different target architectures,
53language front ends, and testsuites.  @xref{gcc Directory, , The
54@file{gcc} Subdirectory}, for details.
55
56@item gnattools
57Support tools for GNAT.
58
59@item include
60Headers for the @code{libiberty} library.
61
62@item intl
63GNU @code{libintl}, from GNU @code{gettext}, for systems which do not
64include it in @code{libc}.
65
66@item libada
67The Ada runtime library.
68
69@item libcpp
70The C preprocessor library.
71
72@item libdecnumber
73The Decimal Float support library.
74
75@item libffi
76The @code{libffi} library, used as part of the Java runtime library.
77
78@item libgcc
79The GCC runtime library.
80
81@item libgfortran
82The Fortran runtime library.
83
84@item libgomp
85The GNU OpenMP runtime library.
86
87@item libiberty
88The @code{libiberty} library, used for portability and for some
89generally useful data structures and algorithms.  @xref{Top, ,
90Introduction, libiberty, @sc{gnu} libiberty}, for more information
91about this library.
92
93@item libjava
94The Java runtime library.
95
96@item libmudflap
97The @code{libmudflap} library, used for instrumenting pointer and array
98dereferencing operations.
99
100@item libobjc
101The Objective-C and Objective-C++ runtime library.
102
103@item libssp
104The Stack protector runtime library.
105
106@item libstdc++-v3
107The C++ runtime library.
108
109@item lto-plugin
110Plugin used by @command{gold} if link-time optimizations are enabled.
111
112@item maintainer-scripts
113Scripts used by the @code{gccadmin} account on @code{gcc.gnu.org}.
114
115@item zlib
116The @code{zlib} compression library, used by the Java front end, as
117part of the Java runtime library, and for compressing and uncompressing
118GCC's intermediate language in LTO object files.
119@end table
120
121The build system in the top level directory, including how recursion
122into subdirectories works and how building runtime libraries for
123multilibs is handled, is documented in a separate manual, included
124with GNU Binutils.  @xref{Top, , GNU configure and build system,
125configure, The GNU configure and build system}, for details.
126
127@node gcc Directory
128@section The @file{gcc} Subdirectory
129
130The @file{gcc} directory contains many files that are part of the C
131sources of GCC, other files used as part of the configuration and
132build process, and subdirectories including documentation and a
133testsuite.  The files that are sources of GCC are documented in a
134separate chapter.  @xref{Passes, , Passes and Files of the Compiler}.
135
136@menu
137* Subdirectories:: Subdirectories of @file{gcc}.
138* Configuration::  The configuration process, and the files it uses.
139* Build::          The build system in the @file{gcc} directory.
140* Makefile::       Targets in @file{gcc/Makefile}.
141* Library Files::  Library source files and headers under @file{gcc/}.
142* Headers::        Headers installed by GCC.
143* Documentation::  Building documentation in GCC.
144* Front End::      Anatomy of a language front end.
145* Back End::       Anatomy of a target back end.
146@end menu
147
148@node Subdirectories
149@subsection Subdirectories of @file{gcc}
150
151The @file{gcc} directory contains the following subdirectories:
152
153@table @file
154@item @var{language}
155Subdirectories for various languages.  Directories containing a file
156@file{config-lang.in} are language subdirectories.  The contents of
157the subdirectories @file{cp} (for C++), @file{lto} (for LTO),
158@file{objc} (for Objective-C) and @file{objcp} (for Objective-C++) are
159documented in this manual (@pxref{Passes, , Passes and Files of the
160Compiler}); those for other languages are not.  @xref{Front End, ,
161Anatomy of a Language Front End}, for details of the files in these
162directories.
163
164@item config
165Configuration files for supported architectures and operating
166systems.  @xref{Back End, , Anatomy of a Target Back End}, for
167details of the files in this directory.
168
169@item doc
170Texinfo documentation for GCC, together with automatically generated
171man pages and support for converting the installation manual to
172HTML@.  @xref{Documentation}.
173
174@item ginclude
175System headers installed by GCC, mainly those required by the C
176standard of freestanding implementations.  @xref{Headers, , Headers
177Installed by GCC}, for details of when these and other headers are
178installed.
179
180@item po
181Message catalogs with translations of messages produced by GCC into
182various languages, @file{@var{language}.po}.  This directory also
183contains @file{gcc.pot}, the template for these message catalogues,
184@file{exgettext}, a wrapper around @command{gettext} to extract the
185messages from the GCC sources and create @file{gcc.pot}, which is run
186by @samp{make gcc.pot}, and @file{EXCLUDES}, a list of files from
187which messages should not be extracted.
188
189@item testsuite
190The GCC testsuites (except for those for runtime libraries).
191@xref{Testsuites}.
192@end table
193
194@node Configuration
195@subsection Configuration in the @file{gcc} Directory
196
197The @file{gcc} directory is configured with an Autoconf-generated
198script @file{configure}.  The @file{configure} script is generated
199from @file{configure.ac} and @file{aclocal.m4}.  From the files
200@file{configure.ac} and @file{acconfig.h}, Autoheader generates the
201file @file{config.in}.  The file @file{cstamp-h.in} is used as a
202timestamp.
203
204@menu
205* Config Fragments::     Scripts used by @file{configure}.
206* System Config::        The @file{config.build}, @file{config.host}, and
207                         @file{config.gcc} files.
208* Configuration Files::  Files created by running @file{configure}.
209@end menu
210
211@node Config Fragments
212@subsubsection Scripts Used by @file{configure}
213
214@file{configure} uses some other scripts to help in its work:
215
216@itemize @bullet
217@item The standard GNU @file{config.sub} and @file{config.guess}
218files, kept in the top level directory, are used.
219
220@item The file @file{config.gcc} is used to handle configuration
221specific to the particular target machine.  The file
222@file{config.build} is used to handle configuration specific to the
223particular build machine.  The file @file{config.host} is used to handle
224configuration specific to the particular host machine.  (In general,
225these should only be used for features that cannot reasonably be tested in
226Autoconf feature tests.)
227@xref{System Config, , The @file{config.build}; @file{config.host};
228and @file{config.gcc} Files}, for details of the contents of these files.
229
230@item Each language subdirectory has a file
231@file{@var{language}/config-lang.in} that is used for
232front-end-specific configuration.  @xref{Front End Config, , The Front
233End @file{config-lang.in} File}, for details of this file.
234
235@item A helper script @file{configure.frag} is used as part of
236creating the output of @file{configure}.
237@end itemize
238
239@node System Config
240@subsubsection The @file{config.build}; @file{config.host}; and @file{config.gcc} Files
241
242The @file{config.build} file contains specific rules for particular systems
243which GCC is built on.  This should be used as rarely as possible, as the
244behavior of the build system can always be detected by autoconf.
245
246The @file{config.host} file contains specific rules for particular systems
247which GCC will run on.  This is rarely needed.
248
249The @file{config.gcc} file contains specific rules for particular systems
250which GCC will generate code for.  This is usually needed.
251
252Each file has a list of the shell variables it sets, with descriptions, at the
253top of the file.
254
255FIXME: document the contents of these files, and what variables should
256be set to control build, host and target configuration.
257
258@include configfiles.texi
259
260@node Build
261@subsection Build System in the @file{gcc} Directory
262
263FIXME: describe the build system, including what is built in what
264stages.  Also list the various source files that are used in the build
265process but aren't source files of GCC itself and so aren't documented
266below (@pxref{Passes}).
267
268@include makefile.texi
269
270@node Library Files
271@subsection Library Source Files and Headers under the @file{gcc} Directory
272
273FIXME: list here, with explanation, all the C source files and headers
274under the @file{gcc} directory that aren't built into the GCC
275executable but rather are part of runtime libraries and object files,
276such as @file{crtstuff.c} and @file{unwind-dw2.c}.  @xref{Headers, ,
277Headers Installed by GCC}, for more information about the
278@file{ginclude} directory.
279
280@node Headers
281@subsection Headers Installed by GCC
282
283In general, GCC expects the system C library to provide most of the
284headers to be used with it.  However, GCC will fix those headers if
285necessary to make them work with GCC, and will install some headers
286required of freestanding implementations.  These headers are installed
287in @file{@var{libsubdir}/include}.  Headers for non-C runtime
288libraries are also installed by GCC; these are not documented here.
289(FIXME: document them somewhere.)
290
291Several of the headers GCC installs are in the @file{ginclude}
292directory.  These headers, @file{iso646.h},
293@file{stdarg.h}, @file{stdbool.h}, and @file{stddef.h},
294are installed in @file{@var{libsubdir}/include},
295unless the target Makefile fragment (@pxref{Target Fragment})
296overrides this by setting @code{USER_H}.
297
298In addition to these headers and those generated by fixing system
299headers to work with GCC, some other headers may also be installed in
300@file{@var{libsubdir}/include}.  @file{config.gcc} may set
301@code{extra_headers}; this specifies additional headers under
302@file{config} to be installed on some systems.
303
304GCC installs its own version of @code{<float.h>}, from @file{ginclude/float.h}.
305This is done to cope with command-line options that change the
306representation of floating point numbers.
307
308GCC also installs its own version of @code{<limits.h>}; this is generated
309from @file{glimits.h}, together with @file{limitx.h} and
310@file{limity.h} if the system also has its own version of
311@code{<limits.h>}.  (GCC provides its own header because it is
312required of ISO C freestanding implementations, but needs to include
313the system header from its own header as well because other standards
314such as POSIX specify additional values to be defined in
315@code{<limits.h>}.)  The system's @code{<limits.h>} header is used via
316@file{@var{libsubdir}/include/syslimits.h}, which is copied from
317@file{gsyslimits.h} if it does not need fixing to work with GCC; if it
318needs fixing, @file{syslimits.h} is the fixed copy.
319
320GCC can also install @code{<tgmath.h>}.  It will do this when
321@file{config.gcc} sets @code{use_gcc_tgmath} to @code{yes}.
322
323@node Documentation
324@subsection Building Documentation
325
326The main GCC documentation is in the form of manuals in Texinfo
327format.  These are installed in Info format; DVI versions may be
328generated by @samp{make dvi}, PDF versions by @samp{make pdf}, and
329HTML versions by @samp{make html}.  In addition, some man pages are
330generated from the Texinfo manuals, there are some other text files
331with miscellaneous documentation, and runtime libraries have their own
332documentation outside the @file{gcc} directory.  FIXME: document the
333documentation for runtime libraries somewhere.
334
335@menu
336* Texinfo Manuals::      GCC manuals in Texinfo format.
337* Man Page Generation::  Generating man pages from Texinfo manuals.
338* Miscellaneous Docs::   Miscellaneous text files with documentation.
339@end menu
340
341@node Texinfo Manuals
342@subsubsection Texinfo Manuals
343
344The manuals for GCC as a whole, and the C and C++ front ends, are in
345files @file{doc/*.texi}.  Other front ends have their own manuals in
346files @file{@var{language}/*.texi}.  Common files
347@file{doc/include/*.texi} are provided which may be included in
348multiple manuals; the following files are in @file{doc/include}:
349
350@table @file
351@item fdl.texi
352The GNU Free Documentation License.
353@item funding.texi
354The section ``Funding Free Software''.
355@item gcc-common.texi
356Common definitions for manuals.
357@item gpl.texi
358@itemx gpl_v3.texi
359The GNU General Public License.
360@item texinfo.tex
361A copy of @file{texinfo.tex} known to work with the GCC manuals.
362@end table
363
364DVI-formatted manuals are generated by @samp{make dvi}, which uses
365@command{texi2dvi} (via the Makefile macro @code{$(TEXI2DVI)}).
366PDF-formatted manuals are generated by @samp{make pdf}, which uses
367@command{texi2pdf} (via the Makefile macro @code{$(TEXI2PDF)}).  HTML
368formatted manuals are generated by @samp{make html}.  Info
369manuals are generated by @samp{make info} (which is run as part of
370a bootstrap); this generates the manuals in the source directory,
371using @command{makeinfo} via the Makefile macro @code{$(MAKEINFO)},
372and they are included in release distributions.
373
374Manuals are also provided on the GCC web site, in both HTML and
375PostScript forms.  This is done via the script
376@file{maintainer-scripts/update_web_docs}.  Each manual to be
377provided online must be listed in the definition of @code{MANUALS} in
378that file; a file @file{@var{name}.texi} must only appear once in the
379source tree, and the output manual must have the same name as the
380source file.  (However, other Texinfo files, included in manuals but
381not themselves the root files of manuals, may have names that appear
382more than once in the source tree.)  The manual file
383@file{@var{name}.texi} should only include other files in its own
384directory or in @file{doc/include}.  HTML manuals will be generated by
385@samp{makeinfo --html}, PostScript manuals by @command{texi2dvi}
386and @command{dvips}, and PDF manuals by @command{texi2pdf}.
387All Texinfo files that are parts of manuals must
388be version-controlled, even if they are generated files, for the
389generation of online manuals to work.
390
391The installation manual, @file{doc/install.texi}, is also provided on
392the GCC web site.  The HTML version is generated by the script
393@file{doc/install.texi2html}.
394
395@node Man Page Generation
396@subsubsection Man Page Generation
397
398Because of user demand, in addition to full Texinfo manuals, man pages
399are provided which contain extracts from those manuals.  These man
400pages are generated from the Texinfo manuals using
401@file{contrib/texi2pod.pl} and @command{pod2man}.  (The man page for
402@command{g++}, @file{cp/g++.1}, just contains a @samp{.so} reference
403to @file{gcc.1}, but all the other man pages are generated from
404Texinfo manuals.)
405
406Because many systems may not have the necessary tools installed to
407generate the man pages, they are only generated if the
408@file{configure} script detects that recent enough tools are
409installed, and the Makefiles allow generating man pages to fail
410without aborting the build.  Man pages are also included in release
411distributions.  They are generated in the source directory.
412
413Magic comments in Texinfo files starting @samp{@@c man} control what
414parts of a Texinfo file go into a man page.  Only a subset of Texinfo
415is supported by @file{texi2pod.pl}, and it may be necessary to add
416support for more Texinfo features to this script when generating new
417man pages.  To improve the man page output, some special Texinfo
418macros are provided in @file{doc/include/gcc-common.texi} which
419@file{texi2pod.pl} understands:
420
421@table @code
422@item @@gcctabopt
423Use in the form @samp{@@table @@gcctabopt} for tables of options,
424where for printed output the effect of @samp{@@code} is better than
425that of @samp{@@option} but for man page output a different effect is
426wanted.
427@item @@gccoptlist
428Use for summary lists of options in manuals.
429@item @@gol
430Use at the end of each line inside @samp{@@gccoptlist}.  This is
431necessary to avoid problems with differences in how the
432@samp{@@gccoptlist} macro is handled by different Texinfo formatters.
433@end table
434
435FIXME: describe the @file{texi2pod.pl} input language and magic
436comments in more detail.
437
438@node Miscellaneous Docs
439@subsubsection Miscellaneous Documentation
440
441In addition to the formal documentation that is installed by GCC,
442there are several other text files in the @file{gcc} subdirectory
443with miscellaneous documentation:
444
445@table @file
446@item ABOUT-GCC-NLS
447Notes on GCC's Native Language Support.  FIXME: this should be part of
448this manual rather than a separate file.
449@item ABOUT-NLS
450Notes on the Free Translation Project.
451@item COPYING
452@itemx COPYING3
453The GNU General Public License, Versions 2 and 3.
454@item COPYING.LIB
455@itemx COPYING3.LIB
456The GNU Lesser General Public License, Versions 2.1 and 3.
457@item *ChangeLog*
458@itemx */ChangeLog*
459Change log files for various parts of GCC@.
460@item LANGUAGES
461Details of a few changes to the GCC front-end interface.  FIXME: the
462information in this file should be part of general documentation of
463the front-end interface in this manual.
464@item ONEWS
465Information about new features in old versions of GCC@.  (For recent
466versions, the information is on the GCC web site.)
467@item README.Portability
468Information about portability issues when writing code in GCC@.  FIXME:
469why isn't this part of this manual or of the GCC Coding Conventions?
470@end table
471
472FIXME: document such files in subdirectories, at least @file{config},
473@file{cp}, @file{objc}, @file{testsuite}.
474
475@node Front End
476@subsection Anatomy of a Language Front End
477
478A front end for a language in GCC has the following parts:
479
480@itemize @bullet
481@item
482A directory @file{@var{language}} under @file{gcc} containing source
483files for that front end.  @xref{Front End Directory, , The Front End
484@file{@var{language}} Directory}, for details.
485@item
486A mention of the language in the list of supported languages in
487@file{gcc/doc/install.texi}.
488@item
489A mention of the name under which the language's runtime library is
490recognized by @option{--enable-shared=@var{package}} in the
491documentation of that option in @file{gcc/doc/install.texi}.
492@item
493A mention of any special prerequisites for building the front end in
494the documentation of prerequisites in @file{gcc/doc/install.texi}.
495@item
496Details of contributors to that front end in
497@file{gcc/doc/contrib.texi}.  If the details are in that front end's
498own manual then there should be a link to that manual's list in
499@file{contrib.texi}.
500@item
501Information about support for that language in
502@file{gcc/doc/frontends.texi}.
503@item
504Information about standards for that language, and the front end's
505support for them, in @file{gcc/doc/standards.texi}.  This may be a
506link to such information in the front end's own manual.
507@item
508Details of source file suffixes for that language and @option{-x
509@var{lang}} options supported, in @file{gcc/doc/invoke.texi}.
510@item
511Entries in @code{default_compilers} in @file{gcc.c} for source file
512suffixes for that language.
513@item
514Preferably testsuites, which may be under @file{gcc/testsuite} or
515runtime library directories.  FIXME: document somewhere how to write
516testsuite harnesses.
517@item
518Probably a runtime library for the language, outside the @file{gcc}
519directory.  FIXME: document this further.
520@item
521Details of the directories of any runtime libraries in
522@file{gcc/doc/sourcebuild.texi}.
523@item
524Check targets in @file{Makefile.def} for the top-level @file{Makefile}
525to check just the compiler or the compiler and runtime library for the
526language.
527@end itemize
528
529If the front end is added to the official GCC source repository, the
530following are also necessary:
531
532@itemize @bullet
533@item
534At least one Bugzilla component for bugs in that front end and runtime
535libraries.  This category needs to be mentioned in
536@file{gcc/gccbug.in}, as well as being added to the Bugzilla database.
537@item
538Normally, one or more maintainers of that front end listed in
539@file{MAINTAINERS}.
540@item
541Mentions on the GCC web site in @file{index.html} and
542@file{frontends.html}, with any relevant links on
543@file{readings.html}.  (Front ends that are not an official part of
544GCC may also be listed on @file{frontends.html}, with relevant links.)
545@item
546A news item on @file{index.html}, and possibly an announcement on the
547@email{gcc-announce@@gcc.gnu.org} mailing list.
548@item
549The front end's manuals should be mentioned in
550@file{maintainer-scripts/update_web_docs} (@pxref{Texinfo Manuals})
551and the online manuals should be linked to from
552@file{onlinedocs/index.html}.
553@item
554Any old releases or CVS repositories of the front end, before its
555inclusion in GCC, should be made available on the GCC FTP site
556@uref{ftp://gcc.gnu.org/pub/gcc/old-releases/}.
557@item
558The release and snapshot script @file{maintainer-scripts/gcc_release}
559should be updated to generate appropriate tarballs for this front end.
560The associated @file{maintainer-scripts/snapshot-README} and
561@file{maintainer-scripts/snapshot-index.html} files should be updated
562to list the tarballs and diffs for this front end.
563@item
564If this front end includes its own version files that include the
565current date, @file{maintainer-scripts/update_version} should be
566updated accordingly.
567@end itemize
568
569@menu
570* Front End Directory::  The front end @file{@var{language}} directory.
571* Front End Config::     The front end @file{config-lang.in} file.
572* Front End Makefile::   The front end @file{Make-lang.in} file.
573@end menu
574
575@node Front End Directory
576@subsubsection The Front End @file{@var{language}} Directory
577
578A front end @file{@var{language}} directory contains the source files
579of that front end (but not of any runtime libraries, which should be
580outside the @file{gcc} directory).  This includes documentation, and
581possibly some subsidiary programs built alongside the front end.
582Certain files are special and other parts of the compiler depend on
583their names:
584
585@table @file
586@item config-lang.in
587This file is required in all language subdirectories.  @xref{Front End
588Config, , The Front End @file{config-lang.in} File}, for details of
589its contents
590@item Make-lang.in
591This file is required in all language subdirectories.  @xref{Front End
592Makefile, , The Front End @file{Make-lang.in} File}, for details of its
593contents.
594@item lang.opt
595This file registers the set of switches that the front end accepts on
596the command line, and their @option{--help} text.  @xref{Options}.
597@item lang-specs.h
598This file provides entries for @code{default_compilers} in
599@file{gcc.c} which override the default of giving an error that a
600compiler for that language is not installed.
601@item @var{language}-tree.def
602This file, which need not exist, defines any language-specific tree
603codes.
604@end table
605
606@node Front End Config
607@subsubsection The Front End @file{config-lang.in} File
608
609Each language subdirectory contains a @file{config-lang.in} file.  In
610addition the main directory contains @file{c-config-lang.in}, which
611contains limited information for the C language.  This file is a shell
612script that may define some variables describing the language:
613
614@table @code
615@item language
616This definition must be present, and gives the name of the language
617for some purposes such as arguments to @option{--enable-languages}.
618@item lang_requires
619If defined, this variable lists (space-separated) language front ends
620other than C that this front end requires to be enabled (with the
621names given being their @code{language} settings).  For example, the
622Java front end depends on the C++ front end, so sets
623@samp{lang_requires=c++}.
624@item subdir_requires
625If defined, this variable lists (space-separated) front end directories
626other than C that this front end requires to be present.  For example,
627the Objective-C++ front end uses source files from the C++ and
628Objective-C front ends, so sets @samp{subdir_requires="cp objc"}.
629@item target_libs
630If defined, this variable lists (space-separated) targets in the top
631level @file{Makefile} to build the runtime libraries for this
632language, such as @code{target-libobjc}.
633@item lang_dirs
634If defined, this variable lists (space-separated) top level
635directories (parallel to @file{gcc}), apart from the runtime libraries,
636that should not be configured if this front end is not built.
637@item build_by_default
638If defined to @samp{no}, this language front end is not built unless
639enabled in a @option{--enable-languages} argument.  Otherwise, front
640ends are built by default, subject to any special logic in
641@file{configure.ac} (as is present to disable the Ada front end if the
642Ada compiler is not already installed).
643@item boot_language
644If defined to @samp{yes}, this front end is built in stage1 of the
645bootstrap.  This is only relevant to front ends written in their own
646languages.
647@item compilers
648If defined, a space-separated list of compiler executables that will
649be run by the driver.  The names here will each end
650with @samp{\$(exeext)}.
651@item outputs
652If defined, a space-separated list of files that should be generated
653by @file{configure} substituting values in them.  This mechanism can
654be used to create a file @file{@var{language}/Makefile} from
655@file{@var{language}/Makefile.in}, but this is deprecated, building
656everything from the single @file{gcc/Makefile} is preferred.
657@item gtfiles
658If defined, a space-separated list of files that should be scanned by
659@file{gengtype.c} to generate the garbage collection tables and routines for
660this language.  This excludes the files that are common to all front
661ends.  @xref{Type Information}.
662
663@end table
664
665@node Front End Makefile
666@subsubsection The Front End @file{Make-lang.in} File
667
668Each language subdirectory contains a @file{Make-lang.in} file.  It contains
669targets @code{@var{lang}.@var{hook}} (where @code{@var{lang}} is the
670setting of @code{language} in @file{config-lang.in}) for the following
671values of @code{@var{hook}}, and any other Makefile rules required to
672build those targets (which may if necessary use other Makefiles
673specified in @code{outputs} in @file{config-lang.in}, although this is
674deprecated).  It also adds any testsuite targets that can use the
675standard rule in @file{gcc/Makefile.in} to the variable
676@code{lang_checks}.
677
678@table @code
679@itemx all.cross
680@itemx start.encap
681@itemx rest.encap
682FIXME: exactly what goes in each of these targets?
683@item tags
684Build an @command{etags} @file{TAGS} file in the language subdirectory
685in the source tree.
686@item info
687Build info documentation for the front end, in the build directory.
688This target is only called by @samp{make bootstrap} if a suitable
689version of @command{makeinfo} is available, so does not need to check
690for this, and should fail if an error occurs.
691@item dvi
692Build DVI documentation for the front end, in the build directory.
693This should be done using @code{$(TEXI2DVI)}, with appropriate
694@option{-I} arguments pointing to directories of included files.
695@item pdf
696Build PDF documentation for the front end, in the build directory.
697This should be done using @code{$(TEXI2PDF)}, with appropriate
698@option{-I} arguments pointing to directories of included files.
699@item html
700Build HTML documentation for the front end, in the build directory.
701@item man
702Build generated man pages for the front end from Texinfo manuals
703(@pxref{Man Page Generation}), in the build directory.  This target
704is only called if the necessary tools are available, but should ignore
705errors so as not to stop the build if errors occur; man pages are
706optional and the tools involved may be installed in a broken way.
707@item install-common
708Install everything that is part of the front end, apart from the
709compiler executables listed in @code{compilers} in
710@file{config-lang.in}.
711@item install-info
712Install info documentation for the front end, if it is present in the
713source directory.  This target should have dependencies on info files
714that should be installed.
715@item install-man
716Install man pages for the front end.  This target should ignore
717errors.
718@item install-plugin
719Install headers needed for plugins.
720@item srcextra
721Copies its dependencies into the source directory.  This generally should
722be used for generated files such as Bison output files which are not
723version-controlled, but should be included in any release tarballs.  This
724target will be executed during a bootstrap if
725@samp{--enable-generated-files-in-srcdir} was specified as a
726@file{configure} option.
727@item srcinfo
728@itemx srcman
729Copies its dependencies into the source directory.  These targets will be
730executed during a bootstrap if @samp{--enable-generated-files-in-srcdir}
731was specified as a @file{configure} option.
732@item uninstall
733Uninstall files installed by installing the compiler.  This is
734currently documented not to be supported, so the hook need not do
735anything.
736@item mostlyclean
737@itemx clean
738@itemx distclean
739@itemx maintainer-clean
740The language parts of the standard GNU
741@samp{*clean} targets.  @xref{Standard Targets, , Standard Targets for
742Users, standards, GNU Coding Standards}, for details of the standard
743targets.  For GCC, @code{maintainer-clean} should delete
744all generated files in the source directory that are not version-controlled,
745but should not delete anything that is.
746@end table
747
748@file{Make-lang.in} must also define a variable @code{@var{lang}_OBJS}
749to a list of host object files that are used by that language.
750
751@node Back End
752@subsection Anatomy of a Target Back End
753
754A back end for a target architecture in GCC has the following parts:
755
756@itemize @bullet
757@item
758A directory @file{@var{machine}} under @file{gcc/config}, containing a
759machine description @file{@var{machine}.md} file (@pxref{Machine Desc,
760, Machine Descriptions}), header files @file{@var{machine}.h} and
761@file{@var{machine}-protos.h} and a source file @file{@var{machine}.c}
762(@pxref{Target Macros, , Target Description Macros and Functions}),
763possibly a target Makefile fragment @file{t-@var{machine}}
764(@pxref{Target Fragment, , The Target Makefile Fragment}), and maybe
765some other files.  The names of these files may be changed from the
766defaults given by explicit specifications in @file{config.gcc}.
767@item
768If necessary, a file @file{@var{machine}-modes.def} in the
769@file{@var{machine}} directory, containing additional machine modes to
770represent condition codes.  @xref{Condition Code}, for further details.
771@item
772An optional @file{@var{machine}.opt} file in the @file{@var{machine}}
773directory, containing a list of target-specific options.  You can also
774add other option files using the @code{extra_options} variable in
775@file{config.gcc}.  @xref{Options}.
776@item
777Entries in @file{config.gcc} (@pxref{System Config, , The
778@file{config.gcc} File}) for the systems with this target
779architecture.
780@item
781Documentation in @file{gcc/doc/invoke.texi} for any command-line
782options supported by this target (@pxref{Run-time Target, , Run-time
783Target Specification}).  This means both entries in the summary table
784of options and details of the individual options.
785@item
786Documentation in @file{gcc/doc/extend.texi} for any target-specific
787attributes supported (@pxref{Target Attributes, , Defining
788target-specific uses of @code{__attribute__}}), including where the
789same attribute is already supported on some targets, which are
790enumerated in the manual.
791@item
792Documentation in @file{gcc/doc/extend.texi} for any target-specific
793pragmas supported.
794@item
795Documentation in @file{gcc/doc/extend.texi} of any target-specific
796built-in functions supported.
797@item
798Documentation in @file{gcc/doc/extend.texi} of any target-specific
799format checking styles supported.
800@item
801Documentation in @file{gcc/doc/md.texi} of any target-specific
802constraint letters (@pxref{Machine Constraints, , Constraints for
803Particular Machines}).
804@item
805A note in @file{gcc/doc/contrib.texi} under the person or people who
806contributed the target support.
807@item
808Entries in @file{gcc/doc/install.texi} for all target triplets
809supported with this target architecture, giving details of any special
810notes about installation for this target, or saying that there are no
811special notes if there are none.
812@item
813Possibly other support outside the @file{gcc} directory for runtime
814libraries.  FIXME: reference docs for this.  The @code{libstdc++} porting
815manual needs to be installed as info for this to work, or to be a
816chapter of this manual.
817@end itemize
818
819If the back end is added to the official GCC source repository, the
820following are also necessary:
821
822@itemize @bullet
823@item
824An entry for the target architecture in @file{readings.html} on the
825GCC web site, with any relevant links.
826@item
827Details of the properties of the back end and target architecture in
828@file{backends.html} on the GCC web site.
829@item
830A news item about the contribution of support for that target
831architecture, in @file{index.html} on the GCC web site.
832@item
833Normally, one or more maintainers of that target listed in
834@file{MAINTAINERS}.  Some existing architectures may be unmaintained,
835but it would be unusual to add support for a target that does not have
836a maintainer when support is added.
837@end itemize
838
839@node Testsuites
840@chapter Testsuites
841
842GCC contains several testsuites to help maintain compiler quality.
843Most of the runtime libraries and language front ends in GCC have
844testsuites.  Currently only the C language testsuites are documented
845here; FIXME: document the others.
846
847@menu
848* Test Idioms::     Idioms used in testsuite code.
849* Test Directives:: Directives used within DejaGnu tests.
850* Ada Tests::       The Ada language testsuites.
851* C Tests::         The C language testsuites.
852* libgcj Tests::    The Java library testsuites.
853* LTO Testing::     Support for testing link-time optimizations.
854* gcov Testing::    Support for testing gcov.
855* profopt Testing:: Support for testing profile-directed optimizations.
856* compat Testing::  Support for testing binary compatibility.
857* Torture Tests::   Support for torture testing using multiple options.
858@end menu
859
860@node Test Idioms
861@section Idioms Used in Testsuite Code
862
863In general, C testcases have a trailing @file{-@var{n}.c}, starting
864with @file{-1.c}, in case other testcases with similar names are added
865later.  If the test is a test of some well-defined feature, it should
866have a name referring to that feature such as
867@file{@var{feature}-1.c}.  If it does not test a well-defined feature
868but just happens to exercise a bug somewhere in the compiler, and a
869bug report has been filed for this bug in the GCC bug database,
870@file{pr@var{bug-number}-1.c} is the appropriate form of name.
871Otherwise (for miscellaneous bugs not filed in the GCC bug database),
872and previously more generally, test cases are named after the date on
873which they were added.  This allows people to tell at a glance whether
874a test failure is because of a recently found bug that has not yet
875been fixed, or whether it may be a regression, but does not give any
876other information about the bug or where discussion of it may be
877found.  Some other language testsuites follow similar conventions.
878
879In the @file{gcc.dg} testsuite, it is often necessary to test that an
880error is indeed a hard error and not just a warning---for example,
881where it is a constraint violation in the C standard, which must
882become an error with @option{-pedantic-errors}.  The following idiom,
883where the first line shown is line @var{line} of the file and the line
884that generates the error, is used for this:
885
886@smallexample
887/* @{ dg-bogus "warning" "warning in place of error" @} */
888/* @{ dg-error "@var{regexp}" "@var{message}" @{ target *-*-* @} @var{line} @} */
889@end smallexample
890
891It may be necessary to check that an expression is an integer constant
892expression and has a certain value.  To check that @code{@var{E}} has
893value @code{@var{V}}, an idiom similar to the following is used:
894
895@smallexample
896char x[((E) == (V) ? 1 : -1)];
897@end smallexample
898
899In @file{gcc.dg} tests, @code{__typeof__} is sometimes used to make
900assertions about the types of expressions.  See, for example,
901@file{gcc.dg/c99-condexpr-1.c}.  The more subtle uses depend on the
902exact rules for the types of conditional expressions in the C
903standard; see, for example, @file{gcc.dg/c99-intconst-1.c}.
904
905It is useful to be able to test that optimizations are being made
906properly.  This cannot be done in all cases, but it can be done where
907the optimization will lead to code being optimized away (for example,
908where flow analysis or alias analysis should show that certain code
909cannot be called) or to functions not being called because they have
910been expanded as built-in functions.  Such tests go in
911@file{gcc.c-torture/execute}.  Where code should be optimized away, a
912call to a nonexistent function such as @code{link_failure ()} may be
913inserted; a definition
914
915@smallexample
916#ifndef __OPTIMIZE__
917void
918link_failure (void)
919@{
920  abort ();
921@}
922#endif
923@end smallexample
924
925@noindent
926will also be needed so that linking still succeeds when the test is
927run without optimization.  When all calls to a built-in function
928should have been optimized and no calls to the non-built-in version of
929the function should remain, that function may be defined as
930@code{static} to call @code{abort ()} (although redeclaring a function
931as static may not work on all targets).
932
933All testcases must be portable.  Target-specific testcases must have
934appropriate code to avoid causing failures on unsupported systems;
935unfortunately, the mechanisms for this differ by directory.
936
937FIXME: discuss non-C testsuites here.
938
939@node Test Directives
940@section Directives used within DejaGnu tests
941
942@menu
943* Directives::  Syntax and descriptions of test directives.
944* Selectors:: Selecting targets to which a test applies.
945* Effective-Target Keywords:: Keywords describing target attributes.
946* Add Options:: Features for @code{dg-add-options}
947* Require Support:: Variants of @code{dg-require-@var{support}}
948* Final Actions:: Commands for use in @code{dg-final}
949@end menu
950
951@node Directives
952@subsection Syntax and Descriptions of test directives
953
954Test directives appear within comments in a test source file and begin
955with @code{dg-}.  Some of these are defined within DejaGnu and others
956are local to the GCC testsuite.
957
958The order in which test directives appear in a test can be important:
959directives local to GCC sometimes override information used by the
960DejaGnu directives, which know nothing about the GCC directives, so the
961DejaGnu directives must precede GCC directives.
962
963Several test directives include selectors (@pxref{Selectors, , })
964which are usually preceded by the keyword @code{target} or @code{xfail}.
965
966@subsubsection Specify how to build the test
967
968@table @code
969@item @{ dg-do @var{do-what-keyword} [@{ target/xfail @var{selector} @}] @}
970@var{do-what-keyword} specifies how the test is compiled and whether
971it is executed.  It is one of:
972
973@table @code
974@item preprocess
975Compile with @option{-E} to run only the preprocessor.
976@item compile
977Compile with @option{-S} to produce an assembly code file.
978@item assemble
979Compile with @option{-c} to produce a relocatable object file.
980@item link
981Compile, assemble, and link to produce an executable file.
982@item run
983Produce and run an executable file, which is expected to return
984an exit code of 0.
985@end table
986
987The default is @code{compile}.  That can be overridden for a set of
988tests by redefining @code{dg-do-what-default} within the @code{.exp}
989file for those tests.
990
991If the directive includes the optional @samp{@{ target @var{selector} @}}
992then the test is skipped unless the target system matches the
993@var{selector}.
994
995If @var{do-what-keyword} is @code{run} and the directive includes
996the optional @samp{@{ xfail @var{selector} @}} and the selector is met
997then the test is expected to fail.  The @code{xfail} clause is ignored
998for other values of @var{do-what-keyword}; those tests can use
999directive @code{dg-xfail-if}.
1000@end table
1001
1002@subsubsection Specify additional compiler options
1003
1004@table @code
1005@item @{ dg-options @var{options} [@{ target @var{selector} @}] @}
1006This DejaGnu directive provides a list of compiler options, to be used
1007if the target system matches @var{selector}, that replace the default
1008options used for this set of tests.
1009
1010@item @{ dg-add-options @var{feature} @dots{} @}
1011Add any compiler options that are needed to access certain features.
1012This directive does nothing on targets that enable the features by
1013default, or that don't provide them at all.  It must come after
1014all @code{dg-options} directives.
1015For supported values of @var{feature} see @ref{Add Options, ,}.
1016@end table
1017
1018@subsubsection Modify the test timeout value
1019
1020The normal timeout limit, in seconds, is found by searching the
1021following in order:
1022
1023@itemize @bullet
1024@item the value defined by an earlier @code{dg-timeout} directive in
1025the test
1026
1027@item variable @var{tool_timeout} defined by the set of tests
1028
1029@item @var{gcc},@var{timeout} set in the target board
1030
1031@item 300
1032@end itemize
1033
1034@table @code
1035@item @{ dg-timeout @var{n} [@{target @var{selector} @}] @}
1036Set the time limit for the compilation and for the execution of the test
1037to the specified number of seconds.
1038
1039@item @{ dg-timeout-factor @var{x} [@{ target @var{selector} @}] @}
1040Multiply the normal time limit for compilation and execution of the test
1041by the specified floating-point factor.
1042@end table
1043
1044@subsubsection Skip a test for some targets
1045
1046@table @code
1047@item @{ dg-skip-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1048Arguments @var{include-opts} and @var{exclude-opts} are lists in which
1049each element is a string of zero or more GCC options.
1050Skip the test if all of the following conditions are met:
1051@itemize @bullet
1052@item the test system is included in @var{selector}
1053
1054@item for at least one of the option strings in @var{include-opts},
1055every option from that string is in the set of options with which
1056the test would be compiled; use @samp{"*"} for an @var{include-opts} list
1057that matches any options; that is the default if @var{include-opts} is
1058not specified
1059
1060@item for each of the option strings in @var{exclude-opts}, at least one
1061option from that string is not in the set of options with which the test
1062would be compiled; use @samp{""} for an empty @var{exclude-opts} list;
1063that is the default if @var{exclude-opts} is not specified
1064@end itemize
1065
1066For example, to skip a test if option @code{-Os} is present:
1067
1068@smallexample
1069/* @{ dg-skip-if "" @{ *-*-* @}  @{ "-Os" @} @{ "" @} @} */
1070@end smallexample
1071
1072To skip a test if both options @code{-O2} and @code{-g} are present:
1073
1074@smallexample
1075/* @{ dg-skip-if "" @{ *-*-* @}  @{ "-O2 -g" @} @{ "" @} @} */
1076@end smallexample
1077
1078To skip a test if either @code{-O2} or @code{-O3} is present:
1079
1080@smallexample
1081/* @{ dg-skip-if "" @{ *-*-* @}  @{ "-O2" "-O3" @} @{ "" @} @} */
1082@end smallexample
1083
1084To skip a test unless option @code{-Os} is present:
1085
1086@smallexample
1087/* @{ dg-skip-if "" @{ *-*-* @}  @{ "*" @} @{ "-Os" @} @} */
1088@end smallexample
1089
1090To skip a test if either @code{-O2} or @code{-O3} is used with @code{-g}
1091but not if @code{-fpic} is also present:
1092
1093@smallexample
1094/* @{ dg-skip-if "" @{ *-*-* @}  @{ "-O2 -g" "-O3 -g" @} @{ "-fpic" @} @} */
1095@end smallexample
1096
1097@item @{ dg-require-effective-target @var{keyword} [@{ @var{selector} @}] @}
1098Skip the test if the test target, including current multilib flags,
1099is not covered by the effective-target keyword.
1100If the directive includes the optional @samp{@{ @var{selector} @}}
1101then the effective-target test is only performed if the target system
1102matches the @var{selector}.
1103This directive must appear after any @code{dg-do} directive in the test
1104and before any @code{dg-additional-sources} directive.
1105@xref{Effective-Target Keywords, , }.
1106
1107@item @{ dg-require-@var{support} args @}
1108Skip the test if the target does not provide the required support.
1109These directives must appear after any @code{dg-do} directive in the test
1110and before any @code{dg-additional-sources} directive.
1111They require at least one argument, which can be an empty string if the
1112specific procedure does not examine the argument.
1113@xref{Require Support, , }, for a complete list of these directives.
1114@end table
1115
1116@subsubsection Expect a test to fail for some targets
1117
1118@table @code
1119@item  @{ dg-xfail-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1120Expect the test to fail if the conditions (which are the same as for
1121@code{dg-skip-if}) are met.  This does not affect the execute step.
1122
1123@item  @{ dg-xfail-run-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1124Expect the execute step of a test to fail if the conditions (which are
1125the same as for @code{dg-skip-if}) are met.
1126@end table
1127
1128@subsubsection Expect the test executable to fail
1129
1130@table @code
1131@item  @{ dg-shouldfail @var{comment} [@{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]]] @}
1132Expect the test executable to return a nonzero exit status if the
1133conditions (which are the same as for @code{dg-skip-if}) are met.
1134@end table
1135
1136@subsubsection Verify compiler messages
1137
1138@table @code
1139@item @{ dg-error @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1140This DejaGnu directive appears on a source line that is expected to get
1141an error message, or else specifies the source line associated with the
1142message.  If there is no message for that line or if the text of that
1143message is not matched by @var{regexp} then the check fails and
1144@var{comment} is included in the @code{FAIL} message.  The check does
1145not look for the string @samp{error} unless it is part of @var{regexp}.
1146
1147@item @{ dg-warning @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1148This DejaGnu directive appears on a source line that is expected to get
1149a warning message, or else specifies the source line associated with the
1150message.  If there is no message for that line or if the text of that
1151message is not matched by @var{regexp} then the check fails and
1152@var{comment} is included in the @code{FAIL} message.  The check does
1153not look for the string @samp{warning} unless it is part of @var{regexp}.
1154
1155@item @{ dg-message @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1156The line is expected to get a message other than an error or warning.
1157If there is no message for that line or if the text of that message is
1158not matched by @var{regexp} then the check fails and @var{comment} is
1159included in the @code{FAIL} message.
1160
1161@item @{ dg-bogus @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1162This DejaGnu directive appears on a source line that should not get a
1163message matching @var{regexp}, or else specifies the source line
1164associated with the bogus message.  It is usually used with @samp{xfail}
1165to indicate that the message is a known problem for a particular set of
1166targets.
1167
1168@item @{ dg-excess-errors @var{comment} [@{ target/xfail @var{selector} @}] @}
1169This DejaGnu directive indicates that the test is expected to fail due
1170to compiler messages that are not handled by @samp{dg-error},
1171@samp{dg-warning} or @samp{dg-bogus}.  For this directive @samp{xfail}
1172has the same effect as @samp{target}.
1173
1174@item @{ dg-prune-output @var{regexp} @}
1175Prune messages matching @var{regexp} from the test output.
1176@end table
1177
1178@subsubsection Verify output of the test executable
1179
1180@table @code
1181@item @{ dg-output @var{regexp} [@{ target/xfail @var{selector} @}] @}
1182This DejaGnu directive compares @var{regexp} to the combined output
1183that the test executable writes to @file{stdout} and @file{stderr}.
1184@end table
1185
1186@subsubsection Specify additional files for a test
1187
1188@table @code
1189@item @{ dg-additional-files "@var{filelist}" @}
1190Specify additional files, other than source files, that must be copied
1191to the system where the compiler runs.
1192
1193@item @{ dg-additional-sources "@var{filelist}" @}
1194Specify additional source files to appear in the compile line
1195following the main test file.
1196@end table
1197
1198@subsubsection Add checks at the end of a test
1199
1200@table @code
1201@item @{ dg-final @{ @var{local-directive} @} @}
1202This DejaGnu directive is placed within a comment anywhere in the
1203source file and is processed after the test has been compiled and run.
1204Multiple @samp{dg-final} commands are processed in the order in which
1205they appear in the source file.  @xref{Final Actions, , }, for a list
1206of directives that can be used within @code{dg-final}.
1207@end table
1208
1209@node Selectors
1210@subsection Selecting targets to which a test applies
1211
1212Several test directives include @var{selector}s to limit the targets
1213for which a test is run or to declare that a test is expected to fail
1214on particular targets.
1215
1216A selector is:
1217@itemize @bullet
1218@item one or more target triplets, possibly including wildcard characters
1219@item a single effective-target keyword (@pxref{Effective-Target Keywords})
1220@item a logical expression
1221@end itemize
1222
1223Depending on the
1224context, the selector specifies whether a test is skipped and reported
1225as unsupported or is expected to fail.  Use @samp{*-*-*} to match any
1226target.
1227
1228A selector expression appears within curly braces and uses a single
1229logical operator: one of @samp{!}, @samp{&&}, or @samp{||}.  An
1230operand is another selector expression, an effective-target keyword,
1231a single target triplet, or a list of target triplets within quotes or
1232curly braces.  For example:
1233
1234@smallexample
1235@{ target @{ ! "hppa*-*-* ia64*-*-*" @} @}
1236@{ target @{ powerpc*-*-* && lp64 @} @}
1237@{ xfail @{ lp64 || vect_no_align @} @}
1238@end smallexample
1239
1240@node Effective-Target Keywords
1241@subsection Keywords describing target attributes
1242
1243Effective-target keywords identify sets of targets that support
1244particular functionality.  They are used to limit tests to be run only
1245for particular targets, or to specify that particular sets of targets
1246are expected to fail some tests.
1247
1248Effective-target keywords are defined in @file{lib/target-supports.exp} in
1249the GCC testsuite, with the exception of those that are documented as
1250being local to a particular test directory.
1251
1252The @samp{effective target} takes into account all of the compiler options
1253with which the test will be compiled, including the multilib options.
1254By convention, keywords ending in @code{_nocache} can also include options
1255specified for the particular test in an earlier @code{dg-options} or
1256@code{dg-add-options} directive.
1257
1258@subsubsection Data type sizes
1259
1260@table @code
1261@item ilp32
1262Target has 32-bit @code{int}, @code{long}, and pointers.
1263
1264@item lp64
1265Target has 32-bit @code{int}, 64-bit @code{long} and pointers.
1266
1267@item llp64
1268Target has 32-bit @code{int} and @code{long}, 64-bit @code{long long}
1269and pointers.
1270
1271@item double64
1272Target has 64-bit @code{double}.
1273
1274@item double64plus
1275Target has @code{double} that is 64 bits or longer.
1276
1277@item int32plus
1278Target has @code{int} that is at 32 bits or longer.
1279
1280@item int16
1281Target has @code{int} that is 16 bits or shorter.
1282
1283@item large_double
1284Target supports @code{double} that is longer than @code{float}.
1285
1286@item large_long_double
1287Target supports @code{long double} that is longer than @code{double}.
1288
1289@item ptr32plus
1290Target has pointers that are 32 bits or longer.
1291
1292@item size32plus
1293Target supports array and structure sizes that are 32 bits or longer.
1294
1295@item 4byte_wchar_t
1296Target has @code{wchar_t} that is at least 4 bytes.
1297@end table
1298
1299@subsubsection Fortran-specific attributes
1300
1301@table @code
1302@item fortran_integer_16
1303Target supports Fortran @code{integer} that is 16 bytes or longer.
1304
1305@item fortran_large_int
1306Target supports Fortran @code{integer} kinds larger than @code{integer(8)}.
1307
1308@item fortran_large_real
1309Target supports Fortran @code{real} kinds larger than @code{real(8)}.
1310@end table
1311
1312@subsubsection Vector-specific attributes
1313
1314@table @code
1315@item vect_condition
1316Target supports vector conditional operations.
1317
1318@item vect_double
1319Target supports hardware vectors of @code{double}.
1320
1321@item vect_float
1322Target supports hardware vectors of @code{float}.
1323
1324@item vect_int
1325Target supports hardware vectors of @code{int}.
1326
1327@item vect_int_mult
1328Target supports a vector widening multiplication of @code{short} operands
1329into an @code{int} result, or supports promotion (unpacking) from
1330@code{short} to @code{int} and a non-widening multiplication of @code{int}.
1331
1332@item vect_long
1333Target supports hardware vectors of @code{long}.
1334
1335@item vect_long_long
1336Target supports hardware vectors of @code{long long}.
1337
1338@item vect_aligned_arrays
1339Target aligns arrays to vector alignment boundary.
1340
1341@item vect_hw_misalign
1342Target supports a vector misalign access.
1343
1344@item vect_no_align
1345Target does not support a vector alignment mechanism.
1346
1347@item vect_no_int_max
1348Target does not support a vector max instruction on @code{int}.
1349
1350@item vect_no_int_add
1351Target does not support a vector add instruction on @code{int}.
1352
1353@item vect_no_bitwise
1354Target does not support vector bitwise instructions.
1355
1356@item vect_char_mult
1357Target supports @code{vector char} multiplication.
1358
1359@item vect_short_mult
1360Target supports @code{vector short} multiplication.
1361
1362@item vect_int_mult
1363Target supports @code{vector int} multiplication.
1364
1365@item vect_extract_even_odd
1366Target supports vector even/odd element extraction.
1367
1368@item vect_extract_even_odd_wide
1369Target supports vector even/odd element extraction of vectors with elements
1370@code{SImode} or larger.
1371
1372@item vect_interleave
1373Target supports vector interleaving.
1374
1375@item vect_strided
1376Target supports vector interleaving and extract even/odd.
1377
1378@item vect_strided_wide
1379Target supports vector interleaving and extract even/odd for wide
1380element types.
1381
1382@item vect_perm
1383Target supports vector permutation.
1384
1385@item vect_shift
1386Target supports a hardware vector shift operation.
1387
1388@item vect_widen_sum_hi_to_si
1389Target supports a vector widening summation of @code{short} operands
1390into @code{int} results, or can promote (unpack) from @code{short}
1391to @code{int}.
1392
1393@item vect_widen_sum_qi_to_hi
1394Target supports a vector widening summation of @code{char} operands
1395into @code{short} results, or can promote (unpack) from @code{char}
1396to @code{short}.
1397
1398@item vect_widen_sum_qi_to_si
1399Target supports a vector widening summation of @code{char} operands
1400into @code{int} results.
1401
1402@item vect_widen_mult_qi_to_hi
1403Target supports a vector widening multiplication of @code{char} operands
1404into @code{short} results, or can promote (unpack) from @code{char} to
1405@code{short} and perform non-widening multiplication of @code{short}.
1406
1407@item vect_widen_mult_hi_to_si
1408Target supports a vector widening multiplication of @code{short} operands
1409into @code{int} results, or can promote (unpack) from @code{short} to
1410@code{int} and perform non-widening multiplication of @code{int}.
1411
1412@item vect_sdot_qi
1413Target supports a vector dot-product of @code{signed char}.
1414
1415@item vect_udot_qi
1416Target supports a vector dot-product of @code{unsigned char}.
1417
1418@item vect_sdot_hi
1419Target supports a vector dot-product of @code{signed short}.
1420
1421@item vect_udot_hi
1422Target supports a vector dot-product of @code{unsigned short}.
1423
1424@item vect_pack_trunc
1425Target supports a vector demotion (packing) of @code{short} to @code{char}
1426and from @code{int} to @code{short} using modulo arithmetic.
1427
1428@item vect_unpack
1429Target supports a vector promotion (unpacking) of @code{char} to @code{short}
1430and from @code{char} to @code{int}.
1431
1432@item vect_intfloat_cvt
1433Target supports conversion from @code{signed int} to @code{float}.
1434
1435@item vect_uintfloat_cvt
1436Target supports conversion from @code{unsigned int} to @code{float}.
1437
1438@item vect_floatint_cvt
1439Target supports conversion from @code{float} to @code{signed int}.
1440
1441@item vect_floatuint_cvt
1442Target supports conversion from @code{float} to @code{unsigned int}.
1443@end table
1444
1445@subsubsection Thread Local Storage attributes
1446
1447@table @code
1448@item tls
1449Target supports thread-local storage.
1450
1451@item tls_native
1452Target supports native (rather than emulated) thread-local storage.
1453
1454@item tls_runtime
1455Test system supports executing TLS executables.
1456@end table
1457
1458@subsubsection Decimal floating point attributes
1459
1460@table @code
1461@item dfp
1462Targets supports compiling decimal floating point extension to C.
1463
1464@item dfp_nocache
1465Including the options used to compile this particular test, the
1466target supports compiling decimal floating point extension to C.
1467
1468@item dfprt
1469Test system can execute decimal floating point tests.
1470
1471@item dfprt_nocache
1472Including the options used to compile this particular test, the
1473test system can execute decimal floating point tests.
1474
1475@item hard_dfp
1476Target generates decimal floating point instructions with current options.
1477@end table
1478
1479@subsubsection ARM-specific attributes
1480
1481@table @code
1482@item arm32
1483ARM target generates 32-bit code.
1484
1485@item arm_eabi
1486ARM target adheres to the ABI for the ARM Architecture.
1487
1488@item arm_hard_vfp_ok
1489ARM target supports @code{-mfpu=vfp -mfloat-abi=hard}.
1490Some multilibs may be incompatible with these options.
1491
1492@item arm_iwmmxt_ok
1493ARM target supports @code{-mcpu=iwmmxt}.
1494Some multilibs may be incompatible with this option.
1495
1496@item arm_neon
1497ARM target supports generating NEON instructions.
1498
1499@item arm_neon_hw
1500Test system supports executing NEON instructions.
1501
1502@item arm_neon_ok
1503ARM Target supports @code{-mfpu=neon -mfloat-abi=softfp}.
1504Some multilibs may be incompatible with these options.
1505
1506@item arm_thumb1_ok
1507ARM target generates Thumb-1 code for @code{-mthumb}.
1508
1509@item arm_thumb2_ok
1510ARM target generates Thumb-2 code for @code{-mthumb}.
1511
1512@item arm_vfp_ok
1513ARM target supports @code{-mfpu=vfp -mfloat-abi=softfp}.
1514Some multilibs may be incompatible with these options.
1515@end table
1516
1517@subsubsection MIPS-specific attributes
1518
1519@table @code
1520@item mips64
1521MIPS target supports 64-bit instructions.
1522
1523@item nomips16
1524MIPS target does not produce MIPS16 code.
1525
1526@item mips16_attribute
1527MIPS target can generate MIPS16 code.
1528
1529@item mips_loongson
1530MIPS target is a Loongson-2E or -2F target using an ABI that supports
1531the Loongson vector modes.
1532
1533@item mips_newabi_large_long_double
1534MIPS target supports @code{long double} larger than @code{double}
1535when using the new ABI.
1536
1537@item mpaired_single
1538MIPS target supports @code{-mpaired-single}.
1539@end table
1540
1541@subsubsection PowerPC-specific attributes
1542
1543@table @code
1544@item powerpc64
1545Test system supports executing 64-bit instructions.
1546
1547@item powerpc_altivec
1548PowerPC target supports AltiVec.
1549
1550@item powerpc_altivec_ok
1551PowerPC target supports @code{-maltivec}.
1552
1553@item powerpc_fprs
1554PowerPC target supports floating-point registers.
1555
1556@item powerpc_hard_double
1557PowerPC target supports hardware double-precision floating-point.
1558
1559@item powerpc_ppu_ok
1560PowerPC target supports @code{-mcpu=cell}.
1561
1562@item powerpc_spe
1563PowerPC target supports PowerPC SPE.
1564
1565@item powerpc_spe_nocache
1566Including the options used to compile this particular test, the
1567PowerPC target supports PowerPC SPE.
1568
1569@item powerpc_spu
1570PowerPC target supports PowerPC SPU.
1571
1572@item spu_auto_overlay
1573SPU target has toolchain that supports automatic overlay generation.
1574
1575@item powerpc_vsx_ok
1576PowerPC target supports @code{-mvsx}.
1577
1578@item powerpc_405_nocache
1579Including the options used to compile this particular test, the
1580PowerPC target supports PowerPC 405.
1581
1582@item vmx_hw
1583PowerPC target supports executing AltiVec instructions.
1584@end table
1585
1586@subsubsection Other hardware attributes
1587
1588@table @code
1589@item avx
1590Target supports compiling AVX instructions.
1591
1592@item cell_hw
1593Test system can execute AltiVec and Cell PPU instructions.
1594
1595@item coldfire_fpu
1596Target uses a ColdFire FPU.
1597
1598@item hard_float
1599Target supports FPU instructions.
1600
1601@item sse
1602Target supports compiling @code{sse} instructions.
1603
1604@item sse_runtime
1605Target supports the execution of @code{sse} instructions.
1606
1607@item sse2
1608Target supports compiling @code{sse2} instructions.
1609
1610@item sse2_runtime
1611Target supports the execution of @code{sse2} instructions.
1612
1613@item sync_char_short
1614Target supports atomic operations on @code{char} and @code{short}.
1615
1616@item sync_int_long
1617Target supports atomic operations on @code{int} and @code{long}.
1618
1619@item ultrasparc_hw
1620Test environment appears to run executables on a simulator that
1621accepts only @code{EM_SPARC} executables and chokes on @code{EM_SPARC32PLUS}
1622or @code{EM_SPARCV9} executables.
1623
1624@item vect_cmdline_needed
1625Target requires a command line argument to enable a SIMD instruction set.
1626@end table
1627
1628@subsubsection Environment attributes
1629
1630@table @code
1631@item c
1632The language for the compiler under test is C.
1633
1634@item c++
1635The language for the compiler under test is C++.
1636
1637@item c99_runtime
1638Target provides a full C99 runtime.
1639
1640@item correct_iso_cpp_string_wchar_protos
1641Target @code{string.h} and @code{wchar.h} headers provide C++ required
1642overloads for @code{strchr} etc. functions.
1643
1644@item dummy_wcsftime
1645Target uses a dummy @code{wcsftime} function that always returns zero.
1646
1647@item fd_truncate
1648Target can truncate a file from a file descriptor, as used by
1649@file{libgfortran/io/unix.c:fd_truncate}; i.e. @code{ftruncate} or
1650@code{chsize}.
1651
1652@item freestanding
1653Target is @samp{freestanding} as defined in section 4 of the C99 standard.
1654Effectively, it is a target which supports no extra headers or libraries
1655other than what is considered essential.
1656
1657@item init_priority
1658Target supports constructors with initialization priority arguments.
1659
1660@item inttypes_types
1661Target has the basic signed and unsigned types in @code{inttypes.h}.
1662This is for tests that GCC's notions of these types agree with those
1663in the header, as some systems have only @code{inttypes.h}.
1664
1665@item lax_strtofp
1666Target might have errors of a few ULP in string to floating-point
1667conversion functions and overflow is not always detected correctly by
1668those functions.
1669
1670@item newlib
1671Target supports Newlib.
1672
1673@item pow10
1674Target provides @code{pow10} function.
1675
1676@item pthread
1677Target can compile using @code{pthread.h} with no errors or warnings.
1678
1679@item pthread_h
1680Target has @code{pthread.h}.
1681
1682@item run_expensive_tests
1683Expensive testcases (usually those that consume excessive amounts of CPU
1684time) should be run on this target.  This can be enabled by setting the
1685@env{GCC_TEST_RUN_EXPENSIVE} environment variable to a non-empty string.
1686
1687@item simulator
1688Test system runs executables on a simulator (i.e. slowly) rather than
1689hardware (i.e. fast).
1690
1691@item stdint_types
1692Target has the basic signed and unsigned C types in @code{stdint.h}.
1693This will be obsolete when GCC ensures a working @code{stdint.h} for
1694all targets.
1695
1696@item trampolines
1697Target supports trampolines.
1698
1699@item uclibc
1700Target supports uClibc.
1701
1702@item unwrapped
1703Target does not use a status wrapper.
1704
1705@item vxworks_kernel
1706Target is a VxWorks kernel.
1707
1708@item vxworks_rtp
1709Target is a VxWorks RTP.
1710
1711@item wchar
1712Target supports wide characters.
1713@end table
1714
1715@subsubsection Other attributes
1716
1717@table @code
1718@item automatic_stack_alignment
1719Target supports automatic stack alignment.
1720
1721@item cxa_atexit
1722Target uses @code{__cxa_atexit}.
1723
1724@item default_packed
1725Target has packed layout of structure members by default.
1726
1727@item fgraphite
1728Target supports Graphite optimizations.
1729
1730@item fixed_point
1731Target supports fixed-point extension to C.
1732
1733@item fopenmp
1734Target supports OpenMP via @option{-fopenmp}.
1735
1736@item fpic
1737Target supports @option{-fpic} and @option{-fPIC}.
1738
1739@item freorder
1740Target supports @option{-freorder-blocks-and-partition}.
1741
1742@item fstack_protector
1743Target supports @option{-fstack-protector}.
1744
1745@item gas
1746Target uses GNU @command{as}.
1747
1748@item gc_sections
1749Target supports @option{--gc-sections}.
1750
1751@item keeps_null_pointer_checks
1752Target keeps null pointer checks, either due to the use of
1753@option{-fno-delete-null-pointer-checks} or hardwired into the target.
1754
1755@item lto
1756Compiler has been configured to support link-time optimization (LTO).
1757
1758@item named_sections
1759Target supports named sections.
1760
1761@item natural_alignment_32
1762Target uses natural alignment (aligned to type size) for types of
176332 bits or less.
1764
1765@item target_natural_alignment_64
1766Target uses natural alignment (aligned to type size) for types of
176764 bits or less.
1768
1769@item nonpic
1770Target does not generate PIC by default.
1771
1772@item pcc_bitfield_type_matters
1773Target defines @code{PCC_BITFIELD_TYPE_MATTERS}.
1774
1775@item pe_aligned_commons
1776Target supports @option{-mpe-aligned-commons}.
1777
1778@item section_anchors
1779Target supports section anchors.
1780
1781@item short_enums
1782Target defaults to short enums.
1783
1784@item static
1785Target supports @option{-static}.
1786
1787@item static_libgfortran
1788Target supports statically linking @samp{libgfortran}.
1789
1790@item string_merging
1791Target supports merging string constants at link time.
1792
1793@item ucn
1794Target supports compiling and assembling UCN.
1795
1796@item ucn_nocache
1797Including the options used to compile this particular test, the
1798target supports compiling and assembling UCN.
1799
1800@item unaligned_stack
1801Target does not guarantee that its @code{STACK_BOUNDARY} is greater than
1802or equal to the required vector alignment.
1803
1804@item vector_alignment_reachable
1805Vector alignment is reachable for types of 32 bits or less.
1806
1807@item vector_alignment_reachable_for_64bit
1808Vector alignment is reachable for types of 64 bits or less.
1809
1810@item wchar_t_char16_t_compatible
1811Target supports @code{wchar_t} that is compatible with @code{char16_t}.
1812
1813@item wchar_t_char32_t_compatible
1814Target supports @code{wchar_t} that is compatible with @code{char32_t}.
1815@end table
1816
1817@subsubsection Local to tests in @code{gcc.target/i386}
1818
1819@table @code
1820@item 3dnow
1821Target supports compiling @code{3dnow} instructions.
1822
1823@item aes
1824Target supports compiling @code{aes} instructions.
1825
1826@item fma4
1827Target supports compiling @code{fma4} instructions.
1828
1829@item ms_hook_prologue
1830Target supports attribute @code{ms_hook_prologue}.
1831
1832@item pclmul
1833Target supports compiling @code{pclmul} instructions.
1834
1835@item sse3
1836Target supports compiling @code{sse3} instructions.
1837
1838@item sse4
1839Target supports compiling @code{sse4} instructions.
1840
1841@item sse4a
1842Target supports compiling @code{sse4a} instructions.
1843
1844@item ssse3
1845Target supports compiling @code{ssse3} instructions.
1846
1847@item vaes
1848Target supports compiling @code{vaes} instructions.
1849
1850@item vpclmul
1851Target supports compiling @code{vpclmul} instructions.
1852
1853@item xop
1854Target supports compiling @code{xop} instructions.
1855@end table
1856
1857@subsubsection Local to tests in @code{gcc.target/spu/ea}
1858
1859@table @code
1860@item ealib
1861Target @code{__ea} library functions are available.
1862@end table
1863
1864@subsubsection Local to tests in @code{gcc.test-framework}
1865
1866@table @code
1867@item no
1868Always returns 0.
1869
1870@item yes
1871Always returns 1.
1872@end table
1873
1874@node Add Options
1875@subsection Features for @code{dg-add-options}
1876
1877The supported values of @var{feature} for directive @code{dg-add-options}
1878are:
1879
1880@table @code
1881@item bind_pic_locally
1882Add the target-specific flags needed to enable functions to bind
1883locally when using pic/PIC passes in the testsuite.
1884
1885@item c99_runtime
1886Add the target-specific flags needed to access the C99 runtime.
1887
1888@item ieee
1889Add the target-specific flags needed to enable full IEEE
1890compliance mode.
1891
1892@item mips16_attribute
1893@code{mips16} function attributes.
1894Only MIPS targets support this feature, and only then in certain modes.
1895
1896@item tls
1897Add the target-specific flags needed to use thread-local storage.
1898@end table
1899
1900@node Require Support
1901@subsection Variants of @code{dg-require-@var{support}}
1902
1903A few of the @code{dg-require} directives take arguments.
1904
1905@table @code
1906@item dg-require-iconv @var{codeset}
1907Skip the test if the target does not support iconv.  @var{codeset} is
1908the codeset to convert to.
1909
1910@item dg-require-profiling @var{profopt}
1911Skip the test if the target does not support profiling with option
1912@var{profopt}.
1913
1914@item dg-require-visibility @var{vis}
1915Skip the test if the target does not support the @code{visibility} attribute.
1916If @var{vis} is @code{""}, support for @code{visibility("hidden")} is
1917checked, for @code{visibility("@var{vis}")} otherwise.
1918@end table
1919
1920The original @code{dg-require} directives were defined before there
1921was support for effective-target keywords.  The directives that do not
1922take arguments could be replaced with effective-target keywords.
1923
1924@table @code
1925@item dg-require-alias ""
1926Skip the test if the target does not support the @samp{alias} attribute.
1927
1928@item dg-require-ascii-locale ""
1929Skip the test if the host does not support an ASCII locale.
1930
1931@item dg-require-compat-dfp ""
1932Skip this test unless both compilers in a @file{compat} testsuite
1933support decimal floating point.
1934
1935@item dg-require-cxa-atexit ""
1936Skip the test if the target does not support @code{__cxa_atexit}.
1937This is equivalent to @code{dg-require-effective-target cxa_atexit}.
1938
1939@item dg-require-dll ""
1940Skip the test if the target does not support DLL attributes.
1941
1942@item dg-require-fork ""
1943Skip the test if the target does not support @code{fork}.
1944
1945@item dg-require-gc-sections ""
1946Skip the test if the target's linker does not support the
1947@code{--gc-sections} flags.
1948This is equivalent to @code{dg-require-effective-target gc-sections}.
1949
1950@item dg-require-host-local ""
1951Skip the test if the host is remote, rather than the same as the build
1952system.  Some tests are incompatible with DejaGnu's handling of remote
1953hosts, which involves copying the source file to the host and compiling
1954it with a relative path and "@code{-o a.out}".
1955
1956@item dg-require-mkfifo ""
1957Skip the test if the target does not support @code{mkfifo}.
1958
1959@item dg-require-named-sections ""
1960Skip the test is the target does not support named sections.
1961This is equivalent to @code{dg-require-effective-target named_sections}.
1962
1963@item dg-require-weak ""
1964Skip the test if the target does not support weak symbols.
1965
1966@item dg-require-weak-override ""
1967Skip the test if the target does not support overriding weak symbols.
1968@end table
1969
1970@node Final Actions
1971@subsection Commands for use in @code{dg-final}
1972
1973The GCC testsuite defines the following directives to be used within
1974@code{dg-final}.
1975
1976@subsubsection Scan a particular file
1977
1978@table @code
1979@item scan-file @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1980Passes if @var{regexp} matches text in @var{filename}.
1981@item scan-file-not @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1982Passes if @var{regexp} does not match text in @var{filename}.
1983@item scan-module @var{module} @var{regexp} [@{ target/xfail @var{selector} @}]
1984Passes if @var{regexp} matches in Fortran module @var{module}.
1985@end table
1986
1987@subsubsection Scan the assembly output
1988
1989@table @code
1990@item scan-assembler @var{regex} [@{ target/xfail @var{selector} @}]
1991Passes if @var{regex} matches text in the test's assembler output.
1992
1993@item scan-assembler-not @var{regex} [@{ target/xfail @var{selector} @}]
1994Passes if @var{regex} does not match text in the test's assembler output.
1995
1996@item scan-assembler-times @var{regex} @var{num} [@{ target/xfail @var{selector} @}]
1997Passes if @var{regex} is matched exactly @var{num} times in the test's
1998assembler output.
1999
2000@item scan-assembler-dem @var{regex} [@{ target/xfail @var{selector} @}]
2001Passes if @var{regex} matches text in the test's demangled assembler output.
2002
2003@item scan-assembler-dem-not @var{regex} [@{ target/xfail @var{selector} @}]
2004Passes if @var{regex} does not match text in the test's demangled assembler
2005output.
2006
2007@item scan-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2008Passes if @var{symbol} is defined as a hidden symbol in the test's
2009assembly output.
2010
2011@item scan-not-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2012Passes if @var{symbol} is not defined as a hidden symbol in the test's
2013assembly output.
2014@end table
2015
2016@subsubsection Scan optimization dump files
2017
2018These commands are available for @var{kind} of @code{tree}, @code{rtl},
2019and @code{ipa}.
2020
2021@table @code
2022@item scan-@var{kind}-dump @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2023Passes if @var{regex} matches text in the dump file with suffix @var{suffix}.
2024
2025@item scan-@var{kind}-dump-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2026Passes if @var{regex} does not match text in the dump file with suffix
2027@var{suffix}.
2028
2029@item scan-@var{kind}-dump-times @var{regex} @var{num} @var{suffix} [@{ target/xfail @var{selector} @}]
2030Passes if @var{regex} is found exactly @var{num} times in the dump file
2031with suffix @var{suffix}.
2032
2033@item scan-@var{kind}-dump-dem @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2034Passes if @var{regex} matches demangled text in the dump file with
2035suffix @var{suffix}.
2036
2037@item scan-@var{kind}-dump-dem-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2038Passes if @var{regex} does not match demangled text in the dump file with
2039suffix @var{suffix}.
2040@end table
2041
2042@subsubsection Verify that an output files exists or not
2043
2044@table @code
2045@item output-exists [@{ target/xfail @var{selector} @}]
2046Passes if compiler output file exists.
2047
2048@item output-exists-not [@{ target/xfail @var{selector} @}]
2049Passes if compiler output file does not exist.
2050@end table
2051
2052@subsubsection Check for LTO tests
2053
2054@table @code
2055@item scan-symbol @var{regexp} [@{ target/xfail @var{selector} @}]
2056Passes if the pattern is present in the final executable.
2057@end table
2058
2059@subsubsection Checks for @command{gcov} tests
2060
2061@table @code
2062@item run-gcov @var{sourcefile}
2063Check line counts in @command{gcov} tests.
2064
2065@item run-gcov [branches] [calls] @{ @var{opts} @var{sourcefile} @}
2066Check branch and/or call counts, in addition to line counts, in
2067@command{gcov} tests.
2068@end table
2069
2070@subsubsection Clean up generated test files
2071
2072@table @code
2073@item cleanup-coverage-files
2074Removes coverage data files generated for this test.
2075
2076@item cleanup-ipa-dump @var{suffix}
2077Removes IPA dump files generated for this test.
2078
2079@item cleanup-modules
2080Removes Fortran module files generated for this test.
2081
2082@item cleanup-profile-file
2083Removes profiling files generated for this test.
2084
2085@item cleanup-repo-files
2086Removes files generated for this test for @option{-frepo}.
2087
2088@item cleanup-rtl-dump @var{suffix}
2089Removes RTL dump files generated for this test.
2090
2091@item cleanup-saved-temps
2092Removes files for the current test which were kept for @option{-save-temps}.
2093
2094@item cleanup-tree-dump @var{suffix}
2095Removes tree dump files matching @var{suffix} which were generated for
2096this test.
2097@end table
2098
2099@node Ada Tests
2100@section Ada Language Testsuites
2101
2102The Ada testsuite includes executable tests from the ACATS 2.5
2103testsuite, publicly available at
2104@uref{http://www.adaic.org/compilers/acats/2.5}.
2105
2106These tests are integrated in the GCC testsuite in the
2107@file{ada/acats} directory, and
2108enabled automatically when running @code{make check}, assuming
2109the Ada language has been enabled when configuring GCC@.
2110
2111You can also run the Ada testsuite independently, using
2112@code{make check-ada}, or run a subset of the tests by specifying which
2113chapter to run, e.g.:
2114
2115@smallexample
2116$ make check-ada CHAPTERS="c3 c9"
2117@end smallexample
2118
2119The tests are organized by directory, each directory corresponding to
2120a chapter of the Ada Reference Manual.  So for example, @file{c9} corresponds
2121to chapter 9, which deals with tasking features of the language.
2122
2123There is also an extra chapter called @file{gcc} containing a template for
2124creating new executable tests, although this is deprecated in favor of
2125the @file{gnat.dg} testsuite.
2126
2127The tests are run using two @command{sh} scripts: @file{run_acats} and
2128@file{run_all.sh}.  To run the tests using a simulator or a cross
2129target, see the small
2130customization section at the top of @file{run_all.sh}.
2131
2132These tests are run using the build tree: they can be run without doing
2133a @code{make install}.
2134
2135@node C Tests
2136@section C Language Testsuites
2137
2138GCC contains the following C language testsuites, in the
2139@file{gcc/testsuite} directory:
2140
2141@table @file
2142@item gcc.dg
2143This contains tests of particular features of the C compiler, using the
2144more modern @samp{dg} harness.  Correctness tests for various compiler
2145features should go here if possible.
2146
2147Magic comments determine whether the file
2148is preprocessed, compiled, linked or run.  In these tests, error and warning
2149message texts are compared against expected texts or regular expressions
2150given in comments.  These tests are run with the options @samp{-ansi -pedantic}
2151unless other options are given in the test.  Except as noted below they
2152are not run with multiple optimization options.
2153@item gcc.dg/compat
2154This subdirectory contains tests for binary compatibility using
2155@file{lib/compat.exp}, which in turn uses the language-independent support
2156(@pxref{compat Testing, , Support for testing binary compatibility}).
2157@item gcc.dg/cpp
2158This subdirectory contains tests of the preprocessor.
2159@item gcc.dg/debug
2160This subdirectory contains tests for debug formats.  Tests in this
2161subdirectory are run for each debug format that the compiler supports.
2162@item gcc.dg/format
2163This subdirectory contains tests of the @option{-Wformat} format
2164checking.  Tests in this directory are run with and without
2165@option{-DWIDE}.
2166@item gcc.dg/noncompile
2167This subdirectory contains tests of code that should not compile and
2168does not need any special compilation options.  They are run with
2169multiple optimization options, since sometimes invalid code crashes
2170the compiler with optimization.
2171@item gcc.dg/special
2172FIXME: describe this.
2173
2174@item gcc.c-torture
2175This contains particular code fragments which have historically broken easily.
2176These tests are run with multiple optimization options, so tests for features
2177which only break at some optimization levels belong here.  This also contains
2178tests to check that certain optimizations occur.  It might be worthwhile to
2179separate the correctness tests cleanly from the code quality tests, but
2180it hasn't been done yet.
2181
2182@item gcc.c-torture/compat
2183FIXME: describe this.
2184
2185This directory should probably not be used for new tests.
2186@item gcc.c-torture/compile
2187This testsuite contains test cases that should compile, but do not
2188need to link or run.  These test cases are compiled with several
2189different combinations of optimization options.  All warnings are
2190disabled for these test cases, so this directory is not suitable if
2191you wish to test for the presence or absence of compiler warnings.
2192While special options can be set, and tests disabled on specific
2193platforms, by the use of @file{.x} files, mostly these test cases
2194should not contain platform dependencies.  FIXME: discuss how defines
2195such as @code{NO_LABEL_VALUES} and @code{STACK_SIZE} are used.
2196@item gcc.c-torture/execute
2197This testsuite contains test cases that should compile, link and run;
2198otherwise the same comments as for @file{gcc.c-torture/compile} apply.
2199@item gcc.c-torture/execute/ieee
2200This contains tests which are specific to IEEE floating point.
2201@item gcc.c-torture/unsorted
2202FIXME: describe this.
2203
2204This directory should probably not be used for new tests.
2205@item gcc.misc-tests
2206This directory contains C tests that require special handling.  Some
2207of these tests have individual expect files, and others share
2208special-purpose expect files:
2209
2210@table @file
2211@item @code{bprob*.c}
2212Test @option{-fbranch-probabilities} using
2213@file{gcc.misc-tests/bprob.exp}, which
2214in turn uses the generic, language-independent framework
2215(@pxref{profopt Testing, , Support for testing profile-directed
2216optimizations}).
2217
2218@item @code{gcov*.c}
2219Test @command{gcov} output using @file{gcov.exp}, which in turn uses the
2220language-independent support (@pxref{gcov Testing, , Support for testing gcov}).
2221
2222@item @code{i386-pf-*.c}
2223Test i386-specific support for data prefetch using @file{i386-prefetch.exp}.
2224@end table
2225
2226@item gcc.test-framework
2227@table @file
2228@item @code{dg-*.c}
2229Test the testsuite itself using @file{gcc.test-framework/test-framework.exp}.
2230@end table
2231
2232@end table
2233
2234FIXME: merge in @file{testsuite/README.gcc} and discuss the format of
2235test cases and magic comments more.
2236
2237@node libgcj Tests
2238@section The Java library testsuites.
2239
2240Runtime tests are executed via @samp{make check} in the
2241@file{@var{target}/libjava/testsuite} directory in the build
2242tree.  Additional runtime tests can be checked into this testsuite.
2243
2244Regression testing of the core packages in libgcj is also covered by the
2245Mauve testsuite.  The @uref{http://sourceware.org/mauve/,,Mauve Project}
2246develops tests for the Java Class Libraries.  These tests are run as part
2247of libgcj testing by placing the Mauve tree within the libjava testsuite
2248sources at @file{libjava/testsuite/libjava.mauve/mauve}, or by specifying
2249the location of that tree when invoking @samp{make}, as in
2250@samp{make MAUVEDIR=~/mauve check}.
2251
2252To detect regressions, a mechanism in @file{mauve.exp} compares the
2253failures for a test run against the list of expected failures in
2254@file{libjava/testsuite/libjava.mauve/xfails} from the source hierarchy.
2255Update this file when adding new failing tests to Mauve, or when fixing
2256bugs in libgcj that had caused Mauve test failures.
2257
2258We encourage developers to contribute test cases to Mauve.
2259
2260@node LTO Testing
2261@section Support for testing link-time optimizations
2262
2263Tests for link-time optimizations usually require multiple source files
2264that are compiled separately, perhaps with different sets of options.
2265There are several special-purpose test directives used for these tests.
2266
2267@table @code
2268@item @{ dg-lto-do @var{do-what-keyword} @}
2269@var{do-what-keyword} specifies how the test is compiled and whether
2270it is executed.  It is one of:
2271
2272@table @code
2273@item assemble
2274Compile with @option{-c} to produce a relocatable object file.
2275@item link
2276Compile, assemble, and link to produce an executable file.
2277@item run
2278Produce and run an executable file, which is expected to return
2279an exit code of 0.
2280@end table
2281
2282The default is @code{assemble}.  That can be overridden for a set of
2283tests by redefining @code{dg-do-what-default} within the @code{.exp}
2284file for those tests.
2285
2286Unlike @code{dg-do}, @code{dg-lto-do} does not support an optional
2287@samp{target} or @samp{xfail} list.  Use @code{dg-skip-if},
2288@code{dg-xfail-if}, or @code{dg-xfail-run-if}.
2289
2290@item @{ dg-lto-options @{ @{ @var{options} @} [@{ @var{options} @}] @} [@{ target @var{selector} @}]@}
2291This directive provides a list of one or more sets of compiler options
2292to override @var{LTO_OPTIONS}.  Each test will be compiled and run with
2293each of these sets of options.
2294
2295@item @{ dg-extra-ld-options @var{options} @}
2296This directive adds @var{options} to the linker options used.
2297
2298@item @{ dg-suppress-ld-options @var{options} @}
2299This directive removes @var{options} from the set of linker options used.
2300@end table
2301
2302@node gcov Testing
2303@section Support for testing @command{gcov}
2304
2305Language-independent support for testing @command{gcov}, and for checking
2306that branch profiling produces expected values, is provided by the
2307expect file @file{lib/gcov.exp}.  @command{gcov} tests also rely on procedures
2308in @file{lib/gcc-dg.exp} to compile and run the test program.  A typical
2309@command{gcov} test contains the following DejaGnu commands within comments:
2310
2311@smallexample
2312@{ dg-options "-fprofile-arcs -ftest-coverage" @}
2313@{ dg-do run @{ target native @} @}
2314@{ dg-final @{ run-gcov sourcefile @} @}
2315@end smallexample
2316
2317Checks of @command{gcov} output can include line counts, branch percentages,
2318and call return percentages.  All of these checks are requested via
2319commands that appear in comments in the test's source file.
2320Commands to check line counts are processed by default.
2321Commands to check branch percentages and call return percentages are
2322processed if the @command{run-gcov} command has arguments @code{branches}
2323or @code{calls}, respectively.  For example, the following specifies
2324checking both, as well as passing @option{-b} to @command{gcov}:
2325
2326@smallexample
2327@{ dg-final @{ run-gcov branches calls @{ -b sourcefile @} @} @}
2328@end smallexample
2329
2330A line count command appears within a comment on the source line
2331that is expected to get the specified count and has the form
2332@code{count(@var{cnt})}.  A test should only check line counts for
2333lines that will get the same count for any architecture.
2334
2335Commands to check branch percentages (@code{branch}) and call
2336return percentages (@code{returns}) are very similar to each other.
2337A beginning command appears on or before the first of a range of
2338lines that will report the percentage, and the ending command
2339follows that range of lines.  The beginning command can include a
2340list of percentages, all of which are expected to be found within
2341the range.  A range is terminated by the next command of the same
2342kind.  A command @code{branch(end)} or @code{returns(end)} marks
2343the end of a range without starting a new one.  For example:
2344
2345@smallexample
2346if (i > 10 && j > i && j < 20)  /* @r{branch(27 50 75)} */
2347                                /* @r{branch(end)} */
2348  foo (i, j);
2349@end smallexample
2350
2351For a call return percentage, the value specified is the
2352percentage of calls reported to return.  For a branch percentage,
2353the value is either the expected percentage or 100 minus that
2354value, since the direction of a branch can differ depending on the
2355target or the optimization level.
2356
2357Not all branches and calls need to be checked.  A test should not
2358check for branches that might be optimized away or replaced with
2359predicated instructions.  Don't check for calls inserted by the
2360compiler or ones that might be inlined or optimized away.
2361
2362A single test can check for combinations of line counts, branch
2363percentages, and call return percentages.  The command to check a
2364line count must appear on the line that will report that count, but
2365commands to check branch percentages and call return percentages can
2366bracket the lines that report them.
2367
2368@node profopt Testing
2369@section Support for testing profile-directed optimizations
2370
2371The file @file{profopt.exp} provides language-independent support for
2372checking correct execution of a test built with profile-directed
2373optimization.  This testing requires that a test program be built and
2374executed twice.  The first time it is compiled to generate profile
2375data, and the second time it is compiled to use the data that was
2376generated during the first execution.  The second execution is to
2377verify that the test produces the expected results.
2378
2379To check that the optimization actually generated better code, a
2380test can be built and run a third time with normal optimizations to
2381verify that the performance is better with the profile-directed
2382optimizations.  @file{profopt.exp} has the beginnings of this kind
2383of support.
2384
2385@file{profopt.exp} provides generic support for profile-directed
2386optimizations.  Each set of tests that uses it provides information
2387about a specific optimization:
2388
2389@table @code
2390@item tool
2391tool being tested, e.g., @command{gcc}
2392
2393@item profile_option
2394options used to generate profile data
2395
2396@item feedback_option
2397options used to optimize using that profile data
2398
2399@item prof_ext
2400suffix of profile data files
2401
2402@item PROFOPT_OPTIONS
2403list of options with which to run each test, similar to the lists for
2404torture tests
2405
2406@item @{ dg-final-generate @{ @var{local-directive} @} @}
2407This directive is similar to @code{dg-final}, but the
2408@var{local-directive} is run after the generation of profile data.
2409
2410@item @{ dg-final-use @{ @var{local-directive} @} @}
2411The @var{local-directive} is run after the profile data have been
2412used.
2413@end table
2414
2415@node compat Testing
2416@section Support for testing binary compatibility
2417
2418The file @file{compat.exp} provides language-independent support for
2419binary compatibility testing.  It supports testing interoperability of
2420two compilers that follow the same ABI, or of multiple sets of
2421compiler options that should not affect binary compatibility.  It is
2422intended to be used for testsuites that complement ABI testsuites.
2423
2424A test supported by this framework has three parts, each in a
2425separate source file: a main program and two pieces that interact
2426with each other to split up the functionality being tested.
2427
2428@table @file
2429@item @var{testname}_main.@var{suffix}
2430Contains the main program, which calls a function in file
2431@file{@var{testname}_x.@var{suffix}}.
2432
2433@item @var{testname}_x.@var{suffix}
2434Contains at least one call to a function in
2435@file{@var{testname}_y.@var{suffix}}.
2436
2437@item @var{testname}_y.@var{suffix}
2438Shares data with, or gets arguments from,
2439@file{@var{testname}_x.@var{suffix}}.
2440@end table
2441
2442Within each test, the main program and one functional piece are
2443compiled by the GCC under test.  The other piece can be compiled by
2444an alternate compiler.  If no alternate compiler is specified,
2445then all three source files are all compiled by the GCC under test.
2446You can specify pairs of sets of compiler options.  The first element
2447of such a pair specifies options used with the GCC under test, and the
2448second element of the pair specifies options used with the alternate
2449compiler.  Each test is compiled with each pair of options.
2450
2451@file{compat.exp} defines default pairs of compiler options.
2452These can be overridden by defining the environment variable
2453@env{COMPAT_OPTIONS} as:
2454
2455@smallexample
2456COMPAT_OPTIONS="[list [list @{@var{tst1}@} @{@var{alt1}@}]
2457  @dots{}[list @{@var{tstn}@} @{@var{altn}@}]]"
2458@end smallexample
2459
2460where @var{tsti} and @var{alti} are lists of options, with @var{tsti}
2461used by the compiler under test and @var{alti} used by the alternate
2462compiler.  For example, with
2463@code{[list [list @{-g -O0@} @{-O3@}] [list @{-fpic@} @{-fPIC -O2@}]]},
2464the test is first built with @option{-g -O0} by the compiler under
2465test and with @option{-O3} by the alternate compiler.  The test is
2466built a second time using @option{-fpic} by the compiler under test
2467and @option{-fPIC -O2} by the alternate compiler.
2468
2469An alternate compiler is specified by defining an environment
2470variable to be the full pathname of an installed compiler; for C
2471define @env{ALT_CC_UNDER_TEST}, and for C++ define
2472@env{ALT_CXX_UNDER_TEST}.  These will be written to the
2473@file{site.exp} file used by DejaGnu.  The default is to build each
2474test with the compiler under test using the first of each pair of
2475compiler options from @env{COMPAT_OPTIONS}.  When
2476@env{ALT_CC_UNDER_TEST} or
2477@env{ALT_CXX_UNDER_TEST} is @code{same}, each test is built using
2478the compiler under test but with combinations of the options from
2479@env{COMPAT_OPTIONS}.
2480
2481To run only the C++ compatibility suite using the compiler under test
2482and another version of GCC using specific compiler options, do the
2483following from @file{@var{objdir}/gcc}:
2484
2485@smallexample
2486rm site.exp
2487make -k \
2488  ALT_CXX_UNDER_TEST=$@{alt_prefix@}/bin/g++ \
2489  COMPAT_OPTIONS="@var{lists as shown above}" \
2490  check-c++ \
2491  RUNTESTFLAGS="compat.exp"
2492@end smallexample
2493
2494A test that fails when the source files are compiled with different
2495compilers, but passes when the files are compiled with the same
2496compiler, demonstrates incompatibility of the generated code or
2497runtime support.  A test that fails for the alternate compiler but
2498passes for the compiler under test probably tests for a bug that was
2499fixed in the compiler under test but is present in the alternate
2500compiler.
2501
2502The binary compatibility tests support a small number of test framework
2503commands that appear within comments in a test file.
2504
2505@table @code
2506@item dg-require-*
2507These commands can be used in @file{@var{testname}_main.@var{suffix}}
2508to skip the test if specific support is not available on the target.
2509
2510@item dg-options
2511The specified options are used for compiling this particular source
2512file, appended to the options from @env{COMPAT_OPTIONS}.  When this
2513command appears in @file{@var{testname}_main.@var{suffix}} the options
2514are also used to link the test program.
2515
2516@item dg-xfail-if
2517This command can be used in a secondary source file to specify that
2518compilation is expected to fail for particular options on particular
2519targets.
2520@end table
2521
2522@node Torture Tests
2523@section Support for torture testing using multiple options
2524
2525Throughout the compiler testsuite there are several directories whose
2526tests are run multiple times, each with a different set of options.
2527These are known as torture tests.
2528@file{lib/torture-options.exp} defines procedures to
2529set up these lists:
2530
2531@table @code
2532@item torture-init
2533Initialize use of torture lists.
2534@item set-torture-options
2535Set lists of torture options to use for tests with and without loops.
2536Optionally combine a set of torture options with a set of other
2537options, as is done with Objective-C runtime options.
2538@item torture-finish
2539Finalize use of torture lists.
2540@end table
2541
2542The @file{.exp} file for a set of tests that use torture options must
2543include calls to these three procedures if:
2544
2545@itemize @bullet
2546@item It calls @code{gcc-dg-runtest} and overrides @var{DG_TORTURE_OPTIONS}.
2547
2548@item It calls @var{$@{tool@}}@code{-torture} or
2549@var{$@{tool@}}@code{-torture-execute}, where @var{tool} is @code{c},
2550@code{fortran}, or @code{objc}.
2551
2552@item It calls @code{dg-pch}.
2553@end itemize
2554
2555It is not necessary for a @file{.exp} file that calls @code{gcc-dg-runtest}
2556to call the torture procedures if the tests should use the list in
2557@var{DG_TORTURE_OPTIONS} defined in @file{gcc-dg.exp}.
2558
2559Most uses of torture options can override the default lists by defining
2560@var{TORTURE_OPTIONS} or add to the default list by defining
2561@var{ADDITIONAL_TORTURE_OPTIONS}.  Define these in a @file{.dejagnurc}
2562file or add them to the @file{site.exp} file; for example
2563
2564@smallexample
2565set ADDITIONAL_TORTURE_OPTIONS  [list \
2566  @{ -O2 -ftree-loop-linear @} \
2567  @{ -O2 -fpeel-loops @} ]
2568@end smallexample
2569