1 @c Copyright (C) 2002-2015 Free Software Foundation, Inc.
2 @c This is part of the GCC manual.
3 @c For copying conditions, see the file gcc.texi.
6 @chapter Source Tree Structure and Build System
8 This chapter describes the structure of the GCC source tree, and how
9 GCC is built. The user documentation for building and installing GCC
10 is in a separate manual (@uref{http://gcc.gnu.org/install/}), with
11 which it is presumed that you are familiar.
14 * Configure Terms:: Configuration terminology and history.
15 * Top Level:: The top level source directory.
16 * gcc Directory:: The @file{gcc} subdirectory.
19 @include configterms.texi
22 @section Top Level Source Directory
24 The top level source directory in a GCC distribution contains several
25 files and directories that are shared with other software
26 distributions such as that of GNU Binutils. It also contains several
27 subdirectories that contain parts of GCC and its runtime libraries:
31 The Boehm conservative garbage collector, used as part of the Java
35 Autoconf macros and Makefile fragments used throughout the tree.
38 Contributed scripts that may be found useful in conjunction with GCC@.
39 One of these, @file{contrib/texi2pod.pl}, is used to generate man
40 pages from Texinfo manuals as part of the GCC build process.
43 The support for fixing system headers to work with GCC@. See
44 @file{fixincludes/README} for more information. The headers fixed by
45 this mechanism are installed in @file{@var{libsubdir}/include-fixed}.
46 Along with those headers, @file{README-fixinc} is also installed, as
47 @file{@var{libsubdir}/include-fixed/README}.
50 The main sources of GCC itself (except for runtime libraries),
51 including optimizers, support for different target architectures,
52 language front ends, and testsuites. @xref{gcc Directory, , The
53 @file{gcc} Subdirectory}, for details.
56 Support tools for GNAT.
59 Headers for the @code{libiberty} library.
62 GNU @code{libintl}, from GNU @code{gettext}, for systems which do not
63 include it in @code{libc}.
66 The Ada runtime library.
69 The runtime support library for atomic operations (e.g. for @code{__sync}
73 The C preprocessor library.
76 The Decimal Float support library.
79 The @code{libffi} library, used as part of the Java runtime library.
82 The GCC runtime library.
85 The Fortran runtime library.
88 The Go runtime library. The bulk of this library is mirrored from the
89 @uref{http://code.google.com/@/p/@/go/, master Go repository}.
92 The GNU Offloading and Multi Processing Runtime Library.
95 The @code{libiberty} library, used for portability and for some
96 generally useful data structures and algorithms. @xref{Top, ,
97 Introduction, libiberty, @sc{gnu} libiberty}, for more information
101 The runtime support library for transactional memory.
104 The Java runtime library.
107 The Objective-C and Objective-C++ runtime library.
110 The runtime support library for quad-precision math operations.
113 The Stack protector runtime library.
116 The C++ runtime library.
119 Plugin used by the linker if link-time optimizations are enabled.
121 @item maintainer-scripts
122 Scripts used by the @code{gccadmin} account on @code{gcc.gnu.org}.
125 The @code{zlib} compression library, used by the Java front end, as
126 part of the Java runtime library, and for compressing and uncompressing
127 GCC's intermediate language in LTO object files.
130 The build system in the top level directory, including how recursion
131 into subdirectories works and how building runtime libraries for
132 multilibs is handled, is documented in a separate manual, included
133 with GNU Binutils. @xref{Top, , GNU configure and build system,
134 configure, The GNU configure and build system}, for details.
137 @section The @file{gcc} Subdirectory
139 The @file{gcc} directory contains many files that are part of the C
140 sources of GCC, other files used as part of the configuration and
141 build process, and subdirectories including documentation and a
142 testsuite. The files that are sources of GCC are documented in a
143 separate chapter. @xref{Passes, , Passes and Files of the Compiler}.
146 * Subdirectories:: Subdirectories of @file{gcc}.
147 * Configuration:: The configuration process, and the files it uses.
148 * Build:: The build system in the @file{gcc} directory.
149 * Makefile:: Targets in @file{gcc/Makefile}.
150 * Library Files:: Library source files and headers under @file{gcc/}.
151 * Headers:: Headers installed by GCC.
152 * Documentation:: Building documentation in GCC.
153 * Front End:: Anatomy of a language front end.
154 * Back End:: Anatomy of a target back end.
158 @subsection Subdirectories of @file{gcc}
160 The @file{gcc} directory contains the following subdirectories:
164 Subdirectories for various languages. Directories containing a file
165 @file{config-lang.in} are language subdirectories. The contents of
166 the subdirectories @file{c} (for C), @file{cp} (for C++),
167 @file{objc} (for Objective-C), @file{objcp} (for Objective-C++),
168 and @file{lto} (for LTO) are documented in this
169 manual (@pxref{Passes, , Passes and Files of the Compiler});
170 those for other languages are not. @xref{Front End, ,
171 Anatomy of a Language Front End}, for details of the files in these
175 Source files shared between the compiler drivers (such as
176 @command{gcc}) and the compilers proper (such as @file{cc1}). If an
177 architecture defines target hooks shared between those places, it also
178 has a subdirectory in @file{common/config}. @xref{Target Structure}.
181 Configuration files for supported architectures and operating
182 systems. @xref{Back End, , Anatomy of a Target Back End}, for
183 details of the files in this directory.
186 Texinfo documentation for GCC, together with automatically generated
187 man pages and support for converting the installation manual to
188 HTML@. @xref{Documentation}.
191 System headers installed by GCC, mainly those required by the C
192 standard of freestanding implementations. @xref{Headers, , Headers
193 Installed by GCC}, for details of when these and other headers are
197 Message catalogs with translations of messages produced by GCC into
198 various languages, @file{@var{language}.po}. This directory also
199 contains @file{gcc.pot}, the template for these message catalogues,
200 @file{exgettext}, a wrapper around @command{gettext} to extract the
201 messages from the GCC sources and create @file{gcc.pot}, which is run
202 by @samp{make gcc.pot}, and @file{EXCLUDES}, a list of files from
203 which messages should not be extracted.
206 The GCC testsuites (except for those for runtime libraries).
211 @subsection Configuration in the @file{gcc} Directory
213 The @file{gcc} directory is configured with an Autoconf-generated
214 script @file{configure}. The @file{configure} script is generated
215 from @file{configure.ac} and @file{aclocal.m4}. From the files
216 @file{configure.ac} and @file{acconfig.h}, Autoheader generates the
217 file @file{config.in}. The file @file{cstamp-h.in} is used as a
221 * Config Fragments:: Scripts used by @file{configure}.
222 * System Config:: The @file{config.build}, @file{config.host}, and
223 @file{config.gcc} files.
224 * Configuration Files:: Files created by running @file{configure}.
227 @node Config Fragments
228 @subsubsection Scripts Used by @file{configure}
230 @file{configure} uses some other scripts to help in its work:
233 @item The standard GNU @file{config.sub} and @file{config.guess}
234 files, kept in the top level directory, are used.
236 @item The file @file{config.gcc} is used to handle configuration
237 specific to the particular target machine. The file
238 @file{config.build} is used to handle configuration specific to the
239 particular build machine. The file @file{config.host} is used to handle
240 configuration specific to the particular host machine. (In general,
241 these should only be used for features that cannot reasonably be tested in
242 Autoconf feature tests.)
243 @xref{System Config, , The @file{config.build}; @file{config.host};
244 and @file{config.gcc} Files}, for details of the contents of these files.
246 @item Each language subdirectory has a file
247 @file{@var{language}/config-lang.in} that is used for
248 front-end-specific configuration. @xref{Front End Config, , The Front
249 End @file{config-lang.in} File}, for details of this file.
251 @item A helper script @file{configure.frag} is used as part of
252 creating the output of @file{configure}.
256 @subsubsection The @file{config.build}; @file{config.host}; and @file{config.gcc} Files
258 The @file{config.build} file contains specific rules for particular systems
259 which GCC is built on. This should be used as rarely as possible, as the
260 behavior of the build system can always be detected by autoconf.
262 The @file{config.host} file contains specific rules for particular systems
263 which GCC will run on. This is rarely needed.
265 The @file{config.gcc} file contains specific rules for particular systems
266 which GCC will generate code for. This is usually needed.
268 Each file has a list of the shell variables it sets, with descriptions, at the
271 FIXME: document the contents of these files, and what variables should
272 be set to control build, host and target configuration.
274 @include configfiles.texi
277 @subsection Build System in the @file{gcc} Directory
279 FIXME: describe the build system, including what is built in what
280 stages. Also list the various source files that are used in the build
281 process but aren't source files of GCC itself and so aren't documented
282 below (@pxref{Passes}).
284 @include makefile.texi
287 @subsection Library Source Files and Headers under the @file{gcc} Directory
289 FIXME: list here, with explanation, all the C source files and headers
290 under the @file{gcc} directory that aren't built into the GCC
291 executable but rather are part of runtime libraries and object files,
292 such as @file{crtstuff.c} and @file{unwind-dw2.c}. @xref{Headers, ,
293 Headers Installed by GCC}, for more information about the
294 @file{ginclude} directory.
297 @subsection Headers Installed by GCC
299 In general, GCC expects the system C library to provide most of the
300 headers to be used with it. However, GCC will fix those headers if
301 necessary to make them work with GCC, and will install some headers
302 required of freestanding implementations. These headers are installed
303 in @file{@var{libsubdir}/include}. Headers for non-C runtime
304 libraries are also installed by GCC; these are not documented here.
305 (FIXME: document them somewhere.)
307 Several of the headers GCC installs are in the @file{ginclude}
308 directory. These headers, @file{iso646.h},
309 @file{stdarg.h}, @file{stdbool.h}, and @file{stddef.h},
310 are installed in @file{@var{libsubdir}/include},
311 unless the target Makefile fragment (@pxref{Target Fragment})
312 overrides this by setting @code{USER_H}.
314 In addition to these headers and those generated by fixing system
315 headers to work with GCC, some other headers may also be installed in
316 @file{@var{libsubdir}/include}. @file{config.gcc} may set
317 @code{extra_headers}; this specifies additional headers under
318 @file{config} to be installed on some systems.
320 GCC installs its own version of @code{<float.h>}, from @file{ginclude/float.h}.
321 This is done to cope with command-line options that change the
322 representation of floating point numbers.
324 GCC also installs its own version of @code{<limits.h>}; this is generated
325 from @file{glimits.h}, together with @file{limitx.h} and
326 @file{limity.h} if the system also has its own version of
327 @code{<limits.h>}. (GCC provides its own header because it is
328 required of ISO C freestanding implementations, but needs to include
329 the system header from its own header as well because other standards
330 such as POSIX specify additional values to be defined in
331 @code{<limits.h>}.) The system's @code{<limits.h>} header is used via
332 @file{@var{libsubdir}/include/syslimits.h}, which is copied from
333 @file{gsyslimits.h} if it does not need fixing to work with GCC; if it
334 needs fixing, @file{syslimits.h} is the fixed copy.
336 GCC can also install @code{<tgmath.h>}. It will do this when
337 @file{config.gcc} sets @code{use_gcc_tgmath} to @code{yes}.
340 @subsection Building Documentation
342 The main GCC documentation is in the form of manuals in Texinfo
343 format. These are installed in Info format; DVI versions may be
344 generated by @samp{make dvi}, PDF versions by @samp{make pdf}, and
345 HTML versions by @samp{make html}. In addition, some man pages are
346 generated from the Texinfo manuals, there are some other text files
347 with miscellaneous documentation, and runtime libraries have their own
348 documentation outside the @file{gcc} directory. FIXME: document the
349 documentation for runtime libraries somewhere.
352 * Texinfo Manuals:: GCC manuals in Texinfo format.
353 * Man Page Generation:: Generating man pages from Texinfo manuals.
354 * Miscellaneous Docs:: Miscellaneous text files with documentation.
357 @node Texinfo Manuals
358 @subsubsection Texinfo Manuals
360 The manuals for GCC as a whole, and the C and C++ front ends, are in
361 files @file{doc/*.texi}. Other front ends have their own manuals in
362 files @file{@var{language}/*.texi}. Common files
363 @file{doc/include/*.texi} are provided which may be included in
364 multiple manuals; the following files are in @file{doc/include}:
368 The GNU Free Documentation License.
370 The section ``Funding Free Software''.
371 @item gcc-common.texi
372 Common definitions for manuals.
374 The GNU General Public License.
376 A copy of @file{texinfo.tex} known to work with the GCC manuals.
379 DVI-formatted manuals are generated by @samp{make dvi}, which uses
380 @command{texi2dvi} (via the Makefile macro @code{$(TEXI2DVI)}).
381 PDF-formatted manuals are generated by @samp{make pdf}, which uses
382 @command{texi2pdf} (via the Makefile macro @code{$(TEXI2PDF)}). HTML
383 formatted manuals are generated by @samp{make html}. Info
384 manuals are generated by @samp{make info} (which is run as part of
385 a bootstrap); this generates the manuals in the source directory,
386 using @command{makeinfo} via the Makefile macro @code{$(MAKEINFO)},
387 and they are included in release distributions.
389 Manuals are also provided on the GCC web site, in both HTML and
390 PostScript forms. This is done via the script
391 @file{maintainer-scripts/update_web_docs_svn}. Each manual to be
392 provided online must be listed in the definition of @code{MANUALS} in
393 that file; a file @file{@var{name}.texi} must only appear once in the
394 source tree, and the output manual must have the same name as the
395 source file. (However, other Texinfo files, included in manuals but
396 not themselves the root files of manuals, may have names that appear
397 more than once in the source tree.) The manual file
398 @file{@var{name}.texi} should only include other files in its own
399 directory or in @file{doc/include}. HTML manuals will be generated by
400 @samp{makeinfo --html}, PostScript manuals by @command{texi2dvi}
401 and @command{dvips}, and PDF manuals by @command{texi2pdf}.
402 All Texinfo files that are parts of manuals must
403 be version-controlled, even if they are generated files, for the
404 generation of online manuals to work.
406 The installation manual, @file{doc/install.texi}, is also provided on
407 the GCC web site. The HTML version is generated by the script
408 @file{doc/install.texi2html}.
410 @node Man Page Generation
411 @subsubsection Man Page Generation
413 Because of user demand, in addition to full Texinfo manuals, man pages
414 are provided which contain extracts from those manuals. These man
415 pages are generated from the Texinfo manuals using
416 @file{contrib/texi2pod.pl} and @command{pod2man}. (The man page for
417 @command{g++}, @file{cp/g++.1}, just contains a @samp{.so} reference
418 to @file{gcc.1}, but all the other man pages are generated from
421 Because many systems may not have the necessary tools installed to
422 generate the man pages, they are only generated if the
423 @file{configure} script detects that recent enough tools are
424 installed, and the Makefiles allow generating man pages to fail
425 without aborting the build. Man pages are also included in release
426 distributions. They are generated in the source directory.
428 Magic comments in Texinfo files starting @samp{@@c man} control what
429 parts of a Texinfo file go into a man page. Only a subset of Texinfo
430 is supported by @file{texi2pod.pl}, and it may be necessary to add
431 support for more Texinfo features to this script when generating new
432 man pages. To improve the man page output, some special Texinfo
433 macros are provided in @file{doc/include/gcc-common.texi} which
434 @file{texi2pod.pl} understands:
438 Use in the form @samp{@@table @@gcctabopt} for tables of options,
439 where for printed output the effect of @samp{@@code} is better than
440 that of @samp{@@option} but for man page output a different effect is
443 Use for summary lists of options in manuals.
445 Use at the end of each line inside @samp{@@gccoptlist}. This is
446 necessary to avoid problems with differences in how the
447 @samp{@@gccoptlist} macro is handled by different Texinfo formatters.
450 FIXME: describe the @file{texi2pod.pl} input language and magic
451 comments in more detail.
453 @node Miscellaneous Docs
454 @subsubsection Miscellaneous Documentation
456 In addition to the formal documentation that is installed by GCC,
457 there are several other text files in the @file{gcc} subdirectory
458 with miscellaneous documentation:
462 Notes on GCC's Native Language Support. FIXME: this should be part of
463 this manual rather than a separate file.
465 Notes on the Free Translation Project.
468 The GNU General Public License, Versions 2 and 3.
471 The GNU Lesser General Public License, Versions 2.1 and 3.
474 Change log files for various parts of GCC@.
476 Details of a few changes to the GCC front-end interface. FIXME: the
477 information in this file should be part of general documentation of
478 the front-end interface in this manual.
480 Information about new features in old versions of GCC@. (For recent
481 versions, the information is on the GCC web site.)
482 @item README.Portability
483 Information about portability issues when writing code in GCC@. FIXME:
484 why isn't this part of this manual or of the GCC Coding Conventions?
487 FIXME: document such files in subdirectories, at least @file{config},
488 @file{c}, @file{cp}, @file{objc}, @file{testsuite}.
491 @subsection Anatomy of a Language Front End
493 A front end for a language in GCC has the following parts:
497 A directory @file{@var{language}} under @file{gcc} containing source
498 files for that front end. @xref{Front End Directory, , The Front End
499 @file{@var{language}} Directory}, for details.
501 A mention of the language in the list of supported languages in
502 @file{gcc/doc/install.texi}.
504 A mention of the name under which the language's runtime library is
505 recognized by @option{--enable-shared=@var{package}} in the
506 documentation of that option in @file{gcc/doc/install.texi}.
508 A mention of any special prerequisites for building the front end in
509 the documentation of prerequisites in @file{gcc/doc/install.texi}.
511 Details of contributors to that front end in
512 @file{gcc/doc/contrib.texi}. If the details are in that front end's
513 own manual then there should be a link to that manual's list in
516 Information about support for that language in
517 @file{gcc/doc/frontends.texi}.
519 Information about standards for that language, and the front end's
520 support for them, in @file{gcc/doc/standards.texi}. This may be a
521 link to such information in the front end's own manual.
523 Details of source file suffixes for that language and @option{-x
524 @var{lang}} options supported, in @file{gcc/doc/invoke.texi}.
526 Entries in @code{default_compilers} in @file{gcc.c} for source file
527 suffixes for that language.
529 Preferably testsuites, which may be under @file{gcc/testsuite} or
530 runtime library directories. FIXME: document somewhere how to write
533 Probably a runtime library for the language, outside the @file{gcc}
534 directory. FIXME: document this further.
536 Details of the directories of any runtime libraries in
537 @file{gcc/doc/sourcebuild.texi}.
539 Check targets in @file{Makefile.def} for the top-level @file{Makefile}
540 to check just the compiler or the compiler and runtime library for the
544 If the front end is added to the official GCC source repository, the
545 following are also necessary:
549 At least one Bugzilla component for bugs in that front end and runtime
550 libraries. This category needs to be added to the Bugzilla database.
552 Normally, one or more maintainers of that front end listed in
555 Mentions on the GCC web site in @file{index.html} and
556 @file{frontends.html}, with any relevant links on
557 @file{readings.html}. (Front ends that are not an official part of
558 GCC may also be listed on @file{frontends.html}, with relevant links.)
560 A news item on @file{index.html}, and possibly an announcement on the
561 @email{gcc-announce@@gcc.gnu.org} mailing list.
563 The front end's manuals should be mentioned in
564 @file{maintainer-scripts/update_web_docs_svn} (@pxref{Texinfo Manuals})
565 and the online manuals should be linked to from
566 @file{onlinedocs/index.html}.
568 Any old releases or CVS repositories of the front end, before its
569 inclusion in GCC, should be made available on the GCC FTP site
570 @uref{ftp://gcc.gnu.org/pub/gcc/old-releases/}.
572 The release and snapshot script @file{maintainer-scripts/gcc_release}
573 should be updated to generate appropriate tarballs for this front end.
575 If this front end includes its own version files that include the
576 current date, @file{maintainer-scripts/update_version} should be
581 * Front End Directory:: The front end @file{@var{language}} directory.
582 * Front End Config:: The front end @file{config-lang.in} file.
583 * Front End Makefile:: The front end @file{Make-lang.in} file.
586 @node Front End Directory
587 @subsubsection The Front End @file{@var{language}} Directory
589 A front end @file{@var{language}} directory contains the source files
590 of that front end (but not of any runtime libraries, which should be
591 outside the @file{gcc} directory). This includes documentation, and
592 possibly some subsidiary programs built alongside the front end.
593 Certain files are special and other parts of the compiler depend on
598 This file is required in all language subdirectories. @xref{Front End
599 Config, , The Front End @file{config-lang.in} File}, for details of
602 This file is required in all language subdirectories. @xref{Front End
603 Makefile, , The Front End @file{Make-lang.in} File}, for details of its
606 This file registers the set of switches that the front end accepts on
607 the command line, and their @option{--help} text. @xref{Options}.
609 This file provides entries for @code{default_compilers} in
610 @file{gcc.c} which override the default of giving an error that a
611 compiler for that language is not installed.
612 @item @var{language}-tree.def
613 This file, which need not exist, defines any language-specific tree
617 @node Front End Config
618 @subsubsection The Front End @file{config-lang.in} File
620 Each language subdirectory contains a @file{config-lang.in} file.
621 This file is a shell script that may define some variables describing
626 This definition must be present, and gives the name of the language
627 for some purposes such as arguments to @option{--enable-languages}.
629 If defined, this variable lists (space-separated) language front ends
630 other than C that this front end requires to be enabled (with the
631 names given being their @code{language} settings). For example, the
632 Java front end depends on the C++ front end, so sets
633 @samp{lang_requires=c++}.
634 @item subdir_requires
635 If defined, this variable lists (space-separated) front end directories
636 other than C that this front end requires to be present. For example,
637 the Objective-C++ front end uses source files from the C++ and
638 Objective-C front ends, so sets @samp{subdir_requires="cp objc"}.
640 If defined, this variable lists (space-separated) targets in the top
641 level @file{Makefile} to build the runtime libraries for this
642 language, such as @code{target-libobjc}.
644 If defined, this variable lists (space-separated) top level
645 directories (parallel to @file{gcc}), apart from the runtime libraries,
646 that should not be configured if this front end is not built.
647 @item build_by_default
648 If defined to @samp{no}, this language front end is not built unless
649 enabled in a @option{--enable-languages} argument. Otherwise, front
650 ends are built by default, subject to any special logic in
651 @file{configure.ac} (as is present to disable the Ada front end if the
652 Ada compiler is not already installed).
654 If defined to @samp{yes}, this front end is built in stage1 of the
655 bootstrap. This is only relevant to front ends written in their own
658 If defined, a space-separated list of compiler executables that will
659 be run by the driver. The names here will each end
660 with @samp{\$(exeext)}.
662 If defined, a space-separated list of files that should be generated
663 by @file{configure} substituting values in them. This mechanism can
664 be used to create a file @file{@var{language}/Makefile} from
665 @file{@var{language}/Makefile.in}, but this is deprecated, building
666 everything from the single @file{gcc/Makefile} is preferred.
668 If defined, a space-separated list of files that should be scanned by
669 @file{gengtype.c} to generate the garbage collection tables and routines for
670 this language. This excludes the files that are common to all front
671 ends. @xref{Type Information}.
675 @node Front End Makefile
676 @subsubsection The Front End @file{Make-lang.in} File
678 Each language subdirectory contains a @file{Make-lang.in} file. It contains
679 targets @code{@var{lang}.@var{hook}} (where @code{@var{lang}} is the
680 setting of @code{language} in @file{config-lang.in}) for the following
681 values of @code{@var{hook}}, and any other Makefile rules required to
682 build those targets (which may if necessary use other Makefiles
683 specified in @code{outputs} in @file{config-lang.in}, although this is
684 deprecated). It also adds any testsuite targets that can use the
685 standard rule in @file{gcc/Makefile.in} to the variable
692 FIXME: exactly what goes in each of these targets?
694 Build an @command{etags} @file{TAGS} file in the language subdirectory
697 Build info documentation for the front end, in the build directory.
698 This target is only called by @samp{make bootstrap} if a suitable
699 version of @command{makeinfo} is available, so does not need to check
700 for this, and should fail if an error occurs.
702 Build DVI documentation for the front end, in the build directory.
703 This should be done using @code{$(TEXI2DVI)}, with appropriate
704 @option{-I} arguments pointing to directories of included files.
706 Build PDF documentation for the front end, in the build directory.
707 This should be done using @code{$(TEXI2PDF)}, with appropriate
708 @option{-I} arguments pointing to directories of included files.
710 Build HTML documentation for the front end, in the build directory.
712 Build generated man pages for the front end from Texinfo manuals
713 (@pxref{Man Page Generation}), in the build directory. This target
714 is only called if the necessary tools are available, but should ignore
715 errors so as not to stop the build if errors occur; man pages are
716 optional and the tools involved may be installed in a broken way.
718 Install everything that is part of the front end, apart from the
719 compiler executables listed in @code{compilers} in
720 @file{config-lang.in}.
722 Install info documentation for the front end, if it is present in the
723 source directory. This target should have dependencies on info files
724 that should be installed.
726 Install man pages for the front end. This target should ignore
729 Install headers needed for plugins.
731 Copies its dependencies into the source directory. This generally should
732 be used for generated files such as Bison output files which are not
733 version-controlled, but should be included in any release tarballs. This
734 target will be executed during a bootstrap if
735 @samp{--enable-generated-files-in-srcdir} was specified as a
736 @file{configure} option.
739 Copies its dependencies into the source directory. These targets will be
740 executed during a bootstrap if @samp{--enable-generated-files-in-srcdir}
741 was specified as a @file{configure} option.
743 Uninstall files installed by installing the compiler. This is
744 currently documented not to be supported, so the hook need not do
749 @itemx maintainer-clean
750 The language parts of the standard GNU
751 @samp{*clean} targets. @xref{Standard Targets, , Standard Targets for
752 Users, standards, GNU Coding Standards}, for details of the standard
753 targets. For GCC, @code{maintainer-clean} should delete
754 all generated files in the source directory that are not version-controlled,
755 but should not delete anything that is.
758 @file{Make-lang.in} must also define a variable @code{@var{lang}_OBJS}
759 to a list of host object files that are used by that language.
762 @subsection Anatomy of a Target Back End
764 A back end for a target architecture in GCC has the following parts:
768 A directory @file{@var{machine}} under @file{gcc/config}, containing a
769 machine description @file{@var{machine}.md} file (@pxref{Machine Desc,
770 , Machine Descriptions}), header files @file{@var{machine}.h} and
771 @file{@var{machine}-protos.h} and a source file @file{@var{machine}.c}
772 (@pxref{Target Macros, , Target Description Macros and Functions}),
773 possibly a target Makefile fragment @file{t-@var{machine}}
774 (@pxref{Target Fragment, , The Target Makefile Fragment}), and maybe
775 some other files. The names of these files may be changed from the
776 defaults given by explicit specifications in @file{config.gcc}.
778 If necessary, a file @file{@var{machine}-modes.def} in the
779 @file{@var{machine}} directory, containing additional machine modes to
780 represent condition codes. @xref{Condition Code}, for further details.
782 An optional @file{@var{machine}.opt} file in the @file{@var{machine}}
783 directory, containing a list of target-specific options. You can also
784 add other option files using the @code{extra_options} variable in
785 @file{config.gcc}. @xref{Options}.
787 Entries in @file{config.gcc} (@pxref{System Config, , The
788 @file{config.gcc} File}) for the systems with this target
791 Documentation in @file{gcc/doc/invoke.texi} for any command-line
792 options supported by this target (@pxref{Run-time Target, , Run-time
793 Target Specification}). This means both entries in the summary table
794 of options and details of the individual options.
796 Documentation in @file{gcc/doc/extend.texi} for any target-specific
797 attributes supported (@pxref{Target Attributes, , Defining
798 target-specific uses of @code{__attribute__}}), including where the
799 same attribute is already supported on some targets, which are
800 enumerated in the manual.
802 Documentation in @file{gcc/doc/extend.texi} for any target-specific
805 Documentation in @file{gcc/doc/extend.texi} of any target-specific
806 built-in functions supported.
808 Documentation in @file{gcc/doc/extend.texi} of any target-specific
809 format checking styles supported.
811 Documentation in @file{gcc/doc/md.texi} of any target-specific
812 constraint letters (@pxref{Machine Constraints, , Constraints for
813 Particular Machines}).
815 A note in @file{gcc/doc/contrib.texi} under the person or people who
816 contributed the target support.
818 Entries in @file{gcc/doc/install.texi} for all target triplets
819 supported with this target architecture, giving details of any special
820 notes about installation for this target, or saying that there are no
821 special notes if there are none.
823 Possibly other support outside the @file{gcc} directory for runtime
824 libraries. FIXME: reference docs for this. The @code{libstdc++} porting
825 manual needs to be installed as info for this to work, or to be a
826 chapter of this manual.
829 If the back end is added to the official GCC source repository, the
830 following are also necessary:
834 An entry for the target architecture in @file{readings.html} on the
835 GCC web site, with any relevant links.
837 Details of the properties of the back end and target architecture in
838 @file{backends.html} on the GCC web site.
840 A news item about the contribution of support for that target
841 architecture, in @file{index.html} on the GCC web site.
843 Normally, one or more maintainers of that target listed in
844 @file{MAINTAINERS}. Some existing architectures may be unmaintained,
845 but it would be unusual to add support for a target that does not have
846 a maintainer when support is added.
848 Target triplets covering all @file{config.gcc} stanzas for the target,
849 in the list in @file{contrib/config-list.mk}.
855 GCC contains several testsuites to help maintain compiler quality.
856 Most of the runtime libraries and language front ends in GCC have
857 testsuites. Currently only the C language testsuites are documented
858 here; FIXME: document the others.
861 * Test Idioms:: Idioms used in testsuite code.
862 * Test Directives:: Directives used within DejaGnu tests.
863 * Ada Tests:: The Ada language testsuites.
864 * C Tests:: The C language testsuites.
865 * libgcj Tests:: The Java library testsuites.
866 * LTO Testing:: Support for testing link-time optimizations.
867 * gcov Testing:: Support for testing gcov.
868 * profopt Testing:: Support for testing profile-directed optimizations.
869 * compat Testing:: Support for testing binary compatibility.
870 * Torture Tests:: Support for torture testing using multiple options.
874 @section Idioms Used in Testsuite Code
876 In general, C testcases have a trailing @file{-@var{n}.c}, starting
877 with @file{-1.c}, in case other testcases with similar names are added
878 later. If the test is a test of some well-defined feature, it should
879 have a name referring to that feature such as
880 @file{@var{feature}-1.c}. If it does not test a well-defined feature
881 but just happens to exercise a bug somewhere in the compiler, and a
882 bug report has been filed for this bug in the GCC bug database,
883 @file{pr@var{bug-number}-1.c} is the appropriate form of name.
884 Otherwise (for miscellaneous bugs not filed in the GCC bug database),
885 and previously more generally, test cases are named after the date on
886 which they were added. This allows people to tell at a glance whether
887 a test failure is because of a recently found bug that has not yet
888 been fixed, or whether it may be a regression, but does not give any
889 other information about the bug or where discussion of it may be
890 found. Some other language testsuites follow similar conventions.
892 In the @file{gcc.dg} testsuite, it is often necessary to test that an
893 error is indeed a hard error and not just a warning---for example,
894 where it is a constraint violation in the C standard, which must
895 become an error with @option{-pedantic-errors}. The following idiom,
896 where the first line shown is line @var{line} of the file and the line
897 that generates the error, is used for this:
900 /* @{ dg-bogus "warning" "warning in place of error" @} */
901 /* @{ dg-error "@var{regexp}" "@var{message}" @{ target *-*-* @} @var{line} @} */
904 It may be necessary to check that an expression is an integer constant
905 expression and has a certain value. To check that @code{@var{E}} has
906 value @code{@var{V}}, an idiom similar to the following is used:
909 char x[((E) == (V) ? 1 : -1)];
912 In @file{gcc.dg} tests, @code{__typeof__} is sometimes used to make
913 assertions about the types of expressions. See, for example,
914 @file{gcc.dg/c99-condexpr-1.c}. The more subtle uses depend on the
915 exact rules for the types of conditional expressions in the C
916 standard; see, for example, @file{gcc.dg/c99-intconst-1.c}.
918 It is useful to be able to test that optimizations are being made
919 properly. This cannot be done in all cases, but it can be done where
920 the optimization will lead to code being optimized away (for example,
921 where flow analysis or alias analysis should show that certain code
922 cannot be called) or to functions not being called because they have
923 been expanded as built-in functions. Such tests go in
924 @file{gcc.c-torture/execute}. Where code should be optimized away, a
925 call to a nonexistent function such as @code{link_failure ()} may be
926 inserted; a definition
939 will also be needed so that linking still succeeds when the test is
940 run without optimization. When all calls to a built-in function
941 should have been optimized and no calls to the non-built-in version of
942 the function should remain, that function may be defined as
943 @code{static} to call @code{abort ()} (although redeclaring a function
944 as static may not work on all targets).
946 All testcases must be portable. Target-specific testcases must have
947 appropriate code to avoid causing failures on unsupported systems;
948 unfortunately, the mechanisms for this differ by directory.
950 FIXME: discuss non-C testsuites here.
952 @node Test Directives
953 @section Directives used within DejaGnu tests
956 * Directives:: Syntax and descriptions of test directives.
957 * Selectors:: Selecting targets to which a test applies.
958 * Effective-Target Keywords:: Keywords describing target attributes.
959 * Add Options:: Features for @code{dg-add-options}
960 * Require Support:: Variants of @code{dg-require-@var{support}}
961 * Final Actions:: Commands for use in @code{dg-final}
965 @subsection Syntax and Descriptions of test directives
967 Test directives appear within comments in a test source file and begin
968 with @code{dg-}. Some of these are defined within DejaGnu and others
969 are local to the GCC testsuite.
971 The order in which test directives appear in a test can be important:
972 directives local to GCC sometimes override information used by the
973 DejaGnu directives, which know nothing about the GCC directives, so the
974 DejaGnu directives must precede GCC directives.
976 Several test directives include selectors (@pxref{Selectors, , })
977 which are usually preceded by the keyword @code{target} or @code{xfail}.
979 @subsubsection Specify how to build the test
982 @item @{ dg-do @var{do-what-keyword} [@{ target/xfail @var{selector} @}] @}
983 @var{do-what-keyword} specifies how the test is compiled and whether
984 it is executed. It is one of:
988 Compile with @option{-E} to run only the preprocessor.
990 Compile with @option{-S} to produce an assembly code file.
992 Compile with @option{-c} to produce a relocatable object file.
994 Compile, assemble, and link to produce an executable file.
996 Produce and run an executable file, which is expected to return
1000 The default is @code{compile}. That can be overridden for a set of
1001 tests by redefining @code{dg-do-what-default} within the @code{.exp}
1002 file for those tests.
1004 If the directive includes the optional @samp{@{ target @var{selector} @}}
1005 then the test is skipped unless the target system matches the
1008 If @var{do-what-keyword} is @code{run} and the directive includes
1009 the optional @samp{@{ xfail @var{selector} @}} and the selector is met
1010 then the test is expected to fail. The @code{xfail} clause is ignored
1011 for other values of @var{do-what-keyword}; those tests can use
1012 directive @code{dg-xfail-if}.
1015 @subsubsection Specify additional compiler options
1018 @item @{ dg-options @var{options} [@{ target @var{selector} @}] @}
1019 This DejaGnu directive provides a list of compiler options, to be used
1020 if the target system matches @var{selector}, that replace the default
1021 options used for this set of tests.
1023 @item @{ dg-add-options @var{feature} @dots{} @}
1024 Add any compiler options that are needed to access certain features.
1025 This directive does nothing on targets that enable the features by
1026 default, or that don't provide them at all. It must come after
1027 all @code{dg-options} directives.
1028 For supported values of @var{feature} see @ref{Add Options, ,}.
1030 @item @{ dg-additional-options @var{options} [@{ target @var{selector} @}] @}
1031 This directive provides a list of compiler options, to be used
1032 if the target system matches @var{selector}, that are added to the default
1033 options used for this set of tests.
1036 @subsubsection Modify the test timeout value
1038 The normal timeout limit, in seconds, is found by searching the
1042 @item the value defined by an earlier @code{dg-timeout} directive in
1045 @item variable @var{tool_timeout} defined by the set of tests
1047 @item @var{gcc},@var{timeout} set in the target board
1053 @item @{ dg-timeout @var{n} [@{target @var{selector} @}] @}
1054 Set the time limit for the compilation and for the execution of the test
1055 to the specified number of seconds.
1057 @item @{ dg-timeout-factor @var{x} [@{ target @var{selector} @}] @}
1058 Multiply the normal time limit for compilation and execution of the test
1059 by the specified floating-point factor.
1062 @subsubsection Skip a test for some targets
1065 @item @{ dg-skip-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1066 Arguments @var{include-opts} and @var{exclude-opts} are lists in which
1067 each element is a string of zero or more GCC options.
1068 Skip the test if all of the following conditions are met:
1070 @item the test system is included in @var{selector}
1072 @item for at least one of the option strings in @var{include-opts},
1073 every option from that string is in the set of options with which
1074 the test would be compiled; use @samp{"*"} for an @var{include-opts} list
1075 that matches any options; that is the default if @var{include-opts} is
1078 @item for each of the option strings in @var{exclude-opts}, at least one
1079 option from that string is not in the set of options with which the test
1080 would be compiled; use @samp{""} for an empty @var{exclude-opts} list;
1081 that is the default if @var{exclude-opts} is not specified
1084 For example, to skip a test if option @code{-Os} is present:
1087 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-Os" @} @{ "" @} @} */
1090 To skip a test if both options @code{-O2} and @code{-g} are present:
1093 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" @} @{ "" @} @} */
1096 To skip a test if either @code{-O2} or @code{-O3} is present:
1099 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2" "-O3" @} @{ "" @} @} */
1102 To skip a test unless option @code{-Os} is present:
1105 /* @{ dg-skip-if "" @{ *-*-* @} @{ "*" @} @{ "-Os" @} @} */
1108 To skip a test if either @code{-O2} or @code{-O3} is used with @code{-g}
1109 but not if @code{-fpic} is also present:
1112 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" "-O3 -g" @} @{ "-fpic" @} @} */
1115 @item @{ dg-require-effective-target @var{keyword} [@{ @var{selector} @}] @}
1116 Skip the test if the test target, including current multilib flags,
1117 is not covered by the effective-target keyword.
1118 If the directive includes the optional @samp{@{ @var{selector} @}}
1119 then the effective-target test is only performed if the target system
1120 matches the @var{selector}.
1121 This directive must appear after any @code{dg-do} directive in the test
1122 and before any @code{dg-additional-sources} directive.
1123 @xref{Effective-Target Keywords, , }.
1125 @item @{ dg-require-@var{support} args @}
1126 Skip the test if the target does not provide the required support.
1127 These directives must appear after any @code{dg-do} directive in the test
1128 and before any @code{dg-additional-sources} directive.
1129 They require at least one argument, which can be an empty string if the
1130 specific procedure does not examine the argument.
1131 @xref{Require Support, , }, for a complete list of these directives.
1134 @subsubsection Expect a test to fail for some targets
1137 @item @{ dg-xfail-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1138 Expect the test to fail if the conditions (which are the same as for
1139 @code{dg-skip-if}) are met. This does not affect the execute step.
1141 @item @{ dg-xfail-run-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1142 Expect the execute step of a test to fail if the conditions (which are
1143 the same as for @code{dg-skip-if}) are met.
1146 @subsubsection Expect the test executable to fail
1149 @item @{ dg-shouldfail @var{comment} [@{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]]] @}
1150 Expect the test executable to return a nonzero exit status if the
1151 conditions (which are the same as for @code{dg-skip-if}) are met.
1154 @subsubsection Verify compiler messages
1157 @item @{ dg-error @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1158 This DejaGnu directive appears on a source line that is expected to get
1159 an error message, or else specifies the source line associated with the
1160 message. If there is no message for that line or if the text of that
1161 message is not matched by @var{regexp} then the check fails and
1162 @var{comment} is included in the @code{FAIL} message. The check does
1163 not look for the string @samp{error} unless it is part of @var{regexp}.
1165 @item @{ dg-warning @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1166 This DejaGnu directive appears on a source line that is expected to get
1167 a warning message, or else specifies the source line associated with the
1168 message. If there is no message for that line or if the text of that
1169 message is not matched by @var{regexp} then the check fails and
1170 @var{comment} is included in the @code{FAIL} message. The check does
1171 not look for the string @samp{warning} unless it is part of @var{regexp}.
1173 @item @{ dg-message @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1174 The line is expected to get a message other than an error or warning.
1175 If there is no message for that line or if the text of that message is
1176 not matched by @var{regexp} then the check fails and @var{comment} is
1177 included in the @code{FAIL} message.
1179 @item @{ dg-bogus @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1180 This DejaGnu directive appears on a source line that should not get a
1181 message matching @var{regexp}, or else specifies the source line
1182 associated with the bogus message. It is usually used with @samp{xfail}
1183 to indicate that the message is a known problem for a particular set of
1186 @item @{ dg-excess-errors @var{comment} [@{ target/xfail @var{selector} @}] @}
1187 This DejaGnu directive indicates that the test is expected to fail due
1188 to compiler messages that are not handled by @samp{dg-error},
1189 @samp{dg-warning} or @samp{dg-bogus}. For this directive @samp{xfail}
1190 has the same effect as @samp{target}.
1192 @item @{ dg-prune-output @var{regexp} @}
1193 Prune messages matching @var{regexp} from the test output.
1196 @subsubsection Verify output of the test executable
1199 @item @{ dg-output @var{regexp} [@{ target/xfail @var{selector} @}] @}
1200 This DejaGnu directive compares @var{regexp} to the combined output
1201 that the test executable writes to @file{stdout} and @file{stderr}.
1204 @subsubsection Specify additional files for a test
1207 @item @{ dg-additional-files "@var{filelist}" @}
1208 Specify additional files, other than source files, that must be copied
1209 to the system where the compiler runs.
1211 @item @{ dg-additional-sources "@var{filelist}" @}
1212 Specify additional source files to appear in the compile line
1213 following the main test file.
1216 @subsubsection Add checks at the end of a test
1219 @item @{ dg-final @{ @var{local-directive} @} @}
1220 This DejaGnu directive is placed within a comment anywhere in the
1221 source file and is processed after the test has been compiled and run.
1222 Multiple @samp{dg-final} commands are processed in the order in which
1223 they appear in the source file. @xref{Final Actions, , }, for a list
1224 of directives that can be used within @code{dg-final}.
1228 @subsection Selecting targets to which a test applies
1230 Several test directives include @var{selector}s to limit the targets
1231 for which a test is run or to declare that a test is expected to fail
1232 on particular targets.
1236 @item one or more target triplets, possibly including wildcard characters;
1237 use @samp{*-*-*} to match any target
1238 @item a single effective-target keyword (@pxref{Effective-Target Keywords})
1239 @item a logical expression
1242 Depending on the context, the selector specifies whether a test is
1243 skipped and reported as unsupported or is expected to fail. A context
1244 that allows either @samp{target} or @samp{xfail} also allows
1245 @samp{@{ target @var{selector1} xfail @var{selector2} @}}
1246 to skip the test for targets that don't match @var{selector1} and the
1247 test to fail for targets that match @var{selector2}.
1249 A selector expression appears within curly braces and uses a single
1250 logical operator: one of @samp{!}, @samp{&&}, or @samp{||}. An
1251 operand is another selector expression, an effective-target keyword,
1252 a single target triplet, or a list of target triplets within quotes or
1253 curly braces. For example:
1256 @{ target @{ ! "hppa*-*-* ia64*-*-*" @} @}
1257 @{ target @{ powerpc*-*-* && lp64 @} @}
1258 @{ xfail @{ lp64 || vect_no_align @} @}
1261 @node Effective-Target Keywords
1262 @subsection Keywords describing target attributes
1264 Effective-target keywords identify sets of targets that support
1265 particular functionality. They are used to limit tests to be run only
1266 for particular targets, or to specify that particular sets of targets
1267 are expected to fail some tests.
1269 Effective-target keywords are defined in @file{lib/target-supports.exp} in
1270 the GCC testsuite, with the exception of those that are documented as
1271 being local to a particular test directory.
1273 The @samp{effective target} takes into account all of the compiler options
1274 with which the test will be compiled, including the multilib options.
1275 By convention, keywords ending in @code{_nocache} can also include options
1276 specified for the particular test in an earlier @code{dg-options} or
1277 @code{dg-add-options} directive.
1279 @subsubsection Data type sizes
1283 Target has 32-bit @code{int}, @code{long}, and pointers.
1286 Target has 32-bit @code{int}, 64-bit @code{long} and pointers.
1289 Target has 32-bit @code{int} and @code{long}, 64-bit @code{long long}
1293 Target has 64-bit @code{double}.
1296 Target has @code{double} that is 64 bits or longer.
1299 Target has 128-bit @code{long double}.
1302 Target has @code{int} that is at 32 bits or longer.
1305 Target has @code{int} that is 16 bits or shorter.
1308 Target has @code{int} and @code{long} with different sizes.
1311 Target supports @code{double} that is longer than @code{float}.
1313 @item large_long_double
1314 Target supports @code{long double} that is longer than @code{double}.
1317 Target has pointers that are 32 bits or longer.
1320 Target supports array and structure sizes that are 32 bits or longer.
1323 Target has @code{wchar_t} that is at least 4 bytes.
1326 @subsubsection Fortran-specific attributes
1329 @item fortran_integer_16
1330 Target supports Fortran @code{integer} that is 16 bytes or longer.
1332 @item fortran_large_int
1333 Target supports Fortran @code{integer} kinds larger than @code{integer(8)}.
1335 @item fortran_large_real
1336 Target supports Fortran @code{real} kinds larger than @code{real(8)}.
1339 @subsubsection Vector-specific attributes
1342 @item vect_condition
1343 Target supports vector conditional operations.
1346 Target supports hardware vectors of @code{double}.
1349 Target supports hardware vectors of @code{float}.
1352 Target supports hardware vectors of @code{int}.
1355 Target supports hardware vectors of @code{long}.
1357 @item vect_long_long
1358 Target supports hardware vectors of @code{long long}.
1360 @item vect_aligned_arrays
1361 Target aligns arrays to vector alignment boundary.
1363 @item vect_hw_misalign
1364 Target supports a vector misalign access.
1367 Target does not support a vector alignment mechanism.
1369 @item vect_no_int_max
1370 Target does not support a vector max instruction on @code{int}.
1372 @item vect_no_int_add
1373 Target does not support a vector add instruction on @code{int}.
1375 @item vect_no_bitwise
1376 Target does not support vector bitwise instructions.
1378 @item vect_char_mult
1379 Target supports @code{vector char} multiplication.
1381 @item vect_short_mult
1382 Target supports @code{vector short} multiplication.
1385 Target supports @code{vector int} multiplication.
1387 @item vect_extract_even_odd
1388 Target supports vector even/odd element extraction.
1390 @item vect_extract_even_odd_wide
1391 Target supports vector even/odd element extraction of vectors with elements
1392 @code{SImode} or larger.
1394 @item vect_interleave
1395 Target supports vector interleaving.
1398 Target supports vector interleaving and extract even/odd.
1400 @item vect_strided_wide
1401 Target supports vector interleaving and extract even/odd for wide
1405 Target supports vector permutation.
1408 Target supports a hardware vector shift operation.
1410 @item vect_widen_sum_hi_to_si
1411 Target supports a vector widening summation of @code{short} operands
1412 into @code{int} results, or can promote (unpack) from @code{short}
1415 @item vect_widen_sum_qi_to_hi
1416 Target supports a vector widening summation of @code{char} operands
1417 into @code{short} results, or can promote (unpack) from @code{char}
1420 @item vect_widen_sum_qi_to_si
1421 Target supports a vector widening summation of @code{char} operands
1422 into @code{int} results.
1424 @item vect_widen_mult_qi_to_hi
1425 Target supports a vector widening multiplication of @code{char} operands
1426 into @code{short} results, or can promote (unpack) from @code{char} to
1427 @code{short} and perform non-widening multiplication of @code{short}.
1429 @item vect_widen_mult_hi_to_si
1430 Target supports a vector widening multiplication of @code{short} operands
1431 into @code{int} results, or can promote (unpack) from @code{short} to
1432 @code{int} and perform non-widening multiplication of @code{int}.
1434 @item vect_widen_mult_si_to_di_pattern
1435 Target supports a vector widening multiplication of @code{int} operands
1436 into @code{long} results.
1439 Target supports a vector dot-product of @code{signed char}.
1442 Target supports a vector dot-product of @code{unsigned char}.
1445 Target supports a vector dot-product of @code{signed short}.
1448 Target supports a vector dot-product of @code{unsigned short}.
1450 @item vect_pack_trunc
1451 Target supports a vector demotion (packing) of @code{short} to @code{char}
1452 and from @code{int} to @code{short} using modulo arithmetic.
1455 Target supports a vector promotion (unpacking) of @code{char} to @code{short}
1456 and from @code{char} to @code{int}.
1458 @item vect_intfloat_cvt
1459 Target supports conversion from @code{signed int} to @code{float}.
1461 @item vect_uintfloat_cvt
1462 Target supports conversion from @code{unsigned int} to @code{float}.
1464 @item vect_floatint_cvt
1465 Target supports conversion from @code{float} to @code{signed int}.
1467 @item vect_floatuint_cvt
1468 Target supports conversion from @code{float} to @code{unsigned int}.
1471 @subsubsection Thread Local Storage attributes
1475 Target supports thread-local storage.
1478 Target supports native (rather than emulated) thread-local storage.
1481 Test system supports executing TLS executables.
1484 @subsubsection Decimal floating point attributes
1488 Targets supports compiling decimal floating point extension to C.
1491 Including the options used to compile this particular test, the
1492 target supports compiling decimal floating point extension to C.
1495 Test system can execute decimal floating point tests.
1498 Including the options used to compile this particular test, the
1499 test system can execute decimal floating point tests.
1502 Target generates decimal floating point instructions with current options.
1505 @subsubsection ARM-specific attributes
1509 ARM target generates 32-bit code.
1512 ARM target adheres to the ABI for the ARM Architecture.
1515 ARM target adheres to the VFP and Advanced SIMD Register Arguments
1516 variant of the ABI for the ARM Architecture (as selected with
1517 @code{-mfloat-abi=hard}).
1519 @item arm_hard_vfp_ok
1520 ARM target supports @code{-mfpu=vfp -mfloat-abi=hard}.
1521 Some multilibs may be incompatible with these options.
1524 ARM target supports @code{-mcpu=iwmmxt}.
1525 Some multilibs may be incompatible with this option.
1528 ARM target supports generating NEON instructions.
1530 @item arm_tune_string_ops_prefer_neon
1531 Test CPU tune supports inlining string operations with NEON instructions.
1534 Test system supports executing NEON instructions.
1537 Test system supports executing NEON v2 instructions.
1540 @anchor{arm_neon_ok}
1541 ARM Target supports @code{-mfpu=neon -mfloat-abi=softfp} or compatible
1542 options. Some multilibs may be incompatible with these options.
1545 @anchor{arm_neonv2_ok}
1546 ARM Target supports @code{-mfpu=neon-vfpv4 -mfloat-abi=softfp} or compatible
1547 options. Some multilibs may be incompatible with these options.
1549 @item arm_neon_fp16_ok
1550 @anchor{arm_neon_fp16_ok}
1551 ARM Target supports @code{-mfpu=neon-fp16 -mfloat-abi=softfp} or compatible
1552 options. Some multilibs may be incompatible with these options.
1555 ARM target generates Thumb-1 code for @code{-mthumb}.
1558 ARM target generates Thumb-2 code for @code{-mthumb}.
1561 ARM target supports @code{-mfpu=vfp -mfloat-abi=softfp}.
1562 Some multilibs may be incompatible with these options.
1565 @anchor{arm_vfp3_ok}
1566 ARM target supports @code{-mfpu=vfp3 -mfloat-abi=softfp}.
1567 Some multilibs may be incompatible with these options.
1570 ARM target supports @code{-mfpu=fp-armv8 -mfloat-abi=softfp}.
1571 Some multilibs may be incompatible with these options.
1573 @item arm_v8_neon_ok
1574 ARM target supports @code{-mfpu=neon-fp-armv8 -mfloat-abi=softfp}.
1575 Some multilibs may be incompatible with these options.
1577 @item arm_prefer_ldrd_strd
1578 ARM target prefers @code{LDRD} and @code{STRD} instructions over
1579 @code{LDM} and @code{STM} instructions.
1583 @subsubsection MIPS-specific attributes
1587 MIPS target supports 64-bit instructions.
1590 MIPS target does not produce MIPS16 code.
1592 @item mips16_attribute
1593 MIPS target can generate MIPS16 code.
1596 MIPS target is a Loongson-2E or -2F target using an ABI that supports
1597 the Loongson vector modes.
1599 @item mips_newabi_large_long_double
1600 MIPS target supports @code{long double} larger than @code{double}
1601 when using the new ABI.
1603 @item mpaired_single
1604 MIPS target supports @code{-mpaired-single}.
1607 @subsubsection PowerPC-specific attributes
1612 PowerPC target supports executing hardware DFP instructions.
1615 PowerPC target supports executing VSX instructions (ISA 2.07).
1618 Test system supports executing 64-bit instructions.
1620 @item powerpc_altivec
1621 PowerPC target supports AltiVec.
1623 @item powerpc_altivec_ok
1624 PowerPC target supports @code{-maltivec}.
1626 @item powerpc_eabi_ok
1627 PowerPC target supports @code{-meabi}.
1630 PowerPC target supports @code{-mabi=elfv2}.
1633 PowerPC target supports floating-point registers.
1635 @item powerpc_hard_double
1636 PowerPC target supports hardware double-precision floating-point.
1638 @item powerpc_htm_ok
1639 PowerPC target supports @code{-mhtm}
1641 @item powerpc_p8vector_ok
1642 PowerPC target supports @code{-mpower8-vector}
1644 @item powerpc_ppu_ok
1645 PowerPC target supports @code{-mcpu=cell}.
1648 PowerPC target supports PowerPC SPE.
1650 @item powerpc_spe_nocache
1651 Including the options used to compile this particular test, the
1652 PowerPC target supports PowerPC SPE.
1655 PowerPC target supports PowerPC SPU.
1657 @item powerpc_vsx_ok
1658 PowerPC target supports @code{-mvsx}.
1660 @item powerpc_405_nocache
1661 Including the options used to compile this particular test, the
1662 PowerPC target supports PowerPC 405.
1665 PowerPC target supports executing reciprocal estimate instructions.
1667 @item spu_auto_overlay
1668 SPU target has toolchain that supports automatic overlay generation.
1671 PowerPC target supports executing AltiVec instructions.
1674 PowerPC target supports executing VSX instructions (ISA 2.06).
1677 @subsubsection Other hardware attributes
1681 Target supports compiling @code{avx} instructions.
1684 Target supports the execution of @code{avx} instructions.
1687 Test system can execute AltiVec and Cell PPU instructions.
1690 Target uses a ColdFire FPU.
1693 Target supports FPU instructions.
1695 @item non_strict_align
1696 Target does not require strict alignment.
1699 Target has a square root instruction that the compiler can generate.
1702 Target supports compiling @code{sse} instructions.
1705 Target supports the execution of @code{sse} instructions.
1708 Target supports compiling @code{sse2} instructions.
1711 Target supports the execution of @code{sse2} instructions.
1713 @item sync_char_short
1714 Target supports atomic operations on @code{char} and @code{short}.
1717 Target supports atomic operations on @code{int} and @code{long}.
1720 Test environment appears to run executables on a simulator that
1721 accepts only @code{EM_SPARC} executables and chokes on @code{EM_SPARC32PLUS}
1722 or @code{EM_SPARCV9} executables.
1724 @item vect_cmdline_needed
1725 Target requires a command line argument to enable a SIMD instruction set.
1728 The x86-64 target linker supports PIE with copy reloc.
1731 @subsubsection Environment attributes
1735 The language for the compiler under test is C.
1738 The language for the compiler under test is C++.
1741 Target provides a full C99 runtime.
1743 @item correct_iso_cpp_string_wchar_protos
1744 Target @code{string.h} and @code{wchar.h} headers provide C++ required
1745 overloads for @code{strchr} etc. functions.
1747 @item dummy_wcsftime
1748 Target uses a dummy @code{wcsftime} function that always returns zero.
1751 Target can truncate a file from a file descriptor, as used by
1752 @file{libgfortran/io/unix.c:fd_truncate}; i.e. @code{ftruncate} or
1756 Target is @samp{freestanding} as defined in section 4 of the C99 standard.
1757 Effectively, it is a target which supports no extra headers or libraries
1758 other than what is considered essential.
1761 Target supports constructors with initialization priority arguments.
1763 @item inttypes_types
1764 Target has the basic signed and unsigned types in @code{inttypes.h}.
1765 This is for tests that GCC's notions of these types agree with those
1766 in the header, as some systems have only @code{inttypes.h}.
1769 Target might have errors of a few ULP in string to floating-point
1770 conversion functions and overflow is not always detected correctly by
1774 Target provides @code{mempcpy} function.
1777 Target supports @code{mmap}.
1780 Target supports Newlib.
1783 Target provides @code{pow10} function.
1786 Target can compile using @code{pthread.h} with no errors or warnings.
1789 Target has @code{pthread.h}.
1791 @item run_expensive_tests
1792 Expensive testcases (usually those that consume excessive amounts of CPU
1793 time) should be run on this target. This can be enabled by setting the
1794 @env{GCC_TEST_RUN_EXPENSIVE} environment variable to a non-empty string.
1797 Test system runs executables on a simulator (i.e. slowly) rather than
1798 hardware (i.e. fast).
1801 Target has the basic signed and unsigned C types in @code{stdint.h}.
1802 This will be obsolete when GCC ensures a working @code{stdint.h} for
1806 Target provides @code{stpcpy} function.
1809 Target supports trampolines.
1812 Target supports uClibc.
1815 Target does not use a status wrapper.
1817 @item vxworks_kernel
1818 Target is a VxWorks kernel.
1821 Target is a VxWorks RTP.
1824 Target supports wide characters.
1827 @subsubsection Other attributes
1830 @item automatic_stack_alignment
1831 Target supports automatic stack alignment.
1834 Target uses @code{__cxa_atexit}.
1836 @item default_packed
1837 Target has packed layout of structure members by default.
1840 Target supports Graphite optimizations.
1843 Target supports fixed-point extension to C.
1846 Target supports OpenACC via @option{-fopenacc}.
1849 Target supports OpenMP via @option{-fopenmp}.
1852 Target supports @option{-fpic} and @option{-fPIC}.
1855 Target supports @option{-freorder-blocks-and-partition}.
1857 @item fstack_protector
1858 Target supports @option{-fstack-protector}.
1861 Target uses GNU @command{as}.
1864 Target supports @option{--gc-sections}.
1867 Target uses GNU @command{ld}.
1869 @item keeps_null_pointer_checks
1870 Target keeps null pointer checks, either due to the use of
1871 @option{-fno-delete-null-pointer-checks} or hardwired into the target.
1874 Compiler has been configured to support link-time optimization (LTO).
1876 @item naked_functions
1877 Target supports the @code{naked} function attribute.
1879 @item named_sections
1880 Target supports named sections.
1882 @item natural_alignment_32
1883 Target uses natural alignment (aligned to type size) for types of
1886 @item target_natural_alignment_64
1887 Target uses natural alignment (aligned to type size) for types of
1891 Target does not generate PIC by default.
1894 Target generates PIE by default.
1896 @item pcc_bitfield_type_matters
1897 Target defines @code{PCC_BITFIELD_TYPE_MATTERS}.
1899 @item pe_aligned_commons
1900 Target supports @option{-mpe-aligned-commons}.
1903 Target supports @option{-pie}, @option{-fpie} and @option{-fPIE}.
1905 @item section_anchors
1906 Target supports section anchors.
1909 Target defaults to short enums.
1912 Target supports @option{-static}.
1914 @item static_libgfortran
1915 Target supports statically linking @samp{libgfortran}.
1917 @item string_merging
1918 Target supports merging string constants at link time.
1921 Target supports compiling and assembling UCN.
1924 Including the options used to compile this particular test, the
1925 target supports compiling and assembling UCN.
1927 @item unaligned_stack
1928 Target does not guarantee that its @code{STACK_BOUNDARY} is greater than
1929 or equal to the required vector alignment.
1931 @item vector_alignment_reachable
1932 Vector alignment is reachable for types of 32 bits or less.
1934 @item vector_alignment_reachable_for_64bit
1935 Vector alignment is reachable for types of 64 bits or less.
1937 @item wchar_t_char16_t_compatible
1938 Target supports @code{wchar_t} that is compatible with @code{char16_t}.
1940 @item wchar_t_char32_t_compatible
1941 Target supports @code{wchar_t} that is compatible with @code{char32_t}.
1944 Target uses comdat groups.
1947 @subsubsection Local to tests in @code{gcc.target/i386}
1951 Target supports compiling @code{3dnow} instructions.
1954 Target supports compiling @code{aes} instructions.
1957 Target supports compiling @code{fma4} instructions.
1959 @item ms_hook_prologue
1960 Target supports attribute @code{ms_hook_prologue}.
1963 Target supports compiling @code{pclmul} instructions.
1966 Target supports compiling @code{sse3} instructions.
1969 Target supports compiling @code{sse4} instructions.
1972 Target supports compiling @code{sse4a} instructions.
1975 Target supports compiling @code{ssse3} instructions.
1978 Target supports compiling @code{vaes} instructions.
1981 Target supports compiling @code{vpclmul} instructions.
1984 Target supports compiling @code{xop} instructions.
1987 @subsubsection Local to tests in @code{gcc.target/spu/ea}
1991 Target @code{__ea} library functions are available.
1994 @subsubsection Local to tests in @code{gcc.test-framework}
2005 @subsection Features for @code{dg-add-options}
2007 The supported values of @var{feature} for directive @code{dg-add-options}
2012 NEON support. Only ARM targets support this feature, and only then
2013 in certain modes; see the @ref{arm_neon_ok,,arm_neon_ok effective target
2017 NEON and half-precision floating point support. Only ARM targets
2018 support this feature, and only then in certain modes; see
2019 the @ref{arm_neon_ok,,arm_neon_fp16_ok effective target keyword}.
2022 arm vfp3 floating point support; see
2023 the @ref{arm_vfp3_ok,,arm_vfp3_ok effective target keyword}.
2025 @item bind_pic_locally
2026 Add the target-specific flags needed to enable functions to bind
2027 locally when using pic/PIC passes in the testsuite.
2030 Add the target-specific flags needed to access the C99 runtime.
2033 Add the target-specific flags needed to enable full IEEE
2036 @item mips16_attribute
2037 @code{mips16} function attributes.
2038 Only MIPS targets support this feature, and only then in certain modes.
2041 Add the target-specific flags needed to use thread-local storage.
2044 @node Require Support
2045 @subsection Variants of @code{dg-require-@var{support}}
2047 A few of the @code{dg-require} directives take arguments.
2050 @item dg-require-iconv @var{codeset}
2051 Skip the test if the target does not support iconv. @var{codeset} is
2052 the codeset to convert to.
2054 @item dg-require-profiling @var{profopt}
2055 Skip the test if the target does not support profiling with option
2058 @item dg-require-visibility @var{vis}
2059 Skip the test if the target does not support the @code{visibility} attribute.
2060 If @var{vis} is @code{""}, support for @code{visibility("hidden")} is
2061 checked, for @code{visibility("@var{vis}")} otherwise.
2064 The original @code{dg-require} directives were defined before there
2065 was support for effective-target keywords. The directives that do not
2066 take arguments could be replaced with effective-target keywords.
2069 @item dg-require-alias ""
2070 Skip the test if the target does not support the @samp{alias} attribute.
2072 @item dg-require-ascii-locale ""
2073 Skip the test if the host does not support an ASCII locale.
2075 @item dg-require-compat-dfp ""
2076 Skip this test unless both compilers in a @file{compat} testsuite
2077 support decimal floating point.
2079 @item dg-require-cxa-atexit ""
2080 Skip the test if the target does not support @code{__cxa_atexit}.
2081 This is equivalent to @code{dg-require-effective-target cxa_atexit}.
2083 @item dg-require-dll ""
2084 Skip the test if the target does not support DLL attributes.
2086 @item dg-require-fork ""
2087 Skip the test if the target does not support @code{fork}.
2089 @item dg-require-gc-sections ""
2090 Skip the test if the target's linker does not support the
2091 @code{--gc-sections} flags.
2092 This is equivalent to @code{dg-require-effective-target gc-sections}.
2094 @item dg-require-host-local ""
2095 Skip the test if the host is remote, rather than the same as the build
2096 system. Some tests are incompatible with DejaGnu's handling of remote
2097 hosts, which involves copying the source file to the host and compiling
2098 it with a relative path and "@code{-o a.out}".
2100 @item dg-require-mkfifo ""
2101 Skip the test if the target does not support @code{mkfifo}.
2103 @item dg-require-named-sections ""
2104 Skip the test is the target does not support named sections.
2105 This is equivalent to @code{dg-require-effective-target named_sections}.
2107 @item dg-require-weak ""
2108 Skip the test if the target does not support weak symbols.
2110 @item dg-require-weak-override ""
2111 Skip the test if the target does not support overriding weak symbols.
2115 @subsection Commands for use in @code{dg-final}
2117 The GCC testsuite defines the following directives to be used within
2120 @subsubsection Scan a particular file
2123 @item scan-file @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
2124 Passes if @var{regexp} matches text in @var{filename}.
2125 @item scan-file-not @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
2126 Passes if @var{regexp} does not match text in @var{filename}.
2127 @item scan-module @var{module} @var{regexp} [@{ target/xfail @var{selector} @}]
2128 Passes if @var{regexp} matches in Fortran module @var{module}.
2131 @subsubsection Scan the assembly output
2134 @item scan-assembler @var{regex} [@{ target/xfail @var{selector} @}]
2135 Passes if @var{regex} matches text in the test's assembler output.
2137 @item scan-assembler-not @var{regex} [@{ target/xfail @var{selector} @}]
2138 Passes if @var{regex} does not match text in the test's assembler output.
2140 @item scan-assembler-times @var{regex} @var{num} [@{ target/xfail @var{selector} @}]
2141 Passes if @var{regex} is matched exactly @var{num} times in the test's
2144 @item scan-assembler-dem @var{regex} [@{ target/xfail @var{selector} @}]
2145 Passes if @var{regex} matches text in the test's demangled assembler output.
2147 @item scan-assembler-dem-not @var{regex} [@{ target/xfail @var{selector} @}]
2148 Passes if @var{regex} does not match text in the test's demangled assembler
2151 @item scan-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2152 Passes if @var{symbol} is defined as a hidden symbol in the test's
2155 @item scan-not-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2156 Passes if @var{symbol} is not defined as a hidden symbol in the test's
2160 @subsubsection Scan optimization dump files
2162 These commands are available for @var{kind} of @code{tree}, @code{rtl},
2166 @item scan-@var{kind}-dump @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2167 Passes if @var{regex} matches text in the dump file with suffix @var{suffix}.
2169 @item scan-@var{kind}-dump-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2170 Passes if @var{regex} does not match text in the dump file with suffix
2173 @item scan-@var{kind}-dump-times @var{regex} @var{num} @var{suffix} [@{ target/xfail @var{selector} @}]
2174 Passes if @var{regex} is found exactly @var{num} times in the dump file
2175 with suffix @var{suffix}.
2177 @item scan-@var{kind}-dump-dem @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2178 Passes if @var{regex} matches demangled text in the dump file with
2179 suffix @var{suffix}.
2181 @item scan-@var{kind}-dump-dem-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2182 Passes if @var{regex} does not match demangled text in the dump file with
2183 suffix @var{suffix}.
2186 @subsubsection Verify that an output files exists or not
2189 @item output-exists [@{ target/xfail @var{selector} @}]
2190 Passes if compiler output file exists.
2192 @item output-exists-not [@{ target/xfail @var{selector} @}]
2193 Passes if compiler output file does not exist.
2196 @subsubsection Check for LTO tests
2199 @item scan-symbol @var{regexp} [@{ target/xfail @var{selector} @}]
2200 Passes if the pattern is present in the final executable.
2203 @subsubsection Checks for @command{gcov} tests
2206 @item run-gcov @var{sourcefile}
2207 Check line counts in @command{gcov} tests.
2209 @item run-gcov [branches] [calls] @{ @var{opts} @var{sourcefile} @}
2210 Check branch and/or call counts, in addition to line counts, in
2211 @command{gcov} tests.
2214 @subsubsection Clean up generated test files
2216 Usually the test-framework removes files that were generated during
2217 testing. If a testcase, for example, uses any dumping mechanism to
2218 inspect a passes dump file, the testsuite recognized the dump option
2219 passed to the tool and schedules a final cleanup to remove these files.
2221 There are, however, following additional cleanup directives that can be
2222 used to annotate a testcase "manually".
2224 @item cleanup-coverage-files
2225 Removes coverage data files generated for this test.
2227 @item cleanup-modules "@var{list-of-extra-modules}"
2228 Removes Fortran module files generated for this test, excluding the
2229 module names listed in keep-modules.
2230 Cleaning up module files is usually done automatically by the testsuite
2231 by looking at the source files and removing the modules after the test
2242 ! @{ dg-final @{ cleanup-modules "mod1 mod2" @} @} ! redundant
2243 ! @{ dg-final @{ keep-modules "mod3 mod4" @} @}
2246 @item keep-modules "@var{list-of-modules-not-to-delete}"
2247 Whitespace separated list of module names that should not be deleted by
2249 If the list of modules is empty, all modules defined in this file are kept.
2251 module maybe_unneeded
2252 end module maybe_unneeded
2257 ! @{ dg-final @{ keep-modules "keep1 keep2" @} @} ! just keep these two
2258 ! @{ dg-final @{ keep-modules "" @} @} ! keep all
2261 @item dg-keep-saved-temps "@var{list-of-suffixes-not-to-delete}"
2262 Whitespace separated list of suffixes that should not be deleted
2263 automatically in a testcase that uses @option{-save-temps}.
2265 // @{ dg-options "-save-temps -fpch-preprocess -I." @}
2266 int main() @{ return 0; @}
2267 // @{ dg-keep-saved-temps ".s" @} ! just keep assembler file
2268 // @{ dg-keep-saved-temps ".s" ".i" @} ! ... and .i
2269 // @{ dg-keep-saved-temps ".ii" ".o" @} ! or just .ii and .o
2272 @item cleanup-profile-file
2273 Removes profiling files generated for this test.
2275 @item cleanup-repo-files
2276 Removes files generated for this test for @option{-frepo}.
2281 @section Ada Language Testsuites
2283 The Ada testsuite includes executable tests from the ACATS
2284 testsuite, publicly available at
2285 @uref{http://www.ada-auth.org/acats.html}.
2287 These tests are integrated in the GCC testsuite in the
2288 @file{ada/acats} directory, and
2289 enabled automatically when running @code{make check}, assuming
2290 the Ada language has been enabled when configuring GCC@.
2292 You can also run the Ada testsuite independently, using
2293 @code{make check-ada}, or run a subset of the tests by specifying which
2294 chapter to run, e.g.:
2297 $ make check-ada CHAPTERS="c3 c9"
2300 The tests are organized by directory, each directory corresponding to
2301 a chapter of the Ada Reference Manual. So for example, @file{c9} corresponds
2302 to chapter 9, which deals with tasking features of the language.
2304 There is also an extra chapter called @file{gcc} containing a template for
2305 creating new executable tests, although this is deprecated in favor of
2306 the @file{gnat.dg} testsuite.
2308 The tests are run using two @command{sh} scripts: @file{run_acats} and
2309 @file{run_all.sh}. To run the tests using a simulator or a cross
2310 target, see the small
2311 customization section at the top of @file{run_all.sh}.
2313 These tests are run using the build tree: they can be run without doing
2314 a @code{make install}.
2317 @section C Language Testsuites
2319 GCC contains the following C language testsuites, in the
2320 @file{gcc/testsuite} directory:
2324 This contains tests of particular features of the C compiler, using the
2325 more modern @samp{dg} harness. Correctness tests for various compiler
2326 features should go here if possible.
2328 Magic comments determine whether the file
2329 is preprocessed, compiled, linked or run. In these tests, error and warning
2330 message texts are compared against expected texts or regular expressions
2331 given in comments. These tests are run with the options @samp{-ansi -pedantic}
2332 unless other options are given in the test. Except as noted below they
2333 are not run with multiple optimization options.
2335 This subdirectory contains tests for binary compatibility using
2336 @file{lib/compat.exp}, which in turn uses the language-independent support
2337 (@pxref{compat Testing, , Support for testing binary compatibility}).
2339 This subdirectory contains tests of the preprocessor.
2341 This subdirectory contains tests for debug formats. Tests in this
2342 subdirectory are run for each debug format that the compiler supports.
2344 This subdirectory contains tests of the @option{-Wformat} format
2345 checking. Tests in this directory are run with and without
2347 @item gcc.dg/noncompile
2348 This subdirectory contains tests of code that should not compile and
2349 does not need any special compilation options. They are run with
2350 multiple optimization options, since sometimes invalid code crashes
2351 the compiler with optimization.
2352 @item gcc.dg/special
2353 FIXME: describe this.
2356 This contains particular code fragments which have historically broken easily.
2357 These tests are run with multiple optimization options, so tests for features
2358 which only break at some optimization levels belong here. This also contains
2359 tests to check that certain optimizations occur. It might be worthwhile to
2360 separate the correctness tests cleanly from the code quality tests, but
2361 it hasn't been done yet.
2363 @item gcc.c-torture/compat
2364 FIXME: describe this.
2366 This directory should probably not be used for new tests.
2367 @item gcc.c-torture/compile
2368 This testsuite contains test cases that should compile, but do not
2369 need to link or run. These test cases are compiled with several
2370 different combinations of optimization options. All warnings are
2371 disabled for these test cases, so this directory is not suitable if
2372 you wish to test for the presence or absence of compiler warnings.
2373 While special options can be set, and tests disabled on specific
2374 platforms, by the use of @file{.x} files, mostly these test cases
2375 should not contain platform dependencies. FIXME: discuss how defines
2376 such as @code{NO_LABEL_VALUES} and @code{STACK_SIZE} are used.
2377 @item gcc.c-torture/execute
2378 This testsuite contains test cases that should compile, link and run;
2379 otherwise the same comments as for @file{gcc.c-torture/compile} apply.
2380 @item gcc.c-torture/execute/ieee
2381 This contains tests which are specific to IEEE floating point.
2382 @item gcc.c-torture/unsorted
2383 FIXME: describe this.
2385 This directory should probably not be used for new tests.
2386 @item gcc.misc-tests
2387 This directory contains C tests that require special handling. Some
2388 of these tests have individual expect files, and others share
2389 special-purpose expect files:
2392 @item @code{bprob*.c}
2393 Test @option{-fbranch-probabilities} using
2394 @file{gcc.misc-tests/bprob.exp}, which
2395 in turn uses the generic, language-independent framework
2396 (@pxref{profopt Testing, , Support for testing profile-directed
2399 @item @code{gcov*.c}
2400 Test @command{gcov} output using @file{gcov.exp}, which in turn uses the
2401 language-independent support (@pxref{gcov Testing, , Support for testing gcov}).
2403 @item @code{i386-pf-*.c}
2404 Test i386-specific support for data prefetch using @file{i386-prefetch.exp}.
2407 @item gcc.test-framework
2410 Test the testsuite itself using @file{gcc.test-framework/test-framework.exp}.
2415 FIXME: merge in @file{testsuite/README.gcc} and discuss the format of
2416 test cases and magic comments more.
2419 @section The Java library testsuites.
2421 Runtime tests are executed via @samp{make check} in the
2422 @file{@var{target}/libjava/testsuite} directory in the build
2423 tree. Additional runtime tests can be checked into this testsuite.
2425 Regression testing of the core packages in libgcj is also covered by the
2426 Mauve testsuite. The @uref{http://sourceware.org/mauve/,,Mauve Project}
2427 develops tests for the Java Class Libraries. These tests are run as part
2428 of libgcj testing by placing the Mauve tree within the libjava testsuite
2429 sources at @file{libjava/testsuite/libjava.mauve/mauve}, or by specifying
2430 the location of that tree when invoking @samp{make}, as in
2431 @samp{make MAUVEDIR=~/mauve check}.
2433 To detect regressions, a mechanism in @file{mauve.exp} compares the
2434 failures for a test run against the list of expected failures in
2435 @file{libjava/testsuite/libjava.mauve/xfails} from the source hierarchy.
2436 Update this file when adding new failing tests to Mauve, or when fixing
2437 bugs in libgcj that had caused Mauve test failures.
2439 We encourage developers to contribute test cases to Mauve.
2442 @section Support for testing link-time optimizations
2444 Tests for link-time optimizations usually require multiple source files
2445 that are compiled separately, perhaps with different sets of options.
2446 There are several special-purpose test directives used for these tests.
2449 @item @{ dg-lto-do @var{do-what-keyword} @}
2450 @var{do-what-keyword} specifies how the test is compiled and whether
2451 it is executed. It is one of:
2455 Compile with @option{-c} to produce a relocatable object file.
2457 Compile, assemble, and link to produce an executable file.
2459 Produce and run an executable file, which is expected to return
2463 The default is @code{assemble}. That can be overridden for a set of
2464 tests by redefining @code{dg-do-what-default} within the @code{.exp}
2465 file for those tests.
2467 Unlike @code{dg-do}, @code{dg-lto-do} does not support an optional
2468 @samp{target} or @samp{xfail} list. Use @code{dg-skip-if},
2469 @code{dg-xfail-if}, or @code{dg-xfail-run-if}.
2471 @item @{ dg-lto-options @{ @{ @var{options} @} [@{ @var{options} @}] @} [@{ target @var{selector} @}]@}
2472 This directive provides a list of one or more sets of compiler options
2473 to override @var{LTO_OPTIONS}. Each test will be compiled and run with
2474 each of these sets of options.
2476 @item @{ dg-extra-ld-options @var{options} [@{ target @var{selector} @}]@}
2477 This directive adds @var{options} to the linker options used.
2479 @item @{ dg-suppress-ld-options @var{options} [@{ target @var{selector} @}]@}
2480 This directive removes @var{options} from the set of linker options used.
2484 @section Support for testing @command{gcov}
2486 Language-independent support for testing @command{gcov}, and for checking
2487 that branch profiling produces expected values, is provided by the
2488 expect file @file{lib/gcov.exp}. @command{gcov} tests also rely on procedures
2489 in @file{lib/gcc-dg.exp} to compile and run the test program. A typical
2490 @command{gcov} test contains the following DejaGnu commands within comments:
2493 @{ dg-options "-fprofile-arcs -ftest-coverage" @}
2494 @{ dg-do run @{ target native @} @}
2495 @{ dg-final @{ run-gcov sourcefile @} @}
2498 Checks of @command{gcov} output can include line counts, branch percentages,
2499 and call return percentages. All of these checks are requested via
2500 commands that appear in comments in the test's source file.
2501 Commands to check line counts are processed by default.
2502 Commands to check branch percentages and call return percentages are
2503 processed if the @command{run-gcov} command has arguments @code{branches}
2504 or @code{calls}, respectively. For example, the following specifies
2505 checking both, as well as passing @option{-b} to @command{gcov}:
2508 @{ dg-final @{ run-gcov branches calls @{ -b sourcefile @} @} @}
2511 A line count command appears within a comment on the source line
2512 that is expected to get the specified count and has the form
2513 @code{count(@var{cnt})}. A test should only check line counts for
2514 lines that will get the same count for any architecture.
2516 Commands to check branch percentages (@code{branch}) and call
2517 return percentages (@code{returns}) are very similar to each other.
2518 A beginning command appears on or before the first of a range of
2519 lines that will report the percentage, and the ending command
2520 follows that range of lines. The beginning command can include a
2521 list of percentages, all of which are expected to be found within
2522 the range. A range is terminated by the next command of the same
2523 kind. A command @code{branch(end)} or @code{returns(end)} marks
2524 the end of a range without starting a new one. For example:
2527 if (i > 10 && j > i && j < 20) /* @r{branch(27 50 75)} */
2528 /* @r{branch(end)} */
2532 For a call return percentage, the value specified is the
2533 percentage of calls reported to return. For a branch percentage,
2534 the value is either the expected percentage or 100 minus that
2535 value, since the direction of a branch can differ depending on the
2536 target or the optimization level.
2538 Not all branches and calls need to be checked. A test should not
2539 check for branches that might be optimized away or replaced with
2540 predicated instructions. Don't check for calls inserted by the
2541 compiler or ones that might be inlined or optimized away.
2543 A single test can check for combinations of line counts, branch
2544 percentages, and call return percentages. The command to check a
2545 line count must appear on the line that will report that count, but
2546 commands to check branch percentages and call return percentages can
2547 bracket the lines that report them.
2549 @node profopt Testing
2550 @section Support for testing profile-directed optimizations
2552 The file @file{profopt.exp} provides language-independent support for
2553 checking correct execution of a test built with profile-directed
2554 optimization. This testing requires that a test program be built and
2555 executed twice. The first time it is compiled to generate profile
2556 data, and the second time it is compiled to use the data that was
2557 generated during the first execution. The second execution is to
2558 verify that the test produces the expected results.
2560 To check that the optimization actually generated better code, a
2561 test can be built and run a third time with normal optimizations to
2562 verify that the performance is better with the profile-directed
2563 optimizations. @file{profopt.exp} has the beginnings of this kind
2566 @file{profopt.exp} provides generic support for profile-directed
2567 optimizations. Each set of tests that uses it provides information
2568 about a specific optimization:
2572 tool being tested, e.g., @command{gcc}
2574 @item profile_option
2575 options used to generate profile data
2577 @item feedback_option
2578 options used to optimize using that profile data
2581 suffix of profile data files
2583 @item PROFOPT_OPTIONS
2584 list of options with which to run each test, similar to the lists for
2587 @item @{ dg-final-generate @{ @var{local-directive} @} @}
2588 This directive is similar to @code{dg-final}, but the
2589 @var{local-directive} is run after the generation of profile data.
2591 @item @{ dg-final-use @{ @var{local-directive} @} @}
2592 The @var{local-directive} is run after the profile data have been
2596 @node compat Testing
2597 @section Support for testing binary compatibility
2599 The file @file{compat.exp} provides language-independent support for
2600 binary compatibility testing. It supports testing interoperability of
2601 two compilers that follow the same ABI, or of multiple sets of
2602 compiler options that should not affect binary compatibility. It is
2603 intended to be used for testsuites that complement ABI testsuites.
2605 A test supported by this framework has three parts, each in a
2606 separate source file: a main program and two pieces that interact
2607 with each other to split up the functionality being tested.
2610 @item @var{testname}_main.@var{suffix}
2611 Contains the main program, which calls a function in file
2612 @file{@var{testname}_x.@var{suffix}}.
2614 @item @var{testname}_x.@var{suffix}
2615 Contains at least one call to a function in
2616 @file{@var{testname}_y.@var{suffix}}.
2618 @item @var{testname}_y.@var{suffix}
2619 Shares data with, or gets arguments from,
2620 @file{@var{testname}_x.@var{suffix}}.
2623 Within each test, the main program and one functional piece are
2624 compiled by the GCC under test. The other piece can be compiled by
2625 an alternate compiler. If no alternate compiler is specified,
2626 then all three source files are all compiled by the GCC under test.
2627 You can specify pairs of sets of compiler options. The first element
2628 of such a pair specifies options used with the GCC under test, and the
2629 second element of the pair specifies options used with the alternate
2630 compiler. Each test is compiled with each pair of options.
2632 @file{compat.exp} defines default pairs of compiler options.
2633 These can be overridden by defining the environment variable
2634 @env{COMPAT_OPTIONS} as:
2637 COMPAT_OPTIONS="[list [list @{@var{tst1}@} @{@var{alt1}@}]
2638 @dots{}[list @{@var{tstn}@} @{@var{altn}@}]]"
2641 where @var{tsti} and @var{alti} are lists of options, with @var{tsti}
2642 used by the compiler under test and @var{alti} used by the alternate
2643 compiler. For example, with
2644 @code{[list [list @{-g -O0@} @{-O3@}] [list @{-fpic@} @{-fPIC -O2@}]]},
2645 the test is first built with @option{-g -O0} by the compiler under
2646 test and with @option{-O3} by the alternate compiler. The test is
2647 built a second time using @option{-fpic} by the compiler under test
2648 and @option{-fPIC -O2} by the alternate compiler.
2650 An alternate compiler is specified by defining an environment
2651 variable to be the full pathname of an installed compiler; for C
2652 define @env{ALT_CC_UNDER_TEST}, and for C++ define
2653 @env{ALT_CXX_UNDER_TEST}. These will be written to the
2654 @file{site.exp} file used by DejaGnu. The default is to build each
2655 test with the compiler under test using the first of each pair of
2656 compiler options from @env{COMPAT_OPTIONS}. When
2657 @env{ALT_CC_UNDER_TEST} or
2658 @env{ALT_CXX_UNDER_TEST} is @code{same}, each test is built using
2659 the compiler under test but with combinations of the options from
2660 @env{COMPAT_OPTIONS}.
2662 To run only the C++ compatibility suite using the compiler under test
2663 and another version of GCC using specific compiler options, do the
2664 following from @file{@var{objdir}/gcc}:
2669 ALT_CXX_UNDER_TEST=$@{alt_prefix@}/bin/g++ \
2670 COMPAT_OPTIONS="@var{lists as shown above}" \
2672 RUNTESTFLAGS="compat.exp"
2675 A test that fails when the source files are compiled with different
2676 compilers, but passes when the files are compiled with the same
2677 compiler, demonstrates incompatibility of the generated code or
2678 runtime support. A test that fails for the alternate compiler but
2679 passes for the compiler under test probably tests for a bug that was
2680 fixed in the compiler under test but is present in the alternate
2683 The binary compatibility tests support a small number of test framework
2684 commands that appear within comments in a test file.
2688 These commands can be used in @file{@var{testname}_main.@var{suffix}}
2689 to skip the test if specific support is not available on the target.
2692 The specified options are used for compiling this particular source
2693 file, appended to the options from @env{COMPAT_OPTIONS}. When this
2694 command appears in @file{@var{testname}_main.@var{suffix}} the options
2695 are also used to link the test program.
2698 This command can be used in a secondary source file to specify that
2699 compilation is expected to fail for particular options on particular
2704 @section Support for torture testing using multiple options
2706 Throughout the compiler testsuite there are several directories whose
2707 tests are run multiple times, each with a different set of options.
2708 These are known as torture tests.
2709 @file{lib/torture-options.exp} defines procedures to
2714 Initialize use of torture lists.
2715 @item set-torture-options
2716 Set lists of torture options to use for tests with and without loops.
2717 Optionally combine a set of torture options with a set of other
2718 options, as is done with Objective-C runtime options.
2719 @item torture-finish
2720 Finalize use of torture lists.
2723 The @file{.exp} file for a set of tests that use torture options must
2724 include calls to these three procedures if:
2727 @item It calls @code{gcc-dg-runtest} and overrides @var{DG_TORTURE_OPTIONS}.
2729 @item It calls @var{$@{tool@}}@code{-torture} or
2730 @var{$@{tool@}}@code{-torture-execute}, where @var{tool} is @code{c},
2731 @code{fortran}, or @code{objc}.
2733 @item It calls @code{dg-pch}.
2736 It is not necessary for a @file{.exp} file that calls @code{gcc-dg-runtest}
2737 to call the torture procedures if the tests should use the list in
2738 @var{DG_TORTURE_OPTIONS} defined in @file{gcc-dg.exp}.
2740 Most uses of torture options can override the default lists by defining
2741 @var{TORTURE_OPTIONS} or add to the default list by defining
2742 @var{ADDITIONAL_TORTURE_OPTIONS}. Define these in a @file{.dejagnurc}
2743 file or add them to the @file{site.exp} file; for example
2746 set ADDITIONAL_TORTURE_OPTIONS [list \
2747 @{ -O2 -ftree-loop-linear @} \
2748 @{ -O2 -fpeel-loops @} ]