1 @c Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
2 @c Free Software Foundation, Inc.
3 @c This is part of the GCC manual.
4 @c For copying conditions, see the file gcc.texi.
7 @chapter Source Tree Structure and Build System
9 This chapter describes the structure of the GCC source tree, and how
10 GCC is built. The user documentation for building and installing GCC
11 is in a separate manual (@uref{http://gcc.gnu.org/install/}), with
12 which it is presumed that you are familiar.
15 * Configure Terms:: Configuration terminology and history.
16 * Top Level:: The top level source directory.
17 * gcc Directory:: The @file{gcc} subdirectory.
20 @include configterms.texi
23 @section Top Level Source Directory
25 The top level source directory in a GCC distribution contains several
26 files and directories that are shared with other software
27 distributions such as that of GNU Binutils. It also contains several
28 subdirectories that contain parts of GCC and its runtime libraries:
32 The Boehm conservative garbage collector, used as part of the Java
36 Autoconf macros and Makefile fragments used throughout the tree.
39 Contributed scripts that may be found useful in conjunction with GCC@.
40 One of these, @file{contrib/texi2pod.pl}, is used to generate man
41 pages from Texinfo manuals as part of the GCC build process.
44 The support for fixing system headers to work with GCC@. See
45 @file{fixincludes/README} for more information. The headers fixed by
46 this mechanism are installed in @file{@var{libsubdir}/include-fixed}.
47 Along with those headers, @file{README-fixinc} is also installed, as
48 @file{@var{libsubdir}/include-fixed/README}.
51 The main sources of GCC itself (except for runtime libraries),
52 including optimizers, support for different target architectures,
53 language front ends, and testsuites. @xref{gcc Directory, , The
54 @file{gcc} Subdirectory}, for details.
57 Support tools for GNAT.
60 Headers for the @code{libiberty} library.
63 GNU @code{libintl}, from GNU @code{gettext}, for systems which do not
64 include it in @code{libc}.
67 The Ada runtime library.
70 The C preprocessor library.
73 The Decimal Float support library.
76 The @code{libffi} library, used as part of the Java runtime library.
79 The GCC runtime library.
82 The Fortran runtime library.
85 The GNU OpenMP runtime library.
88 The @code{libiberty} library, used for portability and for some
89 generally useful data structures and algorithms. @xref{Top, ,
90 Introduction, libiberty, @sc{gnu} libiberty}, for more information
94 The Java runtime library.
97 The @code{libmudflap} library, used for instrumenting pointer and array
98 dereferencing operations.
101 The Objective-C and Objective-C++ runtime library.
104 The Stack protector runtime library.
107 The C++ runtime library.
110 Plugin used by @command{gold} if link-time optimizations are enabled.
112 @item maintainer-scripts
113 Scripts used by the @code{gccadmin} account on @code{gcc.gnu.org}.
116 The @code{zlib} compression library, used by the Java front end, as
117 part of the Java runtime library, and for compressing and uncompressing
118 GCC's intermediate language in LTO object files.
121 The build system in the top level directory, including how recursion
122 into subdirectories works and how building runtime libraries for
123 multilibs is handled, is documented in a separate manual, included
124 with GNU Binutils. @xref{Top, , GNU configure and build system,
125 configure, The GNU configure and build system}, for details.
128 @section The @file{gcc} Subdirectory
130 The @file{gcc} directory contains many files that are part of the C
131 sources of GCC, other files used as part of the configuration and
132 build process, and subdirectories including documentation and a
133 testsuite. The files that are sources of GCC are documented in a
134 separate chapter. @xref{Passes, , Passes and Files of the Compiler}.
137 * Subdirectories:: Subdirectories of @file{gcc}.
138 * Configuration:: The configuration process, and the files it uses.
139 * Build:: The build system in the @file{gcc} directory.
140 * Makefile:: Targets in @file{gcc/Makefile}.
141 * Library Files:: Library source files and headers under @file{gcc/}.
142 * Headers:: Headers installed by GCC.
143 * Documentation:: Building documentation in GCC.
144 * Front End:: Anatomy of a language front end.
145 * Back End:: Anatomy of a target back end.
149 @subsection Subdirectories of @file{gcc}
151 The @file{gcc} directory contains the following subdirectories:
155 Subdirectories for various languages. Directories containing a file
156 @file{config-lang.in} are language subdirectories. The contents of
157 the subdirectories @file{cp} (for C++), @file{lto} (for LTO),
158 @file{objc} (for Objective-C) and @file{objcp} (for Objective-C++) are
159 documented in this manual (@pxref{Passes, , Passes and Files of the
160 Compiler}); those for other languages are not. @xref{Front End, ,
161 Anatomy of a Language Front End}, for details of the files in these
165 Configuration files for supported architectures and operating
166 systems. @xref{Back End, , Anatomy of a Target Back End}, for
167 details of the files in this directory.
170 Texinfo documentation for GCC, together with automatically generated
171 man pages and support for converting the installation manual to
172 HTML@. @xref{Documentation}.
175 System headers installed by GCC, mainly those required by the C
176 standard of freestanding implementations. @xref{Headers, , Headers
177 Installed by GCC}, for details of when these and other headers are
181 Message catalogs with translations of messages produced by GCC into
182 various languages, @file{@var{language}.po}. This directory also
183 contains @file{gcc.pot}, the template for these message catalogues,
184 @file{exgettext}, a wrapper around @command{gettext} to extract the
185 messages from the GCC sources and create @file{gcc.pot}, which is run
186 by @samp{make gcc.pot}, and @file{EXCLUDES}, a list of files from
187 which messages should not be extracted.
190 The GCC testsuites (except for those for runtime libraries).
195 @subsection Configuration in the @file{gcc} Directory
197 The @file{gcc} directory is configured with an Autoconf-generated
198 script @file{configure}. The @file{configure} script is generated
199 from @file{configure.ac} and @file{aclocal.m4}. From the files
200 @file{configure.ac} and @file{acconfig.h}, Autoheader generates the
201 file @file{config.in}. The file @file{cstamp-h.in} is used as a
205 * Config Fragments:: Scripts used by @file{configure}.
206 * System Config:: The @file{config.build}, @file{config.host}, and
207 @file{config.gcc} files.
208 * Configuration Files:: Files created by running @file{configure}.
211 @node Config Fragments
212 @subsubsection Scripts Used by @file{configure}
214 @file{configure} uses some other scripts to help in its work:
217 @item The standard GNU @file{config.sub} and @file{config.guess}
218 files, kept in the top level directory, are used.
220 @item The file @file{config.gcc} is used to handle configuration
221 specific to the particular target machine. The file
222 @file{config.build} is used to handle configuration specific to the
223 particular build machine. The file @file{config.host} is used to handle
224 configuration specific to the particular host machine. (In general,
225 these should only be used for features that cannot reasonably be tested in
226 Autoconf feature tests.)
227 @xref{System Config, , The @file{config.build}; @file{config.host};
228 and @file{config.gcc} Files}, for details of the contents of these files.
230 @item Each language subdirectory has a file
231 @file{@var{language}/config-lang.in} that is used for
232 front-end-specific configuration. @xref{Front End Config, , The Front
233 End @file{config-lang.in} File}, for details of this file.
235 @item A helper script @file{configure.frag} is used as part of
236 creating the output of @file{configure}.
240 @subsubsection The @file{config.build}; @file{config.host}; and @file{config.gcc} Files
242 The @file{config.build} file contains specific rules for particular systems
243 which GCC is built on. This should be used as rarely as possible, as the
244 behavior of the build system can always be detected by autoconf.
246 The @file{config.host} file contains specific rules for particular systems
247 which GCC will run on. This is rarely needed.
249 The @file{config.gcc} file contains specific rules for particular systems
250 which GCC will generate code for. This is usually needed.
252 Each file has a list of the shell variables it sets, with descriptions, at the
255 FIXME: document the contents of these files, and what variables should
256 be set to control build, host and target configuration.
258 @include configfiles.texi
261 @subsection Build System in the @file{gcc} Directory
263 FIXME: describe the build system, including what is built in what
264 stages. Also list the various source files that are used in the build
265 process but aren't source files of GCC itself and so aren't documented
266 below (@pxref{Passes}).
268 @include makefile.texi
271 @subsection Library Source Files and Headers under the @file{gcc} Directory
273 FIXME: list here, with explanation, all the C source files and headers
274 under the @file{gcc} directory that aren't built into the GCC
275 executable but rather are part of runtime libraries and object files,
276 such as @file{crtstuff.c} and @file{unwind-dw2.c}. @xref{Headers, ,
277 Headers Installed by GCC}, for more information about the
278 @file{ginclude} directory.
281 @subsection Headers Installed by GCC
283 In general, GCC expects the system C library to provide most of the
284 headers to be used with it. However, GCC will fix those headers if
285 necessary to make them work with GCC, and will install some headers
286 required of freestanding implementations. These headers are installed
287 in @file{@var{libsubdir}/include}. Headers for non-C runtime
288 libraries are also installed by GCC; these are not documented here.
289 (FIXME: document them somewhere.)
291 Several of the headers GCC installs are in the @file{ginclude}
292 directory. These headers, @file{iso646.h},
293 @file{stdarg.h}, @file{stdbool.h}, and @file{stddef.h},
294 are installed in @file{@var{libsubdir}/include},
295 unless the target Makefile fragment (@pxref{Target Fragment})
296 overrides this by setting @code{USER_H}.
298 In addition to these headers and those generated by fixing system
299 headers to work with GCC, some other headers may also be installed in
300 @file{@var{libsubdir}/include}. @file{config.gcc} may set
301 @code{extra_headers}; this specifies additional headers under
302 @file{config} to be installed on some systems.
304 GCC installs its own version of @code{<float.h>}, from @file{ginclude/float.h}.
305 This is done to cope with command-line options that change the
306 representation of floating point numbers.
308 GCC also installs its own version of @code{<limits.h>}; this is generated
309 from @file{glimits.h}, together with @file{limitx.h} and
310 @file{limity.h} if the system also has its own version of
311 @code{<limits.h>}. (GCC provides its own header because it is
312 required of ISO C freestanding implementations, but needs to include
313 the system header from its own header as well because other standards
314 such as POSIX specify additional values to be defined in
315 @code{<limits.h>}.) The system's @code{<limits.h>} header is used via
316 @file{@var{libsubdir}/include/syslimits.h}, which is copied from
317 @file{gsyslimits.h} if it does not need fixing to work with GCC; if it
318 needs fixing, @file{syslimits.h} is the fixed copy.
320 GCC can also install @code{<tgmath.h>}. It will do this when
321 @file{config.gcc} sets @code{use_gcc_tgmath} to @code{yes}.
324 @subsection Building Documentation
326 The main GCC documentation is in the form of manuals in Texinfo
327 format. These are installed in Info format; DVI versions may be
328 generated by @samp{make dvi}, PDF versions by @samp{make pdf}, and
329 HTML versions by @samp{make html}. In addition, some man pages are
330 generated from the Texinfo manuals, there are some other text files
331 with miscellaneous documentation, and runtime libraries have their own
332 documentation outside the @file{gcc} directory. FIXME: document the
333 documentation for runtime libraries somewhere.
336 * Texinfo Manuals:: GCC manuals in Texinfo format.
337 * Man Page Generation:: Generating man pages from Texinfo manuals.
338 * Miscellaneous Docs:: Miscellaneous text files with documentation.
341 @node Texinfo Manuals
342 @subsubsection Texinfo Manuals
344 The manuals for GCC as a whole, and the C and C++ front ends, are in
345 files @file{doc/*.texi}. Other front ends have their own manuals in
346 files @file{@var{language}/*.texi}. Common files
347 @file{doc/include/*.texi} are provided which may be included in
348 multiple manuals; the following files are in @file{doc/include}:
352 The GNU Free Documentation License.
354 The section ``Funding Free Software''.
355 @item gcc-common.texi
356 Common definitions for manuals.
359 The GNU General Public License.
361 A copy of @file{texinfo.tex} known to work with the GCC manuals.
364 DVI-formatted manuals are generated by @samp{make dvi}, which uses
365 @command{texi2dvi} (via the Makefile macro @code{$(TEXI2DVI)}).
366 PDF-formatted manuals are generated by @samp{make pdf}, which uses
367 @command{texi2pdf} (via the Makefile macro @code{$(TEXI2PDF)}). HTML
368 formatted manuals are generated by @samp{make html}. Info
369 manuals are generated by @samp{make info} (which is run as part of
370 a bootstrap); this generates the manuals in the source directory,
371 using @command{makeinfo} via the Makefile macro @code{$(MAKEINFO)},
372 and they are included in release distributions.
374 Manuals are also provided on the GCC web site, in both HTML and
375 PostScript forms. This is done via the script
376 @file{maintainer-scripts/update_web_docs}. Each manual to be
377 provided online must be listed in the definition of @code{MANUALS} in
378 that file; a file @file{@var{name}.texi} must only appear once in the
379 source tree, and the output manual must have the same name as the
380 source file. (However, other Texinfo files, included in manuals but
381 not themselves the root files of manuals, may have names that appear
382 more than once in the source tree.) The manual file
383 @file{@var{name}.texi} should only include other files in its own
384 directory or in @file{doc/include}. HTML manuals will be generated by
385 @samp{makeinfo --html}, PostScript manuals by @command{texi2dvi}
386 and @command{dvips}, and PDF manuals by @command{texi2pdf}.
387 All Texinfo files that are parts of manuals must
388 be version-controlled, even if they are generated files, for the
389 generation of online manuals to work.
391 The installation manual, @file{doc/install.texi}, is also provided on
392 the GCC web site. The HTML version is generated by the script
393 @file{doc/install.texi2html}.
395 @node Man Page Generation
396 @subsubsection Man Page Generation
398 Because of user demand, in addition to full Texinfo manuals, man pages
399 are provided which contain extracts from those manuals. These man
400 pages are generated from the Texinfo manuals using
401 @file{contrib/texi2pod.pl} and @command{pod2man}. (The man page for
402 @command{g++}, @file{cp/g++.1}, just contains a @samp{.so} reference
403 to @file{gcc.1}, but all the other man pages are generated from
406 Because many systems may not have the necessary tools installed to
407 generate the man pages, they are only generated if the
408 @file{configure} script detects that recent enough tools are
409 installed, and the Makefiles allow generating man pages to fail
410 without aborting the build. Man pages are also included in release
411 distributions. They are generated in the source directory.
413 Magic comments in Texinfo files starting @samp{@@c man} control what
414 parts of a Texinfo file go into a man page. Only a subset of Texinfo
415 is supported by @file{texi2pod.pl}, and it may be necessary to add
416 support for more Texinfo features to this script when generating new
417 man pages. To improve the man page output, some special Texinfo
418 macros are provided in @file{doc/include/gcc-common.texi} which
419 @file{texi2pod.pl} understands:
423 Use in the form @samp{@@table @@gcctabopt} for tables of options,
424 where for printed output the effect of @samp{@@code} is better than
425 that of @samp{@@option} but for man page output a different effect is
428 Use for summary lists of options in manuals.
430 Use at the end of each line inside @samp{@@gccoptlist}. This is
431 necessary to avoid problems with differences in how the
432 @samp{@@gccoptlist} macro is handled by different Texinfo formatters.
435 FIXME: describe the @file{texi2pod.pl} input language and magic
436 comments in more detail.
438 @node Miscellaneous Docs
439 @subsubsection Miscellaneous Documentation
441 In addition to the formal documentation that is installed by GCC,
442 there are several other text files in the @file{gcc} subdirectory
443 with miscellaneous documentation:
447 Notes on GCC's Native Language Support. FIXME: this should be part of
448 this manual rather than a separate file.
450 Notes on the Free Translation Project.
453 The GNU General Public License, Versions 2 and 3.
456 The GNU Lesser General Public License, Versions 2.1 and 3.
459 Change log files for various parts of GCC@.
461 Details of a few changes to the GCC front-end interface. FIXME: the
462 information in this file should be part of general documentation of
463 the front-end interface in this manual.
465 Information about new features in old versions of GCC@. (For recent
466 versions, the information is on the GCC web site.)
467 @item README.Portability
468 Information about portability issues when writing code in GCC@. FIXME:
469 why isn't this part of this manual or of the GCC Coding Conventions?
472 FIXME: document such files in subdirectories, at least @file{config},
473 @file{cp}, @file{objc}, @file{testsuite}.
476 @subsection Anatomy of a Language Front End
478 A front end for a language in GCC has the following parts:
482 A directory @file{@var{language}} under @file{gcc} containing source
483 files for that front end. @xref{Front End Directory, , The Front End
484 @file{@var{language}} Directory}, for details.
486 A mention of the language in the list of supported languages in
487 @file{gcc/doc/install.texi}.
489 A mention of the name under which the language's runtime library is
490 recognized by @option{--enable-shared=@var{package}} in the
491 documentation of that option in @file{gcc/doc/install.texi}.
493 A mention of any special prerequisites for building the front end in
494 the documentation of prerequisites in @file{gcc/doc/install.texi}.
496 Details of contributors to that front end in
497 @file{gcc/doc/contrib.texi}. If the details are in that front end's
498 own manual then there should be a link to that manual's list in
501 Information about support for that language in
502 @file{gcc/doc/frontends.texi}.
504 Information about standards for that language, and the front end's
505 support for them, in @file{gcc/doc/standards.texi}. This may be a
506 link to such information in the front end's own manual.
508 Details of source file suffixes for that language and @option{-x
509 @var{lang}} options supported, in @file{gcc/doc/invoke.texi}.
511 Entries in @code{default_compilers} in @file{gcc.c} for source file
512 suffixes for that language.
514 Preferably testsuites, which may be under @file{gcc/testsuite} or
515 runtime library directories. FIXME: document somewhere how to write
518 Probably a runtime library for the language, outside the @file{gcc}
519 directory. FIXME: document this further.
521 Details of the directories of any runtime libraries in
522 @file{gcc/doc/sourcebuild.texi}.
524 Check targets in @file{Makefile.def} for the top-level @file{Makefile}
525 to check just the compiler or the compiler and runtime library for the
529 If the front end is added to the official GCC source repository, the
530 following are also necessary:
534 At least one Bugzilla component for bugs in that front end and runtime
535 libraries. This category needs to be mentioned in
536 @file{gcc/gccbug.in}, as well as being added to the Bugzilla database.
538 Normally, one or more maintainers of that front end listed in
541 Mentions on the GCC web site in @file{index.html} and
542 @file{frontends.html}, with any relevant links on
543 @file{readings.html}. (Front ends that are not an official part of
544 GCC may also be listed on @file{frontends.html}, with relevant links.)
546 A news item on @file{index.html}, and possibly an announcement on the
547 @email{gcc-announce@@gcc.gnu.org} mailing list.
549 The front end's manuals should be mentioned in
550 @file{maintainer-scripts/update_web_docs} (@pxref{Texinfo Manuals})
551 and the online manuals should be linked to from
552 @file{onlinedocs/index.html}.
554 Any old releases or CVS repositories of the front end, before its
555 inclusion in GCC, should be made available on the GCC FTP site
556 @uref{ftp://gcc.gnu.org/pub/gcc/old-releases/}.
558 The release and snapshot script @file{maintainer-scripts/gcc_release}
559 should be updated to generate appropriate tarballs for this front end.
560 The associated @file{maintainer-scripts/snapshot-README} and
561 @file{maintainer-scripts/snapshot-index.html} files should be updated
562 to list the tarballs and diffs for this front end.
564 If this front end includes its own version files that include the
565 current date, @file{maintainer-scripts/update_version} should be
570 * Front End Directory:: The front end @file{@var{language}} directory.
571 * Front End Config:: The front end @file{config-lang.in} file.
572 * Front End Makefile:: The front end @file{Make-lang.in} file.
575 @node Front End Directory
576 @subsubsection The Front End @file{@var{language}} Directory
578 A front end @file{@var{language}} directory contains the source files
579 of that front end (but not of any runtime libraries, which should be
580 outside the @file{gcc} directory). This includes documentation, and
581 possibly some subsidiary programs built alongside the front end.
582 Certain files are special and other parts of the compiler depend on
587 This file is required in all language subdirectories. @xref{Front End
588 Config, , The Front End @file{config-lang.in} File}, for details of
591 This file is required in all language subdirectories. @xref{Front End
592 Makefile, , The Front End @file{Make-lang.in} File}, for details of its
595 This file registers the set of switches that the front end accepts on
596 the command line, and their @option{--help} text. @xref{Options}.
598 This file provides entries for @code{default_compilers} in
599 @file{gcc.c} which override the default of giving an error that a
600 compiler for that language is not installed.
601 @item @var{language}-tree.def
602 This file, which need not exist, defines any language-specific tree
606 @node Front End Config
607 @subsubsection The Front End @file{config-lang.in} File
609 Each language subdirectory contains a @file{config-lang.in} file. In
610 addition the main directory contains @file{c-config-lang.in}, which
611 contains limited information for the C language. This file is a shell
612 script that may define some variables describing the language:
616 This definition must be present, and gives the name of the language
617 for some purposes such as arguments to @option{--enable-languages}.
619 If defined, this variable lists (space-separated) language front ends
620 other than C that this front end requires to be enabled (with the
621 names given being their @code{language} settings). For example, the
622 Java front end depends on the C++ front end, so sets
623 @samp{lang_requires=c++}.
624 @item subdir_requires
625 If defined, this variable lists (space-separated) front end directories
626 other than C that this front end requires to be present. For example,
627 the Objective-C++ front end uses source files from the C++ and
628 Objective-C front ends, so sets @samp{subdir_requires="cp objc"}.
630 If defined, this variable lists (space-separated) targets in the top
631 level @file{Makefile} to build the runtime libraries for this
632 language, such as @code{target-libobjc}.
634 If defined, this variable lists (space-separated) top level
635 directories (parallel to @file{gcc}), apart from the runtime libraries,
636 that should not be configured if this front end is not built.
637 @item build_by_default
638 If defined to @samp{no}, this language front end is not built unless
639 enabled in a @option{--enable-languages} argument. Otherwise, front
640 ends are built by default, subject to any special logic in
641 @file{configure.ac} (as is present to disable the Ada front end if the
642 Ada compiler is not already installed).
644 If defined to @samp{yes}, this front end is built in stage1 of the
645 bootstrap. This is only relevant to front ends written in their own
648 If defined, a space-separated list of compiler executables that will
649 be run by the driver. The names here will each end
650 with @samp{\$(exeext)}.
652 If defined, a space-separated list of files that should be generated
653 by @file{configure} substituting values in them. This mechanism can
654 be used to create a file @file{@var{language}/Makefile} from
655 @file{@var{language}/Makefile.in}, but this is deprecated, building
656 everything from the single @file{gcc/Makefile} is preferred.
658 If defined, a space-separated list of files that should be scanned by
659 @file{gengtype.c} to generate the garbage collection tables and routines for
660 this language. This excludes the files that are common to all front
661 ends. @xref{Type Information}.
665 @node Front End Makefile
666 @subsubsection The Front End @file{Make-lang.in} File
668 Each language subdirectory contains a @file{Make-lang.in} file. It contains
669 targets @code{@var{lang}.@var{hook}} (where @code{@var{lang}} is the
670 setting of @code{language} in @file{config-lang.in}) for the following
671 values of @code{@var{hook}}, and any other Makefile rules required to
672 build those targets (which may if necessary use other Makefiles
673 specified in @code{outputs} in @file{config-lang.in}, although this is
674 deprecated). It also adds any testsuite targets that can use the
675 standard rule in @file{gcc/Makefile.in} to the variable
682 FIXME: exactly what goes in each of these targets?
684 Build an @command{etags} @file{TAGS} file in the language subdirectory
687 Build info documentation for the front end, in the build directory.
688 This target is only called by @samp{make bootstrap} if a suitable
689 version of @command{makeinfo} is available, so does not need to check
690 for this, and should fail if an error occurs.
692 Build DVI documentation for the front end, in the build directory.
693 This should be done using @code{$(TEXI2DVI)}, with appropriate
694 @option{-I} arguments pointing to directories of included files.
696 Build PDF documentation for the front end, in the build directory.
697 This should be done using @code{$(TEXI2PDF)}, with appropriate
698 @option{-I} arguments pointing to directories of included files.
700 Build HTML documentation for the front end, in the build directory.
702 Build generated man pages for the front end from Texinfo manuals
703 (@pxref{Man Page Generation}), in the build directory. This target
704 is only called if the necessary tools are available, but should ignore
705 errors so as not to stop the build if errors occur; man pages are
706 optional and the tools involved may be installed in a broken way.
708 Install everything that is part of the front end, apart from the
709 compiler executables listed in @code{compilers} in
710 @file{config-lang.in}.
712 Install info documentation for the front end, if it is present in the
713 source directory. This target should have dependencies on info files
714 that should be installed.
716 Install man pages for the front end. This target should ignore
719 Install headers needed for plugins.
721 Copies its dependencies into the source directory. This generally should
722 be used for generated files such as Bison output files which are not
723 version-controlled, but should be included in any release tarballs. This
724 target will be executed during a bootstrap if
725 @samp{--enable-generated-files-in-srcdir} was specified as a
726 @file{configure} option.
729 Copies its dependencies into the source directory. These targets will be
730 executed during a bootstrap if @samp{--enable-generated-files-in-srcdir}
731 was specified as a @file{configure} option.
733 Uninstall files installed by installing the compiler. This is
734 currently documented not to be supported, so the hook need not do
739 @itemx maintainer-clean
740 The language parts of the standard GNU
741 @samp{*clean} targets. @xref{Standard Targets, , Standard Targets for
742 Users, standards, GNU Coding Standards}, for details of the standard
743 targets. For GCC, @code{maintainer-clean} should delete
744 all generated files in the source directory that are not version-controlled,
745 but should not delete anything that is.
748 @file{Make-lang.in} must also define a variable @code{@var{lang}_OBJS}
749 to a list of host object files that are used by that language.
752 @subsection Anatomy of a Target Back End
754 A back end for a target architecture in GCC has the following parts:
758 A directory @file{@var{machine}} under @file{gcc/config}, containing a
759 machine description @file{@var{machine}.md} file (@pxref{Machine Desc,
760 , Machine Descriptions}), header files @file{@var{machine}.h} and
761 @file{@var{machine}-protos.h} and a source file @file{@var{machine}.c}
762 (@pxref{Target Macros, , Target Description Macros and Functions}),
763 possibly a target Makefile fragment @file{t-@var{machine}}
764 (@pxref{Target Fragment, , The Target Makefile Fragment}), and maybe
765 some other files. The names of these files may be changed from the
766 defaults given by explicit specifications in @file{config.gcc}.
768 If necessary, a file @file{@var{machine}-modes.def} in the
769 @file{@var{machine}} directory, containing additional machine modes to
770 represent condition codes. @xref{Condition Code}, for further details.
772 An optional @file{@var{machine}.opt} file in the @file{@var{machine}}
773 directory, containing a list of target-specific options. You can also
774 add other option files using the @code{extra_options} variable in
775 @file{config.gcc}. @xref{Options}.
777 Entries in @file{config.gcc} (@pxref{System Config, , The
778 @file{config.gcc} File}) for the systems with this target
781 Documentation in @file{gcc/doc/invoke.texi} for any command-line
782 options supported by this target (@pxref{Run-time Target, , Run-time
783 Target Specification}). This means both entries in the summary table
784 of options and details of the individual options.
786 Documentation in @file{gcc/doc/extend.texi} for any target-specific
787 attributes supported (@pxref{Target Attributes, , Defining
788 target-specific uses of @code{__attribute__}}), including where the
789 same attribute is already supported on some targets, which are
790 enumerated in the manual.
792 Documentation in @file{gcc/doc/extend.texi} for any target-specific
795 Documentation in @file{gcc/doc/extend.texi} of any target-specific
796 built-in functions supported.
798 Documentation in @file{gcc/doc/extend.texi} of any target-specific
799 format checking styles supported.
801 Documentation in @file{gcc/doc/md.texi} of any target-specific
802 constraint letters (@pxref{Machine Constraints, , Constraints for
803 Particular Machines}).
805 A note in @file{gcc/doc/contrib.texi} under the person or people who
806 contributed the target support.
808 Entries in @file{gcc/doc/install.texi} for all target triplets
809 supported with this target architecture, giving details of any special
810 notes about installation for this target, or saying that there are no
811 special notes if there are none.
813 Possibly other support outside the @file{gcc} directory for runtime
814 libraries. FIXME: reference docs for this. The @code{libstdc++} porting
815 manual needs to be installed as info for this to work, or to be a
816 chapter of this manual.
819 If the back end is added to the official GCC source repository, the
820 following are also necessary:
824 An entry for the target architecture in @file{readings.html} on the
825 GCC web site, with any relevant links.
827 Details of the properties of the back end and target architecture in
828 @file{backends.html} on the GCC web site.
830 A news item about the contribution of support for that target
831 architecture, in @file{index.html} on the GCC web site.
833 Normally, one or more maintainers of that target listed in
834 @file{MAINTAINERS}. Some existing architectures may be unmaintained,
835 but it would be unusual to add support for a target that does not have
836 a maintainer when support is added.
842 GCC contains several testsuites to help maintain compiler quality.
843 Most of the runtime libraries and language front ends in GCC have
844 testsuites. Currently only the C language testsuites are documented
845 here; FIXME: document the others.
848 * Test Idioms:: Idioms used in testsuite code.
849 * Test Directives:: Directives used within DejaGnu tests.
850 * Ada Tests:: The Ada language testsuites.
851 * C Tests:: The C language testsuites.
852 * libgcj Tests:: The Java library testsuites.
853 * LTO Testing:: Support for testing link-time optimizations.
854 * gcov Testing:: Support for testing gcov.
855 * profopt Testing:: Support for testing profile-directed optimizations.
856 * compat Testing:: Support for testing binary compatibility.
857 * Torture Tests:: Support for torture testing using multiple options.
861 @section Idioms Used in Testsuite Code
863 In general, C testcases have a trailing @file{-@var{n}.c}, starting
864 with @file{-1.c}, in case other testcases with similar names are added
865 later. If the test is a test of some well-defined feature, it should
866 have a name referring to that feature such as
867 @file{@var{feature}-1.c}. If it does not test a well-defined feature
868 but just happens to exercise a bug somewhere in the compiler, and a
869 bug report has been filed for this bug in the GCC bug database,
870 @file{pr@var{bug-number}-1.c} is the appropriate form of name.
871 Otherwise (for miscellaneous bugs not filed in the GCC bug database),
872 and previously more generally, test cases are named after the date on
873 which they were added. This allows people to tell at a glance whether
874 a test failure is because of a recently found bug that has not yet
875 been fixed, or whether it may be a regression, but does not give any
876 other information about the bug or where discussion of it may be
877 found. Some other language testsuites follow similar conventions.
879 In the @file{gcc.dg} testsuite, it is often necessary to test that an
880 error is indeed a hard error and not just a warning---for example,
881 where it is a constraint violation in the C standard, which must
882 become an error with @option{-pedantic-errors}. The following idiom,
883 where the first line shown is line @var{line} of the file and the line
884 that generates the error, is used for this:
887 /* @{ dg-bogus "warning" "warning in place of error" @} */
888 /* @{ dg-error "@var{regexp}" "@var{message}" @{ target *-*-* @} @var{line} @} */
891 It may be necessary to check that an expression is an integer constant
892 expression and has a certain value. To check that @code{@var{E}} has
893 value @code{@var{V}}, an idiom similar to the following is used:
896 char x[((E) == (V) ? 1 : -1)];
899 In @file{gcc.dg} tests, @code{__typeof__} is sometimes used to make
900 assertions about the types of expressions. See, for example,
901 @file{gcc.dg/c99-condexpr-1.c}. The more subtle uses depend on the
902 exact rules for the types of conditional expressions in the C
903 standard; see, for example, @file{gcc.dg/c99-intconst-1.c}.
905 It is useful to be able to test that optimizations are being made
906 properly. This cannot be done in all cases, but it can be done where
907 the optimization will lead to code being optimized away (for example,
908 where flow analysis or alias analysis should show that certain code
909 cannot be called) or to functions not being called because they have
910 been expanded as built-in functions. Such tests go in
911 @file{gcc.c-torture/execute}. Where code should be optimized away, a
912 call to a nonexistent function such as @code{link_failure ()} may be
913 inserted; a definition
926 will also be needed so that linking still succeeds when the test is
927 run without optimization. When all calls to a built-in function
928 should have been optimized and no calls to the non-built-in version of
929 the function should remain, that function may be defined as
930 @code{static} to call @code{abort ()} (although redeclaring a function
931 as static may not work on all targets).
933 All testcases must be portable. Target-specific testcases must have
934 appropriate code to avoid causing failures on unsupported systems;
935 unfortunately, the mechanisms for this differ by directory.
937 FIXME: discuss non-C testsuites here.
939 @node Test Directives
940 @section Directives used within DejaGnu tests
943 * Directives:: Syntax and descriptions of test directives.
944 * Selectors:: Selecting targets to which a test applies.
945 * Effective-Target Keywords:: Keywords describing target attributes.
946 * Add Options:: Features for @code{dg-add-options}
947 * Require Support:: Variants of @code{dg-require-@var{support}}
948 * Final Actions:: Commands for use in @code{dg-final}
952 @subsection Syntax and Descriptions of test directives
954 Test directives appear within comments in a test source file and begin
955 with @code{dg-}. Some of these are defined within DejaGnu and others
956 are local to the GCC testsuite.
958 The order in which test directives appear in a test can be important:
959 directives local to GCC sometimes override information used by the
960 DejaGnu directives, which know nothing about the GCC directives, so the
961 DejaGnu directives must precede GCC directives.
963 Several test directives include selectors (@pxref{Selectors, , })
964 which are usually preceded by the keyword @code{target} or @code{xfail}.
966 @subsubsection Specify how to build the test
969 @item @{ dg-do @var{do-what-keyword} [@{ target/xfail @var{selector} @}] @}
970 @var{do-what-keyword} specifies how the test is compiled and whether
971 it is executed. It is one of:
975 Compile with @option{-E} to run only the preprocessor.
977 Compile with @option{-S} to produce an assembly code file.
979 Compile with @option{-c} to produce a relocatable object file.
981 Compile, assemble, and link to produce an executable file.
983 Produce and run an executable file, which is expected to return
987 The default is @code{compile}. That can be overridden for a set of
988 tests by redefining @code{dg-do-what-default} within the @code{.exp}
989 file for those tests.
991 If the directive includes the optional @samp{@{ target @var{selector} @}}
992 then the test is skipped unless the target system matches the
995 If @var{do-what-keyword} is @code{run} and the directive includes
996 the optional @samp{@{ xfail @var{selector} @}} and the selector is met
997 then the test is expected to fail. The @code{xfail} clause is ignored
998 for other values of @var{do-what-keyword}; those tests can use
999 directive @code{dg-xfail-if}.
1002 @subsubsection Specify additional compiler options
1005 @item @{ dg-options @var{options} [@{ target @var{selector} @}] @}
1006 This DejaGnu directive provides a list of compiler options, to be used
1007 if the target system matches @var{selector}, that replace the default
1008 options used for this set of tests.
1010 @item @{ dg-add-options @var{feature} @dots{} @}
1011 Add any compiler options that are needed to access certain features.
1012 This directive does nothing on targets that enable the features by
1013 default, or that don't provide them at all. It must come after
1014 all @code{dg-options} directives.
1015 For supported values of @var{feature} see @ref{Add Options, ,}.
1018 @subsubsection Modify the test timeout value
1020 The normal timeout limit, in seconds, is found by searching the
1024 @item the value defined by an earlier @code{dg-timeout} directive in
1027 @item variable @var{tool_timeout} defined by the set of tests
1029 @item @var{gcc},@var{timeout} set in the target board
1035 @item @{ dg-timeout @var{n} [@{target @var{selector} @}] @}
1036 Set the time limit for the compilation and for the execution of the test
1037 to the specified number of seconds.
1039 @item @{ dg-timeout-factor @var{x} [@{ target @var{selector} @}] @}
1040 Multiply the normal time limit for compilation and execution of the test
1041 by the specified floating-point factor.
1044 @subsubsection Skip a test for some targets
1047 @item @{ dg-skip-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1048 Arguments @var{include-opts} and @var{exclude-opts} are lists in which
1049 each element is a string of zero or more GCC options.
1050 Skip the test if all of the following conditions are met:
1052 @item the test system is included in @var{selector}
1054 @item for at least one of the option strings in @var{include-opts},
1055 every option from that string is in the set of options with which
1056 the test would be compiled; use @samp{"*"} for an @var{include-opts} list
1057 that matches any options; that is the default if @var{include-opts} is
1060 @item for each of the option strings in @var{exclude-opts}, at least one
1061 option from that string is not in the set of options with which the test
1062 would be compiled; use @samp{""} for an empty @var{exclude-opts} list;
1063 that is the default if @var{exclude-opts} is not specified
1066 For example, to skip a test if option @code{-Os} is present:
1069 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-Os" @} @{ "" @} @} */
1072 To skip a test if both options @code{-O2} and @code{-g} are present:
1075 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" @} @{ "" @} @} */
1078 To skip a test if either @code{-O2} or @code{-O3} is present:
1081 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2" "-O3" @} @{ "" @} @} */
1084 To skip a test unless option @code{-Os} is present:
1087 /* @{ dg-skip-if "" @{ *-*-* @} @{ "*" @} @{ "-Os" @} @} */
1090 To skip a test if either @code{-O2} or @code{-O3} is used with @code{-g}
1091 but not if @code{-fpic} is also present:
1094 /* @{ dg-skip-if "" @{ *-*-* @} @{ "-O2 -g" "-O3 -g" @} @{ "-fpic" @} @} */
1097 @item @{ dg-require-effective-target @var{keyword} [@{ @var{selector} @}] @}
1098 Skip the test if the test target, including current multilib flags,
1099 is not covered by the effective-target keyword.
1100 If the directive includes the optional @samp{@{ @var{selector} @}}
1101 then the effective-target test is only performed if the target system
1102 matches the @var{selector}.
1103 This directive must appear after any @code{dg-do} directive in the test
1104 and before any @code{dg-additional-sources} directive.
1105 @xref{Effective-Target Keywords, , }.
1107 @item @{ dg-require-@var{support} args @}
1108 Skip the test if the target does not provide the required support.
1109 These directives must appear after any @code{dg-do} directive in the test
1110 and before any @code{dg-additional-sources} directive.
1111 They require at least one argument, which can be an empty string if the
1112 specific procedure does not examine the argument.
1113 @xref{Require Support, , }, for a complete list of these directives.
1116 @subsubsection Expect a test to fail for some targets
1119 @item @{ dg-xfail-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1120 Expect the test to fail if the conditions (which are the same as for
1121 @code{dg-skip-if}) are met. This does not affect the execute step.
1123 @item @{ dg-xfail-run-if @var{comment} @{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]] @}
1124 Expect the execute step of a test to fail if the conditions (which are
1125 the same as for @code{dg-skip-if}) are met.
1128 @subsubsection Expect the test executable to fail
1131 @item @{ dg-shouldfail @var{comment} [@{ @var{selector} @} [@{ @var{include-opts} @} [@{ @var{exclude-opts} @}]]] @}
1132 Expect the test executable to return a nonzero exit status if the
1133 conditions (which are the same as for @code{dg-skip-if}) are met.
1136 @subsubsection Verify compiler messages
1139 @item @{ dg-error @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1140 This DejaGnu directive appears on a source line that is expected to get
1141 an error message, or else specifies the source line associated with the
1142 message. If there is no message for that line or if the text of that
1143 message is not matched by @var{regexp} then the check fails and
1144 @var{comment} is included in the @code{FAIL} message. The check does
1145 not look for the string @samp{error} unless it is part of @var{regexp}.
1147 @item @{ dg-warning @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1148 This DejaGnu directive appears on a source line that is expected to get
1149 a warning message, or else specifies the source line associated with the
1150 message. If there is no message for that line or if the text of that
1151 message is not matched by @var{regexp} then the check fails and
1152 @var{comment} is included in the @code{FAIL} message. The check does
1153 not look for the string @samp{warning} unless it is part of @var{regexp}.
1155 @item @{ dg-message @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1156 The line is expected to get a message other than an error or warning.
1157 If there is no message for that line or if the text of that message is
1158 not matched by @var{regexp} then the check fails and @var{comment} is
1159 included in the @code{FAIL} message.
1161 @item @{ dg-bogus @var{regexp} [@var{comment} [@{ target/xfail @var{selector} @} [@var{line}] @}]] @}
1162 This DejaGnu directive appears on a source line that should not get a
1163 message matching @var{regexp}, or else specifies the source line
1164 associated with the bogus message. It is usually used with @samp{xfail}
1165 to indicate that the message is a known problem for a particular set of
1168 @item @{ dg-excess-errors @var{comment} [@{ target/xfail @var{selector} @}] @}
1169 This DejaGnu directive indicates that the test is expected to fail due
1170 to compiler messages that are not handled by @samp{dg-error},
1171 @samp{dg-warning} or @samp{dg-bogus}. For this directive @samp{xfail}
1172 has the same effect as @samp{target}.
1174 @item @{ dg-prune-output @var{regexp} @}
1175 Prune messages matching @var{regexp} from the test output.
1178 @subsubsection Verify output of the test executable
1181 @item @{ dg-output @var{regexp} [@{ target/xfail @var{selector} @}] @}
1182 This DejaGnu directive compares @var{regexp} to the combined output
1183 that the test executable writes to @file{stdout} and @file{stderr}.
1186 @subsubsection Specify additional files for a test
1189 @item @{ dg-additional-files "@var{filelist}" @}
1190 Specify additional files, other than source files, that must be copied
1191 to the system where the compiler runs.
1193 @item @{ dg-additional-sources "@var{filelist}" @}
1194 Specify additional source files to appear in the compile line
1195 following the main test file.
1198 @subsubsection Add checks at the end of a test
1201 @item @{ dg-final @{ @var{local-directive} @} @}
1202 This DejaGnu directive is placed within a comment anywhere in the
1203 source file and is processed after the test has been compiled and run.
1204 Multiple @samp{dg-final} commands are processed in the order in which
1205 they appear in the source file. @xref{Final Actions, , }, for a list
1206 of directives that can be used within @code{dg-final}.
1210 @subsection Selecting targets to which a test applies
1212 Several test directives include @var{selector}s to limit the targets
1213 for which a test is run or to declare that a test is expected to fail
1214 on particular targets.
1218 @item one or more target triplets, possibly including wildcard characters
1219 @item a single effective-target keyword (@pxref{Effective-Target Keywords})
1220 @item a logical expression
1224 context, the selector specifies whether a test is skipped and reported
1225 as unsupported or is expected to fail. Use @samp{*-*-*} to match any
1228 A selector expression appears within curly braces and uses a single
1229 logical operator: one of @samp{!}, @samp{&&}, or @samp{||}. An
1230 operand is another selector expression, an effective-target keyword,
1231 a single target triplet, or a list of target triplets within quotes or
1232 curly braces. For example:
1235 @{ target @{ ! "hppa*-*-* ia64*-*-*" @} @}
1236 @{ target @{ powerpc*-*-* && lp64 @} @}
1237 @{ xfail @{ lp64 || vect_no_align @} @}
1240 @node Effective-Target Keywords
1241 @subsection Keywords describing target attributes
1243 Effective-target keywords identify sets of targets that support
1244 particular functionality. They are used to limit tests to be run only
1245 for particular targets, or to specify that particular sets of targets
1246 are expected to fail some tests.
1248 Effective-target keywords are defined in @file{lib/target-supports.exp} in
1249 the GCC testsuite, with the exception of those that are documented as
1250 being local to a particular test directory.
1252 The @samp{effective target} takes into account all of the compiler options
1253 with which the test will be compiled, including the multilib options.
1254 By convention, keywords ending in @code{_nocache} can also include options
1255 specified for the particular test in an earlier @code{dg-options} or
1256 @code{dg-add-options} directive.
1258 @subsubsection Data type sizes
1262 Target has 32-bit @code{int}, @code{long}, and pointers.
1265 Target has 32-bit @code{int}, 64-bit @code{long} and pointers.
1268 Target has 32-bit @code{int} and @code{long}, 64-bit @code{long long}
1272 Target has 64-bit @code{double}.
1275 Target has @code{double} that is 64 bits or longer.
1278 Target has @code{int} that is at 32 bits or longer.
1281 Target has @code{int} that is 16 bits or shorter.
1284 Target supports @code{double} that is longer than @code{float}.
1286 @item large_long_double
1287 Target supports @code{long double} that is longer than @code{double}.
1290 Target has pointers that are 32 bits or longer.
1293 Target supports array and structure sizes that are 32 bits or longer.
1296 Target has @code{wchar_t} that is at least 4 bytes.
1299 @subsubsection Fortran-specific attributes
1302 @item fortran_integer_16
1303 Target supports Fortran @code{integer} that is 16 bytes or longer.
1305 @item fortran_large_int
1306 Target supports Fortran @code{integer} kinds larger than @code{integer(8)}.
1308 @item fortran_large_real
1309 Target supports Fortran @code{real} kinds larger than @code{real(8)}.
1312 @subsubsection Vector-specific attributes
1315 @item vect_condition
1316 Target supports vector conditional operations.
1319 Target supports hardware vectors of @code{double}.
1322 Target supports hardware vectors of @code{float}.
1325 Target supports hardware vectors of @code{int}.
1328 Target supports a vector widening multiplication of @code{short} operands
1329 into an @code{int} result, or supports promotion (unpacking) from
1330 @code{short} to @code{int} and a non-widening multiplication of @code{int}.
1333 Target supports hardware vectors of @code{long}.
1335 @item vect_long_long
1336 Target supports hardware vectors of @code{long long}.
1338 @item vect_aligned_arrays
1339 Target aligns arrays to vector alignment boundary.
1341 @item vect_hw_misalign
1342 Target supports a vector misalign access.
1345 Target does not support a vector alignment mechanism.
1347 @item vect_no_int_max
1348 Target does not support a vector max instruction on @code{int}.
1350 @item vect_no_int_add
1351 Target does not support a vector add instruction on @code{int}.
1353 @item vect_no_bitwise
1354 Target does not support vector bitwise instructions.
1356 @item vect_char_mult
1357 Target supports @code{vector char} multiplication.
1359 @item vect_short_mult
1360 Target supports @code{vector short} multiplication.
1363 Target supports @code{vector int} multiplication.
1365 @item vect_extract_even_odd
1366 Target supports vector even/odd element extraction.
1368 @item vect_extract_even_odd_wide
1369 Target supports vector even/odd element extraction of vectors with elements
1370 @code{SImode} or larger.
1372 @item vect_interleave
1373 Target supports vector interleaving.
1376 Target supports vector interleaving and extract even/odd.
1378 @item vect_strided_wide
1379 Target supports vector interleaving and extract even/odd for wide
1383 Target supports vector permutation.
1386 Target supports a hardware vector shift operation.
1388 @item vect_widen_sum_hi_to_si
1389 Target supports a vector widening summation of @code{short} operands
1390 into @code{int} results, or can promote (unpack) from @code{short}
1393 @item vect_widen_sum_qi_to_hi
1394 Target supports a vector widening summation of @code{char} operands
1395 into @code{short} results, or can promote (unpack) from @code{char}
1398 @item vect_widen_sum_qi_to_si
1399 Target supports a vector widening summation of @code{char} operands
1400 into @code{int} results.
1402 @item vect_widen_mult_qi_to_hi
1403 Target supports a vector widening multiplication of @code{char} operands
1404 into @code{short} results, or can promote (unpack) from @code{char} to
1405 @code{short} and perform non-widening multiplication of @code{short}.
1407 @item vect_widen_mult_hi_to_si
1408 Target supports a vector widening multiplication of @code{short} operands
1409 into @code{int} results, or can promote (unpack) from @code{short} to
1410 @code{int} and perform non-widening multiplication of @code{int}.
1413 Target supports a vector dot-product of @code{signed char}.
1416 Target supports a vector dot-product of @code{unsigned char}.
1419 Target supports a vector dot-product of @code{signed short}.
1422 Target supports a vector dot-product of @code{unsigned short}.
1424 @item vect_pack_trunc
1425 Target supports a vector demotion (packing) of @code{short} to @code{char}
1426 and from @code{int} to @code{short} using modulo arithmetic.
1429 Target supports a vector promotion (unpacking) of @code{char} to @code{short}
1430 and from @code{char} to @code{int}.
1432 @item vect_intfloat_cvt
1433 Target supports conversion from @code{signed int} to @code{float}.
1435 @item vect_uintfloat_cvt
1436 Target supports conversion from @code{unsigned int} to @code{float}.
1438 @item vect_floatint_cvt
1439 Target supports conversion from @code{float} to @code{signed int}.
1441 @item vect_floatuint_cvt
1442 Target supports conversion from @code{float} to @code{unsigned int}.
1445 @subsubsection Thread Local Storage attributes
1449 Target supports thread-local storage.
1452 Target supports native (rather than emulated) thread-local storage.
1455 Test system supports executing TLS executables.
1458 @subsubsection Decimal floating point attributes
1462 Targets supports compiling decimal floating point extension to C.
1465 Including the options used to compile this particular test, the
1466 target supports compiling decimal floating point extension to C.
1469 Test system can execute decimal floating point tests.
1472 Including the options used to compile this particular test, the
1473 test system can execute decimal floating point tests.
1476 Target generates decimal floating point instructions with current options.
1479 @subsubsection ARM-specific attributes
1483 ARM target generates 32-bit code.
1486 ARM target adheres to the ABI for the ARM Architecture.
1488 @item arm_hard_vfp_ok
1489 ARM target supports @code{-mfpu=vfp -mfloat-abi=hard}.
1490 Some multilibs may be incompatible with these options.
1493 ARM target supports @code{-mcpu=iwmmxt}.
1494 Some multilibs may be incompatible with this option.
1497 ARM target supports generating NEON instructions.
1500 Test system supports executing NEON instructions.
1503 @anchor{arm_neon_ok}
1504 ARM Target supports @code{-mfpu=neon -mfloat-abi=softfp} or compatible
1505 options. Some multilibs may be incompatible with these options.
1507 @item arm_neon_fp16_ok
1508 @anchor{arm_neon_fp16_ok}
1509 ARM Target supports @code{-mfpu=neon-fp16 -mfloat-abi=softfp} or compatible
1510 options. Some multilibs may be incompatible with these options.
1513 ARM target generates Thumb-1 code for @code{-mthumb}.
1516 ARM target generates Thumb-2 code for @code{-mthumb}.
1519 ARM target supports @code{-mfpu=vfp -mfloat-abi=softfp}.
1520 Some multilibs may be incompatible with these options.
1523 @subsubsection MIPS-specific attributes
1527 MIPS target supports 64-bit instructions.
1530 MIPS target does not produce MIPS16 code.
1532 @item mips16_attribute
1533 MIPS target can generate MIPS16 code.
1536 MIPS target is a Loongson-2E or -2F target using an ABI that supports
1537 the Loongson vector modes.
1539 @item mips_newabi_large_long_double
1540 MIPS target supports @code{long double} larger than @code{double}
1541 when using the new ABI.
1543 @item mpaired_single
1544 MIPS target supports @code{-mpaired-single}.
1547 @subsubsection PowerPC-specific attributes
1551 Test system supports executing 64-bit instructions.
1553 @item powerpc_altivec
1554 PowerPC target supports AltiVec.
1556 @item powerpc_altivec_ok
1557 PowerPC target supports @code{-maltivec}.
1560 PowerPC target supports floating-point registers.
1562 @item powerpc_hard_double
1563 PowerPC target supports hardware double-precision floating-point.
1565 @item powerpc_ppu_ok
1566 PowerPC target supports @code{-mcpu=cell}.
1569 PowerPC target supports PowerPC SPE.
1571 @item powerpc_spe_nocache
1572 Including the options used to compile this particular test, the
1573 PowerPC target supports PowerPC SPE.
1576 PowerPC target supports PowerPC SPU.
1578 @item spu_auto_overlay
1579 SPU target has toolchain that supports automatic overlay generation.
1581 @item powerpc_vsx_ok
1582 PowerPC target supports @code{-mvsx}.
1584 @item powerpc_405_nocache
1585 Including the options used to compile this particular test, the
1586 PowerPC target supports PowerPC 405.
1589 PowerPC target supports executing AltiVec instructions.
1592 @subsubsection Other hardware attributes
1596 Target supports compiling AVX instructions.
1599 Test system can execute AltiVec and Cell PPU instructions.
1602 Target uses a ColdFire FPU.
1605 Target supports FPU instructions.
1608 Target supports compiling @code{sse2} instructions.
1610 @item sync_char_short
1611 Target supports atomic operations on @code{char} and @code{short}.
1614 Target supports atomic operations on @code{int} and @code{long}.
1617 Test environment appears to run executables on a simulator that
1618 accepts only @code{EM_SPARC} executables and chokes on @code{EM_SPARC32PLUS}
1619 or @code{EM_SPARCV9} executables.
1621 @item vect_cmdline_needed
1622 Target requires a command line argument to enable a SIMD instruction set.
1625 @subsubsection Environment attributes
1629 The language for the compiler under test is C.
1632 The language for the compiler under test is C++.
1635 Target provides a full C99 runtime.
1637 @item correct_iso_cpp_string_wchar_protos
1638 Target @code{string.h} and @code{wchar.h} headers provide C++ required
1639 overloads for @code{strchr} etc. functions.
1641 @item dummy_wcsftime
1642 Target uses a dummy @code{wcsftime} function that always returns zero.
1645 Target can truncate a file from a file descriptor, as used by
1646 @file{libgfortran/io/unix.c:fd_truncate}; i.e. @code{ftruncate} or
1650 Target is @samp{freestanding} as defined in section 4 of the C99 standard.
1651 Effectively, it is a target which supports no extra headers or libraries
1652 other than what is considered essential.
1655 Target supports constructors with initialization priority arguments.
1657 @item inttypes_types
1658 Target has the basic signed and unsigned types in @code{inttypes.h}.
1659 This is for tests that GCC's notions of these types agree with those
1660 in the header, as some systems have only @code{inttypes.h}.
1663 Target might have errors of a few ULP in string to floating-point
1664 conversion functions and overflow is not always detected correctly by
1668 Target supports Newlib.
1671 Target provides @code{pow10} function.
1674 Target can compile using @code{pthread.h} with no errors or warnings.
1677 Target has @code{pthread.h}.
1680 Test system runs executables on a simulator (i.e. slowly) rather than
1681 hardware (i.e. fast).
1684 Target has the basic signed and unsigned C types in @code{stdint.h}.
1685 This will be obsolete when GCC ensures a working @code{stdint.h} for
1689 Target supports trampolines.
1692 Target supports uClibc.
1695 Target does not use a status wrapper.
1697 @item vxworks_kernel
1698 Target is a VxWorks kernel.
1701 Target is a VxWorks RTP.
1704 Target supports wide characters.
1707 @subsubsection Other attributes
1710 @item automatic_stack_alignment
1711 Target supports automatic stack alignment.
1714 Target uses @code{__cxa_atexit}.
1716 @item default_packed
1717 Target has packed layout of structure members by default.
1720 Target supports Graphite optimizations.
1723 Target supports fixed-point extension to C.
1726 Target supports OpenMP via @option{-fopenmp}.
1729 Target supports @option{-fpic} and @option{-fPIC}.
1732 Target supports @option{-freorder-blocks-and-partition}.
1734 @item fstack_protector
1735 Target supports @option{-fstack-protector}.
1738 Target supports @option{--gc-sections}.
1740 @item keeps_null_pointer_checks
1741 Target keeps null pointer checks, either due to the use of
1742 @option{-fno-delete-null-pointer-checks} or hardwired into the target.
1745 Compiler has been configured to support link-time optimization (LTO).
1747 @item named_sections
1748 Target supports named sections.
1750 @item natural_alignment_32
1751 Target uses natural alignment (aligned to type size) for types of
1754 @item target_natural_alignment_64
1755 Target uses natural alignment (aligned to type size) for types of
1759 Target does not generate PIC by default.
1761 @item pcc_bitfield_type_matters
1762 Target defines @code{PCC_BITFIELD_TYPE_MATTERS}.
1764 @item pe_aligned_commons
1765 Target supports @option{-mpe-aligned-commons}.
1767 @item section_anchors
1768 Target supports section anchors.
1771 Target defaults to short enums.
1774 Target supports @option{-static}.
1776 @item static_libgfortran
1777 Target supports statically linking @samp{libgfortran}.
1779 @item string_merging
1780 Target supports merging string constants at link time.
1783 Target supports compiling and assembling UCN.
1786 Including the options used to compile this particular test, the
1787 target supports compiling and assembling UCN.
1789 @item unaligned_stack
1790 Target does not guarantee that its @code{STACK_BOUNDARY} is greater than
1791 or equal to the required vector alignment.
1793 @item vector_alignment_reachable
1794 Vector alignment is reachable for types of 32 bits or less.
1796 @item vector_alignment_reachable_for_64bit
1797 Vector alignment is reachable for types of 64 bits or less.
1799 @item wchar_t_char16_t_compatible
1800 Target supports @code{wchar_t} that is compatible with @code{char16_t}.
1802 @item wchar_t_char32_t_compatible
1803 Target supports @code{wchar_t} that is compatible with @code{char32_t}.
1806 @subsubsection Local to tests in @code{gcc.target/i386}
1810 Target supports compiling @code{3dnow} instructions.
1813 Target supports compiling @code{aes} instructions.
1816 Target supports compiling @code{fma4} instructions.
1818 @item ms_hook_prologue
1819 Target supports attribute @code{ms_hook_prologue}.
1822 Target supports compiling @code{pclmul} instructions.
1825 Target supports compiling @code{sse3} instructions.
1828 Target supports compiling @code{sse4} instructions.
1831 Target supports compiling @code{sse4a} instructions.
1834 Target supports compiling @code{ssse3} instructions.
1837 Target supports compiling @code{vaes} instructions.
1840 Target supports compiling @code{vpclmul} instructions.
1843 Target supports compiling @code{xop} instructions.
1846 @subsubsection Local to tests in @code{gcc.target/spu/ea}
1850 Target @code{__ea} library functions are available.
1853 @subsubsection Local to tests in @code{gcc.test-framework}
1864 @subsection Features for @code{dg-add-options}
1866 The supported values of @var{feature} for directive @code{dg-add-options}
1870 @item bind_pic_locally
1871 Add the target-specific flags needed to enable functions to bind
1872 locally when using pic/PIC passes in the testsuite.
1875 Add the target-specific flags needed to access the C99 runtime.
1878 Add the target-specific flags needed to enable full IEEE
1881 @item mips16_attribute
1882 @code{mips16} function attributes.
1883 Only MIPS targets support this feature, and only then in certain modes.
1886 NEON support. Only ARM targets support this feature, and only then
1887 in certain modes; see the @ref{arm_neon_ok,,arm_neon_ok effective target
1891 NEON and half-precision floating point support. Only ARM targets
1892 support this feature, and only then in certain modes; see
1893 the @ref{arm_neon_ok,,arm_neon_fp16_ok effective target keyword}.
1896 @node Require Support
1897 @subsection Variants of @code{dg-require-@var{support}}
1899 A few of the @code{dg-require} directives take arguments.
1902 @item dg-require-iconv @var{codeset}
1903 Skip the test if the target does not support iconv. @var{codeset} is
1904 the codeset to convert to.
1906 @item dg-require-profiling @var{profopt}
1907 Skip the test if the target does not support profiling with option
1910 @item dg-require-visibility @var{vis}
1911 Skip the test if the target does not support the @code{visibility} attribute.
1912 If @var{vis} is @code{""}, support for @code{visibility("hidden")} is
1913 checked, for @code{visibility("@var{vis}")} otherwise.
1916 The original @code{dg-require} directives were defined before there
1917 was support for effective-target keywords. The directives that do not
1918 take arguments could be replaced with effective-target keywords.
1921 @item dg-require-alias ""
1922 Skip the test if the target does not support the @samp{alias} attribute.
1924 @item dg-require-compat-dfp ""
1925 Skip this test unless both compilers in a @file{compat} testsuite
1926 support decimal floating point.
1928 @item dg-require-cxa-atexit ""
1929 Skip the test if the target does not support @code{__cxa_atexit}.
1930 This is equivalent to @code{dg-require-effective-target cxa_atexit}.
1932 @item dg-require-dll ""
1933 Skip the test if the target does not support DLL attributes.
1935 @item dg-require-fork ""
1936 Skip the test if the target does not support @code{fork}.
1938 @item dg-require-gc-sections ""
1939 Skip the test if the target's linker does not support the
1940 @code{--gc-sections} flags.
1941 This is equivalent to @code{dg-require-effective-target gc-sections}.
1943 @item dg-require-host-local ""
1944 Skip the test if the host is remote, rather than the same as the build
1945 system. Some tests are incompatible with DejaGnu's handling of remote
1946 hosts, which involves copying the source file to the host and compiling
1947 it with a relative path and "@code{-o a.out}".
1949 @item dg-require-mkfifo ""
1950 Skip the test if the target does not support @code{mkfifo}.
1952 @item dg-require-named-sections ""
1953 Skip the test is the target does not support named sections.
1954 This is equivalent to @code{dg-require-effective-target named_sections}.
1956 @item dg-require-weak ""
1957 Skip the test if the target does not support weak symbols.
1959 @item dg-require-weak-override ""
1960 Skip the test if the target does not support overriding weak symbols.
1964 @subsection Commands for use in @code{dg-final}
1966 The GCC testsuite defines the following directives to be used within
1969 @subsubsection Scan a particular file
1972 @item scan-file @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1973 Passes if @var{regexp} matches text in @var{filename}.
1974 @item scan-file-not @var{filename} @var{regexp} [@{ target/xfail @var{selector} @}]
1975 Passes if @var{regexp} does not match text in @var{filename}.
1976 @item scan-module @var{module} @var{regexp} [@{ target/xfail @var{selector} @}]
1977 Passes if @var{regexp} matches in Fortran module @var{module}.
1980 @subsubsection Scan the assembly output
1983 @item scan-assembler @var{regex} [@{ target/xfail @var{selector} @}]
1984 Passes if @var{regex} matches text in the test's assembler output.
1986 @item scan-assembler-not @var{regex} [@{ target/xfail @var{selector} @}]
1987 Passes if @var{regex} does not match text in the test's assembler output.
1989 @item scan-assembler-times @var{regex} @var{num} [@{ target/xfail @var{selector} @}]
1990 Passes if @var{regex} is matched exactly @var{num} times in the test's
1993 @item scan-assembler-dem @var{regex} [@{ target/xfail @var{selector} @}]
1994 Passes if @var{regex} matches text in the test's demangled assembler output.
1996 @item scan-assembler-dem-not @var{regex} [@{ target/xfail @var{selector} @}]
1997 Passes if @var{regex} does not match text in the test's demangled assembler
2000 @item scan-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2001 Passes if @var{symbol} is defined as a hidden symbol in the test's
2004 @item scan-not-hidden @var{symbol} [@{ target/xfail @var{selector} @}]
2005 Passes if @var{symbol} is not defined as a hidden symbol in the test's
2009 @subsubsection Scan optimization dump files
2011 These commands are available for @var{kind} of @code{tree}, @code{rtl},
2015 @item scan-@var{kind}-dump @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2016 Passes if @var{regex} matches text in the dump file with suffix @var{suffix}.
2018 @item scan-@var{kind}-dump-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2019 Passes if @var{regex} does not match text in the dump file with suffix
2022 @item scan-@var{kind}-dump-times @var{regex} @var{num} @var{suffix} [@{ target/xfail @var{selector} @}]
2023 Passes if @var{regex} is found exactly @var{num} times in the dump file
2024 with suffix @var{suffix}.
2026 @item scan-@var{kind}-dump-dem @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2027 Passes if @var{regex} matches demangled text in the dump file with
2028 suffix @var{suffix}.
2030 @item scan-@var{kind}-dump-dem-not @var{regex} @var{suffix} [@{ target/xfail @var{selector} @}]
2031 Passes if @var{regex} does not match demangled text in the dump file with
2032 suffix @var{suffix}.
2035 @subsubsection Verify that an output files exists or not
2038 @item output-exists [@{ target/xfail @var{selector} @}]
2039 Passes if compiler output file exists.
2041 @item output-exists-not [@{ target/xfail @var{selector} @}]
2042 Passes if compiler output file does not exist.
2045 @subsubsection Check for LTO tests
2048 @item scan-symbol @var{regexp} [@{ target/xfail @var{selector} @}]
2049 Passes if the pattern is present in the final executable.
2052 @subsubsection Checks for @command{gcov} tests
2055 @item run-gcov @var{sourcefile}
2056 Check line counts in @command{gcov} tests.
2058 @item run-gcov [branches] [calls] @{ @var{opts} @var{sourcefile} @}
2059 Check branch and/or call counts, in addition to line counts, in
2060 @command{gcov} tests.
2063 @subsubsection Clean up generated test files
2066 @item cleanup-coverage-files
2067 Removes coverage data files generated for this test.
2069 @item cleanup-ipa-dump @var{suffix}
2070 Removes IPA dump files generated for this test.
2072 @item cleanup-modules
2073 Removes Fortran module files generated for this test.
2075 @item cleanup-profile-file
2076 Removes profiling files generated for this test.
2078 @item cleanup-repo-files
2079 Removes files generated for this test for @option{-frepo}.
2081 @item cleanup-rtl-dump @var{suffix}
2082 Removes RTL dump files generated for this test.
2084 @item cleanup-saved-temps
2085 Removes files for the current test which were kept for @option{-save-temps}.
2087 @item cleanup-tree-dump @var{suffix}
2088 Removes tree dump files matching @var{suffix} which were generated for
2093 @section Ada Language Testsuites
2095 The Ada testsuite includes executable tests from the ACATS 2.5
2096 testsuite, publicly available at
2097 @uref{http://www.adaic.org/compilers/acats/2.5}.
2099 These tests are integrated in the GCC testsuite in the
2100 @file{ada/acats} directory, and
2101 enabled automatically when running @code{make check}, assuming
2102 the Ada language has been enabled when configuring GCC@.
2104 You can also run the Ada testsuite independently, using
2105 @code{make check-ada}, or run a subset of the tests by specifying which
2106 chapter to run, e.g.:
2109 $ make check-ada CHAPTERS="c3 c9"
2112 The tests are organized by directory, each directory corresponding to
2113 a chapter of the Ada Reference Manual. So for example, @file{c9} corresponds
2114 to chapter 9, which deals with tasking features of the language.
2116 There is also an extra chapter called @file{gcc} containing a template for
2117 creating new executable tests, although this is deprecated in favor of
2118 the @file{gnat.dg} testsuite.
2120 The tests are run using two @command{sh} scripts: @file{run_acats} and
2121 @file{run_all.sh}. To run the tests using a simulator or a cross
2122 target, see the small
2123 customization section at the top of @file{run_all.sh}.
2125 These tests are run using the build tree: they can be run without doing
2126 a @code{make install}.
2129 @section C Language Testsuites
2131 GCC contains the following C language testsuites, in the
2132 @file{gcc/testsuite} directory:
2136 This contains tests of particular features of the C compiler, using the
2137 more modern @samp{dg} harness. Correctness tests for various compiler
2138 features should go here if possible.
2140 Magic comments determine whether the file
2141 is preprocessed, compiled, linked or run. In these tests, error and warning
2142 message texts are compared against expected texts or regular expressions
2143 given in comments. These tests are run with the options @samp{-ansi -pedantic}
2144 unless other options are given in the test. Except as noted below they
2145 are not run with multiple optimization options.
2147 This subdirectory contains tests for binary compatibility using
2148 @file{lib/compat.exp}, which in turn uses the language-independent support
2149 (@pxref{compat Testing, , Support for testing binary compatibility}).
2151 This subdirectory contains tests of the preprocessor.
2153 This subdirectory contains tests for debug formats. Tests in this
2154 subdirectory are run for each debug format that the compiler supports.
2156 This subdirectory contains tests of the @option{-Wformat} format
2157 checking. Tests in this directory are run with and without
2159 @item gcc.dg/noncompile
2160 This subdirectory contains tests of code that should not compile and
2161 does not need any special compilation options. They are run with
2162 multiple optimization options, since sometimes invalid code crashes
2163 the compiler with optimization.
2164 @item gcc.dg/special
2165 FIXME: describe this.
2168 This contains particular code fragments which have historically broken easily.
2169 These tests are run with multiple optimization options, so tests for features
2170 which only break at some optimization levels belong here. This also contains
2171 tests to check that certain optimizations occur. It might be worthwhile to
2172 separate the correctness tests cleanly from the code quality tests, but
2173 it hasn't been done yet.
2175 @item gcc.c-torture/compat
2176 FIXME: describe this.
2178 This directory should probably not be used for new tests.
2179 @item gcc.c-torture/compile
2180 This testsuite contains test cases that should compile, but do not
2181 need to link or run. These test cases are compiled with several
2182 different combinations of optimization options. All warnings are
2183 disabled for these test cases, so this directory is not suitable if
2184 you wish to test for the presence or absence of compiler warnings.
2185 While special options can be set, and tests disabled on specific
2186 platforms, by the use of @file{.x} files, mostly these test cases
2187 should not contain platform dependencies. FIXME: discuss how defines
2188 such as @code{NO_LABEL_VALUES} and @code{STACK_SIZE} are used.
2189 @item gcc.c-torture/execute
2190 This testsuite contains test cases that should compile, link and run;
2191 otherwise the same comments as for @file{gcc.c-torture/compile} apply.
2192 @item gcc.c-torture/execute/ieee
2193 This contains tests which are specific to IEEE floating point.
2194 @item gcc.c-torture/unsorted
2195 FIXME: describe this.
2197 This directory should probably not be used for new tests.
2198 @item gcc.misc-tests
2199 This directory contains C tests that require special handling. Some
2200 of these tests have individual expect files, and others share
2201 special-purpose expect files:
2204 @item @code{bprob*.c}
2205 Test @option{-fbranch-probabilities} using
2206 @file{gcc.misc-tests/bprob.exp}, which
2207 in turn uses the generic, language-independent framework
2208 (@pxref{profopt Testing, , Support for testing profile-directed
2211 @item @code{gcov*.c}
2212 Test @command{gcov} output using @file{gcov.exp}, which in turn uses the
2213 language-independent support (@pxref{gcov Testing, , Support for testing gcov}).
2215 @item @code{i386-pf-*.c}
2216 Test i386-specific support for data prefetch using @file{i386-prefetch.exp}.
2219 @item gcc.test-framework
2222 Test the testsuite itself using @file{gcc.test-framework/test-framework.exp}.
2227 FIXME: merge in @file{testsuite/README.gcc} and discuss the format of
2228 test cases and magic comments more.
2231 @section The Java library testsuites.
2233 Runtime tests are executed via @samp{make check} in the
2234 @file{@var{target}/libjava/testsuite} directory in the build
2235 tree. Additional runtime tests can be checked into this testsuite.
2237 Regression testing of the core packages in libgcj is also covered by the
2238 Mauve testsuite. The @uref{http://sourceware.org/mauve/,,Mauve Project}
2239 develops tests for the Java Class Libraries. These tests are run as part
2240 of libgcj testing by placing the Mauve tree within the libjava testsuite
2241 sources at @file{libjava/testsuite/libjava.mauve/mauve}, or by specifying
2242 the location of that tree when invoking @samp{make}, as in
2243 @samp{make MAUVEDIR=~/mauve check}.
2245 To detect regressions, a mechanism in @file{mauve.exp} compares the
2246 failures for a test run against the list of expected failures in
2247 @file{libjava/testsuite/libjava.mauve/xfails} from the source hierarchy.
2248 Update this file when adding new failing tests to Mauve, or when fixing
2249 bugs in libgcj that had caused Mauve test failures.
2251 We encourage developers to contribute test cases to Mauve.
2254 @section Support for testing link-time optimizations
2256 Tests for link-time optimizations usually require multiple source files
2257 that are compiled separately, perhaps with different sets of options.
2258 There are several special-purpose test directives used for these tests.
2261 @item @{ dg-lto-do @var{do-what-keyword} @}
2262 @var{do-what-keyword} specifies how the test is compiled and whether
2263 it is executed. It is one of:
2267 Compile with @option{-c} to produce a relocatable object file.
2269 Compile, assemble, and link to produce an executable file.
2271 Produce and run an executable file, which is expected to return
2275 The default is @code{assemble}. That can be overridden for a set of
2276 tests by redefining @code{dg-do-what-default} within the @code{.exp}
2277 file for those tests.
2279 Unlike @code{dg-do}, @code{dg-lto-do} does not support an optional
2280 @samp{target} or @samp{xfail} list. Use @code{dg-skip-if},
2281 @code{dg-xfail-if}, or @code{dg-xfail-run-if}.
2283 @item @{ dg-lto-options @{ @{ @var{options} @} [@{ @var{options} @}] @} [@{ target @var{selector} @}]@}
2284 This directive provides a list of one or more sets of compiler options
2285 to override @var{LTO_OPTIONS}. Each test will be compiled and run with
2286 each of these sets of options.
2288 @item @{ dg-extra-ld-options @var{options} @}
2289 This directive adds @var{options} to the linker options used.
2291 @item @{ dg-suppress-ld-options @var{options} @}
2292 This directive removes @var{options} from the set of linker options used.
2296 @section Support for testing @command{gcov}
2298 Language-independent support for testing @command{gcov}, and for checking
2299 that branch profiling produces expected values, is provided by the
2300 expect file @file{lib/gcov.exp}. @command{gcov} tests also rely on procedures
2301 in @file{lib/gcc-dg.exp} to compile and run the test program. A typical
2302 @command{gcov} test contains the following DejaGnu commands within comments:
2305 @{ dg-options "-fprofile-arcs -ftest-coverage" @}
2306 @{ dg-do run @{ target native @} @}
2307 @{ dg-final @{ run-gcov sourcefile @} @}
2310 Checks of @command{gcov} output can include line counts, branch percentages,
2311 and call return percentages. All of these checks are requested via
2312 commands that appear in comments in the test's source file.
2313 Commands to check line counts are processed by default.
2314 Commands to check branch percentages and call return percentages are
2315 processed if the @command{run-gcov} command has arguments @code{branches}
2316 or @code{calls}, respectively. For example, the following specifies
2317 checking both, as well as passing @option{-b} to @command{gcov}:
2320 @{ dg-final @{ run-gcov branches calls @{ -b sourcefile @} @} @}
2323 A line count command appears within a comment on the source line
2324 that is expected to get the specified count and has the form
2325 @code{count(@var{cnt})}. A test should only check line counts for
2326 lines that will get the same count for any architecture.
2328 Commands to check branch percentages (@code{branch}) and call
2329 return percentages (@code{returns}) are very similar to each other.
2330 A beginning command appears on or before the first of a range of
2331 lines that will report the percentage, and the ending command
2332 follows that range of lines. The beginning command can include a
2333 list of percentages, all of which are expected to be found within
2334 the range. A range is terminated by the next command of the same
2335 kind. A command @code{branch(end)} or @code{returns(end)} marks
2336 the end of a range without starting a new one. For example:
2339 if (i > 10 && j > i && j < 20) /* @r{branch(27 50 75)} */
2340 /* @r{branch(end)} */
2344 For a call return percentage, the value specified is the
2345 percentage of calls reported to return. For a branch percentage,
2346 the value is either the expected percentage or 100 minus that
2347 value, since the direction of a branch can differ depending on the
2348 target or the optimization level.
2350 Not all branches and calls need to be checked. A test should not
2351 check for branches that might be optimized away or replaced with
2352 predicated instructions. Don't check for calls inserted by the
2353 compiler or ones that might be inlined or optimized away.
2355 A single test can check for combinations of line counts, branch
2356 percentages, and call return percentages. The command to check a
2357 line count must appear on the line that will report that count, but
2358 commands to check branch percentages and call return percentages can
2359 bracket the lines that report them.
2361 @node profopt Testing
2362 @section Support for testing profile-directed optimizations
2364 The file @file{profopt.exp} provides language-independent support for
2365 checking correct execution of a test built with profile-directed
2366 optimization. This testing requires that a test program be built and
2367 executed twice. The first time it is compiled to generate profile
2368 data, and the second time it is compiled to use the data that was
2369 generated during the first execution. The second execution is to
2370 verify that the test produces the expected results.
2372 To check that the optimization actually generated better code, a
2373 test can be built and run a third time with normal optimizations to
2374 verify that the performance is better with the profile-directed
2375 optimizations. @file{profopt.exp} has the beginnings of this kind
2378 @file{profopt.exp} provides generic support for profile-directed
2379 optimizations. Each set of tests that uses it provides information
2380 about a specific optimization:
2384 tool being tested, e.g., @command{gcc}
2386 @item profile_option
2387 options used to generate profile data
2389 @item feedback_option
2390 options used to optimize using that profile data
2393 suffix of profile data files
2395 @item PROFOPT_OPTIONS
2396 list of options with which to run each test, similar to the lists for
2399 @item @{ dg-final-generate @{ @var{local-directive} @} @}
2400 This directive is similar to @code{dg-final}, but the
2401 @var{local-directive} is run after the generation of profile data.
2403 @item @{ dg-final-use @{ @var{local-directive} @} @}
2404 The @var{local-directive} is run after the profile data have been
2408 @node compat Testing
2409 @section Support for testing binary compatibility
2411 The file @file{compat.exp} provides language-independent support for
2412 binary compatibility testing. It supports testing interoperability of
2413 two compilers that follow the same ABI, or of multiple sets of
2414 compiler options that should not affect binary compatibility. It is
2415 intended to be used for testsuites that complement ABI testsuites.
2417 A test supported by this framework has three parts, each in a
2418 separate source file: a main program and two pieces that interact
2419 with each other to split up the functionality being tested.
2422 @item @var{testname}_main.@var{suffix}
2423 Contains the main program, which calls a function in file
2424 @file{@var{testname}_x.@var{suffix}}.
2426 @item @var{testname}_x.@var{suffix}
2427 Contains at least one call to a function in
2428 @file{@var{testname}_y.@var{suffix}}.
2430 @item @var{testname}_y.@var{suffix}
2431 Shares data with, or gets arguments from,
2432 @file{@var{testname}_x.@var{suffix}}.
2435 Within each test, the main program and one functional piece are
2436 compiled by the GCC under test. The other piece can be compiled by
2437 an alternate compiler. If no alternate compiler is specified,
2438 then all three source files are all compiled by the GCC under test.
2439 You can specify pairs of sets of compiler options. The first element
2440 of such a pair specifies options used with the GCC under test, and the
2441 second element of the pair specifies options used with the alternate
2442 compiler. Each test is compiled with each pair of options.
2444 @file{compat.exp} defines default pairs of compiler options.
2445 These can be overridden by defining the environment variable
2446 @env{COMPAT_OPTIONS} as:
2449 COMPAT_OPTIONS="[list [list @{@var{tst1}@} @{@var{alt1}@}]
2450 @dots{}[list @{@var{tstn}@} @{@var{altn}@}]]"
2453 where @var{tsti} and @var{alti} are lists of options, with @var{tsti}
2454 used by the compiler under test and @var{alti} used by the alternate
2455 compiler. For example, with
2456 @code{[list [list @{-g -O0@} @{-O3@}] [list @{-fpic@} @{-fPIC -O2@}]]},
2457 the test is first built with @option{-g -O0} by the compiler under
2458 test and with @option{-O3} by the alternate compiler. The test is
2459 built a second time using @option{-fpic} by the compiler under test
2460 and @option{-fPIC -O2} by the alternate compiler.
2462 An alternate compiler is specified by defining an environment
2463 variable to be the full pathname of an installed compiler; for C
2464 define @env{ALT_CC_UNDER_TEST}, and for C++ define
2465 @env{ALT_CXX_UNDER_TEST}. These will be written to the
2466 @file{site.exp} file used by DejaGnu. The default is to build each
2467 test with the compiler under test using the first of each pair of
2468 compiler options from @env{COMPAT_OPTIONS}. When
2469 @env{ALT_CC_UNDER_TEST} or
2470 @env{ALT_CXX_UNDER_TEST} is @code{same}, each test is built using
2471 the compiler under test but with combinations of the options from
2472 @env{COMPAT_OPTIONS}.
2474 To run only the C++ compatibility suite using the compiler under test
2475 and another version of GCC using specific compiler options, do the
2476 following from @file{@var{objdir}/gcc}:
2481 ALT_CXX_UNDER_TEST=$@{alt_prefix@}/bin/g++ \
2482 COMPAT_OPTIONS="@var{lists as shown above}" \
2484 RUNTESTFLAGS="compat.exp"
2487 A test that fails when the source files are compiled with different
2488 compilers, but passes when the files are compiled with the same
2489 compiler, demonstrates incompatibility of the generated code or
2490 runtime support. A test that fails for the alternate compiler but
2491 passes for the compiler under test probably tests for a bug that was
2492 fixed in the compiler under test but is present in the alternate
2495 The binary compatibility tests support a small number of test framework
2496 commands that appear within comments in a test file.
2500 These commands can be used in @file{@var{testname}_main.@var{suffix}}
2501 to skip the test if specific support is not available on the target.
2504 The specified options are used for compiling this particular source
2505 file, appended to the options from @env{COMPAT_OPTIONS}. When this
2506 command appears in @file{@var{testname}_main.@var{suffix}} the options
2507 are also used to link the test program.
2510 This command can be used in a secondary source file to specify that
2511 compilation is expected to fail for particular options on particular
2516 @section Support for torture testing using multiple options
2518 Throughout the compiler testsuite there are several directories whose
2519 tests are run multiple times, each with a different set of options.
2520 These are known as torture tests.
2521 @file{lib/torture-options.exp} defines procedures to
2526 Initialize use of torture lists.
2527 @item set-torture-options
2528 Set lists of torture options to use for tests with and without loops.
2529 Optionally combine a set of torture options with a set of other
2530 options, as is done with Objective-C runtime options.
2531 @item torture-finish
2532 Finalize use of torture lists.
2535 The @file{.exp} file for a set of tests that use torture options must
2536 include calls to these three procedures if:
2539 @item It calls @code{gcc-dg-runtest} and overrides @var{DG_TORTURE_OPTIONS}.
2541 @item It calls @var{$@{tool@}}@code{-torture} or
2542 @var{$@{tool@}}@code{-torture-execute}, where @var{tool} is @code{c},
2543 @code{fortran}, or @code{objc}.
2545 @item It calls @code{dg-pch}.
2548 It is not necessary for a @file{.exp} file that calls @code{gcc-dg-runtest}
2549 to call the torture procedures if the tests should use the list in
2550 @var{DG_TORTURE_OPTIONS} defined in @file{gcc-dg.exp}.
2552 Most uses of torture options can override the default lists by defining
2553 @var{TORTURE_OPTIONS} or add to the default list by defining
2554 @var{ADDITIONAL_TORTURE_OPTIONS}. Define these in a @file{.dejagnurc}
2555 file or add them to the @file{site.exp} file; for example
2558 set ADDITIONAL_TORTURE_OPTIONS [list \
2559 @{ -O2 -ftree-loop-linear @} \
2560 @{ -O2 -fpeel-loops @} ]