1 * Major changes in Autoconf 2.59c
3 ** The configure command now redirects standard input from /dev/null,
4 to help avoid problems with subsidiary commands that might mistakenly
5 read standard input. AS_ORIGINAL_STDIN_FD points to the original
6 standard input before this redirection, if you really want configure to
7 read from standard input.
9 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
10 The following directory variables are new:
12 datarootdir read-only architecture-independent data root [PREFIX/share]
13 localedir locale-specific message catalogs [DATAROOTDIR/locale]
14 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
15 htmldir html documentation [DOCDIR]
16 dvidir dvi documentation [DOCDIR]
17 pdfdir pdf documentation [DOCDIR]
18 psdir ps documentation [DOCDIR]
20 The following variables have new default values:
22 datadir read-only architecture-independent data [DATAROOTDIR]
23 infodir info documentation [DATAROOTDIR/info]
24 mandir man documentation [DATAROOTDIR/man]
26 This means that if you use any of `@datadir@', `@infodir@', or
27 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
30 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
31 a trailing slash. Similar change will be made to ac_top_builddir in a
32 future release; the old style value, which matches (../)*, is (and will
33 continue to be) available as ac_top_build_prefix.
36 New macro to check for support of 'typeof' syntax a la GNU C.
39 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
40 X11/Intrinsic.h and XtMalloc (Xt).
42 ** AC_PROG_CC_C89, AC_PROG_CC_C99
43 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
44 check for ANSI C89 and ISO C99 support respectively.
47 Has been unobsoleted, and will check if the compiler supports ISO
48 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
49 retained for backwards compatibility, assuming the value of
50 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
54 The subtituted value can now contain newlines.
57 The substitution now occurs only when @variable@ is on a line by itself,
58 optionally surrounded by spaces and tabs. The whole line is replaced.
61 New macro which is defined to the name of the first declared config header
62 or undefined if no config headers have been declared yet.
65 New macro for copyright notices in testsuite files.
67 ** ALLOCA, LIBOBJS, LTLIBOBJS
68 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
69 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
70 `Makefile.in' in case the object files lie in a different directory.
72 * Major changes in Autoconf 2.59b
74 Released 2004-08-20, by Paul Eggert.
77 New macro that computes the default alignment of a type.
79 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
80 When cross-compiling, these macros will give a warning if the tool
81 is not prefixed. In the future, unprefixed cross tools will not
82 be detected; please consult the info documentation for information
83 about the reason of this change.
85 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
86 New macros that detect programs whose name is prefixed with the
87 target type, if the build type and target type are different.
89 ** AC_REQUIRE_AUX_FILE
90 New trace macro that declares expected auxiliary files.
93 New macro that tests for a grep program that accepts as a long a line
96 ** AC_PROG_EGREP, AC_PROG_FGREP
97 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
98 FGREP="$GREP -F" respectively if possible, or else run a path search for
99 a program that accepts as long a line as possible.
102 New macro that tests for a sed program that truncates as few characters
105 * Major changes in Autoconf 2.59
107 Released 2003-11-04, by Akim Demaille
109 ** ac_abs_builddir etc.
110 Absolute file names were actually relative in 2.58.
112 * Major changes in Autoconf 2.58
114 Released 2003-11-04, by Akim Demaille
117 core.* files are no longer removed, as they may be valid user files.
119 ** autoreconf and auxiliary directory
120 Autoreconf creates the auxiliary directory if needed. This is
121 especially useful for initial "bootstrapping" of fresh CVS checkouts.
123 ** AC_CONFIG_MACRO_DIR
124 Use this macro to declare the directory for local m4 macros for aclocal.
127 No longer includes twice the same file in LIBOBJS if invoked
130 ** AC_CONFIG_COMMANDS
131 The directory for its first argument is automatically created. For
134 AC_CONFIG_COMMANDS([src/modules.hh], [...])
136 $top_builddir/src/ is created if needed.
138 ** Autotest and local.at
139 The optional file local.at is always included in Autotest test suites.
142 The warnings are always issued, including with cached runs.
143 This became a significant problem since aclocal and automake can
144 run autoconf behind the scene.
146 ** autoheader warnings
147 The warnings of autoheader can be turned off, using --warning.
148 For instance, -Wno-obsolete disables the complaints about acconfig.h
149 and other deprecated constructs.
152 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
155 ** AC_DECL_SYS_SIGLIST
159 Now checks that mktime is the inverse of localtime.
161 ** Improve DJGPP portability
162 The Autoconf tools and configure behave better under DJGPP.
164 ** Present But Cannot Be Compiled
165 New FAQ section dedicated to the mystic
167 configure: WARNING: pi.h: present but cannot be compiled
168 configure: WARNING: pi.h: check for missing prerequisite headers?
169 configure: WARNING: pi.h: proceeding with the preprocessor's result
172 ** Concurrent executions of autom4te
173 autom4te now locks its internal files, which enables concurrent
174 executions of autom4te, likely to happen if automake, autoconf,
175 autoheader etc. are run simultaneously.
178 Use of Libtool 1.5 and higher is encouraged. Compatibility with
179 Libtool pre-1.4 is not checked.
182 Testsuites no longer rerun failed tests in verbose mode; instead,
183 failures are logged while the test is run.
185 In addition, expected failures can be marked as such.
187 * Major changes in Autoconf 2.57
189 Released 2002-12-03 by Paul Eggert.
191 Bug fixes for problems with AIX linker, with freestanding C compilers,
192 with GNU m4 limitations, and with obsolete copies of GNU documents.
194 The Free Documentation License has been upgraded from 1.1 to 1.2.
196 * Major changes in Autoconf 2.56
198 Released 2002-11-15 by Akim Demaille.
200 One packaging problem fixed (config/install-sh was not executable).
202 * Major changes in Autoconf 2.55
204 Released 2002-11-14 by Akim Demaille.
208 Have your configure.ac checked by autoscan ("autoscan").
209 Try the warning options ("autoreconf -fv -Wall").
213 - AC_CHECK_HEADER, AC_CHECK_HEADERS
214 More information on proper use.
216 - Writing Test Programs
218 This sections explains how to write good test sources to use with
219 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
221 - AC_FOO_IFELSE vs. AC_TRY_FOO
223 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
224 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
228 - Is more robust to different Gettext installations.
230 - Produces messages (when --verbose) to be understood by Emacs'
233 - Supports -W/--warnings.
236 Once the GNU Build System reinstalled, run `./config.status
237 --recheck && ./config.status && make' if possible.
241 - Supports --cache, and --no-cache.
243 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
244 (autom4te.cache). See `Customizing autom4te' in the documentation.
251 Support for the obsoleted options -m, --macrodir, -l, --localdir is
252 dropped in favor of the safer --include/--prepend-include scheme.
257 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
258 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
259 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
262 Obsoleted macros are kept for Autoconf backward compatibility, but
263 should be avoided in configure.ac. Running autoupdate is advised.
266 - AC_DEFINE/AC_DEFINE_UNQUOTED
268 We have to stop using the old compatibility scheme --that tried to
269 avoid useless backslashes-- because Libtool 1.4.3 contains a
271 AC_DEFINE([error_t], [int],
272 [Define to a type to use for \`error_t' if it is not
273 otherwise available.])
275 We have to quote the single quotes and backslashes with \. The old
276 compatibility scheme saw that ` was backslashed, and therefore did
277 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
278 compatible with Libtool. Autoconf 2.55 is, but in some cases might
279 produce more \ than wanted.
281 Please, note that in the future the same problem will happen with
282 AC_MSG_*: use `autoreconf -f -Wall'.
286 - Portability of the Autoconf package to Solaris.
288 - Spurious warnings caused by config.status.
289 This bug is benign, but painful: on some systems (typically
290 FreeBSD), warnings such as:
292 config.status: creating Makefile
293 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
295 could be issued. This is fixed.
298 Simultaneous executions of config.status are possible again.
300 - Precious variables accumulation
302 config.status could stack several copies of the precious variables
306 ** Plans for later versions
310 The compatibility hooks with the old scheme will be completely
311 removed. Please, advice/use `--build', `--host', and `--target'
314 - AC_CHECK_HEADER, AC_CHECK_HEADERS
316 The tests will be stricter, please make sure your invocations are
321 Shell functions will gradually be introduced, probably starting with
322 Autotest. If you know machines which are in use that you suspect
323 *not* to support shell functions, please run the test suite of
324 Autoconf 2.55 on it, and report the results to
325 bug-autoconf@gnu.org.
329 Special characters in AC_MSG_* need not be quoted. Currently,
330 Autoconf has heuristics to decide when a string is escaped, or has
331 to be escaped. This scheme is fragile, and will be removed; the
332 only risk is uglified messages. Please, run `autoreconf -f -Wall'
333 to find occurrences that will be affected.
335 * Major changes in Autoconf 2.54
337 Released 2002-09-13 by Akim Demaille.
341 - autoreconf no longer changes the version of the gettext/po/intl
342 support files. It now adds the files the correspond to the
343 AM_GNU_GETTEXT_VERSION declared in configure.ac.
345 Warning: It now relies on the 'autopoint' program, which is part
346 of GNU gettext 0.11.4 and newer.
348 Please note that you need to have a GNU gettext version that
349 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
350 in configure.ac. You can upgrade to newer GNU gettext versions,
351 though, without needing to change configure.ac.
353 - The -I DIR or --include=DIR option now appends DIR to the include path
354 instead of prepending; this is for consistency with other GNU tools.
355 The new -B DIR or --prepend-include=DIR option has the old behavior.
360 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
361 Please, remove lines such as
363 # This is necessary so that .o files in LIBOBJS are also
364 # built via the ANSI2KNR-filtering rules.
365 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
367 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
368 your Makefiles either.
370 - AC_CONFIG_LINKS now makes copies if it can't make links.
372 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
373 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
374 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
376 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
378 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
380 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
384 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
385 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
386 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
389 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
392 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
393 for an AC_LIBOBJ replacement.
397 - Spurious complaints from `m4_bmatch' about invalid regular
398 expressions are suppressed.
400 - Empty top_builddirs are properly handled.
402 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
405 Now colon in the optional path arguments are properly handled.
407 ** Improved portability
409 - Both Autoconf the package, and the scripts it produces, should run
410 more reliably with Zsh. Bear in mind it is the default Bourne shell
413 - Autoconf and the scripts it produces no longer assume the existence of
414 the obsolescent commands egrep and fgrep.
418 - Limitations of Make
422 The GNATS base moved to
423 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
424 (It is no longer available, though.)
429 Now contains the list of ouput variables and files (AC_SUBST,
432 * Major changes in Autoconf 2.53
434 Released 2002-03-08 by Akim Demaille.
438 Perl 5.005_03 or later is required: autom4te is written in Perl and is
439 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
445 Argument requirements, output variables, defined macros.
446 - M4sugar, M4sh, Autotest
448 - Double quoting macros
449 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
451 The Autoconf manual is now distributed under the terms of the GNU FDL.
452 - Section `Hosts and Cross-Compilation'
453 Explains the rationale for the 2.5x changes in the cross-compilation
454 chain, and in the relationships between build, host, and target
456 Emphasizes that `cross-compilation' == `--host is given'.
457 If you are working on compilers etc., be sure to read this section.
458 - Section `AC_LIBOBJ vs. LIBOBJS'
459 Explains why assigning LIBOBJS directly is now an error.
460 Details how to update the code.
465 Now used instead of hard coded line numbers.
466 This eases the comparison of `configure's, and diminishes the
467 pressure over control version archives.
468 Automatic replacement for shells that don't support this feature.
469 - New output variables
470 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
475 Autoconf and Autotest modes are provided.
480 New, used by the Autoconf suite to cache and speed up most processing.
482 Supported by autom4te, autoconf and autoheader.
484 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
485 autoupdate, and autoreconf.
487 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
488 automake options are to be given via AUTOMAKE_OPTIONS.
490 Runs gettextize and libtoolize when appropriate.
492 --m4dir is no longer supported.
494 Now runs only in the specified directories, defaulting to `.',
495 but understands AC_CONFIG_SUBDIRS for dependent directories.
496 Before, it used to run on all the `configure.ac' found in the
498 Independent packages are properly updated.
502 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
504 Under the user pressure, $? is finally available. Probably a mistake.
505 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
506 - Precious variables accumulation
507 config.status could stack several copies of the precious variables
509 - AC_PATH_PROG and family.
510 Works properly when given a literal path.
512 Somewhere since 2.13, the result had been reversed.
516 - AC_C_BIGENDIAN supports the cross-compiling case.
517 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
518 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
519 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
521 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
522 precision than `double'.
527 It now defines the preprocessor symbols PACKAGE_NAME,
528 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
532 Admits a fourth optional parameter: the tar name.
534 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
535 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
536 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
539 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
540 Are much less expensive when using long lists of files.
543 Works with shell variables, and non alphanumeric names.
547 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
548 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
550 - AC_FUNC_STRTOD substitutes POW_LIB.
555 * Major changes in Autoconf 2.52
557 Released 2001-07-18 by Akim Demaille.
562 This feature was present in autoconf 2.50 but was not documented.
563 For example, `@<:@' is translated to `[' just before output. This
564 is useful when writing strings that contain unbalanced quotes, or
565 other hard-to-quote constructs.
566 - m4_pattern_forbid, m4_pattern_allow
567 - Tips for upgrading from 2.13.
568 - Using autoscan to maintain a configure.ac.
571 - Now include stdint.h.
572 - sys/types.h and sys/stat.h are guarded.
573 - strings.h is included if available, and not conflicting with string.h.
576 - The test suite is more robust and presents less false failures.
577 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
578 - configure accepts --prefix='' again.
579 - AC_CHECK_LIB works properly when its first argument is not a
581 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
582 - build_, host_, and target_alias are AC_SUBST as in 2.13.
583 - AC_ARG_VAR properly propagates precious variables inherited from the
584 environment to ./config.status.
585 - Using --program-suffix/--program-prefix is portable.
586 - Failures to detect the default compiler's output extension are less
588 - `config.status foo' works properly when `foo' depends on variables
589 set in an AC_CONFIG_THING INIT-CMD.
590 - autoheader is more robust to broken input.
591 - Fixed Fortran name-mangling and link tests on a number of systems,
592 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
595 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
596 specify pre-includes. In this case, the headers are compiled with
597 cc, not merely preprocessed by cpp. Therefore it is the _usability_
598 of a header which is checked for, not just its availability.
599 - AC_ARG_VAR refuses to run configure when precious variables have
601 - Versions of compilers are dumped in the logs.
602 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
605 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
606 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
607 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
608 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
609 Be sure to read `Upgrading from Version 2.13' to understand why
610 running `autoupdate' is needed.
611 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
612 a main-like routine is required/possible when linking C/C++ with
613 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
614 - AC_FUNC_GETPGRG behaves better when cross-compiling.
616 * Major changes in Autoconf 2.51
617 There was no release of Autoconf 2.51 since some packagers had used
618 this version number without permission to ship intermediary versions
619 of 2.50. The version was skipped to avoid confusion.
621 * Major changes in Autoconf 2.50
623 Released 2001-05-21 by Akim Demaille.
626 There have been far too many to enumerate them here. Check out
627 ChangeLog if you really want to know more.
629 ** Improved documentation
630 In particular, portability issues are better covered.
633 All the standard GNU Makefile targets are supported. The layout has
634 changed: m4/ holds the m4 extensions Autoconf needs for its
635 configuration, doc/ contains the documentation, and tests/ contains
638 ** Man pages are provided
639 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
640 config.guess, config.sub.
644 Provides a safe and powerful means to trace the macro uses. This
645 provide the parsing layer for tools which need to `study'
649 Specify what category of warnings should be enabled.
651 - When recursing into subdirectories, try for configure.gnu before
652 configure to adapt for packages not using autoconf on case-insensitive
656 More errors are now caught (circular AC_REQUIRE dependencies,
657 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
658 etc.). In addition, their location and call stack are given.
661 autoupdate is much more powerful, and is able to provide the glue code
662 which might be needed to move from an old macro to its newer
665 You are strongly encouraged to use it to modernize both your
666 `configure.in' and your .m4 extension files.
669 The internal machinery of autoheader has completely changed. As a
670 result, using `acconfig.h' should be considered to be obsoleted, and
671 you are encouraged to get rid of it using the AH macros.
676 ** Fortran 77 compilers
677 Globally, the support for Fortran 77 is considerably improved.
679 Support for automatically determining a Fortran 77 compiler's
680 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
681 provided to wrap C/C++ identifiers, thus making it easier and more
682 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
683 call C/C++ routines. See the Texinfo documentation for details.
686 The test suite no longer uses DejaGNU. It should be easy to submit
687 test cases in this new framework.
690 - --help, --help=long, -hl
691 no longer dumps useless items.
693 lists only specific options.
694 - --help=recursive, -hr
695 displays the help of all the embedded packages.
696 - Remembers environment variables when reconfiguring.
697 The previous scheme to set envvar before running configure was
699 what prevented configure from remembering the environment in which
700 it was run, therefore --recheck was run in an inconsistent
701 environment. Now, one should run
703 and then --recheck will work properly. Variables declared with
704 AC_ARG_VAR are also preserved.
706 $build defaults to `config.guess`, $host to $build, and then $target
708 Cross-compilation is a global status of the package, it no longer
709 depends upon the current language.
710 Cross compilation is enabled iff the user specified `--host'.
711 `configure' now fails if it can't run the executables it compiles,
712 unless cross-compilation is enabled.
714 The cache file is disabled by default. The new options
715 `--config-cache', `-C' set the cache to `config.cache'.
719 Much faster on most architectures.
720 - concurrent executions
721 It is safe to use `make -j' with config.status.
722 - human interface improved
723 It is possible to invoke
724 ./config.status foobar
725 instead of the former form (still valid)
726 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
727 CONFIG_FILES=foobar:foo.in:bar.in \
729 The same holds for configuration headers and links.
730 You can instantiate unknown files and headers:
731 ./config.status --header foo.h:foo.h.in --file bar:baz
732 - has a useful --help
733 - accepts special file name "-" for stdin/stdout
738 Specify additional copyright information.
741 Now expects the identity of the package as argument.
745 Most macros, if not all, now strictly follow the `one quotation
746 level' rule. This results in a more predictable expansion.
749 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
750 configure scripts, was fixed by Axel Thimm.
754 Document and ask for the registration of an envvar.
757 Specifies the file which `configure' should look for when trying to
758 find the source tree (used to be handled by AC_INIT).
761 To add new actions to config.status. Should be used instead of
765 Replaces AC_LINK_FILES.
767 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
768 AC_CONFIG_LINKS, and AC_CONFIG_FILES
769 They now obey sh: you should no longer use shell variables as
772 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
773 AC_CONFIG_SUBDIRS($my_subdirs)
777 if test "$package_foo_enabled" = yes; then
778 AC_CONFIG_SUBDIRS(foo)
782 To format an Autoconf macro's help string so that it looks pretty
783 when the user executes `configure --help'.
786 ** Generic Test Macros
788 The interface of the AC_CHECK families of macros (decl, header,
789 type, member, func) is now uniform. They support the same set of
792 - AC_CHECK_DECL, AC_CHECK_DECLS
793 To check whether a symbol is declared.
795 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
796 No longer need a cross-compilation default.
799 The test it performs is much more robust than previously, and makes
800 it possible to test builtin types in addition to typedefs.
801 It is now schizophrenic:
802 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
803 remains for backward compatibility, but its use is discouraged.
804 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
805 behaves exactly like the other AC_CHECK macros.
808 Checks whether given types are supported by the system.
810 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
811 Check for given members in aggregates (e.g., pw_gecos in struct
815 Checks if the compiler supports ISO C, included when needs special
819 Checking whether the preprocessor indicates missing includes by the
820 error code. stderr is checked by AC_TRY_CPP only as a fallback.
823 Takes a language as argument and replaces AC_LANG_C,
824 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
826 - AC_LANG_PUSH, AC_LANG_POP
827 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
830 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
831 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
832 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
839 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
842 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
845 Arrange for large-file support.
847 - AC_EXEEXT, AC_OBJEXT
848 You are no longer expected to use them: their computation is
849 performed by default.
852 Every macro has been revisited in order to support at best CC=c++.
854 Major changes in Autoconf 2.14:
855 There was no release of GNU Autoconf 2.14.
857 Major changes in Autoconf 2.13:
859 Released 1999-05-01 by Ben Elliston.
861 * Support for building on Win32 systems where the only available C or
862 C++ compiler is the Microsoft Visual C++ command line compiler
863 (`cl'). Additional support for building on Win32 systems which are
864 using the Cygwin or Mingw32 environments.
865 * Support for alternative object file and executable file extensions.
866 On Win32, for example, these are .obj and .exe. These are discovered
867 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
868 @EXEEXT@ in the output, respectively.
869 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
870 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
871 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
872 * AC_DEFINE now has an optional third argument for a description to be
873 placed in the config header input file (e.g. config.h.in).
874 * The C++ code fragment compiled for the C++ compiler test had to be
875 improved to include an explicit return type for main(). This was
876 causing failures on systems using recent versions of the EGCS C++
878 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
879 script to report that `sometype_t' was present when only `type_t'
881 * Merge of the FSF version of config.guess and config.sub to modernize
882 these scripts. Add support for a few new hosts in config.guess.
883 Incorporate latest versions of install-sh, mkinstalldirs and
884 texinfo.tex from the FSF.
885 * autoreconf is capable of running automake if necessary (and
887 * Support for Fortran 77. See the Texinfo documentation for details.
888 * Bug fixes and workarounds for quirky bugs in vendor utilities.
890 Major changes in Autoconf 2.12:
892 Released 1996-11-26 by David J. MacKenzie
894 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
895 concatenating multiple input files separated by colons, like so:
896 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
897 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
898 The arguments may be shell variables, to compute the lists on the fly.
899 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
900 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
903 Major changes in Autoconf 2.11:
905 Released November 18th, 1996, by David J. MacKenzie
907 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
908 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
909 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
910 * AC_CONFIG_HEADER expands shell variables in its argument.
911 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
912 * The "checking..." messages and the source code for test programs that
913 fail are saved in config.log.
914 * Another workaround has been added for seds with small command length limits.
915 * config.sub and config.guess recognize more system types.
918 Major changes in Autoconf 2.10:
920 Released May 7th, 1996, by Roland McGrath
923 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
924 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
926 Major changes in Autoconf 2.9:
928 Released March 16th, 1996, by Roland McGrath
932 Major changes in Autoconf 2.8:
934 Released March 8th, 1996, by Roland McGrath
938 Major changes in Autoconf 2.7:
940 Released November 22nd, 1995, by David J. MacKenzie
944 Major changes in Autoconf 2.6:
946 Released November 20th, 1995, by David J. MacKenzie
950 Major changes in Autoconf 2.5:
952 Released November 17th, 1995, by Roland McGrath
954 * New configure options --bindir, --libdir, --datadir, etc., with
955 corresponding output variables.
956 * New macro: AC_CACHE_CHECK, to make using the cache easier.
957 * config.log contains the command being run as well as any output from it.
958 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
959 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
960 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
961 AC_CHECK_TOOL can search a path other than $PATH.
962 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
964 Major changes in Autoconf 2.4:
966 Released June 14th, 1995, by David J. MacKenzie
968 * Fix a few bugs found by Emacs testers.
970 Major changes in Autoconf 2.3:
972 Released March 27th, 1995, by David J. MacKenzie
974 * Fix the cleanup trap in several ways.
975 * Handle C compilers that are picky about option placement.
976 * ifnames gets the version number from the right directory.
978 Major changes in Autoconf 2.2:
980 Released March 8th, 1995, by David J. MacKenzie
982 * The ifnames utility is much faster but requires a "new awk" interpreter.
983 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
984 library before existing libs, not after, in case it uses them.
985 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
987 * Many additions to the TODO file :-)
989 Major changes in Autoconf 2.1:
991 Released November 4th, 1994, by David J. MacKenzie
994 * More explanations in the manual.
995 * Fix a spurious failure in the testsuite.
996 * Clarify some warning messages.
997 * autoreconf by default only rebuilds configure and config.h.in files
998 that are older than any of their particular input files; there is a
999 --force option to use after installing a new version of Autoconf.
1001 Thanks to everybody who's submitted changes and additions to Autoconf!
1002 I've incorporated many of them, and am still considering others for
1003 future releases -- but I didn't want to postpone this release indefinitely.
1005 Caution: don't indiscriminately rebuild configure scripts with
1006 Autoconf version 2. Some configure.in files need minor adjustments to
1007 work with it; the documentation has a chapter on upgrading. A few
1008 configure.in files, including those for GNU Emacs and the GNU C
1009 Library, need major changes because they relied on undocumented
1010 internals of version 1. Future releases of those packages will have
1011 updated configure.in files.
1013 It's best to use GNU m4 1.3 (or later) with Autoconf version 2.
1014 Autoconf now makes heavy use of m4 diversions, which were implemented
1015 inefficiently in GNU m4 releases before 1.3.
1017 Major changes in Autoconf 2.0:
1019 Released October 26th, 1994, by David J. MacKenzie
1021 ** New copyright terms:
1022 * There are no restrictions on distribution or use of configure scripts.
1025 * Autoconf manual is reorganized to make information easier to find
1026 and has several new indexes.
1027 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1030 * autoscan to generate a preliminary configure.in for a package by
1031 scanning its source code for commonly used nonportable functions,
1032 programs, and header files.
1033 * ifnames to list the symbols used in #if and #ifdef directives in a
1035 * autoupdate to update a configure.in to use the version 2 macro names.
1036 * autoreconf to recursively remake configure and configuration header
1037 files in a source tree.
1039 ** Changed utilities:
1040 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1041 * autoconf and autoheader can look for package-local definition files
1042 in an alternate directory.
1045 * AC_CACHE_VAL to share results of tests between configure runs.
1046 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1047 that macros invoked with AC_REQUIRE don't interrupt other macros.
1048 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1049 support deciding unguessable features based on the host and target types.
1050 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1051 * AC_ARG_PROGRAM to use the options --program-prefix,
1052 --program-suffix, and --program-transform-name to change the names
1053 of programs being installed.
1054 * AC_PREFIX_DEFAULT to change the default installation prefix.
1055 * AC_TRY_COMPILE to compile a test program without linking it.
1056 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1057 * AC_CHECK_LIB to check for a particular function and library.
1058 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1059 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1060 * AC_SUBST_FILE to insert one file into another.
1061 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1062 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1063 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1064 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1067 * Many macros renamed systematically, but old names are accepted for
1068 backward compatibility.
1069 * AC_OUTPUT adds the "automatically generated" comment to
1070 non-Makefiles where it finds @configure_input@ in an input file, to
1071 support files with various comment syntaxes.
1072 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1073 files when they are not enclosed in @ signs.
1074 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1075 override the file name "config.status".
1076 * AC_OUTPUT takes an optional argument for passing variables from
1077 configure to config.status.
1078 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1079 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1080 CPPFLAGS, and LDFLAGS from the environment.
1081 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1082 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1083 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1084 srcdir/../.. by default.
1085 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1086 * AC_DEFINE no longer prints anything, because of the new result reporting
1087 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1088 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1089 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1090 --enable- and --with- options.
1091 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1092 execute on success or failure.
1093 * Checking for C functions in C++ works.
1096 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1097 better maintained with them.
1098 * AC_ARG_ARRAY removed because no one was likely using it.
1099 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1100 take arguments, for consistency with all of the other specific checks.
1103 * Comes with config.sub and config.guess, and uses them optionally.
1104 * Uses config.cache to cache test results. An alternate cache file
1105 can be selected with the --cache-file=FILE option.
1106 * Uses optional shell scripts $prefix/share/config.site and
1107 $prefix/etc/config.site to perform site or system specific initializations.
1108 * configure saves compiler output to ./config.log for debugging.
1109 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1110 * acsite.m4 is the new name for the system-wide aclocal.m4.
1111 * Has a DejaGnu test suite.
1113 Major changes in Autoconf 1.11:
1115 * AC_PROG_INSTALL calls install.sh with the -c option.
1116 * AC_SET_MAKE cleans up after itself.
1117 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1118 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1120 Plus a few other bug fixes.
1122 Major changes in Autoconf 1.10:
1124 * autoheader uses config.h.bot if present, analogous to config.h.top.
1125 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1127 * AC_PROG_CXX looks for cxx as a C++ compiler.
1129 Plus several bugs fixed.
1131 Major changes in Autoconf 1.9:
1133 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1134 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1135 and autoheader generates entries for those names automatically.
1136 * AC_FIND_X gets the result from xmkmf correctly.
1137 * AC_FIND_X assumes no X if --without-x was given.
1138 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1139 * AC_PROG_INSTALL finds OSF/1 installbsd.
1141 Major changes in Autoconf 1.8:
1144 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1145 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1146 for checking both C++ and C features in one configure script.
1147 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1148 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1149 AC_SET_MAKE, AC_ENABLE.
1152 * AC_FIND_X looks for X in more places.
1153 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1154 install.sh is distributed with Autoconf.
1155 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1156 a rewrite of quoting in AC_DEFINE.
1157 * AC_OUTPUT adds its comments in C format when substituting in C files.
1158 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1160 ** New or changed command line options:
1161 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1162 * configure accepts --without-PACKAGE, which sets withval=no.
1163 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1164 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1165 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1166 * configure accepts and ignores most other Cygnus configure options, and
1167 warns about unknown options.
1168 * config.status accepts --help, --version options.
1170 ** File names and other changes:
1171 * Relative srcdir values are not made absolute.
1172 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1173 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1174 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1175 * The example Makefile dependencies for configure et al. work better.
1176 * Namespace cleanup: all shell variables used internally by Autoconf
1177 have names beginning with `ac_'.
1179 More big improvements are in process for future releases, but have not
1180 yet been (variously) finished, integrated, tested, or documented enough
1183 Major changes in Autoconf 1.7:
1185 * New macro AC_OBSOLETE.
1186 * Bugs in Makefile.in fixed.
1187 * AC_LONG_FILE_NAMES improved.
1189 Major changes in Autoconf 1.6:
1191 * New macro AC_LONG_64_BITS.
1192 * Multiple .h files can be created.
1193 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1194 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1195 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1196 * Unused --no-create option to configure removed.
1197 * autoheader doesn't change the timestamp of its output file if
1198 the file didn't change.
1199 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1200 * config.status checks three optional environment variables to
1201 modify its behavior.
1202 * The usual bug fixes.
1204 Major changes in Autoconf 1.5:
1206 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1207 * autoconf and autoheader scripts have GNU standards conforming
1208 --version and --help options (they print their message and exit).
1211 Major changes in Autoconf 1.4:
1213 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1214 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1215 * autoconf and autoheader use the M4 environment variable to determine the
1216 name of the m4 program to use.
1217 * The --macrodir option to autoconf and autoheader specifies the directory
1218 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1219 * autoconf and autoheader can take `-' as their file names, which means to
1220 read stdin as input.
1221 * Resulting configure scripts can take a --verbose option which causes them
1222 to print the results of their tests.
1223 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1224 shell characters, etc. will be preserved during various stages of
1225 expansion done by the shell. If you don't want this, use
1226 AC_DEFINE_UNQUOTED instead.
1227 * Much textual processing done with external calls to tr and sed have been
1228 internalized with builtin m4 `patsubst' and `translit' calls.
1229 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1230 set the shell variables `gen_files' and `gen_config' to the list of
1231 file names to output.
1232 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1233 "lex.yy" or "lexyy", depending on the system.
1234 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1236 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1237 * AC_CONST works much more reliably on more systems.
1240 Major changes in Autoconf 1.3:
1242 configure no longer requires awk for packages that use a config.h.
1243 Support handling --with-PACKAGE options.
1244 New `autoheader' script to create `config.h.in' from `configure.in'.
1245 Ignore troublesome -lucb and -lPW when searching for alloca.
1246 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1247 Improve detection of STDC library.
1248 Add AC_HAVE_LIBRARY to check for non-default libraries.
1249 Function checking should work with future GNU libc releases.
1251 Major changes in Autoconf 1.2:
1253 The --srcdir option is now usually unnecessary.
1254 Add a file containing sample comments describing CPP macros.
1255 A comment in config.status tells which host it was configured on.
1256 Substituted variable values can now contain commas.
1257 Fix bugs in various feature checks.
1259 Major changes in Autoconf 1.1:
1261 Added AC_STRCOLL macro.
1262 Made AC_GETLOADAVG check for more things.
1263 AC_OUTPUT argument is now optional.
1268 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1269 2003, 2004, 2005 Free Software Foundation, Inc.
1271 This file is part of GNU Autoconf.
1273 GNU Autoconf is free software; you can redistribute it and/or modify
1274 it under the terms of the GNU General Public License as published by
1275 the Free Software Foundation; either version 2, or (at your option)
1278 GNU Autoconf is distributed in the hope that it will be useful,
1279 but WITHOUT ANY WARRANTY; without even the implied warranty of
1280 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1281 GNU General Public License for more details.
1283 You should have received a copy of the GNU General Public License
1284 along with GNU Autoconf; see the file COPYING. If not, write to
1285 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
1286 Boston, MA 02110-1301, USA.