1 * Major changes in Autoconf 2.59e
3 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
4 or LIFO (as in GNU m4 1.4.x). GNU m4 2.0 is expected to conform to Posix
5 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
7 * Major changes in Autoconf 2.59d
9 Released 2006-06-05, by Ralf Wildenhues.
11 ** GNU make now recommended for VPATH builds
12 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
13 only if you use GNU make. In practice, other 'make' implementations
14 have too many subtle incompatibilities in their support for VPATH.
15 Many packages (including Autoconf itself) are portable to other
16 'make' implementations, but some packages are not, and recommending
17 GNU make keeps the installation instructions simpler.
19 ** Even more safety checks for the new Directory variables:
20 Warn about suspicious `${datarootdir}' found in config files output.
22 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
23 These never-documented macros and variables have been marked with
24 comments saying that they may be removed in a future release,
25 because their use can lead to unintended code being executed.
26 If you need functionality that only these macros or variables
27 currently supply, please write bug-autoconf@gnu.org.
29 ** AC_SUBST, AC_DEFINE
30 Literal arguments to these are passed to m4_pattern_allow now.
33 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
34 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
35 obsolete K&R tests in the Automake test suite.
44 Now more robust with special characters in file names, or when
45 multiple processes create the same directory at the same time.
48 The documentation now says that the following macros are obsolescent:
49 they test for problems that are so old that they are no longer of
50 practical importance on current systems.
52 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
53 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
54 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
55 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
56 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
57 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
58 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
59 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
61 New programs need not use these macros. We have no current plans to
65 For compatibility with future Libtool 2.0, autoreconf will invoke
66 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
69 * Major changes in Autoconf 2.59c
71 Released 2006-04-12, by Ralf Wildenhues.
73 ** The configure command now redirects standard input from /dev/null,
74 to help avoid problems with subsidiary commands that might mistakenly
75 read standard input. AS_ORIGINAL_STDIN_FD points to the original
76 standard input before this redirection, if you really want configure to
77 read from standard input.
79 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
80 The following directory variables are new:
82 datarootdir read-only architecture-independent data root [PREFIX/share]
83 localedir locale-specific message catalogs [DATAROOTDIR/locale]
84 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
85 htmldir html documentation [DOCDIR]
86 dvidir dvi documentation [DOCDIR]
87 pdfdir pdf documentation [DOCDIR]
88 psdir ps documentation [DOCDIR]
90 The following variables have new default values:
92 datadir read-only architecture-independent data [DATAROOTDIR]
93 infodir info documentation [DATAROOTDIR/info]
94 mandir man documentation [DATAROOTDIR/man]
96 This means that if you use any of `@datadir@', `@infodir@', or
97 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
98 defined in this file. As a temporary measure, if any of those are
99 found but no mention of `datarootdir', the substitutions will be
100 replaced with values that do not contain `${datarootdir}', and a
101 warning will be issued.
103 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
104 a trailing slash. Similar change will be made to ac_top_builddir in a
105 future release; the old style value, which matches (../)*, is (and will
106 continue to be) available as ac_top_build_prefix.
109 New macro to check for support of 'typeof' syntax a la GNU C.
111 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
112 New "once-only" variants of commonly-used macros, to make 'configure'
113 smaller and faster in common cases.
116 New macro to check for strtold with C99 semantics.
119 New macro that lets builder disable assertions at 'configure'-time.
122 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
123 X11/Intrinsic.h and XtMalloc (Xt).
125 ** AC_PRESERVE_HELP_ORDER
126 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
127 and AC_ARG_WITH arguments in one region, in the order defined. The default
128 behavior is to group options of each classes separately.
130 ** AC_PROG_CC, AC_PROG_CXX
131 No longer automatically arrange to declare the 'exit' function of C,
132 when a C++ compiler is used. Standard Autoconf macros no longer use
133 'exit', so this is no longer an issue for them. If you use C++, and
134 want to call 'exit', you'll have to arrange for its declaration
135 yourself. But we now suggest you return from 'main' instead.
137 ** AC_PROG_CC_C89, AC_PROG_CC_C99
138 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
139 check for ANSI C89 and ISO C99 support respectively.
142 Has been unobsoleted, and will check if the compiler supports ISO
143 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
144 retained for backwards compatibility, assuming the value of
145 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
148 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
149 New macros for checking commonly-used members of struct dirent.
152 The subtituted value can now contain newlines.
155 The substitution now occurs only when @variable@ is on a line by itself,
156 optionally surrounded by spaces and tabs. The whole line is replaced.
158 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
159 New macros to check for long double, and whether it is wider than double.
160 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
161 applications should switch to the new macro.
163 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
164 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
165 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
166 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
167 New macros to check for C99 and POSIX types.
169 ** AC_USE_SYSTEM_EXTENSIONS
170 New macro to enable extensions to Posix.
173 New macro which is defined to the name of the first declared config header
174 or undefined if no config headers have been declared yet.
177 The macro correctly handles quadrigraphs now.
179 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
180 These macros are new or published now.
183 New macro for copyright notices in testsuite files.
185 ** ALLOCA, LIBOBJS, LTLIBOBJS
186 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
187 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
188 `Makefile.in' in case the object files lie in a different directory.
189 The LIBOBJDIR feature is experimental.
192 Supports --no-recursive now.
194 ** New macros to support Erlang/OTP.
195 New macros for configuring paths to Erlang tools and libraries:
196 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
197 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
198 AC_ERLANG_SUBST_LIB_DIR.
200 New macros for configuring installation of Erlang libraries:
201 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
203 ** The manual now mentions Gnulib more prominently.
205 ** New macros to support Objective C.
206 AC_PROG_OBJC, AC_PROG_OBJCPP.
208 * Major changes in Autoconf 2.59b
210 Released 2004-08-20, by Paul Eggert.
213 New macro that computes the default alignment of a type.
215 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
216 When cross-compiling, these macros will give a warning if the tool
217 is not prefixed. In the future, unprefixed cross tools will not
218 be detected; please consult the info documentation for information
219 about the reason of this change.
221 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
222 New macros that detect programs whose name is prefixed with the
223 target type, if the build type and target type are different.
225 ** AC_REQUIRE_AUX_FILE
226 New trace macro that declares expected auxiliary files.
229 New macro that tests for a grep program that accepts as a long a line
232 ** AC_PROG_EGREP, AC_PROG_FGREP
233 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
234 FGREP="$GREP -F" respectively if possible, or else run a path search for
235 a program that accepts as long a line as possible.
238 New macro that tests for a sed program that truncates as few characters
241 * Major changes in Autoconf 2.59
243 Released 2003-11-04, by Akim Demaille
245 ** ac_abs_builddir etc.
246 Absolute file names were actually relative in 2.58.
248 * Major changes in Autoconf 2.58
250 Released 2003-11-04, by Akim Demaille
253 core.* files are no longer removed, as they may be valid user files.
255 ** autoreconf and auxiliary directory
256 Autoreconf creates the auxiliary directory if needed. This is
257 especially useful for initial "bootstrapping" of fresh CVS checkouts.
259 ** AC_CONFIG_MACRO_DIR
260 Use this macro to declare the directory for local m4 macros for aclocal.
263 No longer includes twice the same file in LIBOBJS if invoked
266 ** AC_CONFIG_COMMANDS
267 The directory for its first argument is automatically created. For
270 AC_CONFIG_COMMANDS([src/modules.hh], [...])
272 $top_builddir/src/ is created if needed.
274 ** Autotest and local.at
275 The optional file local.at is always included in Autotest test suites.
278 The warnings are always issued, including with cached runs.
279 This became a significant problem since aclocal and automake can
280 run autoconf behind the scene.
282 ** autoheader warnings
283 The warnings of autoheader can be turned off, using --warning.
284 For instance, -Wno-obsolete disables the complaints about acconfig.h
285 and other deprecated constructs.
288 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
291 ** AC_DECL_SYS_SIGLIST
295 Now checks that mktime is the inverse of localtime.
297 ** Improve DJGPP portability
298 The Autoconf tools and configure behave better under DJGPP.
300 ** Present But Cannot Be Compiled
301 New FAQ section dedicated to the mystic
303 configure: WARNING: pi.h: present but cannot be compiled
304 configure: WARNING: pi.h: check for missing prerequisite headers?
305 configure: WARNING: pi.h: proceeding with the preprocessor's result
308 ** Concurrent executions of autom4te
309 autom4te now locks its internal files, which enables concurrent
310 executions of autom4te, likely to happen if automake, autoconf,
311 autoheader etc. are run simultaneously.
314 Use of Libtool 1.5 and higher is encouraged. Compatibility with
315 Libtool pre-1.4 is not checked.
318 Testsuites no longer rerun failed tests in verbose mode; instead,
319 failures are logged while the test is run.
321 In addition, expected failures can be marked as such.
323 * Major changes in Autoconf 2.57
325 Released 2002-12-03 by Paul Eggert.
327 Bug fixes for problems with AIX linker, with freestanding C compilers,
328 with GNU m4 limitations, and with obsolete copies of GNU documents.
330 The Free Documentation License has been upgraded from 1.1 to 1.2.
332 * Major changes in Autoconf 2.56
334 Released 2002-11-15 by Akim Demaille.
336 One packaging problem fixed (config/install-sh was not executable).
338 * Major changes in Autoconf 2.55
340 Released 2002-11-14 by Akim Demaille.
344 Have your configure.ac checked by autoscan ("autoscan").
345 Try the warning options ("autoreconf -fv -Wall").
349 - AC_CHECK_HEADER, AC_CHECK_HEADERS
350 More information on proper use.
352 - Writing Test Programs
354 This sections explains how to write good test sources to use with
355 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
357 - AC_FOO_IFELSE vs. AC_TRY_FOO
359 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
360 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
364 - Is more robust to different Gettext installations.
366 - Produces messages (when --verbose) to be understood by Emacs'
369 - Supports -W/--warnings.
372 Once the GNU Build System reinstalled, run `./config.status
373 --recheck && ./config.status && make' if possible.
377 - Supports --cache, and --no-cache.
379 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
380 (autom4te.cache). See `Customizing autom4te' in the documentation.
387 Support for the obsoleted options -m, --macrodir, -l, --localdir is
388 dropped in favor of the safer --include/--prepend-include scheme.
393 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
394 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
395 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
398 Obsoleted macros are kept for Autoconf backward compatibility, but
399 should be avoided in configure.ac. Running autoupdate is advised.
402 - AC_DEFINE/AC_DEFINE_UNQUOTED
404 We have to stop using the old compatibility scheme --that tried to
405 avoid useless backslashes-- because Libtool 1.4.3 contains a
407 AC_DEFINE([error_t], [int],
408 [Define to a type to use for \`error_t' if it is not
409 otherwise available.])
411 We have to quote the single quotes and backslashes with \. The old
412 compatibility scheme saw that ` was backslashed, and therefore did
413 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
414 compatible with Libtool. Autoconf 2.55 is, but in some cases might
415 produce more \ than wanted.
417 Please, note that in the future the same problem will happen with
418 AC_MSG_*: use `autoreconf -f -Wall'.
422 - Portability of the Autoconf package to Solaris.
424 - Spurious warnings caused by config.status.
425 This bug is benign, but painful: on some systems (typically
426 FreeBSD), warnings such as:
428 config.status: creating Makefile
429 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
431 could be issued. This is fixed.
434 Simultaneous executions of config.status are possible again.
436 - Precious variables accumulation
438 config.status could stack several copies of the precious variables
442 ** Plans for later versions
446 The compatibility hooks with the old scheme will be completely
447 removed. Please, advice/use `--build', `--host', and `--target'
450 - AC_CHECK_HEADER, AC_CHECK_HEADERS
452 The tests will be stricter, please make sure your invocations are
457 Shell functions will gradually be introduced, probably starting with
458 Autotest. If you know machines which are in use that you suspect
459 *not* to support shell functions, please run the test suite of
460 Autoconf 2.55 on it, and report the results to
461 bug-autoconf@gnu.org.
465 Special characters in AC_MSG_* need not be quoted. Currently,
466 Autoconf has heuristics to decide when a string is escaped, or has
467 to be escaped. This scheme is fragile, and will be removed; the
468 only risk is uglified messages. Please, run `autoreconf -f -Wall'
469 to find occurrences that will be affected.
471 * Major changes in Autoconf 2.54
473 Released 2002-09-13 by Akim Demaille.
477 - autoreconf no longer changes the version of the gettext/po/intl
478 support files. It now adds the files the correspond to the
479 AM_GNU_GETTEXT_VERSION declared in configure.ac.
481 Warning: It now relies on the 'autopoint' program, which is part
482 of GNU gettext 0.11.4 and newer.
484 Please note that you need to have a GNU gettext version that
485 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
486 in configure.ac. You can upgrade to newer GNU gettext versions,
487 though, without needing to change configure.ac.
489 - The -I DIR or --include=DIR option now appends DIR to the include path
490 instead of prepending; this is for consistency with other GNU tools.
491 The new -B DIR or --prepend-include=DIR option has the old behavior.
496 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
497 Please, remove lines such as
499 # This is necessary so that .o files in LIBOBJS are also
500 # built via the ANSI2KNR-filtering rules.
501 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
503 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
504 your Makefiles either.
506 - AC_CONFIG_LINKS now makes copies if it can't make links.
508 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
509 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
510 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
512 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
514 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
516 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
520 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
521 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
522 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
525 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
528 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
529 for an AC_LIBOBJ replacement.
533 - Spurious complaints from `m4_bmatch' about invalid regular
534 expressions are suppressed.
536 - Empty top_builddirs are properly handled.
538 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
541 Now colon in the optional path arguments are properly handled.
543 ** Improved portability
545 - Both Autoconf the package, and the scripts it produces, should run
546 more reliably with Zsh. Bear in mind it is the default Bourne shell
549 - Autoconf and the scripts it produces no longer assume the existence of
550 the obsolescent commands egrep and fgrep.
554 - Limitations of Make
558 The GNATS base moved to
559 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
560 (It is no longer available, though.)
565 Now contains the list of ouput variables and files (AC_SUBST,
568 * Major changes in Autoconf 2.53
570 Released 2002-03-08 by Akim Demaille.
574 Perl 5.005_03 or later is required: autom4te is written in Perl and is
575 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
581 Argument requirements, output variables, defined macros.
582 - M4sugar, M4sh, Autotest
584 - Double quoting macros
585 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
587 The Autoconf manual is now distributed under the terms of the GNU FDL.
588 - Section `Hosts and Cross-Compilation'
589 Explains the rationale for the 2.5x changes in the cross-compilation
590 chain, and in the relationships between build, host, and target
592 Emphasizes that `cross-compilation' == `--host is given'.
593 If you are working on compilers etc., be sure to read this section.
594 - Section `AC_LIBOBJ vs. LIBOBJS'
595 Explains why assigning LIBOBJS directly is now an error.
596 Details how to update the code.
601 Now used instead of hard coded line numbers.
602 This eases the comparison of `configure's, and diminishes the
603 pressure over control version archives.
604 Automatic replacement for shells that don't support this feature.
605 - New output variables
606 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
611 Autoconf and Autotest modes are provided.
616 New, used by the Autoconf suite to cache and speed up most processing.
618 Supported by autom4te, autoconf and autoheader.
620 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
621 autoupdate, and autoreconf.
623 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
624 automake options are to be given via AUTOMAKE_OPTIONS.
626 Runs gettextize and libtoolize when appropriate.
628 --m4dir is no longer supported.
630 Now runs only in the specified directories, defaulting to `.',
631 but understands AC_CONFIG_SUBDIRS for dependent directories.
632 Before, it used to run on all the `configure.ac' found in the
634 Independent packages are properly updated.
638 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
640 Under the user pressure, $? is finally available. Probably a mistake.
641 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
642 - Precious variables accumulation
643 config.status could stack several copies of the precious variables
645 - AC_PATH_PROG and family.
646 Works properly when given a literal path.
648 Somewhere since 2.13, the result had been reversed.
652 - AC_C_BIGENDIAN supports the cross-compiling case.
653 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
654 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
655 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
657 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
658 precision than `double'.
663 It now defines the preprocessor symbols PACKAGE_NAME,
664 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
668 Admits a fourth optional parameter: the tar name.
670 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
671 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
672 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
675 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
676 Are much less expensive when using long lists of files.
679 Works with shell variables, and non alphanumeric names.
683 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
684 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
686 - AC_FUNC_STRTOD substitutes POW_LIB.
691 * Major changes in Autoconf 2.52
693 Released 2001-07-18 by Akim Demaille.
698 This feature was present in autoconf 2.50 but was not documented.
699 For example, `@<:@' is translated to `[' just before output. This
700 is useful when writing strings that contain unbalanced quotes, or
701 other hard-to-quote constructs.
702 - m4_pattern_forbid, m4_pattern_allow
703 - Tips for upgrading from 2.13.
704 - Using autoscan to maintain a configure.ac.
707 - Now include stdint.h.
708 - sys/types.h and sys/stat.h are guarded.
709 - strings.h is included if available, and not conflicting with string.h.
712 - The test suite is more robust and presents less false failures.
713 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
714 - configure accepts --prefix='' again.
715 - AC_CHECK_LIB works properly when its first argument is not a
717 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
718 - build_, host_, and target_alias are AC_SUBST as in 2.13.
719 - AC_ARG_VAR properly propagates precious variables inherited from the
720 environment to ./config.status.
721 - Using --program-suffix/--program-prefix is portable.
722 - Failures to detect the default compiler's output extension are less
724 - `config.status foo' works properly when `foo' depends on variables
725 set in an AC_CONFIG_THING INIT-CMD.
726 - autoheader is more robust to broken input.
727 - Fixed Fortran name-mangling and link tests on a number of systems,
728 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
731 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
732 specify pre-includes. In this case, the headers are compiled with
733 cc, not merely preprocessed by cpp. Therefore it is the _usability_
734 of a header which is checked for, not just its availability.
735 - AC_ARG_VAR refuses to run configure when precious variables have
737 - Versions of compilers are dumped in the logs.
738 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
741 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
742 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
743 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
744 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
745 Be sure to read `Upgrading from Version 2.13' to understand why
746 running `autoupdate' is needed.
747 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
748 a main-like routine is required/possible when linking C/C++ with
749 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
750 - AC_FUNC_GETPGRG behaves better when cross-compiling.
752 * Major changes in Autoconf 2.51
753 There was no release of Autoconf 2.51 since some packagers had used
754 this version number without permission to ship intermediary versions
755 of 2.50. The version was skipped to avoid confusion.
757 * Major changes in Autoconf 2.50
759 Released 2001-05-21 by Akim Demaille.
762 There have been far too many to enumerate them here. Check out
763 ChangeLog if you really want to know more.
765 ** Improved documentation
766 In particular, portability issues are better covered.
769 All the standard GNU Makefile targets are supported. The layout has
770 changed: m4/ holds the m4 extensions Autoconf needs for its
771 configuration, doc/ contains the documentation, and tests/ contains
774 ** Man pages are provided
775 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
776 config.guess, config.sub.
780 Provides a safe and powerful means to trace the macro uses. This
781 provide the parsing layer for tools which need to `study'
785 Specify what category of warnings should be enabled.
787 - When recursing into subdirectories, try for configure.gnu before
788 configure to adapt for packages not using autoconf on case-insensitive
792 More errors are now caught (circular AC_REQUIRE dependencies,
793 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
794 etc.). In addition, their location and call stack are given.
797 autoupdate is much more powerful, and is able to provide the glue code
798 which might be needed to move from an old macro to its newer
801 You are strongly encouraged to use it to modernize both your
802 `configure.in' and your .m4 extension files.
805 The internal machinery of autoheader has completely changed. As a
806 result, using `acconfig.h' should be considered to be obsoleted, and
807 you are encouraged to get rid of it using the AH macros.
812 ** Fortran 77 compilers
813 Globally, the support for Fortran 77 is considerably improved.
815 Support for automatically determining a Fortran 77 compiler's
816 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
817 provided to wrap C/C++ identifiers, thus making it easier and more
818 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
819 call C/C++ routines. See the Texinfo documentation for details.
822 The test suite no longer uses DejaGNU. It should be easy to submit
823 test cases in this new framework.
826 - --help, --help=long, -hl
827 no longer dumps useless items.
829 lists only specific options.
830 - --help=recursive, -hr
831 displays the help of all the embedded packages.
832 - Remembers environment variables when reconfiguring.
833 The previous scheme to set envvar before running configure was
835 what prevented configure from remembering the environment in which
836 it was run, therefore --recheck was run in an inconsistent
837 environment. Now, one should run
839 and then --recheck will work properly. Variables declared with
840 AC_ARG_VAR are also preserved.
842 $build defaults to `config.guess`, $host to $build, and then $target
844 Cross-compilation is a global status of the package, it no longer
845 depends upon the current language.
846 Cross compilation is enabled iff the user specified `--host'.
847 `configure' now fails if it can't run the executables it compiles,
848 unless cross-compilation is enabled.
850 The cache file is disabled by default. The new options
851 `--config-cache', `-C' set the cache to `config.cache'.
855 Much faster on most architectures.
856 - concurrent executions
857 It is safe to use `make -j' with config.status.
858 - human interface improved
859 It is possible to invoke
860 ./config.status foobar
861 instead of the former form (still valid)
862 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
863 CONFIG_FILES=foobar:foo.in:bar.in \
865 The same holds for configuration headers and links.
866 You can instantiate unknown files and headers:
867 ./config.status --header foo.h:foo.h.in --file bar:baz
868 - has a useful --help
869 - accepts special file name "-" for stdin/stdout
874 Specify additional copyright information.
877 Now expects the identity of the package as argument.
881 Most macros, if not all, now strictly follow the `one quotation
882 level' rule. This results in a more predictable expansion.
885 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
886 configure scripts, was fixed by Axel Thimm.
890 Document and ask for the registration of an envvar.
893 Specifies the file which `configure' should look for when trying to
894 find the source tree (used to be handled by AC_INIT).
897 To add new actions to config.status. Should be used instead of
901 Replaces AC_LINK_FILES.
903 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
904 AC_CONFIG_LINKS, and AC_CONFIG_FILES
905 They now obey sh: you should no longer use shell variables as
908 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
909 AC_CONFIG_SUBDIRS($my_subdirs)
913 if test "$package_foo_enabled" = yes; then
914 AC_CONFIG_SUBDIRS(foo)
918 To format an Autoconf macro's help string so that it looks pretty
919 when the user executes `configure --help'.
922 ** Generic Test Macros
924 The interface of the AC_CHECK families of macros (decl, header,
925 type, member, func) is now uniform. They support the same set of
928 - AC_CHECK_DECL, AC_CHECK_DECLS
929 To check whether a symbol is declared.
931 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
932 No longer need a cross-compilation default.
935 The test it performs is much more robust than previously, and makes
936 it possible to test builtin types in addition to typedefs.
937 It is now schizophrenic:
938 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
939 remains for backward compatibility, but its use is discouraged.
940 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
941 behaves exactly like the other AC_CHECK macros.
944 Checks whether given types are supported by the system.
946 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
947 Check for given members in aggregates (e.g., pw_gecos in struct
951 Checks if the compiler supports ISO C, included when needs special
955 Checking whether the preprocessor indicates missing includes by the
956 error code. stderr is checked by AC_TRY_CPP only as a fallback.
959 Takes a language as argument and replaces AC_LANG_C,
960 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
962 - AC_LANG_PUSH, AC_LANG_POP
963 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
966 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
967 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
968 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
975 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
978 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
981 Arrange for large-file support.
983 - AC_EXEEXT, AC_OBJEXT
984 You are no longer expected to use them: their computation is
985 performed by default.
988 Every macro has been revisited in order to support at best CC=c++.
990 Major changes in Autoconf 2.14:
991 There was no release of GNU Autoconf 2.14.
993 Major changes in Autoconf 2.13:
995 Released 1999-05-01 by Ben Elliston.
997 * Support for building on Win32 systems where the only available C or
998 C++ compiler is the Microsoft Visual C++ command line compiler
999 (`cl'). Additional support for building on Win32 systems which are
1000 using the Cygwin or Mingw32 environments.
1001 * Support for alternative object file and executable file extensions.
1002 On Win32, for example, these are .obj and .exe. These are discovered
1003 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1004 @EXEEXT@ in the output, respectively.
1005 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1006 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1007 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1008 * AC_DEFINE now has an optional third argument for a description to be
1009 placed in the config header input file (e.g. config.h.in).
1010 * The C++ code fragment compiled for the C++ compiler test had to be
1011 improved to include an explicit return type for main(). This was
1012 causing failures on systems using recent versions of the EGCS C++
1014 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1015 script to report that `sometype_t' was present when only `type_t'
1017 * Merge of the FSF version of config.guess and config.sub to modernize
1018 these scripts. Add support for a few new hosts in config.guess.
1019 Incorporate latest versions of install-sh, mkinstalldirs and
1020 texinfo.tex from the FSF.
1021 * autoreconf is capable of running automake if necessary (and
1023 * Support for Fortran 77. See the Texinfo documentation for details.
1024 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1026 Major changes in Autoconf 2.12:
1028 Released 1996-11-26 by David J. MacKenzie
1030 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1031 concatenating multiple input files separated by colons, like so:
1032 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1033 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1034 The arguments may be shell variables, to compute the lists on the fly.
1035 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1036 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1039 Major changes in Autoconf 2.11:
1041 Released November 18th, 1996, by David J. MacKenzie
1043 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1044 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1045 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1046 * AC_CONFIG_HEADER expands shell variables in its argument.
1047 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1048 * The "checking..." messages and the source code for test programs that
1049 fail are saved in config.log.
1050 * Another workaround has been added for seds with small command length limits.
1051 * config.sub and config.guess recognize more system types.
1054 Major changes in Autoconf 2.10:
1056 Released May 7th, 1996, by Roland McGrath
1059 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1060 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1062 Major changes in Autoconf 2.9:
1064 Released March 16th, 1996, by Roland McGrath
1068 Major changes in Autoconf 2.8:
1070 Released March 8th, 1996, by Roland McGrath
1074 Major changes in Autoconf 2.7:
1076 Released November 22nd, 1995, by David J. MacKenzie
1080 Major changes in Autoconf 2.6:
1082 Released November 20th, 1995, by David J. MacKenzie
1086 Major changes in Autoconf 2.5:
1088 Released November 17th, 1995, by Roland McGrath
1090 * New configure options --bindir, --libdir, --datadir, etc., with
1091 corresponding output variables.
1092 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1093 * config.log contains the command being run as well as any output from it.
1094 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1095 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1096 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1097 AC_CHECK_TOOL can search a path other than $PATH.
1098 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1100 Major changes in Autoconf 2.4:
1102 Released June 14th, 1995, by David J. MacKenzie
1104 * Fix a few bugs found by Emacs testers.
1106 Major changes in Autoconf 2.3:
1108 Released March 27th, 1995, by David J. MacKenzie
1110 * Fix the cleanup trap in several ways.
1111 * Handle C compilers that are picky about option placement.
1112 * ifnames gets the version number from the right directory.
1114 Major changes in Autoconf 2.2:
1116 Released March 8th, 1995, by David J. MacKenzie
1118 * The ifnames utility is much faster but requires a "new awk" interpreter.
1119 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1120 library before existing libs, not after, in case it uses them.
1121 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1122 * Lots of bug fixes.
1123 * Many additions to the TODO file :-)
1125 Major changes in Autoconf 2.1:
1127 Released November 4th, 1994, by David J. MacKenzie
1130 * More explanations in the manual.
1131 * Fix a spurious failure in the testsuite.
1132 * Clarify some warning messages.
1133 * autoreconf by default only rebuilds configure and config.h.in files
1134 that are older than any of their particular input files; there is a
1135 --force option to use after installing a new version of Autoconf.
1137 Thanks to everybody who's submitted changes and additions to Autoconf!
1138 I've incorporated many of them, and am still considering others for
1139 future releases -- but I didn't want to postpone this release indefinitely.
1141 Caution: don't indiscriminately rebuild configure scripts with
1142 Autoconf version 2. Some configure.in files need minor adjustments to
1143 work with it; the documentation has a chapter on upgrading. A few
1144 configure.in files, including those for GNU Emacs and the GNU C
1145 Library, need major changes because they relied on undocumented
1146 internals of version 1. Future releases of those packages will have
1147 updated configure.in files.
1149 It's best to use GNU m4 1.3 (or later) with Autoconf version 2.
1150 Autoconf now makes heavy use of m4 diversions, which were implemented
1151 inefficiently in GNU m4 releases before 1.3.
1153 Major changes in Autoconf 2.0:
1155 Released October 26th, 1994, by David J. MacKenzie
1157 ** New copyright terms:
1158 * There are no restrictions on distribution or use of configure scripts.
1161 * Autoconf manual is reorganized to make information easier to find
1162 and has several new indexes.
1163 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1166 * autoscan to generate a preliminary configure.in for a package by
1167 scanning its source code for commonly used nonportable functions,
1168 programs, and header files.
1169 * ifnames to list the symbols used in #if and #ifdef directives in a
1171 * autoupdate to update a configure.in to use the version 2 macro names.
1172 * autoreconf to recursively remake configure and configuration header
1173 files in a source tree.
1175 ** Changed utilities:
1176 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1177 * autoconf and autoheader can look for package-local definition files
1178 in an alternate directory.
1181 * AC_CACHE_VAL to share results of tests between configure runs.
1182 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1183 that macros invoked with AC_REQUIRE don't interrupt other macros.
1184 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1185 support deciding unguessable features based on the host and target types.
1186 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1187 * AC_ARG_PROGRAM to use the options --program-prefix,
1188 --program-suffix, and --program-transform-name to change the names
1189 of programs being installed.
1190 * AC_PREFIX_DEFAULT to change the default installation prefix.
1191 * AC_TRY_COMPILE to compile a test program without linking it.
1192 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1193 * AC_CHECK_LIB to check for a particular function and library.
1194 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1195 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1196 * AC_SUBST_FILE to insert one file into another.
1197 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1198 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1199 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1200 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1203 * Many macros renamed systematically, but old names are accepted for
1204 backward compatibility.
1205 * AC_OUTPUT adds the "automatically generated" comment to
1206 non-Makefiles where it finds @configure_input@ in an input file, to
1207 support files with various comment syntaxes.
1208 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1209 files when they are not enclosed in @ signs.
1210 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1211 override the file name "config.status".
1212 * AC_OUTPUT takes an optional argument for passing variables from
1213 configure to config.status.
1214 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1215 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1216 CPPFLAGS, and LDFLAGS from the environment.
1217 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1218 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1219 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1220 srcdir/../.. by default.
1221 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1222 * AC_DEFINE no longer prints anything, because of the new result reporting
1223 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1224 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1225 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1226 --enable- and --with- options.
1227 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1228 execute on success or failure.
1229 * Checking for C functions in C++ works.
1232 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1233 better maintained with them.
1234 * AC_ARG_ARRAY removed because no one was likely using it.
1235 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1236 take arguments, for consistency with all of the other specific checks.
1239 * Comes with config.sub and config.guess, and uses them optionally.
1240 * Uses config.cache to cache test results. An alternate cache file
1241 can be selected with the --cache-file=FILE option.
1242 * Uses optional shell scripts $prefix/share/config.site and
1243 $prefix/etc/config.site to perform site or system specific initializations.
1244 * configure saves compiler output to ./config.log for debugging.
1245 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1246 * acsite.m4 is the new name for the system-wide aclocal.m4.
1247 * Has a DejaGnu test suite.
1249 Major changes in Autoconf 1.11:
1251 * AC_PROG_INSTALL calls install.sh with the -c option.
1252 * AC_SET_MAKE cleans up after itself.
1253 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1254 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1256 Plus a few other bug fixes.
1258 Major changes in Autoconf 1.10:
1260 * autoheader uses config.h.bot if present, analogous to config.h.top.
1261 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1263 * AC_PROG_CXX looks for cxx as a C++ compiler.
1265 Plus several bugs fixed.
1267 Major changes in Autoconf 1.9:
1269 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1270 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1271 and autoheader generates entries for those names automatically.
1272 * AC_FIND_X gets the result from xmkmf correctly.
1273 * AC_FIND_X assumes no X if --without-x was given.
1274 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1275 * AC_PROG_INSTALL finds OSF/1 installbsd.
1277 Major changes in Autoconf 1.8:
1280 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1281 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1282 for checking both C++ and C features in one configure script.
1283 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1284 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1285 AC_SET_MAKE, AC_ENABLE.
1288 * AC_FIND_X looks for X in more places.
1289 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1290 install.sh is distributed with Autoconf.
1291 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1292 a rewrite of quoting in AC_DEFINE.
1293 * AC_OUTPUT adds its comments in C format when substituting in C files.
1294 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1296 ** New or changed command line options:
1297 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1298 * configure accepts --without-PACKAGE, which sets withval=no.
1299 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1300 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1301 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1302 * configure accepts and ignores most other Cygnus configure options, and
1303 warns about unknown options.
1304 * config.status accepts --help, --version options.
1306 ** File names and other changes:
1307 * Relative srcdir values are not made absolute.
1308 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1309 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1310 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1311 * The example Makefile dependencies for configure et al. work better.
1312 * Namespace cleanup: all shell variables used internally by Autoconf
1313 have names beginning with `ac_'.
1315 More big improvements are in process for future releases, but have not
1316 yet been (variously) finished, integrated, tested, or documented enough
1319 Major changes in Autoconf 1.7:
1321 * New macro AC_OBSOLETE.
1322 * Bugs in Makefile.in fixed.
1323 * AC_LONG_FILE_NAMES improved.
1325 Major changes in Autoconf 1.6:
1327 * New macro AC_LONG_64_BITS.
1328 * Multiple .h files can be created.
1329 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1330 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1331 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1332 * Unused --no-create option to configure removed.
1333 * autoheader doesn't change the timestamp of its output file if
1334 the file didn't change.
1335 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1336 * config.status checks three optional environment variables to
1337 modify its behavior.
1338 * The usual bug fixes.
1340 Major changes in Autoconf 1.5:
1342 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1343 * autoconf and autoheader scripts have GNU standards conforming
1344 --version and --help options (they print their message and exit).
1347 Major changes in Autoconf 1.4:
1349 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1350 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1351 * autoconf and autoheader use the M4 environment variable to determine the
1352 name of the m4 program to use.
1353 * The --macrodir option to autoconf and autoheader specifies the directory
1354 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1355 * autoconf and autoheader can take `-' as their file names, which means to
1356 read stdin as input.
1357 * Resulting configure scripts can take a --verbose option which causes them
1358 to print the results of their tests.
1359 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1360 shell characters, etc. will be preserved during various stages of
1361 expansion done by the shell. If you don't want this, use
1362 AC_DEFINE_UNQUOTED instead.
1363 * Much textual processing done with external calls to tr and sed have been
1364 internalized with builtin m4 `patsubst' and `translit' calls.
1365 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1366 set the shell variables `gen_files' and `gen_config' to the list of
1367 file names to output.
1368 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1369 "lex.yy" or "lexyy", depending on the system.
1370 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1372 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1373 * AC_CONST works much more reliably on more systems.
1376 Major changes in Autoconf 1.3:
1378 configure no longer requires awk for packages that use a config.h.
1379 Support handling --with-PACKAGE options.
1380 New `autoheader' script to create `config.h.in' from `configure.in'.
1381 Ignore troublesome -lucb and -lPW when searching for alloca.
1382 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1383 Improve detection of STDC library.
1384 Add AC_HAVE_LIBRARY to check for non-default libraries.
1385 Function checking should work with future GNU libc releases.
1387 Major changes in Autoconf 1.2:
1389 The --srcdir option is now usually unnecessary.
1390 Add a file containing sample comments describing CPP macros.
1391 A comment in config.status tells which host it was configured on.
1392 Substituted variable values can now contain commas.
1393 Fix bugs in various feature checks.
1395 Major changes in Autoconf 1.1:
1397 Added AC_STRCOLL macro.
1398 Made AC_GETLOADAVG check for more things.
1399 AC_OUTPUT argument is now optional.
1404 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1405 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
1407 This file is part of GNU Autoconf.
1409 GNU Autoconf is free software; you can redistribute it and/or modify
1410 it under the terms of the GNU General Public License as published by
1411 the Free Software Foundation; either version 2, or (at your option)
1414 GNU Autoconf is distributed in the hope that it will be useful,
1415 but WITHOUT ANY WARRANTY; without even the implied warranty of
1416 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1417 GNU General Public License for more details.
1419 You should have received a copy of the GNU General Public License
1420 along with GNU Autoconf; see the file COPYING. If not, write to
1421 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
1422 Boston, MA 02110-1301, USA.