1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.61b (????-??-??)
5 ** Autoconf is now licensed under the General Public License version 3
6 or later (GPLv3+). As with earlier versions, the license includes
7 an exception clause so that you may release a configure script
8 generated by autoconf under the license of your own program.
9 FIXME - revisit this line once exception clause is finalized.
11 ** New Autoconf macros AC_OPENMP, AC_PATH_PROGS_FEATURE_CHECK, AC_VERSION.
13 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
15 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
16 like '__restrict' if the variant spelling is available, as this is
17 more likely to work when mixing C and C++ code.
19 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
20 be a string of tokens such that "T y;" is a valid member declaration
23 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
24 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
26 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
27 they did not work for function types. In C++, they now work on any
28 type-id that can be the operand of sizeof; this is similar to C,
29 except it excludes anonymous struct and union types. Formerly,
30 some (but not all) C++ types involving anonymous struct and union
31 were accepted, though this was not documented.
33 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
34 if found, and it works to link against a file of the same name in
35 the source tree, even if both trees coincide.
37 ** AC_INIT no longer alters $@; regression introduced in 2.60.
39 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
41 ** AS_HELP_STRING no longer underquotes its first argument.
43 ** The command 'autoconf -' now correctly processes a file from stdin.
45 ** AT_SETUP now handles macro expansions properly when calculating line
46 length. However, as a side effect, any whitespace immediately
47 following a single-quoted comma is lost. If you previously used
48 AT_SETUP([a, b]), you could change to AT_SETUP([a,[] b]) to keep
51 ** Autotest now determines $srcdir correctly.
53 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
54 a bug in macro tracing that interferes with the interaction between
55 Autoconf and Automake. GNU M4 1.4.8 or later is recommended. The
56 configure search for a working M4 is improved.
58 ** Document the m4sugar macros m4_ifndef and m4_version_compare
59 (available without documentation since at least autoconf 2.53).
60 Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
61 should consider using the new AC_VERSION instead.
63 ** Warnings are now generated by default when an installer invokes
64 'configure' with an unknown --enable-* or --with-* option.
65 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
66 macro, or by invoking 'configure' with --disable-option-checking.
68 ** For portability with the eventual M4 2.0, macros should no longer use
69 anything larger than $9 to refer to arguments.
71 ** Existing obsolete macros
72 The documentation for the following macros is adjusted to make it
73 more clear that they have previously been marked obsolete, as their
74 functionality can be accomplished by other macros. We have no
75 current plans to remove them from Autoconf.
77 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
79 ** Newly obsolete macros
80 The following macros have been marked obsolete, as they only
81 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
84 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
86 ** AC_C_LONG_DOUBLE is obsolescent.
87 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
88 tests for problems that are so old that it is no longer of
89 practical importance on current systems. New programs need not use
90 AC_C_LONG_DOUBLE. We have no current plans to remove it.
92 * Major changes in Autoconf 2.61a (2006-12-11)
94 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
95 on many platforms. This has been fixed.
97 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
98 compatibility but it does nothing. The macro was already
99 obsolescent, as the last systems to have the problem were those
100 based on SVR2, which became obsolete in 1987. The macro had bugs
101 on some modern systems and could no longer be maintained reliably
102 due to lack of ancient systems to test it on.
104 ** config.status now uses awk instead of sed for most substitutions, for speed.
106 - As a side effect multi-line values of substituted variables no
107 longer have a small limit in total size, though for portability
108 each line should not exceed the POSIX length limit for text lines.
110 - It is now documented that Makefile.in should not contain
111 overlapping variable occurrences, e.g., @VAR1@VAR2@.
112 Autoconf's behavior was always iffy in such cases, and the
113 awk implementation has changed the behavior.
115 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
116 scripts have fewer problems with strings or file names containing
117 embedded special characters such as backslash or leading "-". This
118 was implemented by using `printf '%s\n' "$foo"' instead of `echo
119 "$foo"' when printf works. Due to the implementation technique
120 used, Autoconf-generated scripts now run considerably more slowly
121 on ancient implementations lacking printf. However, this should
122 not be a problem, since Autoconf-generated scripts in practice
123 invariably find a more-modern shell these days.
125 * Major changes in Autoconf 2.61 (2006-11-17)
127 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
129 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
131 * Major changes in Autoconf 2.60b (2006-10-22)
134 Autoconf-generated shell scripts no longer export BIN_SH, due to
135 configuration hassles with this. Installers who need BIN_SH in
136 their environment should set it before invoking 'configure' and
137 'make'. As far as we know, this affects only Unixware installations.
139 ** Obsolescent macros
140 The documentation now says that the following macros are obsolescent,
141 as they are superseded by Gnulib:
143 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
145 New programs should use the Gnulib counterparts of these macros.
146 We have no current plans to remove them from Autoconf.
148 ** AC_COMPUTE_INT no longer caches or reports results.
150 ** AC_CHECK_DECL now also works with aggregate objects.
152 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
154 ** GNU M4 1.4.7 or later is now recommended.
157 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
160 Now an alias for m4_mkstemp.
162 * Major changes in Autoconf 2.60a (2006-08-25)
164 ** GNU M4 1.4.6 or later is now recommended.
166 ** The check for C99 now tests for varargs macros, as documented.
167 It also tests that the preprocessor supports 64-bit integers.
169 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
170 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
172 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
173 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
174 two macros are different, so autoupdate will not change the old private name
175 to the new one. _AC_COMPUTE_INT may be removed in a future release.
177 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
178 that long long types be at least 64 bits wide, as C99 and tradition
179 requires. Formerly, they accepted implementations of any width.
182 * Major changes in Autoconf 2.60
184 Released 2006-06-23, by Ralf Wildenhues.
186 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
187 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
188 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
190 ** Provide a way to turn off warnings about the changed directory variables.
192 * Major changes in Autoconf 2.59d
194 Released 2006-06-05, by Ralf Wildenhues.
196 ** GNU make now recommended for VPATH builds
197 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
198 only if you use GNU make. In practice, other 'make' implementations
199 have too many subtle incompatibilities in their support for VPATH.
200 Many packages (including Autoconf itself) are portable to other
201 'make' implementations, but some packages are not, and recommending
202 GNU make keeps the installation instructions simpler.
204 ** Even more safety checks for the new Directory variables:
205 Warn about suspicious `${datarootdir}' found in config files output.
207 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
208 These never-documented macros and variables have been marked with
209 comments saying that they may be removed in a future release,
210 because their use can lead to unintended code being executed.
211 If you need functionality that only these macros or variables
212 currently supply, please write bug-autoconf@gnu.org.
214 ** AC_SUBST, AC_DEFINE
215 Literal arguments to these are passed to m4_pattern_allow now.
218 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
219 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
220 obsolete K&R tests in the Automake test suite.
229 Now more robust with special characters in file names, or when
230 multiple processes create the same directory at the same time.
232 ** Obsolescent macros
233 The documentation now says that the following macros are obsolescent:
234 they test for problems that are so old that they are no longer of
235 practical importance on current systems.
237 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
238 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
239 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
240 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
241 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
242 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
243 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
244 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
246 New programs need not use these macros. We have no current plans to
250 For compatibility with future Libtool 2.0, autoreconf will invoke
251 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
254 * Major changes in Autoconf 2.59c
256 Released 2006-04-12, by Ralf Wildenhues.
258 ** The configure command now redirects standard input from /dev/null,
259 to help avoid problems with subsidiary commands that might mistakenly
260 read standard input. AS_ORIGINAL_STDIN_FD points to the original
261 standard input before this redirection, if you really want configure to
262 read from standard input.
264 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
265 The following directory variables are new:
267 datarootdir read-only architecture-independent data root [PREFIX/share]
268 localedir locale-specific message catalogs [DATAROOTDIR/locale]
269 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
270 htmldir html documentation [DOCDIR]
271 dvidir dvi documentation [DOCDIR]
272 pdfdir pdf documentation [DOCDIR]
273 psdir ps documentation [DOCDIR]
275 The following variables have new default values:
277 datadir read-only architecture-independent data [DATAROOTDIR]
278 infodir info documentation [DATAROOTDIR/info]
279 mandir man documentation [DATAROOTDIR/man]
281 This means that if you use any of `@datadir@', `@infodir@', or
282 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
283 defined in this file. As a temporary measure, if any of those are
284 found but no mention of `datarootdir', the substitutions will be
285 replaced with values that do not contain `${datarootdir}', and a
286 warning will be issued.
288 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
289 a trailing slash. Similar change will be made to ac_top_builddir in a
290 future release; the old style value, which matches (../)*, is (and will
291 continue to be) available as ac_top_build_prefix.
294 New macro to check for support of 'typeof' syntax a la GNU C.
296 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
297 New "once-only" variants of commonly-used macros, to make 'configure'
298 smaller and faster in common cases.
301 New macro to check for strtold with C99 semantics.
304 New macro that lets builder disable assertions at 'configure'-time.
307 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
308 X11/Intrinsic.h and XtMalloc (Xt).
310 ** AC_PRESERVE_HELP_ORDER
311 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
312 and AC_ARG_WITH arguments in one region, in the order defined. The default
313 behavior is to group options of each classes separately.
315 ** AC_PROG_CC, AC_PROG_CXX
316 No longer automatically arrange to declare the 'exit' function of C,
317 when a C++ compiler is used. Standard Autoconf macros no longer use
318 'exit', so this is no longer an issue for them. If you use C++, and
319 want to call 'exit', you'll have to arrange for its declaration
320 yourself. But we now suggest you return from 'main' instead.
322 ** AC_PROG_CC_C89, AC_PROG_CC_C99
323 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
324 check for ANSI C89 and ISO C99 support respectively.
327 Has been unobsoleted, and will check if the compiler supports ISO
328 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
329 retained for backwards compatibility, assuming the value of
330 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
333 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
334 New macros for checking commonly-used members of struct dirent.
337 The substituted value can now contain newlines.
340 The substitution now occurs only when @variable@ is on a line by itself,
341 optionally surrounded by spaces and tabs. The whole line is replaced.
343 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
344 New macros to check for long double, and whether it is wider than double.
345 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
346 applications should switch to the new macro.
348 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
349 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
350 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
351 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
352 New macros to check for C99 and POSIX types.
354 ** AC_USE_SYSTEM_EXTENSIONS
355 New macro to enable extensions to Posix.
358 New macro which is defined to the name of the first declared config header
359 or undefined if no config headers have been declared yet.
362 The macro correctly handles quadrigraphs now.
364 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
365 These macros are new or published now.
368 New macro for copyright notices in testsuite files.
370 ** ALLOCA, LIBOBJS, LTLIBOBJS
371 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
372 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
373 `Makefile.in' in case the object files lie in a different directory.
374 The LIBOBJDIR feature is experimental.
377 Supports --no-recursive now.
379 ** New macros to support Erlang/OTP.
380 New macros for configuring paths to Erlang tools and libraries:
381 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
382 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
383 AC_ERLANG_SUBST_LIB_DIR.
385 New macros for configuring installation of Erlang libraries:
386 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
388 ** The manual now mentions Gnulib more prominently.
390 ** New macros to support Objective C.
391 AC_PROG_OBJC, AC_PROG_OBJCPP.
393 * Major changes in Autoconf 2.59b
395 Released 2004-08-20, by Paul Eggert.
398 New macro that computes the default alignment of a type.
400 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
401 When cross-compiling, these macros will give a warning if the tool
402 is not prefixed. In the future, unprefixed cross tools will not
403 be detected; please consult the info documentation for information
404 about the reason of this change.
406 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
407 New macros that detect programs whose name is prefixed with the
408 target type, if the build type and target type are different.
410 ** AC_REQUIRE_AUX_FILE
411 New trace macro that declares expected auxiliary files.
414 New macro that tests for a grep program that accepts as a long a line
417 ** AC_PROG_EGREP, AC_PROG_FGREP
418 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
419 FGREP="$GREP -F" respectively if possible, or else run a path search for
420 a program that accepts as long a line as possible.
423 New macro that tests for a sed program that truncates as few characters
426 * Major changes in Autoconf 2.59
428 Released 2003-11-04, by Akim Demaille
430 ** ac_abs_builddir etc.
431 Absolute file names were actually relative in 2.58.
433 * Major changes in Autoconf 2.58
435 Released 2003-11-04, by Akim Demaille
438 core.* files are no longer removed, as they may be valid user files.
440 ** autoreconf and auxiliary directory
441 Autoreconf creates the auxiliary directory if needed. This is
442 especially useful for initial "bootstrapping" of fresh CVS checkouts.
444 ** AC_CONFIG_MACRO_DIR
445 Use this macro to declare the directory for local M4 macros for aclocal.
448 No longer includes twice the same file in LIBOBJS if invoked
451 ** AC_CONFIG_COMMANDS
452 The directory for its first argument is automatically created. For
455 AC_CONFIG_COMMANDS([src/modules.hh], [...])
457 $top_builddir/src/ is created if needed.
459 ** Autotest and local.at
460 The optional file local.at is always included in Autotest test suites.
463 The warnings are always issued, including with cached runs.
464 This became a significant problem since aclocal and automake can
465 run autoconf behind the scene.
467 ** autoheader warnings
468 The warnings of autoheader can be turned off, using --warning.
469 For instance, -Wno-obsolete disables the complaints about acconfig.h
470 and other deprecated constructs.
473 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
476 ** AC_DECL_SYS_SIGLIST
480 Now checks that mktime is the inverse of localtime.
482 ** Improve DJGPP portability
483 The Autoconf tools and configure behave better under DJGPP.
485 ** Present But Cannot Be Compiled
486 New FAQ section dedicated to the mystic
488 configure: WARNING: pi.h: present but cannot be compiled
489 configure: WARNING: pi.h: check for missing prerequisite headers?
490 configure: WARNING: pi.h: proceeding with the preprocessor's result
493 ** Concurrent executions of autom4te
494 autom4te now locks its internal files, which enables concurrent
495 executions of autom4te, likely to happen if automake, autoconf,
496 autoheader etc. are run simultaneously.
499 Use of Libtool 1.5 and higher is encouraged. Compatibility with
500 Libtool pre-1.4 is not checked.
503 Testsuites no longer rerun failed tests in verbose mode; instead,
504 failures are logged while the test is run.
506 In addition, expected failures can be marked as such.
508 * Major changes in Autoconf 2.57
510 Released 2002-12-03 by Paul Eggert.
512 Bug fixes for problems with AIX linker, with freestanding C compilers,
513 with GNU M4 limitations, and with obsolete copies of GNU documents.
515 The Free Documentation License has been upgraded from 1.1 to 1.2.
517 * Major changes in Autoconf 2.56
519 Released 2002-11-15 by Akim Demaille.
521 One packaging problem fixed (config/install-sh was not executable).
523 * Major changes in Autoconf 2.55
525 Released 2002-11-14 by Akim Demaille.
529 Have your configure.ac checked by autoscan ("autoscan").
530 Try the warning options ("autoreconf -fv -Wall").
534 - AC_CHECK_HEADER, AC_CHECK_HEADERS
535 More information on proper use.
537 - Writing Test Programs
539 This sections explains how to write good test sources to use with
540 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
542 - AC_FOO_IFELSE vs. AC_TRY_FOO
544 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
545 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
549 - Is more robust to different Gettext installations.
551 - Produces messages (when --verbose) to be understood by Emacs'
554 - Supports -W/--warnings.
557 Once the GNU Build System reinstalled, run `./config.status
558 --recheck && ./config.status && make' if possible.
562 - Supports --cache, and --no-cache.
564 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
565 (autom4te.cache). See `Customizing autom4te' in the documentation.
572 Support for the obsoleted options -m, --macrodir, -l, --localdir is
573 dropped in favor of the safer --include/--prepend-include scheme.
578 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
579 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
580 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
583 Obsoleted macros are kept for Autoconf backward compatibility, but
584 should be avoided in configure.ac. Running autoupdate is advised.
587 - AC_DEFINE/AC_DEFINE_UNQUOTED
589 We have to stop using the old compatibility scheme --that tried to
590 avoid useless backslashes-- because Libtool 1.4.3 contains a
592 AC_DEFINE([error_t], [int],
593 [Define to a type to use for \`error_t' if it is not
594 otherwise available.])
596 We have to quote the single quotes and backslashes with \. The old
597 compatibility scheme saw that ` was backslashed, and therefore did
598 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
599 compatible with Libtool. Autoconf 2.55 is, but in some cases might
600 produce more \ than wanted.
602 Please, note that in the future the same problem will happen with
603 AC_MSG_*: use `autoreconf -f -Wall'.
607 - Portability of the Autoconf package to Solaris.
609 - Spurious warnings caused by config.status.
610 This bug is benign, but painful: on some systems (typically
611 FreeBSD), warnings such as:
613 config.status: creating Makefile
614 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
616 could be issued. This is fixed.
619 Simultaneous executions of config.status are possible again.
621 - Precious variables accumulation
623 config.status could stack several copies of the precious variables
627 ** Plans for later versions
631 The compatibility hooks with the old scheme will be completely
632 removed. Please, advice/use `--build', `--host', and `--target'
635 - AC_CHECK_HEADER, AC_CHECK_HEADERS
637 The tests will be stricter, please make sure your invocations are
642 Shell functions will gradually be introduced, probably starting with
643 Autotest. If you know machines which are in use that you suspect
644 *not* to support shell functions, please run the test suite of
645 Autoconf 2.55 on it, and report the results to
646 bug-autoconf@gnu.org.
650 Special characters in AC_MSG_* need not be quoted. Currently,
651 Autoconf has heuristics to decide when a string is escaped, or has
652 to be escaped. This scheme is fragile, and will be removed; the
653 only risk is uglified messages. Please, run `autoreconf -f -Wall'
654 to find occurrences that will be affected.
656 * Major changes in Autoconf 2.54
658 Released 2002-09-13 by Akim Demaille.
662 - autoreconf no longer changes the version of the gettext/po/intl
663 support files. It now adds the files the correspond to the
664 AM_GNU_GETTEXT_VERSION declared in configure.ac.
666 Warning: It now relies on the 'autopoint' program, which is part
667 of GNU gettext 0.11.4 and newer.
669 Please note that you need to have a GNU gettext version that
670 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
671 in configure.ac. You can upgrade to newer GNU gettext versions,
672 though, without needing to change configure.ac.
674 - The -I DIR or --include=DIR option now appends DIR to the include path
675 instead of prepending; this is for consistency with other GNU tools.
676 The new -B DIR or --prepend-include=DIR option has the old behavior.
681 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
682 Please, remove lines such as
684 # This is necessary so that .o files in LIBOBJS are also
685 # built via the ANSI2KNR-filtering rules.
686 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
688 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
689 your Makefiles either.
691 - AC_CONFIG_LINKS now makes copies if it can't make links.
693 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
694 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
695 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
697 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
699 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
701 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
705 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
706 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
707 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
710 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
713 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
714 for an AC_LIBOBJ replacement.
718 - Spurious complaints from `m4_bmatch' about invalid regular
719 expressions are suppressed.
721 - Empty top_builddirs are properly handled.
723 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
726 Now colon in the optional path arguments are properly handled.
728 ** Improved portability
730 - Both Autoconf the package, and the scripts it produces, should run
731 more reliably with Zsh. Bear in mind it is the default Bourne shell
734 - Autoconf and the scripts it produces no longer assume the existence of
735 the obsolescent commands egrep and fgrep.
739 - Limitations of Make
743 The GNATS base moved to
744 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
745 (It is no longer available, though.)
750 Now contains the list of ouput variables and files (AC_SUBST,
753 * Major changes in Autoconf 2.53
755 Released 2002-03-08 by Akim Demaille.
759 Perl 5.005_03 or later is required: autom4te is written in Perl and is
760 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
766 Argument requirements, output variables, defined macros.
767 - M4sugar, M4sh, Autotest
769 - Double quoting macros
770 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
772 The Autoconf manual is now distributed under the terms of the GNU FDL.
773 - Section `Hosts and Cross-Compilation'
774 Explains the rationale for the 2.5x changes in the cross-compilation
775 chain, and in the relationships between build, host, and target
777 Emphasizes that `cross-compilation' == `--host is given'.
778 If you are working on compilers etc., be sure to read this section.
779 - Section `AC_LIBOBJ vs. LIBOBJS'
780 Explains why assigning LIBOBJS directly is now an error.
781 Details how to update the code.
786 Now used instead of hard coded line numbers.
787 This eases the comparison of `configure's, and diminishes the
788 pressure over control version archives.
789 Automatic replacement for shells that don't support this feature.
790 - New output variables
791 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
796 Autoconf and Autotest modes are provided.
801 New, used by the Autoconf suite to cache and speed up most processing.
803 Supported by autom4te, autoconf and autoheader.
805 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
806 autoupdate, and autoreconf.
808 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
809 automake options are to be given via AUTOMAKE_OPTIONS.
811 Runs gettextize and libtoolize when appropriate.
813 --m4dir is no longer supported.
815 Now runs only in the specified directories, defaulting to `.',
816 but understands AC_CONFIG_SUBDIRS for dependent directories.
817 Before, it used to run on all the `configure.ac' found in the
819 Independent packages are properly updated.
823 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
825 Under the user pressure, $? is finally available. Probably a mistake.
826 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
827 - Precious variables accumulation
828 config.status could stack several copies of the precious variables
830 - AC_PATH_PROG and family.
831 Works properly when given a literal path.
833 Somewhere since 2.13, the result had been reversed.
837 - AC_C_BIGENDIAN supports the cross-compiling case.
838 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
839 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
840 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
842 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
843 precision than `double'.
848 It now defines the preprocessor symbols PACKAGE_NAME,
849 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
853 Admits a fourth optional parameter: the tar name.
855 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
856 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
857 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
860 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
861 Are much less expensive when using long lists of files.
864 Works with shell variables, and non alphanumeric names.
868 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
869 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
871 - AC_FUNC_STRTOD substitutes POW_LIB.
876 * Major changes in Autoconf 2.52
878 Released 2001-07-18 by Akim Demaille.
883 This feature was present in autoconf 2.50 but was not documented.
884 For example, `@<:@' is translated to `[' just before output. This
885 is useful when writing strings that contain unbalanced quotes, or
886 other hard-to-quote constructs.
887 - m4_pattern_forbid, m4_pattern_allow
888 - Tips for upgrading from 2.13.
889 - Using autoscan to maintain a configure.ac.
892 - Now include stdint.h.
893 - sys/types.h and sys/stat.h are guarded.
894 - strings.h is included if available, and not conflicting with string.h.
897 - The test suite is more robust and presents less false failures.
898 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
899 - configure accepts --prefix='' again.
900 - AC_CHECK_LIB works properly when its first argument is not a
902 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
903 - build_, host_, and target_alias are AC_SUBST as in 2.13.
904 - AC_ARG_VAR properly propagates precious variables inherited from the
905 environment to ./config.status.
906 - Using --program-suffix/--program-prefix is portable.
907 - Failures to detect the default compiler's output extension are less
909 - `config.status foo' works properly when `foo' depends on variables
910 set in an AC_CONFIG_THING INIT-CMD.
911 - autoheader is more robust to broken input.
912 - Fixed Fortran name-mangling and link tests on a number of systems,
913 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
916 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
917 specify pre-includes. In this case, the headers are compiled with
918 cc, not merely preprocessed by cpp. Therefore it is the _usability_
919 of a header which is checked for, not just its availability.
920 - AC_ARG_VAR refuses to run configure when precious variables have
922 - Versions of compilers are dumped in the logs.
923 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
926 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
927 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
928 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
929 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
930 Be sure to read `Upgrading from Version 2.13' to understand why
931 running `autoupdate' is needed.
932 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
933 a main-like routine is required/possible when linking C/C++ with
934 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
935 - AC_FUNC_GETPGRG behaves better when cross-compiling.
937 * Major changes in Autoconf 2.51
938 There was no release of Autoconf 2.51 since some packagers had used
939 this version number without permission to ship intermediary versions
940 of 2.50. The version was skipped to avoid confusion.
942 * Major changes in Autoconf 2.50
944 Released 2001-05-21 by Akim Demaille.
947 There have been far too many to enumerate them here. Check out
948 ChangeLog if you really want to know more.
950 ** Improved documentation
951 In particular, portability issues are better covered.
954 All the standard GNU Makefile targets are supported. The layout has
955 changed: m4/ holds the M4 extensions Autoconf needs for its
956 configuration, doc/ contains the documentation, and tests/ contains
959 ** Man pages are provided
960 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
961 config.guess, config.sub.
965 Provides a safe and powerful means to trace the macro uses. This
966 provide the parsing layer for tools which need to `study'
970 Specify what category of warnings should be enabled.
972 - When recursing into subdirectories, try for configure.gnu before
973 configure to adapt for packages not using autoconf on case-insensitive
977 More errors are now caught (circular AC_REQUIRE dependencies,
978 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
979 etc.). In addition, their location and call stack are given.
982 autoupdate is much more powerful, and is able to provide the glue code
983 which might be needed to move from an old macro to its newer
986 You are strongly encouraged to use it to modernize both your
987 `configure.in' and your .m4 extension files.
990 The internal machinery of autoheader has completely changed. As a
991 result, using `acconfig.h' should be considered to be obsoleted, and
992 you are encouraged to get rid of it using the AH macros.
997 ** Fortran 77 compilers
998 Globally, the support for Fortran 77 is considerably improved.
1000 Support for automatically determining a Fortran 77 compiler's
1001 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1002 provided to wrap C/C++ identifiers, thus making it easier and more
1003 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1004 call C/C++ routines. See the Texinfo documentation for details.
1007 The test suite no longer uses DejaGNU. It should be easy to submit
1008 test cases in this new framework.
1011 - --help, --help=long, -hl
1012 no longer dumps useless items.
1014 lists only specific options.
1015 - --help=recursive, -hr
1016 displays the help of all the embedded packages.
1017 - Remembers environment variables when reconfiguring.
1018 The previous scheme to set envvar before running configure was
1020 what prevented configure from remembering the environment in which
1021 it was run, therefore --recheck was run in an inconsistent
1022 environment. Now, one should run
1024 and then --recheck will work properly. Variables declared with
1025 AC_ARG_VAR are also preserved.
1027 $build defaults to `config.guess`, $host to $build, and then $target
1029 Cross-compilation is a global status of the package, it no longer
1030 depends upon the current language.
1031 Cross compilation is enabled iff the user specified `--host'.
1032 `configure' now fails if it can't run the executables it compiles,
1033 unless cross-compilation is enabled.
1035 The cache file is disabled by default. The new options
1036 `--config-cache', `-C' set the cache to `config.cache'.
1040 Much faster on most architectures.
1041 - concurrent executions
1042 It is safe to use `make -j' with config.status.
1043 - human interface improved
1044 It is possible to invoke
1045 ./config.status foobar
1046 instead of the former form (still valid)
1047 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1048 CONFIG_FILES=foobar:foo.in:bar.in \
1050 The same holds for configuration headers and links.
1051 You can instantiate unknown files and headers:
1052 ./config.status --header foo.h:foo.h.in --file bar:baz
1053 - has a useful --help
1054 - accepts special file name "-" for stdin/stdout
1059 Specify additional copyright information.
1062 Now expects the identity of the package as argument.
1066 Most macros, if not all, now strictly follow the `one quotation
1067 level' rule. This results in a more predictable expansion.
1070 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1071 configure scripts, was fixed by Axel Thimm.
1075 Document and ask for the registration of an envvar.
1078 Specifies the file which `configure' should look for when trying to
1079 find the source tree (used to be handled by AC_INIT).
1081 - AC_CONFIG_COMMANDS
1082 To add new actions to config.status. Should be used instead of
1086 Replaces AC_LINK_FILES.
1088 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1089 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1090 They now obey sh: you should no longer use shell variables as
1091 argument. Instead of
1093 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1094 AC_CONFIG_SUBDIRS($my_subdirs)
1098 if test "$package_foo_enabled" = yes; then
1099 AC_CONFIG_SUBDIRS(foo)
1103 To format an Autoconf macro's help string so that it looks pretty
1104 when the user executes `configure --help'.
1107 ** Generic Test Macros
1109 The interface of the AC_CHECK families of macros (decl, header,
1110 type, member, func) is now uniform. They support the same set of
1113 - AC_CHECK_DECL, AC_CHECK_DECLS
1114 To check whether a symbol is declared.
1116 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1117 No longer need a cross-compilation default.
1120 The test it performs is much more robust than previously, and makes
1121 it possible to test builtin types in addition to typedefs.
1122 It is now schizophrenic:
1123 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1124 remains for backward compatibility, but its use is discouraged.
1125 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1126 behaves exactly like the other AC_CHECK macros.
1129 Checks whether given types are supported by the system.
1131 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1132 Check for given members in aggregates (e.g., pw_gecos in struct
1136 Checks if the compiler supports ISO C, included when needs special
1140 Checking whether the preprocessor indicates missing includes by the
1141 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1144 Takes a language as argument and replaces AC_LANG_C,
1145 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1147 - AC_LANG_PUSH, AC_LANG_POP
1148 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1151 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1152 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1153 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1157 Sets GETGROUPS_LIBS.
1159 - AC_FUNC_GETLOADAVG
1160 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1163 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1166 Arrange for large-file support.
1168 - AC_EXEEXT, AC_OBJEXT
1169 You are no longer expected to use them: their computation is
1170 performed by default.
1172 ** C++ compatibility
1173 Every macro has been revisited in order to support at best CC=c++.
1175 Major changes in Autoconf 2.14:
1176 There was no release of GNU Autoconf 2.14.
1178 Major changes in Autoconf 2.13:
1180 Released 1999-05-01 by Ben Elliston.
1182 * Support for building on Win32 systems where the only available C or
1183 C++ compiler is the Microsoft Visual C++ command line compiler
1184 (`cl'). Additional support for building on Win32 systems which are
1185 using the Cygwin or Mingw32 environments.
1186 * Support for alternative object file and executable file extensions.
1187 On Win32, for example, these are .obj and .exe. These are discovered
1188 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1189 @EXEEXT@ in the output, respectively.
1190 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1191 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1192 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1193 * AC_DEFINE now has an optional third argument for a description to be
1194 placed in the config header input file (e.g. config.h.in).
1195 * The C++ code fragment compiled for the C++ compiler test had to be
1196 improved to include an explicit return type for main(). This was
1197 causing failures on systems using recent versions of the EGCS C++
1199 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1200 script to report that `sometype_t' was present when only `type_t'
1202 * Merge of the FSF version of config.guess and config.sub to modernize
1203 these scripts. Add support for a few new hosts in config.guess.
1204 Incorporate latest versions of install-sh, mkinstalldirs and
1205 texinfo.tex from the FSF.
1206 * autoreconf is capable of running automake if necessary (and
1208 * Support for Fortran 77. See the Texinfo documentation for details.
1209 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1211 Major changes in Autoconf 2.12:
1213 Released 1996-11-26 by David J. MacKenzie
1215 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1216 concatenating multiple input files separated by colons, like so:
1217 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1218 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1219 The arguments may be shell variables, to compute the lists on the fly.
1220 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1221 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1224 Major changes in Autoconf 2.11:
1226 Released November 18th, 1996, by David J. MacKenzie
1228 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1229 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1230 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1231 * AC_CONFIG_HEADER expands shell variables in its argument.
1232 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1233 * The "checking..." messages and the source code for test programs that
1234 fail are saved in config.log.
1235 * Another workaround has been added for seds with small command length limits.
1236 * config.sub and config.guess recognize more system types.
1239 Major changes in Autoconf 2.10:
1241 Released May 7th, 1996, by Roland McGrath
1244 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1245 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1247 Major changes in Autoconf 2.9:
1249 Released March 16th, 1996, by Roland McGrath
1253 Major changes in Autoconf 2.8:
1255 Released March 8th, 1996, by Roland McGrath
1259 Major changes in Autoconf 2.7:
1261 Released November 22nd, 1995, by David J. MacKenzie
1265 Major changes in Autoconf 2.6:
1267 Released November 20th, 1995, by David J. MacKenzie
1271 Major changes in Autoconf 2.5:
1273 Released November 17th, 1995, by Roland McGrath
1275 * New configure options --bindir, --libdir, --datadir, etc., with
1276 corresponding output variables.
1277 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1278 * config.log contains the command being run as well as any output from it.
1279 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1280 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1281 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1282 AC_CHECK_TOOL can search a path other than $PATH.
1283 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1285 Major changes in Autoconf 2.4:
1287 Released June 14th, 1995, by David J. MacKenzie
1289 * Fix a few bugs found by Emacs testers.
1291 Major changes in Autoconf 2.3:
1293 Released March 27th, 1995, by David J. MacKenzie
1295 * Fix the cleanup trap in several ways.
1296 * Handle C compilers that are picky about option placement.
1297 * ifnames gets the version number from the right directory.
1299 Major changes in Autoconf 2.2:
1301 Released March 8th, 1995, by David J. MacKenzie
1303 * The ifnames utility is much faster but requires a "new awk" interpreter.
1304 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1305 library before existing libs, not after, in case it uses them.
1306 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1307 * Lots of bug fixes.
1308 * Many additions to the TODO file :-)
1310 Major changes in Autoconf 2.1:
1312 Released November 4th, 1994, by David J. MacKenzie
1315 * More explanations in the manual.
1316 * Fix a spurious failure in the testsuite.
1317 * Clarify some warning messages.
1318 * autoreconf by default only rebuilds configure and config.h.in files
1319 that are older than any of their particular input files; there is a
1320 --force option to use after installing a new version of Autoconf.
1322 Thanks to everybody who's submitted changes and additions to Autoconf!
1323 I've incorporated many of them, and am still considering others for
1324 future releases -- but I didn't want to postpone this release indefinitely.
1326 Caution: don't indiscriminately rebuild configure scripts with
1327 Autoconf version 2. Some configure.in files need minor adjustments to
1328 work with it; the documentation has a chapter on upgrading. A few
1329 configure.in files, including those for GNU Emacs and the GNU C
1330 Library, need major changes because they relied on undocumented
1331 internals of version 1. Future releases of those packages will have
1332 updated configure.in files.
1334 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1335 Autoconf now makes heavy use of M4 diversions, which were implemented
1336 inefficiently in GNU M4 releases before 1.3.
1338 Major changes in Autoconf 2.0:
1340 Released October 26th, 1994, by David J. MacKenzie
1342 ** New copyright terms:
1343 * There are no restrictions on distribution or use of configure scripts.
1346 * Autoconf manual is reorganized to make information easier to find
1347 and has several new indexes.
1348 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1351 * autoscan to generate a preliminary configure.in for a package by
1352 scanning its source code for commonly used nonportable functions,
1353 programs, and header files.
1354 * ifnames to list the symbols used in #if and #ifdef directives in a
1356 * autoupdate to update a configure.in to use the version 2 macro names.
1357 * autoreconf to recursively remake configure and configuration header
1358 files in a source tree.
1360 ** Changed utilities:
1361 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1362 * autoconf and autoheader can look for package-local definition files
1363 in an alternate directory.
1366 * AC_CACHE_VAL to share results of tests between configure runs.
1367 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1368 that macros invoked with AC_REQUIRE don't interrupt other macros.
1369 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1370 support deciding unguessable features based on the host and target types.
1371 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1372 * AC_ARG_PROGRAM to use the options --program-prefix,
1373 --program-suffix, and --program-transform-name to change the names
1374 of programs being installed.
1375 * AC_PREFIX_DEFAULT to change the default installation prefix.
1376 * AC_TRY_COMPILE to compile a test program without linking it.
1377 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1378 * AC_CHECK_LIB to check for a particular function and library.
1379 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1380 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1381 * AC_SUBST_FILE to insert one file into another.
1382 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1383 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1384 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1385 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1388 * Many macros renamed systematically, but old names are accepted for
1389 backward compatibility.
1390 * AC_OUTPUT adds the "automatically generated" comment to
1391 non-Makefiles where it finds @configure_input@ in an input file, to
1392 support files with various comment syntaxes.
1393 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1394 files when they are not enclosed in @ signs.
1395 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1396 override the file name "config.status".
1397 * AC_OUTPUT takes an optional argument for passing variables from
1398 configure to config.status.
1399 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1400 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1401 CPPFLAGS, and LDFLAGS from the environment.
1402 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1403 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1404 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1405 srcdir/../.. by default.
1406 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1407 * AC_DEFINE no longer prints anything, because of the new result reporting
1408 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1409 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1410 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1411 --enable- and --with- options.
1412 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1413 execute on success or failure.
1414 * Checking for C functions in C++ works.
1417 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1418 better maintained with them.
1419 * AC_ARG_ARRAY removed because no one was likely using it.
1420 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1421 take arguments, for consistency with all of the other specific checks.
1424 * Comes with config.sub and config.guess, and uses them optionally.
1425 * Uses config.cache to cache test results. An alternate cache file
1426 can be selected with the --cache-file=FILE option.
1427 * Uses optional shell scripts $prefix/share/config.site and
1428 $prefix/etc/config.site to perform site or system specific initializations.
1429 * configure saves compiler output to ./config.log for debugging.
1430 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1431 * acsite.m4 is the new name for the system-wide aclocal.m4.
1432 * Has a DejaGnu test suite.
1434 Major changes in Autoconf 1.11:
1436 * AC_PROG_INSTALL calls install.sh with the -c option.
1437 * AC_SET_MAKE cleans up after itself.
1438 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1439 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1441 Plus a few other bug fixes.
1443 Major changes in Autoconf 1.10:
1445 * autoheader uses config.h.bot if present, analogous to config.h.top.
1446 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1448 * AC_PROG_CXX looks for cxx as a C++ compiler.
1450 Plus several bugs fixed.
1452 Major changes in Autoconf 1.9:
1454 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1455 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1456 and autoheader generates entries for those names automatically.
1457 * AC_FIND_X gets the result from xmkmf correctly.
1458 * AC_FIND_X assumes no X if --without-x was given.
1459 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1460 * AC_PROG_INSTALL finds OSF/1 installbsd.
1462 Major changes in Autoconf 1.8:
1465 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1466 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1467 for checking both C++ and C features in one configure script.
1468 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1469 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1470 AC_SET_MAKE, AC_ENABLE.
1473 * AC_FIND_X looks for X in more places.
1474 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1475 install.sh is distributed with Autoconf.
1476 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1477 a rewrite of quoting in AC_DEFINE.
1478 * AC_OUTPUT adds its comments in C format when substituting in C files.
1479 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1481 ** New or changed command line options:
1482 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1483 * configure accepts --without-PACKAGE, which sets withval=no.
1484 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1485 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1486 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1487 * configure accepts and ignores most other Cygnus configure options, and
1488 warns about unknown options.
1489 * config.status accepts --help, --version options.
1491 ** File names and other changes:
1492 * Relative srcdir values are not made absolute.
1493 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1494 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1495 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1496 * The example Makefile dependencies for configure et al. work better.
1497 * Namespace cleanup: all shell variables used internally by Autoconf
1498 have names beginning with `ac_'.
1500 More big improvements are in process for future releases, but have not
1501 yet been (variously) finished, integrated, tested, or documented enough
1504 Major changes in Autoconf 1.7:
1506 * New macro AC_OBSOLETE.
1507 * Bugs in Makefile.in fixed.
1508 * AC_LONG_FILE_NAMES improved.
1510 Major changes in Autoconf 1.6:
1512 * New macro AC_LONG_64_BITS.
1513 * Multiple .h files can be created.
1514 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1515 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1516 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1517 * Unused --no-create option to configure removed.
1518 * autoheader doesn't change the timestamp of its output file if
1519 the file didn't change.
1520 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1521 * config.status checks three optional environment variables to
1522 modify its behavior.
1523 * The usual bug fixes.
1525 Major changes in Autoconf 1.5:
1527 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1528 * autoconf and autoheader scripts have GNU standards conforming
1529 --version and --help options (they print their message and exit).
1532 Major changes in Autoconf 1.4:
1534 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1535 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1536 * autoconf and autoheader use the M4 environment variable to determine the
1537 name of the M4 program to use.
1538 * The --macrodir option to autoconf and autoheader specifies the directory
1539 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1540 * autoconf and autoheader can take `-' as their file names, which means to
1541 read stdin as input.
1542 * Resulting configure scripts can take a --verbose option which causes them
1543 to print the results of their tests.
1544 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1545 shell characters, etc. will be preserved during various stages of
1546 expansion done by the shell. If you don't want this, use
1547 AC_DEFINE_UNQUOTED instead.
1548 * Much textual processing done with external calls to tr and sed have been
1549 internalized with builtin M4 `patsubst' and `translit' calls.
1550 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1551 set the shell variables `gen_files' and `gen_config' to the list of
1552 file names to output.
1553 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1554 "lex.yy" or "lexyy", depending on the system.
1555 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1557 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1558 * AC_CONST works much more reliably on more systems.
1561 Major changes in Autoconf 1.3:
1563 configure no longer requires awk for packages that use a config.h.
1564 Support handling --with-PACKAGE options.
1565 New `autoheader' script to create `config.h.in' from `configure.in'.
1566 Ignore troublesome -lucb and -lPW when searching for alloca.
1567 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1568 Improve detection of STDC library.
1569 Add AC_HAVE_LIBRARY to check for non-default libraries.
1570 Function checking should work with future GNU libc releases.
1572 Major changes in Autoconf 1.2:
1574 The --srcdir option is now usually unnecessary.
1575 Add a file containing sample comments describing CPP macros.
1576 A comment in config.status tells which host it was configured on.
1577 Substituted variable values can now contain commas.
1578 Fix bugs in various feature checks.
1580 Major changes in Autoconf 1.1:
1582 Added AC_STRCOLL macro.
1583 Made AC_GETLOADAVG check for more things.
1584 AC_OUTPUT argument is now optional.
1589 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1590 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
1592 This program is free software: you can redistribute it and/or modify
1593 it under the terms of the GNU General Public License as published by
1594 the Free Software Foundation, either version 3 of the License, or
1595 (at your option) any later version.
1597 This program is distributed in the hope that it will be useful,
1598 but WITHOUT ANY WARRANTY; without even the implied warranty of
1599 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1600 GNU General Public License for more details.
1602 You should have received a copy of the GNU General Public License
1603 along with this program. If not, see <http://www.gnu.org/licenses/>.