1 * Major changes in Autoconf 2.61a (??)
3 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
4 compatibility but it does nothing. The macro was already
5 obsolescent, as the last systems to have the problem were those
6 based on SVR2, which became obsolete in 1987. The macro had bugs
7 on some modern systems and could no longer be maintained reliably
8 due to lack of ancient systems to test it on.
10 ** config.status now uses awk instead of sed for most substitutions, for speed.
12 - As a side effect multi-line values of substituted variables are
13 no longer limited in total size, though for portability each line
14 should not exceed the POSIX length limit for text lines.
16 - It is now documented that Makefile.in should not contain
17 overlapping variable occurrences, e.g., @VAR1@VAR2@.
18 Autoconf's behavior was always iffy in such cases, and the
19 awk implementation has changed the behavior.
21 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
22 scripts have fewer problems with strings or file names containing
23 embedded special characters such as backslash or leading "-". This
24 was implemented by using `printf '%s\n' "$foo"' instead of `echo
25 "$foo"' when printf works. Due to the implementation technique
26 used, Autoconf-generated scripts now run considerably more slowly
27 on ancient implementations lacking printf. However, this should
28 not be a problem, since Autoconf-generated scripts in practice
29 invariably find a more-modern shell these days.
31 * Major changes in Autoconf 2.61 (2006-11-17)
33 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
35 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
37 * Major changes in Autoconf 2.60b (2006-10-22)
40 Autoconf-generated shell scripts no longer export BIN_SH, due to
41 configuration hassles with this. Installers who need BIN_SH in
42 their environment should set it before invoking 'configure' and
43 'make'. As far as we know, this affects only Unixware installations.
46 The documentation now says that the following macros are obsolescent,
47 as they are superseded by Gnulib:
49 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
51 New programs should use the Gnulib counterparts of these macros.
52 We have no current plans to remove them from Autoconf.
54 ** AC_COMPUTE_INT no longer caches or reports results.
56 ** AC_CHECK_DECL now also works with aggregate objects.
58 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
60 ** GNU M4 1.4.7 or later is now recommended.
63 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
66 Now an alias for m4_mkstemp.
68 * Major changes in Autoconf 2.60a (2006-08-25)
70 ** GNU M4 1.4.6 or later is now recommended.
72 ** The check for C99 now tests for varargs macros, as documented.
73 It also tests that the preprocessor supports 64-bit integers.
75 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
76 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
78 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
79 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
80 two macros are different, so autoupdate will not change the old private name
81 to the new one. _AC_COMPUTE_INT may be removed in a future release.
83 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
84 that long long types be at least 64 bits wide, as C99 and tradition
85 requires. Formerly, they accepted implementations of any width.
88 * Major changes in Autoconf 2.60
90 Released 2006-06-23, by Ralf Wildenhues.
92 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
93 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
94 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
96 ** Provide a way to turn off warnings about the changed directory variables.
98 * Major changes in Autoconf 2.59d
100 Released 2006-06-05, by Ralf Wildenhues.
102 ** GNU make now recommended for VPATH builds
103 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
104 only if you use GNU make. In practice, other 'make' implementations
105 have too many subtle incompatibilities in their support for VPATH.
106 Many packages (including Autoconf itself) are portable to other
107 'make' implementations, but some packages are not, and recommending
108 GNU make keeps the installation instructions simpler.
110 ** Even more safety checks for the new Directory variables:
111 Warn about suspicious `${datarootdir}' found in config files output.
113 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
114 These never-documented macros and variables have been marked with
115 comments saying that they may be removed in a future release,
116 because their use can lead to unintended code being executed.
117 If you need functionality that only these macros or variables
118 currently supply, please write bug-autoconf@gnu.org.
120 ** AC_SUBST, AC_DEFINE
121 Literal arguments to these are passed to m4_pattern_allow now.
124 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
125 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
126 obsolete K&R tests in the Automake test suite.
135 Now more robust with special characters in file names, or when
136 multiple processes create the same directory at the same time.
138 ** Obsolescent macros
139 The documentation now says that the following macros are obsolescent:
140 they test for problems that are so old that they are no longer of
141 practical importance on current systems.
143 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
144 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
145 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
146 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
147 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
148 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
149 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
150 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
152 New programs need not use these macros. We have no current plans to
156 For compatibility with future Libtool 2.0, autoreconf will invoke
157 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
160 * Major changes in Autoconf 2.59c
162 Released 2006-04-12, by Ralf Wildenhues.
164 ** The configure command now redirects standard input from /dev/null,
165 to help avoid problems with subsidiary commands that might mistakenly
166 read standard input. AS_ORIGINAL_STDIN_FD points to the original
167 standard input before this redirection, if you really want configure to
168 read from standard input.
170 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
171 The following directory variables are new:
173 datarootdir read-only architecture-independent data root [PREFIX/share]
174 localedir locale-specific message catalogs [DATAROOTDIR/locale]
175 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
176 htmldir html documentation [DOCDIR]
177 dvidir dvi documentation [DOCDIR]
178 pdfdir pdf documentation [DOCDIR]
179 psdir ps documentation [DOCDIR]
181 The following variables have new default values:
183 datadir read-only architecture-independent data [DATAROOTDIR]
184 infodir info documentation [DATAROOTDIR/info]
185 mandir man documentation [DATAROOTDIR/man]
187 This means that if you use any of `@datadir@', `@infodir@', or
188 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
189 defined in this file. As a temporary measure, if any of those are
190 found but no mention of `datarootdir', the substitutions will be
191 replaced with values that do not contain `${datarootdir}', and a
192 warning will be issued.
194 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
195 a trailing slash. Similar change will be made to ac_top_builddir in a
196 future release; the old style value, which matches (../)*, is (and will
197 continue to be) available as ac_top_build_prefix.
200 New macro to check for support of 'typeof' syntax a la GNU C.
202 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
203 New "once-only" variants of commonly-used macros, to make 'configure'
204 smaller and faster in common cases.
207 New macro to check for strtold with C99 semantics.
210 New macro that lets builder disable assertions at 'configure'-time.
213 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
214 X11/Intrinsic.h and XtMalloc (Xt).
216 ** AC_PRESERVE_HELP_ORDER
217 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
218 and AC_ARG_WITH arguments in one region, in the order defined. The default
219 behavior is to group options of each classes separately.
221 ** AC_PROG_CC, AC_PROG_CXX
222 No longer automatically arrange to declare the 'exit' function of C,
223 when a C++ compiler is used. Standard Autoconf macros no longer use
224 'exit', so this is no longer an issue for them. If you use C++, and
225 want to call 'exit', you'll have to arrange for its declaration
226 yourself. But we now suggest you return from 'main' instead.
228 ** AC_PROG_CC_C89, AC_PROG_CC_C99
229 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
230 check for ANSI C89 and ISO C99 support respectively.
233 Has been unobsoleted, and will check if the compiler supports ISO
234 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
235 retained for backwards compatibility, assuming the value of
236 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
239 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
240 New macros for checking commonly-used members of struct dirent.
243 The substituted value can now contain newlines.
246 The substitution now occurs only when @variable@ is on a line by itself,
247 optionally surrounded by spaces and tabs. The whole line is replaced.
249 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
250 New macros to check for long double, and whether it is wider than double.
251 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
252 applications should switch to the new macro.
254 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
255 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
256 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
257 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
258 New macros to check for C99 and POSIX types.
260 ** AC_USE_SYSTEM_EXTENSIONS
261 New macro to enable extensions to Posix.
264 New macro which is defined to the name of the first declared config header
265 or undefined if no config headers have been declared yet.
268 The macro correctly handles quadrigraphs now.
270 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
271 These macros are new or published now.
274 New macro for copyright notices in testsuite files.
276 ** ALLOCA, LIBOBJS, LTLIBOBJS
277 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
278 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
279 `Makefile.in' in case the object files lie in a different directory.
280 The LIBOBJDIR feature is experimental.
283 Supports --no-recursive now.
285 ** New macros to support Erlang/OTP.
286 New macros for configuring paths to Erlang tools and libraries:
287 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
288 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
289 AC_ERLANG_SUBST_LIB_DIR.
291 New macros for configuring installation of Erlang libraries:
292 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
294 ** The manual now mentions Gnulib more prominently.
296 ** New macros to support Objective C.
297 AC_PROG_OBJC, AC_PROG_OBJCPP.
299 * Major changes in Autoconf 2.59b
301 Released 2004-08-20, by Paul Eggert.
304 New macro that computes the default alignment of a type.
306 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
307 When cross-compiling, these macros will give a warning if the tool
308 is not prefixed. In the future, unprefixed cross tools will not
309 be detected; please consult the info documentation for information
310 about the reason of this change.
312 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
313 New macros that detect programs whose name is prefixed with the
314 target type, if the build type and target type are different.
316 ** AC_REQUIRE_AUX_FILE
317 New trace macro that declares expected auxiliary files.
320 New macro that tests for a grep program that accepts as a long a line
323 ** AC_PROG_EGREP, AC_PROG_FGREP
324 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
325 FGREP="$GREP -F" respectively if possible, or else run a path search for
326 a program that accepts as long a line as possible.
329 New macro that tests for a sed program that truncates as few characters
332 * Major changes in Autoconf 2.59
334 Released 2003-11-04, by Akim Demaille
336 ** ac_abs_builddir etc.
337 Absolute file names were actually relative in 2.58.
339 * Major changes in Autoconf 2.58
341 Released 2003-11-04, by Akim Demaille
344 core.* files are no longer removed, as they may be valid user files.
346 ** autoreconf and auxiliary directory
347 Autoreconf creates the auxiliary directory if needed. This is
348 especially useful for initial "bootstrapping" of fresh CVS checkouts.
350 ** AC_CONFIG_MACRO_DIR
351 Use this macro to declare the directory for local M4 macros for aclocal.
354 No longer includes twice the same file in LIBOBJS if invoked
357 ** AC_CONFIG_COMMANDS
358 The directory for its first argument is automatically created. For
361 AC_CONFIG_COMMANDS([src/modules.hh], [...])
363 $top_builddir/src/ is created if needed.
365 ** Autotest and local.at
366 The optional file local.at is always included in Autotest test suites.
369 The warnings are always issued, including with cached runs.
370 This became a significant problem since aclocal and automake can
371 run autoconf behind the scene.
373 ** autoheader warnings
374 The warnings of autoheader can be turned off, using --warning.
375 For instance, -Wno-obsolete disables the complaints about acconfig.h
376 and other deprecated constructs.
379 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
382 ** AC_DECL_SYS_SIGLIST
386 Now checks that mktime is the inverse of localtime.
388 ** Improve DJGPP portability
389 The Autoconf tools and configure behave better under DJGPP.
391 ** Present But Cannot Be Compiled
392 New FAQ section dedicated to the mystic
394 configure: WARNING: pi.h: present but cannot be compiled
395 configure: WARNING: pi.h: check for missing prerequisite headers?
396 configure: WARNING: pi.h: proceeding with the preprocessor's result
399 ** Concurrent executions of autom4te
400 autom4te now locks its internal files, which enables concurrent
401 executions of autom4te, likely to happen if automake, autoconf,
402 autoheader etc. are run simultaneously.
405 Use of Libtool 1.5 and higher is encouraged. Compatibility with
406 Libtool pre-1.4 is not checked.
409 Testsuites no longer rerun failed tests in verbose mode; instead,
410 failures are logged while the test is run.
412 In addition, expected failures can be marked as such.
414 * Major changes in Autoconf 2.57
416 Released 2002-12-03 by Paul Eggert.
418 Bug fixes for problems with AIX linker, with freestanding C compilers,
419 with GNU M4 limitations, and with obsolete copies of GNU documents.
421 The Free Documentation License has been upgraded from 1.1 to 1.2.
423 * Major changes in Autoconf 2.56
425 Released 2002-11-15 by Akim Demaille.
427 One packaging problem fixed (config/install-sh was not executable).
429 * Major changes in Autoconf 2.55
431 Released 2002-11-14 by Akim Demaille.
435 Have your configure.ac checked by autoscan ("autoscan").
436 Try the warning options ("autoreconf -fv -Wall").
440 - AC_CHECK_HEADER, AC_CHECK_HEADERS
441 More information on proper use.
443 - Writing Test Programs
445 This sections explains how to write good test sources to use with
446 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
448 - AC_FOO_IFELSE vs. AC_TRY_FOO
450 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
451 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
455 - Is more robust to different Gettext installations.
457 - Produces messages (when --verbose) to be understood by Emacs'
460 - Supports -W/--warnings.
463 Once the GNU Build System reinstalled, run `./config.status
464 --recheck && ./config.status && make' if possible.
468 - Supports --cache, and --no-cache.
470 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
471 (autom4te.cache). See `Customizing autom4te' in the documentation.
478 Support for the obsoleted options -m, --macrodir, -l, --localdir is
479 dropped in favor of the safer --include/--prepend-include scheme.
484 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
485 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
486 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
489 Obsoleted macros are kept for Autoconf backward compatibility, but
490 should be avoided in configure.ac. Running autoupdate is advised.
493 - AC_DEFINE/AC_DEFINE_UNQUOTED
495 We have to stop using the old compatibility scheme --that tried to
496 avoid useless backslashes-- because Libtool 1.4.3 contains a
498 AC_DEFINE([error_t], [int],
499 [Define to a type to use for \`error_t' if it is not
500 otherwise available.])
502 We have to quote the single quotes and backslashes with \. The old
503 compatibility scheme saw that ` was backslashed, and therefore did
504 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
505 compatible with Libtool. Autoconf 2.55 is, but in some cases might
506 produce more \ than wanted.
508 Please, note that in the future the same problem will happen with
509 AC_MSG_*: use `autoreconf -f -Wall'.
513 - Portability of the Autoconf package to Solaris.
515 - Spurious warnings caused by config.status.
516 This bug is benign, but painful: on some systems (typically
517 FreeBSD), warnings such as:
519 config.status: creating Makefile
520 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
522 could be issued. This is fixed.
525 Simultaneous executions of config.status are possible again.
527 - Precious variables accumulation
529 config.status could stack several copies of the precious variables
533 ** Plans for later versions
537 The compatibility hooks with the old scheme will be completely
538 removed. Please, advice/use `--build', `--host', and `--target'
541 - AC_CHECK_HEADER, AC_CHECK_HEADERS
543 The tests will be stricter, please make sure your invocations are
548 Shell functions will gradually be introduced, probably starting with
549 Autotest. If you know machines which are in use that you suspect
550 *not* to support shell functions, please run the test suite of
551 Autoconf 2.55 on it, and report the results to
552 bug-autoconf@gnu.org.
556 Special characters in AC_MSG_* need not be quoted. Currently,
557 Autoconf has heuristics to decide when a string is escaped, or has
558 to be escaped. This scheme is fragile, and will be removed; the
559 only risk is uglified messages. Please, run `autoreconf -f -Wall'
560 to find occurrences that will be affected.
562 * Major changes in Autoconf 2.54
564 Released 2002-09-13 by Akim Demaille.
568 - autoreconf no longer changes the version of the gettext/po/intl
569 support files. It now adds the files the correspond to the
570 AM_GNU_GETTEXT_VERSION declared in configure.ac.
572 Warning: It now relies on the 'autopoint' program, which is part
573 of GNU gettext 0.11.4 and newer.
575 Please note that you need to have a GNU gettext version that
576 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
577 in configure.ac. You can upgrade to newer GNU gettext versions,
578 though, without needing to change configure.ac.
580 - The -I DIR or --include=DIR option now appends DIR to the include path
581 instead of prepending; this is for consistency with other GNU tools.
582 The new -B DIR or --prepend-include=DIR option has the old behavior.
587 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
588 Please, remove lines such as
590 # This is necessary so that .o files in LIBOBJS are also
591 # built via the ANSI2KNR-filtering rules.
592 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
594 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
595 your Makefiles either.
597 - AC_CONFIG_LINKS now makes copies if it can't make links.
599 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
600 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
601 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
603 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
605 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
607 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
611 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
612 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
613 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
616 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
619 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
620 for an AC_LIBOBJ replacement.
624 - Spurious complaints from `m4_bmatch' about invalid regular
625 expressions are suppressed.
627 - Empty top_builddirs are properly handled.
629 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
632 Now colon in the optional path arguments are properly handled.
634 ** Improved portability
636 - Both Autoconf the package, and the scripts it produces, should run
637 more reliably with Zsh. Bear in mind it is the default Bourne shell
640 - Autoconf and the scripts it produces no longer assume the existence of
641 the obsolescent commands egrep and fgrep.
645 - Limitations of Make
649 The GNATS base moved to
650 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
651 (It is no longer available, though.)
656 Now contains the list of ouput variables and files (AC_SUBST,
659 * Major changes in Autoconf 2.53
661 Released 2002-03-08 by Akim Demaille.
665 Perl 5.005_03 or later is required: autom4te is written in Perl and is
666 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
672 Argument requirements, output variables, defined macros.
673 - M4sugar, M4sh, Autotest
675 - Double quoting macros
676 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
678 The Autoconf manual is now distributed under the terms of the GNU FDL.
679 - Section `Hosts and Cross-Compilation'
680 Explains the rationale for the 2.5x changes in the cross-compilation
681 chain, and in the relationships between build, host, and target
683 Emphasizes that `cross-compilation' == `--host is given'.
684 If you are working on compilers etc., be sure to read this section.
685 - Section `AC_LIBOBJ vs. LIBOBJS'
686 Explains why assigning LIBOBJS directly is now an error.
687 Details how to update the code.
692 Now used instead of hard coded line numbers.
693 This eases the comparison of `configure's, and diminishes the
694 pressure over control version archives.
695 Automatic replacement for shells that don't support this feature.
696 - New output variables
697 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
702 Autoconf and Autotest modes are provided.
707 New, used by the Autoconf suite to cache and speed up most processing.
709 Supported by autom4te, autoconf and autoheader.
711 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
712 autoupdate, and autoreconf.
714 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
715 automake options are to be given via AUTOMAKE_OPTIONS.
717 Runs gettextize and libtoolize when appropriate.
719 --m4dir is no longer supported.
721 Now runs only in the specified directories, defaulting to `.',
722 but understands AC_CONFIG_SUBDIRS for dependent directories.
723 Before, it used to run on all the `configure.ac' found in the
725 Independent packages are properly updated.
729 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
731 Under the user pressure, $? is finally available. Probably a mistake.
732 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
733 - Precious variables accumulation
734 config.status could stack several copies of the precious variables
736 - AC_PATH_PROG and family.
737 Works properly when given a literal path.
739 Somewhere since 2.13, the result had been reversed.
743 - AC_C_BIGENDIAN supports the cross-compiling case.
744 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
745 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
746 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
748 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
749 precision than `double'.
754 It now defines the preprocessor symbols PACKAGE_NAME,
755 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
759 Admits a fourth optional parameter: the tar name.
761 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
762 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
763 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
766 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
767 Are much less expensive when using long lists of files.
770 Works with shell variables, and non alphanumeric names.
774 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
775 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
777 - AC_FUNC_STRTOD substitutes POW_LIB.
782 * Major changes in Autoconf 2.52
784 Released 2001-07-18 by Akim Demaille.
789 This feature was present in autoconf 2.50 but was not documented.
790 For example, `@<:@' is translated to `[' just before output. This
791 is useful when writing strings that contain unbalanced quotes, or
792 other hard-to-quote constructs.
793 - m4_pattern_forbid, m4_pattern_allow
794 - Tips for upgrading from 2.13.
795 - Using autoscan to maintain a configure.ac.
798 - Now include stdint.h.
799 - sys/types.h and sys/stat.h are guarded.
800 - strings.h is included if available, and not conflicting with string.h.
803 - The test suite is more robust and presents less false failures.
804 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
805 - configure accepts --prefix='' again.
806 - AC_CHECK_LIB works properly when its first argument is not a
808 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
809 - build_, host_, and target_alias are AC_SUBST as in 2.13.
810 - AC_ARG_VAR properly propagates precious variables inherited from the
811 environment to ./config.status.
812 - Using --program-suffix/--program-prefix is portable.
813 - Failures to detect the default compiler's output extension are less
815 - `config.status foo' works properly when `foo' depends on variables
816 set in an AC_CONFIG_THING INIT-CMD.
817 - autoheader is more robust to broken input.
818 - Fixed Fortran name-mangling and link tests on a number of systems,
819 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
822 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
823 specify pre-includes. In this case, the headers are compiled with
824 cc, not merely preprocessed by cpp. Therefore it is the _usability_
825 of a header which is checked for, not just its availability.
826 - AC_ARG_VAR refuses to run configure when precious variables have
828 - Versions of compilers are dumped in the logs.
829 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
832 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
833 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
834 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
835 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
836 Be sure to read `Upgrading from Version 2.13' to understand why
837 running `autoupdate' is needed.
838 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
839 a main-like routine is required/possible when linking C/C++ with
840 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
841 - AC_FUNC_GETPGRG behaves better when cross-compiling.
843 * Major changes in Autoconf 2.51
844 There was no release of Autoconf 2.51 since some packagers had used
845 this version number without permission to ship intermediary versions
846 of 2.50. The version was skipped to avoid confusion.
848 * Major changes in Autoconf 2.50
850 Released 2001-05-21 by Akim Demaille.
853 There have been far too many to enumerate them here. Check out
854 ChangeLog if you really want to know more.
856 ** Improved documentation
857 In particular, portability issues are better covered.
860 All the standard GNU Makefile targets are supported. The layout has
861 changed: m4/ holds the M4 extensions Autoconf needs for its
862 configuration, doc/ contains the documentation, and tests/ contains
865 ** Man pages are provided
866 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
867 config.guess, config.sub.
871 Provides a safe and powerful means to trace the macro uses. This
872 provide the parsing layer for tools which need to `study'
876 Specify what category of warnings should be enabled.
878 - When recursing into subdirectories, try for configure.gnu before
879 configure to adapt for packages not using autoconf on case-insensitive
883 More errors are now caught (circular AC_REQUIRE dependencies,
884 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
885 etc.). In addition, their location and call stack are given.
888 autoupdate is much more powerful, and is able to provide the glue code
889 which might be needed to move from an old macro to its newer
892 You are strongly encouraged to use it to modernize both your
893 `configure.in' and your .m4 extension files.
896 The internal machinery of autoheader has completely changed. As a
897 result, using `acconfig.h' should be considered to be obsoleted, and
898 you are encouraged to get rid of it using the AH macros.
903 ** Fortran 77 compilers
904 Globally, the support for Fortran 77 is considerably improved.
906 Support for automatically determining a Fortran 77 compiler's
907 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
908 provided to wrap C/C++ identifiers, thus making it easier and more
909 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
910 call C/C++ routines. See the Texinfo documentation for details.
913 The test suite no longer uses DejaGNU. It should be easy to submit
914 test cases in this new framework.
917 - --help, --help=long, -hl
918 no longer dumps useless items.
920 lists only specific options.
921 - --help=recursive, -hr
922 displays the help of all the embedded packages.
923 - Remembers environment variables when reconfiguring.
924 The previous scheme to set envvar before running configure was
926 what prevented configure from remembering the environment in which
927 it was run, therefore --recheck was run in an inconsistent
928 environment. Now, one should run
930 and then --recheck will work properly. Variables declared with
931 AC_ARG_VAR are also preserved.
933 $build defaults to `config.guess`, $host to $build, and then $target
935 Cross-compilation is a global status of the package, it no longer
936 depends upon the current language.
937 Cross compilation is enabled iff the user specified `--host'.
938 `configure' now fails if it can't run the executables it compiles,
939 unless cross-compilation is enabled.
941 The cache file is disabled by default. The new options
942 `--config-cache', `-C' set the cache to `config.cache'.
946 Much faster on most architectures.
947 - concurrent executions
948 It is safe to use `make -j' with config.status.
949 - human interface improved
950 It is possible to invoke
951 ./config.status foobar
952 instead of the former form (still valid)
953 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
954 CONFIG_FILES=foobar:foo.in:bar.in \
956 The same holds for configuration headers and links.
957 You can instantiate unknown files and headers:
958 ./config.status --header foo.h:foo.h.in --file bar:baz
959 - has a useful --help
960 - accepts special file name "-" for stdin/stdout
965 Specify additional copyright information.
968 Now expects the identity of the package as argument.
972 Most macros, if not all, now strictly follow the `one quotation
973 level' rule. This results in a more predictable expansion.
976 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
977 configure scripts, was fixed by Axel Thimm.
981 Document and ask for the registration of an envvar.
984 Specifies the file which `configure' should look for when trying to
985 find the source tree (used to be handled by AC_INIT).
988 To add new actions to config.status. Should be used instead of
992 Replaces AC_LINK_FILES.
994 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
995 AC_CONFIG_LINKS, and AC_CONFIG_FILES
996 They now obey sh: you should no longer use shell variables as
999 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1000 AC_CONFIG_SUBDIRS($my_subdirs)
1004 if test "$package_foo_enabled" = yes; then
1005 AC_CONFIG_SUBDIRS(foo)
1009 To format an Autoconf macro's help string so that it looks pretty
1010 when the user executes `configure --help'.
1013 ** Generic Test Macros
1015 The interface of the AC_CHECK families of macros (decl, header,
1016 type, member, func) is now uniform. They support the same set of
1019 - AC_CHECK_DECL, AC_CHECK_DECLS
1020 To check whether a symbol is declared.
1022 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1023 No longer need a cross-compilation default.
1026 The test it performs is much more robust than previously, and makes
1027 it possible to test builtin types in addition to typedefs.
1028 It is now schizophrenic:
1029 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1030 remains for backward compatibility, but its use is discouraged.
1031 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1032 behaves exactly like the other AC_CHECK macros.
1035 Checks whether given types are supported by the system.
1037 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1038 Check for given members in aggregates (e.g., pw_gecos in struct
1042 Checks if the compiler supports ISO C, included when needs special
1046 Checking whether the preprocessor indicates missing includes by the
1047 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1050 Takes a language as argument and replaces AC_LANG_C,
1051 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1053 - AC_LANG_PUSH, AC_LANG_POP
1054 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1057 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1058 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1059 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1063 Sets GETGROUPS_LIBS.
1065 - AC_FUNC_GETLOADAVG
1066 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1069 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1072 Arrange for large-file support.
1074 - AC_EXEEXT, AC_OBJEXT
1075 You are no longer expected to use them: their computation is
1076 performed by default.
1078 ** C++ compatibility
1079 Every macro has been revisited in order to support at best CC=c++.
1081 Major changes in Autoconf 2.14:
1082 There was no release of GNU Autoconf 2.14.
1084 Major changes in Autoconf 2.13:
1086 Released 1999-05-01 by Ben Elliston.
1088 * Support for building on Win32 systems where the only available C or
1089 C++ compiler is the Microsoft Visual C++ command line compiler
1090 (`cl'). Additional support for building on Win32 systems which are
1091 using the Cygwin or Mingw32 environments.
1092 * Support for alternative object file and executable file extensions.
1093 On Win32, for example, these are .obj and .exe. These are discovered
1094 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1095 @EXEEXT@ in the output, respectively.
1096 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1097 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1098 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1099 * AC_DEFINE now has an optional third argument for a description to be
1100 placed in the config header input file (e.g. config.h.in).
1101 * The C++ code fragment compiled for the C++ compiler test had to be
1102 improved to include an explicit return type for main(). This was
1103 causing failures on systems using recent versions of the EGCS C++
1105 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1106 script to report that `sometype_t' was present when only `type_t'
1108 * Merge of the FSF version of config.guess and config.sub to modernize
1109 these scripts. Add support for a few new hosts in config.guess.
1110 Incorporate latest versions of install-sh, mkinstalldirs and
1111 texinfo.tex from the FSF.
1112 * autoreconf is capable of running automake if necessary (and
1114 * Support for Fortran 77. See the Texinfo documentation for details.
1115 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1117 Major changes in Autoconf 2.12:
1119 Released 1996-11-26 by David J. MacKenzie
1121 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1122 concatenating multiple input files separated by colons, like so:
1123 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1124 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1125 The arguments may be shell variables, to compute the lists on the fly.
1126 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1127 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1130 Major changes in Autoconf 2.11:
1132 Released November 18th, 1996, by David J. MacKenzie
1134 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1135 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1136 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1137 * AC_CONFIG_HEADER expands shell variables in its argument.
1138 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1139 * The "checking..." messages and the source code for test programs that
1140 fail are saved in config.log.
1141 * Another workaround has been added for seds with small command length limits.
1142 * config.sub and config.guess recognize more system types.
1145 Major changes in Autoconf 2.10:
1147 Released May 7th, 1996, by Roland McGrath
1150 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1151 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1153 Major changes in Autoconf 2.9:
1155 Released March 16th, 1996, by Roland McGrath
1159 Major changes in Autoconf 2.8:
1161 Released March 8th, 1996, by Roland McGrath
1165 Major changes in Autoconf 2.7:
1167 Released November 22nd, 1995, by David J. MacKenzie
1171 Major changes in Autoconf 2.6:
1173 Released November 20th, 1995, by David J. MacKenzie
1177 Major changes in Autoconf 2.5:
1179 Released November 17th, 1995, by Roland McGrath
1181 * New configure options --bindir, --libdir, --datadir, etc., with
1182 corresponding output variables.
1183 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1184 * config.log contains the command being run as well as any output from it.
1185 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1186 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1187 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1188 AC_CHECK_TOOL can search a path other than $PATH.
1189 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1191 Major changes in Autoconf 2.4:
1193 Released June 14th, 1995, by David J. MacKenzie
1195 * Fix a few bugs found by Emacs testers.
1197 Major changes in Autoconf 2.3:
1199 Released March 27th, 1995, by David J. MacKenzie
1201 * Fix the cleanup trap in several ways.
1202 * Handle C compilers that are picky about option placement.
1203 * ifnames gets the version number from the right directory.
1205 Major changes in Autoconf 2.2:
1207 Released March 8th, 1995, by David J. MacKenzie
1209 * The ifnames utility is much faster but requires a "new awk" interpreter.
1210 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1211 library before existing libs, not after, in case it uses them.
1212 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1213 * Lots of bug fixes.
1214 * Many additions to the TODO file :-)
1216 Major changes in Autoconf 2.1:
1218 Released November 4th, 1994, by David J. MacKenzie
1221 * More explanations in the manual.
1222 * Fix a spurious failure in the testsuite.
1223 * Clarify some warning messages.
1224 * autoreconf by default only rebuilds configure and config.h.in files
1225 that are older than any of their particular input files; there is a
1226 --force option to use after installing a new version of Autoconf.
1228 Thanks to everybody who's submitted changes and additions to Autoconf!
1229 I've incorporated many of them, and am still considering others for
1230 future releases -- but I didn't want to postpone this release indefinitely.
1232 Caution: don't indiscriminately rebuild configure scripts with
1233 Autoconf version 2. Some configure.in files need minor adjustments to
1234 work with it; the documentation has a chapter on upgrading. A few
1235 configure.in files, including those for GNU Emacs and the GNU C
1236 Library, need major changes because they relied on undocumented
1237 internals of version 1. Future releases of those packages will have
1238 updated configure.in files.
1240 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1241 Autoconf now makes heavy use of M4 diversions, which were implemented
1242 inefficiently in GNU M4 releases before 1.3.
1244 Major changes in Autoconf 2.0:
1246 Released October 26th, 1994, by David J. MacKenzie
1248 ** New copyright terms:
1249 * There are no restrictions on distribution or use of configure scripts.
1252 * Autoconf manual is reorganized to make information easier to find
1253 and has several new indexes.
1254 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1257 * autoscan to generate a preliminary configure.in for a package by
1258 scanning its source code for commonly used nonportable functions,
1259 programs, and header files.
1260 * ifnames to list the symbols used in #if and #ifdef directives in a
1262 * autoupdate to update a configure.in to use the version 2 macro names.
1263 * autoreconf to recursively remake configure and configuration header
1264 files in a source tree.
1266 ** Changed utilities:
1267 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1268 * autoconf and autoheader can look for package-local definition files
1269 in an alternate directory.
1272 * AC_CACHE_VAL to share results of tests between configure runs.
1273 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1274 that macros invoked with AC_REQUIRE don't interrupt other macros.
1275 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1276 support deciding unguessable features based on the host and target types.
1277 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1278 * AC_ARG_PROGRAM to use the options --program-prefix,
1279 --program-suffix, and --program-transform-name to change the names
1280 of programs being installed.
1281 * AC_PREFIX_DEFAULT to change the default installation prefix.
1282 * AC_TRY_COMPILE to compile a test program without linking it.
1283 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1284 * AC_CHECK_LIB to check for a particular function and library.
1285 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1286 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1287 * AC_SUBST_FILE to insert one file into another.
1288 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1289 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1290 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1291 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1294 * Many macros renamed systematically, but old names are accepted for
1295 backward compatibility.
1296 * AC_OUTPUT adds the "automatically generated" comment to
1297 non-Makefiles where it finds @configure_input@ in an input file, to
1298 support files with various comment syntaxes.
1299 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1300 files when they are not enclosed in @ signs.
1301 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1302 override the file name "config.status".
1303 * AC_OUTPUT takes an optional argument for passing variables from
1304 configure to config.status.
1305 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1306 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1307 CPPFLAGS, and LDFLAGS from the environment.
1308 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1309 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1310 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1311 srcdir/../.. by default.
1312 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1313 * AC_DEFINE no longer prints anything, because of the new result reporting
1314 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1315 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1316 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1317 --enable- and --with- options.
1318 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1319 execute on success or failure.
1320 * Checking for C functions in C++ works.
1323 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1324 better maintained with them.
1325 * AC_ARG_ARRAY removed because no one was likely using it.
1326 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1327 take arguments, for consistency with all of the other specific checks.
1330 * Comes with config.sub and config.guess, and uses them optionally.
1331 * Uses config.cache to cache test results. An alternate cache file
1332 can be selected with the --cache-file=FILE option.
1333 * Uses optional shell scripts $prefix/share/config.site and
1334 $prefix/etc/config.site to perform site or system specific initializations.
1335 * configure saves compiler output to ./config.log for debugging.
1336 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1337 * acsite.m4 is the new name for the system-wide aclocal.m4.
1338 * Has a DejaGnu test suite.
1340 Major changes in Autoconf 1.11:
1342 * AC_PROG_INSTALL calls install.sh with the -c option.
1343 * AC_SET_MAKE cleans up after itself.
1344 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1345 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1347 Plus a few other bug fixes.
1349 Major changes in Autoconf 1.10:
1351 * autoheader uses config.h.bot if present, analogous to config.h.top.
1352 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1354 * AC_PROG_CXX looks for cxx as a C++ compiler.
1356 Plus several bugs fixed.
1358 Major changes in Autoconf 1.9:
1360 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1361 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1362 and autoheader generates entries for those names automatically.
1363 * AC_FIND_X gets the result from xmkmf correctly.
1364 * AC_FIND_X assumes no X if --without-x was given.
1365 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1366 * AC_PROG_INSTALL finds OSF/1 installbsd.
1368 Major changes in Autoconf 1.8:
1371 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1372 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1373 for checking both C++ and C features in one configure script.
1374 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1375 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1376 AC_SET_MAKE, AC_ENABLE.
1379 * AC_FIND_X looks for X in more places.
1380 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1381 install.sh is distributed with Autoconf.
1382 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1383 a rewrite of quoting in AC_DEFINE.
1384 * AC_OUTPUT adds its comments in C format when substituting in C files.
1385 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1387 ** New or changed command line options:
1388 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1389 * configure accepts --without-PACKAGE, which sets withval=no.
1390 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1391 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1392 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1393 * configure accepts and ignores most other Cygnus configure options, and
1394 warns about unknown options.
1395 * config.status accepts --help, --version options.
1397 ** File names and other changes:
1398 * Relative srcdir values are not made absolute.
1399 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1400 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1401 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1402 * The example Makefile dependencies for configure et al. work better.
1403 * Namespace cleanup: all shell variables used internally by Autoconf
1404 have names beginning with `ac_'.
1406 More big improvements are in process for future releases, but have not
1407 yet been (variously) finished, integrated, tested, or documented enough
1410 Major changes in Autoconf 1.7:
1412 * New macro AC_OBSOLETE.
1413 * Bugs in Makefile.in fixed.
1414 * AC_LONG_FILE_NAMES improved.
1416 Major changes in Autoconf 1.6:
1418 * New macro AC_LONG_64_BITS.
1419 * Multiple .h files can be created.
1420 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1421 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1422 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1423 * Unused --no-create option to configure removed.
1424 * autoheader doesn't change the timestamp of its output file if
1425 the file didn't change.
1426 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1427 * config.status checks three optional environment variables to
1428 modify its behavior.
1429 * The usual bug fixes.
1431 Major changes in Autoconf 1.5:
1433 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1434 * autoconf and autoheader scripts have GNU standards conforming
1435 --version and --help options (they print their message and exit).
1438 Major changes in Autoconf 1.4:
1440 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1441 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1442 * autoconf and autoheader use the M4 environment variable to determine the
1443 name of the M4 program to use.
1444 * The --macrodir option to autoconf and autoheader specifies the directory
1445 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1446 * autoconf and autoheader can take `-' as their file names, which means to
1447 read stdin as input.
1448 * Resulting configure scripts can take a --verbose option which causes them
1449 to print the results of their tests.
1450 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1451 shell characters, etc. will be preserved during various stages of
1452 expansion done by the shell. If you don't want this, use
1453 AC_DEFINE_UNQUOTED instead.
1454 * Much textual processing done with external calls to tr and sed have been
1455 internalized with builtin M4 `patsubst' and `translit' calls.
1456 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1457 set the shell variables `gen_files' and `gen_config' to the list of
1458 file names to output.
1459 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1460 "lex.yy" or "lexyy", depending on the system.
1461 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1463 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1464 * AC_CONST works much more reliably on more systems.
1467 Major changes in Autoconf 1.3:
1469 configure no longer requires awk for packages that use a config.h.
1470 Support handling --with-PACKAGE options.
1471 New `autoheader' script to create `config.h.in' from `configure.in'.
1472 Ignore troublesome -lucb and -lPW when searching for alloca.
1473 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1474 Improve detection of STDC library.
1475 Add AC_HAVE_LIBRARY to check for non-default libraries.
1476 Function checking should work with future GNU libc releases.
1478 Major changes in Autoconf 1.2:
1480 The --srcdir option is now usually unnecessary.
1481 Add a file containing sample comments describing CPP macros.
1482 A comment in config.status tells which host it was configured on.
1483 Substituted variable values can now contain commas.
1484 Fix bugs in various feature checks.
1486 Major changes in Autoconf 1.1:
1488 Added AC_STRCOLL macro.
1489 Made AC_GETLOADAVG check for more things.
1490 AC_OUTPUT argument is now optional.
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1496 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
1498 This file is part of GNU Autoconf.
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1507 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1508 GNU General Public License for more details.
1510 You should have received a copy of the GNU General Public License
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1513 Boston, MA 02110-1301, USA.