1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.61b (????-??-??)
5 ** Many optimizations have been applied to make overall execution faster.
7 ** Autotest now makes use of shell functions.
9 ** config.status now uses awk instead of sed also for config headers.
11 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
12 values, i.e., backslash-newline combinations are handled correctly.
13 Further, for config headers, the total size of values is not limited by
14 the POSIX length limit of text lines any more, only each single line.
16 ** Autoconf is now licensed under the General Public License version 3
17 or later (GPLv3+). As with earlier versions, the license includes
18 an exception clause so that you may release a configure script
19 generated by autoconf under the license of your own program.
20 FIXME - revisit this line once exception clause is finalized.
22 ** New Autoconf macros:
23 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
25 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
27 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
28 like '__restrict' if the variant spelling is available, as this is
29 more likely to work when mixing C and C++ code.
31 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
32 be a string of tokens such that "T y;" is a valid member declaration
35 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
36 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
38 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
39 they did not work for function types. In C++, they now work on any
40 type-id that can be the operand of sizeof; this is similar to C,
41 except it excludes anonymous struct and union types. Formerly,
42 some (but not all) C++ types involving anonymous struct and union
43 were accepted, though this was not documented.
45 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
46 if found, and it works to link against a file of the same name in
47 the source tree, even if both trees coincide.
49 ** AC_INIT no longer alters $@; regression introduced in 2.60.
51 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
53 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
54 the case where the first argument contains single-quoted commas.
55 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
56 " -a, --arg=[foo] bar"
57 Additionally, the macro now takes two additional arguments,
58 indent-column and wrap-column; these should not normally be needed,
59 but can be used to fine-tune how the output text is wrapped.
61 ** The command 'autoconf -' now correctly processes a file from stdin.
63 ** For all of the directory arguments for 'configure', such as '--prefix'
64 or '--bindir', trailing slashes are stripped. As an example, if
65 tab completion in the user's shell appends trailing slashes, the
66 command './configure --prefix=/usr/' will still result in an
67 expanded libdir value of /usr/lib, not /usr//lib.
69 ** AT_SETUP now handles macro expansions properly when calculating line
72 ** Autotest now determines $srcdir correctly.
74 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
75 a bug in macro tracing that interferes with the interaction between
76 Autoconf and Automake. GNU M4 1.4.8 or later is recommended. The
77 configure search for a working M4 is improved.
79 ** Documentation for m4sugar is improved.
81 - The following macros were previously available as undocumented
82 interfaces; the macros are now documented as stable interfaces.
84 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
85 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
86 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
87 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
88 m4_n m4_shiftn m4_strip m4_warn
90 - The following macros were previously available as undocumented
91 interfaces, but had bug fixes or semantic changes as part of this
92 release. Packages that relied on the undocumented behavior
93 should be analyzed to make sure they will still work with the
94 new documented behavior.
96 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
97 m4_text_box m4_text_wrap m4_version_compare
99 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
100 should consider using the new AC_AUTOCONF_VERSION instead.
102 - m4sugar macros that are not documented in the manual are still
103 deemed experimental, and should not be used outside of Autoconf.
105 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
106 2.60, have been fixed to treat both the string and the separator
107 arguments consistently with regards to quoting. Prior to this fix,
108 m4_append_uniq could mistakenly duplicate entries if the expansion
109 of the separator resulted in a different string (for example, if it
110 contained quotes, a comma, or a macro name). However, it means
111 that programs previously using
112 m4_append([name], [string], [[, ]])
113 are now using a four-character separator instead of the intended
114 comma and space. If you need portability to earlier versions of
115 Autoconf, you can insert the following snippet after AC_INIT but
116 before any other macro expansions, to enforce the new semantics:
117 m4_pushdef([m4_append], [m4_define([$1],
118 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
119 Additionally, m4_append_uniq now takes optional parameters that can
120 be used to take action depending on whether anything was appended.
122 ** The following m4sugar macros are new:
123 m4_apply m4_cond m4_count m4_dquote_elt m4_echo m4_expand
124 m4_ignore m4_make_list m4_max m4_min m4_newline m4_shift2
127 ** Warnings are now generated by default when an installer invokes
128 'configure' with an unknown --enable-* or --with-* option.
129 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
130 macro, or by invoking 'configure' with --disable-option-checking.
132 ** For portability with the eventual M4 2.0, macros should no longer use
133 anything larger than $9 to refer to arguments.
135 ** Existing obsolete macros
136 The documentation for the following macros is adjusted to make it
137 more clear that they have previously been marked obsolete, as their
138 functionality can be accomplished by other macros. We have no
139 current plans to remove them from Autoconf.
141 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
143 ** Newly obsolete macros
144 The following macros have been marked obsolete, as they only
145 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
146 plans to remove them.
148 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
150 ** AC_C_LONG_DOUBLE is obsolescent.
151 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
152 tests for problems that are so old that it is no longer of
153 practical importance on current systems. New programs need not use
154 AC_C_LONG_DOUBLE. We have no current plans to remove it.
156 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
157 The documentation now favors the use of M4sugar macros m4_warn and
158 m4_fatal, since the naming makes it more obvious that the
159 diagnostics are associated with M4 expansion (ie. when running
160 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
161 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
162 when running `configure'. We have no current plans to remove these
165 * Major changes in Autoconf 2.61a (2006-12-11)
167 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
168 on many platforms. This has been fixed.
170 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
171 compatibility but it does nothing. The macro was already
172 obsolescent, as the last systems to have the problem were those
173 based on SVR2, which became obsolete in 1987. The macro had bugs
174 on some modern systems and could no longer be maintained reliably
175 due to lack of ancient systems to test it on.
177 ** config.status now uses awk instead of sed for most substitutions, for speed.
179 - As a side effect multi-line values of substituted variables no
180 longer have a small limit in total size, though for portability
181 each line should not exceed the POSIX length limit for text lines.
183 - It is now documented that Makefile.in should not contain
184 overlapping variable occurrences, e.g., @VAR1@VAR2@.
185 Autoconf's behavior was always iffy in such cases, and the
186 awk implementation has changed the behavior.
188 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
189 scripts have fewer problems with strings or file names containing
190 embedded special characters such as backslash or leading "-". This
191 was implemented by using `printf '%s\n' "$foo"' instead of `echo
192 "$foo"' when printf works. Due to the implementation technique
193 used, Autoconf-generated scripts now run considerably more slowly
194 on ancient implementations lacking printf. However, this should
195 not be a problem, since Autoconf-generated scripts in practice
196 invariably find a more-modern shell these days.
198 * Major changes in Autoconf 2.61 (2006-11-17)
200 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
202 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
204 * Major changes in Autoconf 2.60b (2006-10-22)
207 Autoconf-generated shell scripts no longer export BIN_SH, due to
208 configuration hassles with this. Installers who need BIN_SH in
209 their environment should set it before invoking 'configure' and
210 'make'. As far as we know, this affects only Unixware installations.
212 ** Obsolescent macros
213 The documentation now says that the following macros are obsolescent,
214 as they are superseded by Gnulib:
216 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
218 New programs should use the Gnulib counterparts of these macros.
219 We have no current plans to remove them from Autoconf.
221 ** AC_COMPUTE_INT no longer caches or reports results.
223 ** AC_CHECK_DECL now also works with aggregate objects.
225 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
227 ** GNU M4 1.4.7 or later is now recommended.
230 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
233 Now an alias for m4_mkstemp.
235 * Major changes in Autoconf 2.60a (2006-08-25)
237 ** GNU M4 1.4.6 or later is now recommended.
239 ** The check for C99 now tests for varargs macros, as documented.
240 It also tests that the preprocessor supports 64-bit integers.
242 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
243 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
245 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
246 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
247 two macros are different, so autoupdate will not change the old private name
248 to the new one. _AC_COMPUTE_INT may be removed in a future release.
250 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
251 that long long types be at least 64 bits wide, as C99 and tradition
252 requires. Formerly, they accepted implementations of any width.
255 * Major changes in Autoconf 2.60
257 Released 2006-06-23, by Ralf Wildenhues.
259 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
260 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
261 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
263 ** Provide a way to turn off warnings about the changed directory variables.
265 * Major changes in Autoconf 2.59d
267 Released 2006-06-05, by Ralf Wildenhues.
269 ** GNU make now recommended for VPATH builds
270 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
271 only if you use GNU make. In practice, other 'make' implementations
272 have too many subtle incompatibilities in their support for VPATH.
273 Many packages (including Autoconf itself) are portable to other
274 'make' implementations, but some packages are not, and recommending
275 GNU make keeps the installation instructions simpler.
277 ** Even more safety checks for the new Directory variables:
278 Warn about suspicious `${datarootdir}' found in config files output.
280 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
281 These never-documented macros and variables have been marked with
282 comments saying that they may be removed in a future release,
283 because their use can lead to unintended code being executed.
284 If you need functionality that only these macros or variables
285 currently supply, please write bug-autoconf@gnu.org.
287 ** AC_SUBST, AC_DEFINE
288 Literal arguments to these are passed to m4_pattern_allow now.
291 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
292 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
293 obsolete K&R tests in the Automake test suite.
302 Now more robust with special characters in file names, or when
303 multiple processes create the same directory at the same time.
305 ** Obsolescent macros
306 The documentation now says that the following macros are obsolescent:
307 they test for problems that are so old that they are no longer of
308 practical importance on current systems.
310 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
311 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
312 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
313 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
314 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
315 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
316 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
317 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
319 New programs need not use these macros. We have no current plans to
323 For compatibility with future Libtool 2.0, autoreconf will invoke
324 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
327 * Major changes in Autoconf 2.59c
329 Released 2006-04-12, by Ralf Wildenhues.
331 ** The configure command now redirects standard input from /dev/null,
332 to help avoid problems with subsidiary commands that might mistakenly
333 read standard input. AS_ORIGINAL_STDIN_FD points to the original
334 standard input before this redirection, if you really want configure to
335 read from standard input.
337 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
338 The following directory variables are new:
340 datarootdir read-only architecture-independent data root [PREFIX/share]
341 localedir locale-specific message catalogs [DATAROOTDIR/locale]
342 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
343 htmldir html documentation [DOCDIR]
344 dvidir dvi documentation [DOCDIR]
345 pdfdir pdf documentation [DOCDIR]
346 psdir ps documentation [DOCDIR]
348 The following variables have new default values:
350 datadir read-only architecture-independent data [DATAROOTDIR]
351 infodir info documentation [DATAROOTDIR/info]
352 mandir man documentation [DATAROOTDIR/man]
354 This means that if you use any of `@datadir@', `@infodir@', or
355 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
356 defined in this file. As a temporary measure, if any of those are
357 found but no mention of `datarootdir', the substitutions will be
358 replaced with values that do not contain `${datarootdir}', and a
359 warning will be issued.
361 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
362 a trailing slash. Similar change will be made to ac_top_builddir in a
363 future release; the old style value, which matches (../)*, is (and will
364 continue to be) available as ac_top_build_prefix.
367 New macro to check for support of 'typeof' syntax a la GNU C.
369 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
370 New "once-only" variants of commonly-used macros, to make 'configure'
371 smaller and faster in common cases.
374 New macro to check for strtold with C99 semantics.
377 New macro that lets builder disable assertions at 'configure'-time.
380 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
381 X11/Intrinsic.h and XtMalloc (Xt).
383 ** AC_PRESERVE_HELP_ORDER
384 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
385 and AC_ARG_WITH arguments in one region, in the order defined. The default
386 behavior is to group options of each classes separately.
388 ** AC_PROG_CC, AC_PROG_CXX
389 No longer automatically arrange to declare the 'exit' function of C,
390 when a C++ compiler is used. Standard Autoconf macros no longer use
391 'exit', so this is no longer an issue for them. If you use C++, and
392 want to call 'exit', you'll have to arrange for its declaration
393 yourself. But we now suggest you return from 'main' instead.
395 ** AC_PROG_CC_C89, AC_PROG_CC_C99
396 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
397 check for ANSI C89 and ISO C99 support respectively.
400 Has been unobsoleted, and will check if the compiler supports ISO
401 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
402 retained for backwards compatibility, assuming the value of
403 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
406 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
407 New macros for checking commonly-used members of struct dirent.
410 The substituted value can now contain newlines.
413 The substitution now occurs only when @variable@ is on a line by itself,
414 optionally surrounded by spaces and tabs. The whole line is replaced.
416 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
417 New macros to check for long double, and whether it is wider than double.
418 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
419 applications should switch to the new macro.
421 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
422 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
423 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
424 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
425 New macros to check for C99 and POSIX types.
427 ** AC_USE_SYSTEM_EXTENSIONS
428 New macro to enable extensions to Posix.
431 New macro which is defined to the name of the first declared config header
432 or undefined if no config headers have been declared yet.
435 The macro correctly handles quadrigraphs now.
437 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
438 These macros are new or published now.
441 New macro for copyright notices in testsuite files.
443 ** ALLOCA, LIBOBJS, LTLIBOBJS
444 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
445 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
446 `Makefile.in' in case the object files lie in a different directory.
447 The LIBOBJDIR feature is experimental.
450 Supports --no-recursive now.
452 ** New macros to support Erlang/OTP.
453 New macros for configuring paths to Erlang tools and libraries:
454 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
455 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
456 AC_ERLANG_SUBST_LIB_DIR.
458 New macros for configuring installation of Erlang libraries:
459 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
461 ** The manual now mentions Gnulib more prominently.
463 ** New macros to support Objective C.
464 AC_PROG_OBJC, AC_PROG_OBJCPP.
466 * Major changes in Autoconf 2.59b
468 Released 2004-08-20, by Paul Eggert.
471 New macro that computes the default alignment of a type.
473 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
474 When cross-compiling, these macros will give a warning if the tool
475 is not prefixed. In the future, unprefixed cross tools will not
476 be detected; please consult the info documentation for information
477 about the reason of this change.
479 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
480 New macros that detect programs whose name is prefixed with the
481 target type, if the build type and target type are different.
483 ** AC_REQUIRE_AUX_FILE
484 New trace macro that declares expected auxiliary files.
487 New macro that tests for a grep program that accepts as a long a line
490 ** AC_PROG_EGREP, AC_PROG_FGREP
491 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
492 FGREP="$GREP -F" respectively if possible, or else run a path search for
493 a program that accepts as long a line as possible.
496 New macro that tests for a sed program that truncates as few characters
499 * Major changes in Autoconf 2.59
501 Released 2003-11-04, by Akim Demaille
503 ** ac_abs_builddir etc.
504 Absolute file names were actually relative in 2.58.
506 * Major changes in Autoconf 2.58
508 Released 2003-11-04, by Akim Demaille
511 core.* files are no longer removed, as they may be valid user files.
513 ** autoreconf and auxiliary directory
514 Autoreconf creates the auxiliary directory if needed. This is
515 especially useful for initial "bootstrapping" of fresh CVS checkouts.
517 ** AC_CONFIG_MACRO_DIR
518 Use this macro to declare the directory for local M4 macros for aclocal.
521 No longer includes twice the same file in LIBOBJS if invoked
524 ** AC_CONFIG_COMMANDS
525 The directory for its first argument is automatically created. For
528 AC_CONFIG_COMMANDS([src/modules.hh], [...])
530 $top_builddir/src/ is created if needed.
532 ** Autotest and local.at
533 The optional file local.at is always included in Autotest test suites.
536 The warnings are always issued, including with cached runs.
537 This became a significant problem since aclocal and automake can
538 run autoconf behind the scene.
540 ** autoheader warnings
541 The warnings of autoheader can be turned off, using --warning.
542 For instance, -Wno-obsolete disables the complaints about acconfig.h
543 and other deprecated constructs.
546 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
549 ** AC_DECL_SYS_SIGLIST
553 Now checks that mktime is the inverse of localtime.
555 ** Improve DJGPP portability
556 The Autoconf tools and configure behave better under DJGPP.
558 ** Present But Cannot Be Compiled
559 New FAQ section dedicated to the mystic
561 configure: WARNING: pi.h: present but cannot be compiled
562 configure: WARNING: pi.h: check for missing prerequisite headers?
563 configure: WARNING: pi.h: proceeding with the preprocessor's result
566 ** Concurrent executions of autom4te
567 autom4te now locks its internal files, which enables concurrent
568 executions of autom4te, likely to happen if automake, autoconf,
569 autoheader etc. are run simultaneously.
572 Use of Libtool 1.5 and higher is encouraged. Compatibility with
573 Libtool pre-1.4 is not checked.
576 Testsuites no longer rerun failed tests in verbose mode; instead,
577 failures are logged while the test is run.
579 In addition, expected failures can be marked as such.
581 * Major changes in Autoconf 2.57
583 Released 2002-12-03 by Paul Eggert.
585 Bug fixes for problems with AIX linker, with freestanding C compilers,
586 with GNU M4 limitations, and with obsolete copies of GNU documents.
588 The Free Documentation License has been upgraded from 1.1 to 1.2.
590 * Major changes in Autoconf 2.56
592 Released 2002-11-15 by Akim Demaille.
594 One packaging problem fixed (config/install-sh was not executable).
596 * Major changes in Autoconf 2.55
598 Released 2002-11-14 by Akim Demaille.
602 Have your configure.ac checked by autoscan ("autoscan").
603 Try the warning options ("autoreconf -fv -Wall").
607 - AC_CHECK_HEADER, AC_CHECK_HEADERS
608 More information on proper use.
610 - Writing Test Programs
612 This sections explains how to write good test sources to use with
613 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
615 - AC_FOO_IFELSE vs. AC_TRY_FOO
617 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
618 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
622 - Is more robust to different Gettext installations.
624 - Produces messages (when --verbose) to be understood by Emacs'
627 - Supports -W/--warnings.
630 Once the GNU Build System reinstalled, run `./config.status
631 --recheck && ./config.status && make' if possible.
635 - Supports --cache, and --no-cache.
637 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
638 (autom4te.cache). See `Customizing autom4te' in the documentation.
645 Support for the obsoleted options -m, --macrodir, -l, --localdir is
646 dropped in favor of the safer --include/--prepend-include scheme.
651 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
652 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
653 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
656 Obsoleted macros are kept for Autoconf backward compatibility, but
657 should be avoided in configure.ac. Running autoupdate is advised.
660 - AC_DEFINE/AC_DEFINE_UNQUOTED
662 We have to stop using the old compatibility scheme --that tried to
663 avoid useless backslashes-- because Libtool 1.4.3 contains a
665 AC_DEFINE([error_t], [int],
666 [Define to a type to use for \`error_t' if it is not
667 otherwise available.])
669 We have to quote the single quotes and backslashes with \. The old
670 compatibility scheme saw that ` was backslashed, and therefore did
671 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
672 compatible with Libtool. Autoconf 2.55 is, but in some cases might
673 produce more \ than wanted.
675 Please, note that in the future the same problem will happen with
676 AC_MSG_*: use `autoreconf -f -Wall'.
680 - Portability of the Autoconf package to Solaris.
682 - Spurious warnings caused by config.status.
683 This bug is benign, but painful: on some systems (typically
684 FreeBSD), warnings such as:
686 config.status: creating Makefile
687 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
689 could be issued. This is fixed.
692 Simultaneous executions of config.status are possible again.
694 - Precious variables accumulation
696 config.status could stack several copies of the precious variables
700 ** Plans for later versions
704 The compatibility hooks with the old scheme will be completely
705 removed. Please, advice/use `--build', `--host', and `--target'
708 - AC_CHECK_HEADER, AC_CHECK_HEADERS
710 The tests will be stricter, please make sure your invocations are
715 Shell functions will gradually be introduced, probably starting with
716 Autotest. If you know machines which are in use that you suspect
717 *not* to support shell functions, please run the test suite of
718 Autoconf 2.55 on it, and report the results to
719 bug-autoconf@gnu.org.
723 Special characters in AC_MSG_* need not be quoted. Currently,
724 Autoconf has heuristics to decide when a string is escaped, or has
725 to be escaped. This scheme is fragile, and will be removed; the
726 only risk is uglified messages. Please, run `autoreconf -f -Wall'
727 to find occurrences that will be affected.
729 * Major changes in Autoconf 2.54
731 Released 2002-09-13 by Akim Demaille.
735 - autoreconf no longer changes the version of the gettext/po/intl
736 support files. It now adds the files the correspond to the
737 AM_GNU_GETTEXT_VERSION declared in configure.ac.
739 Warning: It now relies on the 'autopoint' program, which is part
740 of GNU gettext 0.11.4 and newer.
742 Please note that you need to have a GNU gettext version that
743 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
744 in configure.ac. You can upgrade to newer GNU gettext versions,
745 though, without needing to change configure.ac.
747 - The -I DIR or --include=DIR option now appends DIR to the include path
748 instead of prepending; this is for consistency with other GNU tools.
749 The new -B DIR or --prepend-include=DIR option has the old behavior.
754 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
755 Please, remove lines such as
757 # This is necessary so that .o files in LIBOBJS are also
758 # built via the ANSI2KNR-filtering rules.
759 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
761 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
762 your Makefiles either.
764 - AC_CONFIG_LINKS now makes copies if it can't make links.
766 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
767 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
768 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
770 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
772 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
774 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
778 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
779 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
780 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
783 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
786 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
787 for an AC_LIBOBJ replacement.
791 - Spurious complaints from `m4_bmatch' about invalid regular
792 expressions are suppressed.
794 - Empty top_builddirs are properly handled.
796 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
799 Now colon in the optional path arguments are properly handled.
801 ** Improved portability
803 - Both Autoconf the package, and the scripts it produces, should run
804 more reliably with Zsh. Bear in mind it is the default Bourne shell
807 - Autoconf and the scripts it produces no longer assume the existence of
808 the obsolescent commands egrep and fgrep.
812 - Limitations of Make
816 The GNATS base moved to
817 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
818 (It is no longer available, though.)
823 Now contains the list of ouput variables and files (AC_SUBST,
826 * Major changes in Autoconf 2.53
828 Released 2002-03-08 by Akim Demaille.
832 Perl 5.005_03 or later is required: autom4te is written in Perl and is
833 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
839 Argument requirements, output variables, defined macros.
840 - M4sugar, M4sh, Autotest
842 - Double quoting macros
843 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
845 The Autoconf manual is now distributed under the terms of the GNU FDL.
846 - Section `Hosts and Cross-Compilation'
847 Explains the rationale for the 2.5x changes in the cross-compilation
848 chain, and in the relationships between build, host, and target
850 Emphasizes that `cross-compilation' == `--host is given'.
851 If you are working on compilers etc., be sure to read this section.
852 - Section `AC_LIBOBJ vs. LIBOBJS'
853 Explains why assigning LIBOBJS directly is now an error.
854 Details how to update the code.
859 Now used instead of hard coded line numbers.
860 This eases the comparison of `configure's, and diminishes the
861 pressure over control version archives.
862 Automatic replacement for shells that don't support this feature.
863 - New output variables
864 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
869 Autoconf and Autotest modes are provided.
874 New, used by the Autoconf suite to cache and speed up most processing.
876 Supported by autom4te, autoconf and autoheader.
878 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
879 autoupdate, and autoreconf.
881 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
882 automake options are to be given via AUTOMAKE_OPTIONS.
884 Runs gettextize and libtoolize when appropriate.
886 --m4dir is no longer supported.
888 Now runs only in the specified directories, defaulting to `.',
889 but understands AC_CONFIG_SUBDIRS for dependent directories.
890 Before, it used to run on all the `configure.ac' found in the
892 Independent packages are properly updated.
896 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
898 Under the user pressure, $? is finally available. Probably a mistake.
899 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
900 - Precious variables accumulation
901 config.status could stack several copies of the precious variables
903 - AC_PATH_PROG and family.
904 Works properly when given a literal path.
906 Somewhere since 2.13, the result had been reversed.
910 - AC_C_BIGENDIAN supports the cross-compiling case.
911 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
912 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
913 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
915 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
916 precision than `double'.
921 It now defines the preprocessor symbols PACKAGE_NAME,
922 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
926 Admits a fourth optional parameter: the tar name.
928 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
929 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
930 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
933 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
934 Are much less expensive when using long lists of files.
937 Works with shell variables, and non alphanumeric names.
941 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
942 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
944 - AC_FUNC_STRTOD substitutes POW_LIB.
949 * Major changes in Autoconf 2.52
951 Released 2001-07-18 by Akim Demaille.
956 This feature was present in autoconf 2.50 but was not documented.
957 For example, `@<:@' is translated to `[' just before output. This
958 is useful when writing strings that contain unbalanced quotes, or
959 other hard-to-quote constructs.
960 - m4_pattern_forbid, m4_pattern_allow
961 - Tips for upgrading from 2.13.
962 - Using autoscan to maintain a configure.ac.
965 - Now include stdint.h.
966 - sys/types.h and sys/stat.h are guarded.
967 - strings.h is included if available, and not conflicting with string.h.
970 - The test suite is more robust and presents less false failures.
971 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
972 - configure accepts --prefix='' again.
973 - AC_CHECK_LIB works properly when its first argument is not a
975 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
976 - build_, host_, and target_alias are AC_SUBST as in 2.13.
977 - AC_ARG_VAR properly propagates precious variables inherited from the
978 environment to ./config.status.
979 - Using --program-suffix/--program-prefix is portable.
980 - Failures to detect the default compiler's output extension are less
982 - `config.status foo' works properly when `foo' depends on variables
983 set in an AC_CONFIG_THING INIT-CMD.
984 - autoheader is more robust to broken input.
985 - Fixed Fortran name-mangling and link tests on a number of systems,
986 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
989 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
990 specify pre-includes. In this case, the headers are compiled with
991 cc, not merely preprocessed by cpp. Therefore it is the _usability_
992 of a header which is checked for, not just its availability.
993 - AC_ARG_VAR refuses to run configure when precious variables have
995 - Versions of compilers are dumped in the logs.
996 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
999 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1000 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1001 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1002 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1003 Be sure to read `Upgrading from Version 2.13' to understand why
1004 running `autoupdate' is needed.
1005 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1006 a main-like routine is required/possible when linking C/C++ with
1007 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1008 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1010 * Major changes in Autoconf 2.51
1011 There was no release of Autoconf 2.51 since some packagers had used
1012 this version number without permission to ship intermediary versions
1013 of 2.50. The version was skipped to avoid confusion.
1015 * Major changes in Autoconf 2.50
1017 Released 2001-05-21 by Akim Demaille.
1019 ** Lots of bug fixes
1020 There have been far too many to enumerate them here. Check out
1021 ChangeLog if you really want to know more.
1023 ** Improved documentation
1024 In particular, portability issues are better covered.
1027 All the standard GNU Makefile targets are supported. The layout has
1028 changed: m4/ holds the M4 extensions Autoconf needs for its
1029 configuration, doc/ contains the documentation, and tests/ contains
1032 ** Man pages are provided
1033 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1034 config.guess, config.sub.
1038 Provides a safe and powerful means to trace the macro uses. This
1039 provide the parsing layer for tools which need to `study'
1043 Specify what category of warnings should be enabled.
1045 - When recursing into subdirectories, try for configure.gnu before
1046 configure to adapt for packages not using autoconf on case-insensitive
1050 More errors are now caught (circular AC_REQUIRE dependencies,
1051 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1052 etc.). In addition, their location and call stack are given.
1055 autoupdate is much more powerful, and is able to provide the glue code
1056 which might be needed to move from an old macro to its newer
1059 You are strongly encouraged to use it to modernize both your
1060 `configure.in' and your .m4 extension files.
1063 The internal machinery of autoheader has completely changed. As a
1064 result, using `acconfig.h' should be considered to be obsoleted, and
1065 you are encouraged to get rid of it using the AH macros.
1070 ** Fortran 77 compilers
1071 Globally, the support for Fortran 77 is considerably improved.
1073 Support for automatically determining a Fortran 77 compiler's
1074 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1075 provided to wrap C/C++ identifiers, thus making it easier and more
1076 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1077 call C/C++ routines. See the Texinfo documentation for details.
1080 The test suite no longer uses DejaGNU. It should be easy to submit
1081 test cases in this new framework.
1084 - --help, --help=long, -hl
1085 no longer dumps useless items.
1087 lists only specific options.
1088 - --help=recursive, -hr
1089 displays the help of all the embedded packages.
1090 - Remembers environment variables when reconfiguring.
1091 The previous scheme to set envvar before running configure was
1093 what prevented configure from remembering the environment in which
1094 it was run, therefore --recheck was run in an inconsistent
1095 environment. Now, one should run
1097 and then --recheck will work properly. Variables declared with
1098 AC_ARG_VAR are also preserved.
1100 $build defaults to `config.guess`, $host to $build, and then $target
1102 Cross-compilation is a global status of the package, it no longer
1103 depends upon the current language.
1104 Cross compilation is enabled iff the user specified `--host'.
1105 `configure' now fails if it can't run the executables it compiles,
1106 unless cross-compilation is enabled.
1108 The cache file is disabled by default. The new options
1109 `--config-cache', `-C' set the cache to `config.cache'.
1113 Much faster on most architectures.
1114 - concurrent executions
1115 It is safe to use `make -j' with config.status.
1116 - human interface improved
1117 It is possible to invoke
1118 ./config.status foobar
1119 instead of the former form (still valid)
1120 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1121 CONFIG_FILES=foobar:foo.in:bar.in \
1123 The same holds for configuration headers and links.
1124 You can instantiate unknown files and headers:
1125 ./config.status --header foo.h:foo.h.in --file bar:baz
1126 - has a useful --help
1127 - accepts special file name "-" for stdin/stdout
1132 Specify additional copyright information.
1135 Now expects the identity of the package as argument.
1139 Most macros, if not all, now strictly follow the `one quotation
1140 level' rule. This results in a more predictable expansion.
1143 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1144 configure scripts, was fixed by Axel Thimm.
1148 Document and ask for the registration of an envvar.
1151 Specifies the file which `configure' should look for when trying to
1152 find the source tree (used to be handled by AC_INIT).
1154 - AC_CONFIG_COMMANDS
1155 To add new actions to config.status. Should be used instead of
1159 Replaces AC_LINK_FILES.
1161 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1162 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1163 They now obey sh: you should no longer use shell variables as
1164 argument. Instead of
1166 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1167 AC_CONFIG_SUBDIRS($my_subdirs)
1171 if test "$package_foo_enabled" = yes; then
1172 AC_CONFIG_SUBDIRS(foo)
1176 To format an Autoconf macro's help string so that it looks pretty
1177 when the user executes `configure --help'.
1180 ** Generic Test Macros
1182 The interface of the AC_CHECK families of macros (decl, header,
1183 type, member, func) is now uniform. They support the same set of
1186 - AC_CHECK_DECL, AC_CHECK_DECLS
1187 To check whether a symbol is declared.
1189 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1190 No longer need a cross-compilation default.
1193 The test it performs is much more robust than previously, and makes
1194 it possible to test builtin types in addition to typedefs.
1195 It is now schizophrenic:
1196 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1197 remains for backward compatibility, but its use is discouraged.
1198 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1199 behaves exactly like the other AC_CHECK macros.
1202 Checks whether given types are supported by the system.
1204 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1205 Check for given members in aggregates (e.g., pw_gecos in struct
1209 Checks if the compiler supports ISO C, included when needs special
1213 Checking whether the preprocessor indicates missing includes by the
1214 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1217 Takes a language as argument and replaces AC_LANG_C,
1218 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1220 - AC_LANG_PUSH, AC_LANG_POP
1221 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1224 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1225 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1226 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1230 Sets GETGROUPS_LIBS.
1232 - AC_FUNC_GETLOADAVG
1233 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1236 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1239 Arrange for large-file support.
1241 - AC_EXEEXT, AC_OBJEXT
1242 You are no longer expected to use them: their computation is
1243 performed by default.
1245 ** C++ compatibility
1246 Every macro has been revisited in order to support at best CC=c++.
1248 Major changes in Autoconf 2.14:
1249 There was no release of GNU Autoconf 2.14.
1251 Major changes in Autoconf 2.13:
1253 Released 1999-05-01 by Ben Elliston.
1255 * Support for building on Win32 systems where the only available C or
1256 C++ compiler is the Microsoft Visual C++ command line compiler
1257 (`cl'). Additional support for building on Win32 systems which are
1258 using the Cygwin or Mingw32 environments.
1259 * Support for alternative object file and executable file extensions.
1260 On Win32, for example, these are .obj and .exe. These are discovered
1261 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1262 @EXEEXT@ in the output, respectively.
1263 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1264 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1265 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1266 * AC_DEFINE now has an optional third argument for a description to be
1267 placed in the config header input file (e.g. config.h.in).
1268 * The C++ code fragment compiled for the C++ compiler test had to be
1269 improved to include an explicit return type for main(). This was
1270 causing failures on systems using recent versions of the EGCS C++
1272 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1273 script to report that `sometype_t' was present when only `type_t'
1275 * Merge of the FSF version of config.guess and config.sub to modernize
1276 these scripts. Add support for a few new hosts in config.guess.
1277 Incorporate latest versions of install-sh, mkinstalldirs and
1278 texinfo.tex from the FSF.
1279 * autoreconf is capable of running automake if necessary (and
1281 * Support for Fortran 77. See the Texinfo documentation for details.
1282 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1284 Major changes in Autoconf 2.12:
1286 Released 1996-11-26 by David J. MacKenzie
1288 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1289 concatenating multiple input files separated by colons, like so:
1290 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1291 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1292 The arguments may be shell variables, to compute the lists on the fly.
1293 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1294 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1297 Major changes in Autoconf 2.11:
1299 Released November 18th, 1996, by David J. MacKenzie
1301 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1302 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1303 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1304 * AC_CONFIG_HEADER expands shell variables in its argument.
1305 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1306 * The "checking..." messages and the source code for test programs that
1307 fail are saved in config.log.
1308 * Another workaround has been added for seds with small command length limits.
1309 * config.sub and config.guess recognize more system types.
1312 Major changes in Autoconf 2.10:
1314 Released May 7th, 1996, by Roland McGrath
1317 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1318 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1320 Major changes in Autoconf 2.9:
1322 Released March 16th, 1996, by Roland McGrath
1326 Major changes in Autoconf 2.8:
1328 Released March 8th, 1996, by Roland McGrath
1332 Major changes in Autoconf 2.7:
1334 Released November 22nd, 1995, by David J. MacKenzie
1338 Major changes in Autoconf 2.6:
1340 Released November 20th, 1995, by David J. MacKenzie
1344 Major changes in Autoconf 2.5:
1346 Released November 17th, 1995, by Roland McGrath
1348 * New configure options --bindir, --libdir, --datadir, etc., with
1349 corresponding output variables.
1350 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1351 * config.log contains the command being run as well as any output from it.
1352 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1353 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1354 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1355 AC_CHECK_TOOL can search a path other than $PATH.
1356 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1358 Major changes in Autoconf 2.4:
1360 Released June 14th, 1995, by David J. MacKenzie
1362 * Fix a few bugs found by Emacs testers.
1364 Major changes in Autoconf 2.3:
1366 Released March 27th, 1995, by David J. MacKenzie
1368 * Fix the cleanup trap in several ways.
1369 * Handle C compilers that are picky about option placement.
1370 * ifnames gets the version number from the right directory.
1372 Major changes in Autoconf 2.2:
1374 Released March 8th, 1995, by David J. MacKenzie
1376 * The ifnames utility is much faster but requires a "new awk" interpreter.
1377 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1378 library before existing libs, not after, in case it uses them.
1379 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1380 * Lots of bug fixes.
1381 * Many additions to the TODO file :-)
1383 Major changes in Autoconf 2.1:
1385 Released November 4th, 1994, by David J. MacKenzie
1388 * More explanations in the manual.
1389 * Fix a spurious failure in the testsuite.
1390 * Clarify some warning messages.
1391 * autoreconf by default only rebuilds configure and config.h.in files
1392 that are older than any of their particular input files; there is a
1393 --force option to use after installing a new version of Autoconf.
1395 Thanks to everybody who's submitted changes and additions to Autoconf!
1396 I've incorporated many of them, and am still considering others for
1397 future releases -- but I didn't want to postpone this release indefinitely.
1399 Caution: don't indiscriminately rebuild configure scripts with
1400 Autoconf version 2. Some configure.in files need minor adjustments to
1401 work with it; the documentation has a chapter on upgrading. A few
1402 configure.in files, including those for GNU Emacs and the GNU C
1403 Library, need major changes because they relied on undocumented
1404 internals of version 1. Future releases of those packages will have
1405 updated configure.in files.
1407 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1408 Autoconf now makes heavy use of M4 diversions, which were implemented
1409 inefficiently in GNU M4 releases before 1.3.
1411 Major changes in Autoconf 2.0:
1413 Released October 26th, 1994, by David J. MacKenzie
1415 ** New copyright terms:
1416 * There are no restrictions on distribution or use of configure scripts.
1419 * Autoconf manual is reorganized to make information easier to find
1420 and has several new indexes.
1421 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1424 * autoscan to generate a preliminary configure.in for a package by
1425 scanning its source code for commonly used nonportable functions,
1426 programs, and header files.
1427 * ifnames to list the symbols used in #if and #ifdef directives in a
1429 * autoupdate to update a configure.in to use the version 2 macro names.
1430 * autoreconf to recursively remake configure and configuration header
1431 files in a source tree.
1433 ** Changed utilities:
1434 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1435 * autoconf and autoheader can look for package-local definition files
1436 in an alternate directory.
1439 * AC_CACHE_VAL to share results of tests between configure runs.
1440 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1441 that macros invoked with AC_REQUIRE don't interrupt other macros.
1442 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1443 support deciding unguessable features based on the host and target types.
1444 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1445 * AC_ARG_PROGRAM to use the options --program-prefix,
1446 --program-suffix, and --program-transform-name to change the names
1447 of programs being installed.
1448 * AC_PREFIX_DEFAULT to change the default installation prefix.
1449 * AC_TRY_COMPILE to compile a test program without linking it.
1450 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1451 * AC_CHECK_LIB to check for a particular function and library.
1452 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1453 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1454 * AC_SUBST_FILE to insert one file into another.
1455 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1456 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1457 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1458 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1461 * Many macros renamed systematically, but old names are accepted for
1462 backward compatibility.
1463 * AC_OUTPUT adds the "automatically generated" comment to
1464 non-Makefiles where it finds @configure_input@ in an input file, to
1465 support files with various comment syntaxes.
1466 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1467 files when they are not enclosed in @ signs.
1468 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1469 override the file name "config.status".
1470 * AC_OUTPUT takes an optional argument for passing variables from
1471 configure to config.status.
1472 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1473 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1474 CPPFLAGS, and LDFLAGS from the environment.
1475 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1476 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1477 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1478 srcdir/../.. by default.
1479 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1480 * AC_DEFINE no longer prints anything, because of the new result reporting
1481 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1482 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1483 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1484 --enable- and --with- options.
1485 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1486 execute on success or failure.
1487 * Checking for C functions in C++ works.
1490 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1491 better maintained with them.
1492 * AC_ARG_ARRAY removed because no one was likely using it.
1493 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1494 take arguments, for consistency with all of the other specific checks.
1497 * Comes with config.sub and config.guess, and uses them optionally.
1498 * Uses config.cache to cache test results. An alternate cache file
1499 can be selected with the --cache-file=FILE option.
1500 * Uses optional shell scripts $prefix/share/config.site and
1501 $prefix/etc/config.site to perform site or system specific initializations.
1502 * configure saves compiler output to ./config.log for debugging.
1503 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1504 * acsite.m4 is the new name for the system-wide aclocal.m4.
1505 * Has a DejaGnu test suite.
1507 Major changes in Autoconf 1.11:
1509 * AC_PROG_INSTALL calls install.sh with the -c option.
1510 * AC_SET_MAKE cleans up after itself.
1511 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1512 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1514 Plus a few other bug fixes.
1516 Major changes in Autoconf 1.10:
1518 * autoheader uses config.h.bot if present, analogous to config.h.top.
1519 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1521 * AC_PROG_CXX looks for cxx as a C++ compiler.
1523 Plus several bugs fixed.
1525 Major changes in Autoconf 1.9:
1527 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1528 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1529 and autoheader generates entries for those names automatically.
1530 * AC_FIND_X gets the result from xmkmf correctly.
1531 * AC_FIND_X assumes no X if --without-x was given.
1532 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1533 * AC_PROG_INSTALL finds OSF/1 installbsd.
1535 Major changes in Autoconf 1.8:
1538 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1539 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1540 for checking both C++ and C features in one configure script.
1541 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1542 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1543 AC_SET_MAKE, AC_ENABLE.
1546 * AC_FIND_X looks for X in more places.
1547 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1548 install.sh is distributed with Autoconf.
1549 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1550 a rewrite of quoting in AC_DEFINE.
1551 * AC_OUTPUT adds its comments in C format when substituting in C files.
1552 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1554 ** New or changed command line options:
1555 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1556 * configure accepts --without-PACKAGE, which sets withval=no.
1557 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1558 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1559 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1560 * configure accepts and ignores most other Cygnus configure options, and
1561 warns about unknown options.
1562 * config.status accepts --help, --version options.
1564 ** File names and other changes:
1565 * Relative srcdir values are not made absolute.
1566 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1567 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1568 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1569 * The example Makefile dependencies for configure et al. work better.
1570 * Namespace cleanup: all shell variables used internally by Autoconf
1571 have names beginning with `ac_'.
1573 More big improvements are in process for future releases, but have not
1574 yet been (variously) finished, integrated, tested, or documented enough
1577 Major changes in Autoconf 1.7:
1579 * New macro AC_OBSOLETE.
1580 * Bugs in Makefile.in fixed.
1581 * AC_LONG_FILE_NAMES improved.
1583 Major changes in Autoconf 1.6:
1585 * New macro AC_LONG_64_BITS.
1586 * Multiple .h files can be created.
1587 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1588 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1589 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1590 * Unused --no-create option to configure removed.
1591 * autoheader doesn't change the timestamp of its output file if
1592 the file didn't change.
1593 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1594 * config.status checks three optional environment variables to
1595 modify its behavior.
1596 * The usual bug fixes.
1598 Major changes in Autoconf 1.5:
1600 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1601 * autoconf and autoheader scripts have GNU standards conforming
1602 --version and --help options (they print their message and exit).
1605 Major changes in Autoconf 1.4:
1607 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1608 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1609 * autoconf and autoheader use the M4 environment variable to determine the
1610 name of the M4 program to use.
1611 * The --macrodir option to autoconf and autoheader specifies the directory
1612 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1613 * autoconf and autoheader can take `-' as their file names, which means to
1614 read stdin as input.
1615 * Resulting configure scripts can take a --verbose option which causes them
1616 to print the results of their tests.
1617 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1618 shell characters, etc. will be preserved during various stages of
1619 expansion done by the shell. If you don't want this, use
1620 AC_DEFINE_UNQUOTED instead.
1621 * Much textual processing done with external calls to tr and sed have been
1622 internalized with builtin M4 `patsubst' and `translit' calls.
1623 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1624 set the shell variables `gen_files' and `gen_config' to the list of
1625 file names to output.
1626 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1627 "lex.yy" or "lexyy", depending on the system.
1628 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1630 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1631 * AC_CONST works much more reliably on more systems.
1634 Major changes in Autoconf 1.3:
1636 configure no longer requires awk for packages that use a config.h.
1637 Support handling --with-PACKAGE options.
1638 New `autoheader' script to create `config.h.in' from `configure.in'.
1639 Ignore troublesome -lucb and -lPW when searching for alloca.
1640 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1641 Improve detection of STDC library.
1642 Add AC_HAVE_LIBRARY to check for non-default libraries.
1643 Function checking should work with future GNU libc releases.
1645 Major changes in Autoconf 1.2:
1647 The --srcdir option is now usually unnecessary.
1648 Add a file containing sample comments describing CPP macros.
1649 A comment in config.status tells which host it was configured on.
1650 Substituted variable values can now contain commas.
1651 Fix bugs in various feature checks.
1653 Major changes in Autoconf 1.1:
1655 Added AC_STRCOLL macro.
1656 Made AC_GETLOADAVG check for more things.
1657 AC_OUTPUT argument is now optional.
1662 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1663 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
1665 This program is free software: you can redistribute it and/or modify
1666 it under the terms of the GNU General Public License as published by
1667 the Free Software Foundation, either version 3 of the License, or
1668 (at your option) any later version.
1670 This program is distributed in the hope that it will be useful,
1671 but WITHOUT ANY WARRANTY; without even the implied warranty of
1672 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
1673 GNU General Public License for more details.
1675 You should have received a copy of the GNU General Public License
1676 along with this program. If not, see <http://www.gnu.org/licenses/>.