1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.64a (????-??-??) [experimental]
6 ** Autoconf is now licensed under the General Public License version 3
7 or later (GPLv3+). As with earlier versions, the license includes
8 an exception clause so that you may release a configure script
9 generated by autoconf under the license of your own program.
11 ** New macros to support Objective C++.
12 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
14 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
18 These macros are present only for backwards compatibility purposes.
20 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
21 lack fopen in the C library, such as AVR or RTEMS (regression
24 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
25 made it fail with some Fortran compilers (regression introduced in
28 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
29 longer mistakenly select a 32-bit type on some compilers (bug present
30 since macros were introduced in 2.59c).
32 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
33 Cygwin (bug present since macro was introduced in 2.0).
35 ** The following documented autotest macros are new:
38 ** The following m4sugar macros now quote their expansion:
41 ** The following m4sugar macros are new:
44 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
45 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
46 this gives the intuitive behavior of "[b c]" in the output (2.63
47 gave the output of "[b], [c]", and 2.64 encountered a failure).
49 ** The `$tmp' temporary directory used in config.status is documented for
52 ** config.status now provides a --config option to produce the configuration.
54 ** Many cache variables used by Autoconf's macros are now documented.
56 ** Configure scripts work better on DJGPP by avoiding a bug present in
57 the DJGPP port of bash 2.04 in handling 'return' in a shell
58 function (regression introduced in 2.64).
60 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
61 Released by Eric Blake, based on git versions 2.63b.*.
63 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
64 have a bug in regular expression handling that interferes with some
65 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
68 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
69 given arguments that expand to just whitespace.
71 ** The following documented autoconf macros are new:
72 AC_ERLANG_SUBST_ERTS_VER
74 ** The autoheader tool now understands m4 macro arguments passed to
75 AC_DEFINE and AC_DEFINE_UNQUOTED.
77 ** Ensure AT_CHECK can support commands that include a # given with
78 proper m4 quoting. For shell comments, this is a new feature; for
79 non-shell comments, this fixes a regression introduced in 2.63b.
80 Additionally, AT_CHECK correctly supplies shell escapes for
81 metacharacters occurring in m4 macro expansions within the expected
82 stdout and stderr parameters.
84 ** The macro AT_CHECK now understands the concept of hard failure. If
85 a test exits with an unexpected status 99, cleanup actions for the
86 test are inhibited and the test is treated as a failure regardless
87 of AT_XFAIL_IF. It also understands the new directives
88 ignore-nolog, stdout-nolog, and stderr-nolog.
90 ** The following documented autotest macros are new:
91 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
93 ** The following documented m4sugar macros are new:
94 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
95 m4_ifblank m4_ifnblank m4_rename_force
97 ** The autoconf testsuite now exercises all Erlang macros.
99 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
100 Released by Eric Blake, based on git versions 2.63.*.
102 ** The manual is now shipped under the terms of the GNU FDL 1.3.
104 ** AC_REQUIRE now detects the case of an outer macro which first expands
105 then later indirectly requires the same inner macro. Previously,
106 this case led to silent out-of-order expansion (bug present since
107 2.50); it now issues a syntax warning, and duplicates the expansion
108 of the inner macro to guarantee dependencies have been met. See
109 the manual for advice on how to refactor macros in order to avoid
110 the bug in earlier autoconf versions and avoid increased script
111 size in the current version.
113 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
114 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
115 expansion was still possible. Now, dependencies are guaranteed,
116 and subsequent invocations are a silent no-op. This makes
117 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
119 ** The following macros are now defined with AC_DEFUN_ONCE. This means
120 a subtle change in semantics; previously, an AC_DEFUN macro could
121 expand one of these macros multiple times or surround the macro
122 inside shell conditional text to bypass the effects of these
123 macros, but now the macro will expand exactly once, and prior to
124 the start of any enclosing AC_DEFUN macro:
125 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
126 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
127 AC_USE_SYSTEM_EXTENSIONS
129 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
131 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
132 longer mistakenly disables assertions.
134 ** AC_INIT now takes an optional fifth parameter that can be used to
135 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
136 used in `configure --help' and is also available via AC_DEFINE.
138 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
139 This feature is still in testing, and may not work on every
140 platform, help in improving it would be appreciated.
142 ** Autotest testsuites do not attempt to write startup error messages
143 to the log file before that is opened (regression introduced in 2.63).
145 ** Configure scripts now use shell functions. This feature leads to
146 smaller configure files and faster execution.
148 ** Present But Cannot Be Compiled: Autoconf will now proceed with
149 the compiler's result if a header is present but cannot be compiled.
150 The warning is still printed, and you should really fix it by
151 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
153 ** Autoreconf added aclocal to the set of programs affected by the
154 `autoreconf -I dir' option.
156 ** The following documented m4sugar macros are new:
157 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
158 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
159 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
160 m4_stack_foreach_lifo m4_stack_foreach_sep
161 m4_stack_foreach_sep_lifo
163 ** The following m4sugar macros are documented now, but in some cases
164 with slightly different semantics than what the previous
165 undocumented version had:
166 m4_copy m4_dumpdefs m4_rename m4_version_prereq
168 ** The m4sugar macro m4_expand has been taught to handle unterminated
169 comments and shell case statements. As a result, it is used
170 internally in more places, such as AC_DEFINE and AT_CHECK. Most
171 uses of AC_DEFINE and AT_CHECK should not behave any differently;
172 however, it may be necessary to add double-quoting around
173 unbalanced `(' where single-quoting used to be sufficient.
175 ** The following documented m4sh macros are new:
176 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
177 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
179 ** The following m4sh macros are documented now, but in some cases
180 with slightly different semantics than what the previous
181 undocumented version had:
182 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
183 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
184 AS_VAR_TEST_SET AS_VERSION_COMPARE
186 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
187 The responsibility for supplying a trailing newline now belongs to
188 the call site, but since most users did not add dnl, this generally
189 results in fewer empty lines in configure.
192 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
193 Released by Eric Blake, based on git versions 2.62.*.
195 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
196 bigendian hosts, a regression introduced with universal binary
199 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
202 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
203 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
204 2.62 when using macros such as AC_AIX that were made obsolete in
205 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
207 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
209 ** Newly obsolete macros
210 The following macro has been marked obsolete, since current porting
211 targets can safely assume C89 semantics that signal handlers return
212 void. We have no current plans to remove the macro.
216 ** The macros m4_map and m4_map_sep now ignore any list elements
217 consisting of just empty quotes, and m4_map_sep now expands its
218 separator. This fixes a regression in 2.62 when these macros were
219 first documented, for the sake of clients expecting the semantics
220 that these macros had prior to that time. The new macros m4_mapall
221 and m4_mapall_sep, along with extra quoting of the separator, can
222 be used to get the semantics that m4_map_sep had in 2.62.
224 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
225 handle properly quoted but otherwise unbalanced parentheses (for
226 some macros, this fixes a regression in 2.62).
228 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
229 allowing the output of unbalanced parentheses in more contexts.
231 ** The following m4sugar macros are new:
232 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
233 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
234 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
235 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
236 m4_set_remove m4_set_size m4_set_union
238 ** The following m4sugar macros now accept multiple arguments, as is the
239 case with underlying m4:
240 m4_defn m4_popdef m4_undefine
242 ** The following m4sugar macros now guarantee linear scaling; they
243 previously had linear scaling with m4 1.6 but quadratic scaling
244 when using m4 1.4.x. All macros built on top of these also gain
245 the scaling improvements.
246 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
247 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
250 ** AT_KEYWORDS once again performs expansion on its argument, such that
251 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
252 the possibly unexpanded m4_if [regression introduced in 2.62].
254 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
255 nested comments any more; regression introduced in 2.62.
258 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
259 Released by Eric Blake, based on git versions 2.61a.*.
261 ** Many optimizations have been applied to make overall execution faster.
263 ** Autotest now makes use of shell functions.
265 ** config.status now uses awk instead of sed also for config headers.
267 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
268 values, i.e., backslash-newline combinations are handled correctly.
269 Further, for config headers, the total size of values is not limited by
270 the POSIX length limit of text lines any more, only each single line.
272 ** New config variable `top_build_prefix'.
274 ** New Autoconf macros:
275 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
277 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
279 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
280 like '__restrict' if the variant spelling is available, as this is
281 more likely to work when mixing C and C++ code.
283 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
284 be a string of tokens such that "T y;" is a valid member declaration
287 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
288 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
290 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
291 they did not work for function types. In C++, they now work on any
292 type-id that can be the operand of sizeof; this is similar to C,
293 except it excludes anonymous struct and union types. Formerly,
294 some (but not all) C++ types involving anonymous struct and union
295 were accepted, though this was not documented.
297 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
298 if found, and it works to link against a file of the same name in
299 the source tree, even if both trees coincide.
301 ** AC_INIT no longer alters $@; regression introduced in 2.60.
303 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
305 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
306 the case where the first argument contains single-quoted commas.
307 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
308 " -a, --arg[=foo] bar"
309 Additionally, the macro now takes two additional arguments,
310 indent-column and wrap-column; these should not normally be needed,
311 but can be used to fine-tune how the output text is wrapped.
313 ** AC_PROG_INSTALL now requires an install program that can install multiple
314 files into a target directory.
316 ** The command 'autoconf -' now correctly processes a file from stdin.
318 ** 'autoreconf -m' now honors $MAKE.
320 ** For all of the directory arguments for 'configure', such as '--prefix'
321 or '--bindir', trailing slashes are stripped. As an example, if
322 tab completion in the user's shell appends trailing slashes, the
323 command './configure --prefix=/usr/' will still result in an
324 expanded libdir value of /usr/lib, not /usr//lib.
326 ** `configure --help=recursive' now works in read-only trees and from
327 unconfigured build trees.
329 ** If precious variables differ only in whitespace, then the cache consistency
330 check warns instead of fails, and reuses the old value.
332 ** AT_BANNER is now documented.
334 ** AT_SETUP now handles macro expansions properly when calculating line
337 ** Autotest now determines $srcdir correctly.
339 ** Testsuites built by autotest now accept a -C/--directory=DIR option
340 to adjust the working directory prior to creating files.
342 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
343 a bug in macro tracing that interferes with the interaction between
344 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
345 configure search for a working M4 is improved.
347 ** For portability with the eventual M4 2.0, macros should no longer use
348 anything larger than $9 to refer to arguments.
350 ** Documentation for m4sugar is improved.
352 - The following macros were previously available as undocumented
353 interfaces; the macros are now documented as stable interfaces.
355 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
356 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
357 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
358 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
359 m4_n m4_shiftn m4_strip m4_warn
361 - The following macros were previously available as undocumented
362 interfaces, but had bug fixes or semantic changes as part of this
363 release. Packages that relied on the undocumented behavior
364 should be analyzed to make sure they will still work with the
365 new documented behavior.
367 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
368 m4_text_box m4_text_wrap m4_version_compare
370 - The m4_wrap macro used to have unspecified order, but now
371 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
374 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
375 should consider using the new AC_AUTOCONF_VERSION instead.
377 - m4sugar macros that are not documented in the manual are still
378 deemed experimental, and should not be used outside of Autoconf.
380 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
381 2.60, have been fixed to treat both the string and the separator
382 arguments consistently with regards to quoting. Prior to this fix,
383 m4_append_uniq could mistakenly duplicate entries if the expansion
384 of the separator resulted in a different string (for example, if it
385 contained quotes, a comma, or a macro name). However, it means
386 that programs previously using
387 m4_append([name], [string], [[, ]])
388 are now using a four-character separator instead of the intended
389 comma and space. If you need portability to earlier versions of
390 Autoconf, you can insert the following snippet after AC_INIT but
391 before any other macro expansions, to enforce the new semantics:
392 m4_pushdef([m4_append], [m4_define([$1],
393 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
394 Additionally, m4_append_uniq now takes optional parameters that can
395 be used to take action depending on whether anything was appended,
396 and warns if a non-empty separator occurs within the string being
397 appended, since that can lead to duplicates.
399 ** The following m4sugar macros are new:
400 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
401 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
402 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
404 ** Warnings are now generated by default when an installer invokes
405 'configure' with an unknown --enable-* or --with-* option.
406 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
407 macro, or by invoking 'configure' with --disable-option-checking.
409 ** Existing obsolete macros
410 The documentation for the following macros is adjusted to make it
411 more clear that they have previously been marked obsolete, as their
412 functionality can be accomplished by other macros. We have no
413 current plans to remove them from Autoconf.
415 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
417 ** Newly obsolete macros
418 The following macros have been marked obsolete, as they only
419 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
420 plans to remove them.
422 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
424 ** AC_C_LONG_DOUBLE is obsolescent.
425 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
426 tests for problems that are so old that it is no longer of
427 practical importance on current systems. New programs need not use
428 AC_C_LONG_DOUBLE. We have no current plans to remove it.
430 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
431 The documentation now favors the use of M4sugar macros m4_warn and
432 m4_fatal, since the naming makes it more obvious that the
433 diagnostics are associated with M4 expansion (ie. when running
434 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
435 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
436 when running `configure'. We have no current plans to remove these
440 * Major changes in Autoconf 2.61a (2006-12-11)
442 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
443 on many platforms. This has been fixed.
445 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
446 compatibility but it does nothing. The macro was already
447 obsolescent, as the last systems to have the problem were those
448 based on SVR2, which became obsolete in 1987. The macro had bugs
449 on some modern systems and could no longer be maintained reliably
450 due to lack of ancient systems to test it on.
452 ** config.status now uses awk instead of sed for most substitutions, for speed.
454 - As a side effect multi-line values of substituted variables no
455 longer have a small limit in total size, though for portability
456 each line should not exceed the POSIX length limit for text lines.
458 - It is now documented that Makefile.in should not contain
459 overlapping variable occurrences, e.g., @VAR1@VAR2@.
460 Autoconf's behavior was always iffy in such cases, and the
461 awk implementation has changed the behavior.
463 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
464 scripts have fewer problems with strings or file names containing
465 embedded special characters such as backslash or leading "-". This
466 was implemented by using `printf '%s\n' "$foo"' instead of `echo
467 "$foo"' when printf works. Due to the implementation technique
468 used, Autoconf-generated scripts now run considerably more slowly
469 on ancient implementations lacking printf. However, this should
470 not be a problem, since Autoconf-generated scripts in practice
471 invariably find a more-modern shell these days.
474 * Major changes in Autoconf 2.61 (2006-11-17)
476 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
478 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
481 * Major changes in Autoconf 2.60b (2006-10-22)
484 Autoconf-generated shell scripts no longer export BIN_SH, due to
485 configuration hassles with this. Installers who need BIN_SH in
486 their environment should set it before invoking 'configure' and
487 'make'. As far as we know, this affects only Unixware installations.
489 ** Obsolescent macros
490 The documentation now says that the following macros are obsolescent,
491 as they are superseded by Gnulib:
493 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
495 New programs should use the Gnulib counterparts of these macros.
496 We have no current plans to remove them from Autoconf.
498 ** AC_COMPUTE_INT no longer caches or reports results.
500 ** AC_CHECK_DECL now also works with aggregate objects.
502 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
504 ** GNU M4 1.4.7 or later is now recommended.
507 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
510 Now an alias for m4_mkstemp.
512 * Major changes in Autoconf 2.60a (2006-08-25)
514 ** GNU M4 1.4.6 or later is now recommended.
516 ** The check for C99 now tests for varargs macros, as documented.
517 It also tests that the preprocessor supports 64-bit integers.
519 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
520 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
522 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
523 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
524 two macros are different, so autoupdate will not change the old private name
525 to the new one. _AC_COMPUTE_INT may be removed in a future release.
527 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
528 that long long types be at least 64 bits wide, as C99 and tradition
529 requires. Formerly, they accepted implementations of any width.
532 * Major changes in Autoconf 2.60
534 Released 2006-06-23, by Ralf Wildenhues.
536 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
537 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
538 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
540 ** Provide a way to turn off warnings about the changed directory variables.
542 * Major changes in Autoconf 2.59d
544 Released 2006-06-05, by Ralf Wildenhues.
546 ** GNU make now recommended for VPATH builds
547 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
548 only if you use GNU make. In practice, other 'make' implementations
549 have too many subtle incompatibilities in their support for VPATH.
550 Many packages (including Autoconf itself) are portable to other
551 'make' implementations, but some packages are not, and recommending
552 GNU make keeps the installation instructions simpler.
554 ** Even more safety checks for the new Directory variables:
555 Warn about suspicious `${datarootdir}' found in config files output.
557 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
558 These never-documented macros and variables have been marked with
559 comments saying that they may be removed in a future release,
560 because their use can lead to unintended code being executed.
561 If you need functionality that only these macros or variables
562 currently supply, please write bug-autoconf@gnu.org.
564 ** AC_SUBST, AC_DEFINE
565 Literal arguments to these are passed to m4_pattern_allow now.
568 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
569 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
570 obsolete K&R tests in the Automake test suite.
579 Now more robust with special characters in file names, or when
580 multiple processes create the same directory at the same time.
582 ** Obsolescent macros
583 The documentation now says that the following macros are obsolescent:
584 they test for problems that are so old that they are no longer of
585 practical importance on current systems.
587 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
588 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
589 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
590 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
591 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
592 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
593 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
594 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
596 New programs need not use these macros. We have no current plans to
600 For compatibility with future Libtool 2.0, autoreconf will invoke
601 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
604 * Major changes in Autoconf 2.59c
606 Released 2006-04-12, by Ralf Wildenhues.
608 ** The configure command now redirects standard input from /dev/null,
609 to help avoid problems with subsidiary commands that might mistakenly
610 read standard input. AS_ORIGINAL_STDIN_FD points to the original
611 standard input before this redirection, if you really want configure to
612 read from standard input.
614 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
615 The following directory variables are new:
617 datarootdir read-only architecture-independent data root [PREFIX/share]
618 localedir locale-specific message catalogs [DATAROOTDIR/locale]
619 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
620 htmldir html documentation [DOCDIR]
621 dvidir dvi documentation [DOCDIR]
622 pdfdir pdf documentation [DOCDIR]
623 psdir ps documentation [DOCDIR]
625 The following variables have new default values:
627 datadir read-only architecture-independent data [DATAROOTDIR]
628 infodir info documentation [DATAROOTDIR/info]
629 mandir man documentation [DATAROOTDIR/man]
631 This means that if you use any of `@datadir@', `@infodir@', or
632 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
633 defined in this file. As a temporary measure, if any of those are
634 found but no mention of `datarootdir', the substitutions will be
635 replaced with values that do not contain `${datarootdir}', and a
636 warning will be issued.
638 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
639 a trailing slash. Similar change will be made to ac_top_builddir in a
640 future release; the old style value, which matches (../)*, is (and will
641 continue to be) available as ac_top_build_prefix.
644 New macro to check for support of 'typeof' syntax a la GNU C.
646 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
647 New "once-only" variants of commonly-used macros, to make 'configure'
648 smaller and faster in common cases.
651 New macro to check for strtold with C99 semantics.
654 New macro that lets builder disable assertions at 'configure'-time.
657 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
658 X11/Intrinsic.h and XtMalloc (Xt).
660 ** AC_PRESERVE_HELP_ORDER
661 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
662 and AC_ARG_WITH arguments in one region, in the order defined. The default
663 behavior is to group options of each classes separately.
665 ** AC_PROG_CC, AC_PROG_CXX
666 No longer automatically arrange to declare the 'exit' function of C,
667 when a C++ compiler is used. Standard Autoconf macros no longer use
668 'exit', so this is no longer an issue for them. If you use C++, and
669 want to call 'exit', you'll have to arrange for its declaration
670 yourself. But we now suggest you return from 'main' instead.
672 ** AC_PROG_CC_C89, AC_PROG_CC_C99
673 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
674 check for ANSI C89 and ISO C99 support respectively.
677 Has been unobsoleted, and will check if the compiler supports ISO
678 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
679 retained for backwards compatibility, assuming the value of
680 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
683 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
684 New macros for checking commonly-used members of struct dirent.
687 The substituted value can now contain newlines.
690 The substitution now occurs only when @variable@ is on a line by itself,
691 optionally surrounded by spaces and tabs. The whole line is replaced.
693 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
694 New macros to check for long double, and whether it is wider than double.
695 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
696 applications should switch to the new macro.
698 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
699 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
700 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
701 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
702 New macros to check for C99 and POSIX types.
704 ** AC_USE_SYSTEM_EXTENSIONS
705 New macro to enable extensions to Posix.
708 New macro which is defined to the name of the first declared config header
709 or undefined if no config headers have been declared yet.
712 The macro correctly handles quadrigraphs now.
714 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
715 These macros are new or published now.
718 New macro for copyright notices in testsuite files.
720 ** ALLOCA, LIBOBJS, LTLIBOBJS
721 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
722 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
723 `Makefile.in' in case the object files lie in a different directory.
724 The LIBOBJDIR feature is experimental.
727 Supports --no-recursive now.
729 ** New macros to support Erlang/OTP.
730 New macros for configuring paths to Erlang tools and libraries:
731 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
732 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
733 AC_ERLANG_SUBST_LIB_DIR.
735 New macros for configuring installation of Erlang libraries:
736 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
738 ** The manual now mentions Gnulib more prominently.
740 ** New macros to support Objective C.
741 AC_PROG_OBJC, AC_PROG_OBJCPP.
743 * Major changes in Autoconf 2.59b
745 Released 2004-08-20, by Paul Eggert.
748 New macro that computes the default alignment of a type.
750 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
751 When cross-compiling, these macros will give a warning if the tool
752 is not prefixed. In the future, unprefixed cross tools will not
753 be detected; please consult the info documentation for information
754 about the reason of this change.
756 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
757 New macros that detect programs whose name is prefixed with the
758 target type, if the build type and target type are different.
760 ** AC_REQUIRE_AUX_FILE
761 New trace macro that declares expected auxiliary files.
764 New macro that tests for a grep program that accepts as a long a line
767 ** AC_PROG_EGREP, AC_PROG_FGREP
768 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
769 FGREP="$GREP -F" respectively if possible, or else run a path search for
770 a program that accepts as long a line as possible.
773 New macro that tests for a sed program that truncates as few characters
776 * Major changes in Autoconf 2.59
778 Released 2003-11-04, by Akim Demaille
780 ** ac_abs_builddir etc.
781 Absolute file names were actually relative in 2.58.
783 * Major changes in Autoconf 2.58
785 Released 2003-11-04, by Akim Demaille
788 core.* files are no longer removed, as they may be valid user files.
790 ** autoreconf and auxiliary directory
791 Autoreconf creates the auxiliary directory if needed. This is
792 especially useful for initial "bootstrapping" of fresh CVS checkouts.
794 ** AC_CONFIG_MACRO_DIR
795 Use this macro to declare the directory for local M4 macros for aclocal.
798 No longer includes twice the same file in LIBOBJS if invoked
801 ** AC_CONFIG_COMMANDS
802 The directory for its first argument is automatically created. For
805 AC_CONFIG_COMMANDS([src/modules.hh], [...])
807 $top_builddir/src/ is created if needed.
809 ** Autotest and local.at
810 The optional file local.at is always included in Autotest test suites.
813 The warnings are always issued, including with cached runs.
814 This became a significant problem since aclocal and automake can
815 run autoconf behind the scene.
817 ** autoheader warnings
818 The warnings of autoheader can be turned off, using --warning.
819 For instance, -Wno-obsolete disables the complaints about acconfig.h
820 and other deprecated constructs.
823 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
826 ** AC_DECL_SYS_SIGLIST
830 Now checks that mktime is the inverse of localtime.
832 ** Improve DJGPP portability
833 The Autoconf tools and configure behave better under DJGPP.
835 ** Present But Cannot Be Compiled
836 New FAQ section dedicated to the mystic
838 configure: WARNING: pi.h: present but cannot be compiled
839 configure: WARNING: pi.h: check for missing prerequisite headers?
840 configure: WARNING: pi.h: proceeding with the preprocessor's result
843 ** Concurrent executions of autom4te
844 autom4te now locks its internal files, which enables concurrent
845 executions of autom4te, likely to happen if automake, autoconf,
846 autoheader etc. are run simultaneously.
849 Use of Libtool 1.5 and higher is encouraged. Compatibility with
850 Libtool pre-1.4 is not checked.
853 Testsuites no longer rerun failed tests in verbose mode; instead,
854 failures are logged while the test is run.
856 In addition, expected failures can be marked as such.
858 * Major changes in Autoconf 2.57
860 Released 2002-12-03 by Paul Eggert.
862 Bug fixes for problems with AIX linker, with freestanding C compilers,
863 with GNU M4 limitations, and with obsolete copies of GNU documents.
865 The Free Documentation License has been upgraded from 1.1 to 1.2.
867 * Major changes in Autoconf 2.56
869 Released 2002-11-15 by Akim Demaille.
871 One packaging problem fixed (config/install-sh was not executable).
873 * Major changes in Autoconf 2.55
875 Released 2002-11-14 by Akim Demaille.
879 Have your configure.ac checked by autoscan ("autoscan").
880 Try the warning options ("autoreconf -fv -Wall").
884 - AC_CHECK_HEADER, AC_CHECK_HEADERS
885 More information on proper use.
887 - Writing Test Programs
889 This sections explains how to write good test sources to use with
890 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
892 - AC_FOO_IFELSE vs. AC_TRY_FOO
894 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
895 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
899 - Is more robust to different Gettext installations.
901 - Produces messages (when --verbose) to be understood by Emacs'
904 - Supports -W/--warnings.
907 Once the GNU Build System reinstalled, run `./config.status
908 --recheck && ./config.status && make' if possible.
912 - Supports --cache, and --no-cache.
914 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
915 (autom4te.cache). See `Customizing autom4te' in the documentation.
922 Support for the obsoleted options -m, --macrodir, -l, --localdir is
923 dropped in favor of the safer --include/--prepend-include scheme.
928 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
929 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
930 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
933 Obsoleted macros are kept for Autoconf backward compatibility, but
934 should be avoided in configure.ac. Running autoupdate is advised.
937 - AC_DEFINE/AC_DEFINE_UNQUOTED
939 We have to stop using the old compatibility scheme --that tried to
940 avoid useless backslashes-- because Libtool 1.4.3 contains a
942 AC_DEFINE([error_t], [int],
943 [Define to a type to use for \`error_t' if it is not
944 otherwise available.])
946 We have to quote the single quotes and backslashes with \. The old
947 compatibility scheme saw that ` was backslashed, and therefore did
948 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
949 compatible with Libtool. Autoconf 2.55 is, but in some cases might
950 produce more \ than wanted.
952 Please, note that in the future the same problem will happen with
953 AC_MSG_*: use `autoreconf -f -Wall'.
957 - Portability of the Autoconf package to Solaris.
959 - Spurious warnings caused by config.status.
960 This bug is benign, but painful: on some systems (typically
961 FreeBSD), warnings such as:
963 config.status: creating Makefile
964 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
966 could be issued. This is fixed.
969 Simultaneous executions of config.status are possible again.
971 - Precious variables accumulation
973 config.status could stack several copies of the precious variables
977 ** Plans for later versions
981 The compatibility hooks with the old scheme will be completely
982 removed. Please, advice/use `--build', `--host', and `--target'
985 - AC_CHECK_HEADER, AC_CHECK_HEADERS
987 The tests will be stricter, please make sure your invocations are
992 Shell functions will gradually be introduced, probably starting with
993 Autotest. If you know machines which are in use that you suspect
994 *not* to support shell functions, please run the test suite of
995 Autoconf 2.55 on it, and report the results to
996 bug-autoconf@gnu.org.
1000 Special characters in AC_MSG_* need not be quoted. Currently,
1001 Autoconf has heuristics to decide when a string is escaped, or has
1002 to be escaped. This scheme is fragile, and will be removed; the
1003 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1004 to find occurrences that will be affected.
1006 * Major changes in Autoconf 2.54
1008 Released 2002-09-13 by Akim Demaille.
1012 - autoreconf no longer changes the version of the gettext/po/intl
1013 support files. It now adds the files the correspond to the
1014 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1016 Warning: It now relies on the 'autopoint' program, which is part
1017 of GNU gettext 0.11.4 and newer.
1019 Please note that you need to have a GNU gettext version that
1020 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1021 in configure.ac. You can upgrade to newer GNU gettext versions,
1022 though, without needing to change configure.ac.
1024 - The -I DIR or --include=DIR option now appends DIR to the include path
1025 instead of prepending; this is for consistency with other GNU tools.
1026 The new -B DIR or --prepend-include=DIR option has the old behavior.
1031 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1032 Please, remove lines such as
1034 # This is necessary so that .o files in LIBOBJS are also
1035 # built via the ANSI2KNR-filtering rules.
1036 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1038 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1039 your Makefiles either.
1041 - AC_CONFIG_LINKS now makes copies if it can't make links.
1043 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1044 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1045 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1047 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1049 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1051 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1055 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1056 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1057 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1059 - AC_FUNC_GETLOADAVG
1060 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1063 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1064 for an AC_LIBOBJ replacement.
1068 - Spurious complaints from `m4_bmatch' about invalid regular
1069 expressions are suppressed.
1071 - Empty top_builddirs are properly handled.
1073 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1076 Now colon in the optional path arguments are properly handled.
1078 ** Improved portability
1080 - Both Autoconf the package, and the scripts it produces, should run
1081 more reliably with Zsh. Bear in mind it is the default Bourne shell
1084 - Autoconf and the scripts it produces no longer assume the existence of
1085 the obsolescent commands egrep and fgrep.
1089 - Limitations of Make
1093 The GNATS base moved to
1094 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1095 (It is no longer available, though.)
1100 Now contains the list of ouput variables and files (AC_SUBST,
1103 * Major changes in Autoconf 2.53
1105 Released 2002-03-08 by Akim Demaille.
1109 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1110 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1116 Argument requirements, output variables, defined macros.
1117 - M4sugar, M4sh, Autotest
1119 - Double quoting macros
1120 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1122 The Autoconf manual is now distributed under the terms of the GNU FDL.
1123 - Section `Hosts and Cross-Compilation'
1124 Explains the rationale for the 2.5x changes in the cross-compilation
1125 chain, and in the relationships between build, host, and target
1127 Emphasizes that `cross-compilation' == `--host is given'.
1128 If you are working on compilers etc., be sure to read this section.
1129 - Section `AC_LIBOBJ vs. LIBOBJS'
1130 Explains why assigning LIBOBJS directly is now an error.
1131 Details how to update the code.
1136 Now used instead of hard coded line numbers.
1137 This eases the comparison of `configure's, and diminishes the
1138 pressure over control version archives.
1139 Automatic replacement for shells that don't support this feature.
1140 - New output variables
1141 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1146 Autoconf and Autotest modes are provided.
1151 New, used by the Autoconf suite to cache and speed up most processing.
1153 Supported by autom4te, autoconf and autoheader.
1155 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1156 autoupdate, and autoreconf.
1158 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1159 automake options are to be given via AUTOMAKE_OPTIONS.
1161 Runs gettextize and libtoolize when appropriate.
1163 --m4dir is no longer supported.
1165 Now runs only in the specified directories, defaulting to `.',
1166 but understands AC_CONFIG_SUBDIRS for dependent directories.
1167 Before, it used to run on all the `configure.ac' found in the
1169 Independent packages are properly updated.
1173 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1175 Under the user pressure, $? is finally available. Probably a mistake.
1176 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1177 - Precious variables accumulation
1178 config.status could stack several copies of the precious variables
1180 - AC_PATH_PROG and family.
1181 Works properly when given a literal path.
1183 Somewhere since 2.13, the result had been reversed.
1187 - AC_C_BIGENDIAN supports the cross-compiling case.
1188 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1189 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1190 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1192 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1193 precision than `double'.
1198 It now defines the preprocessor symbols PACKAGE_NAME,
1199 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1203 Admits a fourth optional parameter: the tar name.
1205 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1206 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1207 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1208 ac_abs_top_builddir.
1210 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1211 Are much less expensive when using long lists of files.
1214 Works with shell variables, and non alphanumeric names.
1218 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1219 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1221 - AC_FUNC_STRTOD substitutes POW_LIB.
1226 * Major changes in Autoconf 2.52
1228 Released 2001-07-18 by Akim Demaille.
1233 This feature was present in autoconf 2.50 but was not documented.
1234 For example, `@<:@' is translated to `[' just before output. This
1235 is useful when writing strings that contain unbalanced quotes, or
1236 other hard-to-quote constructs.
1237 - m4_pattern_forbid, m4_pattern_allow
1238 - Tips for upgrading from 2.13.
1239 - Using autoscan to maintain a configure.ac.
1242 - Now include stdint.h.
1243 - sys/types.h and sys/stat.h are guarded.
1244 - strings.h is included if available, and not conflicting with string.h.
1247 - The test suite is more robust and presents less false failures.
1248 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1249 - configure accepts --prefix='' again.
1250 - AC_CHECK_LIB works properly when its first argument is not a
1252 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1253 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1254 - AC_ARG_VAR properly propagates precious variables inherited from the
1255 environment to ./config.status.
1256 - Using --program-suffix/--program-prefix is portable.
1257 - Failures to detect the default compiler's output extension are less
1259 - `config.status foo' works properly when `foo' depends on variables
1260 set in an AC_CONFIG_THING INIT-CMD.
1261 - autoheader is more robust to broken input.
1262 - Fixed Fortran name-mangling and link tests on a number of systems,
1263 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1266 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1267 specify pre-includes. In this case, the headers are compiled with
1268 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1269 of a header which is checked for, not just its availability.
1270 - AC_ARG_VAR refuses to run configure when precious variables have
1272 - Versions of compilers are dumped in the logs.
1273 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1276 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1277 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1278 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1279 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1280 Be sure to read `Upgrading from Version 2.13' to understand why
1281 running `autoupdate' is needed.
1282 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1283 a main-like routine is required/possible when linking C/C++ with
1284 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1285 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1287 * Major changes in Autoconf 2.51
1288 There was no release of Autoconf 2.51 since some packagers had used
1289 this version number without permission to ship intermediary versions
1290 of 2.50. The version was skipped to avoid confusion.
1292 * Major changes in Autoconf 2.50
1294 Released 2001-05-21 by Akim Demaille.
1296 ** Lots of bug fixes
1297 There have been far too many to enumerate them here. Check out
1298 ChangeLog if you really want to know more.
1300 ** Improved documentation
1301 In particular, portability issues are better covered.
1304 All the standard GNU Makefile targets are supported. The layout has
1305 changed: m4/ holds the M4 extensions Autoconf needs for its
1306 configuration, doc/ contains the documentation, and tests/ contains
1309 ** Man pages are provided
1310 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1311 config.guess, config.sub.
1315 Provides a safe and powerful means to trace the macro uses. This
1316 provide the parsing layer for tools which need to `study'
1320 Specify what category of warnings should be enabled.
1322 - When recursing into subdirectories, try for configure.gnu before
1323 configure to adapt for packages not using autoconf on case-insensitive
1327 More errors are now caught (circular AC_REQUIRE dependencies,
1328 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1329 etc.). In addition, their location and call stack are given.
1332 autoupdate is much more powerful, and is able to provide the glue code
1333 which might be needed to move from an old macro to its newer
1336 You are strongly encouraged to use it to modernize both your
1337 `configure.in' and your .m4 extension files.
1340 The internal machinery of autoheader has completely changed. As a
1341 result, using `acconfig.h' should be considered to be obsoleted, and
1342 you are encouraged to get rid of it using the AH macros.
1347 ** Fortran 77 compilers
1348 Globally, the support for Fortran 77 is considerably improved.
1350 Support for automatically determining a Fortran 77 compiler's
1351 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1352 provided to wrap C/C++ identifiers, thus making it easier and more
1353 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1354 call C/C++ routines. See the Texinfo documentation for details.
1357 The test suite no longer uses DejaGNU. It should be easy to submit
1358 test cases in this new framework.
1361 - --help, --help=long, -hl
1362 no longer dumps useless items.
1364 lists only specific options.
1365 - --help=recursive, -hr
1366 displays the help of all the embedded packages.
1367 - Remembers environment variables when reconfiguring.
1368 The previous scheme to set envvar before running configure was
1370 what prevented configure from remembering the environment in which
1371 it was run, therefore --recheck was run in an inconsistent
1372 environment. Now, one should run
1374 and then --recheck will work properly. Variables declared with
1375 AC_ARG_VAR are also preserved.
1377 $build defaults to `config.guess`, $host to $build, and then $target
1379 Cross-compilation is a global status of the package, it no longer
1380 depends upon the current language.
1381 Cross compilation is enabled iff the user specified `--host'.
1382 `configure' now fails if it can't run the executables it compiles,
1383 unless cross-compilation is enabled.
1385 The cache file is disabled by default. The new options
1386 `--config-cache', `-C' set the cache to `config.cache'.
1390 Much faster on most architectures.
1391 - concurrent executions
1392 It is safe to use `make -j' with config.status.
1393 - human interface improved
1394 It is possible to invoke
1395 ./config.status foobar
1396 instead of the former form (still valid)
1397 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1398 CONFIG_FILES=foobar:foo.in:bar.in \
1400 The same holds for configuration headers and links.
1401 You can instantiate unknown files and headers:
1402 ./config.status --header foo.h:foo.h.in --file bar:baz
1403 - has a useful --help
1404 - accepts special file name "-" for stdin/stdout
1409 Specify additional copyright information.
1412 Now expects the identity of the package as argument.
1416 Most macros, if not all, now strictly follow the `one quotation
1417 level' rule. This results in a more predictable expansion.
1420 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1421 configure scripts, was fixed by Axel Thimm.
1425 Document and ask for the registration of an envvar.
1428 Specifies the file which `configure' should look for when trying to
1429 find the source tree (used to be handled by AC_INIT).
1431 - AC_CONFIG_COMMANDS
1432 To add new actions to config.status. Should be used instead of
1436 Replaces AC_LINK_FILES.
1438 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1439 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1440 They now obey sh: you should no longer use shell variables as
1441 argument. Instead of
1443 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1444 AC_CONFIG_SUBDIRS($my_subdirs)
1448 if test "$package_foo_enabled" = yes; then
1449 AC_CONFIG_SUBDIRS(foo)
1453 To format an Autoconf macro's help string so that it looks pretty
1454 when the user executes `configure --help'.
1457 ** Generic Test Macros
1459 The interface of the AC_CHECK families of macros (decl, header,
1460 type, member, func) is now uniform. They support the same set of
1463 - AC_CHECK_DECL, AC_CHECK_DECLS
1464 To check whether a symbol is declared.
1466 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1467 No longer need a cross-compilation default.
1470 The test it performs is much more robust than previously, and makes
1471 it possible to test builtin types in addition to typedefs.
1472 It is now schizophrenic:
1473 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1474 remains for backward compatibility, but its use is discouraged.
1475 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1476 behaves exactly like the other AC_CHECK macros.
1479 Checks whether given types are supported by the system.
1481 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1482 Check for given members in aggregates (e.g., pw_gecos in struct
1486 Checks if the compiler supports ISO C, included when needs special
1490 Checking whether the preprocessor indicates missing includes by the
1491 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1494 Takes a language as argument and replaces AC_LANG_C,
1495 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1497 - AC_LANG_PUSH, AC_LANG_POP
1498 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1501 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1502 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1503 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1507 Sets GETGROUPS_LIBS.
1509 - AC_FUNC_GETLOADAVG
1510 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1513 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1516 Arrange for large-file support.
1518 - AC_EXEEXT, AC_OBJEXT
1519 You are no longer expected to use them: their computation is
1520 performed by default.
1522 ** C++ compatibility
1523 Every macro has been revisited in order to support at best CC=c++.
1525 Major changes in Autoconf 2.14:
1526 There was no release of GNU Autoconf 2.14.
1528 Major changes in Autoconf 2.13:
1530 Released 1999-05-01 by Ben Elliston.
1532 * Support for building on Win32 systems where the only available C or
1533 C++ compiler is the Microsoft Visual C++ command line compiler
1534 (`cl'). Additional support for building on Win32 systems which are
1535 using the Cygwin or Mingw32 environments.
1536 * Support for alternative object file and executable file extensions.
1537 On Win32, for example, these are .obj and .exe. These are discovered
1538 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1539 @EXEEXT@ in the output, respectively.
1540 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1541 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1542 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1543 * AC_DEFINE now has an optional third argument for a description to be
1544 placed in the config header input file (e.g. config.h.in).
1545 * The C++ code fragment compiled for the C++ compiler test had to be
1546 improved to include an explicit return type for main(). This was
1547 causing failures on systems using recent versions of the EGCS C++
1549 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1550 script to report that `sometype_t' was present when only `type_t'
1552 * Merge of the FSF version of config.guess and config.sub to modernize
1553 these scripts. Add support for a few new hosts in config.guess.
1554 Incorporate latest versions of install-sh, mkinstalldirs and
1555 texinfo.tex from the FSF.
1556 * autoreconf is capable of running automake if necessary (and
1558 * Support for Fortran 77. See the Texinfo documentation for details.
1559 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1561 Major changes in Autoconf 2.12:
1563 Released 1996-11-26 by David J. MacKenzie
1565 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1566 concatenating multiple input files separated by colons, like so:
1567 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1568 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1569 The arguments may be shell variables, to compute the lists on the fly.
1570 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1571 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1574 Major changes in Autoconf 2.11:
1576 Released November 18th, 1996, by David J. MacKenzie
1578 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1579 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1580 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1581 * AC_CONFIG_HEADER expands shell variables in its argument.
1582 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1583 * The "checking..." messages and the source code for test programs that
1584 fail are saved in config.log.
1585 * Another workaround has been added for seds with small command length limits.
1586 * config.sub and config.guess recognize more system types.
1589 Major changes in Autoconf 2.10:
1591 Released May 7th, 1996, by Roland McGrath
1594 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1595 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1597 Major changes in Autoconf 2.9:
1599 Released March 16th, 1996, by Roland McGrath
1603 Major changes in Autoconf 2.8:
1605 Released March 8th, 1996, by Roland McGrath
1609 Major changes in Autoconf 2.7:
1611 Released November 22nd, 1995, by David J. MacKenzie
1615 Major changes in Autoconf 2.6:
1617 Released November 20th, 1995, by David J. MacKenzie
1621 Major changes in Autoconf 2.5:
1623 Released November 17th, 1995, by Roland McGrath
1625 * New configure options --bindir, --libdir, --datadir, etc., with
1626 corresponding output variables.
1627 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1628 * config.log contains the command being run as well as any output from it.
1629 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1630 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1631 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1632 AC_CHECK_TOOL can search a path other than $PATH.
1633 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1635 Major changes in Autoconf 2.4:
1637 Released June 14th, 1995, by David J. MacKenzie
1639 * Fix a few bugs found by Emacs testers.
1641 Major changes in Autoconf 2.3:
1643 Released March 27th, 1995, by David J. MacKenzie
1645 * Fix the cleanup trap in several ways.
1646 * Handle C compilers that are picky about option placement.
1647 * ifnames gets the version number from the right directory.
1649 Major changes in Autoconf 2.2:
1651 Released March 8th, 1995, by David J. MacKenzie
1653 * The ifnames utility is much faster but requires a "new awk" interpreter.
1654 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1655 library before existing libs, not after, in case it uses them.
1656 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1657 * Lots of bug fixes.
1658 * Many additions to the TODO file :-)
1660 Major changes in Autoconf 2.1:
1662 Released November 4th, 1994, by David J. MacKenzie
1665 * More explanations in the manual.
1666 * Fix a spurious failure in the testsuite.
1667 * Clarify some warning messages.
1668 * autoreconf by default only rebuilds configure and config.h.in files
1669 that are older than any of their particular input files; there is a
1670 --force option to use after installing a new version of Autoconf.
1672 Thanks to everybody who's submitted changes and additions to Autoconf!
1673 I've incorporated many of them, and am still considering others for
1674 future releases -- but I didn't want to postpone this release indefinitely.
1676 Caution: don't indiscriminately rebuild configure scripts with
1677 Autoconf version 2. Some configure.in files need minor adjustments to
1678 work with it; the documentation has a chapter on upgrading. A few
1679 configure.in files, including those for GNU Emacs and the GNU C
1680 Library, need major changes because they relied on undocumented
1681 internals of version 1. Future releases of those packages will have
1682 updated configure.in files.
1684 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1685 Autoconf now makes heavy use of M4 diversions, which were implemented
1686 inefficiently in GNU M4 releases before 1.3.
1688 Major changes in Autoconf 2.0:
1690 Released October 26th, 1994, by David J. MacKenzie
1692 ** New copyright terms:
1693 * There are no restrictions on distribution or use of configure scripts.
1696 * Autoconf manual is reorganized to make information easier to find
1697 and has several new indexes.
1698 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1701 * autoscan to generate a preliminary configure.in for a package by
1702 scanning its source code for commonly used nonportable functions,
1703 programs, and header files.
1704 * ifnames to list the symbols used in #if and #ifdef directives in a
1706 * autoupdate to update a configure.in to use the version 2 macro names.
1707 * autoreconf to recursively remake configure and configuration header
1708 files in a source tree.
1710 ** Changed utilities:
1711 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1712 * autoconf and autoheader can look for package-local definition files
1713 in an alternate directory.
1716 * AC_CACHE_VAL to share results of tests between configure runs.
1717 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1718 that macros invoked with AC_REQUIRE don't interrupt other macros.
1719 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1720 support deciding unguessable features based on the host and target types.
1721 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1722 * AC_ARG_PROGRAM to use the options --program-prefix,
1723 --program-suffix, and --program-transform-name to change the names
1724 of programs being installed.
1725 * AC_PREFIX_DEFAULT to change the default installation prefix.
1726 * AC_TRY_COMPILE to compile a test program without linking it.
1727 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1728 * AC_CHECK_LIB to check for a particular function and library.
1729 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1730 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1731 * AC_SUBST_FILE to insert one file into another.
1732 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1733 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1734 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1735 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1738 * Many macros renamed systematically, but old names are accepted for
1739 backward compatibility.
1740 * AC_OUTPUT adds the "automatically generated" comment to
1741 non-Makefiles where it finds @configure_input@ in an input file, to
1742 support files with various comment syntaxes.
1743 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1744 files when they are not enclosed in @ signs.
1745 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1746 override the file name "config.status".
1747 * AC_OUTPUT takes an optional argument for passing variables from
1748 configure to config.status.
1749 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1750 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1751 CPPFLAGS, and LDFLAGS from the environment.
1752 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1753 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1754 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1755 srcdir/../.. by default.
1756 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1757 * AC_DEFINE no longer prints anything, because of the new result reporting
1758 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1759 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1760 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1761 --enable- and --with- options.
1762 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1763 execute on success or failure.
1764 * Checking for C functions in C++ works.
1767 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1768 better maintained with them.
1769 * AC_ARG_ARRAY removed because no one was likely using it.
1770 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1771 take arguments, for consistency with all of the other specific checks.
1774 * Comes with config.sub and config.guess, and uses them optionally.
1775 * Uses config.cache to cache test results. An alternate cache file
1776 can be selected with the --cache-file=FILE option.
1777 * Uses optional shell scripts $prefix/share/config.site and
1778 $prefix/etc/config.site to perform site or system specific initializations.
1779 * configure saves compiler output to ./config.log for debugging.
1780 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1781 * acsite.m4 is the new name for the system-wide aclocal.m4.
1782 * Has a DejaGnu test suite.
1784 Major changes in Autoconf 1.11:
1786 * AC_PROG_INSTALL calls install.sh with the -c option.
1787 * AC_SET_MAKE cleans up after itself.
1788 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1789 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1791 Plus a few other bug fixes.
1793 Major changes in Autoconf 1.10:
1795 * autoheader uses config.h.bot if present, analogous to config.h.top.
1796 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1798 * AC_PROG_CXX looks for cxx as a C++ compiler.
1800 Plus several bugs fixed.
1802 Major changes in Autoconf 1.9:
1804 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1805 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1806 and autoheader generates entries for those names automatically.
1807 * AC_FIND_X gets the result from xmkmf correctly.
1808 * AC_FIND_X assumes no X if --without-x was given.
1809 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1810 * AC_PROG_INSTALL finds OSF/1 installbsd.
1812 Major changes in Autoconf 1.8:
1815 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1816 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1817 for checking both C++ and C features in one configure script.
1818 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1819 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1820 AC_SET_MAKE, AC_ENABLE.
1823 * AC_FIND_X looks for X in more places.
1824 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1825 install.sh is distributed with Autoconf.
1826 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1827 a rewrite of quoting in AC_DEFINE.
1828 * AC_OUTPUT adds its comments in C format when substituting in C files.
1829 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1831 ** New or changed command line options:
1832 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1833 * configure accepts --without-PACKAGE, which sets withval=no.
1834 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1835 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1836 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1837 * configure accepts and ignores most other Cygnus configure options, and
1838 warns about unknown options.
1839 * config.status accepts --help, --version options.
1841 ** File names and other changes:
1842 * Relative srcdir values are not made absolute.
1843 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1844 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1845 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1846 * The example Makefile dependencies for configure et al. work better.
1847 * Namespace cleanup: all shell variables used internally by Autoconf
1848 have names beginning with `ac_'.
1850 More big improvements are in process for future releases, but have not
1851 yet been (variously) finished, integrated, tested, or documented enough
1854 Major changes in Autoconf 1.7:
1856 * New macro AC_OBSOLETE.
1857 * Bugs in Makefile.in fixed.
1858 * AC_LONG_FILE_NAMES improved.
1860 Major changes in Autoconf 1.6:
1862 * New macro AC_LONG_64_BITS.
1863 * Multiple .h files can be created.
1864 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1865 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1866 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1867 * Unused --no-create option to configure removed.
1868 * autoheader doesn't change the timestamp of its output file if
1869 the file didn't change.
1870 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1871 * config.status checks three optional environment variables to
1872 modify its behavior.
1873 * The usual bug fixes.
1875 Major changes in Autoconf 1.5:
1877 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1878 * autoconf and autoheader scripts have GNU standards conforming
1879 --version and --help options (they print their message and exit).
1882 Major changes in Autoconf 1.4:
1884 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1885 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1886 * autoconf and autoheader use the M4 environment variable to determine the
1887 name of the M4 program to use.
1888 * The --macrodir option to autoconf and autoheader specifies the directory
1889 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1890 * autoconf and autoheader can take `-' as their file names, which means to
1891 read stdin as input.
1892 * Resulting configure scripts can take a --verbose option which causes them
1893 to print the results of their tests.
1894 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1895 shell characters, etc. will be preserved during various stages of
1896 expansion done by the shell. If you don't want this, use
1897 AC_DEFINE_UNQUOTED instead.
1898 * Much textual processing done with external calls to tr and sed have been
1899 internalized with builtin M4 `patsubst' and `translit' calls.
1900 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1901 set the shell variables `gen_files' and `gen_config' to the list of
1902 file names to output.
1903 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1904 "lex.yy" or "lexyy", depending on the system.
1905 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1907 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1908 * AC_CONST works much more reliably on more systems.
1911 Major changes in Autoconf 1.3:
1913 configure no longer requires awk for packages that use a config.h.
1914 Support handling --with-PACKAGE options.
1915 New `autoheader' script to create `config.h.in' from `configure.in'.
1916 Ignore troublesome -lucb and -lPW when searching for alloca.
1917 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1918 Improve detection of STDC library.
1919 Add AC_HAVE_LIBRARY to check for non-default libraries.
1920 Function checking should work with future GNU libc releases.
1922 Major changes in Autoconf 1.2:
1924 The --srcdir option is now usually unnecessary.
1925 Add a file containing sample comments describing CPP macros.
1926 A comment in config.status tells which host it was configured on.
1927 Substituted variable values can now contain commas.
1928 Fix bugs in various feature checks.
1930 Major changes in Autoconf 1.1:
1932 Added AC_STRCOLL macro.
1933 Made AC_GETLOADAVG check for more things.
1934 AC_OUTPUT argument is now optional.
1939 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1940 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
1942 Copying and distribution of this file, with or without modification,
1943 are permitted in any medium without royalty provided the copyright
1944 notice and this notice are preserved. This file is offered as-is,
1945 without warranty of any kind.