1 GNU Autoconf NEWS - User visible changes.
3 * Major changes in Autoconf 2.65a (????-??-??) [experimental]
6 ** AC_FUNC_MMAP works in C++ mode again. Regression introduced in 2.65.
8 ** Use of m4_divert without a named diversion now issues a syntax warning,
9 since it is seldom right to change diversions behind autoconf's back.
11 ** The macros AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, and
12 AC_TYPE_INT64_T work again. Regression introduced in 2.65.
14 ** AC_PROG_INSTALL correctly uses `shtool' again. Regression introduced
17 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
18 Released by Eric Blake, based on git versions 2.64.*.
20 ** Autoconf is now licensed under the General Public License version 3
21 or later (GPLv3+). As with earlier versions, the license includes
22 an exception clause so that you may release a configure script
23 generated by autoconf under the license of your own program.
25 ** New macros to support Objective C++.
26 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
28 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
32 These macros are present only for backwards compatibility purposes.
34 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
35 lack fopen in the C library, such as AVR or RTEMS (regression
38 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
39 made it fail with some Fortran compilers (regression introduced in
42 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
43 longer mistakenly select a 32-bit type on some compilers (bug present
44 since macros were introduced in 2.59c).
46 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
47 Cygwin (bug present since macro was introduced in 2.0).
49 ** The following documented autotest macros are new:
52 ** The following m4sugar macros now quote their expansion:
55 ** The following m4sugar macros are new:
58 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
59 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
60 this gives the intuitive behavior of "[b c]" in the output (2.63
61 gave the output of "[b], [c]", and 2.64 encountered a failure).
63 ** The `$tmp' temporary directory used in config.status is documented for
66 ** config.status now provides a --config option to produce the configuration.
68 ** Many cache variables used by Autoconf's macros are now documented.
70 ** Configure scripts work better on DJGPP by avoiding a bug present in
71 the DJGPP port of bash 2.04 in handling 'return' in a shell
72 function (regression introduced in 2.64).
74 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
75 Released by Eric Blake, based on git versions 2.63b.*.
77 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
78 have a bug in regular expression handling that interferes with some
79 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
82 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
83 given arguments that expand to just whitespace.
85 ** The following documented autoconf macros are new:
86 AC_ERLANG_SUBST_ERTS_VER
88 ** The autoheader tool now understands m4 macro arguments passed to
89 AC_DEFINE and AC_DEFINE_UNQUOTED.
91 ** Ensure AT_CHECK can support commands that include a # given with
92 proper m4 quoting. For shell comments, this is a new feature; for
93 non-shell comments, this fixes a regression introduced in 2.63b.
94 Additionally, AT_CHECK correctly supplies shell escapes for
95 metacharacters occurring in m4 macro expansions within the expected
96 stdout and stderr parameters.
98 ** The macro AT_CHECK now understands the concept of hard failure. If
99 a test exits with an unexpected status 99, cleanup actions for the
100 test are inhibited and the test is treated as a failure regardless
101 of AT_XFAIL_IF. It also understands the new directives
102 ignore-nolog, stdout-nolog, and stderr-nolog.
104 ** The following documented autotest macros are new:
105 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
107 ** The following documented m4sugar macros are new:
108 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
109 m4_ifblank m4_ifnblank m4_rename_force
111 ** The autoconf testsuite now exercises all Erlang macros.
113 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
114 Released by Eric Blake, based on git versions 2.63.*.
116 ** The manual is now shipped under the terms of the GNU FDL 1.3.
118 ** AC_REQUIRE now detects the case of an outer macro which first expands
119 then later indirectly requires the same inner macro. Previously,
120 this case led to silent out-of-order expansion (bug present since
121 2.50); it now issues a syntax warning, and duplicates the expansion
122 of the inner macro to guarantee dependencies have been met. See
123 the manual for advice on how to refactor macros in order to avoid
124 the bug in earlier autoconf versions and avoid increased script
125 size in the current version.
127 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
128 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
129 expansion was still possible. Now, dependencies are guaranteed,
130 and subsequent invocations are a silent no-op. This makes
131 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
133 ** The following macros are now defined with AC_DEFUN_ONCE. This means
134 a subtle change in semantics; previously, an AC_DEFUN macro could
135 expand one of these macros multiple times or surround the macro
136 inside shell conditional text to bypass the effects of these
137 macros, but now the macro will expand exactly once, and prior to
138 the start of any enclosing AC_DEFUN macro:
139 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
140 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
141 AC_USE_SYSTEM_EXTENSIONS
143 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
145 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
146 longer mistakenly disables assertions.
148 ** AC_INIT now takes an optional fifth parameter that can be used to
149 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
150 used in `configure --help' and is also available via AC_DEFINE.
152 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
153 This feature is still in testing, and may not work on every
154 platform, help in improving it would be appreciated.
156 ** Autotest testsuites do not attempt to write startup error messages
157 to the log file before that is opened (regression introduced in 2.63).
159 ** Configure scripts now use shell functions. This feature leads to
160 smaller configure files and faster execution.
162 ** Present But Cannot Be Compiled: Autoconf will now proceed with
163 the compiler's result if a header is present but cannot be compiled.
164 The warning is still printed, and you should really fix it by
165 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
167 ** Autoreconf added aclocal to the set of programs affected by the
168 `autoreconf -I dir' option.
170 ** The following documented m4sugar macros are new:
171 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
172 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
173 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
174 m4_stack_foreach_lifo m4_stack_foreach_sep
175 m4_stack_foreach_sep_lifo
177 ** The following m4sugar macros are documented now, but in some cases
178 with slightly different semantics than what the previous
179 undocumented version had:
180 m4_copy m4_dumpdefs m4_rename m4_version_prereq
182 ** The m4sugar macro m4_expand has been taught to handle unterminated
183 comments and shell case statements. As a result, it is used
184 internally in more places, such as AC_DEFINE and AT_CHECK. Most
185 uses of AC_DEFINE and AT_CHECK should not behave any differently;
186 however, it may be necessary to add double-quoting around
187 unbalanced `(' where single-quoting used to be sufficient.
189 ** The following documented m4sh macros are new:
190 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
191 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
193 ** The following m4sh macros are documented now, but in some cases
194 with slightly different semantics than what the previous
195 undocumented version had:
196 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
197 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
198 AS_VAR_TEST_SET AS_VERSION_COMPARE
200 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
201 The responsibility for supplying a trailing newline now belongs to
202 the call site, but since most users did not add dnl, this generally
203 results in fewer empty lines in configure.
206 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
207 Released by Eric Blake, based on git versions 2.62.*.
209 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
210 bigendian hosts, a regression introduced with universal binary
213 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
216 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
217 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
218 2.62 when using macros such as AC_AIX that were made obsolete in
219 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
221 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
223 ** Newly obsolete macros
224 The following macro has been marked obsolete, since current porting
225 targets can safely assume C89 semantics that signal handlers return
226 void. We have no current plans to remove the macro.
230 ** The macros m4_map and m4_map_sep now ignore any list elements
231 consisting of just empty quotes, and m4_map_sep now expands its
232 separator. This fixes a regression in 2.62 when these macros were
233 first documented, for the sake of clients expecting the semantics
234 that these macros had prior to that time. The new macros m4_mapall
235 and m4_mapall_sep, along with extra quoting of the separator, can
236 be used to get the semantics that m4_map_sep had in 2.62.
238 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
239 handle properly quoted but otherwise unbalanced parentheses (for
240 some macros, this fixes a regression in 2.62).
242 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
243 allowing the output of unbalanced parentheses in more contexts.
245 ** The following m4sugar macros are new:
246 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
247 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
248 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
249 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
250 m4_set_remove m4_set_size m4_set_union
252 ** The following m4sugar macros now accept multiple arguments, as is the
253 case with underlying m4:
254 m4_defn m4_popdef m4_undefine
256 ** The following m4sugar macros now guarantee linear scaling; they
257 previously had linear scaling with m4 1.6 but quadratic scaling
258 when using m4 1.4.x. All macros built on top of these also gain
259 the scaling improvements.
260 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
261 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
264 ** AT_KEYWORDS once again performs expansion on its argument, such that
265 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
266 the possibly unexpanded m4_if [regression introduced in 2.62].
268 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
269 nested comments any more; regression introduced in 2.62.
272 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
273 Released by Eric Blake, based on git versions 2.61a.*.
275 ** Many optimizations have been applied to make overall execution faster.
277 ** Autotest now makes use of shell functions.
279 ** config.status now uses awk instead of sed also for config headers.
281 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
282 values, i.e., backslash-newline combinations are handled correctly.
283 Further, for config headers, the total size of values is not limited by
284 the POSIX length limit of text lines any more, only each single line.
286 ** New config variable `top_build_prefix'.
288 ** New Autoconf macros:
289 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
291 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
293 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
294 like '__restrict' if the variant spelling is available, as this is
295 more likely to work when mixing C and C++ code.
297 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
298 be a string of tokens such that "T y;" is a valid member declaration
301 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
302 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
304 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
305 they did not work for function types. In C++, they now work on any
306 type-id that can be the operand of sizeof; this is similar to C,
307 except it excludes anonymous struct and union types. Formerly,
308 some (but not all) C++ types involving anonymous struct and union
309 were accepted, though this was not documented.
311 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
312 if found, and it works to link against a file of the same name in
313 the source tree, even if both trees coincide.
315 ** AC_INIT no longer alters $@; regression introduced in 2.60.
317 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
319 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
320 the case where the first argument contains single-quoted commas.
321 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
322 " -a, --arg[=foo] bar"
323 Additionally, the macro now takes two additional arguments,
324 indent-column and wrap-column; these should not normally be needed,
325 but can be used to fine-tune how the output text is wrapped.
327 ** AC_PROG_INSTALL now requires an install program that can install multiple
328 files into a target directory.
330 ** The command 'autoconf -' now correctly processes a file from stdin.
332 ** 'autoreconf -m' now honors $MAKE.
334 ** For all of the directory arguments for 'configure', such as '--prefix'
335 or '--bindir', trailing slashes are stripped. As an example, if
336 tab completion in the user's shell appends trailing slashes, the
337 command './configure --prefix=/usr/' will still result in an
338 expanded libdir value of /usr/lib, not /usr//lib.
340 ** `configure --help=recursive' now works in read-only trees and from
341 unconfigured build trees.
343 ** If precious variables differ only in whitespace, then the cache consistency
344 check warns instead of fails, and reuses the old value.
346 ** AT_BANNER is now documented.
348 ** AT_SETUP now handles macro expansions properly when calculating line
351 ** Autotest now determines $srcdir correctly.
353 ** Testsuites built by autotest now accept a -C/--directory=DIR option
354 to adjust the working directory prior to creating files.
356 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
357 a bug in macro tracing that interferes with the interaction between
358 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
359 configure search for a working M4 is improved.
361 ** For portability with the eventual M4 2.0, macros should no longer use
362 anything larger than $9 to refer to arguments.
364 ** Documentation for m4sugar is improved.
366 - The following macros were previously available as undocumented
367 interfaces; the macros are now documented as stable interfaces.
369 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
370 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
371 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
372 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
373 m4_n m4_shiftn m4_strip m4_warn
375 - The following macros were previously available as undocumented
376 interfaces, but had bug fixes or semantic changes as part of this
377 release. Packages that relied on the undocumented behavior
378 should be analyzed to make sure they will still work with the
379 new documented behavior.
381 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
382 m4_text_box m4_text_wrap m4_version_compare
384 - The m4_wrap macro used to have unspecified order, but now
385 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
388 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
389 should consider using the new AC_AUTOCONF_VERSION instead.
391 - m4sugar macros that are not documented in the manual are still
392 deemed experimental, and should not be used outside of Autoconf.
394 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
395 2.60, have been fixed to treat both the string and the separator
396 arguments consistently with regards to quoting. Prior to this fix,
397 m4_append_uniq could mistakenly duplicate entries if the expansion
398 of the separator resulted in a different string (for example, if it
399 contained quotes, a comma, or a macro name). However, it means
400 that programs previously using
401 m4_append([name], [string], [[, ]])
402 are now using a four-character separator instead of the intended
403 comma and space. If you need portability to earlier versions of
404 Autoconf, you can insert the following snippet after AC_INIT but
405 before any other macro expansions, to enforce the new semantics:
406 m4_pushdef([m4_append], [m4_define([$1],
407 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
408 Additionally, m4_append_uniq now takes optional parameters that can
409 be used to take action depending on whether anything was appended,
410 and warns if a non-empty separator occurs within the string being
411 appended, since that can lead to duplicates.
413 ** The following m4sugar macros are new:
414 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
415 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
416 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
418 ** Warnings are now generated by default when an installer invokes
419 'configure' with an unknown --enable-* or --with-* option.
420 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
421 macro, or by invoking 'configure' with --disable-option-checking.
423 ** Existing obsolete macros
424 The documentation for the following macros is adjusted to make it
425 more clear that they have previously been marked obsolete, as their
426 functionality can be accomplished by other macros. We have no
427 current plans to remove them from Autoconf.
429 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
431 ** Newly obsolete macros
432 The following macros have been marked obsolete, as they only
433 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
434 plans to remove them.
436 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
438 ** AC_C_LONG_DOUBLE is obsolescent.
439 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
440 tests for problems that are so old that it is no longer of
441 practical importance on current systems. New programs need not use
442 AC_C_LONG_DOUBLE. We have no current plans to remove it.
444 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
445 The documentation now favors the use of M4sugar macros m4_warn and
446 m4_fatal, since the naming makes it more obvious that the
447 diagnostics are associated with M4 expansion (ie. when running
448 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
449 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
450 when running `configure'. We have no current plans to remove these
454 * Major changes in Autoconf 2.61a (2006-12-11)
456 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
457 on many platforms. This has been fixed.
459 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
460 compatibility but it does nothing. The macro was already
461 obsolescent, as the last systems to have the problem were those
462 based on SVR2, which became obsolete in 1987. The macro had bugs
463 on some modern systems and could no longer be maintained reliably
464 due to lack of ancient systems to test it on.
466 ** config.status now uses awk instead of sed for most substitutions, for speed.
468 - As a side effect multi-line values of substituted variables no
469 longer have a small limit in total size, though for portability
470 each line should not exceed the POSIX length limit for text lines.
472 - It is now documented that Makefile.in should not contain
473 overlapping variable occurrences, e.g., @VAR1@VAR2@.
474 Autoconf's behavior was always iffy in such cases, and the
475 awk implementation has changed the behavior.
477 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
478 scripts have fewer problems with strings or file names containing
479 embedded special characters such as backslash or leading "-". This
480 was implemented by using `printf '%s\n' "$foo"' instead of `echo
481 "$foo"' when printf works. Due to the implementation technique
482 used, Autoconf-generated scripts now run considerably more slowly
483 on ancient implementations lacking printf. However, this should
484 not be a problem, since Autoconf-generated scripts in practice
485 invariably find a more-modern shell these days.
488 * Major changes in Autoconf 2.61 (2006-11-17)
490 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
492 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
495 * Major changes in Autoconf 2.60b (2006-10-22)
498 Autoconf-generated shell scripts no longer export BIN_SH, due to
499 configuration hassles with this. Installers who need BIN_SH in
500 their environment should set it before invoking 'configure' and
501 'make'. As far as we know, this affects only Unixware installations.
503 ** Obsolescent macros
504 The documentation now says that the following macros are obsolescent,
505 as they are superseded by Gnulib:
507 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
509 New programs should use the Gnulib counterparts of these macros.
510 We have no current plans to remove them from Autoconf.
512 ** AC_COMPUTE_INT no longer caches or reports results.
514 ** AC_CHECK_DECL now also works with aggregate objects.
516 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
518 ** GNU M4 1.4.7 or later is now recommended.
521 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
524 Now an alias for m4_mkstemp.
526 * Major changes in Autoconf 2.60a (2006-08-25)
528 ** GNU M4 1.4.6 or later is now recommended.
530 ** The check for C99 now tests for varargs macros, as documented.
531 It also tests that the preprocessor supports 64-bit integers.
533 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
534 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
536 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
537 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
538 two macros are different, so autoupdate will not change the old private name
539 to the new one. _AC_COMPUTE_INT may be removed in a future release.
541 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
542 that long long types be at least 64 bits wide, as C99 and tradition
543 requires. Formerly, they accepted implementations of any width.
546 * Major changes in Autoconf 2.60
548 Released 2006-06-23, by Ralf Wildenhues.
550 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
551 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
552 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
554 ** Provide a way to turn off warnings about the changed directory variables.
556 * Major changes in Autoconf 2.59d
558 Released 2006-06-05, by Ralf Wildenhues.
560 ** GNU make now recommended for VPATH builds
561 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
562 only if you use GNU make. In practice, other 'make' implementations
563 have too many subtle incompatibilities in their support for VPATH.
564 Many packages (including Autoconf itself) are portable to other
565 'make' implementations, but some packages are not, and recommending
566 GNU make keeps the installation instructions simpler.
568 ** Even more safety checks for the new Directory variables:
569 Warn about suspicious `${datarootdir}' found in config files output.
571 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
572 These never-documented macros and variables have been marked with
573 comments saying that they may be removed in a future release,
574 because their use can lead to unintended code being executed.
575 If you need functionality that only these macros or variables
576 currently supply, please write bug-autoconf@gnu.org.
578 ** AC_SUBST, AC_DEFINE
579 Literal arguments to these are passed to m4_pattern_allow now.
582 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
583 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
584 obsolete K&R tests in the Automake test suite.
593 Now more robust with special characters in file names, or when
594 multiple processes create the same directory at the same time.
596 ** Obsolescent macros
597 The documentation now says that the following macros are obsolescent:
598 they test for problems that are so old that they are no longer of
599 practical importance on current systems.
601 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
602 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
603 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
604 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
605 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
606 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
607 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
608 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
610 New programs need not use these macros. We have no current plans to
614 For compatibility with future Libtool 2.0, autoreconf will invoke
615 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
618 * Major changes in Autoconf 2.59c
620 Released 2006-04-12, by Ralf Wildenhues.
622 ** The configure command now redirects standard input from /dev/null,
623 to help avoid problems with subsidiary commands that might mistakenly
624 read standard input. AS_ORIGINAL_STDIN_FD points to the original
625 standard input before this redirection, if you really want configure to
626 read from standard input.
628 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
629 The following directory variables are new:
631 datarootdir read-only architecture-independent data root [PREFIX/share]
632 localedir locale-specific message catalogs [DATAROOTDIR/locale]
633 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
634 htmldir html documentation [DOCDIR]
635 dvidir dvi documentation [DOCDIR]
636 pdfdir pdf documentation [DOCDIR]
637 psdir ps documentation [DOCDIR]
639 The following variables have new default values:
641 datadir read-only architecture-independent data [DATAROOTDIR]
642 infodir info documentation [DATAROOTDIR/info]
643 mandir man documentation [DATAROOTDIR/man]
645 This means that if you use any of `@datadir@', `@infodir@', or
646 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
647 defined in this file. As a temporary measure, if any of those are
648 found but no mention of `datarootdir', the substitutions will be
649 replaced with values that do not contain `${datarootdir}', and a
650 warning will be issued.
652 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
653 a trailing slash. Similar change will be made to ac_top_builddir in a
654 future release; the old style value, which matches (../)*, is (and will
655 continue to be) available as ac_top_build_prefix.
658 New macro to check for support of 'typeof' syntax a la GNU C.
660 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
661 New "once-only" variants of commonly-used macros, to make 'configure'
662 smaller and faster in common cases.
665 New macro to check for strtold with C99 semantics.
668 New macro that lets builder disable assertions at 'configure'-time.
671 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
672 X11/Intrinsic.h and XtMalloc (Xt).
674 ** AC_PRESERVE_HELP_ORDER
675 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
676 and AC_ARG_WITH arguments in one region, in the order defined. The default
677 behavior is to group options of each classes separately.
679 ** AC_PROG_CC, AC_PROG_CXX
680 No longer automatically arrange to declare the 'exit' function of C,
681 when a C++ compiler is used. Standard Autoconf macros no longer use
682 'exit', so this is no longer an issue for them. If you use C++, and
683 want to call 'exit', you'll have to arrange for its declaration
684 yourself. But we now suggest you return from 'main' instead.
686 ** AC_PROG_CC_C89, AC_PROG_CC_C99
687 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
688 check for ANSI C89 and ISO C99 support respectively.
691 Has been unobsoleted, and will check if the compiler supports ISO
692 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
693 retained for backwards compatibility, assuming the value of
694 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
697 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
698 New macros for checking commonly-used members of struct dirent.
701 The substituted value can now contain newlines.
704 The substitution now occurs only when @variable@ is on a line by itself,
705 optionally surrounded by spaces and tabs. The whole line is replaced.
707 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
708 New macros to check for long double, and whether it is wider than double.
709 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
710 applications should switch to the new macro.
712 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
713 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
714 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
715 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
716 New macros to check for C99 and POSIX types.
718 ** AC_USE_SYSTEM_EXTENSIONS
719 New macro to enable extensions to Posix.
722 New macro which is defined to the name of the first declared config header
723 or undefined if no config headers have been declared yet.
726 The macro correctly handles quadrigraphs now.
728 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
729 These macros are new or published now.
732 New macro for copyright notices in testsuite files.
734 ** ALLOCA, LIBOBJS, LTLIBOBJS
735 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
736 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
737 `Makefile.in' in case the object files lie in a different directory.
738 The LIBOBJDIR feature is experimental.
741 Supports --no-recursive now.
743 ** New macros to support Erlang/OTP.
744 New macros for configuring paths to Erlang tools and libraries:
745 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
746 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
747 AC_ERLANG_SUBST_LIB_DIR.
749 New macros for configuring installation of Erlang libraries:
750 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
752 ** The manual now mentions Gnulib more prominently.
754 ** New macros to support Objective C.
755 AC_PROG_OBJC, AC_PROG_OBJCPP.
757 * Major changes in Autoconf 2.59b
759 Released 2004-08-20, by Paul Eggert.
762 New macro that computes the default alignment of a type.
764 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
765 When cross-compiling, these macros will give a warning if the tool
766 is not prefixed. In the future, unprefixed cross tools will not
767 be detected; please consult the info documentation for information
768 about the reason of this change.
770 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
771 New macros that detect programs whose name is prefixed with the
772 target type, if the build type and target type are different.
774 ** AC_REQUIRE_AUX_FILE
775 New trace macro that declares expected auxiliary files.
778 New macro that tests for a grep program that accepts as a long a line
781 ** AC_PROG_EGREP, AC_PROG_FGREP
782 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
783 FGREP="$GREP -F" respectively if possible, or else run a path search for
784 a program that accepts as long a line as possible.
787 New macro that tests for a sed program that truncates as few characters
790 * Major changes in Autoconf 2.59
792 Released 2003-11-04, by Akim Demaille
794 ** ac_abs_builddir etc.
795 Absolute file names were actually relative in 2.58.
797 * Major changes in Autoconf 2.58
799 Released 2003-11-04, by Akim Demaille
802 core.* files are no longer removed, as they may be valid user files.
804 ** autoreconf and auxiliary directory
805 Autoreconf creates the auxiliary directory if needed. This is
806 especially useful for initial "bootstrapping" of fresh CVS checkouts.
808 ** AC_CONFIG_MACRO_DIR
809 Use this macro to declare the directory for local M4 macros for aclocal.
812 No longer includes twice the same file in LIBOBJS if invoked
815 ** AC_CONFIG_COMMANDS
816 The directory for its first argument is automatically created. For
819 AC_CONFIG_COMMANDS([src/modules.hh], [...])
821 $top_builddir/src/ is created if needed.
823 ** Autotest and local.at
824 The optional file local.at is always included in Autotest test suites.
827 The warnings are always issued, including with cached runs.
828 This became a significant problem since aclocal and automake can
829 run autoconf behind the scene.
831 ** autoheader warnings
832 The warnings of autoheader can be turned off, using --warning.
833 For instance, -Wno-obsolete disables the complaints about acconfig.h
834 and other deprecated constructs.
837 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
840 ** AC_DECL_SYS_SIGLIST
844 Now checks that mktime is the inverse of localtime.
846 ** Improve DJGPP portability
847 The Autoconf tools and configure behave better under DJGPP.
849 ** Present But Cannot Be Compiled
850 New FAQ section dedicated to the mystic
852 configure: WARNING: pi.h: present but cannot be compiled
853 configure: WARNING: pi.h: check for missing prerequisite headers?
854 configure: WARNING: pi.h: proceeding with the preprocessor's result
857 ** Concurrent executions of autom4te
858 autom4te now locks its internal files, which enables concurrent
859 executions of autom4te, likely to happen if automake, autoconf,
860 autoheader etc. are run simultaneously.
863 Use of Libtool 1.5 and higher is encouraged. Compatibility with
864 Libtool pre-1.4 is not checked.
867 Testsuites no longer rerun failed tests in verbose mode; instead,
868 failures are logged while the test is run.
870 In addition, expected failures can be marked as such.
872 * Major changes in Autoconf 2.57
874 Released 2002-12-03 by Paul Eggert.
876 Bug fixes for problems with AIX linker, with freestanding C compilers,
877 with GNU M4 limitations, and with obsolete copies of GNU documents.
879 The Free Documentation License has been upgraded from 1.1 to 1.2.
881 * Major changes in Autoconf 2.56
883 Released 2002-11-15 by Akim Demaille.
885 One packaging problem fixed (config/install-sh was not executable).
887 * Major changes in Autoconf 2.55
889 Released 2002-11-14 by Akim Demaille.
893 Have your configure.ac checked by autoscan ("autoscan").
894 Try the warning options ("autoreconf -fv -Wall").
898 - AC_CHECK_HEADER, AC_CHECK_HEADERS
899 More information on proper use.
901 - Writing Test Programs
903 This sections explains how to write good test sources to use with
904 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
906 - AC_FOO_IFELSE vs. AC_TRY_FOO
908 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
909 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
913 - Is more robust to different Gettext installations.
915 - Produces messages (when --verbose) to be understood by Emacs'
918 - Supports -W/--warnings.
921 Once the GNU Build System reinstalled, run `./config.status
922 --recheck && ./config.status && make' if possible.
926 - Supports --cache, and --no-cache.
928 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
929 (autom4te.cache). See `Customizing autom4te' in the documentation.
936 Support for the obsoleted options -m, --macrodir, -l, --localdir is
937 dropped in favor of the safer --include/--prepend-include scheme.
942 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
943 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
944 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
947 Obsoleted macros are kept for Autoconf backward compatibility, but
948 should be avoided in configure.ac. Running autoupdate is advised.
951 - AC_DEFINE/AC_DEFINE_UNQUOTED
953 We have to stop using the old compatibility scheme --that tried to
954 avoid useless backslashes-- because Libtool 1.4.3 contains a
956 AC_DEFINE([error_t], [int],
957 [Define to a type to use for \`error_t' if it is not
958 otherwise available.])
960 We have to quote the single quotes and backslashes with \. The old
961 compatibility scheme saw that ` was backslashed, and therefore did
962 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
963 compatible with Libtool. Autoconf 2.55 is, but in some cases might
964 produce more \ than wanted.
966 Please, note that in the future the same problem will happen with
967 AC_MSG_*: use `autoreconf -f -Wall'.
971 - Portability of the Autoconf package to Solaris.
973 - Spurious warnings caused by config.status.
974 This bug is benign, but painful: on some systems (typically
975 FreeBSD), warnings such as:
977 config.status: creating Makefile
978 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
980 could be issued. This is fixed.
983 Simultaneous executions of config.status are possible again.
985 - Precious variables accumulation
987 config.status could stack several copies of the precious variables
991 ** Plans for later versions
995 The compatibility hooks with the old scheme will be completely
996 removed. Please, advice/use `--build', `--host', and `--target'
999 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1001 The tests will be stricter, please make sure your invocations are
1006 Shell functions will gradually be introduced, probably starting with
1007 Autotest. If you know machines which are in use that you suspect
1008 *not* to support shell functions, please run the test suite of
1009 Autoconf 2.55 on it, and report the results to
1010 bug-autoconf@gnu.org.
1014 Special characters in AC_MSG_* need not be quoted. Currently,
1015 Autoconf has heuristics to decide when a string is escaped, or has
1016 to be escaped. This scheme is fragile, and will be removed; the
1017 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1018 to find occurrences that will be affected.
1020 * Major changes in Autoconf 2.54
1022 Released 2002-09-13 by Akim Demaille.
1026 - autoreconf no longer changes the version of the gettext/po/intl
1027 support files. It now adds the files the correspond to the
1028 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1030 Warning: It now relies on the 'autopoint' program, which is part
1031 of GNU gettext 0.11.4 and newer.
1033 Please note that you need to have a GNU gettext version that
1034 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1035 in configure.ac. You can upgrade to newer GNU gettext versions,
1036 though, without needing to change configure.ac.
1038 - The -I DIR or --include=DIR option now appends DIR to the include path
1039 instead of prepending; this is for consistency with other GNU tools.
1040 The new -B DIR or --prepend-include=DIR option has the old behavior.
1045 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1046 Please, remove lines such as
1048 # This is necessary so that .o files in LIBOBJS are also
1049 # built via the ANSI2KNR-filtering rules.
1050 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1052 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1053 your Makefiles either.
1055 - AC_CONFIG_LINKS now makes copies if it can't make links.
1057 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1058 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1059 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1061 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1063 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1065 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1069 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1070 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1071 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1073 - AC_FUNC_GETLOADAVG
1074 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1077 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1078 for an AC_LIBOBJ replacement.
1082 - Spurious complaints from `m4_bmatch' about invalid regular
1083 expressions are suppressed.
1085 - Empty top_builddirs are properly handled.
1087 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1090 Now colon in the optional path arguments are properly handled.
1092 ** Improved portability
1094 - Both Autoconf the package, and the scripts it produces, should run
1095 more reliably with Zsh. Bear in mind it is the default Bourne shell
1098 - Autoconf and the scripts it produces no longer assume the existence of
1099 the obsolescent commands egrep and fgrep.
1103 - Limitations of Make
1107 The GNATS base moved to
1108 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1109 (It is no longer available, though.)
1114 Now contains the list of ouput variables and files (AC_SUBST,
1117 * Major changes in Autoconf 2.53
1119 Released 2002-03-08 by Akim Demaille.
1123 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1124 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1130 Argument requirements, output variables, defined macros.
1131 - M4sugar, M4sh, Autotest
1133 - Double quoting macros
1134 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1136 The Autoconf manual is now distributed under the terms of the GNU FDL.
1137 - Section `Hosts and Cross-Compilation'
1138 Explains the rationale for the 2.5x changes in the cross-compilation
1139 chain, and in the relationships between build, host, and target
1141 Emphasizes that `cross-compilation' == `--host is given'.
1142 If you are working on compilers etc., be sure to read this section.
1143 - Section `AC_LIBOBJ vs. LIBOBJS'
1144 Explains why assigning LIBOBJS directly is now an error.
1145 Details how to update the code.
1150 Now used instead of hard coded line numbers.
1151 This eases the comparison of `configure's, and diminishes the
1152 pressure over control version archives.
1153 Automatic replacement for shells that don't support this feature.
1154 - New output variables
1155 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1160 Autoconf and Autotest modes are provided.
1165 New, used by the Autoconf suite to cache and speed up most processing.
1167 Supported by autom4te, autoconf and autoheader.
1169 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1170 autoupdate, and autoreconf.
1172 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1173 automake options are to be given via AUTOMAKE_OPTIONS.
1175 Runs gettextize and libtoolize when appropriate.
1177 --m4dir is no longer supported.
1179 Now runs only in the specified directories, defaulting to `.',
1180 but understands AC_CONFIG_SUBDIRS for dependent directories.
1181 Before, it used to run on all the `configure.ac' found in the
1183 Independent packages are properly updated.
1187 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1189 Under the user pressure, $? is finally available. Probably a mistake.
1190 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1191 - Precious variables accumulation
1192 config.status could stack several copies of the precious variables
1194 - AC_PATH_PROG and family.
1195 Works properly when given a literal path.
1197 Somewhere since 2.13, the result had been reversed.
1201 - AC_C_BIGENDIAN supports the cross-compiling case.
1202 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1203 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1204 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1206 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1207 precision than `double'.
1212 It now defines the preprocessor symbols PACKAGE_NAME,
1213 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1217 Admits a fourth optional parameter: the tar name.
1219 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1220 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1221 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1222 ac_abs_top_builddir.
1224 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1225 Are much less expensive when using long lists of files.
1228 Works with shell variables, and non alphanumeric names.
1232 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1233 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1235 - AC_FUNC_STRTOD substitutes POW_LIB.
1240 * Major changes in Autoconf 2.52
1242 Released 2001-07-18 by Akim Demaille.
1247 This feature was present in autoconf 2.50 but was not documented.
1248 For example, `@<:@' is translated to `[' just before output. This
1249 is useful when writing strings that contain unbalanced quotes, or
1250 other hard-to-quote constructs.
1251 - m4_pattern_forbid, m4_pattern_allow
1252 - Tips for upgrading from 2.13.
1253 - Using autoscan to maintain a configure.ac.
1256 - Now include stdint.h.
1257 - sys/types.h and sys/stat.h are guarded.
1258 - strings.h is included if available, and not conflicting with string.h.
1261 - The test suite is more robust and presents less false failures.
1262 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1263 - configure accepts --prefix='' again.
1264 - AC_CHECK_LIB works properly when its first argument is not a
1266 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1267 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1268 - AC_ARG_VAR properly propagates precious variables inherited from the
1269 environment to ./config.status.
1270 - Using --program-suffix/--program-prefix is portable.
1271 - Failures to detect the default compiler's output extension are less
1273 - `config.status foo' works properly when `foo' depends on variables
1274 set in an AC_CONFIG_THING INIT-CMD.
1275 - autoheader is more robust to broken input.
1276 - Fixed Fortran name-mangling and link tests on a number of systems,
1277 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1280 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1281 specify pre-includes. In this case, the headers are compiled with
1282 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1283 of a header which is checked for, not just its availability.
1284 - AC_ARG_VAR refuses to run configure when precious variables have
1286 - Versions of compilers are dumped in the logs.
1287 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1290 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1291 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1292 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1293 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1294 Be sure to read `Upgrading from Version 2.13' to understand why
1295 running `autoupdate' is needed.
1296 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1297 a main-like routine is required/possible when linking C/C++ with
1298 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1299 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1301 * Major changes in Autoconf 2.51
1302 There was no release of Autoconf 2.51 since some packagers had used
1303 this version number without permission to ship intermediary versions
1304 of 2.50. The version was skipped to avoid confusion.
1306 * Major changes in Autoconf 2.50
1308 Released 2001-05-21 by Akim Demaille.
1310 ** Lots of bug fixes
1311 There have been far too many to enumerate them here. Check out
1312 ChangeLog if you really want to know more.
1314 ** Improved documentation
1315 In particular, portability issues are better covered.
1318 All the standard GNU Makefile targets are supported. The layout has
1319 changed: m4/ holds the M4 extensions Autoconf needs for its
1320 configuration, doc/ contains the documentation, and tests/ contains
1323 ** Man pages are provided
1324 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1325 config.guess, config.sub.
1329 Provides a safe and powerful means to trace the macro uses. This
1330 provide the parsing layer for tools which need to `study'
1334 Specify what category of warnings should be enabled.
1336 - When recursing into subdirectories, try for configure.gnu before
1337 configure to adapt for packages not using autoconf on case-insensitive
1341 More errors are now caught (circular AC_REQUIRE dependencies,
1342 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1343 etc.). In addition, their location and call stack are given.
1346 autoupdate is much more powerful, and is able to provide the glue code
1347 which might be needed to move from an old macro to its newer
1350 You are strongly encouraged to use it to modernize both your
1351 `configure.in' and your .m4 extension files.
1354 The internal machinery of autoheader has completely changed. As a
1355 result, using `acconfig.h' should be considered to be obsoleted, and
1356 you are encouraged to get rid of it using the AH macros.
1361 ** Fortran 77 compilers
1362 Globally, the support for Fortran 77 is considerably improved.
1364 Support for automatically determining a Fortran 77 compiler's
1365 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1366 provided to wrap C/C++ identifiers, thus making it easier and more
1367 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1368 call C/C++ routines. See the Texinfo documentation for details.
1371 The test suite no longer uses DejaGNU. It should be easy to submit
1372 test cases in this new framework.
1375 - --help, --help=long, -hl
1376 no longer dumps useless items.
1378 lists only specific options.
1379 - --help=recursive, -hr
1380 displays the help of all the embedded packages.
1381 - Remembers environment variables when reconfiguring.
1382 The previous scheme to set envvar before running configure was
1384 what prevented configure from remembering the environment in which
1385 it was run, therefore --recheck was run in an inconsistent
1386 environment. Now, one should run
1388 and then --recheck will work properly. Variables declared with
1389 AC_ARG_VAR are also preserved.
1391 $build defaults to `config.guess`, $host to $build, and then $target
1393 Cross-compilation is a global status of the package, it no longer
1394 depends upon the current language.
1395 Cross compilation is enabled iff the user specified `--host'.
1396 `configure' now fails if it can't run the executables it compiles,
1397 unless cross-compilation is enabled.
1399 The cache file is disabled by default. The new options
1400 `--config-cache', `-C' set the cache to `config.cache'.
1404 Much faster on most architectures.
1405 - concurrent executions
1406 It is safe to use `make -j' with config.status.
1407 - human interface improved
1408 It is possible to invoke
1409 ./config.status foobar
1410 instead of the former form (still valid)
1411 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1412 CONFIG_FILES=foobar:foo.in:bar.in \
1414 The same holds for configuration headers and links.
1415 You can instantiate unknown files and headers:
1416 ./config.status --header foo.h:foo.h.in --file bar:baz
1417 - has a useful --help
1418 - accepts special file name "-" for stdin/stdout
1423 Specify additional copyright information.
1426 Now expects the identity of the package as argument.
1430 Most macros, if not all, now strictly follow the `one quotation
1431 level' rule. This results in a more predictable expansion.
1434 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1435 configure scripts, was fixed by Axel Thimm.
1439 Document and ask for the registration of an envvar.
1442 Specifies the file which `configure' should look for when trying to
1443 find the source tree (used to be handled by AC_INIT).
1445 - AC_CONFIG_COMMANDS
1446 To add new actions to config.status. Should be used instead of
1450 Replaces AC_LINK_FILES.
1452 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1453 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1454 They now obey sh: you should no longer use shell variables as
1455 argument. Instead of
1457 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1458 AC_CONFIG_SUBDIRS($my_subdirs)
1462 if test "$package_foo_enabled" = yes; then
1463 AC_CONFIG_SUBDIRS(foo)
1467 To format an Autoconf macro's help string so that it looks pretty
1468 when the user executes `configure --help'.
1471 ** Generic Test Macros
1473 The interface of the AC_CHECK families of macros (decl, header,
1474 type, member, func) is now uniform. They support the same set of
1477 - AC_CHECK_DECL, AC_CHECK_DECLS
1478 To check whether a symbol is declared.
1480 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1481 No longer need a cross-compilation default.
1484 The test it performs is much more robust than previously, and makes
1485 it possible to test builtin types in addition to typedefs.
1486 It is now schizophrenic:
1487 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1488 remains for backward compatibility, but its use is discouraged.
1489 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1490 behaves exactly like the other AC_CHECK macros.
1493 Checks whether given types are supported by the system.
1495 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1496 Check for given members in aggregates (e.g., pw_gecos in struct
1500 Checks if the compiler supports ISO C, included when needs special
1504 Checking whether the preprocessor indicates missing includes by the
1505 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1508 Takes a language as argument and replaces AC_LANG_C,
1509 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1511 - AC_LANG_PUSH, AC_LANG_POP
1512 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1515 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1516 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1517 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1521 Sets GETGROUPS_LIBS.
1523 - AC_FUNC_GETLOADAVG
1524 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1527 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1530 Arrange for large-file support.
1532 - AC_EXEEXT, AC_OBJEXT
1533 You are no longer expected to use them: their computation is
1534 performed by default.
1536 ** C++ compatibility
1537 Every macro has been revisited in order to support at best CC=c++.
1539 Major changes in Autoconf 2.14:
1540 There was no release of GNU Autoconf 2.14.
1542 Major changes in Autoconf 2.13:
1544 Released 1999-05-01 by Ben Elliston.
1546 * Support for building on Win32 systems where the only available C or
1547 C++ compiler is the Microsoft Visual C++ command line compiler
1548 (`cl'). Additional support for building on Win32 systems which are
1549 using the Cygwin or Mingw32 environments.
1550 * Support for alternative object file and executable file extensions.
1551 On Win32, for example, these are .obj and .exe. These are discovered
1552 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1553 @EXEEXT@ in the output, respectively.
1554 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1555 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1556 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1557 * AC_DEFINE now has an optional third argument for a description to be
1558 placed in the config header input file (e.g. config.h.in).
1559 * The C++ code fragment compiled for the C++ compiler test had to be
1560 improved to include an explicit return type for main(). This was
1561 causing failures on systems using recent versions of the EGCS C++
1563 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1564 script to report that `sometype_t' was present when only `type_t'
1566 * Merge of the FSF version of config.guess and config.sub to modernize
1567 these scripts. Add support for a few new hosts in config.guess.
1568 Incorporate latest versions of install-sh, mkinstalldirs and
1569 texinfo.tex from the FSF.
1570 * autoreconf is capable of running automake if necessary (and
1572 * Support for Fortran 77. See the Texinfo documentation for details.
1573 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1575 Major changes in Autoconf 2.12:
1577 Released 1996-11-26 by David J. MacKenzie
1579 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1580 concatenating multiple input files separated by colons, like so:
1581 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1582 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1583 The arguments may be shell variables, to compute the lists on the fly.
1584 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1585 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1588 Major changes in Autoconf 2.11:
1590 Released November 18th, 1996, by David J. MacKenzie
1592 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1593 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1594 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1595 * AC_CONFIG_HEADER expands shell variables in its argument.
1596 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1597 * The "checking..." messages and the source code for test programs that
1598 fail are saved in config.log.
1599 * Another workaround has been added for seds with small command length limits.
1600 * config.sub and config.guess recognize more system types.
1603 Major changes in Autoconf 2.10:
1605 Released May 7th, 1996, by Roland McGrath
1608 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1609 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1611 Major changes in Autoconf 2.9:
1613 Released March 16th, 1996, by Roland McGrath
1617 Major changes in Autoconf 2.8:
1619 Released March 8th, 1996, by Roland McGrath
1623 Major changes in Autoconf 2.7:
1625 Released November 22nd, 1995, by David J. MacKenzie
1629 Major changes in Autoconf 2.6:
1631 Released November 20th, 1995, by David J. MacKenzie
1635 Major changes in Autoconf 2.5:
1637 Released November 17th, 1995, by Roland McGrath
1639 * New configure options --bindir, --libdir, --datadir, etc., with
1640 corresponding output variables.
1641 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1642 * config.log contains the command being run as well as any output from it.
1643 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1644 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1645 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1646 AC_CHECK_TOOL can search a path other than $PATH.
1647 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1649 Major changes in Autoconf 2.4:
1651 Released June 14th, 1995, by David J. MacKenzie
1653 * Fix a few bugs found by Emacs testers.
1655 Major changes in Autoconf 2.3:
1657 Released March 27th, 1995, by David J. MacKenzie
1659 * Fix the cleanup trap in several ways.
1660 * Handle C compilers that are picky about option placement.
1661 * ifnames gets the version number from the right directory.
1663 Major changes in Autoconf 2.2:
1665 Released March 8th, 1995, by David J. MacKenzie
1667 * The ifnames utility is much faster but requires a "new awk" interpreter.
1668 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1669 library before existing libs, not after, in case it uses them.
1670 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1671 * Lots of bug fixes.
1672 * Many additions to the TODO file :-)
1674 Major changes in Autoconf 2.1:
1676 Released November 4th, 1994, by David J. MacKenzie
1679 * More explanations in the manual.
1680 * Fix a spurious failure in the testsuite.
1681 * Clarify some warning messages.
1682 * autoreconf by default only rebuilds configure and config.h.in files
1683 that are older than any of their particular input files; there is a
1684 --force option to use after installing a new version of Autoconf.
1686 Thanks to everybody who's submitted changes and additions to Autoconf!
1687 I've incorporated many of them, and am still considering others for
1688 future releases -- but I didn't want to postpone this release indefinitely.
1690 Caution: don't indiscriminately rebuild configure scripts with
1691 Autoconf version 2. Some configure.in files need minor adjustments to
1692 work with it; the documentation has a chapter on upgrading. A few
1693 configure.in files, including those for GNU Emacs and the GNU C
1694 Library, need major changes because they relied on undocumented
1695 internals of version 1. Future releases of those packages will have
1696 updated configure.in files.
1698 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1699 Autoconf now makes heavy use of M4 diversions, which were implemented
1700 inefficiently in GNU M4 releases before 1.3.
1702 Major changes in Autoconf 2.0:
1704 Released October 26th, 1994, by David J. MacKenzie
1706 ** New copyright terms:
1707 * There are no restrictions on distribution or use of configure scripts.
1710 * Autoconf manual is reorganized to make information easier to find
1711 and has several new indexes.
1712 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1715 * autoscan to generate a preliminary configure.in for a package by
1716 scanning its source code for commonly used nonportable functions,
1717 programs, and header files.
1718 * ifnames to list the symbols used in #if and #ifdef directives in a
1720 * autoupdate to update a configure.in to use the version 2 macro names.
1721 * autoreconf to recursively remake configure and configuration header
1722 files in a source tree.
1724 ** Changed utilities:
1725 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1726 * autoconf and autoheader can look for package-local definition files
1727 in an alternate directory.
1730 * AC_CACHE_VAL to share results of tests between configure runs.
1731 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1732 that macros invoked with AC_REQUIRE don't interrupt other macros.
1733 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1734 support deciding unguessable features based on the host and target types.
1735 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1736 * AC_ARG_PROGRAM to use the options --program-prefix,
1737 --program-suffix, and --program-transform-name to change the names
1738 of programs being installed.
1739 * AC_PREFIX_DEFAULT to change the default installation prefix.
1740 * AC_TRY_COMPILE to compile a test program without linking it.
1741 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1742 * AC_CHECK_LIB to check for a particular function and library.
1743 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1744 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1745 * AC_SUBST_FILE to insert one file into another.
1746 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1747 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1748 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1749 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1752 * Many macros renamed systematically, but old names are accepted for
1753 backward compatibility.
1754 * AC_OUTPUT adds the "automatically generated" comment to
1755 non-Makefiles where it finds @configure_input@ in an input file, to
1756 support files with various comment syntaxes.
1757 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1758 files when they are not enclosed in @ signs.
1759 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1760 override the file name "config.status".
1761 * AC_OUTPUT takes an optional argument for passing variables from
1762 configure to config.status.
1763 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1764 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1765 CPPFLAGS, and LDFLAGS from the environment.
1766 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1767 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1768 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1769 srcdir/../.. by default.
1770 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1771 * AC_DEFINE no longer prints anything, because of the new result reporting
1772 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1773 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1774 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1775 --enable- and --with- options.
1776 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1777 execute on success or failure.
1778 * Checking for C functions in C++ works.
1781 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1782 better maintained with them.
1783 * AC_ARG_ARRAY removed because no one was likely using it.
1784 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1785 take arguments, for consistency with all of the other specific checks.
1788 * Comes with config.sub and config.guess, and uses them optionally.
1789 * Uses config.cache to cache test results. An alternate cache file
1790 can be selected with the --cache-file=FILE option.
1791 * Uses optional shell scripts $prefix/share/config.site and
1792 $prefix/etc/config.site to perform site or system specific initializations.
1793 * configure saves compiler output to ./config.log for debugging.
1794 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1795 * acsite.m4 is the new name for the system-wide aclocal.m4.
1796 * Has a DejaGnu test suite.
1798 Major changes in Autoconf 1.11:
1800 * AC_PROG_INSTALL calls install.sh with the -c option.
1801 * AC_SET_MAKE cleans up after itself.
1802 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1803 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1805 Plus a few other bug fixes.
1807 Major changes in Autoconf 1.10:
1809 * autoheader uses config.h.bot if present, analogous to config.h.top.
1810 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1812 * AC_PROG_CXX looks for cxx as a C++ compiler.
1814 Plus several bugs fixed.
1816 Major changes in Autoconf 1.9:
1818 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1819 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1820 and autoheader generates entries for those names automatically.
1821 * AC_FIND_X gets the result from xmkmf correctly.
1822 * AC_FIND_X assumes no X if --without-x was given.
1823 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1824 * AC_PROG_INSTALL finds OSF/1 installbsd.
1826 Major changes in Autoconf 1.8:
1829 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1830 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1831 for checking both C++ and C features in one configure script.
1832 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1833 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1834 AC_SET_MAKE, AC_ENABLE.
1837 * AC_FIND_X looks for X in more places.
1838 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1839 install.sh is distributed with Autoconf.
1840 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1841 a rewrite of quoting in AC_DEFINE.
1842 * AC_OUTPUT adds its comments in C format when substituting in C files.
1843 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1845 ** New or changed command line options:
1846 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1847 * configure accepts --without-PACKAGE, which sets withval=no.
1848 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1849 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1850 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1851 * configure accepts and ignores most other Cygnus configure options, and
1852 warns about unknown options.
1853 * config.status accepts --help, --version options.
1855 ** File names and other changes:
1856 * Relative srcdir values are not made absolute.
1857 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1858 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1859 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1860 * The example Makefile dependencies for configure et al. work better.
1861 * Namespace cleanup: all shell variables used internally by Autoconf
1862 have names beginning with `ac_'.
1864 More big improvements are in process for future releases, but have not
1865 yet been (variously) finished, integrated, tested, or documented enough
1868 Major changes in Autoconf 1.7:
1870 * New macro AC_OBSOLETE.
1871 * Bugs in Makefile.in fixed.
1872 * AC_LONG_FILE_NAMES improved.
1874 Major changes in Autoconf 1.6:
1876 * New macro AC_LONG_64_BITS.
1877 * Multiple .h files can be created.
1878 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1879 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1880 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1881 * Unused --no-create option to configure removed.
1882 * autoheader doesn't change the timestamp of its output file if
1883 the file didn't change.
1884 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1885 * config.status checks three optional environment variables to
1886 modify its behavior.
1887 * The usual bug fixes.
1889 Major changes in Autoconf 1.5:
1891 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1892 * autoconf and autoheader scripts have GNU standards conforming
1893 --version and --help options (they print their message and exit).
1896 Major changes in Autoconf 1.4:
1898 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1899 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1900 * autoconf and autoheader use the M4 environment variable to determine the
1901 name of the M4 program to use.
1902 * The --macrodir option to autoconf and autoheader specifies the directory
1903 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1904 * autoconf and autoheader can take `-' as their file names, which means to
1905 read stdin as input.
1906 * Resulting configure scripts can take a --verbose option which causes them
1907 to print the results of their tests.
1908 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1909 shell characters, etc. will be preserved during various stages of
1910 expansion done by the shell. If you don't want this, use
1911 AC_DEFINE_UNQUOTED instead.
1912 * Much textual processing done with external calls to tr and sed have been
1913 internalized with builtin M4 `patsubst' and `translit' calls.
1914 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1915 set the shell variables `gen_files' and `gen_config' to the list of
1916 file names to output.
1917 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1918 "lex.yy" or "lexyy", depending on the system.
1919 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1921 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1922 * AC_CONST works much more reliably on more systems.
1925 Major changes in Autoconf 1.3:
1927 configure no longer requires awk for packages that use a config.h.
1928 Support handling --with-PACKAGE options.
1929 New `autoheader' script to create `config.h.in' from `configure.in'.
1930 Ignore troublesome -lucb and -lPW when searching for alloca.
1931 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1932 Improve detection of STDC library.
1933 Add AC_HAVE_LIBRARY to check for non-default libraries.
1934 Function checking should work with future GNU libc releases.
1936 Major changes in Autoconf 1.2:
1938 The --srcdir option is now usually unnecessary.
1939 Add a file containing sample comments describing CPP macros.
1940 A comment in config.status tells which host it was configured on.
1941 Substituted variable values can now contain commas.
1942 Fix bugs in various feature checks.
1944 Major changes in Autoconf 1.1:
1946 Added AC_STRCOLL macro.
1947 Made AC_GETLOADAVG check for more things.
1948 AC_OUTPUT argument is now optional.
1953 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1954 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation,
1957 Copying and distribution of this file, with or without modification,
1958 are permitted in any medium without royalty provided the copyright
1959 notice and this notice are preserved. This file is offered as-is,
1960 without warranty of any kind.