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 ** Autoconf should work on EBCDIC hosts.
19 ** AC_CHECK_DECL and AC_CHECK_DECLS accept optional function argument types
20 for overloaded C++ functions.
22 ** AS_SET_CATFILE accepts nonliterals in its variable name argument now.
24 ** Autotest testsuites accept an option --recheck to rerun tests that
25 failed or passed unexpectedly during the last non-debug testsuite run.
27 ** AC_ARG_ENABLE and AC_ARG_WITH now also accept `+' signs in `--enable-*'
28 and `--with-*' arguments, converting them to underscores for the variable
31 ** In configure scripts, loading CONFIG_SITE no longer searches PATH,
32 and problems in loading the configuration site files are diagnosed.
34 ** Autotest testsuites may optionally provide colored test results.
36 ** The previously undocumented Autotest macros AT_ARG_OPTION and
37 AT_ARG_OPTION_ARG have seen bug fixes and are documented now.
38 AT_ARG_OPTION has been changed in that the negative of a long option
39 --OPTION is now --no-OPTION rather than --noOPTION.
41 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
42 Released by Eric Blake, based on git versions 2.64.*.
44 ** Autoconf is now licensed under the General Public License version 3
45 or later (GPLv3+). As with earlier versions, the license includes
46 an exception clause so that you may release a configure script
47 generated by autoconf under the license of your own program.
49 ** New macros to support Objective C++.
50 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
52 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
56 These macros are present only for backwards compatibility purposes.
58 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
59 lack fopen in the C library, such as AVR or RTEMS (regression
62 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
63 made it fail with some Fortran compilers (regression introduced in
66 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
67 longer mistakenly select a 32-bit type on some compilers (bug present
68 since macros were introduced in 2.59c).
70 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
71 Cygwin (bug present since macro was introduced in 2.0).
73 ** The following documented autotest macros are new:
76 ** The following m4sugar macros now quote their expansion:
79 ** The following m4sugar macros are new:
82 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
83 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
84 this gives the intuitive behavior of "[b c]" in the output (2.63
85 gave the output of "[b], [c]", and 2.64 encountered a failure).
87 ** The `$tmp' temporary directory used in config.status is documented for
90 ** config.status now provides a --config option to produce the configuration.
92 ** Many cache variables used by Autoconf's macros are now documented.
94 ** Configure scripts work better on DJGPP by avoiding a bug present in
95 the DJGPP port of bash 2.04 in handling 'return' in a shell
96 function (regression introduced in 2.64).
98 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
99 Released by Eric Blake, based on git versions 2.63b.*.
101 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
102 have a bug in regular expression handling that interferes with some
103 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
104 later is recommended.
106 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
107 given arguments that expand to just whitespace.
109 ** The following documented autoconf macros are new:
110 AC_ERLANG_SUBST_ERTS_VER
112 ** The autoheader tool now understands m4 macro arguments passed to
113 AC_DEFINE and AC_DEFINE_UNQUOTED.
115 ** Ensure AT_CHECK can support commands that include a # given with
116 proper m4 quoting. For shell comments, this is a new feature; for
117 non-shell comments, this fixes a regression introduced in 2.63b.
118 Additionally, AT_CHECK correctly supplies shell escapes for
119 metacharacters occurring in m4 macro expansions within the expected
120 stdout and stderr parameters.
122 ** The macro AT_CHECK now understands the concept of hard failure. If
123 a test exits with an unexpected status 99, cleanup actions for the
124 test are inhibited and the test is treated as a failure regardless
125 of AT_XFAIL_IF. It also understands the new directives
126 ignore-nolog, stdout-nolog, and stderr-nolog.
128 ** The following documented autotest macros are new:
129 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
131 ** The following documented m4sugar macros are new:
132 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
133 m4_ifblank m4_ifnblank m4_rename_force
135 ** The autoconf testsuite now exercises all Erlang macros.
137 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
138 Released by Eric Blake, based on git versions 2.63.*.
140 ** The manual is now shipped under the terms of the GNU FDL 1.3.
142 ** AC_REQUIRE now detects the case of an outer macro which first expands
143 then later indirectly requires the same inner macro. Previously,
144 this case led to silent out-of-order expansion (bug present since
145 2.50); it now issues a syntax warning, and duplicates the expansion
146 of the inner macro to guarantee dependencies have been met. See
147 the manual for advice on how to refactor macros in order to avoid
148 the bug in earlier autoconf versions and avoid increased script
149 size in the current version.
151 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
152 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
153 expansion was still possible. Now, dependencies are guaranteed,
154 and subsequent invocations are a silent no-op. This makes
155 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
157 ** The following macros are now defined with AC_DEFUN_ONCE. This means
158 a subtle change in semantics; previously, an AC_DEFUN macro could
159 expand one of these macros multiple times or surround the macro
160 inside shell conditional text to bypass the effects of these
161 macros, but now the macro will expand exactly once, and prior to
162 the start of any enclosing AC_DEFUN macro:
163 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
164 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
165 AC_USE_SYSTEM_EXTENSIONS
167 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
169 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
170 longer mistakenly disables assertions.
172 ** AC_INIT now takes an optional fifth parameter that can be used to
173 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
174 used in `configure --help' and is also available via AC_DEFINE.
176 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
177 This feature is still in testing, and may not work on every
178 platform, help in improving it would be appreciated.
180 ** Autotest testsuites do not attempt to write startup error messages
181 to the log file before that is opened (regression introduced in 2.63).
183 ** Configure scripts now use shell functions. This feature leads to
184 smaller configure files and faster execution.
186 ** Present But Cannot Be Compiled: Autoconf will now proceed with
187 the compiler's result if a header is present but cannot be compiled.
188 The warning is still printed, and you should really fix it by
189 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
191 ** Autoreconf added aclocal to the set of programs affected by the
192 `autoreconf -I dir' option.
194 ** The following documented m4sugar macros are new:
195 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
196 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
197 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
198 m4_stack_foreach_lifo m4_stack_foreach_sep
199 m4_stack_foreach_sep_lifo
201 ** The following m4sugar macros are documented now, but in some cases
202 with slightly different semantics than what the previous
203 undocumented version had:
204 m4_copy m4_dumpdefs m4_rename m4_version_prereq
206 ** The m4sugar macro m4_expand has been taught to handle unterminated
207 comments and shell case statements. As a result, it is used
208 internally in more places, such as AC_DEFINE and AT_CHECK. Most
209 uses of AC_DEFINE and AT_CHECK should not behave any differently;
210 however, it may be necessary to add double-quoting around
211 unbalanced `(' where single-quoting used to be sufficient.
213 ** The following documented m4sh macros are new:
214 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
215 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
217 ** The following m4sh macros are documented now, but in some cases
218 with slightly different semantics than what the previous
219 undocumented version had:
220 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
221 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
222 AS_VAR_TEST_SET AS_VERSION_COMPARE
224 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
225 The responsibility for supplying a trailing newline now belongs to
226 the call site, but since most users did not add dnl, this generally
227 results in fewer empty lines in configure.
230 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
231 Released by Eric Blake, based on git versions 2.62.*.
233 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
234 bigendian hosts, a regression introduced with universal binary
237 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
240 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
241 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
242 2.62 when using macros such as AC_AIX that were made obsolete in
243 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
245 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
247 ** Newly obsolete macros
248 The following macro has been marked obsolete, since current porting
249 targets can safely assume C89 semantics that signal handlers return
250 void. We have no current plans to remove the macro.
254 ** The macros m4_map and m4_map_sep now ignore any list elements
255 consisting of just empty quotes, and m4_map_sep now expands its
256 separator. This fixes a regression in 2.62 when these macros were
257 first documented, for the sake of clients expecting the semantics
258 that these macros had prior to that time. The new macros m4_mapall
259 and m4_mapall_sep, along with extra quoting of the separator, can
260 be used to get the semantics that m4_map_sep had in 2.62.
262 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
263 handle properly quoted but otherwise unbalanced parentheses (for
264 some macros, this fixes a regression in 2.62).
266 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
267 allowing the output of unbalanced parentheses in more contexts.
269 ** The following m4sugar macros are new:
270 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
271 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
272 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
273 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
274 m4_set_remove m4_set_size m4_set_union
276 ** The following m4sugar macros now accept multiple arguments, as is the
277 case with underlying m4:
278 m4_defn m4_popdef m4_undefine
280 ** The following m4sugar macros now guarantee linear scaling; they
281 previously had linear scaling with m4 1.6 but quadratic scaling
282 when using m4 1.4.x. All macros built on top of these also gain
283 the scaling improvements.
284 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
285 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
288 ** AT_KEYWORDS once again performs expansion on its argument, such that
289 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
290 the possibly unexpanded m4_if [regression introduced in 2.62].
292 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
293 nested comments any more; regression introduced in 2.62.
296 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
297 Released by Eric Blake, based on git versions 2.61a.*.
299 ** Many optimizations have been applied to make overall execution faster.
301 ** Autotest now makes use of shell functions.
303 ** config.status now uses awk instead of sed also for config headers.
305 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
306 values, i.e., backslash-newline combinations are handled correctly.
307 Further, for config headers, the total size of values is not limited by
308 the POSIX length limit of text lines any more, only each single line.
310 ** New config variable `top_build_prefix'.
312 ** New Autoconf macros:
313 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
315 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
317 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
318 like '__restrict' if the variant spelling is available, as this is
319 more likely to work when mixing C and C++ code.
321 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
322 be a string of tokens such that "T y;" is a valid member declaration
325 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
326 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
328 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
329 they did not work for function types. In C++, they now work on any
330 type-id that can be the operand of sizeof; this is similar to C,
331 except it excludes anonymous struct and union types. Formerly,
332 some (but not all) C++ types involving anonymous struct and union
333 were accepted, though this was not documented.
335 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
336 if found, and it works to link against a file of the same name in
337 the source tree, even if both trees coincide.
339 ** AC_INIT no longer alters $@; regression introduced in 2.60.
341 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
343 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
344 the case where the first argument contains single-quoted commas.
345 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
346 " -a, --arg[=foo] bar"
347 Additionally, the macro now takes two additional arguments,
348 indent-column and wrap-column; these should not normally be needed,
349 but can be used to fine-tune how the output text is wrapped.
351 ** AC_PROG_INSTALL now requires an install program that can install multiple
352 files into a target directory.
354 ** The command 'autoconf -' now correctly processes a file from stdin.
356 ** 'autoreconf -m' now honors $MAKE.
358 ** For all of the directory arguments for 'configure', such as '--prefix'
359 or '--bindir', trailing slashes are stripped. As an example, if
360 tab completion in the user's shell appends trailing slashes, the
361 command './configure --prefix=/usr/' will still result in an
362 expanded libdir value of /usr/lib, not /usr//lib.
364 ** `configure --help=recursive' now works in read-only trees and from
365 unconfigured build trees.
367 ** If precious variables differ only in whitespace, then the cache consistency
368 check warns instead of fails, and reuses the old value.
370 ** AT_BANNER is now documented.
372 ** AT_SETUP now handles macro expansions properly when calculating line
375 ** Autotest now determines $srcdir correctly.
377 ** Testsuites built by autotest now accept a -C/--directory=DIR option
378 to adjust the working directory prior to creating files.
380 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
381 a bug in macro tracing that interferes with the interaction between
382 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
383 configure search for a working M4 is improved.
385 ** For portability with the eventual M4 2.0, macros should no longer use
386 anything larger than $9 to refer to arguments.
388 ** Documentation for m4sugar is improved.
390 - The following macros were previously available as undocumented
391 interfaces; the macros are now documented as stable interfaces.
393 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
394 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
395 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
396 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
397 m4_n m4_shiftn m4_strip m4_warn
399 - The following macros were previously available as undocumented
400 interfaces, but had bug fixes or semantic changes as part of this
401 release. Packages that relied on the undocumented behavior
402 should be analyzed to make sure they will still work with the
403 new documented behavior.
405 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
406 m4_text_box m4_text_wrap m4_version_compare
408 - The m4_wrap macro used to have unspecified order, but now
409 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
412 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
413 should consider using the new AC_AUTOCONF_VERSION instead.
415 - m4sugar macros that are not documented in the manual are still
416 deemed experimental, and should not be used outside of Autoconf.
418 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
419 2.60, have been fixed to treat both the string and the separator
420 arguments consistently with regards to quoting. Prior to this fix,
421 m4_append_uniq could mistakenly duplicate entries if the expansion
422 of the separator resulted in a different string (for example, if it
423 contained quotes, a comma, or a macro name). However, it means
424 that programs previously using
425 m4_append([name], [string], [[, ]])
426 are now using a four-character separator instead of the intended
427 comma and space. If you need portability to earlier versions of
428 Autoconf, you can insert the following snippet after AC_INIT but
429 before any other macro expansions, to enforce the new semantics:
430 m4_pushdef([m4_append], [m4_define([$1],
431 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
432 Additionally, m4_append_uniq now takes optional parameters that can
433 be used to take action depending on whether anything was appended,
434 and warns if a non-empty separator occurs within the string being
435 appended, since that can lead to duplicates.
437 ** The following m4sugar macros are new:
438 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
439 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
440 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
442 ** Warnings are now generated by default when an installer invokes
443 'configure' with an unknown --enable-* or --with-* option.
444 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
445 macro, or by invoking 'configure' with --disable-option-checking.
447 ** Existing obsolete macros
448 The documentation for the following macros is adjusted to make it
449 more clear that they have previously been marked obsolete, as their
450 functionality can be accomplished by other macros. We have no
451 current plans to remove them from Autoconf.
453 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
455 ** Newly obsolete macros
456 The following macros have been marked obsolete, as they only
457 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
458 plans to remove them.
460 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
462 ** AC_C_LONG_DOUBLE is obsolescent.
463 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
464 tests for problems that are so old that it is no longer of
465 practical importance on current systems. New programs need not use
466 AC_C_LONG_DOUBLE. We have no current plans to remove it.
468 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
469 The documentation now favors the use of M4sugar macros m4_warn and
470 m4_fatal, since the naming makes it more obvious that the
471 diagnostics are associated with M4 expansion (ie. when running
472 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
473 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
474 when running `configure'. We have no current plans to remove these
478 * Major changes in Autoconf 2.61a (2006-12-11)
480 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
481 on many platforms. This has been fixed.
483 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
484 compatibility but it does nothing. The macro was already
485 obsolescent, as the last systems to have the problem were those
486 based on SVR2, which became obsolete in 1987. The macro had bugs
487 on some modern systems and could no longer be maintained reliably
488 due to lack of ancient systems to test it on.
490 ** config.status now uses awk instead of sed for most substitutions, for speed.
492 - As a side effect multi-line values of substituted variables no
493 longer have a small limit in total size, though for portability
494 each line should not exceed the POSIX length limit for text lines.
496 - It is now documented that Makefile.in should not contain
497 overlapping variable occurrences, e.g., @VAR1@VAR2@.
498 Autoconf's behavior was always iffy in such cases, and the
499 awk implementation has changed the behavior.
501 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
502 scripts have fewer problems with strings or file names containing
503 embedded special characters such as backslash or leading "-". This
504 was implemented by using `printf '%s\n' "$foo"' instead of `echo
505 "$foo"' when printf works. Due to the implementation technique
506 used, Autoconf-generated scripts now run considerably more slowly
507 on ancient implementations lacking printf. However, this should
508 not be a problem, since Autoconf-generated scripts in practice
509 invariably find a more-modern shell these days.
512 * Major changes in Autoconf 2.61 (2006-11-17)
514 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
516 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
519 * Major changes in Autoconf 2.60b (2006-10-22)
522 Autoconf-generated shell scripts no longer export BIN_SH, due to
523 configuration hassles with this. Installers who need BIN_SH in
524 their environment should set it before invoking 'configure' and
525 'make'. As far as we know, this affects only Unixware installations.
527 ** Obsolescent macros
528 The documentation now says that the following macros are obsolescent,
529 as they are superseded by Gnulib:
531 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
533 New programs should use the Gnulib counterparts of these macros.
534 We have no current plans to remove them from Autoconf.
536 ** AC_COMPUTE_INT no longer caches or reports results.
538 ** AC_CHECK_DECL now also works with aggregate objects.
540 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
542 ** GNU M4 1.4.7 or later is now recommended.
545 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
548 Now an alias for m4_mkstemp.
550 * Major changes in Autoconf 2.60a (2006-08-25)
552 ** GNU M4 1.4.6 or later is now recommended.
554 ** The check for C99 now tests for varargs macros, as documented.
555 It also tests that the preprocessor supports 64-bit integers.
557 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
558 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
560 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
561 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
562 two macros are different, so autoupdate will not change the old private name
563 to the new one. _AC_COMPUTE_INT may be removed in a future release.
565 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
566 that long long types be at least 64 bits wide, as C99 and tradition
567 requires. Formerly, they accepted implementations of any width.
570 * Major changes in Autoconf 2.60
572 Released 2006-06-23, by Ralf Wildenhues.
574 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
575 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
576 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
578 ** Provide a way to turn off warnings about the changed directory variables.
580 * Major changes in Autoconf 2.59d
582 Released 2006-06-05, by Ralf Wildenhues.
584 ** GNU make now recommended for VPATH builds
585 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
586 only if you use GNU make. In practice, other 'make' implementations
587 have too many subtle incompatibilities in their support for VPATH.
588 Many packages (including Autoconf itself) are portable to other
589 'make' implementations, but some packages are not, and recommending
590 GNU make keeps the installation instructions simpler.
592 ** Even more safety checks for the new Directory variables:
593 Warn about suspicious `${datarootdir}' found in config files output.
595 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
596 These never-documented macros and variables have been marked with
597 comments saying that they may be removed in a future release,
598 because their use can lead to unintended code being executed.
599 If you need functionality that only these macros or variables
600 currently supply, please write bug-autoconf@gnu.org.
602 ** AC_SUBST, AC_DEFINE
603 Literal arguments to these are passed to m4_pattern_allow now.
606 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
607 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
608 obsolete K&R tests in the Automake test suite.
617 Now more robust with special characters in file names, or when
618 multiple processes create the same directory at the same time.
620 ** Obsolescent macros
621 The documentation now says that the following macros are obsolescent:
622 they test for problems that are so old that they are no longer of
623 practical importance on current systems.
625 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
626 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
627 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
628 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
629 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
630 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
631 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
632 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
634 New programs need not use these macros. We have no current plans to
638 For compatibility with future Libtool 2.0, autoreconf will invoke
639 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
642 * Major changes in Autoconf 2.59c
644 Released 2006-04-12, by Ralf Wildenhues.
646 ** The configure command now redirects standard input from /dev/null,
647 to help avoid problems with subsidiary commands that might mistakenly
648 read standard input. AS_ORIGINAL_STDIN_FD points to the original
649 standard input before this redirection, if you really want configure to
650 read from standard input.
652 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
653 The following directory variables are new:
655 datarootdir read-only architecture-independent data root [PREFIX/share]
656 localedir locale-specific message catalogs [DATAROOTDIR/locale]
657 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
658 htmldir html documentation [DOCDIR]
659 dvidir dvi documentation [DOCDIR]
660 pdfdir pdf documentation [DOCDIR]
661 psdir ps documentation [DOCDIR]
663 The following variables have new default values:
665 datadir read-only architecture-independent data [DATAROOTDIR]
666 infodir info documentation [DATAROOTDIR/info]
667 mandir man documentation [DATAROOTDIR/man]
669 This means that if you use any of `@datadir@', `@infodir@', or
670 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
671 defined in this file. As a temporary measure, if any of those are
672 found but no mention of `datarootdir', the substitutions will be
673 replaced with values that do not contain `${datarootdir}', and a
674 warning will be issued.
676 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
677 a trailing slash. Similar change will be made to ac_top_builddir in a
678 future release; the old style value, which matches (../)*, is (and will
679 continue to be) available as ac_top_build_prefix.
682 New macro to check for support of 'typeof' syntax a la GNU C.
684 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
685 New "once-only" variants of commonly-used macros, to make 'configure'
686 smaller and faster in common cases.
689 New macro to check for strtold with C99 semantics.
692 New macro that lets builder disable assertions at 'configure'-time.
695 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
696 X11/Intrinsic.h and XtMalloc (Xt).
698 ** AC_PRESERVE_HELP_ORDER
699 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
700 and AC_ARG_WITH arguments in one region, in the order defined. The default
701 behavior is to group options of each classes separately.
703 ** AC_PROG_CC, AC_PROG_CXX
704 No longer automatically arrange to declare the 'exit' function of C,
705 when a C++ compiler is used. Standard Autoconf macros no longer use
706 'exit', so this is no longer an issue for them. If you use C++, and
707 want to call 'exit', you'll have to arrange for its declaration
708 yourself. But we now suggest you return from 'main' instead.
710 ** AC_PROG_CC_C89, AC_PROG_CC_C99
711 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
712 check for ANSI C89 and ISO C99 support respectively.
715 Has been unobsoleted, and will check if the compiler supports ISO
716 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
717 retained for backwards compatibility, assuming the value of
718 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
721 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
722 New macros for checking commonly-used members of struct dirent.
725 The substituted value can now contain newlines.
728 The substitution now occurs only when @variable@ is on a line by itself,
729 optionally surrounded by spaces and tabs. The whole line is replaced.
731 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
732 New macros to check for long double, and whether it is wider than double.
733 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
734 applications should switch to the new macro.
736 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
737 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
738 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
739 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
740 New macros to check for C99 and POSIX types.
742 ** AC_USE_SYSTEM_EXTENSIONS
743 New macro to enable extensions to Posix.
746 New macro which is defined to the name of the first declared config header
747 or undefined if no config headers have been declared yet.
750 The macro correctly handles quadrigraphs now.
752 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
753 These macros are new or published now.
756 New macro for copyright notices in testsuite files.
758 ** ALLOCA, LIBOBJS, LTLIBOBJS
759 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
760 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
761 `Makefile.in' in case the object files lie in a different directory.
762 The LIBOBJDIR feature is experimental.
765 Supports --no-recursive now.
767 ** New macros to support Erlang/OTP.
768 New macros for configuring paths to Erlang tools and libraries:
769 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
770 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
771 AC_ERLANG_SUBST_LIB_DIR.
773 New macros for configuring installation of Erlang libraries:
774 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
776 ** The manual now mentions Gnulib more prominently.
778 ** New macros to support Objective C.
779 AC_PROG_OBJC, AC_PROG_OBJCPP.
781 * Major changes in Autoconf 2.59b
783 Released 2004-08-20, by Paul Eggert.
786 New macro that computes the default alignment of a type.
788 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
789 When cross-compiling, these macros will give a warning if the tool
790 is not prefixed. In the future, unprefixed cross tools will not
791 be detected; please consult the info documentation for information
792 about the reason of this change.
794 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
795 New macros that detect programs whose name is prefixed with the
796 target type, if the build type and target type are different.
798 ** AC_REQUIRE_AUX_FILE
799 New trace macro that declares expected auxiliary files.
802 New macro that tests for a grep program that accepts as a long a line
805 ** AC_PROG_EGREP, AC_PROG_FGREP
806 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
807 FGREP="$GREP -F" respectively if possible, or else run a path search for
808 a program that accepts as long a line as possible.
811 New macro that tests for a sed program that truncates as few characters
814 * Major changes in Autoconf 2.59
816 Released 2003-11-04, by Akim Demaille
818 ** ac_abs_builddir etc.
819 Absolute file names were actually relative in 2.58.
821 * Major changes in Autoconf 2.58
823 Released 2003-11-04, by Akim Demaille
826 core.* files are no longer removed, as they may be valid user files.
828 ** autoreconf and auxiliary directory
829 Autoreconf creates the auxiliary directory if needed. This is
830 especially useful for initial "bootstrapping" of fresh CVS checkouts.
832 ** AC_CONFIG_MACRO_DIR
833 Use this macro to declare the directory for local M4 macros for aclocal.
836 No longer includes twice the same file in LIBOBJS if invoked
839 ** AC_CONFIG_COMMANDS
840 The directory for its first argument is automatically created. For
843 AC_CONFIG_COMMANDS([src/modules.hh], [...])
845 $top_builddir/src/ is created if needed.
847 ** Autotest and local.at
848 The optional file local.at is always included in Autotest test suites.
851 The warnings are always issued, including with cached runs.
852 This became a significant problem since aclocal and automake can
853 run autoconf behind the scene.
855 ** autoheader warnings
856 The warnings of autoheader can be turned off, using --warning.
857 For instance, -Wno-obsolete disables the complaints about acconfig.h
858 and other deprecated constructs.
861 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
864 ** AC_DECL_SYS_SIGLIST
868 Now checks that mktime is the inverse of localtime.
870 ** Improve DJGPP portability
871 The Autoconf tools and configure behave better under DJGPP.
873 ** Present But Cannot Be Compiled
874 New FAQ section dedicated to the mystic
876 configure: WARNING: pi.h: present but cannot be compiled
877 configure: WARNING: pi.h: check for missing prerequisite headers?
878 configure: WARNING: pi.h: proceeding with the preprocessor's result
881 ** Concurrent executions of autom4te
882 autom4te now locks its internal files, which enables concurrent
883 executions of autom4te, likely to happen if automake, autoconf,
884 autoheader etc. are run simultaneously.
887 Use of Libtool 1.5 and higher is encouraged. Compatibility with
888 Libtool pre-1.4 is not checked.
891 Testsuites no longer rerun failed tests in verbose mode; instead,
892 failures are logged while the test is run.
894 In addition, expected failures can be marked as such.
896 * Major changes in Autoconf 2.57
898 Released 2002-12-03 by Paul Eggert.
900 Bug fixes for problems with AIX linker, with freestanding C compilers,
901 with GNU M4 limitations, and with obsolete copies of GNU documents.
903 The Free Documentation License has been upgraded from 1.1 to 1.2.
905 * Major changes in Autoconf 2.56
907 Released 2002-11-15 by Akim Demaille.
909 One packaging problem fixed (config/install-sh was not executable).
911 * Major changes in Autoconf 2.55
913 Released 2002-11-14 by Akim Demaille.
917 Have your configure.ac checked by autoscan ("autoscan").
918 Try the warning options ("autoreconf -fv -Wall").
922 - AC_CHECK_HEADER, AC_CHECK_HEADERS
923 More information on proper use.
925 - Writing Test Programs
927 This sections explains how to write good test sources to use with
928 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
930 - AC_FOO_IFELSE vs. AC_TRY_FOO
932 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
933 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
937 - Is more robust to different Gettext installations.
939 - Produces messages (when --verbose) to be understood by Emacs'
942 - Supports -W/--warnings.
945 Once the GNU Build System reinstalled, run `./config.status
946 --recheck && ./config.status && make' if possible.
950 - Supports --cache, and --no-cache.
952 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
953 (autom4te.cache). See `Customizing autom4te' in the documentation.
960 Support for the obsoleted options -m, --macrodir, -l, --localdir is
961 dropped in favor of the safer --include/--prepend-include scheme.
966 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
967 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
968 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
971 Obsoleted macros are kept for Autoconf backward compatibility, but
972 should be avoided in configure.ac. Running autoupdate is advised.
975 - AC_DEFINE/AC_DEFINE_UNQUOTED
977 We have to stop using the old compatibility scheme --that tried to
978 avoid useless backslashes-- because Libtool 1.4.3 contains a
980 AC_DEFINE([error_t], [int],
981 [Define to a type to use for \`error_t' if it is not
982 otherwise available.])
984 We have to quote the single quotes and backslashes with \. The old
985 compatibility scheme saw that ` was backslashed, and therefore did
986 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
987 compatible with Libtool. Autoconf 2.55 is, but in some cases might
988 produce more \ than wanted.
990 Please, note that in the future the same problem will happen with
991 AC_MSG_*: use `autoreconf -f -Wall'.
995 - Portability of the Autoconf package to Solaris.
997 - Spurious warnings caused by config.status.
998 This bug is benign, but painful: on some systems (typically
999 FreeBSD), warnings such as:
1001 config.status: creating Makefile
1002 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
1004 could be issued. This is fixed.
1007 Simultaneous executions of config.status are possible again.
1009 - Precious variables accumulation
1011 config.status could stack several copies of the precious variables
1015 ** Plans for later versions
1017 - ./configure <host>
1019 The compatibility hooks with the old scheme will be completely
1020 removed. Please, advice/use `--build', `--host', and `--target'
1023 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1025 The tests will be stricter, please make sure your invocations are
1030 Shell functions will gradually be introduced, probably starting with
1031 Autotest. If you know machines which are in use that you suspect
1032 *not* to support shell functions, please run the test suite of
1033 Autoconf 2.55 on it, and report the results to
1034 bug-autoconf@gnu.org.
1038 Special characters in AC_MSG_* need not be quoted. Currently,
1039 Autoconf has heuristics to decide when a string is escaped, or has
1040 to be escaped. This scheme is fragile, and will be removed; the
1041 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1042 to find occurrences that will be affected.
1044 * Major changes in Autoconf 2.54
1046 Released 2002-09-13 by Akim Demaille.
1050 - autoreconf no longer changes the version of the gettext/po/intl
1051 support files. It now adds the files the correspond to the
1052 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1054 Warning: It now relies on the 'autopoint' program, which is part
1055 of GNU gettext 0.11.4 and newer.
1057 Please note that you need to have a GNU gettext version that
1058 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1059 in configure.ac. You can upgrade to newer GNU gettext versions,
1060 though, without needing to change configure.ac.
1062 - The -I DIR or --include=DIR option now appends DIR to the include path
1063 instead of prepending; this is for consistency with other GNU tools.
1064 The new -B DIR or --prepend-include=DIR option has the old behavior.
1069 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1070 Please, remove lines such as
1072 # This is necessary so that .o files in LIBOBJS are also
1073 # built via the ANSI2KNR-filtering rules.
1074 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1076 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1077 your Makefiles either.
1079 - AC_CONFIG_LINKS now makes copies if it can't make links.
1081 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1082 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1083 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1085 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1087 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1089 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1093 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1094 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1095 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1097 - AC_FUNC_GETLOADAVG
1098 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1101 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1102 for an AC_LIBOBJ replacement.
1106 - Spurious complaints from `m4_bmatch' about invalid regular
1107 expressions are suppressed.
1109 - Empty top_builddirs are properly handled.
1111 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1114 Now colon in the optional path arguments are properly handled.
1116 ** Improved portability
1118 - Both Autoconf the package, and the scripts it produces, should run
1119 more reliably with Zsh. Bear in mind it is the default Bourne shell
1122 - Autoconf and the scripts it produces no longer assume the existence of
1123 the obsolescent commands egrep and fgrep.
1127 - Limitations of Make
1131 The GNATS base moved to
1132 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1133 (It is no longer available, though.)
1138 Now contains the list of ouput variables and files (AC_SUBST,
1141 * Major changes in Autoconf 2.53
1143 Released 2002-03-08 by Akim Demaille.
1147 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1148 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1154 Argument requirements, output variables, defined macros.
1155 - M4sugar, M4sh, Autotest
1157 - Double quoting macros
1158 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1160 The Autoconf manual is now distributed under the terms of the GNU FDL.
1161 - Section `Hosts and Cross-Compilation'
1162 Explains the rationale for the 2.5x changes in the cross-compilation
1163 chain, and in the relationships between build, host, and target
1165 Emphasizes that `cross-compilation' == `--host is given'.
1166 If you are working on compilers etc., be sure to read this section.
1167 - Section `AC_LIBOBJ vs. LIBOBJS'
1168 Explains why assigning LIBOBJS directly is now an error.
1169 Details how to update the code.
1174 Now used instead of hard coded line numbers.
1175 This eases the comparison of `configure's, and diminishes the
1176 pressure over control version archives.
1177 Automatic replacement for shells that don't support this feature.
1178 - New output variables
1179 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1184 Autoconf and Autotest modes are provided.
1189 New, used by the Autoconf suite to cache and speed up most processing.
1191 Supported by autom4te, autoconf and autoheader.
1193 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1194 autoupdate, and autoreconf.
1196 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1197 automake options are to be given via AUTOMAKE_OPTIONS.
1199 Runs gettextize and libtoolize when appropriate.
1201 --m4dir is no longer supported.
1203 Now runs only in the specified directories, defaulting to `.',
1204 but understands AC_CONFIG_SUBDIRS for dependent directories.
1205 Before, it used to run on all the `configure.ac' found in the
1207 Independent packages are properly updated.
1211 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1213 Under the user pressure, $? is finally available. Probably a mistake.
1214 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1215 - Precious variables accumulation
1216 config.status could stack several copies of the precious variables
1218 - AC_PATH_PROG and family.
1219 Works properly when given a literal path.
1221 Somewhere since 2.13, the result had been reversed.
1225 - AC_C_BIGENDIAN supports the cross-compiling case.
1226 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1227 ACTION-IF-UNKNOWN arguments. All are facultative, and the default
1228 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1230 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1231 precision than `double'.
1236 It now defines the preprocessor symbols PACKAGE_NAME,
1237 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1241 Admits a fourth optional parameter: the tar name.
1243 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1244 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1245 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1246 ac_abs_top_builddir.
1248 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1249 Are much less expensive when using long lists of files.
1252 Works with shell variables, and non alphanumeric names.
1256 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1257 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1259 - AC_FUNC_STRTOD substitutes POW_LIB.
1264 * Major changes in Autoconf 2.52
1266 Released 2001-07-18 by Akim Demaille.
1271 This feature was present in autoconf 2.50 but was not documented.
1272 For example, `@<:@' is translated to `[' just before output. This
1273 is useful when writing strings that contain unbalanced quotes, or
1274 other hard-to-quote constructs.
1275 - m4_pattern_forbid, m4_pattern_allow
1276 - Tips for upgrading from 2.13.
1277 - Using autoscan to maintain a configure.ac.
1280 - Now include stdint.h.
1281 - sys/types.h and sys/stat.h are guarded.
1282 - strings.h is included if available, and not conflicting with string.h.
1285 - The test suite is more robust and presents less false failures.
1286 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1287 - configure accepts --prefix='' again.
1288 - AC_CHECK_LIB works properly when its first argument is not a
1290 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1291 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1292 - AC_ARG_VAR properly propagates precious variables inherited from the
1293 environment to ./config.status.
1294 - Using --program-suffix/--program-prefix is portable.
1295 - Failures to detect the default compiler's output extension are less
1297 - `config.status foo' works properly when `foo' depends on variables
1298 set in an AC_CONFIG_THING INIT-CMD.
1299 - autoheader is more robust to broken input.
1300 - Fixed Fortran name-mangling and link tests on a number of systems,
1301 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1304 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1305 specify pre-includes. In this case, the headers are compiled with
1306 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1307 of a header which is checked for, not just its availability.
1308 - AC_ARG_VAR refuses to run configure when precious variables have
1310 - Versions of compilers are dumped in the logs.
1311 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1314 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1315 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1316 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1317 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1318 Be sure to read `Upgrading from Version 2.13' to understand why
1319 running `autoupdate' is needed.
1320 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1321 a main-like routine is required/possible when linking C/C++ with
1322 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1323 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1325 * Major changes in Autoconf 2.51
1326 There was no release of Autoconf 2.51 since some packagers had used
1327 this version number without permission to ship intermediary versions
1328 of 2.50. The version was skipped to avoid confusion.
1330 * Major changes in Autoconf 2.50
1332 Released 2001-05-21 by Akim Demaille.
1334 ** Lots of bug fixes
1335 There have been far too many to enumerate them here. Check out
1336 ChangeLog if you really want to know more.
1338 ** Improved documentation
1339 In particular, portability issues are better covered.
1342 All the standard GNU Makefile targets are supported. The layout has
1343 changed: m4/ holds the M4 extensions Autoconf needs for its
1344 configuration, doc/ contains the documentation, and tests/ contains
1347 ** Man pages are provided
1348 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1349 config.guess, config.sub.
1353 Provides a safe and powerful means to trace the macro uses. This
1354 provide the parsing layer for tools which need to `study'
1358 Specify what category of warnings should be enabled.
1360 - When recursing into subdirectories, try for configure.gnu before
1361 configure to adapt for packages not using autoconf on case-insensitive
1365 More errors are now caught (circular AC_REQUIRE dependencies,
1366 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1367 etc.). In addition, their location and call stack are given.
1370 autoupdate is much more powerful, and is able to provide the glue code
1371 which might be needed to move from an old macro to its newer
1374 You are strongly encouraged to use it to modernize both your
1375 `configure.in' and your .m4 extension files.
1378 The internal machinery of autoheader has completely changed. As a
1379 result, using `acconfig.h' should be considered to be obsoleted, and
1380 you are encouraged to get rid of it using the AH macros.
1385 ** Fortran 77 compilers
1386 Globally, the support for Fortran 77 is considerably improved.
1388 Support for automatically determining a Fortran 77 compiler's
1389 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1390 provided to wrap C/C++ identifiers, thus making it easier and more
1391 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1392 call C/C++ routines. See the Texinfo documentation for details.
1395 The test suite no longer uses DejaGNU. It should be easy to submit
1396 test cases in this new framework.
1399 - --help, --help=long, -hl
1400 no longer dumps useless items.
1402 lists only specific options.
1403 - --help=recursive, -hr
1404 displays the help of all the embedded packages.
1405 - Remembers environment variables when reconfiguring.
1406 The previous scheme to set envvar before running configure was
1408 what prevented configure from remembering the environment in which
1409 it was run, therefore --recheck was run in an inconsistent
1410 environment. Now, one should run
1412 and then --recheck will work properly. Variables declared with
1413 AC_ARG_VAR are also preserved.
1415 $build defaults to `config.guess`, $host to $build, and then $target
1417 Cross-compilation is a global status of the package, it no longer
1418 depends upon the current language.
1419 Cross compilation is enabled iff the user specified `--host'.
1420 `configure' now fails if it can't run the executables it compiles,
1421 unless cross-compilation is enabled.
1423 The cache file is disabled by default. The new options
1424 `--config-cache', `-C' set the cache to `config.cache'.
1428 Much faster on most architectures.
1429 - concurrent executions
1430 It is safe to use `make -j' with config.status.
1431 - human interface improved
1432 It is possible to invoke
1433 ./config.status foobar
1434 instead of the former form (still valid)
1435 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1436 CONFIG_FILES=foobar:foo.in:bar.in \
1438 The same holds for configuration headers and links.
1439 You can instantiate unknown files and headers:
1440 ./config.status --header foo.h:foo.h.in --file bar:baz
1441 - has a useful --help
1442 - accepts special file name "-" for stdin/stdout
1447 Specify additional copyright information.
1450 Now expects the identity of the package as argument.
1454 Most macros, if not all, now strictly follow the `one quotation
1455 level' rule. This results in a more predictable expansion.
1458 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1459 configure scripts, was fixed by Axel Thimm.
1463 Document and ask for the registration of an envvar.
1466 Specifies the file which `configure' should look for when trying to
1467 find the source tree (used to be handled by AC_INIT).
1469 - AC_CONFIG_COMMANDS
1470 To add new actions to config.status. Should be used instead of
1474 Replaces AC_LINK_FILES.
1476 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1477 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1478 They now obey sh: you should no longer use shell variables as
1479 argument. Instead of
1481 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1482 AC_CONFIG_SUBDIRS($my_subdirs)
1486 if test "$package_foo_enabled" = yes; then
1487 AC_CONFIG_SUBDIRS(foo)
1491 To format an Autoconf macro's help string so that it looks pretty
1492 when the user executes `configure --help'.
1495 ** Generic Test Macros
1497 The interface of the AC_CHECK families of macros (decl, header,
1498 type, member, func) is now uniform. They support the same set of
1501 - AC_CHECK_DECL, AC_CHECK_DECLS
1502 To check whether a symbol is declared.
1504 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1505 No longer need a cross-compilation default.
1508 The test it performs is much more robust than previously, and makes
1509 it possible to test builtin types in addition to typedefs.
1510 It is now schizophrenic:
1511 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1512 remains for backward compatibility, but its use is discouraged.
1513 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1514 behaves exactly like the other AC_CHECK macros.
1517 Checks whether given types are supported by the system.
1519 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1520 Check for given members in aggregates (e.g., pw_gecos in struct
1524 Checks if the compiler supports ISO C, included when needs special
1528 Checking whether the preprocessor indicates missing includes by the
1529 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1532 Takes a language as argument and replaces AC_LANG_C,
1533 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1535 - AC_LANG_PUSH, AC_LANG_POP
1536 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1539 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1540 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1541 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1545 Sets GETGROUPS_LIBS.
1547 - AC_FUNC_GETLOADAVG
1548 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1551 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1554 Arrange for large-file support.
1556 - AC_EXEEXT, AC_OBJEXT
1557 You are no longer expected to use them: their computation is
1558 performed by default.
1560 ** C++ compatibility
1561 Every macro has been revisited in order to support at best CC=c++.
1563 Major changes in Autoconf 2.14:
1564 There was no release of GNU Autoconf 2.14.
1566 Major changes in Autoconf 2.13:
1568 Released 1999-05-01 by Ben Elliston.
1570 * Support for building on Win32 systems where the only available C or
1571 C++ compiler is the Microsoft Visual C++ command line compiler
1572 (`cl'). Additional support for building on Win32 systems which are
1573 using the Cygwin or Mingw32 environments.
1574 * Support for alternative object file and executable file extensions.
1575 On Win32, for example, these are .obj and .exe. These are discovered
1576 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1577 @EXEEXT@ in the output, respectively.
1578 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1579 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1580 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1581 * AC_DEFINE now has an optional third argument for a description to be
1582 placed in the config header input file (e.g. config.h.in).
1583 * The C++ code fragment compiled for the C++ compiler test had to be
1584 improved to include an explicit return type for main(). This was
1585 causing failures on systems using recent versions of the EGCS C++
1587 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1588 script to report that `sometype_t' was present when only `type_t'
1590 * Merge of the FSF version of config.guess and config.sub to modernize
1591 these scripts. Add support for a few new hosts in config.guess.
1592 Incorporate latest versions of install-sh, mkinstalldirs and
1593 texinfo.tex from the FSF.
1594 * autoreconf is capable of running automake if necessary (and
1596 * Support for Fortran 77. See the Texinfo documentation for details.
1597 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1599 Major changes in Autoconf 2.12:
1601 Released 1996-11-26 by David J. MacKenzie
1603 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1604 concatenating multiple input files separated by colons, like so:
1605 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1606 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1607 The arguments may be shell variables, to compute the lists on the fly.
1608 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1609 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1612 Major changes in Autoconf 2.11:
1614 Released November 18th, 1996, by David J. MacKenzie
1616 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1617 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1618 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1619 * AC_CONFIG_HEADER expands shell variables in its argument.
1620 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1621 * The "checking..." messages and the source code for test programs that
1622 fail are saved in config.log.
1623 * Another workaround has been added for seds with small command length limits.
1624 * config.sub and config.guess recognize more system types.
1627 Major changes in Autoconf 2.10:
1629 Released May 7th, 1996, by Roland McGrath
1632 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1633 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1635 Major changes in Autoconf 2.9:
1637 Released March 16th, 1996, by Roland McGrath
1641 Major changes in Autoconf 2.8:
1643 Released March 8th, 1996, by Roland McGrath
1647 Major changes in Autoconf 2.7:
1649 Released November 22nd, 1995, by David J. MacKenzie
1653 Major changes in Autoconf 2.6:
1655 Released November 20th, 1995, by David J. MacKenzie
1659 Major changes in Autoconf 2.5:
1661 Released November 17th, 1995, by Roland McGrath
1663 * New configure options --bindir, --libdir, --datadir, etc., with
1664 corresponding output variables.
1665 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1666 * config.log contains the command being run as well as any output from it.
1667 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1668 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1669 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1670 AC_CHECK_TOOL can search a path other than $PATH.
1671 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1673 Major changes in Autoconf 2.4:
1675 Released June 14th, 1995, by David J. MacKenzie
1677 * Fix a few bugs found by Emacs testers.
1679 Major changes in Autoconf 2.3:
1681 Released March 27th, 1995, by David J. MacKenzie
1683 * Fix the cleanup trap in several ways.
1684 * Handle C compilers that are picky about option placement.
1685 * ifnames gets the version number from the right directory.
1687 Major changes in Autoconf 2.2:
1689 Released March 8th, 1995, by David J. MacKenzie
1691 * The ifnames utility is much faster but requires a "new awk" interpreter.
1692 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1693 library before existing libs, not after, in case it uses them.
1694 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1695 * Lots of bug fixes.
1696 * Many additions to the TODO file :-)
1698 Major changes in Autoconf 2.1:
1700 Released November 4th, 1994, by David J. MacKenzie
1703 * More explanations in the manual.
1704 * Fix a spurious failure in the testsuite.
1705 * Clarify some warning messages.
1706 * autoreconf by default only rebuilds configure and config.h.in files
1707 that are older than any of their particular input files; there is a
1708 --force option to use after installing a new version of Autoconf.
1710 Thanks to everybody who's submitted changes and additions to Autoconf!
1711 I've incorporated many of them, and am still considering others for
1712 future releases -- but I didn't want to postpone this release indefinitely.
1714 Caution: don't indiscriminately rebuild configure scripts with
1715 Autoconf version 2. Some configure.in files need minor adjustments to
1716 work with it; the documentation has a chapter on upgrading. A few
1717 configure.in files, including those for GNU Emacs and the GNU C
1718 Library, need major changes because they relied on undocumented
1719 internals of version 1. Future releases of those packages will have
1720 updated configure.in files.
1722 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1723 Autoconf now makes heavy use of M4 diversions, which were implemented
1724 inefficiently in GNU M4 releases before 1.3.
1726 Major changes in Autoconf 2.0:
1728 Released October 26th, 1994, by David J. MacKenzie
1730 ** New copyright terms:
1731 * There are no restrictions on distribution or use of configure scripts.
1734 * Autoconf manual is reorganized to make information easier to find
1735 and has several new indexes.
1736 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1739 * autoscan to generate a preliminary configure.in for a package by
1740 scanning its source code for commonly used nonportable functions,
1741 programs, and header files.
1742 * ifnames to list the symbols used in #if and #ifdef directives in a
1744 * autoupdate to update a configure.in to use the version 2 macro names.
1745 * autoreconf to recursively remake configure and configuration header
1746 files in a source tree.
1748 ** Changed utilities:
1749 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1750 * autoconf and autoheader can look for package-local definition files
1751 in an alternate directory.
1754 * AC_CACHE_VAL to share results of tests between configure runs.
1755 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1756 that macros invoked with AC_REQUIRE don't interrupt other macros.
1757 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1758 support deciding unguessable features based on the host and target types.
1759 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1760 * AC_ARG_PROGRAM to use the options --program-prefix,
1761 --program-suffix, and --program-transform-name to change the names
1762 of programs being installed.
1763 * AC_PREFIX_DEFAULT to change the default installation prefix.
1764 * AC_TRY_COMPILE to compile a test program without linking it.
1765 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1766 * AC_CHECK_LIB to check for a particular function and library.
1767 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1768 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1769 * AC_SUBST_FILE to insert one file into another.
1770 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1771 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1772 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1773 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1776 * Many macros renamed systematically, but old names are accepted for
1777 backward compatibility.
1778 * AC_OUTPUT adds the "automatically generated" comment to
1779 non-Makefiles where it finds @configure_input@ in an input file, to
1780 support files with various comment syntaxes.
1781 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1782 files when they are not enclosed in @ signs.
1783 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1784 override the file name "config.status".
1785 * AC_OUTPUT takes an optional argument for passing variables from
1786 configure to config.status.
1787 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1788 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1789 CPPFLAGS, and LDFLAGS from the environment.
1790 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1791 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1792 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1793 srcdir/../.. by default.
1794 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1795 * AC_DEFINE no longer prints anything, because of the new result reporting
1796 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1797 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1798 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1799 --enable- and --with- options.
1800 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1801 execute on success or failure.
1802 * Checking for C functions in C++ works.
1805 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1806 better maintained with them.
1807 * AC_ARG_ARRAY removed because no one was likely using it.
1808 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1809 take arguments, for consistency with all of the other specific checks.
1812 * Comes with config.sub and config.guess, and uses them optionally.
1813 * Uses config.cache to cache test results. An alternate cache file
1814 can be selected with the --cache-file=FILE option.
1815 * Uses optional shell scripts $prefix/share/config.site and
1816 $prefix/etc/config.site to perform site or system specific initializations.
1817 * configure saves compiler output to ./config.log for debugging.
1818 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1819 * acsite.m4 is the new name for the system-wide aclocal.m4.
1820 * Has a DejaGnu test suite.
1822 Major changes in Autoconf 1.11:
1824 * AC_PROG_INSTALL calls install.sh with the -c option.
1825 * AC_SET_MAKE cleans up after itself.
1826 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1827 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1829 Plus a few other bug fixes.
1831 Major changes in Autoconf 1.10:
1833 * autoheader uses config.h.bot if present, analogous to config.h.top.
1834 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
1836 * AC_PROG_CXX looks for cxx as a C++ compiler.
1838 Plus several bugs fixed.
1840 Major changes in Autoconf 1.9:
1842 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
1843 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
1844 and autoheader generates entries for those names automatically.
1845 * AC_FIND_X gets the result from xmkmf correctly.
1846 * AC_FIND_X assumes no X if --without-x was given.
1847 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
1848 * AC_PROG_INSTALL finds OSF/1 installbsd.
1850 Major changes in Autoconf 1.8:
1853 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
1854 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
1855 for checking both C++ and C features in one configure script.
1856 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
1857 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
1858 AC_SET_MAKE, AC_ENABLE.
1861 * AC_FIND_X looks for X in more places.
1862 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
1863 install.sh is distributed with Autoconf.
1864 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
1865 a rewrite of quoting in AC_DEFINE.
1866 * AC_OUTPUT adds its comments in C format when substituting in C files.
1867 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
1869 ** New or changed command line options:
1870 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
1871 * configure accepts --without-PACKAGE, which sets withval=no.
1872 * configure accepts --x-includes=DIR and --x-libraries=DIR.
1873 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
1874 * configure accepts --help, --version, --silent/--quiet, --no-create options.
1875 * configure accepts and ignores most other Cygnus configure options, and
1876 warns about unknown options.
1877 * config.status accepts --help, --version options.
1879 ** File names and other changes:
1880 * Relative srcdir values are not made absolute.
1881 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
1882 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
1883 * autoheader optionally copies config.h.top to the beginning of config.h.in.
1884 * The example Makefile dependencies for configure et al. work better.
1885 * Namespace cleanup: all shell variables used internally by Autoconf
1886 have names beginning with `ac_'.
1888 More big improvements are in process for future releases, but have not
1889 yet been (variously) finished, integrated, tested, or documented enough
1892 Major changes in Autoconf 1.7:
1894 * New macro AC_OBSOLETE.
1895 * Bugs in Makefile.in fixed.
1896 * AC_LONG_FILE_NAMES improved.
1898 Major changes in Autoconf 1.6:
1900 * New macro AC_LONG_64_BITS.
1901 * Multiple .h files can be created.
1902 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
1903 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
1904 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
1905 * Unused --no-create option to configure removed.
1906 * autoheader doesn't change the timestamp of its output file if
1907 the file didn't change.
1908 * All macros that look for libraries now use AC_HAVE_LIBRARY.
1909 * config.status checks three optional environment variables to
1910 modify its behavior.
1911 * The usual bug fixes.
1913 Major changes in Autoconf 1.5:
1915 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
1916 * autoconf and autoheader scripts have GNU standards conforming
1917 --version and --help options (they print their message and exit).
1920 Major changes in Autoconf 1.4:
1922 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
1923 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
1924 * autoconf and autoheader use the M4 environment variable to determine the
1925 name of the M4 program to use.
1926 * The --macrodir option to autoconf and autoheader specifies the directory
1927 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
1928 * autoconf and autoheader can take `-' as their file names, which means to
1929 read stdin as input.
1930 * Resulting configure scripts can take a --verbose option which causes them
1931 to print the results of their tests.
1932 * AC_DEFINE quotes its second argument in such a way that spaces, magic
1933 shell characters, etc. will be preserved during various stages of
1934 expansion done by the shell. If you don't want this, use
1935 AC_DEFINE_UNQUOTED instead.
1936 * Much textual processing done with external calls to tr and sed have been
1937 internalized with builtin M4 `patsubst' and `translit' calls.
1938 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
1939 set the shell variables `gen_files' and `gen_config' to the list of
1940 file names to output.
1941 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
1942 "lex.yy" or "lexyy", depending on the system.
1943 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
1945 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
1946 * AC_CONST works much more reliably on more systems.
1949 Major changes in Autoconf 1.3:
1951 configure no longer requires awk for packages that use a config.h.
1952 Support handling --with-PACKAGE options.
1953 New `autoheader' script to create `config.h.in' from `configure.in'.
1954 Ignore troublesome -lucb and -lPW when searching for alloca.
1955 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
1956 Improve detection of STDC library.
1957 Add AC_HAVE_LIBRARY to check for non-default libraries.
1958 Function checking should work with future GNU libc releases.
1960 Major changes in Autoconf 1.2:
1962 The --srcdir option is now usually unnecessary.
1963 Add a file containing sample comments describing CPP macros.
1964 A comment in config.status tells which host it was configured on.
1965 Substituted variable values can now contain commas.
1966 Fix bugs in various feature checks.
1968 Major changes in Autoconf 1.1:
1970 Added AC_STRCOLL macro.
1971 Made AC_GETLOADAVG check for more things.
1972 AC_OUTPUT argument is now optional.
1977 Copyright (C) 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002,
1978 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation,
1981 Copying and distribution of this file, with or without modification,
1982 are permitted in any medium without royalty provided the copyright
1983 notice and this notice are preserved. This file is offered as-is,
1984 without warranty of any kind.