1 GNU Autoconf NEWS - User visible changes.
3 * Noteworthy changes in release ?.? (????-??-??) [?]
5 ** The use of the long-deprecated name 'configure.in' for the autoconf
6 input file now elicits a warning in the 'obsolete' category.
8 ** Older version of automake and aclocal (< 1.8) are no longer supported
13 - AC_CONFIG_MACRO_DIRS
14 New macro, used to declare multiple directories when looking for
15 local M4 macros. This macro overcomes some of the shortfalls in the
16 older AC_CONFIG_MACRO_DIR, which could only be used once; although
17 the older macro remains for compatibility with older tools. The
18 newer macro will be used by the upcoming Automake 1.13 release to
19 eliminate the need to specify ACLOCAL_AMFLAGS in Makefile.am.
21 - AC_PROG_CC now prefers C11 if available, falling back on C99 and
22 then on C89 as before.
24 - AC_PROG_CC is now defined via AC_DEFUN_ONCE, to avoid bloat in 'configure'.
26 - AC_PROG_CC_STDC, AC_PROG_CC_C89, AC_PROG_CC_C99 have been marked as obsolete.
27 Applications should use AC_PROG_CC.
29 - AC_FUNC_VFORK now checks for the signal-handling bug in Solaris 2.4 'vfork'.
30 Formerly, it ignored this bug, so that Emacs could use some tricky
31 code on that platform. Solaris 2.4 has not been supported since
32 2003 and nowadays it's better to omit that old trick.
34 - Autotest provides a new macro AT_DATA_UNQUOTED, similar to AT_DATA
35 but processing variable substitutions, command substitutions and
36 backslashes in the contents argument.
38 - AC_CONFIG_TESTDIR will automatically pass EXEEXT to a testsuite (via
41 - AT_TESTED arguments can use variable or command substitutions, including
44 * Noteworthy changes in release 2.69 (2012-04-24) [stable]
46 ** Autoconf now requires perl 5.6 or better (but generated configure
47 scripts continue to run without perl).
49 * Noteworthy changes in release 2.68b (2012-03-01) [beta]
50 Released by Eric Blake, based on git versions 2.68.*.
52 ** Autoconf-generated configure scripts now unconditionally re-execute
53 themselves with $CONFIG_SHELL, if that's set in the environment.
55 ** The texinfo documentation no longer specifies "front-cover" or
56 "back-cover" texts, so that it may now be included in Debian's
59 ** Support for the Go programming language has been added. The new macro
60 AC_LANG_GO sets variables GOC and GOFLAGS.
62 ** AS_LITERAL_IF again treats '=' as a literal. Regression introduced in
65 ** The macro AS_EXECUTABLE_P, present since 2.50, is now documented.
69 - AC_PROG_LN_S and AS_LN_S now fall back on 'cp -pR' (not 'cp -p') if 'ln -s'
70 does not work. This works better for symlinks to directories.
72 - New macro AC_HEADER_CHECK_STDBOOL.
74 - New and updated macros for Fortran support:
76 AC_FC_CHECK_BOUNDS to enable array bounds checking
77 AC_F77_IMPLICIT_NONE and AC_FC_IMPLICIT_NONE to disable implicit integer
78 AC_FC_MODULE_EXTENSION to compute the Fortran 90 module name extension
79 AC_FC_MODULE_FLAG for the Fortran 90 module search path flag
80 AC_FC_MODULE_OUTPUT_FLAG for the Fortran 90 module output directory flag
81 AC_FC_PP_SRCEXT for preprocessed Fortran source files extensions
82 AC_FC_PP_DEFINE for the Fortran preprocessor define flag
84 * Noteworthy changes in release 2.68 (2010-09-22) [stable]
85 Released by Eric Blake, based on git versions 2.67.*.
87 ** AC_MSG_ERROR (and AS_ERROR) can once again be followed immediately by
88 `dnl'. Regression introduced in 2.66.
90 ** AC_INIT again allows URLs with '?' for its BUG-REPORT argument.
91 Regression introduced in 2.66.
93 ** AC_REPLACE_FUNCS again allows a non-literal argument, such as a shell
94 variable that expands to a list of functions to check. Regression
97 ** AT_BANNER() with empty argument will cause visual separation from previous
100 ** The macros AC_PREPROC_IFELSE, AC_COMPILE_IFELSE, AC_LINK_IFELSE, and
101 AC_RUN_IFELSE now warn if the first argument failed to use
102 AC_LANG_SOURCE or AC_LANG_PROGRAM to generate the conftest file
103 contents. A new macro AC_LANG_DEFINES_PROVIDED exists if you have
104 a compelling reason why you cannot use AC_LANG_SOURCE but must
107 ** The macro m4_define_default is now documented.
109 ** Symlinked config.cache files are supported; configure now tries to
110 update non-symlinked cache files atomically, so that concurrent configure
111 runs do not leave behind broken cache files. It is still unspecified
112 which subset or union of results is cached though.
114 ** Autotest testsuites should not contain long text lines any more, and be
115 portable even when very many test groups are used.
117 ** AT_CHECK semantics with respect to the Autotest variable $at_status and
118 shell execution environment of the arguments are documented now.
120 ** AC_FC_LIBRARY_LDFLAGS now tolerates output from newer gfortran.
122 ** Newly obsolete macros
123 The following macros have been marked obsolete. New programs
124 should use the corresponding Gnulib modules. Gnulib not only
125 detects a larger set of portability problems with these functions,
126 but also provides complete workarounds.
128 AC_FUNC_ERROR_AT_LINE AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
129 AC_FUNC_MKTIME AC_FUNC_STRTOD
132 * Major changes in Autoconf 2.67 (2010-07-21) [stable]
133 Released by Eric Blake, based on git versions 2.66.*.
135 ** AC_CONFIG_SUBDIRS with more than one subdirectory at a time works again.
136 Regression introduced in 2.66.
138 ** AC_CHECK_SIZEOF of a pointer type works again. Regression introduced in
141 ** New macro AC_FC_LINE_LENGTH to accept long Fortran source code lines.
143 ** AC_PREPROC_IFELSE now keeps the preprocessed output in the conftest.i
144 file for inspection by the commands in the ACTION-IF-TRUE argument.
146 ** AC_INIT again allows parentheses and other characters that are literal
147 in single- or double-quoted strings, and in quoted and unquoted
148 here-documents, for its PACKAGE and VERSION arguments. Regression
151 ** autoreconf passes warning flags to new enough versions of aclocal.
153 ** Running an Autotest testsuite in parallel mode no longer triggers a
154 race condition that could cause the testsuite run to end early,
155 fixing a sporadic failure in autoconf's own testsuite. Bug present
156 since introduction of parallel tests in 2.63b.
159 * Major changes in Autoconf 2.66 (2010-07-02) [stable]
160 Released by Eric Blake, based on git versions 2.65.*.
162 ** AC_FUNC_MMAP works in C++ mode again. Regression introduced in 2.65.
164 ** Use of m4_divert without a named diversion now issues a syntax warning,
165 since it is seldom right to change diversions behind autoconf's back.
167 ** The macros AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, and
168 AC_TYPE_INT64_T work again. Regression introduced in 2.65.
170 ** AC_PROG_INSTALL correctly uses `shtool' again. Regression introduced
173 ** Autoconf should work on EBCDIC hosts.
175 ** AC_CHECK_DECL and AC_CHECK_DECLS accept optional function argument types
176 for overloaded C++ functions.
178 ** AS_SET_CATFILE accepts nonliterals in its variable name argument now.
180 ** Autotest testsuites accept an option --recheck to rerun tests that
181 failed or passed unexpectedly during the last non-debug testsuite run.
183 ** AC_ARG_ENABLE and AC_ARG_WITH now also accept `+' signs in `--enable-*'
184 and `--with-*' arguments, converting them to underscores for the variable
187 ** In configure scripts, loading CONFIG_SITE no longer searches PATH,
188 and problems in loading the configuration site files are diagnosed.
190 ** Autotest testsuites may optionally provide colored test results.
192 ** The previously undocumented Autotest macros AT_ARG_OPTION and
193 AT_ARG_OPTION_ARG have seen bug fixes and are documented now.
194 AT_ARG_OPTION has been changed in that the negative of a long option
195 --OPTION is now --no-OPTION rather than --noOPTION.
197 ** The macro AS_LITERAL_IF is slightly more conservative; text
198 containing shell quotes are no longer treated as literals.
199 Furthermore, a new macro, AS_LITERAL_WORD_IF, adds an additional
200 level of checking that no whitespace occurs in literals.
202 ** The macros AS_TR_SH and AS_TR_CPP no longer expand their results.
204 ** The following macros are now documented:
207 ** New macro AC_FC_FIXEDFORM to accept fixed-form Fortran.
210 * Major changes in Autoconf 2.65 (2009-11-21) [stable]
211 Released by Eric Blake, based on git versions 2.64.*.
213 ** Autoconf is now licensed under the General Public License version 3
214 or later (GPLv3+). As with earlier versions, the license includes
215 an exception clause so that you may release a configure script
216 generated by autoconf under the license of your own program.
218 ** New macros to support Objective C++.
219 AC_PROG_OBJCXX AC_PROG_OBJCXXCPP
221 ** The following undocumented autoconf macros, removed in Autoconf 2.64,
222 have been reinstated:
225 These macros are present only for backwards compatibility purposes.
227 ** The macro AC_LANG_COMPILER no longer fails on embedded systems that
228 lack fopen in the C library, such as AVR or RTEMS (regression
231 ** The AC_FC_FREEFORM macro no longer suffers from a whitespace bug that
232 made it fail with some Fortran compilers (regression introduced in
235 ** The AC_TYPE_UINT64_T and AC_TYPE_INT64_T macros have been fixed to no
236 longer mistakenly select a 32-bit type on some compilers (bug present
237 since macros were introduced in 2.59c).
239 ** The AC_FUNC_MMAP macro has been fixed to be portable to systems like
240 Cygwin (bug present since macro was introduced in 2.0).
242 ** The following documented autotest macros are new:
245 ** The following m4sugar macros now quote their expansion:
246 m4_toupper m4_tolower
248 ** The following m4sugar macros are new:
251 ** The m4sugar macro m4_text_wrap now copes with embedded quoting without
252 requiring quadrigraphs. For uses like AC_ARG_VAR([a], [[b c]]),
253 this gives the intuitive behavior of "[b c]" in the output (2.63
254 gave the output of "[b], [c]", and 2.64 encountered a failure).
256 ** The `$tmp' temporary directory used in config.status is documented for
259 ** config.status now provides a --config option to produce the configuration.
261 ** Many cache variables used by Autoconf's macros are now documented.
263 ** Configure scripts work better on DJGPP by avoiding a bug present in
264 the DJGPP port of bash 2.04 in handling 'return' in a shell
265 function (regression introduced in 2.64).
267 * Major changes in Autoconf 2.64 (2009-07-26) [stable]
268 Released by Eric Blake, based on git versions 2.63b.*.
270 ** Autoconf now requires GNU M4 1.4.6 or later. Earlier versions of M4
271 have a bug in regular expression handling that interferes with some
272 of the speedups provided since Autoconf 2.63. GNU M4 1.4.13 or
273 later is recommended.
275 ** AS_IF and AS_CASE have been taught to avoid syntax errors even when
276 given arguments that expand to just whitespace.
278 ** The following documented autoconf macros are new:
279 AC_ERLANG_SUBST_ERTS_VER
281 ** The autoheader tool now understands m4 macro arguments passed to
282 AC_DEFINE and AC_DEFINE_UNQUOTED.
284 ** Ensure AT_CHECK can support commands that include a # given with
285 proper m4 quoting. For shell comments, this is a new feature; for
286 non-shell comments, this fixes a regression introduced in 2.63b.
287 Additionally, AT_CHECK correctly supplies shell escapes for
288 metacharacters occurring in m4 macro expansions within the expected
289 stdout and stderr parameters.
291 ** The macro AT_CHECK now understands the concept of hard failure. If
292 a test exits with an unexpected status 99, cleanup actions for the
293 test are inhibited and the test is treated as a failure regardless
294 of AT_XFAIL_IF. It also understands the new directives
295 ignore-nolog, stdout-nolog, and stderr-nolog.
297 ** The following documented autotest macros are new:
298 AT_CHECK_UNQUOTED AT_FAIL_IF AT_SKIP_IF
300 ** The following documented m4sugar macros are new:
301 m4_argn m4_copy_force m4_default_nblank m4_default_nblank_quoted
302 m4_ifblank m4_ifnblank m4_rename_force
304 ** The autoconf testsuite now exercises all Erlang macros.
306 * Major changes in Autoconf 2.63b (2009-03-31) [beta]
307 Released by Eric Blake, based on git versions 2.63.*.
309 ** The manual is now shipped under the terms of the GNU FDL 1.3.
311 ** AC_REQUIRE now detects the case of an outer macro which first expands
312 then later indirectly requires the same inner macro. Previously,
313 this case led to silent out-of-order expansion (bug present since
314 2.50); it now issues a syntax warning, and duplicates the expansion
315 of the inner macro to guarantee dependencies have been met. See
316 the manual for advice on how to refactor macros in order to avoid
317 the bug in earlier autoconf versions and avoid increased script
318 size in the current version.
320 ** AC_DEFUN_ONCE has improved semantics. Previously, a macro declared
321 with AC_DEFUN_ONCE warned on a second invocation; and out-of-order
322 expansion was still possible. Now, dependencies are guaranteed,
323 and subsequent invocations are a silent no-op. This makes
324 AC_DEFUN_ONCE an ideal macro for silencing AC_REQUIRE warnings.
326 ** The following macros are now defined with AC_DEFUN_ONCE. This means
327 a subtle change in semantics; previously, an AC_DEFUN macro could
328 expand one of these macros multiple times or surround the macro
329 inside shell conditional text to bypass the effects of these
330 macros, but now the macro will expand exactly once, and prior to
331 the start of any enclosing AC_DEFUN macro:
332 AC_CANONICAL_BUILD AC_CANONICAL_HOST AC_CANONICAL_TARGET
333 AC_HEADER_ASSERT AC_PROG_INSTALL AC_PROG_MKDIR_P
334 AC_USE_SYSTEM_EXTENSIONS
336 ** AC_LANG_ERLANG works once again (regression introduced in 2.61a).
338 ** AC_HEADER_ASSERT is fixed so that './configure --enable-assert' no
339 longer mistakenly disables assertions.
341 ** AC_INIT now takes an optional fifth parameter that can be used to
342 set AC_PACKAGE_URL, a URL for the package's home page; the URL is
343 used in `configure --help' and is also available via AC_DEFINE.
345 ** Autotest testsuites accept an option --jobs[=N] for parallel testing.
346 This feature is still in testing, and may not work on every
347 platform, help in improving it would be appreciated.
349 ** Autotest testsuites do not attempt to write startup error messages
350 to the log file before that is opened (regression introduced in 2.63).
352 ** Configure scripts now use shell functions. This feature leads to
353 smaller configure files and faster execution.
355 ** Present But Cannot Be Compiled: Autoconf will now proceed with
356 the compiler's result if a header is present but cannot be compiled.
357 The warning is still printed, and you should really fix it by
358 providing a fourth parameter to AC_CHECK_HEADER/AC_CHECK_HEADERS.
360 ** Autoreconf added aclocal to the set of programs affected by the
361 `autoreconf -I dir' option.
363 ** The following documented m4sugar macros are new:
364 m4_chomp m4_chomp_all m4_cleardivert m4_curry m4_default_quoted
365 m4_esyscmd_s m4_map_args m4_map_args_pair m4_map_args_sep
366 m4_map_args_w m4_set_map m4_set_map_sep m4_stack_foreach
367 m4_stack_foreach_lifo m4_stack_foreach_sep
368 m4_stack_foreach_sep_lifo
370 ** The following m4sugar macros are documented now, but in some cases
371 with slightly different semantics than what the previous
372 undocumented version had:
373 m4_copy m4_dumpdefs m4_rename m4_version_prereq
375 ** The m4sugar macro m4_expand has been taught to handle unterminated
376 comments and shell case statements. As a result, it is used
377 internally in more places, such as AC_DEFINE and AT_CHECK. Most
378 uses of AC_DEFINE and AT_CHECK should not behave any differently;
379 however, it may be necessary to add double-quoting around
380 unbalanced `(' where single-quoting used to be sufficient.
382 ** The following documented m4sh macros are new:
383 AS_INIT_GENERATED AS_LINENO_PREPARE AS_ME_PREPARE AS_SET_STATUS
384 AS_VAR_APPEND AS_VAR_ARITH AS_VAR_COPY
386 ** The following m4sh macros are documented now, but in some cases
387 with slightly different semantics than what the previous
388 undocumented version had:
389 AS_ECHO AS_ECHO_N AS_ESCAPE AS_EXIT AS_LITERAL_IF AS_UNSET
390 AS_VAR_IF AS_VAR_POPDEF AS_VAR_PUSHDEF AS_VAR_SET AS_VAR_SET_IF
391 AS_VAR_TEST_SET AS_VERSION_COMPARE
393 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
394 The responsibility for supplying a trailing newline now belongs to
395 the call site, but since most users did not add dnl, this generally
396 results in fewer empty lines in configure.
399 * Major changes in Autoconf 2.63 (2008-09-09) [stable]
400 Released by Eric Blake, based on git versions 2.62.*.
402 ** AC_C_BIGENDIAN does not mistakenly report "universal" for some
403 bigendian hosts, a regression introduced with universal binary
406 ** AC_PATH_X now includes /lib64 and /usr/lib64 in its list of default
409 ** AC_USE_SYSTEM_EXTENSIONS no longer conflicts with an external
410 AC_DEFINE([__EXTENSIONS__]). This fixes a regression introduced in
411 2.62 when using macros such as AC_AIX that were made obsolete in
412 favor of the more portable AC_USE_SYSTEM_EXTENSIONS.
414 ** AC_CHECK_TARGET_TOOLS is usable in the non-cross-compile case.
416 ** Newly obsolete macros
417 The following macro has been marked obsolete, since current porting
418 targets can safely assume C89 semantics that signal handlers return
419 void. We have no current plans to remove the macro.
423 ** The macros m4_map and m4_map_sep now ignore any list elements
424 consisting of just empty quotes, and m4_map_sep now expands its
425 separator. This fixes a regression in 2.62 when these macros were
426 first documented, for the sake of clients expecting the semantics
427 that these macros had prior to that time. The new macros m4_mapall
428 and m4_mapall_sep, along with extra quoting of the separator, can
429 be used to get the semantics that m4_map_sep had in 2.62.
431 ** Clients of m4_expand, such as AS_HELP_STRING and AT_SETUP, can now
432 handle properly quoted but otherwise unbalanced parentheses (for
433 some macros, this fixes a regression in 2.62).
435 ** Two new quadrigraphs have been introduced: @{:@ for (, and @:}@ for ),
436 allowing the output of unbalanced parentheses in more contexts.
438 ** The following m4sugar macros are new:
439 m4_cleardivert m4_joinall m4_mapall m4_mapall_sep m4_reverse
440 m4_set_add m4_set_add_all m4_set_contains m4_set_contents
441 m4_set_delete m4_set_difference m4_set_dump m4_set_empty
442 m4_set_foreach m4_set_intersection m4_set_list m4_set_listc
443 m4_set_remove m4_set_size m4_set_union
445 ** The following m4sugar macros now accept multiple arguments, as is the
446 case with underlying m4:
447 m4_defn m4_popdef m4_undefine
449 ** The following m4sugar macros now guarantee linear scaling; they
450 previously had linear scaling with m4 1.6 but quadratic scaling
451 when using m4 1.4.x. All macros built on top of these also gain
452 the scaling improvements.
453 m4_bmatch m4_bpatsubsts m4_case m4_cond m4_do m4_dquote_elt
454 m4_foreach m4_join m4_list_cmp m4_map m4_map_sep m4_max
457 ** AT_KEYWORDS once again performs expansion on its argument, such that
458 AT_KEYWORDS([m4_if([$1], [], [default])]) no longer complains about
459 the possibly unexpanded m4_if [regression introduced in 2.62].
461 ** Config header templates `#undef UNDEFINED /* comment */' do not lead to
462 nested comments any more; regression introduced in 2.62.
465 * Major changes in Autoconf 2.62 (2008-04-05) [stable]
466 Released by Eric Blake, based on git versions 2.61a.*.
468 ** Many optimizations have been applied to make overall execution faster.
470 ** Autotest now makes use of shell functions.
472 ** config.status now uses awk instead of sed also for config headers.
474 - As a side effect, AC_DEFINE and AC_DEFINE_UNQUOTED now handle multi-line
475 values, i.e., backslash-newline combinations are handled correctly.
476 Further, for config headers, the total size of values is not limited by
477 the POSIX length limit of text lines any more, only each single line.
479 ** New config variable `top_build_prefix'.
481 ** New Autoconf macros:
482 AC_AUTOCONF_VERSION AC_OPENMP AC_PATH_PROGS_FEATURE_CHECK
484 ** AC_C_BIGENDIAN now supports universal binaries a la Mac OS X.
486 ** AC_C_RESTRICT now prefers to #define 'restrict' to a variant spelling
487 like '__restrict' if the variant spelling is available, as this is
488 more likely to work when mixing C and C++ code.
490 ** AC_CHECK_ALIGNOF's type argument T is now documented better: it must
491 be a string of tokens such that "T y;" is a valid member declaration
494 ** AC_CHECK_SIZEOF now accepts objects as well as types: the general rule
495 is that sizeof (X) works, then AC_CHECK_SIZEOF (X) should work.
497 ** AC_CHECK_TYPE and AC_CHECK_TYPES now work on any C type-name; formerly,
498 they did not work for function types. In C++, they now work on any
499 type-id that can be the operand of sizeof; this is similar to C,
500 except it excludes anonymous struct and union types. Formerly,
501 some (but not all) C++ types involving anonymous struct and union
502 were accepted, though this was not documented.
504 ** AC_CONFIG_LINKS now prefers to link against files in the build tree
505 if found, and it works to link against a file of the same name in
506 the source tree, even if both trees coincide.
508 ** AC_INIT no longer alters $@; regression introduced in 2.60.
510 ** AC_USE_SYSTEM_EXTENSIONS now defines _ALL_SOURCE for Interix platforms.
512 ** AS_HELP_STRING no longer underquotes its first argument; it also handles
513 the case where the first argument contains single-quoted commas.
514 For example, "AS_HELP_STRING([-a, [--arg[=foo]]], [bar])" produces:
515 " -a, --arg[=foo] bar"
516 Additionally, the macro now takes two additional arguments,
517 indent-column and wrap-column; these should not normally be needed,
518 but can be used to fine-tune how the output text is wrapped.
520 ** AC_PROG_INSTALL now requires an install program that can install multiple
521 files into a target directory.
523 ** The command 'autoconf -' now correctly processes a file from stdin.
525 ** 'autoreconf -m' now honors $MAKE.
527 ** For all of the directory arguments for 'configure', such as '--prefix'
528 or '--bindir', trailing slashes are stripped. As an example, if
529 tab completion in the user's shell appends trailing slashes, the
530 command './configure --prefix=/usr/' will still result in an
531 expanded libdir value of /usr/lib, not /usr//lib.
533 ** `configure --help=recursive' now works in read-only trees and from
534 unconfigured build trees.
536 ** If precious variables differ only in whitespace, then the cache consistency
537 check warns instead of fails, and reuses the old value.
539 ** AT_BANNER is now documented.
541 ** AT_SETUP now handles macro expansions properly when calculating line
544 ** Autotest now determines $srcdir correctly.
546 ** Testsuites built by autotest now accept a -C/--directory=DIR option
547 to adjust the working directory prior to creating files.
549 ** Autoconf now requires GNU M4 1.4.5 or later. Earlier versions of M4 have
550 a bug in macro tracing that interferes with the interaction between
551 Autoconf and Automake. GNU M4 1.4.11 or later is recommended. The
552 configure search for a working M4 is improved.
554 ** For portability with the eventual M4 2.0, macros should no longer use
555 anything larger than $9 to refer to arguments.
557 ** Documentation for m4sugar is improved.
559 - The following macros were previously available as undocumented
560 interfaces; the macros are now documented as stable interfaces.
562 __oline__ m4_assert m4_bmatch m4_bpatsubsts m4_car m4_case
563 m4_cdr m4_default m4_divert_once m4_divert_pop m4_divert_push
564 m4_divert_text m4_do m4_errprintn m4_fatal m4_flatten
565 m4_ifndef m4_ifset m4_ifval m4_ifvaln m4_location
566 m4_n m4_shiftn m4_strip m4_warn
568 - The following macros were previously available as undocumented
569 interfaces, but had bug fixes or semantic changes as part of this
570 release. Packages that relied on the undocumented behavior
571 should be analyzed to make sure they will still work with the
572 new documented behavior.
574 m4_cmp m4_list_cmp m4_join m4_map m4_map_sep m4_sign
575 m4_text_box m4_text_wrap m4_version_compare
577 - The m4_wrap macro used to have unspecified order, but now
578 guarantees FIFO order. m4_wrap_lifo was added to guarantee LIFO
581 - Packages using the undocumented m4sugar macro m4_PACKAGE_VERSION
582 should consider using the new AC_AUTOCONF_VERSION instead.
584 - m4sugar macros that are not documented in the manual are still
585 deemed experimental, and should not be used outside of Autoconf.
587 ** The m4sugar macros m4_append and m4_append_uniq, first documented in
588 2.60, have been fixed to treat both the string and the separator
589 arguments consistently with regards to quoting. Prior to this fix,
590 m4_append_uniq could mistakenly duplicate entries if the expansion
591 of the separator resulted in a different string (for example, if it
592 contained quotes, a comma, or a macro name). However, it means
593 that programs previously using
594 m4_append([name], [string], [[, ]])
595 are now using a four-character separator instead of the intended
596 comma and space. If you need portability to earlier versions of
597 Autoconf, you can insert the following snippet after AC_INIT but
598 before any other macro expansions, to enforce the new semantics:
599 m4_pushdef([m4_append], [m4_define([$1],
600 m4_ifdef([$1], [m4_defn([$1])[$3]])[$2])])
601 Additionally, m4_append_uniq now takes optional parameters that can
602 be used to take action depending on whether anything was appended,
603 and warns if a non-empty separator occurs within the string being
604 appended, since that can lead to duplicates.
606 ** The following m4sugar macros are new:
607 m4_append_uniq_w m4_apply m4_combine m4_cond m4_count
608 m4_dquote_elt m4_echo m4_expand m4_ignore m4_make_list m4_max
609 m4_min m4_newline m4_shift2 m4_shift3 m4_unquote m4_wrap_lifo
611 ** Warnings are now generated by default when an installer invokes
612 'configure' with an unknown --enable-* or --with-* option.
613 These warnings can be disabled with the new AC_DISABLE_OPTION_CHECKING
614 macro, or by invoking 'configure' with --disable-option-checking.
616 ** Existing obsolete macros
617 The documentation for the following macros is adjusted to make it
618 more clear that they have previously been marked obsolete, as their
619 functionality can be accomplished by other macros. We have no
620 current plans to remove them from Autoconf.
622 AC_ENABLE AC_STRUCT_ST_BLKSIZE AC_STRUCT_ST_RDEV AC_WITH
624 ** Newly obsolete macros
625 The following macros have been marked obsolete, as they only
626 perform a subset of AC_USE_SYSTEM_EXTENSIONS. We have no current
627 plans to remove them.
629 AC_AIX AC_GNU_SOURCE AC_ISC_POSIX AC_MINIX
631 ** AC_C_LONG_DOUBLE is obsolescent.
632 The documentation now says that AC_C_LONG_DOUBLE is obsolescent: it
633 tests for problems that are so old that it is no longer of
634 practical importance on current systems. New programs need not use
635 AC_C_LONG_DOUBLE. We have no current plans to remove it.
637 ** AC_DIAGNOSE, AC_WARNING, and AC_FATAL are obsolescent.
638 The documentation now favors the use of M4sugar macros m4_warn and
639 m4_fatal, since the naming makes it more obvious that the
640 diagnostics are associated with M4 expansion (ie. when running
641 `autoconf'), and offers less confusion with the AC_MSG_ERROR,
642 AC_MSG_FAILURE, and AC_MSG_WARN macros which manage diagnostics
643 when running `configure'. We have no current plans to remove these
647 * Major changes in Autoconf 2.61a (2006-12-11)
649 ** AC_FUNC_FSEEKO was broken in 2.61; it didn't make fseeko and ftello visible
650 on many platforms. This has been fixed.
652 ** AC_FUNC_SETVBUF_REVERSED is now obsolete. It is still defined for backward
653 compatibility but it does nothing. The macro was already
654 obsolescent, as the last systems to have the problem were those
655 based on SVR2, which became obsolete in 1987. The macro had bugs
656 on some modern systems and could no longer be maintained reliably
657 due to lack of ancient systems to test it on.
659 ** config.status now uses awk instead of sed for most substitutions, for speed.
661 - As a side effect multi-line values of substituted variables no
662 longer have a small limit in total size, though for portability
663 each line should not exceed the POSIX length limit for text lines.
665 - It is now documented that Makefile.in should not contain
666 overlapping variable occurrences, e.g., @VAR1@VAR2@.
667 Autoconf's behavior was always iffy in such cases, and the
668 awk implementation has changed the behavior.
670 ** Many uses of 'echo' have been rewritten so that Autoconf-generated
671 scripts have fewer problems with strings or file names containing
672 embedded special characters such as backslash or leading "-". This
673 was implemented by using `printf '%s\n' "$foo"' instead of `echo
674 "$foo"' when printf works. Due to the implementation technique
675 used, Autoconf-generated scripts now run considerably more slowly
676 on ancient implementations lacking printf. However, this should
677 not be a problem, since Autoconf-generated scripts in practice
678 invariably find a more-modern shell these days.
681 * Major changes in Autoconf 2.61 (2006-11-17)
683 ** New macros AC_C_FLEXIBLE_ARRAY_MEMBER, AC_C_VARARRAYS.
685 ** AC_ARG_ENABLE and AC_ARG_WITH now allow '.' in feature and package names.
688 * Major changes in Autoconf 2.60b (2006-10-22)
691 Autoconf-generated shell scripts no longer export BIN_SH, due to
692 configuration hassles with this. Installers who need BIN_SH in
693 their environment should set it before invoking 'configure' and
694 'make'. As far as we know, this affects only Unixware installations.
696 ** Obsolescent macros
697 The documentation now says that the following macros are obsolescent,
698 as they are superseded by Gnulib:
700 AC_FUNC_FNMATCH AC_FUNC_FNMATCH_GNU AC_FUNC_GETLOADVG AC_REPLACE_FNMATCH
702 New programs should use the Gnulib counterparts of these macros.
703 We have no current plans to remove them from Autoconf.
705 ** AC_COMPUTE_INT no longer caches or reports results.
707 ** AC_CHECK_DECL now also works with aggregate objects.
709 ** AC_USE_SYSTEM_EXTENSIONS now defines _TANDEM_SOURCE for NonStop platforms.
711 ** GNU M4 1.4.7 or later is now recommended.
714 New M4sugar macro, which is more secure than the POSIX M4 maketemp.
717 Now an alias for m4_mkstemp.
719 * Major changes in Autoconf 2.60a (2006-08-25)
721 ** GNU M4 1.4.6 or later is now recommended.
723 ** The check for C99 now tests for varargs macros, as documented.
724 It also tests that the preprocessor supports 64-bit integers.
726 ** Autoconf now uses constructs like "#ifdef HAVE_STDLIB_H" rather than
727 "#if HAVE_STDLIB_H", so that it now works with "gcc -Wundef -Werror".
729 ** The functionality of the undocumented _AC_COMPUTE_INT is now provided
730 by a public and documented macro, AC_COMPUTE_INT. The parameters to the
731 two macros are different, so autoupdate will not change the old private name
732 to the new one. _AC_COMPUTE_INT may be removed in a future release.
734 ** AC_TYPE_LONG_LONG_INT and AC_TYPE_UNSIGNED_LONG_LONG_INT now require
735 that long long types be at least 64 bits wide, as C99 and tradition
736 requires. Formerly, they accepted implementations of any width.
739 * Major changes in Autoconf 2.60
741 Released 2006-06-23, by Ralf Wildenhues.
743 ** Autoconf no longer depends on whether m4wrap is FIFO (as Posix requires)
744 or LIFO (as in GNU M4 1.4.x). GNU M4 2.0 is expected to conform to Posix
745 here, so m4wrap/m4_wrap users should no longer depend on LIFO behavior.
747 ** Provide a way to turn off warnings about the changed directory variables.
749 * Major changes in Autoconf 2.59d
751 Released 2006-06-05, by Ralf Wildenhues.
753 ** GNU make now recommended for VPATH builds
754 INSTALL now suggests VPATH builds (e.g., "sh ../srcdir/configure")
755 only if you use GNU make. In practice, other 'make' implementations
756 have too many subtle incompatibilities in their support for VPATH.
757 Many packages (including Autoconf itself) are portable to other
758 'make' implementations, but some packages are not, and recommending
759 GNU make keeps the installation instructions simpler.
761 ** Even more safety checks for the new Directory variables:
762 Warn about suspicious `${datarootdir}' found in config files output.
764 ** AC_TRY_COMMAND, AC_TRY_EVAL, ac_config_guess, ac_config_sub, ac_configure
765 These never-documented macros and variables have been marked with
766 comments saying that they may be removed in a future release,
767 because their use can lead to unintended code being executed.
768 If you need functionality that only these macros or variables
769 currently supply, please write bug-autoconf@gnu.org.
771 ** AC_SUBST, AC_DEFINE
772 Literal arguments to these are passed to m4_pattern_allow now.
775 Passing 'ac_cv_prog_cc_stdc=no' to 'configure' now sets ac_cv_prog_cc_c99
776 and ac_cv_prog_cc_c89 to 'no' as well, for backward compatibility with
777 obsolete K&R tests in the Automake test suite.
786 Now more robust with special characters in file names, or when
787 multiple processes create the same directory at the same time.
789 ** Obsolescent macros
790 The documentation now says that the following macros are obsolescent:
791 they test for problems that are so old that they are no longer of
792 practical importance on current systems.
794 AC_C_BACKSLASH_A AC_FUNC_MEMCMP AC_HEADER_DIRENT
795 AC_C_CONST AC_FUNC_SELECT_ARGTYPES AC_HEADER_STAT
796 AC_C_PROTOTYPES AC_FUNC_SETPGRP AC_HEADER_STDC
797 AC_C_STRINGIZE AC_FUNC_SETVBUF_REVERSED AC_HEADER_SYS_WAIT
798 AC_C_VOLATILE AC_FUNC_STAT AC_HEADER_TIME
799 AC_FUNC_CLOSEDIR_VOID AC_FUNC_STRFTIME AC_ISC_POSIX
800 AC_FUNC_GETPGRP AC_FUNC_UTIME_NULL AC_PROG_GCC_TRADITIONAL
801 AC_FUNC_LSTAT AC_FUNC_VPRINTF AC_STRUCT_TM
803 New programs need not use these macros. We have no current plans to
807 For compatibility with future Libtool 2.0, autoreconf will invoke
808 libtoolize with the option `--ltdl' now, if LT_CONFIG_LTDL_DIR is
811 * Major changes in Autoconf 2.59c
813 Released 2006-04-12, by Ralf Wildenhues.
815 ** The configure command now redirects standard input from /dev/null,
816 to help avoid problems with subsidiary commands that might mistakenly
817 read standard input. AS_ORIGINAL_STDIN_FD points to the original
818 standard input before this redirection, if you really want configure to
819 read from standard input.
821 ** Directory variables adjusted to recent changes in the GNU Coding Standards.
822 The following directory variables are new:
824 datarootdir read-only architecture-independent data root [PREFIX/share]
825 localedir locale-specific message catalogs [DATAROOTDIR/locale]
826 docdir documentation root [DATAROOTDIR/doc/PACKAGE]
827 htmldir html documentation [DOCDIR]
828 dvidir dvi documentation [DOCDIR]
829 pdfdir pdf documentation [DOCDIR]
830 psdir ps documentation [DOCDIR]
832 The following variables have new default values:
834 datadir read-only architecture-independent data [DATAROOTDIR]
835 infodir info documentation [DATAROOTDIR/info]
836 mandir man documentation [DATAROOTDIR/man]
838 This means that if you use any of `@datadir@', `@infodir@', or
839 `@mandir@' in a file, you will have to ensure `${datarootdir}' is
840 defined in this file. As a temporary measure, if any of those are
841 found but no mention of `datarootdir', the substitutions will be
842 replaced with values that do not contain `${datarootdir}', and a
843 warning will be issued.
845 ** @top_builddir@ is now a dir name: it is always nonempty and doesn't have
846 a trailing slash. Similar change will be made to ac_top_builddir in a
847 future release; the old style value, which matches (../)*, is (and will
848 continue to be) available as ac_top_build_prefix.
851 New macro to check for support of 'typeof' syntax a la GNU C.
853 ** AC_CHECK_DECLS_ONCE, AC_CHECK_FUNCS_ONCE, AC_CHECK_HEADERS_ONCE
854 New "once-only" variants of commonly-used macros, to make 'configure'
855 smaller and faster in common cases.
858 New macro to check for strtold with C99 semantics.
861 New macro that lets builder disable assertions at 'configure'-time.
864 Now checks for X11/Xlib.h and XrmInitialize (X proper) rather than
865 X11/Intrinsic.h and XtMalloc (Xt).
867 ** AC_PRESERVE_HELP_ORDER
868 New macro that causes `configure' to display help strings for AC_ARG_ENABLE
869 and AC_ARG_WITH arguments in one region, in the order defined. The default
870 behavior is to group options of each classes separately.
872 ** AC_PROG_CC, AC_PROG_CXX
873 No longer automatically arrange to declare the 'exit' function of C,
874 when a C++ compiler is used. Standard Autoconf macros no longer use
875 'exit', so this is no longer an issue for them. If you use C++, and
876 want to call 'exit', you'll have to arrange for its declaration
877 yourself. But we now suggest you return from 'main' instead.
879 ** AC_PROG_CC_C89, AC_PROG_CC_C99
880 New macros for ISO C99 support. AC_PROG_CC_C89 and AC_PROG_CC_C99
881 check for ANSI C89 and ISO C99 support respectively.
884 Has been unobsoleted, and will check if the compiler supports ISO
885 C99, falling back to ANSI C89 if not. ac_cv_prog_cc_stdc is
886 retained for backwards compatibility, assuming the value of
887 ac_cv_prog_cc_c99 or ac_cv_prog_cc_c89 (whichever is valid, in
890 ** AC_STRUCT_DIRENT_D_INO, AC_STRUCT_DIRENT_D_TYPE
891 New macros for checking commonly-used members of struct dirent.
894 The substituted value can now contain newlines.
897 The substitution now occurs only when @variable@ is on a line by itself,
898 optionally surrounded by spaces and tabs. The whole line is replaced.
900 ** AC_TYPE_LONG_DOUBLE, AC_TYPE_LONG_DOUBLE_WIDER
901 New macros to check for long double, and whether it is wider than double.
902 The old macro AC_C_TYPE_LONG_DOUBLE has been marked as obsolete;
903 applications should switch to the new macro.
905 ** AC_TYPE_INT8_T, AC_TYPE_INT16_T, AC_TYPE_INT32_T, AC_TYPE_INT64_T,
906 AC_TYPE_INTMAX_T, AC_TYPE_INTPTR_T, AC_TYPE_LONG_LONG_INT, AC_TYPE_SSIZE_T,
907 AC_TYPE_UINT8_T, AC_TYPE_UINT16_T, AC_TYPE_UINT32_T, AC_TYPE_UINT64_T,
908 AC_TYPE_UINTMAX_T, AC_TYPE_UINTPTR_T, AC_TYPE_UNSIGNED_LONG_LONG_INT
909 New macros to check for C99 and POSIX types.
911 ** AC_USE_SYSTEM_EXTENSIONS
912 New macro to enable extensions to Posix.
915 New macro which is defined to the name of the first declared config header
916 or undefined if no config headers have been declared yet.
919 The macro correctly handles quadrigraphs now.
921 ** AS_BOURNE_COMPATIBLE, AS_SHELL_SANITIZE, AS_CASE
922 These macros are new or published now.
925 New macro for copyright notices in testsuite files.
927 ** ALLOCA, LIBOBJS, LTLIBOBJS
928 Object names added to these variables are now prefixed with `${LIBOBJDIR}',
929 as in `${LIBOBJDIR}alloca.o'. LIBOBJDIR is meant to be defined from
930 `Makefile.in' in case the object files lie in a different directory.
931 The LIBOBJDIR feature is experimental.
934 Supports --no-recursive now.
936 ** New macros to support Erlang/OTP.
937 New macros for configuring paths to Erlang tools and libraries:
938 AC_ERLANG_PATH_ERLC, AC_ERLANG_NEED_ERLC, AC_ERLANG_PATH_ERL,
939 AC_ERLANG_NEED_ERL, AC_ERLANG_CHECK_LIB, AC_ERLANG_SUBST_ROOT_DIR,
940 AC_ERLANG_SUBST_LIB_DIR.
942 New macros for configuring installation of Erlang libraries:
943 AC_ERLANG_SUBST_INSTALL_LIB_DIR, AC_ERLANG_SUBST_INSTALL_LIB_SUBDIR.
945 ** The manual now mentions Gnulib more prominently.
947 ** New macros to support Objective C.
948 AC_PROG_OBJC, AC_PROG_OBJCPP.
950 * Major changes in Autoconf 2.59b
952 Released 2004-08-20, by Paul Eggert.
955 New macro that computes the default alignment of a type.
957 ** AC_CHECK_TOOL, AC_PATH_TOOL, AC_CHECK_TOOLS
958 When cross-compiling, these macros will give a warning if the tool
959 is not prefixed. In the future, unprefixed cross tools will not
960 be detected; please consult the info documentation for information
961 about the reason of this change.
963 ** AC_CHECK_TARGET_TOOL, AC_PATH_TARGET_TOOL, AC_CHECK_TARGET_TOOLS
964 New macros that detect programs whose name is prefixed with the
965 target type, if the build type and target type are different.
967 ** AC_REQUIRE_AUX_FILE
968 New trace macro that declares expected auxiliary files.
971 New macro that tests for a grep program that accepts as a long a line
974 ** AC_PROG_EGREP, AC_PROG_FGREP
975 These macros now require AC_PROG_GREP, and try EGREP="$GREP -E" and
976 FGREP="$GREP -F" respectively if possible, or else run a path search for
977 a program that accepts as long a line as possible.
980 New macro that tests for a sed program that truncates as few characters
983 * Major changes in Autoconf 2.59
985 Released 2003-11-04, by Akim Demaille
987 ** ac_abs_builddir etc.
988 Absolute file names were actually relative in 2.58.
990 * Major changes in Autoconf 2.58
992 Released 2003-11-04, by Akim Demaille
995 core.* files are no longer removed, as they may be valid user files.
997 ** autoreconf and auxiliary directory
998 Autoreconf creates the auxiliary directory if needed. This is
999 especially useful for initial "bootstrapping" of fresh CVS checkouts.
1001 ** AC_CONFIG_MACRO_DIR
1002 Use this macro to declare the directory for local M4 macros for aclocal.
1005 No longer includes twice the same file in LIBOBJS if invoked
1008 ** AC_CONFIG_COMMANDS
1009 The directory for its first argument is automatically created. For
1012 AC_CONFIG_COMMANDS([src/modules.hh], [...])
1014 $top_builddir/src/ is created if needed.
1016 ** Autotest and local.at
1017 The optional file local.at is always included in Autotest test suites.
1020 The warnings are always issued, including with cached runs.
1021 This became a significant problem since aclocal and automake can
1022 run autoconf behind the scene.
1024 ** autoheader warnings
1025 The warnings of autoheader can be turned off, using --warning.
1026 For instance, -Wno-obsolete disables the complaints about acconfig.h
1027 and other deprecated constructs.
1030 AC_C_RESTRICT, AC_INCLUDES_DEFAULT, AC_LANG_ASSERT, AC_LANG_WERROR,
1033 ** AC_DECL_SYS_SIGLIST
1037 Now checks that mktime is the inverse of localtime.
1039 ** Improve DJGPP portability
1040 The Autoconf tools and configure behave better under DJGPP.
1042 ** Present But Cannot Be Compiled
1043 New FAQ section dedicated to the mystic
1045 configure: WARNING: pi.h: present but cannot be compiled
1046 configure: WARNING: pi.h: check for missing prerequisite headers?
1047 configure: WARNING: pi.h: proceeding with the preprocessor's result
1050 ** Concurrent executions of autom4te
1051 autom4te now locks its internal files, which enables concurrent
1052 executions of autom4te, likely to happen if automake, autoconf,
1053 autoheader etc. are run simultaneously.
1056 Use of Libtool 1.5 and higher is encouraged. Compatibility with
1057 Libtool pre-1.4 is not checked.
1060 Testsuites no longer rerun failed tests in verbose mode; instead,
1061 failures are logged while the test is run.
1063 In addition, expected failures can be marked as such.
1065 * Major changes in Autoconf 2.57
1067 Released 2002-12-03 by Paul Eggert.
1069 Bug fixes for problems with AIX linker, with freestanding C compilers,
1070 with GNU M4 limitations, and with obsolete copies of GNU documents.
1072 The Free Documentation License has been upgraded from 1.1 to 1.2.
1074 * Major changes in Autoconf 2.56
1076 Released 2002-11-15 by Akim Demaille.
1078 One packaging problem fixed (config/install-sh was not executable).
1080 * Major changes in Autoconf 2.55
1082 Released 2002-11-14 by Akim Demaille.
1086 Have your configure.ac checked by autoscan ("autoscan").
1087 Try the warning options ("autoreconf -fv -Wall").
1091 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1092 More information on proper use.
1094 - Writing Test Programs
1096 This sections explains how to write good test sources to use with
1097 AC_COMPILE_IFELSE etc. It documents AC_LANG_PROGRAM and so forth.
1099 - AC_FOO_IFELSE vs. AC_TRY_FOO
1101 Explains why Autoconf moves from AC_TRY_COMPILE etc. to
1102 AC_COMPILE_IFELSE and AC_LANG_PROGRAM etc.
1106 - Is more robust to different Gettext installations.
1108 - Produces messages (when --verbose) to be understood by Emacs'
1111 - Supports -W/--warnings.
1114 Once the GNU Build System reinstalled, run `./config.status
1115 --recheck && ./config.status && make' if possible.
1119 - Supports --cache, and --no-cache.
1121 - ~/.autom4te.cfg makes it possible to disable the caching mechanism
1122 (autom4te.cache). See `Customizing autom4te' in the documentation.
1129 Support for the obsoleted options -m, --macrodir, -l, --localdir is
1130 dropped in favor of the safer --include/--prepend-include scheme.
1135 AC_COMPILER_IFELSE, AC_FUNC_MBRTOWC, AC_HEADER_STDBOOL,
1136 AC_LANG_CONFTEST, AC_LANG_SOURCE, AC_LANG_PROGRAM, AC_LANG_CALL,
1137 AC_LANG_FUNC_TRY_LINK, AC_MSG_FAILURE, AC_PREPROC_IFELSE.
1140 Obsoleted macros are kept for Autoconf backward compatibility, but
1141 should be avoided in configure.ac. Running autoupdate is advised.
1142 AC_DECL_SYS_SIGLIST.
1144 - AC_DEFINE/AC_DEFINE_UNQUOTED
1146 We have to stop using the old compatibility scheme --that tried to
1147 avoid useless backslashes-- because Libtool 1.4.3 contains a
1149 AC_DEFINE([error_t], [int],
1150 [Define to a type to use for \`error_t' if it is not
1151 otherwise available.])
1153 We have to quote the single quotes and backslashes with \. The old
1154 compatibility scheme saw that ` was backslashed, and therefore did
1155 not quote the single quote... Failure. Hence, Autoconf 2.54 is not
1156 compatible with Libtool. Autoconf 2.55 is, but in some cases might
1157 produce more \ than wanted.
1159 Please, note that in the future the same problem will happen with
1160 AC_MSG_*: use `autoreconf -f -Wall'.
1164 - Portability of the Autoconf package to Solaris.
1166 - Spurious warnings caused by config.status.
1167 This bug is benign, but painful: on some systems (typically
1168 FreeBSD), warnings such as:
1170 config.status: creating Makefile
1171 mv: Makefile: set owner/group (was: 1357/0): Operation not permitted
1173 could be issued. This is fixed.
1176 Simultaneous executions of config.status are possible again.
1178 - Precious variables accumulation
1180 config.status could stack several copies of the precious variables
1184 ** Plans for later versions
1186 - ./configure <host>
1188 The compatibility hooks with the old scheme will be completely
1189 removed. Please, advice/use `--build', `--host', and `--target'
1192 - AC_CHECK_HEADER, AC_CHECK_HEADERS
1194 The tests will be stricter, please make sure your invocations are
1199 Shell functions will gradually be introduced, probably starting with
1200 Autotest. If you know machines which are in use that you suspect
1201 *not* to support shell functions, please run the test suite of
1202 Autoconf 2.55 on it, and report the results to
1203 bug-autoconf@gnu.org.
1207 Special characters in AC_MSG_* need not be quoted. Currently,
1208 Autoconf has heuristics to decide when a string is escaped, or has
1209 to be escaped. This scheme is fragile, and will be removed; the
1210 only risk is uglified messages. Please, run `autoreconf -f -Wall'
1211 to find occurrences that will be affected.
1213 * Major changes in Autoconf 2.54
1215 Released 2002-09-13 by Akim Demaille.
1219 - autoreconf no longer changes the version of the gettext/po/intl
1220 support files. It now adds the files the correspond to the
1221 AM_GNU_GETTEXT_VERSION declared in configure.ac.
1223 Warning: It now relies on the 'autopoint' program, which is part
1224 of GNU gettext 0.11.4 and newer.
1226 Please note that you need to have a GNU gettext version that
1227 corresponds at least to the AM_GNU_GETTEXT_VERSION declared
1228 in configure.ac. You can upgrade to newer GNU gettext versions,
1229 though, without needing to change configure.ac.
1231 - The -I DIR or --include=DIR option now appends DIR to the include path
1232 instead of prepending; this is for consistency with other GNU tools.
1233 The new -B DIR or --prepend-include=DIR option has the old behavior.
1238 Now handles all the gory details about LIBOBJS and LTLIBOBJS.
1239 Please, remove lines such as
1241 # This is necessary so that .o files in LIBOBJS are also
1242 # built via the ANSI2KNR-filtering rules.
1243 LIBOBJS=`echo $LIBOBJS|sed 's/\.o /\$U.o /g;s/\.o$/\$U.o/'`
1245 and read the `AC_LIBOBJ vs LIBOBJS' section. Do not define U in
1246 your Makefiles either.
1248 - AC_CONFIG_LINKS now makes copies if it can't make links.
1250 - AC_FUNC_FNMATCH now tests only for POSIX compatibility, reverting to
1251 Autoconf 2.13 behavior. The new macro AC_FUNC_FNMATCH_GNU also
1252 tests for GNU extensions to fnmatch, and replaces fnmatch if needed.
1254 - AC_FUNC_SETVBUF_REVERSED no longer fails when cross-compiling.
1256 - AC_PROG_CC_STDC is integrated into AC_PROG_CC.
1258 - AC_PROG_F77 default search no longer includes cf77 and cfg77.
1262 AC_C_BACKSLASH_A, AC_CONFIG_LIBOBJ_DIR, AC_GNU_SOURCE,
1263 AC_PROG_EGREP, AC_PROG_FGREP, AC_REPLACE_FNMATCH,
1264 AC_FUNC_FNMATCH_GNU, AC_FUNC_REALLOC, AC_TYPE_MBSTATE_T.
1266 - AC_FUNC_GETLOADAVG
1267 looks for getloadavg.c in the CONFIG_LIBOBJ_DIR.
1270 Now defines HAVE_MALLOC to 0 if `malloc' does not work, and asks
1271 for an AC_LIBOBJ replacement.
1275 - Spurious complaints from `m4_bmatch' about invalid regular
1276 expressions are suppressed.
1278 - Empty top_builddirs are properly handled.
1280 - AC_CHECK_MEMBER works correctly when the member is an aggregate.
1283 Now colon in the optional path arguments are properly handled.
1285 ** Improved portability
1287 - Both Autoconf the package, and the scripts it produces, should run
1288 more reliably with Zsh. Bear in mind it is the default Bourne shell
1291 - Autoconf and the scripts it produces no longer assume the existence of
1292 the obsolescent commands egrep and fgrep.
1296 - Limitations of Make
1300 The GNATS base moved to
1301 http://bugs.gnu.org/cgi-bin/gnatsweb.pl?database=autoconf
1302 (It is no longer available, though.)
1307 Now contains the list of output variables and files (AC_SUBST,
1310 * Major changes in Autoconf 2.53
1312 Released 2002-03-08 by Akim Demaille.
1316 Perl 5.005_03 or later is required: autom4te is written in Perl and is
1317 needed by autoconf. autoheader, autoreconf, ifnames, and autoscan are
1323 Argument requirements, output variables, defined macros.
1324 - M4sugar, M4sh, Autotest
1326 - Double quoting macros
1327 AC_TRY_CPP, AC_TRY_COMPILE, AC_TRY_LINK and AC_TRY_RUN.
1329 The Autoconf manual is now distributed under the terms of the GNU FDL.
1330 - Section `Hosts and Cross-Compilation'
1331 Explains the rationale for the 2.5x changes in the cross-compilation
1332 chain, and in the relationships between build, host, and target
1334 Emphasizes that `cross-compilation' == `--host is given'.
1335 If you are working on compilers etc., be sure to read this section.
1336 - Section `AC_LIBOBJ vs. LIBOBJS'
1337 Explains why assigning LIBOBJS directly is now an error.
1338 Details how to update the code.
1343 Now used instead of hard coded line numbers.
1344 This eases the comparison of `configure's, and diminishes the
1345 pressure over control version archives.
1346 Automatic replacement for shells that don't support this feature.
1347 - New output variables
1348 @builddir@, @top_builddir@, @abs_srcdir@, @abs_top_srcdir@, @abs_builddir@,
1353 Autoconf and Autotest modes are provided.
1358 New, used by the Autoconf suite to cache and speed up most processing.
1360 Supported by autom4te, autoconf and autoheader.
1362 Replaces --autoconf-dir and --localdir in autoconf, autoheader,
1363 autoupdate, and autoreconf.
1365 No longer passes --cygnus, --foreign, --gnits, --gnu, --include-deps:
1366 automake options are to be given via AUTOMAKE_OPTIONS.
1368 Runs gettextize and libtoolize when appropriate.
1370 --m4dir is no longer supported.
1372 Now runs only in the specified directories, defaulting to `.',
1373 but understands AC_CONFIG_SUBDIRS for dependent directories.
1374 Before, it used to run on all the `configure.ac' found in the
1376 Independent packages are properly updated.
1380 - The top level $prefix is propagated to the AC_CONFIG_SUBDIRS configures.
1382 Under the user pressure, $? is finally available. Probably a mistake.
1383 - AC_F77_LIBRARY_LDFLAGS now supports the HP/UX f90 compiler.
1384 - Precious variables accumulation
1385 config.status could stack several copies of the precious variables
1387 - AC_PATH_PROG and family.
1388 Works properly when given a literal path.
1390 Somewhere since 2.13, the result had been reversed.
1394 - AC_C_BIGENDIAN supports the cross-compiling case.
1395 - AC_C_BIGENDIAN accepts ACTION-IF-TRUE, ACTION-IF-FALSE, and
1396 ACTION-IF-UNKNOWN arguments. All are optional, and the default
1397 for ACTION-IF-TRUE is to define WORDS_BIGENDIAN like AC_C_BIGENDIAN
1399 - AC_C_LONG_DOUBLE now succeeds only if `long double' has more range or
1400 precision than `double'.
1405 It now defines the preprocessor symbols PACKAGE_NAME,
1406 PACKAGE_TARNAME, PACKAGE_VERSION, PACKAGE_STRING, and
1410 Admits a fourth optional parameter: the tar name.
1412 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS.
1413 Provide the user with srcdir, ac_srcdir, ac_top_srcdir, ac_builddir,
1414 ac_top_builddir, ac_abs_srcdir, ac_abs_top_srcdir, ac_abs_builddir,
1415 ac_abs_top_builddir.
1417 - AC_CONFIG_COMMANDS, HEADERS, FILES, LINKS and AC_OUTPUT.
1418 Are much less expensive when using long lists of files.
1421 Works with shell variables, and non alphanumeric names.
1425 - AC_FUNC_STRERROR_R now sets STRERROR_R_CHAR_P, not HAVE_WORKING_STRERROR_R,
1426 because POSIX 1003.1-200x draft 7 says strerror_r returns int, not char *.
1428 - AC_FUNC_STRTOD substitutes POW_LIB.
1433 * Major changes in Autoconf 2.52
1435 Released 2001-07-18 by Akim Demaille.
1440 This feature was present in autoconf 2.50 but was not documented.
1441 For example, `@<:@' is translated to `[' just before output. This
1442 is useful when writing strings that contain unbalanced quotes, or
1443 other hard-to-quote constructs.
1444 - m4_pattern_forbid, m4_pattern_allow
1445 - Tips for upgrading from 2.13.
1446 - Using autoscan to maintain a configure.ac.
1449 - Now include stdint.h.
1450 - sys/types.h and sys/stat.h are guarded.
1451 - strings.h is included if available, and not conflicting with string.h.
1454 - The test suite is more robust and presents less false failures.
1455 - Invocation of GNU M4 now robust to POSIXLY_CORRECT.
1456 - configure accepts --prefix='' again.
1457 - AC_CHECK_LIB works properly when its first argument is not a
1459 - HAVE_INTTYPES_H is defined only if not conflicting with sys/types.h.
1460 - build_, host_, and target_alias are AC_SUBST as in 2.13.
1461 - AC_ARG_VAR properly propagates precious variables inherited from the
1462 environment to ./config.status.
1463 - Using --program-suffix/--program-prefix is portable.
1464 - Failures to detect the default compiler's output extension are less
1466 - `config.status foo' works properly when `foo' depends on variables
1467 set in an AC_CONFIG_THING INIT-CMD.
1468 - autoheader is more robust to broken input.
1469 - Fixed Fortran name-mangling and link tests on a number of systems,
1470 e.g. NetBSD; see AC_F77_DUMMY_MAIN, below.
1473 - AC_CHECK_HEADER and AC_CHECK_HEADERS support a fourth argument to
1474 specify pre-includes. In this case, the headers are compiled with
1475 cc, not merely preprocessed by cpp. Therefore it is the _usability_
1476 of a header which is checked for, not just its availability.
1477 - AC_ARG_VAR refuses to run configure when precious variables have
1479 - Versions of compilers are dumped in the logs.
1480 - AC_CHECK_TYPE recognizes use of `foo_t' as a replacement type.
1483 - AC_PATH_XTRA only adds -ldnet to $LIBS if it's needed to link.
1484 - AC_FUNC_WAIT3 and AC_SYS_RESTARTABLE_SYSCALLS are obsoleted.
1485 - AM_FUNC_ERROR_AT_LINE, AM_FUNC_FNMATCH, AM_FUNC_MKTIME,
1486 AM_FUNC_OBSTACK, and AM_FUNC_STRTOD are now activated.
1487 Be sure to read `Upgrading from Version 2.13' to understand why
1488 running `autoupdate' is needed.
1489 - AC_F77_DUMMY_MAIN, AC_F77_MAIN: new macros to detect whether
1490 a main-like routine is required/possible when linking C/C++ with
1491 Fortran. Users of e.g. AC_F77_WRAPPERS should be aware of these.
1492 - AC_FUNC_GETPGRG behaves better when cross-compiling.
1494 * Major changes in Autoconf 2.51
1495 There was no release of Autoconf 2.51 since some packagers had used
1496 this version number without permission to ship intermediary versions
1497 of 2.50. The version was skipped to avoid confusion.
1499 * Major changes in Autoconf 2.50
1501 Released 2001-05-21 by Akim Demaille.
1503 ** Lots of bug fixes
1504 There have been far too many to enumerate them here. Check out
1505 ChangeLog if you really want to know more.
1507 ** Improved documentation
1508 In particular, portability issues are better covered.
1511 All the standard GNU Makefile targets are supported. The layout has
1512 changed: m4/ holds the M4 extensions Autoconf needs for its
1513 configuration, doc/ contains the documentation, and tests/ contains
1516 ** Man pages are provided
1517 For autoconf, autoreconf, autoupdate, autoheader, autoscan, ifnames,
1518 config.guess, config.sub.
1522 Provides a safe and powerful means to trace the macro uses. This
1523 provide the parsing layer for tools which need to `study'
1527 Specify what category of warnings should be enabled.
1529 - When recursing into subdirectories, try for configure.gnu before
1530 configure to adapt for packages not using autoconf on case-insensitive
1534 More errors are now caught (circular AC_REQUIRE dependencies,
1535 AC_DEFINE in the action part of an AC_CACHE_CHECK, too many pops
1536 etc.). In addition, their location and call stack are given.
1539 autoupdate is much more powerful, and is able to provide the glue code
1540 which might be needed to move from an old macro to its newer
1543 You are strongly encouraged to use it to modernize both your
1544 `configure.in' and your .m4 extension files.
1547 The internal machinery of autoheader has completely changed. As a
1548 result, using `acconfig.h' should be considered to be obsoleted, and
1549 you are encouraged to get rid of it using the AH macros.
1554 ** Fortran 77 compilers
1555 Globally, the support for Fortran 77 is considerably improved.
1557 Support for automatically determining a Fortran 77 compiler's
1558 name-mangling scheme. New CPP macros F77_FUNC and F77_FUNC_ are
1559 provided to wrap C/C++ identifiers, thus making it easier and more
1560 transparent for C/C++ to call Fortran 77 routines, and Fortran 77 to
1561 call C/C++ routines. See the Texinfo documentation for details.
1564 The test suite no longer uses DejaGNU. It should be easy to submit
1565 test cases in this new framework.
1568 - --help, --help=long, -hl
1569 no longer dumps useless items.
1571 lists only specific options.
1572 - --help=recursive, -hr
1573 displays the help of all the embedded packages.
1574 - Remembers environment variables when reconfiguring.
1575 The previous scheme to set envvar before running configure was
1577 what prevented configure from remembering the environment in which
1578 it was run, therefore --recheck was run in an inconsistent
1579 environment. Now, one should run
1581 and then --recheck will work properly. Variables declared with
1582 AC_ARG_VAR are also preserved.
1584 $build defaults to `config.guess`, $host to $build, and then $target
1586 Cross-compilation is a global status of the package, it no longer
1587 depends upon the current language.
1588 Cross compilation is enabled iff the user specified `--host'.
1589 `configure' now fails if it can't run the executables it compiles,
1590 unless cross-compilation is enabled.
1592 The cache file is disabled by default. The new options
1593 `--config-cache', `-C' set the cache to `config.cache'.
1597 Much faster on most architectures.
1598 - concurrent executions
1599 It is safe to use `make -j' with config.status.
1600 - human interface improved
1601 It is possible to invoke
1602 ./config.status foobar
1603 instead of the former form (still valid)
1604 CONFIG_COMMANDS= CONFIG_HEADERS= CONFIG_LINKS= \
1605 CONFIG_FILES=foobar:foo.in:bar.in \
1607 The same holds for configuration headers and links.
1608 You can instantiate unknown files and headers:
1609 ./config.status --header foo.h:foo.h.in --file bar:baz
1610 - has a useful --help
1611 - accepts special file name "-" for stdin/stdout
1616 Specify additional copyright information.
1619 Now expects the identity of the package as argument.
1623 Most macros, if not all, now strictly follow the `one quotation
1624 level' rule. This results in a more predictable expansion.
1627 A sly bug in the AC_REQUIRE machinery, which could produce incorrect
1628 configure scripts, was fixed by Axel Thimm.
1632 Document and ask for the registration of an envvar.
1635 Specifies the file which `configure' should look for when trying to
1636 find the source tree (used to be handled by AC_INIT).
1638 - AC_CONFIG_COMMANDS
1639 To add new actions to config.status. Should be used instead of
1643 Replaces AC_LINK_FILES.
1645 - AC_CONFIG_HEADERS, AC_CONFIG_COMMANDS, AC_CONFIG_SUBDIRS,
1646 AC_CONFIG_LINKS, and AC_CONFIG_FILES
1647 They now obey sh: you should no longer use shell variables as
1648 argument. Instead of
1650 test "$package_foo_enabled" = yes && $my_subdirs="$my_subdirs foo"
1651 AC_CONFIG_SUBDIRS($my_subdirs)
1655 if test "$package_foo_enabled" = yes; then
1656 AC_CONFIG_SUBDIRS(foo)
1660 To format an Autoconf macro's help string so that it looks pretty
1661 when the user executes `configure --help'.
1664 ** Generic Test Macros
1666 The interface of the AC_CHECK families of macros (decl, header,
1667 type, member, func) is now uniform. They support the same set of
1670 - AC_CHECK_DECL, AC_CHECK_DECLS
1671 To check whether a symbol is declared.
1673 - AC_CHECK_SIZEOF, AC_C_CHAR_UNSIGNED.
1674 No longer need a cross-compilation default.
1677 The test it performs is much more robust than previously, and makes
1678 it possible to test builtin types in addition to typedefs.
1679 It is now schizophrenic:
1680 - AC_CHECK_TYPE(TYPE, REPLACEMENT)
1681 remains for backward compatibility, but its use is discouraged.
1682 - AC_CHECK_TYPE(TYPE, IF-FOUND, IF-NOT-FOUND, INCLUDES)
1683 behaves exactly like the other AC_CHECK macros.
1686 Checks whether given types are supported by the system.
1688 - AC_CHECK_MEMBER, AC_CHECK_MEMBERS
1689 Check for given members in aggregates (e.g., pw_gecos in struct
1693 Checks if the compiler supports ISO C, included when needs special
1697 Checking whether the preprocessor indicates missing includes by the
1698 error code. stderr is checked by AC_TRY_CPP only as a fallback.
1701 Takes a language as argument and replaces AC_LANG_C,
1702 AC_LANG_CPLUSPLUS and AC_LANG_FORTRAN77.
1704 - AC_LANG_PUSH, AC_LANG_POP
1705 Are preferred to AC_LANG_SAVE, AC_LANG_RESTORE.
1708 - AC_FUNC_CHOWN, AC_FUNC_MALLOC, AC_FUNC_STRERROR_R,
1709 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK, AC_FUNC_STAT, AC_FUNC_LSTAT,
1710 AC_FUNC_ERROR_AT_LINE, AC_FUNC_OBSTACK, AC_FUNC_STRTOD, AC_FUNC_FSEEKO.
1714 Sets GETGROUPS_LIBS.
1716 - AC_FUNC_GETLOADAVG
1717 Defines `HAVE_STRUCT_NLIST_N_UN_N_NAME' instead of `NLIST_NAME_UNION'.
1720 Now integrates `AC_DECL_YYTEXT' which is obsoleted.
1723 Arrange for large-file support.
1725 - AC_EXEEXT, AC_OBJEXT
1726 You are no longer expected to use them: their computation is
1727 performed by default.
1729 ** C++ compatibility
1730 Every macro has been revisited in order to support at best CC=c++.
1732 Major changes in Autoconf 2.14:
1733 There was no release of GNU Autoconf 2.14.
1735 Major changes in Autoconf 2.13:
1737 Released 1999-05-01 by Ben Elliston.
1739 * Support for building on 32-bit Windows systems where the only available C or
1740 C++ compiler is the Microsoft Visual C++ command line compiler
1741 (`cl'). Additional support for building on 32-bit Windows systems which are
1742 using the Cygwin or Mingw32 environments.
1743 * Support for alternative object file and executable file extensions.
1744 On 32-bit Windows, for example, these are .obj and .exe. These are discovered
1745 using AC_OBJEXT and AC_EXEEXT, which substitute @OBJEXT@ and
1746 @EXEEXT@ in the output, respectively.
1747 * New macros: AC_CACHE_LOAD, AC_CACHE_SAVE, AC_FUNC_SELECT_ARGTYPES,
1748 AC_VALIDATE_CACHED_SYSTEM_TUPLE, AC_SEARCH_LIBS, AC_TRY_LINK_FUNC,
1749 AC_C_STRINGIZE, AC_CHECK_FILE(S), AC_PROG_F77 (and friends).
1750 * AC_DEFINE now has an optional third argument for a description to be
1751 placed in the config header input file (e.g. config.h.in).
1752 * The C++ code fragment compiled for the C++ compiler test had to be
1753 improved to include an explicit return type for main(). This was
1754 causing failures on systems using recent versions of the EGCS C++
1756 * Fixed an important bug in AC_CHECK_TYPE that would cause a configure
1757 script to report that `sometype_t' was present when only `type_t'
1759 * Merge of the FSF version of config.guess and config.sub to modernize
1760 these scripts. Add support for a few new hosts in config.guess.
1761 Incorporate latest versions of install-sh, mkinstalldirs and
1762 texinfo.tex from the FSF.
1763 * autoreconf is capable of running automake if necessary (and
1765 * Support for Fortran 77. See the Texinfo documentation for details.
1766 * Bug fixes and workarounds for quirky bugs in vendor utilities.
1768 Major changes in Autoconf 2.12:
1770 Released 1996-11-26 by David J. MacKenzie
1772 * AC_OUTPUT and AC_CONFIG_HEADER can create output files by
1773 concatenating multiple input files separated by colons, like so:
1774 AC_CONFIG_HEADER(config.h:conf.pre:config.h.in:conf.post)
1775 AC_OUTPUT(Makefile:Makefile.in:Makefile.rules)
1776 The arguments may be shell variables, to compute the lists on the fly.
1777 * AC_LINK_FILES and AC_CONFIG_SUBDIRS may be called multiple times.
1778 * New macro AC_OUTPUT_COMMANDS adds more commands to run in config.status.
1781 Major changes in Autoconf 2.11:
1783 Released November 18th, 1996, by David J. MacKenzie
1785 * AC_PROG_CC and AC_PROG_CXX check whether the compiler works.
1786 They also default CFLAGS/CXXFLAGS to "-g -O2" for gcc, instead of "-g -O".
1787 * AC_REPLACE_FUNCS defines HAVE_foo if the system has the function `foo'.
1788 * AC_CONFIG_HEADER expands shell variables in its argument.
1789 * New macros: AC_FUNC_FNMATCH, AC_FUNC_SETPGRP.
1790 * The "checking..." messages and the source code for test programs that
1791 fail are saved in config.log.
1792 * Another workaround has been added for seds with small command length limits.
1793 * config.sub and config.guess recognize more system types.
1796 Major changes in Autoconf 2.10:
1798 Released May 7th, 1996, by Roland McGrath
1801 * The cache variable names used by `AC_CHECK_LIB(LIB, FUNC, ...)' has
1802 changed: now $ac_cv_lib_LIB_FUNC, previously $ac_cv_lib_LIB.
1804 Major changes in Autoconf 2.9:
1806 Released March 16th, 1996, by Roland McGrath
1810 Major changes in Autoconf 2.8:
1812 Released March 8th, 1996, by Roland McGrath
1816 Major changes in Autoconf 2.7:
1818 Released November 22nd, 1995, by David J. MacKenzie
1822 Major changes in Autoconf 2.6:
1824 Released November 20th, 1995, by David J. MacKenzie
1828 Major changes in Autoconf 2.5:
1830 Released November 17th, 1995, by Roland McGrath
1832 * New configure options --bindir, --libdir, --datadir, etc., with
1833 corresponding output variables.
1834 * New macro: AC_CACHE_CHECK, to make using the cache easier.
1835 * config.log contains the command being run as well as any output from it.
1836 * AC_CHECK_LIB can check for libraries with "." or "/" or "+" in their name.
1837 * AC_PROG_INSTALL doesn't cache a name for install-sh, for sharing caches.
1838 * AC_CHECK_PROG, AC_PATH_PROG, AC_CHECK_PROGS, AC_PATH_PROGS, and
1839 AC_CHECK_TOOL can search a path other than $PATH.
1840 * AC_CHECK_SIZEOF takes an optional size to use when cross-compiling.
1842 Major changes in Autoconf 2.4:
1844 Released June 14th, 1995, by David J. MacKenzie
1846 * Fix a few bugs found by Emacs testers.
1848 Major changes in Autoconf 2.3:
1850 Released March 27th, 1995, by David J. MacKenzie
1852 * Fix the cleanup trap in several ways.
1853 * Handle C compilers that are picky about option placement.
1854 * ifnames gets the version number from the right directory.
1856 Major changes in Autoconf 2.2:
1858 Released March 8th, 1995, by David J. MacKenzie
1860 * The ifnames utility is much faster but requires a "new awk" interpreter.
1861 * AC_CHECK_LIB and AC_HAVE_LIBRARY check and add the new
1862 library before existing libs, not after, in case it uses them.
1863 * New macros: AC_FUNC_GETPGRP, AC_CHECK_TOOL.
1864 * Lots of bug fixes.
1865 * Many additions to the TODO file :-)
1867 Major changes in Autoconf 2.1:
1869 Released November 4th, 1994, by David J. MacKenzie
1872 * More explanations in the manual.
1873 * Fix a spurious failure in the testsuite.
1874 * Clarify some warning messages.
1875 * autoreconf by default only rebuilds configure and config.h.in files
1876 that are older than any of their particular input files; there is a
1877 --force option to use after installing a new version of Autoconf.
1879 Thanks to everybody who's submitted changes and additions to Autoconf!
1880 I've incorporated many of them, and am still considering others for
1881 future releases -- but I didn't want to postpone this release indefinitely.
1883 Caution: don't indiscriminately rebuild configure scripts with
1884 Autoconf version 2. Some configure.in files need minor adjustments to
1885 work with it; the documentation has a chapter on upgrading. A few
1886 configure.in files, including those for GNU Emacs and the GNU C
1887 Library, need major changes because they relied on undocumented
1888 internals of version 1. Future releases of those packages will have
1889 updated configure.in files.
1891 It's best to use GNU M4 1.3 (or later) with Autoconf version 2.
1892 Autoconf now makes heavy use of M4 diversions, which were implemented
1893 inefficiently in GNU M4 releases before 1.3.
1895 Major changes in Autoconf 2.0:
1897 Released October 26th, 1994, by David J. MacKenzie
1899 ** New copyright terms:
1900 * There are no restrictions on distribution or use of configure scripts.
1903 * Autoconf manual is reorganized to make information easier to find
1904 and has several new indexes.
1905 * INSTALL is reorganized and clearer and is now made from Texinfo source.
1908 * autoscan to generate a preliminary configure.in for a package by
1909 scanning its source code for commonly used nonportable functions,
1910 programs, and header files.
1911 * ifnames to list the symbols used in #if and #ifdef directives in a
1913 * autoupdate to update a configure.in to use the version 2 macro names.
1914 * autoreconf to recursively remake configure and configuration header
1915 files in a source tree.
1917 ** Changed utilities:
1918 * autoheader can take pieces of acconfig.h to replace config.h.{top,bot}.
1919 * autoconf and autoheader can look for package-local definition files
1920 in an alternate directory.
1923 * AC_CACHE_VAL to share results of tests between configure runs.
1924 * AC_DEFUN to define macros, automatically AC_PROVIDE them, and ensure
1925 that macros invoked with AC_REQUIRE don't interrupt other macros.
1926 * AC_CONFIG_AUX_DIR, AC_CANONICAL_SYSTEM, AC_CANONICAL_HOST, AC_LINK_FILES to
1927 support deciding unguessable features based on the host and target types.
1928 * AC_CONFIG_SUBDIRS to recursively configure a source tree.
1929 * AC_ARG_PROGRAM to use the options --program-prefix,
1930 --program-suffix, and --program-transform-name to change the names
1931 of programs being installed.
1932 * AC_PREFIX_DEFAULT to change the default installation prefix.
1933 * AC_TRY_COMPILE to compile a test program without linking it.
1934 * AC_CHECK_TYPE to check whether sys/types.h or stdlib.h defines a given type.
1935 * AC_CHECK_LIB to check for a particular function and library.
1936 * AC_MSG_CHECKING and AC_MSG_RESULT to print test results, on a single line,
1937 whether or not the test succeeds. They obsolete AC_CHECKING and AC_VERBOSE.
1938 * AC_SUBST_FILE to insert one file into another.
1939 * AC_FUNC_MEMCMP to check whether memcmp is 8-bit clean.
1940 * AC_FUNC_STRFTIME to find strftime even if it's in -lintl.
1941 * AC_FUNC_GETMNTENT to find getmntent even if it's in -lsun or -lseq.
1942 * AC_HEADER_SYS_WAIT to check whether sys/wait.h is POSIX.1 compatible.
1945 * Many macros renamed systematically, but old names are accepted for
1946 backward compatibility.
1947 * AC_OUTPUT adds the "automatically generated" comment to
1948 non-Makefiles where it finds @configure_input@ in an input file, to
1949 support files with various comment syntaxes.
1950 * AC_OUTPUT does not replace "prefix" and "exec_prefix" in generated
1951 files when they are not enclosed in @ signs.
1952 * AC_OUTPUT allows the optional environment variable CONFIG_STATUS to
1953 override the file name "config.status".
1954 * AC_OUTPUT takes an optional argument for passing variables from
1955 configure to config.status.
1956 * AC_OUTPUT and AC_CONFIG_HEADER allow you to override the input-file names.
1957 * AC_OUTPUT automatically substitutes the values of CFLAGS, CXXFLAGS,
1958 CPPFLAGS, and LDFLAGS from the environment.
1959 * AC_PROG_CC and AC_PROG_CXX now set CFLAGS and CXXFLAGS, respectively.
1960 * AC_PROG_INSTALL looks for install-sh or install.sh in the directory
1961 specified by AC_CONFIG_AUXDIR, or srcdir or srcdir/.. or
1962 srcdir/../.. by default.
1963 * AC_DEFINE, AC_DEFINE_UNQUOTED, and AC_SUBST are more robust and smaller.
1964 * AC_DEFINE no longer prints anything, because of the new result reporting
1965 mechanism (AC_MSG_CHECKING and AC_MSG_RESULT).
1966 * AC_VERBOSE pays attention to --quiet/--silent, not --verbose.
1967 * AC_ARG_ENABLE and AC_ARG_WITH support whitespace in the arguments to
1968 --enable- and --with- options.
1969 * AC_CHECK_FUNCS and AC_CHECK_HEADERS take optional shell commands to
1970 execute on success or failure.
1971 * Checking for C functions in C++ works.
1974 * AC_REMOTE_TAPE and AC_RSH removed; too specific to tar and cpio, and
1975 better maintained with them.
1976 * AC_ARG_ARRAY removed because no one was likely using it.
1977 * AC_HAVE_POUNDBANG replaced with AC_SYS_INTERPRETER, which doesn't
1978 take arguments, for consistency with all of the other specific checks.
1981 * Comes with config.sub and config.guess, and uses them optionally.
1982 * Uses config.cache to cache test results. An alternate cache file
1983 can be selected with the --cache-file=FILE option.
1984 * Uses optional shell scripts $prefix/share/config.site and
1985 $prefix/etc/config.site to perform site or system specific initializations.
1986 * configure saves compiler output to ./config.log for debugging.
1987 * New files autoconf.m4 and autoheader.m4 load the other Autoconf macros.
1988 * acsite.m4 is the new name for the system-wide aclocal.m4.
1989 * Has a DejaGnu test suite.
1991 Major changes in Autoconf 1.11:
1993 * AC_PROG_INSTALL calls install.sh with the -c option.
1994 * AC_SET_MAKE cleans up after itself.
1995 * AC_OUTPUT sets prefix and exec_prefix if they weren't set already.
1996 * AC_OUTPUT prevents shells from looking in PATH for config.status.
1998 Plus a few other bug fixes.
2000 Major changes in Autoconf 1.10:
2002 * autoheader uses config.h.bot if present, analogous to config.h.top.
2003 * AC_PROG_INSTALL looks for install.sh in srcdir or srcdir/.. and
2005 * AC_PROG_CXX looks for cxx as a C++ compiler.
2007 Plus several bugs fixed.
2009 Major changes in Autoconf 1.9:
2011 * AC_YYTEXT_POINTER replaces AC_DECLARE_YYTEXT.
2012 * AC_SIZEOF_TYPE generates the cpp symbol name automatically,
2013 and autoheader generates entries for those names automatically.
2014 * AC_FIND_X gets the result from xmkmf correctly.
2015 * AC_FIND_X assumes no X if --without-x was given.
2016 * AC_FIND_XTRA adds libraries to the variable X_EXTRA_LIBS.
2017 * AC_PROG_INSTALL finds OSF/1 installbsd.
2019 Major changes in Autoconf 1.8:
2022 * New macros AC_LANG_C, AC_LANG_CPLUSPLUS, AC_LANG_SAVE, AC_LANG_RESTORE,
2023 AC_PROG_CXX, AC_PROG_CXXCPP, AC_REQUIRE_CPP
2024 for checking both C++ and C features in one configure script.
2025 * New macros AC_CHECKING, AC_VERBOSE, AC_WARN, AC_ERROR for printing messages.
2026 * New macros AC_FIND_XTRA, AC_MMAP, AC_SIZEOF_TYPE, AC_PREREQ,
2027 AC_SET_MAKE, AC_ENABLE.
2030 * AC_FIND_X looks for X in more places.
2031 * AC_PROG_INSTALL defaults to install.sh instead of cp, if it's in srcdir.
2032 install.sh is distributed with Autoconf.
2033 * AC_DECLARE_YYTEXT has been removed because it can't work, pending
2034 a rewrite of quoting in AC_DEFINE.
2035 * AC_OUTPUT adds its comments in C format when substituting in C files.
2036 * AC_COMPILE_CHECK protects its ECHO-TEXT argument with double quotes.
2038 ** New or changed command line options:
2039 * configure accepts --enable-FEATURE[=ARG] and --disable-FEATURE options.
2040 * configure accepts --without-PACKAGE, which sets withval=no.
2041 * configure accepts --x-includes=DIR and --x-libraries=DIR.
2042 * Giving --with-PACKAGE no argument sets withval=yes instead of withval=1.
2043 * configure accepts --help, --version, --silent/--quiet, --no-create options.
2044 * configure accepts and ignores most other Cygnus configure options, and
2045 warns about unknown options.
2046 * config.status accepts --help, --version options.
2048 ** File names and other changes:
2049 * Relative srcdir values are not made absolute.
2050 * The values of @prefix@ and @exec_prefix@ and @top_srcdir@ get substituted.
2051 * Autoconf library files are installed in ${datadir}/autoconf, not ${datadir}.
2052 * autoheader optionally copies config.h.top to the beginning of config.h.in.
2053 * The example Makefile dependencies for configure et al. work better.
2054 * Namespace cleanup: all shell variables used internally by Autoconf
2055 have names beginning with `ac_'.
2057 More big improvements are in process for future releases, but have not
2058 yet been (variously) finished, integrated, tested, or documented enough
2061 Major changes in Autoconf 1.7:
2063 * New macro AC_OBSOLETE.
2064 * Bugs in Makefile.in fixed.
2065 * AC_LONG_FILE_NAMES improved.
2067 Major changes in Autoconf 1.6:
2069 * New macro AC_LONG_64_BITS.
2070 * Multiple .h files can be created.
2071 * AC_FIND_X looks for X files directly if it doesn't find xmkmf.
2072 * AC_ALLOCA defines C_ALLOCA if using alloca.c.
2073 * --with-NAME can take a value, e.g., --with-targets=sun4,hp300bsd.
2074 * Unused --no-create option to configure removed.
2075 * autoheader doesn't change the timestamp of its output file if
2076 the file didn't change.
2077 * All macros that look for libraries now use AC_HAVE_LIBRARY.
2078 * config.status checks three optional environment variables to
2079 modify its behavior.
2080 * The usual bug fixes.
2082 Major changes in Autoconf 1.5:
2084 * New macros AC_FIND_X, AC_OFF_T, AC_STAT_MACROS_BROKEN, AC_REVISION.
2085 * autoconf and autoheader scripts have GNU standards conforming
2086 --version and --help options (they print their message and exit).
2089 Major changes in Autoconf 1.4:
2091 * New macros AC_HAVE_POUNDBANG, AC_TIME_WITH_SYS_TIME, AC_LONG_DOUBLE,
2092 AC_GETGROUPS_T, AC_DEFINE_UNQUOTED.
2093 * autoconf and autoheader use the M4 environment variable to determine the
2094 name of the M4 program to use.
2095 * The --macrodir option to autoconf and autoheader specifies the directory
2096 in which acspecific.m4, acgeneral.m4, etc. reside if not the default.
2097 * autoconf and autoheader can take `-' as their file names, which means to
2098 read stdin as input.
2099 * Resulting configure scripts can take a --verbose option which causes them
2100 to print the results of their tests.
2101 * AC_DEFINE quotes its second argument in such a way that spaces, magic
2102 shell characters, etc. will be preserved during various stages of
2103 expansion done by the shell. If you don't want this, use
2104 AC_DEFINE_UNQUOTED instead.
2105 * Much textual processing done with external calls to tr and sed have been
2106 internalized with builtin M4 `patsubst' and `translit' calls.
2107 * AC_OUTPUT doesn't hardwire the file names it outputs. Instead, you can
2108 set the shell variables `gen_files' and `gen_config' to the list of
2109 file names to output.
2110 * AC_DECLARE_YYTEXT does an AC_SUBST of `LEX_OUTPUT_ROOT', which may be
2111 "lex.yy" or "lexyy", depending on the system.
2112 * AC_PROGRAMS_CHECK takes an optional third arg. If given, it is used as
2114 * If AC_ALLOCA chooses alloca.c, it also defines STACK_DIRECTION.
2115 * AC_CONST works much more reliably on more systems.
2118 Major changes in Autoconf 1.3:
2120 configure no longer requires awk for packages that use a config.h.
2121 Support handling --with-PACKAGE options.
2122 New `autoheader' script to create `config.h.in' from `configure.in'.
2123 Ignore troublesome -lucb and -lPW when searching for alloca.
2124 Rename --exec_prefix to --exec-prefix for GNU standards conformance.
2125 Improve detection of STDC library.
2126 Add AC_HAVE_LIBRARY to check for non-default libraries.
2127 Function checking should work with future GNU libc releases.
2129 Major changes in Autoconf 1.2:
2131 The --srcdir option is now usually unnecessary.
2132 Add a file containing sample comments describing CPP macros.
2133 A comment in config.status tells which host it was configured on.
2134 Substituted variable values can now contain commas.
2135 Fix bugs in various feature checks.
2137 Major changes in Autoconf 1.1:
2139 Added AC_STRCOLL macro.
2140 Made AC_GETLOADAVG check for more things.
2141 AC_OUTPUT argument is now optional.
2146 Copyright (C) 1993-1996, 1998-2012 Free Software Foundation, Inc.
2148 Copying and distribution of this file, with or without modification,
2149 are permitted in any medium without royalty provided the copyright
2150 notice and this notice are preserved. This file is offered as-is,
2151 without warranty of any kind.