1# gnulib-common.m4 serial 50
2dnl Copyright (C) 2007-2020 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7AC_PREREQ([2.62])
8
9# gl_COMMON
10# is expanded unconditionally through gnulib-tool magic.
11AC_DEFUN([gl_COMMON], [
12  dnl Use AC_REQUIRE here, so that the code is expanded once only.
13  AC_REQUIRE([gl_00GNULIB])
14  AC_REQUIRE([gl_COMMON_BODY])
15  AC_REQUIRE([gl_ZZGNULIB])
16])
17AC_DEFUN([gl_COMMON_BODY], [
18  AH_VERBATIM([_GL_GNUC_PREREQ],
19[/* True if the compiler says it groks GNU C version MAJOR.MINOR.  */
20#if defined __GNUC__ && defined __GNUC_MINOR__
21# define _GL_GNUC_PREREQ(major, minor) \
22    ((major) < __GNUC__ + ((minor) <= __GNUC_MINOR__))
23#else
24# define _GL_GNUC_PREREQ(major, minor) 0
25#endif
26])
27  AH_VERBATIM([_Noreturn],
28[/* The _Noreturn keyword of C11.  */
29#ifndef _Noreturn
30# if (defined __cplusplus \
31      && ((201103 <= __cplusplus && !(__GNUC__ == 4 && __GNUC_MINOR__ == 7)) \
32          || (defined _MSC_VER && 1900 <= _MSC_VER)) \
33      && 0)
34    /* [[noreturn]] is not practically usable, because with it the syntax
35         extern _Noreturn void func (...);
36       would not be valid; such a declaration would only be valid with 'extern'
37       and '_Noreturn' swapped, or without the 'extern' keyword.  However, some
38       AIX system header files and several gnulib header files use precisely
39       this syntax with 'extern'.  */
40#  define _Noreturn [[noreturn]]
41# elif ((!defined __cplusplus || defined __clang__) \
42        && (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0)  \
43            || _GL_GNUC_PREREQ (4, 7) \
44            || (defined __apple_build_version__ \
45                ? 6000000 <= __apple_build_version__ \
46                : 3 < __clang_major__ + (5 <= __clang_minor__))))
47   /* _Noreturn works as-is.  */
48# elif _GL_GNUC_PREREQ (2, 8) || 0x5110 <= __SUNPRO_C
49#  define _Noreturn __attribute__ ((__noreturn__))
50# elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
51#  define _Noreturn __declspec (noreturn)
52# else
53#  define _Noreturn
54# endif
55#endif
56])
57  AH_VERBATIM([isoc99_inline],
58[/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
59   the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
60   earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
61   __APPLE__ && __MACH__ test for Mac OS X.
62   __APPLE_CC__ tests for the Apple compiler and its version.
63   __STDC_VERSION__ tests for the C99 mode.  */
64#if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
65# define __GNUC_STDC_INLINE__ 1
66#endif])
67  AH_VERBATIM([attribute],
68[/* Attributes.  */
69#ifdef __has_attribute
70# define _GL_HAS_ATTRIBUTE(attr) __has_attribute (__##attr##__)
71#else
72# define _GL_HAS_ATTRIBUTE(attr) _GL_ATTR_##attr
73# define _GL_ATTR_alloc_size _GL_GNUC_PREREQ (4, 3)
74# define _GL_ATTR_always_inline _GL_GNUC_PREREQ (3, 2)
75# define _GL_ATTR_artificial _GL_GNUC_PREREQ (4, 3)
76# define _GL_ATTR_cold _GL_GNUC_PREREQ (4, 3)
77# define _GL_ATTR_const _GL_GNUC_PREREQ (2, 95)
78# define _GL_ATTR_deprecated _GL_GNUC_PREREQ (3, 1)
79# define _GL_ATTR_error _GL_GNUC_PREREQ (4, 3)
80# define _GL_ATTR_externally_visible _GL_GNUC_PREREQ (4, 1)
81# define _GL_ATTR_fallthrough _GL_GNUC_PREREQ (7, 0)
82# define _GL_ATTR_format _GL_GNUC_PREREQ (2, 7)
83# define _GL_ATTR_leaf _GL_GNUC_PREREQ (4, 6)
84# ifdef _ICC
85#  define _GL_ATTR_may_alias 0
86# else
87#  define _GL_ATTR_may_alias _GL_GNUC_PREREQ (3, 3)
88# endif
89# define _GL_ATTR_malloc _GL_GNUC_PREREQ (3, 0)
90# define _GL_ATTR_noinline _GL_GNUC_PREREQ (3, 1)
91# define _GL_ATTR_nonnull _GL_GNUC_PREREQ (3, 3)
92# define _GL_ATTR_nonstring _GL_GNUC_PREREQ (8, 0)
93# define _GL_ATTR_nothrow _GL_GNUC_PREREQ (3, 3)
94# define _GL_ATTR_packed _GL_GNUC_PREREQ (2, 7)
95# define _GL_ATTR_pure _GL_GNUC_PREREQ (2, 96)
96# define _GL_ATTR_returns_nonnull _GL_GNUC_PREREQ (4, 9)
97# define _GL_ATTR_sentinel _GL_GNUC_PREREQ (4, 0)
98# define _GL_ATTR_unused _GL_GNUC_PREREQ (2, 7)
99# define _GL_ATTR_warn_unused_result _GL_GNUC_PREREQ (3, 4)
100#endif
101
102]dnl There is no _GL_ATTRIBUTE_ALIGNED; use stdalign's _Alignas instead.
103[
104#if _GL_HAS_ATTRIBUTE (alloc_size)
105# define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
106#else
107# define _GL_ATTRIBUTE_ALLOC_SIZE(args)
108#endif
109
110#if _GL_HAS_ATTRIBUTE (always_inline)
111# define _GL_ATTRIBUTE_ALWAYS_INLINE __attribute__ ((__always_inline__))
112#else
113# define _GL_ATTRIBUTE_ALWAYS_INLINE
114#endif
115
116#if _GL_HAS_ATTRIBUTE (artificial)
117# define _GL_ATTRIBUTE_ARTIFICIAL __attribute__ ((__artificial__))
118#else
119# define _GL_ATTRIBUTE_ARTIFICIAL
120#endif
121
122/* Avoid __attribute__ ((cold)) on MinGW; see thread starting at
123   <https://lists.gnu.org/r/emacs-devel/2019-04/msg01152.html>. */
124#if _GL_HAS_ATTRIBUTE (cold) && !defined __MINGW32__
125# define _GL_ATTRIBUTE_COLD __attribute__ ((__cold__))
126#else
127# define _GL_ATTRIBUTE_COLD
128#endif
129
130#if _GL_HAS_ATTRIBUTE (const)
131# define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
132#else
133# define _GL_ATTRIBUTE_CONST
134#endif
135
136#if 201710L < __STDC_VERSION__
137# define _GL_ATTRIBUTE_DEPRECATED [[__deprecated__]]
138#elif _GL_HAS_ATTRIBUTE (deprecated)
139# define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
140#else
141# define _GL_ATTRIBUTE_DEPRECATED
142#endif
143
144#if _GL_HAS_ATTRIBUTE (error)
145# define _GL_ATTRIBUTE_ERROR(msg) __attribute__ ((__error__ (msg)))
146# define _GL_ATTRIBUTE_WARNING(msg) __attribute__ ((__warning__ (msg)))
147#else
148# define _GL_ATTRIBUTE_ERROR(msg)
149# define _GL_ATTRIBUTE_WARNING(msg)
150#endif
151
152#if _GL_HAS_ATTRIBUTE (externally_visible)
153# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE __attribute__ ((externally_visible))
154#else
155# define _GL_ATTRIBUTE_EXTERNALLY_VISIBLE
156#endif
157
158/* FALLTHROUGH is special, because it always expands to something.  */
159#if 201710L < __STDC_VERSION__
160# define _GL_ATTRIBUTE_FALLTHROUGH [[__fallthrough__]]
161#elif _GL_HAS_ATTRIBUTE (fallthrough)
162# define _GL_ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
163#else
164# define _GL_ATTRIBUTE_FALLTHROUGH ((void) 0)
165#endif
166
167#if _GL_HAS_ATTRIBUTE (format)
168# define _GL_ATTRIBUTE_FORMAT(spec) __attribute__ ((__format__ spec))
169#else
170# define _GL_ATTRIBUTE_FORMAT(spec)
171#endif
172
173#if _GL_HAS_ATTRIBUTE (leaf)
174# define _GL_ATTRIBUTE_LEAF __attribute__ ((__leaf__))
175#else
176# define _GL_ATTRIBUTE_LEAF
177#endif
178
179#if _GL_HAS_ATTRIBUTE (may_alias)
180# define _GL_ATTRIBUTE_MAY_ALIAS __attribute__ ((__may_alias__))
181#else
182# define _GL_ATTRIBUTE_MAY_ALIAS
183#endif
184
185#if 201710L < __STDC_VERSION__
186# define _GL_ATTRIBUTE_MAYBE_UNUSED [[__maybe_unused__]]
187#elif _GL_HAS_ATTRIBUTE (unused)
188# define _GL_ATTRIBUTE_MAYBE_UNUSED __attribute__ ((__unused__))
189#else
190# define _GL_ATTRIBUTE_MAYBE_UNUSED
191#endif
192/* Earlier spellings of this macro.  */
193#define _GL_UNUSED _GL_ATTRIBUTE_MAYBE_UNUSED
194#define _UNUSED_PARAMETER_ _GL_ATTRIBUTE_MAYBE_UNUSED
195
196#if _GL_HAS_ATTRIBUTE (malloc)
197# define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
198#else
199# define _GL_ATTRIBUTE_MALLOC
200#endif
201
202#if 201710L < __STDC_VERSION__
203# define _GL_ATTRIBUTE_NODISCARD [[__nodiscard__]]
204#elif _GL_HAS_ATTRIBUTE (warn_unused_result)
205# define _GL_ATTRIBUTE_NODISCARD __attribute__ ((__warn_unused_result__))
206#else
207# define _GL_ATTRIBUTE_NODISCARD
208#endif
209
210#if _GL_HAS_ATTRIBUTE (noinline)
211# define _GL_ATTRIBUTE_NOINLINE __attribute__ ((__noinline__))
212#else
213# define _GL_ATTRIBUTE_NOINLINE
214#endif
215
216#if _GL_HAS_ATTRIBUTE (nonnull)
217# define _GL_ATTRIBUTE_NONNULL(args) __attribute__ ((__nonnull__ args))
218#else
219# define _GL_ATTRIBUTE_NONNULL(args)
220#endif
221
222#if _GL_HAS_ATTRIBUTE (nonstring)
223# define _GL_ATTRIBUTE_NONSTRING __attribute__ ((__nonstring__))
224#else
225# define _GL_ATTRIBUTE_NONSTRING
226#endif
227
228/* There is no _GL_ATTRIBUTE_NORETURN; use _Noreturn instead.  */
229
230#if _GL_HAS_ATTRIBUTE (nothrow) && !defined __cplusplus
231# define _GL_ATTRIBUTE_NOTHROW __attribute__ ((__nothrow__))
232#else
233# define _GL_ATTRIBUTE_NOTHROW
234#endif
235
236#if _GL_HAS_ATTRIBUTE (packed)
237# define _GL_ATTRIBUTE_PACKED __attribute__ ((__packed__))
238#else
239# define _GL_ATTRIBUTE_PACKED
240#endif
241
242#if _GL_HAS_ATTRIBUTE (pure)
243# define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
244#else
245# define _GL_ATTRIBUTE_PURE
246#endif
247
248#if _GL_HAS_ATTRIBUTE (returns_nonnull)
249# define _GL_ATTRIBUTE_RETURNS_NONNULL __attribute__ ((__returns_nonnull__))
250#else
251# define _GL_ATTRIBUTE_RETURNS_NONNULL
252#endif
253
254#if _GL_HAS_ATTRIBUTE (sentinel)
255# define _GL_ATTRIBUTE_SENTINEL(pos) __attribute__ ((__sentinel__ pos))
256#else
257# define _GL_ATTRIBUTE_SENTINEL(pos)
258#endif
259
260]dnl There is no _GL_ATTRIBUTE_VISIBILITY; see m4/visibility.m4 instead.
261[
262/* To support C++ as well as C, use _GL_UNUSED_LABEL with trailing ';'.  */
263#if !defined __cplusplus || _GL_GNUC_PREREQ (4, 5)
264# define _GL_UNUSED_LABEL _GL_ATTRIBUTE_MAYBE_UNUSED
265#else
266# define _GL_UNUSED_LABEL
267#endif
268])
269  AH_VERBATIM([async_safe],
270[/* The _GL_ASYNC_SAFE marker should be attached to functions that are
271   signal handlers (for signals other than SIGABRT, SIGPIPE) or can be
272   invoked from such signal handlers.  Such functions have some restrictions:
273     * All functions that it calls should be marked _GL_ASYNC_SAFE as well,
274       or should be listed as async-signal-safe in POSIX
275       <https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html#tag_15_04>
276       section 2.4.3.  Note that malloc(), sprintf(), and fwrite(), in
277       particular, are NOT async-signal-safe.
278     * All memory locations (variables and struct fields) that these functions
279       access must be marked 'volatile'.  This holds for both read and write
280       accesses.  Otherwise the compiler might optimize away stores to and
281       reads from such locations that occur in the program, depending on its
282       data flow analysis.  For example, when the program contains a loop
283       that is intended to inspect a variable set from within a signal handler
284           while (!signal_occurred)
285             ;
286       the compiler is allowed to transform this into an endless loop if the
287       variable 'signal_occurred' is not declared 'volatile'.
288   Additionally, recall that:
289     * A signal handler should not modify errno (except if it is a handler
290       for a fatal signal and ends by raising the same signal again, thus
291       provoking the termination of the process).  If it invokes a function
292       that may clobber errno, it needs to save and restore the value of
293       errno.  */
294#define _GL_ASYNC_SAFE
295])
296  dnl Hint which direction to take regarding cross-compilation guesses:
297  dnl When a user installs a program on a platform they are not intimately
298  dnl familiar with, --enable-cross-guesses=conservative is the appropriate
299  dnl choice.  It implements the "If we don't know, assume the worst" principle.
300  dnl However, when an operating system developer (on a platform which is not
301  dnl yet known to gnulib) builds packages for their platform, they want to
302  dnl expose, not hide, possible platform bugs; in this case,
303  dnl --enable-cross-guesses=risky is the appropriate choice.
304  dnl Sets the variables
305  dnl gl_cross_guess_normal    (to be used when 'yes' is good and 'no' is bad),
306  dnl gl_cross_guess_inverted  (to be used when 'no' is good and 'yes' is bad).
307  AC_ARG_ENABLE([cross-guesses],
308    [AS_HELP_STRING([--enable-cross-guesses={conservative|risky}],
309       [specify policy for cross-compilation guesses])],
310    [if test "x$enableval" != xconservative && test "x$enableval" != xrisky; then
311       AC_MSG_WARN([invalid argument supplied to --enable-cross-guesses])
312       enableval=conservative
313     fi
314     gl_cross_guesses="$enableval"],
315    [gl_cross_guesses=conservative])
316  if test $gl_cross_guesses = risky; then
317    gl_cross_guess_normal="guessing yes"
318    gl_cross_guess_inverted="guessing no"
319  else
320    gl_cross_guess_normal="guessing no"
321    gl_cross_guess_inverted="guessing yes"
322  fi
323  dnl Preparation for running test programs:
324  dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
325  dnl to /dev/tty, so they can be redirected to log files.  Such diagnostics
326  dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
327  LIBC_FATAL_STDERR_=1
328  export LIBC_FATAL_STDERR_
329])
330
331# gl_MODULE_INDICATOR_CONDITION
332# expands to a C preprocessor expression that evaluates to 1 or 0, depending
333# whether a gnulib module that has been requested shall be considered present
334# or not.
335m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
336
337# gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
338# sets the shell variable that indicates the presence of the given module to
339# a C preprocessor expression that will evaluate to 1.
340AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
341[
342  gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
343    [GNULIB_[]m4_translit([[$1]],
344                          [abcdefghijklmnopqrstuvwxyz./-],
345                          [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
346    [gl_MODULE_INDICATOR_CONDITION])
347])
348
349# gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
350# modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
351# The shell variable's value is a C preprocessor expression that evaluates
352# to 0 or 1.
353AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
354[
355  m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
356    [
357     dnl Simplify the expression VALUE || 1 to 1.
358     $1=1
359    ],
360    [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
361                                             [gl_MODULE_INDICATOR_CONDITION])])
362])
363
364# gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
365# modifies the shell variable to include the given condition.  The shell
366# variable's value is a C preprocessor expression that evaluates to 0 or 1.
367AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
368[
369  dnl Simplify the expression 1 || CONDITION to 1.
370  if test "$[]$1" != 1; then
371    dnl Simplify the expression 0 || CONDITION to CONDITION.
372    if test "$[]$1" = 0; then
373      $1=$2
374    else
375      $1="($[]$1 || $2)"
376    fi
377  fi
378])
379
380# gl_MODULE_INDICATOR([modulename])
381# defines a C macro indicating the presence of the given module
382# in a location where it can be used.
383#                                             |  Value  |   Value   |
384#                                             | in lib/ | in tests/ |
385# --------------------------------------------+---------+-----------+
386# Module present among main modules:          |    1    |     1     |
387# --------------------------------------------+---------+-----------+
388# Module present among tests-related modules: |    0    |     1     |
389# --------------------------------------------+---------+-----------+
390# Module not present at all:                  |    0    |     0     |
391# --------------------------------------------+---------+-----------+
392AC_DEFUN([gl_MODULE_INDICATOR],
393[
394  AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
395      [abcdefghijklmnopqrstuvwxyz./-],
396      [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
397    [gl_MODULE_INDICATOR_CONDITION],
398    [Define to a C preprocessor expression that evaluates to 1 or 0,
399     depending whether the gnulib module $1 shall be considered present.])
400])
401
402# gl_MODULE_INDICATOR_FOR_TESTS([modulename])
403# defines a C macro indicating the presence of the given module
404# in lib or tests. This is useful to determine whether the module
405# should be tested.
406#                                             |  Value  |   Value   |
407#                                             | in lib/ | in tests/ |
408# --------------------------------------------+---------+-----------+
409# Module present among main modules:          |    1    |     1     |
410# --------------------------------------------+---------+-----------+
411# Module present among tests-related modules: |    1    |     1     |
412# --------------------------------------------+---------+-----------+
413# Module not present at all:                  |    0    |     0     |
414# --------------------------------------------+---------+-----------+
415AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
416[
417  AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
418      [abcdefghijklmnopqrstuvwxyz./-],
419      [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
420    [Define to 1 when the gnulib module $1 should be tested.])
421])
422
423# gl_ASSERT_NO_GNULIB_POSIXCHECK
424# asserts that there will never be a need to #define GNULIB_POSIXCHECK.
425# and thereby enables an optimization of configure and config.h.
426# Used by Emacs.
427AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
428[
429  dnl Override gl_WARN_ON_USE_PREPARE.
430  dnl But hide this definition from 'aclocal'.
431  AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
432])
433
434# gl_ASSERT_NO_GNULIB_TESTS
435# asserts that there will be no gnulib tests in the scope of the configure.ac
436# and thereby enables an optimization of config.h.
437# Used by Emacs.
438AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
439[
440  dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
441  AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
442])
443
444# Test whether <features.h> exists.
445# Set HAVE_FEATURES_H.
446AC_DEFUN([gl_FEATURES_H],
447[
448  AC_CHECK_HEADERS_ONCE([features.h])
449  if test $ac_cv_header_features_h = yes; then
450    HAVE_FEATURES_H=1
451  else
452    HAVE_FEATURES_H=0
453  fi
454  AC_SUBST([HAVE_FEATURES_H])
455])
456
457# AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
458# ----------------------------------------------------
459# Backport of autoconf-2.63b's macro.
460# Remove this macro when we can assume autoconf >= 2.64.
461m4_ifndef([AS_VAR_IF],
462[m4_define([AS_VAR_IF],
463[AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
464
465# gl_PROG_CC_C99
466# Modifies the value of the shell variable CC in an attempt to make $CC
467# understand ISO C99 source code.
468# This is like AC_PROG_CC_C99, except that
469# - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
470#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00367.html>,
471#   but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
472#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00441.html>.
473# Remaining problems:
474# - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options
475#   to CC twice
476#   <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00431.html>.
477# - AC_PROG_CC_STDC is likely to change now that C11 is an ISO standard.
478AC_DEFUN([gl_PROG_CC_C99],
479[
480  dnl Change that version number to the minimum Autoconf version that supports
481  dnl mixing AC_PROG_CC_C99 calls with AC_PROG_CC_STDC calls.
482  m4_version_prereq([9.0],
483    [AC_REQUIRE([AC_PROG_CC_C99])],
484    [AC_REQUIRE([AC_PROG_CC_STDC])])
485])
486
487# gl_PROG_AR_RANLIB
488# Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
489# The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
490# the values.
491AC_DEFUN([gl_PROG_AR_RANLIB],
492[
493  dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler
494  dnl as "cc", and GCC as "gcc". They have different object file formats and
495  dnl library formats. In particular, the GNU binutils programs ar and ranlib
496  dnl produce libraries that work only with gcc, not with cc.
497  AC_REQUIRE([AC_PROG_CC])
498  dnl The '][' hides this use from 'aclocal'.
499  AC_BEFORE([$0], [A][M_PROG_AR])
500  AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler],
501    [
502      AC_EGREP_CPP([Amsterdam],
503        [
504#ifdef __ACK__
505Amsterdam
506#endif
507        ],
508        [gl_cv_c_amsterdam_compiler=yes],
509        [gl_cv_c_amsterdam_compiler=no])
510    ])
511
512  dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not
513  dnl building with __ACK__.
514  if test $gl_cv_c_amsterdam_compiler = yes; then
515    if test -z "$AR"; then
516      AR='cc -c.a'
517    fi
518    if test -z "$ARFLAGS"; then
519      ARFLAGS='-o'
520    fi
521  else
522    dnl AM_PROG_AR was added in automake v1.11.2.  AM_PROG_AR does not AC_SUBST
523    dnl ARFLAGS variable (it is filed into Makefile.in directly by automake
524    dnl script on-demand, if not specified by ./configure of course).
525    dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above
526    dnl will be ignored.  Also, pay attention to call AM_PROG_AR in else block
527    dnl because AM_PROG_AR is written so it could re-set AR variable even for
528    dnl __ACK__.  It may seem like its easier to avoid calling the macro here,
529    dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good
530    dnl default value and automake should usually know them).
531    dnl
532    dnl The '][' hides this use from 'aclocal'.
533    m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:])
534  fi
535
536  dnl In case the code above has not helped with setting AR/ARFLAGS, use
537  dnl Automake-documented default values for AR and ARFLAGS, but prefer
538  dnl ${host}-ar over ar (useful for cross-compiling).
539  AC_CHECK_TOOL([AR], [ar], [ar])
540  if test -z "$ARFLAGS"; then
541    ARFLAGS='cr'
542  fi
543
544  AC_SUBST([AR])
545  AC_SUBST([ARFLAGS])
546  if test -z "$RANLIB"; then
547    if test $gl_cv_c_amsterdam_compiler = yes; then
548      RANLIB=':'
549    else
550      dnl Use the ranlib program if it is available.
551      AC_PROG_RANLIB
552    fi
553  fi
554  AC_SUBST([RANLIB])
555])
556
557# AC_C_RESTRICT
558# This definition is copied from post-2.69 Autoconf and overrides the
559# AC_C_RESTRICT macro from autoconf 2.60..2.69.  It can be removed
560# once autoconf >= 2.70 can be assumed.  It's painful to check version
561# numbers, and in practice this macro is more up-to-date than Autoconf
562# is, so override Autoconf unconditionally.
563AC_DEFUN([AC_C_RESTRICT],
564[AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
565  [ac_cv_c_restrict=no
566   # The order here caters to the fact that C++ does not require restrict.
567   for ac_kw in __restrict __restrict__ _Restrict restrict; do
568     AC_COMPILE_IFELSE(
569      [AC_LANG_PROGRAM(
570         [[typedef int *int_ptr;
571           int foo (int_ptr $ac_kw ip) { return ip[0]; }
572           int bar (int [$ac_kw]); /* Catch GCC bug 14050.  */
573           int bar (int ip[$ac_kw]) { return ip[0]; }
574         ]],
575         [[int s[1];
576           int *$ac_kw t = s;
577           t[0] = 0;
578           return foo (t) + bar (t);
579         ]])],
580      [ac_cv_c_restrict=$ac_kw])
581     test "$ac_cv_c_restrict" != no && break
582   done
583  ])
584 AH_VERBATIM([restrict],
585[/* Define to the equivalent of the C99 'restrict' keyword, or to
586   nothing if this is not supported.  Do not define if restrict is
587   supported directly.  */
588#undef restrict
589/* Work around a bug in older versions of Sun C++, which did not
590   #define __restrict__ or support _Restrict or __restrict__
591   even though the corresponding Sun C compiler ended up with
592   "#define restrict _Restrict" or "#define restrict __restrict__"
593   in the previous line.  This workaround can be removed once
594   we assume Oracle Developer Studio 12.5 (2016) or later.  */
595#if defined __SUNPRO_CC && !defined __RESTRICT && !defined __restrict__
596# define _Restrict
597# define __restrict__
598#endif])
599 case $ac_cv_c_restrict in
600   restrict) ;;
601   no) AC_DEFINE([restrict], []) ;;
602   *)  AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
603 esac
604])# AC_C_RESTRICT
605
606# gl_BIGENDIAN
607# is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
608# Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
609# macros invoke AC_C_BIGENDIAN with arguments.
610AC_DEFUN([gl_BIGENDIAN],
611[
612  AC_C_BIGENDIAN
613])
614
615# gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
616# is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
617# output a spurious "(cached)" mark in the midst of other configure output.
618# This macro should be used instead of AC_CACHE_VAL when it is not surrounded
619# by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
620AC_DEFUN([gl_CACHE_VAL_SILENT],
621[
622  saved_as_echo_n="$as_echo_n"
623  as_echo_n=':'
624  AC_CACHE_VAL([$1], [$2])
625  as_echo_n="$saved_as_echo_n"
626])
627
628# AS_VAR_COPY was added in autoconf 2.63b
629m4_define_default([AS_VAR_COPY],
630[AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])
631