1 # gnulib-common.m4 serial 41
2 dnl Copyright (C) 2007-2018 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved.
10 # is expanded unconditionally through gnulib-tool magic.
11 AC_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])
16 AC_DEFUN([gl_COMMON_BODY], [
17 AH_VERBATIM([_Noreturn],
18 [/* The _Noreturn keyword of C11. */
20 # if 201103 <= (defined __cplusplus ? __cplusplus : 0)
21 # define _Noreturn [[noreturn]]
22 # elif (201112 <= (defined __STDC_VERSION__ ? __STDC_VERSION__ : 0) \
23 || 4 < __GNUC__ + (7 <= __GNUC_MINOR__))
24 /* _Noreturn works as-is. */
25 # elif 2 < __GNUC__ + (8 <= __GNUC_MINOR__) || 0x5110 <= __SUNPRO_C
26 # define _Noreturn __attribute__ ((__noreturn__))
27 # elif 1200 <= (defined _MSC_VER ? _MSC_VER : 0)
28 # define _Noreturn __declspec (noreturn)
34 AH_VERBATIM([isoc99_inline],
35 [/* Work around a bug in Apple GCC 4.0.1 build 5465: In C99 mode, it supports
36 the ISO C 99 semantics of 'extern inline' (unlike the GNU C semantics of
37 earlier versions), but does not display it by setting __GNUC_STDC_INLINE__.
38 __APPLE__ && __MACH__ test for Mac OS X.
39 __APPLE_CC__ tests for the Apple compiler and its version.
40 __STDC_VERSION__ tests for the C99 mode. */
41 #if defined __APPLE__ && defined __MACH__ && __APPLE_CC__ >= 5465 && !defined __cplusplus && __STDC_VERSION__ >= 199901L && !defined __GNUC_STDC_INLINE__
42 # define __GNUC_STDC_INLINE__ 1
44 AH_VERBATIM([unused_parameter],
45 [/* Define as a marker that can be attached to declarations that might not
46 be used. This helps to reduce warnings, such as from
47 GCC -Wunused-parameter. */
48 #if __GNUC__ >= 3 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 7)
49 # define _GL_UNUSED __attribute__ ((__unused__))
53 /* The name _UNUSED_PARAMETER_ is an earlier spelling, although the name
54 is a misnomer outside of parameter lists. */
55 #define _UNUSED_PARAMETER_ _GL_UNUSED
57 /* gcc supports the "unused" attribute on possibly unused labels, and
58 g++ has since version 4.5. Note to support C++ as well as C,
59 _GL_UNUSED_LABEL should be used with a trailing ; */
60 #if !defined __cplusplus || __GNUC__ > 4 \
61 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
62 # define _GL_UNUSED_LABEL _GL_UNUSED
64 # define _GL_UNUSED_LABEL
67 /* The __pure__ attribute was added in gcc 2.96. */
68 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 96)
69 # define _GL_ATTRIBUTE_PURE __attribute__ ((__pure__))
71 # define _GL_ATTRIBUTE_PURE /* empty */
74 /* The __const__ attribute was added in gcc 2.95. */
75 #if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 95)
76 # define _GL_ATTRIBUTE_CONST __attribute__ ((__const__))
78 # define _GL_ATTRIBUTE_CONST /* empty */
81 /* The __malloc__ attribute was added in gcc 3. */
83 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
85 # define _GL_ATTRIBUTE_MALLOC /* empty */
88 dnl Preparation for running test programs:
89 dnl Tell glibc to write diagnostics from -D_FORTIFY_SOURCE=2 to stderr, not
90 dnl to /dev/tty, so they can be redirected to log files. Such diagnostics
91 dnl arise e.g., in the macros gl_PRINTF_DIRECTIVE_N, gl_SNPRINTF_DIRECTIVE_N.
93 export LIBC_FATAL_STDERR_
96 # gl_MODULE_INDICATOR_CONDITION
97 # expands to a C preprocessor expression that evaluates to 1 or 0, depending
98 # whether a gnulib module that has been requested shall be considered present
100 m4_define([gl_MODULE_INDICATOR_CONDITION], [1])
102 # gl_MODULE_INDICATOR_SET_VARIABLE([modulename])
103 # sets the shell variable that indicates the presence of the given module to
104 # a C preprocessor expression that will evaluate to 1.
105 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE],
107 gl_MODULE_INDICATOR_SET_VARIABLE_AUX(
108 [GNULIB_[]m4_translit([[$1]],
109 [abcdefghijklmnopqrstuvwxyz./-],
110 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___])],
111 [gl_MODULE_INDICATOR_CONDITION])
114 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX([variable])
115 # modifies the shell variable to include the gl_MODULE_INDICATOR_CONDITION.
116 # The shell variable's value is a C preprocessor expression that evaluates
118 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX],
120 m4_if(m4_defn([gl_MODULE_INDICATOR_CONDITION]), [1],
122 dnl Simplify the expression VALUE || 1 to 1.
125 [gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([$1],
126 [gl_MODULE_INDICATOR_CONDITION])])
129 # gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR([variable], [condition])
130 # modifies the shell variable to include the given condition. The shell
131 # variable's value is a C preprocessor expression that evaluates to 0 or 1.
132 AC_DEFUN([gl_MODULE_INDICATOR_SET_VARIABLE_AUX_OR],
134 dnl Simplify the expression 1 || CONDITION to 1.
135 if test "$[]$1" != 1; then
136 dnl Simplify the expression 0 || CONDITION to CONDITION.
137 if test "$[]$1" = 0; then
145 # gl_MODULE_INDICATOR([modulename])
146 # defines a C macro indicating the presence of the given module
147 # in a location where it can be used.
149 # | in lib/ | in tests/ |
150 # --------------------------------------------+---------+-----------+
151 # Module present among main modules: | 1 | 1 |
152 # --------------------------------------------+---------+-----------+
153 # Module present among tests-related modules: | 0 | 1 |
154 # --------------------------------------------+---------+-----------+
155 # Module not present at all: | 0 | 0 |
156 # --------------------------------------------+---------+-----------+
157 AC_DEFUN([gl_MODULE_INDICATOR],
159 AC_DEFINE_UNQUOTED([GNULIB_]m4_translit([[$1]],
160 [abcdefghijklmnopqrstuvwxyz./-],
161 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]),
162 [gl_MODULE_INDICATOR_CONDITION],
163 [Define to a C preprocessor expression that evaluates to 1 or 0,
164 depending whether the gnulib module $1 shall be considered present.])
167 # gl_MODULE_INDICATOR_FOR_TESTS([modulename])
168 # defines a C macro indicating the presence of the given module
169 # in lib or tests. This is useful to determine whether the module
172 # | in lib/ | in tests/ |
173 # --------------------------------------------+---------+-----------+
174 # Module present among main modules: | 1 | 1 |
175 # --------------------------------------------+---------+-----------+
176 # Module present among tests-related modules: | 1 | 1 |
177 # --------------------------------------------+---------+-----------+
178 # Module not present at all: | 0 | 0 |
179 # --------------------------------------------+---------+-----------+
180 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS],
182 AC_DEFINE([GNULIB_TEST_]m4_translit([[$1]],
183 [abcdefghijklmnopqrstuvwxyz./-],
184 [ABCDEFGHIJKLMNOPQRSTUVWXYZ___]), [1],
185 [Define to 1 when the gnulib module $1 should be tested.])
188 # gl_ASSERT_NO_GNULIB_POSIXCHECK
189 # asserts that there will never be a need to #define GNULIB_POSIXCHECK.
190 # and thereby enables an optimization of configure and config.h.
192 AC_DEFUN([gl_ASSERT_NO_GNULIB_POSIXCHECK],
194 dnl Override gl_WARN_ON_USE_PREPARE.
195 dnl But hide this definition from 'aclocal'.
196 AC_DEFUN([gl_W][ARN_ON_USE_PREPARE], [])
199 # gl_ASSERT_NO_GNULIB_TESTS
200 # asserts that there will be no gnulib tests in the scope of the configure.ac
201 # and thereby enables an optimization of config.h.
203 AC_DEFUN([gl_ASSERT_NO_GNULIB_TESTS],
205 dnl Override gl_MODULE_INDICATOR_FOR_TESTS.
206 AC_DEFUN([gl_MODULE_INDICATOR_FOR_TESTS], [])
209 # Test whether <features.h> exists.
210 # Set HAVE_FEATURES_H.
211 AC_DEFUN([gl_FEATURES_H],
213 AC_CHECK_HEADERS_ONCE([features.h])
214 if test $ac_cv_header_features_h = yes; then
219 AC_SUBST([HAVE_FEATURES_H])
222 # AS_VAR_IF(VAR, VALUE, [IF-MATCH], [IF-NOT-MATCH])
223 # ----------------------------------------------------
224 # Backport of autoconf-2.63b's macro.
225 # Remove this macro when we can assume autoconf >= 2.64.
226 m4_ifndef([AS_VAR_IF],
227 [m4_define([AS_VAR_IF],
228 [AS_IF([test x"AS_VAR_GET([$1])" = x""$2], [$3], [$4])])])
231 # Modifies the value of the shell variable CC in an attempt to make $CC
232 # understand ISO C99 source code.
233 # This is like AC_PROG_CC_C99, except that
234 # - AC_PROG_CC_C99 does not mix well with AC_PROG_CC_STDC
235 # <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00367.html>,
236 # but many more packages use AC_PROG_CC_STDC than AC_PROG_CC_C99
237 # <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00441.html>.
238 # Remaining problems:
239 # - When AC_PROG_CC_STDC is invoked twice, it adds the C99 enabling options
241 # <https://lists.gnu.org/r/bug-gnulib/2011-09/msg00431.html>.
242 # - AC_PROG_CC_STDC is likely to change now that C11 is an ISO standard.
243 AC_DEFUN([gl_PROG_CC_C99],
245 dnl Change that version number to the minimum Autoconf version that supports
246 dnl mixing AC_PROG_CC_C99 calls with AC_PROG_CC_STDC calls.
247 m4_version_prereq([9.0],
248 [AC_REQUIRE([AC_PROG_CC_C99])],
249 [AC_REQUIRE([AC_PROG_CC_STDC])])
253 # Determines the values for AR, ARFLAGS, RANLIB that fit with the compiler.
254 # The user can set the variables AR, ARFLAGS, RANLIB if he wants to override
256 AC_DEFUN([gl_PROG_AR_RANLIB],
258 dnl Minix 3 comes with two toolchains: The Amsterdam Compiler Kit compiler
259 dnl as "cc", and GCC as "gcc". They have different object file formats and
260 dnl library formats. In particular, the GNU binutils programs ar and ranlib
261 dnl produce libraries that work only with gcc, not with cc.
262 AC_REQUIRE([AC_PROG_CC])
263 dnl The '][' hides this use from 'aclocal'.
264 AC_BEFORE([$0], [A][M_PROG_AR])
265 AC_CACHE_CHECK([for Minix Amsterdam compiler], [gl_cv_c_amsterdam_compiler],
267 AC_EGREP_CPP([Amsterdam],
273 [gl_cv_c_amsterdam_compiler=yes],
274 [gl_cv_c_amsterdam_compiler=no])
277 dnl Don't compete with AM_PROG_AR's decision about AR/ARFLAGS if we are not
278 dnl building with __ACK__.
279 if test $gl_cv_c_amsterdam_compiler = yes; then
280 if test -z "$AR"; then
283 if test -z "$ARFLAGS"; then
287 dnl AM_PROG_AR was added in automake v1.11.2. AM_PROG_AR does not AC_SUBST
288 dnl ARFLAGS variable (it is filed into Makefile.in directly by automake
289 dnl script on-demand, if not specified by ./configure of course).
290 dnl Don't AC_REQUIRE the AM_PROG_AR otherwise the code for __ACK__ above
291 dnl will be ignored. Also, pay attention to call AM_PROG_AR in else block
292 dnl because AM_PROG_AR is written so it could re-set AR variable even for
293 dnl __ACK__. It may seem like its easier to avoid calling the macro here,
294 dnl but we need to AC_SUBST both AR/ARFLAGS (thus those must have some good
295 dnl default value and automake should usually know them).
297 dnl The '][' hides this use from 'aclocal'.
298 m4_ifdef([A][M_PROG_AR], [A][M_PROG_AR], [:])
301 dnl In case the code above has not helped with setting AR/ARFLAGS, use
302 dnl Automake-documented default values for AR and ARFLAGS, but prefer
303 dnl ${host}-ar over ar (useful for cross-compiling).
304 AC_CHECK_TOOL([AR], [ar], [ar])
305 if test -z "$ARFLAGS"; then
311 if test -z "$RANLIB"; then
312 if test $gl_cv_c_amsterdam_compiler = yes; then
315 dnl Use the ranlib program if it is available.
323 # This definition is copied from post-2.69 Autoconf and overrides the
324 # AC_C_RESTRICT macro from autoconf 2.60..2.69. It can be removed
325 # once autoconf >= 2.70 can be assumed. It's painful to check version
326 # numbers, and in practice this macro is more up-to-date than Autoconf
327 # is, so override Autoconf unconditionally.
328 AC_DEFUN([AC_C_RESTRICT],
329 [AC_CACHE_CHECK([for C/C++ restrict keyword], [ac_cv_c_restrict],
331 # The order here caters to the fact that C++ does not require restrict.
332 for ac_kw in __restrict __restrict__ _Restrict restrict; do
335 [[typedef int *int_ptr;
336 int foo (int_ptr $ac_kw ip) { return ip[0]; }
337 int bar (int [$ac_kw]); /* Catch GCC bug 14050. */
338 int bar (int ip[$ac_kw]) { return ip[0]; }
343 return foo (t) + bar (t);
345 [ac_cv_c_restrict=$ac_kw])
346 test "$ac_cv_c_restrict" != no && break
349 AH_VERBATIM([restrict],
350 [/* Define to the equivalent of the C99 'restrict' keyword, or to
351 nothing if this is not supported. Do not define if restrict is
352 supported directly. */
354 /* Work around a bug in Sun C++: it does not support _Restrict or
355 __restrict__, even though the corresponding Sun C compiler ends up with
356 "#define restrict _Restrict" or "#define restrict __restrict__" in the
357 previous line. Perhaps some future version of Sun C++ will work with
358 restrict; if so, hopefully it defines __RESTRICT like Sun C does. */
359 #if defined __SUNPRO_CC && !defined __RESTRICT
361 # define __restrict__
363 case $ac_cv_c_restrict in
365 no) AC_DEFINE([restrict], []) ;;
366 *) AC_DEFINE_UNQUOTED([restrict], [$ac_cv_c_restrict]) ;;
371 # is like AC_C_BIGENDIAN, except that it can be AC_REQUIREd.
372 # Note that AC_REQUIRE([AC_C_BIGENDIAN]) does not work reliably because some
373 # macros invoke AC_C_BIGENDIAN with arguments.
374 AC_DEFUN([gl_BIGENDIAN],
379 # gl_CACHE_VAL_SILENT(cache-id, command-to-set-it)
380 # is like AC_CACHE_VAL(cache-id, command-to-set-it), except that it does not
381 # output a spurious "(cached)" mark in the midst of other configure output.
382 # This macro should be used instead of AC_CACHE_VAL when it is not surrounded
383 # by an AC_MSG_CHECKING/AC_MSG_RESULT pair.
384 AC_DEFUN([gl_CACHE_VAL_SILENT],
386 saved_as_echo_n="$as_echo_n"
388 AC_CACHE_VAL([$1], [$2])
389 as_echo_n="$saved_as_echo_n"
392 # AS_VAR_COPY was added in autoconf 2.63b
393 m4_define_default([AS_VAR_COPY],
394 [AS_LITERAL_IF([$1[]$2], [$1=$$2], [eval $1=\$$2])])