1 dnl Macros to check the presence of generic (non-typed) symbols.
2 dnl Copyright (c) 2006-2007 Diego Pettenò <flameeyes@gmail.com>
3 dnl Copyright (c) 2006-2007 xine project
5 dnl This program is free software; you can redistribute it and/or modify
6 dnl it under the terms of the GNU General Public License as published by
7 dnl the Free Software Foundation; either version 2, or (at your option)
10 dnl This program is distributed in the hope that it will be useful,
11 dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
12 dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 dnl GNU General Public License for more details.
15 dnl You should have received a copy of the GNU General Public License
16 dnl along with this program; if not, write to the Free Software
17 dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 dnl As a special exception, the copyright owners of the
21 dnl macro gives unlimited permission to copy, distribute and modify the
22 dnl configure scripts that are the output of Autoconf when processing the
23 dnl Macro. You need not follow the terms of the GNU General Public
24 dnl License when using or distributing such scripts, even though portions
25 dnl of the text of the Macro appear in them. The GNU General Public
26 dnl License (GPL) does govern all other use of the material that
27 dnl constitutes the Autoconf Macro.
29 dnl This special exception to the GPL applies to versions of the
30 dnl Autoconf Macro released by this project. When you make and
31 dnl distribute a modified version of the Autoconf Macro, you may extend
32 dnl this special exception to the GPL to apply to your modified version as
35 dnl Check if the flag is supported by compiler
36 dnl CC_CHECK_CFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
38 AC_DEFUN([CC_CHECK_CFLAGS_SILENT], [
39 AC_CACHE_VAL(AS_TR_SH([cc_cv_cflags_$1]),
40 [ac_save_CFLAGS="$CFLAGS"
42 AC_LINK_IFELSE([AC_LANG_SOURCE([int main() { return 0; }])],
43 [eval "AS_TR_SH([cc_cv_cflags_$1])='yes'"],
44 [eval "AS_TR_SH([cc_cv_cflags_$1])='no'"])
45 CFLAGS="$ac_save_CFLAGS"
48 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
52 dnl Check if the flag is supported by compiler (cacheable)
53 dnl CC_CHECK_CFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
55 AC_DEFUN([CC_CHECK_CFLAGS], [
56 AC_CACHE_CHECK([if $CC supports $1 flag],
57 AS_TR_SH([cc_cv_cflags_$1]),
58 CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
61 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
65 dnl CC_CHECK_CFLAG_APPEND(FLAG, [action-if-found], [action-if-not-found])
66 dnl Check for CFLAG and appends them to CFLAGS if supported
67 AC_DEFUN([CC_CHECK_CFLAG_APPEND], [
68 AC_CACHE_CHECK([if $CC supports $1 flag],
69 AS_TR_SH([cc_cv_cflags_$1]),
70 CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
73 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
74 [CFLAGS="$CFLAGS $1"; $2], [$3])
77 dnl CC_CHECK_CFLAGS_APPEND([FLAG1 FLAG2], [action-if-found], [action-if-not])
78 AC_DEFUN([CC_CHECK_CFLAGS_APPEND], [
80 CC_CHECK_CFLAG_APPEND($flag, [$2], [$3])
84 dnl Check if the flag is supported by linker (cacheable)
85 dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
87 AC_DEFUN([CC_CHECK_LDFLAGS], [
88 AC_CACHE_CHECK([if $CC supports $1 flag],
89 AS_TR_SH([cc_cv_ldflags_$1]),
90 [ac_save_LDFLAGS="$LDFLAGS"
92 AC_LINK_IFELSE([AC_LANG_SOURCE([int main() { return 1; }])],
93 [eval "AS_TR_SH([cc_cv_ldflags_$1])='yes'"],
94 [eval "AS_TR_SH([cc_cv_ldflags_$1])="])
95 LDFLAGS="$ac_save_LDFLAGS"
98 AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes],
102 dnl Check for a -Werror flag or equivalent. -Werror is the GCC
103 dnl and ICC flag that tells the compiler to treat all the warnings
104 dnl as fatal. We usually need this option to make sure that some
105 dnl constructs (like attributes) are not simply ignored.
107 dnl Other compilers don't support -Werror per se, but they support
108 dnl an equivalent flag:
109 dnl - Sun Studio compiler supports -errwarn=%all
110 AC_DEFUN([CC_CHECK_WERROR], [
112 [for $CC way to treat warnings as errors],
114 [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror],
115 [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])])
119 AC_DEFUN([CC_CHECK_ATTRIBUTE], [
120 AC_REQUIRE([CC_CHECK_WERROR])
121 AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))],
122 AS_TR_SH([cc_cv_attribute_$1]),
123 [ac_save_CFLAGS="$CFLAGS"
124 CFLAGS="$CFLAGS $cc_cv_werror"
125 AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])],
126 [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"],
127 [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"])
128 CFLAGS="$ac_save_CFLAGS"
131 AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes],
133 AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1,
134 [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))]
140 AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [
144 void __attribute__((constructor)) ctor() { foo(); }],
148 AC_DEFUN([CC_ATTRIBUTE_DESTRUCTOR], [
152 void __attribute__((destructor)) dtor() { foo(); }],
156 AC_DEFUN([CC_ATTRIBUTE_FORMAT], [
158 [format], [format(printf, n, n)],
159 [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }],
163 AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [
165 [format_arg], [format_arg(printf)],
166 [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }],
170 AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [
172 [visibility_$1], [visibility("$1")],
173 [void __attribute__((visibility("$1"))) $1_function() { }],
177 AC_DEFUN([CC_ATTRIBUTE_NONNULL], [
179 [nonnull], [nonnull()],
180 [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }],
184 AC_DEFUN([CC_ATTRIBUTE_UNUSED], [
187 [void some_function(void *foo, __attribute__((unused)) void *bar);],
191 AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [
194 [void some_function(void *foo, ...) __attribute__((sentinel));],
198 AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [
201 [void some_function(void *foo, ...) __attribute__((deprecated));],
205 AC_DEFUN([CC_ATTRIBUTE_ALIAS], [
207 [alias], [weak, alias],
208 [void other_function(void *foo) { }
209 void some_function(void *foo) __attribute__((weak, alias("other_function")));],
213 AC_DEFUN([CC_ATTRIBUTE_MALLOC], [
216 [void * __attribute__((malloc)) my_alloc(int n);],
220 AC_DEFUN([CC_ATTRIBUTE_PACKED], [
223 [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));],
227 AC_DEFUN([CC_ATTRIBUTE_CONST], [
230 [int __attribute__((const)) twopow(int n) { return 1 << n; } ],
234 AC_DEFUN([CC_FLAG_VISIBILITY], [
235 AC_REQUIRE([CC_CHECK_WERROR])
236 AC_CACHE_CHECK([if $CC supports -fvisibility=hidden],
237 [cc_cv_flag_visibility],
238 [cc_flag_visibility_save_CFLAGS="$CFLAGS"
239 CFLAGS="$CFLAGS $cc_cv_werror"
240 CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden],
241 cc_cv_flag_visibility='yes',
242 cc_cv_flag_visibility='no')
243 CFLAGS="$cc_flag_visibility_save_CFLAGS"])
245 AS_IF([test "x$cc_cv_flag_visibility" = "xyes"],
246 [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1,
247 [Define this if the compiler supports the -fvisibility flag])
252 AC_DEFUN([CC_FUNC_EXPECT], [
253 AC_REQUIRE([CC_CHECK_WERROR])
254 AC_CACHE_CHECK([if compiler has __builtin_expect function],
256 [ac_save_CFLAGS="$CFLAGS"
257 CFLAGS="$CFLAGS $cc_cv_werror"
259 [int some_function() {
261 return (int)__builtin_expect(a, 3);
263 [cc_cv_func_expect=yes],
264 [cc_cv_func_expect=no])
265 CFLAGS="$ac_save_CFLAGS"
268 AS_IF([test "x$cc_cv_func_expect" = "xyes"],
269 [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1,
270 [Define this if the compiler supports __builtin_expect() function])
275 AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [
276 AC_REQUIRE([CC_CHECK_WERROR])
277 AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported],
278 [cc_cv_attribute_aligned],
279 [ac_save_CFLAGS="$CFLAGS"
280 CFLAGS="$CFLAGS $cc_cv_werror"
281 for cc_attribute_align_try in 64 32 16 8 4 2; do
284 static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0;
286 }], [cc_cv_attribute_aligned=$cc_attribute_align_try; break])
288 CFLAGS="$ac_save_CFLAGS"
291 if test "x$cc_cv_attribute_aligned" != "x"; then
292 AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned],
293 [Define the highest alignment supported])