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1 | dnl Macros to check the presence of generic (non-typed) symbols. |
2 | dnl Copyright (c) 2006-2008 Diego Pettenò <flameeyes@gmail.com> | |
3 | dnl Copyright (c) 2006-2008 xine project | |
4 | dnl Copyright (c) 2012 Lucas De Marchi <lucas.de.marchi@gmail.com> | |
5 | dnl | |
6 | dnl This program is free software; you can redistribute it and/or modify | |
7 | dnl it under the terms of the GNU General Public License as published by | |
8 | dnl the Free Software Foundation; either version 2, or (at your option) | |
9 | dnl any later version. | |
10 | dnl | |
11 | dnl This program is distributed in the hope that it will be useful, | |
12 | dnl but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | dnl GNU General Public License for more details. | |
15 | dnl | |
16 | dnl You should have received a copy of the GNU General Public License | |
17 | dnl along with this program; if not, write to the Free Software | |
18 | dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
19 | dnl 02110-1301, USA. | |
20 | dnl | |
21 | dnl As a special exception, the copyright owners of the | |
22 | dnl macro gives unlimited permission to copy, distribute and modify the | |
23 | dnl configure scripts that are the output of Autoconf when processing the | |
24 | dnl Macro. You need not follow the terms of the GNU General Public | |
25 | dnl License when using or distributing such scripts, even though portions | |
26 | dnl of the text of the Macro appear in them. The GNU General Public | |
27 | dnl License (GPL) does govern all other use of the material that | |
28 | dnl constitutes the Autoconf Macro. | |
29 | dnl | |
30 | dnl This special exception to the GPL applies to versions of the | |
31 | dnl Autoconf Macro released by this project. When you make and | |
32 | dnl distribute a modified version of the Autoconf Macro, you may extend | |
33 | dnl this special exception to the GPL to apply to your modified version as | |
34 | dnl well. | |
35 | ||
36 | dnl Check if FLAG in ENV-VAR is supported by compiler and append it | |
37 | dnl to WHERE-TO-APPEND variable | |
38 | dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG]) | |
39 | ||
40 | AC_DEFUN([CC_CHECK_FLAG_APPEND], [ | |
41 | AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2], | |
42 | AS_TR_SH([cc_cv_$2_$3]), | |
43 | [eval "AS_TR_SH([cc_save_$2])='${$2}'" | |
44 | eval "AS_TR_SH([$2])='-Werror $3'" | |
45 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([int a = 0; int main(void) { return a; } ])], | |
46 | [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"], | |
47 | [eval "AS_TR_SH([cc_cv_$2_$3])='no'"]) | |
48 | eval "AS_TR_SH([$2])='$cc_save_$2'"]) | |
49 | ||
50 | AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes], | |
51 | [eval "$1='${$1} $3'"]) | |
52 | ]) | |
53 | ||
54 | dnl CC_CHECK_FLAGS_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG1 FLAG2]) | |
55 | AC_DEFUN([CC_CHECK_FLAGS_APPEND], [ | |
56 | for flag in $3; do | |
57 | CC_CHECK_FLAG_APPEND($1, $2, $flag) | |
58 | done | |
59 | ]) | |
60 | ||
61 | dnl Check if the flag is supported by linker (cacheable) | |
62 | dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) | |
63 | ||
64 | AC_DEFUN([CC_CHECK_LDFLAGS], [ | |
65 | AC_CACHE_CHECK([if $CC supports $1 flag], | |
66 | AS_TR_SH([cc_cv_ldflags_$1]), | |
67 | [ac_save_LDFLAGS="$LDFLAGS" | |
68 | LDFLAGS="$LDFLAGS $1" | |
69 | AC_LINK_IFELSE([int main() { return 1; }], | |
70 | [eval "AS_TR_SH([cc_cv_ldflags_$1])='yes'"], | |
71 | [eval "AS_TR_SH([cc_cv_ldflags_$1])="]) | |
72 | LDFLAGS="$ac_save_LDFLAGS" | |
73 | ]) | |
74 | ||
75 | AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], | |
76 | [$2], [$3]) | |
77 | ]) | |
78 | ||
79 | dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for | |
80 | dnl the current linker to avoid undefined references in a shared object. | |
81 | AC_DEFUN([CC_NOUNDEFINED], [ | |
82 | dnl We check $host for which systems to enable this for. | |
83 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
84 | ||
85 | case $host in | |
86 | dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads | |
87 | dnl are requested, as different implementations are present; to avoid problems | |
88 | dnl use -Wl,-z,defs only for those platform not behaving this way. | |
89 | *-freebsd* | *-openbsd*) ;; | |
90 | *) | |
91 | dnl First of all check for the --no-undefined variant of GNU ld. This allows | |
92 | dnl for a much more readable commandline, so that people can understand what | |
93 | dnl it does without going to look for what the heck -z defs does. | |
94 | for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do | |
95 | CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) | |
96 | break | |
97 | done | |
98 | ;; | |
99 | esac | |
100 | ||
101 | AC_SUBST([LDFLAGS_NOUNDEFINED]) | |
102 | ]) | |
103 | ||
104 | dnl Check for a -Werror flag or equivalent. -Werror is the GCC | |
105 | dnl and ICC flag that tells the compiler to treat all the warnings | |
106 | dnl as fatal. We usually need this option to make sure that some | |
107 | dnl constructs (like attributes) are not simply ignored. | |
108 | dnl | |
109 | dnl Other compilers don't support -Werror per se, but they support | |
110 | dnl an equivalent flag: | |
111 | dnl - Sun Studio compiler supports -errwarn=%all | |
112 | AC_DEFUN([CC_CHECK_WERROR], [ | |
113 | AC_CACHE_CHECK( | |
114 | [for $CC way to treat warnings as errors], | |
115 | [cc_cv_werror], | |
116 | [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror], | |
117 | [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])]) | |
118 | ]) | |
119 | ]) | |
120 | ||
121 | AC_DEFUN([CC_CHECK_ATTRIBUTE], [ | |
122 | AC_REQUIRE([CC_CHECK_WERROR]) | |
123 | AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))], | |
124 | AS_TR_SH([cc_cv_attribute_$1]), | |
125 | [ac_save_CFLAGS="$CFLAGS" | |
126 | CFLAGS="$CFLAGS $cc_cv_werror" | |
127 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])], | |
128 | [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"], | |
129 | [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"]) | |
130 | CFLAGS="$ac_save_CFLAGS" | |
131 | ]) | |
132 | ||
133 | AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes], | |
134 | [AC_DEFINE( | |
135 | AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1, | |
136 | [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))] | |
137 | ) | |
138 | $4], | |
139 | [$5]) | |
140 | ]) | |
141 | ||
142 | AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [ | |
143 | CC_CHECK_ATTRIBUTE( | |
144 | [constructor],, | |
145 | [void __attribute__((constructor)) ctor() { int a; }], | |
146 | [$1], [$2]) | |
147 | ]) | |
148 | ||
149 | AC_DEFUN([CC_ATTRIBUTE_FORMAT], [ | |
150 | CC_CHECK_ATTRIBUTE( | |
151 | [format], [format(printf, n, n)], | |
152 | [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }], | |
153 | [$1], [$2]) | |
154 | ]) | |
155 | ||
156 | AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [ | |
157 | CC_CHECK_ATTRIBUTE( | |
158 | [format_arg], [format_arg(printf)], | |
159 | [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }], | |
160 | [$1], [$2]) | |
161 | ]) | |
162 | ||
163 | AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [ | |
164 | CC_CHECK_ATTRIBUTE( | |
165 | [visibility_$1], [visibility("$1")], | |
166 | [void __attribute__((visibility("$1"))) $1_function() { }], | |
167 | [$2], [$3]) | |
168 | ]) | |
169 | ||
170 | AC_DEFUN([CC_ATTRIBUTE_NONNULL], [ | |
171 | CC_CHECK_ATTRIBUTE( | |
172 | [nonnull], [nonnull()], | |
173 | [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }], | |
174 | [$1], [$2]) | |
175 | ]) | |
176 | ||
177 | AC_DEFUN([CC_ATTRIBUTE_UNUSED], [ | |
178 | CC_CHECK_ATTRIBUTE( | |
179 | [unused], , | |
180 | [void some_function(void *foo, __attribute__((unused)) void *bar);], | |
181 | [$1], [$2]) | |
182 | ]) | |
183 | ||
184 | AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [ | |
185 | CC_CHECK_ATTRIBUTE( | |
186 | [sentinel], , | |
187 | [void some_function(void *foo, ...) __attribute__((sentinel));], | |
188 | [$1], [$2]) | |
189 | ]) | |
190 | ||
191 | AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [ | |
192 | CC_CHECK_ATTRIBUTE( | |
193 | [deprecated], , | |
194 | [void some_function(void *foo, ...) __attribute__((deprecated));], | |
195 | [$1], [$2]) | |
196 | ]) | |
197 | ||
198 | AC_DEFUN([CC_ATTRIBUTE_ALIAS], [ | |
199 | CC_CHECK_ATTRIBUTE( | |
200 | [alias], [weak, alias], | |
201 | [void other_function(void *foo) { } | |
202 | void some_function(void *foo) __attribute__((weak, alias("other_function")));], | |
203 | [$1], [$2]) | |
204 | ]) | |
205 | ||
206 | AC_DEFUN([CC_ATTRIBUTE_MALLOC], [ | |
207 | CC_CHECK_ATTRIBUTE( | |
208 | [malloc], , | |
209 | [void * __attribute__((malloc)) my_alloc(int n);], | |
210 | [$1], [$2]) | |
211 | ]) | |
212 | ||
213 | AC_DEFUN([CC_ATTRIBUTE_PACKED], [ | |
214 | CC_CHECK_ATTRIBUTE( | |
215 | [packed], , | |
216 | [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));], | |
217 | [$1], [$2]) | |
218 | ]) | |
219 | ||
220 | AC_DEFUN([CC_ATTRIBUTE_CONST], [ | |
221 | CC_CHECK_ATTRIBUTE( | |
222 | [const], , | |
223 | [int __attribute__((const)) twopow(int n) { return 1 << n; } ], | |
224 | [$1], [$2]) | |
225 | ]) | |
226 | ||
227 | AC_DEFUN([CC_FLAG_VISIBILITY], [ | |
228 | AC_REQUIRE([CC_CHECK_WERROR]) | |
229 | AC_CACHE_CHECK([if $CC supports -fvisibility=hidden], | |
230 | [cc_cv_flag_visibility], | |
231 | [cc_flag_visibility_save_CFLAGS="$CFLAGS" | |
232 | CFLAGS="$CFLAGS $cc_cv_werror" | |
233 | CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden], | |
234 | cc_cv_flag_visibility='yes', | |
235 | cc_cv_flag_visibility='no') | |
236 | CFLAGS="$cc_flag_visibility_save_CFLAGS"]) | |
237 | ||
238 | AS_IF([test "x$cc_cv_flag_visibility" = "xyes"], | |
239 | [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1, | |
240 | [Define this if the compiler supports the -fvisibility flag]) | |
241 | $1], | |
242 | [$2]) | |
243 | ]) | |
244 | ||
245 | AC_DEFUN([CC_FUNC_EXPECT], [ | |
246 | AC_REQUIRE([CC_CHECK_WERROR]) | |
247 | AC_CACHE_CHECK([if compiler has __builtin_expect function], | |
248 | [cc_cv_func_expect], | |
249 | [ac_save_CFLAGS="$CFLAGS" | |
250 | CFLAGS="$CFLAGS $cc_cv_werror" | |
251 | AC_COMPILE_IFELSE([AC_LANG_SOURCE( | |
252 | [int some_function() { | |
253 | int a = 3; | |
254 | return (int)__builtin_expect(a, 3); | |
255 | }])], | |
256 | [cc_cv_func_expect=yes], | |
257 | [cc_cv_func_expect=no]) | |
258 | CFLAGS="$ac_save_CFLAGS" | |
259 | ]) | |
260 | ||
261 | AS_IF([test "x$cc_cv_func_expect" = "xyes"], | |
262 | [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1, | |
263 | [Define this if the compiler supports __builtin_expect() function]) | |
264 | $1], | |
265 | [$2]) | |
266 | ]) | |
267 | ||
268 | AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [ | |
269 | AC_REQUIRE([CC_CHECK_WERROR]) | |
270 | AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported], | |
271 | [cc_cv_attribute_aligned], | |
272 | [ac_save_CFLAGS="$CFLAGS" | |
273 | CFLAGS="$CFLAGS $cc_cv_werror" | |
274 | for cc_attribute_align_try in 64 32 16 8 4 2; do | |
275 | AC_COMPILE_IFELSE([AC_LANG_SOURCE([ | |
276 | int main() { | |
277 | static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0; | |
278 | return c; | |
279 | }])], [cc_cv_attribute_aligned=$cc_attribute_align_try; break]) | |
280 | done | |
281 | CFLAGS="$ac_save_CFLAGS" | |
282 | ]) | |
283 | ||
284 | if test "x$cc_cv_attribute_aligned" != "x"; then | |
285 | AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned], | |
286 | [Define the highest alignment supported]) | |
287 | fi | |
288 | ]) |