1 dnl Macros to check the presence of generic (non-typed) symbols. 2 dnl Copyright (c) 2006-2007 Diego Petten <flameeyes (a] gmail.com> 3 dnl Copyright (c) 2006-2007 xine project 4 dnl 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) 8 dnl any later version. 9 dnl 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. 14 dnl 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 18 dnl 02110-1301, USA. 19 dnl 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. 28 dnl 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 33 dnl well. 34 35 dnl Check if the flag is supported by compiler 36 dnl CC_CHECK_CFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 37 38 AC_DEFUN([CC_CHECK_CFLAGS_SILENT], [ 39 AC_CACHE_VAL(AS_TR_SH([cc_cv_cflags_$1]), 40 [ac_save_CFLAGS="$CFLAGS" 41 CFLAGS="$CFLAGS $1" 42 AC_COMPILE_IFELSE([int a;], 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" 46 ]) 47 48 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes], 49 [$2], [$3]) 50 ]) 51 52 dnl Check if the flag is supported by compiler (cacheable) 53 dnl CC_CHECK_CFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 54 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([$1]) dnl Don't execute actions here! 59 ) 60 61 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes], 62 [$2], [$3]) 63 ]) 64 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([$1]) dnl Don't execute actions here! 71 ) 72 73 AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes], 74 [CFLAGS="$CFLAGS $1"; $2], [$3]) 75 ]) 76 77 dnl CC_CHECK_CFLAGS_APPEND([FLAG1 FLAG2], [action-if-found], [action-if-not]) 78 AC_DEFUN([CC_CHECK_CFLAGS_APPEND], [ 79 for flag in $1; do 80 CC_CHECK_CFLAG_APPEND($flag, [$2], [$3]) 81 done 82 ]) 83 84 dnl Check if the flag is supported by linker (cacheable) 85 dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 86 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" 91 LDFLAGS="$LDFLAGS $1" 92 AC_LINK_IFELSE([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" 96 ]) 97 98 AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], 99 [$2], [$3]) 100 ]) 101 102 dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for 103 dnl the current linker to avoid undefined references in a shared object. 104 AC_DEFUN([CC_NOUNDEFINED], [ 105 dnl We check $host for which systems to enable this for. 106 AC_REQUIRE([AC_CANONICAL_HOST]) 107 108 case $host in 109 dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads 110 dnl are requested, as different implementations are present; to avoid problems 111 dnl use -Wl,-z,defs only for those platform not behaving this way. 112 *-freebsd*) ;; 113 *) 114 dnl First of all check for the --no-undefined variant of GNU ld. This allows 115 dnl for a much more readable commandline, so that people can understand what 116 dnl it does without going to look for what the heck -z defs does. 117 for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do 118 CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) 119 break 120 done 121 ;; 122 esac 123 124 AC_SUBST([LDFLAGS_NOUNDEFINED]) 125 ]) 126 127 dnl Check for a -Werror flag or equivalent. -Werror is the GCC 128 dnl and ICC flag that tells the compiler to treat all the warnings 129 dnl as fatal. We usually need this option to make sure that some 130 dnl constructs (like attributes) are not simply ignored. 131 dnl 132 dnl Other compilers don't support -Werror per se, but they support 133 dnl an equivalent flag: 134 dnl - Sun Studio compiler supports -errwarn=%all 135 AC_DEFUN([CC_CHECK_WERROR], [ 136 AC_CACHE_CHECK( 137 [for $CC way to treat warnings as errors], 138 [cc_cv_werror], 139 [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror], 140 [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])]) 141 ]) 142 ]) 143 144 AC_DEFUN([CC_CHECK_ATTRIBUTE], [ 145 AC_REQUIRE([CC_CHECK_WERROR]) 146 AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))], 147 AS_TR_SH([cc_cv_attribute_$1]), 148 [ac_save_CFLAGS="$CFLAGS" 149 CFLAGS="$CFLAGS $cc_cv_werror" 150 AC_COMPILE_IFELSE([$3], 151 [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"], 152 [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"]) 153 CFLAGS="$ac_save_CFLAGS" 154 ]) 155 156 AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes], 157 [AC_DEFINE( 158 AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1, 159 [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))] 160 ) 161 $4], 162 [$5]) 163 ]) 164 165 AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [ 166 CC_CHECK_ATTRIBUTE( 167 [constructor],, 168 [void __attribute__((constructor)) ctor() { int a; }], 169 [$1], [$2]) 170 ]) 171 172 AC_DEFUN([CC_ATTRIBUTE_FORMAT], [ 173 CC_CHECK_ATTRIBUTE( 174 [format], [format(printf, n, n)], 175 [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }], 176 [$1], [$2]) 177 ]) 178 179 AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [ 180 CC_CHECK_ATTRIBUTE( 181 [format_arg], [format_arg(printf)], 182 [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }], 183 [$1], [$2]) 184 ]) 185 186 AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [ 187 CC_CHECK_ATTRIBUTE( 188 [visibility_$1], [visibility("$1")], 189 [void __attribute__((visibility("$1"))) $1_function() { }], 190 [$2], [$3]) 191 ]) 192 193 AC_DEFUN([CC_ATTRIBUTE_NONNULL], [ 194 CC_CHECK_ATTRIBUTE( 195 [nonnull], [nonnull()], 196 [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }], 197 [$1], [$2]) 198 ]) 199 200 AC_DEFUN([CC_ATTRIBUTE_UNUSED], [ 201 CC_CHECK_ATTRIBUTE( 202 [unused], , 203 [void some_function(void *foo, __attribute__((unused)) void *bar);], 204 [$1], [$2]) 205 ]) 206 207 AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [ 208 CC_CHECK_ATTRIBUTE( 209 [sentinel], , 210 [void some_function(void *foo, ...) __attribute__((sentinel));], 211 [$1], [$2]) 212 ]) 213 214 AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [ 215 CC_CHECK_ATTRIBUTE( 216 [deprecated], , 217 [void some_function(void *foo, ...) __attribute__((deprecated));], 218 [$1], [$2]) 219 ]) 220 221 AC_DEFUN([CC_ATTRIBUTE_ALIAS], [ 222 CC_CHECK_ATTRIBUTE( 223 [alias], [weak, alias], 224 [void other_function(void *foo) { } 225 void some_function(void *foo) __attribute__((weak, alias("other_function")));], 226 [$1], [$2]) 227 ]) 228 229 AC_DEFUN([CC_ATTRIBUTE_MALLOC], [ 230 CC_CHECK_ATTRIBUTE( 231 [malloc], , 232 [void * __attribute__((malloc)) my_alloc(int n);], 233 [$1], [$2]) 234 ]) 235 236 AC_DEFUN([CC_ATTRIBUTE_PACKED], [ 237 CC_CHECK_ATTRIBUTE( 238 [packed], , 239 [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));], 240 [$1], [$2]) 241 ]) 242 243 AC_DEFUN([CC_ATTRIBUTE_CONST], [ 244 CC_CHECK_ATTRIBUTE( 245 [const], , 246 [int __attribute__((const)) twopow(int n) { return 1 << n; } ], 247 [$1], [$2]) 248 ]) 249 250 AC_DEFUN([CC_FLAG_VISIBILITY], [ 251 AC_REQUIRE([CC_CHECK_WERROR]) 252 AC_CACHE_CHECK([if $CC supports -fvisibility=hidden], 253 [cc_cv_flag_visibility], 254 [cc_flag_visibility_save_CFLAGS="$CFLAGS" 255 CFLAGS="$CFLAGS $cc_cv_werror" 256 CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden], 257 cc_cv_flag_visibility='yes', 258 cc_cv_flag_visibility='no') 259 CFLAGS="$cc_flag_visibility_save_CFLAGS"]) 260 261 AS_IF([test "x$cc_cv_flag_visibility" = "xyes"], 262 [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1, 263 [Define this if the compiler supports the -fvisibility flag]) 264 $1], 265 [$2]) 266 ]) 267 268 AC_DEFUN([CC_FUNC_EXPECT], [ 269 AC_REQUIRE([CC_CHECK_WERROR]) 270 AC_CACHE_CHECK([if compiler has __builtin_expect function], 271 [cc_cv_func_expect], 272 [ac_save_CFLAGS="$CFLAGS" 273 CFLAGS="$CFLAGS $cc_cv_werror" 274 AC_COMPILE_IFELSE( 275 [int some_function() { 276 int a = 3; 277 return (int)__builtin_expect(a, 3); 278 }], 279 [cc_cv_func_expect=yes], 280 [cc_cv_func_expect=no]) 281 CFLAGS="$ac_save_CFLAGS" 282 ]) 283 284 AS_IF([test "x$cc_cv_func_expect" = "xyes"], 285 [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1, 286 [Define this if the compiler supports __builtin_expect() function]) 287 $1], 288 [$2]) 289 ]) 290 291 AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [ 292 AC_REQUIRE([CC_CHECK_WERROR]) 293 AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported], 294 [cc_cv_attribute_aligned], 295 [ac_save_CFLAGS="$CFLAGS" 296 CFLAGS="$CFLAGS $cc_cv_werror" 297 for cc_attribute_align_try in 64 32 16 8 4 2; do 298 AC_COMPILE_IFELSE([ 299 int main() { 300 static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0; 301 return c; 302 }], [cc_cv_attribute_aligned=$cc_attribute_align_try; break]) 303 done 304 CFLAGS="$ac_save_CFLAGS" 305 ]) 306 307 if test "x$cc_cv_attribute_aligned" != "x"; then 308 AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned], 309 [Define the highest alignment supported]) 310 fi 311 ]) 312
