1dnl Macros to check the presence of generic (non-typed) symbols. 2dnl Copyright (c) 2006-2008 Diego Pettenò <flameeyes@gmail.com> 3dnl Copyright (c) 2006-2008 xine project 4dnl 5dnl This program is free software; you can redistribute it and/or modify 6dnl it under the terms of the GNU General Public License as published by 7dnl the Free Software Foundation; either version 2, or (at your option) 8dnl any later version. 9dnl 10dnl This program is distributed in the hope that it will be useful, 11dnl but WITHOUT ANY WARRANTY; without even the implied warranty of 12dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13dnl GNU General Public License for more details. 14dnl 15dnl You should have received a copy of the GNU General Public License 16dnl along with this program; if not, write to the Free Software 17dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18dnl 02110-1301, USA. 19dnl 20dnl As a special exception, the copyright owners of the 21dnl macro gives unlimited permission to copy, distribute and modify the 22dnl configure scripts that are the output of Autoconf when processing the 23dnl Macro. You need not follow the terms of the GNU General Public 24dnl License when using or distributing such scripts, even though portions 25dnl of the text of the Macro appear in them. The GNU General Public 26dnl License (GPL) does govern all other use of the material that 27dnl constitutes the Autoconf Macro. 28dnl 29dnl This special exception to the GPL applies to versions of the 30dnl Autoconf Macro released by this project. When you make and 31dnl distribute a modified version of the Autoconf Macro, you may extend 32dnl this special exception to the GPL to apply to your modified version as 33dnl well. 34 35dnl Check if the flag is supported by compiler 36dnl CC_CHECK_CFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 37 38AC_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([AC_LANG_SOURCE([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 52dnl Check if the flag is supported by compiler (cacheable) 53dnl CC_CHECK_CFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 54 55AC_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 65dnl CC_CHECK_CFLAG_APPEND(FLAG, [action-if-found], [action-if-not-found]) 66dnl Check for CFLAG and appends them to CFLAGS if supported 67AC_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 $1"; DEBUG_CFLAGS="$DEBUG_CFLAGS $1"; $2], [$3]) 75]) 76 77dnl CC_CHECK_CFLAGS_APPEND([FLAG1 FLAG2], [action-if-found], [action-if-not]) 78AC_DEFUN([CC_CHECK_CFLAGS_APPEND], [ 79 for flag in $1; do 80 CC_CHECK_CFLAG_APPEND($flag, [$2], [$3]) 81 done 82]) 83 84dnl Check if the flag is supported by linker (cacheable) 85dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 86 87AC_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([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" 96 ]) 97 98 AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], 99 [$2], [$3]) 100]) 101 102dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for 103dnl the current linker to avoid undefined references in a shared object. 104AC_DEFUN([CC_NOUNDEFINED], [ 105 dnl We check $host for which systems to enable this for. 106 AC_REQUIRE([AC_CANONICAL_HOST]) 107 108 case $host in 109 dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads 110 dnl are requested, as different implementations are present; to avoid problems 111 dnl use -Wl,-z,defs only for those platform not behaving this way. 112 dnl 113 dnl MinGW platforms: for libraries required -no-undefined, 114 dnl use it only for libraries in mingw32-w64 115 116 *-freebsd* | *-openbsd*) ;; 117 *-mingw*) 118 LDFLAGS_NOUNDEFINED="-no-undefined" 119 ;; 120 *) 121 dnl First of all check for the --no-undefined variant of GNU ld. This allows 122 dnl for a much more readable commandline, so that people can understand what 123 dnl it does without going to look for what the heck -z defs does. 124 for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do 125 CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) 126 if test "x$LDFLAGS_NOUNDEFINED" = "x"; then break; fi 127 done 128 ;; 129 esac 130 131 AC_SUBST([LDFLAGS_NOUNDEFINED]) 132]) 133 134dnl Check for a -Werror flag or equivalent. -Werror is the GCC 135dnl and ICC flag that tells the compiler to treat all the warnings 136dnl as fatal. We usually need this option to make sure that some 137dnl constructs (like attributes) are not simply ignored. 138dnl 139dnl Other compilers don't support -Werror per se, but they support 140dnl an equivalent flag: 141dnl - Sun Studio compiler supports -errwarn=%all 142AC_DEFUN([CC_CHECK_WERROR], [ 143 AC_CACHE_CHECK( 144 [for $CC way to treat warnings as errors], 145 [cc_cv_werror], 146 [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror], 147 [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])]) 148 ]) 149]) 150 151AC_DEFUN([CC_CHECK_ATTRIBUTE], [ 152 AC_REQUIRE([CC_CHECK_WERROR]) 153 AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))], 154 AS_TR_SH([cc_cv_attribute_$1]), 155 [ac_save_CFLAGS="$CFLAGS" 156 CFLAGS="$CFLAGS $cc_cv_werror" 157 AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])], 158 [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"], 159 [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"]) 160 CFLAGS="$ac_save_CFLAGS" 161 ]) 162 163 AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes], 164 [AC_DEFINE( 165 AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1, 166 [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))] 167 ) 168 $4], 169 [$5]) 170]) 171 172AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [ 173 CC_CHECK_ATTRIBUTE( 174 [constructor],, 175 [void __attribute__((constructor)) ctor() { int a; }], 176 [$1], [$2]) 177]) 178 179AC_DEFUN([CC_ATTRIBUTE_FORMAT], [ 180 CC_CHECK_ATTRIBUTE( 181 [format], [format(printf, n, n)], 182 [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }], 183 [$1], [$2]) 184]) 185 186AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [ 187 CC_CHECK_ATTRIBUTE( 188 [format_arg], [format_arg(printf)], 189 [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }], 190 [$1], [$2]) 191]) 192 193AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [ 194 CC_CHECK_ATTRIBUTE( 195 [visibility_$1], [visibility("$1")], 196 [void __attribute__((visibility("$1"))) $1_function() { }], 197 [$2], [$3]) 198]) 199 200AC_DEFUN([CC_ATTRIBUTE_NONNULL], [ 201 CC_CHECK_ATTRIBUTE( 202 [nonnull], [nonnull()], 203 [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }], 204 [$1], [$2]) 205]) 206 207AC_DEFUN([CC_ATTRIBUTE_UNUSED], [ 208 CC_CHECK_ATTRIBUTE( 209 [unused], , 210 [void some_function(void *foo, __attribute__((unused)) void *bar);], 211 [$1], [$2]) 212]) 213 214AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [ 215 CC_CHECK_ATTRIBUTE( 216 [sentinel], , 217 [void some_function(void *foo, ...) __attribute__((sentinel));], 218 [$1], [$2]) 219]) 220 221AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [ 222 CC_CHECK_ATTRIBUTE( 223 [deprecated], , 224 [void some_function(void *foo, ...) __attribute__((deprecated));], 225 [$1], [$2]) 226]) 227 228AC_DEFUN([CC_ATTRIBUTE_ALIAS], [ 229 CC_CHECK_ATTRIBUTE( 230 [alias], [weak, alias], 231 [void other_function(void *foo) { } 232 void some_function(void *foo) __attribute__((weak, alias("other_function")));], 233 [$1], [$2]) 234]) 235 236AC_DEFUN([CC_ATTRIBUTE_MALLOC], [ 237 CC_CHECK_ATTRIBUTE( 238 [malloc], , 239 [void * __attribute__((malloc)) my_alloc(int n);], 240 [$1], [$2]) 241]) 242 243AC_DEFUN([CC_ATTRIBUTE_PACKED], [ 244 CC_CHECK_ATTRIBUTE( 245 [packed], , 246 [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));], 247 [$1], [$2]) 248]) 249 250AC_DEFUN([CC_ATTRIBUTE_CONST], [ 251 CC_CHECK_ATTRIBUTE( 252 [const], , 253 [int __attribute__((const)) twopow(int n) { return 1 << n; } ], 254 [$1], [$2]) 255]) 256 257AC_DEFUN([CC_FLAG_VISIBILITY], [ 258 AC_REQUIRE([CC_CHECK_WERROR]) 259 AC_CACHE_CHECK([if $CC supports -fvisibility=hidden], 260 [cc_cv_flag_visibility], 261 [cc_flag_visibility_save_CFLAGS="$CFLAGS" 262 CFLAGS="$CFLAGS $cc_cv_werror" 263 CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden], 264 cc_cv_flag_visibility='yes', 265 cc_cv_flag_visibility='no') 266 CFLAGS="$cc_flag_visibility_save_CFLAGS"]) 267 268 AS_IF([test "x$cc_cv_flag_visibility" = "xyes"], 269 [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1, 270 [Define this if the compiler supports the -fvisibility flag]) 271 $1], 272 [$2]) 273]) 274 275AC_DEFUN([CC_FUNC_EXPECT], [ 276 AC_REQUIRE([CC_CHECK_WERROR]) 277 AC_CACHE_CHECK([if compiler has __builtin_expect function], 278 [cc_cv_func_expect], 279 [ac_save_CFLAGS="$CFLAGS" 280 CFLAGS="$CFLAGS $cc_cv_werror" 281 AC_COMPILE_IFELSE( 282 [int some_function() { 283 int a = 3; 284 return (int)__builtin_expect(a, 3); 285 }], 286 [cc_cv_func_expect=yes], 287 [cc_cv_func_expect=no]) 288 CFLAGS="$ac_save_CFLAGS" 289 ]) 290 291 AS_IF([test "x$cc_cv_func_expect" = "xyes"], 292 [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1, 293 [Define this if the compiler supports __builtin_expect() function]) 294 $1], 295 [$2]) 296]) 297 298AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [ 299 AC_REQUIRE([CC_CHECK_WERROR]) 300 AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported], 301 [cc_cv_attribute_aligned], 302 [ac_save_CFLAGS="$CFLAGS" 303 CFLAGS="$CFLAGS $cc_cv_werror" 304 for cc_attribute_align_try in 64 32 16 8 4 2; do 305 AC_COMPILE_IFELSE([AC_LANG_SOURCE([ 306 int main() { 307 static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0; 308 return c; 309 }])], [cc_cv_attribute_aligned=$cc_attribute_align_try; break]) 310 done 311 CFLAGS="$ac_save_CFLAGS" 312 ]) 313 314 if test "x$cc_cv_attribute_aligned" != "x"; then 315 AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned], 316 [Define the highest alignment supported]) 317 fi 318]) 319