1 dnl Macros to check the presence of generic (non-typed) symbols. 2 dnl Copyright (c) 2006-2008 Diego Petten <flameeyes (a] gmail.com> 3 dnl Copyright (c) 2006-2008 xine project 4 dnl Copyright (c) 2012 Lucas De Marchi <lucas.de.marchi (a] 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. Note that we invert -Wno-* checks to 38 dnl -W* as gcc cannot test for negated warnings. 39 dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG]) 40 41 AC_DEFUN([CC_CHECK_FLAG_APPEND], [ 42 AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2], 43 AS_TR_SH([cc_cv_$2_$3]), 44 [eval "AS_TR_SH([cc_save_$2])='${$2}'" 45 eval "AS_TR_SH([$2])='-Werror `echo "$3" | sed 's/^-Wno-/-W/'`'" 46 AC_LINK_IFELSE([AC_LANG_SOURCE([int main(void) { return 0; } ])], 47 [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"], 48 [eval "AS_TR_SH([cc_cv_$2_$3])='no'"]) 49 eval "AS_TR_SH([$2])='$cc_save_$2'"]) 50 51 AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes], 52 [eval "$1='${$1} $3'"]) 53 ]) 54 55 dnl CC_CHECK_FLAGS_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG1 FLAG2]) 56 AC_DEFUN([CC_CHECK_FLAGS_APPEND], [ 57 for flag in $3; do 58 CC_CHECK_FLAG_APPEND($1, $2, $flag) 59 done 60 ]) 61 62 dnl Check if the flag is supported by linker (cacheable) 63 dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 64 65 66 dnl Check if the flag is supported by linker 67 dnl CC_CHECK_LDFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 68 AC_DEFUN([CC_CHECK_LDFLAGS_SILENT], [ 69 AC_CACHE_VAL(AS_TR_SH([cc_cv_ldflags_$1]), 70 [ac_save_LDFLAGS="$LDFLAGS" 71 LDFLAGS="$LDFLAGS $1" 72 AC_LINK_IFELSE([AC_LANG_SOURCE([int main() { return 1; }])], 73 [eval "AS_TR_SH([cc_cv_ldflags_$1])='yes'"], 74 [eval "AS_TR_SH([cc_cv_ldflags_$1])="]) 75 LDFLAGS="$ac_save_LDFLAGS" 76 ]) 77 78 AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], 79 [$2], [$3]) 80 ]) 81 82 dnl Check if the flag is supported by linker (cacheable) 83 dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) 84 85 AC_DEFUN([CC_CHECK_LDFLAGS], [ 86 AC_CACHE_CHECK([if $CC supports $1 flag], 87 AS_TR_SH([cc_cv_ldflags_$1]), 88 CC_CHECK_LDFLAGS_SILENT([$1]) dnl Don't execute actions here! 89 ) 90 91 AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], 92 [$2], [$3]) 93 ]) 94 95 dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for 96 dnl the current linker to avoid undefined references in a shared object. 97 AC_DEFUN([CC_NOUNDEFINED], [ 98 dnl We check $host for which systems to enable this for. 99 AC_REQUIRE([AC_CANONICAL_HOST]) 100 101 case $host in 102 dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads 103 dnl are requested, as different implementations are present; to avoid problems 104 dnl use -Wl,-z,defs only for those platform not behaving this way. 105 *-freebsd* | *-openbsd*) ;; 106 *) 107 dnl First of all check for the --no-undefined variant of GNU ld. This allows 108 dnl for a much more readable command line, so that people can understand what 109 dnl it does without going to look for what the heck -z defs does. 110 for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do 111 CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) 112 break 113 done 114 ;; 115 esac 116 117 AC_SUBST([LDFLAGS_NOUNDEFINED]) 118 ]) 119 120 dnl Check for a -Werror flag or equivalent. -Werror is the GCC 121 dnl and ICC flag that tells the compiler to treat all the warnings 122 dnl as fatal. We usually need this option to make sure that some 123 dnl constructs (like attributes) are not simply ignored. 124 dnl 125 dnl Other compilers don't support -Werror per se, but they support 126 dnl an equivalent flag: 127 dnl - Sun Studio compiler supports -errwarn=%all 128 AC_DEFUN([CC_CHECK_WERROR], [ 129 AC_CACHE_CHECK( 130 [for $CC way to treat warnings as errors], 131 [cc_cv_werror], 132 [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror], 133 [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])]) 134 ]) 135 ]) 136 137 AC_DEFUN([CC_CHECK_ATTRIBUTE], [ 138 AC_REQUIRE([CC_CHECK_WERROR]) 139 AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))], 140 AS_TR_SH([cc_cv_attribute_$1]), 141 [ac_save_CFLAGS="$CFLAGS" 142 CFLAGS="$CFLAGS $cc_cv_werror" 143 AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])], 144 [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"], 145 [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"]) 146 CFLAGS="$ac_save_CFLAGS" 147 ]) 148 149 AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes], 150 [AC_DEFINE( 151 AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1, 152 [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))] 153 ) 154 $4], 155 [$5]) 156 ]) 157 158 AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [ 159 CC_CHECK_ATTRIBUTE( 160 [constructor],, 161 [void __attribute__((constructor)) ctor() { int a; }], 162 [$1], [$2]) 163 ]) 164 165 AC_DEFUN([CC_ATTRIBUTE_FORMAT], [ 166 CC_CHECK_ATTRIBUTE( 167 [format], [format(printf, n, n)], 168 [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }], 169 [$1], [$2]) 170 ]) 171 172 AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [ 173 CC_CHECK_ATTRIBUTE( 174 [format_arg], [format_arg(printf)], 175 [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }], 176 [$1], [$2]) 177 ]) 178 179 AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [ 180 CC_CHECK_ATTRIBUTE( 181 [visibility_$1], [visibility("$1")], 182 [void __attribute__((visibility("$1"))) $1_function() { }], 183 [$2], [$3]) 184 ]) 185 186 AC_DEFUN([CC_ATTRIBUTE_NONNULL], [ 187 CC_CHECK_ATTRIBUTE( 188 [nonnull], [nonnull()], 189 [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }], 190 [$1], [$2]) 191 ]) 192 193 AC_DEFUN([CC_ATTRIBUTE_UNUSED], [ 194 CC_CHECK_ATTRIBUTE( 195 [unused], , 196 [void some_function(void *foo, __attribute__((unused)) void *bar);], 197 [$1], [$2]) 198 ]) 199 200 AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [ 201 CC_CHECK_ATTRIBUTE( 202 [sentinel], , 203 [void some_function(void *foo, ...) __attribute__((sentinel));], 204 [$1], [$2]) 205 ]) 206 207 AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [ 208 CC_CHECK_ATTRIBUTE( 209 [deprecated], , 210 [void some_function(void *foo, ...) __attribute__((deprecated));], 211 [$1], [$2]) 212 ]) 213 214 AC_DEFUN([CC_ATTRIBUTE_ALIAS], [ 215 CC_CHECK_ATTRIBUTE( 216 [alias], [weak, alias], 217 [void other_function(void *foo) { } 218 void some_function(void *foo) __attribute__((weak, alias("other_function")));], 219 [$1], [$2]) 220 ]) 221 222 AC_DEFUN([CC_ATTRIBUTE_MALLOC], [ 223 CC_CHECK_ATTRIBUTE( 224 [malloc], , 225 [void * __attribute__((malloc)) my_alloc(int n);], 226 [$1], [$2]) 227 ]) 228 229 AC_DEFUN([CC_ATTRIBUTE_PACKED], [ 230 CC_CHECK_ATTRIBUTE( 231 [packed], , 232 [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));], 233 [$1], [$2]) 234 ]) 235 236 AC_DEFUN([CC_ATTRIBUTE_CONST], [ 237 CC_CHECK_ATTRIBUTE( 238 [const], , 239 [int __attribute__((const)) twopow(int n) { return 1 << n; } ], 240 [$1], [$2]) 241 ]) 242 243 AC_DEFUN([CC_FLAG_VISIBILITY], [ 244 AC_REQUIRE([CC_CHECK_WERROR]) 245 AC_CACHE_CHECK([if $CC supports -fvisibility=hidden], 246 [cc_cv_flag_visibility], 247 [cc_flag_visibility_save_CFLAGS="$CFLAGS" 248 CFLAGS="$CFLAGS $cc_cv_werror" 249 CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden], 250 cc_cv_flag_visibility='yes', 251 cc_cv_flag_visibility='no') 252 CFLAGS="$cc_flag_visibility_save_CFLAGS"]) 253 254 AS_IF([test "x$cc_cv_flag_visibility" = "xyes"], 255 [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1, 256 [Define this if the compiler supports the -fvisibility flag]) 257 $1], 258 [$2]) 259 ]) 260 261 AC_DEFUN([CC_CHECK_FUNC_BUILTIN], [ 262 m4_pushdef([UPNAME], m4_translit([$1], [-a-z], [_A-Z])) 263 AC_CACHE_CHECK([if compiler has $1 builtin function], 264 [cc_cv_have_$1], 265 [AC_LINK_IFELSE([AC_LANG_PROGRAM([], [ 266 m4_case([$1], 267 [__builtin_clz], [$1(0)], 268 [__builtin_types_compatible_p], [$1(int, int)], 269 [__builtin_uaddl_overflow], [$1(0UL, 0UL, (void*)0)], 270 [__builtin_uaddll_overflow], [$1(0ULL, 0ULL, (void*)0)], 271 [__builtin_expect], [$1(0, 0)] 272 )])], 273 [cc_cv_have_$1=yes], 274 [cc_cv_have_$1=no])]) 275 276 AS_IF([test "x$cc_cv_have_$1" = "xyes"], 277 [AC_DEFINE([HAVE_]m4_defn([UPNAME]), 1, [Define to 1 if compiler has $1() builtin function]) 278 $2], 279 [AS_IF([test "x$3" = "x"], [AC_MSG_ERROR([*** builtin function not found: $1()])], 280 [AC_DEFINE([HAVE_]m4_defn([UPNAME]), 0) 281 $3])] 282 ) 283 m4_popdef([UPNAME]) 284 ]) 285 286 AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [ 287 AC_REQUIRE([CC_CHECK_WERROR]) 288 AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported], 289 [cc_cv_attribute_aligned], 290 [ac_save_CFLAGS="$CFLAGS" 291 CFLAGS="$CFLAGS $cc_cv_werror" 292 for cc_attribute_align_try in 64 32 16 8 4 2; do 293 AC_COMPILE_IFELSE([AC_LANG_SOURCE([ 294 int main() { 295 static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0; 296 return c; 297 }])], [cc_cv_attribute_aligned=$cc_attribute_align_try; break]) 298 done 299 CFLAGS="$ac_save_CFLAGS" 300 ]) 301 302 if test "x$cc_cv_attribute_aligned" != "x"; then 303 AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned], 304 [Define the highest alignment supported]) 305 fi 306 ]) 307
