diff options
Diffstat (limited to 'm4/attributes.m4')
-rw-r--r-- | m4/attributes.m4 | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/m4/attributes.m4 b/m4/attributes.m4 new file mode 100644 index 0000000000..51ac88be61 --- /dev/null +++ b/m4/attributes.m4 @@ -0,0 +1,292 @@ +dnl Macros to check the presence of generic (non-typed) symbols. +dnl Copyright (c) 2006-2008 Diego Pettenò <flameeyes@gmail.com> +dnl Copyright (c) 2006-2008 xine project +dnl Copyright (c) 2012 Lucas De Marchi <lucas.de.marchi@gmail.com> +dnl +dnl This program is free software; you can redistribute it and/or modify +dnl it under the terms of the GNU General Public License as published by +dnl the Free Software Foundation; either version 2, or (at your option) +dnl any later version. +dnl +dnl This program is distributed in the hope that it will be useful, +dnl but WITHOUT ANY WARRANTY; without even the implied warranty of +dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +dnl GNU General Public License for more details. +dnl +dnl You should have received a copy of the GNU General Public License +dnl along with this program; if not, write to the Free Software +dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +dnl 02110-1301, USA. +dnl +dnl As a special exception, the copyright owners of the +dnl macro gives unlimited permission to copy, distribute and modify the +dnl configure scripts that are the output of Autoconf when processing the +dnl Macro. You need not follow the terms of the GNU General Public +dnl License when using or distributing such scripts, even though portions +dnl of the text of the Macro appear in them. The GNU General Public +dnl License (GPL) does govern all other use of the material that +dnl constitutes the Autoconf Macro. +dnl +dnl This special exception to the GPL applies to versions of the +dnl Autoconf Macro released by this project. When you make and +dnl distribute a modified version of the Autoconf Macro, you may extend +dnl this special exception to the GPL to apply to your modified version as +dnl well. + +dnl Check if FLAG in ENV-VAR is supported by compiler and append it +dnl to WHERE-TO-APPEND variable. Note that we invert -Wno-* checks to +dnl -W* as gcc cannot test for negated warnings. If a C snippet is passed, +dnl use it, otherwise use a simple main() definition that just returns 0. +dnl CC_CHECK_FLAG_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG], [C-SNIPPET]) + +AC_DEFUN([CC_CHECK_FLAG_APPEND], [ + AC_CACHE_CHECK([if $CC supports flag $3 in envvar $2], + AS_TR_SH([cc_cv_$2_$3]), + [eval "AS_TR_SH([cc_save_$2])='${$2}'" + eval "AS_TR_SH([$2])='${cc_save_$2} -Werror `echo "$3" | sed 's/^-Wno-/-W/'`'" + AC_LINK_IFELSE([AC_LANG_SOURCE(ifelse([$4], [], + [int main(void) { return 0; } ], + [$4]))], + [eval "AS_TR_SH([cc_cv_$2_$3])='yes'"], + [eval "AS_TR_SH([cc_cv_$2_$3])='no'"]) + eval "AS_TR_SH([$2])='$cc_save_$2'"]) + + AS_IF([eval test x$]AS_TR_SH([cc_cv_$2_$3])[ = xyes], + [eval "$1='${$1} $3'"]) +]) + +dnl CC_CHECK_FLAGS_APPEND([WHERE-TO-APPEND], [ENV-VAR], [FLAG1 FLAG2], [C-SNIPPET]) +AC_DEFUN([CC_CHECK_FLAGS_APPEND], [ + for flag in [$3]; do + CC_CHECK_FLAG_APPEND([$1], [$2], $flag, [$4]) + done +]) + +dnl Check if the flag is supported by linker (cacheable) +dnl CC_CHECK_LDFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND]) + +AC_DEFUN([CC_CHECK_LDFLAGS], [ + AC_CACHE_CHECK([if $CC supports $1 flag], + AS_TR_SH([cc_cv_ldflags_$1]), + [ac_save_LDFLAGS="$LDFLAGS" + LDFLAGS="$LDFLAGS $1" + AC_LINK_IFELSE([int main() { return 1; }], + [eval "AS_TR_SH([cc_cv_ldflags_$1])='yes'"], + [eval "AS_TR_SH([cc_cv_ldflags_$1])="]) + LDFLAGS="$ac_save_LDFLAGS" + ]) + + AS_IF([eval test x$]AS_TR_SH([cc_cv_ldflags_$1])[ = xyes], + [$2], [$3]) +]) + +dnl define the LDFLAGS_NOUNDEFINED variable with the correct value for +dnl the current linker to avoid undefined references in a shared object. +AC_DEFUN([CC_NOUNDEFINED], [ + dnl We check $host for which systems to enable this for. + AC_REQUIRE([AC_CANONICAL_HOST]) + + case $host in + dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads + dnl are requested, as different implementations are present; to avoid problems + dnl use -Wl,-z,defs only for those platform not behaving this way. + *-freebsd* | *-openbsd*) ;; + *) + dnl First of all check for the --no-undefined variant of GNU ld. This allows + dnl for a much more readable command line, so that people can understand what + dnl it does without going to look for what the heck -z defs does. + for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do + CC_CHECK_LDFLAGS([$possible_flags], [LDFLAGS_NOUNDEFINED="$possible_flags"]) + break + done + ;; + esac + + AC_SUBST([LDFLAGS_NOUNDEFINED]) +]) + +dnl Check for a -Werror flag or equivalent. -Werror is the GCC +dnl and ICC flag that tells the compiler to treat all the warnings +dnl as fatal. We usually need this option to make sure that some +dnl constructs (like attributes) are not simply ignored. +dnl +dnl Other compilers don't support -Werror per se, but they support +dnl an equivalent flag: +dnl - Sun Studio compiler supports -errwarn=%all +AC_DEFUN([CC_CHECK_WERROR], [ + AC_CACHE_CHECK( + [for $CC way to treat warnings as errors], + [cc_cv_werror], + [CC_CHECK_CFLAGS_SILENT([-Werror], [cc_cv_werror=-Werror], + [CC_CHECK_CFLAGS_SILENT([-errwarn=%all], [cc_cv_werror=-errwarn=%all])]) + ]) +]) + +AC_DEFUN([CC_CHECK_ATTRIBUTE], [ + AC_REQUIRE([CC_CHECK_WERROR]) + AC_CACHE_CHECK([if $CC supports __attribute__(( ifelse([$2], , [$1], [$2]) ))], + AS_TR_SH([cc_cv_attribute_$1]), + [ac_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS $cc_cv_werror" + AC_COMPILE_IFELSE([AC_LANG_SOURCE([$3])], + [eval "AS_TR_SH([cc_cv_attribute_$1])='yes'"], + [eval "AS_TR_SH([cc_cv_attribute_$1])='no'"]) + CFLAGS="$ac_save_CFLAGS" + ]) + + AS_IF([eval test x$]AS_TR_SH([cc_cv_attribute_$1])[ = xyes], + [AC_DEFINE( + AS_TR_CPP([SUPPORT_ATTRIBUTE_$1]), 1, + [Define this if the compiler supports __attribute__(( ifelse([$2], , [$1], [$2]) ))] + ) + $4], + [$5]) +]) + +AC_DEFUN([CC_ATTRIBUTE_CONSTRUCTOR], [ + CC_CHECK_ATTRIBUTE( + [constructor],, + [void __attribute__((constructor)) ctor() { int a; }], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_FORMAT], [ + CC_CHECK_ATTRIBUTE( + [format], [format(printf, n, n)], + [void __attribute__((format(printf, 1, 2))) printflike(const char *fmt, ...) { fmt = (void *)0; }], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_FORMAT_ARG], [ + CC_CHECK_ATTRIBUTE( + [format_arg], [format_arg(printf)], + [char *__attribute__((format_arg(1))) gettextlike(const char *fmt) { fmt = (void *)0; }], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_VISIBILITY], [ + CC_CHECK_ATTRIBUTE( + [visibility_$1], [visibility("$1")], + [void __attribute__((visibility("$1"))) $1_function() { }], + [$2], [$3]) +]) + +AC_DEFUN([CC_ATTRIBUTE_NONNULL], [ + CC_CHECK_ATTRIBUTE( + [nonnull], [nonnull()], + [void __attribute__((nonnull())) some_function(void *foo, void *bar) { foo = (void*)0; bar = (void*)0; }], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_UNUSED], [ + CC_CHECK_ATTRIBUTE( + [unused], , + [void some_function(void *foo, __attribute__((unused)) void *bar);], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_SENTINEL], [ + CC_CHECK_ATTRIBUTE( + [sentinel], , + [void some_function(void *foo, ...) __attribute__((sentinel));], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_DEPRECATED], [ + CC_CHECK_ATTRIBUTE( + [deprecated], , + [void some_function(void *foo, ...) __attribute__((deprecated));], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_ALIAS], [ + CC_CHECK_ATTRIBUTE( + [alias], [weak, alias], + [void other_function(void *foo) { } + void some_function(void *foo) __attribute__((weak, alias("other_function")));], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_MALLOC], [ + CC_CHECK_ATTRIBUTE( + [malloc], , + [void * __attribute__((malloc)) my_alloc(int n);], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_PACKED], [ + CC_CHECK_ATTRIBUTE( + [packed], , + [struct astructure { char a; int b; long c; void *d; } __attribute__((packed));], + [$1], [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_CONST], [ + CC_CHECK_ATTRIBUTE( + [const], , + [int __attribute__((const)) twopow(int n) { return 1 << n; } ], + [$1], [$2]) +]) + +AC_DEFUN([CC_FLAG_VISIBILITY], [ + AC_REQUIRE([CC_CHECK_WERROR]) + AC_CACHE_CHECK([if $CC supports -fvisibility=hidden], + [cc_cv_flag_visibility], + [cc_flag_visibility_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS $cc_cv_werror" + CC_CHECK_CFLAGS_SILENT([-fvisibility=hidden], + cc_cv_flag_visibility='yes', + cc_cv_flag_visibility='no') + CFLAGS="$cc_flag_visibility_save_CFLAGS"]) + + AS_IF([test "x$cc_cv_flag_visibility" = "xyes"], + [AC_DEFINE([SUPPORT_FLAG_VISIBILITY], 1, + [Define this if the compiler supports the -fvisibility flag]) + $1], + [$2]) +]) + +AC_DEFUN([CC_FUNC_EXPECT], [ + AC_REQUIRE([CC_CHECK_WERROR]) + AC_CACHE_CHECK([if compiler has __builtin_expect function], + [cc_cv_func_expect], + [ac_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS $cc_cv_werror" + AC_COMPILE_IFELSE([AC_LANG_SOURCE( + [int some_function() { + int a = 3; + return (int)__builtin_expect(a, 3); + }])], + [cc_cv_func_expect=yes], + [cc_cv_func_expect=no]) + CFLAGS="$ac_save_CFLAGS" + ]) + + AS_IF([test "x$cc_cv_func_expect" = "xyes"], + [AC_DEFINE([SUPPORT__BUILTIN_EXPECT], 1, + [Define this if the compiler supports __builtin_expect() function]) + $1], + [$2]) +]) + +AC_DEFUN([CC_ATTRIBUTE_ALIGNED], [ + AC_REQUIRE([CC_CHECK_WERROR]) + AC_CACHE_CHECK([highest __attribute__ ((aligned ())) supported], + [cc_cv_attribute_aligned], + [ac_save_CFLAGS="$CFLAGS" + CFLAGS="$CFLAGS $cc_cv_werror" + for cc_attribute_align_try in 64 32 16 8 4 2; do + AC_COMPILE_IFELSE([AC_LANG_SOURCE([ + int main() { + static char c __attribute__ ((aligned($cc_attribute_align_try))) = 0; + return c; + }])], [cc_cv_attribute_aligned=$cc_attribute_align_try; break]) + done + CFLAGS="$ac_save_CFLAGS" + ]) + + if test "x$cc_cv_attribute_aligned" != "x"; then + AC_DEFINE_UNQUOTED([ATTRIBUTE_ALIGNED_MAX], [$cc_cv_attribute_aligned], + [Define the highest alignment supported]) + fi +]) |