build: basic autoconfization

1 files changed, 311 insertions, 0 deletions

diff --git a/m4/attributes.m4 b/m4/attributes.m4
new file mode 100644
index 000000000..3bf96a304
--- /dev/null
+++ b/m4/attributes.m4
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+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
+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 the flag is supported by compiler
+dnl CC_CHECK_CFLAGS_SILENT([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
+
+AC_DEFUN([CC_CHECK_CFLAGS_SILENT], [
+  AC_CACHE_VAL(AS_TR_SH([cc_cv_cflags_$1]),
+    [ac_save_CFLAGS="$CFLAGS"
+     CFLAGS="$CFLAGS $1"
+     AC_COMPILE_IFELSE([int a;],
+       [eval "AS_TR_SH([cc_cv_cflags_$1])='yes'"],
+       [eval "AS_TR_SH([cc_cv_cflags_$1])='no'"])
+     CFLAGS="$ac_save_CFLAGS"
+    ])
+
+  AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
+    [$2], [$3])
+])
+
+dnl Check if the flag is supported by compiler (cacheable)
+dnl CC_CHECK_CFLAGS([FLAG], [ACTION-IF-FOUND],[ACTION-IF-NOT-FOUND])
+
+AC_DEFUN([CC_CHECK_CFLAGS], [
+  AC_CACHE_CHECK([if $CC supports $1 flag],
+    AS_TR_SH([cc_cv_cflags_$1]),
+    CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
+  )
+
+  AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
+    [$2], [$3])
+])
+
+dnl CC_CHECK_CFLAG_APPEND(FLAG, [action-if-found], [action-if-not-found])
+dnl Check for CFLAG and appends them to CFLAGS if supported
+AC_DEFUN([CC_CHECK_CFLAG_APPEND], [
+  AC_CACHE_CHECK([if $CC supports $1 flag],
+    AS_TR_SH([cc_cv_cflags_$1]),
+    CC_CHECK_CFLAGS_SILENT([$1]) dnl Don't execute actions here!
+  )
+
+  AS_IF([eval test x$]AS_TR_SH([cc_cv_cflags_$1])[ = xyes],
+    [CFLAGS="$CFLAGS $1"; DEBUG_CFLAGS="$DEBUG_CFLAGS $1"; $2], [$3])
+])
+
+dnl CC_CHECK_CFLAGS_APPEND([FLAG1 FLAG2], [action-if-found], [action-if-not])
+AC_DEFUN([CC_CHECK_CFLAGS_APPEND], [
+  for flag in $1; do
+    CC_CHECK_CFLAG_APPEND($flag, [$2], [$3])
+  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 $host in
+     dnl FreeBSD (et al.) does not complete linking for shared objects when pthreads
+     dnl are requested, as different implementations are present; to avoid problems
+     dnl use -Wl,-z,defs only for those platform not behaving this way.
+     *-freebsd* | *-openbsd*) ;;
+     *)
+        dnl First of all check for the --no-undefined variant of GNU ld. This allows
+        dnl for a much more readable commandline, so that people can understand what
+        dnl it does without going to look for what the heck -z defs does.
+        for possible_flags in "-Wl,--no-undefined" "-Wl,-z,defs"; do
+          CC_CHECK_LDFLAGS([$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([$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 $cc_cv_werror"
+     AC_COMPILE_IFELSE(
+       [int some_function() {
+        int a = 3;
+        return (int)__builtin_expect(a, 3);
+	}],
+       [cc_cv_func_expect=yes],
+       [cc_cv_func_expect=no])
+     CFLAGS="$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 $cc_cv_werror"
+     for cc_attribute_align_try in 64 32 16 8 4 2; do
+        AC_COMPILE_IFELSE([
+          int main() {
+            static char c __attribute__ ((aligned($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
+])