Merge branch 'pull-request/2124'

* pull-request/2124:
  Use AX_CHECK_COMPILE_FLAG macro to check for -fvisibility=hidden

Author: krakjoe

acinclude.m4

@@ -3218,3 +3218,6 @@ AC_DEFUN([PHP_CHECK_BUILTIN_SSUBLL_OVERFLOW], [
    [$have_builtin_ssubll_overflow], [Whether the compiler supports __builtin_ssubll_overflow])
 
 ])
+
+dnl Load the AX_CHECK_COMPILE_FLAG macro from the autoconf archive.
+m4_include([m4/ax_check_compile_flag.m4])

configure.in

@@ -271,20 +271,10 @@ case $host_cpu in
     ;;
 esac
 
-dnl activate some gcc specific optimizations for gcc >= 4
-if test "$GCC" = "yes"; then
-  case $host_alias in
-  *darwin*)
-    GCC_MAJOR_VERSION=`$CC -dumpversion | /usr/bin/sed -nE '1s/([[0-9]]+)\.[[0-9]]+\..*/\1/;1p'`
-    ;;
-  *)
-    GCC_MAJOR_VERSION=`$CC --version | $SED -n '1s/[[^0-9]]*//;1s/\..*//;1p'`
-    ;;
-  esac
-  if test $GCC_MAJOR_VERSION -ge 4; then
-    CFLAGS="$CFLAGS -fvisibility=hidden"
-  fi
-fi
+dnl Mark symbols hidden by default if the compiler (for example, gcc >= 4)
+dnl supports it. This can help reduce the binary size and startup time.
+AX_CHECK_COMPILE_FLAG([-fvisibility=hidden],
+                       [CFLAGS="$CFLAGS -fvisibility=hidden"])
 
 case $host_alias in
   *solaris*)

m4/ax_check_compile_flag.m4

@@ -0,0 +1,74 @@
+# ===========================================================================
+#   http://www.gnu.org/software/autoconf-archive/ax_check_compile_flag.html
+# ===========================================================================
+#
+# SYNOPSIS
+#
+#   AX_CHECK_COMPILE_FLAG(FLAG, [ACTION-SUCCESS], [ACTION-FAILURE], [EXTRA-FLAGS], [INPUT])
+#
+# DESCRIPTION
+#
+#   Check whether the given FLAG works with the current language's compiler
+#   or gives an error.  (Warnings, however, are ignored)
+#
+#   ACTION-SUCCESS/ACTION-FAILURE are shell commands to execute on
+#   success/failure.
+#
+#   If EXTRA-FLAGS is defined, it is added to the current language's default
+#   flags (e.g. CFLAGS) when the check is done.  The check is thus made with
+#   the flags: "CFLAGS EXTRA-FLAGS FLAG".  This can for example be used to
+#   force the compiler to issue an error when a bad flag is given.
+#
+#   INPUT gives an alternative input source to AC_COMPILE_IFELSE.
+#
+#   NOTE: Implementation based on AX_CFLAGS_GCC_OPTION. Please keep this
+#   macro in sync with AX_CHECK_{PREPROC,LINK}_FLAG.
+#
+# LICENSE
+#
+#   Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
+#   Copyright (c) 2011 Maarten Bosmans <mkbosmans@gmail.com>
+#
+#   This program is free software: you can redistribute it and/or modify it
+#   under the terms of the GNU General Public License as published by the
+#   Free Software Foundation, either version 3 of the License, or (at your
+#   option) any later version.
+#
+#   This program is distributed in the hope that it will be useful, but
+#   WITHOUT ANY WARRANTY; without even the implied warranty of
+#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+#   Public License for more details.
+#
+#   You should have received a copy of the GNU General Public License along
+#   with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+#   As a special exception, the respective Autoconf Macro's copyright owner
+#   gives unlimited permission to copy, distribute and modify the configure
+#   scripts that are the output of Autoconf when processing the Macro. You
+#   need not follow the terms of the GNU General Public License when using
+#   or distributing such scripts, even though portions of the text of the
+#   Macro appear in them. The GNU General Public License (GPL) does govern
+#   all other use of the material that constitutes the Autoconf Macro.
+#
+#   This special exception to the GPL applies to versions of the Autoconf
+#   Macro released by the Autoconf Archive. When you make and distribute a
+#   modified version of the Autoconf Macro, you may extend this special
+#   exception to the GPL to apply to your modified version as well.
+
+#serial 4
+
+AC_DEFUN([AX_CHECK_COMPILE_FLAG],
+[AC_PREREQ(2.64)dnl for _AC_LANG_PREFIX and AS_VAR_IF
+AS_VAR_PUSHDEF([CACHEVAR],[ax_cv_check_[]_AC_LANG_ABBREV[]flags_$4_$1])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler accepts $1], CACHEVAR, [
+  ax_check_save_flags=$[]_AC_LANG_PREFIX[]FLAGS
+  _AC_LANG_PREFIX[]FLAGS="$[]_AC_LANG_PREFIX[]FLAGS $4 $1"
+  AC_COMPILE_IFELSE([m4_default([$5],[AC_LANG_PROGRAM()])],
+    [AS_VAR_SET(CACHEVAR,[yes])],
+    [AS_VAR_SET(CACHEVAR,[no])])
+  _AC_LANG_PREFIX[]FLAGS=$ax_check_save_flags])
+AS_VAR_IF(CACHEVAR,yes,
+  [m4_default([$2], :)],
+  [m4_default([$3], :)])
+AS_VAR_POPDEF([CACHEVAR])dnl
+])dnl AX_CHECK_COMPILE_FLAGS