Try to use -fvisibility=hidden on gcc4 and later.

libsdl-org · Jan 5, 2010 · dfe32da · dfe32da
1 parent 8826199
commit dfe32da
Showing 1 changed file with 29 additions and 0 deletions.
diff --git a/configure.in b/configure.in
@@ -144,6 +144,33 @@ $srcdir/music.c"
 dnl set this to use on systems that use lib64 instead of lib
 base_libdir=`echo \${libdir} | sed 's/.*\/\(.*\)/\1/; q'`
 
+dnl See if GCC's -fvisibility=hidden is supported (gcc4 and later, usually).
+dnl  Details of this flag are here: http://gcc.gnu.org/wiki/Visibility
+CheckVisibilityHidden()
+{
+    AC_MSG_CHECKING(for GCC -fvisibility=hidden option)
+    have_gcc_fvisibility=no
+
+    visibility_CFLAGS="-fvisibility=hidden"
+    save_CFLAGS="$CFLAGS"
+    CFLAGS="$save_CFLAGS $visibility_CFLAGS -Werror"
+    AC_TRY_COMPILE([
+    #if !defined(__GNUC__) || __GNUC__ < 4
+    #error SDL only uses visibility attributes in GCC 4 or newer
+    #endif
+    ],[
+    ],[
+    have_gcc_fvisibility=yes
+    ])
+    AC_MSG_RESULT($have_gcc_fvisibility)
+    CFLAGS="$save_CFLAGS"
+
+    if test x$have_gcc_fvisibility = xyes; then
+        EXTRA_CFLAGS="$EXTRA_CFLAGS $visibility_CFLAGS"
+    fi
+}
+
+
 dnl Function to find a library in the compiler search path
 find_lib()
 {
@@ -178,6 +205,8 @@ AC_CHECK_LIB(m, pow, [LIBM="-lm"])
 
 dnl Check command-line options
 
+CheckVisibilityHidden
+
 AC_ARG_ENABLE([music-cmd],
 AC_HELP_STRING([--enable-music-cmd], [support an external music player [[default=yes]]]),
               [], [enable_music_cmd=detect])