Implement the same PLT reduction technique used in GTK+:

Thu Sep 16 02:03:15 2004  Matthias Clasen  <maclas@gmx.de>

	Implement the same PLT reduction technique used in GTK+:

configure.in

@@ -149,6 +149,7 @@ case "$host" in
 esac
 AC_MSG_RESULT([$glib_native_win32])
 AM_CONDITIONAL(OS_WIN32, [test "$glib_native_win32" = "yes"])
+AM_CONDITIONAL(OS_UNIX, [test "$glib_native_win32" != "yes"])
 AC_SUBST(G_LIB_WIN32_RESOURCE)
 AC_SUBST(G_MODULE_WIN32_RESOURCE)
 AC_SUBST(G_OBJECT_WIN32_RESOURCE)
@@ -164,6 +165,16 @@ if test "$glib_native_win32" = "yes"; then
 fi
 AM_CONDITIONAL(MS_LIB_AVAILABLE, [test x$ms_librarian = xyes])
 
+if test "$glib_native_win32" != yes; then
+    # libtool option to control which symbols are exported
+    # right now, symbols starting with _ are not exported
+    LIBTOOL_EXPORT_OPTIONS='-export-symbols-regex "^[[^_]].*"'
+else
+    # We currently use .def files on Windows
+    LIBTOOL_EXPORT_OPTIONS=
+fi
+AC_SUBST(LIBTOOL_EXPORT_OPTIONS)
+
 dnl declare --enable-* args and collect ac_help strings
 AC_ARG_ENABLE(debug,
               AC_HELP_STRING([--enable-debug=@<:@no/minimum/yes@:>@],
@@ -191,6 +202,10 @@ AC_ARG_ENABLE(rebuilds,
               [AC_HELP_STRING([--disable-rebuilds],
                               [disable all source autogeneration rules])],,
               [enable_rebuilds=yes])
+AC_ARG_ENABLE(visibility,
+              [AC_HELP_STRING([--disable-visibility],
+                              [don't use ELF visibility attributes])],,
+              [enable_visibility=yes])
 
 if test "x$enable_threads" != "xyes"; then
   enable_threads=no
@@ -275,6 +290,10 @@ else
   fi
 fi
 
+if test "x$enable_visibility" = "xno"; then
+  GLIB_DEBUG_FLAGS="$GLIB_DEBUG_FLAGS -DDISABLE_VISIBILITY"
+fi
+
 # Ensure MSVC-compatible struct packing convention is used when
 # compiling for Win32 with gcc.
 # What flag to depends on gcc version: gcc3 uses "-mms-bitfields", while