Index: expat-2.1.0/configure.in
===================================================================
--- expat-2.1.0.orig/configure.in
+++ expat-2.1.0/configure.in
@@ -53,15 +53,19 @@ AC_CONFIG_HEADER(expat_config.h)
 
 sinclude(conftools/ac_c_bigendian_cross.m4)
 
-AC_LIBTOOL_WIN32_DLL
-AC_PROG_LIBTOOL
+sinclude(conftools/visibility.m4)
 
 AC_SUBST(LIBCURRENT)
 AC_SUBST(LIBREVISION)
 AC_SUBST(LIBAGE)
 
 dnl Checks for programs.
-AC_PROG_CC
+AC_PROG_CC_STDC
+AC_USE_SYSTEM_EXTENSIONS
+AC_SYS_LARGEFILE
+gl_VISIBILITY
+AC_LIBTOOL_WIN32_DLL
+AC_PROG_LIBTOOL
 AC_PROG_CXX
 AC_PROG_INSTALL
 
Index: expat-2.1.0/conftools/visibility.m4
===================================================================
--- /dev/null
+++ expat-2.1.0/conftools/visibility.m4
@@ -0,0 +1,77 @@
+# visibility.m4 serial 4 (gettext-0.18.2)
+dnl Copyright (C) 2005, 2008, 2010-2011 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Bruno Haible.
+
+dnl Tests whether the compiler supports the command-line option
+dnl -fvisibility=hidden and the function and variable attributes
+dnl __attribute__((__visibility__("hidden"))) and
+dnl __attribute__((__visibility__("default"))).
+dnl Does *not* test for __visibility__("protected") - which has tricky
+dnl semantics (see the 'vismain' test in glibc) and does not exist e.g. on
+dnl MacOS X.
+dnl Does *not* test for __visibility__("internal") - which has processor
+dnl dependent semantics.
+dnl Does *not* test for #pragma GCC visibility push(hidden) - which is
+dnl "really only recommended for legacy code".
+dnl Set the variable CFLAG_VISIBILITY.
+dnl Defines and sets the variable HAVE_VISIBILITY.
+
+AC_DEFUN([gl_VISIBILITY],
+[
+  AC_REQUIRE([AC_PROG_CC])
+  CFLAG_VISIBILITY=
+  HAVE_VISIBILITY=0
+  if test -n "$GCC"; then
+    dnl First, check whether -Werror can be added to the command line, or
+    dnl whether it leads to an error because of some other option that the
+    dnl user has put into $CC $CFLAGS $CPPFLAGS.
+    AC_MSG_CHECKING([whether the -Werror option is usable])
+    AC_CACHE_VAL([gl_cv_cc_vis_werror], [
+      gl_save_CFLAGS="$CFLAGS"
+      CFLAGS="$CFLAGS -Werror"
+      AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM([[]], [[]])],
+        [gl_cv_cc_vis_werror=yes],
+        [gl_cv_cc_vis_werror=no])
+      CFLAGS="$gl_save_CFLAGS"])
+    AC_MSG_RESULT([$gl_cv_cc_vis_werror])
+    dnl Now check whether visibility declarations are supported.
+    AC_MSG_CHECKING([for simple visibility declarations])
+    AC_CACHE_VAL([gl_cv_cc_visibility], [
+      gl_save_CFLAGS="$CFLAGS"
+      CFLAGS="$CFLAGS -fvisibility=hidden"
+      dnl We use the option -Werror and a function dummyfunc, because on some
+      dnl platforms (Cygwin 1.7) the use of -fvisibility triggers a warning
+      dnl "visibility attribute not supported in this configuration; ignored"
+      dnl at the first function definition in every compilation unit, and we
+      dnl don't want to use the option in this case.
+      if test $gl_cv_cc_vis_werror = yes; then
+        CFLAGS="$CFLAGS -Werror"
+      fi
+      AC_COMPILE_IFELSE(
+        [AC_LANG_PROGRAM(
+           [[extern __attribute__((__visibility__("hidden"))) int hiddenvar;
+             extern __attribute__((__visibility__("default"))) int exportedvar;
+             extern __attribute__((__visibility__("hidden"))) int hiddenfunc (void);
+             extern __attribute__((__visibility__("default"))) int exportedfunc (void);
+             void dummyfunc (void) {}
+           ]],
+           [[]])],
+        [gl_cv_cc_visibility=yes],
+        [gl_cv_cc_visibility=no])
+      CFLAGS="$gl_save_CFLAGS"])
+    AC_MSG_RESULT([$gl_cv_cc_visibility])
+    if test $gl_cv_cc_visibility = yes; then
+      CFLAG_VISIBILITY="-fvisibility=hidden -DXML_HAVE_VISIBILITY=1"
+      HAVE_VISIBILITY=1
+    fi
+  fi
+  AC_SUBST([CFLAG_VISIBILITY])
+  AC_SUBST([HAVE_VISIBILITY])
+  AC_DEFINE_UNQUOTED([HAVE_VISIBILITY], [$HAVE_VISIBILITY],
+    [Define to 1 or 0, depending whether the compiler supports simple visibility declarations.])
+])
Index: expat-2.1.0/lib/expat_external.h
===================================================================
--- expat-2.1.0.orig/lib/expat_external.h
+++ expat-2.1.0/lib/expat_external.h
@@ -65,6 +65,9 @@
 #endif
 #endif  /* not defined XML_STATIC */
 
+#if XML_HAVE_VISIBILITY
+#define XMLIMPORT __attribute__ ((visibility ("default")))
+#endif
 
 /* If we didn't define it above, define it away: */
 #ifndef XMLIMPORT
Index: expat-2.1.0/Makefile.in
===================================================================
--- expat-2.1.0.orig/Makefile.in
+++ expat-2.1.0/Makefile.in
@@ -114,11 +114,12 @@ CPPFLAGS = @CPPFLAGS@ -DHAVE_EXPAT_CONFI
 CFLAGS = @CFLAGS@
 CXXFLAGS = @CXXFLAGS@
 VSNFLAG = -version-info @LIBCURRENT@:@LIBREVISION@:@LIBAGE@
+CFLAG_VISIBILITY=@CFLAG_VISIBILITY@
 
 ### autoconf this?
 LTFLAGS = --silent
 
-COMPILE = $(CC) $(INCLUDES) $(CFLAGS) $(DEFS) $(CPPFLAGS)
+COMPILE = $(CC) $(CFLAG_VISIBILITY) $(INCLUDES) $(CFLAGS) $(DEFS) $(CPPFLAGS)
 CXXCOMPILE = $(CXX) $(INCLUDES) $(CXXFLAGS) $(DEFS) $(CPPFLAGS)
 LTCOMPILE = $(LIBTOOL) $(LTFLAGS) --mode=compile $(COMPILE)
 LINK_LIB = $(LIBTOOL) $(LTFLAGS) --mode=link $(COMPILE) -no-undefined $(VSNFLAG) -rpath $(libdir) $(LDFLAGS) -o $@