From eab4a561974eb54796a0a51f11f7167f8d2a7e0c Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Wed, 11 Jan 2006 00:56:49 +0000
Subject: r12836: use: -fvisibility=hidden
 -D_PUBLIC_="__attribute__((visibility(\"default\")))" if the compiler
 supports it, this will cause that modules can only access public functions
 (gcc 4 supports this)

metze
(This used to be commit bcf4c362556b8168fc0b63af5708e4a78c7b93fb)
---
 source4/build/m4/check_cc.m4 | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

(limited to 'source4/build')

diff --git a/source4/build/m4/check_cc.m4 b/source4/build/m4/check_cc.m4
index aa6c8752ed..7551b67b17 100644
--- a/source4/build/m4/check_cc.m4
+++ b/source4/build/m4/check_cc.m4
@@ -116,6 +116,25 @@ AC_TRY_RUN([#include "${srcdir-.}/build/tests/trivial.c"],
 	    AC_MSG_ERROR([cant find test code. Aborting config]),
 	    AC_MSG_WARN([cannot run when cross-compiling]))
 
+#
+# Check if the compiler support ELF visibility for symbols
+#
+if test x"$GCC" = x"yes" ; then
+    AX_CFLAGS_GCC_OPTION([-fvisibility=hidden], VISIBILITY_CFLAGS)
+fi
+if test -n "$VISIBILITY_CFLAGS"; then
+	OLD_CFLAGS="${CFLAGS}"
+	CFLAGS="${CFLAGS} ${VISIBILITY_CFLAGS} -D_PUBLIC_=__attribute__((visibility(\"default\")))"
+	VISIBILITY_CFLAGS="${VISIBILITY_CFLAGS} -D_PUBLIC_=\"__attribute__((visibility(\\\"default\\\")))\""
+	AC_MSG_CHECKING([that the C compiler can use the VISIBILITY_CFLAGS])
+	AC_TRY_RUN([
+		_PUBLIC_ void vis_foo1(void) {}
+		__attribute__((visibility("default"))) void vis_foo2(void) {}
+		#include "${srcdir-.}/build/tests/trivial.c"
+		], AC_MSG_RESULT(yes), [AC_MSG_RESULT(no);VISIBILITY_CFLAGS=""])
+	CFLAGS="${OLD_CFLAGS}"
+fi
+
 #
 # Check if the compiler can handle the options we selected by
 # --enable-*developer
-- 
cgit