Individual autoconf function broken out of acincludes.m4. This change
per the recommended style guide for autoconf and so that individual
autoconf functions can more easily be shared across projects.
llvm-svn: 16223
diff --git a/llvm/autoconf/m4/cxx_namespaces.m4 b/llvm/autoconf/m4/cxx_namespaces.m4
new file mode 100644
index 0000000..756e378
--- /dev/null
+++ b/llvm/autoconf/m4/cxx_namespaces.m4
@@ -0,0 +1,18 @@
+# Check for C++ namespace support. This is from
+# http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_namespaces.html
+#
+AC_DEFUN([AC_CXX_NAMESPACES],
+[AC_CACHE_CHECK(whether the compiler implements namespaces,
+ac_cv_cxx_namespaces,
+[AC_LANG_SAVE
+ AC_LANG_CPLUSPLUS
+ AC_TRY_COMPILE([namespace Outer { namespace Inner { int i = 0; }}],
+ [using namespace Outer::Inner; return i;],
+ ac_cv_cxx_namespaces=yes, ac_cv_cxx_namespaces=no)
+ AC_LANG_RESTORE
+])
+if test "$ac_cv_cxx_namespaces" = yes; then
+ AC_DEFINE(HAVE_NAMESPACES,,[define if the compiler implements namespaces])
+fi
+])
+