[PATCH RFA] libstdc++: avoid __GLIBCXX__ redefinition

[Jason Merrill]

Tested x86_64-pc-linux-gnu, OK for trunk?

-- 8< --

testsuite/lib/dg-options.exp defines __GLIBCXX__ to 9999999; avoid a macro
redefinition warning in that case.

libstdc++-v3/ChangeLog:

	* include/bits/c++config: Avoid redefining __GLIBCXX__.
---
 libstdc++-v3/include/bits/c++config | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libstdc++-v3/include/bits/c++config b/libstdc++-v3/include/bits/c++config
index 0f0cc7cd659..4095ac89741 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -36,7 +36,9 @@
 #define _GLIBCXX_RELEASE
 
 // The datestamp of the C++ library in compressed ISO date format.
+#ifndef __GLIBCXX__ /* The testsuite defines it to 99999999.  */
 #define __GLIBCXX__
+#endif
 
 // Macros for various attributes.
 //   _GLIBCXX_PURE

base-commit: 7f4f1bb29a47fbe63a15dda8acfe247b2e934959
-- 
2.46.0