[PATCH] Don't redefine _GLIBCXX_ASSERTIONS if already defined

[Jonathan Wakely]

This avoids a potential redefinition warning if users define both
_GLIBCXX_DEBUG and _GLIBCXX_ASSERTIONS.

        * include/bits/c++config (_GLIBCXX_ASSERTIONS): Avoid redefinition.

Tested powerpc64le-linux, committed to trunk.


commit e6b4586112080ac1912d336451207cba963a2c48
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Fri Jan 6 11:30:25 2017 +0000

    Don't redefine _GLIBCXX_ASSERTIONS if already defined
    
        * include/bits/c++config (_GLIBCXX_ASSERTIONS): Avoid redefinition.

diff --git a/libstdc++-v3/include/bits/c++config 
b/libstdc++-v3/include/bits/c++config
index b2eea3c..0cc1865 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -423,7 +423,7 @@ namespace std
 #endif
 
 // Debug Mode implies checking assertions.
-#ifdef _GLIBCXX_DEBUG
+#if defined(_GLIBCXX_DEBUG) && !defined(_GLIBCXX_ASSERTIONS)
 # define _GLIBCXX_ASSERTIONS 1
 #endif