re PR c++/51832 (Rev.182970 causes LTO link errors (multiple definitions of allocator_traits))

	PR c++/51832
	* varpool.c (varpool_analyze_pending_decls): Copy DECL_EXTERNAL
	for extra name aliases.

From-SVN: r183396

gcc/ChangeLog

+2012-01-22  Jason Merrill  <jason@redhat.com>
+
+	PR c++/51832
+	* varpool.c (varpool_analyze_pending_decls): Copy DECL_EXTERNAL
+	for extra name aliases.
+
 2012-01-22  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR rtl-optimization/51924

gcc/testsuite/ChangeLog

+2012-01-22  Jason Merrill  <jason@redhat.com>
+
+	PR c++/51832
+	* g++.dg/lto/pr51832.h: New.
+	* g++.dg/lto/pr51832_0.C: New.
+	* g++.dg/lto/pr51832_1.C: New.
+
 2012-01-22  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gcc.dg/ext-elim-1.c: New test.

gcc/testsuite/g++.dg/lto/pr51832.h

+template<class...T> struct A
+{
+  static int i;
+};
+
+inline void f() { A<int>::i = 0; }

gcc/testsuite/g++.dg/lto/pr51832_0.C

+// PR c++/51832
+// { dg-lto-do link }
+// { dg-lto-options { "-std=c++11 -flto -fabi-version=2" } }
+
+#include "pr51832.h"
+
+int main() { }

gcc/testsuite/g++.dg/lto/pr51832_1.C

+#include "pr51832.h"

gcc/varpool.c

@@ -484,6 +484,7 @@ varpool_analyze_pending_decls (void)
 	    {
 	      DECL_WEAK (node->decl) = DECL_WEAK (node->alias_of);
 	      TREE_PUBLIC (node->decl) = TREE_PUBLIC (node->alias_of);
+	      DECL_EXTERNAL (node->decl) = DECL_EXTERNAL (node->alias_of);
 	      DECL_VISIBILITY (node->decl) = DECL_VISIBILITY (node->alias_of);
 	      if (TREE_PUBLIC (node->decl))
 		{