As a result of my recent mangling work, any code that uses variadic
templates will use the forward-compatibility aliases because the
mangling of argument packs has changed. This exposed an issue that we
weren't copying DECL_EXTERNAL from decl to alias along with other
linkage flags in varpool_analyze_pending_decls. Fixed thus. It would
be nice for the front end to fix up the linkage flags appropriately, but
this small change seems preferable for 4.7.
Tested x86_64-pc-linux-gnu. OK for trunk?
commit ef67d3adcc8accbc75acb6b81a28f231aaddfc35
Author: Jason Merrill <ja...@redhat.com>
Date: Fri Jan 20 13:32:39 2012 -0500
PR c++/51832
* varpool.c (varpool_analyze_pending_decls): Copy DECL_EXTERNAL
for extra name aliases.
diff --git a/gcc/testsuite/g++.dg/lto/pr51832.h b/gcc/testsuite/g++.dg/lto/pr51832.h
new file mode 100644
index 0000000..fee3693
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/pr51832.h
@@ -0,0 +1,6 @@
+template<class...T> struct A
+{
+ static int i;
+};
+
+inline void f() { A<int>::i = 0; }
diff --git a/gcc/testsuite/g++.dg/lto/pr51832_0.C b/gcc/testsuite/g++.dg/lto/pr51832_0.C
new file mode 100644
index 0000000..e99cea4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/pr51832_0.C
@@ -0,0 +1,8 @@
+// PR c++/51832
+// { dg-lto-do link }
+// { dg-lto-options { "-std=c++11 -flto -fabi-version=2" } }
+
+#include "pr51832.h"
+
+int main() { }
+
diff --git a/gcc/testsuite/g++.dg/lto/pr51832_1.C b/gcc/testsuite/g++.dg/lto/pr51832_1.C
new file mode 100644
index 0000000..6f0137b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/lto/pr51832_1.C
@@ -0,0 +1 @@
+#include "pr51832.h"
diff --git a/gcc/varpool.c b/gcc/varpool.c
index 74fc1ba..e01accb 100644
--- a/gcc/varpool.c
+++ b/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))
{
