Fix implementation of C11 6.2.7/4 and C++11 [dcl.array]p3:

When a local extern declaration redeclares some other entity, the type of that
entity is merged with the prior type if the prior declaration is visible (in C)
or is declared in the same scope (in C++).

 - Make LookupRedeclarationWithLinkage actually work in C++, use it in the right
   set of cases, and make it track whether it found a shadowed declaration.
 - Track whether we found a declaration in the same scope (for C++) including
   across serialization and template instantiation.

llvm-svn: 188307

1 files changed, 15 insertions, 0 deletions

diff --git a/clang/test/PCH/cxx-templates.h b/clang/test/PCH/cxx-templates.h
index ce6b7051ecc..992f478e33e 100644
--- a/clang/test/PCH/cxx-templates.h
+++ b/clang/test/PCH/cxx-templates.h
@@ -296,3 +296,18 @@ namespace cyclic_module_load {
     };
   }
 }
+
+namespace local_extern {
+  template<typename T> int f() {
+    extern int arr[3];
+    {
+      extern T arr;
+      return sizeof(arr);
+    }
+  }
+  template<typename T> int g() {
+    extern int arr[3];
+    extern T arr;
+    return sizeof(arr);
+  }
+}