Use lexical contexts when checking for conflicting language linkages.

This fixes pr14958. I will audit other calls to isExternCContext to see
if there are any similar bugs left.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181163 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 10 insertions, 2 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 7b332f9fda..b5e2c6ebe8 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -2247,10 +2247,10 @@ static bool haveIncompatibleLanguageLinkages(const T *Old, const T *New) {
 
   LanguageLinkage OldLinkage = Old->getLanguageLinkage();
   if (OldLinkage == CXXLanguageLinkage &&
-      New->getDeclContext()->isExternCContext())
+      New->getLexicalDeclContext()->isExternCContext())
     return true;
   if (OldLinkage == CLanguageLinkage &&
-      New->getDeclContext()->isExternCXXContext())
+      New->getLexicalDeclContext()->isExternCXXContext())
     return true;
   return false;
 }
diff --git a/test/SemaCXX/linkage-spec.cpp b/test/SemaCXX/linkage-spec.cpp
index 0ba9508124..504df0d35c 100644
--- a/test/SemaCXX/linkage-spec.cpp
+++ b/test/SemaCXX/linkage-spec.cpp
@@ -106,3 +106,11 @@ namespace PR9162 {
     return sizeof(ArtsSink);
   }
 }
+
+namespace pr14958 {
+  namespace js { extern int ObjectClass; }
+  extern "C" {
+    namespace js {}
+  }
+  int js::ObjectClass;
+}