When performing unqualified name lookup in C++, don't look directly

into transparent contexts; instead, we'll look into their nearest
enclosing non-transparent contexts further up the stack. Fixes PR5479.

llvm-svn: 90859

clang/lib/Sema/SemaLookup.cpp

@@ -480,7 +480,12 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
       DeclContext *OuterCtx = findOuterContext(S);
       for (; Ctx && Ctx->getPrimaryContext() != OuterCtx; 
            Ctx = Ctx->getLookupParent()) {
-        if (Ctx->isFunctionOrMethod())
+        // We do not directly look into function or method contexts
+        // (since all local variables are found via the identifier
+        // changes) or in transparent contexts (since those entities
+        // will be found in the nearest enclosing non-transparent
+        // context).
+        if (Ctx->isFunctionOrMethod() || Ctx->isTransparentContext())
           continue;
         
         // Perform qualified name lookup into this context.

clang/test/SemaCXX/linkage-spec.cpp

@@ -40,3 +40,17 @@ namespace pr5430 {
 }
 using namespace pr5430;
 extern "C" void pr5430::func(void) { }
+
+// PR5404
+int f2(char *)
+{
+        return 0;
+}
+
+extern "C"
+{
+    int f2(int)
+    {
+        return f2((char *)0);
+    }
+}

clang/test/SemaCXX/using-directive.cpp

@@ -112,3 +112,12 @@ using namespace Alias;
 void testAlias() {
   inAliased();
 }
+
+namespace N { void f2(int); }
+
+extern "C++" {
+  using namespace N;
+  void f3() { f2(1); }
+}
+
+void f4() { f2(1); }