<rdar://problem/13317030> Consider using directives when performing unqualified name lookup into declarations contexts represented by the qualified-id but not in the actual scope hierarchy.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@178136 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 45 insertions, 1 deletions

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index ad5b89a43a..0fe3db1901 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -945,6 +945,21 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
           continue;
         }
 
+        // If this is a file context, we need to perform unqualified name
+        // lookup considering using directives.
+        if (Ctx->isFileContext()) {
+          UnqualUsingDirectiveSet UDirs;
+          UDirs.visit(Ctx, Ctx);
+          UDirs.done();
+
+          if (CppNamespaceLookup(*this, R, Context, Ctx, UDirs)) {
+            R.resolveKind();
+            return true;
+          }
+
+          continue;
+        }
+
         // Perform qualified name lookup into this context.
         // FIXME: In some cases, we know that every name that could be found by
         // this qualified name lookup will also be on the identifier chain. For
@@ -979,7 +994,6 @@ bool Sema::CppLookupName(LookupResult &R, Scope *S) {
   // Unqualified name lookup in C++ requires looking into scopes
   // that aren't strictly lexical, and therefore we walk through the
   // context as well as walking through the scopes.
-
   for (; S; S = S->getParent()) {
     // Check whether the IdResolver has anything in this scope.
     bool Found = false;
diff --git a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
index 4ffe538beb..7da3087e7d 100644
--- a/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
+++ b/test/CXX/basic/basic.lookup/basic.lookup.unqual/p14.cpp
@@ -17,3 +17,33 @@ namespace N {
 int i = 2; 
 N::S N::j = i;
 N::S N::j2(i);
+
+// <rdar://problem/13317030>
+namespace M {
+  class X { };
+  inline X operator-(int, X);
+
+  template<typename T>
+  class Y { };
+
+  typedef Y<float> YFloat;
+
+  namespace yfloat {
+    YFloat operator-(YFloat, YFloat);
+  }
+  using namespace yfloat;
+}
+
+using namespace M;
+
+namespace M {
+
+class Other {
+  void foo(YFloat a, YFloat b);
+};
+
+}
+
+void Other::foo(YFloat a, YFloat b) {
+  YFloat c = a - b;
+}