5 files changed, 39 insertions, 3 deletions
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 2af10b22fb..8d56b57c08 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -398,6 +398,10 @@ def err_init_reference_member_uninitialized : Error<
 def note_uninit_reference_member : Note<
   "uninitialized reference member is here">;
 
+// C++0x decltype
+def err_cannot_determine_declared_type_of_overloaded_function : Error<
+    "can't determine the declared type of an overloaded function">;
+    
 // C++0x auto
 def err_auto_variable_cannot_appear_in_own_initializer : Error<
   "variable %0 declared with 'auto' type cannot appear in its own initializer">;
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index a53e420db3..cbd4f58d48 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -406,6 +406,9 @@ public:
 
   QualType getQualifiedNameType(const CXXScopeSpec &SS, QualType T);
 
+  QualType BuildTypeofExprType(Expr *E);
+  QualType BuildDecltypeType(Expr *E);
+  
   //===--------------------------------------------------------------------===//
   // Symbol table / Decl tracking callbacks: SemaDecl.cpp.
   //
diff --git a/lib/Sema/SemaTemplateInstantiate.cpp b/lib/Sema/SemaTemplateInstantiate.cpp
index aed348966a..f05323b511 100644
--- a/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/lib/Sema/SemaTemplateInstantiate.cpp
@@ -530,7 +530,7 @@ TemplateTypeInstantiator::InstantiateTypeOfExprType(
   if (E.isInvalid())
     return QualType();
 
-  return SemaRef.Context.getTypeOfExprType(E.takeAs<Expr>());
+  return SemaRef.BuildTypeofExprType(E.takeAs<Expr>());
 }
 
 QualType 
@@ -555,7 +555,7 @@ TemplateTypeInstantiator::InstantiateDecltypeType(const DecltypeType *T) const {
   if (E.isInvalid())
     return QualType();
   
-  return SemaRef.Context.getDecltypeType(E.takeAs<Expr>());
+  return SemaRef.BuildDecltypeType(E.takeAs<Expr>());
 }
 
 QualType 
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 1c67daece0..c0b4e9fbec 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -242,7 +242,11 @@ QualType Sema::ConvertDeclSpecToType(const DeclSpec &DS,
     Expr *E = static_cast<Expr *>(DS.getTypeRep());
     assert(E && "Didn't get an expression for decltype?");
     // TypeQuals handled by caller.
-    Result = Context.getDecltypeType(E);
+    Result = BuildDecltypeType(E);
+    if (Result.isNull()) {
+      Result = Context.IntTy;
+      isInvalid = true;
+    }
     break;
   }
   case DeclSpec::TST_auto: {
@@ -1463,3 +1467,16 @@ QualType Sema::getQualifiedNameType(const CXXScopeSpec &SS, QualType T) {
     = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
   return Context.getQualifiedNameType(NNS, T);
 }
+
+QualType Sema::BuildTypeofExprType(Expr *E) {
+  return Context.getTypeOfExprType(E);
+}
+
+QualType Sema::BuildDecltypeType(Expr *E) {
+  if (E->getType() == Context.OverloadTy) {
+    Diag(E->getLocStart(), 
+         diag::err_cannot_determine_declared_type_of_overloaded_function);
+    return QualType();
+  }
+  return Context.getDecltypeType(E);
+}
diff --git a/test/SemaCXX/decltype-overloaded-functions.cpp b/test/SemaCXX/decltype-overloaded-functions.cpp
new file mode 100644
index 0000000000..4c5349b858
--- /dev/null
+++ b/test/SemaCXX/decltype-overloaded-functions.cpp
@@ -0,0 +1,12 @@
+// RUN: clang-cc -fsyntax-only -verify %s -std=c++0x
+
+void f();
+void f(int);
+decltype(f) a; // expected-error{{can't determine the declared type of an overloaded function}}
+
+template<typename T> struct S {
+  decltype(T::f) * f; // expected-error{{can't determine the declared type of an overloaded function}}
+};
+
+struct K { void f(); void f(int); };
+S<K> b; // expected-note{{in instantiation of template class 'struct S<struct K>' requested here}}