Fix PR4448.

llvm-svn: 74257

clang/lib/Parse/ParseDeclCXX.cpp

@@ -365,14 +365,12 @@ void Parser::ParseDecltypeSpecifier(DeclSpec &DS) {
   SourceLocation StartLoc = ConsumeToken();
   SourceLocation LParenLoc = Tok.getLocation();
   
-    
   if (ExpectAndConsume(tok::l_paren, diag::err_expected_lparen_after, 
                        "decltype")) {
     SkipUntil(tok::r_paren);
     return;
   }
   
-  
   // Parse the expression
   
   // C++0x [dcl.type.simple]p4:

clang/lib/Sema/SemaTemplateInstantiate.cpp

@@ -560,6 +560,11 @@ TemplateTypeInstantiator::InstantiateTypeOfType(const TypeOfType *T,
 QualType
 TemplateTypeInstantiator::InstantiateDecltypeType(const DecltypeType *T,
                                                   unsigned Quals) const {
+  // C++0x [dcl.type.simple]p4:
+  //   The operand of the decltype specifier is an unevaluated operand.
+  EnterExpressionEvaluationContext Unevaluated(SemaRef,
+                                               Action::Unevaluated);
+  
   Sema::OwningExprResult E 
     = SemaRef.InstantiateExpr(T->getUnderlyingExpr(), TemplateArgs);
 

clang/lib/Sema/SemaTemplateInstantiateExpr.cpp

@@ -119,6 +119,14 @@ TemplateExprInstantiator::VisitDeclRefExpr(DeclRefExpr *E) {
       // FIXME: Clone the expression!
       return SemaRef.Owned(Arg.getAsExpr());
 
+    if (Arg.getKind() == TemplateArgument::Declaration) {
+      ValueDecl *VD = cast<ValueDecl>(Arg.getAsDecl());
+
+      // FIXME: Can VD ever have a dependent type?
+      return SemaRef.BuildDeclRefExpr(VD, VD->getType(), E->getLocation(), 
+                                      false, false);
+    }
+    
     assert(Arg.getKind() == TemplateArgument::Integral);
     QualType T = Arg.getIntegralType();
     if (T->isCharType() || T->isWideCharType())

clang/test/SemaCXX/decltype-pr4448.cpp

@@ -0,0 +1,8 @@
+// RUN: clang-cc -fsyntax-only -verify %s -std=c++0x
+
+template< typename T, T t, decltype(t+2) v >
+struct Convoluted {};
+
+int test_array[5];
+
+Convoluted< int *, test_array, nullptr > tarray;