1 files changed, 34 insertions, 22 deletions

diff --git a/lib/AST/ASTDiagnostic.cpp b/lib/AST/ASTDiagnostic.cpp
index 23f323d0286a..5bf8a38199b6 100644
--- a/lib/AST/ASTDiagnostic.cpp
+++ b/lib/AST/ASTDiagnostic.cpp
@@ -28,14 +28,26 @@ static QualType Desugar(ASTContext &Context, QualType QT, bool &ShouldAKA) {
     const Type *Ty = QC.strip(QT);
 
     // Don't aka just because we saw an elaborated type...
-    if (isa<ElaboratedType>(Ty)) {
-      QT = cast<ElaboratedType>(Ty)->desugar();
+    if (const ElaboratedType *ET = dyn_cast<ElaboratedType>(Ty)) {
+      QT = ET->desugar();
       continue;
     }
-
-    // ...or a substituted template type parameter.
-    if (isa<SubstTemplateTypeParmType>(Ty)) {
-      QT = cast<SubstTemplateTypeParmType>(Ty)->desugar();
+    // ... or a paren type ...
+    if (const ParenType *PT = dyn_cast<ParenType>(Ty)) {
+      QT = PT->desugar();
+      continue;
+    }
+    // ...or a substituted template type parameter ...
+    if (const SubstTemplateTypeParmType *ST =
+          dyn_cast<SubstTemplateTypeParmType>(Ty)) {
+      QT = ST->desugar();
+      continue;
+    }
+    // ... or an auto type.
+    if (const AutoType *AT = dyn_cast<AutoType>(Ty)) {
+      if (!AT->isSugared())
+        break;
+      QT = AT->desugar();
       continue;
     }
 
@@ -81,10 +93,10 @@ break; \
       break;
 
     // Don't desugar through the primary typedef of an anonymous type.
-    if (isa<TagType>(Underlying) && isa<TypedefType>(QT))
-      if (cast<TagType>(Underlying)->getDecl()->getTypedefForAnonDecl() ==
-          cast<TypedefType>(QT)->getDecl())
-        break;
+    if (const TagType *UTT = Underlying->getAs<TagType>())
+      if (const TypedefType *QTT = dyn_cast<TypedefType>(QT))
+        if (UTT->getDecl()->getTypedefForAnonDecl() == QTT->getDecl())
+          break;
 
     // Record that we actually looked through an opaque type here.
     ShouldAKA = true;
@@ -94,14 +106,17 @@ break; \
   // If we have a pointer-like type, desugar the pointee as well.
   // FIXME: Handle other pointer-like types.
   if (const PointerType *Ty = QT->getAs<PointerType>()) {
-      QT = Context.getPointerType(Desugar(Context, Ty->getPointeeType(),
-                                          ShouldAKA));
+    QT = Context.getPointerType(Desugar(Context, Ty->getPointeeType(),
+                                        ShouldAKA));
   } else if (const LValueReferenceType *Ty = QT->getAs<LValueReferenceType>()) {
-      QT = Context.getLValueReferenceType(Desugar(Context, Ty->getPointeeType(),
-                                                  ShouldAKA));
+    QT = Context.getLValueReferenceType(Desugar(Context, Ty->getPointeeType(),
+                                                ShouldAKA));
+  } else if (const RValueReferenceType *Ty = QT->getAs<RValueReferenceType>()) {
+    QT = Context.getRValueReferenceType(Desugar(Context, Ty->getPointeeType(),
+                                                ShouldAKA));
   }
 
-  return QC.apply(QT);
+  return QC.apply(Context, QT);
 }
 
 /// \brief Convert the given type to a string suitable for printing as part of 
@@ -151,13 +166,10 @@ ConvertTypeToDiagnosticString(ASTContext &Context, QualType Ty,
     bool ShouldAKA = false;
     QualType DesugaredTy = Desugar(Context, Ty, ShouldAKA);
     if (ShouldAKA) {
-      std::string D = DesugaredTy.getAsString(Context.PrintingPolicy);
-      if (D != S) {
-        S = "'" + S + "' (aka '";
-        S += D;
-        S += "')";
-        return S;
-      }
+      S = "'" + S + "' (aka '";
+      S += DesugaredTy.getAsString(Context.PrintingPolicy);
+      S += "')";
+      return S;
     }
   }