1 files changed, 733 insertions, 634 deletions
diff --git a/contrib/llvm/tools/clang/lib/AST/ASTDiagnostic.cpp b/contrib/llvm/tools/clang/lib/AST/ASTDiagnostic.cpp
index 0ab1fa7..2ab5a32 100644
--- a/contrib/llvm/tools/clang/lib/AST/ASTDiagnostic.cpp
+++ b/contrib/llvm/tools/clang/lib/AST/ASTDiagnostic.cpp
@@ -473,14 +473,14 @@ class TemplateDiff {
   /// ShowColor - Diagnostics support color, so bolding will be used.
   bool ShowColor;
 
-  /// FromType - When single type printing is selected, this is the type to be
-  /// be printed.  When tree printing is selected, this type will show up first
-  /// in the tree.
-  QualType FromType;
+  /// FromTemplateType - When single type printing is selected, this is the
+  /// type to be be printed.  When tree printing is selected, this type will
+  /// show up first in the tree.
+  QualType FromTemplateType;
 
-  /// ToType - The type that FromType is compared to.  Only in tree printing
-  /// will this type be outputed.
-  QualType ToType;
+  /// ToTemplateType - The type that FromType is compared to.  Only in tree
+  /// printing will this type be outputed.
+  QualType ToTemplateType;
 
   /// OS - The stream used to construct the output strings.
   raw_ostream &OS;
@@ -491,82 +491,70 @@ class TemplateDiff {
   /// DiffTree - A tree representation the differences between two types.
   class DiffTree {
   public:
-    /// DiffKind - The difference in a DiffNode and which fields are used.
+    /// DiffKind - The difference in a DiffNode.  Fields of
+    /// TemplateArgumentInfo needed by each difference can be found in the
+    /// Set* and Get* functions.
     enum DiffKind {
       /// Incomplete or invalid node.
       Invalid,
-      /// Another level of templates, uses TemplateDecl and Qualifiers
+      /// Another level of templates, requires that
       Template,
-      /// Type difference, uses QualType
+      /// Type difference, all type differences except those falling under
+      /// the Template difference.
       Type,
-      /// Expression difference, uses Expr
+      /// Expression difference, this is only when both arguments are
+      /// expressions.  If one argument is an expression and the other is
+      /// Integer or Declaration, then use that diff type instead.
       Expression,
-      /// Template argument difference, uses TemplateDecl
+      /// Template argument difference
       TemplateTemplate,
-      /// Integer difference, uses APSInt and Expr
+      /// Integer difference
       Integer,
-      /// Declaration difference, uses ValueDecl
-      Declaration
+      /// Declaration difference, nullptr arguments are included here
+      Declaration,
+      /// One argument being integer and the other being declaration
+      FromIntegerAndToDeclaration,
+      FromDeclarationAndToInteger
     };
+
   private:
+    /// TemplateArgumentInfo - All the information needed to pretty print
+    /// a template argument.  See the Set* and Get* functions to see which
+    /// fields are used for each DiffKind.
+    struct TemplateArgumentInfo {
+      QualType ArgType;
+      Qualifiers Qual;
+      llvm::APSInt Val;
+      bool IsValidInt = false;
+      Expr *ArgExpr = nullptr;
+      TemplateDecl *TD = nullptr;
+      ValueDecl *VD = nullptr;
+      bool NeedAddressOf = false;
+      bool IsNullPtr = false;
+      bool IsDefault = false;
+    };
+
     /// DiffNode - The root node stores the original type.  Each child node
     /// stores template arguments of their parents.  For templated types, the
     /// template decl is also stored.
     struct DiffNode {
-      DiffKind Kind;
+      DiffKind Kind = Invalid;
 
       /// NextNode - The index of the next sibling node or 0.
-      unsigned NextNode;
+      unsigned NextNode = 0;
 
       /// ChildNode - The index of the first child node or 0.
-      unsigned ChildNode;
+      unsigned ChildNode = 0;
 
       /// ParentNode - The index of the parent node.
-      unsigned ParentNode;
-
-      /// FromType, ToType - The type arguments.
-      QualType FromType, ToType;
-
-      /// FromExpr, ToExpr - The expression arguments.
-      Expr *FromExpr, *ToExpr;
-
-      /// FromNullPtr, ToNullPtr - If the template argument is a nullptr
-      bool FromNullPtr, ToNullPtr;
-
-      /// FromTD, ToTD - The template decl for template template
-      /// arguments or the type arguments that are templates.
-      TemplateDecl *FromTD, *ToTD;
-
-      /// FromQual, ToQual - Qualifiers for template types.
-      Qualifiers FromQual, ToQual;
+      unsigned ParentNode = 0;
 
-      /// FromInt, ToInt - APSInt's for integral arguments.
-      llvm::APSInt FromInt, ToInt;
-
-      /// IsValidFromInt, IsValidToInt - Whether the APSInt's are valid.
-      bool IsValidFromInt, IsValidToInt;
-
-      /// FromValueDecl, ToValueDecl - Whether the argument is a decl.
-      ValueDecl *FromValueDecl, *ToValueDecl;
-
-      /// FromAddressOf, ToAddressOf - Whether the ValueDecl needs an address of
-      /// operator before it.
-      bool FromAddressOf, ToAddressOf;
-
-      /// FromDefault, ToDefault - Whether the argument is a default argument.
-      bool FromDefault, ToDefault;
+      TemplateArgumentInfo FromArgInfo, ToArgInfo;
 
       /// Same - Whether the two arguments evaluate to the same value.
-      bool Same;
-
-      DiffNode(unsigned ParentNode = 0)
-        : Kind(Invalid), NextNode(0), ChildNode(0), ParentNode(ParentNode),
-          FromType(), ToType(), FromExpr(nullptr), ToExpr(nullptr),
-          FromNullPtr(false), ToNullPtr(false),
-          FromTD(nullptr), ToTD(nullptr), IsValidFromInt(false),
-          IsValidToInt(false), FromValueDecl(nullptr), ToValueDecl(nullptr),
-          FromAddressOf(false), ToAddressOf(false), FromDefault(false),
-          ToDefault(false), Same(false) {}
+      bool Same = false;
+
+      DiffNode(unsigned ParentNode = 0) : ParentNode(ParentNode) {}
     };
 
     /// FlatTree - A flattened tree used to store the DiffNodes.
@@ -581,54 +569,127 @@ class TemplateDiff {
 
     /// ReadNode - The index of the current node being read.
     unsigned ReadNode;
-  
+
   public:
     DiffTree() :
         CurrentNode(0), NextFreeNode(1) {
       FlatTree.push_back(DiffNode());
     }
 
-    // Node writing functions.
-    /// SetNode - Sets FromTD and ToTD of the current node.
-    void SetNode(TemplateDecl *FromTD, TemplateDecl *ToTD) {
-      FlatTree[CurrentNode].FromTD = FromTD;
-      FlatTree[CurrentNode].ToTD = ToTD;
+    // Node writing functions, one for each valid DiffKind element.
+    void SetTemplateDiff(TemplateDecl *FromTD, TemplateDecl *ToTD,
+                         Qualifiers FromQual, Qualifiers ToQual,
+                         bool FromDefault, bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = Template;
+      FlatTree[CurrentNode].FromArgInfo.TD = FromTD;
+      FlatTree[CurrentNode].ToArgInfo.TD = ToTD;
+      FlatTree[CurrentNode].FromArgInfo.Qual = FromQual;
+      FlatTree[CurrentNode].ToArgInfo.Qual = ToQual;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetTypeDiff(QualType FromType, QualType ToType, bool FromDefault,
+                     bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = Type;
+      FlatTree[CurrentNode].FromArgInfo.ArgType = FromType;
+      FlatTree[CurrentNode].ToArgInfo.ArgType = ToType;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetExpressionDiff(Expr *FromExpr, Expr *ToExpr, bool FromDefault,
+                           bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = Expression;
+      FlatTree[CurrentNode].FromArgInfo.ArgExpr = FromExpr;
+      FlatTree[CurrentNode].ToArgInfo.ArgExpr = ToExpr;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetTemplateTemplateDiff(TemplateDecl *FromTD, TemplateDecl *ToTD,
+                                 bool FromDefault, bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = TemplateTemplate;
+      FlatTree[CurrentNode].FromArgInfo.TD = FromTD;
+      FlatTree[CurrentNode].ToArgInfo.TD = ToTD;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetIntegerDiff(llvm::APSInt FromInt, llvm::APSInt ToInt,
+                        bool IsValidFromInt, bool IsValidToInt,
+                        QualType FromIntType, QualType ToIntType,
+                        Expr *FromExpr, Expr *ToExpr, bool FromDefault,
+                        bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = Integer;
+      FlatTree[CurrentNode].FromArgInfo.Val = FromInt;
+      FlatTree[CurrentNode].ToArgInfo.Val = ToInt;
+      FlatTree[CurrentNode].FromArgInfo.IsValidInt = IsValidFromInt;
+      FlatTree[CurrentNode].ToArgInfo.IsValidInt = IsValidToInt;
+      FlatTree[CurrentNode].FromArgInfo.ArgType = FromIntType;
+      FlatTree[CurrentNode].ToArgInfo.ArgType = ToIntType;
+      FlatTree[CurrentNode].FromArgInfo.ArgExpr = FromExpr;
+      FlatTree[CurrentNode].ToArgInfo.ArgExpr = ToExpr;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetDeclarationDiff(ValueDecl *FromValueDecl, ValueDecl *ToValueDecl,
+                            bool FromAddressOf, bool ToAddressOf,
+                            bool FromNullPtr, bool ToNullPtr, Expr *FromExpr,
+                            Expr *ToExpr, bool FromDefault, bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = Declaration;
+      FlatTree[CurrentNode].FromArgInfo.VD = FromValueDecl;
+      FlatTree[CurrentNode].ToArgInfo.VD = ToValueDecl;
+      FlatTree[CurrentNode].FromArgInfo.NeedAddressOf = FromAddressOf;
+      FlatTree[CurrentNode].ToArgInfo.NeedAddressOf = ToAddressOf;
+      FlatTree[CurrentNode].FromArgInfo.IsNullPtr = FromNullPtr;
+      FlatTree[CurrentNode].ToArgInfo.IsNullPtr = ToNullPtr;
+      FlatTree[CurrentNode].FromArgInfo.ArgExpr = FromExpr;
+      FlatTree[CurrentNode].ToArgInfo.ArgExpr = ToExpr;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetFromDeclarationAndToIntegerDiff(
+        ValueDecl *FromValueDecl, bool FromAddressOf, bool FromNullPtr,
+        Expr *FromExpr, llvm::APSInt ToInt, bool IsValidToInt,
+        QualType ToIntType, Expr *ToExpr, bool FromDefault, bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = FromDeclarationAndToInteger;
+      FlatTree[CurrentNode].FromArgInfo.VD = FromValueDecl;
+      FlatTree[CurrentNode].FromArgInfo.NeedAddressOf = FromAddressOf;
+      FlatTree[CurrentNode].FromArgInfo.IsNullPtr = FromNullPtr;
+      FlatTree[CurrentNode].FromArgInfo.ArgExpr = FromExpr;
+      FlatTree[CurrentNode].ToArgInfo.Val = ToInt;
+      FlatTree[CurrentNode].ToArgInfo.IsValidInt = IsValidToInt;
+      FlatTree[CurrentNode].ToArgInfo.ArgType = ToIntType;
+      FlatTree[CurrentNode].ToArgInfo.ArgExpr = ToExpr;
+      SetDefault(FromDefault, ToDefault);
+    }
+
+    void SetFromIntegerAndToDeclarationDiff(
+        llvm::APSInt FromInt, bool IsValidFromInt, QualType FromIntType,
+        Expr *FromExpr, ValueDecl *ToValueDecl, bool ToAddressOf,
+        bool ToNullPtr, Expr *ToExpr, bool FromDefault, bool ToDefault) {
+      assert(FlatTree[CurrentNode].Kind == Invalid && "Node is not empty.");
+      FlatTree[CurrentNode].Kind = FromIntegerAndToDeclaration;
+      FlatTree[CurrentNode].FromArgInfo.Val = FromInt;
+      FlatTree[CurrentNode].FromArgInfo.IsValidInt = IsValidFromInt;
+      FlatTree[CurrentNode].FromArgInfo.ArgType = FromIntType;
+      FlatTree[CurrentNode].FromArgInfo.ArgExpr = FromExpr;
+      FlatTree[CurrentNode].ToArgInfo.VD = ToValueDecl;
+      FlatTree[CurrentNode].ToArgInfo.NeedAddressOf = ToAddressOf;
+      FlatTree[CurrentNode].ToArgInfo.IsNullPtr = ToNullPtr;
+      FlatTree[CurrentNode].ToArgInfo.ArgExpr = ToExpr;
+      SetDefault(FromDefault, ToDefault);
     }
 
-    /// SetNode - Sets FromType and ToType of the current node.
-    void SetNode(QualType FromType, QualType ToType) {
-      FlatTree[CurrentNode].FromType = FromType;
-      FlatTree[CurrentNode].ToType = ToType;
-    }
-
-    /// SetNode - Set FromExpr and ToExpr of the current node.
-    void SetNode(Expr *FromExpr, Expr *ToExpr) {
-      FlatTree[CurrentNode].FromExpr = FromExpr;
-      FlatTree[CurrentNode].ToExpr = ToExpr;
-    }
-
-    /// SetNode - Set FromInt and ToInt of the current node.
-    void SetNode(llvm::APSInt FromInt, llvm::APSInt ToInt,
-                 bool IsValidFromInt, bool IsValidToInt) {
-      FlatTree[CurrentNode].FromInt = FromInt;
-      FlatTree[CurrentNode].ToInt = ToInt;
-      FlatTree[CurrentNode].IsValidFromInt = IsValidFromInt;
-      FlatTree[CurrentNode].IsValidToInt = IsValidToInt;
-    }
-
-    /// SetNode - Set FromQual and ToQual of the current node.
-    void SetNode(Qualifiers FromQual, Qualifiers ToQual) {
-      FlatTree[CurrentNode].FromQual = FromQual;
-      FlatTree[CurrentNode].ToQual = ToQual;
-    }
-
-    /// SetNode - Set FromValueDecl and ToValueDecl of the current node.
-    void SetNode(ValueDecl *FromValueDecl, ValueDecl *ToValueDecl,
-                 bool FromAddressOf, bool ToAddressOf) {
-      FlatTree[CurrentNode].FromValueDecl = FromValueDecl;
-      FlatTree[CurrentNode].ToValueDecl = ToValueDecl;
-      FlatTree[CurrentNode].FromAddressOf = FromAddressOf;
-      FlatTree[CurrentNode].ToAddressOf = ToAddressOf;
+    /// SetDefault - Sets FromDefault and ToDefault flags of the current node.
+    void SetDefault(bool FromDefault, bool ToDefault) {
+      assert((!FromDefault || !ToDefault) && "Both arguments cannot be default.");
+      FlatTree[CurrentNode].FromArgInfo.IsDefault = FromDefault;
+      FlatTree[CurrentNode].ToArgInfo.IsDefault = ToDefault;
     }
 
     /// SetSame - Sets the same flag of the current node.
@@ -636,18 +697,6 @@ class TemplateDiff {
       FlatTree[CurrentNode].Same = Same;
     }
 
-    /// SetNullPtr - Sets the NullPtr flags of the current node.
-    void SetNullPtr(bool FromNullPtr, bool ToNullPtr) {
-      FlatTree[CurrentNode].FromNullPtr = FromNullPtr;
-      FlatTree[CurrentNode].ToNullPtr = ToNullPtr;
-    }
-
-    /// SetDefault - Sets FromDefault and ToDefault flags of the current node.
-    void SetDefault(bool FromDefault, bool ToDefault) {
-      FlatTree[CurrentNode].FromDefault = FromDefault;
-      FlatTree[CurrentNode].ToDefault = ToDefault;
-    }
-
     /// SetKind - Sets the current node's type.
     void SetKind(DiffKind Kind) {
       FlatTree[CurrentNode].Kind = Kind;
@@ -655,12 +704,16 @@ class TemplateDiff {
 
     /// Up - Changes the node to the parent of the current node.
     void Up() {
+      assert(FlatTree[CurrentNode].Kind != Invalid &&
+             "Cannot exit node before setting node information.");
       CurrentNode = FlatTree[CurrentNode].ParentNode;
     }
 
     /// AddNode - Adds a child node to the current node, then sets that node
     /// node as the current node.
     void AddNode() {
+      assert(FlatTree[CurrentNode].Kind == Template &&
+             "Only Template nodes can have children nodes.");
       FlatTree.push_back(DiffNode(CurrentNode));
       DiffNode &Node = FlatTree[CurrentNode];
       if (Node.ChildNode == 0) {
@@ -692,46 +745,103 @@ class TemplateDiff {
       ReadNode = FlatTree[ReadNode].ParentNode;
     }
 
-    /// GetNode - Gets the FromType and ToType.
-    void GetNode(QualType &FromType, QualType &ToType) {
-      FromType = FlatTree[ReadNode].FromType;
-      ToType = FlatTree[ReadNode].ToType;
+    void GetTemplateDiff(TemplateDecl *&FromTD, TemplateDecl *&ToTD,
+                         Qualifiers &FromQual, Qualifiers &ToQual) {
+      assert(FlatTree[ReadNode].Kind == Template && "Unexpected kind.");
+      FromTD = FlatTree[ReadNode].FromArgInfo.TD;
+      ToTD = FlatTree[ReadNode].ToArgInfo.TD;
+      FromQual = FlatTree[ReadNode].FromArgInfo.Qual;
+      ToQual = FlatTree[ReadNode].ToArgInfo.Qual;
+    }
+
+    void GetTypeDiff(QualType &FromType, QualType &ToType) {
+      assert(FlatTree[ReadNode].Kind == Type && "Unexpected kind");
+      FromType = FlatTree[ReadNode].FromArgInfo.ArgType;
+      ToType = FlatTree[ReadNode].ToArgInfo.ArgType;
+    }
+
+    void GetExpressionDiff(Expr *&FromExpr, Expr *&ToExpr) {
+      assert(FlatTree[ReadNode].Kind == Expression && "Unexpected kind");
+      FromExpr = FlatTree[ReadNode].FromArgInfo.ArgExpr;
+      ToExpr = FlatTree[ReadNode].ToArgInfo.ArgExpr;
+    }
+
+    void GetTemplateTemplateDiff(TemplateDecl *&FromTD, TemplateDecl *&ToTD) {
+      assert(FlatTree[ReadNode].Kind == TemplateTemplate && "Unexpected kind.");
+      FromTD = FlatTree[ReadNode].FromArgInfo.TD;
+      ToTD = FlatTree[ReadNode].ToArgInfo.TD;
+    }
+
+    void GetIntegerDiff(llvm::APSInt &FromInt, llvm::APSInt &ToInt,
+                        bool &IsValidFromInt, bool &IsValidToInt,
+                        QualType &FromIntType, QualType &ToIntType,
+                        Expr *&FromExpr, Expr *&ToExpr) {
+      assert(FlatTree[ReadNode].Kind == Integer && "Unexpected kind.");
+      FromInt = FlatTree[ReadNode].FromArgInfo.Val;
+      ToInt = FlatTree[ReadNode].ToArgInfo.Val;
+      IsValidFromInt = FlatTree[ReadNode].FromArgInfo.IsValidInt;
+      IsValidToInt = FlatTree[ReadNode].ToArgInfo.IsValidInt;
+      FromIntType = FlatTree[ReadNode].FromArgInfo.ArgType;
+      ToIntType = FlatTree[ReadNode].ToArgInfo.ArgType;
+      FromExpr = FlatTree[ReadNode].FromArgInfo.ArgExpr;
+      ToExpr = FlatTree[ReadNode].ToArgInfo.ArgExpr;
+    }
+
+    void GetDeclarationDiff(ValueDecl *&FromValueDecl, ValueDecl *&ToValueDecl,
+                            bool &FromAddressOf, bool &ToAddressOf,
+                            bool &FromNullPtr, bool &ToNullPtr, Expr *&FromExpr,
+                            Expr *&ToExpr) {
+      assert(FlatTree[ReadNode].Kind == Declaration && "Unexpected kind.");
+      FromValueDecl = FlatTree[ReadNode].FromArgInfo.VD;
+      ToValueDecl = FlatTree[ReadNode].ToArgInfo.VD;
+      FromAddressOf = FlatTree[ReadNode].FromArgInfo.NeedAddressOf;
+      ToAddressOf = FlatTree[ReadNode].ToArgInfo.NeedAddressOf;
+      FromNullPtr = FlatTree[ReadNode].FromArgInfo.IsNullPtr;
+      ToNullPtr = FlatTree[ReadNode].ToArgInfo.IsNullPtr;
+      FromExpr = FlatTree[ReadNode].FromArgInfo.ArgExpr;
+      ToExpr = FlatTree[ReadNode].ToArgInfo.ArgExpr;
+    }
+
+    void GetFromDeclarationAndToIntegerDiff(
+        ValueDecl *&FromValueDecl, bool &FromAddressOf, bool &FromNullPtr,
+        Expr *&FromExpr, llvm::APSInt &ToInt, bool &IsValidToInt,
+        QualType &ToIntType, Expr *&ToExpr) {
+      assert(FlatTree[ReadNode].Kind == FromDeclarationAndToInteger &&
+             "Unexpected kind.");
+      FromValueDecl = FlatTree[ReadNode].FromArgInfo.VD;
+      FromAddressOf = FlatTree[ReadNode].FromArgInfo.NeedAddressOf;
+      FromNullPtr = FlatTree[ReadNode].FromArgInfo.IsNullPtr;
+      FromExpr = FlatTree[ReadNode].FromArgInfo.ArgExpr;
+      ToInt = FlatTree[ReadNode].ToArgInfo.Val;
+      IsValidToInt = FlatTree[ReadNode].ToArgInfo.IsValidInt;
+      ToIntType = FlatTree[ReadNode].ToArgInfo.ArgType;
+      ToExpr = FlatTree[ReadNode].ToArgInfo.ArgExpr;
+    }
+
+    void GetFromIntegerAndToDeclarationDiff(
+        llvm::APSInt &FromInt, bool &IsValidFromInt, QualType &FromIntType,
+        Expr *&FromExpr, ValueDecl *&ToValueDecl, bool &ToAddressOf,
+        bool &ToNullPtr, Expr *&ToExpr) {
+      assert(FlatTree[ReadNode].Kind == FromIntegerAndToDeclaration &&
+             "Unexpected kind.");
+      FromInt = FlatTree[ReadNode].FromArgInfo.Val;
+      IsValidFromInt = FlatTree[ReadNode].FromArgInfo.IsValidInt;
+      FromIntType = FlatTree[ReadNode].FromArgInfo.ArgType;
+      FromExpr = FlatTree[ReadNode].FromArgInfo.ArgExpr;
+      ToValueDecl = FlatTree[ReadNode].ToArgInfo.VD;
+      ToAddressOf = FlatTree[ReadNode].ToArgInfo.NeedAddressOf;
+      ToNullPtr = FlatTree[ReadNode].ToArgInfo.IsNullPtr;
+      ToExpr = FlatTree[ReadNode].ToArgInfo.ArgExpr;
     }
 
-    /// GetNode - Gets the FromExpr and ToExpr.
-    void GetNode(Expr *&FromExpr, Expr *&ToExpr) {
-      FromExpr = FlatTree[ReadNode].FromExpr;
-      ToExpr = FlatTree[ReadNode].ToExpr;
-    }
-
-    /// GetNode - Gets the FromTD and ToTD.
-    void GetNode(TemplateDecl *&FromTD, TemplateDecl *&ToTD) {
-      FromTD = FlatTree[ReadNode].FromTD;
-      ToTD = FlatTree[ReadNode].ToTD;
-    }
-
-    /// GetNode - Gets the FromInt and ToInt.
-    void GetNode(llvm::APSInt &FromInt, llvm::APSInt &ToInt,
-                 bool &IsValidFromInt, bool &IsValidToInt) {
-      FromInt = FlatTree[ReadNode].FromInt;
-      ToInt = FlatTree[ReadNode].ToInt;
-      IsValidFromInt = FlatTree[ReadNode].IsValidFromInt;
-      IsValidToInt = FlatTree[ReadNode].IsValidToInt;
-    }
-
-    /// GetNode - Gets the FromQual and ToQual.
-    void GetNode(Qualifiers &FromQual, Qualifiers &ToQual) {
-      FromQual = FlatTree[ReadNode].FromQual;
-      ToQual = FlatTree[ReadNode].ToQual;
+    /// FromDefault - Return true if the from argument is the default.
+    bool FromDefault() {
+      return FlatTree[ReadNode].FromArgInfo.IsDefault;
     }
 
-    /// GetNode - Gets the FromValueDecl and ToValueDecl.
-    void GetNode(ValueDecl *&FromValueDecl, ValueDecl *&ToValueDecl,
-                 bool &FromAddressOf, bool &ToAddressOf) {
-      FromValueDecl = FlatTree[ReadNode].FromValueDecl;
-      ToValueDecl = FlatTree[ReadNode].ToValueDecl;
-      FromAddressOf = FlatTree[ReadNode].FromAddressOf;
-      ToAddressOf = FlatTree[ReadNode].ToAddressOf;
+    /// ToDefault - Return true if the to argument is the default.
+    bool ToDefault() {
+      return FlatTree[ReadNode].ToArgInfo.IsDefault;
     }
 
     /// NodeIsSame - Returns true the arguments are the same.
@@ -764,26 +874,6 @@ class TemplateDiff {
       return FlatTree[ReadNode].NextNode != 0;
     }
 
-    /// FromNullPtr - Returns true if the from argument is null.
-    bool FromNullPtr() {
-      return FlatTree[ReadNode].FromNullPtr;
-    }
-
-    /// ToNullPtr - Returns true if the to argument is null.
-    bool ToNullPtr() {
-      return FlatTree[ReadNode].ToNullPtr;
-    }
-
-    /// FromDefault - Return true if the from argument is the default.
-    bool FromDefault() {
-      return FlatTree[ReadNode].FromDefault;
-    }
-
-    /// ToDefault - Return true if the to argument is the default.
-    bool ToDefault() {
-      return FlatTree[ReadNode].ToDefault;
-    }
-
     /// Empty - Returns true if the tree has no information.
     bool Empty() {
       return GetKind() == Invalid;
@@ -797,102 +887,128 @@ class TemplateDiff {
 
   DiffTree Tree;
 
-  /// TSTiterator - an iterator that is used to enter a
-  /// TemplateSpecializationType and read TemplateArguments inside template
-  /// parameter packs in order with the rest of the TemplateArguments.
-  struct TSTiterator {
+  /// TSTiterator - a pair of iterators that walks the
+  /// TemplateSpecializationType and the desugared TemplateSpecializationType.
+  /// The deseguared TemplateArgument should provide the canonical argument
+  /// for comparisons.
+  class TSTiterator {
     typedef const TemplateArgument& reference;
     typedef const TemplateArgument* pointer;
 
-    /// TST - the template specialization whose arguments this iterator
-    /// traverse over.
-    const TemplateSpecializationType *TST;
+    /// InternalIterator - an iterator that is used to enter a
+    /// TemplateSpecializationType and read TemplateArguments inside template
+    /// parameter packs in order with the rest of the TemplateArguments.
+    struct InternalIterator {
+      /// TST - the template specialization whose arguments this iterator
+      /// traverse over.
+      const TemplateSpecializationType *TST;
 
-    /// DesugarTST - desugared template specialization used to extract
-    /// default argument information
-    const TemplateSpecializationType *DesugarTST;
+      /// Index - the index of the template argument in TST.
+      unsigned Index;
 
-    /// Index - the index of the template argument in TST.
-    unsigned Index;
+      /// CurrentTA - if CurrentTA is not the same as EndTA, then CurrentTA
+      /// points to a TemplateArgument within a parameter pack.
+      TemplateArgument::pack_iterator CurrentTA;
 
-    /// CurrentTA - if CurrentTA is not the same as EndTA, then CurrentTA
-    /// points to a TemplateArgument within a parameter pack.
-    TemplateArgument::pack_iterator CurrentTA;
+      /// EndTA - the end iterator of a parameter pack
+      TemplateArgument::pack_iterator EndTA;
 
-    /// EndTA - the end iterator of a parameter pack
-    TemplateArgument::pack_iterator EndTA;
+      /// InternalIterator - Constructs an iterator and sets it to the first
+      /// template argument.
+      InternalIterator(const TemplateSpecializationType *TST)
+          : TST(TST), Index(0), CurrentTA(nullptr), EndTA(nullptr) {
+        if (isEnd()) return;
 
-    /// TSTiterator - Constructs an iterator and sets it to the first template
-    /// argument.
-    TSTiterator(ASTContext &Context, const TemplateSpecializationType *TST)
-        : TST(TST),
-          DesugarTST(GetTemplateSpecializationType(Context, TST->desugar())),
-          Index(0), CurrentTA(nullptr), EndTA(nullptr) {
-      if (isEnd()) return;
+        // Set to first template argument.  If not a parameter pack, done.
+        TemplateArgument TA = TST->getArg(0);
+        if (TA.getKind() != TemplateArgument::Pack) return;
 
-      // Set to first template argument.  If not a parameter pack, done.
-      TemplateArgument TA = TST->getArg(0);
-      if (TA.getKind() != TemplateArgument::Pack) return;
+        // Start looking into the parameter pack.
+        CurrentTA = TA.pack_begin();
+        EndTA = TA.pack_end();
 
-      // Start looking into the parameter pack.
-      CurrentTA = TA.pack_begin();
-      EndTA = TA.pack_end();
+        // Found a valid template argument.
+        if (CurrentTA != EndTA) return;
 
-      // Found a valid template argument.
-      if (CurrentTA != EndTA) return;
+        // Parameter pack is empty, use the increment to get to a valid
+        // template argument.
+        ++(*this);
+      }
 
-      // Parameter pack is empty, use the increment to get to a valid
-      // template argument.
-      ++(*this);
-    }
+      /// isEnd - Returns true if the iterator is one past the end.
+      bool isEnd() const {
+        return Index >= TST->getNumArgs();
+      }
 
-    /// isEnd - Returns true if the iterator is one past the end.
-    bool isEnd() const {
-      return Index >= TST->getNumArgs();
-    }
+      /// &operator++ - Increment the iterator to the next template argument.
+      InternalIterator &operator++() {
+        if (isEnd()) {
+          return *this;
+        }
 
-    /// &operator++ - Increment the iterator to the next template argument.
-    TSTiterator &operator++() {
-      // After the end, Index should be the default argument position in
-      // DesugarTST, if it exists.
-      if (isEnd()) {
-        ++Index;
+        // If in a parameter pack, advance in the parameter pack.
+        if (CurrentTA != EndTA) {
+          ++CurrentTA;
+          if (CurrentTA != EndTA)
+            return *this;
+        }
+
+        // Loop until a template argument is found, or the end is reached.
+        while (true) {
+          // Advance to the next template argument.  Break if reached the end.
+          if (++Index == TST->getNumArgs())
+            break;
+
+          // If the TemplateArgument is not a parameter pack, done.
+          TemplateArgument TA = TST->getArg(Index);
+          if (TA.getKind() != TemplateArgument::Pack)
+            break;
+
+          // Handle parameter packs.
+          CurrentTA = TA.pack_begin();
+          EndTA = TA.pack_end();
+
+          // If the parameter pack is empty, try to advance again.
+          if (CurrentTA != EndTA)
+            break;
+        }
         return *this;
       }
 
-      // If in a parameter pack, advance in the parameter pack.
-      if (CurrentTA != EndTA) {
-        ++CurrentTA;
-        if (CurrentTA != EndTA)
-          return *this;
+      /// operator* - Returns the appropriate TemplateArgument.
+      reference operator*() const {
+        assert(!isEnd() && "Index exceeds number of arguments.");
+        if (CurrentTA == EndTA)
+          return TST->getArg(Index);
+        else
+          return *CurrentTA;
       }
 
-      // Loop until a template argument is found, or the end is reached.
-      while (true) {
-        // Advance to the next template argument.  Break if reached the end.
-        if (++Index == TST->getNumArgs()) break;
+      /// operator-> - Allow access to the underlying TemplateArgument.
+      pointer operator->() const {
+        return &operator*();
+      }
+    };
 
-        // If the TemplateArgument is not a parameter pack, done.
-        TemplateArgument TA = TST->getArg(Index);
-        if (TA.getKind() != TemplateArgument::Pack) break;
+    InternalIterator SugaredIterator;
+    InternalIterator DesugaredIterator;
 
-        // Handle parameter packs.
-        CurrentTA = TA.pack_begin();
-        EndTA = TA.pack_end();
+  public:
+    TSTiterator(ASTContext &Context, const TemplateSpecializationType *TST)
+        : SugaredIterator(TST),
+          DesugaredIterator(
+              GetTemplateSpecializationType(Context, TST->desugar())) {}
 
-        // If the parameter pack is empty, try to advance again.
-        if (CurrentTA != EndTA) break;
-      }
+    /// &operator++ - Increment the iterator to the next template argument.
+    TSTiterator &operator++() {
+      ++SugaredIterator;
+      ++DesugaredIterator;
       return *this;
     }
 
     /// operator* - Returns the appropriate TemplateArgument.
     reference operator*() const {
-      assert(!isEnd() && "Index exceeds number of arguments.");
-      if (CurrentTA == EndTA)
-        return TST->getArg(Index);
-      else
-        return *CurrentTA;
+      return *SugaredIterator;
     }
 
     /// operator-> - Allow access to the underlying TemplateArgument.
@@ -900,16 +1016,27 @@ class TemplateDiff {
       return &operator*();
     }
 
-    /// getDesugar - Returns the deduced template argument from DesguarTST
-    reference getDesugar() const {
-      return DesugarTST->getArg(Index);
+    /// isEnd - Returns true if no more TemplateArguments are available.
+    bool isEnd() const {
+      return SugaredIterator.isEnd();
+    }
+
+    /// hasDesugaredTA - Returns true if there is another TemplateArgument
+    /// available.
+    bool hasDesugaredTA() const {
+      return !DesugaredIterator.isEnd();
+    }
+
+    /// getDesugaredTA - Returns the desugared TemplateArgument.
+    reference getDesugaredTA() const {
+      return *DesugaredIterator;
     }
   };
 
   // These functions build up the template diff tree, including functions to
-  // retrieve and compare template arguments. 
+  // retrieve and compare template arguments.
 
-  static const TemplateSpecializationType * GetTemplateSpecializationType(
+  static const TemplateSpecializationType *GetTemplateSpecializationType(
       ASTContext &Context, QualType Ty) {
     if (const TemplateSpecializationType *TST =
             Ty->getAs<TemplateSpecializationType>())
@@ -935,108 +1062,136 @@ class TemplateDiff {
     return Ty->getAs<TemplateSpecializationType>();
   }
 
-  /// DiffTypes - Fills a DiffNode with information about a type difference.
-  void DiffTypes(const TSTiterator &FromIter, const TSTiterator &ToIter,
-                 TemplateTypeParmDecl *FromDefaultTypeDecl,
-                 TemplateTypeParmDecl *ToDefaultTypeDecl) {
-    QualType FromType = GetType(FromIter, FromDefaultTypeDecl);
-    QualType ToType = GetType(ToIter, ToDefaultTypeDecl);
-
-    Tree.SetNode(FromType, ToType);
-    Tree.SetDefault(FromIter.isEnd() && !FromType.isNull(),
-                    ToIter.isEnd() && !ToType.isNull());
-    Tree.SetKind(DiffTree::Type);
+  /// Returns true if the DiffType is Type and false for Template.
+  static bool OnlyPerformTypeDiff(ASTContext &Context, QualType FromType,
+                                  QualType ToType,
+                                  const TemplateSpecializationType *&FromArgTST,
+                                  const TemplateSpecializationType *&ToArgTST) {
     if (FromType.isNull() || ToType.isNull())
-      return;
+      return true;
 
-    if (Context.hasSameType(FromType, ToType)) {
-      Tree.SetSame(true);
-      return;
-    }
+    if (Context.hasSameType(FromType, ToType))
+      return true;
 
-    const TemplateSpecializationType *FromArgTST =
-        GetTemplateSpecializationType(Context, FromType);
-    if (!FromArgTST)
-      return;
+    FromArgTST = GetTemplateSpecializationType(Context, FromType);
+    ToArgTST = GetTemplateSpecializationType(Context, ToType);
 
-    const TemplateSpecializationType *ToArgTST =
-        GetTemplateSpecializationType(Context, ToType);
-    if (!ToArgTST)
-      return;
+    if (!FromArgTST || !ToArgTST)
+      return true;
 
     if (!hasSameTemplate(FromArgTST, ToArgTST))
-      return;
+      return true;
 
-    Qualifiers FromQual = FromType.getQualifiers(),
-               ToQual = ToType.getQualifiers();
-    FromQual -= QualType(FromArgTST, 0).getQualifiers();
-    ToQual -= QualType(ToArgTST, 0).getQualifiers();
-    Tree.SetNode(FromArgTST->getTemplateName().getAsTemplateDecl(),
-                 ToArgTST->getTemplateName().getAsTemplateDecl());
-    Tree.SetNode(FromQual, ToQual);
-    Tree.SetKind(DiffTree::Template);
-    DiffTemplate(FromArgTST, ToArgTST);
+    return false;
+  }
+
+  /// DiffTypes - Fills a DiffNode with information about a type difference.
+  void DiffTypes(const TSTiterator &FromIter, const TSTiterator &ToIter) {
+    QualType FromType = GetType(FromIter);
+    QualType ToType = GetType(ToIter);
+
+    bool FromDefault = FromIter.isEnd() && !FromType.isNull();
+    bool ToDefault = ToIter.isEnd() && !ToType.isNull();
+
+    const TemplateSpecializationType *FromArgTST = nullptr;
+    const TemplateSpecializationType *ToArgTST = nullptr;
+    if (OnlyPerformTypeDiff(Context, FromType, ToType, FromArgTST, ToArgTST)) {
+      Tree.SetTypeDiff(FromType, ToType, FromDefault, ToDefault);
+      Tree.SetSame(!FromType.isNull() && !ToType.isNull() &&
+                   Context.hasSameType(FromType, ToType));
+    } else {
+      assert(FromArgTST && ToArgTST &&
+             "Both template specializations need to be valid.");
+      Qualifiers FromQual = FromType.getQualifiers(),
+                 ToQual = ToType.getQualifiers();
+      FromQual -= QualType(FromArgTST, 0).getQualifiers();
+      ToQual -= QualType(ToArgTST, 0).getQualifiers();
+      Tree.SetTemplateDiff(FromArgTST->getTemplateName().getAsTemplateDecl(),
+                           ToArgTST->getTemplateName().getAsTemplateDecl(),
+                           FromQual, ToQual, FromDefault, ToDefault);
+      DiffTemplate(FromArgTST, ToArgTST);
+    }
   }
 
   /// DiffTemplateTemplates - Fills a DiffNode with information about a
   /// template template difference.
   void DiffTemplateTemplates(const TSTiterator &FromIter,
-                             const TSTiterator &ToIter,
-                             TemplateTemplateParmDecl *FromDefaultTemplateDecl,
-                             TemplateTemplateParmDecl *ToDefaultTemplateDecl) {
-    TemplateDecl *FromDecl = GetTemplateDecl(FromIter, FromDefaultTemplateDecl);
-    TemplateDecl *ToDecl = GetTemplateDecl(ToIter, ToDefaultTemplateDecl);
-    Tree.SetNode(FromDecl, ToDecl);
+                             const TSTiterator &ToIter) {
+    TemplateDecl *FromDecl = GetTemplateDecl(FromIter);
+    TemplateDecl *ToDecl = GetTemplateDecl(ToIter);
+    Tree.SetTemplateTemplateDiff(FromDecl, ToDecl, FromIter.isEnd() && FromDecl,
+                                 ToIter.isEnd() && ToDecl);
     Tree.SetSame(FromDecl && ToDecl &&
                  FromDecl->getCanonicalDecl() == ToDecl->getCanonicalDecl());
-    Tree.SetDefault(FromIter.isEnd() && FromDecl, ToIter.isEnd() && ToDecl);
-    Tree.SetKind(DiffTree::TemplateTemplate);
   }
 
   /// InitializeNonTypeDiffVariables - Helper function for DiffNonTypes
-  static void InitializeNonTypeDiffVariables(
-      ASTContext &Context, const TSTiterator &Iter,
-      NonTypeTemplateParmDecl *Default, bool &HasInt, bool &HasValueDecl,
-      bool &IsNullPtr, Expr *&E, llvm::APSInt &Value, ValueDecl *&VD) {
-    HasInt = !Iter.isEnd() && Iter->getKind() == TemplateArgument::Integral;
-
-    HasValueDecl =
-        !Iter.isEnd() && Iter->getKind() == TemplateArgument::Declaration;
-
-    IsNullPtr = !Iter.isEnd() && Iter->getKind() == TemplateArgument::NullPtr;
-
-    if (HasInt)
-      Value = Iter->getAsIntegral();
-    else if (HasValueDecl)
-      VD = Iter->getAsDecl();
-    else if (!IsNullPtr)
-      E = GetExpr(Iter, Default);
-
-    if (E && Default->getType()->isPointerType())
-      IsNullPtr = CheckForNullPtr(Context, E);
-  }
-
-  /// NeedsAddressOf - Helper function for DiffNonTypes.  Returns true if the
-  /// ValueDecl needs a '&' when printed.
-  static bool NeedsAddressOf(ValueDecl *VD, Expr *E,
-                             NonTypeTemplateParmDecl *Default) {
-    if (!VD)
-      return false;
-
-    if (E) {
-      if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens())) {
-        if (UO->getOpcode() == UO_AddrOf) {
-          return true;
+  static void InitializeNonTypeDiffVariables(ASTContext &Context,
+                                             const TSTiterator &Iter,
+                                             NonTypeTemplateParmDecl *Default,
+                                             llvm::APSInt &Value, bool &HasInt,
+                                             QualType &IntType, bool &IsNullPtr,
+                                             Expr *&E, ValueDecl *&VD,
+                                             bool &NeedAddressOf) {
+    if (!Iter.isEnd()) {
+      switch (Iter->getKind()) {
+        default:
+          llvm_unreachable("unknown ArgumentKind");
+        case TemplateArgument::Integral:
+          Value = Iter->getAsIntegral();
+          HasInt = true;
+          IntType = Iter->getIntegralType();
+          return;
+        case TemplateArgument::Declaration: {
+          VD = Iter->getAsDecl();
+          QualType ArgType = Iter->getParamTypeForDecl();
+          QualType VDType = VD->getType();
+          if (ArgType->isPointerType() &&
+              Context.hasSameType(ArgType->getPointeeType(), VDType))
+            NeedAddressOf = true;
+          return;
         }
+        case TemplateArgument::NullPtr:
+          IsNullPtr = true;
+          return;
+        case TemplateArgument::Expression:
+          E = Iter->getAsExpr();
       }
-      return false;
+    } else if (!Default->isParameterPack()) {
+      E = Default->getDefaultArgument();
     }
 
-    if (!Default->getType()->isReferenceType()) {
-      return true;
-    }
+    if (!Iter.hasDesugaredTA()) return;
 
-    return false;
+    const TemplateArgument& TA = Iter.getDesugaredTA();
+    switch (TA.getKind()) {
+      default:
+        llvm_unreachable("unknown ArgumentKind");
+      case TemplateArgument::Integral:
+        Value = TA.getAsIntegral();
+        HasInt = true;
+        IntType = TA.getIntegralType();
+        return;
+      case TemplateArgument::Declaration: {
+        VD = TA.getAsDecl();
+        QualType ArgType = TA.getParamTypeForDecl();
+        QualType VDType = VD->getType();
+        if (ArgType->isPointerType() &&
+            Context.hasSameType(ArgType->getPointeeType(), VDType))
+          NeedAddressOf = true;
+        return;
+      }
+      case TemplateArgument::NullPtr:
+        IsNullPtr = true;
+        return;
+      case TemplateArgument::Expression:
+        // TODO: Sometimes, the desugared template argument Expr differs from
+        // the sugared template argument Expr.  It may be useful in the future
+        // but for now, it is just discarded.
+        if (!E)
+          E = TA.getAsExpr();
+        return;
+    }
   }
 
   /// DiffNonTypes - Handles any template parameters not handled by DiffTypes
@@ -1046,85 +1201,68 @@ class TemplateDiff {
                     NonTypeTemplateParmDecl *ToDefaultNonTypeDecl) {
     Expr *FromExpr = nullptr, *ToExpr = nullptr;
     llvm::APSInt FromInt, ToInt;
+    QualType FromIntType, ToIntType;
     ValueDecl *FromValueDecl = nullptr, *ToValueDecl = nullptr;
-    bool HasFromInt = false, HasToInt = false, HasFromValueDecl = false,
-         HasToValueDecl = false, FromNullPtr = false, ToNullPtr = false;
-    InitializeNonTypeDiffVariables(Context, FromIter, FromDefaultNonTypeDecl,
-                                     HasFromInt, HasFromValueDecl, FromNullPtr,
-                                     FromExpr, FromInt, FromValueDecl);
-    InitializeNonTypeDiffVariables(Context, ToIter, ToDefaultNonTypeDecl,
-                                     HasToInt, HasToValueDecl, ToNullPtr,
-                                     ToExpr, ToInt, ToValueDecl);
-
-    assert(((!HasFromInt && !HasToInt) ||
-            (!HasFromValueDecl && !HasToValueDecl)) &&
-           "Template argument cannot be both integer and declaration");
-
-    if (!HasFromInt && !HasToInt && !HasFromValueDecl && !HasToValueDecl) {
-      Tree.SetNode(FromExpr, ToExpr);
-      Tree.SetDefault(FromIter.isEnd() && FromExpr, ToIter.isEnd() && ToExpr);
-      if (FromDefaultNonTypeDecl->getType()->isIntegralOrEnumerationType()) {
-        if (FromExpr)
-          HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt,
-                              FromDefaultNonTypeDecl->getType());
-        if (ToExpr)
-          HasToInt = GetInt(Context, ToIter, ToExpr, ToInt,
-                            ToDefaultNonTypeDecl->getType());
-      }
-      if (HasFromInt && HasToInt) {
-        Tree.SetNode(FromInt, ToInt, HasFromInt, HasToInt);
-        Tree.SetSame(FromInt == ToInt);
-        Tree.SetKind(DiffTree::Integer);
-      } else if (HasFromInt || HasToInt) {
-        Tree.SetNode(FromInt, ToInt, HasFromInt, HasToInt);
-        Tree.SetSame(false);
-        Tree.SetKind(DiffTree::Integer);
-      } else {
-        Tree.SetSame(IsEqualExpr(Context, FromExpr, ToExpr) ||
-                     (FromNullPtr && ToNullPtr));
-        Tree.SetNullPtr(FromNullPtr, ToNullPtr);
-        Tree.SetKind(DiffTree::Expression);
-      }
+    bool HasFromInt = false, HasToInt = false, FromNullPtr = false,
+         ToNullPtr = false, NeedFromAddressOf = false, NeedToAddressOf = false;
+    InitializeNonTypeDiffVariables(
+        Context, FromIter, FromDefaultNonTypeDecl, FromInt, HasFromInt,
+        FromIntType, FromNullPtr, FromExpr, FromValueDecl, NeedFromAddressOf);
+    InitializeNonTypeDiffVariables(Context, ToIter, ToDefaultNonTypeDecl, ToInt,
+                                   HasToInt, ToIntType, ToNullPtr, ToExpr,
+                                   ToValueDecl, NeedToAddressOf);
+
+    bool FromDefault = FromIter.isEnd() &&
+                       (FromExpr || FromValueDecl || HasFromInt || FromNullPtr);
+    bool ToDefault = ToIter.isEnd() &&
+                     (ToExpr || ToValueDecl || HasToInt || ToNullPtr);
+
+    bool FromDeclaration = FromValueDecl || FromNullPtr;
+    bool ToDeclaration = ToValueDecl || ToNullPtr;
+
+    if (FromDeclaration && HasToInt) {
+      Tree.SetFromDeclarationAndToIntegerDiff(
+          FromValueDecl, NeedFromAddressOf, FromNullPtr, FromExpr, ToInt,
+          HasToInt, ToIntType, ToExpr, FromDefault, ToDefault);
+      Tree.SetSame(false);
+      return;
+
+    }
+
+    if (HasFromInt && ToDeclaration) {
+      Tree.SetFromIntegerAndToDeclarationDiff(
+          FromInt, HasFromInt, FromIntType, FromExpr, ToValueDecl,
+          NeedToAddressOf, ToNullPtr, ToExpr, FromDefault, ToDefault);
+      Tree.SetSame(false);
       return;
     }
 
     if (HasFromInt || HasToInt) {
-      if (!HasFromInt && FromExpr)
-        HasFromInt = GetInt(Context, FromIter, FromExpr, FromInt,
-                            FromDefaultNonTypeDecl->getType());
-      if (!HasToInt && ToExpr)
-        HasToInt = GetInt(Context, ToIter, ToExpr, ToInt,
-                          ToDefaultNonTypeDecl->getType());
-      Tree.SetNode(FromInt, ToInt, HasFromInt, HasToInt);
+      Tree.SetIntegerDiff(FromInt, ToInt, HasFromInt, HasToInt, FromIntType,
+                          ToIntType, FromExpr, ToExpr, FromDefault, ToDefault);
       if (HasFromInt && HasToInt) {
-        Tree.SetSame(FromInt == ToInt);
-      } else {
-        Tree.SetSame(false);
+        Tree.SetSame(Context.hasSameType(FromIntType, ToIntType) &&
+                     FromInt == ToInt);
       }
-      Tree.SetDefault(FromIter.isEnd() && HasFromInt,
-                      ToIter.isEnd() && HasToInt);
-      Tree.SetKind(DiffTree::Integer);
       return;
     }
 
-    if (!HasFromValueDecl && FromExpr)
-      FromValueDecl = GetValueDecl(FromIter, FromExpr);
-    if (!HasToValueDecl && ToExpr)
-      ToValueDecl = GetValueDecl(ToIter, ToExpr);
-
-    bool FromAddressOf =
-        NeedsAddressOf(FromValueDecl, FromExpr, FromDefaultNonTypeDecl);
-    bool ToAddressOf =
-        NeedsAddressOf(ToValueDecl, ToExpr, ToDefaultNonTypeDecl);
-
-    Tree.SetNullPtr(FromNullPtr, ToNullPtr);
-    Tree.SetNode(FromValueDecl, ToValueDecl, FromAddressOf, ToAddressOf);
-    Tree.SetSame(FromValueDecl && ToValueDecl &&
-                 FromValueDecl->getCanonicalDecl() ==
-                     ToValueDecl->getCanonicalDecl());
-    Tree.SetDefault(FromIter.isEnd() && FromValueDecl,
-                    ToIter.isEnd() && ToValueDecl);
-    Tree.SetKind(DiffTree::Declaration);
+    if (FromDeclaration || ToDeclaration) {
+      Tree.SetDeclarationDiff(FromValueDecl, ToValueDecl, NeedFromAddressOf,
+                              NeedToAddressOf, FromNullPtr, ToNullPtr, FromExpr,
+                              ToExpr, FromDefault, ToDefault);
+      bool BothNull = FromNullPtr && ToNullPtr;
+      bool SameValueDecl =
+          FromValueDecl && ToValueDecl &&
+          NeedFromAddressOf == NeedToAddressOf &&
+          FromValueDecl->getCanonicalDecl() == ToValueDecl->getCanonicalDecl();
+      Tree.SetSame(BothNull || SameValueDecl);
+      return;
+    }
+
+    assert((FromExpr || ToExpr) && "Both template arguments cannot be empty.");
+    Tree.SetExpressionDiff(FromExpr, ToExpr, FromDefault, ToDefault);
+    Tree.SetSame(IsEqualExpr(Context, FromExpr, ToExpr));
   }
 
   /// DiffTemplate - recursively visits template arguments and stores the
@@ -1149,28 +1287,23 @@ class TemplateDiff {
       NamedDecl *FromParamND = ParamsFrom->getParam(FromParamIndex);
       NamedDecl *ToParamND = ParamsTo->getParam(ToParamIndex);
 
-      TemplateTypeParmDecl *FromDefaultTypeDecl =
-          dyn_cast<TemplateTypeParmDecl>(FromParamND);
-      TemplateTypeParmDecl *ToDefaultTypeDecl =
-          dyn_cast<TemplateTypeParmDecl>(ToParamND);
-      if (FromDefaultTypeDecl && ToDefaultTypeDecl)
-        DiffTypes(FromIter, ToIter, FromDefaultTypeDecl, ToDefaultTypeDecl);
-
-      TemplateTemplateParmDecl *FromDefaultTemplateDecl =
-          dyn_cast<TemplateTemplateParmDecl>(FromParamND);
-      TemplateTemplateParmDecl *ToDefaultTemplateDecl =
-          dyn_cast<TemplateTemplateParmDecl>(ToParamND);
-      if (FromDefaultTemplateDecl && ToDefaultTemplateDecl)
-        DiffTemplateTemplates(FromIter, ToIter, FromDefaultTemplateDecl,
-                              ToDefaultTemplateDecl);
-
-      NonTypeTemplateParmDecl *FromDefaultNonTypeDecl =
-          dyn_cast<NonTypeTemplateParmDecl>(FromParamND);
-      NonTypeTemplateParmDecl *ToDefaultNonTypeDecl =
-          dyn_cast<NonTypeTemplateParmDecl>(ToParamND);
-      if (FromDefaultNonTypeDecl && ToDefaultNonTypeDecl)
+      assert(FromParamND->getKind() == ToParamND->getKind() &&
+             "Parameter Decl are not the same kind.");
+
+      if (isa<TemplateTypeParmDecl>(FromParamND)) {
+        DiffTypes(FromIter, ToIter);
+      } else if (isa<TemplateTemplateParmDecl>(FromParamND)) {
+        DiffTemplateTemplates(FromIter, ToIter);
+      } else if (isa<NonTypeTemplateParmDecl>(FromParamND)) {
+        NonTypeTemplateParmDecl *FromDefaultNonTypeDecl =
+            cast<NonTypeTemplateParmDecl>(FromParamND);
+        NonTypeTemplateParmDecl *ToDefaultNonTypeDecl =
+            cast<NonTypeTemplateParmDecl>(ToParamND);
         DiffNonTypes(FromIter, ToIter, FromDefaultNonTypeDecl,
                      ToDefaultNonTypeDecl);
+      } else {
+        llvm_unreachable("Unexpected Decl type.");
+      }
 
       ++FromIter;
       ++ToIter;
@@ -1239,140 +1372,27 @@ class TemplateDiff {
 
   /// GetType - Retrieves the template type arguments, including default
   /// arguments.
-  static QualType GetType(const TSTiterator &Iter,
-                          TemplateTypeParmDecl *DefaultTTPD) {
-    bool isVariadic = DefaultTTPD->isParameterPack();
-
+  static QualType GetType(const TSTiterator &Iter) {
     if (!Iter.isEnd())
       return Iter->getAsType();
-    if (isVariadic)
-      return QualType();
-
-    QualType ArgType = DefaultTTPD->getDefaultArgument();
-    if (ArgType->isDependentType())
-      return Iter.getDesugar().getAsType();
-
-    return ArgType;
-  }
-
-  /// GetExpr - Retrieves the template expression argument, including default
-  /// arguments.
-  static Expr *GetExpr(const TSTiterator &Iter,
-                       NonTypeTemplateParmDecl *DefaultNTTPD) {
-    Expr *ArgExpr = nullptr;
-    bool isVariadic = DefaultNTTPD->isParameterPack();
-
-    if (!Iter.isEnd())
-      ArgExpr = Iter->getAsExpr();
-    else if (!isVariadic)
-      ArgExpr = DefaultNTTPD->getDefaultArgument();
-
-    if (ArgExpr)
-      while (SubstNonTypeTemplateParmExpr *SNTTPE =
-                 dyn_cast<SubstNonTypeTemplateParmExpr>(ArgExpr))
-        ArgExpr = SNTTPE->getReplacement();
-
-    return ArgExpr;
-  }
-
-  /// GetInt - Retrieves the template integer argument, including evaluating
-  /// default arguments.  If the value comes from an expression, extend the
-  /// APSInt to size of IntegerType to match the behavior in
-  /// Sema::CheckTemplateArgument
-  static bool GetInt(ASTContext &Context, const TSTiterator &Iter,
-                     Expr *ArgExpr, llvm::APSInt &Int, QualType IntegerType) {
-    // Default, value-depenedent expressions require fetching
-    // from the desugared TemplateArgument, otherwise expression needs to
-    // be evaluatable.
-    if (Iter.isEnd() && ArgExpr->isValueDependent()) {
-      switch (Iter.getDesugar().getKind()) {
-        case TemplateArgument::Integral:
-          Int = Iter.getDesugar().getAsIntegral();
-          return true;
-        case TemplateArgument::Expression:
-          ArgExpr = Iter.getDesugar().getAsExpr();
-          Int = ArgExpr->EvaluateKnownConstInt(Context);
-          Int = Int.extOrTrunc(Context.getTypeSize(IntegerType));
-          return true;
-        default:
-          llvm_unreachable("Unexpected template argument kind");
-      }
-    } else if (ArgExpr->isEvaluatable(Context)) {
-      Int = ArgExpr->EvaluateKnownConstInt(Context);
-      Int = Int.extOrTrunc(Context.getTypeSize(IntegerType));
-      return true;
-    }
-
-    return false;
-  }
-
-  /// GetValueDecl - Retrieves the template Decl argument, including
-  /// default expression argument.
-  static ValueDecl *GetValueDecl(const TSTiterator &Iter, Expr *ArgExpr) {
-    // Default, value-depenedent expressions require fetching
-    // from the desugared TemplateArgument
-    if (Iter.isEnd() && ArgExpr->isValueDependent())
-      switch (Iter.getDesugar().getKind()) {
-        case TemplateArgument::Declaration:
-          return Iter.getDesugar().getAsDecl();
-        case TemplateArgument::Expression:
-          ArgExpr = Iter.getDesugar().getAsExpr();
-          return cast<DeclRefExpr>(ArgExpr)->getDecl();
-        default:
-          llvm_unreachable("Unexpected template argument kind");
-      }
-    DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr);
-    if (!DRE) {
-      UnaryOperator *UO = dyn_cast<UnaryOperator>(ArgExpr->IgnoreParens());
-      if (!UO)
-        return nullptr;
-      DRE = cast<DeclRefExpr>(UO->getSubExpr());
-    }
-
-    return DRE->getDecl();
-  }
-
-  /// CheckForNullPtr - returns true if the expression can be evaluated as
-  /// a null pointer
-  static bool CheckForNullPtr(ASTContext &Context, Expr *E) {
-    assert(E && "Expected expression");
-
-    E = E->IgnoreParenCasts();
-    if (E->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull))
-      return true;
-
-    DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E);
-    if (!DRE)
-      return false;
-
-    VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl());
-    if (!VD || !VD->hasInit())
-      return false;
-
-    return VD->getInit()->IgnoreParenCasts()->isNullPointerConstant(
-        Context, Expr::NPC_ValueDependentIsNull);
+    if (Iter.hasDesugaredTA())
+      return Iter.getDesugaredTA().getAsType();
+    return QualType();
   }
 
   /// GetTemplateDecl - Retrieves the template template arguments, including
   /// default arguments.
-  static TemplateDecl *GetTemplateDecl(const TSTiterator &Iter,
-                                TemplateTemplateParmDecl *DefaultTTPD) {
-    bool isVariadic = DefaultTTPD->isParameterPack();
-
-    TemplateArgument TA = DefaultTTPD->getDefaultArgument().getArgument();
-    TemplateDecl *DefaultTD = nullptr;
-    if (TA.getKind() != TemplateArgument::Null)
-      DefaultTD = TA.getAsTemplate().getAsTemplateDecl();
-
+  static TemplateDecl *GetTemplateDecl(const TSTiterator &Iter) {
     if (!Iter.isEnd())
       return Iter->getAsTemplate().getAsTemplateDecl();
-    if (!isVariadic)
-      return DefaultTD;
-
+    if (Iter.hasDesugaredTA())
+      return Iter.getDesugaredTA().getAsTemplate().getAsTemplateDecl();
     return nullptr;
   }
 
-  /// IsEqualExpr - Returns true if the expressions evaluate to the same value.
+  /// IsEqualExpr - Returns true if the expressions are the same in regards to
+  /// template arguments.  These expressions are dependent, so profile them
+  /// instead of trying to evaluate them.
   static bool IsEqualExpr(ASTContext &Context, Expr *FromExpr, Expr *ToExpr) {
     if (FromExpr == ToExpr)
       return true;
@@ -1380,47 +1400,10 @@ class TemplateDiff {
     if (!FromExpr || !ToExpr)
       return false;
 
-    DeclRefExpr *FromDRE = dyn_cast<DeclRefExpr>(FromExpr->IgnoreParens()),
-                *ToDRE = dyn_cast<DeclRefExpr>(ToExpr->IgnoreParens());
-
-    if (FromDRE || ToDRE) {
-      if (!FromDRE || !ToDRE)
-        return false;
-      return FromDRE->getDecl() == ToDRE->getDecl();
-    }
-
-    Expr::EvalResult FromResult, ToResult;
-    if (!FromExpr->EvaluateAsRValue(FromResult, Context) ||
-        !ToExpr->EvaluateAsRValue(ToResult, Context)) {
-      llvm::FoldingSetNodeID FromID, ToID;
-      FromExpr->Profile(FromID, Context, true);
-      ToExpr->Profile(ToID, Context, true);
-      return FromID == ToID;
-    }
-
-    APValue &FromVal = FromResult.Val;
-    APValue &ToVal = ToResult.Val;
-
-    if (FromVal.getKind() != ToVal.getKind()) return false;
-
-    switch (FromVal.getKind()) {
-      case APValue::Int:
-        return FromVal.getInt() == ToVal.getInt();
-      case APValue::LValue: {
-        APValue::LValueBase FromBase = FromVal.getLValueBase();
-        APValue::LValueBase ToBase = ToVal.getLValueBase();
-        if (FromBase.isNull() && ToBase.isNull())
-          return true;
-        if (FromBase.isNull() || ToBase.isNull())
-          return false;
-        return FromBase.get<const ValueDecl*>() ==
-               ToBase.get<const ValueDecl*>();
-      }
-      case APValue::MemberPointer:
-        return FromVal.getMemberPointerDecl() == ToVal.getMemberPointerDecl();
-      default:
-        llvm_unreachable("Unknown template argument expression.");
-    }
+    llvm::FoldingSetNodeID FromID, ToID;
+    FromExpr->Profile(FromID, Context, true);
+    ToExpr->Profile(ToID, Context, true);
+    return FromID == ToID;
   }
 
   // These functions converts the tree representation of the template
@@ -1442,21 +1425,21 @@ class TemplateDiff {
         llvm_unreachable("Template diffing failed with bad DiffNode");
       case DiffTree::Type: {
         QualType FromType, ToType;
-        Tree.GetNode(FromType, ToType);
+        Tree.GetTypeDiff(FromType, ToType);
         PrintTypeNames(FromType, ToType, Tree.FromDefault(), Tree.ToDefault(),
                        Tree.NodeIsSame());
         return;
       }
       case DiffTree::Expression: {
         Expr *FromExpr, *ToExpr;
-        Tree.GetNode(FromExpr, ToExpr);
-        PrintExpr(FromExpr, ToExpr, Tree.FromNullPtr(), Tree.ToNullPtr(),
-                  Tree.FromDefault(), Tree.ToDefault(), Tree.NodeIsSame());
+        Tree.GetExpressionDiff(FromExpr, ToExpr);
+        PrintExpr(FromExpr, ToExpr, Tree.FromDefault(), Tree.ToDefault(),
+                  Tree.NodeIsSame());
         return;
       }
       case DiffTree::TemplateTemplate: {
         TemplateDecl *FromTD, *ToTD;
-        Tree.GetNode(FromTD, ToTD);
+        Tree.GetTemplateTemplateDiff(FromTD, ToTD);
         PrintTemplateTemplate(FromTD, ToTD, Tree.FromDefault(),
                               Tree.ToDefault(), Tree.NodeIsSame());
         return;
@@ -1465,26 +1448,70 @@ class TemplateDiff {
         llvm::APSInt FromInt, ToInt;
         Expr *FromExpr, *ToExpr;
         bool IsValidFromInt, IsValidToInt;
-        Tree.GetNode(FromExpr, ToExpr);
-        Tree.GetNode(FromInt, ToInt, IsValidFromInt, IsValidToInt);
-        PrintAPSInt(FromInt, ToInt, IsValidFromInt, IsValidToInt,
-                    FromExpr, ToExpr, Tree.FromDefault(), Tree.ToDefault(),
-                    Tree.NodeIsSame());
+        QualType FromIntType, ToIntType;
+        Tree.GetIntegerDiff(FromInt, ToInt, IsValidFromInt, IsValidToInt,
+                            FromIntType, ToIntType, FromExpr, ToExpr);
+        PrintAPSInt(FromInt, ToInt, IsValidFromInt, IsValidToInt, FromIntType,
+                    ToIntType, FromExpr, ToExpr, Tree.FromDefault(),
+                    Tree.ToDefault(), Tree.NodeIsSame());
         return;
       }
       case DiffTree::Declaration: {
         ValueDecl *FromValueDecl, *ToValueDecl;
         bool FromAddressOf, ToAddressOf;
-        Tree.GetNode(FromValueDecl, ToValueDecl, FromAddressOf, ToAddressOf);
+        bool FromNullPtr, ToNullPtr;
+        Expr *FromExpr, *ToExpr;
+        Tree.GetDeclarationDiff(FromValueDecl, ToValueDecl, FromAddressOf,
+                                ToAddressOf, FromNullPtr, ToNullPtr, FromExpr,
+                                ToExpr);
         PrintValueDecl(FromValueDecl, ToValueDecl, FromAddressOf, ToAddressOf,
-                       Tree.FromNullPtr(), Tree.ToNullPtr(), Tree.FromDefault(),
-                       Tree.ToDefault(), Tree.NodeIsSame());
+                       FromNullPtr, ToNullPtr, FromExpr, ToExpr,
+                       Tree.FromDefault(), Tree.ToDefault(), Tree.NodeIsSame());
+        return;
+      }
+      case DiffTree::FromDeclarationAndToInteger: {
+        ValueDecl *FromValueDecl;
+        bool FromAddressOf;
+        bool FromNullPtr;
+        Expr *FromExpr;
+        llvm::APSInt ToInt;
+        bool IsValidToInt;
+        QualType ToIntType;
+        Expr *ToExpr;
+        Tree.GetFromDeclarationAndToIntegerDiff(
+            FromValueDecl, FromAddressOf, FromNullPtr, FromExpr, ToInt,
+            IsValidToInt, ToIntType, ToExpr);
+        assert((FromValueDecl || FromNullPtr) && IsValidToInt);
+        PrintValueDeclAndInteger(FromValueDecl, FromAddressOf, FromNullPtr,
+                                 FromExpr, Tree.FromDefault(), ToInt, ToIntType,
+                                 ToExpr, Tree.ToDefault());
+        return;
+      }
+      case DiffTree::FromIntegerAndToDeclaration: {
+        llvm::APSInt FromInt;
+        bool IsValidFromInt;
+        QualType FromIntType;
+        Expr *FromExpr;
+        ValueDecl *ToValueDecl;
+        bool ToAddressOf;
+        bool ToNullPtr;
+        Expr *ToExpr;
+        Tree.GetFromIntegerAndToDeclarationDiff(
+            FromInt, IsValidFromInt, FromIntType, FromExpr, ToValueDecl,
+            ToAddressOf, ToNullPtr, ToExpr);
+        assert(IsValidFromInt && (ToValueDecl || ToNullPtr));
+        PrintIntegerAndValueDecl(FromInt, FromIntType, FromExpr,
+                                 Tree.FromDefault(), ToValueDecl, ToAddressOf,
+                                 ToNullPtr, ToExpr, Tree.ToDefault());
         return;
       }
       case DiffTree::Template: {
         // Node is root of template.  Recurse on children.
         TemplateDecl *FromTD, *ToTD;
-        Tree.GetNode(FromTD, ToTD);
+        Qualifiers FromQual, ToQual;
+        Tree.GetTemplateDiff(FromTD, ToTD, FromQual, ToQual);
+
+        PrintQualifiers(FromQual, ToQual);
 
         if (!Tree.HasChildren()) {
           // If we're dealing with a template specialization with zero
@@ -1493,11 +1520,7 @@ class TemplateDiff {
           return;
         }
 
-        Qualifiers FromQual, ToQual;
-        Tree.GetNode(FromQual, ToQual);
-        PrintQualifiers(FromQual, ToQual);
-
-        OS << FromTD->getNameAsString() << '<'; 
+        OS << FromTD->getNameAsString() << '<';
         Tree.MoveToChild();
         unsigned NumElideArgs = 0;
         do {
@@ -1604,40 +1627,36 @@ class TemplateDiff {
 
   /// PrintExpr - Prints out the expr template arguments, highlighting argument
   /// differences.
-  void PrintExpr(const Expr *FromExpr, const Expr *ToExpr, bool FromNullPtr,
-                 bool ToNullPtr, bool FromDefault, bool ToDefault, bool Same) {
+  void PrintExpr(const Expr *FromExpr, const Expr *ToExpr, bool FromDefault,
+                 bool ToDefault, bool Same) {
     assert((FromExpr || ToExpr) &&
             "Only one template argument may be missing.");
     if (Same) {
-      PrintExpr(FromExpr, FromNullPtr);
+      PrintExpr(FromExpr);
     } else if (!PrintTree) {
       OS << (FromDefault ? "(default) " : "");
       Bold();
-      PrintExpr(FromExpr, FromNullPtr);
+      PrintExpr(FromExpr);
       Unbold();
     } else {
       OS << (FromDefault ? "[(default) " : "[");
       Bold();
-      PrintExpr(FromExpr, FromNullPtr);
+      PrintExpr(FromExpr);
       Unbold();
       OS << " != " << (ToDefault ? "(default) " : "");
       Bold();
-      PrintExpr(ToExpr, ToNullPtr);
+      PrintExpr(ToExpr);
       Unbold();
       OS << ']';
     }
   }
 
   /// PrintExpr - Actual formatting and printing of expressions.
-  void PrintExpr(const Expr *E, bool NullPtr = false) {
+  void PrintExpr(const Expr *E) {
     if (E) {
       E->printPretty(OS, nullptr, Policy);
       return;
     }
-    if (NullPtr) {
-      OS << "nullptr";
-      return;
-    }
     OS << "(no argument)";
   }
 
@@ -1677,28 +1696,40 @@ class TemplateDiff {
   /// PrintAPSInt - Handles printing of integral arguments, highlighting
   /// argument differences.
   void PrintAPSInt(llvm::APSInt FromInt, llvm::APSInt ToInt,
-                   bool IsValidFromInt, bool IsValidToInt, Expr *FromExpr,
-                   Expr *ToExpr, bool FromDefault, bool ToDefault, bool Same) {
+                   bool IsValidFromInt, bool IsValidToInt, QualType FromIntType,
+                   QualType ToIntType, Expr *FromExpr, Expr *ToExpr,
+                   bool FromDefault, bool ToDefault, bool Same) {
     assert((IsValidFromInt || IsValidToInt) &&
            "Only one integral argument may be missing.");
 
     if (Same) {
-      OS << FromInt.toString(10);
-    } else if (!PrintTree) {
+      if (FromIntType->isBooleanType()) {
+        OS << ((FromInt == 0) ? "false" : "true");
+      } else {
+        OS << FromInt.toString(10);
+      }
+      return;
+    }
+
+    bool PrintType = IsValidFromInt && IsValidToInt &&
+                     !Context.hasSameType(FromIntType, ToIntType);
+
+    if (!PrintTree) {
       OS << (FromDefault ? "(default) " : "");
-      PrintAPSInt(FromInt, FromExpr, IsValidFromInt);
+      PrintAPSInt(FromInt, FromExpr, IsValidFromInt, FromIntType, PrintType);
     } else {
       OS << (FromDefault ? "[(default) " : "[");
-      PrintAPSInt(FromInt, FromExpr, IsValidFromInt);
+      PrintAPSInt(FromInt, FromExpr, IsValidFromInt, FromIntType, PrintType);
       OS << " != " << (ToDefault ? "(default) " : "");
-      PrintAPSInt(ToInt, ToExpr, IsValidToInt);
+      PrintAPSInt(ToInt, ToExpr, IsValidToInt, ToIntType, PrintType);
       OS << ']';
     }
   }
 
   /// PrintAPSInt - If valid, print the APSInt.  If the expression is
   /// gives more information, print it too.
-  void PrintAPSInt(llvm::APSInt Val, Expr *E, bool Valid) {
+  void PrintAPSInt(llvm::APSInt Val, Expr *E, bool Valid, QualType IntType,
+                   bool PrintType) {
     Bold();
     if (Valid) {
       if (HasExtraInfo(E)) {
@@ -1707,7 +1738,20 @@ class TemplateDiff {
         OS << " aka ";
         Bold();
       }
-      OS << Val.toString(10);
+      if (PrintType) {
+        Unbold();
+        OS << "(";
+        Bold();
+        IntType.print(OS, Context.getPrintingPolicy());
+        Unbold();
+        OS << ") ";
+        Bold();
+      }
+      if (IntType->isBooleanType()) {
+        OS << ((Val == 0) ? "false" : "true");
+      } else {
+        OS << Val.toString(10);
+      }
     } else if (E) {
       PrintExpr(E);
     } else {
@@ -1716,8 +1760,8 @@ class TemplateDiff {
     Unbold();
   }
 
-  /// HasExtraInfo - Returns true if E is not an integer literal or the
-  /// negation of an integer literal
+  /// HasExtraInfo - Returns true if E is not an integer literal, the
+  /// negation of an integer literal, or a boolean literal.
   bool HasExtraInfo(Expr *E) {
     if (!E) return false;
 
@@ -1730,10 +1774,13 @@ class TemplateDiff {
         if (isa<IntegerLiteral>(UO->getSubExpr()))
           return false;
 
+    if (isa<CXXBoolLiteralExpr>(E))
+      return false;
+
     return true;
   }
 
-  void PrintValueDecl(ValueDecl *VD, bool AddressOf, bool NullPtr) {
+  void PrintValueDecl(ValueDecl *VD, bool AddressOf, Expr *E, bool NullPtr) {
     if (VD) {
       if (AddressOf)
         OS << "&";
@@ -1742,6 +1789,17 @@ class TemplateDiff {
     }
 
     if (NullPtr) {
+      if (E && !isa<CXXNullPtrLiteralExpr>(E)) {
+        PrintExpr(E);
+        if (IsBold) {
+          Unbold();
+          OS << " aka ";
+          Bold();
+        } else {
+          OS << " aka ";
+        }
+      }
+
       OS << "nullptr";
       return;
     }
@@ -1753,30 +1811,72 @@ class TemplateDiff {
   /// argument differences.
   void PrintValueDecl(ValueDecl *FromValueDecl, ValueDecl *ToValueDecl,
                       bool FromAddressOf, bool ToAddressOf, bool FromNullPtr,
-                      bool ToNullPtr, bool FromDefault, bool ToDefault,
-                      bool Same) {
+                      bool ToNullPtr, Expr *FromExpr, Expr *ToExpr,
+                      bool FromDefault, bool ToDefault, bool Same) {
     assert((FromValueDecl || FromNullPtr || ToValueDecl || ToNullPtr) &&
            "Only one Decl argument may be NULL");
 
     if (Same) {
-      PrintValueDecl(FromValueDecl, FromAddressOf, FromNullPtr);
+      PrintValueDecl(FromValueDecl, FromAddressOf, FromExpr, FromNullPtr);
     } else if (!PrintTree) {
       OS << (FromDefault ? "(default) " : "");
       Bold();
-      PrintValueDecl(FromValueDecl, FromAddressOf, FromNullPtr);
+      PrintValueDecl(FromValueDecl, FromAddressOf, FromExpr, FromNullPtr);
       Unbold();
     } else {
       OS << (FromDefault ? "[(default) " : "[");
       Bold();
-      PrintValueDecl(FromValueDecl, FromAddressOf, FromNullPtr);
+      PrintValueDecl(FromValueDecl, FromAddressOf, FromExpr, FromNullPtr);
       Unbold();
       OS << " != " << (ToDefault ? "(default) " : "");
       Bold();
-      PrintValueDecl(ToValueDecl, ToAddressOf, ToNullPtr);
+      PrintValueDecl(ToValueDecl, ToAddressOf, ToExpr, ToNullPtr);
+      Unbold();
+      OS << ']';
+    }
+
+  }
+
+  /// PrintValueDeclAndInteger - Uses the print functions for ValueDecl and
+  /// APSInt to print a mixed difference.
+  void PrintValueDeclAndInteger(ValueDecl *VD, bool NeedAddressOf,
+                                bool IsNullPtr, Expr *VDExpr, bool DefaultDecl,
+                                llvm::APSInt Val, QualType IntType,
+                                Expr *IntExpr, bool DefaultInt) {
+    if (!PrintTree) {
+      OS << (DefaultDecl ? "(default) " : "");
+      Bold();
+      PrintValueDecl(VD, NeedAddressOf, VDExpr, IsNullPtr);
       Unbold();
+    } else {
+      OS << (DefaultDecl ? "[(default) " : "[");
+      Bold();
+      PrintValueDecl(VD, NeedAddressOf, VDExpr, IsNullPtr);
+      Unbold();
+      OS << " != " << (DefaultInt ? "(default) " : "");
+      PrintAPSInt(Val, IntExpr, true /*Valid*/, IntType, false /*PrintType*/);
       OS << ']';
     }
+  }
 
+  /// PrintIntegerAndValueDecl - Uses the print functions for APSInt and
+  /// ValueDecl to print a mixed difference.
+  void PrintIntegerAndValueDecl(llvm::APSInt Val, QualType IntType,
+                                Expr *IntExpr, bool DefaultInt, ValueDecl *VD,
+                                bool NeedAddressOf, bool IsNullPtr,
+                                Expr *VDExpr, bool DefaultDecl) {
+    if (!PrintTree) {
+      OS << (DefaultInt ? "(default) " : "");
+      PrintAPSInt(Val, IntExpr, true /*Valid*/, IntType, false /*PrintType*/);
+    } else {
+      OS << (DefaultInt ? "[(default) " : "[");
+      PrintAPSInt(Val, IntExpr, true /*Valid*/, IntType, false /*PrintType*/);
+      OS << " != " << (DefaultDecl ? "(default) " : "");
+      Bold();
+      PrintValueDecl(VD, NeedAddressOf, VDExpr, IsNullPtr);
+      Unbold();
+      OS << ']';
+    }
   }
 
   // Prints the appropriate placeholder for elided template arguments.
@@ -1866,21 +1966,21 @@ public:
       PrintTree(PrintTree),
       ShowColor(ShowColor),
       // When printing a single type, the FromType is the one printed.
-      FromType(PrintFromType ? FromType : ToType),
-      ToType(PrintFromType ? ToType : FromType),
+      FromTemplateType(PrintFromType ? FromType : ToType),
+      ToTemplateType(PrintFromType ? ToType : FromType),
       OS(OS),
       IsBold(false) {
   }
 
   /// DiffTemplate - Start the template type diffing.
   void DiffTemplate() {
-    Qualifiers FromQual = FromType.getQualifiers(),
-               ToQual = ToType.getQualifiers();
+    Qualifiers FromQual = FromTemplateType.getQualifiers(),
+               ToQual = ToTemplateType.getQualifiers();
 
     const TemplateSpecializationType *FromOrigTST =
-        GetTemplateSpecializationType(Context, FromType);
+        GetTemplateSpecializationType(Context, FromTemplateType);
     const TemplateSpecializationType *ToOrigTST =
-        GetTemplateSpecializationType(Context, ToType);
+        GetTemplateSpecializationType(Context, ToTemplateType);
 
     // Only checking templates.
     if (!FromOrigTST || !ToOrigTST)
@@ -1893,13 +1993,12 @@ public:
 
     FromQual -= QualType(FromOrigTST, 0).getQualifiers();
     ToQual -= QualType(ToOrigTST, 0).getQualifiers();
-    Tree.SetNode(FromType, ToType);
-    Tree.SetNode(FromQual, ToQual);
-    Tree.SetKind(DiffTree::Template);
 
     // Same base template, but different arguments.
-    Tree.SetNode(FromOrigTST->getTemplateName().getAsTemplateDecl(),
-                 ToOrigTST->getTemplateName().getAsTemplateDecl());
+    Tree.SetTemplateDiff(FromOrigTST->getTemplateName().getAsTemplateDecl(),
+                         ToOrigTST->getTemplateName().getAsTemplateDecl(),
+                         FromQual, ToQual, false /*FromDefault*/,
+                         false /*ToDefault*/);
 
     DiffTemplate(FromOrigTST, ToOrigTST);
   }