[clang-diff] Move printing of matches and changes to clang-diff

Summary:
This also changes the output order of the changes. Now the matches are
printed in pre-order, intertwined with insertions, updates, and moves.
Deletions are printed afterwards.

Reviewers: arphaman

Subscribers: klimek

Differential Revision: https://reviews.llvm.org/D36179

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@311200 91177308-0d34-0410-b5e6-96231b3b80d8

Author: krobelus

include/clang/Tooling/ASTDiff/ASTDiff.h

@@ -25,37 +25,22 @@
 namespace clang {
 namespace diff {
 
-/// This represents a match between two nodes in the source and destination
-/// trees, meaning that they are likely to be related.
-struct Match {
-  NodeId Src, Dst;
-};
-
 enum ChangeKind {
-  Delete, // (Src): delete node Src.
-  Update, // (Src, Dst): update the value of node Src to match Dst.
-  Insert, // (Src, Dst, Pos): insert Src as child of Dst at offset Pos.
-  Move    // (Src, Dst, Pos): move Src to be a child of Dst at offset Pos.
-};
-
-struct Change {
-  ChangeKind Kind;
-  NodeId Src, Dst;
-  size_t Position;
-
-  Change(ChangeKind Kind, NodeId Src, NodeId Dst, size_t Position)
-      : Kind(Kind), Src(Src), Dst(Dst), Position(Position) {}
-  Change(ChangeKind Kind, NodeId Src) : Kind(Kind), Src(Src) {}
-  Change(ChangeKind Kind, NodeId Src, NodeId Dst)
-      : Kind(Kind), Src(Src), Dst(Dst) {}
+  None,
+  Delete,    // (Src): delete node Src.
+  Update,    // (Src, Dst): update the value of node Src to match Dst.
+  Insert,    // (Src, Dst, Pos): insert Src as child of Dst at offset Pos.
+  Move,      // (Src, Dst, Pos): move Src to be a child of Dst at offset Pos.
+  UpdateMove // Same as Move plus Update.
 };
 
 /// Represents a Clang AST node, alongside some additional information.
 struct Node {
   NodeId Parent, LeftMostDescendant, RightMostDescendant;
-  int Depth, Height;
+  int Depth, Height, Shift = 0;
   ast_type_traits::DynTypedNode ASTNode;
   SmallVector<NodeId, 4> Children;
+  ChangeKind ChangeKind = None;
 
   ast_type_traits::ASTNodeKind getType() const;
   StringRef getTypeLabel() const;
@@ -67,15 +52,8 @@ class ASTDiff {
   ASTDiff(SyntaxTree &Src, SyntaxTree &Dst, const ComparisonOptions &Options);
   ~ASTDiff();
 
-  // Returns a list of matches.
-  std::vector<Match> getMatches();
-  /// Returns an edit script.
-  std::vector<Change> getChanges();
-
-  // Prints an edit action.
-  void printChange(raw_ostream &OS, const Change &Chg) const;
-  // Prints a match between two nodes.
-  void printMatch(raw_ostream &OS, const Match &M) const;
+  // Returns the ID of the node that is mapped to the given node in SourceTree.
+  NodeId getMapped(const SyntaxTree &SourceTree, NodeId Id) const;
 
   class Impl;
 
@@ -99,16 +77,23 @@ class SyntaxTree {
   const ASTContext &getASTContext() const;
   StringRef getFilename() const;
 
-  const Node &getNode(NodeId Id) const;
+  int getSize() const;
   NodeId getRootId() const;
+  using PreorderIterator = NodeId;
+  PreorderIterator begin() const;
+  PreorderIterator end() const;
+
+  const Node &getNode(NodeId Id) const;
+  int findPositionInParent(NodeId Id) const;
 
   // Returns the starting and ending offset of the node in its source file.
   std::pair<unsigned, unsigned> getSourceRangeOffsets(const Node &N) const;
 
   /// Serialize the node attributes to a string representation. This should
   /// uniquely distinguish nodes of the same kind. Note that this function just
   /// returns a representation of the node value, not considering descendants.
-  std::string getNodeValue(const DynTypedNode &DTN) const;
+  std::string getNodeValue(NodeId Id) const;
+  std::string getNodeValue(const Node &Node) const;
 
   class Impl;
   std::unique_ptr<Impl> TreeImpl;
@@ -131,8 +116,8 @@ struct ComparisonOptions {
   bool EnableMatchingWithUnmatchableParents = false;
 
   /// Returns false if the nodes should never be matched.
-  bool isMatchingAllowed(const DynTypedNode &N1, const DynTypedNode &N2) const {
-    return N1.getNodeKind().isSame(N2.getNodeKind());
+  bool isMatchingAllowed(const Node &N1, const Node &N2) const {
+    return N1.getType().isSame(N2.getType());
   }
 };
 

include/clang/Tooling/ASTDiff/ASTDiffInternal.h

@@ -36,6 +36,8 @@ struct NodeId {
   operator int() const { return Id; }
   NodeId &operator++() { return ++Id, *this; }
   NodeId &operator--() { return --Id, *this; }
+  // Support defining iterators on NodeId.
+  NodeId &operator*() { return *this; }
 
   bool isValid() const { return Id != InvalidNodeId; }
   bool isInvalid() const { return Id == InvalidNodeId; }