[clang-diff] Support templates

[johannes]

Summary

TemplateName and TemplateArgument are now treated as nodes.

[arphaman]

lib/Tooling/ASTDiff/ASTDiff.cpp

295

Interesting, I didn't know that this iteration happened out-of-order. My https://reviews.llvm.org/D35012 patch (I'll commit it right now) has a RecursiveASTVisitor subclass that tries to traverse the tree in the source order, I think you should move this code:

DEF_TRAVERSE_TMPL_DECL_(Class)
DEF_TRAVERSE_TMPL_DECL_(Var)
DEF_TRAVERSE_TMPL_DECL_(Function)

to LexicallyOrderedRecursiveASTVisitor subclass instead and change your visitor to derive from LexicallyOrderedRecursiveASTVisitor. You can probably repurpose https://reviews.llvm.org/D36998 and have both the visibility change and the move to LexicallyOrderedRecursiveASTVisitor in that patch.

[johannes]

use LexicallyOrderedRecursiveASTVisitor

[johannes]

update

lib/Tooling/ASTDiff/ASTDiff.cpp

 //===- ASTDiff.cpp - AST differencing implementation-----------*- C++ -*- -===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file contains definitons for the AST differencing interface.
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Tooling/ASTDiff/ASTDiff.h"
 
-#include "clang/AST/RecursiveASTVisitor.h"
+#include "clang/AST/LexicallyOrderedRecursiveASTVisitor.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/ADT/PriorityQueue.h"
 #include "llvm/Support/MD5.h"
 
 #include <limits>
 #include <memory>
 #include <unordered_set>
 
public:
   ASTUnit &AST;
   PrintingPolicy TypePP;
   /// Nodes in preorder.
   std::vector<Node> Nodes;
   NodeList Leaves;
   // Maps preorder indices to postorder ones.
   std::vector<int> PostorderIds;
   NodeList NodesBfs;
+  std::map<NodeId, SourceRange> TemplateArgumentLocations;
 
   int getSize() const { return Nodes.size(); }
   NodeRef getRoot() const { return getNode(getRootId()); }
   NodeId getRootId() const { return 0; }
   PreorderIterator begin() const { return &getRoot(); }
   PreorderIterator end() const { return begin() + getSize(); }
 
   NodeRef getNode(NodeId Id) const { return Nodes[Id]; }
bool NodeRefIterator::operator!=(const NodeRefIterator &Other) const {
   return IdPointer != Other.IdPointer;
 }
 
 static bool isSpecializedNodeExcluded(const Decl *D) { return D->isImplicit(); }
 static bool isSpecializedNodeExcluded(const Stmt *S) { return false; }
 static bool isSpecializedNodeExcluded(CXXCtorInitializer *I) {
   return !I->isWritten();
 }
+static bool isSpecializedNodeExcluded(const TemplateArgumentLoc *S) {
+  return false;
+}
+
+static bool isNodeExcluded(ASTUnit &AST, TemplateName *Template) {
+  return false;
+}
 
 template <class T> static bool isNodeExcluded(ASTUnit &AST, T *N) {
   const SourceManager &SM = AST.getSourceManager();
   if (!N)
     return true;
   SourceLocation SLoc = N->getSourceRange().getBegin();
   if (SLoc.isValid()) {
     // Ignore everything from other files.
     if (!SM.isInMainFile(SLoc))
       return true;
     const Preprocessor &PP = AST.getPreprocessor();
     if (SLoc.isMacroID() && !PP.isAtStartOfMacroExpansion(SLoc))
       return true;
   }
   return isSpecializedNodeExcluded(N);
 }
 
 namespace {
 // Sets Height, Parent and Children for each node.
-struct PreorderVisitor : public RecursiveASTVisitor<PreorderVisitor> {
+struct PreorderVisitor
+    : public LexicallyOrderedRecursiveASTVisitor<PreorderVisitor> {
+  using BaseType = LexicallyOrderedRecursiveASTVisitor<PreorderVisitor>;
+
   int Id = 0, Depth = 0;
   NodeId Parent;
   SyntaxTree::Impl &Tree;
 
-  PreorderVisitor(SyntaxTree::Impl &Tree) : Tree(Tree) {}
+  PreorderVisitor(SyntaxTree::Impl &Tree)
+      : BaseType(Tree.AST.getSourceManager()), Tree(Tree) {}
 
-  template <class T> std::tuple<NodeId, NodeId> PreTraverse(T *ASTNode) {
+  template <class T> std::tuple<NodeId, NodeId> PreTraverse(const T &ASTNode) {
     NodeId MyId = Id;
     Tree.Nodes.emplace_back(Tree);
     Node &N = Tree.getMutableNode(MyId);
     N.Parent = Parent;
     N.Depth = Depth;
-    N.ASTNode = DynTypedNode::create(*ASTNode);
+    N.ASTNode = DynTypedNode::create(ASTNode);
     assert(!N.ASTNode.getNodeKind().isNone() &&
            "Expected nodes to have a valid kind.");
     if (Parent.isValid()) {
       Node &P = Tree.getMutableNode(Parent);
       P.Children.push_back(MyId);
     }
     Parent = MyId;
     ++Id;
if (N.isLeaf())
       Tree.Leaves.push_back(MyId);
     N.Height = 1;
     for (NodeId Child : N.Children)
       N.Height = std::max(N.Height, 1 + Tree.getNode(Child).Height);
   }
   bool TraverseDecl(Decl *D) {
     if (isNodeExcluded(Tree.AST, D))
       return true;
-    auto SavedState = PreTraverse(D);
-    RecursiveASTVisitor<PreorderVisitor>::TraverseDecl(D);
+    auto SavedState = PreTraverse(*D);
+    BaseType::TraverseDecl(D);
     PostTraverse(SavedState);
     return true;
   }
   bool TraverseStmt(Stmt *S) {
     if (S)
       S = S->IgnoreImplicit();
     if (isNodeExcluded(Tree.AST, S))
       return true;
-    auto SavedState = PreTraverse(S);
-    RecursiveASTVisitor<PreorderVisitor>::TraverseStmt(S);
+    auto SavedState = PreTraverse(*S);
+    BaseType::TraverseStmt(S);
     PostTraverse(SavedState);
     return true;
   }
   bool TraverseType(QualType T) { return true; }
   bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
     if (isNodeExcluded(Tree.AST, Init))
       return true;
-    auto SavedState = PreTraverse(Init);
-    RecursiveASTVisitor<PreorderVisitor>::TraverseConstructorInitializer(Init);
+    auto SavedState = PreTraverse(*Init);
+    BaseType::TraverseConstructorInitializer(Init);
+    PostTraverse(SavedState);
+    return true;
+  }
+  bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
+    if (isNodeExcluded(Tree.AST, &ArgLoc))
+      return true;
+    Tree.TemplateArgumentLocations.emplace(Id, ArgLoc.getSourceRange());
+    auto SavedState = PreTraverse(ArgLoc.getArgument());
+    BaseType::TraverseTemplateArgumentLoc(ArgLoc);
+    PostTraverse(SavedState);
+    return true;
+  }
+  bool TraverseTemplateName(TemplateName Template) {
+    if (isNodeExcluded(Tree.AST, &Template))
+      return true;
+    auto SavedState = PreTraverse(Template);
+    BaseType::TraverseTemplateName(Template);
     PostTraverse(SavedState);
     return true;
   }
 };
 } // end anonymous namespace
 
 SyntaxTree::Impl::Impl(SyntaxTree *Parent, ASTUnit &AST)
     : Parent(Parent), AST(AST), TypePP(AST.getLangOpts()), Leaves(*this),
       NodesBfs(*this) {
   TypePP.AnonymousTagLocations = false;
 }
 

test/Tooling/Inputs/clang-diff-basic-src.cpp

 #define M2 return 1 + 2
 #define F(a, b) return a + b;
 
 int f2() {
   M1;
   M1;
   F(1, 1);
 }
+
+template <class T, class U = void>
+U visit(T &t) {
+  int x = t;
+  return U();
+}
+
+void tmp() {
+  int x;
+  visit<int>(x);
+}
+
+int x = 1;

test/Tooling/clang-diff-ast.cpp

 // CHECK-NEXT: NamespaceDecl(63)
 namespace world {
 // nodes from other files are excluded, there should be no output here
 #include "clang-diff-ast.cpp"
 }
 // CHECK-NEXT: FunctionDecl(64)
 void sentinel();
 #endif
+
+// CHECK-NEXT: ClassTemplateDecl(65)
+// CHECK-NEXT: TemplateTypeParmDecl(66)
+// CHECK-NEXT: CXXRecordDecl(67)
+template <class T> class C {
+  // CHECK-NEXT: FieldDecl(68)
+  T t;
+};
+
+// CHECK-NEXT: CXXRecordDecl(69)
+// CHECK-NEXT: TemplateName(70)
+// CHECK-NEXT: TemplateArgument(71)
+class I : C<int> {};

test/Tooling/clang-diff-basic.cpp

-// RUN: clang-diff -dump-matches %S/Inputs/clang-diff-basic-src.cpp %s -- | FileCheck %s
+// RUN: clang-diff -dump-matches %S/Inputs/clang-diff-basic-src.cpp %s -- -std=c++11 | FileCheck %s
 
 // CHECK: Match TranslationUnitDecl(0) to TranslationUnitDecl(0)
 // CHECK: Match NamespaceDecl(1) to NamespaceDecl(1)
 namespace dst {
 // CHECK-NOT: Match NamespaceDecl(1) to NamespaceDecl(2)
 namespace inner {
 void foo() {
   // CHECK: Match IntegerLiteral(6) to IntegerLiteral(7)
int f2() {
   // CHECK: Match Macro(72) to Macro(71)
   M1;
   // CHECK: Update Macro(73)
   M2;
   // CHECK: Match Macro(74)
   F(1, /*b=*/1);
 }
 
+// CHECK: Match TemplateTypeParmDecl(77)
+template <class Type, class U = int>
+U visit(Type &t) {
+  int x = t;
+  return U();
+}
+
+void tmp() {
+  long x;
+  // CHECK: Match TemplateArgument(93)
+  visit<long>(x);
+}
+
 // CHECK: Delete AccessSpecDecl(39)
 // CHECK: Delete CXXMethodDecl(42)

test/Tooling/clang-diff-html.test

-RUN: clang-diff -html %S/Inputs/clang-diff-basic-src.cpp %S/clang-diff-basic.cpp -- | FileCheck %s
+RUN: clang-diff -html %S/Inputs/clang-diff-basic-src.cpp %S/clang-diff-basic.cpp -- -std=c++11 | FileCheck %s
 
 CHECK: <pre><div id='L' class='code'><span id='L0' tid='R0' title='TranslationUnitDecl
 CHECK-NEXT: 0 -> 0' class='u'>
 
 match, update
 CHECK: <span id='L[[L:[0-9]+]]' tid='R[[R:[0-9]+]]' title='NamespaceDecl
 CHECK-NEXT: [[L]] -> [[R]]' class='u'>namespace src {