Handling of DependentScopeDeclRefExpr and CXXDependentScopeMemberExpr nodes.

tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp

Index: tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
diff --git a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
index 85a9661d70f190f8cc0f4857067739b9de772cf6..24fd5e323ee558bdd4f4c0d35d40ff2c02e7668b 100644
--- a/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
+++ b/tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp
@@ -55,6 +55,14 @@ const clang::ast_matchers::internal::
     VariadicDynCastAllOfMatcher<clang::Expr, clang::UnresolvedMemberExpr>
         unresolvedMemberExpr;
 
+const clang::ast_matchers::internal::
+    VariadicDynCastAllOfMatcher<clang::Expr, clang::DependentScopeDeclRefExpr>
+        dependentScopeDeclRefExpr;
+
+const clang::ast_matchers::internal::
+    VariadicDynCastAllOfMatcher<clang::Expr, clang::CXXDependentScopeMemberExpr>
+        cxxDependentScopeMemberExpr;
+
 AST_MATCHER(clang::FunctionDecl, isOverloadedOperator) {
   return Node.isOverloadedOperator();
 }
@@ -158,6 +166,34 @@ AST_MATCHER_P(clang::CXXMethodDecl,
   return MatchAllOverriddenMethods(Node, InnerMatcher, Finder, Builder);
 }
 
+// Matches |x.m| CXXDependentScopeMemberExpr if InnerMatcher matches |x|.
+AST_MATCHER_P(clang::CXXDependentScopeMemberExpr,
+              hasBaseExprMissingOrMatching,
+              clang::ast_matchers::internal::Matcher<clang::Expr>,
+              InnerMatcher) {
+  clang::Expr* base_expr = Node.isImplicitAccess() ? nullptr : Node.getBase();
+  return !base_expr || InnerMatcher.matches(*base_expr, Finder, Builder);
+}
+
+// Matches |T::m| CXXDependentScopeMemberExpr if InnerMatcher matches |T|.
+AST_MATCHER_P(
+    clang::CXXDependentScopeMemberExpr,
+    hasQualifierMissingOrMatching,
+    clang::ast_matchers::internal::Matcher<clang::NestedNameSpecifier>,
+    InnerMatcher) {
+  clang::NestedNameSpecifier* qual = Node.getQualifier();
+  return !qual || InnerMatcher.matches(*qual, Finder, Builder);
+}
+
+// Matches |const Class<T>&| QualType if InnerMatcher matches |Class<T>|.
+AST_MATCHER_P(clang::QualType,
+              hasBaseType,
+              clang::ast_matchers::internal::Matcher<clang::Type>,
+              InnerMatcher) {
+  const clang::Type* type = Node.getTypePtrOrNull();
+  return type && InnerMatcher.matches(*type, Finder, Builder);
+}
+
 bool IsMethodOverrideOf(const clang::CXXMethodDecl& decl,
                         const char* class_name) {
   if (decl.getParent()->getQualifiedNameAsString() == class_name)
@@ -491,6 +527,24 @@ struct TargetNodeTraits<clang::DeclRefExpr> {
 };
 
 template <>
+struct TargetNodeTraits<clang::DependentScopeDeclRefExpr> {
+  static clang::SourceLocation GetLoc(
+      const clang::DependentScopeDeclRefExpr& expr) {
+    return expr.getLocation();
+  }
+  static const char* GetName() { return "expr"; }
+};
+
+template <>
+struct TargetNodeTraits<clang::CXXDependentScopeMemberExpr> {
+  static clang::SourceLocation GetLoc(
+      const clang::CXXDependentScopeMemberExpr& expr) {
+    return expr.getMemberLoc();
+  }
+  static const char* GetName() { return "expr"; }
+};
+
+template <>
 struct TargetNodeTraits<clang::CXXCtorInitializer> {
   static clang::SourceLocation GetLoc(const clang::CXXCtorInitializer& init) {
     assert(init.isWritten());
@@ -602,6 +656,16 @@ clang::DeclarationName GetUnresolvedName(
 }
 
 clang::DeclarationName GetUnresolvedName(
+    const clang::DependentScopeDeclRefExpr& expr) {
+  return expr.getDeclName();
+}
+
+clang::DeclarationName GetUnresolvedName(
+    const clang::CXXDependentScopeMemberExpr& expr) {
+  return expr.getMember();
+}
+
+clang::DeclarationName GetUnresolvedName(
     const clang::UnresolvedUsingValueDecl& decl) {
   return decl.getDeclName();
 }
@@ -633,7 +697,22 @@ class UnresolvedRewriterBase : public RewriterBase<TargetNode> {
 
   void run(const MatchFinder::MatchResult& result) override {
     const TargetNode& expr = Base::GetTargetNode(result);
-    llvm::StringRef old_name = GetUnresolvedName(expr).getAsString();
+
+    clang::DeclarationName unresolved_name = GetUnresolvedName(expr);
+    switch (unresolved_name.getNameKind()) {
+      // Do not rewrite this:
+      //   return operator T*();
+      // into this:
+      //   return Operator type - parameter - 0 - 0 * T * ();
+      case clang::DeclarationName::NameKind::CXXConversionFunctionName:
+      case clang::DeclarationName::NameKind::CXXOperatorName:
+      case clang::DeclarationName::NameKind::CXXLiteralOperatorName:
+        return;
+      default:
+        break;
+    }
+
+    llvm::StringRef old_name = unresolved_name.getAsString();
     std::string new_name;
     if (GuessNameForUnresolvedDependentNode(expr, *result.Context, old_name,
                                             new_name)) {
@@ -716,6 +795,12 @@ using UnresolvedUsingValueDeclRewriter =
 
 using UsingDeclRewriter = DeclRewriterBase<clang::UsingDecl, clang::NamedDecl>;
 
+using DependentScopeDeclRefExprRewriter =
+    UnresolvedRewriterBase<clang::DependentScopeDeclRefExpr>;
+
+using CXXDependentScopeMemberExprRewriter =
+    UnresolvedRewriterBase<clang::CXXDependentScopeMemberExpr>;
+
 }  // namespace
 
 static llvm::cl::extrahelp common_help(CommonOptionsParser::HelpMessage);
@@ -1042,6 +1127,65 @@ int main(int argc, const char* argv[]) {
   UsingDeclRewriter using_decl_rewriter(&replacements);
   match_finder.addMatcher(using_decl_matcher, &using_decl_rewriter);
 
+  // Matches any QualType that refers to a blink type:
+  // - const blink::Foo&
+  // - blink::Foo*
+  // - blink::Foo<T>
+  // - ...
+  // TODO(lukasza): The matchers below can be simplified after
+  // https://llvm.org/bugs/show_bug.cgi?id=30331 is fixed.
+  // Simplified matchers:
+  //    auto blink_qual_type_base_matcher =
+  //        qualType(hasDeclaration(in_blink_namespace));
+  //    auto blink_qual_type_matcher = qualType(anyOf(
+  //        blink_qual_type_base_matcher,
+  //        pointsTo(blink_qual_type_base_matcher),
+  //        references(blink_qual_type_base_matcher)));
+  auto blink_qual_type_bug_workaround_matcher1 = hasBaseType(
+      anyOf(enumType(hasDeclaration(in_blink_namespace)),
+            recordType(hasDeclaration(in_blink_namespace)),
+            templateSpecializationType(hasDeclaration(in_blink_namespace)),
+            templateTypeParmType(hasDeclaration(in_blink_namespace)),
+            typedefType(hasDeclaration(in_blink_namespace))));
+  auto blink_qual_type_base_matcher =
+      qualType(anyOf(blink_qual_type_bug_workaround_matcher1,
+                     hasBaseType(elaboratedType(
+                         namesType(blink_qual_type_bug_workaround_matcher1)))));
+  auto blink_qual_type_matcher =
+      qualType(anyOf(blink_qual_type_base_matcher, pointsTo(in_blink_namespace),
+                     references(in_blink_namespace)));
+
+  // Template-dependent decl lookup ========
+  // Given
+  //   template <typename T> void f() { T::foo(); }
+  // matches |T::foo|.
+  auto dependent_scope_decl_ref_expr_matcher =
+      expr(id("expr", dependentScopeDeclRefExpr(has(nestedNameSpecifier(
+                          specifiesType(blink_qual_type_matcher))))));
+  DependentScopeDeclRefExprRewriter dependent_scope_decl_ref_expr_rewriter(
+      &replacements);
+  match_finder.addMatcher(dependent_scope_decl_ref_expr_matcher,
+                          &dependent_scope_decl_ref_expr_rewriter);
+
+  // Template-dependent member lookup ========
+  // Given
+  //   template <typename T>
+  //   class Foo {
+  //     void f() { T::foo(); }
+  //     void g(T x) { x.bar(); }
+  //   };
+  // matches |T::foo| and |x.bar|.
+  auto cxx_dependent_scope_member_expr_matcher = expr(
+      id("expr",
+         cxxDependentScopeMemberExpr(allOf(
+             hasBaseExprMissingOrMatching(hasType(blink_qual_type_matcher)),
+             hasQualifierMissingOrMatching(
+                 specifiesType(blink_qual_type_matcher))))));
+  CXXDependentScopeMemberExprRewriter cxx_dependent_scope_member_expr_rewriter(
+      &replacements);
+  match_finder.addMatcher(cxx_dependent_scope_member_expr_matcher,
+                          &cxx_dependent_scope_member_expr_rewriter);
+
   std::unique_ptr<clang::tooling::FrontendActionFactory> factory =
       clang::tooling::newFrontendActionFactory(&match_finder);
   int result = tool.run(factory.get());