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 4f607edfe19262d174add2b3ebb3c66375277b66..670a636d01fb9e9b96ab6bb4d906b932879688c8 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();
 }
@@ -150,6 +158,44 @@ AST_MATCHER_P(clang::CXXMethodDecl,
   return MatchAllOverriddenMethods(Node, InnerMatcher, Finder, Builder);
 }
 
+// Matches |x.m| CXXDependentScopeMemberExpr if InnerMatcher matches |x|.
+AST_MATCHER_P(clang::CXXDependentScopeMemberExpr,
+              hasBaseExpr,
+              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,
+    hasDependentQualifier,
+    clang::ast_matchers::internal::Matcher<clang::NestedNameSpecifier>,
+    InnerMatcher) {
+  clang::NestedNameSpecifier* qual = Node.getQualifier();
+  return qual && InnerMatcher.matches(*qual, Finder, Builder);
+}
+
+// Matches |T::m| DependentScopeDeclRefExpr if InnerMatcher matches |T|.
+AST_MATCHER_P(
+    clang::DependentScopeDeclRefExpr,
+    dependentScopeIfQualifier,
+    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,
+              hasUnderlyingType,
+              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)
@@ -477,6 +523,24 @@ 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());
@@ -586,6 +650,14 @@ llvm::StringRef GetCurrentName(const clang::UnresolvedMemberExpr& expr) {
   return expr.getMemberName().getAsString();
 }
 
+llvm::StringRef GetCurrentName(const clang::DependentScopeDeclRefExpr& expr) {
+  return expr.getDeclName().getAsString();
+}
+
+llvm::StringRef GetCurrentName(const clang::CXXDependentScopeMemberExpr& expr) {
+  return expr.getMember().getAsString();
+}
+
 llvm::StringRef GetCurrentName(const clang::NamedDecl& decl) {
   return decl.getName();
 }
@@ -696,6 +768,12 @@ 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);
@@ -995,6 +1073,50 @@ 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>
+  // - ...
+  auto blink_qual_type_matcher = qualType(
+      anyOf(pointsTo(in_blink_namespace), references(in_blink_namespace),

[Łukasz Anforowicz, 2016/08/25 18:11:13]

This strips only 1 layer of indirection, but I don't know how to improve this. 
In another CR (*), your suggestion (to call QualType::getBaseTypeIdentifier())
helps, but here we need something like |getBaseType| (without the identifier
part).

(*)
https://codereview.chromium.org/2276983002/diff/1/tools/clang/rewrite_to_chro...

+            hasUnderlyingType(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))))));

[Łukasz Anforowicz, 2016/08/25 18:11:13]

I don't know how I can avoid listing all the various type flavors here...

+
+  // 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(dependentScopeIfQualifier(
+                          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(anyOf(
+             hasBaseExpr(hasType(blink_qual_type_matcher)),
+             hasDependentQualifier(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());