Handling of DependentScopeDeclRefExpr and CXXDependentScopeMemberExpr nodes.

tools/clang/rewrite_to_chrome_style/RewriteToChromeStyle.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Changes Blink-style names to Chrome-style names. Currently transforms:
 //   fields:
 //     int m_operationCount => int operation_count_
 //   variables (including parameters):
 //     int mySuperVariable => int my_super_variable
 //   constants:
@@ skipping 37 matching lines @@
 namespace {
 
 const char kBlinkFieldPrefix[] = "m_";
 const char kBlinkStaticMemberPrefix[] = "s_";
 const char kGeneratedFileRegex[] = "^gen/|/gen/";
 
 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();
 }
 
 AST_MATCHER_P(clang::FunctionTemplateDecl,
               templatedDecl,
               clang::ast_matchers::internal::Matcher<clang::FunctionDecl>,
               InnerMatcher) {
   return InnerMatcher.matches(*Node.getTemplatedDecl(), Finder, Builder);
 }
@@ skipping 79 matching lines @@
   return inner_matcher.matches(decl, finder, builder);
 }
 
 AST_MATCHER_P(clang::CXXMethodDecl,
               includeAllOverriddenMethods,
               clang::ast_matchers::internal::Matcher<clang::CXXMethodDecl>,
               InnerMatcher) {
   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,
+              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)
     return true;
   for (auto it = decl.begin_overridden_methods();
        it != decl.end_overridden_methods(); ++it) {
     if (IsMethodOverrideOf(**it, class_name))
       return true;
   }
   return false;
@@ skipping 313 matching lines @@
 
 template <>
 struct TargetNodeTraits<clang::DeclRefExpr> {
   static clang::SourceLocation GetLoc(const clang::DeclRefExpr& expr) {
     return expr.getLocation();
   }
   static const char* GetName() { return "expr"; }
 };
 
 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());
     return init.getSourceLocation();
   }
   static const char* GetName() { return "initializer"; }
 };
 
 template <>
 struct TargetNodeTraits<clang::UnresolvedLookupExpr> {
@@ skipping 85 matching lines @@
     }
     clang::ASTContext* context = result.Context;
     std::string new_name;
     if (!GetNameForDecl(*decl, *context, new_name))
       return;  // If false, the name was not suitable for renaming.
     llvm::StringRef old_name = decl->getName();
     Base::AddReplacement(result, old_name, std::move(new_name));
   }
 };
 
-llvm::StringRef GetCurrentName(const clang::UnresolvedMemberExpr& expr) {
-  return expr.getMemberName().getAsString();
+clang::DeclarationName GetUnresolvedName(
+    const clang::UnresolvedMemberExpr& expr) {
+  return expr.getMemberName();
 }
 
-llvm::StringRef GetCurrentName(const clang::NamedDecl& decl) {
-  return decl.getName();
+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();
 }
 
 // Returns whether |expr| is a callee of a method or function call.
 bool IsCallee(const clang::Expr& expr, clang::ASTContext& context) {
   auto parents = context.getParents(expr);
   return std::all_of(
       parents.begin(), parents.end(),
       [&expr](const clang::ast_type_traits::DynTypedNode& parent) {
         const clang::CallExpr* call = parent.get<clang::CallExpr>();
         return call && call->getCallee() == &expr;
       });
 }
 
 bool IsCallee(const clang::UnresolvedUsingValueDecl& /* decl */,
               clang::ASTContext& /* context */) {
   // Heuristic - assuming that |using Base::foo| refers to a method.
   return true;
 }
 
 template <typename TargetNode>
 class UnresolvedRewriterBase : public RewriterBase<TargetNode> {
  public:
   using Base = RewriterBase<TargetNode>;
 
   explicit UnresolvedRewriterBase(std::set<Replacement>* replacements)
       : RewriterBase<TargetNode>(replacements) {}
 
   void run(const MatchFinder::MatchResult& result) override {
     const TargetNode& expr = Base::GetTargetNode(result);
-    llvm::StringRef old_name = GetCurrentName(expr);
+
+    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)) {
       Base::AddReplacement(result, old_name, std::move(new_name));
     }
   }
 
  private:
   // This method calculates a new name for nodes that depend on template
   // parameters (http://en.cppreference.com/w/cpp/language/dependent_name).  The
@@ skipping 62 matching lines @@
     DeclRewriterBase<clang::NamedDecl, clang::UnresolvedMemberExpr>;
 
 using UnresolvedDependentMemberRewriter =
     UnresolvedRewriterBase<clang::UnresolvedMemberExpr>;
 
 using UnresolvedUsingValueDeclRewriter =
     UnresolvedRewriterBase<clang::UnresolvedUsingValueDecl>;
 
 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);
 
 int main(int argc, const char* argv[]) {
   // TODO(dcheng): Clang tooling should do this itself.
   // http://llvm.org/bugs/show_bug.cgi?id=21627
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmParser();
   llvm::cl::OptionCategory category(
@@ skipping 304 matching lines @@
   //   using blink::X;
   // matches |using blink::X|.
   auto using_decl_matcher = id(
       "decl", usingDecl(hasAnyUsingShadowDecl(hasTargetDecl(anyOf(
                   var_decl_matcher, field_decl_matcher, function_decl_matcher,
                   method_decl_matcher, function_template_decl_matcher,
                   method_template_decl_matcher, enum_member_decl_matcher)))));
   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),
+            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))))));
+
+  // 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());
   if (result != 0)
     return result;
 
 #if defined(_WIN32)
   HANDLE lockfd = CreateFile("rewrite-sym.lock", GENERIC_READ, FILE_SHARE_READ,
                              NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
   OVERLAPPED overlapped = {};
@@ skipping 31 matching lines @@
   for (const auto& r : replacements) {
     std::string replacement_text = r.getReplacementText().str();
     std::replace(replacement_text.begin(), replacement_text.end(), '\n', '\0');
     llvm::outs() << "r:::" << r.getFilePath() << ":::" << r.getOffset()
                  << ":::" << r.getLength() << ":::" << replacement_text << "\n";
   }
   llvm::outs() << "==== END EDITS ====\n";
 
   return 0;
 }