Prepending "Get" when type with conflicting name is hidden inside return type.

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 272 matching lines @@
   // instantiation of the template and see if they are all compile-time
   // isEvaluable().
   if (initializer->isInstantiationDependent())
     return false;
 
   // If the expression can be evaluated at compile time, then it should have a
   // kFoo style name. Otherwise, not.
   return initializer->isEvaluatable(context);
 }
 
+AST_MATCHER_P(clang::QualType, hasString, std::string, ExpectedString) {
+  return ExpectedString == Node.getAsString();
+}
+
 bool GetNameForDecl(const clang::FunctionDecl& decl,
                     clang::ASTContext& context,
                     std::string& name) {
   name = decl.getName().str();
   name[0] = clang::toUppercase(name[0]);
 
   // https://crbug.com/582312: Prepend "Get" if method name conflicts with type.
-  const clang::IdentifierInfo* return_type =
-      decl.getReturnType().getBaseTypeIdentifier();
-  if (return_type && return_type->getName() == name)
+  auto type_with_same_name_as_function = qualType(
+      anyOf(hasDeclaration(namedDecl(hasName(name))), hasString(name)));

[Łukasz Anforowicz, 2016/09/07 23:14:28]

Without |hasString| we wouldn't properly handle the new test case from
functions-xxx.cc that goes through a typedef/using declaration:

class Foo582312 {};
using Bar = Foo582312;
static Bar* bar() {
  return nullptr;
}

I am not happy with |hasString| but I have tried various other things and I was
not able to work around the fact that QualType's -> goes directly to the final
type (so hasDeclaration matches the final type and not the intermediate types).

[danakj, 2016/09/08 23:30:40]

Can you leave a comment here saying that hasName() gives the true name, which
can differ from how it's written (ie typedefs) and hasString() gives the true
way it is written?

[Łukasz Anforowicz, 2016/09/09 00:20:35]

Done.

+  auto type_containing_same_name_as_function =
+      qualType(anyOf(type_with_same_name_as_function,
+                     hasDescendant(type_with_same_name_as_function)));

[Łukasz Anforowicz, 2016/09/07 23:14:28]

|hasDescendant| helps catch the RefPtr<SameNameAsFunction> case.

+  auto conflict_matcher =
+      functionDecl(returns(type_containing_same_name_as_function));
+  if (!match(conflict_matcher, decl, context).empty())
     name = "Get" + name;
 
   return true;
 }
 
 bool GetNameForDecl(const clang::EnumConstantDecl& decl,
                     clang::ASTContext& context,
                     std::string& name) {
   StringRef original_name = decl.getName();
 
@@ skipping 619 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;
 }