rewrite_to_chrome_style: Fix assert calling getName() when there's none

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 41 matching lines @@
 AST_MATCHER(clang::FunctionDecl, isOverloadedOperator) {
   return Node.isOverloadedOperator();
 }
 
 constexpr char kBlinkFieldPrefix[] = "m_";
 constexpr char kBlinkStaticMemberPrefix[] = "s_";
 
 bool GetNameForDecl(const clang::FunctionDecl& decl,
                     const clang::ASTContext& context,
                     std::string& name) {
-  name = decl.getNameAsString();
+  // If there's no name to change, return.
+  if (!decl.getIdentifier())
+    return false;
+  StringRef original_name = decl.getName();
 
   if (const auto* method = clang::dyn_cast<const clang::CXXMethodDecl>(&decl)) {
     if (!method->isStatic()) {
       // Some methods shouldn't be renamed because reasons.
       static const char* kBlacklist[] = {"begin", "end", "rbegin", "rend",
                                          "trace"};
       for (const auto& b : kBlacklist) {
-        if (name == b)
+        if (original_name == b)
           return false;
       }
     }
   }
 
+  name = original_name.str();
   name[0] = clang::toUppercase(name[0]);
   return true;
 }
 
 // Helper to convert from a camelCaseName to camel_case_name. It uses some
 // heuristics to try to handle acronyms in camel case names correctly.
 std::string CamelCaseToUnderscoreCase(StringRef input) {
   std::string output;
   bool needs_underscore = false;
   bool was_lowercase = false;
@@ skipping 21 matching lines @@
     was_lowercase = is_lowercase;
     was_uppercase = is_uppercase;
   }
   std::reverse(output.begin(), output.end());
   return output;
 }
 
 bool GetNameForDecl(const clang::FieldDecl& decl,
                     const clang::ASTContext& context,
                     std::string& name) {
+  // If there's no name to change, return.
+  if (!decl.getIdentifier())
+    return false;
   StringRef original_name = decl.getName();
   // Blink style field names are prefixed with `m_`. If this prefix isn't
   // present, assume it's already been converted to Google style.
   if (original_name.size() < strlen(kBlinkFieldPrefix) ||
       !original_name.startswith(kBlinkFieldPrefix))
     return false;
   name = CamelCaseToUnderscoreCase(
       original_name.substr(strlen(kBlinkFieldPrefix)));
   // The few examples I could find used struct-style naming with no `_` suffix
   // for unions.
@@ skipping 24 matching lines @@
     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);
 }
 
 bool GetNameForDecl(const clang::VarDecl& decl,
                     const clang::ASTContext& context,
                     std::string& name) {
+  // If there's no name to change, return.
+  if (!decl.getIdentifier())

[dcheng, 2016/01/29 01:13:05]

Does it makes sense to move this into RewriteBase::run(), after we get the decl?

[danakj, 2016/01/29 01:15:05]

Hm ya sure.

+    return false;
   StringRef original_name = decl.getName();
 
   // Nothing to do for unnamed parameters.
   if (clang::isa<clang::ParmVarDecl>(decl) && original_name.empty())
     return false;
 
   // static class members match against VarDecls. Blink style dictates that
   // these should be prefixed with `s_`, so strip that off. Also check for `m_`
   // and strip that off too, for code that accidentally uses the wrong prefix.
   if (original_name.startswith(kBlinkStaticMemberPrefix))
@@ skipping 403 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;
 }