rewrite_to_chrome_style: making globals great again.

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 357 matching lines @@
     const clang::CXXRecordDecl* parent =
         clang::dyn_cast_or_null<clang::CXXRecordDecl>(decl_context);
     if (is_in_wtf && parent && parent->isStruct())
       return false;
 
     name = 'k';
     name.append(original_name.data(), original_name.size());
     name[1] = clang::toUppercase(name[1]);
   } else {
     name = CamelCaseToUnderscoreCase(original_name);
+
+    // Non-const variables with static storage duration at namespace scope are
+    // prefixed with `g_' to reduce the likelihood of a naming collision.
+    const clang::DeclContext* decl_context = decl.getDeclContext();
+    if (name.find("g_") != 0 && decl.hasGlobalStorage() &&
+        decl_context->isNamespace())
+      name.insert(0, "g_");
   }
 
   // Static members end with _ just like other members, but constants should
   // not.
   if (!is_const && decl.isStaticDataMember()) {
     name += '_';
   }
 
   return true;
 }
@@ skipping 454 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;
 }