Add clang tool to rewrite scoped_array<T> to scoped_ptr<T[]>.

tools/clang/rewrite_scoped_array/RewriteScopedArray.cpp

Index: tools/clang/rewrite_scoped_array/RewriteScopedArray.cpp
diff --git a/tools/clang/rewrite_scoped_array/RewriteScopedArray.cpp b/tools/clang/rewrite_scoped_array/RewriteScopedArray.cpp
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+++ b/tools/clang/rewrite_scoped_array/RewriteScopedArray.cpp
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+// Copyright (c) 2013 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.
+//
+// This implements a Clang tool to rewrite all instances of scoped_array<T> to
+// scoped_ptr<T[]>. The former is being deprecated in favor of the latter, to
+// allow for an eventual transition from scoped_ptr to unique_ptr.
+
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/Basic/SourceManager.h"
+#include "clang/Frontend/FrontendActions.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Tooling/CommonOptionsParser.h"
+#include "clang/Tooling/Refactoring.h"
+#include "clang/Tooling/Tooling.h"
+#include "llvm/Support/CommandLine.h"
+
+using clang::ast_matchers::MatchFinder;
+using clang::ast_matchers::hasDeclaration;
+using clang::ast_matchers::hasName;
+using clang::ast_matchers::id;
+using clang::ast_matchers::loc;
+using clang::ast_matchers::qualType;
+using clang::ast_matchers::recordDecl;
+using clang::tooling::CommonOptionsParser;
+using clang::tooling::Replacement;
+using clang::tooling::Replacements;
+using llvm::StringRef;
+
+namespace {
+
+class RewriterCallback : public MatchFinder::MatchCallback {
+ public:
+  RewriterCallback(Replacements* replacements) : replacements_(replacements) {}
+  virtual void run(const MatchFinder::MatchResult& result) LLVM_OVERRIDE;
+
+ private:
+  Replacements* const replacements_;
+};
+
+void RewriterCallback::run(const MatchFinder::MatchResult& result) {
+  const clang::TypeLoc type_location =
+      *result.Nodes.getNodeAs<clang::TypeLoc>("loc");
+  clang::CharSourceRange range = clang::CharSourceRange::getTokenRange(
+      result.SourceManager->getSpellingLoc(type_location.getLocStart()),
+      result.SourceManager->getSpellingLoc(type_location.getLocEnd()));
+  // TODO(dcheng): Log an error?
+  if (!range.isValid())
+    return;
+  std::string replacement_text = clang::Lexer::getSourceText(
+      range, *result.SourceManager, result.Context->getLangOpts());
+  // TODO(dcheng): Log errors?
+  if (!StringRef(replacement_text).startswith("scoped_array<") ||
+      !StringRef(replacement_text).endswith(">"))
+    return;
+  replacement_text.replace(strlen("scoped_"), strlen("array"), "ptr");
+  replacement_text.insert(replacement_text.size() - 1, "[]");
+  replacements_->insert(
+      Replacement(*result.SourceManager, range, replacement_text));
+}
+
+}  // namespace
+
+static llvm::cl::extrahelp common_help(CommonOptionsParser::HelpMessage);
+
+int main(int argc, const char* argv[]) {
+  CommonOptionsParser options(argc, argv);
+  clang::tooling::ClangTool tool(options.getCompilations(),
+                                 options.getSourcePathList());
+
+  Replacements replacements;
+  RewriterCallback callback(&replacements);
+  MatchFinder match_finder;
+  match_finder.addMatcher(
+      id("loc",
+         loc(qualType(hasDeclaration(recordDecl(hasName("::scoped_array")))))),
+      &callback);
+
+  int result =
+      tool.run(clang::tooling::newFrontendActionFactory(&match_finder));
+  if (result != 0)
+    return result;
+
+  // Serialization format is documented in tools/clang/scripts/run_tool.py
+  llvm::outs() << "==== BEGIN EDITS ====\n";
+  for (const Replacement& r : replacements) {
+    llvm::outs() << "r:" << r.getFilePath() << ":" << r.getOffset() << ":"
+                 << r.getLength() << ":" << r.getReplacementText() << "\n";
+  }
+  llvm::outs() << "==== END EDITS ====\n";
+
+  return 0;
+}