Add a clang tool to detect std::move(raw ptr)

tools/clang/move_raw/MoveRaw.cpp

+// Copyright 2017 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.
+//
+// Clang tool to find where std::move is called on a raw pointer.
+// Calling std::move on a raw pointer has no useful effect and is likely a
+// sign of an error (e.g., mistaking a raw pointer for a smart pointer).
+// TODO(crbug.com/731577): Make this a clang-tidy check instead.
+
+#include <memory>
+#include <set>
+#include <string>
+
+#include "clang/AST/ASTContext.h"
+#include "clang/ASTMatchers/ASTMatchFinder.h"
+#include "clang/ASTMatchers/ASTMatchers.h"
+#include "clang/ASTMatchers/ASTMatchersMacros.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"
+#include "llvm/Support/TargetSelect.h"
+
+using namespace clang::ast_matchers;
+using clang::tooling::CommonOptionsParser;
+
+namespace {
+
+class MoveCallCollector : public MatchFinder::MatchCallback {
+ public:
+  explicit MoveCallCollector(
+      std::set<clang::tooling::Replacement>* replacements)
+      : replacements_(replacements) {}
+  virtual void run(const MatchFinder::MatchResult& result) override;
+
+ private:
+  std::set<clang::tooling::Replacement>* const replacements_;
+};
+
+void MoveCallCollector::run(const MatchFinder::MatchResult& result) {
+  const clang::Expr* callsite =
+      result.Nodes.getNodeAs<clang::Expr>("move_call");
+  replacements_->insert(clang::tooling::Replacement(
+      *result.SourceManager,
+      result.SourceManager->getSpellingLoc(callsite->getLocStart()), 0,
+      "/*This tries to move a raw pointer!*/"));
+}
+
+}  // namespace
+
+static llvm::cl::extrahelp common_help(CommonOptionsParser::HelpMessage);
+
+int main(int argc, const char* argv[]) {
+  // TODO(dcheng): Clang tooling should do this itself.
+  // https://llvm.org/bugs/show_bug.cgi?id=21627
+  llvm::InitializeNativeTarget();
+  llvm::InitializeNativeTargetAsmParser();
+  llvm::cl::OptionCategory category(
+      "Catching red flags: calling std::move on raw pointers");
+  CommonOptionsParser options(argc, argv, category);
+  clang::tooling::ClangTool tool(options.getCompilations(),
+                                 options.getSourcePathList());
+
+  MatchFinder match_finder;
+  std::set<clang::tooling::Replacement> replacements;
+
+  StatementMatcher move_on_raw_matcher =
+      callExpr(argumentCountIs(1), callee(functionDecl(hasName("::std::move"))),
+               hasArgument(0, hasType(pointerType())))
+          .bind("move_call");
+  MoveCallCollector callback(&replacements);
+  match_finder.addMatcher(move_on_raw_matcher, &callback);
+
+  std::unique_ptr<clang::tooling::FrontendActionFactory> factory =
+      clang::tooling::newFrontendActionFactory(&match_finder);
+  int result = tool.run(factory.get());
+  if (result != 0)
+    return result;
+
+  if (replacements.empty())
+    return 0;
+
+  // Serialization format is documented in tools/clang/scripts/run_tool.py
+  llvm::outs() << "==== BEGIN EDITS ====\n";
+  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;
+}