1// Copyright 2016 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4//
5// This file containts a clang tool to update base::Bind() callers:
6//  * Remove unneeded scoped_refptr<>::get() on method binding.
7
8#include <assert.h>
9#include <algorithm>
10#include <memory>
11#include <string>
12
13#include "clang/AST/ASTContext.h"
14#include "clang/ASTMatchers/ASTMatchers.h"
15#include "clang/ASTMatchers/ASTMatchersMacros.h"
16#include "clang/ASTMatchers/ASTMatchFinder.h"
17#include "clang/Basic/SourceManager.h"
18#include "clang/Frontend/FrontendActions.h"
19#include "clang/Lex/Lexer.h"
20#include "clang/Tooling/CommonOptionsParser.h"
21#include "clang/Tooling/Refactoring.h"
22#include "clang/Tooling/Tooling.h"
23#include "llvm/Support/CommandLine.h"
24#include "llvm/Support/TargetSelect.h"
25
26using namespace clang::ast_matchers;
27using clang::tooling::CommonOptionsParser;
28using Replacements = std::vector<clang::tooling::Replacement>;
29
30namespace {
31
32// Remove unneeded scoped_refptr<>::get on a receivers of method bind.
33// Example:
34//   // Before
35//   scoped_refptr<Foo> foo;
36//   base::Bind(&Foo::Bar, foo.get());
37//
38//   // After
39//   scoped_refptr<Foo> foo;
40//   base::Bind(&Foo::Bar, foo);
41//
42class ScopedRefptrGetRewriter : public MatchFinder::MatchCallback {
43 public:
44  explicit ScopedRefptrGetRewriter(Replacements* replacements)
45      : replacements_(replacements) {}
46
47  StatementMatcher GetMatcher() {
48    auto is_bind_call = callee(namedDecl(hasName("::base::Bind")));
49    auto is_method_bind = hasArgument(0, hasType(memberPointerType()));
50    auto is_raw_pointer_receiver = hasArgument(1, hasType(pointerType()));
51    auto is_scoped_refptr_get_call =
52        cxxMemberCallExpr(thisPointerType(namedDecl(hasName("scoped_refptr"))),
53                          callee(namedDecl(hasName("get"))));
54    return callExpr(is_bind_call, is_method_bind, is_raw_pointer_receiver,
55                    hasArgument(1, is_scoped_refptr_get_call),
56                    hasArgument(1, stmt().bind("target")));
57  }
58
59  void run(const MatchFinder::MatchResult& result) override {
60    auto* target = result.Nodes.getNodeAs<clang::CXXMemberCallExpr>("target");
61    auto* member = llvm::cast<clang::MemberExpr>(target->getCallee());
62    assert(target && member && "Unexpected match! No Expr captured!");
63    auto range = clang::CharSourceRange::getTokenRange(
64        result.SourceManager->getSpellingLoc(member->getOperatorLoc()),
65        result.SourceManager->getSpellingLoc(target->getLocEnd()));
66
67    replacements_->emplace_back(*result.SourceManager, range, "");
68  }
69
70 private:
71  Replacements* replacements_;
72};
73
74llvm::cl::extrahelp common_help(CommonOptionsParser::HelpMessage);
75
76}  // namespace.
77
78int main(int argc, const char* argv[]) {
79  llvm::InitializeNativeTarget();
80  llvm::InitializeNativeTargetAsmParser();
81  llvm::cl::OptionCategory category(
82      "Remove raw pointer on the receiver of Bind() target");
83  CommonOptionsParser options(argc, argv, category);
84  clang::tooling::ClangTool tool(options.getCompilations(),
85                                 options.getSourcePathList());
86
87  MatchFinder match_finder;
88  std::vector<clang::tooling::Replacement> replacements;
89
90
91  ScopedRefptrGetRewriter scoped_refptr_rewriter(&replacements);
92  match_finder.addMatcher(scoped_refptr_rewriter.GetMatcher(),
93                          &scoped_refptr_rewriter);
94
95  std::unique_ptr<clang::tooling::FrontendActionFactory> factory =
96      clang::tooling::newFrontendActionFactory(&match_finder);
97  int result = tool.run(factory.get());
98  if (result != 0)
99    return result;
100
101  // Serialization format is documented in tools/clang/scripts/run_tool.py
102  llvm::outs() << "==== BEGIN EDITS ====\n";
103  for (const auto& r : replacements) {
104    std::string replacement_text = r.getReplacementText().str();
105    std::replace(replacement_text.begin(), replacement_text.end(), '\n', '\0');
106    llvm::outs() << "r:::" << r.getFilePath() << ":::" << r.getOffset()
107                 << ":::" << r.getLength() << ":::" << replacement_text << "\n";
108  }
109  llvm::outs() << "==== END EDITS ====\n";
110
111  return 0;
112}
113