clang-tools  5.0.0
CloexecFopenCheck.cpp
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1 //===--- CloexecFopenCheck.cpp - clang-tidy--------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details. //
7 //===----------------------------------------------------------------------===//
8 
9 #include "CloexecFopenCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/AST/Type.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14 
15 using namespace clang::ast_matchers;
16 
17 namespace clang {
18 namespace tidy {
19 namespace android {
20 
21 namespace {
22 static const char MODE = 'e';
23 
24 // Build the replace text. If it's string constant, add 'e' directly in the end
25 // of the string. Else, add "e".
26 std::string BuildReplaceText(const Expr *Arg, const SourceManager &SM,
27  const LangOptions &LangOpts) {
28  if (Arg->getLocStart().isMacroID())
29  return (Lexer::getSourceText(
30  CharSourceRange::getTokenRange(Arg->getSourceRange()), SM,
31  LangOpts) +
32  " \"" + Twine(MODE) + "\"")
33  .str();
34 
35  StringRef SR = cast<StringLiteral>(Arg->IgnoreParenCasts())->getString();
36  return ("\"" + SR + Twine(MODE) + "\"").str();
37 }
38 } // namespace
39 
40 void CloexecFopenCheck::registerMatchers(MatchFinder *Finder) {
41  auto CharPointerType = hasType(pointerType(pointee(isAnyCharacter())));
42 
43  Finder->addMatcher(
44  callExpr(callee(functionDecl(isExternC(), returns(asString("FILE *")),
45  hasName("fopen"),
46  hasParameter(0, CharPointerType),
47  hasParameter(1, CharPointerType))
48  .bind("funcDecl")))
49  .bind("fopenFn"),
50  this);
51 }
52 
53 void CloexecFopenCheck::check(const MatchFinder::MatchResult &Result) {
54  const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>("fopenFn");
55  const auto *FD = Result.Nodes.getNodeAs<FunctionDecl>("funcDecl");
56  const Expr *ModeArg = MatchedCall->getArg(1);
57 
58  // Check if the 'e' may be in the mode string.
59  const auto *ModeStr = dyn_cast<StringLiteral>(ModeArg->IgnoreParenCasts());
60  if (!ModeStr || (ModeStr->getString().find(MODE) != StringRef::npos))
61  return;
62 
63  const std::string &ReplacementText = BuildReplaceText(
64  ModeArg, *Result.SourceManager, Result.Context->getLangOpts());
65 
66  diag(ModeArg->getLocStart(), "use %0 mode 'e' to set O_CLOEXEC")
67  << FD
68  << FixItHint::CreateReplacement(ModeArg->getSourceRange(),
69  ReplacementText);
70 }
71 
72 } // namespace android
73 } // namespace tidy
74 } // namespace clang
LangOptions LangOpts
Definition: ClangTidy.cpp:253
std::unique_ptr< ast_matchers::MatchFinder > Finder
Definition: ClangTidy.cpp:275
SourceManager & SM