1 //===--- CloexecCheck.cpp - clang-tidy-------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 #include "CloexecCheck.h"
10 #include "../utils/ASTUtils.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/ASTMatchers/ASTMatchFinder.h"
13 #include "clang/Lex/Lexer.h"
14
15 using namespace clang::ast_matchers;
16
17 namespace clang::tidy::android {
18
19 namespace {
20 // Helper function to form the correct string mode for Type3.
21 // Build the replace text. If it's string constant, add <Mode> directly in the
22 // end of the string. Else, add <Mode>.
buildFixMsgForStringFlag(const Expr * Arg,const SourceManager & SM,const LangOptions & LangOpts,char Mode)23 std::string buildFixMsgForStringFlag(const Expr *Arg, const SourceManager &SM,
24 const LangOptions &LangOpts, char Mode) {
25 if (Arg->getBeginLoc().isMacroID())
26 return (Lexer::getSourceText(
27 CharSourceRange::getTokenRange(Arg->getSourceRange()), SM,
28 LangOpts) +
29 " \"" + Twine(Mode) + "\"")
30 .str();
31
32 StringRef SR = cast<StringLiteral>(Arg->IgnoreParenCasts())->getString();
33 return ("\"" + SR + Twine(Mode) + "\"").str();
34 }
35 } // namespace
36
37 const char *CloexecCheck::FuncDeclBindingStr = "funcDecl";
38
39 const char *CloexecCheck::FuncBindingStr ="func";
40
registerMatchersImpl(MatchFinder * Finder,internal::Matcher<FunctionDecl> Function)41 void CloexecCheck::registerMatchersImpl(
42 MatchFinder *Finder, internal::Matcher<FunctionDecl> Function) {
43 // We assume all the checked APIs are C functions.
44 Finder->addMatcher(
45 callExpr(
46 callee(functionDecl(isExternC(), Function).bind(FuncDeclBindingStr)))
47 .bind(FuncBindingStr),
48 this);
49 }
50
insertMacroFlag(const MatchFinder::MatchResult & Result,StringRef MacroFlag,int ArgPos)51 void CloexecCheck::insertMacroFlag(const MatchFinder::MatchResult &Result,
52 StringRef MacroFlag, int ArgPos) {
53 const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>(FuncBindingStr);
54 const auto *FlagArg = MatchedCall->getArg(ArgPos);
55 const auto *FD = Result.Nodes.getNodeAs<FunctionDecl>(FuncDeclBindingStr);
56 SourceManager &SM = *Result.SourceManager;
57
58 if (utils::exprHasBitFlagWithSpelling(FlagArg->IgnoreParenCasts(), SM,
59 Result.Context->getLangOpts(),
60 MacroFlag))
61 return;
62
63 SourceLocation EndLoc =
64 Lexer::getLocForEndOfToken(SM.getFileLoc(FlagArg->getEndLoc()), 0, SM,
65 Result.Context->getLangOpts());
66
67 diag(EndLoc, "%0 should use %1 where possible")
68 << FD << MacroFlag
69 << FixItHint::CreateInsertion(EndLoc, (Twine(" | ") + MacroFlag).str());
70 }
71
replaceFunc(const MatchFinder::MatchResult & Result,StringRef WarningMsg,StringRef FixMsg)72 void CloexecCheck::replaceFunc(const MatchFinder::MatchResult &Result,
73 StringRef WarningMsg, StringRef FixMsg) {
74 const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>(FuncBindingStr);
75 diag(MatchedCall->getBeginLoc(), WarningMsg)
76 << FixItHint::CreateReplacement(MatchedCall->getSourceRange(), FixMsg);
77 }
78
insertStringFlag(const ast_matchers::MatchFinder::MatchResult & Result,const char Mode,const int ArgPos)79 void CloexecCheck::insertStringFlag(
80 const ast_matchers::MatchFinder::MatchResult &Result, const char Mode,
81 const int ArgPos) {
82 const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>(FuncBindingStr);
83 const auto *FD = Result.Nodes.getNodeAs<FunctionDecl>(FuncDeclBindingStr);
84 const auto *ModeArg = MatchedCall->getArg(ArgPos);
85
86 // Check if the <Mode> may be in the mode string.
87 const auto *ModeStr = dyn_cast<StringLiteral>(ModeArg->IgnoreParenCasts());
88 if (!ModeStr || ModeStr->getString().contains(Mode))
89 return;
90
91 std::string ReplacementText = buildFixMsgForStringFlag(
92 ModeArg, *Result.SourceManager, Result.Context->getLangOpts(), Mode);
93
94 diag(ModeArg->getBeginLoc(), "use %0 mode '%1' to set O_CLOEXEC")
95 << FD << std::string(1, Mode)
96 << FixItHint::CreateReplacement(ModeArg->getSourceRange(),
97 ReplacementText);
98 }
99
getSpellingArg(const MatchFinder::MatchResult & Result,int N) const100 StringRef CloexecCheck::getSpellingArg(const MatchFinder::MatchResult &Result,
101 int N) const {
102 const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>(FuncBindingStr);
103 const SourceManager &SM = *Result.SourceManager;
104 return Lexer::getSourceText(
105 CharSourceRange::getTokenRange(MatchedCall->getArg(N)->getSourceRange()),
106 SM, Result.Context->getLangOpts());
107 }
108
109 } // namespace clang::tidy::android
110