1 //===--- BadSignalToKillThreadCheck.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 "BadSignalToKillThreadCheck.h"
10 #include "clang/AST/ASTContext.h"
11 #include "clang/ASTMatchers/ASTMatchFinder.h"
12 #include "clang/Lex/Preprocessor.h"
13 
14 using namespace clang::ast_matchers;
15 
16 namespace clang {
17 namespace tidy {
18 namespace bugprone {
19 
20 void BadSignalToKillThreadCheck::registerMatchers(MatchFinder *Finder) {
21   Finder->addMatcher(
22       callExpr(allOf(callee(functionDecl(hasName("::pthread_kill"))),
23                      argumentCountIs(2)),
24                hasArgument(1, integerLiteral().bind("integer-literal")))
25           .bind("thread-kill"),
26       this);
27 }
28 
29 static Preprocessor *PP;
30 
31 void BadSignalToKillThreadCheck::check(const MatchFinder::MatchResult &Result) {
32   const auto IsSigterm = [](const auto &KeyValue) -> bool {
33     return KeyValue.first->getName() == "SIGTERM" &&
34            KeyValue.first->hasMacroDefinition();
35   };
36   const auto TryExpandAsInteger =
37       [](Preprocessor::macro_iterator It) -> Optional<unsigned> {
38     if (It == PP->macro_end())
39       return llvm::None;
40     const MacroInfo *MI = PP->getMacroInfo(It->first);
41     const Token &T = MI->tokens().back();
42     if (!T.isLiteral() || !T.getLiteralData())
43       return llvm::None;
44     StringRef ValueStr = StringRef(T.getLiteralData(), T.getLength());
45 
46     llvm::APInt IntValue;
47     constexpr unsigned AutoSenseRadix = 0;
48     if (ValueStr.getAsInteger(AutoSenseRadix, IntValue))
49       return llvm::None;
50     return IntValue.getZExtValue();
51   };
52 
53   const auto SigtermMacro = llvm::find_if(PP->macros(), IsSigterm);
54 
55   if (!SigtermValue && !(SigtermValue = TryExpandAsInteger(SigtermMacro)))
56     return;
57 
58   const auto *MatchedExpr = Result.Nodes.getNodeAs<Expr>("thread-kill");
59   const auto *MatchedIntLiteral =
60       Result.Nodes.getNodeAs<IntegerLiteral>("integer-literal");
61   if (MatchedIntLiteral->getValue() == *SigtermValue) {
62     diag(MatchedExpr->getBeginLoc(),
63          "thread should not be terminated by raising the 'SIGTERM' signal");
64   }
65 }
66 
67 void BadSignalToKillThreadCheck::registerPPCallbacks(
68     const SourceManager &SM, Preprocessor *Pp, Preprocessor *ModuleExpanderPP) {
69   PP = Pp;
70 }
71 
72 } // namespace bugprone
73 } // namespace tidy
74 } // namespace clang
75