93 lines · cpp
1//===----------------------------------------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "PosixReturnCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/ASTMatchers/ASTMatchFinder.h"12#include "clang/ASTMatchers/ASTMatchers.h"13#include "clang/Lex/Lexer.h"14 15using namespace clang::ast_matchers;16 17namespace clang::tidy::bugprone {18 19static StringRef getFunctionSpelling(const MatchFinder::MatchResult &Result) {20 const auto *MatchedCall = Result.Nodes.getNodeAs<CallExpr>("call");21 const SourceManager &SM = *Result.SourceManager;22 return Lexer::getSourceText(CharSourceRange::getTokenRange(23 MatchedCall->getCallee()->getSourceRange()),24 SM, Result.Context->getLangOpts());25}26 27void PosixReturnCheck::registerMatchers(MatchFinder *Finder) {28 const auto PosixCall =29 callExpr(callee(functionDecl(30 anyOf(matchesName("^::posix_"), matchesName("^::pthread_")),31 unless(hasName("::posix_openpt")))))32 .bind("call");33 const auto ZeroIntegerLiteral = integerLiteral(equals(0));34 const auto NegIntegerLiteral =35 unaryOperator(hasOperatorName("-"), hasUnaryOperand(integerLiteral()));36 37 Finder->addMatcher(38 binaryOperator(39 anyOf(allOf(hasOperatorName("<"), hasLHS(PosixCall),40 hasRHS(ZeroIntegerLiteral)),41 allOf(hasOperatorName(">"), hasLHS(ZeroIntegerLiteral),42 hasRHS(PosixCall))))43 .bind("ltzop"),44 this);45 Finder->addMatcher(46 binaryOperator(47 anyOf(allOf(hasOperatorName(">="), hasLHS(PosixCall),48 hasRHS(ZeroIntegerLiteral)),49 allOf(hasOperatorName("<="), hasLHS(ZeroIntegerLiteral),50 hasRHS(PosixCall))))51 .bind("atop"),52 this);53 Finder->addMatcher(binaryOperator(hasAnyOperatorName("==", "!="),54 hasOperands(PosixCall, NegIntegerLiteral))55 .bind("binop"),56 this);57 Finder->addMatcher(58 binaryOperator(anyOf(allOf(hasAnyOperatorName("<=", "<"),59 hasLHS(PosixCall), hasRHS(NegIntegerLiteral)),60 allOf(hasAnyOperatorName(">", ">="),61 hasLHS(NegIntegerLiteral), hasRHS(PosixCall))))62 .bind("binop"),63 this);64}65 66void PosixReturnCheck::check(const MatchFinder::MatchResult &Result) {67 if (const auto *LessThanZeroOp =68 Result.Nodes.getNodeAs<BinaryOperator>("ltzop")) {69 const SourceLocation OperatorLoc = LessThanZeroOp->getOperatorLoc();70 const StringRef NewBinOp =71 LessThanZeroOp->getOpcode() == BinaryOperator::Opcode::BO_LT ? ">"72 : "<";73 diag(OperatorLoc, "the comparison always evaluates to false because %0 "74 "always returns non-negative values")75 << getFunctionSpelling(Result)76 << FixItHint::CreateReplacement(OperatorLoc, NewBinOp);77 return;78 }79 if (const auto *AlwaysTrueOp =80 Result.Nodes.getNodeAs<BinaryOperator>("atop")) {81 diag(AlwaysTrueOp->getOperatorLoc(),82 "the comparison always evaluates to true because %0 always returns "83 "non-negative values")84 << getFunctionSpelling(Result);85 return;86 }87 const auto *BinOp = Result.Nodes.getNodeAs<BinaryOperator>("binop");88 diag(BinOp->getOperatorLoc(), "%0 only returns non-negative values")89 << getFunctionSpelling(Result);90}91 92} // namespace clang::tidy::bugprone93