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//===--- PosixReturnCheck.cpp - clang-tidy---------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "PosixReturnCheck.h"
#include "../utils/Matchers.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace bugprone {
static StringRef getFunctionSpelling(const MatchFinder::MatchResult &Result,
const char *BindingStr) {
const CallExpr *MatchedCall = cast<CallExpr>(
(Result.Nodes.getNodeAs<BinaryOperator>(BindingStr))->getLHS());
const SourceManager &SM = *Result.SourceManager;
return Lexer::getSourceText(CharSourceRange::getTokenRange(
MatchedCall->getCallee()->getSourceRange()),
SM, Result.Context->getLangOpts());
}
void PosixReturnCheck::registerMatchers(MatchFinder *Finder) {
Finder->addMatcher(
binaryOperator(
hasOperatorName("<"),
hasLHS(callExpr(callee(functionDecl(
anyOf(matchesName("^::posix_"), matchesName("^::pthread_")),
unless(hasName("::posix_openpt")))))),
hasRHS(integerLiteral(equals(0))))
.bind("ltzop"),
this);
Finder->addMatcher(
binaryOperator(
hasOperatorName(">="),
hasLHS(callExpr(callee(functionDecl(
anyOf(matchesName("^::posix_"), matchesName("^::pthread_")),
unless(hasName("::posix_openpt")))))),
hasRHS(integerLiteral(equals(0))))
.bind("atop"),
this);
Finder->addMatcher(
binaryOperator(
anyOf(hasOperatorName("=="), hasOperatorName("!="),
hasOperatorName("<="), hasOperatorName("<")),
hasLHS(callExpr(callee(functionDecl(
anyOf(matchesName("^::posix_"), matchesName("^::pthread_")),
unless(hasName("::posix_openpt")))))),
hasRHS(unaryOperator(hasOperatorName("-"),
hasUnaryOperand(integerLiteral()))))
.bind("binop"),
this);
}
void PosixReturnCheck::check(const MatchFinder::MatchResult &Result) {
if (const auto *LessThanZeroOp =
Result.Nodes.getNodeAs<BinaryOperator>("ltzop")) {
SourceLocation OperatorLoc = LessThanZeroOp->getOperatorLoc();
diag(OperatorLoc, "the comparison always evaluates to false because %0 "
"always returns non-negative values")
<< getFunctionSpelling(Result, "ltzop")
<< FixItHint::CreateReplacement(OperatorLoc, Twine(">").str());
return;
}
if (const auto *AlwaysTrueOp =
Result.Nodes.getNodeAs<BinaryOperator>("atop")) {
diag(AlwaysTrueOp->getOperatorLoc(),
"the comparison always evaluates to true because %0 always returns "
"non-negative values")
<< getFunctionSpelling(Result, "atop");
return;
}
const auto *BinOp = Result.Nodes.getNodeAs<BinaryOperator>("binop");
diag(BinOp->getOperatorLoc(), "%0 only returns non-negative values")
<< getFunctionSpelling(Result, "binop");
}
} // namespace bugprone
} // namespace tidy
} // namespace clang
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