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