llvm-project/clang-tools-extra/clang-tidy/bugprone/MisplacedPointerArithmeticI...

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3.7 KiB
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//===--- MisplacedPointerArithmeticInAllocCheck.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 "MisplacedPointerArithmeticInAllocCheck.h"
#include "clang/AST/ASTContext.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/Lex/Lexer.h"
using namespace clang::ast_matchers;
namespace clang {
namespace tidy {
namespace bugprone {
void MisplacedPointerArithmeticInAllocCheck::registerMatchers(
MatchFinder *Finder) {
const auto AllocFunc =
functionDecl(hasAnyName("::malloc", "std::malloc", "::alloca", "::calloc",
"std::calloc", "::realloc", "std::realloc"));
const auto AllocFuncPtr =
varDecl(hasType(isConstQualified()),
hasInitializer(ignoringParenImpCasts(
declRefExpr(hasDeclaration(AllocFunc)))));
const auto AdditiveOperator = binaryOperator(hasAnyOperatorName("+", "-"));
const auto IntExpr = expr(hasType(isInteger()));
const auto AllocCall = callExpr(callee(decl(anyOf(AllocFunc, AllocFuncPtr))));
Finder->addMatcher(
binaryOperator(
AdditiveOperator,
hasLHS(anyOf(AllocCall, castExpr(hasSourceExpression(AllocCall)))),
hasRHS(IntExpr))
.bind("PtrArith"),
this);
const auto New = cxxNewExpr(unless(isArray()));
Finder->addMatcher(binaryOperator(AdditiveOperator,
hasLHS(anyOf(New, castExpr(New))),
hasRHS(IntExpr))
.bind("PtrArith"),
this);
const auto ArrayNew = cxxNewExpr(isArray());
Finder->addMatcher(binaryOperator(AdditiveOperator,
hasLHS(anyOf(ArrayNew, castExpr(ArrayNew))),
hasRHS(IntExpr))
.bind("PtrArith"),
this);
}
void MisplacedPointerArithmeticInAllocCheck::check(
const MatchFinder::MatchResult &Result) {
const auto *PtrArith = Result.Nodes.getNodeAs<BinaryOperator>("PtrArith");
const Expr *AllocExpr = PtrArith->getLHS()->IgnoreParenCasts();
std::string CallName;
if (const auto *Call = dyn_cast<CallExpr>(AllocExpr)) {
const NamedDecl *Func = Call->getDirectCallee();
if (!Func) {
Func = cast<NamedDecl>(Call->getCalleeDecl());
}
CallName = Func->getName().str();
} else {
const auto *New = cast<CXXNewExpr>(AllocExpr);
if (New->isArray()) {
CallName = "operator new[]";
} else {
const auto *CtrE = New->getConstructExpr();
if (!CtrE || !CtrE->getArg(CtrE->getNumArgs() - 1)
->getType()
->isIntegralOrEnumerationType())
return;
CallName = "operator new";
}
}
const SourceRange OldRParen = SourceRange(PtrArith->getLHS()->getEndLoc());
const StringRef RParen =
Lexer::getSourceText(CharSourceRange::getTokenRange(OldRParen),
*Result.SourceManager, getLangOpts());
const SourceLocation NewRParen = Lexer::getLocForEndOfToken(
PtrArith->getEndLoc(), 0, *Result.SourceManager, getLangOpts());
diag(PtrArith->getBeginLoc(),
"arithmetic operation is applied to the result of %0() instead of its "
"size-like argument")
<< CallName << FixItHint::CreateRemoval(OldRParen)
<< FixItHint::CreateInsertion(NewRParen, RParen);
}
} // namespace bugprone
} // namespace tidy
} // namespace clang