100 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 "MultiLevelImplicitPointerConversionCheck.h"10#include "clang/AST/ASTContext.h"11#include "clang/ASTMatchers/ASTMatchFinder.h"12 13using namespace clang::ast_matchers;14 15namespace clang::tidy::bugprone {16 17static unsigned getPointerLevel(const QualType &PtrType) {18 if (!PtrType->isPointerType())19 return 0U;20 21 return 1U + getPointerLevel(PtrType->castAs<PointerType>()->getPointeeType());22}23 24namespace {25 26AST_MATCHER(ImplicitCastExpr, isMultiLevelPointerConversion) {27 const QualType TargetType = Node.getType()28 .getCanonicalType()29 .getNonReferenceType()30 .getUnqualifiedType();31 const QualType SourceType = Node.getSubExpr()32 ->getType()33 .getCanonicalType()34 .getNonReferenceType()35 .getUnqualifiedType();36 37 if (TargetType == SourceType)38 return false;39 40 const unsigned TargetPtrLevel = getPointerLevel(TargetType);41 if (0U == TargetPtrLevel)42 return false;43 44 const unsigned SourcePtrLevel = getPointerLevel(SourceType);45 if (0U == SourcePtrLevel)46 return false;47 48 return SourcePtrLevel != TargetPtrLevel;49}50 51AST_MATCHER(QualType, isPointerType) {52 const QualType Type =53 Node.getCanonicalType().getNonReferenceType().getUnqualifiedType();54 55 return !Type.isNull() && Type->isPointerType();56}57 58} // namespace59 60MultiLevelImplicitPointerConversionCheck::61 MultiLevelImplicitPointerConversionCheck(StringRef Name,62 ClangTidyContext *Context)63 : ClangTidyCheck(Name, Context), EnableInC(Options.get("EnableInC", true)) {64}65 66void MultiLevelImplicitPointerConversionCheck::storeOptions(67 ClangTidyOptions::OptionMap &Opts) {68 Options.store(Opts, "EnableInC", EnableInC);69}70 71void MultiLevelImplicitPointerConversionCheck::registerMatchers(72 MatchFinder *Finder) {73 Finder->addMatcher(74 implicitCastExpr(hasCastKind(CK_BitCast), isMultiLevelPointerConversion(),75 unless(hasParent(explicitCastExpr(76 hasDestinationType(isPointerType())))))77 .bind("expr"),78 this);79}80 81std::optional<TraversalKind>82MultiLevelImplicitPointerConversionCheck::getCheckTraversalKind() const {83 return TK_AsIs;84}85 86void MultiLevelImplicitPointerConversionCheck::check(87 const MatchFinder::MatchResult &Result) {88 const auto *MatchedExpr = Result.Nodes.getNodeAs<ImplicitCastExpr>("expr");89 const QualType Target =90 MatchedExpr->getType().getDesugaredType(*Result.Context);91 const QualType Source =92 MatchedExpr->getSubExpr()->getType().getDesugaredType(*Result.Context);93 94 diag(MatchedExpr->getExprLoc(), "multilevel pointer conversion from %0 to "95 "%1, please use explicit cast")96 << Source << Target;97}98 99} // namespace clang::tidy::bugprone100