| //=======- RawPtrRefMemberChecker.cpp ----------------------------*- C++ -*-==// |
| // |
| // 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 "DiagOutputUtils.h" |
| #include "PtrTypesSemantics.h" |
| #include "clang/AST/Decl.h" |
| #include "clang/AST/DeclCXX.h" |
| #include "clang/AST/DynamicRecursiveASTVisitor.h" |
| #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h" |
| #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" |
| #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" |
| #include "clang/StaticAnalyzer/Core/Checker.h" |
| #include "llvm/Support/Casting.h" |
| #include <optional> |
| |
| using namespace clang; |
| using namespace ento; |
| |
| namespace { |
| |
| class RawPtrRefMemberChecker |
| : public Checker<check::ASTDecl<TranslationUnitDecl>> { |
| private: |
| BugType Bug; |
| mutable BugReporter *BR; |
| mutable llvm::DenseSet<const ObjCIvarDecl *> IvarDeclsToIgnore; |
| |
| protected: |
| mutable std::optional<RetainTypeChecker> RTC; |
| |
| public: |
| RawPtrRefMemberChecker(const char *description) |
| : Bug(this, description, "WebKit coding guidelines") {} |
| |
| virtual std::optional<bool> isUnsafePtr(QualType, |
| bool ignoreARC = false) const = 0; |
| virtual const char *typeName() const = 0; |
| virtual const char *invariant() const = 0; |
| |
| void checkASTDecl(const TranslationUnitDecl *TUD, AnalysisManager &MGR, |
| BugReporter &BRArg) const { |
| BR = &BRArg; |
| |
| // The calls to checkAST* from AnalysisConsumer don't |
| // visit template instantiations or lambda classes. We |
| // want to visit those, so we make our own RecursiveASTVisitor. |
| struct LocalVisitor : ConstDynamicRecursiveASTVisitor { |
| const RawPtrRefMemberChecker *Checker; |
| explicit LocalVisitor(const RawPtrRefMemberChecker *Checker) |
| : Checker(Checker) { |
| assert(Checker); |
| ShouldVisitTemplateInstantiations = true; |
| ShouldVisitImplicitCode = false; |
| } |
| |
| bool VisitTypedefDecl(const TypedefDecl *TD) override { |
| if (Checker->RTC) |
| Checker->RTC->visitTypedef(TD); |
| return true; |
| } |
| |
| bool VisitRecordDecl(const RecordDecl *RD) override { |
| Checker->visitRecordDecl(RD); |
| return true; |
| } |
| |
| bool VisitObjCContainerDecl(const ObjCContainerDecl *CD) override { |
| Checker->visitObjCDecl(CD); |
| return true; |
| } |
| }; |
| |
| LocalVisitor visitor(this); |
| if (RTC) |
| RTC->visitTranslationUnitDecl(TUD); |
| visitor.TraverseDecl(TUD); |
| } |
| |
| void visitRecordDecl(const RecordDecl *RD) const { |
| if (shouldSkipDecl(RD)) |
| return; |
| |
| for (auto *Member : RD->fields()) |
| visitMember(Member, RD); |
| } |
| |
| void visitMember(const FieldDecl *Member, const RecordDecl *RD) const { |
| auto QT = Member->getType(); |
| const Type *MemberType = QT.getTypePtrOrNull(); |
| |
| while (MemberType) { |
| auto IsUnsafePtr = isUnsafePtr(QT); |
| if (IsUnsafePtr && *IsUnsafePtr) |
| break; |
| if (!MemberType->isPointerType()) |
| return; |
| QT = MemberType->getPointeeType(); |
| MemberType = QT.getTypePtrOrNull(); |
| } |
| |
| if (!MemberType) |
| return; |
| |
| if (auto *MemberCXXRD = MemberType->getPointeeCXXRecordDecl()) |
| reportBug(Member, MemberType, MemberCXXRD, RD); |
| else if (auto *ObjCDecl = getObjCDecl(MemberType)) |
| reportBug(Member, MemberType, ObjCDecl, RD); |
| } |
| |
| ObjCInterfaceDecl *getObjCDecl(const Type *TypePtr) const { |
| auto *PointeeType = TypePtr->getPointeeType().getTypePtrOrNull(); |
| if (!PointeeType) |
| return nullptr; |
| auto *Desugared = PointeeType->getUnqualifiedDesugaredType(); |
| if (!Desugared) |
| return nullptr; |
| auto *ObjCType = dyn_cast<ObjCInterfaceType>(Desugared); |
| if (!ObjCType) |
| return nullptr; |
| return ObjCType->getDecl(); |
| } |
| |
| void visitObjCDecl(const ObjCContainerDecl *CD) const { |
| if (BR->getSourceManager().isInSystemHeader(CD->getLocation())) |
| return; |
| |
| ObjCContainerDecl::PropertyMap map; |
| CD->collectPropertiesToImplement(map); |
| for (auto it : map) |
| visitObjCPropertyDecl(CD, it.second); |
| |
| if (auto *ID = dyn_cast<ObjCInterfaceDecl>(CD)) { |
| for (auto *Ivar : ID->ivars()) |
| visitIvarDecl(CD, Ivar); |
| return; |
| } |
| if (auto *ID = dyn_cast<ObjCImplementationDecl>(CD)) { |
| for (auto *PropImpl : ID->property_impls()) |
| visitPropImpl(CD, PropImpl); |
| for (auto *Ivar : ID->ivars()) |
| visitIvarDecl(CD, Ivar); |
| return; |
| } |
| } |
| |
| void visitIvarDecl(const ObjCContainerDecl *CD, |
| const ObjCIvarDecl *Ivar) const { |
| if (BR->getSourceManager().isInSystemHeader(Ivar->getLocation())) |
| return; |
| |
| if (IvarDeclsToIgnore.contains(Ivar)) |
| return; |
| |
| auto QT = Ivar->getType(); |
| const Type *IvarType = QT.getTypePtrOrNull(); |
| if (!IvarType) |
| return; |
| |
| auto IsUnsafePtr = isUnsafePtr(QT); |
| if (!IsUnsafePtr || !*IsUnsafePtr) |
| return; |
| |
| IvarDeclsToIgnore.insert(Ivar); |
| |
| if (auto *MemberCXXRD = IvarType->getPointeeCXXRecordDecl()) |
| reportBug(Ivar, IvarType, MemberCXXRD, CD); |
| else if (auto *ObjCDecl = getObjCDecl(IvarType)) |
| reportBug(Ivar, IvarType, ObjCDecl, CD); |
| } |
| |
| void visitObjCPropertyDecl(const ObjCContainerDecl *CD, |
| const ObjCPropertyDecl *PD) const { |
| if (BR->getSourceManager().isInSystemHeader(PD->getLocation())) |
| return; |
| |
| if (const ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CD)) { |
| if (!RTC || !RTC->defaultSynthProperties() || |
| ID->isObjCRequiresPropertyDefs()) |
| return; |
| } |
| |
| auto [IsUnsafe, PropType] = isPropImplUnsafePtr(PD); |
| if (!IsUnsafe) |
| return; |
| |
| if (auto *MemberCXXRD = PropType->getPointeeCXXRecordDecl()) |
| reportBug(PD, PropType, MemberCXXRD, CD); |
| else if (auto *ObjCDecl = getObjCDecl(PropType)) |
| reportBug(PD, PropType, ObjCDecl, CD); |
| } |
| |
| void visitPropImpl(const ObjCContainerDecl *CD, |
| const ObjCPropertyImplDecl *PID) const { |
| if (BR->getSourceManager().isInSystemHeader(PID->getLocation())) |
| return; |
| |
| if (PID->getPropertyImplementation() != ObjCPropertyImplDecl::Synthesize) |
| return; |
| |
| auto *PropDecl = PID->getPropertyDecl(); |
| if (auto *IvarDecl = PID->getPropertyIvarDecl()) { |
| if (IvarDeclsToIgnore.contains(IvarDecl)) |
| return; |
| IvarDeclsToIgnore.insert(IvarDecl); |
| } |
| auto [IsUnsafe, PropType] = isPropImplUnsafePtr(PropDecl); |
| if (!IsUnsafe) |
| return; |
| |
| if (auto *MemberCXXRD = PropType->getPointeeCXXRecordDecl()) |
| reportBug(PropDecl, PropType, MemberCXXRD, CD); |
| else if (auto *ObjCDecl = getObjCDecl(PropType)) |
| reportBug(PropDecl, PropType, ObjCDecl, CD); |
| } |
| |
| std::pair<bool, const Type *> |
| isPropImplUnsafePtr(const ObjCPropertyDecl *PD) const { |
| if (!PD) |
| return {false, nullptr}; |
| |
| auto QT = PD->getType(); |
| const Type *PropType = QT.getTypePtrOrNull(); |
| if (!PropType) |
| return {false, nullptr}; |
| |
| // "assign" property doesn't retain even under ARC so treat it as unsafe. |
| bool ignoreARC = |
| !PD->isReadOnly() && PD->getSetterKind() == ObjCPropertyDecl::Assign; |
| auto IsUnsafePtr = isUnsafePtr(QT, ignoreARC); |
| return {IsUnsafePtr && *IsUnsafePtr, PropType}; |
| } |
| |
| bool shouldSkipDecl(const RecordDecl *RD) const { |
| if (!RD->isThisDeclarationADefinition()) |
| return true; |
| |
| if (RD->isImplicit()) |
| return true; |
| |
| if (RD->isLambda()) |
| return true; |
| |
| // If the construct doesn't have a source file, then it's not something |
| // we want to diagnose. |
| const auto RDLocation = RD->getLocation(); |
| if (!RDLocation.isValid()) |
| return true; |
| |
| const auto Kind = RD->getTagKind(); |
| if (Kind != TagTypeKind::Struct && Kind != TagTypeKind::Class && |
| Kind != TagTypeKind::Union) |
| return true; |
| |
| // Ignore CXXRecords that come from system headers. |
| if (BR->getSourceManager().isInSystemHeader(RDLocation)) |
| return true; |
| |
| // Ref-counted smartpointers actually have raw-pointer to uncounted type as |
| // a member but we trust them to handle it correctly. |
| auto CXXRD = llvm::dyn_cast_or_null<CXXRecordDecl>(RD); |
| if (CXXRD && isSmartPtr(CXXRD)) |
| return true; |
| |
| return false; |
| } |
| |
| template <typename DeclType, typename PointeeType, typename ParentDeclType> |
| void reportBug(const DeclType *Member, const Type *MemberType, |
| const PointeeType *Pointee, |
| const ParentDeclType *ClassCXXRD) const { |
| assert(Member); |
| assert(MemberType); |
| assert(Pointee); |
| |
| SmallString<100> Buf; |
| llvm::raw_svector_ostream Os(Buf); |
| |
| if (isa<ObjCContainerDecl>(ClassCXXRD)) { |
| if (isa<ObjCPropertyDecl>(Member)) |
| Os << "Property "; |
| else |
| Os << "Instance variable "; |
| } else |
| Os << "Member variable "; |
| printQuotedName(Os, Member); |
| Os << " in "; |
| printQuotedQualifiedName(Os, ClassCXXRD); |
| if (Member->getType().getTypePtrOrNull() == MemberType) |
| Os << " is a "; |
| else |
| Os << " contains a "; |
| if (printPointer(Os, MemberType) == PrintDeclKind::Pointer) { |
| auto Typedef = MemberType->getAs<TypedefType>(); |
| assert(Typedef); |
| printQuotedQualifiedName(Os, Typedef->getDecl()); |
| } else |
| printQuotedQualifiedName(Os, Pointee); |
| Os << "; " << invariant() << "."; |
| |
| PathDiagnosticLocation BSLoc(Member->getSourceRange().getBegin(), |
| BR->getSourceManager()); |
| auto Report = std::make_unique<BasicBugReport>(Bug, Os.str(), BSLoc); |
| Report->addRange(Member->getSourceRange()); |
| BR->emitReport(std::move(Report)); |
| } |
| |
| enum class PrintDeclKind { Pointee, Pointer }; |
| virtual PrintDeclKind printPointer(llvm::raw_svector_ostream &Os, |
| const Type *T) const { |
| T = T->getUnqualifiedDesugaredType(); |
| bool IsPtr = isa<PointerType>(T) || isa<ObjCObjectPointerType>(T); |
| Os << (IsPtr ? "raw pointer" : "reference") << " to " << typeName() << " "; |
| return PrintDeclKind::Pointee; |
| } |
| }; |
| |
| class NoUncountedMemberChecker final : public RawPtrRefMemberChecker { |
| public: |
| NoUncountedMemberChecker() |
| : RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to " |
| "reference-countable type") {} |
| |
| std::optional<bool> isUnsafePtr(QualType QT, bool) const final { |
| return isUncountedPtr(QT.getCanonicalType()); |
| } |
| |
| const char *typeName() const final { return "ref-countable type"; } |
| |
| const char *invariant() const final { |
| return "member variables must be Ref, RefPtr, WeakRef, or WeakPtr"; |
| } |
| }; |
| |
| class NoUncheckedPtrMemberChecker final : public RawPtrRefMemberChecker { |
| public: |
| NoUncheckedPtrMemberChecker() |
| : RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to " |
| "checked-pointer capable type") {} |
| |
| std::optional<bool> isUnsafePtr(QualType QT, bool) const final { |
| return isUncheckedPtr(QT.getCanonicalType()); |
| } |
| |
| const char *typeName() const final { return "CheckedPtr capable type"; } |
| |
| const char *invariant() const final { |
| return "member variables must be a CheckedPtr, CheckedRef, WeakRef, or " |
| "WeakPtr"; |
| } |
| }; |
| |
| class NoUnretainedMemberChecker final : public RawPtrRefMemberChecker { |
| public: |
| NoUnretainedMemberChecker() |
| : RawPtrRefMemberChecker("Member variable is a raw-pointer/reference to " |
| "retainable type") { |
| RTC = RetainTypeChecker(); |
| } |
| |
| std::optional<bool> isUnsafePtr(QualType QT, bool ignoreARC) const final { |
| return RTC->isUnretained(QT, ignoreARC); |
| } |
| |
| const char *typeName() const final { return "retainable type"; } |
| |
| const char *invariant() const final { |
| return "member variables must be a RetainPtr"; |
| } |
| |
| PrintDeclKind printPointer(llvm::raw_svector_ostream &Os, |
| const Type *T) const final { |
| if (!isa<ObjCObjectPointerType>(T) && T->getAs<TypedefType>()) { |
| Os << typeName() << " "; |
| return PrintDeclKind::Pointer; |
| } |
| return RawPtrRefMemberChecker::printPointer(Os, T); |
| } |
| }; |
| |
| } // namespace |
| |
| void ento::registerNoUncountedMemberChecker(CheckerManager &Mgr) { |
| Mgr.registerChecker<NoUncountedMemberChecker>(); |
| } |
| |
| bool ento::shouldRegisterNoUncountedMemberChecker(const CheckerManager &Mgr) { |
| return true; |
| } |
| |
| void ento::registerNoUncheckedPtrMemberChecker(CheckerManager &Mgr) { |
| Mgr.registerChecker<NoUncheckedPtrMemberChecker>(); |
| } |
| |
| bool ento::shouldRegisterNoUncheckedPtrMemberChecker( |
| const CheckerManager &Mgr) { |
| return true; |
| } |
| |
| void ento::registerNoUnretainedMemberChecker(CheckerManager &Mgr) { |
| Mgr.registerChecker<NoUnretainedMemberChecker>(); |
| } |
| |
| bool ento::shouldRegisterNoUnretainedMemberChecker(const CheckerManager &Mgr) { |
| return true; |
| } |