1 //==- ObjCPropertyChecker.cpp - Check ObjC properties ------------*- C++ -*-==//
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-exception
7 //===----------------------------------------------------------------------===//
9 // This checker finds issues with Objective-C properties.
10 // Currently finds only one kind of issue:
11 // - Find synthesized properties with copy attribute of mutable NS collection
12 // types. Calling -copy on such collections produces an immutable copy,
13 // which contradicts the type of the property.
15 //===----------------------------------------------------------------------===//
17 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
18 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
19 #include "clang/StaticAnalyzer/Core/Checker.h"
21 using namespace clang;
25 class ObjCPropertyChecker
26 : public Checker<check::ASTDecl<ObjCPropertyDecl>> {
27 void checkCopyMutable(const ObjCPropertyDecl *D, BugReporter &BR) const;
30 void checkASTDecl(const ObjCPropertyDecl *D, AnalysisManager &Mgr,
31 BugReporter &BR) const;
33 } // end anonymous namespace.
35 void ObjCPropertyChecker::checkASTDecl(const ObjCPropertyDecl *D,
37 BugReporter &BR) const {
38 checkCopyMutable(D, BR);
41 void ObjCPropertyChecker::checkCopyMutable(const ObjCPropertyDecl *D,
42 BugReporter &BR) const {
43 if (D->isReadOnly() || D->getSetterKind() != ObjCPropertyDecl::Copy)
46 QualType T = D->getType();
47 if (!T->isObjCObjectPointerType())
50 const std::string &PropTypeName(T->getPointeeType().getCanonicalType()
53 if (!StringRef(PropTypeName).startswith("NSMutable"))
56 const ObjCImplDecl *ImplD = nullptr;
57 if (const ObjCInterfaceDecl *IntD =
58 dyn_cast<ObjCInterfaceDecl>(D->getDeclContext())) {
59 ImplD = IntD->getImplementation();
60 } else if (auto *CatD = dyn_cast<ObjCCategoryDecl>(D->getDeclContext())) {
61 ImplD = CatD->getClassInterface()->getImplementation();
64 if (!ImplD || ImplD->HasUserDeclaredSetterMethod(D))
68 llvm::raw_svector_ostream OS(Str);
69 OS << "Property of mutable type '" << PropTypeName
70 << "' has 'copy' attribute; an immutable object will be stored instead";
73 D, this, "Objective-C property misuse", "Logic error", OS.str(),
74 PathDiagnosticLocation::createBegin(D, BR.getSourceManager()),
78 void ento::registerObjCPropertyChecker(CheckerManager &Mgr) {
79 Mgr.registerChecker<ObjCPropertyChecker>();
82 bool ento::shouldRegisterObjCPropertyChecker(const LangOptions &LO) {