ObjCPropertyChecker.cpp source code [clang_source_code/lib/StaticAnalyzer/Checkers/ObjCPropertyChecker.cpp]

1	//==- ObjCPropertyChecker.cpp - Check ObjC properties ------------- C++ --==//
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-exception
6	//
7	//===----------------------------------------------------------------------===//
8	//
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.
14	//
15	//===----------------------------------------------------------------------===//
16
17	#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
18	#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
19	#include "clang/StaticAnalyzer/Core/Checker.h"
20
21	using namespace clang;
22	using namespace ento;
23
24	namespace {
25	class ObjCPropertyChecker
26	: public Checker<check::ASTDecl<ObjCPropertyDecl>> {
27	void checkCopyMutable(const ObjCPropertyDecl *D, BugReporter &BR) const;
28
29	public:
30	void checkASTDecl(const ObjCPropertyDecl *D, AnalysisManager &Mgr,
31	BugReporter &BR) const;
32	};
33	} // end anonymous namespace.
34
35	void ObjCPropertyChecker::checkASTDecl(const ObjCPropertyDecl *D,
36	AnalysisManager &Mgr,
37	BugReporter &BR) const {
38	checkCopyMutable(D, BR);
39	}
40
41	void ObjCPropertyChecker::checkCopyMutable(const ObjCPropertyDecl *D,
42	BugReporter &BR) const {
43	if (D->isReadOnly() \|\| D->getSetterKind() != ObjCPropertyDecl::Copy)
44	return;
45
46	QualType T = D->getType();
47	if (!T->isObjCObjectPointerType())
48	return;
49
50	const std::string &PropTypeName(T->getPointeeType().getCanonicalType()
51	.getUnqualifiedType()
52	.getAsString());
53	if (!StringRef(PropTypeName).startswith("NSMutable"))
54	return;
55
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();
62	}
63
64	if (!ImplD \|\| ImplD->HasUserDeclaredSetterMethod(D))
65	return;
66
67	SmallString<128> Str;
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";
71
72	BR.EmitBasicReport(
73	D, this, "Objective-C property misuse", "Logic error", OS.str(),
74	PathDiagnosticLocation::createBegin(D, BR.getSourceManager()),
75	D->getSourceRange());
76	}
77
78	void ento::registerObjCPropertyChecker(CheckerManager &Mgr) {
79	Mgr.registerChecker<ObjCPropertyChecker>();
80	}
81
82	bool ento::shouldRegisterObjCPropertyChecker(const LangOptions &LO) {
83	return true;
84	}
85

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