clang 10.0.0git

ObjCPropertyChecker.cpp
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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 }
ento
clang::ObjCPropertyDecl::Copy
Definition: DeclObjC.h:773
clang::QualType
A (possibly-)qualified type.
Definition: Type.h:654
clang::Type::getPointeeType
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:557
clang::ObjCPropertyDecl::getSetterKind
SetterKind getSetterKind() const
getSetterKind - Return the method used for doing assignment in the property setter.
Definition: DeclObjC.h:908
Checker.h
clang::LangOptions
Keeps track of the various options that can be enabled, which controls the dialect of C or C++ that i...
Definition: LangOptions.h:53
clang::ObjCPropertyDecl::isReadOnly
bool isReadOnly() const
isReadOnly - Return true iff the property has a setter.
Definition: DeclObjC.h:876
clang::ObjCInterfaceDecl
Represents an ObjC class declaration.
Definition: DeclObjC.h:1186
llvm::SmallString< 128 >
BugReporter.h
clang::ObjCContainerDecl::HasUserDeclaredSetterMethod
bool HasUserDeclaredSetterMethod(const ObjCPropertyDecl *P) const
This routine returns &#39;true&#39; if a user declared setter method was found in the class, its protocols, its super classes or categories.
Definition: DeclObjC.cpp:123
clang::Decl::getDeclContext
DeclContext * getDeclContext()
Definition: DeclBase.h:438
BuiltinCheckerRegistration.h
clang::ObjCPropertyDecl::getType
QualType getType() const
Definition: DeclObjC.h:842
clang::ento::PathDiagnosticLocation::createBegin
static PathDiagnosticLocation createBegin(const Decl *D, const SourceManager &SM)
Create a location for the beginning of the declaration.
Definition: PathDiagnostic.cpp:564
clang::QualType::getCanonicalType
QualType getCanonicalType() const
Definition: Type.h:6295
clang::Type::isObjCObjectPointerType
bool isObjCObjectPointerType() const
Definition: Type.h:6618
clang::ObjCPropertyDecl
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:741
clang::ObjCInterfaceDecl::getImplementation
ObjCImplementationDecl * getImplementation() const
Definition: DeclObjC.cpp:1574
clang::ObjCImplDecl::getClassInterface
const ObjCInterfaceDecl * getClassInterface() const
Definition: DeclObjC.h:2454
clang
Dataflow Directional Tag Classes.
Definition: CFGReachabilityAnalysis.h:21
clang::ObjCImplDecl
Definition: DeclObjC.h:2439
clang::ObjCPropertyDecl::getSourceRange
SourceRange getSourceRange() const override LLVM_READONLY
Source range that this declaration covers.
Definition: DeclObjC.h:963
clang::QualType::getAsString
static std::string getAsString(SplitQualType split, const PrintingPolicy &Policy)
Definition: Type.h:990
clang::ento::ObjKind::OS
Indicates that the tracking object is a descendant of a referenced-counted OSObject, used in the Darwin kernel.
clang::QualType::getUnqualifiedType
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:6336