1 //=- CheckObjCInstMethodRetTy.cpp - Check ObjC method signatures -*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a CheckObjCInstMethSignature, a flow-insenstive check
11 // that determines if an Objective-C class interface incorrectly redefines
12 // the method signature in a subclass.
14 //===----------------------------------------------------------------------===//
16 #include "ClangSACheckers.h"
17 #include "clang/StaticAnalyzer/Core/Checker.h"
18 #include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
19 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
20 #include "clang/AST/DeclObjC.h"
21 #include "clang/AST/Type.h"
22 #include "clang/AST/ASTContext.h"
24 #include "llvm/ADT/DenseMap.h"
25 #include "llvm/Support/raw_ostream.h"
27 using namespace clang;
30 static bool AreTypesCompatible(QualType Derived, QualType Ancestor,
33 // Right now don't compare the compatibility of pointers. That involves
34 // looking at subtyping relationships. FIXME: Future patch.
35 if (Derived->isAnyPointerType() && Ancestor->isAnyPointerType())
38 return C.typesAreCompatible(Derived, Ancestor);
41 static void CompareReturnTypes(const ObjCMethodDecl *MethDerived,
42 const ObjCMethodDecl *MethAncestor,
43 BugReporter &BR, ASTContext &Ctx,
44 const ObjCImplementationDecl *ID) {
46 QualType ResDerived = MethDerived->getResultType();
47 QualType ResAncestor = MethAncestor->getResultType();
49 if (!AreTypesCompatible(ResDerived, ResAncestor, Ctx)) {
51 llvm::raw_string_ostream os(sbuf);
53 os << "The Objective-C class '"
54 << *MethDerived->getClassInterface()
55 << "', which is derived from class '"
56 << *MethAncestor->getClassInterface()
57 << "', defines the instance method '"
58 << MethDerived->getSelector().getAsString()
59 << "' whose return type is '"
60 << ResDerived.getAsString()
61 << "'. A method with the same name (same selector) is also defined in "
63 << *MethAncestor->getClassInterface()
64 << "' and has a return type of '"
65 << ResAncestor.getAsString()
66 << "'. These two types are incompatible, and may result in undefined "
67 "behavior for clients of these classes.";
69 PathDiagnosticLocation MethDLoc =
70 PathDiagnosticLocation::createBegin(MethDerived,
71 BR.getSourceManager());
73 BR.EmitBasicReport("Incompatible instance method return type",
78 static void CheckObjCInstMethSignature(const ObjCImplementationDecl *ID,
81 const ObjCInterfaceDecl *D = ID->getClassInterface();
82 const ObjCInterfaceDecl *C = D->getSuperClass();
87 ASTContext &Ctx = BR.getContext();
89 // Build a DenseMap of the methods for quick querying.
90 typedef llvm::DenseMap<Selector,ObjCMethodDecl*> MapTy;
92 unsigned NumMethods = 0;
94 for (ObjCImplementationDecl::instmeth_iterator I=ID->instmeth_begin(),
95 E=ID->instmeth_end(); I!=E; ++I) {
97 ObjCMethodDecl *M = *I;
98 IMeths[M->getSelector()] = M;
102 // Now recurse the class hierarchy chain looking for methods with the
104 while (C && NumMethods) {
105 for (ObjCInterfaceDecl::instmeth_iterator I=C->instmeth_begin(),
106 E=C->instmeth_end(); I!=E; ++I) {
108 ObjCMethodDecl *M = *I;
109 Selector S = M->getSelector();
111 MapTy::iterator MI = IMeths.find(S);
113 if (MI == IMeths.end() || MI->second == 0)
117 ObjCMethodDecl *MethDerived = MI->second;
120 CompareReturnTypes(MethDerived, M, BR, Ctx, ID);
123 C = C->getSuperClass();
127 //===----------------------------------------------------------------------===//
128 // ObjCMethSigsChecker
129 //===----------------------------------------------------------------------===//
132 class ObjCMethSigsChecker : public Checker<
133 check::ASTDecl<ObjCImplementationDecl> > {
135 void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& mgr,
136 BugReporter &BR) const {
137 CheckObjCInstMethSignature(D, BR);
142 void ento::registerObjCMethSigsChecker(CheckerManager &mgr) {
143 mgr.registerChecker<ObjCMethSigsChecker>();