1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
//=- CheckObjCInstMethodRetTy.cpp - Check ObjC method signatures -*- C++ -*-==//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a CheckObjCInstMethSignature, a flow-insenstive check
// that determines if an Objective-C class interface incorrectly redefines
// the method signature in a subclass.
//
//===----------------------------------------------------------------------===//
#include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Type.h"
#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h"
#include "clang/StaticAnalyzer/Core/Checker.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
using namespace ento;
static bool AreTypesCompatible(QualType Derived, QualType Ancestor,
ASTContext &C) {
// Right now don't compare the compatibility of pointers. That involves
// looking at subtyping relationships. FIXME: Future patch.
if (Derived->isAnyPointerType() && Ancestor->isAnyPointerType())
return true;
return C.typesAreCompatible(Derived, Ancestor);
}
static void CompareReturnTypes(const ObjCMethodDecl *MethDerived,
const ObjCMethodDecl *MethAncestor,
BugReporter &BR, ASTContext &Ctx,
const ObjCImplementationDecl *ID,
const CheckerBase *Checker) {
QualType ResDerived = MethDerived->getReturnType();
QualType ResAncestor = MethAncestor->getReturnType();
if (!AreTypesCompatible(ResDerived, ResAncestor, Ctx)) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "The Objective-C class '"
<< *MethDerived->getClassInterface()
<< "', which is derived from class '"
<< *MethAncestor->getClassInterface()
<< "', defines the instance method '";
MethDerived->getSelector().print(os);
os << "' whose return type is '"
<< ResDerived.getAsString()
<< "'. A method with the same name (same selector) is also defined in "
"class '"
<< *MethAncestor->getClassInterface()
<< "' and has a return type of '"
<< ResAncestor.getAsString()
<< "'. These two types are incompatible, and may result in undefined "
"behavior for clients of these classes.";
PathDiagnosticLocation MethDLoc =
PathDiagnosticLocation::createBegin(MethDerived,
BR.getSourceManager());
BR.EmitBasicReport(
MethDerived, Checker, "Incompatible instance method return type",
categories::CoreFoundationObjectiveC, os.str(), MethDLoc);
}
}
static void CheckObjCInstMethSignature(const ObjCImplementationDecl *ID,
BugReporter &BR,
const CheckerBase *Checker) {
const ObjCInterfaceDecl *D = ID->getClassInterface();
const ObjCInterfaceDecl *C = D->getSuperClass();
if (!C)
return;
ASTContext &Ctx = BR.getContext();
// Build a DenseMap of the methods for quick querying.
typedef llvm::DenseMap<Selector,ObjCMethodDecl*> MapTy;
MapTy IMeths;
unsigned NumMethods = 0;
for (auto *M : ID->instance_methods()) {
IMeths[M->getSelector()] = M;
++NumMethods;
}
// Now recurse the class hierarchy chain looking for methods with the
// same signatures.
while (C && NumMethods) {
for (const auto *M : C->instance_methods()) {
Selector S = M->getSelector();
MapTy::iterator MI = IMeths.find(S);
if (MI == IMeths.end() || MI->second == nullptr)
continue;
--NumMethods;
ObjCMethodDecl *MethDerived = MI->second;
MI->second = nullptr;
CompareReturnTypes(MethDerived, M, BR, Ctx, ID, Checker);
}
C = C->getSuperClass();
}
}
//===----------------------------------------------------------------------===//
// ObjCMethSigsChecker
//===----------------------------------------------------------------------===//
namespace {
class ObjCMethSigsChecker : public Checker<
check::ASTDecl<ObjCImplementationDecl> > {
public:
void checkASTDecl(const ObjCImplementationDecl *D, AnalysisManager& mgr,
BugReporter &BR) const {
CheckObjCInstMethSignature(D, BR, this);
}
};
}
void ento::registerObjCMethSigsChecker(CheckerManager &mgr) {
mgr.registerChecker<ObjCMethSigsChecker>();
}
|
