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
|
//=- 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/Analysis/LocalCheckers.h"
#include "clang/Analysis/PathDiagnostic.h"
#include "clang/Analysis/PathSensitive/BugReporter.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/Type.h"
#include "clang/AST/ASTContext.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/Support/raw_ostream.h"
using namespace clang;
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) {
QualType ResDerived = MethDerived->getResultType();
QualType ResAncestor = MethAncestor->getResultType();
if (!AreTypesCompatible(ResDerived, ResAncestor, Ctx)) {
std::string sbuf;
llvm::raw_string_ostream os(sbuf);
os << "The Objective-C class '"
<< MethDerived->getClassInterface()->getNameAsString()
<< "', which is derived from class '"
<< MethAncestor->getClassInterface()->getNameAsString()
<< "', defines the instance method '"
<< MethDerived->getSelector().getAsString()
<< "' whose return type is '"
<< ResDerived.getAsString()
<< "'. A method with the same name (same selector) is also defined in "
"class '"
<< MethAncestor->getClassInterface()->getNameAsString()
<< "' and has a return type of '"
<< ResAncestor.getAsString()
<< "'. These two types are incompatible, and may result in undefined "
"behavior for clients of these classes.";
BR.EmitBasicReport("Incompatible instance method return type",
os.str().c_str(), MethDerived->getLocStart());
}
}
void clang::CheckObjCInstMethSignature(const ObjCImplementationDecl* ID,
BugReporter& BR) {
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 (ObjCImplementationDecl::instmeth_iterator I=ID->instmeth_begin(),
E=ID->instmeth_end(); I!=E; ++I) {
ObjCMethodDecl* M = *I;
IMeths[M->getSelector()] = M;
++NumMethods;
}
// Now recurse the class hierarchy chain looking for methods with the
// same signatures.
while (C && NumMethods) {
for (ObjCInterfaceDecl::instmeth_iterator I=C->instmeth_begin(),
E=C->instmeth_end(); I!=E; ++I) {
ObjCMethodDecl* M = *I;
Selector S = M->getSelector();
MapTy::iterator MI = IMeths.find(S);
if (MI == IMeths.end() || MI->second == 0)
continue;
--NumMethods;
ObjCMethodDecl* MethDerived = MI->second;
MI->second = 0;
CompareReturnTypes(MethDerived, M, BR, Ctx, ID);
}
C = C->getSuperClass();
}
}
|
