1 //===- CocoaConventions.h - Special handling of Cocoa conventions -*- C++ -*--//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements cocoa naming convention analysis.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "clang/Analysis/DomainSpecific/CocoaConventions.h"
15 #include "clang/AST/Decl.h"
16 #include "clang/AST/DeclObjC.h"
17 #include "clang/AST/Type.h"
18 #include "clang/Basic/CharInfo.h"
19 #include "llvm/ADT/StringExtras.h"
20 #include "llvm/Support/ErrorHandling.h"
21
22 using namespace clang;
23 using namespace ento;
24
isRefType(QualType RetTy,StringRef Prefix,StringRef Name)25 bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
26 StringRef Name) {
27 // Recursively walk the typedef stack, allowing typedefs of reference types.
28 while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
29 StringRef TDName = TD->getDecl()->getIdentifier()->getName();
30 if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
31 return true;
32 // XPC unfortunately uses CF-style function names, but aren't CF types.
33 if (TDName.startswith("xpc_"))
34 return false;
35 RetTy = TD->getDecl()->getUnderlyingType();
36 }
37
38 if (Name.empty())
39 return false;
40
41 // Is the type void*?
42 const PointerType* PT = RetTy->getAs<PointerType>();
43 if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
44 return false;
45
46 // Does the name start with the prefix?
47 return Name.startswith(Prefix);
48 }
49
isCFObjectRef(QualType T)50 bool coreFoundation::isCFObjectRef(QualType T) {
51 return cocoa::isRefType(T, "CF") || // Core Foundation.
52 cocoa::isRefType(T, "CG") || // Core Graphics.
53 cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
54 cocoa::isRefType(T, "DADissenter") ||
55 cocoa::isRefType(T, "DASessionRef");
56 }
57
58
isCocoaObjectRef(QualType Ty)59 bool cocoa::isCocoaObjectRef(QualType Ty) {
60 if (!Ty->isObjCObjectPointerType())
61 return false;
62
63 const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
64
65 // Can be true for objects with the 'NSObject' attribute.
66 if (!PT)
67 return true;
68
69 // We assume that id<..>, id, Class, and Class<..> all represent tracked
70 // objects.
71 if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
72 PT->isObjCClassType() || PT->isObjCQualifiedClassType())
73 return true;
74
75 // Does the interface subclass NSObject?
76 // FIXME: We can memoize here if this gets too expensive.
77 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
78
79 // Assume that anything declared with a forward declaration and no
80 // @interface subclasses NSObject.
81 if (!ID->hasDefinition())
82 return true;
83
84 for ( ; ID ; ID = ID->getSuperClass())
85 if (ID->getIdentifier()->getName() == "NSObject")
86 return true;
87
88 return false;
89 }
90
followsCreateRule(const FunctionDecl * fn)91 bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
92 // For now, *just* base this on the function name, not on anything else.
93
94 const IdentifierInfo *ident = fn->getIdentifier();
95 if (!ident) return false;
96 StringRef functionName = ident->getName();
97
98 StringRef::iterator it = functionName.begin();
99 StringRef::iterator start = it;
100 StringRef::iterator endI = functionName.end();
101
102 while (true) {
103 // Scan for the start of 'create' or 'copy'.
104 for ( ; it != endI ; ++it) {
105 // Search for the first character. It can either be 'C' or 'c'.
106 char ch = *it;
107 if (ch == 'C' || ch == 'c') {
108 // Make sure this isn't something like 'recreate' or 'Scopy'.
109 if (ch == 'c' && it != start && isLetter(*(it - 1)))
110 continue;
111
112 ++it;
113 break;
114 }
115 }
116
117 // Did we hit the end of the string? If so, we didn't find a match.
118 if (it == endI)
119 return false;
120
121 // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
122 // character.
123 StringRef suffix = functionName.substr(it - start);
124 if (suffix.startswith("reate")) {
125 it += 5;
126 }
127 else if (suffix.startswith("opy")) {
128 it += 3;
129 } else {
130 // Keep scanning.
131 continue;
132 }
133
134 if (it == endI || !isLowercase(*it))
135 return true;
136
137 // If we matched a lowercase character, it isn't the end of the
138 // word. Keep scanning.
139 }
140 }
141