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 = RetTy->getAs<TypedefType>()) {
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
50 /// Returns true when the passed-in type is a CF-style reference-counted
51 /// type from the DiskArbitration framework.
isDiskArbitrationAPIRefType(QualType T)52 static bool isDiskArbitrationAPIRefType(QualType T) {
53 return cocoa::isRefType(T, "DADisk") ||
54 cocoa::isRefType(T, "DADissenter") ||
55 cocoa::isRefType(T, "DASessionRef");
56 }
57
isCFObjectRef(QualType T)58 bool coreFoundation::isCFObjectRef(QualType T) {
59 return cocoa::isRefType(T, "CF") || // Core Foundation.
60 cocoa::isRefType(T, "CG") || // Core Graphics.
61 cocoa::isRefType(T, "CM") || // Core Media.
62 isDiskArbitrationAPIRefType(T);
63 }
64
65
isCocoaObjectRef(QualType Ty)66 bool cocoa::isCocoaObjectRef(QualType Ty) {
67 if (!Ty->isObjCObjectPointerType())
68 return false;
69
70 const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
71
72 // Can be true for objects with the 'NSObject' attribute.
73 if (!PT)
74 return true;
75
76 // We assume that id<..>, id, Class, and Class<..> all represent tracked
77 // objects.
78 if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
79 PT->isObjCClassType() || PT->isObjCQualifiedClassType())
80 return true;
81
82 // Does the interface subclass NSObject?
83 // FIXME: We can memoize here if this gets too expensive.
84 const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
85
86 // Assume that anything declared with a forward declaration and no
87 // @interface subclasses NSObject.
88 if (!ID->hasDefinition())
89 return true;
90
91 for ( ; ID ; ID = ID->getSuperClass())
92 if (ID->getIdentifier()->getName() == "NSObject")
93 return true;
94
95 return false;
96 }
97
followsCreateRule(const FunctionDecl * fn)98 bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
99 // For now, *just* base this on the function name, not on anything else.
100
101 const IdentifierInfo *ident = fn->getIdentifier();
102 if (!ident) return false;
103 StringRef functionName = ident->getName();
104
105 StringRef::iterator it = functionName.begin();
106 StringRef::iterator start = it;
107 StringRef::iterator endI = functionName.end();
108
109 while (true) {
110 // Scan for the start of 'create' or 'copy'.
111 for ( ; it != endI ; ++it) {
112 // Search for the first character. It can either be 'C' or 'c'.
113 char ch = *it;
114 if (ch == 'C' || ch == 'c') {
115 // Make sure this isn't something like 'recreate' or 'Scopy'.
116 if (ch == 'c' && it != start && isLetter(*(it - 1)))
117 continue;
118
119 ++it;
120 break;
121 }
122 }
123
124 // Did we hit the end of the string? If so, we didn't find a match.
125 if (it == endI)
126 return false;
127
128 // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
129 // character.
130 StringRef suffix = functionName.substr(it - start);
131 if (suffix.startswith("reate")) {
132 it += 5;
133 }
134 else if (suffix.startswith("opy")) {
135 it += 3;
136 } else {
137 // Keep scanning.
138 continue;
139 }
140
141 if (it == endI || !isLowercase(*it))
142 return true;
143
144 // If we matched a lowercase character, it isn't the end of the
145 // word. Keep scanning.
146 }
147 }
148