CocoaConventions.cpp revision 797a7be0de6fbedaa85082b07ec9ce0674f30773
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/Type.h"
16#include "clang/AST/Decl.h"
17#include "clang/AST/DeclObjC.h"
18#include "llvm/ADT/StringExtras.h"
19#include "llvm/Support/ErrorHandling.h"
20
21using namespace clang;
22using namespace ento;
23
24using llvm::StringRef;
25
26// The "fundamental rule" for naming conventions of methods:
27//  (url broken into two lines)
28//  http://developer.apple.com/documentation/Cocoa/Conceptual/
29//     MemoryMgmt/Tasks/MemoryManagementRules.html
30//
31// "You take ownership of an object if you create it using a method whose name
32//  begins with "alloc" or "new" or contains "copy" (for example, alloc,
33//  newObject, or mutableCopy), or if you send it a retain message. You are
34//  responsible for relinquishing ownership of objects you own using release
35//  or autorelease. Any other time you receive an object, you must
36//  not release it."
37//
38
39cocoa::NamingConvention cocoa::deriveNamingConvention(Selector S,
40                                                    const ObjCMethodDecl *MD) {
41  switch (MD && MD->hasAttr<ObjCMethodFamilyAttr>()? MD->getMethodFamily()
42                                                   : S.getMethodFamily()) {
43  case OMF_None:
44  case OMF_autorelease:
45  case OMF_dealloc:
46  case OMF_release:
47  case OMF_retain:
48  case OMF_retainCount:
49  case OMF_self:
50  case OMF_performSelector:
51    return NoConvention;
52
53  case OMF_init:
54    return InitRule;
55
56  case OMF_alloc:
57  case OMF_copy:
58  case OMF_mutableCopy:
59  case OMF_new:
60    return CreateRule;
61  }
62  llvm_unreachable("unexpected naming convention");
63  return NoConvention;
64}
65
66bool cocoa::isRefType(QualType RetTy, llvm::StringRef Prefix,
67                      llvm::StringRef Name) {
68  // Recursively walk the typedef stack, allowing typedefs of reference types.
69  while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
70    llvm::StringRef TDName = TD->getDecl()->getIdentifier()->getName();
71    if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
72      return true;
73
74    RetTy = TD->getDecl()->getUnderlyingType();
75  }
76
77  if (Name.empty())
78    return false;
79
80  // Is the type void*?
81  const PointerType* PT = RetTy->getAs<PointerType>();
82  if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
83    return false;
84
85  // Does the name start with the prefix?
86  return Name.startswith(Prefix);
87}
88
89bool coreFoundation::isCFObjectRef(QualType T) {
90  return cocoa::isRefType(T, "CF") || // Core Foundation.
91         cocoa::isRefType(T, "CG") || // Core Graphics.
92         cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
93         cocoa::isRefType(T, "DADissenter") ||
94         cocoa::isRefType(T, "DASessionRef");
95}
96
97
98bool cocoa::isCocoaObjectRef(QualType Ty) {
99  if (!Ty->isObjCObjectPointerType())
100    return false;
101
102  const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
103
104  // Can be true for objects with the 'NSObject' attribute.
105  if (!PT)
106    return true;
107
108  // We assume that id<..>, id, Class, and Class<..> all represent tracked
109  // objects.
110  if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
111      PT->isObjCClassType() || PT->isObjCQualifiedClassType())
112    return true;
113
114  // Does the interface subclass NSObject?
115  // FIXME: We can memoize here if this gets too expensive.
116  const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
117
118  // Assume that anything declared with a forward declaration and no
119  // @interface subclasses NSObject.
120  if (ID->isForwardDecl())
121    return true;
122
123  for ( ; ID ; ID = ID->getSuperClass())
124    if (ID->getIdentifier()->getName() == "NSObject")
125      return true;
126
127  return false;
128}
129
130bool coreFoundation::followsCreateRule(llvm::StringRef functionName) {
131  llvm::StringRef::iterator it = functionName.begin();
132  llvm::StringRef::iterator start = it;
133  llvm::StringRef::iterator endI = functionName.end();
134
135  while (true) {
136    // Scan for the start of 'create' or 'copy'.
137    for ( ; it != endI ; ++it) {
138      // Search for the first character.  It can either be 'C' or 'c'.
139      char ch = *it;
140      if (ch == 'C' || ch == 'c') {
141        ++it;
142        break;
143      }
144    }
145
146    // Did we hit the end of the string?  If so, we didn't find a match.
147    if (it == endI)
148      return false;
149
150    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
151    // character.
152    llvm::StringRef suffix = functionName.substr(it - start);
153    if (suffix.startswith("reate")) {
154      it += 5;
155    }
156    else if (suffix.startswith("opy")) {
157      it += 3;
158    }
159    else {
160      // Keep scanning.
161      continue;
162    }
163
164    if (it == endI || !islower(*it))
165      return true;
166
167    // If we matched a lowercase character, it isn't the end of the
168    // word.  Keep scanning.
169  }
170
171  return false;
172}
173