CocoaConventions.cpp revision 3060178ad9df29789505c1e6debcfc80a3a13587 
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"
20using namespace clang;
21using namespace ento;
22
23// The "fundamental rule" for naming conventions of methods:
24//  (url broken into two lines)
25//  http://developer.apple.com/documentation/Cocoa/Conceptual/
26//     MemoryMgmt/Tasks/MemoryManagementRules.html
27//
28// "You take ownership of an object if you create it using a method whose name
29//  begins with "alloc" or "new" or contains "copy" (for example, alloc,
30//  newObject, or mutableCopy), or if you send it a retain message. You are
31//  responsible for relinquishing ownership of objects you own using release
32//  or autorelease. Any other time you receive an object, you must
33//  not release it."
34//
35
36cocoa::NamingConvention cocoa::deriveNamingConvention(Selector S,
37                                                    const ObjCMethodDecl *MD) {
38  switch (MD && MD->hasAttr<ObjCMethodFamilyAttr>()? MD->getMethodFamily()
39                                                   : S.getMethodFamily()) {
40  case OMF_None:
41  case OMF_autorelease:
42  case OMF_dealloc:
43  case OMF_release:
44  case OMF_retain:
45  case OMF_retainCount:
46  case OMF_self:
47  case OMF_performSelector:
48    return NoConvention;
49
50  case OMF_init:
51    return InitRule;
52
53  case OMF_alloc:
54  case OMF_copy:
55  case OMF_mutableCopy:
56  case OMF_new:
57    return CreateRule;
58  }
59  llvm_unreachable("unexpected naming convention");
60  return NoConvention;
61}
62
63bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
64                      StringRef Name) {
65  // Recursively walk the typedef stack, allowing typedefs of reference types.
66  while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
67    StringRef TDName = TD->getDecl()->getIdentifier()->getName();
68    if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
69      return true;
70
71    RetTy = TD->getDecl()->getUnderlyingType();
72  }
73
74  if (Name.empty())
75    return false;
76
77  // Is the type void*?
78  const PointerType* PT = RetTy->getAs<PointerType>();
79  if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
80    return false;
81
82  // Does the name start with the prefix?
83  return Name.startswith(Prefix);
84}
85
86bool coreFoundation::isCFObjectRef(QualType T) {
87  return cocoa::isRefType(T, "CF") || // Core Foundation.
88         cocoa::isRefType(T, "CG") || // Core Graphics.
89         cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
90         cocoa::isRefType(T, "DADissenter") ||
91         cocoa::isRefType(T, "DASessionRef");
92}
93
94
95bool cocoa::isCocoaObjectRef(QualType Ty) {
96  if (!Ty->isObjCObjectPointerType())
97    return false;
98
99  const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
100
101  // Can be true for objects with the 'NSObject' attribute.
102  if (!PT)
103    return true;
104
105  // We assume that id<..>, id, Class, and Class<..> all represent tracked
106  // objects.
107  if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
108      PT->isObjCClassType() || PT->isObjCQualifiedClassType())
109    return true;
110
111  // Does the interface subclass NSObject?
112  // FIXME: We can memoize here if this gets too expensive.
113  const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
114
115  // Assume that anything declared with a forward declaration and no
116  // @interface subclasses NSObject.
117  if (ID->isForwardDecl())
118    return true;
119
120  for ( ; ID ; ID = ID->getSuperClass())
121    if (ID->getIdentifier()->getName() == "NSObject")
122      return true;
123
124  return false;
125}
126
127bool coreFoundation::followsCreateRule(StringRef functionName) {
128  StringRef::iterator it = functionName.begin();
129  StringRef::iterator start = it;
130  StringRef::iterator endI = functionName.end();
131
132  while (true) {
133    // Scan for the start of 'create' or 'copy'.
134    for ( ; it != endI ; ++it) {
135      // Search for the first character.  It can either be 'C' or 'c'.
136      char ch = *it;
137      if (ch == 'C' || ch == 'c') {
138        ++it;
139        break;
140      }
141    }
142
143    // Did we hit the end of the string?  If so, we didn't find a match.
144    if (it == endI)
145      return false;
146
147    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
148    // character.
149    StringRef suffix = functionName.substr(it - start);
150    if (suffix.startswith("reate")) {
151      it += 5;
152    }
153    else if (suffix.startswith("opy")) {
154      it += 3;
155    } else {
156      // Keep scanning.
157      continue;
158    }
159
160    if (it == endI || !islower(*it))
161      return true;
162
163    // If we matched a lowercase character, it isn't the end of the
164    // word.  Keep scanning.
165  }
166
167  return false;
168}
169