CocoaConventions.cpp revision 3026348bd4c13a0f83b59839f64065e0fcbea253 
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_finalize:
44  case OMF_release:
45  case OMF_retain:
46  case OMF_retainCount:
47  case OMF_self:
48  case OMF_performSelector:
49    return NoConvention;
50
51  case OMF_init:
52    return InitRule;
53
54  case OMF_alloc:
55  case OMF_copy:
56  case OMF_mutableCopy:
57  case OMF_new:
58    return CreateRule;
59  }
60  llvm_unreachable("unexpected naming convention");
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    // XPC unfortunately uses CF-style function names, but aren't CF types.
71    if (TDName.startswith("xpc_"))
72      return false;
73    RetTy = TD->getDecl()->getUnderlyingType();
74  }
75
76  if (Name.empty())
77    return false;
78
79  // Is the type void*?
80  const PointerType* PT = RetTy->getAs<PointerType>();
81  if (!(PT->getPointeeType().getUnqualifiedType()->isVoidType()))
82    return false;
83
84  // Does the name start with the prefix?
85  return Name.startswith(Prefix);
86}
87
88bool coreFoundation::isCFObjectRef(QualType T) {
89  return cocoa::isRefType(T, "CF") || // Core Foundation.
90         cocoa::isRefType(T, "CG") || // Core Graphics.
91         cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
92         cocoa::isRefType(T, "DADissenter") ||
93         cocoa::isRefType(T, "DASessionRef");
94}
95
96
97bool cocoa::isCocoaObjectRef(QualType Ty) {
98  if (!Ty->isObjCObjectPointerType())
99    return false;
100
101  const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
102
103  // Can be true for objects with the 'NSObject' attribute.
104  if (!PT)
105    return true;
106
107  // We assume that id<..>, id, Class, and Class<..> all represent tracked
108  // objects.
109  if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
110      PT->isObjCClassType() || PT->isObjCQualifiedClassType())
111    return true;
112
113  // Does the interface subclass NSObject?
114  // FIXME: We can memoize here if this gets too expensive.
115  const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
116
117  // Assume that anything declared with a forward declaration and no
118  // @interface subclasses NSObject.
119  if (!ID->hasDefinition())
120    return true;
121
122  for ( ; ID ; ID = ID->getSuperClass())
123    if (ID->getIdentifier()->getName() == "NSObject")
124      return true;
125
126  return false;
127}
128
129bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
130  // For now, *just* base this on the function name, not on anything else.
131
132  const IdentifierInfo *ident = fn->getIdentifier();
133  if (!ident) return false;
134  StringRef functionName = ident->getName();
135
136  StringRef::iterator it = functionName.begin();
137  StringRef::iterator start = it;
138  StringRef::iterator endI = functionName.end();
139
140  while (true) {
141    // Scan for the start of 'create' or 'copy'.
142    for ( ; it != endI ; ++it) {
143      // Search for the first character.  It can either be 'C' or 'c'.
144      char ch = *it;
145      if (ch == 'C' || ch == 'c') {
146        // Make sure this isn't something like 'recreate' or 'Scopy'.
147        if (ch == 'c' && it != start && isalpha(*(it - 1)))
148          continue;
149
150        ++it;
151        break;
152      }
153    }
154
155    // Did we hit the end of the string?  If so, we didn't find a match.
156    if (it == endI)
157      return false;
158
159    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
160    // character.
161    StringRef suffix = functionName.substr(it - start);
162    if (suffix.startswith("reate")) {
163      it += 5;
164    }
165    else if (suffix.startswith("opy")) {
166      it += 3;
167    } else {
168      // Keep scanning.
169      continue;
170    }
171
172    if (it == endI || !islower(*it))
173      return true;
174
175    // If we matched a lowercase character, it isn't the end of the
176    // word.  Keep scanning.
177  }
178}
179