CocoaConventions.cpp revision 1c87980ef18dbf4669c7194d60138ff9747d7ab7 
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  return NoConvention;
62}
63
64bool cocoa::isRefType(QualType RetTy, StringRef Prefix,
65                      StringRef Name) {
66  // Recursively walk the typedef stack, allowing typedefs of reference types.
67  while (const TypedefType *TD = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
68    StringRef TDName = TD->getDecl()->getIdentifier()->getName();
69    if (TDName.startswith(Prefix) && TDName.endswith("Ref"))
70      return true;
71    // XPC unfortunately uses CF-style function names, but aren't CF types.
72    if (TDName.startswith("xpc_"))
73      return false;
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->hasDefinition())
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(const FunctionDecl *fn) {
131  // For now, *just* base this on the function name, not on anything else.
132
133  const IdentifierInfo *ident = fn->getIdentifier();
134  if (!ident) return false;
135  StringRef functionName = ident->getName();
136
137  StringRef::iterator it = functionName.begin();
138  StringRef::iterator start = it;
139  StringRef::iterator endI = functionName.end();
140
141  while (true) {
142    // Scan for the start of 'create' or 'copy'.
143    for ( ; it != endI ; ++it) {
144      // Search for the first character.  It can either be 'C' or 'c'.
145      char ch = *it;
146      if (ch == 'C' || ch == 'c') {
147        // Make sure this isn't something like 'recreate' or 'Scopy'.
148        if (ch == 'c' && it != start && isalpha(*(it - 1)))
149          continue;
150
151        ++it;
152        break;
153      }
154    }
155
156    // Did we hit the end of the string?  If so, we didn't find a match.
157    if (it == endI)
158      return false;
159
160    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
161    // character.
162    StringRef suffix = functionName.substr(it - start);
163    if (suffix.startswith("reate")) {
164      it += 5;
165    }
166    else if (suffix.startswith("opy")) {
167      it += 3;
168    } else {
169      // Keep scanning.
170      continue;
171    }
172
173    if (it == endI || !islower(*it))
174      return true;
175
176    // If we matched a lowercase character, it isn't the end of the
177    // word.  Keep scanning.
178  }
179
180  return false;
181}
182