CocoaConventions.cpp revision 55fc873017f10f6f566b182b70f6fc22aefa3464 
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 "llvm/ADT/StringExtras.h"
19#include "llvm/Support/ErrorHandling.h"
20#include <cctype>
21
22using namespace clang;
23using namespace ento;
24
25bool 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 = dyn_cast<TypedefType>(RetTy.getTypePtr())) {
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
50bool coreFoundation::isCFObjectRef(QualType T) {
51  return cocoa::isRefType(T, "CF") || // Core Foundation.
52         cocoa::isRefType(T, "CG") || // Core Graphics.
53         cocoa::isRefType(T, "DADisk") || // Disk Arbitration API.
54         cocoa::isRefType(T, "DADissenter") ||
55         cocoa::isRefType(T, "DASessionRef");
56}
57
58
59bool cocoa::isCocoaObjectRef(QualType Ty) {
60  if (!Ty->isObjCObjectPointerType())
61    return false;
62
63  const ObjCObjectPointerType *PT = Ty->getAs<ObjCObjectPointerType>();
64
65  // Can be true for objects with the 'NSObject' attribute.
66  if (!PT)
67    return true;
68
69  // We assume that id<..>, id, Class, and Class<..> all represent tracked
70  // objects.
71  if (PT->isObjCIdType() || PT->isObjCQualifiedIdType() ||
72      PT->isObjCClassType() || PT->isObjCQualifiedClassType())
73    return true;
74
75  // Does the interface subclass NSObject?
76  // FIXME: We can memoize here if this gets too expensive.
77  const ObjCInterfaceDecl *ID = PT->getInterfaceDecl();
78
79  // Assume that anything declared with a forward declaration and no
80  // @interface subclasses NSObject.
81  if (!ID->hasDefinition())
82    return true;
83
84  for ( ; ID ; ID = ID->getSuperClass())
85    if (ID->getIdentifier()->getName() == "NSObject")
86      return true;
87
88  return false;
89}
90
91bool coreFoundation::followsCreateRule(const FunctionDecl *fn) {
92  // For now, *just* base this on the function name, not on anything else.
93
94  const IdentifierInfo *ident = fn->getIdentifier();
95  if (!ident) return false;
96  StringRef functionName = ident->getName();
97
98  StringRef::iterator it = functionName.begin();
99  StringRef::iterator start = it;
100  StringRef::iterator endI = functionName.end();
101
102  while (true) {
103    // Scan for the start of 'create' or 'copy'.
104    for ( ; it != endI ; ++it) {
105      // Search for the first character.  It can either be 'C' or 'c'.
106      char ch = *it;
107      if (ch == 'C' || ch == 'c') {
108        // Make sure this isn't something like 'recreate' or 'Scopy'.
109        if (ch == 'c' && it != start && isalpha(*(it - 1)))
110          continue;
111
112        ++it;
113        break;
114      }
115    }
116
117    // Did we hit the end of the string?  If so, we didn't find a match.
118    if (it == endI)
119      return false;
120
121    // Scan for *lowercase* 'reate' or 'opy', followed by no lowercase
122    // character.
123    StringRef suffix = functionName.substr(it - start);
124    if (suffix.startswith("reate")) {
125      it += 5;
126    }
127    else if (suffix.startswith("opy")) {
128      it += 3;
129    } else {
130      // Keep scanning.
131      continue;
132    }
133
134    if (it == endI || !islower(*it))
135      return true;
136
137    // If we matched a lowercase character, it isn't the end of the
138    // word.  Keep scanning.
139  }
140}
141