1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
//===--- TransUnbridgedCasts.cpp - Tranformations to ARC mode -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// rewriteUnbridgedCasts:
//
// A cast of non-objc pointer to an objc one is checked. If the non-objc pointer
// is from a file-level variable, __bridge cast is used to convert it.
// For the result of a function call that we know is +1/+0,
// __bridge/__bridge_transfer is used.
//
// NSString *str = (NSString *)kUTTypePlainText;
// str = b ? kUTTypeRTF : kUTTypePlainText;
// NSString *_uuidString = (NSString *)CFUUIDCreateString(kCFAllocatorDefault,
// _uuid);
// ---->
// NSString *str = (__bridge NSString *)kUTTypePlainText;
// str = (__bridge NSString *)(b ? kUTTypeRTF : kUTTypePlainText);
// NSString *_uuidString = (__bridge_transfer NSString *)
// CFUUIDCreateString(kCFAllocatorDefault, _uuid);
//
// For a C pointer to ObjC, for casting 'self', __bridge is used.
//
// CFStringRef str = (CFStringRef)self;
// ---->
// CFStringRef str = (__bridge CFStringRef)self;
//
//===----------------------------------------------------------------------===//
#include "Transforms.h"
#include "Internals.h"
#include "clang/Analysis/DomainSpecific/CocoaConventions.h"
#include "clang/Sema/SemaDiagnostic.h"
#include "clang/Basic/SourceManager.h"
using namespace clang;
using namespace arcmt;
using namespace trans;
using llvm::StringRef;
namespace {
class UnbridgedCastRewriter : public RecursiveASTVisitor<UnbridgedCastRewriter>{
MigrationPass &Pass;
IdentifierInfo *SelfII;
public:
UnbridgedCastRewriter(MigrationPass &pass) : Pass(pass) {
SelfII = &Pass.Ctx.Idents.get("self");
}
bool VisitCastExpr(CastExpr *E) {
if (E->getCastKind() != CK_AnyPointerToObjCPointerCast
&& E->getCastKind() != CK_BitCast)
return true;
QualType castType = E->getType();
Expr *castExpr = E->getSubExpr();
QualType castExprType = castExpr->getType();
if (castType->isObjCObjectPointerType() &&
castExprType->isObjCObjectPointerType())
return true;
if (!castType->isObjCObjectPointerType() &&
!castExprType->isObjCObjectPointerType())
return true;
bool exprRetainable = castExprType->isObjCIndirectLifetimeType();
bool castRetainable = castType->isObjCIndirectLifetimeType();
if (exprRetainable == castRetainable) return true;
if (castExpr->isNullPointerConstant(Pass.Ctx,
Expr::NPC_ValueDependentIsNull))
return true;
SourceLocation loc = castExpr->getExprLoc();
if (loc.isValid() && Pass.Ctx.getSourceManager().isInSystemHeader(loc))
return true;
if (castType->isObjCObjectPointerType())
transformNonObjCToObjCCast(E);
else
transformObjCToNonObjCCast(E);
return true;
}
private:
void transformNonObjCToObjCCast(CastExpr *E) {
if (!E) return;
// Global vars are assumed that are cast as unretained.
if (isGlobalVar(E))
if (E->getSubExpr()->getType()->isPointerType()) {
castToObjCObject(E, /*retained=*/false);
return;
}
// If the cast is directly over the result of a Core Foundation function
// try to figure out whether it should be cast as retained or unretained.
Expr *inner = E->IgnoreParenCasts();
if (CallExpr *callE = dyn_cast<CallExpr>(inner)) {
if (FunctionDecl *FD = callE->getDirectCallee()) {
if (FD->getAttr<CFReturnsRetainedAttr>()) {
castToObjCObject(E, /*retained=*/true);
return;
}
if (FD->getAttr<CFReturnsNotRetainedAttr>()) {
castToObjCObject(E, /*retained=*/false);
return;
}
if (FD->isGlobal() &&
FD->getIdentifier() &&
ento::cocoa::isRefType(E->getSubExpr()->getType(), "CF",
FD->getIdentifier()->getName())) {
StringRef fname = FD->getIdentifier()->getName();
if (fname.endswith("Retain") ||
fname.find("Create") != StringRef::npos ||
fname.find("Copy") != StringRef::npos) {
castToObjCObject(E, /*retained=*/true);
return;
}
if (fname.find("Get") != StringRef::npos) {
castToObjCObject(E, /*retained=*/false);
return;
}
}
}
}
}
void castToObjCObject(CastExpr *E, bool retained) {
rewriteToBridgedCast(E, retained ? OBC_BridgeTransfer : OBC_Bridge);
}
void rewriteToBridgedCast(CastExpr *E, ObjCBridgeCastKind Kind) {
TransformActions &TA = Pass.TA;
// We will remove the compiler diagnostic.
if (!TA.hasDiagnostic(diag::err_arc_mismatched_cast,
diag::err_arc_cast_requires_bridge,
E->getLocStart()))
return;
StringRef bridge;
switch(Kind) {
case OBC_Bridge:
bridge = "__bridge "; break;
case OBC_BridgeTransfer:
bridge = "__bridge_transfer "; break;
case OBC_BridgeRetained:
bridge = "__bridge_retained "; break;
}
Transaction Trans(TA);
TA.clearDiagnostic(diag::err_arc_mismatched_cast,
diag::err_arc_cast_requires_bridge,
E->getLocStart());
if (CStyleCastExpr *CCE = dyn_cast<CStyleCastExpr>(E)) {
TA.insertAfterToken(CCE->getLParenLoc(), bridge);
} else {
SourceLocation insertLoc = E->getSubExpr()->getLocStart();
llvm::SmallString<128> newCast;
newCast += '(';
newCast += bridge;
newCast += E->getType().getAsString(Pass.Ctx.PrintingPolicy);
newCast += ')';
if (isa<ParenExpr>(E->getSubExpr())) {
TA.insert(insertLoc, newCast.str());
} else {
newCast += '(';
TA.insert(insertLoc, newCast.str());
TA.insertAfterToken(E->getLocEnd(), ")");
}
}
}
void transformObjCToNonObjCCast(CastExpr *E) {
if (isSelf(E->getSubExpr()))
return rewriteToBridgedCast(E, OBC_Bridge);
}
bool isSelf(Expr *E) {
E = E->IgnoreParenLValueCasts();
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
if (DRE->getDecl()->getIdentifier() == SelfII)
return true;
return false;
}
};
} // end anonymous namespace
void trans::rewriteUnbridgedCasts(MigrationPass &pass) {
UnbridgedCastRewriter trans(pass);
trans.TraverseDecl(pass.Ctx.getTranslationUnitDecl());
}
|
