1 //===--- TransAPIUses.cpp - Tranformations to ARC mode --------------------===//
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 // checkAPIUses:
11 //
12 // Emits error with some API uses that are not safe in ARC mode:
13 //
14 // - NSInvocation's [get/set]ReturnValue and [get/set]Argument are only safe
15 // with __unsafe_unretained objects.
16 // - When a NSData's 'bytes' family of methods are used on a local var,
17 // add __attribute__((objc_precise_lifetime)) to make it safer.
18 //
19 //===----------------------------------------------------------------------===//
20
21 #include "Transforms.h"
22 #include "Internals.h"
23
24 using namespace clang;
25 using namespace arcmt;
26 using namespace trans;
27 using llvm::StringRef;
28
29 namespace {
30
31 class APIChecker : public RecursiveASTVisitor<APIChecker> {
32 MigrationPass &Pass;
33
34 Selector getReturnValueSel, setReturnValueSel;
35 Selector getArgumentSel, setArgumentSel;
36
37 Selector bytesSel, getBytesSel, getBytesLengthSel, getBytesRangeSel;
38
39 llvm::DenseSet<VarDecl *> ChangedNSDataVars;
40 public:
APIChecker(MigrationPass & pass)41 APIChecker(MigrationPass &pass) : Pass(pass) {
42 SelectorTable &sels = Pass.Ctx.Selectors;
43 IdentifierTable &ids = Pass.Ctx.Idents;
44 getReturnValueSel = sels.getUnarySelector(&ids.get("getReturnValue"));
45 setReturnValueSel = sels.getUnarySelector(&ids.get("setReturnValue"));
46
47 IdentifierInfo *selIds[2];
48 selIds[0] = &ids.get("getArgument");
49 selIds[1] = &ids.get("atIndex");
50 getArgumentSel = sels.getSelector(2, selIds);
51 selIds[0] = &ids.get("setArgument");
52 setArgumentSel = sels.getSelector(2, selIds);
53
54 bytesSel = sels.getNullarySelector(&ids.get("bytes"));
55 getBytesSel = sels.getUnarySelector(&ids.get("getBytes"));
56 selIds[0] = &ids.get("getBytes");
57 selIds[1] = &ids.get("length");
58 getBytesLengthSel = sels.getSelector(2, selIds);
59 selIds[1] = &ids.get("range");
60 getBytesRangeSel = sels.getSelector(2, selIds);
61 }
62
VisitObjCMessageExpr(ObjCMessageExpr * E)63 bool VisitObjCMessageExpr(ObjCMessageExpr *E) {
64 if (E->isInstanceMessage() &&
65 E->getReceiverInterface() &&
66 E->getReceiverInterface()->getName() == "NSInvocation") {
67 StringRef selName;
68 if (E->getSelector() == getReturnValueSel)
69 selName = "getReturnValue";
70 else if (E->getSelector() == setReturnValueSel)
71 selName = "setReturnValue";
72 else if (E->getSelector() == getArgumentSel)
73 selName = "getArgument";
74 else if (E->getSelector() == setArgumentSel)
75 selName = "setArgument";
76
77 if (selName.empty())
78 return true;
79
80 Expr *parm = E->getArg(0)->IgnoreParenCasts();
81 QualType pointee = parm->getType()->getPointeeType();
82 if (pointee.isNull())
83 return true;
84
85 if (pointee.getObjCLifetime() > Qualifiers::OCL_ExplicitNone) {
86 std::string err = "NSInvocation's ";
87 err += selName;
88 err += " is not safe to be used with an object with ownership other "
89 "than __unsafe_unretained";
90 Pass.TA.reportError(err, parm->getLocStart(), parm->getSourceRange());
91 }
92 return true;
93 }
94
95 if (E->isInstanceMessage() &&
96 E->getReceiverInterface() &&
97 E->getReceiverInterface()->getName() == "NSData" &&
98 E->getInstanceReceiver() &&
99 (E->getSelector() == bytesSel ||
100 E->getSelector() == getBytesSel ||
101 E->getSelector() == getBytesLengthSel ||
102 E->getSelector() == getBytesRangeSel)) {
103 Expr *rec = E->getInstanceReceiver();
104 rec = rec->IgnoreParenCasts();
105 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(rec))
106 if (VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl()))
107 if (VD->hasLocalStorage() && !ChangedNSDataVars.count(VD)) {
108 Transaction Trans(Pass.TA);
109 Pass.TA.insertAfterToken(VD->getLocation(),
110 " __attribute__((objc_precise_lifetime))");
111 ChangedNSDataVars.insert(VD);
112 }
113 }
114
115 return true;
116 }
117 };
118
119 } // anonymous namespace
120
checkAPIUses(MigrationPass & pass)121 void trans::checkAPIUses(MigrationPass &pass) {
122 APIChecker(pass).TraverseDecl(pass.Ctx.getTranslationUnitDecl());
123 }
124