1 //===--- TransGCAttrs.cpp - Transformations 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 #include "Transforms.h"
11 #include "Internals.h"
12 #include "clang/AST/ASTContext.h"
13 #include "clang/Basic/SourceManager.h"
14 #include "clang/Lex/Lexer.h"
15 #include "clang/Sema/SemaDiagnostic.h"
16 #include "llvm/ADT/SmallString.h"
17 #include "llvm/ADT/TinyPtrVector.h"
18 #include "llvm/Support/SaveAndRestore.h"
19
20 using namespace clang;
21 using namespace arcmt;
22 using namespace trans;
23
24 namespace {
25
26 /// \brief Collects all the places where GC attributes __strong/__weak occur.
27 class GCAttrsCollector : public RecursiveASTVisitor<GCAttrsCollector> {
28 MigrationContext &MigrateCtx;
29 bool FullyMigratable;
30 std::vector<ObjCPropertyDecl *> &AllProps;
31
32 typedef RecursiveASTVisitor<GCAttrsCollector> base;
33 public:
GCAttrsCollector(MigrationContext & ctx,std::vector<ObjCPropertyDecl * > & AllProps)34 GCAttrsCollector(MigrationContext &ctx,
35 std::vector<ObjCPropertyDecl *> &AllProps)
36 : MigrateCtx(ctx), FullyMigratable(false),
37 AllProps(AllProps) { }
38
shouldWalkTypesOfTypeLocs() const39 bool shouldWalkTypesOfTypeLocs() const { return false; }
40
VisitAttributedTypeLoc(AttributedTypeLoc TL)41 bool VisitAttributedTypeLoc(AttributedTypeLoc TL) {
42 handleAttr(TL);
43 return true;
44 }
45
TraverseDecl(Decl * D)46 bool TraverseDecl(Decl *D) {
47 if (!D || D->isImplicit())
48 return true;
49
50 SaveAndRestore<bool> Save(FullyMigratable, isMigratable(D));
51
52 if (ObjCPropertyDecl *PropD = dyn_cast<ObjCPropertyDecl>(D)) {
53 lookForAttribute(PropD, PropD->getTypeSourceInfo());
54 AllProps.push_back(PropD);
55 } else if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
56 lookForAttribute(DD, DD->getTypeSourceInfo());
57 }
58 return base::TraverseDecl(D);
59 }
60
lookForAttribute(Decl * D,TypeSourceInfo * TInfo)61 void lookForAttribute(Decl *D, TypeSourceInfo *TInfo) {
62 if (!TInfo)
63 return;
64 TypeLoc TL = TInfo->getTypeLoc();
65 while (TL) {
66 if (QualifiedTypeLoc QL = TL.getAs<QualifiedTypeLoc>()) {
67 TL = QL.getUnqualifiedLoc();
68 } else if (AttributedTypeLoc Attr = TL.getAs<AttributedTypeLoc>()) {
69 if (handleAttr(Attr, D))
70 break;
71 TL = Attr.getModifiedLoc();
72 } else if (ArrayTypeLoc Arr = TL.getAs<ArrayTypeLoc>()) {
73 TL = Arr.getElementLoc();
74 } else if (PointerTypeLoc PT = TL.getAs<PointerTypeLoc>()) {
75 TL = PT.getPointeeLoc();
76 } else if (ReferenceTypeLoc RT = TL.getAs<ReferenceTypeLoc>())
77 TL = RT.getPointeeLoc();
78 else
79 break;
80 }
81 }
82
handleAttr(AttributedTypeLoc TL,Decl * D=0)83 bool handleAttr(AttributedTypeLoc TL, Decl *D = 0) {
84 if (TL.getAttrKind() != AttributedType::attr_objc_ownership)
85 return false;
86
87 SourceLocation Loc = TL.getAttrNameLoc();
88 unsigned RawLoc = Loc.getRawEncoding();
89 if (MigrateCtx.AttrSet.count(RawLoc))
90 return true;
91
92 ASTContext &Ctx = MigrateCtx.Pass.Ctx;
93 SourceManager &SM = Ctx.getSourceManager();
94 if (Loc.isMacroID())
95 Loc = SM.getImmediateExpansionRange(Loc).first;
96 SmallString<32> Buf;
97 bool Invalid = false;
98 StringRef Spell = Lexer::getSpelling(
99 SM.getSpellingLoc(TL.getAttrEnumOperandLoc()),
100 Buf, SM, Ctx.getLangOpts(), &Invalid);
101 if (Invalid)
102 return false;
103 MigrationContext::GCAttrOccurrence::AttrKind Kind;
104 if (Spell == "strong")
105 Kind = MigrationContext::GCAttrOccurrence::Strong;
106 else if (Spell == "weak")
107 Kind = MigrationContext::GCAttrOccurrence::Weak;
108 else
109 return false;
110
111 MigrateCtx.AttrSet.insert(RawLoc);
112 MigrateCtx.GCAttrs.push_back(MigrationContext::GCAttrOccurrence());
113 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs.back();
114
115 Attr.Kind = Kind;
116 Attr.Loc = Loc;
117 Attr.ModifiedType = TL.getModifiedLoc().getType();
118 Attr.Dcl = D;
119 Attr.FullyMigratable = FullyMigratable;
120 return true;
121 }
122
isMigratable(Decl * D)123 bool isMigratable(Decl *D) {
124 if (isa<TranslationUnitDecl>(D))
125 return false;
126
127 if (isInMainFile(D))
128 return true;
129
130 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
131 return FD->hasBody();
132
133 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D))
134 return hasObjCImpl(ContD);
135
136 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
137 for (CXXRecordDecl::method_iterator
138 MI = RD->method_begin(), ME = RD->method_end(); MI != ME; ++MI) {
139 if (MI->isOutOfLine())
140 return true;
141 }
142 return false;
143 }
144
145 return isMigratable(cast<Decl>(D->getDeclContext()));
146 }
147
hasObjCImpl(Decl * D)148 static bool hasObjCImpl(Decl *D) {
149 if (!D)
150 return false;
151 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D)) {
152 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(ContD))
153 return ID->getImplementation() != 0;
154 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContD))
155 return CD->getImplementation() != 0;
156 if (isa<ObjCImplDecl>(ContD))
157 return true;
158 return false;
159 }
160 return false;
161 }
162
isInMainFile(Decl * D)163 bool isInMainFile(Decl *D) {
164 if (!D)
165 return false;
166
167 for (Decl::redecl_iterator
168 I = D->redecls_begin(), E = D->redecls_end(); I != E; ++I)
169 if (!isInMainFile(I->getLocation()))
170 return false;
171
172 return true;
173 }
174
isInMainFile(SourceLocation Loc)175 bool isInMainFile(SourceLocation Loc) {
176 if (Loc.isInvalid())
177 return false;
178
179 SourceManager &SM = MigrateCtx.Pass.Ctx.getSourceManager();
180 return SM.isInFileID(SM.getExpansionLoc(Loc), SM.getMainFileID());
181 }
182 };
183
184 } // anonymous namespace
185
errorForGCAttrsOnNonObjC(MigrationContext & MigrateCtx)186 static void errorForGCAttrsOnNonObjC(MigrationContext &MigrateCtx) {
187 TransformActions &TA = MigrateCtx.Pass.TA;
188
189 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
190 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
191 if (Attr.FullyMigratable && Attr.Dcl) {
192 if (Attr.ModifiedType.isNull())
193 continue;
194 if (!Attr.ModifiedType->isObjCRetainableType()) {
195 TA.reportError("GC managed memory will become unmanaged in ARC",
196 Attr.Loc);
197 }
198 }
199 }
200 }
201
checkWeakGCAttrs(MigrationContext & MigrateCtx)202 static void checkWeakGCAttrs(MigrationContext &MigrateCtx) {
203 TransformActions &TA = MigrateCtx.Pass.TA;
204
205 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
206 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
207 if (Attr.Kind == MigrationContext::GCAttrOccurrence::Weak) {
208 if (Attr.ModifiedType.isNull() ||
209 !Attr.ModifiedType->isObjCRetainableType())
210 continue;
211 if (!canApplyWeak(MigrateCtx.Pass.Ctx, Attr.ModifiedType,
212 /*AllowOnUnknownClass=*/true)) {
213 Transaction Trans(TA);
214 if (!MigrateCtx.RemovedAttrSet.count(Attr.Loc.getRawEncoding()))
215 TA.replaceText(Attr.Loc, "__weak", "__unsafe_unretained");
216 TA.clearDiagnostic(diag::err_arc_weak_no_runtime,
217 diag::err_arc_unsupported_weak_class,
218 Attr.Loc);
219 }
220 }
221 }
222 }
223
224 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
225
checkAllAtProps(MigrationContext & MigrateCtx,SourceLocation AtLoc,IndivPropsTy & IndProps)226 static void checkAllAtProps(MigrationContext &MigrateCtx,
227 SourceLocation AtLoc,
228 IndivPropsTy &IndProps) {
229 if (IndProps.empty())
230 return;
231
232 for (IndivPropsTy::iterator
233 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
234 QualType T = (*PI)->getType();
235 if (T.isNull() || !T->isObjCRetainableType())
236 return;
237 }
238
239 SmallVector<std::pair<AttributedTypeLoc, ObjCPropertyDecl *>, 4> ATLs;
240 bool hasWeak = false, hasStrong = false;
241 ObjCPropertyDecl::PropertyAttributeKind
242 Attrs = ObjCPropertyDecl::OBJC_PR_noattr;
243 for (IndivPropsTy::iterator
244 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
245 ObjCPropertyDecl *PD = *PI;
246 Attrs = PD->getPropertyAttributesAsWritten();
247 TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
248 if (!TInfo)
249 return;
250 TypeLoc TL = TInfo->getTypeLoc();
251 if (AttributedTypeLoc ATL =
252 TL.getAs<AttributedTypeLoc>()) {
253 ATLs.push_back(std::make_pair(ATL, PD));
254 if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
255 hasWeak = true;
256 } else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
257 hasStrong = true;
258 else
259 return;
260 }
261 }
262 if (ATLs.empty())
263 return;
264 if (hasWeak && hasStrong)
265 return;
266
267 TransformActions &TA = MigrateCtx.Pass.TA;
268 Transaction Trans(TA);
269
270 if (GCAttrsCollector::hasObjCImpl(
271 cast<Decl>(IndProps.front()->getDeclContext()))) {
272 if (hasWeak)
273 MigrateCtx.AtPropsWeak.insert(AtLoc.getRawEncoding());
274
275 } else {
276 StringRef toAttr = "strong";
277 if (hasWeak) {
278 if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
279 /*AllowOnUnkwownClass=*/true))
280 toAttr = "weak";
281 else
282 toAttr = "unsafe_unretained";
283 }
284 if (Attrs & ObjCPropertyDecl::OBJC_PR_assign)
285 MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
286 else
287 MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
288 }
289
290 for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
291 SourceLocation Loc = ATLs[i].first.getAttrNameLoc();
292 if (Loc.isMacroID())
293 Loc = MigrateCtx.Pass.Ctx.getSourceManager()
294 .getImmediateExpansionRange(Loc).first;
295 TA.remove(Loc);
296 TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
297 TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
298 ATLs[i].second->getLocation());
299 MigrateCtx.RemovedAttrSet.insert(Loc.getRawEncoding());
300 }
301 }
302
checkAllProps(MigrationContext & MigrateCtx,std::vector<ObjCPropertyDecl * > & AllProps)303 static void checkAllProps(MigrationContext &MigrateCtx,
304 std::vector<ObjCPropertyDecl *> &AllProps) {
305 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
306 llvm::DenseMap<unsigned, IndivPropsTy> AtProps;
307
308 for (unsigned i = 0, e = AllProps.size(); i != e; ++i) {
309 ObjCPropertyDecl *PD = AllProps[i];
310 if (PD->getPropertyAttributesAsWritten() &
311 (ObjCPropertyDecl::OBJC_PR_assign |
312 ObjCPropertyDecl::OBJC_PR_readonly)) {
313 SourceLocation AtLoc = PD->getAtLoc();
314 if (AtLoc.isInvalid())
315 continue;
316 unsigned RawAt = AtLoc.getRawEncoding();
317 AtProps[RawAt].push_back(PD);
318 }
319 }
320
321 for (llvm::DenseMap<unsigned, IndivPropsTy>::iterator
322 I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
323 SourceLocation AtLoc = SourceLocation::getFromRawEncoding(I->first);
324 IndivPropsTy &IndProps = I->second;
325 checkAllAtProps(MigrateCtx, AtLoc, IndProps);
326 }
327 }
328
traverseTU(MigrationContext & MigrateCtx)329 void GCAttrsTraverser::traverseTU(MigrationContext &MigrateCtx) {
330 std::vector<ObjCPropertyDecl *> AllProps;
331 GCAttrsCollector(MigrateCtx, AllProps).TraverseDecl(
332 MigrateCtx.Pass.Ctx.getTranslationUnitDecl());
333
334 errorForGCAttrsOnNonObjC(MigrateCtx);
335 checkAllProps(MigrateCtx, AllProps);
336 checkWeakGCAttrs(MigrateCtx);
337 }
338
dumpGCAttrs()339 void MigrationContext::dumpGCAttrs() {
340 llvm::errs() << "\n################\n";
341 for (unsigned i = 0, e = GCAttrs.size(); i != e; ++i) {
342 GCAttrOccurrence &Attr = GCAttrs[i];
343 llvm::errs() << "KIND: "
344 << (Attr.Kind == GCAttrOccurrence::Strong ? "strong" : "weak");
345 llvm::errs() << "\nLOC: ";
346 Attr.Loc.dump(Pass.Ctx.getSourceManager());
347 llvm::errs() << "\nTYPE: ";
348 Attr.ModifiedType.dump();
349 if (Attr.Dcl) {
350 llvm::errs() << "DECL:\n";
351 Attr.Dcl->dump();
352 } else {
353 llvm::errs() << "DECL: NONE";
354 }
355 llvm::errs() << "\nMIGRATABLE: " << Attr.FullyMigratable;
356 llvm::errs() << "\n----------------\n";
357 }
358 llvm::errs() << "\n################\n";
359 }
360