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=nullptr)83 bool handleAttr(AttributedTypeLoc TL, Decl *D = nullptr) {
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 (const auto *MI : RD->methods()) {
138 if (MI->isOutOfLine())
139 return true;
140 }
141 return false;
142 }
143
144 return isMigratable(cast<Decl>(D->getDeclContext()));
145 }
146
hasObjCImpl(Decl * D)147 static bool hasObjCImpl(Decl *D) {
148 if (!D)
149 return false;
150 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D)) {
151 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(ContD))
152 return ID->getImplementation() != nullptr;
153 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContD))
154 return CD->getImplementation() != nullptr;
155 if (isa<ObjCImplDecl>(ContD))
156 return true;
157 return false;
158 }
159 return false;
160 }
161
isInMainFile(Decl * D)162 bool isInMainFile(Decl *D) {
163 if (!D)
164 return false;
165
166 for (auto I : D->redecls())
167 if (!isInMainFile(I->getLocation()))
168 return false;
169
170 return true;
171 }
172
isInMainFile(SourceLocation Loc)173 bool isInMainFile(SourceLocation Loc) {
174 if (Loc.isInvalid())
175 return false;
176
177 SourceManager &SM = MigrateCtx.Pass.Ctx.getSourceManager();
178 return SM.isInFileID(SM.getExpansionLoc(Loc), SM.getMainFileID());
179 }
180 };
181
182 } // anonymous namespace
183
errorForGCAttrsOnNonObjC(MigrationContext & MigrateCtx)184 static void errorForGCAttrsOnNonObjC(MigrationContext &MigrateCtx) {
185 TransformActions &TA = MigrateCtx.Pass.TA;
186
187 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
188 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
189 if (Attr.FullyMigratable && Attr.Dcl) {
190 if (Attr.ModifiedType.isNull())
191 continue;
192 if (!Attr.ModifiedType->isObjCRetainableType()) {
193 TA.reportError("GC managed memory will become unmanaged in ARC",
194 Attr.Loc);
195 }
196 }
197 }
198 }
199
checkWeakGCAttrs(MigrationContext & MigrateCtx)200 static void checkWeakGCAttrs(MigrationContext &MigrateCtx) {
201 TransformActions &TA = MigrateCtx.Pass.TA;
202
203 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
204 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
205 if (Attr.Kind == MigrationContext::GCAttrOccurrence::Weak) {
206 if (Attr.ModifiedType.isNull() ||
207 !Attr.ModifiedType->isObjCRetainableType())
208 continue;
209 if (!canApplyWeak(MigrateCtx.Pass.Ctx, Attr.ModifiedType,
210 /*AllowOnUnknownClass=*/true)) {
211 Transaction Trans(TA);
212 if (!MigrateCtx.RemovedAttrSet.count(Attr.Loc.getRawEncoding()))
213 TA.replaceText(Attr.Loc, "__weak", "__unsafe_unretained");
214 TA.clearDiagnostic(diag::err_arc_weak_no_runtime,
215 diag::err_arc_unsupported_weak_class,
216 Attr.Loc);
217 }
218 }
219 }
220 }
221
222 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
223
checkAllAtProps(MigrationContext & MigrateCtx,SourceLocation AtLoc,IndivPropsTy & IndProps)224 static void checkAllAtProps(MigrationContext &MigrateCtx,
225 SourceLocation AtLoc,
226 IndivPropsTy &IndProps) {
227 if (IndProps.empty())
228 return;
229
230 for (IndivPropsTy::iterator
231 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
232 QualType T = (*PI)->getType();
233 if (T.isNull() || !T->isObjCRetainableType())
234 return;
235 }
236
237 SmallVector<std::pair<AttributedTypeLoc, ObjCPropertyDecl *>, 4> ATLs;
238 bool hasWeak = false, hasStrong = false;
239 ObjCPropertyDecl::PropertyAttributeKind
240 Attrs = ObjCPropertyDecl::OBJC_PR_noattr;
241 for (IndivPropsTy::iterator
242 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
243 ObjCPropertyDecl *PD = *PI;
244 Attrs = PD->getPropertyAttributesAsWritten();
245 TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
246 if (!TInfo)
247 return;
248 TypeLoc TL = TInfo->getTypeLoc();
249 if (AttributedTypeLoc ATL =
250 TL.getAs<AttributedTypeLoc>()) {
251 ATLs.push_back(std::make_pair(ATL, PD));
252 if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
253 hasWeak = true;
254 } else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
255 hasStrong = true;
256 else
257 return;
258 }
259 }
260 if (ATLs.empty())
261 return;
262 if (hasWeak && hasStrong)
263 return;
264
265 TransformActions &TA = MigrateCtx.Pass.TA;
266 Transaction Trans(TA);
267
268 if (GCAttrsCollector::hasObjCImpl(
269 cast<Decl>(IndProps.front()->getDeclContext()))) {
270 if (hasWeak)
271 MigrateCtx.AtPropsWeak.insert(AtLoc.getRawEncoding());
272
273 } else {
274 StringRef toAttr = "strong";
275 if (hasWeak) {
276 if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
277 /*AllowOnUnkwownClass=*/true))
278 toAttr = "weak";
279 else
280 toAttr = "unsafe_unretained";
281 }
282 if (Attrs & ObjCPropertyDecl::OBJC_PR_assign)
283 MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
284 else
285 MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
286 }
287
288 for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
289 SourceLocation Loc = ATLs[i].first.getAttrNameLoc();
290 if (Loc.isMacroID())
291 Loc = MigrateCtx.Pass.Ctx.getSourceManager()
292 .getImmediateExpansionRange(Loc).first;
293 TA.remove(Loc);
294 TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
295 TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
296 ATLs[i].second->getLocation());
297 MigrateCtx.RemovedAttrSet.insert(Loc.getRawEncoding());
298 }
299 }
300
checkAllProps(MigrationContext & MigrateCtx,std::vector<ObjCPropertyDecl * > & AllProps)301 static void checkAllProps(MigrationContext &MigrateCtx,
302 std::vector<ObjCPropertyDecl *> &AllProps) {
303 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
304 llvm::DenseMap<unsigned, IndivPropsTy> AtProps;
305
306 for (unsigned i = 0, e = AllProps.size(); i != e; ++i) {
307 ObjCPropertyDecl *PD = AllProps[i];
308 if (PD->getPropertyAttributesAsWritten() &
309 (ObjCPropertyDecl::OBJC_PR_assign |
310 ObjCPropertyDecl::OBJC_PR_readonly)) {
311 SourceLocation AtLoc = PD->getAtLoc();
312 if (AtLoc.isInvalid())
313 continue;
314 unsigned RawAt = AtLoc.getRawEncoding();
315 AtProps[RawAt].push_back(PD);
316 }
317 }
318
319 for (llvm::DenseMap<unsigned, IndivPropsTy>::iterator
320 I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
321 SourceLocation AtLoc = SourceLocation::getFromRawEncoding(I->first);
322 IndivPropsTy &IndProps = I->second;
323 checkAllAtProps(MigrateCtx, AtLoc, IndProps);
324 }
325 }
326
traverseTU(MigrationContext & MigrateCtx)327 void GCAttrsTraverser::traverseTU(MigrationContext &MigrateCtx) {
328 std::vector<ObjCPropertyDecl *> AllProps;
329 GCAttrsCollector(MigrateCtx, AllProps).TraverseDecl(
330 MigrateCtx.Pass.Ctx.getTranslationUnitDecl());
331
332 errorForGCAttrsOnNonObjC(MigrateCtx);
333 checkAllProps(MigrateCtx, AllProps);
334 checkWeakGCAttrs(MigrateCtx);
335 }
336
dumpGCAttrs()337 void MigrationContext::dumpGCAttrs() {
338 llvm::errs() << "\n################\n";
339 for (unsigned i = 0, e = GCAttrs.size(); i != e; ++i) {
340 GCAttrOccurrence &Attr = GCAttrs[i];
341 llvm::errs() << "KIND: "
342 << (Attr.Kind == GCAttrOccurrence::Strong ? "strong" : "weak");
343 llvm::errs() << "\nLOC: ";
344 Attr.Loc.dump(Pass.Ctx.getSourceManager());
345 llvm::errs() << "\nTYPE: ";
346 Attr.ModifiedType.dump();
347 if (Attr.Dcl) {
348 llvm::errs() << "DECL:\n";
349 Attr.Dcl->dump();
350 } else {
351 llvm::errs() << "DECL: NONE";
352 }
353 llvm::errs() << "\nMIGRATABLE: " << Attr.FullyMigratable;
354 llvm::errs() << "\n----------------\n";
355 }
356 llvm::errs() << "\n################\n";
357 }
358