1 //===--- TransGCAttrs.cpp - Transformations to ARC mode --------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 #include "Transforms.h"
10 #include "Internals.h"
11 #include "clang/AST/ASTContext.h"
12 #include "clang/Basic/SourceManager.h"
13 #include "clang/Lex/Lexer.h"
14 #include "clang/Sema/SemaDiagnostic.h"
15 #include "llvm/ADT/SmallString.h"
16 #include "llvm/ADT/TinyPtrVector.h"
17 #include "llvm/Support/SaveAndRestore.h"
19 using namespace clang;
20 using namespace arcmt;
21 using namespace trans;
25 /// Collects all the places where GC attributes __strong/__weak occur.
26 class GCAttrsCollector : public RecursiveASTVisitor<GCAttrsCollector> {
27 MigrationContext &MigrateCtx;
29 std::vector<ObjCPropertyDecl *> &AllProps;
31 typedef RecursiveASTVisitor<GCAttrsCollector> base;
33 GCAttrsCollector(MigrationContext &ctx,
34 std::vector<ObjCPropertyDecl *> &AllProps)
35 : MigrateCtx(ctx), FullyMigratable(false),
36 AllProps(AllProps) { }
38 bool shouldWalkTypesOfTypeLocs() const { return false; }
40 bool VisitAttributedTypeLoc(AttributedTypeLoc TL) {
45 bool TraverseDecl(Decl *D) {
46 if (!D || D->isImplicit())
49 SaveAndRestore<bool> Save(FullyMigratable, isMigratable(D));
51 if (ObjCPropertyDecl *PropD = dyn_cast<ObjCPropertyDecl>(D)) {
52 lookForAttribute(PropD, PropD->getTypeSourceInfo());
53 AllProps.push_back(PropD);
54 } else if (DeclaratorDecl *DD = dyn_cast<DeclaratorDecl>(D)) {
55 lookForAttribute(DD, DD->getTypeSourceInfo());
57 return base::TraverseDecl(D);
60 void lookForAttribute(Decl *D, TypeSourceInfo *TInfo) {
63 TypeLoc TL = TInfo->getTypeLoc();
65 if (QualifiedTypeLoc QL = TL.getAs<QualifiedTypeLoc>()) {
66 TL = QL.getUnqualifiedLoc();
67 } else if (AttributedTypeLoc Attr = TL.getAs<AttributedTypeLoc>()) {
68 if (handleAttr(Attr, D))
70 TL = Attr.getModifiedLoc();
71 } else if (MacroQualifiedTypeLoc MDTL =
72 TL.getAs<MacroQualifiedTypeLoc>()) {
73 TL = MDTL.getInnerLoc();
74 } else if (ArrayTypeLoc Arr = TL.getAs<ArrayTypeLoc>()) {
75 TL = Arr.getElementLoc();
76 } else if (PointerTypeLoc PT = TL.getAs<PointerTypeLoc>()) {
77 TL = PT.getPointeeLoc();
78 } else if (ReferenceTypeLoc RT = TL.getAs<ReferenceTypeLoc>())
79 TL = RT.getPointeeLoc();
85 bool handleAttr(AttributedTypeLoc TL, Decl *D = nullptr) {
86 auto *OwnershipAttr = TL.getAttrAs<ObjCOwnershipAttr>();
90 SourceLocation Loc = OwnershipAttr->getLocation();
91 unsigned RawLoc = Loc.getRawEncoding();
92 if (MigrateCtx.AttrSet.count(RawLoc))
95 ASTContext &Ctx = MigrateCtx.Pass.Ctx;
96 SourceManager &SM = Ctx.getSourceManager();
98 Loc = SM.getImmediateExpansionRange(Loc).getBegin();
99 StringRef Spell = OwnershipAttr->getKind()->getName();
100 MigrationContext::GCAttrOccurrence::AttrKind Kind;
101 if (Spell == "strong")
102 Kind = MigrationContext::GCAttrOccurrence::Strong;
103 else if (Spell == "weak")
104 Kind = MigrationContext::GCAttrOccurrence::Weak;
108 MigrateCtx.AttrSet.insert(RawLoc);
109 MigrateCtx.GCAttrs.push_back(MigrationContext::GCAttrOccurrence());
110 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs.back();
114 Attr.ModifiedType = TL.getModifiedLoc().getType();
116 Attr.FullyMigratable = FullyMigratable;
120 bool isMigratable(Decl *D) {
121 if (isa<TranslationUnitDecl>(D))
127 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
128 return FD->hasBody();
130 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D))
131 return hasObjCImpl(ContD);
133 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
134 for (const auto *MI : RD->methods()) {
135 if (MI->isOutOfLine())
141 return isMigratable(cast<Decl>(D->getDeclContext()));
144 static bool hasObjCImpl(Decl *D) {
147 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D)) {
148 if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(ContD))
149 return ID->getImplementation() != nullptr;
150 if (ObjCCategoryDecl *CD = dyn_cast<ObjCCategoryDecl>(ContD))
151 return CD->getImplementation() != nullptr;
152 return isa<ObjCImplDecl>(ContD);
157 bool isInMainFile(Decl *D) {
161 for (auto I : D->redecls())
162 if (!isInMainFile(I->getLocation()))
168 bool isInMainFile(SourceLocation Loc) {
172 SourceManager &SM = MigrateCtx.Pass.Ctx.getSourceManager();
173 return SM.isInFileID(SM.getExpansionLoc(Loc), SM.getMainFileID());
177 } // anonymous namespace
179 static void errorForGCAttrsOnNonObjC(MigrationContext &MigrateCtx) {
180 TransformActions &TA = MigrateCtx.Pass.TA;
182 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
183 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
184 if (Attr.FullyMigratable && Attr.Dcl) {
185 if (Attr.ModifiedType.isNull())
187 if (!Attr.ModifiedType->isObjCRetainableType()) {
188 TA.reportError("GC managed memory will become unmanaged in ARC",
195 static void checkWeakGCAttrs(MigrationContext &MigrateCtx) {
196 TransformActions &TA = MigrateCtx.Pass.TA;
198 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
199 MigrationContext::GCAttrOccurrence &Attr = MigrateCtx.GCAttrs[i];
200 if (Attr.Kind == MigrationContext::GCAttrOccurrence::Weak) {
201 if (Attr.ModifiedType.isNull() ||
202 !Attr.ModifiedType->isObjCRetainableType())
204 if (!canApplyWeak(MigrateCtx.Pass.Ctx, Attr.ModifiedType,
205 /*AllowOnUnknownClass=*/true)) {
206 Transaction Trans(TA);
207 if (!MigrateCtx.RemovedAttrSet.count(Attr.Loc.getRawEncoding()))
208 TA.replaceText(Attr.Loc, "__weak", "__unsafe_unretained");
209 TA.clearDiagnostic(diag::err_arc_weak_no_runtime,
210 diag::err_arc_unsupported_weak_class,
217 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
219 static void checkAllAtProps(MigrationContext &MigrateCtx,
220 SourceLocation AtLoc,
221 IndivPropsTy &IndProps) {
222 if (IndProps.empty())
225 for (IndivPropsTy::iterator
226 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
227 QualType T = (*PI)->getType();
228 if (T.isNull() || !T->isObjCRetainableType())
232 SmallVector<std::pair<AttributedTypeLoc, ObjCPropertyDecl *>, 4> ATLs;
233 bool hasWeak = false, hasStrong = false;
234 ObjCPropertyDecl::PropertyAttributeKind
235 Attrs = ObjCPropertyDecl::OBJC_PR_noattr;
236 for (IndivPropsTy::iterator
237 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
238 ObjCPropertyDecl *PD = *PI;
239 Attrs = PD->getPropertyAttributesAsWritten();
240 TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
243 TypeLoc TL = TInfo->getTypeLoc();
244 if (AttributedTypeLoc ATL =
245 TL.getAs<AttributedTypeLoc>()) {
246 ATLs.push_back(std::make_pair(ATL, PD));
247 if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
249 } else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
257 if (hasWeak && hasStrong)
260 TransformActions &TA = MigrateCtx.Pass.TA;
261 Transaction Trans(TA);
263 if (GCAttrsCollector::hasObjCImpl(
264 cast<Decl>(IndProps.front()->getDeclContext()))) {
266 MigrateCtx.AtPropsWeak.insert(AtLoc.getRawEncoding());
269 StringRef toAttr = "strong";
271 if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
272 /*AllowOnUnknownClass=*/true))
275 toAttr = "unsafe_unretained";
277 if (Attrs & ObjCPropertyDecl::OBJC_PR_assign)
278 MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
280 MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
283 for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
284 SourceLocation Loc = ATLs[i].first.getAttr()->getLocation();
286 Loc = MigrateCtx.Pass.Ctx.getSourceManager()
287 .getImmediateExpansionRange(Loc)
290 TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
291 TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
292 ATLs[i].second->getLocation());
293 MigrateCtx.RemovedAttrSet.insert(Loc.getRawEncoding());
297 static void checkAllProps(MigrationContext &MigrateCtx,
298 std::vector<ObjCPropertyDecl *> &AllProps) {
299 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
300 llvm::DenseMap<unsigned, IndivPropsTy> AtProps;
302 for (unsigned i = 0, e = AllProps.size(); i != e; ++i) {
303 ObjCPropertyDecl *PD = AllProps[i];
304 if (PD->getPropertyAttributesAsWritten() &
305 (ObjCPropertyDecl::OBJC_PR_assign |
306 ObjCPropertyDecl::OBJC_PR_readonly)) {
307 SourceLocation AtLoc = PD->getAtLoc();
308 if (AtLoc.isInvalid())
310 unsigned RawAt = AtLoc.getRawEncoding();
311 AtProps[RawAt].push_back(PD);
315 for (llvm::DenseMap<unsigned, IndivPropsTy>::iterator
316 I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
317 SourceLocation AtLoc = SourceLocation::getFromRawEncoding(I->first);
318 IndivPropsTy &IndProps = I->second;
319 checkAllAtProps(MigrateCtx, AtLoc, IndProps);
323 void GCAttrsTraverser::traverseTU(MigrationContext &MigrateCtx) {
324 std::vector<ObjCPropertyDecl *> AllProps;
325 GCAttrsCollector(MigrateCtx, AllProps).TraverseDecl(
326 MigrateCtx.Pass.Ctx.getTranslationUnitDecl());
328 errorForGCAttrsOnNonObjC(MigrateCtx);
329 checkAllProps(MigrateCtx, AllProps);
330 checkWeakGCAttrs(MigrateCtx);
333 void MigrationContext::dumpGCAttrs() {
334 llvm::errs() << "\n################\n";
335 for (unsigned i = 0, e = GCAttrs.size(); i != e; ++i) {
336 GCAttrOccurrence &Attr = GCAttrs[i];
337 llvm::errs() << "KIND: "
338 << (Attr.Kind == GCAttrOccurrence::Strong ? "strong" : "weak");
339 llvm::errs() << "\nLOC: ";
340 Attr.Loc.print(llvm::errs(), Pass.Ctx.getSourceManager());
341 llvm::errs() << "\nTYPE: ";
342 Attr.ModifiedType.dump();
344 llvm::errs() << "DECL:\n";
347 llvm::errs() << "DECL: NONE";
349 llvm::errs() << "\nMIGRATABLE: " << Attr.FullyMigratable;
350 llvm::errs() << "\n----------------\n";
352 llvm::errs() << "\n################\n";