clang 19.0.0git
TransGCAttrs.cpp
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1//===--- TransGCAttrs.cpp - Transformations to ARC mode --------------------===//
2//
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
6//
7//===----------------------------------------------------------------------===//
8
9#include "Transforms.h"
10#include "Internals.h"
13#include "clang/Lex/Lexer.h"
15#include "llvm/ADT/SmallString.h"
16#include "llvm/ADT/TinyPtrVector.h"
17#include "llvm/Support/SaveAndRestore.h"
18
19using namespace clang;
20using namespace arcmt;
21using namespace trans;
22
23namespace {
24
25/// Collects all the places where GC attributes __strong/__weak occur.
26class GCAttrsCollector : public RecursiveASTVisitor<GCAttrsCollector> {
27 MigrationContext &MigrateCtx;
28 bool FullyMigratable;
29 std::vector<ObjCPropertyDecl *> &AllProps;
30
32public:
33 GCAttrsCollector(MigrationContext &ctx,
34 std::vector<ObjCPropertyDecl *> &AllProps)
35 : MigrateCtx(ctx), FullyMigratable(false),
36 AllProps(AllProps) { }
37
38 bool shouldWalkTypesOfTypeLocs() const { return false; }
39
40 bool VisitAttributedTypeLoc(AttributedTypeLoc TL) {
41 handleAttr(TL);
42 return true;
43 }
44
45 bool TraverseDecl(Decl *D) {
46 if (!D || D->isImplicit())
47 return true;
48
49 SaveAndRestore Save(FullyMigratable, isMigratable(D));
50
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());
56 }
57 return base::TraverseDecl(D);
58 }
59
60 void lookForAttribute(Decl *D, TypeSourceInfo *TInfo) {
61 if (!TInfo)
62 return;
63 TypeLoc TL = TInfo->getTypeLoc();
64 while (TL) {
66 TL = QL.getUnqualifiedLoc();
67 } else if (AttributedTypeLoc Attr = TL.getAs<AttributedTypeLoc>()) {
68 if (handleAttr(Attr, D))
69 break;
70 TL = Attr.getModifiedLoc();
71 } else if (MacroQualifiedTypeLoc MDTL =
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();
80 else
81 break;
82 }
83 }
84
85 bool handleAttr(AttributedTypeLoc TL, Decl *D = nullptr) {
86 auto *OwnershipAttr = TL.getAttrAs<ObjCOwnershipAttr>();
87 if (!OwnershipAttr)
88 return false;
89
90 SourceLocation Loc = OwnershipAttr->getLocation();
91 SourceLocation OrigLoc = Loc;
92 if (MigrateCtx.AttrSet.count(OrigLoc))
93 return true;
94
95 ASTContext &Ctx = MigrateCtx.Pass.Ctx;
97 if (Loc.isMacroID())
98 Loc = SM.getImmediateExpansionRange(Loc).getBegin();
99 StringRef Spell = OwnershipAttr->getKind()->getName();
101 if (Spell == "strong")
103 else if (Spell == "weak")
105 else
106 return false;
107
108 MigrateCtx.AttrSet.insert(OrigLoc);
109 MigrateCtx.GCAttrs.push_back(MigrationContext::GCAttrOccurrence());
111
112 Attr.Kind = Kind;
113 Attr.Loc = Loc;
114 Attr.ModifiedType = TL.getModifiedLoc().getType();
115 Attr.Dcl = D;
116 Attr.FullyMigratable = FullyMigratable;
117 return true;
118 }
119
120 bool isMigratable(Decl *D) {
121 if (isa<TranslationUnitDecl>(D))
122 return false;
123
124 if (isInMainFile(D))
125 return true;
126
127 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
128 return FD->hasBody();
129
130 if (ObjCContainerDecl *ContD = dyn_cast<ObjCContainerDecl>(D))
131 return hasObjCImpl(ContD);
132
133 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D)) {
134 for (const auto *MI : RD->methods()) {
135 if (MI->isOutOfLine())
136 return true;
137 }
138 return false;
139 }
140
141 return isMigratable(cast<Decl>(D->getDeclContext()));
142 }
143
144 static bool hasObjCImpl(Decl *D) {
145 if (!D)
146 return false;
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);
153 }
154 return false;
155 }
156
157 bool isInMainFile(Decl *D) {
158 if (!D)
159 return false;
160
161 for (auto *I : D->redecls())
162 if (!isInMainFile(I->getLocation()))
163 return false;
164
165 return true;
166 }
167
168 bool isInMainFile(SourceLocation Loc) {
169 if (Loc.isInvalid())
170 return false;
171
172 SourceManager &SM = MigrateCtx.Pass.Ctx.getSourceManager();
173 return SM.isInFileID(SM.getExpansionLoc(Loc), SM.getMainFileID());
174 }
175};
176
177} // anonymous namespace
178
180 TransformActions &TA = MigrateCtx.Pass.TA;
181
182 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
184 if (Attr.FullyMigratable && Attr.Dcl) {
185 if (Attr.ModifiedType.isNull())
186 continue;
187 if (!Attr.ModifiedType->isObjCRetainableType()) {
188 TA.reportError("GC managed memory will become unmanaged in ARC",
189 Attr.Loc);
190 }
191 }
192 }
193}
194
195static void checkWeakGCAttrs(MigrationContext &MigrateCtx) {
196 TransformActions &TA = MigrateCtx.Pass.TA;
197
198 for (unsigned i = 0, e = MigrateCtx.GCAttrs.size(); i != e; ++i) {
201 if (Attr.ModifiedType.isNull() ||
202 !Attr.ModifiedType->isObjCRetainableType())
203 continue;
204 if (!canApplyWeak(MigrateCtx.Pass.Ctx, Attr.ModifiedType,
205 /*AllowOnUnknownClass=*/true)) {
206 Transaction Trans(TA);
207 if (!MigrateCtx.RemovedAttrSet.count(Attr.Loc))
208 TA.replaceText(Attr.Loc, "__weak", "__unsafe_unretained");
209 TA.clearDiagnostic(diag::err_arc_weak_no_runtime,
210 diag::err_arc_unsupported_weak_class,
211 Attr.Loc);
212 }
213 }
214 }
215}
216
217typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
218
219static void checkAllAtProps(MigrationContext &MigrateCtx,
220 SourceLocation AtLoc,
221 IndivPropsTy &IndProps) {
222 if (IndProps.empty())
223 return;
224
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())
229 return;
230 }
231
233 bool hasWeak = false, hasStrong = false;
235 for (IndivPropsTy::iterator
236 PI = IndProps.begin(), PE = IndProps.end(); PI != PE; ++PI) {
237 ObjCPropertyDecl *PD = *PI;
238 Attrs = PD->getPropertyAttributesAsWritten();
239 TypeSourceInfo *TInfo = PD->getTypeSourceInfo();
240 if (!TInfo)
241 return;
242 TypeLoc TL = TInfo->getTypeLoc();
243 if (AttributedTypeLoc ATL =
244 TL.getAs<AttributedTypeLoc>()) {
245 ATLs.push_back(std::make_pair(ATL, PD));
246 if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Weak) {
247 hasWeak = true;
248 } else if (TInfo->getType().getObjCLifetime() == Qualifiers::OCL_Strong)
249 hasStrong = true;
250 else
251 return;
252 }
253 }
254 if (ATLs.empty())
255 return;
256 if (hasWeak && hasStrong)
257 return;
258
259 TransformActions &TA = MigrateCtx.Pass.TA;
260 Transaction Trans(TA);
261
262 if (GCAttrsCollector::hasObjCImpl(
263 cast<Decl>(IndProps.front()->getDeclContext()))) {
264 if (hasWeak)
265 MigrateCtx.AtPropsWeak.insert(AtLoc);
266
267 } else {
268 StringRef toAttr = "strong";
269 if (hasWeak) {
270 if (canApplyWeak(MigrateCtx.Pass.Ctx, IndProps.front()->getType(),
271 /*AllowOnUnknownClass=*/true))
272 toAttr = "weak";
273 else
274 toAttr = "unsafe_unretained";
275 }
277 MigrateCtx.rewritePropertyAttribute("assign", toAttr, AtLoc);
278 else
279 MigrateCtx.addPropertyAttribute(toAttr, AtLoc);
280 }
281
282 for (unsigned i = 0, e = ATLs.size(); i != e; ++i) {
283 SourceLocation Loc = ATLs[i].first.getAttr()->getLocation();
284 if (Loc.isMacroID())
285 Loc = MigrateCtx.Pass.Ctx.getSourceManager()
287 .getBegin();
288 TA.remove(Loc);
289 TA.clearDiagnostic(diag::err_objc_property_attr_mutually_exclusive, AtLoc);
290 TA.clearDiagnostic(diag::err_arc_inconsistent_property_ownership,
291 ATLs[i].second->getLocation());
292 MigrateCtx.RemovedAttrSet.insert(Loc);
293 }
294}
295
296static void checkAllProps(MigrationContext &MigrateCtx,
297 std::vector<ObjCPropertyDecl *> &AllProps) {
298 typedef llvm::TinyPtrVector<ObjCPropertyDecl *> IndivPropsTy;
299 llvm::DenseMap<SourceLocation, IndivPropsTy> AtProps;
300
301 for (unsigned i = 0, e = AllProps.size(); i != e; ++i) {
302 ObjCPropertyDecl *PD = AllProps[i];
306 SourceLocation AtLoc = PD->getAtLoc();
307 if (AtLoc.isInvalid())
308 continue;
309 AtProps[AtLoc].push_back(PD);
310 }
311 }
312
313 for (auto I = AtProps.begin(), E = AtProps.end(); I != E; ++I) {
314 SourceLocation AtLoc = I->first;
315 IndivPropsTy &IndProps = I->second;
316 checkAllAtProps(MigrateCtx, AtLoc, IndProps);
317 }
318}
319
321 std::vector<ObjCPropertyDecl *> AllProps;
322 GCAttrsCollector(MigrateCtx, AllProps).TraverseDecl(
323 MigrateCtx.Pass.Ctx.getTranslationUnitDecl());
324
325 errorForGCAttrsOnNonObjC(MigrateCtx);
326 checkAllProps(MigrateCtx, AllProps);
327 checkWeakGCAttrs(MigrateCtx);
328}
329
331 llvm::errs() << "\n################\n";
332 for (unsigned i = 0, e = GCAttrs.size(); i != e; ++i) {
334 llvm::errs() << "KIND: "
335 << (Attr.Kind == GCAttrOccurrence::Strong ? "strong" : "weak");
336 llvm::errs() << "\nLOC: ";
337 Attr.Loc.print(llvm::errs(), Pass.Ctx.getSourceManager());
338 llvm::errs() << "\nTYPE: ";
339 Attr.ModifiedType.dump();
340 if (Attr.Dcl) {
341 llvm::errs() << "DECL:\n";
342 Attr.Dcl->dump();
343 } else {
344 llvm::errs() << "DECL: NONE";
345 }
346 llvm::errs() << "\nMIGRATABLE: " << Attr.FullyMigratable;
347 llvm::errs() << "\n----------------\n";
348 }
349 llvm::errs() << "\n################\n";
350}
Defines the clang::ASTContext interface.
static bool isInMainFile(const clang::Diagnostic &D)
Definition: ASTUnit.cpp:721
#define SM(sm)
Definition: Cuda.cpp:82
Defines the SourceManager interface.
static void checkAllProps(MigrationContext &MigrateCtx, std::vector< ObjCPropertyDecl * > &AllProps)
static void checkAllAtProps(MigrationContext &MigrateCtx, SourceLocation AtLoc, IndivPropsTy &IndProps)
llvm::TinyPtrVector< ObjCPropertyDecl * > IndivPropsTy
static void checkWeakGCAttrs(MigrationContext &MigrateCtx)
static void errorForGCAttrsOnNonObjC(MigrationContext &MigrateCtx)
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:182
SourceManager & getSourceManager()
Definition: ASTContext.h:700
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1068
Wrapper for source info for arrays.
Definition: TypeLoc.h:1535
Attr - This represents one attribute.
Definition: Attr.h:42
Type source information for an attributed type.
Definition: TypeLoc.h:875
const T * getAttrAs()
Definition: TypeLoc.h:905
TypeLoc getModifiedLoc() const
The modified type, which is generally canonically different from the attribute type.
Definition: TypeLoc.h:889
Represents a C++ struct/union/class.
Definition: DeclCXX.h:258
SourceLocation getBegin() const
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:85
bool isImplicit() const
isImplicit - Indicates whether the declaration was implicitly generated by the implementation.
Definition: DeclBase.h:598
redecl_range redecls() const
Returns an iterator range for all the redeclarations of the same decl.
Definition: DeclBase.h:1039
DeclContext * getDeclContext()
Definition: DeclBase.h:453
Represents a ValueDecl that came out of a declarator.
Definition: Decl.h:770
Represents a function declaration or definition.
Definition: Decl.h:1959
ObjCCategoryDecl - Represents a category declaration.
Definition: DeclObjC.h:2323
ObjCContainerDecl - Represents a container for method declarations.
Definition: DeclObjC.h:944
Represents an ObjC class declaration.
Definition: DeclObjC.h:1150
Represents one property declaration in an Objective-C interface.
Definition: DeclObjC.h:729
SourceLocation getAtLoc() const
Definition: DeclObjC.h:792
TypeSourceInfo * getTypeSourceInfo() const
Definition: DeclObjC.h:798
ObjCPropertyAttribute::Kind getPropertyAttributesAsWritten() const
Definition: DeclObjC.h:823
Wrapper for source info for pointers.
Definition: TypeLoc.h:1275
A (possibly-)qualified type.
Definition: Type.h:737
bool isNull() const
Return true if this QualType doesn't point to a type yet.
Definition: Type.h:804
Qualifiers::ObjCLifetime getObjCLifetime() const
Returns lifetime attribute of this type.
Definition: Type.h:1229
Wrapper of type source information for a type with non-trivial direct qualifiers.
Definition: TypeLoc.h:289
@ OCL_Strong
Assigning into this object requires the old value to be released and the new value to be retained.
Definition: Type.h:175
@ OCL_Weak
Reading or writing from this object requires a barrier call.
Definition: Type.h:178
A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each...
bool TraverseDecl(Decl *D)
Recursively visit a declaration, by dispatching to Traverse*Decl() based on the argument's dynamic ty...
bool shouldWalkTypesOfTypeLocs() const
Return whether this visitor should recurse into the types of TypeLocs.
Encodes a location in the source.
This class handles loading and caching of source files into memory.
CharSourceRange getImmediateExpansionRange(SourceLocation Loc) const
Return the start/end of the expansion information for an expansion location.
Base wrapper for a particular "section" of type source info.
Definition: TypeLoc.h:59
UnqualTypeLoc getUnqualifiedLoc() const
Skips past any qualifiers, if this is qualified.
Definition: TypeLoc.h:338
QualType getType() const
Get the type for which this source info wrapper provides information.
Definition: TypeLoc.h:133
T getAs() const
Convert to the specified TypeLoc type, returning a null TypeLoc if this TypeLoc is not of the desired...
Definition: TypeLoc.h:89
A container of type source information.
Definition: Type.h:6872
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:256
QualType getType() const
Return the type wrapped by this type source info.
Definition: Type.h:6883
bool isObjCRetainableType() const
Definition: Type.cpp:4756
TransformActions & TA
Definition: Internals.h:152
bool clearDiagnostic(ArrayRef< unsigned > IDs, SourceRange range)
void remove(SourceRange range)
void reportError(StringRef error, SourceLocation loc, SourceRange range=SourceRange())
void replaceText(SourceLocation loc, StringRef text, StringRef replacementText)
void traverseTU(MigrationContext &MigrateCtx) override
llvm::DenseSet< SourceLocation > AttrSet
Definition: Transforms.h:96
bool addPropertyAttribute(StringRef attr, SourceLocation atLoc)
Definition: Transforms.cpp:460
std::vector< GCAttrOccurrence > GCAttrs
Definition: Transforms.h:95
llvm::DenseSet< SourceLocation > AtPropsWeak
Set of raw '@' locations for 'assign' properties group that contain GC __weak.
Definition: Transforms.h:101
bool rewritePropertyAttribute(StringRef fromAttr, StringRef toAttr, SourceLocation atLoc)
Definition: Transforms.cpp:378
llvm::DenseSet< SourceLocation > RemovedAttrSet
Definition: Transforms.h:97
bool canApplyWeak(ASTContext &Ctx, QualType type, bool AllowOnUnknownClass=false)
Determine whether we can add weak to the given type.
Definition: Transforms.cpp:38
The JSON file list parser is used to communicate input to InstallAPI.
#define false
Definition: stdbool.h:22