1	//===--- SemaObjCProperty.cpp - Semantic Analysis for ObjC @property ------===//
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	// This file implements semantic analysis for Objective C @property and
10	// @synthesize declarations.
11	//
12	//===----------------------------------------------------------------------===//
13
14	#include "clang/Sema/SemaInternal.h"
15	#include "clang/AST/ASTMutationListener.h"
16	#include "clang/AST/DeclObjC.h"
17	#include "clang/AST/ExprCXX.h"
18	#include "clang/AST/ExprObjC.h"
19	#include "clang/Basic/SourceManager.h"
20	#include "clang/Lex/Lexer.h"
21	#include "clang/Lex/Preprocessor.h"
22	#include "clang/Sema/Initialization.h"
23	#include "llvm/ADT/DenseSet.h"
24	#include "llvm/ADT/SmallString.h"
25
26	using namespace clang;
27
28	//===----------------------------------------------------------------------===//
29	// Grammar actions.
30	//===----------------------------------------------------------------------===//
31
32	/// getImpliedARCOwnership - Given a set of property attributes and a
33	/// type, infer an expected lifetime. The type's ownership qualification
34	/// is not considered.
35	///
36	/// Returns OCL_None if the attributes as stated do not imply an ownership.
37	/// Never returns OCL_Autoreleasing.
38	static Qualifiers::ObjCLifetime
39	getImpliedARCOwnership(ObjCPropertyAttribute::Kind attrs, QualType type) {
40	// retain, strong, copy, weak, and unsafe_unretained are only legal
41	// on properties of retainable pointer type.
42	if (attrs &
43	(ObjCPropertyAttribute::kind_retain | ObjCPropertyAttribute::kind_strong |
44	ObjCPropertyAttribute::kind_copy)) {
45	return Qualifiers::OCL_Strong;
46	} else if (attrs & ObjCPropertyAttribute::kind_weak) {
47	return Qualifiers::OCL_Weak;
48	} else if (attrs & ObjCPropertyAttribute::kind_unsafe_unretained) {
49	return Qualifiers::OCL_ExplicitNone;
50	}
51
52	// assign can appear on other types, so we have to check the
53	// property type.
54	if (attrs & ObjCPropertyAttribute::kind_assign &&
55	type->isObjCRetainableType()) {
56	return Qualifiers::OCL_ExplicitNone;
57	}
58
59	return Qualifiers::OCL_None;
60	}
61
62	/// Check the internal consistency of a property declaration with
63	/// an explicit ownership qualifier.
64	static void checkPropertyDeclWithOwnership(Sema &S,
65	ObjCPropertyDecl *property) {
66	if (property->isInvalidDecl()) return;
67
68	ObjCPropertyAttribute::Kind propertyKind = property->getPropertyAttributes();
69	Qualifiers::ObjCLifetime propertyLifetime
70	= property->getType().getObjCLifetime();
71
72	assert(propertyLifetime != Qualifiers::OCL_None);
73
74	Qualifiers::ObjCLifetime expectedLifetime
75	= getImpliedARCOwnership(attrs: propertyKind, type: property->getType());
76	if (!expectedLifetime) {
77	// We have a lifetime qualifier but no dominating property
78	// attribute. That's okay, but restore reasonable invariants by
79	// setting the property attribute according to the lifetime
80	// qualifier.
81	ObjCPropertyAttribute::Kind attr;
82	if (propertyLifetime == Qualifiers::OCL_Strong) {
83	attr = ObjCPropertyAttribute::kind_strong;
84	} else if (propertyLifetime == Qualifiers::OCL_Weak) {
85	attr = ObjCPropertyAttribute::kind_weak;
86	} else {
87	assert(propertyLifetime == Qualifiers::OCL_ExplicitNone);
88	attr = ObjCPropertyAttribute::kind_unsafe_unretained;
89	}
90	property->setPropertyAttributes(attr);
91	return;
92	}
93
94	if (propertyLifetime == expectedLifetime) return;
95
96	property->setInvalidDecl();
97	S.Diag(property->getLocation(),
98	diag::err_arc_inconsistent_property_ownership)
99	<< property->getDeclName()
100	<< expectedLifetime
101	<< propertyLifetime;
102	}
103
104	/// Check this Objective-C property against a property declared in the
105	/// given protocol.
106	static void
107	CheckPropertyAgainstProtocol(Sema &S, ObjCPropertyDecl *Prop,
108	ObjCProtocolDecl *Proto,
109	llvm::SmallPtrSetImpl<ObjCProtocolDecl *> &Known) {
110	// Have we seen this protocol before?
111	if (!Known.insert(Ptr: Proto).second)
112	return;
113
114	// Look for a property with the same name.
115	if (ObjCPropertyDecl *ProtoProp = Proto->getProperty(
116	Id: Prop->getIdentifier(), IsInstance: Prop->isInstanceProperty())) {
117	S.DiagnosePropertyMismatch(Property: Prop, SuperProperty: ProtoProp, Name: Proto->getIdentifier(), OverridingProtocolProperty: true);
118	return;
119	}
120
121	// Check this property against any protocols we inherit.
122	for (auto *P : Proto->protocols())
123	CheckPropertyAgainstProtocol(S, Prop, Proto: P, Known);
124	}
125
126	static unsigned deducePropertyOwnershipFromType(Sema &S, QualType T) {
127	// In GC mode, just look for the __weak qualifier.
128	if (S.getLangOpts().getGC() != LangOptions::NonGC) {
129	if (T.isObjCGCWeak())
130	return ObjCPropertyAttribute::kind_weak;
131
132	// In ARC/MRC, look for an explicit ownership qualifier.
133	// For some reason, this only applies to __weak.
134	} else if (auto ownership = T.getObjCLifetime()) {
135	switch (ownership) {
136	case Qualifiers::OCL_Weak:
137	return ObjCPropertyAttribute::kind_weak;
138	case Qualifiers::OCL_Strong:
139	return ObjCPropertyAttribute::kind_strong;
140	case Qualifiers::OCL_ExplicitNone:
141	return ObjCPropertyAttribute::kind_unsafe_unretained;
142	case Qualifiers::OCL_Autoreleasing:
143	case Qualifiers::OCL_None:
144	return 0;
145	}
146	llvm_unreachable("bad qualifier");
147	}
148
149	return 0;
150	}
151
152	static const unsigned OwnershipMask =
153	(ObjCPropertyAttribute::kind_assign | ObjCPropertyAttribute::kind_retain |
154	ObjCPropertyAttribute::kind_copy | ObjCPropertyAttribute::kind_weak |
155	ObjCPropertyAttribute::kind_strong |
156	ObjCPropertyAttribute::kind_unsafe_unretained);
157
158	static unsigned getOwnershipRule(unsigned attr) {
159	unsigned result = attr & OwnershipMask;
160
161	// From an ownership perspective, assign and unsafe_unretained are
162	// identical; make sure one also implies the other.
163	if (result & (ObjCPropertyAttribute::kind_assign |
164	ObjCPropertyAttribute::kind_unsafe_unretained)) {
165	result |= ObjCPropertyAttribute::kind_assign |
166	ObjCPropertyAttribute::kind_unsafe_unretained;
167	}
168
169	return result;
170	}
171
172	Decl *Sema::ActOnProperty(Scope *S, SourceLocation AtLoc,
173	SourceLocation LParenLoc,
174	FieldDeclarator &FD,
175	ObjCDeclSpec &ODS,
176	Selector GetterSel,
177	Selector SetterSel,
178	tok::ObjCKeywordKind MethodImplKind,
179	DeclContext *lexicalDC) {
180	unsigned Attributes = ODS.getPropertyAttributes();
181	FD.D.setObjCWeakProperty((Attributes & ObjCPropertyAttribute::kind_weak) !=
182	0);
183	TypeSourceInfo *TSI = GetTypeForDeclarator(D&: FD.D);
184	QualType T = TSI->getType();
185	if (!getOwnershipRule(attr: Attributes)) {
186	Attributes |= deducePropertyOwnershipFromType(S&: *this, T);
187	}
188	bool isReadWrite = ((Attributes & ObjCPropertyAttribute::kind_readwrite) ||
189	// default is readwrite!
190	!(Attributes & ObjCPropertyAttribute::kind_readonly));
191
192	// Proceed with constructing the ObjCPropertyDecls.
193	ObjCContainerDecl *ClassDecl = cast<ObjCContainerDecl>(Val: CurContext);
194	ObjCPropertyDecl *Res = nullptr;
195	if (ObjCCategoryDecl *CDecl = dyn_cast<ObjCCategoryDecl>(Val: ClassDecl)) {
196	if (CDecl->IsClassExtension()) {
197	Res = HandlePropertyInClassExtension(S, AtLoc, LParenLoc,
198	FD,
199	GetterSel, GetterNameLoc: ODS.getGetterNameLoc(),
200	SetterSel, SetterNameLoc: ODS.getSetterNameLoc(),
201	isReadWrite, Attributes,
202	AttributesAsWritten: ODS.getPropertyAttributes(),
203	T, TSI, MethodImplKind);
204	if (!Res)
205	return nullptr;
206	}
207	}
208
209	if (!Res) {
210	Res = CreatePropertyDecl(S, CDecl: ClassDecl, AtLoc, LParenLoc, FD,
211	GetterSel, GetterNameLoc: ODS.getGetterNameLoc(), SetterSel,
212	SetterNameLoc: ODS.getSetterNameLoc(), isReadWrite, Attributes,
213	AttributesAsWritten: ODS.getPropertyAttributes(), T, TSI,
214	MethodImplKind);
215	if (lexicalDC)
216	Res->setLexicalDeclContext(lexicalDC);
217	}
218
219	// Validate the attributes on the @property.
220	CheckObjCPropertyAttributes(Res, AtLoc, Attributes,
221	(isa<ObjCInterfaceDecl>(Val: ClassDecl) ||
222	isa<ObjCProtocolDecl>(Val: ClassDecl)));
223
224	// Check consistency if the type has explicit ownership qualification.
225	if (Res->getType().getObjCLifetime())
226	checkPropertyDeclWithOwnership(S&: *this, property: Res);
227
228	llvm::SmallPtrSet<ObjCProtocolDecl *, 16> KnownProtos;
229	if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Val: ClassDecl)) {
230	// For a class, compare the property against a property in our superclass.
231	bool FoundInSuper = false;
232	ObjCInterfaceDecl *CurrentInterfaceDecl = IFace;
233	while (ObjCInterfaceDecl *Super = CurrentInterfaceDecl->getSuperClass()) {
234	if (ObjCPropertyDecl *SuperProp = Super->getProperty(
235	Id: Res->getIdentifier(), IsInstance: Res->isInstanceProperty())) {
236	DiagnosePropertyMismatch(Property: Res, SuperProperty: SuperProp, Name: Super->getIdentifier(), OverridingProtocolProperty: false);
237	FoundInSuper = true;
238	break;
239	}
240	CurrentInterfaceDecl = Super;
241	}
242
243	if (FoundInSuper) {
244	// Also compare the property against a property in our protocols.
245	for (auto *P : CurrentInterfaceDecl->protocols()) {
246	CheckPropertyAgainstProtocol(S&: *this, Prop: Res, Proto: P, Known&: KnownProtos);
247	}
248	} else {
249	// Slower path: look in all protocols we referenced.
250	for (auto *P : IFace->all_referenced_protocols()) {
251	CheckPropertyAgainstProtocol(S&: *this, Prop: Res, Proto: P, Known&: KnownProtos);
252	}
253	}
254	} else if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(Val: ClassDecl)) {
255	// We don't check if class extension. Because properties in class extension
256	// are meant to override some of the attributes and checking has already done
257	// when property in class extension is constructed.
258	if (!Cat->IsClassExtension())
259	for (auto *P : Cat->protocols())
260	CheckPropertyAgainstProtocol(S&: *this, Prop: Res, Proto: P, Known&: KnownProtos);
261	} else {
262	ObjCProtocolDecl *Proto = cast<ObjCProtocolDecl>(Val: ClassDecl);
263	for (auto *P : Proto->protocols())
264	CheckPropertyAgainstProtocol(S&: *this, Prop: Res, Proto: P, Known&: KnownProtos);
265	}
266
267	ActOnDocumentableDecl(Res);
268	return Res;
269	}
270
271	static ObjCPropertyAttribute::Kind
272	makePropertyAttributesAsWritten(unsigned Attributes) {
273	unsigned attributesAsWritten = 0;
274	if (Attributes & ObjCPropertyAttribute::kind_readonly)
275	attributesAsWritten |= ObjCPropertyAttribute::kind_readonly;
276	if (Attributes & ObjCPropertyAttribute::kind_readwrite)
277	attributesAsWritten |= ObjCPropertyAttribute::kind_readwrite;
278	if (Attributes & ObjCPropertyAttribute::kind_getter)
279	attributesAsWritten |= ObjCPropertyAttribute::kind_getter;
280	if (Attributes & ObjCPropertyAttribute::kind_setter)
281	attributesAsWritten |= ObjCPropertyAttribute::kind_setter;
282	if (Attributes & ObjCPropertyAttribute::kind_assign)
283	attributesAsWritten |= ObjCPropertyAttribute::kind_assign;
284	if (Attributes & ObjCPropertyAttribute::kind_retain)
285	attributesAsWritten |= ObjCPropertyAttribute::kind_retain;
286	if (Attributes & ObjCPropertyAttribute::kind_strong)
287	attributesAsWritten |= ObjCPropertyAttribute::kind_strong;
288	if (Attributes & ObjCPropertyAttribute::kind_weak)
289	attributesAsWritten |= ObjCPropertyAttribute::kind_weak;
290	if (Attributes & ObjCPropertyAttribute::kind_copy)
291	attributesAsWritten |= ObjCPropertyAttribute::kind_copy;
292	if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
293	attributesAsWritten |= ObjCPropertyAttribute::kind_unsafe_unretained;
294	if (Attributes & ObjCPropertyAttribute::kind_nonatomic)
295	attributesAsWritten |= ObjCPropertyAttribute::kind_nonatomic;
296	if (Attributes & ObjCPropertyAttribute::kind_atomic)
297	attributesAsWritten |= ObjCPropertyAttribute::kind_atomic;
298	if (Attributes & ObjCPropertyAttribute::kind_class)
299	attributesAsWritten |= ObjCPropertyAttribute::kind_class;
300	if (Attributes & ObjCPropertyAttribute::kind_direct)
301	attributesAsWritten |= ObjCPropertyAttribute::kind_direct;
302
303	return (ObjCPropertyAttribute::Kind)attributesAsWritten;
304	}
305
306	static bool LocPropertyAttribute( ASTContext &Context, const char *attrName,
307	SourceLocation LParenLoc, SourceLocation &Loc) {
308	if (LParenLoc.isMacroID())
309	return false;
310
311	SourceManager &SM = Context.getSourceManager();
312	std::pair<FileID, unsigned> locInfo = SM.getDecomposedLoc(Loc: LParenLoc);
313	// Try to load the file buffer.
314	bool invalidTemp = false;
315	StringRef file = SM.getBufferData(FID: locInfo.first, Invalid: &invalidTemp);
316	if (invalidTemp)
317	return false;
318	const char *tokenBegin = file.data() + locInfo.second;
319
320	// Lex from the start of the given location.
321	Lexer lexer(SM.getLocForStartOfFile(FID: locInfo.first),
322	Context.getLangOpts(),
323	file.begin(), tokenBegin, file.end());
324	Token Tok;
325	do {
326	lexer.LexFromRawLexer(Result&: Tok);
327	if (Tok.is(K: tok::raw_identifier) && Tok.getRawIdentifier() == attrName) {
328	Loc = Tok.getLocation();
329	return true;
330	}
331	} while (Tok.isNot(K: tok::r_paren));
332	return false;
333	}
334
335	/// Check for a mismatch in the atomicity of the given properties.
336	static void checkAtomicPropertyMismatch(Sema &S,
337	ObjCPropertyDecl *OldProperty,
338	ObjCPropertyDecl *NewProperty,
339	bool PropagateAtomicity) {
340	// If the atomicity of both matches, we're done.
341	bool OldIsAtomic = (OldProperty->getPropertyAttributes() &
342	ObjCPropertyAttribute::kind_nonatomic) == 0;
343	bool NewIsAtomic = (NewProperty->getPropertyAttributes() &
344	ObjCPropertyAttribute::kind_nonatomic) == 0;
345	if (OldIsAtomic == NewIsAtomic) return;
346
347	// Determine whether the given property is readonly and implicitly
348	// atomic.
349	auto isImplicitlyReadonlyAtomic = [](ObjCPropertyDecl *Property) -> bool {
350	// Is it readonly?
351	auto Attrs = Property->getPropertyAttributes();
352	if ((Attrs & ObjCPropertyAttribute::kind_readonly) == 0)
353	return false;
354
355	// Is it nonatomic?
356	if (Attrs & ObjCPropertyAttribute::kind_nonatomic)
357	return false;
358
359	// Was 'atomic' specified directly?
360	if (Property->getPropertyAttributesAsWritten() &
361	ObjCPropertyAttribute::kind_atomic)
362	return false;
363
364	return true;
365	};
366
367	// If we're allowed to propagate atomicity, and the new property did
368	// not specify atomicity at all, propagate.
369	const unsigned AtomicityMask = (ObjCPropertyAttribute::kind_atomic |
370	ObjCPropertyAttribute::kind_nonatomic);
371	if (PropagateAtomicity &&
372	((NewProperty->getPropertyAttributesAsWritten() & AtomicityMask) == 0)) {
373	unsigned Attrs = NewProperty->getPropertyAttributes();
374	Attrs = Attrs & ~AtomicityMask;
375	if (OldIsAtomic)
376	Attrs |= ObjCPropertyAttribute::kind_atomic;
377	else
378	Attrs |= ObjCPropertyAttribute::kind_nonatomic;
379
380	NewProperty->overwritePropertyAttributes(PRVal: Attrs);
381	return;
382	}
383
384	// One of the properties is atomic; if it's a readonly property, and
385	// 'atomic' wasn't explicitly specified, we're okay.
386	if ((OldIsAtomic && isImplicitlyReadonlyAtomic(OldProperty)) ||
387	(NewIsAtomic && isImplicitlyReadonlyAtomic(NewProperty)))
388	return;
389
390	// Diagnose the conflict.
391	const IdentifierInfo *OldContextName;
392	auto *OldDC = OldProperty->getDeclContext();
393	if (auto Category = dyn_cast<ObjCCategoryDecl>(OldDC))
394	OldContextName = Category->getClassInterface()->getIdentifier();
395	else
396	OldContextName = cast<ObjCContainerDecl>(OldDC)->getIdentifier();
397
398	S.Diag(NewProperty->getLocation(), diag::warn_property_attribute)
399	<< NewProperty->getDeclName() << "atomic"
400	<< OldContextName;
401	S.Diag(OldProperty->getLocation(), diag::note_property_declare);
402	}
403
404	ObjCPropertyDecl *
405	Sema::HandlePropertyInClassExtension(Scope *S,
406	SourceLocation AtLoc,
407	SourceLocation LParenLoc,
408	FieldDeclarator &FD,
409	Selector GetterSel,
410	SourceLocation GetterNameLoc,
411	Selector SetterSel,
412	SourceLocation SetterNameLoc,
413	const bool isReadWrite,
414	unsigned &Attributes,
415	const unsigned AttributesAsWritten,
416	QualType T,
417	TypeSourceInfo *TSI,
418	tok::ObjCKeywordKind MethodImplKind) {
419	ObjCCategoryDecl *CDecl = cast<ObjCCategoryDecl>(Val: CurContext);
420	// Diagnose if this property is already in continuation class.
421	DeclContext *DC = CurContext;
422	const IdentifierInfo *PropertyId = FD.D.getIdentifier();
423	ObjCInterfaceDecl *CCPrimary = CDecl->getClassInterface();
424
425	// We need to look in the @interface to see if the @property was
426	// already declared.
427	if (!CCPrimary) {
428	Diag(CDecl->getLocation(), diag::err_continuation_class);
429	return nullptr;
430	}
431
432	bool isClassProperty =
433	(AttributesAsWritten & ObjCPropertyAttribute::kind_class) ||
434	(Attributes & ObjCPropertyAttribute::kind_class);
435
436	// Find the property in the extended class's primary class or
437	// extensions.
438	ObjCPropertyDecl *PIDecl = CCPrimary->FindPropertyVisibleInPrimaryClass(
439	PropertyId, QueryKind: ObjCPropertyDecl::getQueryKind(isClassProperty));
440
441	// If we found a property in an extension, complain.
442	if (PIDecl && isa<ObjCCategoryDecl>(PIDecl->getDeclContext())) {
443	Diag(AtLoc, diag::err_duplicate_property);
444	Diag(PIDecl->getLocation(), diag::note_property_declare);
445	return nullptr;
446	}
447
448	// Check for consistency with the previous declaration, if there is one.
449	if (PIDecl) {
450	// A readonly property declared in the primary class can be refined
451	// by adding a readwrite property within an extension.
452	// Anything else is an error.
453	if (!(PIDecl->isReadOnly() && isReadWrite)) {
454	// Tailor the diagnostics for the common case where a readwrite
455	// property is declared both in the @interface and the continuation.
456	// This is a common error where the user often intended the original
457	// declaration to be readonly.
458	unsigned diag =
459	(Attributes & ObjCPropertyAttribute::kind_readwrite) &&
460	(PIDecl->getPropertyAttributesAsWritten() &
461	ObjCPropertyAttribute::kind_readwrite)
462	? diag::err_use_continuation_class_redeclaration_readwrite
463	: diag::err_use_continuation_class;
464	Diag(AtLoc, diag)
465	<< CCPrimary->getDeclName();
466	Diag(PIDecl->getLocation(), diag::note_property_declare);
467	return nullptr;
468	}
469
470	// Check for consistency of getters.
471	if (PIDecl->getGetterName() != GetterSel) {
472	// If the getter was written explicitly, complain.
473	if (AttributesAsWritten & ObjCPropertyAttribute::kind_getter) {
474	Diag(AtLoc, diag::warn_property_redecl_getter_mismatch)
475	<< PIDecl->getGetterName() << GetterSel;
476	Diag(PIDecl->getLocation(), diag::note_property_declare);
477	}
478
479	// Always adopt the getter from the original declaration.
480	GetterSel = PIDecl->getGetterName();
481	Attributes |= ObjCPropertyAttribute::kind_getter;
482	}
483
484	// Check consistency of ownership.
485	unsigned ExistingOwnership
486	= getOwnershipRule(attr: PIDecl->getPropertyAttributes());
487	unsigned NewOwnership = getOwnershipRule(attr: Attributes);
488	if (ExistingOwnership && NewOwnership != ExistingOwnership) {
489	// If the ownership was written explicitly, complain.
490	if (getOwnershipRule(attr: AttributesAsWritten)) {
491	Diag(AtLoc, diag::warn_property_attr_mismatch);
492	Diag(PIDecl->getLocation(), diag::note_property_declare);
493	}
494
495	// Take the ownership from the original property.
496	Attributes = (Attributes & ~OwnershipMask) | ExistingOwnership;
497	}
498
499	// If the redeclaration is 'weak' but the original property is not,
500	if ((Attributes & ObjCPropertyAttribute::kind_weak) &&
501	!(PIDecl->getPropertyAttributesAsWritten() &
502	ObjCPropertyAttribute::kind_weak) &&
503	PIDecl->getType()->getAs<ObjCObjectPointerType>() &&
504	PIDecl->getType().getObjCLifetime() == Qualifiers::OCL_None) {
505	Diag(AtLoc, diag::warn_property_implicitly_mismatched);
506	Diag(PIDecl->getLocation(), diag::note_property_declare);
507	}
508	}
509
510	// Create a new ObjCPropertyDecl with the DeclContext being
511	// the class extension.
512	ObjCPropertyDecl *PDecl = CreatePropertyDecl(S, CDecl, AtLoc, LParenLoc,
513	FD, GetterSel, GetterNameLoc,
514	SetterSel, SetterNameLoc,
515	isReadWrite,
516	Attributes, AttributesAsWritten,
517	T, TSI, MethodImplKind, DC);
518
519	// If there was no declaration of a property with the same name in
520	// the primary class, we're done.
521	if (!PIDecl) {
522	ProcessPropertyDecl(property: PDecl);
523	return PDecl;
524	}
525
526	if (!Context.hasSameType(T1: PIDecl->getType(), T2: PDecl->getType())) {
527	bool IncompatibleObjC = false;
528	QualType ConvertedType;
529	// Relax the strict type matching for property type in continuation class.
530	// Allow property object type of continuation class to be different as long
531	// as it narrows the object type in its primary class property. Note that
532	// this conversion is safe only because the wider type is for a 'readonly'
533	// property in primary class and 'narrowed' type for a 'readwrite' property
534	// in continuation class.
535	QualType PrimaryClassPropertyT = Context.getCanonicalType(T: PIDecl->getType());
536	QualType ClassExtPropertyT = Context.getCanonicalType(T: PDecl->getType());
537	if (!isa<ObjCObjectPointerType>(Val: PrimaryClassPropertyT) ||
538	!isa<ObjCObjectPointerType>(Val: ClassExtPropertyT) ||
539	(!isObjCPointerConversion(FromType: ClassExtPropertyT, ToType: PrimaryClassPropertyT,
540	ConvertedType, IncompatibleObjC))
541	|| IncompatibleObjC) {
542	Diag(AtLoc,
543	diag::err_type_mismatch_continuation_class) << PDecl->getType();
544	Diag(PIDecl->getLocation(), diag::note_property_declare);
545	return nullptr;
546	}
547	}
548
549	// Check that atomicity of property in class extension matches the previous
550	// declaration.
551	checkAtomicPropertyMismatch(S&: *this, OldProperty: PIDecl, NewProperty: PDecl, PropagateAtomicity: true);
552
553	// Make sure getter/setter are appropriately synthesized.
554	ProcessPropertyDecl(property: PDecl);
555	return PDecl;
556	}
557
558	ObjCPropertyDecl *Sema::CreatePropertyDecl(Scope *S,
559	ObjCContainerDecl *CDecl,
560	SourceLocation AtLoc,
561	SourceLocation LParenLoc,
562	FieldDeclarator &FD,
563	Selector GetterSel,
564	SourceLocation GetterNameLoc,
565	Selector SetterSel,
566	SourceLocation SetterNameLoc,
567	const bool isReadWrite,
568	const unsigned Attributes,
569	const unsigned AttributesAsWritten,
570	QualType T,
571	TypeSourceInfo *TInfo,
572	tok::ObjCKeywordKind MethodImplKind,
573	DeclContext *lexicalDC){
574	const IdentifierInfo *PropertyId = FD.D.getIdentifier();
575
576	// Property defaults to 'assign' if it is readwrite, unless this is ARC
577	// and the type is retainable.
578	bool isAssign;
579	if (Attributes & (ObjCPropertyAttribute::kind_assign |
580	ObjCPropertyAttribute::kind_unsafe_unretained)) {
581	isAssign = true;
582	} else if (getOwnershipRule(attr: Attributes) || !isReadWrite) {
583	isAssign = false;
584	} else {
585	isAssign = (!getLangOpts().ObjCAutoRefCount ||
586	!T->isObjCRetainableType());
587	}
588
589	// Issue a warning if property is 'assign' as default and its
590	// object, which is gc'able conforms to NSCopying protocol
591	if (getLangOpts().getGC() != LangOptions::NonGC && isAssign &&
592	!(Attributes & ObjCPropertyAttribute::kind_assign)) {
593	if (const ObjCObjectPointerType *ObjPtrTy =
594	T->getAs<ObjCObjectPointerType>()) {
595	ObjCInterfaceDecl *IDecl = ObjPtrTy->getObjectType()->getInterface();
596	if (IDecl)
597	if (ObjCProtocolDecl* PNSCopying =
598	LookupProtocol(&Context.Idents.get("NSCopying"), AtLoc))
599	if (IDecl->ClassImplementsProtocol(PNSCopying, true))
600	Diag(AtLoc, diag::warn_implements_nscopying) << PropertyId;
601	}
602	}
603
604	if (T->isObjCObjectType()) {
605	SourceLocation StarLoc = TInfo->getTypeLoc().getEndLoc();
606	StarLoc = getLocForEndOfToken(Loc: StarLoc);
607	Diag(FD.D.getIdentifierLoc(), diag::err_statically_allocated_object)
608	<< FixItHint::CreateInsertion(StarLoc, "*");
609	T = Context.getObjCObjectPointerType(OIT: T);
610	SourceLocation TLoc = TInfo->getTypeLoc().getBeginLoc();
611	TInfo = Context.getTrivialTypeSourceInfo(T, Loc: TLoc);
612	}
613
614	DeclContext *DC = CDecl;
615	ObjCPropertyDecl *PDecl = ObjCPropertyDecl::Create(C&: Context, DC,
616	L: FD.D.getIdentifierLoc(),
617	Id: PropertyId, AtLocation: AtLoc,
618	LParenLocation: LParenLoc, T, TSI: TInfo);
619
620	bool isClassProperty =
621	(AttributesAsWritten & ObjCPropertyAttribute::kind_class) ||
622	(Attributes & ObjCPropertyAttribute::kind_class);
623	// Class property and instance property can have the same name.
624	if (ObjCPropertyDecl *prevDecl = ObjCPropertyDecl::findPropertyDecl(
625	DC, propertyID: PropertyId, queryKind: ObjCPropertyDecl::getQueryKind(isClassProperty))) {
626	Diag(PDecl->getLocation(), diag::err_duplicate_property);
627	Diag(prevDecl->getLocation(), diag::note_property_declare);
628	PDecl->setInvalidDecl();
629	}
630	else {
631	DC->addDecl(PDecl);
632	if (lexicalDC)
633	PDecl->setLexicalDeclContext(lexicalDC);
634	}
635
636	if (T->isArrayType() || T->isFunctionType()) {
637	Diag(AtLoc, diag::err_property_type) << T;
638	PDecl->setInvalidDecl();
639	}
640
641	// Regardless of setter/getter attribute, we save the default getter/setter
642	// selector names in anticipation of declaration of setter/getter methods.
643	PDecl->setGetterName(Sel: GetterSel, Loc: GetterNameLoc);
644	PDecl->setSetterName(Sel: SetterSel, Loc: SetterNameLoc);
645	PDecl->setPropertyAttributesAsWritten(
646	makePropertyAttributesAsWritten(Attributes: AttributesAsWritten));
647
648	ProcessDeclAttributes(S, PDecl, FD.D);
649
650	if (Attributes & ObjCPropertyAttribute::kind_readonly)
651	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_readonly);
652
653	if (Attributes & ObjCPropertyAttribute::kind_getter)
654	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_getter);
655
656	if (Attributes & ObjCPropertyAttribute::kind_setter)
657	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_setter);
658
659	if (isReadWrite)
660	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_readwrite);
661
662	if (Attributes & ObjCPropertyAttribute::kind_retain)
663	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_retain);
664
665	if (Attributes & ObjCPropertyAttribute::kind_strong)
666	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
667
668	if (Attributes & ObjCPropertyAttribute::kind_weak)
669	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_weak);
670
671	if (Attributes & ObjCPropertyAttribute::kind_copy)
672	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_copy);
673
674	if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
675	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_unsafe_unretained);
676
677	if (isAssign)
678	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_assign);
679
680	// In the semantic attributes, one of nonatomic or atomic is always set.
681	if (Attributes & ObjCPropertyAttribute::kind_nonatomic)
682	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_nonatomic);
683	else
684	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_atomic);
685
686	// 'unsafe_unretained' is alias for 'assign'.
687	if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained)
688	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_assign);
689	if (isAssign)
690	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_unsafe_unretained);
691
692	if (MethodImplKind == tok::objc_required)
693	PDecl->setPropertyImplementation(ObjCPropertyDecl::Required);
694	else if (MethodImplKind == tok::objc_optional)
695	PDecl->setPropertyImplementation(ObjCPropertyDecl::Optional);
696
697	if (Attributes & ObjCPropertyAttribute::kind_nullability)
698	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_nullability);
699
700	if (Attributes & ObjCPropertyAttribute::kind_null_resettable)
701	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_null_resettable);
702
703	if (Attributes & ObjCPropertyAttribute::kind_class)
704	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_class);
705
706	if ((Attributes & ObjCPropertyAttribute::kind_direct) ||
707	CDecl->hasAttr<ObjCDirectMembersAttr>()) {
708	if (isa<ObjCProtocolDecl>(Val: CDecl)) {
709	Diag(PDecl->getLocation(), diag::err_objc_direct_on_protocol) << true;
710	} else if (getLangOpts().ObjCRuntime.allowsDirectDispatch()) {
711	PDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_direct);
712	} else {
713	Diag(PDecl->getLocation(), diag::warn_objc_direct_property_ignored)
714	<< PDecl->getDeclName();
715	}
716	}
717
718	return PDecl;
719	}
720
721	static void checkARCPropertyImpl(Sema &S, SourceLocation propertyImplLoc,
722	ObjCPropertyDecl *property,
723	ObjCIvarDecl *ivar) {
724	if (property->isInvalidDecl() || ivar->isInvalidDecl()) return;
725
726	QualType ivarType = ivar->getType();
727	Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
728
729	// The lifetime implied by the property's attributes.
730	Qualifiers::ObjCLifetime propertyLifetime =
731	getImpliedARCOwnership(attrs: property->getPropertyAttributes(),
732	type: property->getType());
733
734	// We're fine if they match.
735	if (propertyLifetime == ivarLifetime) return;
736
737	// None isn't a valid lifetime for an object ivar in ARC, and
738	// __autoreleasing is never valid; don't diagnose twice.
739	if ((ivarLifetime == Qualifiers::OCL_None &&
740	S.getLangOpts().ObjCAutoRefCount) ||
741	ivarLifetime == Qualifiers::OCL_Autoreleasing)
742	return;
743
744	// If the ivar is private, and it's implicitly __unsafe_unretained
745	// because of its type, then pretend it was actually implicitly
746	// __strong. This is only sound because we're processing the
747	// property implementation before parsing any method bodies.
748	if (ivarLifetime == Qualifiers::OCL_ExplicitNone &&
749	propertyLifetime == Qualifiers::OCL_Strong &&
750	ivar->getAccessControl() == ObjCIvarDecl::Private) {
751	SplitQualType split = ivarType.split();
752	if (split.Quals.hasObjCLifetime()) {
753	assert(ivarType->isObjCARCImplicitlyUnretainedType());
754	split.Quals.setObjCLifetime(Qualifiers::OCL_Strong);
755	ivarType = S.Context.getQualifiedType(split);
756	ivar->setType(ivarType);
757	return;
758	}
759	}
760
761	switch (propertyLifetime) {
762	case Qualifiers::OCL_Strong:
763	S.Diag(ivar->getLocation(), diag::err_arc_strong_property_ownership)
764	<< property->getDeclName()
765	<< ivar->getDeclName()
766	<< ivarLifetime;
767	break;
768
769	case Qualifiers::OCL_Weak:
770	S.Diag(ivar->getLocation(), diag::err_weak_property)
771	<< property->getDeclName()
772	<< ivar->getDeclName();
773	break;
774
775	case Qualifiers::OCL_ExplicitNone:
776	S.Diag(ivar->getLocation(), diag::err_arc_assign_property_ownership)
777	<< property->getDeclName() << ivar->getDeclName()
778	<< ((property->getPropertyAttributesAsWritten() &
779	ObjCPropertyAttribute::kind_assign) != 0);
780	break;
781
782	case Qualifiers::OCL_Autoreleasing:
783	llvm_unreachable("properties cannot be autoreleasing");
784
785	case Qualifiers::OCL_None:
786	// Any other property should be ignored.
787	return;
788	}
789
790	S.Diag(property->getLocation(), diag::note_property_declare);
791	if (propertyImplLoc.isValid())
792	S.Diag(propertyImplLoc, diag::note_property_synthesize);
793	}
794
795	/// setImpliedPropertyAttributeForReadOnlyProperty -
796	/// This routine evaludates life-time attributes for a 'readonly'
797	/// property with no known lifetime of its own, using backing
798	/// 'ivar's attribute, if any. If no backing 'ivar', property's
799	/// life-time is assumed 'strong'.
800	static void setImpliedPropertyAttributeForReadOnlyProperty(
801	ObjCPropertyDecl *property, ObjCIvarDecl *ivar) {
802	Qualifiers::ObjCLifetime propertyLifetime =
803	getImpliedARCOwnership(attrs: property->getPropertyAttributes(),
804	type: property->getType());
805	if (propertyLifetime != Qualifiers::OCL_None)
806	return;
807
808	if (!ivar) {
809	// if no backing ivar, make property 'strong'.
810	property->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
811	return;
812	}
813	// property assumes owenership of backing ivar.
814	QualType ivarType = ivar->getType();
815	Qualifiers::ObjCLifetime ivarLifetime = ivarType.getObjCLifetime();
816	if (ivarLifetime == Qualifiers::OCL_Strong)
817	property->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
818	else if (ivarLifetime == Qualifiers::OCL_Weak)
819	property->setPropertyAttributes(ObjCPropertyAttribute::kind_weak);
820	}
821
822	static bool isIncompatiblePropertyAttribute(unsigned Attr1, unsigned Attr2,
823	ObjCPropertyAttribute::Kind Kind) {
824	return (Attr1 & Kind) != (Attr2 & Kind);
825	}
826
827	static bool areIncompatiblePropertyAttributes(unsigned Attr1, unsigned Attr2,
828	unsigned Kinds) {
829	return ((Attr1 & Kinds) != 0) != ((Attr2 & Kinds) != 0);
830	}
831
832	/// SelectPropertyForSynthesisFromProtocols - Finds the most appropriate
833	/// property declaration that should be synthesised in all of the inherited
834	/// protocols. It also diagnoses properties declared in inherited protocols with
835	/// mismatched types or attributes, since any of them can be candidate for
836	/// synthesis.
837	static ObjCPropertyDecl *
838	SelectPropertyForSynthesisFromProtocols(Sema &S, SourceLocation AtLoc,
839	ObjCInterfaceDecl *ClassDecl,
840	ObjCPropertyDecl *Property) {
841	assert(isa<ObjCProtocolDecl>(Property->getDeclContext()) &&
842	"Expected a property from a protocol");
843	ObjCInterfaceDecl::ProtocolPropertySet ProtocolSet;
844	ObjCInterfaceDecl::PropertyDeclOrder Properties;
845	for (const auto *PI : ClassDecl->all_referenced_protocols()) {
846	if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
847	PDecl->collectInheritedProtocolProperties(Property, PS&: ProtocolSet,
848	PO&: Properties);
849	}
850	if (ObjCInterfaceDecl *SDecl = ClassDecl->getSuperClass()) {
851	while (SDecl) {
852	for (const auto *PI : SDecl->all_referenced_protocols()) {
853	if (const ObjCProtocolDecl *PDecl = PI->getDefinition())
854	PDecl->collectInheritedProtocolProperties(Property, PS&: ProtocolSet,
855	PO&: Properties);
856	}
857	SDecl = SDecl->getSuperClass();
858	}
859	}
860
861	if (Properties.empty())
862	return Property;
863
864	ObjCPropertyDecl *OriginalProperty = Property;
865	size_t SelectedIndex = 0;
866	for (const auto &Prop : llvm::enumerate(First&: Properties)) {
867	// Select the 'readwrite' property if such property exists.
868	if (Property->isReadOnly() && !Prop.value()->isReadOnly()) {
869	Property = Prop.value();
870	SelectedIndex = Prop.index();
871	}
872	}
873	if (Property != OriginalProperty) {
874	// Check that the old property is compatible with the new one.
875	Properties[SelectedIndex] = OriginalProperty;
876	}
877
878	QualType RHSType = S.Context.getCanonicalType(T: Property->getType());
879	unsigned OriginalAttributes = Property->getPropertyAttributesAsWritten();
880	enum MismatchKind {
881	IncompatibleType = 0,
882	HasNoExpectedAttribute,
883	HasUnexpectedAttribute,
884	DifferentGetter,
885	DifferentSetter
886	};
887	// Represents a property from another protocol that conflicts with the
888	// selected declaration.
889	struct MismatchingProperty {
890	const ObjCPropertyDecl *Prop;
891	MismatchKind Kind;
892	StringRef AttributeName;
893	};
894	SmallVector<MismatchingProperty, 4> Mismatches;
895	for (ObjCPropertyDecl *Prop : Properties) {
896	// Verify the property attributes.
897	unsigned Attr = Prop->getPropertyAttributesAsWritten();
898	if (Attr != OriginalAttributes) {
899	auto Diag = [&](bool OriginalHasAttribute, StringRef AttributeName) {
900	MismatchKind Kind = OriginalHasAttribute ? HasNoExpectedAttribute
901	: HasUnexpectedAttribute;
902	Mismatches.push_back(Elt: {.Prop: Prop, .Kind: Kind, .AttributeName: AttributeName});
903	};
904	// The ownership might be incompatible unless the property has no explicit
905	// ownership.
906	bool HasOwnership =
907	(Attr & (ObjCPropertyAttribute::kind_retain |
908	ObjCPropertyAttribute::kind_strong |
909	ObjCPropertyAttribute::kind_copy |
910	ObjCPropertyAttribute::kind_assign |
911	ObjCPropertyAttribute::kind_unsafe_unretained |
912	ObjCPropertyAttribute::kind_weak)) != 0;
913	if (HasOwnership &&
914	isIncompatiblePropertyAttribute(Attr1: OriginalAttributes, Attr2: Attr,
915	Kind: ObjCPropertyAttribute::kind_copy)) {
916	Diag(OriginalAttributes & ObjCPropertyAttribute::kind_copy, "copy");
917	continue;
918	}
919	if (HasOwnership && areIncompatiblePropertyAttributes(
920	Attr1: OriginalAttributes, Attr2: Attr,
921	Kinds: ObjCPropertyAttribute::kind_retain |
922	ObjCPropertyAttribute::kind_strong)) {
923	Diag(OriginalAttributes & (ObjCPropertyAttribute::kind_retain |
924	ObjCPropertyAttribute::kind_strong),
925	"retain (or strong)");
926	continue;
927	}
928	if (isIncompatiblePropertyAttribute(Attr1: OriginalAttributes, Attr2: Attr,
929	Kind: ObjCPropertyAttribute::kind_atomic)) {
930	Diag(OriginalAttributes & ObjCPropertyAttribute::kind_atomic, "atomic");
931	continue;
932	}
933	}
934	if (Property->getGetterName() != Prop->getGetterName()) {
935	Mismatches.push_back(Elt: {.Prop: Prop, .Kind: DifferentGetter, .AttributeName: ""});
936	continue;
937	}
938	if (!Property->isReadOnly() && !Prop->isReadOnly() &&
939	Property->getSetterName() != Prop->getSetterName()) {
940	Mismatches.push_back(Elt: {.Prop: Prop, .Kind: DifferentSetter, .AttributeName: ""});
941	continue;
942	}
943	QualType LHSType = S.Context.getCanonicalType(T: Prop->getType());
944	if (!S.Context.propertyTypesAreCompatible(LHSType, RHSType)) {
945	bool IncompatibleObjC = false;
946	QualType ConvertedType;
947	if (!S.isObjCPointerConversion(FromType: RHSType, ToType: LHSType, ConvertedType, IncompatibleObjC)
948	|| IncompatibleObjC) {
949	Mismatches.push_back(Elt: {.Prop: Prop, .Kind: IncompatibleType, .AttributeName: ""});
950	continue;
951	}
952	}
953	}
954
955	if (Mismatches.empty())
956	return Property;
957
958	// Diagnose incompability.
959	{
960	bool HasIncompatibleAttributes = false;
961	for (const auto &Note : Mismatches)
962	HasIncompatibleAttributes =
963	Note.Kind != IncompatibleType ? true : HasIncompatibleAttributes;
964	// Promote the warning to an error if there are incompatible attributes or
965	// incompatible types together with readwrite/readonly incompatibility.
966	auto Diag = S.Diag(Property->getLocation(),
967	Property != OriginalProperty || HasIncompatibleAttributes
968	? diag::err_protocol_property_mismatch
969	: diag::warn_protocol_property_mismatch);
970	Diag << Mismatches[0].Kind;
971	switch (Mismatches[0].Kind) {
972	case IncompatibleType:
973	Diag << Property->getType();
974	break;
975	case HasNoExpectedAttribute:
976	case HasUnexpectedAttribute:
977	Diag << Mismatches[0].AttributeName;
978	break;
979	case DifferentGetter:
980	Diag << Property->getGetterName();
981	break;
982	case DifferentSetter:
983	Diag << Property->getSetterName();
984	break;
985	}
986	}
987	for (const auto &Note : Mismatches) {
988	auto Diag =
989	S.Diag(Note.Prop->getLocation(), diag::note_protocol_property_declare)
990	<< Note.Kind;
991	switch (Note.Kind) {
992	case IncompatibleType:
993	Diag << Note.Prop->getType();
994	break;
995	case HasNoExpectedAttribute:
996	case HasUnexpectedAttribute:
997	Diag << Note.AttributeName;
998	break;
999	case DifferentGetter:
1000	Diag << Note.Prop->getGetterName();
1001	break;
1002	case DifferentSetter:
1003	Diag << Note.Prop->getSetterName();
1004	break;
1005	}
1006	}
1007	if (AtLoc.isValid())
1008	S.Diag(AtLoc, diag::note_property_synthesize);
1009
1010	return Property;
1011	}
1012
1013	/// Determine whether any storage attributes were written on the property.
1014	static bool hasWrittenStorageAttribute(ObjCPropertyDecl *Prop,
1015	ObjCPropertyQueryKind QueryKind) {
1016	if (Prop->getPropertyAttributesAsWritten() & OwnershipMask) return true;
1017
1018	// If this is a readwrite property in a class extension that refines
1019	// a readonly property in the original class definition, check it as
1020	// well.
1021
1022	// If it's a readonly property, we're not interested.
1023	if (Prop->isReadOnly()) return false;
1024
1025	// Is it declared in an extension?
1026	auto Category = dyn_cast<ObjCCategoryDecl>(Prop->getDeclContext());
1027	if (!Category || !Category->IsClassExtension()) return false;
1028
1029	// Find the corresponding property in the primary class definition.
1030	auto OrigClass = Category->getClassInterface();
1031	for (auto *Found : OrigClass->lookup(Prop->getDeclName())) {
1032	if (ObjCPropertyDecl *OrigProp = dyn_cast<ObjCPropertyDecl>(Found))
1033	return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1034	}
1035
1036	// Look through all of the protocols.
1037	for (const auto *Proto : OrigClass->all_referenced_protocols()) {
1038	if (ObjCPropertyDecl *OrigProp = Proto->FindPropertyDeclaration(
1039	Prop->getIdentifier(), QueryKind))
1040	return OrigProp->getPropertyAttributesAsWritten() & OwnershipMask;
1041	}
1042
1043	return false;
1044	}
1045
1046	/// Create a synthesized property accessor stub inside the \@implementation.
1047	static ObjCMethodDecl *
1048	RedeclarePropertyAccessor(ASTContext &Context, ObjCImplementationDecl *Impl,
1049	ObjCMethodDecl *AccessorDecl, SourceLocation AtLoc,
1050	SourceLocation PropertyLoc) {
1051	ObjCMethodDecl *Decl = AccessorDecl;
1052	ObjCMethodDecl *ImplDecl = ObjCMethodDecl::Create(
1053	C&: Context, beginLoc: AtLoc.isValid() ? AtLoc : Decl->getBeginLoc(),
1054	endLoc: PropertyLoc.isValid() ? PropertyLoc : Decl->getEndLoc(),
1055	SelInfo: Decl->getSelector(), T: Decl->getReturnType(),
1056	ReturnTInfo: Decl->getReturnTypeSourceInfo(), contextDecl: Impl, isInstance: Decl->isInstanceMethod(),
1057	isVariadic: Decl->isVariadic(), isPropertyAccessor: Decl->isPropertyAccessor(),
1058	/* isSynthesized*/ isSynthesizedAccessorStub: true, isImplicitlyDeclared: Decl->isImplicit(), isDefined: Decl->isDefined(),
1059	impControl: Decl->getImplementationControl(), HasRelatedResultType: Decl->hasRelatedResultType());
1060	ImplDecl->getMethodFamily();
1061	if (Decl->hasAttrs())
1062	ImplDecl->setAttrs(Decl->getAttrs());
1063	ImplDecl->setSelfDecl(Decl->getSelfDecl());
1064	ImplDecl->setCmdDecl(Decl->getCmdDecl());
1065	SmallVector<SourceLocation, 1> SelLocs;
1066	Decl->getSelectorLocs(SelLocs);
1067	ImplDecl->setMethodParams(C&: Context, Params: Decl->parameters(), SelLocs);
1068	ImplDecl->setLexicalDeclContext(Impl);
1069	ImplDecl->setDefined(false);
1070	return ImplDecl;
1071	}
1072
1073	/// ActOnPropertyImplDecl - This routine performs semantic checks and
1074	/// builds the AST node for a property implementation declaration; declared
1075	/// as \@synthesize or \@dynamic.
1076	///
1077	Decl *Sema::ActOnPropertyImplDecl(Scope *S,
1078	SourceLocation AtLoc,
1079	SourceLocation PropertyLoc,
1080	bool Synthesize,
1081	IdentifierInfo *PropertyId,
1082	IdentifierInfo *PropertyIvar,
1083	SourceLocation PropertyIvarLoc,
1084	ObjCPropertyQueryKind QueryKind) {
1085	ObjCContainerDecl *ClassImpDecl =
1086	dyn_cast<ObjCContainerDecl>(Val: CurContext);
1087	// Make sure we have a context for the property implementation declaration.
1088	if (!ClassImpDecl) {
1089	Diag(AtLoc, diag::err_missing_property_context);
1090	return nullptr;
1091	}
1092	if (PropertyIvarLoc.isInvalid())
1093	PropertyIvarLoc = PropertyLoc;
1094	SourceLocation PropertyDiagLoc = PropertyLoc;
1095	if (PropertyDiagLoc.isInvalid())
1096	PropertyDiagLoc = ClassImpDecl->getBeginLoc();
1097	ObjCPropertyDecl *property = nullptr;
1098	ObjCInterfaceDecl *IDecl = nullptr;
1099	// Find the class or category class where this property must have
1100	// a declaration.
1101	ObjCImplementationDecl *IC = nullptr;
1102	ObjCCategoryImplDecl *CatImplClass = nullptr;
1103	if ((IC = dyn_cast<ObjCImplementationDecl>(Val: ClassImpDecl))) {
1104	IDecl = IC->getClassInterface();
1105	// We always synthesize an interface for an implementation
1106	// without an interface decl. So, IDecl is always non-zero.
1107	assert(IDecl &&
1108	"ActOnPropertyImplDecl - @implementation without @interface");
1109
1110	// Look for this property declaration in the @implementation's @interface
1111	property = IDecl->FindPropertyDeclaration(PropertyId, QueryKind);
1112	if (!property) {
1113	Diag(PropertyLoc, diag::err_bad_property_decl) << IDecl->getDeclName();
1114	return nullptr;
1115	}
1116	if (property->isClassProperty() && Synthesize) {
1117	Diag(PropertyLoc, diag::err_synthesize_on_class_property) << PropertyId;
1118	return nullptr;
1119	}
1120	unsigned PIkind = property->getPropertyAttributesAsWritten();
1121	if ((PIkind & (ObjCPropertyAttribute::kind_atomic |
1122	ObjCPropertyAttribute::kind_nonatomic)) == 0) {
1123	if (AtLoc.isValid())
1124	Diag(AtLoc, diag::warn_implicit_atomic_property);
1125	else
1126	Diag(IC->getLocation(), diag::warn_auto_implicit_atomic_property);
1127	Diag(property->getLocation(), diag::note_property_declare);
1128	}
1129
1130	if (const ObjCCategoryDecl *CD =
1131	dyn_cast<ObjCCategoryDecl>(property->getDeclContext())) {
1132	if (!CD->IsClassExtension()) {
1133	Diag(PropertyLoc, diag::err_category_property) << CD->getDeclName();
1134	Diag(property->getLocation(), diag::note_property_declare);
1135	return nullptr;
1136	}
1137	}
1138	if (Synthesize && (PIkind & ObjCPropertyAttribute::kind_readonly) &&
1139	property->hasAttr<IBOutletAttr>() && !AtLoc.isValid()) {
1140	bool ReadWriteProperty = false;
1141	// Search into the class extensions and see if 'readonly property is
1142	// redeclared 'readwrite', then no warning is to be issued.
1143	for (auto *Ext : IDecl->known_extensions()) {
1144	DeclContext::lookup_result R = Ext->lookup(Name: property->getDeclName());
1145	if (auto *ExtProp = R.find_first<ObjCPropertyDecl>()) {
1146	PIkind = ExtProp->getPropertyAttributesAsWritten();
1147	if (PIkind & ObjCPropertyAttribute::kind_readwrite) {
1148	ReadWriteProperty = true;
1149	break;
1150	}
1151	}
1152	}
1153
1154	if (!ReadWriteProperty) {
1155	Diag(property->getLocation(), diag::warn_auto_readonly_iboutlet_property)
1156	<< property;
1157	SourceLocation readonlyLoc;
1158	if (LocPropertyAttribute(Context, attrName: "readonly",
1159	LParenLoc: property->getLParenLoc(), Loc&: readonlyLoc)) {
1160	SourceLocation endLoc =
1161	readonlyLoc.getLocWithOffset(Offset: strlen(s: "readonly")-1);
1162	SourceRange ReadonlySourceRange(readonlyLoc, endLoc);
1163	Diag(property->getLocation(),
1164	diag::note_auto_readonly_iboutlet_fixup_suggest) <<
1165	FixItHint::CreateReplacement(ReadonlySourceRange, "readwrite");
1166	}
1167	}
1168	}
1169	if (Synthesize && isa<ObjCProtocolDecl>(property->getDeclContext()))
1170	property = SelectPropertyForSynthesisFromProtocols(S&: *this, AtLoc, ClassDecl: IDecl,
1171	Property: property);
1172
1173	} else if ((CatImplClass = dyn_cast<ObjCCategoryImplDecl>(Val: ClassImpDecl))) {
1174	if (Synthesize) {
1175	Diag(AtLoc, diag::err_synthesize_category_decl);
1176	return nullptr;
1177	}
1178	IDecl = CatImplClass->getClassInterface();
1179	if (!IDecl) {
1180	Diag(AtLoc, diag::err_missing_property_interface);
1181	return nullptr;
1182	}
1183	ObjCCategoryDecl *Category =
1184	IDecl->FindCategoryDeclaration(CategoryId: CatImplClass->getIdentifier());
1185
1186	// If category for this implementation not found, it is an error which
1187	// has already been reported eralier.
1188	if (!Category)
1189	return nullptr;
1190	// Look for this property declaration in @implementation's category
1191	property = Category->FindPropertyDeclaration(PropertyId, QueryKind);
1192	if (!property) {
1193	Diag(PropertyLoc, diag::err_bad_category_property_decl)
1194	<< Category->getDeclName();
1195	return nullptr;
1196	}
1197	} else {
1198	Diag(AtLoc, diag::err_bad_property_context);
1199	return nullptr;
1200	}
1201	ObjCIvarDecl *Ivar = nullptr;
1202	bool CompleteTypeErr = false;
1203	bool compat = true;
1204	// Check that we have a valid, previously declared ivar for @synthesize
1205	if (Synthesize) {
1206	// @synthesize
1207	if (!PropertyIvar)
1208	PropertyIvar = PropertyId;
1209	// Check that this is a previously declared 'ivar' in 'IDecl' interface
1210	ObjCInterfaceDecl *ClassDeclared;
1211	Ivar = IDecl->lookupInstanceVariable(IVarName: PropertyIvar, ClassDeclared);
1212	QualType PropType = property->getType();
1213	QualType PropertyIvarType = PropType.getNonReferenceType();
1214
1215	if (RequireCompleteType(PropertyDiagLoc, PropertyIvarType,
1216	diag::err_incomplete_synthesized_property,
1217	property->getDeclName())) {
1218	Diag(property->getLocation(), diag::note_property_declare);
1219	CompleteTypeErr = true;
1220	}
1221
1222	if (getLangOpts().ObjCAutoRefCount &&
1223	(property->getPropertyAttributesAsWritten() &
1224	ObjCPropertyAttribute::kind_readonly) &&
1225	PropertyIvarType->isObjCRetainableType()) {
1226	setImpliedPropertyAttributeForReadOnlyProperty(property, ivar: Ivar);
1227	}
1228
1229	ObjCPropertyAttribute::Kind kind = property->getPropertyAttributes();
1230
1231	bool isARCWeak = false;
1232	if (kind & ObjCPropertyAttribute::kind_weak) {
1233	// Add GC __weak to the ivar type if the property is weak.
1234	if (getLangOpts().getGC() != LangOptions::NonGC) {
1235	assert(!getLangOpts().ObjCAutoRefCount);
1236	if (PropertyIvarType.isObjCGCStrong()) {
1237	Diag(PropertyDiagLoc, diag::err_gc_weak_property_strong_type);
1238	Diag(property->getLocation(), diag::note_property_declare);
1239	} else {
1240	PropertyIvarType =
1241	Context.getObjCGCQualType(T: PropertyIvarType, gcAttr: Qualifiers::Weak);
1242	}
1243
1244	// Otherwise, check whether ARC __weak is enabled and works with
1245	// the property type.
1246	} else {
1247	if (!getLangOpts().ObjCWeak) {
1248	// Only complain here when synthesizing an ivar.
1249	if (!Ivar) {
1250	Diag(PropertyDiagLoc,
1251	getLangOpts().ObjCWeakRuntime
1252	? diag::err_synthesizing_arc_weak_property_disabled
1253	: diag::err_synthesizing_arc_weak_property_no_runtime);
1254	Diag(property->getLocation(), diag::note_property_declare);
1255	}
1256	CompleteTypeErr = true; // suppress later diagnostics about the ivar
1257	} else {
1258	isARCWeak = true;
1259	if (const ObjCObjectPointerType *ObjT =
1260	PropertyIvarType->getAs<ObjCObjectPointerType>()) {
1261	const ObjCInterfaceDecl *ObjI = ObjT->getInterfaceDecl();
1262	if (ObjI && ObjI->isArcWeakrefUnavailable()) {
1263	Diag(property->getLocation(),
1264	diag::err_arc_weak_unavailable_property)
1265	<< PropertyIvarType;
1266	Diag(ClassImpDecl->getLocation(), diag::note_implemented_by_class)
1267	<< ClassImpDecl->getName();
1268	}
1269	}
1270	}
1271	}
1272	}
1273
1274	if (AtLoc.isInvalid()) {
1275	// Check when default synthesizing a property that there is
1276	// an ivar matching property name and issue warning; since this
1277	// is the most common case of not using an ivar used for backing
1278	// property in non-default synthesis case.
1279	ObjCInterfaceDecl *ClassDeclared=nullptr;
1280	ObjCIvarDecl *originalIvar =
1281	IDecl->lookupInstanceVariable(property->getIdentifier(),
1282	ClassDeclared);
1283	if (originalIvar) {
1284	Diag(PropertyDiagLoc,
1285	diag::warn_autosynthesis_property_ivar_match)
1286	<< PropertyId << (Ivar == nullptr) << PropertyIvar
1287	<< originalIvar->getIdentifier();
1288	Diag(property->getLocation(), diag::note_property_declare);
1289	Diag(originalIvar->getLocation(), diag::note_ivar_decl);
1290	}
1291	}
1292
1293	if (!Ivar) {
1294	// In ARC, give the ivar a lifetime qualifier based on the
1295	// property attributes.
1296	if ((getLangOpts().ObjCAutoRefCount || isARCWeak) &&
1297	!PropertyIvarType.getObjCLifetime() &&
1298	PropertyIvarType->isObjCRetainableType()) {
1299
1300	// It's an error if we have to do this and the user didn't
1301	// explicitly write an ownership attribute on the property.
1302	if (!hasWrittenStorageAttribute(Prop: property, QueryKind) &&
1303	!(kind & ObjCPropertyAttribute::kind_strong)) {
1304	Diag(PropertyDiagLoc,
1305	diag::err_arc_objc_property_default_assign_on_object);
1306	Diag(property->getLocation(), diag::note_property_declare);
1307	} else {
1308	Qualifiers::ObjCLifetime lifetime =
1309	getImpliedARCOwnership(attrs: kind, type: PropertyIvarType);
1310	assert(lifetime && "no lifetime for property?");
1311
1312	Qualifiers qs;
1313	qs.addObjCLifetime(type: lifetime);
1314	PropertyIvarType = Context.getQualifiedType(T: PropertyIvarType, Qs: qs);
1315	}
1316	}
1317
1318	Ivar = ObjCIvarDecl::Create(C&: Context, DC: ClassImpDecl,
1319	StartLoc: PropertyIvarLoc,IdLoc: PropertyIvarLoc, Id: PropertyIvar,
1320	T: PropertyIvarType, /*TInfo=*/nullptr,
1321	ac: ObjCIvarDecl::Private,
1322	BW: (Expr *)nullptr, synthesized: true);
1323	if (RequireNonAbstractType(PropertyIvarLoc,
1324	PropertyIvarType,
1325	diag::err_abstract_type_in_decl,
1326	AbstractSynthesizedIvarType)) {
1327	Diag(property->getLocation(), diag::note_property_declare);
1328	// An abstract type is as bad as an incomplete type.
1329	CompleteTypeErr = true;
1330	}
1331	if (!CompleteTypeErr) {
1332	const RecordType *RecordTy = PropertyIvarType->getAs<RecordType>();
1333	if (RecordTy && RecordTy->getDecl()->hasFlexibleArrayMember()) {
1334	Diag(PropertyIvarLoc, diag::err_synthesize_variable_sized_ivar)
1335	<< PropertyIvarType;
1336	CompleteTypeErr = true; // suppress later diagnostics about the ivar
1337	}
1338	}
1339	if (CompleteTypeErr)
1340	Ivar->setInvalidDecl();
1341	ClassImpDecl->addDecl(Ivar);
1342	IDecl->makeDeclVisibleInContext(Ivar);
1343
1344	if (getLangOpts().ObjCRuntime.isFragile())
1345	Diag(PropertyDiagLoc, diag::err_missing_property_ivar_decl)
1346	<< PropertyId;
1347	// Note! I deliberately want it to fall thru so, we have a
1348	// a property implementation and to avoid future warnings.
1349	} else if (getLangOpts().ObjCRuntime.isNonFragile() &&
1350	!declaresSameEntity(ClassDeclared, IDecl)) {
1351	Diag(PropertyDiagLoc, diag::err_ivar_in_superclass_use)
1352	<< property->getDeclName() << Ivar->getDeclName()
1353	<< ClassDeclared->getDeclName();
1354	Diag(Ivar->getLocation(), diag::note_previous_access_declaration)
1355	<< Ivar << Ivar->getName();
1356	// Note! I deliberately want it to fall thru so more errors are caught.
1357	}
1358	property->setPropertyIvarDecl(Ivar);
1359
1360	QualType IvarType = Context.getCanonicalType(Ivar->getType());
1361
1362	// Check that type of property and its ivar are type compatible.
1363	if (!Context.hasSameType(T1: PropertyIvarType, T2: IvarType)) {
1364	if (isa<ObjCObjectPointerType>(Val: PropertyIvarType)
1365	&& isa<ObjCObjectPointerType>(Val: IvarType))
1366	compat = Context.canAssignObjCInterfaces(
1367	LHSOPT: PropertyIvarType->castAs<ObjCObjectPointerType>(),
1368	RHSOPT: IvarType->castAs<ObjCObjectPointerType>());
1369	else {
1370	compat = (CheckAssignmentConstraints(Loc: PropertyIvarLoc, LHSType: PropertyIvarType,
1371	RHSType: IvarType)
1372	== Compatible);
1373	}
1374	if (!compat) {
1375	Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1376	<< property->getDeclName() << PropType
1377	<< Ivar->getDeclName() << IvarType;
1378	Diag(Ivar->getLocation(), diag::note_ivar_decl);
1379	// Note! I deliberately want it to fall thru so, we have a
1380	// a property implementation and to avoid future warnings.
1381	}
1382	else {
1383	// FIXME! Rules for properties are somewhat different that those
1384	// for assignments. Use a new routine to consolidate all cases;
1385	// specifically for property redeclarations as well as for ivars.
1386	QualType lhsType =Context.getCanonicalType(T: PropertyIvarType).getUnqualifiedType();
1387	QualType rhsType =Context.getCanonicalType(T: IvarType).getUnqualifiedType();
1388	if (lhsType != rhsType &&
1389	lhsType->isArithmeticType()) {
1390	Diag(PropertyDiagLoc, diag::err_property_ivar_type)
1391	<< property->getDeclName() << PropType
1392	<< Ivar->getDeclName() << IvarType;
1393	Diag(Ivar->getLocation(), diag::note_ivar_decl);
1394	// Fall thru - see previous comment
1395	}
1396	}
1397	// __weak is explicit. So it works on Canonical type.
1398	if ((PropType.isObjCGCWeak() && !IvarType.isObjCGCWeak() &&
1399	getLangOpts().getGC() != LangOptions::NonGC)) {
1400	Diag(PropertyDiagLoc, diag::err_weak_property)
1401	<< property->getDeclName() << Ivar->getDeclName();
1402	Diag(Ivar->getLocation(), diag::note_ivar_decl);
1403	// Fall thru - see previous comment
1404	}
1405	// Fall thru - see previous comment
1406	if ((property->getType()->isObjCObjectPointerType() ||
1407	PropType.isObjCGCStrong()) && IvarType.isObjCGCWeak() &&
1408	getLangOpts().getGC() != LangOptions::NonGC) {
1409	Diag(PropertyDiagLoc, diag::err_strong_property)
1410	<< property->getDeclName() << Ivar->getDeclName();
1411	// Fall thru - see previous comment
1412	}
1413	}
1414	if (getLangOpts().ObjCAutoRefCount || isARCWeak ||
1415	Ivar->getType().getObjCLifetime())
1416	checkARCPropertyImpl(S&: *this, propertyImplLoc: PropertyLoc, property, ivar: Ivar);
1417	} else if (PropertyIvar)
1418	// @dynamic
1419	Diag(PropertyDiagLoc, diag::err_dynamic_property_ivar_decl);
1420
1421	assert (property && "ActOnPropertyImplDecl - property declaration missing");
1422	ObjCPropertyImplDecl *PIDecl =
1423	ObjCPropertyImplDecl::Create(C&: Context, DC: CurContext, atLoc: AtLoc, L: PropertyLoc,
1424	property,
1425	PK: (Synthesize ?
1426	ObjCPropertyImplDecl::Synthesize
1427	: ObjCPropertyImplDecl::Dynamic),
1428	ivarDecl: Ivar, ivarLoc: PropertyIvarLoc);
1429
1430	if (CompleteTypeErr || !compat)
1431	PIDecl->setInvalidDecl();
1432
1433	if (ObjCMethodDecl *getterMethod = property->getGetterMethodDecl()) {
1434	getterMethod->createImplicitParams(Context, ID: IDecl);
1435
1436	// Redeclare the getter within the implementation as DeclContext.
1437	if (Synthesize) {
1438	// If the method hasn't been overridden, create a synthesized implementation.
1439	ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
1440	Sel: getterMethod->getSelector(), isInstance: getterMethod->isInstanceMethod());
1441	if (!OMD)
1442	OMD = RedeclarePropertyAccessor(Context, Impl: IC, AccessorDecl: getterMethod, AtLoc,
1443	PropertyLoc);
1444	PIDecl->setGetterMethodDecl(OMD);
1445	}
1446
1447	if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1448	Ivar->getType()->isRecordType()) {
1449	// For Objective-C++, need to synthesize the AST for the IVAR object to be
1450	// returned by the getter as it must conform to C++'s copy-return rules.
1451	// FIXME. Eventually we want to do this for Objective-C as well.
1452	SynthesizedFunctionScope Scope(*this, getterMethod);
1453	ImplicitParamDecl *SelfDecl = getterMethod->getSelfDecl();
1454	DeclRefExpr *SelfExpr = new (Context)
1455	DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1456	PropertyDiagLoc);
1457	MarkDeclRefReferenced(E: SelfExpr);
1458	Expr *LoadSelfExpr = ImplicitCastExpr::Create(
1459	Context, T: SelfDecl->getType(), Kind: CK_LValueToRValue, Operand: SelfExpr, BasePath: nullptr,
1460	Cat: VK_PRValue, FPO: FPOptionsOverride());
1461	Expr *IvarRefExpr =
1462	new (Context) ObjCIvarRefExpr(Ivar,
1463	Ivar->getUsageType(objectType: SelfDecl->getType()),
1464	PropertyDiagLoc,
1465	Ivar->getLocation(),
1466	LoadSelfExpr, true, true);
1467	ExprResult Res = PerformCopyInitialization(
1468	Entity: InitializedEntity::InitializeResult(ReturnLoc: PropertyDiagLoc,
1469	Type: getterMethod->getReturnType()),
1470	EqualLoc: PropertyDiagLoc, Init: IvarRefExpr);
1471	if (!Res.isInvalid()) {
1472	Expr *ResExpr = Res.getAs<Expr>();
1473	if (ResExpr)
1474	ResExpr = MaybeCreateExprWithCleanups(SubExpr: ResExpr);
1475	PIDecl->setGetterCXXConstructor(ResExpr);
1476	}
1477	}
1478	if (property->hasAttr<NSReturnsNotRetainedAttr>() &&
1479	!getterMethod->hasAttr<NSReturnsNotRetainedAttr>()) {
1480	Diag(getterMethod->getLocation(),
1481	diag::warn_property_getter_owning_mismatch);
1482	Diag(property->getLocation(), diag::note_property_declare);
1483	}
1484	if (getLangOpts().ObjCAutoRefCount && Synthesize)
1485	switch (getterMethod->getMethodFamily()) {
1486	case OMF_retain:
1487	case OMF_retainCount:
1488	case OMF_release:
1489	case OMF_autorelease:
1490	Diag(getterMethod->getLocation(), diag::err_arc_illegal_method_def)
1491	<< 1 << getterMethod->getSelector();
1492	break;
1493	default:
1494	break;
1495	}
1496	}
1497
1498	if (ObjCMethodDecl *setterMethod = property->getSetterMethodDecl()) {
1499	setterMethod->createImplicitParams(Context, ID: IDecl);
1500
1501	// Redeclare the setter within the implementation as DeclContext.
1502	if (Synthesize) {
1503	ObjCMethodDecl *OMD = ClassImpDecl->getMethod(
1504	Sel: setterMethod->getSelector(), isInstance: setterMethod->isInstanceMethod());
1505	if (!OMD)
1506	OMD = RedeclarePropertyAccessor(Context, Impl: IC, AccessorDecl: setterMethod,
1507	AtLoc, PropertyLoc);
1508	PIDecl->setSetterMethodDecl(OMD);
1509	}
1510
1511	if (getLangOpts().CPlusPlus && Synthesize && !CompleteTypeErr &&
1512	Ivar->getType()->isRecordType()) {
1513	// FIXME. Eventually we want to do this for Objective-C as well.
1514	SynthesizedFunctionScope Scope(*this, setterMethod);
1515	ImplicitParamDecl *SelfDecl = setterMethod->getSelfDecl();
1516	DeclRefExpr *SelfExpr = new (Context)
1517	DeclRefExpr(Context, SelfDecl, false, SelfDecl->getType(), VK_LValue,
1518	PropertyDiagLoc);
1519	MarkDeclRefReferenced(E: SelfExpr);
1520	Expr *LoadSelfExpr = ImplicitCastExpr::Create(
1521	Context, T: SelfDecl->getType(), Kind: CK_LValueToRValue, Operand: SelfExpr, BasePath: nullptr,
1522	Cat: VK_PRValue, FPO: FPOptionsOverride());
1523	Expr *lhs =
1524	new (Context) ObjCIvarRefExpr(Ivar,
1525	Ivar->getUsageType(objectType: SelfDecl->getType()),
1526	PropertyDiagLoc,
1527	Ivar->getLocation(),
1528	LoadSelfExpr, true, true);
1529	ObjCMethodDecl::param_iterator P = setterMethod->param_begin();
1530	ParmVarDecl *Param = (*P);
1531	QualType T = Param->getType().getNonReferenceType();
1532	DeclRefExpr *rhs = new (Context)
1533	DeclRefExpr(Context, Param, false, T, VK_LValue, PropertyDiagLoc);
1534	MarkDeclRefReferenced(E: rhs);
1535	ExprResult Res = BuildBinOp(S, PropertyDiagLoc,
1536	BO_Assign, lhs, rhs);
1537	if (property->getPropertyAttributes() &
1538	ObjCPropertyAttribute::kind_atomic) {
1539	Expr *callExpr = Res.getAs<Expr>();
1540	if (const CXXOperatorCallExpr *CXXCE =
1541	dyn_cast_or_null<CXXOperatorCallExpr>(Val: callExpr))
1542	if (const FunctionDecl *FuncDecl = CXXCE->getDirectCallee())
1543	if (!FuncDecl->isTrivial())
1544	if (property->getType()->isReferenceType()) {
1545	Diag(PropertyDiagLoc,
1546	diag::err_atomic_property_nontrivial_assign_op)
1547	<< property->getType();
1548	Diag(FuncDecl->getBeginLoc(), diag::note_callee_decl)
1549	<< FuncDecl;
1550	}
1551	}
1552	PIDecl->setSetterCXXAssignment(Res.getAs<Expr>());
1553	}
1554	}
1555
1556	if (IC) {
1557	if (Synthesize)
1558	if (ObjCPropertyImplDecl *PPIDecl =
1559	IC->FindPropertyImplIvarDecl(PropertyIvar)) {
1560	Diag(PropertyLoc, diag::err_duplicate_ivar_use)
1561	<< PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1562	<< PropertyIvar;
1563	Diag(PPIDecl->getLocation(), diag::note_previous_use);
1564	}
1565
1566	if (ObjCPropertyImplDecl *PPIDecl
1567	= IC->FindPropertyImplDecl(PropertyId, QueryKind)) {
1568	Diag(PropertyLoc, diag::err_property_implemented) << PropertyId;
1569	Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1570	return nullptr;
1571	}
1572	IC->addPropertyImplementation(PIDecl);
1573	if (getLangOpts().ObjCDefaultSynthProperties &&
1574	getLangOpts().ObjCRuntime.isNonFragile() &&
1575	!IDecl->isObjCRequiresPropertyDefs()) {
1576	// Diagnose if an ivar was lazily synthesdized due to a previous
1577	// use and if 1) property is @dynamic or 2) property is synthesized
1578	// but it requires an ivar of different name.
1579	ObjCInterfaceDecl *ClassDeclared=nullptr;
1580	ObjCIvarDecl *Ivar = nullptr;
1581	if (!Synthesize)
1582	Ivar = IDecl->lookupInstanceVariable(IVarName: PropertyId, ClassDeclared);
1583	else {
1584	if (PropertyIvar && PropertyIvar != PropertyId)
1585	Ivar = IDecl->lookupInstanceVariable(IVarName: PropertyId, ClassDeclared);
1586	}
1587	// Issue diagnostics only if Ivar belongs to current class.
1588	if (Ivar && Ivar->getSynthesize() &&
1589	declaresSameEntity(IC->getClassInterface(), ClassDeclared)) {
1590	Diag(Ivar->getLocation(), diag::err_undeclared_var_use)
1591	<< PropertyId;
1592	Ivar->setInvalidDecl();
1593	}
1594	}
1595	} else {
1596	if (Synthesize)
1597	if (ObjCPropertyImplDecl *PPIDecl =
1598	CatImplClass->FindPropertyImplIvarDecl(PropertyIvar)) {
1599	Diag(PropertyDiagLoc, diag::err_duplicate_ivar_use)
1600	<< PropertyId << PPIDecl->getPropertyDecl()->getIdentifier()
1601	<< PropertyIvar;
1602	Diag(PPIDecl->getLocation(), diag::note_previous_use);
1603	}
1604
1605	if (ObjCPropertyImplDecl *PPIDecl =
1606	CatImplClass->FindPropertyImplDecl(PropertyId, QueryKind)) {
1607	Diag(PropertyDiagLoc, diag::err_property_implemented) << PropertyId;
1608	Diag(PPIDecl->getLocation(), diag::note_previous_declaration);
1609	return nullptr;
1610	}
1611	CatImplClass->addPropertyImplementation(PIDecl);
1612	}
1613
1614	if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic &&
1615	PIDecl->getPropertyDecl() &&
1616	PIDecl->getPropertyDecl()->isDirectProperty()) {
1617	Diag(PropertyLoc, diag::err_objc_direct_dynamic_property);
1618	Diag(PIDecl->getPropertyDecl()->getLocation(),
1619	diag::note_previous_declaration);
1620	return nullptr;
1621	}
1622
1623	return PIDecl;
1624	}
1625
1626	//===----------------------------------------------------------------------===//
1627	// Helper methods.
1628	//===----------------------------------------------------------------------===//
1629
1630	/// DiagnosePropertyMismatch - Compares two properties for their
1631	/// attributes and types and warns on a variety of inconsistencies.
1632	///
1633	void
1634	Sema::DiagnosePropertyMismatch(ObjCPropertyDecl *Property,
1635	ObjCPropertyDecl *SuperProperty,
1636	const IdentifierInfo *inheritedName,
1637	bool OverridingProtocolProperty) {
1638	ObjCPropertyAttribute::Kind CAttr = Property->getPropertyAttributes();
1639	ObjCPropertyAttribute::Kind SAttr = SuperProperty->getPropertyAttributes();
1640
1641	// We allow readonly properties without an explicit ownership
1642	// (assign/unsafe_unretained/weak/retain/strong/copy) in super class
1643	// to be overridden by a property with any explicit ownership in the subclass.
1644	if (!OverridingProtocolProperty &&
1645	!getOwnershipRule(attr: SAttr) && getOwnershipRule(attr: CAttr))
1646	;
1647	else {
1648	if ((CAttr & ObjCPropertyAttribute::kind_readonly) &&
1649	(SAttr & ObjCPropertyAttribute::kind_readwrite))
1650	Diag(Property->getLocation(), diag::warn_readonly_property)
1651	<< Property->getDeclName() << inheritedName;
1652	if ((CAttr & ObjCPropertyAttribute::kind_copy) !=
1653	(SAttr & ObjCPropertyAttribute::kind_copy))
1654	Diag(Property->getLocation(), diag::warn_property_attribute)
1655	<< Property->getDeclName() << "copy" << inheritedName;
1656	else if (!(SAttr & ObjCPropertyAttribute::kind_readonly)) {
1657	unsigned CAttrRetain = (CAttr & (ObjCPropertyAttribute::kind_retain |
1658	ObjCPropertyAttribute::kind_strong));
1659	unsigned SAttrRetain = (SAttr & (ObjCPropertyAttribute::kind_retain |
1660	ObjCPropertyAttribute::kind_strong));
1661	bool CStrong = (CAttrRetain != 0);
1662	bool SStrong = (SAttrRetain != 0);
1663	if (CStrong != SStrong)
1664	Diag(Property->getLocation(), diag::warn_property_attribute)
1665	<< Property->getDeclName() << "retain (or strong)" << inheritedName;
1666	}
1667	}
1668
1669	// Check for nonatomic; note that nonatomic is effectively
1670	// meaningless for readonly properties, so don't diagnose if the
1671	// atomic property is 'readonly'.
1672	checkAtomicPropertyMismatch(S&: *this, OldProperty: SuperProperty, NewProperty: Property, PropagateAtomicity: false);
1673	// Readonly properties from protocols can be implemented as "readwrite"
1674	// with a custom setter name.
1675	if (Property->getSetterName() != SuperProperty->getSetterName() &&
1676	!(SuperProperty->isReadOnly() &&
1677	isa<ObjCProtocolDecl>(SuperProperty->getDeclContext()))) {
1678	Diag(Property->getLocation(), diag::warn_property_attribute)
1679	<< Property->getDeclName() << "setter" << inheritedName;
1680	Diag(SuperProperty->getLocation(), diag::note_property_declare);
1681	}
1682	if (Property->getGetterName() != SuperProperty->getGetterName()) {
1683	Diag(Property->getLocation(), diag::warn_property_attribute)
1684	<< Property->getDeclName() << "getter" << inheritedName;
1685	Diag(SuperProperty->getLocation(), diag::note_property_declare);
1686	}
1687
1688	QualType LHSType =
1689	Context.getCanonicalType(T: SuperProperty->getType());
1690	QualType RHSType =
1691	Context.getCanonicalType(T: Property->getType());
1692
1693	if (!Context.propertyTypesAreCompatible(LHSType, RHSType)) {
1694	// Do cases not handled in above.
1695	// FIXME. For future support of covariant property types, revisit this.
1696	bool IncompatibleObjC = false;
1697	QualType ConvertedType;
1698	if (!isObjCPointerConversion(FromType: RHSType, ToType: LHSType,
1699	ConvertedType, IncompatibleObjC) ||
1700	IncompatibleObjC) {
1701	Diag(Property->getLocation(), diag::warn_property_types_are_incompatible)
1702	<< Property->getType() << SuperProperty->getType() << inheritedName;
1703	Diag(SuperProperty->getLocation(), diag::note_property_declare);
1704	}
1705	}
1706	}
1707
1708	bool Sema::DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *property,
1709	ObjCMethodDecl *GetterMethod,
1710	SourceLocation Loc) {
1711	if (!GetterMethod)
1712	return false;
1713	QualType GetterType = GetterMethod->getReturnType().getNonReferenceType();
1714	QualType PropertyRValueType =
1715	property->getType().getNonReferenceType().getAtomicUnqualifiedType();
1716	bool compat = Context.hasSameType(T1: PropertyRValueType, T2: GetterType);
1717	if (!compat) {
1718	const ObjCObjectPointerType *propertyObjCPtr = nullptr;
1719	const ObjCObjectPointerType *getterObjCPtr = nullptr;
1720	if ((propertyObjCPtr =
1721	PropertyRValueType->getAs<ObjCObjectPointerType>()) &&
1722	(getterObjCPtr = GetterType->getAs<ObjCObjectPointerType>()))
1723	compat = Context.canAssignObjCInterfaces(LHSOPT: getterObjCPtr, RHSOPT: propertyObjCPtr);
1724	else if (CheckAssignmentConstraints(Loc, LHSType: GetterType, RHSType: PropertyRValueType)
1725	!= Compatible) {
1726	Diag(Loc, diag::err_property_accessor_type)
1727	<< property->getDeclName() << PropertyRValueType
1728	<< GetterMethod->getSelector() << GetterType;
1729	Diag(GetterMethod->getLocation(), diag::note_declared_at);
1730	return true;
1731	} else {
1732	compat = true;
1733	QualType lhsType = Context.getCanonicalType(T: PropertyRValueType);
1734	QualType rhsType =Context.getCanonicalType(T: GetterType).getUnqualifiedType();
1735	if (lhsType != rhsType && lhsType->isArithmeticType())
1736	compat = false;
1737	}
1738	}
1739
1740	if (!compat) {
1741	Diag(Loc, diag::warn_accessor_property_type_mismatch)
1742	<< property->getDeclName()
1743	<< GetterMethod->getSelector();
1744	Diag(GetterMethod->getLocation(), diag::note_declared_at);
1745	return true;
1746	}
1747
1748	return false;
1749	}
1750
1751	/// CollectImmediateProperties - This routine collects all properties in
1752	/// the class and its conforming protocols; but not those in its super class.
1753	static void
1754	CollectImmediateProperties(ObjCContainerDecl *CDecl,
1755	ObjCContainerDecl::PropertyMap &PropMap,
1756	ObjCContainerDecl::PropertyMap &SuperPropMap,
1757	bool CollectClassPropsOnly = false,
1758	bool IncludeProtocols = true) {
1759	if (ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(Val: CDecl)) {
1760	for (auto *Prop : IDecl->properties()) {
1761	if (CollectClassPropsOnly && !Prop->isClassProperty())
1762	continue;
1763	PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1764	Prop;
1765	}
1766
1767	// Collect the properties from visible extensions.
1768	for (auto *Ext : IDecl->visible_extensions())
1769	CollectImmediateProperties(Ext, PropMap, SuperPropMap,
1770	CollectClassPropsOnly, IncludeProtocols);
1771
1772	if (IncludeProtocols) {
1773	// Scan through class's protocols.
1774	for (auto *PI : IDecl->all_referenced_protocols())
1775	CollectImmediateProperties(PI, PropMap, SuperPropMap,
1776	CollectClassPropsOnly);
1777	}
1778	}
1779	if (ObjCCategoryDecl *CATDecl = dyn_cast<ObjCCategoryDecl>(Val: CDecl)) {
1780	for (auto *Prop : CATDecl->properties()) {
1781	if (CollectClassPropsOnly && !Prop->isClassProperty())
1782	continue;
1783	PropMap[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] =
1784	Prop;
1785	}
1786	if (IncludeProtocols) {
1787	// Scan through class's protocols.
1788	for (auto *PI : CATDecl->protocols())
1789	CollectImmediateProperties(PI, PropMap, SuperPropMap,
1790	CollectClassPropsOnly);
1791	}
1792	}
1793	else if (ObjCProtocolDecl *PDecl = dyn_cast<ObjCProtocolDecl>(Val: CDecl)) {
1794	for (auto *Prop : PDecl->properties()) {
1795	if (CollectClassPropsOnly && !Prop->isClassProperty())
1796	continue;
1797	ObjCPropertyDecl *PropertyFromSuper =
1798	SuperPropMap[std::make_pair(Prop->getIdentifier(),
1799	Prop->isClassProperty())];
1800	// Exclude property for protocols which conform to class's super-class,
1801	// as super-class has to implement the property.
1802	if (!PropertyFromSuper ||
1803	PropertyFromSuper->getIdentifier() != Prop->getIdentifier()) {
1804	ObjCPropertyDecl *&PropEntry =
1805	PropMap[std::make_pair(Prop->getIdentifier(),
1806	Prop->isClassProperty())];
1807	if (!PropEntry)
1808	PropEntry = Prop;
1809	}
1810	}
1811	// Scan through protocol's protocols.
1812	for (auto *PI : PDecl->protocols())
1813	CollectImmediateProperties(PI, PropMap, SuperPropMap,
1814	CollectClassPropsOnly);
1815	}
1816	}
1817
1818	/// CollectSuperClassPropertyImplementations - This routine collects list of
1819	/// properties to be implemented in super class(s) and also coming from their
1820	/// conforming protocols.
1821	static void CollectSuperClassPropertyImplementations(ObjCInterfaceDecl *CDecl,
1822	ObjCInterfaceDecl::PropertyMap &PropMap) {
1823	if (ObjCInterfaceDecl *SDecl = CDecl->getSuperClass()) {
1824	while (SDecl) {
1825	SDecl->collectPropertiesToImplement(PM&: PropMap);
1826	SDecl = SDecl->getSuperClass();
1827	}
1828	}
1829	}
1830
1831	/// IvarBacksCurrentMethodAccessor - This routine returns 'true' if 'IV' is
1832	/// an ivar synthesized for 'Method' and 'Method' is a property accessor
1833	/// declared in class 'IFace'.
1834	bool
1835	Sema::IvarBacksCurrentMethodAccessor(ObjCInterfaceDecl *IFace,
1836	ObjCMethodDecl *Method, ObjCIvarDecl *IV) {
1837	if (!IV->getSynthesize())
1838	return false;
1839	ObjCMethodDecl *IMD = IFace->lookupMethod(Sel: Method->getSelector(),
1840	isInstance: Method->isInstanceMethod());
1841	if (!IMD || !IMD->isPropertyAccessor())
1842	return false;
1843
1844	// look up a property declaration whose one of its accessors is implemented
1845	// by this method.
1846	for (const auto *Property : IFace->instance_properties()) {
1847	if ((Property->getGetterName() == IMD->getSelector() ||
1848	Property->getSetterName() == IMD->getSelector()) &&
1849	(Property->getPropertyIvarDecl() == IV))
1850	return true;
1851	}
1852	// Also look up property declaration in class extension whose one of its
1853	// accessors is implemented by this method.
1854	for (const auto *Ext : IFace->known_extensions())
1855	for (const auto *Property : Ext->instance_properties())
1856	if ((Property->getGetterName() == IMD->getSelector() ||
1857	Property->getSetterName() == IMD->getSelector()) &&
1858	(Property->getPropertyIvarDecl() == IV))
1859	return true;
1860	return false;
1861	}
1862
1863	static bool SuperClassImplementsProperty(ObjCInterfaceDecl *IDecl,
1864	ObjCPropertyDecl *Prop) {
1865	bool SuperClassImplementsGetter = false;
1866	bool SuperClassImplementsSetter = false;
1867	if (Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_readonly)
1868	SuperClassImplementsSetter = true;
1869
1870	while (IDecl->getSuperClass()) {
1871	ObjCInterfaceDecl *SDecl = IDecl->getSuperClass();
1872	if (!SuperClassImplementsGetter && SDecl->getInstanceMethod(Prop->getGetterName()))
1873	SuperClassImplementsGetter = true;
1874
1875	if (!SuperClassImplementsSetter && SDecl->getInstanceMethod(Prop->getSetterName()))
1876	SuperClassImplementsSetter = true;
1877	if (SuperClassImplementsGetter && SuperClassImplementsSetter)
1878	return true;
1879	IDecl = IDecl->getSuperClass();
1880	}
1881	return false;
1882	}
1883
1884	/// Default synthesizes all properties which must be synthesized
1885	/// in class's \@implementation.
1886	void Sema::DefaultSynthesizeProperties(Scope *S, ObjCImplDecl *IMPDecl,
1887	ObjCInterfaceDecl *IDecl,
1888	SourceLocation AtEnd) {
1889	ObjCInterfaceDecl::PropertyMap PropMap;
1890	IDecl->collectPropertiesToImplement(PM&: PropMap);
1891	if (PropMap.empty())
1892	return;
1893	ObjCInterfaceDecl::PropertyMap SuperPropMap;
1894	CollectSuperClassPropertyImplementations(CDecl: IDecl, PropMap&: SuperPropMap);
1895
1896	for (const auto &PropEntry : PropMap) {
1897	ObjCPropertyDecl *Prop = PropEntry.second;
1898	// Is there a matching property synthesize/dynamic?
1899	if (Prop->isInvalidDecl() ||
1900	Prop->isClassProperty() ||
1901	Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
1902	continue;
1903	// Property may have been synthesized by user.
1904	if (IMPDecl->FindPropertyImplDecl(
1905	propertyId: Prop->getIdentifier(), queryKind: Prop->getQueryKind()))
1906	continue;
1907	ObjCMethodDecl *ImpMethod = IMPDecl->getInstanceMethod(Prop->getGetterName());
1908	if (ImpMethod && !ImpMethod->getBody()) {
1909	if (Prop->getPropertyAttributes() & ObjCPropertyAttribute::kind_readonly)
1910	continue;
1911	ImpMethod = IMPDecl->getInstanceMethod(Prop->getSetterName());
1912	if (ImpMethod && !ImpMethod->getBody())
1913	continue;
1914	}
1915	if (ObjCPropertyImplDecl *PID =
1916	IMPDecl->FindPropertyImplIvarDecl(ivarId: Prop->getIdentifier())) {
1917	Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
1918	<< Prop->getIdentifier();
1919	if (PID->getLocation().isValid())
1920	Diag(PID->getLocation(), diag::note_property_synthesize);
1921	continue;
1922	}
1923	ObjCPropertyDecl *PropInSuperClass =
1924	SuperPropMap[std::make_pair(Prop->getIdentifier(),
1925	Prop->isClassProperty())];
1926	if (ObjCProtocolDecl *Proto =
1927	dyn_cast<ObjCProtocolDecl>(Prop->getDeclContext())) {
1928	// We won't auto-synthesize properties declared in protocols.
1929	// Suppress the warning if class's superclass implements property's
1930	// getter and implements property's setter (if readwrite property).
1931	// Or, if property is going to be implemented in its super class.
1932	if (!SuperClassImplementsProperty(IDecl, Prop) && !PropInSuperClass) {
1933	Diag(IMPDecl->getLocation(),
1934	diag::warn_auto_synthesizing_protocol_property)
1935	<< Prop << Proto;
1936	Diag(Prop->getLocation(), diag::note_property_declare);
1937	std::string FixIt =
1938	(Twine("@synthesize ") + Prop->getName() + ";\n\n").str();
1939	Diag(AtEnd, diag::note_add_synthesize_directive)
1940	<< FixItHint::CreateInsertion(AtEnd, FixIt);
1941	}
1942	continue;
1943	}
1944	// If property to be implemented in the super class, ignore.
1945	if (PropInSuperClass) {
1946	if ((Prop->getPropertyAttributes() &
1947	ObjCPropertyAttribute::kind_readwrite) &&
1948	(PropInSuperClass->getPropertyAttributes() &
1949	ObjCPropertyAttribute::kind_readonly) &&
1950	!IMPDecl->getInstanceMethod(Prop->getSetterName()) &&
1951	!IDecl->HasUserDeclaredSetterMethod(Prop)) {
1952	Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
1953	<< Prop->getIdentifier();
1954	Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1955	} else {
1956	Diag(Prop->getLocation(), diag::warn_autosynthesis_property_in_superclass)
1957	<< Prop->getIdentifier();
1958	Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
1959	Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1960	}
1961	continue;
1962	}
1963	// We use invalid SourceLocations for the synthesized ivars since they
1964	// aren't really synthesized at a particular location; they just exist.
1965	// Saying that they are located at the @implementation isn't really going
1966	// to help users.
1967	ObjCPropertyImplDecl *PIDecl = dyn_cast_or_null<ObjCPropertyImplDecl>(
1968	ActOnPropertyImplDecl(S, AtLoc: SourceLocation(), PropertyLoc: SourceLocation(),
1969	Synthesize: true,
1970	/* property = */ PropertyId: Prop->getIdentifier(),
1971	/* ivar = */ PropertyIvar: Prop->getDefaultSynthIvarName(Ctx&: Context),
1972	PropertyIvarLoc: Prop->getLocation(), QueryKind: Prop->getQueryKind()));
1973	if (PIDecl && !Prop->isUnavailable()) {
1974	Diag(Prop->getLocation(), diag::warn_missing_explicit_synthesis);
1975	Diag(IMPDecl->getLocation(), diag::note_while_in_implementation);
1976	}
1977	}
1978	}
1979
1980	void Sema::DefaultSynthesizeProperties(Scope *S, Decl *D,
1981	SourceLocation AtEnd) {
1982	if (!LangOpts.ObjCDefaultSynthProperties || LangOpts.ObjCRuntime.isFragile())
1983	return;
1984	ObjCImplementationDecl *IC=dyn_cast_or_null<ObjCImplementationDecl>(Val: D);
1985	if (!IC)
1986	return;
1987	if (ObjCInterfaceDecl* IDecl = IC->getClassInterface())
1988	if (!IDecl->isObjCRequiresPropertyDefs())
1989	DefaultSynthesizeProperties(S, IC, IDecl, AtEnd);
1990	}
1991
1992	static void DiagnoseUnimplementedAccessor(
1993	Sema &S, ObjCInterfaceDecl *PrimaryClass, Selector Method,
1994	ObjCImplDecl *IMPDecl, ObjCContainerDecl *CDecl, ObjCCategoryDecl *C,
1995	ObjCPropertyDecl *Prop,
1996	llvm::SmallPtrSet<const ObjCMethodDecl *, 8> &SMap) {
1997	// Check to see if we have a corresponding selector in SMap and with the
1998	// right method type.
1999	auto I = llvm::find_if(Range&: SMap, P: [&](const ObjCMethodDecl *x) {
2000	return x->getSelector() == Method &&
2001	x->isClassMethod() == Prop->isClassProperty();
2002	});
2003	// When reporting on missing property setter/getter implementation in
2004	// categories, do not report when they are declared in primary class,
2005	// class's protocol, or one of it super classes. This is because,
2006	// the class is going to implement them.
2007	if (I == SMap.end() &&
2008	(PrimaryClass == nullptr ||
2009	!PrimaryClass->lookupPropertyAccessor(Sel: Method, Cat: C,
2010	IsClassProperty: Prop->isClassProperty()))) {
2011	unsigned diag =
2012	isa<ObjCCategoryDecl>(CDecl)
2013	? (Prop->isClassProperty()
2014	? diag::warn_impl_required_in_category_for_class_property
2015	: diag::warn_setter_getter_impl_required_in_category)
2016	: (Prop->isClassProperty()
2017	? diag::warn_impl_required_for_class_property
2018	: diag::warn_setter_getter_impl_required);
2019	S.Diag(IMPDecl->getLocation(), diag) << Prop->getDeclName() << Method;
2020	S.Diag(Prop->getLocation(), diag::note_property_declare);
2021	if (S.LangOpts.ObjCDefaultSynthProperties &&
2022	S.LangOpts.ObjCRuntime.isNonFragile())
2023	if (ObjCInterfaceDecl *ID = dyn_cast<ObjCInterfaceDecl>(CDecl))
2024	if (const ObjCInterfaceDecl *RID = ID->isObjCRequiresPropertyDefs())
2025	S.Diag(RID->getLocation(), diag::note_suppressed_class_declare);
2026	}
2027	}
2028
2029	void Sema::DiagnoseUnimplementedProperties(Scope *S, ObjCImplDecl* IMPDecl,
2030	ObjCContainerDecl *CDecl,
2031	bool SynthesizeProperties) {
2032	ObjCContainerDecl::PropertyMap PropMap;
2033	ObjCInterfaceDecl *IDecl = dyn_cast<ObjCInterfaceDecl>(Val: CDecl);
2034
2035	// Since we don't synthesize class properties, we should emit diagnose even
2036	// if SynthesizeProperties is true.
2037	ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2038	// Gather properties which need not be implemented in this class
2039	// or category.
2040	if (!IDecl)
2041	if (ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(Val: CDecl)) {
2042	// For categories, no need to implement properties declared in
2043	// its primary class (and its super classes) if property is
2044	// declared in one of those containers.
2045	if ((IDecl = C->getClassInterface())) {
2046	IDecl->collectPropertiesToImplement(PM&: NoNeedToImplPropMap);
2047	}
2048	}
2049	if (IDecl)
2050	CollectSuperClassPropertyImplementations(CDecl: IDecl, PropMap&: NoNeedToImplPropMap);
2051
2052	// When SynthesizeProperties is true, we only check class properties.
2053	CollectImmediateProperties(CDecl, PropMap, SuperPropMap&: NoNeedToImplPropMap,
2054	CollectClassPropsOnly: SynthesizeProperties/*CollectClassPropsOnly*/);
2055
2056	// Scan the @interface to see if any of the protocols it adopts
2057	// require an explicit implementation, via attribute
2058	// 'objc_protocol_requires_explicit_implementation'.
2059	if (IDecl) {
2060	std::unique_ptr<ObjCContainerDecl::PropertyMap> LazyMap;
2061
2062	for (auto *PDecl : IDecl->all_referenced_protocols()) {
2063	if (!PDecl->hasAttr<ObjCExplicitProtocolImplAttr>())
2064	continue;
2065	// Lazily construct a set of all the properties in the @interface
2066	// of the class, without looking at the superclass. We cannot
2067	// use the call to CollectImmediateProperties() above as that
2068	// utilizes information from the super class's properties as well
2069	// as scans the adopted protocols. This work only triggers for protocols
2070	// with the attribute, which is very rare, and only occurs when
2071	// analyzing the @implementation.
2072	if (!LazyMap) {
2073	ObjCContainerDecl::PropertyMap NoNeedToImplPropMap;
2074	LazyMap.reset(p: new ObjCContainerDecl::PropertyMap());
2075	CollectImmediateProperties(CDecl, PropMap&: *LazyMap, SuperPropMap&: NoNeedToImplPropMap,
2076	/* CollectClassPropsOnly */ false,
2077	/* IncludeProtocols */ false);
2078	}
2079	// Add the properties of 'PDecl' to the list of properties that
2080	// need to be implemented.
2081	for (auto *PropDecl : PDecl->properties()) {
2082	if ((*LazyMap)[std::make_pair(PropDecl->getIdentifier(),
2083	PropDecl->isClassProperty())])
2084	continue;
2085	PropMap[std::make_pair(PropDecl->getIdentifier(),
2086	PropDecl->isClassProperty())] = PropDecl;
2087	}
2088	}
2089	}
2090
2091	if (PropMap.empty())
2092	return;
2093
2094	llvm::DenseSet<ObjCPropertyDecl *> PropImplMap;
2095	for (const auto *I : IMPDecl->property_impls())
2096	PropImplMap.insert(V: I->getPropertyDecl());
2097
2098	llvm::SmallPtrSet<const ObjCMethodDecl *, 8> InsMap;
2099	// Collect property accessors implemented in current implementation.
2100	for (const auto *I : IMPDecl->methods())
2101	InsMap.insert(I);
2102
2103	ObjCCategoryDecl *C = dyn_cast<ObjCCategoryDecl>(Val: CDecl);
2104	ObjCInterfaceDecl *PrimaryClass = nullptr;
2105	if (C && !C->IsClassExtension())
2106	if ((PrimaryClass = C->getClassInterface()))
2107	// Report unimplemented properties in the category as well.
2108	if (ObjCImplDecl *IMP = PrimaryClass->getImplementation()) {
2109	// When reporting on missing setter/getters, do not report when
2110	// setter/getter is implemented in category's primary class
2111	// implementation.
2112	for (const auto *I : IMP->methods())
2113	InsMap.insert(I);
2114	}
2115
2116	for (ObjCContainerDecl::PropertyMap::iterator
2117	P = PropMap.begin(), E = PropMap.end(); P != E; ++P) {
2118	ObjCPropertyDecl *Prop = P->second;
2119	// Is there a matching property synthesize/dynamic?
2120	if (Prop->isInvalidDecl() ||
2121	Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
2122	PropImplMap.count(V: Prop) ||
2123	Prop->getAvailability() == AR_Unavailable)
2124	continue;
2125
2126	// Diagnose unimplemented getters and setters.
2127	DiagnoseUnimplementedAccessor(S&: *this,
2128	PrimaryClass, Method: Prop->getGetterName(), IMPDecl, CDecl, C, Prop, SMap&: InsMap);
2129	if (!Prop->isReadOnly())
2130	DiagnoseUnimplementedAccessor(S&: *this,
2131	PrimaryClass, Method: Prop->getSetterName(),
2132	IMPDecl, CDecl, C, Prop, SMap&: InsMap);
2133	}
2134	}
2135
2136	void Sema::diagnoseNullResettableSynthesizedSetters(const ObjCImplDecl *impDecl) {
2137	for (const auto *propertyImpl : impDecl->property_impls()) {
2138	const auto *property = propertyImpl->getPropertyDecl();
2139	// Warn about null_resettable properties with synthesized setters,
2140	// because the setter won't properly handle nil.
2141	if (propertyImpl->getPropertyImplementation() ==
2142	ObjCPropertyImplDecl::Synthesize &&
2143	(property->getPropertyAttributes() &
2144	ObjCPropertyAttribute::kind_null_resettable) &&
2145	property->getGetterMethodDecl() && property->getSetterMethodDecl()) {
2146	auto *getterImpl = propertyImpl->getGetterMethodDecl();
2147	auto *setterImpl = propertyImpl->getSetterMethodDecl();
2148	if ((!getterImpl || getterImpl->isSynthesizedAccessorStub()) &&
2149	(!setterImpl || setterImpl->isSynthesizedAccessorStub())) {
2150	SourceLocation loc = propertyImpl->getLocation();
2151	if (loc.isInvalid())
2152	loc = impDecl->getBeginLoc();
2153
2154	Diag(loc, diag::warn_null_resettable_setter)
2155	<< setterImpl->getSelector() << property->getDeclName();
2156	}
2157	}
2158	}
2159	}
2160
2161	void
2162	Sema::AtomicPropertySetterGetterRules (ObjCImplDecl* IMPDecl,
2163	ObjCInterfaceDecl* IDecl) {
2164	// Rules apply in non-GC mode only
2165	if (getLangOpts().getGC() != LangOptions::NonGC)
2166	return;
2167	ObjCContainerDecl::PropertyMap PM;
2168	for (auto *Prop : IDecl->properties())
2169	PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2170	for (const auto *Ext : IDecl->known_extensions())
2171	for (auto *Prop : Ext->properties())
2172	PM[std::make_pair(Prop->getIdentifier(), Prop->isClassProperty())] = Prop;
2173
2174	for (ObjCContainerDecl::PropertyMap::iterator I = PM.begin(), E = PM.end();
2175	I != E; ++I) {
2176	const ObjCPropertyDecl *Property = I->second;
2177	ObjCMethodDecl *GetterMethod = nullptr;
2178	ObjCMethodDecl *SetterMethod = nullptr;
2179
2180	unsigned Attributes = Property->getPropertyAttributes();
2181	unsigned AttributesAsWritten = Property->getPropertyAttributesAsWritten();
2182
2183	if (!(AttributesAsWritten & ObjCPropertyAttribute::kind_atomic) &&
2184	!(AttributesAsWritten & ObjCPropertyAttribute::kind_nonatomic)) {
2185	GetterMethod = Property->isClassProperty() ?
2186	IMPDecl->getClassMethod(Property->getGetterName()) :
2187	IMPDecl->getInstanceMethod(Property->getGetterName());
2188	SetterMethod = Property->isClassProperty() ?
2189	IMPDecl->getClassMethod(Property->getSetterName()) :
2190	IMPDecl->getInstanceMethod(Property->getSetterName());
2191	if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
2192	GetterMethod = nullptr;
2193	if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
2194	SetterMethod = nullptr;
2195	if (GetterMethod) {
2196	Diag(GetterMethod->getLocation(),
2197	diag::warn_default_atomic_custom_getter_setter)
2198	<< Property->getIdentifier() << 0;
2199	Diag(Property->getLocation(), diag::note_property_declare);
2200	}
2201	if (SetterMethod) {
2202	Diag(SetterMethod->getLocation(),
2203	diag::warn_default_atomic_custom_getter_setter)
2204	<< Property->getIdentifier() << 1;
2205	Diag(Property->getLocation(), diag::note_property_declare);
2206	}
2207	}
2208
2209	// We only care about readwrite atomic property.
2210	if ((Attributes & ObjCPropertyAttribute::kind_nonatomic) ||
2211	!(Attributes & ObjCPropertyAttribute::kind_readwrite))
2212	continue;
2213	if (const ObjCPropertyImplDecl *PIDecl = IMPDecl->FindPropertyImplDecl(
2214	propertyId: Property->getIdentifier(), queryKind: Property->getQueryKind())) {
2215	if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic)
2216	continue;
2217	GetterMethod = PIDecl->getGetterMethodDecl();
2218	SetterMethod = PIDecl->getSetterMethodDecl();
2219	if (GetterMethod && GetterMethod->isSynthesizedAccessorStub())
2220	GetterMethod = nullptr;
2221	if (SetterMethod && SetterMethod->isSynthesizedAccessorStub())
2222	SetterMethod = nullptr;
2223	if ((bool)GetterMethod ^ (bool)SetterMethod) {
2224	SourceLocation MethodLoc =
2225	(GetterMethod ? GetterMethod->getLocation()
2226	: SetterMethod->getLocation());
2227	Diag(MethodLoc, diag::warn_atomic_property_rule)
2228	<< Property->getIdentifier() << (GetterMethod != nullptr)
2229	<< (SetterMethod != nullptr);
2230	// fixit stuff.
2231	if (Property->getLParenLoc().isValid() &&
2232	!(AttributesAsWritten & ObjCPropertyAttribute::kind_atomic)) {
2233	// @property () ... case.
2234	SourceLocation AfterLParen =
2235	getLocForEndOfToken(Loc: Property->getLParenLoc());
2236	StringRef NonatomicStr = AttributesAsWritten? "nonatomic, "
2237	: "nonatomic";
2238	Diag(Property->getLocation(),
2239	diag::note_atomic_property_fixup_suggest)
2240	<< FixItHint::CreateInsertion(AfterLParen, NonatomicStr);
2241	} else if (Property->getLParenLoc().isInvalid()) {
2242	//@property id etc.
2243	SourceLocation startLoc =
2244	Property->getTypeSourceInfo()->getTypeLoc().getBeginLoc();
2245	Diag(Property->getLocation(),
2246	diag::note_atomic_property_fixup_suggest)
2247	<< FixItHint::CreateInsertion(startLoc, "(nonatomic) ");
2248	} else
2249	Diag(MethodLoc, diag::note_atomic_property_fixup_suggest);
2250	Diag(Property->getLocation(), diag::note_property_declare);
2251	}
2252	}
2253	}
2254	}
2255
2256	void Sema::DiagnoseOwningPropertyGetterSynthesis(const ObjCImplementationDecl *D) {
2257	if (getLangOpts().getGC() == LangOptions::GCOnly)
2258	return;
2259
2260	for (const auto *PID : D->property_impls()) {
2261	const ObjCPropertyDecl *PD = PID->getPropertyDecl();
2262	if (PD && !PD->hasAttr<NSReturnsNotRetainedAttr>() &&
2263	!PD->isClassProperty()) {
2264	ObjCMethodDecl *IM = PID->getGetterMethodDecl();
2265	if (IM && !IM->isSynthesizedAccessorStub())
2266	continue;
2267	ObjCMethodDecl *method = PD->getGetterMethodDecl();
2268	if (!method)
2269	continue;
2270	ObjCMethodFamily family = method->getMethodFamily();
2271	if (family == OMF_alloc || family == OMF_copy ||
2272	family == OMF_mutableCopy || family == OMF_new) {
2273	if (getLangOpts().ObjCAutoRefCount)
2274	Diag(PD->getLocation(), diag::err_cocoa_naming_owned_rule);
2275	else
2276	Diag(PD->getLocation(), diag::warn_cocoa_naming_owned_rule);
2277
2278	// Look for a getter explicitly declared alongside the property.
2279	// If we find one, use its location for the note.
2280	SourceLocation noteLoc = PD->getLocation();
2281	SourceLocation fixItLoc;
2282	for (auto *getterRedecl : method->redecls()) {
2283	if (getterRedecl->isImplicit())
2284	continue;
2285	if (getterRedecl->getDeclContext() != PD->getDeclContext())
2286	continue;
2287	noteLoc = getterRedecl->getLocation();
2288	fixItLoc = getterRedecl->getEndLoc();
2289	}
2290
2291	Preprocessor &PP = getPreprocessor();
2292	TokenValue tokens[] = {
2293	tok::kw___attribute, tok::l_paren, tok::l_paren,
2294	PP.getIdentifierInfo("objc_method_family"), tok::l_paren,
2295	PP.getIdentifierInfo("none"), tok::r_paren,
2296	tok::r_paren, tok::r_paren
2297	};
2298	StringRef spelling = "__attribute__((objc_method_family(none)))";
2299	StringRef macroName = PP.getLastMacroWithSpelling(noteLoc, tokens);
2300	if (!macroName.empty())
2301	spelling = macroName;
2302
2303	auto noteDiag = Diag(noteLoc, diag::note_cocoa_naming_declare_family)
2304	<< method->getDeclName() << spelling;
2305	if (fixItLoc.isValid()) {
2306	SmallString<64> fixItText(" ");
2307	fixItText += spelling;
2308	noteDiag << FixItHint::CreateInsertion(fixItLoc, fixItText);
2309	}
2310	}
2311	}
2312	}
2313	}
2314
2315	void Sema::DiagnoseMissingDesignatedInitOverrides(
2316	const ObjCImplementationDecl *ImplD,
2317	const ObjCInterfaceDecl *IFD) {
2318	assert(IFD->hasDesignatedInitializers());
2319	const ObjCInterfaceDecl *SuperD = IFD->getSuperClass();
2320	if (!SuperD)
2321	return;
2322
2323	SelectorSet InitSelSet;
2324	for (const auto *I : ImplD->instance_methods())
2325	if (I->getMethodFamily() == OMF_init)
2326	InitSelSet.insert(I->getSelector());
2327
2328	SmallVector<const ObjCMethodDecl *, 8> DesignatedInits;
2329	SuperD->getDesignatedInitializers(Methods&: DesignatedInits);
2330	for (SmallVector<const ObjCMethodDecl *, 8>::iterator
2331	I = DesignatedInits.begin(), E = DesignatedInits.end(); I != E; ++I) {
2332	const ObjCMethodDecl *MD = *I;
2333	if (!InitSelSet.count(Ptr: MD->getSelector())) {
2334	// Don't emit a diagnostic if the overriding method in the subclass is
2335	// marked as unavailable.
2336	bool Ignore = false;
2337	if (auto *IMD = IFD->getInstanceMethod(MD->getSelector())) {
2338	Ignore = IMD->isUnavailable();
2339	} else {
2340	// Check the methods declared in the class extensions too.
2341	for (auto *Ext : IFD->visible_extensions())
2342	if (auto *IMD = Ext->getInstanceMethod(MD->getSelector())) {
2343	Ignore = IMD->isUnavailable();
2344	break;
2345	}
2346	}
2347	if (!Ignore) {
2348	Diag(ImplD->getLocation(),
2349	diag::warn_objc_implementation_missing_designated_init_override)
2350	<< MD->getSelector();
2351	Diag(MD->getLocation(), diag::note_objc_designated_init_marked_here);
2352	}
2353	}
2354	}
2355	}
2356
2357	/// AddPropertyAttrs - Propagates attributes from a property to the
2358	/// implicitly-declared getter or setter for that property.
2359	static void AddPropertyAttrs(Sema &S, ObjCMethodDecl *PropertyMethod,
2360	ObjCPropertyDecl *Property) {
2361	// Should we just clone all attributes over?
2362	for (const auto *A : Property->attrs()) {
2363	if (isa<DeprecatedAttr>(A) ||
2364	isa<UnavailableAttr>(A) ||
2365	isa<AvailabilityAttr>(A))
2366	PropertyMethod->addAttr(A->clone(S.Context));
2367	}
2368	}
2369
2370	/// ProcessPropertyDecl - Make sure that any user-defined setter/getter methods
2371	/// have the property type and issue diagnostics if they don't.
2372	/// Also synthesize a getter/setter method if none exist (and update the
2373	/// appropriate lookup tables.
2374	void Sema::ProcessPropertyDecl(ObjCPropertyDecl *property) {
2375	ObjCMethodDecl *GetterMethod, *SetterMethod;
2376	ObjCContainerDecl *CD = cast<ObjCContainerDecl>(property->getDeclContext());
2377	if (CD->isInvalidDecl())
2378	return;
2379
2380	bool IsClassProperty = property->isClassProperty();
2381	GetterMethod = IsClassProperty ?
2382	CD->getClassMethod(Sel: property->getGetterName()) :
2383	CD->getInstanceMethod(Sel: property->getGetterName());
2384
2385	// if setter or getter is not found in class extension, it might be
2386	// in the primary class.
2387	if (!GetterMethod)
2388	if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(Val: CD))
2389	if (CatDecl->IsClassExtension())
2390	GetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2391	getClassMethod(property->getGetterName()) :
2392	CatDecl->getClassInterface()->
2393	getInstanceMethod(property->getGetterName());
2394
2395	SetterMethod = IsClassProperty ?
2396	CD->getClassMethod(Sel: property->getSetterName()) :
2397	CD->getInstanceMethod(Sel: property->getSetterName());
2398	if (!SetterMethod)
2399	if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(Val: CD))
2400	if (CatDecl->IsClassExtension())
2401	SetterMethod = IsClassProperty ? CatDecl->getClassInterface()->
2402	getClassMethod(property->getSetterName()) :
2403	CatDecl->getClassInterface()->
2404	getInstanceMethod(property->getSetterName());
2405	DiagnosePropertyAccessorMismatch(property, GetterMethod,
2406	Loc: property->getLocation());
2407
2408	// synthesizing accessors must not result in a direct method that is not
2409	// monomorphic
2410	if (!GetterMethod) {
2411	if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(Val: CD)) {
2412	auto *ExistingGetter = CatDecl->getClassInterface()->lookupMethod(
2413	Sel: property->getGetterName(), isInstance: !IsClassProperty, shallowCategoryLookup: true, followSuper: false, C: CatDecl);
2414	if (ExistingGetter) {
2415	if (ExistingGetter->isDirectMethod() || property->isDirectProperty()) {
2416	Diag(property->getLocation(), diag::err_objc_direct_duplicate_decl)
2417	<< property->isDirectProperty() << 1 /* property */
2418	<< ExistingGetter->isDirectMethod()
2419	<< ExistingGetter->getDeclName();
2420	Diag(ExistingGetter->getLocation(), diag::note_previous_declaration);
2421	}
2422	}
2423	}
2424	}
2425
2426	if (!property->isReadOnly() && !SetterMethod) {
2427	if (const ObjCCategoryDecl *CatDecl = dyn_cast<ObjCCategoryDecl>(Val: CD)) {
2428	auto *ExistingSetter = CatDecl->getClassInterface()->lookupMethod(
2429	Sel: property->getSetterName(), isInstance: !IsClassProperty, shallowCategoryLookup: true, followSuper: false, C: CatDecl);
2430	if (ExistingSetter) {
2431	if (ExistingSetter->isDirectMethod() || property->isDirectProperty()) {
2432	Diag(property->getLocation(), diag::err_objc_direct_duplicate_decl)
2433	<< property->isDirectProperty() << 1 /* property */
2434	<< ExistingSetter->isDirectMethod()
2435	<< ExistingSetter->getDeclName();
2436	Diag(ExistingSetter->getLocation(), diag::note_previous_declaration);
2437	}
2438	}
2439	}
2440	}
2441
2442	if (!property->isReadOnly() && SetterMethod) {
2443	if (Context.getCanonicalType(SetterMethod->getReturnType()) !=
2444	Context.VoidTy)
2445	Diag(SetterMethod->getLocation(), diag::err_setter_type_void);
2446	if (SetterMethod->param_size() != 1 ||
2447	!Context.hasSameUnqualifiedType(
2448	T1: (*SetterMethod->param_begin())->getType().getNonReferenceType(),
2449	T2: property->getType().getNonReferenceType())) {
2450	Diag(property->getLocation(),
2451	diag::warn_accessor_property_type_mismatch)
2452	<< property->getDeclName()
2453	<< SetterMethod->getSelector();
2454	Diag(SetterMethod->getLocation(), diag::note_declared_at);
2455	}
2456	}
2457
2458	// Synthesize getter/setter methods if none exist.
2459	// Find the default getter and if one not found, add one.
2460	// FIXME: The synthesized property we set here is misleading. We almost always
2461	// synthesize these methods unless the user explicitly provided prototypes
2462	// (which is odd, but allowed). Sema should be typechecking that the
2463	// declarations jive in that situation (which it is not currently).
2464	if (!GetterMethod) {
2465	// No instance/class method of same name as property getter name was found.
2466	// Declare a getter method and add it to the list of methods
2467	// for this class.
2468	SourceLocation Loc = property->getLocation();
2469
2470	// The getter returns the declared property type with all qualifiers
2471	// removed.
2472	QualType resultTy = property->getType().getAtomicUnqualifiedType();
2473
2474	// If the property is null_resettable, the getter returns nonnull.
2475	if (property->getPropertyAttributes() &
2476	ObjCPropertyAttribute::kind_null_resettable) {
2477	QualType modifiedTy = resultTy;
2478	if (auto nullability = AttributedType::stripOuterNullability(T&: modifiedTy)) {
2479	if (*nullability == NullabilityKind::Unspecified)
2480	resultTy = Context.getAttributedType(attr::TypeNonNull,
2481	modifiedTy, modifiedTy);
2482	}
2483	}
2484
2485	GetterMethod = ObjCMethodDecl::Create(
2486	Context, Loc, Loc, property->getGetterName(), resultTy, nullptr, CD,
2487	!IsClassProperty, /*isVariadic=*/false,
2488	/*isPropertyAccessor=*/true, /*isSynthesizedAccessorStub=*/false,
2489	/*isImplicitlyDeclared=*/true, /*isDefined=*/false,
2490	(property->getPropertyImplementation() == ObjCPropertyDecl::Optional)
2491	? ObjCImplementationControl::Optional
2492	: ObjCImplementationControl::Required);
2493	CD->addDecl(GetterMethod);
2494
2495	AddPropertyAttrs(S&: *this, PropertyMethod: GetterMethod, Property: property);
2496
2497	if (property->isDirectProperty())
2498	GetterMethod->addAttr(ObjCDirectAttr::CreateImplicit(Context, Loc));
2499
2500	if (property->hasAttr<NSReturnsNotRetainedAttr>())
2501	GetterMethod->addAttr(NSReturnsNotRetainedAttr::CreateImplicit(Context,
2502	Loc));
2503
2504	if (property->hasAttr<ObjCReturnsInnerPointerAttr>())
2505	GetterMethod->addAttr(
2506	ObjCReturnsInnerPointerAttr::CreateImplicit(Context, Loc));
2507
2508	if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2509	GetterMethod->addAttr(SectionAttr::CreateImplicit(
2510	Context, SA->getName(), Loc, SectionAttr::GNU_section));
2511
2512	ProcessAPINotes(GetterMethod);
2513
2514	if (getLangOpts().ObjCAutoRefCount)
2515	CheckARCMethodDecl(method: GetterMethod);
2516	} else
2517	// A user declared getter will be synthesize when @synthesize of
2518	// the property with the same name is seen in the @implementation
2519	GetterMethod->setPropertyAccessor(true);
2520
2521	GetterMethod->createImplicitParams(Context,
2522	ID: GetterMethod->getClassInterface());
2523	property->setGetterMethodDecl(GetterMethod);
2524
2525	// Skip setter if property is read-only.
2526	if (!property->isReadOnly()) {
2527	// Find the default setter and if one not found, add one.
2528	if (!SetterMethod) {
2529	// No instance/class method of same name as property setter name was
2530	// found.
2531	// Declare a setter method and add it to the list of methods
2532	// for this class.
2533	SourceLocation Loc = property->getLocation();
2534
2535	SetterMethod = ObjCMethodDecl::Create(
2536	C&: Context, beginLoc: Loc, endLoc: Loc, SelInfo: property->getSetterName(), T: Context.VoidTy, ReturnTInfo: nullptr,
2537	contextDecl: CD, isInstance: !IsClassProperty,
2538	/*isVariadic=*/false,
2539	/*isPropertyAccessor=*/true,
2540	/*isSynthesizedAccessorStub=*/false,
2541	/*isImplicitlyDeclared=*/true,
2542	/*isDefined=*/false,
2543	impControl: (property->getPropertyImplementation() == ObjCPropertyDecl::Optional)
2544	? ObjCImplementationControl::Optional
2545	: ObjCImplementationControl::Required);
2546
2547	// Remove all qualifiers from the setter's parameter type.
2548	QualType paramTy =
2549	property->getType().getUnqualifiedType().getAtomicUnqualifiedType();
2550
2551	// If the property is null_resettable, the setter accepts a
2552	// nullable value.
2553	if (property->getPropertyAttributes() &
2554	ObjCPropertyAttribute::kind_null_resettable) {
2555	QualType modifiedTy = paramTy;
2556	if (auto nullability = AttributedType::stripOuterNullability(T&: modifiedTy)){
2557	if (*nullability == NullabilityKind::Unspecified)
2558	paramTy = Context.getAttributedType(attr::TypeNullable,
2559	modifiedTy, modifiedTy);
2560	}
2561	}
2562
2563	// Invent the arguments for the setter. We don't bother making a
2564	// nice name for the argument.
2565	ParmVarDecl *Argument = ParmVarDecl::Create(C&: Context, DC: SetterMethod,
2566	StartLoc: Loc, IdLoc: Loc,
2567	Id: property->getIdentifier(),
2568	T: paramTy,
2569	/*TInfo=*/nullptr,
2570	S: SC_None,
2571	DefArg: nullptr);
2572	SetterMethod->setMethodParams(C&: Context, Params: Argument, SelLocs: std::nullopt);
2573
2574	AddPropertyAttrs(S&: *this, PropertyMethod: SetterMethod, Property: property);
2575
2576	if (property->isDirectProperty())
2577	SetterMethod->addAttr(ObjCDirectAttr::CreateImplicit(Context, Loc));
2578
2579	CD->addDecl(SetterMethod);
2580	if (const SectionAttr *SA = property->getAttr<SectionAttr>())
2581	SetterMethod->addAttr(SectionAttr::CreateImplicit(
2582	Context, SA->getName(), Loc, SectionAttr::GNU_section));
2583
2584	ProcessAPINotes(SetterMethod);
2585
2586	// It's possible for the user to have set a very odd custom
2587	// setter selector that causes it to have a method family.
2588	if (getLangOpts().ObjCAutoRefCount)
2589	CheckARCMethodDecl(method: SetterMethod);
2590	} else
2591	// A user declared setter will be synthesize when @synthesize of
2592	// the property with the same name is seen in the @implementation
2593	SetterMethod->setPropertyAccessor(true);
2594
2595	SetterMethod->createImplicitParams(Context,
2596	ID: SetterMethod->getClassInterface());
2597	property->setSetterMethodDecl(SetterMethod);
2598	}
2599	// Add any synthesized methods to the global pool. This allows us to
2600	// handle the following, which is supported by GCC (and part of the design).
2601	//
2602	// @interface Foo
2603	// @property double bar;
2604	// @end
2605	//
2606	// void thisIsUnfortunate() {
2607	// id foo;
2608	// double bar = [foo bar];
2609	// }
2610	//
2611	if (!IsClassProperty) {
2612	if (GetterMethod)
2613	AddInstanceMethodToGlobalPool(Method: GetterMethod);
2614	if (SetterMethod)
2615	AddInstanceMethodToGlobalPool(Method: SetterMethod);
2616	} else {
2617	if (GetterMethod)
2618	AddFactoryMethodToGlobalPool(Method: GetterMethod);
2619	if (SetterMethod)
2620	AddFactoryMethodToGlobalPool(Method: SetterMethod);
2621	}
2622
2623	ObjCInterfaceDecl *CurrentClass = dyn_cast<ObjCInterfaceDecl>(Val: CD);
2624	if (!CurrentClass) {
2625	if (ObjCCategoryDecl *Cat = dyn_cast<ObjCCategoryDecl>(Val: CD))
2626	CurrentClass = Cat->getClassInterface();
2627	else if (ObjCImplDecl *Impl = dyn_cast<ObjCImplDecl>(Val: CD))
2628	CurrentClass = Impl->getClassInterface();
2629	}
2630	if (GetterMethod)
2631	CheckObjCMethodOverrides(ObjCMethod: GetterMethod, CurrentClass, RTC: Sema::RTC_Unknown);
2632	if (SetterMethod)
2633	CheckObjCMethodOverrides(ObjCMethod: SetterMethod, CurrentClass, RTC: Sema::RTC_Unknown);
2634	}
2635
2636	void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
2637	SourceLocation Loc,
2638	unsigned &Attributes,
2639	bool propertyInPrimaryClass) {
2640	// FIXME: Improve the reported location.
2641	if (!PDecl || PDecl->isInvalidDecl())
2642	return;
2643
2644	if ((Attributes & ObjCPropertyAttribute::kind_readonly) &&
2645	(Attributes & ObjCPropertyAttribute::kind_readwrite))
2646	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2647	<< "readonly" << "readwrite";
2648
2649	ObjCPropertyDecl *PropertyDecl = cast<ObjCPropertyDecl>(Val: PDecl);
2650	QualType PropertyTy = PropertyDecl->getType();
2651
2652	// Check for copy or retain on non-object types.
2653	if ((Attributes &
2654	(ObjCPropertyAttribute::kind_weak | ObjCPropertyAttribute::kind_copy |
2655	ObjCPropertyAttribute::kind_retain |
2656	ObjCPropertyAttribute::kind_strong)) &&
2657	!PropertyTy->isObjCRetainableType() &&
2658	!PropertyDecl->hasAttr<ObjCNSObjectAttr>()) {
2659	Diag(Loc, diag::err_objc_property_requires_object)
2660	<< (Attributes & ObjCPropertyAttribute::kind_weak
2661	? "weak"
2662	: Attributes & ObjCPropertyAttribute::kind_copy
2663	? "copy"
2664	: "retain (or strong)");
2665	Attributes &=
2666	~(ObjCPropertyAttribute::kind_weak | ObjCPropertyAttribute::kind_copy |
2667	ObjCPropertyAttribute::kind_retain |
2668	ObjCPropertyAttribute::kind_strong);
2669	PropertyDecl->setInvalidDecl();
2670	}
2671
2672	// Check for assign on object types.
2673	if ((Attributes & ObjCPropertyAttribute::kind_assign) &&
2674	!(Attributes & ObjCPropertyAttribute::kind_unsafe_unretained) &&
2675	PropertyTy->isObjCRetainableType() &&
2676	!PropertyTy->isObjCARCImplicitlyUnretainedType()) {
2677	Diag(Loc, diag::warn_objc_property_assign_on_object);
2678	}
2679
2680	// Check for more than one of { assign, copy, retain }.
2681	if (Attributes & ObjCPropertyAttribute::kind_assign) {
2682	if (Attributes & ObjCPropertyAttribute::kind_copy) {
2683	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2684	<< "assign" << "copy";
2685	Attributes &= ~ObjCPropertyAttribute::kind_copy;
2686	}
2687	if (Attributes & ObjCPropertyAttribute::kind_retain) {
2688	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2689	<< "assign" << "retain";
2690	Attributes &= ~ObjCPropertyAttribute::kind_retain;
2691	}
2692	if (Attributes & ObjCPropertyAttribute::kind_strong) {
2693	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2694	<< "assign" << "strong";
2695	Attributes &= ~ObjCPropertyAttribute::kind_strong;
2696	}
2697	if (getLangOpts().ObjCAutoRefCount &&
2698	(Attributes & ObjCPropertyAttribute::kind_weak)) {
2699	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2700	<< "assign" << "weak";
2701	Attributes &= ~ObjCPropertyAttribute::kind_weak;
2702	}
2703	if (PropertyDecl->hasAttr<IBOutletCollectionAttr>())
2704	Diag(Loc, diag::warn_iboutletcollection_property_assign);
2705	} else if (Attributes & ObjCPropertyAttribute::kind_unsafe_unretained) {
2706	if (Attributes & ObjCPropertyAttribute::kind_copy) {
2707	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2708	<< "unsafe_unretained" << "copy";
2709	Attributes &= ~ObjCPropertyAttribute::kind_copy;
2710	}
2711	if (Attributes & ObjCPropertyAttribute::kind_retain) {
2712	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2713	<< "unsafe_unretained" << "retain";
2714	Attributes &= ~ObjCPropertyAttribute::kind_retain;
2715	}
2716	if (Attributes & ObjCPropertyAttribute::kind_strong) {
2717	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2718	<< "unsafe_unretained" << "strong";
2719	Attributes &= ~ObjCPropertyAttribute::kind_strong;
2720	}
2721	if (getLangOpts().ObjCAutoRefCount &&
2722	(Attributes & ObjCPropertyAttribute::kind_weak)) {
2723	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2724	<< "unsafe_unretained" << "weak";
2725	Attributes &= ~ObjCPropertyAttribute::kind_weak;
2726	}
2727	} else if (Attributes & ObjCPropertyAttribute::kind_copy) {
2728	if (Attributes & ObjCPropertyAttribute::kind_retain) {
2729	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2730	<< "copy" << "retain";
2731	Attributes &= ~ObjCPropertyAttribute::kind_retain;
2732	}
2733	if (Attributes & ObjCPropertyAttribute::kind_strong) {
2734	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2735	<< "copy" << "strong";
2736	Attributes &= ~ObjCPropertyAttribute::kind_strong;
2737	}
2738	if (Attributes & ObjCPropertyAttribute::kind_weak) {
2739	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2740	<< "copy" << "weak";
2741	Attributes &= ~ObjCPropertyAttribute::kind_weak;
2742	}
2743	} else if ((Attributes & ObjCPropertyAttribute::kind_retain) &&
2744	(Attributes & ObjCPropertyAttribute::kind_weak)) {
2745	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "retain"
2746	<< "weak";
2747	Attributes &= ~ObjCPropertyAttribute::kind_retain;
2748	} else if ((Attributes & ObjCPropertyAttribute::kind_strong) &&
2749	(Attributes & ObjCPropertyAttribute::kind_weak)) {
2750	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "strong"
2751	<< "weak";
2752	Attributes &= ~ObjCPropertyAttribute::kind_weak;
2753	}
2754
2755	if (Attributes & ObjCPropertyAttribute::kind_weak) {
2756	// 'weak' and 'nonnull' are mutually exclusive.
2757	if (auto nullability = PropertyTy->getNullability()) {
2758	if (*nullability == NullabilityKind::NonNull)
2759	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive)
2760	<< "nonnull" << "weak";
2761	}
2762	}
2763
2764	if ((Attributes & ObjCPropertyAttribute::kind_atomic) &&
2765	(Attributes & ObjCPropertyAttribute::kind_nonatomic)) {
2766	Diag(Loc, diag::err_objc_property_attr_mutually_exclusive) << "atomic"
2767	<< "nonatomic";
2768	Attributes &= ~ObjCPropertyAttribute::kind_atomic;
2769	}
2770
2771	// Warn if user supplied no assignment attribute, property is
2772	// readwrite, and this is an object type.
2773	if (!getOwnershipRule(attr: Attributes) && PropertyTy->isObjCRetainableType()) {
2774	if (Attributes & ObjCPropertyAttribute::kind_readonly) {
2775	// do nothing
2776	} else if (getLangOpts().ObjCAutoRefCount) {
2777	// With arc, @property definitions should default to strong when
2778	// not specified.
2779	PropertyDecl->setPropertyAttributes(ObjCPropertyAttribute::kind_strong);
2780	} else if (PropertyTy->isObjCObjectPointerType()) {
2781	bool isAnyClassTy = (PropertyTy->isObjCClassType() ||
2782	PropertyTy->isObjCQualifiedClassType());
2783	// In non-gc, non-arc mode, 'Class' is treated as a 'void *' no need to
2784	// issue any warning.
2785	if (isAnyClassTy && getLangOpts().getGC() == LangOptions::NonGC)
2786	;
2787	else if (propertyInPrimaryClass) {
2788	// Don't issue warning on property with no life time in class
2789	// extension as it is inherited from property in primary class.
2790	// Skip this warning in gc-only mode.
2791	if (getLangOpts().getGC() != LangOptions::GCOnly)
2792	Diag(Loc, diag::warn_objc_property_no_assignment_attribute);
2793
2794	// If non-gc code warn that this is likely inappropriate.
2795	if (getLangOpts().getGC() == LangOptions::NonGC)
2796	Diag(Loc, diag::warn_objc_property_default_assign_on_object);
2797	}
2798	}
2799
2800	// FIXME: Implement warning dependent on NSCopying being
2801	// implemented.
2802	}
2803
2804	if (!(Attributes & ObjCPropertyAttribute::kind_copy) &&
2805	!(Attributes & ObjCPropertyAttribute::kind_readonly) &&
2806	getLangOpts().getGC() == LangOptions::GCOnly &&
2807	PropertyTy->isBlockPointerType())
2808	Diag(Loc, diag::warn_objc_property_copy_missing_on_block);
2809	else if ((Attributes & ObjCPropertyAttribute::kind_retain) &&
2810	!(Attributes & ObjCPropertyAttribute::kind_readonly) &&
2811	!(Attributes & ObjCPropertyAttribute::kind_strong) &&
2812	PropertyTy->isBlockPointerType())
2813	Diag(Loc, diag::warn_objc_property_retain_of_block);
2814
2815	if ((Attributes & ObjCPropertyAttribute::kind_readonly) &&
2816	(Attributes & ObjCPropertyAttribute::kind_setter))
2817	Diag(Loc, diag::warn_objc_readonly_property_has_setter);
2818	}
2819