1 //===---- CGObjC.cpp - Emit LLVM Code for Objective-C ---------------------===//
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 contains code to emit Objective-C code as LLVM code.
10 //
11 //===----------------------------------------------------------------------===//
12
13 #include "CGDebugInfo.h"
14 #include "CGObjCRuntime.h"
15 #include "CodeGenFunction.h"
16 #include "CodeGenModule.h"
17 #include "ConstantEmitter.h"
18 #include "TargetInfo.h"
19 #include "clang/AST/ASTContext.h"
20 #include "clang/AST/Attr.h"
21 #include "clang/AST/DeclObjC.h"
22 #include "clang/AST/StmtObjC.h"
23 #include "clang/Basic/Diagnostic.h"
24 #include "clang/CodeGen/CGFunctionInfo.h"
25 #include "clang/CodeGen/CodeGenABITypes.h"
26 #include "llvm/ADT/STLExtras.h"
27 #include "llvm/Analysis/ObjCARCUtil.h"
28 #include "llvm/BinaryFormat/MachO.h"
29 #include "llvm/IR/Constants.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/InlineAsm.h"
32 #include <optional>
33 using namespace clang;
34 using namespace CodeGen;
35
36 typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult;
37 static TryEmitResult
38 tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e);
39 static RValue AdjustObjCObjectType(CodeGenFunction &CGF,
40 QualType ET,
41 RValue Result);
42
43 /// Given the address of a variable of pointer type, find the correct
44 /// null to store into it.
getNullForVariable(Address addr)45 static llvm::Constant *getNullForVariable(Address addr) {
46 llvm::Type *type = addr.getElementType();
47 return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type));
48 }
49
50 /// Emits an instance of NSConstantString representing the object.
EmitObjCStringLiteral(const ObjCStringLiteral * E)51 llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E)
52 {
53 llvm::Constant *C =
54 CGM.getObjCRuntime().GenerateConstantString(E->getString()).getPointer();
55 return C;
56 }
57
58 /// EmitObjCBoxedExpr - This routine generates code to call
59 /// the appropriate expression boxing method. This will either be
60 /// one of +[NSNumber numberWith<Type>:], or +[NSString stringWithUTF8String:],
61 /// or [NSValue valueWithBytes:objCType:].
62 ///
63 llvm::Value *
EmitObjCBoxedExpr(const ObjCBoxedExpr * E)64 CodeGenFunction::EmitObjCBoxedExpr(const ObjCBoxedExpr *E) {
65 // Generate the correct selector for this literal's concrete type.
66 // Get the method.
67 const ObjCMethodDecl *BoxingMethod = E->getBoxingMethod();
68 const Expr *SubExpr = E->getSubExpr();
69
70 if (E->isExpressibleAsConstantInitializer()) {
71 ConstantEmitter ConstEmitter(CGM);
72 return ConstEmitter.tryEmitAbstract(E, E->getType());
73 }
74
75 assert(BoxingMethod->isClassMethod() && "BoxingMethod must be a class method");
76 Selector Sel = BoxingMethod->getSelector();
77
78 // Generate a reference to the class pointer, which will be the receiver.
79 // Assumes that the method was introduced in the class that should be
80 // messaged (avoids pulling it out of the result type).
81 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
82 const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface();
83 llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl);
84
85 CallArgList Args;
86 const ParmVarDecl *ArgDecl = *BoxingMethod->param_begin();
87 QualType ArgQT = ArgDecl->getType().getUnqualifiedType();
88
89 // ObjCBoxedExpr supports boxing of structs and unions
90 // via [NSValue valueWithBytes:objCType:]
91 const QualType ValueType(SubExpr->getType().getCanonicalType());
92 if (ValueType->isObjCBoxableRecordType()) {
93 // Emit CodeGen for first parameter
94 // and cast value to correct type
95 Address Temporary = CreateMemTemp(SubExpr->getType());
96 EmitAnyExprToMem(SubExpr, Temporary, Qualifiers(), /*isInit*/ true);
97 llvm::Value *BitCast =
98 Builder.CreateBitCast(Temporary.getPointer(), ConvertType(ArgQT));
99 Args.add(RValue::get(BitCast), ArgQT);
100
101 // Create char array to store type encoding
102 std::string Str;
103 getContext().getObjCEncodingForType(ValueType, Str);
104 llvm::Constant *GV = CGM.GetAddrOfConstantCString(Str).getPointer();
105
106 // Cast type encoding to correct type
107 const ParmVarDecl *EncodingDecl = BoxingMethod->parameters()[1];
108 QualType EncodingQT = EncodingDecl->getType().getUnqualifiedType();
109 llvm::Value *Cast = Builder.CreateBitCast(GV, ConvertType(EncodingQT));
110
111 Args.add(RValue::get(Cast), EncodingQT);
112 } else {
113 Args.add(EmitAnyExpr(SubExpr), ArgQT);
114 }
115
116 RValue result = Runtime.GenerateMessageSend(
117 *this, ReturnValueSlot(), BoxingMethod->getReturnType(), Sel, Receiver,
118 Args, ClassDecl, BoxingMethod);
119 return Builder.CreateBitCast(result.getScalarVal(),
120 ConvertType(E->getType()));
121 }
122
EmitObjCCollectionLiteral(const Expr * E,const ObjCMethodDecl * MethodWithObjects)123 llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E,
124 const ObjCMethodDecl *MethodWithObjects) {
125 ASTContext &Context = CGM.getContext();
126 const ObjCDictionaryLiteral *DLE = nullptr;
127 const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E);
128 if (!ALE)
129 DLE = cast<ObjCDictionaryLiteral>(E);
130
131 // Optimize empty collections by referencing constants, when available.
132 uint64_t NumElements =
133 ALE ? ALE->getNumElements() : DLE->getNumElements();
134 if (NumElements == 0 && CGM.getLangOpts().ObjCRuntime.hasEmptyCollections()) {
135 StringRef ConstantName = ALE ? "__NSArray0__" : "__NSDictionary0__";
136 QualType IdTy(CGM.getContext().getObjCIdType());
137 llvm::Constant *Constant =
138 CGM.CreateRuntimeVariable(ConvertType(IdTy), ConstantName);
139 LValue LV = MakeNaturalAlignAddrLValue(Constant, IdTy);
140 llvm::Value *Ptr = EmitLoadOfScalar(LV, E->getBeginLoc());
141 cast<llvm::LoadInst>(Ptr)->setMetadata(
142 llvm::LLVMContext::MD_invariant_load,
143 llvm::MDNode::get(getLLVMContext(), std::nullopt));
144 return Builder.CreateBitCast(Ptr, ConvertType(E->getType()));
145 }
146
147 // Compute the type of the array we're initializing.
148 llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()),
149 NumElements);
150 QualType ElementType = Context.getObjCIdType().withConst();
151 QualType ElementArrayType = Context.getConstantArrayType(
152 ElementType, APNumElements, nullptr, ArraySizeModifier::Normal,
153 /*IndexTypeQuals=*/0);
154
155 // Allocate the temporary array(s).
156 Address Objects = CreateMemTemp(ElementArrayType, "objects");
157 Address Keys = Address::invalid();
158 if (DLE)
159 Keys = CreateMemTemp(ElementArrayType, "keys");
160
161 // In ARC, we may need to do extra work to keep all the keys and
162 // values alive until after the call.
163 SmallVector<llvm::Value *, 16> NeededObjects;
164 bool TrackNeededObjects =
165 (getLangOpts().ObjCAutoRefCount &&
166 CGM.getCodeGenOpts().OptimizationLevel != 0);
167
168 // Perform the actual initialialization of the array(s).
169 for (uint64_t i = 0; i < NumElements; i++) {
170 if (ALE) {
171 // Emit the element and store it to the appropriate array slot.
172 const Expr *Rhs = ALE->getElement(i);
173 LValue LV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
174 ElementType, AlignmentSource::Decl);
175
176 llvm::Value *value = EmitScalarExpr(Rhs);
177 EmitStoreThroughLValue(RValue::get(value), LV, true);
178 if (TrackNeededObjects) {
179 NeededObjects.push_back(value);
180 }
181 } else {
182 // Emit the key and store it to the appropriate array slot.
183 const Expr *Key = DLE->getKeyValueElement(i).Key;
184 LValue KeyLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Keys, i),
185 ElementType, AlignmentSource::Decl);
186 llvm::Value *keyValue = EmitScalarExpr(Key);
187 EmitStoreThroughLValue(RValue::get(keyValue), KeyLV, /*isInit=*/true);
188
189 // Emit the value and store it to the appropriate array slot.
190 const Expr *Value = DLE->getKeyValueElement(i).Value;
191 LValue ValueLV = MakeAddrLValue(Builder.CreateConstArrayGEP(Objects, i),
192 ElementType, AlignmentSource::Decl);
193 llvm::Value *valueValue = EmitScalarExpr(Value);
194 EmitStoreThroughLValue(RValue::get(valueValue), ValueLV, /*isInit=*/true);
195 if (TrackNeededObjects) {
196 NeededObjects.push_back(keyValue);
197 NeededObjects.push_back(valueValue);
198 }
199 }
200 }
201
202 // Generate the argument list.
203 CallArgList Args;
204 ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin();
205 const ParmVarDecl *argDecl = *PI++;
206 QualType ArgQT = argDecl->getType().getUnqualifiedType();
207 Args.add(RValue::get(Objects.getPointer()), ArgQT);
208 if (DLE) {
209 argDecl = *PI++;
210 ArgQT = argDecl->getType().getUnqualifiedType();
211 Args.add(RValue::get(Keys.getPointer()), ArgQT);
212 }
213 argDecl = *PI;
214 ArgQT = argDecl->getType().getUnqualifiedType();
215 llvm::Value *Count =
216 llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements);
217 Args.add(RValue::get(Count), ArgQT);
218
219 // Generate a reference to the class pointer, which will be the receiver.
220 Selector Sel = MethodWithObjects->getSelector();
221 QualType ResultType = E->getType();
222 const ObjCObjectPointerType *InterfacePointerType
223 = ResultType->getAsObjCInterfacePointerType();
224 assert(InterfacePointerType && "Unexpected InterfacePointerType - null");
225 ObjCInterfaceDecl *Class
226 = InterfacePointerType->getObjectType()->getInterface();
227 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
228 llvm::Value *Receiver = Runtime.GetClass(*this, Class);
229
230 // Generate the message send.
231 RValue result = Runtime.GenerateMessageSend(
232 *this, ReturnValueSlot(), MethodWithObjects->getReturnType(), Sel,
233 Receiver, Args, Class, MethodWithObjects);
234
235 // The above message send needs these objects, but in ARC they are
236 // passed in a buffer that is essentially __unsafe_unretained.
237 // Therefore we must prevent the optimizer from releasing them until
238 // after the call.
239 if (TrackNeededObjects) {
240 EmitARCIntrinsicUse(NeededObjects);
241 }
242
243 return Builder.CreateBitCast(result.getScalarVal(),
244 ConvertType(E->getType()));
245 }
246
EmitObjCArrayLiteral(const ObjCArrayLiteral * E)247 llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) {
248 return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod());
249 }
250
EmitObjCDictionaryLiteral(const ObjCDictionaryLiteral * E)251 llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral(
252 const ObjCDictionaryLiteral *E) {
253 return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod());
254 }
255
256 /// Emit a selector.
EmitObjCSelectorExpr(const ObjCSelectorExpr * E)257 llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) {
258 // Untyped selector.
259 // Note that this implementation allows for non-constant strings to be passed
260 // as arguments to @selector(). Currently, the only thing preventing this
261 // behaviour is the type checking in the front end.
262 return CGM.getObjCRuntime().GetSelector(*this, E->getSelector());
263 }
264
EmitObjCProtocolExpr(const ObjCProtocolExpr * E)265 llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) {
266 // FIXME: This should pass the Decl not the name.
267 return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol());
268 }
269
270 /// Adjust the type of an Objective-C object that doesn't match up due
271 /// to type erasure at various points, e.g., related result types or the use
272 /// of parameterized classes.
AdjustObjCObjectType(CodeGenFunction & CGF,QualType ExpT,RValue Result)273 static RValue AdjustObjCObjectType(CodeGenFunction &CGF, QualType ExpT,
274 RValue Result) {
275 if (!ExpT->isObjCRetainableType())
276 return Result;
277
278 // If the converted types are the same, we're done.
279 llvm::Type *ExpLLVMTy = CGF.ConvertType(ExpT);
280 if (ExpLLVMTy == Result.getScalarVal()->getType())
281 return Result;
282
283 // We have applied a substitution. Cast the rvalue appropriately.
284 return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(),
285 ExpLLVMTy));
286 }
287
288 /// Decide whether to extend the lifetime of the receiver of a
289 /// returns-inner-pointer message.
290 static bool
shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr * message)291 shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) {
292 switch (message->getReceiverKind()) {
293
294 // For a normal instance message, we should extend unless the
295 // receiver is loaded from a variable with precise lifetime.
296 case ObjCMessageExpr::Instance: {
297 const Expr *receiver = message->getInstanceReceiver();
298
299 // Look through OVEs.
300 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
301 if (opaque->getSourceExpr())
302 receiver = opaque->getSourceExpr()->IgnoreParens();
303 }
304
305 const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver);
306 if (!ice || ice->getCastKind() != CK_LValueToRValue) return true;
307 receiver = ice->getSubExpr()->IgnoreParens();
308
309 // Look through OVEs.
310 if (auto opaque = dyn_cast<OpaqueValueExpr>(receiver)) {
311 if (opaque->getSourceExpr())
312 receiver = opaque->getSourceExpr()->IgnoreParens();
313 }
314
315 // Only __strong variables.
316 if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong)
317 return true;
318
319 // All ivars and fields have precise lifetime.
320 if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver))
321 return false;
322
323 // Otherwise, check for variables.
324 const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr());
325 if (!declRef) return true;
326 const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl());
327 if (!var) return true;
328
329 // All variables have precise lifetime except local variables with
330 // automatic storage duration that aren't specially marked.
331 return (var->hasLocalStorage() &&
332 !var->hasAttr<ObjCPreciseLifetimeAttr>());
333 }
334
335 case ObjCMessageExpr::Class:
336 case ObjCMessageExpr::SuperClass:
337 // It's never necessary for class objects.
338 return false;
339
340 case ObjCMessageExpr::SuperInstance:
341 // We generally assume that 'self' lives throughout a method call.
342 return false;
343 }
344
345 llvm_unreachable("invalid receiver kind");
346 }
347
348 /// Given an expression of ObjC pointer type, check whether it was
349 /// immediately loaded from an ARC __weak l-value.
findWeakLValue(const Expr * E)350 static const Expr *findWeakLValue(const Expr *E) {
351 assert(E->getType()->isObjCRetainableType());
352 E = E->IgnoreParens();
353 if (auto CE = dyn_cast<CastExpr>(E)) {
354 if (CE->getCastKind() == CK_LValueToRValue) {
355 if (CE->getSubExpr()->getType().getObjCLifetime() == Qualifiers::OCL_Weak)
356 return CE->getSubExpr();
357 }
358 }
359
360 return nullptr;
361 }
362
363 /// The ObjC runtime may provide entrypoints that are likely to be faster
364 /// than an ordinary message send of the appropriate selector.
365 ///
366 /// The entrypoints are guaranteed to be equivalent to just sending the
367 /// corresponding message. If the entrypoint is implemented naively as just a
368 /// message send, using it is a trade-off: it sacrifices a few cycles of
369 /// overhead to save a small amount of code. However, it's possible for
370 /// runtimes to detect and special-case classes that use "standard"
371 /// behavior; if that's dynamically a large proportion of all objects, using
372 /// the entrypoint will also be faster than using a message send.
373 ///
374 /// If the runtime does support a required entrypoint, then this method will
375 /// generate a call and return the resulting value. Otherwise it will return
376 /// std::nullopt and the caller can generate a msgSend instead.
tryGenerateSpecializedMessageSend(CodeGenFunction & CGF,QualType ResultType,llvm::Value * Receiver,const CallArgList & Args,Selector Sel,const ObjCMethodDecl * method,bool isClassMessage)377 static std::optional<llvm::Value *> tryGenerateSpecializedMessageSend(
378 CodeGenFunction &CGF, QualType ResultType, llvm::Value *Receiver,
379 const CallArgList &Args, Selector Sel, const ObjCMethodDecl *method,
380 bool isClassMessage) {
381 auto &CGM = CGF.CGM;
382 if (!CGM.getCodeGenOpts().ObjCConvertMessagesToRuntimeCalls)
383 return std::nullopt;
384
385 auto &Runtime = CGM.getLangOpts().ObjCRuntime;
386 switch (Sel.getMethodFamily()) {
387 case OMF_alloc:
388 if (isClassMessage &&
389 Runtime.shouldUseRuntimeFunctionsForAlloc() &&
390 ResultType->isObjCObjectPointerType()) {
391 // [Foo alloc] -> objc_alloc(Foo) or
392 // [self alloc] -> objc_alloc(self)
393 if (Sel.isUnarySelector() && Sel.getNameForSlot(0) == "alloc")
394 return CGF.EmitObjCAlloc(Receiver, CGF.ConvertType(ResultType));
395 // [Foo allocWithZone:nil] -> objc_allocWithZone(Foo) or
396 // [self allocWithZone:nil] -> objc_allocWithZone(self)
397 if (Sel.isKeywordSelector() && Sel.getNumArgs() == 1 &&
398 Args.size() == 1 && Args.front().getType()->isPointerType() &&
399 Sel.getNameForSlot(0) == "allocWithZone") {
400 const llvm::Value* arg = Args.front().getKnownRValue().getScalarVal();
401 if (isa<llvm::ConstantPointerNull>(arg))
402 return CGF.EmitObjCAllocWithZone(Receiver,
403 CGF.ConvertType(ResultType));
404 return std::nullopt;
405 }
406 }
407 break;
408
409 case OMF_autorelease:
410 if (ResultType->isObjCObjectPointerType() &&
411 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
412 Runtime.shouldUseARCFunctionsForRetainRelease())
413 return CGF.EmitObjCAutorelease(Receiver, CGF.ConvertType(ResultType));
414 break;
415
416 case OMF_retain:
417 if (ResultType->isObjCObjectPointerType() &&
418 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
419 Runtime.shouldUseARCFunctionsForRetainRelease())
420 return CGF.EmitObjCRetainNonBlock(Receiver, CGF.ConvertType(ResultType));
421 break;
422
423 case OMF_release:
424 if (ResultType->isVoidType() &&
425 CGM.getLangOpts().getGC() == LangOptions::NonGC &&
426 Runtime.shouldUseARCFunctionsForRetainRelease()) {
427 CGF.EmitObjCRelease(Receiver, ARCPreciseLifetime);
428 return nullptr;
429 }
430 break;
431
432 default:
433 break;
434 }
435 return std::nullopt;
436 }
437
GeneratePossiblySpecializedMessageSend(CodeGenFunction & CGF,ReturnValueSlot Return,QualType ResultType,Selector Sel,llvm::Value * Receiver,const CallArgList & Args,const ObjCInterfaceDecl * OID,const ObjCMethodDecl * Method,bool isClassMessage)438 CodeGen::RValue CGObjCRuntime::GeneratePossiblySpecializedMessageSend(
439 CodeGenFunction &CGF, ReturnValueSlot Return, QualType ResultType,
440 Selector Sel, llvm::Value *Receiver, const CallArgList &Args,
441 const ObjCInterfaceDecl *OID, const ObjCMethodDecl *Method,
442 bool isClassMessage) {
443 if (std::optional<llvm::Value *> SpecializedResult =
444 tryGenerateSpecializedMessageSend(CGF, ResultType, Receiver, Args,
445 Sel, Method, isClassMessage)) {
446 return RValue::get(*SpecializedResult);
447 }
448 return GenerateMessageSend(CGF, Return, ResultType, Sel, Receiver, Args, OID,
449 Method);
450 }
451
AppendFirstImpliedRuntimeProtocols(const ObjCProtocolDecl * PD,llvm::UniqueVector<const ObjCProtocolDecl * > & PDs)452 static void AppendFirstImpliedRuntimeProtocols(
453 const ObjCProtocolDecl *PD,
454 llvm::UniqueVector<const ObjCProtocolDecl *> &PDs) {
455 if (!PD->isNonRuntimeProtocol()) {
456 const auto *Can = PD->getCanonicalDecl();
457 PDs.insert(Can);
458 return;
459 }
460
461 for (const auto *ParentPD : PD->protocols())
462 AppendFirstImpliedRuntimeProtocols(ParentPD, PDs);
463 }
464
465 std::vector<const ObjCProtocolDecl *>
GetRuntimeProtocolList(ObjCProtocolDecl::protocol_iterator begin,ObjCProtocolDecl::protocol_iterator end)466 CGObjCRuntime::GetRuntimeProtocolList(ObjCProtocolDecl::protocol_iterator begin,
467 ObjCProtocolDecl::protocol_iterator end) {
468 std::vector<const ObjCProtocolDecl *> RuntimePds;
469 llvm::DenseSet<const ObjCProtocolDecl *> NonRuntimePDs;
470
471 for (; begin != end; ++begin) {
472 const auto *It = *begin;
473 const auto *Can = It->getCanonicalDecl();
474 if (Can->isNonRuntimeProtocol())
475 NonRuntimePDs.insert(Can);
476 else
477 RuntimePds.push_back(Can);
478 }
479
480 // If there are no non-runtime protocols then we can just stop now.
481 if (NonRuntimePDs.empty())
482 return RuntimePds;
483
484 // Else we have to search through the non-runtime protocol's inheritancy
485 // hierarchy DAG stopping whenever a branch either finds a runtime protocol or
486 // a non-runtime protocol without any parents. These are the "first-implied"
487 // protocols from a non-runtime protocol.
488 llvm::UniqueVector<const ObjCProtocolDecl *> FirstImpliedProtos;
489 for (const auto *PD : NonRuntimePDs)
490 AppendFirstImpliedRuntimeProtocols(PD, FirstImpliedProtos);
491
492 // Walk the Runtime list to get all protocols implied via the inclusion of
493 // this protocol, e.g. all protocols it inherits from including itself.
494 llvm::DenseSet<const ObjCProtocolDecl *> AllImpliedProtocols;
495 for (const auto *PD : RuntimePds) {
496 const auto *Can = PD->getCanonicalDecl();
497 AllImpliedProtocols.insert(Can);
498 Can->getImpliedProtocols(AllImpliedProtocols);
499 }
500
501 // Similar to above, walk the list of first-implied protocols to find the set
502 // all the protocols implied excluding the listed protocols themselves since
503 // they are not yet a part of the `RuntimePds` list.
504 for (const auto *PD : FirstImpliedProtos) {
505 PD->getImpliedProtocols(AllImpliedProtocols);
506 }
507
508 // From the first-implied list we have to finish building the final protocol
509 // list. If a protocol in the first-implied list was already implied via some
510 // inheritance path through some other protocols then it would be redundant to
511 // add it here and so we skip over it.
512 for (const auto *PD : FirstImpliedProtos) {
513 if (!AllImpliedProtocols.contains(PD)) {
514 RuntimePds.push_back(PD);
515 }
516 }
517
518 return RuntimePds;
519 }
520
521 /// Instead of '[[MyClass alloc] init]', try to generate
522 /// 'objc_alloc_init(MyClass)'. This provides a code size improvement on the
523 /// caller side, as well as the optimized objc_alloc.
524 static std::optional<llvm::Value *>
tryEmitSpecializedAllocInit(CodeGenFunction & CGF,const ObjCMessageExpr * OME)525 tryEmitSpecializedAllocInit(CodeGenFunction &CGF, const ObjCMessageExpr *OME) {
526 auto &Runtime = CGF.getLangOpts().ObjCRuntime;
527 if (!Runtime.shouldUseRuntimeFunctionForCombinedAllocInit())
528 return std::nullopt;
529
530 // Match the exact pattern '[[MyClass alloc] init]'.
531 Selector Sel = OME->getSelector();
532 if (OME->getReceiverKind() != ObjCMessageExpr::Instance ||
533 !OME->getType()->isObjCObjectPointerType() || !Sel.isUnarySelector() ||
534 Sel.getNameForSlot(0) != "init")
535 return std::nullopt;
536
537 // Okay, this is '[receiver init]', check if 'receiver' is '[cls alloc]'
538 // with 'cls' a Class.
539 auto *SubOME =
540 dyn_cast<ObjCMessageExpr>(OME->getInstanceReceiver()->IgnoreParenCasts());
541 if (!SubOME)
542 return std::nullopt;
543 Selector SubSel = SubOME->getSelector();
544
545 if (!SubOME->getType()->isObjCObjectPointerType() ||
546 !SubSel.isUnarySelector() || SubSel.getNameForSlot(0) != "alloc")
547 return std::nullopt;
548
549 llvm::Value *Receiver = nullptr;
550 switch (SubOME->getReceiverKind()) {
551 case ObjCMessageExpr::Instance:
552 if (!SubOME->getInstanceReceiver()->getType()->isObjCClassType())
553 return std::nullopt;
554 Receiver = CGF.EmitScalarExpr(SubOME->getInstanceReceiver());
555 break;
556
557 case ObjCMessageExpr::Class: {
558 QualType ReceiverType = SubOME->getClassReceiver();
559 const ObjCObjectType *ObjTy = ReceiverType->castAs<ObjCObjectType>();
560 const ObjCInterfaceDecl *ID = ObjTy->getInterface();
561 assert(ID && "null interface should be impossible here");
562 Receiver = CGF.CGM.getObjCRuntime().GetClass(CGF, ID);
563 break;
564 }
565 case ObjCMessageExpr::SuperInstance:
566 case ObjCMessageExpr::SuperClass:
567 return std::nullopt;
568 }
569
570 return CGF.EmitObjCAllocInit(Receiver, CGF.ConvertType(OME->getType()));
571 }
572
EmitObjCMessageExpr(const ObjCMessageExpr * E,ReturnValueSlot Return)573 RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E,
574 ReturnValueSlot Return) {
575 // Only the lookup mechanism and first two arguments of the method
576 // implementation vary between runtimes. We can get the receiver and
577 // arguments in generic code.
578
579 bool isDelegateInit = E->isDelegateInitCall();
580
581 const ObjCMethodDecl *method = E->getMethodDecl();
582
583 // If the method is -retain, and the receiver's being loaded from
584 // a __weak variable, peephole the entire operation to objc_loadWeakRetained.
585 if (method && E->getReceiverKind() == ObjCMessageExpr::Instance &&
586 method->getMethodFamily() == OMF_retain) {
587 if (auto lvalueExpr = findWeakLValue(E->getInstanceReceiver())) {
588 LValue lvalue = EmitLValue(lvalueExpr);
589 llvm::Value *result = EmitARCLoadWeakRetained(lvalue.getAddress(*this));
590 return AdjustObjCObjectType(*this, E->getType(), RValue::get(result));
591 }
592 }
593
594 if (std::optional<llvm::Value *> Val = tryEmitSpecializedAllocInit(*this, E))
595 return AdjustObjCObjectType(*this, E->getType(), RValue::get(*Val));
596
597 // We don't retain the receiver in delegate init calls, and this is
598 // safe because the receiver value is always loaded from 'self',
599 // which we zero out. We don't want to Block_copy block receivers,
600 // though.
601 bool retainSelf =
602 (!isDelegateInit &&
603 CGM.getLangOpts().ObjCAutoRefCount &&
604 method &&
605 method->hasAttr<NSConsumesSelfAttr>());
606
607 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
608 bool isSuperMessage = false;
609 bool isClassMessage = false;
610 ObjCInterfaceDecl *OID = nullptr;
611 // Find the receiver
612 QualType ReceiverType;
613 llvm::Value *Receiver = nullptr;
614 switch (E->getReceiverKind()) {
615 case ObjCMessageExpr::Instance:
616 ReceiverType = E->getInstanceReceiver()->getType();
617 isClassMessage = ReceiverType->isObjCClassType();
618 if (retainSelf) {
619 TryEmitResult ter = tryEmitARCRetainScalarExpr(*this,
620 E->getInstanceReceiver());
621 Receiver = ter.getPointer();
622 if (ter.getInt()) retainSelf = false;
623 } else
624 Receiver = EmitScalarExpr(E->getInstanceReceiver());
625 break;
626
627 case ObjCMessageExpr::Class: {
628 ReceiverType = E->getClassReceiver();
629 OID = ReceiverType->castAs<ObjCObjectType>()->getInterface();
630 assert(OID && "Invalid Objective-C class message send");
631 Receiver = Runtime.GetClass(*this, OID);
632 isClassMessage = true;
633 break;
634 }
635
636 case ObjCMessageExpr::SuperInstance:
637 ReceiverType = E->getSuperType();
638 Receiver = LoadObjCSelf();
639 isSuperMessage = true;
640 break;
641
642 case ObjCMessageExpr::SuperClass:
643 ReceiverType = E->getSuperType();
644 Receiver = LoadObjCSelf();
645 isSuperMessage = true;
646 isClassMessage = true;
647 break;
648 }
649
650 if (retainSelf)
651 Receiver = EmitARCRetainNonBlock(Receiver);
652
653 // In ARC, we sometimes want to "extend the lifetime"
654 // (i.e. retain+autorelease) of receivers of returns-inner-pointer
655 // messages.
656 if (getLangOpts().ObjCAutoRefCount && method &&
657 method->hasAttr<ObjCReturnsInnerPointerAttr>() &&
658 shouldExtendReceiverForInnerPointerMessage(E))
659 Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver);
660
661 QualType ResultType = method ? method->getReturnType() : E->getType();
662
663 CallArgList Args;
664 EmitCallArgs(Args, method, E->arguments(), /*AC*/AbstractCallee(method));
665
666 // For delegate init calls in ARC, do an unsafe store of null into
667 // self. This represents the call taking direct ownership of that
668 // value. We have to do this after emitting the other call
669 // arguments because they might also reference self, but we don't
670 // have to worry about any of them modifying self because that would
671 // be an undefined read and write of an object in unordered
672 // expressions.
673 if (isDelegateInit) {
674 assert(getLangOpts().ObjCAutoRefCount &&
675 "delegate init calls should only be marked in ARC");
676
677 // Do an unsafe store of null into self.
678 Address selfAddr =
679 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
680 Builder.CreateStore(getNullForVariable(selfAddr), selfAddr);
681 }
682
683 RValue result;
684 if (isSuperMessage) {
685 // super is only valid in an Objective-C method
686 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
687 bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext());
688 result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType,
689 E->getSelector(),
690 OMD->getClassInterface(),
691 isCategoryImpl,
692 Receiver,
693 isClassMessage,
694 Args,
695 method);
696 } else {
697 // Call runtime methods directly if we can.
698 result = Runtime.GeneratePossiblySpecializedMessageSend(
699 *this, Return, ResultType, E->getSelector(), Receiver, Args, OID,
700 method, isClassMessage);
701 }
702
703 // For delegate init calls in ARC, implicitly store the result of
704 // the call back into self. This takes ownership of the value.
705 if (isDelegateInit) {
706 Address selfAddr =
707 GetAddrOfLocalVar(cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl());
708 llvm::Value *newSelf = result.getScalarVal();
709
710 // The delegate return type isn't necessarily a matching type; in
711 // fact, it's quite likely to be 'id'.
712 llvm::Type *selfTy = selfAddr.getElementType();
713 newSelf = Builder.CreateBitCast(newSelf, selfTy);
714
715 Builder.CreateStore(newSelf, selfAddr);
716 }
717
718 return AdjustObjCObjectType(*this, E->getType(), result);
719 }
720
721 namespace {
722 struct FinishARCDealloc final : EHScopeStack::Cleanup {
Emit__anone2b48d8e0111::FinishARCDealloc723 void Emit(CodeGenFunction &CGF, Flags flags) override {
724 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl);
725
726 const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext());
727 const ObjCInterfaceDecl *iface = impl->getClassInterface();
728 if (!iface->getSuperClass()) return;
729
730 bool isCategory = isa<ObjCCategoryImplDecl>(impl);
731
732 // Call [super dealloc] if we have a superclass.
733 llvm::Value *self = CGF.LoadObjCSelf();
734
735 CallArgList args;
736 CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(),
737 CGF.getContext().VoidTy,
738 method->getSelector(),
739 iface,
740 isCategory,
741 self,
742 /*is class msg*/ false,
743 args,
744 method);
745 }
746 };
747 }
748
749 /// StartObjCMethod - Begin emission of an ObjCMethod. This generates
750 /// the LLVM function and sets the other context used by
751 /// CodeGenFunction.
StartObjCMethod(const ObjCMethodDecl * OMD,const ObjCContainerDecl * CD)752 void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD,
753 const ObjCContainerDecl *CD) {
754 SourceLocation StartLoc = OMD->getBeginLoc();
755 FunctionArgList args;
756 // Check if we should generate debug info for this method.
757 if (OMD->hasAttr<NoDebugAttr>())
758 DebugInfo = nullptr; // disable debug info indefinitely for this function
759
760 llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD);
761
762 const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD);
763 if (OMD->isDirectMethod()) {
764 Fn->setVisibility(llvm::Function::HiddenVisibility);
765 CGM.SetLLVMFunctionAttributes(OMD, FI, Fn, /*IsThunk=*/false);
766 CGM.SetLLVMFunctionAttributesForDefinition(OMD, Fn);
767 } else {
768 CGM.SetInternalFunctionAttributes(OMD, Fn, FI);
769 }
770
771 args.push_back(OMD->getSelfDecl());
772 if (!OMD->isDirectMethod())
773 args.push_back(OMD->getCmdDecl());
774
775 args.append(OMD->param_begin(), OMD->param_end());
776
777 CurGD = OMD;
778 CurEHLocation = OMD->getEndLoc();
779
780 StartFunction(OMD, OMD->getReturnType(), Fn, FI, args,
781 OMD->getLocation(), StartLoc);
782
783 if (OMD->isDirectMethod()) {
784 // This function is a direct call, it has to implement a nil check
785 // on entry.
786 //
787 // TODO: possibly have several entry points to elide the check
788 CGM.getObjCRuntime().GenerateDirectMethodPrologue(*this, Fn, OMD, CD);
789 }
790
791 // In ARC, certain methods get an extra cleanup.
792 if (CGM.getLangOpts().ObjCAutoRefCount &&
793 OMD->isInstanceMethod() &&
794 OMD->getSelector().isUnarySelector()) {
795 const IdentifierInfo *ident =
796 OMD->getSelector().getIdentifierInfoForSlot(0);
797 if (ident->isStr("dealloc"))
798 EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind());
799 }
800 }
801
802 static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
803 LValue lvalue, QualType type);
804
805 /// Generate an Objective-C method. An Objective-C method is a C function with
806 /// its pointer, name, and types registered in the class structure.
GenerateObjCMethod(const ObjCMethodDecl * OMD)807 void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) {
808 StartObjCMethod(OMD, OMD->getClassInterface());
809 PGO.assignRegionCounters(GlobalDecl(OMD), CurFn);
810 assert(isa<CompoundStmt>(OMD->getBody()));
811 incrementProfileCounter(OMD->getBody());
812 EmitCompoundStmtWithoutScope(*cast<CompoundStmt>(OMD->getBody()));
813 FinishFunction(OMD->getBodyRBrace());
814 }
815
816 /// emitStructGetterCall - Call the runtime function to load a property
817 /// into the return value slot.
emitStructGetterCall(CodeGenFunction & CGF,ObjCIvarDecl * ivar,bool isAtomic,bool hasStrong)818 static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar,
819 bool isAtomic, bool hasStrong) {
820 ASTContext &Context = CGF.getContext();
821
822 llvm::Value *src =
823 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
824 .getPointer(CGF);
825
826 // objc_copyStruct (ReturnValue, &structIvar,
827 // sizeof (Type of Ivar), isAtomic, false);
828 CallArgList args;
829
830 llvm::Value *dest = CGF.ReturnValue.getPointer();
831 args.add(RValue::get(dest), Context.VoidPtrTy);
832 args.add(RValue::get(src), Context.VoidPtrTy);
833
834 CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType());
835 args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType());
836 args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy);
837 args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy);
838
839 llvm::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetGetStructFunction();
840 CGCallee callee = CGCallee::forDirect(fn);
841 CGF.EmitCall(CGF.getTypes().arrangeBuiltinFunctionCall(Context.VoidTy, args),
842 callee, ReturnValueSlot(), args);
843 }
844
845 /// Determine whether the given architecture supports unaligned atomic
846 /// accesses. They don't have to be fast, just faster than a function
847 /// call and a mutex.
hasUnalignedAtomics(llvm::Triple::ArchType arch)848 static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) {
849 // FIXME: Allow unaligned atomic load/store on x86. (It is not
850 // currently supported by the backend.)
851 return false;
852 }
853
854 /// Return the maximum size that permits atomic accesses for the given
855 /// architecture.
getMaxAtomicAccessSize(CodeGenModule & CGM,llvm::Triple::ArchType arch)856 static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM,
857 llvm::Triple::ArchType arch) {
858 // ARM has 8-byte atomic accesses, but it's not clear whether we
859 // want to rely on them here.
860
861 // In the default case, just assume that any size up to a pointer is
862 // fine given adequate alignment.
863 return CharUnits::fromQuantity(CGM.PointerSizeInBytes);
864 }
865
866 namespace {
867 class PropertyImplStrategy {
868 public:
869 enum StrategyKind {
870 /// The 'native' strategy is to use the architecture's provided
871 /// reads and writes.
872 Native,
873
874 /// Use objc_setProperty and objc_getProperty.
875 GetSetProperty,
876
877 /// Use objc_setProperty for the setter, but use expression
878 /// evaluation for the getter.
879 SetPropertyAndExpressionGet,
880
881 /// Use objc_copyStruct.
882 CopyStruct,
883
884 /// The 'expression' strategy is to emit normal assignment or
885 /// lvalue-to-rvalue expressions.
886 Expression
887 };
888
getKind() const889 StrategyKind getKind() const { return StrategyKind(Kind); }
890
hasStrongMember() const891 bool hasStrongMember() const { return HasStrong; }
isAtomic() const892 bool isAtomic() const { return IsAtomic; }
isCopy() const893 bool isCopy() const { return IsCopy; }
894
getIvarSize() const895 CharUnits getIvarSize() const { return IvarSize; }
getIvarAlignment() const896 CharUnits getIvarAlignment() const { return IvarAlignment; }
897
898 PropertyImplStrategy(CodeGenModule &CGM,
899 const ObjCPropertyImplDecl *propImpl);
900
901 private:
902 unsigned Kind : 8;
903 unsigned IsAtomic : 1;
904 unsigned IsCopy : 1;
905 unsigned HasStrong : 1;
906
907 CharUnits IvarSize;
908 CharUnits IvarAlignment;
909 };
910 }
911
912 /// Pick an implementation strategy for the given property synthesis.
PropertyImplStrategy(CodeGenModule & CGM,const ObjCPropertyImplDecl * propImpl)913 PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
914 const ObjCPropertyImplDecl *propImpl) {
915 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
916 ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind();
917
918 IsCopy = (setterKind == ObjCPropertyDecl::Copy);
919 IsAtomic = prop->isAtomic();
920 HasStrong = false; // doesn't matter here.
921
922 // Evaluate the ivar's size and alignment.
923 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
924 QualType ivarType = ivar->getType();
925 auto TInfo = CGM.getContext().getTypeInfoInChars(ivarType);
926 IvarSize = TInfo.Width;
927 IvarAlignment = TInfo.Align;
928
929 // If we have a copy property, we always have to use setProperty.
930 // If the property is atomic we need to use getProperty, but in
931 // the nonatomic case we can just use expression.
932 if (IsCopy) {
933 Kind = IsAtomic ? GetSetProperty : SetPropertyAndExpressionGet;
934 return;
935 }
936
937 // Handle retain.
938 if (setterKind == ObjCPropertyDecl::Retain) {
939 // In GC-only, there's nothing special that needs to be done.
940 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) {
941 // fallthrough
942
943 // In ARC, if the property is non-atomic, use expression emission,
944 // which translates to objc_storeStrong. This isn't required, but
945 // it's slightly nicer.
946 } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) {
947 // Using standard expression emission for the setter is only
948 // acceptable if the ivar is __strong, which won't be true if
949 // the property is annotated with __attribute__((NSObject)).
950 // TODO: falling all the way back to objc_setProperty here is
951 // just laziness, though; we could still use objc_storeStrong
952 // if we hacked it right.
953 if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong)
954 Kind = Expression;
955 else
956 Kind = SetPropertyAndExpressionGet;
957 return;
958
959 // Otherwise, we need to at least use setProperty. However, if
960 // the property isn't atomic, we can use normal expression
961 // emission for the getter.
962 } else if (!IsAtomic) {
963 Kind = SetPropertyAndExpressionGet;
964 return;
965
966 // Otherwise, we have to use both setProperty and getProperty.
967 } else {
968 Kind = GetSetProperty;
969 return;
970 }
971 }
972
973 // If we're not atomic, just use expression accesses.
974 if (!IsAtomic) {
975 Kind = Expression;
976 return;
977 }
978
979 // Properties on bitfield ivars need to be emitted using expression
980 // accesses even if they're nominally atomic.
981 if (ivar->isBitField()) {
982 Kind = Expression;
983 return;
984 }
985
986 // GC-qualified or ARC-qualified ivars need to be emitted as
987 // expressions. This actually works out to being atomic anyway,
988 // except for ARC __strong, but that should trigger the above code.
989 if (ivarType.hasNonTrivialObjCLifetime() ||
990 (CGM.getLangOpts().getGC() &&
991 CGM.getContext().getObjCGCAttrKind(ivarType))) {
992 Kind = Expression;
993 return;
994 }
995
996 // Compute whether the ivar has strong members.
997 if (CGM.getLangOpts().getGC())
998 if (const RecordType *recordType = ivarType->getAs<RecordType>())
999 HasStrong = recordType->getDecl()->hasObjectMember();
1000
1001 // We can never access structs with object members with a native
1002 // access, because we need to use write barriers. This is what
1003 // objc_copyStruct is for.
1004 if (HasStrong) {
1005 Kind = CopyStruct;
1006 return;
1007 }
1008
1009 // Otherwise, this is target-dependent and based on the size and
1010 // alignment of the ivar.
1011
1012 // If the size of the ivar is not a power of two, give up. We don't
1013 // want to get into the business of doing compare-and-swaps.
1014 if (!IvarSize.isPowerOfTwo()) {
1015 Kind = CopyStruct;
1016 return;
1017 }
1018
1019 llvm::Triple::ArchType arch =
1020 CGM.getTarget().getTriple().getArch();
1021
1022 // Most architectures require memory to fit within a single cache
1023 // line, so the alignment has to be at least the size of the access.
1024 // Otherwise we have to grab a lock.
1025 if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) {
1026 Kind = CopyStruct;
1027 return;
1028 }
1029
1030 // If the ivar's size exceeds the architecture's maximum atomic
1031 // access size, we have to use CopyStruct.
1032 if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) {
1033 Kind = CopyStruct;
1034 return;
1035 }
1036
1037 // Otherwise, we can use native loads and stores.
1038 Kind = Native;
1039 }
1040
1041 /// Generate an Objective-C property getter function.
1042 ///
1043 /// The given Decl must be an ObjCImplementationDecl. \@synthesize
1044 /// is illegal within a category.
GenerateObjCGetter(ObjCImplementationDecl * IMP,const ObjCPropertyImplDecl * PID)1045 void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP,
1046 const ObjCPropertyImplDecl *PID) {
1047 llvm::Constant *AtomicHelperFn =
1048 CodeGenFunction(CGM).GenerateObjCAtomicGetterCopyHelperFunction(PID);
1049 ObjCMethodDecl *OMD = PID->getGetterMethodDecl();
1050 assert(OMD && "Invalid call to generate getter (empty method)");
1051 StartObjCMethod(OMD, IMP->getClassInterface());
1052
1053 generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn);
1054
1055 FinishFunction(OMD->getEndLoc());
1056 }
1057
hasTrivialGetExpr(const ObjCPropertyImplDecl * propImpl)1058 static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) {
1059 const Expr *getter = propImpl->getGetterCXXConstructor();
1060 if (!getter) return true;
1061
1062 // Sema only makes only of these when the ivar has a C++ class type,
1063 // so the form is pretty constrained.
1064
1065 // If the property has a reference type, we might just be binding a
1066 // reference, in which case the result will be a gl-value. We should
1067 // treat this as a non-trivial operation.
1068 if (getter->isGLValue())
1069 return false;
1070
1071 // If we selected a trivial copy-constructor, we're okay.
1072 if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter))
1073 return (construct->getConstructor()->isTrivial());
1074
1075 // The constructor might require cleanups (in which case it's never
1076 // trivial).
1077 assert(isa<ExprWithCleanups>(getter));
1078 return false;
1079 }
1080
1081 /// emitCPPObjectAtomicGetterCall - Call the runtime function to
1082 /// copy the ivar into the resturn slot.
emitCPPObjectAtomicGetterCall(CodeGenFunction & CGF,llvm::Value * returnAddr,ObjCIvarDecl * ivar,llvm::Constant * AtomicHelperFn)1083 static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF,
1084 llvm::Value *returnAddr,
1085 ObjCIvarDecl *ivar,
1086 llvm::Constant *AtomicHelperFn) {
1087 // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar,
1088 // AtomicHelperFn);
1089 CallArgList args;
1090
1091 // The 1st argument is the return Slot.
1092 args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy);
1093
1094 // The 2nd argument is the address of the ivar.
1095 llvm::Value *ivarAddr =
1096 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1097 .getPointer(CGF);
1098 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1099
1100 // Third argument is the helper function.
1101 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
1102
1103 llvm::FunctionCallee copyCppAtomicObjectFn =
1104 CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction();
1105 CGCallee callee = CGCallee::forDirect(copyCppAtomicObjectFn);
1106 CGF.EmitCall(
1107 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1108 callee, ReturnValueSlot(), args);
1109 }
1110
1111 // emitCmdValueForGetterSetterBody - Handle emitting the load necessary for
1112 // the `_cmd` selector argument for getter/setter bodies. For direct methods,
1113 // this returns an undefined/poison value; this matches behavior prior to `_cmd`
1114 // being removed from the direct method ABI as the getter/setter caller would
1115 // never load one. For non-direct methods, this emits a load of the implicit
1116 // `_cmd` storage.
emitCmdValueForGetterSetterBody(CodeGenFunction & CGF,ObjCMethodDecl * MD)1117 static llvm::Value *emitCmdValueForGetterSetterBody(CodeGenFunction &CGF,
1118 ObjCMethodDecl *MD) {
1119 if (MD->isDirectMethod()) {
1120 // Direct methods do not have a `_cmd` argument. Emit an undefined/poison
1121 // value. This will be passed to objc_getProperty/objc_setProperty, which
1122 // has not appeared bothered by the `_cmd` argument being undefined before.
1123 llvm::Type *selType = CGF.ConvertType(CGF.getContext().getObjCSelType());
1124 return llvm::PoisonValue::get(selType);
1125 }
1126
1127 return CGF.Builder.CreateLoad(CGF.GetAddrOfLocalVar(MD->getCmdDecl()), "cmd");
1128 }
1129
1130 void
generateObjCGetterBody(const ObjCImplementationDecl * classImpl,const ObjCPropertyImplDecl * propImpl,const ObjCMethodDecl * GetterMethodDecl,llvm::Constant * AtomicHelperFn)1131 CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl,
1132 const ObjCPropertyImplDecl *propImpl,
1133 const ObjCMethodDecl *GetterMethodDecl,
1134 llvm::Constant *AtomicHelperFn) {
1135
1136 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1137
1138 if (ivar->getType().isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
1139 if (!AtomicHelperFn) {
1140 LValue Src =
1141 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1142 LValue Dst = MakeAddrLValue(ReturnValue, ivar->getType());
1143 callCStructCopyConstructor(Dst, Src);
1144 } else {
1145 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1146 emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(), ivar,
1147 AtomicHelperFn);
1148 }
1149 return;
1150 }
1151
1152 // If there's a non-trivial 'get' expression, we just have to emit that.
1153 if (!hasTrivialGetExpr(propImpl)) {
1154 if (!AtomicHelperFn) {
1155 auto *ret = ReturnStmt::Create(getContext(), SourceLocation(),
1156 propImpl->getGetterCXXConstructor(),
1157 /* NRVOCandidate=*/nullptr);
1158 EmitReturnStmt(*ret);
1159 }
1160 else {
1161 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1162 emitCPPObjectAtomicGetterCall(*this, ReturnValue.getPointer(),
1163 ivar, AtomicHelperFn);
1164 }
1165 return;
1166 }
1167
1168 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl();
1169 QualType propType = prop->getType();
1170 ObjCMethodDecl *getterMethod = propImpl->getGetterMethodDecl();
1171
1172 // Pick an implementation strategy.
1173 PropertyImplStrategy strategy(CGM, propImpl);
1174 switch (strategy.getKind()) {
1175 case PropertyImplStrategy::Native: {
1176 // We don't need to do anything for a zero-size struct.
1177 if (strategy.getIvarSize().isZero())
1178 return;
1179
1180 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1181
1182 // Currently, all atomic accesses have to be through integer
1183 // types, so there's no point in trying to pick a prettier type.
1184 uint64_t ivarSize = getContext().toBits(strategy.getIvarSize());
1185 llvm::Type *bitcastType = llvm::Type::getIntNTy(getLLVMContext(), ivarSize);
1186
1187 // Perform an atomic load. This does not impose ordering constraints.
1188 Address ivarAddr = LV.getAddress(*this);
1189 ivarAddr = ivarAddr.withElementType(bitcastType);
1190 llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load");
1191 load->setAtomic(llvm::AtomicOrdering::Unordered);
1192
1193 // Store that value into the return address. Doing this with a
1194 // bitcast is likely to produce some pretty ugly IR, but it's not
1195 // the *most* terrible thing in the world.
1196 llvm::Type *retTy = ConvertType(getterMethod->getReturnType());
1197 uint64_t retTySize = CGM.getDataLayout().getTypeSizeInBits(retTy);
1198 llvm::Value *ivarVal = load;
1199 if (ivarSize > retTySize) {
1200 bitcastType = llvm::Type::getIntNTy(getLLVMContext(), retTySize);
1201 ivarVal = Builder.CreateTrunc(load, bitcastType);
1202 }
1203 Builder.CreateStore(ivarVal, ReturnValue.withElementType(bitcastType));
1204
1205 // Make sure we don't do an autorelease.
1206 AutoreleaseResult = false;
1207 return;
1208 }
1209
1210 case PropertyImplStrategy::GetSetProperty: {
1211 llvm::FunctionCallee getPropertyFn =
1212 CGM.getObjCRuntime().GetPropertyGetFunction();
1213 if (!getPropertyFn) {
1214 CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy");
1215 return;
1216 }
1217 CGCallee callee = CGCallee::forDirect(getPropertyFn);
1218
1219 // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true).
1220 // FIXME: Can't this be simpler? This might even be worse than the
1221 // corresponding gcc code.
1222 llvm::Value *cmd = emitCmdValueForGetterSetterBody(*this, getterMethod);
1223 llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
1224 llvm::Value *ivarOffset =
1225 EmitIvarOffsetAsPointerDiff(classImpl->getClassInterface(), ivar);
1226
1227 CallArgList args;
1228 args.add(RValue::get(self), getContext().getObjCIdType());
1229 args.add(RValue::get(cmd), getContext().getObjCSelType());
1230 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1231 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
1232 getContext().BoolTy);
1233
1234 // FIXME: We shouldn't need to get the function info here, the
1235 // runtime already should have computed it to build the function.
1236 llvm::CallBase *CallInstruction;
1237 RValue RV = EmitCall(getTypes().arrangeBuiltinFunctionCall(
1238 getContext().getObjCIdType(), args),
1239 callee, ReturnValueSlot(), args, &CallInstruction);
1240 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(CallInstruction))
1241 call->setTailCall();
1242
1243 // We need to fix the type here. Ivars with copy & retain are
1244 // always objects so we don't need to worry about complex or
1245 // aggregates.
1246 RV = RValue::get(Builder.CreateBitCast(
1247 RV.getScalarVal(),
1248 getTypes().ConvertType(getterMethod->getReturnType())));
1249
1250 EmitReturnOfRValue(RV, propType);
1251
1252 // objc_getProperty does an autorelease, so we should suppress ours.
1253 AutoreleaseResult = false;
1254
1255 return;
1256 }
1257
1258 case PropertyImplStrategy::CopyStruct:
1259 emitStructGetterCall(*this, ivar, strategy.isAtomic(),
1260 strategy.hasStrongMember());
1261 return;
1262
1263 case PropertyImplStrategy::Expression:
1264 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1265 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0);
1266
1267 QualType ivarType = ivar->getType();
1268 switch (getEvaluationKind(ivarType)) {
1269 case TEK_Complex: {
1270 ComplexPairTy pair = EmitLoadOfComplex(LV, SourceLocation());
1271 EmitStoreOfComplex(pair, MakeAddrLValue(ReturnValue, ivarType),
1272 /*init*/ true);
1273 return;
1274 }
1275 case TEK_Aggregate: {
1276 // The return value slot is guaranteed to not be aliased, but
1277 // that's not necessarily the same as "on the stack", so
1278 // we still potentially need objc_memmove_collectable.
1279 EmitAggregateCopy(/* Dest= */ MakeAddrLValue(ReturnValue, ivarType),
1280 /* Src= */ LV, ivarType, getOverlapForReturnValue());
1281 return;
1282 }
1283 case TEK_Scalar: {
1284 llvm::Value *value;
1285 if (propType->isReferenceType()) {
1286 value = LV.getAddress(*this).getPointer();
1287 } else {
1288 // We want to load and autoreleaseReturnValue ARC __weak ivars.
1289 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) {
1290 if (getLangOpts().ObjCAutoRefCount) {
1291 value = emitARCRetainLoadOfScalar(*this, LV, ivarType);
1292 } else {
1293 value = EmitARCLoadWeak(LV.getAddress(*this));
1294 }
1295
1296 // Otherwise we want to do a simple load, suppressing the
1297 // final autorelease.
1298 } else {
1299 value = EmitLoadOfLValue(LV, SourceLocation()).getScalarVal();
1300 AutoreleaseResult = false;
1301 }
1302
1303 value = Builder.CreateBitCast(
1304 value, ConvertType(GetterMethodDecl->getReturnType()));
1305 }
1306
1307 EmitReturnOfRValue(RValue::get(value), propType);
1308 return;
1309 }
1310 }
1311 llvm_unreachable("bad evaluation kind");
1312 }
1313
1314 }
1315 llvm_unreachable("bad @property implementation strategy!");
1316 }
1317
1318 /// emitStructSetterCall - Call the runtime function to store the value
1319 /// from the first formal parameter into the given ivar.
emitStructSetterCall(CodeGenFunction & CGF,ObjCMethodDecl * OMD,ObjCIvarDecl * ivar)1320 static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD,
1321 ObjCIvarDecl *ivar) {
1322 // objc_copyStruct (&structIvar, &Arg,
1323 // sizeof (struct something), true, false);
1324 CallArgList args;
1325
1326 // The first argument is the address of the ivar.
1327 llvm::Value *ivarAddr =
1328 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1329 .getPointer(CGF);
1330 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy);
1331 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1332
1333 // The second argument is the address of the parameter variable.
1334 ParmVarDecl *argVar = *OMD->param_begin();
1335 DeclRefExpr argRef(CGF.getContext(), argVar, false,
1336 argVar->getType().getNonReferenceType(), VK_LValue,
1337 SourceLocation());
1338 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
1339 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1340
1341 // The third argument is the sizeof the type.
1342 llvm::Value *size =
1343 CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType()));
1344 args.add(RValue::get(size), CGF.getContext().getSizeType());
1345
1346 // The fourth argument is the 'isAtomic' flag.
1347 args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy);
1348
1349 // The fifth argument is the 'hasStrong' flag.
1350 // FIXME: should this really always be false?
1351 args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy);
1352
1353 llvm::FunctionCallee fn = CGF.CGM.getObjCRuntime().GetSetStructFunction();
1354 CGCallee callee = CGCallee::forDirect(fn);
1355 CGF.EmitCall(
1356 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1357 callee, ReturnValueSlot(), args);
1358 }
1359
1360 /// emitCPPObjectAtomicSetterCall - Call the runtime function to store
1361 /// the value from the first formal parameter into the given ivar, using
1362 /// the Cpp API for atomic Cpp objects with non-trivial copy assignment.
emitCPPObjectAtomicSetterCall(CodeGenFunction & CGF,ObjCMethodDecl * OMD,ObjCIvarDecl * ivar,llvm::Constant * AtomicHelperFn)1363 static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF,
1364 ObjCMethodDecl *OMD,
1365 ObjCIvarDecl *ivar,
1366 llvm::Constant *AtomicHelperFn) {
1367 // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg,
1368 // AtomicHelperFn);
1369 CallArgList args;
1370
1371 // The first argument is the address of the ivar.
1372 llvm::Value *ivarAddr =
1373 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), ivar, 0)
1374 .getPointer(CGF);
1375 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy);
1376
1377 // The second argument is the address of the parameter variable.
1378 ParmVarDecl *argVar = *OMD->param_begin();
1379 DeclRefExpr argRef(CGF.getContext(), argVar, false,
1380 argVar->getType().getNonReferenceType(), VK_LValue,
1381 SourceLocation());
1382 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getPointer(CGF);
1383 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy);
1384
1385 // Third argument is the helper function.
1386 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy);
1387
1388 llvm::FunctionCallee fn =
1389 CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction();
1390 CGCallee callee = CGCallee::forDirect(fn);
1391 CGF.EmitCall(
1392 CGF.getTypes().arrangeBuiltinFunctionCall(CGF.getContext().VoidTy, args),
1393 callee, ReturnValueSlot(), args);
1394 }
1395
1396
hasTrivialSetExpr(const ObjCPropertyImplDecl * PID)1397 static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) {
1398 Expr *setter = PID->getSetterCXXAssignment();
1399 if (!setter) return true;
1400
1401 // Sema only makes only of these when the ivar has a C++ class type,
1402 // so the form is pretty constrained.
1403
1404 // An operator call is trivial if the function it calls is trivial.
1405 // This also implies that there's nothing non-trivial going on with
1406 // the arguments, because operator= can only be trivial if it's a
1407 // synthesized assignment operator and therefore both parameters are
1408 // references.
1409 if (CallExpr *call = dyn_cast<CallExpr>(setter)) {
1410 if (const FunctionDecl *callee
1411 = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl()))
1412 if (callee->isTrivial())
1413 return true;
1414 return false;
1415 }
1416
1417 assert(isa<ExprWithCleanups>(setter));
1418 return false;
1419 }
1420
UseOptimizedSetter(CodeGenModule & CGM)1421 static bool UseOptimizedSetter(CodeGenModule &CGM) {
1422 if (CGM.getLangOpts().getGC() != LangOptions::NonGC)
1423 return false;
1424 return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter();
1425 }
1426
1427 void
generateObjCSetterBody(const ObjCImplementationDecl * classImpl,const ObjCPropertyImplDecl * propImpl,llvm::Constant * AtomicHelperFn)1428 CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl,
1429 const ObjCPropertyImplDecl *propImpl,
1430 llvm::Constant *AtomicHelperFn) {
1431 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl();
1432 ObjCMethodDecl *setterMethod = propImpl->getSetterMethodDecl();
1433
1434 if (ivar->getType().isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
1435 ParmVarDecl *PVD = *setterMethod->param_begin();
1436 if (!AtomicHelperFn) {
1437 // Call the move assignment operator instead of calling the copy
1438 // assignment operator and destructor.
1439 LValue Dst = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar,
1440 /*quals*/ 0);
1441 LValue Src = MakeAddrLValue(GetAddrOfLocalVar(PVD), ivar->getType());
1442 callCStructMoveAssignmentOperator(Dst, Src);
1443 } else {
1444 // If atomic, assignment is called via a locking api.
1445 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar, AtomicHelperFn);
1446 }
1447 // Decativate the destructor for the setter parameter.
1448 DeactivateCleanupBlock(CalleeDestructedParamCleanups[PVD], AllocaInsertPt);
1449 return;
1450 }
1451
1452 // Just use the setter expression if Sema gave us one and it's
1453 // non-trivial.
1454 if (!hasTrivialSetExpr(propImpl)) {
1455 if (!AtomicHelperFn)
1456 // If non-atomic, assignment is called directly.
1457 EmitStmt(propImpl->getSetterCXXAssignment());
1458 else
1459 // If atomic, assignment is called via a locking api.
1460 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar,
1461 AtomicHelperFn);
1462 return;
1463 }
1464
1465 PropertyImplStrategy strategy(CGM, propImpl);
1466 switch (strategy.getKind()) {
1467 case PropertyImplStrategy::Native: {
1468 // We don't need to do anything for a zero-size struct.
1469 if (strategy.getIvarSize().isZero())
1470 return;
1471
1472 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1473
1474 LValue ivarLValue =
1475 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0);
1476 Address ivarAddr = ivarLValue.getAddress(*this);
1477
1478 // Currently, all atomic accesses have to be through integer
1479 // types, so there's no point in trying to pick a prettier type.
1480 llvm::Type *castType = llvm::Type::getIntNTy(
1481 getLLVMContext(), getContext().toBits(strategy.getIvarSize()));
1482
1483 // Cast both arguments to the chosen operation type.
1484 argAddr = argAddr.withElementType(castType);
1485 ivarAddr = ivarAddr.withElementType(castType);
1486
1487 llvm::Value *load = Builder.CreateLoad(argAddr);
1488
1489 // Perform an atomic store. There are no memory ordering requirements.
1490 llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr);
1491 store->setAtomic(llvm::AtomicOrdering::Unordered);
1492 return;
1493 }
1494
1495 case PropertyImplStrategy::GetSetProperty:
1496 case PropertyImplStrategy::SetPropertyAndExpressionGet: {
1497
1498 llvm::FunctionCallee setOptimizedPropertyFn = nullptr;
1499 llvm::FunctionCallee setPropertyFn = nullptr;
1500 if (UseOptimizedSetter(CGM)) {
1501 // 10.8 and iOS 6.0 code and GC is off
1502 setOptimizedPropertyFn =
1503 CGM.getObjCRuntime().GetOptimizedPropertySetFunction(
1504 strategy.isAtomic(), strategy.isCopy());
1505 if (!setOptimizedPropertyFn) {
1506 CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI");
1507 return;
1508 }
1509 }
1510 else {
1511 setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction();
1512 if (!setPropertyFn) {
1513 CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy");
1514 return;
1515 }
1516 }
1517
1518 // Emit objc_setProperty((id) self, _cmd, offset, arg,
1519 // <is-atomic>, <is-copy>).
1520 llvm::Value *cmd = emitCmdValueForGetterSetterBody(*this, setterMethod);
1521 llvm::Value *self =
1522 Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy);
1523 llvm::Value *ivarOffset =
1524 EmitIvarOffsetAsPointerDiff(classImpl->getClassInterface(), ivar);
1525 Address argAddr = GetAddrOfLocalVar(*setterMethod->param_begin());
1526 llvm::Value *arg = Builder.CreateLoad(argAddr, "arg");
1527 arg = Builder.CreateBitCast(arg, VoidPtrTy);
1528
1529 CallArgList args;
1530 args.add(RValue::get(self), getContext().getObjCIdType());
1531 args.add(RValue::get(cmd), getContext().getObjCSelType());
1532 if (setOptimizedPropertyFn) {
1533 args.add(RValue::get(arg), getContext().getObjCIdType());
1534 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1535 CGCallee callee = CGCallee::forDirect(setOptimizedPropertyFn);
1536 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1537 callee, ReturnValueSlot(), args);
1538 } else {
1539 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType());
1540 args.add(RValue::get(arg), getContext().getObjCIdType());
1541 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())),
1542 getContext().BoolTy);
1543 args.add(RValue::get(Builder.getInt1(strategy.isCopy())),
1544 getContext().BoolTy);
1545 // FIXME: We shouldn't need to get the function info here, the runtime
1546 // already should have computed it to build the function.
1547 CGCallee callee = CGCallee::forDirect(setPropertyFn);
1548 EmitCall(getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, args),
1549 callee, ReturnValueSlot(), args);
1550 }
1551
1552 return;
1553 }
1554
1555 case PropertyImplStrategy::CopyStruct:
1556 emitStructSetterCall(*this, setterMethod, ivar);
1557 return;
1558
1559 case PropertyImplStrategy::Expression:
1560 break;
1561 }
1562
1563 // Otherwise, fake up some ASTs and emit a normal assignment.
1564 ValueDecl *selfDecl = setterMethod->getSelfDecl();
1565 DeclRefExpr self(getContext(), selfDecl, false, selfDecl->getType(),
1566 VK_LValue, SourceLocation());
1567 ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack, selfDecl->getType(),
1568 CK_LValueToRValue, &self, VK_PRValue,
1569 FPOptionsOverride());
1570 ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(),
1571 SourceLocation(), SourceLocation(),
1572 &selfLoad, true, true);
1573
1574 ParmVarDecl *argDecl = *setterMethod->param_begin();
1575 QualType argType = argDecl->getType().getNonReferenceType();
1576 DeclRefExpr arg(getContext(), argDecl, false, argType, VK_LValue,
1577 SourceLocation());
1578 ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack,
1579 argType.getUnqualifiedType(), CK_LValueToRValue,
1580 &arg, VK_PRValue, FPOptionsOverride());
1581
1582 // The property type can differ from the ivar type in some situations with
1583 // Objective-C pointer types, we can always bit cast the RHS in these cases.
1584 // The following absurdity is just to ensure well-formed IR.
1585 CastKind argCK = CK_NoOp;
1586 if (ivarRef.getType()->isObjCObjectPointerType()) {
1587 if (argLoad.getType()->isObjCObjectPointerType())
1588 argCK = CK_BitCast;
1589 else if (argLoad.getType()->isBlockPointerType())
1590 argCK = CK_BlockPointerToObjCPointerCast;
1591 else
1592 argCK = CK_CPointerToObjCPointerCast;
1593 } else if (ivarRef.getType()->isBlockPointerType()) {
1594 if (argLoad.getType()->isBlockPointerType())
1595 argCK = CK_BitCast;
1596 else
1597 argCK = CK_AnyPointerToBlockPointerCast;
1598 } else if (ivarRef.getType()->isPointerType()) {
1599 argCK = CK_BitCast;
1600 } else if (argLoad.getType()->isAtomicType() &&
1601 !ivarRef.getType()->isAtomicType()) {
1602 argCK = CK_AtomicToNonAtomic;
1603 } else if (!argLoad.getType()->isAtomicType() &&
1604 ivarRef.getType()->isAtomicType()) {
1605 argCK = CK_NonAtomicToAtomic;
1606 }
1607 ImplicitCastExpr argCast(ImplicitCastExpr::OnStack, ivarRef.getType(), argCK,
1608 &argLoad, VK_PRValue, FPOptionsOverride());
1609 Expr *finalArg = &argLoad;
1610 if (!getContext().hasSameUnqualifiedType(ivarRef.getType(),
1611 argLoad.getType()))
1612 finalArg = &argCast;
1613
1614 BinaryOperator *assign = BinaryOperator::Create(
1615 getContext(), &ivarRef, finalArg, BO_Assign, ivarRef.getType(),
1616 VK_PRValue, OK_Ordinary, SourceLocation(), FPOptionsOverride());
1617 EmitStmt(assign);
1618 }
1619
1620 /// Generate an Objective-C property setter function.
1621 ///
1622 /// The given Decl must be an ObjCImplementationDecl. \@synthesize
1623 /// is illegal within a category.
GenerateObjCSetter(ObjCImplementationDecl * IMP,const ObjCPropertyImplDecl * PID)1624 void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP,
1625 const ObjCPropertyImplDecl *PID) {
1626 llvm::Constant *AtomicHelperFn =
1627 CodeGenFunction(CGM).GenerateObjCAtomicSetterCopyHelperFunction(PID);
1628 ObjCMethodDecl *OMD = PID->getSetterMethodDecl();
1629 assert(OMD && "Invalid call to generate setter (empty method)");
1630 StartObjCMethod(OMD, IMP->getClassInterface());
1631
1632 generateObjCSetterBody(IMP, PID, AtomicHelperFn);
1633
1634 FinishFunction(OMD->getEndLoc());
1635 }
1636
1637 namespace {
1638 struct DestroyIvar final : EHScopeStack::Cleanup {
1639 private:
1640 llvm::Value *addr;
1641 const ObjCIvarDecl *ivar;
1642 CodeGenFunction::Destroyer *destroyer;
1643 bool useEHCleanupForArray;
1644 public:
DestroyIvar__anone2b48d8e0311::DestroyIvar1645 DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar,
1646 CodeGenFunction::Destroyer *destroyer,
1647 bool useEHCleanupForArray)
1648 : addr(addr), ivar(ivar), destroyer(destroyer),
1649 useEHCleanupForArray(useEHCleanupForArray) {}
1650
Emit__anone2b48d8e0311::DestroyIvar1651 void Emit(CodeGenFunction &CGF, Flags flags) override {
1652 LValue lvalue
1653 = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0);
1654 CGF.emitDestroy(lvalue.getAddress(CGF), ivar->getType(), destroyer,
1655 flags.isForNormalCleanup() && useEHCleanupForArray);
1656 }
1657 };
1658 }
1659
1660 /// Like CodeGenFunction::destroyARCStrong, but do it with a call.
destroyARCStrongWithStore(CodeGenFunction & CGF,Address addr,QualType type)1661 static void destroyARCStrongWithStore(CodeGenFunction &CGF,
1662 Address addr,
1663 QualType type) {
1664 llvm::Value *null = getNullForVariable(addr);
1665 CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
1666 }
1667
emitCXXDestructMethod(CodeGenFunction & CGF,ObjCImplementationDecl * impl)1668 static void emitCXXDestructMethod(CodeGenFunction &CGF,
1669 ObjCImplementationDecl *impl) {
1670 CodeGenFunction::RunCleanupsScope scope(CGF);
1671
1672 llvm::Value *self = CGF.LoadObjCSelf();
1673
1674 const ObjCInterfaceDecl *iface = impl->getClassInterface();
1675 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin();
1676 ivar; ivar = ivar->getNextIvar()) {
1677 QualType type = ivar->getType();
1678
1679 // Check whether the ivar is a destructible type.
1680 QualType::DestructionKind dtorKind = type.isDestructedType();
1681 if (!dtorKind) continue;
1682
1683 CodeGenFunction::Destroyer *destroyer = nullptr;
1684
1685 // Use a call to objc_storeStrong to destroy strong ivars, for the
1686 // general benefit of the tools.
1687 if (dtorKind == QualType::DK_objc_strong_lifetime) {
1688 destroyer = destroyARCStrongWithStore;
1689
1690 // Otherwise use the default for the destruction kind.
1691 } else {
1692 destroyer = CGF.getDestroyer(dtorKind);
1693 }
1694
1695 CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind);
1696
1697 CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer,
1698 cleanupKind & EHCleanup);
1699 }
1700
1701 assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?");
1702 }
1703
GenerateObjCCtorDtorMethod(ObjCImplementationDecl * IMP,ObjCMethodDecl * MD,bool ctor)1704 void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP,
1705 ObjCMethodDecl *MD,
1706 bool ctor) {
1707 MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface());
1708 StartObjCMethod(MD, IMP->getClassInterface());
1709
1710 // Emit .cxx_construct.
1711 if (ctor) {
1712 // Suppress the final autorelease in ARC.
1713 AutoreleaseResult = false;
1714
1715 for (const auto *IvarInit : IMP->inits()) {
1716 FieldDecl *Field = IvarInit->getAnyMember();
1717 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field);
1718 LValue LV = EmitLValueForIvar(TypeOfSelfObject(),
1719 LoadObjCSelf(), Ivar, 0);
1720 EmitAggExpr(IvarInit->getInit(),
1721 AggValueSlot::forLValue(LV, *this, AggValueSlot::IsDestructed,
1722 AggValueSlot::DoesNotNeedGCBarriers,
1723 AggValueSlot::IsNotAliased,
1724 AggValueSlot::DoesNotOverlap));
1725 }
1726 // constructor returns 'self'.
1727 CodeGenTypes &Types = CGM.getTypes();
1728 QualType IdTy(CGM.getContext().getObjCIdType());
1729 llvm::Value *SelfAsId =
1730 Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy));
1731 EmitReturnOfRValue(RValue::get(SelfAsId), IdTy);
1732
1733 // Emit .cxx_destruct.
1734 } else {
1735 emitCXXDestructMethod(*this, IMP);
1736 }
1737 FinishFunction();
1738 }
1739
LoadObjCSelf()1740 llvm::Value *CodeGenFunction::LoadObjCSelf() {
1741 VarDecl *Self = cast<ObjCMethodDecl>(CurFuncDecl)->getSelfDecl();
1742 DeclRefExpr DRE(getContext(), Self,
1743 /*is enclosing local*/ (CurFuncDecl != CurCodeDecl),
1744 Self->getType(), VK_LValue, SourceLocation());
1745 return EmitLoadOfScalar(EmitDeclRefLValue(&DRE), SourceLocation());
1746 }
1747
TypeOfSelfObject()1748 QualType CodeGenFunction::TypeOfSelfObject() {
1749 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl);
1750 ImplicitParamDecl *selfDecl = OMD->getSelfDecl();
1751 const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>(
1752 getContext().getCanonicalType(selfDecl->getType()));
1753 return PTy->getPointeeType();
1754 }
1755
EmitObjCForCollectionStmt(const ObjCForCollectionStmt & S)1756 void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){
1757 llvm::FunctionCallee EnumerationMutationFnPtr =
1758 CGM.getObjCRuntime().EnumerationMutationFunction();
1759 if (!EnumerationMutationFnPtr) {
1760 CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime");
1761 return;
1762 }
1763 CGCallee EnumerationMutationFn =
1764 CGCallee::forDirect(EnumerationMutationFnPtr);
1765
1766 CGDebugInfo *DI = getDebugInfo();
1767 if (DI)
1768 DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin());
1769
1770 RunCleanupsScope ForScope(*this);
1771
1772 // The local variable comes into scope immediately.
1773 AutoVarEmission variable = AutoVarEmission::invalid();
1774 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement()))
1775 variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl()));
1776
1777 JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end");
1778
1779 // Fast enumeration state.
1780 QualType StateTy = CGM.getObjCFastEnumerationStateType();
1781 Address StatePtr = CreateMemTemp(StateTy, "state.ptr");
1782 EmitNullInitialization(StatePtr, StateTy);
1783
1784 // Number of elements in the items array.
1785 static const unsigned NumItems = 16;
1786
1787 // Fetch the countByEnumeratingWithState:objects:count: selector.
1788 IdentifierInfo *II[] = {
1789 &CGM.getContext().Idents.get("countByEnumeratingWithState"),
1790 &CGM.getContext().Idents.get("objects"),
1791 &CGM.getContext().Idents.get("count")
1792 };
1793 Selector FastEnumSel =
1794 CGM.getContext().Selectors.getSelector(std::size(II), &II[0]);
1795
1796 QualType ItemsTy = getContext().getConstantArrayType(
1797 getContext().getObjCIdType(), llvm::APInt(32, NumItems), nullptr,
1798 ArraySizeModifier::Normal, 0);
1799 Address ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr");
1800
1801 // Emit the collection pointer. In ARC, we do a retain.
1802 llvm::Value *Collection;
1803 if (getLangOpts().ObjCAutoRefCount) {
1804 Collection = EmitARCRetainScalarExpr(S.getCollection());
1805
1806 // Enter a cleanup to do the release.
1807 EmitObjCConsumeObject(S.getCollection()->getType(), Collection);
1808 } else {
1809 Collection = EmitScalarExpr(S.getCollection());
1810 }
1811
1812 // The 'continue' label needs to appear within the cleanup for the
1813 // collection object.
1814 JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next");
1815
1816 // Send it our message:
1817 CallArgList Args;
1818
1819 // The first argument is a temporary of the enumeration-state type.
1820 Args.add(RValue::get(StatePtr.getPointer()),
1821 getContext().getPointerType(StateTy));
1822
1823 // The second argument is a temporary array with space for NumItems
1824 // pointers. We'll actually be loading elements from the array
1825 // pointer written into the control state; this buffer is so that
1826 // collections that *aren't* backed by arrays can still queue up
1827 // batches of elements.
1828 Args.add(RValue::get(ItemsPtr.getPointer()),
1829 getContext().getPointerType(ItemsTy));
1830
1831 // The third argument is the capacity of that temporary array.
1832 llvm::Type *NSUIntegerTy = ConvertType(getContext().getNSUIntegerType());
1833 llvm::Constant *Count = llvm::ConstantInt::get(NSUIntegerTy, NumItems);
1834 Args.add(RValue::get(Count), getContext().getNSUIntegerType());
1835
1836 // Start the enumeration.
1837 RValue CountRV =
1838 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
1839 getContext().getNSUIntegerType(),
1840 FastEnumSel, Collection, Args);
1841
1842 // The initial number of objects that were returned in the buffer.
1843 llvm::Value *initialBufferLimit = CountRV.getScalarVal();
1844
1845 llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty");
1846 llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit");
1847
1848 llvm::Value *zero = llvm::Constant::getNullValue(NSUIntegerTy);
1849
1850 // If the limit pointer was zero to begin with, the collection is
1851 // empty; skip all this. Set the branch weight assuming this has the same
1852 // probability of exiting the loop as any other loop exit.
1853 uint64_t EntryCount = getCurrentProfileCount();
1854 Builder.CreateCondBr(
1855 Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), EmptyBB,
1856 LoopInitBB,
1857 createProfileWeights(EntryCount, getProfileCount(S.getBody())));
1858
1859 // Otherwise, initialize the loop.
1860 EmitBlock(LoopInitBB);
1861
1862 // Save the initial mutations value. This is the value at an
1863 // address that was written into the state object by
1864 // countByEnumeratingWithState:objects:count:.
1865 Address StateMutationsPtrPtr =
1866 Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr");
1867 llvm::Value *StateMutationsPtr
1868 = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1869
1870 llvm::Type *UnsignedLongTy = ConvertType(getContext().UnsignedLongTy);
1871 llvm::Value *initialMutations =
1872 Builder.CreateAlignedLoad(UnsignedLongTy, StateMutationsPtr,
1873 getPointerAlign(), "forcoll.initial-mutations");
1874
1875 // Start looping. This is the point we return to whenever we have a
1876 // fresh, non-empty batch of objects.
1877 llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody");
1878 EmitBlock(LoopBodyBB);
1879
1880 // The current index into the buffer.
1881 llvm::PHINode *index = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.index");
1882 index->addIncoming(zero, LoopInitBB);
1883
1884 // The current buffer size.
1885 llvm::PHINode *count = Builder.CreatePHI(NSUIntegerTy, 3, "forcoll.count");
1886 count->addIncoming(initialBufferLimit, LoopInitBB);
1887
1888 incrementProfileCounter(&S);
1889
1890 // Check whether the mutations value has changed from where it was
1891 // at start. StateMutationsPtr should actually be invariant between
1892 // refreshes.
1893 StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr");
1894 llvm::Value *currentMutations
1895 = Builder.CreateAlignedLoad(UnsignedLongTy, StateMutationsPtr,
1896 getPointerAlign(), "statemutations");
1897
1898 llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated");
1899 llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated");
1900
1901 Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations),
1902 WasNotMutatedBB, WasMutatedBB);
1903
1904 // If so, call the enumeration-mutation function.
1905 EmitBlock(WasMutatedBB);
1906 llvm::Type *ObjCIdType = ConvertType(getContext().getObjCIdType());
1907 llvm::Value *V =
1908 Builder.CreateBitCast(Collection, ObjCIdType);
1909 CallArgList Args2;
1910 Args2.add(RValue::get(V), getContext().getObjCIdType());
1911 // FIXME: We shouldn't need to get the function info here, the runtime already
1912 // should have computed it to build the function.
1913 EmitCall(
1914 CGM.getTypes().arrangeBuiltinFunctionCall(getContext().VoidTy, Args2),
1915 EnumerationMutationFn, ReturnValueSlot(), Args2);
1916
1917 // Otherwise, or if the mutation function returns, just continue.
1918 EmitBlock(WasNotMutatedBB);
1919
1920 // Initialize the element variable.
1921 RunCleanupsScope elementVariableScope(*this);
1922 bool elementIsVariable;
1923 LValue elementLValue;
1924 QualType elementType;
1925 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) {
1926 // Initialize the variable, in case it's a __block variable or something.
1927 EmitAutoVarInit(variable);
1928
1929 const VarDecl *D = cast<VarDecl>(SD->getSingleDecl());
1930 DeclRefExpr tempDRE(getContext(), const_cast<VarDecl *>(D), false,
1931 D->getType(), VK_LValue, SourceLocation());
1932 elementLValue = EmitLValue(&tempDRE);
1933 elementType = D->getType();
1934 elementIsVariable = true;
1935
1936 if (D->isARCPseudoStrong())
1937 elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone);
1938 } else {
1939 elementLValue = LValue(); // suppress warning
1940 elementType = cast<Expr>(S.getElement())->getType();
1941 elementIsVariable = false;
1942 }
1943 llvm::Type *convertedElementType = ConvertType(elementType);
1944
1945 // Fetch the buffer out of the enumeration state.
1946 // TODO: this pointer should actually be invariant between
1947 // refreshes, which would help us do certain loop optimizations.
1948 Address StateItemsPtr =
1949 Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr");
1950 llvm::Value *EnumStateItems =
1951 Builder.CreateLoad(StateItemsPtr, "stateitems");
1952
1953 // Fetch the value at the current index from the buffer.
1954 llvm::Value *CurrentItemPtr = Builder.CreateGEP(
1955 ObjCIdType, EnumStateItems, index, "currentitem.ptr");
1956 llvm::Value *CurrentItem =
1957 Builder.CreateAlignedLoad(ObjCIdType, CurrentItemPtr, getPointerAlign());
1958
1959 if (SanOpts.has(SanitizerKind::ObjCCast)) {
1960 // Before using an item from the collection, check that the implicit cast
1961 // from id to the element type is valid. This is done with instrumentation
1962 // roughly corresponding to:
1963 //
1964 // if (![item isKindOfClass:expectedCls]) { /* emit diagnostic */ }
1965 const ObjCObjectPointerType *ObjPtrTy =
1966 elementType->getAsObjCInterfacePointerType();
1967 const ObjCInterfaceType *InterfaceTy =
1968 ObjPtrTy ? ObjPtrTy->getInterfaceType() : nullptr;
1969 if (InterfaceTy) {
1970 SanitizerScope SanScope(this);
1971 auto &C = CGM.getContext();
1972 assert(InterfaceTy->getDecl() && "No decl for ObjC interface type");
1973 Selector IsKindOfClassSel = GetUnarySelector("isKindOfClass", C);
1974 CallArgList IsKindOfClassArgs;
1975 llvm::Value *Cls =
1976 CGM.getObjCRuntime().GetClass(*this, InterfaceTy->getDecl());
1977 IsKindOfClassArgs.add(RValue::get(Cls), C.getObjCClassType());
1978 llvm::Value *IsClass =
1979 CGM.getObjCRuntime()
1980 .GenerateMessageSend(*this, ReturnValueSlot(), C.BoolTy,
1981 IsKindOfClassSel, CurrentItem,
1982 IsKindOfClassArgs)
1983 .getScalarVal();
1984 llvm::Constant *StaticData[] = {
1985 EmitCheckSourceLocation(S.getBeginLoc()),
1986 EmitCheckTypeDescriptor(QualType(InterfaceTy, 0))};
1987 EmitCheck({{IsClass, SanitizerKind::ObjCCast}},
1988 SanitizerHandler::InvalidObjCCast,
1989 ArrayRef<llvm::Constant *>(StaticData), CurrentItem);
1990 }
1991 }
1992
1993 // Cast that value to the right type.
1994 CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType,
1995 "currentitem");
1996
1997 // Make sure we have an l-value. Yes, this gets evaluated every
1998 // time through the loop.
1999 if (!elementIsVariable) {
2000 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
2001 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue);
2002 } else {
2003 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue,
2004 /*isInit*/ true);
2005 }
2006
2007 // If we do have an element variable, this assignment is the end of
2008 // its initialization.
2009 if (elementIsVariable)
2010 EmitAutoVarCleanups(variable);
2011
2012 // Perform the loop body, setting up break and continue labels.
2013 BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody));
2014 {
2015 RunCleanupsScope Scope(*this);
2016 EmitStmt(S.getBody());
2017 }
2018 BreakContinueStack.pop_back();
2019
2020 // Destroy the element variable now.
2021 elementVariableScope.ForceCleanup();
2022
2023 // Check whether there are more elements.
2024 EmitBlock(AfterBody.getBlock());
2025
2026 llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch");
2027
2028 // First we check in the local buffer.
2029 llvm::Value *indexPlusOne =
2030 Builder.CreateAdd(index, llvm::ConstantInt::get(NSUIntegerTy, 1));
2031
2032 // If we haven't overrun the buffer yet, we can continue.
2033 // Set the branch weights based on the simplifying assumption that this is
2034 // like a while-loop, i.e., ignoring that the false branch fetches more
2035 // elements and then returns to the loop.
2036 Builder.CreateCondBr(
2037 Builder.CreateICmpULT(indexPlusOne, count), LoopBodyBB, FetchMoreBB,
2038 createProfileWeights(getProfileCount(S.getBody()), EntryCount));
2039
2040 index->addIncoming(indexPlusOne, AfterBody.getBlock());
2041 count->addIncoming(count, AfterBody.getBlock());
2042
2043 // Otherwise, we have to fetch more elements.
2044 EmitBlock(FetchMoreBB);
2045
2046 CountRV =
2047 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
2048 getContext().getNSUIntegerType(),
2049 FastEnumSel, Collection, Args);
2050
2051 // If we got a zero count, we're done.
2052 llvm::Value *refetchCount = CountRV.getScalarVal();
2053
2054 // (note that the message send might split FetchMoreBB)
2055 index->addIncoming(zero, Builder.GetInsertBlock());
2056 count->addIncoming(refetchCount, Builder.GetInsertBlock());
2057
2058 Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero),
2059 EmptyBB, LoopBodyBB);
2060
2061 // No more elements.
2062 EmitBlock(EmptyBB);
2063
2064 if (!elementIsVariable) {
2065 // If the element was not a declaration, set it to be null.
2066
2067 llvm::Value *null = llvm::Constant::getNullValue(convertedElementType);
2068 elementLValue = EmitLValue(cast<Expr>(S.getElement()));
2069 EmitStoreThroughLValue(RValue::get(null), elementLValue);
2070 }
2071
2072 if (DI)
2073 DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd());
2074
2075 ForScope.ForceCleanup();
2076 EmitBlock(LoopEnd.getBlock());
2077 }
2078
EmitObjCAtTryStmt(const ObjCAtTryStmt & S)2079 void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) {
2080 CGM.getObjCRuntime().EmitTryStmt(*this, S);
2081 }
2082
EmitObjCAtThrowStmt(const ObjCAtThrowStmt & S)2083 void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) {
2084 CGM.getObjCRuntime().EmitThrowStmt(*this, S);
2085 }
2086
EmitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt & S)2087 void CodeGenFunction::EmitObjCAtSynchronizedStmt(
2088 const ObjCAtSynchronizedStmt &S) {
2089 CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S);
2090 }
2091
2092 namespace {
2093 struct CallObjCRelease final : EHScopeStack::Cleanup {
CallObjCRelease__anone2b48d8e0411::CallObjCRelease2094 CallObjCRelease(llvm::Value *object) : object(object) {}
2095 llvm::Value *object;
2096
Emit__anone2b48d8e0411::CallObjCRelease2097 void Emit(CodeGenFunction &CGF, Flags flags) override {
2098 // Releases at the end of the full-expression are imprecise.
2099 CGF.EmitARCRelease(object, ARCImpreciseLifetime);
2100 }
2101 };
2102 }
2103
2104 /// Produce the code for a CK_ARCConsumeObject. Does a primitive
2105 /// release at the end of the full-expression.
EmitObjCConsumeObject(QualType type,llvm::Value * object)2106 llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type,
2107 llvm::Value *object) {
2108 // If we're in a conditional branch, we need to make the cleanup
2109 // conditional.
2110 pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object);
2111 return object;
2112 }
2113
EmitObjCExtendObjectLifetime(QualType type,llvm::Value * value)2114 llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type,
2115 llvm::Value *value) {
2116 return EmitARCRetainAutorelease(type, value);
2117 }
2118
2119 /// Given a number of pointers, inform the optimizer that they're
2120 /// being intrinsically used up until this point in the program.
EmitARCIntrinsicUse(ArrayRef<llvm::Value * > values)2121 void CodeGenFunction::EmitARCIntrinsicUse(ArrayRef<llvm::Value*> values) {
2122 llvm::Function *&fn = CGM.getObjCEntrypoints().clang_arc_use;
2123 if (!fn)
2124 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_clang_arc_use);
2125
2126 // This isn't really a "runtime" function, but as an intrinsic it
2127 // doesn't really matter as long as we align things up.
2128 EmitNounwindRuntimeCall(fn, values);
2129 }
2130
2131 /// Emit a call to "clang.arc.noop.use", which consumes the result of a call
2132 /// that has operand bundle "clang.arc.attachedcall".
EmitARCNoopIntrinsicUse(ArrayRef<llvm::Value * > values)2133 void CodeGenFunction::EmitARCNoopIntrinsicUse(ArrayRef<llvm::Value *> values) {
2134 llvm::Function *&fn = CGM.getObjCEntrypoints().clang_arc_noop_use;
2135 if (!fn)
2136 fn = CGM.getIntrinsic(llvm::Intrinsic::objc_clang_arc_noop_use);
2137 EmitNounwindRuntimeCall(fn, values);
2138 }
2139
setARCRuntimeFunctionLinkage(CodeGenModule & CGM,llvm::Value * RTF)2140 static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM, llvm::Value *RTF) {
2141 if (auto *F = dyn_cast<llvm::Function>(RTF)) {
2142 // If the target runtime doesn't naturally support ARC, emit weak
2143 // references to the runtime support library. We don't really
2144 // permit this to fail, but we need a particular relocation style.
2145 if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC() &&
2146 !CGM.getTriple().isOSBinFormatCOFF()) {
2147 F->setLinkage(llvm::Function::ExternalWeakLinkage);
2148 }
2149 }
2150 }
2151
setARCRuntimeFunctionLinkage(CodeGenModule & CGM,llvm::FunctionCallee RTF)2152 static void setARCRuntimeFunctionLinkage(CodeGenModule &CGM,
2153 llvm::FunctionCallee RTF) {
2154 setARCRuntimeFunctionLinkage(CGM, RTF.getCallee());
2155 }
2156
getARCIntrinsic(llvm::Intrinsic::ID IntID,CodeGenModule & CGM)2157 static llvm::Function *getARCIntrinsic(llvm::Intrinsic::ID IntID,
2158 CodeGenModule &CGM) {
2159 llvm::Function *fn = CGM.getIntrinsic(IntID);
2160 setARCRuntimeFunctionLinkage(CGM, fn);
2161 return fn;
2162 }
2163
2164 /// Perform an operation having the signature
2165 /// i8* (i8*)
2166 /// where a null input causes a no-op and returns null.
emitARCValueOperation(CodeGenFunction & CGF,llvm::Value * value,llvm::Type * returnType,llvm::Function * & fn,llvm::Intrinsic::ID IntID,llvm::CallInst::TailCallKind tailKind=llvm::CallInst::TCK_None)2167 static llvm::Value *emitARCValueOperation(
2168 CodeGenFunction &CGF, llvm::Value *value, llvm::Type *returnType,
2169 llvm::Function *&fn, llvm::Intrinsic::ID IntID,
2170 llvm::CallInst::TailCallKind tailKind = llvm::CallInst::TCK_None) {
2171 if (isa<llvm::ConstantPointerNull>(value))
2172 return value;
2173
2174 if (!fn)
2175 fn = getARCIntrinsic(IntID, CGF.CGM);
2176
2177 // Cast the argument to 'id'.
2178 llvm::Type *origType = returnType ? returnType : value->getType();
2179 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
2180
2181 // Call the function.
2182 llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value);
2183 call->setTailCallKind(tailKind);
2184
2185 // Cast the result back to the original type.
2186 return CGF.Builder.CreateBitCast(call, origType);
2187 }
2188
2189 /// Perform an operation having the following signature:
2190 /// i8* (i8**)
emitARCLoadOperation(CodeGenFunction & CGF,Address addr,llvm::Function * & fn,llvm::Intrinsic::ID IntID)2191 static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF, Address addr,
2192 llvm::Function *&fn,
2193 llvm::Intrinsic::ID IntID) {
2194 if (!fn)
2195 fn = getARCIntrinsic(IntID, CGF.CGM);
2196
2197 return CGF.EmitNounwindRuntimeCall(fn, addr.getPointer());
2198 }
2199
2200 /// Perform an operation having the following signature:
2201 /// i8* (i8**, i8*)
emitARCStoreOperation(CodeGenFunction & CGF,Address addr,llvm::Value * value,llvm::Function * & fn,llvm::Intrinsic::ID IntID,bool ignored)2202 static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, Address addr,
2203 llvm::Value *value,
2204 llvm::Function *&fn,
2205 llvm::Intrinsic::ID IntID,
2206 bool ignored) {
2207 assert(addr.getElementType() == value->getType());
2208
2209 if (!fn)
2210 fn = getARCIntrinsic(IntID, CGF.CGM);
2211
2212 llvm::Type *origType = value->getType();
2213
2214 llvm::Value *args[] = {
2215 CGF.Builder.CreateBitCast(addr.getPointer(), CGF.Int8PtrPtrTy),
2216 CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy)
2217 };
2218 llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args);
2219
2220 if (ignored) return nullptr;
2221
2222 return CGF.Builder.CreateBitCast(result, origType);
2223 }
2224
2225 /// Perform an operation having the following signature:
2226 /// void (i8**, i8**)
emitARCCopyOperation(CodeGenFunction & CGF,Address dst,Address src,llvm::Function * & fn,llvm::Intrinsic::ID IntID)2227 static void emitARCCopyOperation(CodeGenFunction &CGF, Address dst, Address src,
2228 llvm::Function *&fn,
2229 llvm::Intrinsic::ID IntID) {
2230 assert(dst.getType() == src.getType());
2231
2232 if (!fn)
2233 fn = getARCIntrinsic(IntID, CGF.CGM);
2234
2235 llvm::Value *args[] = {
2236 CGF.Builder.CreateBitCast(dst.getPointer(), CGF.Int8PtrPtrTy),
2237 CGF.Builder.CreateBitCast(src.getPointer(), CGF.Int8PtrPtrTy)
2238 };
2239 CGF.EmitNounwindRuntimeCall(fn, args);
2240 }
2241
2242 /// Perform an operation having the signature
2243 /// i8* (i8*)
2244 /// where a null input causes a no-op and returns null.
emitObjCValueOperation(CodeGenFunction & CGF,llvm::Value * value,llvm::Type * returnType,llvm::FunctionCallee & fn,StringRef fnName)2245 static llvm::Value *emitObjCValueOperation(CodeGenFunction &CGF,
2246 llvm::Value *value,
2247 llvm::Type *returnType,
2248 llvm::FunctionCallee &fn,
2249 StringRef fnName) {
2250 if (isa<llvm::ConstantPointerNull>(value))
2251 return value;
2252
2253 if (!fn) {
2254 llvm::FunctionType *fnType =
2255 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false);
2256 fn = CGF.CGM.CreateRuntimeFunction(fnType, fnName);
2257
2258 // We have Native ARC, so set nonlazybind attribute for performance
2259 if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
2260 if (fnName == "objc_retain")
2261 f->addFnAttr(llvm::Attribute::NonLazyBind);
2262 }
2263
2264 // Cast the argument to 'id'.
2265 llvm::Type *origType = returnType ? returnType : value->getType();
2266 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy);
2267
2268 // Call the function.
2269 llvm::CallBase *Inst = CGF.EmitCallOrInvoke(fn, value);
2270
2271 // Mark calls to objc_autorelease as tail on the assumption that methods
2272 // overriding autorelease do not touch anything on the stack.
2273 if (fnName == "objc_autorelease")
2274 if (auto *Call = dyn_cast<llvm::CallInst>(Inst))
2275 Call->setTailCall();
2276
2277 // Cast the result back to the original type.
2278 return CGF.Builder.CreateBitCast(Inst, origType);
2279 }
2280
2281 /// Produce the code to do a retain. Based on the type, calls one of:
2282 /// call i8* \@objc_retain(i8* %value)
2283 /// call i8* \@objc_retainBlock(i8* %value)
EmitARCRetain(QualType type,llvm::Value * value)2284 llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) {
2285 if (type->isBlockPointerType())
2286 return EmitARCRetainBlock(value, /*mandatory*/ false);
2287 else
2288 return EmitARCRetainNonBlock(value);
2289 }
2290
2291 /// Retain the given object, with normal retain semantics.
2292 /// call i8* \@objc_retain(i8* %value)
EmitARCRetainNonBlock(llvm::Value * value)2293 llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) {
2294 return emitARCValueOperation(*this, value, nullptr,
2295 CGM.getObjCEntrypoints().objc_retain,
2296 llvm::Intrinsic::objc_retain);
2297 }
2298
2299 /// Retain the given block, with _Block_copy semantics.
2300 /// call i8* \@objc_retainBlock(i8* %value)
2301 ///
2302 /// \param mandatory - If false, emit the call with metadata
2303 /// indicating that it's okay for the optimizer to eliminate this call
2304 /// if it can prove that the block never escapes except down the stack.
EmitARCRetainBlock(llvm::Value * value,bool mandatory)2305 llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value,
2306 bool mandatory) {
2307 llvm::Value *result
2308 = emitARCValueOperation(*this, value, nullptr,
2309 CGM.getObjCEntrypoints().objc_retainBlock,
2310 llvm::Intrinsic::objc_retainBlock);
2311
2312 // If the copy isn't mandatory, add !clang.arc.copy_on_escape to
2313 // tell the optimizer that it doesn't need to do this copy if the
2314 // block doesn't escape, where being passed as an argument doesn't
2315 // count as escaping.
2316 if (!mandatory && isa<llvm::Instruction>(result)) {
2317 llvm::CallInst *call
2318 = cast<llvm::CallInst>(result->stripPointerCasts());
2319 assert(call->getCalledOperand() ==
2320 CGM.getObjCEntrypoints().objc_retainBlock);
2321
2322 call->setMetadata("clang.arc.copy_on_escape",
2323 llvm::MDNode::get(Builder.getContext(), std::nullopt));
2324 }
2325
2326 return result;
2327 }
2328
emitAutoreleasedReturnValueMarker(CodeGenFunction & CGF)2329 static void emitAutoreleasedReturnValueMarker(CodeGenFunction &CGF) {
2330 // Fetch the void(void) inline asm which marks that we're going to
2331 // do something with the autoreleased return value.
2332 llvm::InlineAsm *&marker
2333 = CGF.CGM.getObjCEntrypoints().retainAutoreleasedReturnValueMarker;
2334 if (!marker) {
2335 StringRef assembly
2336 = CGF.CGM.getTargetCodeGenInfo()
2337 .getARCRetainAutoreleasedReturnValueMarker();
2338
2339 // If we have an empty assembly string, there's nothing to do.
2340 if (assembly.empty()) {
2341
2342 // Otherwise, at -O0, build an inline asm that we're going to call
2343 // in a moment.
2344 } else if (CGF.CGM.getCodeGenOpts().OptimizationLevel == 0) {
2345 llvm::FunctionType *type =
2346 llvm::FunctionType::get(CGF.VoidTy, /*variadic*/false);
2347
2348 marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true);
2349
2350 // If we're at -O1 and above, we don't want to litter the code
2351 // with this marker yet, so leave a breadcrumb for the ARC
2352 // optimizer to pick up.
2353 } else {
2354 const char *retainRVMarkerKey = llvm::objcarc::getRVMarkerModuleFlagStr();
2355 if (!CGF.CGM.getModule().getModuleFlag(retainRVMarkerKey)) {
2356 auto *str = llvm::MDString::get(CGF.getLLVMContext(), assembly);
2357 CGF.CGM.getModule().addModuleFlag(llvm::Module::Error,
2358 retainRVMarkerKey, str);
2359 }
2360 }
2361 }
2362
2363 // Call the marker asm if we made one, which we do only at -O0.
2364 if (marker)
2365 CGF.Builder.CreateCall(marker, std::nullopt,
2366 CGF.getBundlesForFunclet(marker));
2367 }
2368
emitOptimizedARCReturnCall(llvm::Value * value,bool IsRetainRV,CodeGenFunction & CGF)2369 static llvm::Value *emitOptimizedARCReturnCall(llvm::Value *value,
2370 bool IsRetainRV,
2371 CodeGenFunction &CGF) {
2372 emitAutoreleasedReturnValueMarker(CGF);
2373
2374 // Add operand bundle "clang.arc.attachedcall" to the call instead of emitting
2375 // retainRV or claimRV calls in the IR. We currently do this only when the
2376 // optimization level isn't -O0 since global-isel, which is currently run at
2377 // -O0, doesn't know about the operand bundle.
2378 ObjCEntrypoints &EPs = CGF.CGM.getObjCEntrypoints();
2379 llvm::Function *&EP = IsRetainRV
2380 ? EPs.objc_retainAutoreleasedReturnValue
2381 : EPs.objc_unsafeClaimAutoreleasedReturnValue;
2382 llvm::Intrinsic::ID IID =
2383 IsRetainRV ? llvm::Intrinsic::objc_retainAutoreleasedReturnValue
2384 : llvm::Intrinsic::objc_unsafeClaimAutoreleasedReturnValue;
2385 EP = getARCIntrinsic(IID, CGF.CGM);
2386
2387 llvm::Triple::ArchType Arch = CGF.CGM.getTriple().getArch();
2388
2389 // FIXME: Do this on all targets and at -O0 too. This can be enabled only if
2390 // the target backend knows how to handle the operand bundle.
2391 if (CGF.CGM.getCodeGenOpts().OptimizationLevel > 0 &&
2392 (Arch == llvm::Triple::aarch64 || Arch == llvm::Triple::x86_64)) {
2393 llvm::Value *bundleArgs[] = {EP};
2394 llvm::OperandBundleDef OB("clang.arc.attachedcall", bundleArgs);
2395 auto *oldCall = cast<llvm::CallBase>(value);
2396 llvm::CallBase *newCall = llvm::CallBase::addOperandBundle(
2397 oldCall, llvm::LLVMContext::OB_clang_arc_attachedcall, OB, oldCall);
2398 newCall->copyMetadata(*oldCall);
2399 oldCall->replaceAllUsesWith(newCall);
2400 oldCall->eraseFromParent();
2401 CGF.EmitARCNoopIntrinsicUse(newCall);
2402 return newCall;
2403 }
2404
2405 bool isNoTail =
2406 CGF.CGM.getTargetCodeGenInfo().markARCOptimizedReturnCallsAsNoTail();
2407 llvm::CallInst::TailCallKind tailKind =
2408 isNoTail ? llvm::CallInst::TCK_NoTail : llvm::CallInst::TCK_None;
2409 return emitARCValueOperation(CGF, value, nullptr, EP, IID, tailKind);
2410 }
2411
2412 /// Retain the given object which is the result of a function call.
2413 /// call i8* \@objc_retainAutoreleasedReturnValue(i8* %value)
2414 ///
2415 /// Yes, this function name is one character away from a different
2416 /// call with completely different semantics.
2417 llvm::Value *
EmitARCRetainAutoreleasedReturnValue(llvm::Value * value)2418 CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) {
2419 return emitOptimizedARCReturnCall(value, true, *this);
2420 }
2421
2422 /// Claim a possibly-autoreleased return value at +0. This is only
2423 /// valid to do in contexts which do not rely on the retain to keep
2424 /// the object valid for all of its uses; for example, when
2425 /// the value is ignored, or when it is being assigned to an
2426 /// __unsafe_unretained variable.
2427 ///
2428 /// call i8* \@objc_unsafeClaimAutoreleasedReturnValue(i8* %value)
2429 llvm::Value *
EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value * value)2430 CodeGenFunction::EmitARCUnsafeClaimAutoreleasedReturnValue(llvm::Value *value) {
2431 return emitOptimizedARCReturnCall(value, false, *this);
2432 }
2433
2434 /// Release the given object.
2435 /// call void \@objc_release(i8* %value)
EmitARCRelease(llvm::Value * value,ARCPreciseLifetime_t precise)2436 void CodeGenFunction::EmitARCRelease(llvm::Value *value,
2437 ARCPreciseLifetime_t precise) {
2438 if (isa<llvm::ConstantPointerNull>(value)) return;
2439
2440 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_release;
2441 if (!fn)
2442 fn = getARCIntrinsic(llvm::Intrinsic::objc_release, CGM);
2443
2444 // Cast the argument to 'id'.
2445 value = Builder.CreateBitCast(value, Int8PtrTy);
2446
2447 // Call objc_release.
2448 llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value);
2449
2450 if (precise == ARCImpreciseLifetime) {
2451 call->setMetadata("clang.imprecise_release",
2452 llvm::MDNode::get(Builder.getContext(), std::nullopt));
2453 }
2454 }
2455
2456 /// Destroy a __strong variable.
2457 ///
2458 /// At -O0, emit a call to store 'null' into the address;
2459 /// instrumenting tools prefer this because the address is exposed,
2460 /// but it's relatively cumbersome to optimize.
2461 ///
2462 /// At -O1 and above, just load and call objc_release.
2463 ///
2464 /// call void \@objc_storeStrong(i8** %addr, i8* null)
EmitARCDestroyStrong(Address addr,ARCPreciseLifetime_t precise)2465 void CodeGenFunction::EmitARCDestroyStrong(Address addr,
2466 ARCPreciseLifetime_t precise) {
2467 if (CGM.getCodeGenOpts().OptimizationLevel == 0) {
2468 llvm::Value *null = getNullForVariable(addr);
2469 EmitARCStoreStrongCall(addr, null, /*ignored*/ true);
2470 return;
2471 }
2472
2473 llvm::Value *value = Builder.CreateLoad(addr);
2474 EmitARCRelease(value, precise);
2475 }
2476
2477 /// Store into a strong object. Always calls this:
2478 /// call void \@objc_storeStrong(i8** %addr, i8* %value)
EmitARCStoreStrongCall(Address addr,llvm::Value * value,bool ignored)2479 llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(Address addr,
2480 llvm::Value *value,
2481 bool ignored) {
2482 assert(addr.getElementType() == value->getType());
2483
2484 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_storeStrong;
2485 if (!fn)
2486 fn = getARCIntrinsic(llvm::Intrinsic::objc_storeStrong, CGM);
2487
2488 llvm::Value *args[] = {
2489 Builder.CreateBitCast(addr.getPointer(), Int8PtrPtrTy),
2490 Builder.CreateBitCast(value, Int8PtrTy)
2491 };
2492 EmitNounwindRuntimeCall(fn, args);
2493
2494 if (ignored) return nullptr;
2495 return value;
2496 }
2497
2498 /// Store into a strong object. Sometimes calls this:
2499 /// call void \@objc_storeStrong(i8** %addr, i8* %value)
2500 /// Other times, breaks it down into components.
EmitARCStoreStrong(LValue dst,llvm::Value * newValue,bool ignored)2501 llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst,
2502 llvm::Value *newValue,
2503 bool ignored) {
2504 QualType type = dst.getType();
2505 bool isBlock = type->isBlockPointerType();
2506
2507 // Use a store barrier at -O0 unless this is a block type or the
2508 // lvalue is inadequately aligned.
2509 if (shouldUseFusedARCCalls() &&
2510 !isBlock &&
2511 (dst.getAlignment().isZero() ||
2512 dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) {
2513 return EmitARCStoreStrongCall(dst.getAddress(*this), newValue, ignored);
2514 }
2515
2516 // Otherwise, split it out.
2517
2518 // Retain the new value.
2519 newValue = EmitARCRetain(type, newValue);
2520
2521 // Read the old value.
2522 llvm::Value *oldValue = EmitLoadOfScalar(dst, SourceLocation());
2523
2524 // Store. We do this before the release so that any deallocs won't
2525 // see the old value.
2526 EmitStoreOfScalar(newValue, dst);
2527
2528 // Finally, release the old value.
2529 EmitARCRelease(oldValue, dst.isARCPreciseLifetime());
2530
2531 return newValue;
2532 }
2533
2534 /// Autorelease the given object.
2535 /// call i8* \@objc_autorelease(i8* %value)
EmitARCAutorelease(llvm::Value * value)2536 llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) {
2537 return emitARCValueOperation(*this, value, nullptr,
2538 CGM.getObjCEntrypoints().objc_autorelease,
2539 llvm::Intrinsic::objc_autorelease);
2540 }
2541
2542 /// Autorelease the given object.
2543 /// call i8* \@objc_autoreleaseReturnValue(i8* %value)
2544 llvm::Value *
EmitARCAutoreleaseReturnValue(llvm::Value * value)2545 CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) {
2546 return emitARCValueOperation(*this, value, nullptr,
2547 CGM.getObjCEntrypoints().objc_autoreleaseReturnValue,
2548 llvm::Intrinsic::objc_autoreleaseReturnValue,
2549 llvm::CallInst::TCK_Tail);
2550 }
2551
2552 /// Do a fused retain/autorelease of the given object.
2553 /// call i8* \@objc_retainAutoreleaseReturnValue(i8* %value)
2554 llvm::Value *
EmitARCRetainAutoreleaseReturnValue(llvm::Value * value)2555 CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) {
2556 return emitARCValueOperation(*this, value, nullptr,
2557 CGM.getObjCEntrypoints().objc_retainAutoreleaseReturnValue,
2558 llvm::Intrinsic::objc_retainAutoreleaseReturnValue,
2559 llvm::CallInst::TCK_Tail);
2560 }
2561
2562 /// Do a fused retain/autorelease of the given object.
2563 /// call i8* \@objc_retainAutorelease(i8* %value)
2564 /// or
2565 /// %retain = call i8* \@objc_retainBlock(i8* %value)
2566 /// call i8* \@objc_autorelease(i8* %retain)
EmitARCRetainAutorelease(QualType type,llvm::Value * value)2567 llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type,
2568 llvm::Value *value) {
2569 if (!type->isBlockPointerType())
2570 return EmitARCRetainAutoreleaseNonBlock(value);
2571
2572 if (isa<llvm::ConstantPointerNull>(value)) return value;
2573
2574 llvm::Type *origType = value->getType();
2575 value = Builder.CreateBitCast(value, Int8PtrTy);
2576 value = EmitARCRetainBlock(value, /*mandatory*/ true);
2577 value = EmitARCAutorelease(value);
2578 return Builder.CreateBitCast(value, origType);
2579 }
2580
2581 /// Do a fused retain/autorelease of the given object.
2582 /// call i8* \@objc_retainAutorelease(i8* %value)
2583 llvm::Value *
EmitARCRetainAutoreleaseNonBlock(llvm::Value * value)2584 CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) {
2585 return emitARCValueOperation(*this, value, nullptr,
2586 CGM.getObjCEntrypoints().objc_retainAutorelease,
2587 llvm::Intrinsic::objc_retainAutorelease);
2588 }
2589
2590 /// i8* \@objc_loadWeak(i8** %addr)
2591 /// Essentially objc_autorelease(objc_loadWeakRetained(addr)).
EmitARCLoadWeak(Address addr)2592 llvm::Value *CodeGenFunction::EmitARCLoadWeak(Address addr) {
2593 return emitARCLoadOperation(*this, addr,
2594 CGM.getObjCEntrypoints().objc_loadWeak,
2595 llvm::Intrinsic::objc_loadWeak);
2596 }
2597
2598 /// i8* \@objc_loadWeakRetained(i8** %addr)
EmitARCLoadWeakRetained(Address addr)2599 llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(Address addr) {
2600 return emitARCLoadOperation(*this, addr,
2601 CGM.getObjCEntrypoints().objc_loadWeakRetained,
2602 llvm::Intrinsic::objc_loadWeakRetained);
2603 }
2604
2605 /// i8* \@objc_storeWeak(i8** %addr, i8* %value)
2606 /// Returns %value.
EmitARCStoreWeak(Address addr,llvm::Value * value,bool ignored)2607 llvm::Value *CodeGenFunction::EmitARCStoreWeak(Address addr,
2608 llvm::Value *value,
2609 bool ignored) {
2610 return emitARCStoreOperation(*this, addr, value,
2611 CGM.getObjCEntrypoints().objc_storeWeak,
2612 llvm::Intrinsic::objc_storeWeak, ignored);
2613 }
2614
2615 /// i8* \@objc_initWeak(i8** %addr, i8* %value)
2616 /// Returns %value. %addr is known to not have a current weak entry.
2617 /// Essentially equivalent to:
2618 /// *addr = nil; objc_storeWeak(addr, value);
EmitARCInitWeak(Address addr,llvm::Value * value)2619 void CodeGenFunction::EmitARCInitWeak(Address addr, llvm::Value *value) {
2620 // If we're initializing to null, just write null to memory; no need
2621 // to get the runtime involved. But don't do this if optimization
2622 // is enabled, because accounting for this would make the optimizer
2623 // much more complicated.
2624 if (isa<llvm::ConstantPointerNull>(value) &&
2625 CGM.getCodeGenOpts().OptimizationLevel == 0) {
2626 Builder.CreateStore(value, addr);
2627 return;
2628 }
2629
2630 emitARCStoreOperation(*this, addr, value,
2631 CGM.getObjCEntrypoints().objc_initWeak,
2632 llvm::Intrinsic::objc_initWeak, /*ignored*/ true);
2633 }
2634
2635 /// void \@objc_destroyWeak(i8** %addr)
2636 /// Essentially objc_storeWeak(addr, nil).
EmitARCDestroyWeak(Address addr)2637 void CodeGenFunction::EmitARCDestroyWeak(Address addr) {
2638 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_destroyWeak;
2639 if (!fn)
2640 fn = getARCIntrinsic(llvm::Intrinsic::objc_destroyWeak, CGM);
2641
2642 EmitNounwindRuntimeCall(fn, addr.getPointer());
2643 }
2644
2645 /// void \@objc_moveWeak(i8** %dest, i8** %src)
2646 /// Disregards the current value in %dest. Leaves %src pointing to nothing.
2647 /// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)).
EmitARCMoveWeak(Address dst,Address src)2648 void CodeGenFunction::EmitARCMoveWeak(Address dst, Address src) {
2649 emitARCCopyOperation(*this, dst, src,
2650 CGM.getObjCEntrypoints().objc_moveWeak,
2651 llvm::Intrinsic::objc_moveWeak);
2652 }
2653
2654 /// void \@objc_copyWeak(i8** %dest, i8** %src)
2655 /// Disregards the current value in %dest. Essentially
2656 /// objc_release(objc_initWeak(dest, objc_readWeakRetained(src)))
EmitARCCopyWeak(Address dst,Address src)2657 void CodeGenFunction::EmitARCCopyWeak(Address dst, Address src) {
2658 emitARCCopyOperation(*this, dst, src,
2659 CGM.getObjCEntrypoints().objc_copyWeak,
2660 llvm::Intrinsic::objc_copyWeak);
2661 }
2662
emitARCCopyAssignWeak(QualType Ty,Address DstAddr,Address SrcAddr)2663 void CodeGenFunction::emitARCCopyAssignWeak(QualType Ty, Address DstAddr,
2664 Address SrcAddr) {
2665 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2666 Object = EmitObjCConsumeObject(Ty, Object);
2667 EmitARCStoreWeak(DstAddr, Object, false);
2668 }
2669
emitARCMoveAssignWeak(QualType Ty,Address DstAddr,Address SrcAddr)2670 void CodeGenFunction::emitARCMoveAssignWeak(QualType Ty, Address DstAddr,
2671 Address SrcAddr) {
2672 llvm::Value *Object = EmitARCLoadWeakRetained(SrcAddr);
2673 Object = EmitObjCConsumeObject(Ty, Object);
2674 EmitARCStoreWeak(DstAddr, Object, false);
2675 EmitARCDestroyWeak(SrcAddr);
2676 }
2677
2678 /// Produce the code to do a objc_autoreleasepool_push.
2679 /// call i8* \@objc_autoreleasePoolPush(void)
EmitObjCAutoreleasePoolPush()2680 llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() {
2681 llvm::Function *&fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPush;
2682 if (!fn)
2683 fn = getARCIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPush, CGM);
2684
2685 return EmitNounwindRuntimeCall(fn);
2686 }
2687
2688 /// Produce the code to do a primitive release.
2689 /// call void \@objc_autoreleasePoolPop(i8* %ptr)
EmitObjCAutoreleasePoolPop(llvm::Value * value)2690 void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) {
2691 assert(value->getType() == Int8PtrTy);
2692
2693 if (getInvokeDest()) {
2694 // Call the runtime method not the intrinsic if we are handling exceptions
2695 llvm::FunctionCallee &fn =
2696 CGM.getObjCEntrypoints().objc_autoreleasePoolPopInvoke;
2697 if (!fn) {
2698 llvm::FunctionType *fnType =
2699 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2700 fn = CGM.CreateRuntimeFunction(fnType, "objc_autoreleasePoolPop");
2701 setARCRuntimeFunctionLinkage(CGM, fn);
2702 }
2703
2704 // objc_autoreleasePoolPop can throw.
2705 EmitRuntimeCallOrInvoke(fn, value);
2706 } else {
2707 llvm::FunctionCallee &fn = CGM.getObjCEntrypoints().objc_autoreleasePoolPop;
2708 if (!fn)
2709 fn = getARCIntrinsic(llvm::Intrinsic::objc_autoreleasePoolPop, CGM);
2710
2711 EmitRuntimeCall(fn, value);
2712 }
2713 }
2714
2715 /// Produce the code to do an MRR version objc_autoreleasepool_push.
2716 /// Which is: [[NSAutoreleasePool alloc] init];
2717 /// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class.
2718 /// init is declared as: - (id) init; in its NSObject super class.
2719 ///
EmitObjCMRRAutoreleasePoolPush()2720 llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() {
2721 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
2722 llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(*this);
2723 // [NSAutoreleasePool alloc]
2724 IdentifierInfo *II = &CGM.getContext().Idents.get("alloc");
2725 Selector AllocSel = getContext().Selectors.getSelector(0, &II);
2726 CallArgList Args;
2727 RValue AllocRV =
2728 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2729 getContext().getObjCIdType(),
2730 AllocSel, Receiver, Args);
2731
2732 // [Receiver init]
2733 Receiver = AllocRV.getScalarVal();
2734 II = &CGM.getContext().Idents.get("init");
2735 Selector InitSel = getContext().Selectors.getSelector(0, &II);
2736 RValue InitRV =
2737 Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
2738 getContext().getObjCIdType(),
2739 InitSel, Receiver, Args);
2740 return InitRV.getScalarVal();
2741 }
2742
2743 /// Allocate the given objc object.
2744 /// call i8* \@objc_alloc(i8* %value)
EmitObjCAlloc(llvm::Value * value,llvm::Type * resultType)2745 llvm::Value *CodeGenFunction::EmitObjCAlloc(llvm::Value *value,
2746 llvm::Type *resultType) {
2747 return emitObjCValueOperation(*this, value, resultType,
2748 CGM.getObjCEntrypoints().objc_alloc,
2749 "objc_alloc");
2750 }
2751
2752 /// Allocate the given objc object.
2753 /// call i8* \@objc_allocWithZone(i8* %value)
EmitObjCAllocWithZone(llvm::Value * value,llvm::Type * resultType)2754 llvm::Value *CodeGenFunction::EmitObjCAllocWithZone(llvm::Value *value,
2755 llvm::Type *resultType) {
2756 return emitObjCValueOperation(*this, value, resultType,
2757 CGM.getObjCEntrypoints().objc_allocWithZone,
2758 "objc_allocWithZone");
2759 }
2760
EmitObjCAllocInit(llvm::Value * value,llvm::Type * resultType)2761 llvm::Value *CodeGenFunction::EmitObjCAllocInit(llvm::Value *value,
2762 llvm::Type *resultType) {
2763 return emitObjCValueOperation(*this, value, resultType,
2764 CGM.getObjCEntrypoints().objc_alloc_init,
2765 "objc_alloc_init");
2766 }
2767
2768 /// Produce the code to do a primitive release.
2769 /// [tmp drain];
EmitObjCMRRAutoreleasePoolPop(llvm::Value * Arg)2770 void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) {
2771 IdentifierInfo *II = &CGM.getContext().Idents.get("drain");
2772 Selector DrainSel = getContext().Selectors.getSelector(0, &II);
2773 CallArgList Args;
2774 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(),
2775 getContext().VoidTy, DrainSel, Arg, Args);
2776 }
2777
destroyARCStrongPrecise(CodeGenFunction & CGF,Address addr,QualType type)2778 void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF,
2779 Address addr,
2780 QualType type) {
2781 CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime);
2782 }
2783
destroyARCStrongImprecise(CodeGenFunction & CGF,Address addr,QualType type)2784 void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF,
2785 Address addr,
2786 QualType type) {
2787 CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime);
2788 }
2789
destroyARCWeak(CodeGenFunction & CGF,Address addr,QualType type)2790 void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF,
2791 Address addr,
2792 QualType type) {
2793 CGF.EmitARCDestroyWeak(addr);
2794 }
2795
emitARCIntrinsicUse(CodeGenFunction & CGF,Address addr,QualType type)2796 void CodeGenFunction::emitARCIntrinsicUse(CodeGenFunction &CGF, Address addr,
2797 QualType type) {
2798 llvm::Value *value = CGF.Builder.CreateLoad(addr);
2799 CGF.EmitARCIntrinsicUse(value);
2800 }
2801
2802 /// Autorelease the given object.
2803 /// call i8* \@objc_autorelease(i8* %value)
EmitObjCAutorelease(llvm::Value * value,llvm::Type * returnType)2804 llvm::Value *CodeGenFunction::EmitObjCAutorelease(llvm::Value *value,
2805 llvm::Type *returnType) {
2806 return emitObjCValueOperation(
2807 *this, value, returnType,
2808 CGM.getObjCEntrypoints().objc_autoreleaseRuntimeFunction,
2809 "objc_autorelease");
2810 }
2811
2812 /// Retain the given object, with normal retain semantics.
2813 /// call i8* \@objc_retain(i8* %value)
EmitObjCRetainNonBlock(llvm::Value * value,llvm::Type * returnType)2814 llvm::Value *CodeGenFunction::EmitObjCRetainNonBlock(llvm::Value *value,
2815 llvm::Type *returnType) {
2816 return emitObjCValueOperation(
2817 *this, value, returnType,
2818 CGM.getObjCEntrypoints().objc_retainRuntimeFunction, "objc_retain");
2819 }
2820
2821 /// Release the given object.
2822 /// call void \@objc_release(i8* %value)
EmitObjCRelease(llvm::Value * value,ARCPreciseLifetime_t precise)2823 void CodeGenFunction::EmitObjCRelease(llvm::Value *value,
2824 ARCPreciseLifetime_t precise) {
2825 if (isa<llvm::ConstantPointerNull>(value)) return;
2826
2827 llvm::FunctionCallee &fn =
2828 CGM.getObjCEntrypoints().objc_releaseRuntimeFunction;
2829 if (!fn) {
2830 llvm::FunctionType *fnType =
2831 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false);
2832 fn = CGM.CreateRuntimeFunction(fnType, "objc_release");
2833 setARCRuntimeFunctionLinkage(CGM, fn);
2834 // We have Native ARC, so set nonlazybind attribute for performance
2835 if (llvm::Function *f = dyn_cast<llvm::Function>(fn.getCallee()))
2836 f->addFnAttr(llvm::Attribute::NonLazyBind);
2837 }
2838
2839 // Cast the argument to 'id'.
2840 value = Builder.CreateBitCast(value, Int8PtrTy);
2841
2842 // Call objc_release.
2843 llvm::CallBase *call = EmitCallOrInvoke(fn, value);
2844
2845 if (precise == ARCImpreciseLifetime) {
2846 call->setMetadata("clang.imprecise_release",
2847 llvm::MDNode::get(Builder.getContext(), std::nullopt));
2848 }
2849 }
2850
2851 namespace {
2852 struct CallObjCAutoreleasePoolObject final : EHScopeStack::Cleanup {
2853 llvm::Value *Token;
2854
CallObjCAutoreleasePoolObject__anone2b48d8e0511::CallObjCAutoreleasePoolObject2855 CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2856
Emit__anone2b48d8e0511::CallObjCAutoreleasePoolObject2857 void Emit(CodeGenFunction &CGF, Flags flags) override {
2858 CGF.EmitObjCAutoreleasePoolPop(Token);
2859 }
2860 };
2861 struct CallObjCMRRAutoreleasePoolObject final : EHScopeStack::Cleanup {
2862 llvm::Value *Token;
2863
CallObjCMRRAutoreleasePoolObject__anone2b48d8e0511::CallObjCMRRAutoreleasePoolObject2864 CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {}
2865
Emit__anone2b48d8e0511::CallObjCMRRAutoreleasePoolObject2866 void Emit(CodeGenFunction &CGF, Flags flags) override {
2867 CGF.EmitObjCMRRAutoreleasePoolPop(Token);
2868 }
2869 };
2870 }
2871
EmitObjCAutoreleasePoolCleanup(llvm::Value * Ptr)2872 void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) {
2873 if (CGM.getLangOpts().ObjCAutoRefCount)
2874 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr);
2875 else
2876 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr);
2877 }
2878
shouldRetainObjCLifetime(Qualifiers::ObjCLifetime lifetime)2879 static bool shouldRetainObjCLifetime(Qualifiers::ObjCLifetime lifetime) {
2880 switch (lifetime) {
2881 case Qualifiers::OCL_None:
2882 case Qualifiers::OCL_ExplicitNone:
2883 case Qualifiers::OCL_Strong:
2884 case Qualifiers::OCL_Autoreleasing:
2885 return true;
2886
2887 case Qualifiers::OCL_Weak:
2888 return false;
2889 }
2890
2891 llvm_unreachable("impossible lifetime!");
2892 }
2893
tryEmitARCRetainLoadOfScalar(CodeGenFunction & CGF,LValue lvalue,QualType type)2894 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2895 LValue lvalue,
2896 QualType type) {
2897 llvm::Value *result;
2898 bool shouldRetain = shouldRetainObjCLifetime(type.getObjCLifetime());
2899 if (shouldRetain) {
2900 result = CGF.EmitLoadOfLValue(lvalue, SourceLocation()).getScalarVal();
2901 } else {
2902 assert(type.getObjCLifetime() == Qualifiers::OCL_Weak);
2903 result = CGF.EmitARCLoadWeakRetained(lvalue.getAddress(CGF));
2904 }
2905 return TryEmitResult(result, !shouldRetain);
2906 }
2907
tryEmitARCRetainLoadOfScalar(CodeGenFunction & CGF,const Expr * e)2908 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF,
2909 const Expr *e) {
2910 e = e->IgnoreParens();
2911 QualType type = e->getType();
2912
2913 // If we're loading retained from a __strong xvalue, we can avoid
2914 // an extra retain/release pair by zeroing out the source of this
2915 // "move" operation.
2916 if (e->isXValue() &&
2917 !type.isConstQualified() &&
2918 type.getObjCLifetime() == Qualifiers::OCL_Strong) {
2919 // Emit the lvalue.
2920 LValue lv = CGF.EmitLValue(e);
2921
2922 // Load the object pointer.
2923 llvm::Value *result = CGF.EmitLoadOfLValue(lv,
2924 SourceLocation()).getScalarVal();
2925
2926 // Set the source pointer to NULL.
2927 CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress(CGF)), lv);
2928
2929 return TryEmitResult(result, true);
2930 }
2931
2932 // As a very special optimization, in ARC++, if the l-value is the
2933 // result of a non-volatile assignment, do a simple retain of the
2934 // result of the call to objc_storeWeak instead of reloading.
2935 if (CGF.getLangOpts().CPlusPlus &&
2936 !type.isVolatileQualified() &&
2937 type.getObjCLifetime() == Qualifiers::OCL_Weak &&
2938 isa<BinaryOperator>(e) &&
2939 cast<BinaryOperator>(e)->getOpcode() == BO_Assign)
2940 return TryEmitResult(CGF.EmitScalarExpr(e), false);
2941
2942 // Try to emit code for scalar constant instead of emitting LValue and
2943 // loading it because we are not guaranteed to have an l-value. One of such
2944 // cases is DeclRefExpr referencing non-odr-used constant-evaluated variable.
2945 if (const auto *decl_expr = dyn_cast<DeclRefExpr>(e)) {
2946 auto *DRE = const_cast<DeclRefExpr *>(decl_expr);
2947 if (CodeGenFunction::ConstantEmission constant = CGF.tryEmitAsConstant(DRE))
2948 return TryEmitResult(CGF.emitScalarConstant(constant, DRE),
2949 !shouldRetainObjCLifetime(type.getObjCLifetime()));
2950 }
2951
2952 return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type);
2953 }
2954
2955 typedef llvm::function_ref<llvm::Value *(CodeGenFunction &CGF,
2956 llvm::Value *value)>
2957 ValueTransform;
2958
2959 /// Insert code immediately after a call.
2960
2961 // FIXME: We should find a way to emit the runtime call immediately
2962 // after the call is emitted to eliminate the need for this function.
emitARCOperationAfterCall(CodeGenFunction & CGF,llvm::Value * value,ValueTransform doAfterCall,ValueTransform doFallback)2963 static llvm::Value *emitARCOperationAfterCall(CodeGenFunction &CGF,
2964 llvm::Value *value,
2965 ValueTransform doAfterCall,
2966 ValueTransform doFallback) {
2967 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP();
2968 auto *callBase = dyn_cast<llvm::CallBase>(value);
2969
2970 if (callBase && llvm::objcarc::hasAttachedCallOpBundle(callBase)) {
2971 // Fall back if the call base has operand bundle "clang.arc.attachedcall".
2972 value = doFallback(CGF, value);
2973 } else if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) {
2974 // Place the retain immediately following the call.
2975 CGF.Builder.SetInsertPoint(call->getParent(),
2976 ++llvm::BasicBlock::iterator(call));
2977 value = doAfterCall(CGF, value);
2978 } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) {
2979 // Place the retain at the beginning of the normal destination block.
2980 llvm::BasicBlock *BB = invoke->getNormalDest();
2981 CGF.Builder.SetInsertPoint(BB, BB->begin());
2982 value = doAfterCall(CGF, value);
2983
2984 // Bitcasts can arise because of related-result returns. Rewrite
2985 // the operand.
2986 } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) {
2987 // Change the insert point to avoid emitting the fall-back call after the
2988 // bitcast.
2989 CGF.Builder.SetInsertPoint(bitcast->getParent(), bitcast->getIterator());
2990 llvm::Value *operand = bitcast->getOperand(0);
2991 operand = emitARCOperationAfterCall(CGF, operand, doAfterCall, doFallback);
2992 bitcast->setOperand(0, operand);
2993 value = bitcast;
2994 } else {
2995 auto *phi = dyn_cast<llvm::PHINode>(value);
2996 if (phi && phi->getNumIncomingValues() == 2 &&
2997 isa<llvm::ConstantPointerNull>(phi->getIncomingValue(1)) &&
2998 isa<llvm::CallBase>(phi->getIncomingValue(0))) {
2999 // Handle phi instructions that are generated when it's necessary to check
3000 // whether the receiver of a message is null.
3001 llvm::Value *inVal = phi->getIncomingValue(0);
3002 inVal = emitARCOperationAfterCall(CGF, inVal, doAfterCall, doFallback);
3003 phi->setIncomingValue(0, inVal);
3004 value = phi;
3005 } else {
3006 // Generic fall-back case.
3007 // Retain using the non-block variant: we never need to do a copy
3008 // of a block that's been returned to us.
3009 value = doFallback(CGF, value);
3010 }
3011 }
3012
3013 CGF.Builder.restoreIP(ip);
3014 return value;
3015 }
3016
3017 /// Given that the given expression is some sort of call (which does
3018 /// not return retained), emit a retain following it.
emitARCRetainCallResult(CodeGenFunction & CGF,const Expr * e)3019 static llvm::Value *emitARCRetainCallResult(CodeGenFunction &CGF,
3020 const Expr *e) {
3021 llvm::Value *value = CGF.EmitScalarExpr(e);
3022 return emitARCOperationAfterCall(CGF, value,
3023 [](CodeGenFunction &CGF, llvm::Value *value) {
3024 return CGF.EmitARCRetainAutoreleasedReturnValue(value);
3025 },
3026 [](CodeGenFunction &CGF, llvm::Value *value) {
3027 return CGF.EmitARCRetainNonBlock(value);
3028 });
3029 }
3030
3031 /// Given that the given expression is some sort of call (which does
3032 /// not return retained), perform an unsafeClaim following it.
emitARCUnsafeClaimCallResult(CodeGenFunction & CGF,const Expr * e)3033 static llvm::Value *emitARCUnsafeClaimCallResult(CodeGenFunction &CGF,
3034 const Expr *e) {
3035 llvm::Value *value = CGF.EmitScalarExpr(e);
3036 return emitARCOperationAfterCall(CGF, value,
3037 [](CodeGenFunction &CGF, llvm::Value *value) {
3038 return CGF.EmitARCUnsafeClaimAutoreleasedReturnValue(value);
3039 },
3040 [](CodeGenFunction &CGF, llvm::Value *value) {
3041 return value;
3042 });
3043 }
3044
EmitARCReclaimReturnedObject(const Expr * E,bool allowUnsafeClaim)3045 llvm::Value *CodeGenFunction::EmitARCReclaimReturnedObject(const Expr *E,
3046 bool allowUnsafeClaim) {
3047 if (allowUnsafeClaim &&
3048 CGM.getLangOpts().ObjCRuntime.hasARCUnsafeClaimAutoreleasedReturnValue()) {
3049 return emitARCUnsafeClaimCallResult(*this, E);
3050 } else {
3051 llvm::Value *value = emitARCRetainCallResult(*this, E);
3052 return EmitObjCConsumeObject(E->getType(), value);
3053 }
3054 }
3055
3056 /// Determine whether it might be important to emit a separate
3057 /// objc_retain_block on the result of the given expression, or
3058 /// whether it's okay to just emit it in a +1 context.
shouldEmitSeparateBlockRetain(const Expr * e)3059 static bool shouldEmitSeparateBlockRetain(const Expr *e) {
3060 assert(e->getType()->isBlockPointerType());
3061 e = e->IgnoreParens();
3062
3063 // For future goodness, emit block expressions directly in +1
3064 // contexts if we can.
3065 if (isa<BlockExpr>(e))
3066 return false;
3067
3068 if (const CastExpr *cast = dyn_cast<CastExpr>(e)) {
3069 switch (cast->getCastKind()) {
3070 // Emitting these operations in +1 contexts is goodness.
3071 case CK_LValueToRValue:
3072 case CK_ARCReclaimReturnedObject:
3073 case CK_ARCConsumeObject:
3074 case CK_ARCProduceObject:
3075 return false;
3076
3077 // These operations preserve a block type.
3078 case CK_NoOp:
3079 case CK_BitCast:
3080 return shouldEmitSeparateBlockRetain(cast->getSubExpr());
3081
3082 // These operations are known to be bad (or haven't been considered).
3083 case CK_AnyPointerToBlockPointerCast:
3084 default:
3085 return true;
3086 }
3087 }
3088
3089 return true;
3090 }
3091
3092 namespace {
3093 /// A CRTP base class for emitting expressions of retainable object
3094 /// pointer type in ARC.
3095 template <typename Impl, typename Result> class ARCExprEmitter {
3096 protected:
3097 CodeGenFunction &CGF;
asImpl()3098 Impl &asImpl() { return *static_cast<Impl*>(this); }
3099
ARCExprEmitter(CodeGenFunction & CGF)3100 ARCExprEmitter(CodeGenFunction &CGF) : CGF(CGF) {}
3101
3102 public:
3103 Result visit(const Expr *e);
3104 Result visitCastExpr(const CastExpr *e);
3105 Result visitPseudoObjectExpr(const PseudoObjectExpr *e);
3106 Result visitBlockExpr(const BlockExpr *e);
3107 Result visitBinaryOperator(const BinaryOperator *e);
3108 Result visitBinAssign(const BinaryOperator *e);
3109 Result visitBinAssignUnsafeUnretained(const BinaryOperator *e);
3110 Result visitBinAssignAutoreleasing(const BinaryOperator *e);
3111 Result visitBinAssignWeak(const BinaryOperator *e);
3112 Result visitBinAssignStrong(const BinaryOperator *e);
3113
3114 // Minimal implementation:
3115 // Result visitLValueToRValue(const Expr *e)
3116 // Result visitConsumeObject(const Expr *e)
3117 // Result visitExtendBlockObject(const Expr *e)
3118 // Result visitReclaimReturnedObject(const Expr *e)
3119 // Result visitCall(const Expr *e)
3120 // Result visitExpr(const Expr *e)
3121 //
3122 // Result emitBitCast(Result result, llvm::Type *resultType)
3123 // llvm::Value *getValueOfResult(Result result)
3124 };
3125 }
3126
3127 /// Try to emit a PseudoObjectExpr under special ARC rules.
3128 ///
3129 /// This massively duplicates emitPseudoObjectRValue.
3130 template <typename Impl, typename Result>
3131 Result
visitPseudoObjectExpr(const PseudoObjectExpr * E)3132 ARCExprEmitter<Impl,Result>::visitPseudoObjectExpr(const PseudoObjectExpr *E) {
3133 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques;
3134
3135 // Find the result expression.
3136 const Expr *resultExpr = E->getResultExpr();
3137 assert(resultExpr);
3138 Result result;
3139
3140 for (PseudoObjectExpr::const_semantics_iterator
3141 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) {
3142 const Expr *semantic = *i;
3143
3144 // If this semantic expression is an opaque value, bind it
3145 // to the result of its source expression.
3146 if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) {
3147 typedef CodeGenFunction::OpaqueValueMappingData OVMA;
3148 OVMA opaqueData;
3149
3150 // If this semantic is the result of the pseudo-object
3151 // expression, try to evaluate the source as +1.
3152 if (ov == resultExpr) {
3153 assert(!OVMA::shouldBindAsLValue(ov));
3154 result = asImpl().visit(ov->getSourceExpr());
3155 opaqueData = OVMA::bind(CGF, ov,
3156 RValue::get(asImpl().getValueOfResult(result)));
3157
3158 // Otherwise, just bind it.
3159 } else {
3160 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr());
3161 }
3162 opaques.push_back(opaqueData);
3163
3164 // Otherwise, if the expression is the result, evaluate it
3165 // and remember the result.
3166 } else if (semantic == resultExpr) {
3167 result = asImpl().visit(semantic);
3168
3169 // Otherwise, evaluate the expression in an ignored context.
3170 } else {
3171 CGF.EmitIgnoredExpr(semantic);
3172 }
3173 }
3174
3175 // Unbind all the opaques now.
3176 for (unsigned i = 0, e = opaques.size(); i != e; ++i)
3177 opaques[i].unbind(CGF);
3178
3179 return result;
3180 }
3181
3182 template <typename Impl, typename Result>
visitBlockExpr(const BlockExpr * e)3183 Result ARCExprEmitter<Impl, Result>::visitBlockExpr(const BlockExpr *e) {
3184 // The default implementation just forwards the expression to visitExpr.
3185 return asImpl().visitExpr(e);
3186 }
3187
3188 template <typename Impl, typename Result>
visitCastExpr(const CastExpr * e)3189 Result ARCExprEmitter<Impl,Result>::visitCastExpr(const CastExpr *e) {
3190 switch (e->getCastKind()) {
3191
3192 // No-op casts don't change the type, so we just ignore them.
3193 case CK_NoOp:
3194 return asImpl().visit(e->getSubExpr());
3195
3196 // These casts can change the type.
3197 case CK_CPointerToObjCPointerCast:
3198 case CK_BlockPointerToObjCPointerCast:
3199 case CK_AnyPointerToBlockPointerCast:
3200 case CK_BitCast: {
3201 llvm::Type *resultType = CGF.ConvertType(e->getType());
3202 assert(e->getSubExpr()->getType()->hasPointerRepresentation());
3203 Result result = asImpl().visit(e->getSubExpr());
3204 return asImpl().emitBitCast(result, resultType);
3205 }
3206
3207 // Handle some casts specially.
3208 case CK_LValueToRValue:
3209 return asImpl().visitLValueToRValue(e->getSubExpr());
3210 case CK_ARCConsumeObject:
3211 return asImpl().visitConsumeObject(e->getSubExpr());
3212 case CK_ARCExtendBlockObject:
3213 return asImpl().visitExtendBlockObject(e->getSubExpr());
3214 case CK_ARCReclaimReturnedObject:
3215 return asImpl().visitReclaimReturnedObject(e->getSubExpr());
3216
3217 // Otherwise, use the default logic.
3218 default:
3219 return asImpl().visitExpr(e);
3220 }
3221 }
3222
3223 template <typename Impl, typename Result>
3224 Result
visitBinaryOperator(const BinaryOperator * e)3225 ARCExprEmitter<Impl,Result>::visitBinaryOperator(const BinaryOperator *e) {
3226 switch (e->getOpcode()) {
3227 case BO_Comma:
3228 CGF.EmitIgnoredExpr(e->getLHS());
3229 CGF.EnsureInsertPoint();
3230 return asImpl().visit(e->getRHS());
3231
3232 case BO_Assign:
3233 return asImpl().visitBinAssign(e);
3234
3235 default:
3236 return asImpl().visitExpr(e);
3237 }
3238 }
3239
3240 template <typename Impl, typename Result>
visitBinAssign(const BinaryOperator * e)3241 Result ARCExprEmitter<Impl,Result>::visitBinAssign(const BinaryOperator *e) {
3242 switch (e->getLHS()->getType().getObjCLifetime()) {
3243 case Qualifiers::OCL_ExplicitNone:
3244 return asImpl().visitBinAssignUnsafeUnretained(e);
3245
3246 case Qualifiers::OCL_Weak:
3247 return asImpl().visitBinAssignWeak(e);
3248
3249 case Qualifiers::OCL_Autoreleasing:
3250 return asImpl().visitBinAssignAutoreleasing(e);
3251
3252 case Qualifiers::OCL_Strong:
3253 return asImpl().visitBinAssignStrong(e);
3254
3255 case Qualifiers::OCL_None:
3256 return asImpl().visitExpr(e);
3257 }
3258 llvm_unreachable("bad ObjC ownership qualifier");
3259 }
3260
3261 /// The default rule for __unsafe_unretained emits the RHS recursively,
3262 /// stores into the unsafe variable, and propagates the result outward.
3263 template <typename Impl, typename Result>
3264 Result ARCExprEmitter<Impl,Result>::
visitBinAssignUnsafeUnretained(const BinaryOperator * e)3265 visitBinAssignUnsafeUnretained(const BinaryOperator *e) {
3266 // Recursively emit the RHS.
3267 // For __block safety, do this before emitting the LHS.
3268 Result result = asImpl().visit(e->getRHS());
3269
3270 // Perform the store.
3271 LValue lvalue =
3272 CGF.EmitCheckedLValue(e->getLHS(), CodeGenFunction::TCK_Store);
3273 CGF.EmitStoreThroughLValue(RValue::get(asImpl().getValueOfResult(result)),
3274 lvalue);
3275
3276 return result;
3277 }
3278
3279 template <typename Impl, typename Result>
3280 Result
visitBinAssignAutoreleasing(const BinaryOperator * e)3281 ARCExprEmitter<Impl,Result>::visitBinAssignAutoreleasing(const BinaryOperator *e) {
3282 return asImpl().visitExpr(e);
3283 }
3284
3285 template <typename Impl, typename Result>
3286 Result
visitBinAssignWeak(const BinaryOperator * e)3287 ARCExprEmitter<Impl,Result>::visitBinAssignWeak(const BinaryOperator *e) {
3288 return asImpl().visitExpr(e);
3289 }
3290
3291 template <typename Impl, typename Result>
3292 Result
visitBinAssignStrong(const BinaryOperator * e)3293 ARCExprEmitter<Impl,Result>::visitBinAssignStrong(const BinaryOperator *e) {
3294 return asImpl().visitExpr(e);
3295 }
3296
3297 /// The general expression-emission logic.
3298 template <typename Impl, typename Result>
visit(const Expr * e)3299 Result ARCExprEmitter<Impl,Result>::visit(const Expr *e) {
3300 // We should *never* see a nested full-expression here, because if
3301 // we fail to emit at +1, our caller must not retain after we close
3302 // out the full-expression. This isn't as important in the unsafe
3303 // emitter.
3304 assert(!isa<ExprWithCleanups>(e));
3305
3306 // Look through parens, __extension__, generic selection, etc.
3307 e = e->IgnoreParens();
3308
3309 // Handle certain kinds of casts.
3310 if (const CastExpr *ce = dyn_cast<CastExpr>(e)) {
3311 return asImpl().visitCastExpr(ce);
3312
3313 // Handle the comma operator.
3314 } else if (auto op = dyn_cast<BinaryOperator>(e)) {
3315 return asImpl().visitBinaryOperator(op);
3316
3317 // TODO: handle conditional operators here
3318
3319 // For calls and message sends, use the retained-call logic.
3320 // Delegate inits are a special case in that they're the only
3321 // returns-retained expression that *isn't* surrounded by
3322 // a consume.
3323 } else if (isa<CallExpr>(e) ||
3324 (isa<ObjCMessageExpr>(e) &&
3325 !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) {
3326 return asImpl().visitCall(e);
3327
3328 // Look through pseudo-object expressions.
3329 } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) {
3330 return asImpl().visitPseudoObjectExpr(pseudo);
3331 } else if (auto *be = dyn_cast<BlockExpr>(e))
3332 return asImpl().visitBlockExpr(be);
3333
3334 return asImpl().visitExpr(e);
3335 }
3336
3337 namespace {
3338
3339 /// An emitter for +1 results.
3340 struct ARCRetainExprEmitter :
3341 public ARCExprEmitter<ARCRetainExprEmitter, TryEmitResult> {
3342
ARCRetainExprEmitter__anone2b48d8e0b11::ARCRetainExprEmitter3343 ARCRetainExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
3344
getValueOfResult__anone2b48d8e0b11::ARCRetainExprEmitter3345 llvm::Value *getValueOfResult(TryEmitResult result) {
3346 return result.getPointer();
3347 }
3348
emitBitCast__anone2b48d8e0b11::ARCRetainExprEmitter3349 TryEmitResult emitBitCast(TryEmitResult result, llvm::Type *resultType) {
3350 llvm::Value *value = result.getPointer();
3351 value = CGF.Builder.CreateBitCast(value, resultType);
3352 result.setPointer(value);
3353 return result;
3354 }
3355
visitLValueToRValue__anone2b48d8e0b11::ARCRetainExprEmitter3356 TryEmitResult visitLValueToRValue(const Expr *e) {
3357 return tryEmitARCRetainLoadOfScalar(CGF, e);
3358 }
3359
3360 /// For consumptions, just emit the subexpression and thus elide
3361 /// the retain/release pair.
visitConsumeObject__anone2b48d8e0b11::ARCRetainExprEmitter3362 TryEmitResult visitConsumeObject(const Expr *e) {
3363 llvm::Value *result = CGF.EmitScalarExpr(e);
3364 return TryEmitResult(result, true);
3365 }
3366
visitBlockExpr__anone2b48d8e0b11::ARCRetainExprEmitter3367 TryEmitResult visitBlockExpr(const BlockExpr *e) {
3368 TryEmitResult result = visitExpr(e);
3369 // Avoid the block-retain if this is a block literal that doesn't need to be
3370 // copied to the heap.
3371 if (CGF.CGM.getCodeGenOpts().ObjCAvoidHeapifyLocalBlocks &&
3372 e->getBlockDecl()->canAvoidCopyToHeap())
3373 result.setInt(true);
3374 return result;
3375 }
3376
3377 /// Block extends are net +0. Naively, we could just recurse on
3378 /// the subexpression, but actually we need to ensure that the
3379 /// value is copied as a block, so there's a little filter here.
visitExtendBlockObject__anone2b48d8e0b11::ARCRetainExprEmitter3380 TryEmitResult visitExtendBlockObject(const Expr *e) {
3381 llvm::Value *result; // will be a +0 value
3382
3383 // If we can't safely assume the sub-expression will produce a
3384 // block-copied value, emit the sub-expression at +0.
3385 if (shouldEmitSeparateBlockRetain(e)) {
3386 result = CGF.EmitScalarExpr(e);
3387
3388 // Otherwise, try to emit the sub-expression at +1 recursively.
3389 } else {
3390 TryEmitResult subresult = asImpl().visit(e);
3391
3392 // If that produced a retained value, just use that.
3393 if (subresult.getInt()) {
3394 return subresult;
3395 }
3396
3397 // Otherwise it's +0.
3398 result = subresult.getPointer();
3399 }
3400
3401 // Retain the object as a block.
3402 result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true);
3403 return TryEmitResult(result, true);
3404 }
3405
3406 /// For reclaims, emit the subexpression as a retained call and
3407 /// skip the consumption.
visitReclaimReturnedObject__anone2b48d8e0b11::ARCRetainExprEmitter3408 TryEmitResult visitReclaimReturnedObject(const Expr *e) {
3409 llvm::Value *result = emitARCRetainCallResult(CGF, e);
3410 return TryEmitResult(result, true);
3411 }
3412
3413 /// When we have an undecorated call, retroactively do a claim.
visitCall__anone2b48d8e0b11::ARCRetainExprEmitter3414 TryEmitResult visitCall(const Expr *e) {
3415 llvm::Value *result = emitARCRetainCallResult(CGF, e);
3416 return TryEmitResult(result, true);
3417 }
3418
3419 // TODO: maybe special-case visitBinAssignWeak?
3420
visitExpr__anone2b48d8e0b11::ARCRetainExprEmitter3421 TryEmitResult visitExpr(const Expr *e) {
3422 // We didn't find an obvious production, so emit what we've got and
3423 // tell the caller that we didn't manage to retain.
3424 llvm::Value *result = CGF.EmitScalarExpr(e);
3425 return TryEmitResult(result, false);
3426 }
3427 };
3428 }
3429
3430 static TryEmitResult
tryEmitARCRetainScalarExpr(CodeGenFunction & CGF,const Expr * e)3431 tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) {
3432 return ARCRetainExprEmitter(CGF).visit(e);
3433 }
3434
emitARCRetainLoadOfScalar(CodeGenFunction & CGF,LValue lvalue,QualType type)3435 static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF,
3436 LValue lvalue,
3437 QualType type) {
3438 TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type);
3439 llvm::Value *value = result.getPointer();
3440 if (!result.getInt())
3441 value = CGF.EmitARCRetain(type, value);
3442 return value;
3443 }
3444
3445 /// EmitARCRetainScalarExpr - Semantically equivalent to
3446 /// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a
3447 /// best-effort attempt to peephole expressions that naturally produce
3448 /// retained objects.
EmitARCRetainScalarExpr(const Expr * e)3449 llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) {
3450 // The retain needs to happen within the full-expression.
3451 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
3452 RunCleanupsScope scope(*this);
3453 return EmitARCRetainScalarExpr(cleanups->getSubExpr());
3454 }
3455
3456 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
3457 llvm::Value *value = result.getPointer();
3458 if (!result.getInt())
3459 value = EmitARCRetain(e->getType(), value);
3460 return value;
3461 }
3462
3463 llvm::Value *
EmitARCRetainAutoreleaseScalarExpr(const Expr * e)3464 CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) {
3465 // The retain needs to happen within the full-expression.
3466 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
3467 RunCleanupsScope scope(*this);
3468 return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr());
3469 }
3470
3471 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e);
3472 llvm::Value *value = result.getPointer();
3473 if (result.getInt())
3474 value = EmitARCAutorelease(value);
3475 else
3476 value = EmitARCRetainAutorelease(e->getType(), value);
3477 return value;
3478 }
3479
EmitARCExtendBlockObject(const Expr * e)3480 llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) {
3481 llvm::Value *result;
3482 bool doRetain;
3483
3484 if (shouldEmitSeparateBlockRetain(e)) {
3485 result = EmitScalarExpr(e);
3486 doRetain = true;
3487 } else {
3488 TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e);
3489 result = subresult.getPointer();
3490 doRetain = !subresult.getInt();
3491 }
3492
3493 if (doRetain)
3494 result = EmitARCRetainBlock(result, /*mandatory*/ true);
3495 return EmitObjCConsumeObject(e->getType(), result);
3496 }
3497
EmitObjCThrowOperand(const Expr * expr)3498 llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) {
3499 // In ARC, retain and autorelease the expression.
3500 if (getLangOpts().ObjCAutoRefCount) {
3501 // Do so before running any cleanups for the full-expression.
3502 // EmitARCRetainAutoreleaseScalarExpr does this for us.
3503 return EmitARCRetainAutoreleaseScalarExpr(expr);
3504 }
3505
3506 // Otherwise, use the normal scalar-expression emission. The
3507 // exception machinery doesn't do anything special with the
3508 // exception like retaining it, so there's no safety associated with
3509 // only running cleanups after the throw has started, and when it
3510 // matters it tends to be substantially inferior code.
3511 return EmitScalarExpr(expr);
3512 }
3513
3514 namespace {
3515
3516 /// An emitter for assigning into an __unsafe_unretained context.
3517 struct ARCUnsafeUnretainedExprEmitter :
3518 public ARCExprEmitter<ARCUnsafeUnretainedExprEmitter, llvm::Value*> {
3519
ARCUnsafeUnretainedExprEmitter__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3520 ARCUnsafeUnretainedExprEmitter(CodeGenFunction &CGF) : ARCExprEmitter(CGF) {}
3521
getValueOfResult__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3522 llvm::Value *getValueOfResult(llvm::Value *value) {
3523 return value;
3524 }
3525
emitBitCast__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3526 llvm::Value *emitBitCast(llvm::Value *value, llvm::Type *resultType) {
3527 return CGF.Builder.CreateBitCast(value, resultType);
3528 }
3529
visitLValueToRValue__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3530 llvm::Value *visitLValueToRValue(const Expr *e) {
3531 return CGF.EmitScalarExpr(e);
3532 }
3533
3534 /// For consumptions, just emit the subexpression and perform the
3535 /// consumption like normal.
visitConsumeObject__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3536 llvm::Value *visitConsumeObject(const Expr *e) {
3537 llvm::Value *value = CGF.EmitScalarExpr(e);
3538 return CGF.EmitObjCConsumeObject(e->getType(), value);
3539 }
3540
3541 /// No special logic for block extensions. (This probably can't
3542 /// actually happen in this emitter, though.)
visitExtendBlockObject__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3543 llvm::Value *visitExtendBlockObject(const Expr *e) {
3544 return CGF.EmitARCExtendBlockObject(e);
3545 }
3546
3547 /// For reclaims, perform an unsafeClaim if that's enabled.
visitReclaimReturnedObject__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3548 llvm::Value *visitReclaimReturnedObject(const Expr *e) {
3549 return CGF.EmitARCReclaimReturnedObject(e, /*unsafe*/ true);
3550 }
3551
3552 /// When we have an undecorated call, just emit it without adding
3553 /// the unsafeClaim.
visitCall__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3554 llvm::Value *visitCall(const Expr *e) {
3555 return CGF.EmitScalarExpr(e);
3556 }
3557
3558 /// Just do normal scalar emission in the default case.
visitExpr__anone2b48d8e0c11::ARCUnsafeUnretainedExprEmitter3559 llvm::Value *visitExpr(const Expr *e) {
3560 return CGF.EmitScalarExpr(e);
3561 }
3562 };
3563 }
3564
emitARCUnsafeUnretainedScalarExpr(CodeGenFunction & CGF,const Expr * e)3565 static llvm::Value *emitARCUnsafeUnretainedScalarExpr(CodeGenFunction &CGF,
3566 const Expr *e) {
3567 return ARCUnsafeUnretainedExprEmitter(CGF).visit(e);
3568 }
3569
3570 /// EmitARCUnsafeUnretainedScalarExpr - Semantically equivalent to
3571 /// immediately releasing the resut of EmitARCRetainScalarExpr, but
3572 /// avoiding any spurious retains, including by performing reclaims
3573 /// with objc_unsafeClaimAutoreleasedReturnValue.
EmitARCUnsafeUnretainedScalarExpr(const Expr * e)3574 llvm::Value *CodeGenFunction::EmitARCUnsafeUnretainedScalarExpr(const Expr *e) {
3575 // Look through full-expressions.
3576 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) {
3577 RunCleanupsScope scope(*this);
3578 return emitARCUnsafeUnretainedScalarExpr(*this, cleanups->getSubExpr());
3579 }
3580
3581 return emitARCUnsafeUnretainedScalarExpr(*this, e);
3582 }
3583
3584 std::pair<LValue,llvm::Value*>
EmitARCStoreUnsafeUnretained(const BinaryOperator * e,bool ignored)3585 CodeGenFunction::EmitARCStoreUnsafeUnretained(const BinaryOperator *e,
3586 bool ignored) {
3587 // Evaluate the RHS first. If we're ignoring the result, assume
3588 // that we can emit at an unsafe +0.
3589 llvm::Value *value;
3590 if (ignored) {
3591 value = EmitARCUnsafeUnretainedScalarExpr(e->getRHS());
3592 } else {
3593 value = EmitScalarExpr(e->getRHS());
3594 }
3595
3596 // Emit the LHS and perform the store.
3597 LValue lvalue = EmitLValue(e->getLHS());
3598 EmitStoreOfScalar(value, lvalue);
3599
3600 return std::pair<LValue,llvm::Value*>(std::move(lvalue), value);
3601 }
3602
3603 std::pair<LValue,llvm::Value*>
EmitARCStoreStrong(const BinaryOperator * e,bool ignored)3604 CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e,
3605 bool ignored) {
3606 // Evaluate the RHS first.
3607 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS());
3608 llvm::Value *value = result.getPointer();
3609
3610 bool hasImmediateRetain = result.getInt();
3611
3612 // If we didn't emit a retained object, and the l-value is of block
3613 // type, then we need to emit the block-retain immediately in case
3614 // it invalidates the l-value.
3615 if (!hasImmediateRetain && e->getType()->isBlockPointerType()) {
3616 value = EmitARCRetainBlock(value, /*mandatory*/ false);
3617 hasImmediateRetain = true;
3618 }
3619
3620 LValue lvalue = EmitLValue(e->getLHS());
3621
3622 // If the RHS was emitted retained, expand this.
3623 if (hasImmediateRetain) {
3624 llvm::Value *oldValue = EmitLoadOfScalar(lvalue, SourceLocation());
3625 EmitStoreOfScalar(value, lvalue);
3626 EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime());
3627 } else {
3628 value = EmitARCStoreStrong(lvalue, value, ignored);
3629 }
3630
3631 return std::pair<LValue,llvm::Value*>(lvalue, value);
3632 }
3633
3634 std::pair<LValue,llvm::Value*>
EmitARCStoreAutoreleasing(const BinaryOperator * e)3635 CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) {
3636 llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS());
3637 LValue lvalue = EmitLValue(e->getLHS());
3638
3639 EmitStoreOfScalar(value, lvalue);
3640
3641 return std::pair<LValue,llvm::Value*>(lvalue, value);
3642 }
3643
EmitObjCAutoreleasePoolStmt(const ObjCAutoreleasePoolStmt & ARPS)3644 void CodeGenFunction::EmitObjCAutoreleasePoolStmt(
3645 const ObjCAutoreleasePoolStmt &ARPS) {
3646 const Stmt *subStmt = ARPS.getSubStmt();
3647 const CompoundStmt &S = cast<CompoundStmt>(*subStmt);
3648
3649 CGDebugInfo *DI = getDebugInfo();
3650 if (DI)
3651 DI->EmitLexicalBlockStart(Builder, S.getLBracLoc());
3652
3653 // Keep track of the current cleanup stack depth.
3654 RunCleanupsScope Scope(*this);
3655 if (CGM.getLangOpts().ObjCRuntime.hasNativeARC()) {
3656 llvm::Value *token = EmitObjCAutoreleasePoolPush();
3657 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token);
3658 } else {
3659 llvm::Value *token = EmitObjCMRRAutoreleasePoolPush();
3660 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token);
3661 }
3662
3663 for (const auto *I : S.body())
3664 EmitStmt(I);
3665
3666 if (DI)
3667 DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc());
3668 }
3669
3670 /// EmitExtendGCLifetime - Given a pointer to an Objective-C object,
3671 /// make sure it survives garbage collection until this point.
EmitExtendGCLifetime(llvm::Value * object)3672 void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) {
3673 // We just use an inline assembly.
3674 llvm::FunctionType *extenderType
3675 = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All);
3676 llvm::InlineAsm *extender = llvm::InlineAsm::get(extenderType,
3677 /* assembly */ "",
3678 /* constraints */ "r",
3679 /* side effects */ true);
3680
3681 EmitNounwindRuntimeCall(extender, object);
3682 }
3683
3684 /// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with
3685 /// non-trivial copy assignment function, produce following helper function.
3686 /// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; }
3687 ///
3688 llvm::Constant *
GenerateObjCAtomicSetterCopyHelperFunction(const ObjCPropertyImplDecl * PID)3689 CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction(
3690 const ObjCPropertyImplDecl *PID) {
3691 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3692 if ((!(PD->getPropertyAttributes() & ObjCPropertyAttribute::kind_atomic)))
3693 return nullptr;
3694
3695 QualType Ty = PID->getPropertyIvarDecl()->getType();
3696 ASTContext &C = getContext();
3697
3698 if (Ty.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
3699 // Call the move assignment operator instead of calling the copy assignment
3700 // operator and destructor.
3701 CharUnits Alignment = C.getTypeAlignInChars(Ty);
3702 llvm::Constant *Fn = getNonTrivialCStructMoveAssignmentOperator(
3703 CGM, Alignment, Alignment, Ty.isVolatileQualified(), Ty);
3704 return Fn;
3705 }
3706
3707 if (!getLangOpts().CPlusPlus ||
3708 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3709 return nullptr;
3710 if (!Ty->isRecordType())
3711 return nullptr;
3712 llvm::Constant *HelperFn = nullptr;
3713 if (hasTrivialSetExpr(PID))
3714 return nullptr;
3715 assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null");
3716 if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty)))
3717 return HelperFn;
3718
3719 IdentifierInfo *II
3720 = &CGM.getContext().Idents.get("__assign_helper_atomic_property_");
3721
3722 QualType ReturnTy = C.VoidTy;
3723 QualType DestTy = C.getPointerType(Ty);
3724 QualType SrcTy = Ty;
3725 SrcTy.addConst();
3726 SrcTy = C.getPointerType(SrcTy);
3727
3728 SmallVector<QualType, 2> ArgTys;
3729 ArgTys.push_back(DestTy);
3730 ArgTys.push_back(SrcTy);
3731 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
3732
3733 FunctionDecl *FD = FunctionDecl::Create(
3734 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
3735 FunctionTy, nullptr, SC_Static, false, false, false);
3736
3737 FunctionArgList args;
3738 ParmVarDecl *Params[2];
3739 ParmVarDecl *DstDecl = ParmVarDecl::Create(
3740 C, FD, SourceLocation(), SourceLocation(), nullptr, DestTy,
3741 C.getTrivialTypeSourceInfo(DestTy, SourceLocation()), SC_None,
3742 /*DefArg=*/nullptr);
3743 args.push_back(Params[0] = DstDecl);
3744 ParmVarDecl *SrcDecl = ParmVarDecl::Create(
3745 C, FD, SourceLocation(), SourceLocation(), nullptr, SrcTy,
3746 C.getTrivialTypeSourceInfo(SrcTy, SourceLocation()), SC_None,
3747 /*DefArg=*/nullptr);
3748 args.push_back(Params[1] = SrcDecl);
3749 FD->setParams(Params);
3750
3751 const CGFunctionInfo &FI =
3752 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
3753
3754 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3755
3756 llvm::Function *Fn =
3757 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage,
3758 "__assign_helper_atomic_property_",
3759 &CGM.getModule());
3760
3761 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3762
3763 StartFunction(FD, ReturnTy, Fn, FI, args);
3764
3765 DeclRefExpr DstExpr(C, DstDecl, false, DestTy, VK_PRValue, SourceLocation());
3766 UnaryOperator *DST = UnaryOperator::Create(
3767 C, &DstExpr, UO_Deref, DestTy->getPointeeType(), VK_LValue, OK_Ordinary,
3768 SourceLocation(), false, FPOptionsOverride());
3769
3770 DeclRefExpr SrcExpr(C, SrcDecl, false, SrcTy, VK_PRValue, SourceLocation());
3771 UnaryOperator *SRC = UnaryOperator::Create(
3772 C, &SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary,
3773 SourceLocation(), false, FPOptionsOverride());
3774
3775 Expr *Args[2] = {DST, SRC};
3776 CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment());
3777 CXXOperatorCallExpr *TheCall = CXXOperatorCallExpr::Create(
3778 C, OO_Equal, CalleeExp->getCallee(), Args, DestTy->getPointeeType(),
3779 VK_LValue, SourceLocation(), FPOptionsOverride());
3780
3781 EmitStmt(TheCall);
3782
3783 FinishFunction();
3784 HelperFn = Fn;
3785 CGM.setAtomicSetterHelperFnMap(Ty, HelperFn);
3786 return HelperFn;
3787 }
3788
GenerateObjCAtomicGetterCopyHelperFunction(const ObjCPropertyImplDecl * PID)3789 llvm::Constant *CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction(
3790 const ObjCPropertyImplDecl *PID) {
3791 const ObjCPropertyDecl *PD = PID->getPropertyDecl();
3792 if ((!(PD->getPropertyAttributes() & ObjCPropertyAttribute::kind_atomic)))
3793 return nullptr;
3794
3795 QualType Ty = PD->getType();
3796 ASTContext &C = getContext();
3797
3798 if (Ty.isNonTrivialToPrimitiveCopy() == QualType::PCK_Struct) {
3799 CharUnits Alignment = C.getTypeAlignInChars(Ty);
3800 llvm::Constant *Fn = getNonTrivialCStructCopyConstructor(
3801 CGM, Alignment, Alignment, Ty.isVolatileQualified(), Ty);
3802 return Fn;
3803 }
3804
3805 if (!getLangOpts().CPlusPlus ||
3806 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper())
3807 return nullptr;
3808 if (!Ty->isRecordType())
3809 return nullptr;
3810 llvm::Constant *HelperFn = nullptr;
3811 if (hasTrivialGetExpr(PID))
3812 return nullptr;
3813 assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null");
3814 if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty)))
3815 return HelperFn;
3816
3817 IdentifierInfo *II =
3818 &CGM.getContext().Idents.get("__copy_helper_atomic_property_");
3819
3820 QualType ReturnTy = C.VoidTy;
3821 QualType DestTy = C.getPointerType(Ty);
3822 QualType SrcTy = Ty;
3823 SrcTy.addConst();
3824 SrcTy = C.getPointerType(SrcTy);
3825
3826 SmallVector<QualType, 2> ArgTys;
3827 ArgTys.push_back(DestTy);
3828 ArgTys.push_back(SrcTy);
3829 QualType FunctionTy = C.getFunctionType(ReturnTy, ArgTys, {});
3830
3831 FunctionDecl *FD = FunctionDecl::Create(
3832 C, C.getTranslationUnitDecl(), SourceLocation(), SourceLocation(), II,
3833 FunctionTy, nullptr, SC_Static, false, false, false);
3834
3835 FunctionArgList args;
3836 ParmVarDecl *Params[2];
3837 ParmVarDecl *DstDecl = ParmVarDecl::Create(
3838 C, FD, SourceLocation(), SourceLocation(), nullptr, DestTy,
3839 C.getTrivialTypeSourceInfo(DestTy, SourceLocation()), SC_None,
3840 /*DefArg=*/nullptr);
3841 args.push_back(Params[0] = DstDecl);
3842 ParmVarDecl *SrcDecl = ParmVarDecl::Create(
3843 C, FD, SourceLocation(), SourceLocation(), nullptr, SrcTy,
3844 C.getTrivialTypeSourceInfo(SrcTy, SourceLocation()), SC_None,
3845 /*DefArg=*/nullptr);
3846 args.push_back(Params[1] = SrcDecl);
3847 FD->setParams(Params);
3848
3849 const CGFunctionInfo &FI =
3850 CGM.getTypes().arrangeBuiltinFunctionDeclaration(ReturnTy, args);
3851
3852 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI);
3853
3854 llvm::Function *Fn = llvm::Function::Create(
3855 LTy, llvm::GlobalValue::InternalLinkage, "__copy_helper_atomic_property_",
3856 &CGM.getModule());
3857
3858 CGM.SetInternalFunctionAttributes(GlobalDecl(), Fn, FI);
3859
3860 StartFunction(FD, ReturnTy, Fn, FI, args);
3861
3862 DeclRefExpr SrcExpr(getContext(), SrcDecl, false, SrcTy, VK_PRValue,
3863 SourceLocation());
3864
3865 UnaryOperator *SRC = UnaryOperator::Create(
3866 C, &SrcExpr, UO_Deref, SrcTy->getPointeeType(), VK_LValue, OK_Ordinary,
3867 SourceLocation(), false, FPOptionsOverride());
3868
3869 CXXConstructExpr *CXXConstExpr =
3870 cast<CXXConstructExpr>(PID->getGetterCXXConstructor());
3871
3872 SmallVector<Expr*, 4> ConstructorArgs;
3873 ConstructorArgs.push_back(SRC);
3874 ConstructorArgs.append(std::next(CXXConstExpr->arg_begin()),
3875 CXXConstExpr->arg_end());
3876
3877 CXXConstructExpr *TheCXXConstructExpr =
3878 CXXConstructExpr::Create(C, Ty, SourceLocation(),
3879 CXXConstExpr->getConstructor(),
3880 CXXConstExpr->isElidable(),
3881 ConstructorArgs,
3882 CXXConstExpr->hadMultipleCandidates(),
3883 CXXConstExpr->isListInitialization(),
3884 CXXConstExpr->isStdInitListInitialization(),
3885 CXXConstExpr->requiresZeroInitialization(),
3886 CXXConstExpr->getConstructionKind(),
3887 SourceRange());
3888
3889 DeclRefExpr DstExpr(getContext(), DstDecl, false, DestTy, VK_PRValue,
3890 SourceLocation());
3891
3892 RValue DV = EmitAnyExpr(&DstExpr);
3893 CharUnits Alignment =
3894 getContext().getTypeAlignInChars(TheCXXConstructExpr->getType());
3895 EmitAggExpr(TheCXXConstructExpr,
3896 AggValueSlot::forAddr(
3897 Address(DV.getScalarVal(), ConvertTypeForMem(Ty), Alignment),
3898 Qualifiers(), AggValueSlot::IsDestructed,
3899 AggValueSlot::DoesNotNeedGCBarriers,
3900 AggValueSlot::IsNotAliased, AggValueSlot::DoesNotOverlap));
3901
3902 FinishFunction();
3903 HelperFn = Fn;
3904 CGM.setAtomicGetterHelperFnMap(Ty, HelperFn);
3905 return HelperFn;
3906 }
3907
3908 llvm::Value *
EmitBlockCopyAndAutorelease(llvm::Value * Block,QualType Ty)3909 CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) {
3910 // Get selectors for retain/autorelease.
3911 IdentifierInfo *CopyID = &getContext().Idents.get("copy");
3912 Selector CopySelector =
3913 getContext().Selectors.getNullarySelector(CopyID);
3914 IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease");
3915 Selector AutoreleaseSelector =
3916 getContext().Selectors.getNullarySelector(AutoreleaseID);
3917
3918 // Emit calls to retain/autorelease.
3919 CGObjCRuntime &Runtime = CGM.getObjCRuntime();
3920 llvm::Value *Val = Block;
3921 RValue Result;
3922 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3923 Ty, CopySelector,
3924 Val, CallArgList(), nullptr, nullptr);
3925 Val = Result.getScalarVal();
3926 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(),
3927 Ty, AutoreleaseSelector,
3928 Val, CallArgList(), nullptr, nullptr);
3929 Val = Result.getScalarVal();
3930 return Val;
3931 }
3932
getBaseMachOPlatformID(const llvm::Triple & TT)3933 static unsigned getBaseMachOPlatformID(const llvm::Triple &TT) {
3934 switch (TT.getOS()) {
3935 case llvm::Triple::Darwin:
3936 case llvm::Triple::MacOSX:
3937 return llvm::MachO::PLATFORM_MACOS;
3938 case llvm::Triple::IOS:
3939 return llvm::MachO::PLATFORM_IOS;
3940 case llvm::Triple::TvOS:
3941 return llvm::MachO::PLATFORM_TVOS;
3942 case llvm::Triple::WatchOS:
3943 return llvm::MachO::PLATFORM_WATCHOS;
3944 case llvm::Triple::XROS:
3945 return llvm::MachO::PLATFORM_XROS;
3946 case llvm::Triple::DriverKit:
3947 return llvm::MachO::PLATFORM_DRIVERKIT;
3948 default:
3949 return llvm::MachO::PLATFORM_UNKNOWN;
3950 }
3951 }
3952
emitIsPlatformVersionAtLeast(CodeGenFunction & CGF,const VersionTuple & Version)3953 static llvm::Value *emitIsPlatformVersionAtLeast(CodeGenFunction &CGF,
3954 const VersionTuple &Version) {
3955 CodeGenModule &CGM = CGF.CGM;
3956 // Note: we intend to support multi-platform version checks, so reserve
3957 // the room for a dual platform checking invocation that will be
3958 // implemented in the future.
3959 llvm::SmallVector<llvm::Value *, 8> Args;
3960
3961 auto EmitArgs = [&](const VersionTuple &Version, const llvm::Triple &TT) {
3962 std::optional<unsigned> Min = Version.getMinor(),
3963 SMin = Version.getSubminor();
3964 Args.push_back(
3965 llvm::ConstantInt::get(CGM.Int32Ty, getBaseMachOPlatformID(TT)));
3966 Args.push_back(llvm::ConstantInt::get(CGM.Int32Ty, Version.getMajor()));
3967 Args.push_back(llvm::ConstantInt::get(CGM.Int32Ty, Min.value_or(0)));
3968 Args.push_back(llvm::ConstantInt::get(CGM.Int32Ty, SMin.value_or(0)));
3969 };
3970
3971 assert(!Version.empty() && "unexpected empty version");
3972 EmitArgs(Version, CGM.getTarget().getTriple());
3973
3974 if (!CGM.IsPlatformVersionAtLeastFn) {
3975 llvm::FunctionType *FTy = llvm::FunctionType::get(
3976 CGM.Int32Ty, {CGM.Int32Ty, CGM.Int32Ty, CGM.Int32Ty, CGM.Int32Ty},
3977 false);
3978 CGM.IsPlatformVersionAtLeastFn =
3979 CGM.CreateRuntimeFunction(FTy, "__isPlatformVersionAtLeast");
3980 }
3981
3982 llvm::Value *Check =
3983 CGF.EmitNounwindRuntimeCall(CGM.IsPlatformVersionAtLeastFn, Args);
3984 return CGF.Builder.CreateICmpNE(Check,
3985 llvm::Constant::getNullValue(CGM.Int32Ty));
3986 }
3987
3988 llvm::Value *
EmitBuiltinAvailable(const VersionTuple & Version)3989 CodeGenFunction::EmitBuiltinAvailable(const VersionTuple &Version) {
3990 // Darwin uses the new __isPlatformVersionAtLeast family of routines.
3991 if (CGM.getTarget().getTriple().isOSDarwin())
3992 return emitIsPlatformVersionAtLeast(*this, Version);
3993
3994 if (!CGM.IsOSVersionAtLeastFn) {
3995 llvm::FunctionType *FTy =
3996 llvm::FunctionType::get(Int32Ty, {Int32Ty, Int32Ty, Int32Ty}, false);
3997 CGM.IsOSVersionAtLeastFn =
3998 CGM.CreateRuntimeFunction(FTy, "__isOSVersionAtLeast");
3999 }
4000
4001 std::optional<unsigned> Min = Version.getMinor(),
4002 SMin = Version.getSubminor();
4003 llvm::Value *Args[] = {
4004 llvm::ConstantInt::get(CGM.Int32Ty, Version.getMajor()),
4005 llvm::ConstantInt::get(CGM.Int32Ty, Min.value_or(0)),
4006 llvm::ConstantInt::get(CGM.Int32Ty, SMin.value_or(0))};
4007
4008 llvm::Value *CallRes =
4009 EmitNounwindRuntimeCall(CGM.IsOSVersionAtLeastFn, Args);
4010
4011 return Builder.CreateICmpNE(CallRes, llvm::Constant::getNullValue(Int32Ty));
4012 }
4013
isFoundationNeededForDarwinAvailabilityCheck(const llvm::Triple & TT,const VersionTuple & TargetVersion)4014 static bool isFoundationNeededForDarwinAvailabilityCheck(
4015 const llvm::Triple &TT, const VersionTuple &TargetVersion) {
4016 VersionTuple FoundationDroppedInVersion;
4017 switch (TT.getOS()) {
4018 case llvm::Triple::IOS:
4019 case llvm::Triple::TvOS:
4020 FoundationDroppedInVersion = VersionTuple(/*Major=*/13);
4021 break;
4022 case llvm::Triple::WatchOS:
4023 FoundationDroppedInVersion = VersionTuple(/*Major=*/6);
4024 break;
4025 case llvm::Triple::Darwin:
4026 case llvm::Triple::MacOSX:
4027 FoundationDroppedInVersion = VersionTuple(/*Major=*/10, /*Minor=*/15);
4028 break;
4029 case llvm::Triple::XROS:
4030 // XROS doesn't need Foundation.
4031 return false;
4032 case llvm::Triple::DriverKit:
4033 // DriverKit doesn't need Foundation.
4034 return false;
4035 default:
4036 llvm_unreachable("Unexpected OS");
4037 }
4038 return TargetVersion < FoundationDroppedInVersion;
4039 }
4040
emitAtAvailableLinkGuard()4041 void CodeGenModule::emitAtAvailableLinkGuard() {
4042 if (!IsPlatformVersionAtLeastFn)
4043 return;
4044 // @available requires CoreFoundation only on Darwin.
4045 if (!Target.getTriple().isOSDarwin())
4046 return;
4047 // @available doesn't need Foundation on macOS 10.15+, iOS/tvOS 13+, or
4048 // watchOS 6+.
4049 if (!isFoundationNeededForDarwinAvailabilityCheck(
4050 Target.getTriple(), Target.getPlatformMinVersion()))
4051 return;
4052 // Add -framework CoreFoundation to the linker commands. We still want to
4053 // emit the core foundation reference down below because otherwise if
4054 // CoreFoundation is not used in the code, the linker won't link the
4055 // framework.
4056 auto &Context = getLLVMContext();
4057 llvm::Metadata *Args[2] = {llvm::MDString::get(Context, "-framework"),
4058 llvm::MDString::get(Context, "CoreFoundation")};
4059 LinkerOptionsMetadata.push_back(llvm::MDNode::get(Context, Args));
4060 // Emit a reference to a symbol from CoreFoundation to ensure that
4061 // CoreFoundation is linked into the final binary.
4062 llvm::FunctionType *FTy =
4063 llvm::FunctionType::get(Int32Ty, {VoidPtrTy}, false);
4064 llvm::FunctionCallee CFFunc =
4065 CreateRuntimeFunction(FTy, "CFBundleGetVersionNumber");
4066
4067 llvm::FunctionType *CheckFTy = llvm::FunctionType::get(VoidTy, {}, false);
4068 llvm::FunctionCallee CFLinkCheckFuncRef = CreateRuntimeFunction(
4069 CheckFTy, "__clang_at_available_requires_core_foundation_framework",
4070 llvm::AttributeList(), /*Local=*/true);
4071 llvm::Function *CFLinkCheckFunc =
4072 cast<llvm::Function>(CFLinkCheckFuncRef.getCallee()->stripPointerCasts());
4073 if (CFLinkCheckFunc->empty()) {
4074 CFLinkCheckFunc->setLinkage(llvm::GlobalValue::LinkOnceAnyLinkage);
4075 CFLinkCheckFunc->setVisibility(llvm::GlobalValue::HiddenVisibility);
4076 CodeGenFunction CGF(*this);
4077 CGF.Builder.SetInsertPoint(CGF.createBasicBlock("", CFLinkCheckFunc));
4078 CGF.EmitNounwindRuntimeCall(CFFunc,
4079 llvm::Constant::getNullValue(VoidPtrTy));
4080 CGF.Builder.CreateUnreachable();
4081 addCompilerUsedGlobal(CFLinkCheckFunc);
4082 }
4083 }
4084
~CGObjCRuntime()4085 CGObjCRuntime::~CGObjCRuntime() {}
4086