1 //===---- CGBuiltin.cpp - Emit LLVM Code for builtins ---------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This contains code to emit Objective-C code as LLVM code. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "CGDebugInfo.h" 15 #include "CGObjCRuntime.h" 16 #include "CodeGenFunction.h" 17 #include "CodeGenModule.h" 18 #include "TargetInfo.h" 19 #include "clang/AST/ASTContext.h" 20 #include "clang/AST/DeclObjC.h" 21 #include "clang/AST/StmtObjC.h" 22 #include "clang/Basic/Diagnostic.h" 23 #include "llvm/ADT/STLExtras.h" 24 #include "llvm/IR/DataLayout.h" 25 #include "llvm/IR/InlineAsm.h" 26 using namespace clang; 27 using namespace CodeGen; 28 29 typedef llvm::PointerIntPair<llvm::Value*,1,bool> TryEmitResult; 30 static TryEmitResult 31 tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e); 32 static RValue AdjustRelatedResultType(CodeGenFunction &CGF, 33 QualType ET, 34 const ObjCMethodDecl *Method, 35 RValue Result); 36 37 /// Given the address of a variable of pointer type, find the correct 38 /// null to store into it. 39 static llvm::Constant *getNullForVariable(llvm::Value *addr) { 40 llvm::Type *type = 41 cast<llvm::PointerType>(addr->getType())->getElementType(); 42 return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(type)); 43 } 44 45 /// Emits an instance of NSConstantString representing the object. 46 llvm::Value *CodeGenFunction::EmitObjCStringLiteral(const ObjCStringLiteral *E) 47 { 48 llvm::Constant *C = 49 CGM.getObjCRuntime().GenerateConstantString(E->getString()); 50 // FIXME: This bitcast should just be made an invariant on the Runtime. 51 return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType())); 52 } 53 54 /// EmitObjCBoxedExpr - This routine generates code to call 55 /// the appropriate expression boxing method. This will either be 56 /// one of +[NSNumber numberWith<Type>:], or +[NSString stringWithUTF8String:]. 57 /// 58 llvm::Value * 59 CodeGenFunction::EmitObjCBoxedExpr(const ObjCBoxedExpr *E) { 60 // Generate the correct selector for this literal's concrete type. 61 const Expr *SubExpr = E->getSubExpr(); 62 // Get the method. 63 const ObjCMethodDecl *BoxingMethod = E->getBoxingMethod(); 64 assert(BoxingMethod && "BoxingMethod is null"); 65 assert(BoxingMethod->isClassMethod() && "BoxingMethod must be a class method"); 66 Selector Sel = BoxingMethod->getSelector(); 67 68 // Generate a reference to the class pointer, which will be the receiver. 69 // Assumes that the method was introduced in the class that should be 70 // messaged (avoids pulling it out of the result type). 71 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 72 const ObjCInterfaceDecl *ClassDecl = BoxingMethod->getClassInterface(); 73 llvm::Value *Receiver = Runtime.GetClass(*this, ClassDecl); 74 75 const ParmVarDecl *argDecl = *BoxingMethod->param_begin(); 76 QualType ArgQT = argDecl->getType().getUnqualifiedType(); 77 RValue RV = EmitAnyExpr(SubExpr); 78 CallArgList Args; 79 Args.add(RV, ArgQT); 80 81 RValue result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 82 BoxingMethod->getResultType(), Sel, Receiver, Args, 83 ClassDecl, BoxingMethod); 84 return Builder.CreateBitCast(result.getScalarVal(), 85 ConvertType(E->getType())); 86 } 87 88 llvm::Value *CodeGenFunction::EmitObjCCollectionLiteral(const Expr *E, 89 const ObjCMethodDecl *MethodWithObjects) { 90 ASTContext &Context = CGM.getContext(); 91 const ObjCDictionaryLiteral *DLE = 0; 92 const ObjCArrayLiteral *ALE = dyn_cast<ObjCArrayLiteral>(E); 93 if (!ALE) 94 DLE = cast<ObjCDictionaryLiteral>(E); 95 96 // Compute the type of the array we're initializing. 97 uint64_t NumElements = 98 ALE ? ALE->getNumElements() : DLE->getNumElements(); 99 llvm::APInt APNumElements(Context.getTypeSize(Context.getSizeType()), 100 NumElements); 101 QualType ElementType = Context.getObjCIdType().withConst(); 102 QualType ElementArrayType 103 = Context.getConstantArrayType(ElementType, APNumElements, 104 ArrayType::Normal, /*IndexTypeQuals=*/0); 105 106 // Allocate the temporary array(s). 107 llvm::Value *Objects = CreateMemTemp(ElementArrayType, "objects"); 108 llvm::Value *Keys = 0; 109 if (DLE) 110 Keys = CreateMemTemp(ElementArrayType, "keys"); 111 112 // Perform the actual initialialization of the array(s). 113 for (uint64_t i = 0; i < NumElements; i++) { 114 if (ALE) { 115 // Emit the initializer. 116 const Expr *Rhs = ALE->getElement(i); 117 LValue LV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i), 118 ElementType, 119 Context.getTypeAlignInChars(Rhs->getType()), 120 Context); 121 EmitScalarInit(Rhs, /*D=*/0, LV, /*capturedByInit=*/false); 122 } else { 123 // Emit the key initializer. 124 const Expr *Key = DLE->getKeyValueElement(i).Key; 125 LValue KeyLV = LValue::MakeAddr(Builder.CreateStructGEP(Keys, i), 126 ElementType, 127 Context.getTypeAlignInChars(Key->getType()), 128 Context); 129 EmitScalarInit(Key, /*D=*/0, KeyLV, /*capturedByInit=*/false); 130 131 // Emit the value initializer. 132 const Expr *Value = DLE->getKeyValueElement(i).Value; 133 LValue ValueLV = LValue::MakeAddr(Builder.CreateStructGEP(Objects, i), 134 ElementType, 135 Context.getTypeAlignInChars(Value->getType()), 136 Context); 137 EmitScalarInit(Value, /*D=*/0, ValueLV, /*capturedByInit=*/false); 138 } 139 } 140 141 // Generate the argument list. 142 CallArgList Args; 143 ObjCMethodDecl::param_const_iterator PI = MethodWithObjects->param_begin(); 144 const ParmVarDecl *argDecl = *PI++; 145 QualType ArgQT = argDecl->getType().getUnqualifiedType(); 146 Args.add(RValue::get(Objects), ArgQT); 147 if (DLE) { 148 argDecl = *PI++; 149 ArgQT = argDecl->getType().getUnqualifiedType(); 150 Args.add(RValue::get(Keys), ArgQT); 151 } 152 argDecl = *PI; 153 ArgQT = argDecl->getType().getUnqualifiedType(); 154 llvm::Value *Count = 155 llvm::ConstantInt::get(CGM.getTypes().ConvertType(ArgQT), NumElements); 156 Args.add(RValue::get(Count), ArgQT); 157 158 // Generate a reference to the class pointer, which will be the receiver. 159 Selector Sel = MethodWithObjects->getSelector(); 160 QualType ResultType = E->getType(); 161 const ObjCObjectPointerType *InterfacePointerType 162 = ResultType->getAsObjCInterfacePointerType(); 163 ObjCInterfaceDecl *Class 164 = InterfacePointerType->getObjectType()->getInterface(); 165 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 166 llvm::Value *Receiver = Runtime.GetClass(*this, Class); 167 168 // Generate the message send. 169 RValue result 170 = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 171 MethodWithObjects->getResultType(), 172 Sel, 173 Receiver, Args, Class, 174 MethodWithObjects); 175 return Builder.CreateBitCast(result.getScalarVal(), 176 ConvertType(E->getType())); 177 } 178 179 llvm::Value *CodeGenFunction::EmitObjCArrayLiteral(const ObjCArrayLiteral *E) { 180 return EmitObjCCollectionLiteral(E, E->getArrayWithObjectsMethod()); 181 } 182 183 llvm::Value *CodeGenFunction::EmitObjCDictionaryLiteral( 184 const ObjCDictionaryLiteral *E) { 185 return EmitObjCCollectionLiteral(E, E->getDictWithObjectsMethod()); 186 } 187 188 /// Emit a selector. 189 llvm::Value *CodeGenFunction::EmitObjCSelectorExpr(const ObjCSelectorExpr *E) { 190 // Untyped selector. 191 // Note that this implementation allows for non-constant strings to be passed 192 // as arguments to @selector(). Currently, the only thing preventing this 193 // behaviour is the type checking in the front end. 194 return CGM.getObjCRuntime().GetSelector(*this, E->getSelector()); 195 } 196 197 llvm::Value *CodeGenFunction::EmitObjCProtocolExpr(const ObjCProtocolExpr *E) { 198 // FIXME: This should pass the Decl not the name. 199 return CGM.getObjCRuntime().GenerateProtocolRef(*this, E->getProtocol()); 200 } 201 202 /// \brief Adjust the type of the result of an Objective-C message send 203 /// expression when the method has a related result type. 204 static RValue AdjustRelatedResultType(CodeGenFunction &CGF, 205 QualType ExpT, 206 const ObjCMethodDecl *Method, 207 RValue Result) { 208 if (!Method) 209 return Result; 210 211 if (!Method->hasRelatedResultType() || 212 CGF.getContext().hasSameType(ExpT, Method->getResultType()) || 213 !Result.isScalar()) 214 return Result; 215 216 // We have applied a related result type. Cast the rvalue appropriately. 217 return RValue::get(CGF.Builder.CreateBitCast(Result.getScalarVal(), 218 CGF.ConvertType(ExpT))); 219 } 220 221 /// Decide whether to extend the lifetime of the receiver of a 222 /// returns-inner-pointer message. 223 static bool 224 shouldExtendReceiverForInnerPointerMessage(const ObjCMessageExpr *message) { 225 switch (message->getReceiverKind()) { 226 227 // For a normal instance message, we should extend unless the 228 // receiver is loaded from a variable with precise lifetime. 229 case ObjCMessageExpr::Instance: { 230 const Expr *receiver = message->getInstanceReceiver(); 231 const ImplicitCastExpr *ice = dyn_cast<ImplicitCastExpr>(receiver); 232 if (!ice || ice->getCastKind() != CK_LValueToRValue) return true; 233 receiver = ice->getSubExpr()->IgnoreParens(); 234 235 // Only __strong variables. 236 if (receiver->getType().getObjCLifetime() != Qualifiers::OCL_Strong) 237 return true; 238 239 // All ivars and fields have precise lifetime. 240 if (isa<MemberExpr>(receiver) || isa<ObjCIvarRefExpr>(receiver)) 241 return false; 242 243 // Otherwise, check for variables. 244 const DeclRefExpr *declRef = dyn_cast<DeclRefExpr>(ice->getSubExpr()); 245 if (!declRef) return true; 246 const VarDecl *var = dyn_cast<VarDecl>(declRef->getDecl()); 247 if (!var) return true; 248 249 // All variables have precise lifetime except local variables with 250 // automatic storage duration that aren't specially marked. 251 return (var->hasLocalStorage() && 252 !var->hasAttr<ObjCPreciseLifetimeAttr>()); 253 } 254 255 case ObjCMessageExpr::Class: 256 case ObjCMessageExpr::SuperClass: 257 // It's never necessary for class objects. 258 return false; 259 260 case ObjCMessageExpr::SuperInstance: 261 // We generally assume that 'self' lives throughout a method call. 262 return false; 263 } 264 265 llvm_unreachable("invalid receiver kind"); 266 } 267 268 RValue CodeGenFunction::EmitObjCMessageExpr(const ObjCMessageExpr *E, 269 ReturnValueSlot Return) { 270 // Only the lookup mechanism and first two arguments of the method 271 // implementation vary between runtimes. We can get the receiver and 272 // arguments in generic code. 273 274 bool isDelegateInit = E->isDelegateInitCall(); 275 276 const ObjCMethodDecl *method = E->getMethodDecl(); 277 278 // We don't retain the receiver in delegate init calls, and this is 279 // safe because the receiver value is always loaded from 'self', 280 // which we zero out. We don't want to Block_copy block receivers, 281 // though. 282 bool retainSelf = 283 (!isDelegateInit && 284 CGM.getLangOpts().ObjCAutoRefCount && 285 method && 286 method->hasAttr<NSConsumesSelfAttr>()); 287 288 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 289 bool isSuperMessage = false; 290 bool isClassMessage = false; 291 ObjCInterfaceDecl *OID = 0; 292 // Find the receiver 293 QualType ReceiverType; 294 llvm::Value *Receiver = 0; 295 switch (E->getReceiverKind()) { 296 case ObjCMessageExpr::Instance: 297 ReceiverType = E->getInstanceReceiver()->getType(); 298 if (retainSelf) { 299 TryEmitResult ter = tryEmitARCRetainScalarExpr(*this, 300 E->getInstanceReceiver()); 301 Receiver = ter.getPointer(); 302 if (ter.getInt()) retainSelf = false; 303 } else 304 Receiver = EmitScalarExpr(E->getInstanceReceiver()); 305 break; 306 307 case ObjCMessageExpr::Class: { 308 ReceiverType = E->getClassReceiver(); 309 const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>(); 310 assert(ObjTy && "Invalid Objective-C class message send"); 311 OID = ObjTy->getInterface(); 312 assert(OID && "Invalid Objective-C class message send"); 313 Receiver = Runtime.GetClass(*this, OID); 314 isClassMessage = true; 315 break; 316 } 317 318 case ObjCMessageExpr::SuperInstance: 319 ReceiverType = E->getSuperType(); 320 Receiver = LoadObjCSelf(); 321 isSuperMessage = true; 322 break; 323 324 case ObjCMessageExpr::SuperClass: 325 ReceiverType = E->getSuperType(); 326 Receiver = LoadObjCSelf(); 327 isSuperMessage = true; 328 isClassMessage = true; 329 break; 330 } 331 332 if (retainSelf) 333 Receiver = EmitARCRetainNonBlock(Receiver); 334 335 // In ARC, we sometimes want to "extend the lifetime" 336 // (i.e. retain+autorelease) of receivers of returns-inner-pointer 337 // messages. 338 if (getLangOpts().ObjCAutoRefCount && method && 339 method->hasAttr<ObjCReturnsInnerPointerAttr>() && 340 shouldExtendReceiverForInnerPointerMessage(E)) 341 Receiver = EmitARCRetainAutorelease(ReceiverType, Receiver); 342 343 QualType ResultType = 344 method ? method->getResultType() : E->getType(); 345 346 CallArgList Args; 347 EmitCallArgs(Args, method, E->arg_begin(), E->arg_end()); 348 349 // For delegate init calls in ARC, do an unsafe store of null into 350 // self. This represents the call taking direct ownership of that 351 // value. We have to do this after emitting the other call 352 // arguments because they might also reference self, but we don't 353 // have to worry about any of them modifying self because that would 354 // be an undefined read and write of an object in unordered 355 // expressions. 356 if (isDelegateInit) { 357 assert(getLangOpts().ObjCAutoRefCount && 358 "delegate init calls should only be marked in ARC"); 359 360 // Do an unsafe store of null into self. 361 llvm::Value *selfAddr = 362 LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()]; 363 assert(selfAddr && "no self entry for a delegate init call?"); 364 365 Builder.CreateStore(getNullForVariable(selfAddr), selfAddr); 366 } 367 368 RValue result; 369 if (isSuperMessage) { 370 // super is only valid in an Objective-C method 371 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); 372 bool isCategoryImpl = isa<ObjCCategoryImplDecl>(OMD->getDeclContext()); 373 result = Runtime.GenerateMessageSendSuper(*this, Return, ResultType, 374 E->getSelector(), 375 OMD->getClassInterface(), 376 isCategoryImpl, 377 Receiver, 378 isClassMessage, 379 Args, 380 method); 381 } else { 382 result = Runtime.GenerateMessageSend(*this, Return, ResultType, 383 E->getSelector(), 384 Receiver, Args, OID, 385 method); 386 } 387 388 // For delegate init calls in ARC, implicitly store the result of 389 // the call back into self. This takes ownership of the value. 390 if (isDelegateInit) { 391 llvm::Value *selfAddr = 392 LocalDeclMap[cast<ObjCMethodDecl>(CurCodeDecl)->getSelfDecl()]; 393 llvm::Value *newSelf = result.getScalarVal(); 394 395 // The delegate return type isn't necessarily a matching type; in 396 // fact, it's quite likely to be 'id'. 397 llvm::Type *selfTy = 398 cast<llvm::PointerType>(selfAddr->getType())->getElementType(); 399 newSelf = Builder.CreateBitCast(newSelf, selfTy); 400 401 Builder.CreateStore(newSelf, selfAddr); 402 } 403 404 return AdjustRelatedResultType(*this, E->getType(), method, result); 405 } 406 407 namespace { 408 struct FinishARCDealloc : EHScopeStack::Cleanup { 409 void Emit(CodeGenFunction &CGF, Flags flags) { 410 const ObjCMethodDecl *method = cast<ObjCMethodDecl>(CGF.CurCodeDecl); 411 412 const ObjCImplDecl *impl = cast<ObjCImplDecl>(method->getDeclContext()); 413 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 414 if (!iface->getSuperClass()) return; 415 416 bool isCategory = isa<ObjCCategoryImplDecl>(impl); 417 418 // Call [super dealloc] if we have a superclass. 419 llvm::Value *self = CGF.LoadObjCSelf(); 420 421 CallArgList args; 422 CGF.CGM.getObjCRuntime().GenerateMessageSendSuper(CGF, ReturnValueSlot(), 423 CGF.getContext().VoidTy, 424 method->getSelector(), 425 iface, 426 isCategory, 427 self, 428 /*is class msg*/ false, 429 args, 430 method); 431 } 432 }; 433 } 434 435 /// StartObjCMethod - Begin emission of an ObjCMethod. This generates 436 /// the LLVM function and sets the other context used by 437 /// CodeGenFunction. 438 void CodeGenFunction::StartObjCMethod(const ObjCMethodDecl *OMD, 439 const ObjCContainerDecl *CD, 440 SourceLocation StartLoc) { 441 FunctionArgList args; 442 // Check if we should generate debug info for this method. 443 if (!OMD->hasAttr<NoDebugAttr>()) 444 maybeInitializeDebugInfo(); 445 446 llvm::Function *Fn = CGM.getObjCRuntime().GenerateMethod(OMD, CD); 447 448 const CGFunctionInfo &FI = CGM.getTypes().arrangeObjCMethodDeclaration(OMD); 449 CGM.SetInternalFunctionAttributes(OMD, Fn, FI); 450 451 args.push_back(OMD->getSelfDecl()); 452 args.push_back(OMD->getCmdDecl()); 453 454 for (ObjCMethodDecl::param_const_iterator PI = OMD->param_begin(), 455 E = OMD->param_end(); PI != E; ++PI) 456 args.push_back(*PI); 457 458 CurGD = OMD; 459 460 StartFunction(OMD, OMD->getResultType(), Fn, FI, args, StartLoc); 461 462 // In ARC, certain methods get an extra cleanup. 463 if (CGM.getLangOpts().ObjCAutoRefCount && 464 OMD->isInstanceMethod() && 465 OMD->getSelector().isUnarySelector()) { 466 const IdentifierInfo *ident = 467 OMD->getSelector().getIdentifierInfoForSlot(0); 468 if (ident->isStr("dealloc")) 469 EHStack.pushCleanup<FinishARCDealloc>(getARCCleanupKind()); 470 } 471 } 472 473 static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF, 474 LValue lvalue, QualType type); 475 476 /// Generate an Objective-C method. An Objective-C method is a C function with 477 /// its pointer, name, and types registered in the class struture. 478 void CodeGenFunction::GenerateObjCMethod(const ObjCMethodDecl *OMD) { 479 StartObjCMethod(OMD, OMD->getClassInterface(), OMD->getLocStart()); 480 EmitStmt(OMD->getBody()); 481 FinishFunction(OMD->getBodyRBrace()); 482 } 483 484 /// emitStructGetterCall - Call the runtime function to load a property 485 /// into the return value slot. 486 static void emitStructGetterCall(CodeGenFunction &CGF, ObjCIvarDecl *ivar, 487 bool isAtomic, bool hasStrong) { 488 ASTContext &Context = CGF.getContext(); 489 490 llvm::Value *src = 491 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), CGF.LoadObjCSelf(), 492 ivar, 0).getAddress(); 493 494 // objc_copyStruct (ReturnValue, &structIvar, 495 // sizeof (Type of Ivar), isAtomic, false); 496 CallArgList args; 497 498 llvm::Value *dest = CGF.Builder.CreateBitCast(CGF.ReturnValue, CGF.VoidPtrTy); 499 args.add(RValue::get(dest), Context.VoidPtrTy); 500 501 src = CGF.Builder.CreateBitCast(src, CGF.VoidPtrTy); 502 args.add(RValue::get(src), Context.VoidPtrTy); 503 504 CharUnits size = CGF.getContext().getTypeSizeInChars(ivar->getType()); 505 args.add(RValue::get(CGF.CGM.getSize(size)), Context.getSizeType()); 506 args.add(RValue::get(CGF.Builder.getInt1(isAtomic)), Context.BoolTy); 507 args.add(RValue::get(CGF.Builder.getInt1(hasStrong)), Context.BoolTy); 508 509 llvm::Value *fn = CGF.CGM.getObjCRuntime().GetGetStructFunction(); 510 CGF.EmitCall(CGF.getTypes().arrangeFreeFunctionCall(Context.VoidTy, args, 511 FunctionType::ExtInfo(), 512 RequiredArgs::All), 513 fn, ReturnValueSlot(), args); 514 } 515 516 /// Determine whether the given architecture supports unaligned atomic 517 /// accesses. They don't have to be fast, just faster than a function 518 /// call and a mutex. 519 static bool hasUnalignedAtomics(llvm::Triple::ArchType arch) { 520 // FIXME: Allow unaligned atomic load/store on x86. (It is not 521 // currently supported by the backend.) 522 return 0; 523 } 524 525 /// Return the maximum size that permits atomic accesses for the given 526 /// architecture. 527 static CharUnits getMaxAtomicAccessSize(CodeGenModule &CGM, 528 llvm::Triple::ArchType arch) { 529 // ARM has 8-byte atomic accesses, but it's not clear whether we 530 // want to rely on them here. 531 532 // In the default case, just assume that any size up to a pointer is 533 // fine given adequate alignment. 534 return CharUnits::fromQuantity(CGM.PointerSizeInBytes); 535 } 536 537 namespace { 538 class PropertyImplStrategy { 539 public: 540 enum StrategyKind { 541 /// The 'native' strategy is to use the architecture's provided 542 /// reads and writes. 543 Native, 544 545 /// Use objc_setProperty and objc_getProperty. 546 GetSetProperty, 547 548 /// Use objc_setProperty for the setter, but use expression 549 /// evaluation for the getter. 550 SetPropertyAndExpressionGet, 551 552 /// Use objc_copyStruct. 553 CopyStruct, 554 555 /// The 'expression' strategy is to emit normal assignment or 556 /// lvalue-to-rvalue expressions. 557 Expression 558 }; 559 560 StrategyKind getKind() const { return StrategyKind(Kind); } 561 562 bool hasStrongMember() const { return HasStrong; } 563 bool isAtomic() const { return IsAtomic; } 564 bool isCopy() const { return IsCopy; } 565 566 CharUnits getIvarSize() const { return IvarSize; } 567 CharUnits getIvarAlignment() const { return IvarAlignment; } 568 569 PropertyImplStrategy(CodeGenModule &CGM, 570 const ObjCPropertyImplDecl *propImpl); 571 572 private: 573 unsigned Kind : 8; 574 unsigned IsAtomic : 1; 575 unsigned IsCopy : 1; 576 unsigned HasStrong : 1; 577 578 CharUnits IvarSize; 579 CharUnits IvarAlignment; 580 }; 581 } 582 583 /// Pick an implementation strategy for the given property synthesis. 584 PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM, 585 const ObjCPropertyImplDecl *propImpl) { 586 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); 587 ObjCPropertyDecl::SetterKind setterKind = prop->getSetterKind(); 588 589 IsCopy = (setterKind == ObjCPropertyDecl::Copy); 590 IsAtomic = prop->isAtomic(); 591 HasStrong = false; // doesn't matter here. 592 593 // Evaluate the ivar's size and alignment. 594 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 595 QualType ivarType = ivar->getType(); 596 llvm::tie(IvarSize, IvarAlignment) 597 = CGM.getContext().getTypeInfoInChars(ivarType); 598 599 // If we have a copy property, we always have to use getProperty/setProperty. 600 // TODO: we could actually use setProperty and an expression for non-atomics. 601 if (IsCopy) { 602 Kind = GetSetProperty; 603 return; 604 } 605 606 // Handle retain. 607 if (setterKind == ObjCPropertyDecl::Retain) { 608 // In GC-only, there's nothing special that needs to be done. 609 if (CGM.getLangOpts().getGC() == LangOptions::GCOnly) { 610 // fallthrough 611 612 // In ARC, if the property is non-atomic, use expression emission, 613 // which translates to objc_storeStrong. This isn't required, but 614 // it's slightly nicer. 615 } else if (CGM.getLangOpts().ObjCAutoRefCount && !IsAtomic) { 616 // Using standard expression emission for the setter is only 617 // acceptable if the ivar is __strong, which won't be true if 618 // the property is annotated with __attribute__((NSObject)). 619 // TODO: falling all the way back to objc_setProperty here is 620 // just laziness, though; we could still use objc_storeStrong 621 // if we hacked it right. 622 if (ivarType.getObjCLifetime() == Qualifiers::OCL_Strong) 623 Kind = Expression; 624 else 625 Kind = SetPropertyAndExpressionGet; 626 return; 627 628 // Otherwise, we need to at least use setProperty. However, if 629 // the property isn't atomic, we can use normal expression 630 // emission for the getter. 631 } else if (!IsAtomic) { 632 Kind = SetPropertyAndExpressionGet; 633 return; 634 635 // Otherwise, we have to use both setProperty and getProperty. 636 } else { 637 Kind = GetSetProperty; 638 return; 639 } 640 } 641 642 // If we're not atomic, just use expression accesses. 643 if (!IsAtomic) { 644 Kind = Expression; 645 return; 646 } 647 648 // Properties on bitfield ivars need to be emitted using expression 649 // accesses even if they're nominally atomic. 650 if (ivar->isBitField()) { 651 Kind = Expression; 652 return; 653 } 654 655 // GC-qualified or ARC-qualified ivars need to be emitted as 656 // expressions. This actually works out to being atomic anyway, 657 // except for ARC __strong, but that should trigger the above code. 658 if (ivarType.hasNonTrivialObjCLifetime() || 659 (CGM.getLangOpts().getGC() && 660 CGM.getContext().getObjCGCAttrKind(ivarType))) { 661 Kind = Expression; 662 return; 663 } 664 665 // Compute whether the ivar has strong members. 666 if (CGM.getLangOpts().getGC()) 667 if (const RecordType *recordType = ivarType->getAs<RecordType>()) 668 HasStrong = recordType->getDecl()->hasObjectMember(); 669 670 // We can never access structs with object members with a native 671 // access, because we need to use write barriers. This is what 672 // objc_copyStruct is for. 673 if (HasStrong) { 674 Kind = CopyStruct; 675 return; 676 } 677 678 // Otherwise, this is target-dependent and based on the size and 679 // alignment of the ivar. 680 681 // If the size of the ivar is not a power of two, give up. We don't 682 // want to get into the business of doing compare-and-swaps. 683 if (!IvarSize.isPowerOfTwo()) { 684 Kind = CopyStruct; 685 return; 686 } 687 688 llvm::Triple::ArchType arch = 689 CGM.getContext().getTargetInfo().getTriple().getArch(); 690 691 // Most architectures require memory to fit within a single cache 692 // line, so the alignment has to be at least the size of the access. 693 // Otherwise we have to grab a lock. 694 if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) { 695 Kind = CopyStruct; 696 return; 697 } 698 699 // If the ivar's size exceeds the architecture's maximum atomic 700 // access size, we have to use CopyStruct. 701 if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) { 702 Kind = CopyStruct; 703 return; 704 } 705 706 // Otherwise, we can use native loads and stores. 707 Kind = Native; 708 } 709 710 /// \brief Generate an Objective-C property getter function. 711 /// 712 /// The given Decl must be an ObjCImplementationDecl. \@synthesize 713 /// is illegal within a category. 714 void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP, 715 const ObjCPropertyImplDecl *PID) { 716 llvm::Constant *AtomicHelperFn = 717 GenerateObjCAtomicGetterCopyHelperFunction(PID); 718 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 719 ObjCMethodDecl *OMD = PD->getGetterMethodDecl(); 720 assert(OMD && "Invalid call to generate getter (empty method)"); 721 StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart()); 722 723 generateObjCGetterBody(IMP, PID, OMD, AtomicHelperFn); 724 725 FinishFunction(); 726 } 727 728 static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) { 729 const Expr *getter = propImpl->getGetterCXXConstructor(); 730 if (!getter) return true; 731 732 // Sema only makes only of these when the ivar has a C++ class type, 733 // so the form is pretty constrained. 734 735 // If the property has a reference type, we might just be binding a 736 // reference, in which case the result will be a gl-value. We should 737 // treat this as a non-trivial operation. 738 if (getter->isGLValue()) 739 return false; 740 741 // If we selected a trivial copy-constructor, we're okay. 742 if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter)) 743 return (construct->getConstructor()->isTrivial()); 744 745 // The constructor might require cleanups (in which case it's never 746 // trivial). 747 assert(isa<ExprWithCleanups>(getter)); 748 return false; 749 } 750 751 /// emitCPPObjectAtomicGetterCall - Call the runtime function to 752 /// copy the ivar into the resturn slot. 753 static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF, 754 llvm::Value *returnAddr, 755 ObjCIvarDecl *ivar, 756 llvm::Constant *AtomicHelperFn) { 757 // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar, 758 // AtomicHelperFn); 759 CallArgList args; 760 761 // The 1st argument is the return Slot. 762 args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy); 763 764 // The 2nd argument is the address of the ivar. 765 llvm::Value *ivarAddr = 766 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 767 CGF.LoadObjCSelf(), ivar, 0).getAddress(); 768 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 769 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 770 771 // Third argument is the helper function. 772 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); 773 774 llvm::Value *copyCppAtomicObjectFn = 775 CGF.CGM.getObjCRuntime().GetCppAtomicObjectGetFunction(); 776 CGF.EmitCall(CGF.getTypes().arrangeFreeFunctionCall(CGF.getContext().VoidTy, 777 args, 778 FunctionType::ExtInfo(), 779 RequiredArgs::All), 780 copyCppAtomicObjectFn, ReturnValueSlot(), args); 781 } 782 783 void 784 CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl, 785 const ObjCPropertyImplDecl *propImpl, 786 const ObjCMethodDecl *GetterMethodDecl, 787 llvm::Constant *AtomicHelperFn) { 788 // If there's a non-trivial 'get' expression, we just have to emit that. 789 if (!hasTrivialGetExpr(propImpl)) { 790 if (!AtomicHelperFn) { 791 ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(), 792 /*nrvo*/ 0); 793 EmitReturnStmt(ret); 794 } 795 else { 796 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 797 emitCPPObjectAtomicGetterCall(*this, ReturnValue, 798 ivar, AtomicHelperFn); 799 } 800 return; 801 } 802 803 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); 804 QualType propType = prop->getType(); 805 ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl(); 806 807 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 808 809 // Pick an implementation strategy. 810 PropertyImplStrategy strategy(CGM, propImpl); 811 switch (strategy.getKind()) { 812 case PropertyImplStrategy::Native: { 813 // We don't need to do anything for a zero-size struct. 814 if (strategy.getIvarSize().isZero()) 815 return; 816 817 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); 818 819 // Currently, all atomic accesses have to be through integer 820 // types, so there's no point in trying to pick a prettier type. 821 llvm::Type *bitcastType = 822 llvm::Type::getIntNTy(getLLVMContext(), 823 getContext().toBits(strategy.getIvarSize())); 824 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay 825 826 // Perform an atomic load. This does not impose ordering constraints. 827 llvm::Value *ivarAddr = LV.getAddress(); 828 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType); 829 llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load"); 830 load->setAlignment(strategy.getIvarAlignment().getQuantity()); 831 load->setAtomic(llvm::Unordered); 832 833 // Store that value into the return address. Doing this with a 834 // bitcast is likely to produce some pretty ugly IR, but it's not 835 // the *most* terrible thing in the world. 836 Builder.CreateStore(load, Builder.CreateBitCast(ReturnValue, bitcastType)); 837 838 // Make sure we don't do an autorelease. 839 AutoreleaseResult = false; 840 return; 841 } 842 843 case PropertyImplStrategy::GetSetProperty: { 844 llvm::Value *getPropertyFn = 845 CGM.getObjCRuntime().GetPropertyGetFunction(); 846 if (!getPropertyFn) { 847 CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy"); 848 return; 849 } 850 851 // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true). 852 // FIXME: Can't this be simpler? This might even be worse than the 853 // corresponding gcc code. 854 llvm::Value *cmd = 855 Builder.CreateLoad(LocalDeclMap[getterMethod->getCmdDecl()], "cmd"); 856 llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); 857 llvm::Value *ivarOffset = 858 EmitIvarOffset(classImpl->getClassInterface(), ivar); 859 860 CallArgList args; 861 args.add(RValue::get(self), getContext().getObjCIdType()); 862 args.add(RValue::get(cmd), getContext().getObjCSelType()); 863 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 864 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), 865 getContext().BoolTy); 866 867 // FIXME: We shouldn't need to get the function info here, the 868 // runtime already should have computed it to build the function. 869 RValue RV = EmitCall(getTypes().arrangeFreeFunctionCall(propType, args, 870 FunctionType::ExtInfo(), 871 RequiredArgs::All), 872 getPropertyFn, ReturnValueSlot(), args); 873 874 // We need to fix the type here. Ivars with copy & retain are 875 // always objects so we don't need to worry about complex or 876 // aggregates. 877 RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(), 878 getTypes().ConvertType(getterMethod->getResultType()))); 879 880 EmitReturnOfRValue(RV, propType); 881 882 // objc_getProperty does an autorelease, so we should suppress ours. 883 AutoreleaseResult = false; 884 885 return; 886 } 887 888 case PropertyImplStrategy::CopyStruct: 889 emitStructGetterCall(*this, ivar, strategy.isAtomic(), 890 strategy.hasStrongMember()); 891 return; 892 893 case PropertyImplStrategy::Expression: 894 case PropertyImplStrategy::SetPropertyAndExpressionGet: { 895 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); 896 897 QualType ivarType = ivar->getType(); 898 switch (getEvaluationKind(ivarType)) { 899 case TEK_Complex: { 900 ComplexPairTy pair = EmitLoadOfComplex(LV); 901 EmitStoreOfComplex(pair, 902 MakeNaturalAlignAddrLValue(ReturnValue, ivarType), 903 /*init*/ true); 904 return; 905 } 906 case TEK_Aggregate: 907 // The return value slot is guaranteed to not be aliased, but 908 // that's not necessarily the same as "on the stack", so 909 // we still potentially need objc_memmove_collectable. 910 EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType); 911 return; 912 case TEK_Scalar: { 913 llvm::Value *value; 914 if (propType->isReferenceType()) { 915 value = LV.getAddress(); 916 } else { 917 // We want to load and autoreleaseReturnValue ARC __weak ivars. 918 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) { 919 value = emitARCRetainLoadOfScalar(*this, LV, ivarType); 920 921 // Otherwise we want to do a simple load, suppressing the 922 // final autorelease. 923 } else { 924 value = EmitLoadOfLValue(LV).getScalarVal(); 925 AutoreleaseResult = false; 926 } 927 928 value = Builder.CreateBitCast(value, ConvertType(propType)); 929 value = Builder.CreateBitCast(value, 930 ConvertType(GetterMethodDecl->getResultType())); 931 } 932 933 EmitReturnOfRValue(RValue::get(value), propType); 934 return; 935 } 936 } 937 llvm_unreachable("bad evaluation kind"); 938 } 939 940 } 941 llvm_unreachable("bad @property implementation strategy!"); 942 } 943 944 /// emitStructSetterCall - Call the runtime function to store the value 945 /// from the first formal parameter into the given ivar. 946 static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD, 947 ObjCIvarDecl *ivar) { 948 // objc_copyStruct (&structIvar, &Arg, 949 // sizeof (struct something), true, false); 950 CallArgList args; 951 952 // The first argument is the address of the ivar. 953 llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 954 CGF.LoadObjCSelf(), ivar, 0) 955 .getAddress(); 956 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 957 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 958 959 // The second argument is the address of the parameter variable. 960 ParmVarDecl *argVar = *OMD->param_begin(); 961 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 962 VK_LValue, SourceLocation()); 963 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress(); 964 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); 965 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); 966 967 // The third argument is the sizeof the type. 968 llvm::Value *size = 969 CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType())); 970 args.add(RValue::get(size), CGF.getContext().getSizeType()); 971 972 // The fourth argument is the 'isAtomic' flag. 973 args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy); 974 975 // The fifth argument is the 'hasStrong' flag. 976 // FIXME: should this really always be false? 977 args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy); 978 979 llvm::Value *copyStructFn = CGF.CGM.getObjCRuntime().GetSetStructFunction(); 980 CGF.EmitCall(CGF.getTypes().arrangeFreeFunctionCall(CGF.getContext().VoidTy, 981 args, 982 FunctionType::ExtInfo(), 983 RequiredArgs::All), 984 copyStructFn, ReturnValueSlot(), args); 985 } 986 987 /// emitCPPObjectAtomicSetterCall - Call the runtime function to store 988 /// the value from the first formal parameter into the given ivar, using 989 /// the Cpp API for atomic Cpp objects with non-trivial copy assignment. 990 static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF, 991 ObjCMethodDecl *OMD, 992 ObjCIvarDecl *ivar, 993 llvm::Constant *AtomicHelperFn) { 994 // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg, 995 // AtomicHelperFn); 996 CallArgList args; 997 998 // The first argument is the address of the ivar. 999 llvm::Value *ivarAddr = 1000 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 1001 CGF.LoadObjCSelf(), ivar, 0).getAddress(); 1002 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 1003 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 1004 1005 // The second argument is the address of the parameter variable. 1006 ParmVarDecl *argVar = *OMD->param_begin(); 1007 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 1008 VK_LValue, SourceLocation()); 1009 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress(); 1010 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); 1011 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); 1012 1013 // Third argument is the helper function. 1014 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); 1015 1016 llvm::Value *copyCppAtomicObjectFn = 1017 CGF.CGM.getObjCRuntime().GetCppAtomicObjectSetFunction(); 1018 CGF.EmitCall(CGF.getTypes().arrangeFreeFunctionCall(CGF.getContext().VoidTy, 1019 args, 1020 FunctionType::ExtInfo(), 1021 RequiredArgs::All), 1022 copyCppAtomicObjectFn, ReturnValueSlot(), args); 1023 1024 1025 } 1026 1027 1028 static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) { 1029 Expr *setter = PID->getSetterCXXAssignment(); 1030 if (!setter) return true; 1031 1032 // Sema only makes only of these when the ivar has a C++ class type, 1033 // so the form is pretty constrained. 1034 1035 // An operator call is trivial if the function it calls is trivial. 1036 // This also implies that there's nothing non-trivial going on with 1037 // the arguments, because operator= can only be trivial if it's a 1038 // synthesized assignment operator and therefore both parameters are 1039 // references. 1040 if (CallExpr *call = dyn_cast<CallExpr>(setter)) { 1041 if (const FunctionDecl *callee 1042 = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl())) 1043 if (callee->isTrivial()) 1044 return true; 1045 return false; 1046 } 1047 1048 assert(isa<ExprWithCleanups>(setter)); 1049 return false; 1050 } 1051 1052 static bool UseOptimizedSetter(CodeGenModule &CGM) { 1053 if (CGM.getLangOpts().getGC() != LangOptions::NonGC) 1054 return false; 1055 return CGM.getLangOpts().ObjCRuntime.hasOptimizedSetter(); 1056 } 1057 1058 void 1059 CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl, 1060 const ObjCPropertyImplDecl *propImpl, 1061 llvm::Constant *AtomicHelperFn) { 1062 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); 1063 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 1064 ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl(); 1065 1066 // Just use the setter expression if Sema gave us one and it's 1067 // non-trivial. 1068 if (!hasTrivialSetExpr(propImpl)) { 1069 if (!AtomicHelperFn) 1070 // If non-atomic, assignment is called directly. 1071 EmitStmt(propImpl->getSetterCXXAssignment()); 1072 else 1073 // If atomic, assignment is called via a locking api. 1074 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar, 1075 AtomicHelperFn); 1076 return; 1077 } 1078 1079 PropertyImplStrategy strategy(CGM, propImpl); 1080 switch (strategy.getKind()) { 1081 case PropertyImplStrategy::Native: { 1082 // We don't need to do anything for a zero-size struct. 1083 if (strategy.getIvarSize().isZero()) 1084 return; 1085 1086 llvm::Value *argAddr = LocalDeclMap[*setterMethod->param_begin()]; 1087 1088 LValue ivarLValue = 1089 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0); 1090 llvm::Value *ivarAddr = ivarLValue.getAddress(); 1091 1092 // Currently, all atomic accesses have to be through integer 1093 // types, so there's no point in trying to pick a prettier type. 1094 llvm::Type *bitcastType = 1095 llvm::Type::getIntNTy(getLLVMContext(), 1096 getContext().toBits(strategy.getIvarSize())); 1097 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay 1098 1099 // Cast both arguments to the chosen operation type. 1100 argAddr = Builder.CreateBitCast(argAddr, bitcastType); 1101 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType); 1102 1103 // This bitcast load is likely to cause some nasty IR. 1104 llvm::Value *load = Builder.CreateLoad(argAddr); 1105 1106 // Perform an atomic store. There are no memory ordering requirements. 1107 llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr); 1108 store->setAlignment(strategy.getIvarAlignment().getQuantity()); 1109 store->setAtomic(llvm::Unordered); 1110 return; 1111 } 1112 1113 case PropertyImplStrategy::GetSetProperty: 1114 case PropertyImplStrategy::SetPropertyAndExpressionGet: { 1115 1116 llvm::Value *setOptimizedPropertyFn = 0; 1117 llvm::Value *setPropertyFn = 0; 1118 if (UseOptimizedSetter(CGM)) { 1119 // 10.8 and iOS 6.0 code and GC is off 1120 setOptimizedPropertyFn = 1121 CGM.getObjCRuntime() 1122 .GetOptimizedPropertySetFunction(strategy.isAtomic(), 1123 strategy.isCopy()); 1124 if (!setOptimizedPropertyFn) { 1125 CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI"); 1126 return; 1127 } 1128 } 1129 else { 1130 setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction(); 1131 if (!setPropertyFn) { 1132 CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy"); 1133 return; 1134 } 1135 } 1136 1137 // Emit objc_setProperty((id) self, _cmd, offset, arg, 1138 // <is-atomic>, <is-copy>). 1139 llvm::Value *cmd = 1140 Builder.CreateLoad(LocalDeclMap[setterMethod->getCmdDecl()]); 1141 llvm::Value *self = 1142 Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); 1143 llvm::Value *ivarOffset = 1144 EmitIvarOffset(classImpl->getClassInterface(), ivar); 1145 llvm::Value *arg = LocalDeclMap[*setterMethod->param_begin()]; 1146 arg = Builder.CreateBitCast(Builder.CreateLoad(arg, "arg"), VoidPtrTy); 1147 1148 CallArgList args; 1149 args.add(RValue::get(self), getContext().getObjCIdType()); 1150 args.add(RValue::get(cmd), getContext().getObjCSelType()); 1151 if (setOptimizedPropertyFn) { 1152 args.add(RValue::get(arg), getContext().getObjCIdType()); 1153 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 1154 EmitCall(getTypes().arrangeFreeFunctionCall(getContext().VoidTy, args, 1155 FunctionType::ExtInfo(), 1156 RequiredArgs::All), 1157 setOptimizedPropertyFn, ReturnValueSlot(), args); 1158 } else { 1159 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 1160 args.add(RValue::get(arg), getContext().getObjCIdType()); 1161 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), 1162 getContext().BoolTy); 1163 args.add(RValue::get(Builder.getInt1(strategy.isCopy())), 1164 getContext().BoolTy); 1165 // FIXME: We shouldn't need to get the function info here, the runtime 1166 // already should have computed it to build the function. 1167 EmitCall(getTypes().arrangeFreeFunctionCall(getContext().VoidTy, args, 1168 FunctionType::ExtInfo(), 1169 RequiredArgs::All), 1170 setPropertyFn, ReturnValueSlot(), args); 1171 } 1172 1173 return; 1174 } 1175 1176 case PropertyImplStrategy::CopyStruct: 1177 emitStructSetterCall(*this, setterMethod, ivar); 1178 return; 1179 1180 case PropertyImplStrategy::Expression: 1181 break; 1182 } 1183 1184 // Otherwise, fake up some ASTs and emit a normal assignment. 1185 ValueDecl *selfDecl = setterMethod->getSelfDecl(); 1186 DeclRefExpr self(selfDecl, false, selfDecl->getType(), 1187 VK_LValue, SourceLocation()); 1188 ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack, 1189 selfDecl->getType(), CK_LValueToRValue, &self, 1190 VK_RValue); 1191 ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(), 1192 SourceLocation(), &selfLoad, true, true); 1193 1194 ParmVarDecl *argDecl = *setterMethod->param_begin(); 1195 QualType argType = argDecl->getType().getNonReferenceType(); 1196 DeclRefExpr arg(argDecl, false, argType, VK_LValue, SourceLocation()); 1197 ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack, 1198 argType.getUnqualifiedType(), CK_LValueToRValue, 1199 &arg, VK_RValue); 1200 1201 // The property type can differ from the ivar type in some situations with 1202 // Objective-C pointer types, we can always bit cast the RHS in these cases. 1203 // The following absurdity is just to ensure well-formed IR. 1204 CastKind argCK = CK_NoOp; 1205 if (ivarRef.getType()->isObjCObjectPointerType()) { 1206 if (argLoad.getType()->isObjCObjectPointerType()) 1207 argCK = CK_BitCast; 1208 else if (argLoad.getType()->isBlockPointerType()) 1209 argCK = CK_BlockPointerToObjCPointerCast; 1210 else 1211 argCK = CK_CPointerToObjCPointerCast; 1212 } else if (ivarRef.getType()->isBlockPointerType()) { 1213 if (argLoad.getType()->isBlockPointerType()) 1214 argCK = CK_BitCast; 1215 else 1216 argCK = CK_AnyPointerToBlockPointerCast; 1217 } else if (ivarRef.getType()->isPointerType()) { 1218 argCK = CK_BitCast; 1219 } 1220 ImplicitCastExpr argCast(ImplicitCastExpr::OnStack, 1221 ivarRef.getType(), argCK, &argLoad, 1222 VK_RValue); 1223 Expr *finalArg = &argLoad; 1224 if (!getContext().hasSameUnqualifiedType(ivarRef.getType(), 1225 argLoad.getType())) 1226 finalArg = &argCast; 1227 1228 1229 BinaryOperator assign(&ivarRef, finalArg, BO_Assign, 1230 ivarRef.getType(), VK_RValue, OK_Ordinary, 1231 SourceLocation(), false); 1232 EmitStmt(&assign); 1233 } 1234 1235 /// \brief Generate an Objective-C property setter function. 1236 /// 1237 /// The given Decl must be an ObjCImplementationDecl. \@synthesize 1238 /// is illegal within a category. 1239 void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP, 1240 const ObjCPropertyImplDecl *PID) { 1241 llvm::Constant *AtomicHelperFn = 1242 GenerateObjCAtomicSetterCopyHelperFunction(PID); 1243 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1244 ObjCMethodDecl *OMD = PD->getSetterMethodDecl(); 1245 assert(OMD && "Invalid call to generate setter (empty method)"); 1246 StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart()); 1247 1248 generateObjCSetterBody(IMP, PID, AtomicHelperFn); 1249 1250 FinishFunction(); 1251 } 1252 1253 namespace { 1254 struct DestroyIvar : EHScopeStack::Cleanup { 1255 private: 1256 llvm::Value *addr; 1257 const ObjCIvarDecl *ivar; 1258 CodeGenFunction::Destroyer *destroyer; 1259 bool useEHCleanupForArray; 1260 public: 1261 DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar, 1262 CodeGenFunction::Destroyer *destroyer, 1263 bool useEHCleanupForArray) 1264 : addr(addr), ivar(ivar), destroyer(destroyer), 1265 useEHCleanupForArray(useEHCleanupForArray) {} 1266 1267 void Emit(CodeGenFunction &CGF, Flags flags) { 1268 LValue lvalue 1269 = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0); 1270 CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer, 1271 flags.isForNormalCleanup() && useEHCleanupForArray); 1272 } 1273 }; 1274 } 1275 1276 /// Like CodeGenFunction::destroyARCStrong, but do it with a call. 1277 static void destroyARCStrongWithStore(CodeGenFunction &CGF, 1278 llvm::Value *addr, 1279 QualType type) { 1280 llvm::Value *null = getNullForVariable(addr); 1281 CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true); 1282 } 1283 1284 static void emitCXXDestructMethod(CodeGenFunction &CGF, 1285 ObjCImplementationDecl *impl) { 1286 CodeGenFunction::RunCleanupsScope scope(CGF); 1287 1288 llvm::Value *self = CGF.LoadObjCSelf(); 1289 1290 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 1291 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 1292 ivar; ivar = ivar->getNextIvar()) { 1293 QualType type = ivar->getType(); 1294 1295 // Check whether the ivar is a destructible type. 1296 QualType::DestructionKind dtorKind = type.isDestructedType(); 1297 if (!dtorKind) continue; 1298 1299 CodeGenFunction::Destroyer *destroyer = 0; 1300 1301 // Use a call to objc_storeStrong to destroy strong ivars, for the 1302 // general benefit of the tools. 1303 if (dtorKind == QualType::DK_objc_strong_lifetime) { 1304 destroyer = destroyARCStrongWithStore; 1305 1306 // Otherwise use the default for the destruction kind. 1307 } else { 1308 destroyer = CGF.getDestroyer(dtorKind); 1309 } 1310 1311 CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind); 1312 1313 CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer, 1314 cleanupKind & EHCleanup); 1315 } 1316 1317 assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?"); 1318 } 1319 1320 void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP, 1321 ObjCMethodDecl *MD, 1322 bool ctor) { 1323 MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface()); 1324 StartObjCMethod(MD, IMP->getClassInterface(), MD->getLocStart()); 1325 1326 // Emit .cxx_construct. 1327 if (ctor) { 1328 // Suppress the final autorelease in ARC. 1329 AutoreleaseResult = false; 1330 1331 SmallVector<CXXCtorInitializer *, 8> IvarInitializers; 1332 for (ObjCImplementationDecl::init_const_iterator B = IMP->init_begin(), 1333 E = IMP->init_end(); B != E; ++B) { 1334 CXXCtorInitializer *IvarInit = (*B); 1335 FieldDecl *Field = IvarInit->getAnyMember(); 1336 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field); 1337 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), 1338 LoadObjCSelf(), Ivar, 0); 1339 EmitAggExpr(IvarInit->getInit(), 1340 AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, 1341 AggValueSlot::DoesNotNeedGCBarriers, 1342 AggValueSlot::IsNotAliased)); 1343 } 1344 // constructor returns 'self'. 1345 CodeGenTypes &Types = CGM.getTypes(); 1346 QualType IdTy(CGM.getContext().getObjCIdType()); 1347 llvm::Value *SelfAsId = 1348 Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy)); 1349 EmitReturnOfRValue(RValue::get(SelfAsId), IdTy); 1350 1351 // Emit .cxx_destruct. 1352 } else { 1353 emitCXXDestructMethod(*this, IMP); 1354 } 1355 FinishFunction(); 1356 } 1357 1358 bool CodeGenFunction::IndirectObjCSetterArg(const CGFunctionInfo &FI) { 1359 CGFunctionInfo::const_arg_iterator it = FI.arg_begin(); 1360 it++; it++; 1361 const ABIArgInfo &AI = it->info; 1362 // FIXME. Is this sufficient check? 1363 return (AI.getKind() == ABIArgInfo::Indirect); 1364 } 1365 1366 bool CodeGenFunction::IvarTypeWithAggrGCObjects(QualType Ty) { 1367 if (CGM.getLangOpts().getGC() == LangOptions::NonGC) 1368 return false; 1369 if (const RecordType *FDTTy = Ty.getTypePtr()->getAs<RecordType>()) 1370 return FDTTy->getDecl()->hasObjectMember(); 1371 return false; 1372 } 1373 1374 llvm::Value *CodeGenFunction::LoadObjCSelf() { 1375 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); 1376 return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self"); 1377 } 1378 1379 QualType CodeGenFunction::TypeOfSelfObject() { 1380 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); 1381 ImplicitParamDecl *selfDecl = OMD->getSelfDecl(); 1382 const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>( 1383 getContext().getCanonicalType(selfDecl->getType())); 1384 return PTy->getPointeeType(); 1385 } 1386 1387 void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){ 1388 llvm::Constant *EnumerationMutationFn = 1389 CGM.getObjCRuntime().EnumerationMutationFunction(); 1390 1391 if (!EnumerationMutationFn) { 1392 CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime"); 1393 return; 1394 } 1395 1396 CGDebugInfo *DI = getDebugInfo(); 1397 if (DI) 1398 DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin()); 1399 1400 // The local variable comes into scope immediately. 1401 AutoVarEmission variable = AutoVarEmission::invalid(); 1402 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) 1403 variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl())); 1404 1405 JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end"); 1406 1407 // Fast enumeration state. 1408 QualType StateTy = CGM.getObjCFastEnumerationStateType(); 1409 llvm::Value *StatePtr = CreateMemTemp(StateTy, "state.ptr"); 1410 EmitNullInitialization(StatePtr, StateTy); 1411 1412 // Number of elements in the items array. 1413 static const unsigned NumItems = 16; 1414 1415 // Fetch the countByEnumeratingWithState:objects:count: selector. 1416 IdentifierInfo *II[] = { 1417 &CGM.getContext().Idents.get("countByEnumeratingWithState"), 1418 &CGM.getContext().Idents.get("objects"), 1419 &CGM.getContext().Idents.get("count") 1420 }; 1421 Selector FastEnumSel = 1422 CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]); 1423 1424 QualType ItemsTy = 1425 getContext().getConstantArrayType(getContext().getObjCIdType(), 1426 llvm::APInt(32, NumItems), 1427 ArrayType::Normal, 0); 1428 llvm::Value *ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr"); 1429 1430 // Emit the collection pointer. In ARC, we do a retain. 1431 llvm::Value *Collection; 1432 if (getLangOpts().ObjCAutoRefCount) { 1433 Collection = EmitARCRetainScalarExpr(S.getCollection()); 1434 1435 // Enter a cleanup to do the release. 1436 EmitObjCConsumeObject(S.getCollection()->getType(), Collection); 1437 } else { 1438 Collection = EmitScalarExpr(S.getCollection()); 1439 } 1440 1441 // The 'continue' label needs to appear within the cleanup for the 1442 // collection object. 1443 JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next"); 1444 1445 // Send it our message: 1446 CallArgList Args; 1447 1448 // The first argument is a temporary of the enumeration-state type. 1449 Args.add(RValue::get(StatePtr), getContext().getPointerType(StateTy)); 1450 1451 // The second argument is a temporary array with space for NumItems 1452 // pointers. We'll actually be loading elements from the array 1453 // pointer written into the control state; this buffer is so that 1454 // collections that *aren't* backed by arrays can still queue up 1455 // batches of elements. 1456 Args.add(RValue::get(ItemsPtr), getContext().getPointerType(ItemsTy)); 1457 1458 // The third argument is the capacity of that temporary array. 1459 llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy); 1460 llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems); 1461 Args.add(RValue::get(Count), getContext().UnsignedLongTy); 1462 1463 // Start the enumeration. 1464 RValue CountRV = 1465 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 1466 getContext().UnsignedLongTy, 1467 FastEnumSel, 1468 Collection, Args); 1469 1470 // The initial number of objects that were returned in the buffer. 1471 llvm::Value *initialBufferLimit = CountRV.getScalarVal(); 1472 1473 llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty"); 1474 llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit"); 1475 1476 llvm::Value *zero = llvm::Constant::getNullValue(UnsignedLongLTy); 1477 1478 // If the limit pointer was zero to begin with, the collection is 1479 // empty; skip all this. 1480 Builder.CreateCondBr(Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), 1481 EmptyBB, LoopInitBB); 1482 1483 // Otherwise, initialize the loop. 1484 EmitBlock(LoopInitBB); 1485 1486 // Save the initial mutations value. This is the value at an 1487 // address that was written into the state object by 1488 // countByEnumeratingWithState:objects:count:. 1489 llvm::Value *StateMutationsPtrPtr = 1490 Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr"); 1491 llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, 1492 "mutationsptr"); 1493 1494 llvm::Value *initialMutations = 1495 Builder.CreateLoad(StateMutationsPtr, "forcoll.initial-mutations"); 1496 1497 // Start looping. This is the point we return to whenever we have a 1498 // fresh, non-empty batch of objects. 1499 llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody"); 1500 EmitBlock(LoopBodyBB); 1501 1502 // The current index into the buffer. 1503 llvm::PHINode *index = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.index"); 1504 index->addIncoming(zero, LoopInitBB); 1505 1506 // The current buffer size. 1507 llvm::PHINode *count = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.count"); 1508 count->addIncoming(initialBufferLimit, LoopInitBB); 1509 1510 // Check whether the mutations value has changed from where it was 1511 // at start. StateMutationsPtr should actually be invariant between 1512 // refreshes. 1513 StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); 1514 llvm::Value *currentMutations 1515 = Builder.CreateLoad(StateMutationsPtr, "statemutations"); 1516 1517 llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated"); 1518 llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated"); 1519 1520 Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations), 1521 WasNotMutatedBB, WasMutatedBB); 1522 1523 // If so, call the enumeration-mutation function. 1524 EmitBlock(WasMutatedBB); 1525 llvm::Value *V = 1526 Builder.CreateBitCast(Collection, 1527 ConvertType(getContext().getObjCIdType())); 1528 CallArgList Args2; 1529 Args2.add(RValue::get(V), getContext().getObjCIdType()); 1530 // FIXME: We shouldn't need to get the function info here, the runtime already 1531 // should have computed it to build the function. 1532 EmitCall(CGM.getTypes().arrangeFreeFunctionCall(getContext().VoidTy, Args2, 1533 FunctionType::ExtInfo(), 1534 RequiredArgs::All), 1535 EnumerationMutationFn, ReturnValueSlot(), Args2); 1536 1537 // Otherwise, or if the mutation function returns, just continue. 1538 EmitBlock(WasNotMutatedBB); 1539 1540 // Initialize the element variable. 1541 RunCleanupsScope elementVariableScope(*this); 1542 bool elementIsVariable; 1543 LValue elementLValue; 1544 QualType elementType; 1545 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) { 1546 // Initialize the variable, in case it's a __block variable or something. 1547 EmitAutoVarInit(variable); 1548 1549 const VarDecl* D = cast<VarDecl>(SD->getSingleDecl()); 1550 DeclRefExpr tempDRE(const_cast<VarDecl*>(D), false, D->getType(), 1551 VK_LValue, SourceLocation()); 1552 elementLValue = EmitLValue(&tempDRE); 1553 elementType = D->getType(); 1554 elementIsVariable = true; 1555 1556 if (D->isARCPseudoStrong()) 1557 elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone); 1558 } else { 1559 elementLValue = LValue(); // suppress warning 1560 elementType = cast<Expr>(S.getElement())->getType(); 1561 elementIsVariable = false; 1562 } 1563 llvm::Type *convertedElementType = ConvertType(elementType); 1564 1565 // Fetch the buffer out of the enumeration state. 1566 // TODO: this pointer should actually be invariant between 1567 // refreshes, which would help us do certain loop optimizations. 1568 llvm::Value *StateItemsPtr = 1569 Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr"); 1570 llvm::Value *EnumStateItems = 1571 Builder.CreateLoad(StateItemsPtr, "stateitems"); 1572 1573 // Fetch the value at the current index from the buffer. 1574 llvm::Value *CurrentItemPtr = 1575 Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr"); 1576 llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr); 1577 1578 // Cast that value to the right type. 1579 CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType, 1580 "currentitem"); 1581 1582 // Make sure we have an l-value. Yes, this gets evaluated every 1583 // time through the loop. 1584 if (!elementIsVariable) { 1585 elementLValue = EmitLValue(cast<Expr>(S.getElement())); 1586 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue); 1587 } else { 1588 EmitScalarInit(CurrentItem, elementLValue); 1589 } 1590 1591 // If we do have an element variable, this assignment is the end of 1592 // its initialization. 1593 if (elementIsVariable) 1594 EmitAutoVarCleanups(variable); 1595 1596 // Perform the loop body, setting up break and continue labels. 1597 BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody)); 1598 { 1599 RunCleanupsScope Scope(*this); 1600 EmitStmt(S.getBody()); 1601 } 1602 BreakContinueStack.pop_back(); 1603 1604 // Destroy the element variable now. 1605 elementVariableScope.ForceCleanup(); 1606 1607 // Check whether there are more elements. 1608 EmitBlock(AfterBody.getBlock()); 1609 1610 llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch"); 1611 1612 // First we check in the local buffer. 1613 llvm::Value *indexPlusOne 1614 = Builder.CreateAdd(index, llvm::ConstantInt::get(UnsignedLongLTy, 1)); 1615 1616 // If we haven't overrun the buffer yet, we can continue. 1617 Builder.CreateCondBr(Builder.CreateICmpULT(indexPlusOne, count), 1618 LoopBodyBB, FetchMoreBB); 1619 1620 index->addIncoming(indexPlusOne, AfterBody.getBlock()); 1621 count->addIncoming(count, AfterBody.getBlock()); 1622 1623 // Otherwise, we have to fetch more elements. 1624 EmitBlock(FetchMoreBB); 1625 1626 CountRV = 1627 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 1628 getContext().UnsignedLongTy, 1629 FastEnumSel, 1630 Collection, Args); 1631 1632 // If we got a zero count, we're done. 1633 llvm::Value *refetchCount = CountRV.getScalarVal(); 1634 1635 // (note that the message send might split FetchMoreBB) 1636 index->addIncoming(zero, Builder.GetInsertBlock()); 1637 count->addIncoming(refetchCount, Builder.GetInsertBlock()); 1638 1639 Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero), 1640 EmptyBB, LoopBodyBB); 1641 1642 // No more elements. 1643 EmitBlock(EmptyBB); 1644 1645 if (!elementIsVariable) { 1646 // If the element was not a declaration, set it to be null. 1647 1648 llvm::Value *null = llvm::Constant::getNullValue(convertedElementType); 1649 elementLValue = EmitLValue(cast<Expr>(S.getElement())); 1650 EmitStoreThroughLValue(RValue::get(null), elementLValue); 1651 } 1652 1653 if (DI) 1654 DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd()); 1655 1656 // Leave the cleanup we entered in ARC. 1657 if (getLangOpts().ObjCAutoRefCount) 1658 PopCleanupBlock(); 1659 1660 EmitBlock(LoopEnd.getBlock()); 1661 } 1662 1663 void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) { 1664 CGM.getObjCRuntime().EmitTryStmt(*this, S); 1665 } 1666 1667 void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) { 1668 CGM.getObjCRuntime().EmitThrowStmt(*this, S); 1669 } 1670 1671 void CodeGenFunction::EmitObjCAtSynchronizedStmt( 1672 const ObjCAtSynchronizedStmt &S) { 1673 CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S); 1674 } 1675 1676 /// Produce the code for a CK_ARCProduceObject. Just does a 1677 /// primitive retain. 1678 llvm::Value *CodeGenFunction::EmitObjCProduceObject(QualType type, 1679 llvm::Value *value) { 1680 return EmitARCRetain(type, value); 1681 } 1682 1683 namespace { 1684 struct CallObjCRelease : EHScopeStack::Cleanup { 1685 CallObjCRelease(llvm::Value *object) : object(object) {} 1686 llvm::Value *object; 1687 1688 void Emit(CodeGenFunction &CGF, Flags flags) { 1689 // Releases at the end of the full-expression are imprecise. 1690 CGF.EmitARCRelease(object, ARCImpreciseLifetime); 1691 } 1692 }; 1693 } 1694 1695 /// Produce the code for a CK_ARCConsumeObject. Does a primitive 1696 /// release at the end of the full-expression. 1697 llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type, 1698 llvm::Value *object) { 1699 // If we're in a conditional branch, we need to make the cleanup 1700 // conditional. 1701 pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object); 1702 return object; 1703 } 1704 1705 llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type, 1706 llvm::Value *value) { 1707 return EmitARCRetainAutorelease(type, value); 1708 } 1709 1710 1711 static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM, 1712 llvm::FunctionType *type, 1713 StringRef fnName) { 1714 llvm::Constant *fn = CGM.CreateRuntimeFunction(type, fnName); 1715 1716 if (llvm::Function *f = dyn_cast<llvm::Function>(fn)) { 1717 // If the target runtime doesn't naturally support ARC, emit weak 1718 // references to the runtime support library. We don't really 1719 // permit this to fail, but we need a particular relocation style. 1720 if (!CGM.getLangOpts().ObjCRuntime.hasNativeARC()) { 1721 f->setLinkage(llvm::Function::ExternalWeakLinkage); 1722 } else if (fnName == "objc_retain" || fnName == "objc_release") { 1723 // If we have Native ARC, set nonlazybind attribute for these APIs for 1724 // performance. 1725 f->addFnAttr(llvm::Attribute::NonLazyBind); 1726 } 1727 } 1728 1729 return fn; 1730 } 1731 1732 /// Perform an operation having the signature 1733 /// i8* (i8*) 1734 /// where a null input causes a no-op and returns null. 1735 static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF, 1736 llvm::Value *value, 1737 llvm::Constant *&fn, 1738 StringRef fnName, 1739 bool isTailCall = false) { 1740 if (isa<llvm::ConstantPointerNull>(value)) return value; 1741 1742 if (!fn) { 1743 llvm::FunctionType *fnType = 1744 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrTy, false); 1745 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1746 } 1747 1748 // Cast the argument to 'id'. 1749 llvm::Type *origType = value->getType(); 1750 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy); 1751 1752 // Call the function. 1753 llvm::CallInst *call = CGF.EmitNounwindRuntimeCall(fn, value); 1754 if (isTailCall) 1755 call->setTailCall(); 1756 1757 // Cast the result back to the original type. 1758 return CGF.Builder.CreateBitCast(call, origType); 1759 } 1760 1761 /// Perform an operation having the following signature: 1762 /// i8* (i8**) 1763 static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF, 1764 llvm::Value *addr, 1765 llvm::Constant *&fn, 1766 StringRef fnName) { 1767 if (!fn) { 1768 llvm::FunctionType *fnType = 1769 llvm::FunctionType::get(CGF.Int8PtrTy, CGF.Int8PtrPtrTy, false); 1770 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1771 } 1772 1773 // Cast the argument to 'id*'. 1774 llvm::Type *origType = addr->getType(); 1775 addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy); 1776 1777 // Call the function. 1778 llvm::Value *result = CGF.EmitNounwindRuntimeCall(fn, addr); 1779 1780 // Cast the result back to a dereference of the original type. 1781 if (origType != CGF.Int8PtrPtrTy) 1782 result = CGF.Builder.CreateBitCast(result, 1783 cast<llvm::PointerType>(origType)->getElementType()); 1784 1785 return result; 1786 } 1787 1788 /// Perform an operation having the following signature: 1789 /// i8* (i8**, i8*) 1790 static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, 1791 llvm::Value *addr, 1792 llvm::Value *value, 1793 llvm::Constant *&fn, 1794 StringRef fnName, 1795 bool ignored) { 1796 assert(cast<llvm::PointerType>(addr->getType())->getElementType() 1797 == value->getType()); 1798 1799 if (!fn) { 1800 llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy }; 1801 1802 llvm::FunctionType *fnType 1803 = llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false); 1804 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1805 } 1806 1807 llvm::Type *origType = value->getType(); 1808 1809 llvm::Value *args[] = { 1810 CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy), 1811 CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy) 1812 }; 1813 llvm::CallInst *result = CGF.EmitNounwindRuntimeCall(fn, args); 1814 1815 if (ignored) return 0; 1816 1817 return CGF.Builder.CreateBitCast(result, origType); 1818 } 1819 1820 /// Perform an operation having the following signature: 1821 /// void (i8**, i8**) 1822 static void emitARCCopyOperation(CodeGenFunction &CGF, 1823 llvm::Value *dst, 1824 llvm::Value *src, 1825 llvm::Constant *&fn, 1826 StringRef fnName) { 1827 assert(dst->getType() == src->getType()); 1828 1829 if (!fn) { 1830 llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrPtrTy }; 1831 1832 llvm::FunctionType *fnType 1833 = llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false); 1834 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1835 } 1836 1837 llvm::Value *args[] = { 1838 CGF.Builder.CreateBitCast(dst, CGF.Int8PtrPtrTy), 1839 CGF.Builder.CreateBitCast(src, CGF.Int8PtrPtrTy) 1840 }; 1841 CGF.EmitNounwindRuntimeCall(fn, args); 1842 } 1843 1844 /// Produce the code to do a retain. Based on the type, calls one of: 1845 /// call i8* \@objc_retain(i8* %value) 1846 /// call i8* \@objc_retainBlock(i8* %value) 1847 llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) { 1848 if (type->isBlockPointerType()) 1849 return EmitARCRetainBlock(value, /*mandatory*/ false); 1850 else 1851 return EmitARCRetainNonBlock(value); 1852 } 1853 1854 /// Retain the given object, with normal retain semantics. 1855 /// call i8* \@objc_retain(i8* %value) 1856 llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) { 1857 return emitARCValueOperation(*this, value, 1858 CGM.getARCEntrypoints().objc_retain, 1859 "objc_retain"); 1860 } 1861 1862 /// Retain the given block, with _Block_copy semantics. 1863 /// call i8* \@objc_retainBlock(i8* %value) 1864 /// 1865 /// \param mandatory - If false, emit the call with metadata 1866 /// indicating that it's okay for the optimizer to eliminate this call 1867 /// if it can prove that the block never escapes except down the stack. 1868 llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value, 1869 bool mandatory) { 1870 llvm::Value *result 1871 = emitARCValueOperation(*this, value, 1872 CGM.getARCEntrypoints().objc_retainBlock, 1873 "objc_retainBlock"); 1874 1875 // If the copy isn't mandatory, add !clang.arc.copy_on_escape to 1876 // tell the optimizer that it doesn't need to do this copy if the 1877 // block doesn't escape, where being passed as an argument doesn't 1878 // count as escaping. 1879 if (!mandatory && isa<llvm::Instruction>(result)) { 1880 llvm::CallInst *call 1881 = cast<llvm::CallInst>(result->stripPointerCasts()); 1882 assert(call->getCalledValue() == CGM.getARCEntrypoints().objc_retainBlock); 1883 1884 SmallVector<llvm::Value*,1> args; 1885 call->setMetadata("clang.arc.copy_on_escape", 1886 llvm::MDNode::get(Builder.getContext(), args)); 1887 } 1888 1889 return result; 1890 } 1891 1892 /// Retain the given object which is the result of a function call. 1893 /// call i8* \@objc_retainAutoreleasedReturnValue(i8* %value) 1894 /// 1895 /// Yes, this function name is one character away from a different 1896 /// call with completely different semantics. 1897 llvm::Value * 1898 CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) { 1899 // Fetch the void(void) inline asm which marks that we're going to 1900 // retain the autoreleased return value. 1901 llvm::InlineAsm *&marker 1902 = CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker; 1903 if (!marker) { 1904 StringRef assembly 1905 = CGM.getTargetCodeGenInfo() 1906 .getARCRetainAutoreleasedReturnValueMarker(); 1907 1908 // If we have an empty assembly string, there's nothing to do. 1909 if (assembly.empty()) { 1910 1911 // Otherwise, at -O0, build an inline asm that we're going to call 1912 // in a moment. 1913 } else if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1914 llvm::FunctionType *type = 1915 llvm::FunctionType::get(VoidTy, /*variadic*/false); 1916 1917 marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true); 1918 1919 // If we're at -O1 and above, we don't want to litter the code 1920 // with this marker yet, so leave a breadcrumb for the ARC 1921 // optimizer to pick up. 1922 } else { 1923 llvm::NamedMDNode *metadata = 1924 CGM.getModule().getOrInsertNamedMetadata( 1925 "clang.arc.retainAutoreleasedReturnValueMarker"); 1926 assert(metadata->getNumOperands() <= 1); 1927 if (metadata->getNumOperands() == 0) { 1928 llvm::Value *string = llvm::MDString::get(getLLVMContext(), assembly); 1929 metadata->addOperand(llvm::MDNode::get(getLLVMContext(), string)); 1930 } 1931 } 1932 } 1933 1934 // Call the marker asm if we made one, which we do only at -O0. 1935 if (marker) Builder.CreateCall(marker); 1936 1937 return emitARCValueOperation(*this, value, 1938 CGM.getARCEntrypoints().objc_retainAutoreleasedReturnValue, 1939 "objc_retainAutoreleasedReturnValue"); 1940 } 1941 1942 /// Release the given object. 1943 /// call void \@objc_release(i8* %value) 1944 void CodeGenFunction::EmitARCRelease(llvm::Value *value, 1945 ARCPreciseLifetime_t precise) { 1946 if (isa<llvm::ConstantPointerNull>(value)) return; 1947 1948 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_release; 1949 if (!fn) { 1950 llvm::FunctionType *fnType = 1951 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false); 1952 fn = createARCRuntimeFunction(CGM, fnType, "objc_release"); 1953 } 1954 1955 // Cast the argument to 'id'. 1956 value = Builder.CreateBitCast(value, Int8PtrTy); 1957 1958 // Call objc_release. 1959 llvm::CallInst *call = EmitNounwindRuntimeCall(fn, value); 1960 1961 if (precise == ARCImpreciseLifetime) { 1962 SmallVector<llvm::Value*,1> args; 1963 call->setMetadata("clang.imprecise_release", 1964 llvm::MDNode::get(Builder.getContext(), args)); 1965 } 1966 } 1967 1968 /// Destroy a __strong variable. 1969 /// 1970 /// At -O0, emit a call to store 'null' into the address; 1971 /// instrumenting tools prefer this because the address is exposed, 1972 /// but it's relatively cumbersome to optimize. 1973 /// 1974 /// At -O1 and above, just load and call objc_release. 1975 /// 1976 /// call void \@objc_storeStrong(i8** %addr, i8* null) 1977 void CodeGenFunction::EmitARCDestroyStrong(llvm::Value *addr, 1978 ARCPreciseLifetime_t precise) { 1979 if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1980 llvm::PointerType *addrTy = cast<llvm::PointerType>(addr->getType()); 1981 llvm::Value *null = llvm::ConstantPointerNull::get( 1982 cast<llvm::PointerType>(addrTy->getElementType())); 1983 EmitARCStoreStrongCall(addr, null, /*ignored*/ true); 1984 return; 1985 } 1986 1987 llvm::Value *value = Builder.CreateLoad(addr); 1988 EmitARCRelease(value, precise); 1989 } 1990 1991 /// Store into a strong object. Always calls this: 1992 /// call void \@objc_storeStrong(i8** %addr, i8* %value) 1993 llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(llvm::Value *addr, 1994 llvm::Value *value, 1995 bool ignored) { 1996 assert(cast<llvm::PointerType>(addr->getType())->getElementType() 1997 == value->getType()); 1998 1999 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_storeStrong; 2000 if (!fn) { 2001 llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy }; 2002 llvm::FunctionType *fnType 2003 = llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false); 2004 fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong"); 2005 } 2006 2007 llvm::Value *args[] = { 2008 Builder.CreateBitCast(addr, Int8PtrPtrTy), 2009 Builder.CreateBitCast(value, Int8PtrTy) 2010 }; 2011 EmitNounwindRuntimeCall(fn, args); 2012 2013 if (ignored) return 0; 2014 return value; 2015 } 2016 2017 /// Store into a strong object. Sometimes calls this: 2018 /// call void \@objc_storeStrong(i8** %addr, i8* %value) 2019 /// Other times, breaks it down into components. 2020 llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst, 2021 llvm::Value *newValue, 2022 bool ignored) { 2023 QualType type = dst.getType(); 2024 bool isBlock = type->isBlockPointerType(); 2025 2026 // Use a store barrier at -O0 unless this is a block type or the 2027 // lvalue is inadequately aligned. 2028 if (shouldUseFusedARCCalls() && 2029 !isBlock && 2030 (dst.getAlignment().isZero() || 2031 dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) { 2032 return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored); 2033 } 2034 2035 // Otherwise, split it out. 2036 2037 // Retain the new value. 2038 newValue = EmitARCRetain(type, newValue); 2039 2040 // Read the old value. 2041 llvm::Value *oldValue = EmitLoadOfScalar(dst); 2042 2043 // Store. We do this before the release so that any deallocs won't 2044 // see the old value. 2045 EmitStoreOfScalar(newValue, dst); 2046 2047 // Finally, release the old value. 2048 EmitARCRelease(oldValue, dst.isARCPreciseLifetime()); 2049 2050 return newValue; 2051 } 2052 2053 /// Autorelease the given object. 2054 /// call i8* \@objc_autorelease(i8* %value) 2055 llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) { 2056 return emitARCValueOperation(*this, value, 2057 CGM.getARCEntrypoints().objc_autorelease, 2058 "objc_autorelease"); 2059 } 2060 2061 /// Autorelease the given object. 2062 /// call i8* \@objc_autoreleaseReturnValue(i8* %value) 2063 llvm::Value * 2064 CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) { 2065 return emitARCValueOperation(*this, value, 2066 CGM.getARCEntrypoints().objc_autoreleaseReturnValue, 2067 "objc_autoreleaseReturnValue", 2068 /*isTailCall*/ true); 2069 } 2070 2071 /// Do a fused retain/autorelease of the given object. 2072 /// call i8* \@objc_retainAutoreleaseReturnValue(i8* %value) 2073 llvm::Value * 2074 CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) { 2075 return emitARCValueOperation(*this, value, 2076 CGM.getARCEntrypoints().objc_retainAutoreleaseReturnValue, 2077 "objc_retainAutoreleaseReturnValue", 2078 /*isTailCall*/ true); 2079 } 2080 2081 /// Do a fused retain/autorelease of the given object. 2082 /// call i8* \@objc_retainAutorelease(i8* %value) 2083 /// or 2084 /// %retain = call i8* \@objc_retainBlock(i8* %value) 2085 /// call i8* \@objc_autorelease(i8* %retain) 2086 llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type, 2087 llvm::Value *value) { 2088 if (!type->isBlockPointerType()) 2089 return EmitARCRetainAutoreleaseNonBlock(value); 2090 2091 if (isa<llvm::ConstantPointerNull>(value)) return value; 2092 2093 llvm::Type *origType = value->getType(); 2094 value = Builder.CreateBitCast(value, Int8PtrTy); 2095 value = EmitARCRetainBlock(value, /*mandatory*/ true); 2096 value = EmitARCAutorelease(value); 2097 return Builder.CreateBitCast(value, origType); 2098 } 2099 2100 /// Do a fused retain/autorelease of the given object. 2101 /// call i8* \@objc_retainAutorelease(i8* %value) 2102 llvm::Value * 2103 CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) { 2104 return emitARCValueOperation(*this, value, 2105 CGM.getARCEntrypoints().objc_retainAutorelease, 2106 "objc_retainAutorelease"); 2107 } 2108 2109 /// i8* \@objc_loadWeak(i8** %addr) 2110 /// Essentially objc_autorelease(objc_loadWeakRetained(addr)). 2111 llvm::Value *CodeGenFunction::EmitARCLoadWeak(llvm::Value *addr) { 2112 return emitARCLoadOperation(*this, addr, 2113 CGM.getARCEntrypoints().objc_loadWeak, 2114 "objc_loadWeak"); 2115 } 2116 2117 /// i8* \@objc_loadWeakRetained(i8** %addr) 2118 llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(llvm::Value *addr) { 2119 return emitARCLoadOperation(*this, addr, 2120 CGM.getARCEntrypoints().objc_loadWeakRetained, 2121 "objc_loadWeakRetained"); 2122 } 2123 2124 /// i8* \@objc_storeWeak(i8** %addr, i8* %value) 2125 /// Returns %value. 2126 llvm::Value *CodeGenFunction::EmitARCStoreWeak(llvm::Value *addr, 2127 llvm::Value *value, 2128 bool ignored) { 2129 return emitARCStoreOperation(*this, addr, value, 2130 CGM.getARCEntrypoints().objc_storeWeak, 2131 "objc_storeWeak", ignored); 2132 } 2133 2134 /// i8* \@objc_initWeak(i8** %addr, i8* %value) 2135 /// Returns %value. %addr is known to not have a current weak entry. 2136 /// Essentially equivalent to: 2137 /// *addr = nil; objc_storeWeak(addr, value); 2138 void CodeGenFunction::EmitARCInitWeak(llvm::Value *addr, llvm::Value *value) { 2139 // If we're initializing to null, just write null to memory; no need 2140 // to get the runtime involved. But don't do this if optimization 2141 // is enabled, because accounting for this would make the optimizer 2142 // much more complicated. 2143 if (isa<llvm::ConstantPointerNull>(value) && 2144 CGM.getCodeGenOpts().OptimizationLevel == 0) { 2145 Builder.CreateStore(value, addr); 2146 return; 2147 } 2148 2149 emitARCStoreOperation(*this, addr, value, 2150 CGM.getARCEntrypoints().objc_initWeak, 2151 "objc_initWeak", /*ignored*/ true); 2152 } 2153 2154 /// void \@objc_destroyWeak(i8** %addr) 2155 /// Essentially objc_storeWeak(addr, nil). 2156 void CodeGenFunction::EmitARCDestroyWeak(llvm::Value *addr) { 2157 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_destroyWeak; 2158 if (!fn) { 2159 llvm::FunctionType *fnType = 2160 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrPtrTy, false); 2161 fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak"); 2162 } 2163 2164 // Cast the argument to 'id*'. 2165 addr = Builder.CreateBitCast(addr, Int8PtrPtrTy); 2166 2167 EmitNounwindRuntimeCall(fn, addr); 2168 } 2169 2170 /// void \@objc_moveWeak(i8** %dest, i8** %src) 2171 /// Disregards the current value in %dest. Leaves %src pointing to nothing. 2172 /// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)). 2173 void CodeGenFunction::EmitARCMoveWeak(llvm::Value *dst, llvm::Value *src) { 2174 emitARCCopyOperation(*this, dst, src, 2175 CGM.getARCEntrypoints().objc_moveWeak, 2176 "objc_moveWeak"); 2177 } 2178 2179 /// void \@objc_copyWeak(i8** %dest, i8** %src) 2180 /// Disregards the current value in %dest. Essentially 2181 /// objc_release(objc_initWeak(dest, objc_readWeakRetained(src))) 2182 void CodeGenFunction::EmitARCCopyWeak(llvm::Value *dst, llvm::Value *src) { 2183 emitARCCopyOperation(*this, dst, src, 2184 CGM.getARCEntrypoints().objc_copyWeak, 2185 "objc_copyWeak"); 2186 } 2187 2188 /// Produce the code to do a objc_autoreleasepool_push. 2189 /// call i8* \@objc_autoreleasePoolPush(void) 2190 llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() { 2191 llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPush; 2192 if (!fn) { 2193 llvm::FunctionType *fnType = 2194 llvm::FunctionType::get(Int8PtrTy, false); 2195 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush"); 2196 } 2197 2198 return EmitNounwindRuntimeCall(fn); 2199 } 2200 2201 /// Produce the code to do a primitive release. 2202 /// call void \@objc_autoreleasePoolPop(i8* %ptr) 2203 void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) { 2204 assert(value->getType() == Int8PtrTy); 2205 2206 llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPop; 2207 if (!fn) { 2208 llvm::FunctionType *fnType = 2209 llvm::FunctionType::get(Builder.getVoidTy(), Int8PtrTy, false); 2210 2211 // We don't want to use a weak import here; instead we should not 2212 // fall into this path. 2213 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop"); 2214 } 2215 2216 EmitNounwindRuntimeCall(fn, value); 2217 } 2218 2219 /// Produce the code to do an MRR version objc_autoreleasepool_push. 2220 /// Which is: [[NSAutoreleasePool alloc] init]; 2221 /// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class. 2222 /// init is declared as: - (id) init; in its NSObject super class. 2223 /// 2224 llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() { 2225 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 2226 llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(*this); 2227 // [NSAutoreleasePool alloc] 2228 IdentifierInfo *II = &CGM.getContext().Idents.get("alloc"); 2229 Selector AllocSel = getContext().Selectors.getSelector(0, &II); 2230 CallArgList Args; 2231 RValue AllocRV = 2232 Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2233 getContext().getObjCIdType(), 2234 AllocSel, Receiver, Args); 2235 2236 // [Receiver init] 2237 Receiver = AllocRV.getScalarVal(); 2238 II = &CGM.getContext().Idents.get("init"); 2239 Selector InitSel = getContext().Selectors.getSelector(0, &II); 2240 RValue InitRV = 2241 Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2242 getContext().getObjCIdType(), 2243 InitSel, Receiver, Args); 2244 return InitRV.getScalarVal(); 2245 } 2246 2247 /// Produce the code to do a primitive release. 2248 /// [tmp drain]; 2249 void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) { 2250 IdentifierInfo *II = &CGM.getContext().Idents.get("drain"); 2251 Selector DrainSel = getContext().Selectors.getSelector(0, &II); 2252 CallArgList Args; 2253 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 2254 getContext().VoidTy, DrainSel, Arg, Args); 2255 } 2256 2257 void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF, 2258 llvm::Value *addr, 2259 QualType type) { 2260 CGF.EmitARCDestroyStrong(addr, ARCPreciseLifetime); 2261 } 2262 2263 void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF, 2264 llvm::Value *addr, 2265 QualType type) { 2266 CGF.EmitARCDestroyStrong(addr, ARCImpreciseLifetime); 2267 } 2268 2269 void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF, 2270 llvm::Value *addr, 2271 QualType type) { 2272 CGF.EmitARCDestroyWeak(addr); 2273 } 2274 2275 namespace { 2276 struct CallObjCAutoreleasePoolObject : EHScopeStack::Cleanup { 2277 llvm::Value *Token; 2278 2279 CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {} 2280 2281 void Emit(CodeGenFunction &CGF, Flags flags) { 2282 CGF.EmitObjCAutoreleasePoolPop(Token); 2283 } 2284 }; 2285 struct CallObjCMRRAutoreleasePoolObject : EHScopeStack::Cleanup { 2286 llvm::Value *Token; 2287 2288 CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {} 2289 2290 void Emit(CodeGenFunction &CGF, Flags flags) { 2291 CGF.EmitObjCMRRAutoreleasePoolPop(Token); 2292 } 2293 }; 2294 } 2295 2296 void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) { 2297 if (CGM.getLangOpts().ObjCAutoRefCount) 2298 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr); 2299 else 2300 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr); 2301 } 2302 2303 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2304 LValue lvalue, 2305 QualType type) { 2306 switch (type.getObjCLifetime()) { 2307 case Qualifiers::OCL_None: 2308 case Qualifiers::OCL_ExplicitNone: 2309 case Qualifiers::OCL_Strong: 2310 case Qualifiers::OCL_Autoreleasing: 2311 return TryEmitResult(CGF.EmitLoadOfLValue(lvalue).getScalarVal(), 2312 false); 2313 2314 case Qualifiers::OCL_Weak: 2315 return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()), 2316 true); 2317 } 2318 2319 llvm_unreachable("impossible lifetime!"); 2320 } 2321 2322 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2323 const Expr *e) { 2324 e = e->IgnoreParens(); 2325 QualType type = e->getType(); 2326 2327 // If we're loading retained from a __strong xvalue, we can avoid 2328 // an extra retain/release pair by zeroing out the source of this 2329 // "move" operation. 2330 if (e->isXValue() && 2331 !type.isConstQualified() && 2332 type.getObjCLifetime() == Qualifiers::OCL_Strong) { 2333 // Emit the lvalue. 2334 LValue lv = CGF.EmitLValue(e); 2335 2336 // Load the object pointer. 2337 llvm::Value *result = CGF.EmitLoadOfLValue(lv).getScalarVal(); 2338 2339 // Set the source pointer to NULL. 2340 CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv); 2341 2342 return TryEmitResult(result, true); 2343 } 2344 2345 // As a very special optimization, in ARC++, if the l-value is the 2346 // result of a non-volatile assignment, do a simple retain of the 2347 // result of the call to objc_storeWeak instead of reloading. 2348 if (CGF.getLangOpts().CPlusPlus && 2349 !type.isVolatileQualified() && 2350 type.getObjCLifetime() == Qualifiers::OCL_Weak && 2351 isa<BinaryOperator>(e) && 2352 cast<BinaryOperator>(e)->getOpcode() == BO_Assign) 2353 return TryEmitResult(CGF.EmitScalarExpr(e), false); 2354 2355 return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type); 2356 } 2357 2358 static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF, 2359 llvm::Value *value); 2360 2361 /// Given that the given expression is some sort of call (which does 2362 /// not return retained), emit a retain following it. 2363 static llvm::Value *emitARCRetainCall(CodeGenFunction &CGF, const Expr *e) { 2364 llvm::Value *value = CGF.EmitScalarExpr(e); 2365 return emitARCRetainAfterCall(CGF, value); 2366 } 2367 2368 static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF, 2369 llvm::Value *value) { 2370 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) { 2371 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); 2372 2373 // Place the retain immediately following the call. 2374 CGF.Builder.SetInsertPoint(call->getParent(), 2375 ++llvm::BasicBlock::iterator(call)); 2376 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 2377 2378 CGF.Builder.restoreIP(ip); 2379 return value; 2380 } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) { 2381 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); 2382 2383 // Place the retain at the beginning of the normal destination block. 2384 llvm::BasicBlock *BB = invoke->getNormalDest(); 2385 CGF.Builder.SetInsertPoint(BB, BB->begin()); 2386 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 2387 2388 CGF.Builder.restoreIP(ip); 2389 return value; 2390 2391 // Bitcasts can arise because of related-result returns. Rewrite 2392 // the operand. 2393 } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) { 2394 llvm::Value *operand = bitcast->getOperand(0); 2395 operand = emitARCRetainAfterCall(CGF, operand); 2396 bitcast->setOperand(0, operand); 2397 return bitcast; 2398 2399 // Generic fall-back case. 2400 } else { 2401 // Retain using the non-block variant: we never need to do a copy 2402 // of a block that's been returned to us. 2403 return CGF.EmitARCRetainNonBlock(value); 2404 } 2405 } 2406 2407 /// Determine whether it might be important to emit a separate 2408 /// objc_retain_block on the result of the given expression, or 2409 /// whether it's okay to just emit it in a +1 context. 2410 static bool shouldEmitSeparateBlockRetain(const Expr *e) { 2411 assert(e->getType()->isBlockPointerType()); 2412 e = e->IgnoreParens(); 2413 2414 // For future goodness, emit block expressions directly in +1 2415 // contexts if we can. 2416 if (isa<BlockExpr>(e)) 2417 return false; 2418 2419 if (const CastExpr *cast = dyn_cast<CastExpr>(e)) { 2420 switch (cast->getCastKind()) { 2421 // Emitting these operations in +1 contexts is goodness. 2422 case CK_LValueToRValue: 2423 case CK_ARCReclaimReturnedObject: 2424 case CK_ARCConsumeObject: 2425 case CK_ARCProduceObject: 2426 return false; 2427 2428 // These operations preserve a block type. 2429 case CK_NoOp: 2430 case CK_BitCast: 2431 return shouldEmitSeparateBlockRetain(cast->getSubExpr()); 2432 2433 // These operations are known to be bad (or haven't been considered). 2434 case CK_AnyPointerToBlockPointerCast: 2435 default: 2436 return true; 2437 } 2438 } 2439 2440 return true; 2441 } 2442 2443 /// Try to emit a PseudoObjectExpr at +1. 2444 /// 2445 /// This massively duplicates emitPseudoObjectRValue. 2446 static TryEmitResult tryEmitARCRetainPseudoObject(CodeGenFunction &CGF, 2447 const PseudoObjectExpr *E) { 2448 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques; 2449 2450 // Find the result expression. 2451 const Expr *resultExpr = E->getResultExpr(); 2452 assert(resultExpr); 2453 TryEmitResult result; 2454 2455 for (PseudoObjectExpr::const_semantics_iterator 2456 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) { 2457 const Expr *semantic = *i; 2458 2459 // If this semantic expression is an opaque value, bind it 2460 // to the result of its source expression. 2461 if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) { 2462 typedef CodeGenFunction::OpaqueValueMappingData OVMA; 2463 OVMA opaqueData; 2464 2465 // If this semantic is the result of the pseudo-object 2466 // expression, try to evaluate the source as +1. 2467 if (ov == resultExpr) { 2468 assert(!OVMA::shouldBindAsLValue(ov)); 2469 result = tryEmitARCRetainScalarExpr(CGF, ov->getSourceExpr()); 2470 opaqueData = OVMA::bind(CGF, ov, RValue::get(result.getPointer())); 2471 2472 // Otherwise, just bind it. 2473 } else { 2474 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr()); 2475 } 2476 opaques.push_back(opaqueData); 2477 2478 // Otherwise, if the expression is the result, evaluate it 2479 // and remember the result. 2480 } else if (semantic == resultExpr) { 2481 result = tryEmitARCRetainScalarExpr(CGF, semantic); 2482 2483 // Otherwise, evaluate the expression in an ignored context. 2484 } else { 2485 CGF.EmitIgnoredExpr(semantic); 2486 } 2487 } 2488 2489 // Unbind all the opaques now. 2490 for (unsigned i = 0, e = opaques.size(); i != e; ++i) 2491 opaques[i].unbind(CGF); 2492 2493 return result; 2494 } 2495 2496 static TryEmitResult 2497 tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) { 2498 // We should *never* see a nested full-expression here, because if 2499 // we fail to emit at +1, our caller must not retain after we close 2500 // out the full-expression. 2501 assert(!isa<ExprWithCleanups>(e)); 2502 2503 // The desired result type, if it differs from the type of the 2504 // ultimate opaque expression. 2505 llvm::Type *resultType = 0; 2506 2507 while (true) { 2508 e = e->IgnoreParens(); 2509 2510 // There's a break at the end of this if-chain; anything 2511 // that wants to keep looping has to explicitly continue. 2512 if (const CastExpr *ce = dyn_cast<CastExpr>(e)) { 2513 switch (ce->getCastKind()) { 2514 // No-op casts don't change the type, so we just ignore them. 2515 case CK_NoOp: 2516 e = ce->getSubExpr(); 2517 continue; 2518 2519 case CK_LValueToRValue: { 2520 TryEmitResult loadResult 2521 = tryEmitARCRetainLoadOfScalar(CGF, ce->getSubExpr()); 2522 if (resultType) { 2523 llvm::Value *value = loadResult.getPointer(); 2524 value = CGF.Builder.CreateBitCast(value, resultType); 2525 loadResult.setPointer(value); 2526 } 2527 return loadResult; 2528 } 2529 2530 // These casts can change the type, so remember that and 2531 // soldier on. We only need to remember the outermost such 2532 // cast, though. 2533 case CK_CPointerToObjCPointerCast: 2534 case CK_BlockPointerToObjCPointerCast: 2535 case CK_AnyPointerToBlockPointerCast: 2536 case CK_BitCast: 2537 if (!resultType) 2538 resultType = CGF.ConvertType(ce->getType()); 2539 e = ce->getSubExpr(); 2540 assert(e->getType()->hasPointerRepresentation()); 2541 continue; 2542 2543 // For consumptions, just emit the subexpression and thus elide 2544 // the retain/release pair. 2545 case CK_ARCConsumeObject: { 2546 llvm::Value *result = CGF.EmitScalarExpr(ce->getSubExpr()); 2547 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2548 return TryEmitResult(result, true); 2549 } 2550 2551 // Block extends are net +0. Naively, we could just recurse on 2552 // the subexpression, but actually we need to ensure that the 2553 // value is copied as a block, so there's a little filter here. 2554 case CK_ARCExtendBlockObject: { 2555 llvm::Value *result; // will be a +0 value 2556 2557 // If we can't safely assume the sub-expression will produce a 2558 // block-copied value, emit the sub-expression at +0. 2559 if (shouldEmitSeparateBlockRetain(ce->getSubExpr())) { 2560 result = CGF.EmitScalarExpr(ce->getSubExpr()); 2561 2562 // Otherwise, try to emit the sub-expression at +1 recursively. 2563 } else { 2564 TryEmitResult subresult 2565 = tryEmitARCRetainScalarExpr(CGF, ce->getSubExpr()); 2566 result = subresult.getPointer(); 2567 2568 // If that produced a retained value, just use that, 2569 // possibly casting down. 2570 if (subresult.getInt()) { 2571 if (resultType) 2572 result = CGF.Builder.CreateBitCast(result, resultType); 2573 return TryEmitResult(result, true); 2574 } 2575 2576 // Otherwise it's +0. 2577 } 2578 2579 // Retain the object as a block, then cast down. 2580 result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true); 2581 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2582 return TryEmitResult(result, true); 2583 } 2584 2585 // For reclaims, emit the subexpression as a retained call and 2586 // skip the consumption. 2587 case CK_ARCReclaimReturnedObject: { 2588 llvm::Value *result = emitARCRetainCall(CGF, ce->getSubExpr()); 2589 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2590 return TryEmitResult(result, true); 2591 } 2592 2593 default: 2594 break; 2595 } 2596 2597 // Skip __extension__. 2598 } else if (const UnaryOperator *op = dyn_cast<UnaryOperator>(e)) { 2599 if (op->getOpcode() == UO_Extension) { 2600 e = op->getSubExpr(); 2601 continue; 2602 } 2603 2604 // For calls and message sends, use the retained-call logic. 2605 // Delegate inits are a special case in that they're the only 2606 // returns-retained expression that *isn't* surrounded by 2607 // a consume. 2608 } else if (isa<CallExpr>(e) || 2609 (isa<ObjCMessageExpr>(e) && 2610 !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) { 2611 llvm::Value *result = emitARCRetainCall(CGF, e); 2612 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2613 return TryEmitResult(result, true); 2614 2615 // Look through pseudo-object expressions. 2616 } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) { 2617 TryEmitResult result 2618 = tryEmitARCRetainPseudoObject(CGF, pseudo); 2619 if (resultType) { 2620 llvm::Value *value = result.getPointer(); 2621 value = CGF.Builder.CreateBitCast(value, resultType); 2622 result.setPointer(value); 2623 } 2624 return result; 2625 } 2626 2627 // Conservatively halt the search at any other expression kind. 2628 break; 2629 } 2630 2631 // We didn't find an obvious production, so emit what we've got and 2632 // tell the caller that we didn't manage to retain. 2633 llvm::Value *result = CGF.EmitScalarExpr(e); 2634 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2635 return TryEmitResult(result, false); 2636 } 2637 2638 static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2639 LValue lvalue, 2640 QualType type) { 2641 TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type); 2642 llvm::Value *value = result.getPointer(); 2643 if (!result.getInt()) 2644 value = CGF.EmitARCRetain(type, value); 2645 return value; 2646 } 2647 2648 /// EmitARCRetainScalarExpr - Semantically equivalent to 2649 /// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a 2650 /// best-effort attempt to peephole expressions that naturally produce 2651 /// retained objects. 2652 llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) { 2653 // The retain needs to happen within the full-expression. 2654 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { 2655 enterFullExpression(cleanups); 2656 RunCleanupsScope scope(*this); 2657 return EmitARCRetainScalarExpr(cleanups->getSubExpr()); 2658 } 2659 2660 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); 2661 llvm::Value *value = result.getPointer(); 2662 if (!result.getInt()) 2663 value = EmitARCRetain(e->getType(), value); 2664 return value; 2665 } 2666 2667 llvm::Value * 2668 CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) { 2669 // The retain needs to happen within the full-expression. 2670 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { 2671 enterFullExpression(cleanups); 2672 RunCleanupsScope scope(*this); 2673 return EmitARCRetainAutoreleaseScalarExpr(cleanups->getSubExpr()); 2674 } 2675 2676 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); 2677 llvm::Value *value = result.getPointer(); 2678 if (result.getInt()) 2679 value = EmitARCAutorelease(value); 2680 else 2681 value = EmitARCRetainAutorelease(e->getType(), value); 2682 return value; 2683 } 2684 2685 llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) { 2686 llvm::Value *result; 2687 bool doRetain; 2688 2689 if (shouldEmitSeparateBlockRetain(e)) { 2690 result = EmitScalarExpr(e); 2691 doRetain = true; 2692 } else { 2693 TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e); 2694 result = subresult.getPointer(); 2695 doRetain = !subresult.getInt(); 2696 } 2697 2698 if (doRetain) 2699 result = EmitARCRetainBlock(result, /*mandatory*/ true); 2700 return EmitObjCConsumeObject(e->getType(), result); 2701 } 2702 2703 llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) { 2704 // In ARC, retain and autorelease the expression. 2705 if (getLangOpts().ObjCAutoRefCount) { 2706 // Do so before running any cleanups for the full-expression. 2707 // EmitARCRetainAutoreleaseScalarExpr does this for us. 2708 return EmitARCRetainAutoreleaseScalarExpr(expr); 2709 } 2710 2711 // Otherwise, use the normal scalar-expression emission. The 2712 // exception machinery doesn't do anything special with the 2713 // exception like retaining it, so there's no safety associated with 2714 // only running cleanups after the throw has started, and when it 2715 // matters it tends to be substantially inferior code. 2716 return EmitScalarExpr(expr); 2717 } 2718 2719 std::pair<LValue,llvm::Value*> 2720 CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e, 2721 bool ignored) { 2722 // Evaluate the RHS first. 2723 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS()); 2724 llvm::Value *value = result.getPointer(); 2725 2726 bool hasImmediateRetain = result.getInt(); 2727 2728 // If we didn't emit a retained object, and the l-value is of block 2729 // type, then we need to emit the block-retain immediately in case 2730 // it invalidates the l-value. 2731 if (!hasImmediateRetain && e->getType()->isBlockPointerType()) { 2732 value = EmitARCRetainBlock(value, /*mandatory*/ false); 2733 hasImmediateRetain = true; 2734 } 2735 2736 LValue lvalue = EmitLValue(e->getLHS()); 2737 2738 // If the RHS was emitted retained, expand this. 2739 if (hasImmediateRetain) { 2740 llvm::Value *oldValue = 2741 EmitLoadOfScalar(lvalue); 2742 EmitStoreOfScalar(value, lvalue); 2743 EmitARCRelease(oldValue, lvalue.isARCPreciseLifetime()); 2744 } else { 2745 value = EmitARCStoreStrong(lvalue, value, ignored); 2746 } 2747 2748 return std::pair<LValue,llvm::Value*>(lvalue, value); 2749 } 2750 2751 std::pair<LValue,llvm::Value*> 2752 CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) { 2753 llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS()); 2754 LValue lvalue = EmitLValue(e->getLHS()); 2755 2756 EmitStoreOfScalar(value, lvalue); 2757 2758 return std::pair<LValue,llvm::Value*>(lvalue, value); 2759 } 2760 2761 void CodeGenFunction::EmitObjCAutoreleasePoolStmt( 2762 const ObjCAutoreleasePoolStmt &ARPS) { 2763 const Stmt *subStmt = ARPS.getSubStmt(); 2764 const CompoundStmt &S = cast<CompoundStmt>(*subStmt); 2765 2766 CGDebugInfo *DI = getDebugInfo(); 2767 if (DI) 2768 DI->EmitLexicalBlockStart(Builder, S.getLBracLoc()); 2769 2770 // Keep track of the current cleanup stack depth. 2771 RunCleanupsScope Scope(*this); 2772 if (CGM.getLangOpts().ObjCRuntime.hasNativeARC()) { 2773 llvm::Value *token = EmitObjCAutoreleasePoolPush(); 2774 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token); 2775 } else { 2776 llvm::Value *token = EmitObjCMRRAutoreleasePoolPush(); 2777 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token); 2778 } 2779 2780 for (CompoundStmt::const_body_iterator I = S.body_begin(), 2781 E = S.body_end(); I != E; ++I) 2782 EmitStmt(*I); 2783 2784 if (DI) 2785 DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc()); 2786 } 2787 2788 /// EmitExtendGCLifetime - Given a pointer to an Objective-C object, 2789 /// make sure it survives garbage collection until this point. 2790 void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) { 2791 // We just use an inline assembly. 2792 llvm::FunctionType *extenderType 2793 = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All); 2794 llvm::Value *extender 2795 = llvm::InlineAsm::get(extenderType, 2796 /* assembly */ "", 2797 /* constraints */ "r", 2798 /* side effects */ true); 2799 2800 object = Builder.CreateBitCast(object, VoidPtrTy); 2801 EmitNounwindRuntimeCall(extender, object); 2802 } 2803 2804 /// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with 2805 /// non-trivial copy assignment function, produce following helper function. 2806 /// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; } 2807 /// 2808 llvm::Constant * 2809 CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction( 2810 const ObjCPropertyImplDecl *PID) { 2811 if (!getLangOpts().CPlusPlus || 2812 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper()) 2813 return 0; 2814 QualType Ty = PID->getPropertyIvarDecl()->getType(); 2815 if (!Ty->isRecordType()) 2816 return 0; 2817 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2818 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) 2819 return 0; 2820 llvm::Constant * HelperFn = 0; 2821 if (hasTrivialSetExpr(PID)) 2822 return 0; 2823 assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null"); 2824 if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty))) 2825 return HelperFn; 2826 2827 ASTContext &C = getContext(); 2828 IdentifierInfo *II 2829 = &CGM.getContext().Idents.get("__assign_helper_atomic_property_"); 2830 FunctionDecl *FD = FunctionDecl::Create(C, 2831 C.getTranslationUnitDecl(), 2832 SourceLocation(), 2833 SourceLocation(), II, C.VoidTy, 0, 2834 SC_Static, 2835 SC_None, 2836 false, 2837 false); 2838 2839 QualType DestTy = C.getPointerType(Ty); 2840 QualType SrcTy = Ty; 2841 SrcTy.addConst(); 2842 SrcTy = C.getPointerType(SrcTy); 2843 2844 FunctionArgList args; 2845 ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy); 2846 args.push_back(&dstDecl); 2847 ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy); 2848 args.push_back(&srcDecl); 2849 2850 const CGFunctionInfo &FI = 2851 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 2852 FunctionType::ExtInfo(), 2853 RequiredArgs::All); 2854 2855 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 2856 2857 llvm::Function *Fn = 2858 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 2859 "__assign_helper_atomic_property_", 2860 &CGM.getModule()); 2861 2862 // Initialize debug info if needed. 2863 maybeInitializeDebugInfo(); 2864 2865 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 2866 2867 DeclRefExpr DstExpr(&dstDecl, false, DestTy, 2868 VK_RValue, SourceLocation()); 2869 UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(), 2870 VK_LValue, OK_Ordinary, SourceLocation()); 2871 2872 DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, 2873 VK_RValue, SourceLocation()); 2874 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), 2875 VK_LValue, OK_Ordinary, SourceLocation()); 2876 2877 Expr *Args[2] = { &DST, &SRC }; 2878 CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment()); 2879 CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(), 2880 Args, DestTy->getPointeeType(), 2881 VK_LValue, SourceLocation(), false); 2882 2883 EmitStmt(&TheCall); 2884 2885 FinishFunction(); 2886 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 2887 CGM.setAtomicSetterHelperFnMap(Ty, HelperFn); 2888 return HelperFn; 2889 } 2890 2891 llvm::Constant * 2892 CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction( 2893 const ObjCPropertyImplDecl *PID) { 2894 if (!getLangOpts().CPlusPlus || 2895 !getLangOpts().ObjCRuntime.hasAtomicCopyHelper()) 2896 return 0; 2897 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2898 QualType Ty = PD->getType(); 2899 if (!Ty->isRecordType()) 2900 return 0; 2901 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) 2902 return 0; 2903 llvm::Constant * HelperFn = 0; 2904 2905 if (hasTrivialGetExpr(PID)) 2906 return 0; 2907 assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null"); 2908 if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty))) 2909 return HelperFn; 2910 2911 2912 ASTContext &C = getContext(); 2913 IdentifierInfo *II 2914 = &CGM.getContext().Idents.get("__copy_helper_atomic_property_"); 2915 FunctionDecl *FD = FunctionDecl::Create(C, 2916 C.getTranslationUnitDecl(), 2917 SourceLocation(), 2918 SourceLocation(), II, C.VoidTy, 0, 2919 SC_Static, 2920 SC_None, 2921 false, 2922 false); 2923 2924 QualType DestTy = C.getPointerType(Ty); 2925 QualType SrcTy = Ty; 2926 SrcTy.addConst(); 2927 SrcTy = C.getPointerType(SrcTy); 2928 2929 FunctionArgList args; 2930 ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy); 2931 args.push_back(&dstDecl); 2932 ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy); 2933 args.push_back(&srcDecl); 2934 2935 const CGFunctionInfo &FI = 2936 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 2937 FunctionType::ExtInfo(), 2938 RequiredArgs::All); 2939 2940 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 2941 2942 llvm::Function *Fn = 2943 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 2944 "__copy_helper_atomic_property_", &CGM.getModule()); 2945 2946 // Initialize debug info if needed. 2947 maybeInitializeDebugInfo(); 2948 2949 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 2950 2951 DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, 2952 VK_RValue, SourceLocation()); 2953 2954 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), 2955 VK_LValue, OK_Ordinary, SourceLocation()); 2956 2957 CXXConstructExpr *CXXConstExpr = 2958 cast<CXXConstructExpr>(PID->getGetterCXXConstructor()); 2959 2960 SmallVector<Expr*, 4> ConstructorArgs; 2961 ConstructorArgs.push_back(&SRC); 2962 CXXConstructExpr::arg_iterator A = CXXConstExpr->arg_begin(); 2963 ++A; 2964 2965 for (CXXConstructExpr::arg_iterator AEnd = CXXConstExpr->arg_end(); 2966 A != AEnd; ++A) 2967 ConstructorArgs.push_back(*A); 2968 2969 CXXConstructExpr *TheCXXConstructExpr = 2970 CXXConstructExpr::Create(C, Ty, SourceLocation(), 2971 CXXConstExpr->getConstructor(), 2972 CXXConstExpr->isElidable(), 2973 ConstructorArgs, 2974 CXXConstExpr->hadMultipleCandidates(), 2975 CXXConstExpr->isListInitialization(), 2976 CXXConstExpr->requiresZeroInitialization(), 2977 CXXConstExpr->getConstructionKind(), 2978 SourceRange()); 2979 2980 DeclRefExpr DstExpr(&dstDecl, false, DestTy, 2981 VK_RValue, SourceLocation()); 2982 2983 RValue DV = EmitAnyExpr(&DstExpr); 2984 CharUnits Alignment 2985 = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType()); 2986 EmitAggExpr(TheCXXConstructExpr, 2987 AggValueSlot::forAddr(DV.getScalarVal(), Alignment, Qualifiers(), 2988 AggValueSlot::IsDestructed, 2989 AggValueSlot::DoesNotNeedGCBarriers, 2990 AggValueSlot::IsNotAliased)); 2991 2992 FinishFunction(); 2993 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 2994 CGM.setAtomicGetterHelperFnMap(Ty, HelperFn); 2995 return HelperFn; 2996 } 2997 2998 llvm::Value * 2999 CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) { 3000 // Get selectors for retain/autorelease. 3001 IdentifierInfo *CopyID = &getContext().Idents.get("copy"); 3002 Selector CopySelector = 3003 getContext().Selectors.getNullarySelector(CopyID); 3004 IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease"); 3005 Selector AutoreleaseSelector = 3006 getContext().Selectors.getNullarySelector(AutoreleaseID); 3007 3008 // Emit calls to retain/autorelease. 3009 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 3010 llvm::Value *Val = Block; 3011 RValue Result; 3012 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 3013 Ty, CopySelector, 3014 Val, CallArgList(), 0, 0); 3015 Val = Result.getScalarVal(); 3016 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 3017 Ty, AutoreleaseSelector, 3018 Val, CallArgList(), 0, 0); 3019 Val = Result.getScalarVal(); 3020 return Val; 3021 } 3022 3023 3024 CGObjCRuntime::~CGObjCRuntime() {} 3025