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/Target/TargetData.h" 25 #include "llvm/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 const Expr *E, 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(Builder, 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(Builder, 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(Builder, 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(Builder, 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 const Expr *E, 206 const ObjCMethodDecl *Method, 207 RValue Result) { 208 if (!Method) 209 return Result; 210 211 if (!Method->hasRelatedResultType() || 212 CGF.getContext().hasSameType(E->getType(), 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(E->getType()))); 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(Builder, 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, 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 (CGM.getModuleDebugInfo() && !OMD->hasAttr<NoDebugAttr>()) 444 DebugInfo = CGM.getModuleDebugInfo(); 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().arrangeFunctionCall(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 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 Kind = Expression; 617 return; 618 619 // Otherwise, we need to at least use setProperty. However, if 620 // the property isn't atomic, we can use normal expression 621 // emission for the getter. 622 } else if (!IsAtomic) { 623 Kind = SetPropertyAndExpressionGet; 624 return; 625 626 // Otherwise, we have to use both setProperty and getProperty. 627 } else { 628 Kind = GetSetProperty; 629 return; 630 } 631 } 632 633 // If we're not atomic, just use expression accesses. 634 if (!IsAtomic) { 635 Kind = Expression; 636 return; 637 } 638 639 // Properties on bitfield ivars need to be emitted using expression 640 // accesses even if they're nominally atomic. 641 if (ivar->isBitField()) { 642 Kind = Expression; 643 return; 644 } 645 646 // GC-qualified or ARC-qualified ivars need to be emitted as 647 // expressions. This actually works out to being atomic anyway, 648 // except for ARC __strong, but that should trigger the above code. 649 if (ivarType.hasNonTrivialObjCLifetime() || 650 (CGM.getLangOpts().getGC() && 651 CGM.getContext().getObjCGCAttrKind(ivarType))) { 652 Kind = Expression; 653 return; 654 } 655 656 // Compute whether the ivar has strong members. 657 if (CGM.getLangOpts().getGC()) 658 if (const RecordType *recordType = ivarType->getAs<RecordType>()) 659 HasStrong = recordType->getDecl()->hasObjectMember(); 660 661 // We can never access structs with object members with a native 662 // access, because we need to use write barriers. This is what 663 // objc_copyStruct is for. 664 if (HasStrong) { 665 Kind = CopyStruct; 666 return; 667 } 668 669 // Otherwise, this is target-dependent and based on the size and 670 // alignment of the ivar. 671 672 // If the size of the ivar is not a power of two, give up. We don't 673 // want to get into the business of doing compare-and-swaps. 674 if (!IvarSize.isPowerOfTwo()) { 675 Kind = CopyStruct; 676 return; 677 } 678 679 llvm::Triple::ArchType arch = 680 CGM.getContext().getTargetInfo().getTriple().getArch(); 681 682 // Most architectures require memory to fit within a single cache 683 // line, so the alignment has to be at least the size of the access. 684 // Otherwise we have to grab a lock. 685 if (IvarAlignment < IvarSize && !hasUnalignedAtomics(arch)) { 686 Kind = CopyStruct; 687 return; 688 } 689 690 // If the ivar's size exceeds the architecture's maximum atomic 691 // access size, we have to use CopyStruct. 692 if (IvarSize > getMaxAtomicAccessSize(CGM, arch)) { 693 Kind = CopyStruct; 694 return; 695 } 696 697 // Otherwise, we can use native loads and stores. 698 Kind = Native; 699 } 700 701 /// GenerateObjCGetter - Generate an Objective-C property getter 702 /// function. The given Decl must be an ObjCImplementationDecl. @synthesize 703 /// is illegal within a category. 704 void CodeGenFunction::GenerateObjCGetter(ObjCImplementationDecl *IMP, 705 const ObjCPropertyImplDecl *PID) { 706 llvm::Constant *AtomicHelperFn = 707 GenerateObjCAtomicGetterCopyHelperFunction(PID); 708 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 709 ObjCMethodDecl *OMD = PD->getGetterMethodDecl(); 710 assert(OMD && "Invalid call to generate getter (empty method)"); 711 StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart()); 712 713 generateObjCGetterBody(IMP, PID, AtomicHelperFn); 714 715 FinishFunction(); 716 } 717 718 static bool hasTrivialGetExpr(const ObjCPropertyImplDecl *propImpl) { 719 const Expr *getter = propImpl->getGetterCXXConstructor(); 720 if (!getter) return true; 721 722 // Sema only makes only of these when the ivar has a C++ class type, 723 // so the form is pretty constrained. 724 725 // If the property has a reference type, we might just be binding a 726 // reference, in which case the result will be a gl-value. We should 727 // treat this as a non-trivial operation. 728 if (getter->isGLValue()) 729 return false; 730 731 // If we selected a trivial copy-constructor, we're okay. 732 if (const CXXConstructExpr *construct = dyn_cast<CXXConstructExpr>(getter)) 733 return (construct->getConstructor()->isTrivial()); 734 735 // The constructor might require cleanups (in which case it's never 736 // trivial). 737 assert(isa<ExprWithCleanups>(getter)); 738 return false; 739 } 740 741 /// emitCPPObjectAtomicGetterCall - Call the runtime function to 742 /// copy the ivar into the resturn slot. 743 static void emitCPPObjectAtomicGetterCall(CodeGenFunction &CGF, 744 llvm::Value *returnAddr, 745 ObjCIvarDecl *ivar, 746 llvm::Constant *AtomicHelperFn) { 747 // objc_copyCppObjectAtomic (&returnSlot, &CppObjectIvar, 748 // AtomicHelperFn); 749 CallArgList args; 750 751 // The 1st argument is the return Slot. 752 args.add(RValue::get(returnAddr), CGF.getContext().VoidPtrTy); 753 754 // The 2nd argument is the address of the ivar. 755 llvm::Value *ivarAddr = 756 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 757 CGF.LoadObjCSelf(), ivar, 0).getAddress(); 758 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 759 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 760 761 // Third argument is the helper function. 762 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); 763 764 llvm::Value *copyCppAtomicObjectFn = 765 CGF.CGM.getObjCRuntime().GetCppAtomicObjectFunction(); 766 CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args, 767 FunctionType::ExtInfo(), 768 RequiredArgs::All), 769 copyCppAtomicObjectFn, ReturnValueSlot(), args); 770 } 771 772 void 773 CodeGenFunction::generateObjCGetterBody(const ObjCImplementationDecl *classImpl, 774 const ObjCPropertyImplDecl *propImpl, 775 llvm::Constant *AtomicHelperFn) { 776 // If there's a non-trivial 'get' expression, we just have to emit that. 777 if (!hasTrivialGetExpr(propImpl)) { 778 if (!AtomicHelperFn) { 779 ReturnStmt ret(SourceLocation(), propImpl->getGetterCXXConstructor(), 780 /*nrvo*/ 0); 781 EmitReturnStmt(ret); 782 } 783 else { 784 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 785 emitCPPObjectAtomicGetterCall(*this, ReturnValue, 786 ivar, AtomicHelperFn); 787 } 788 return; 789 } 790 791 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); 792 QualType propType = prop->getType(); 793 ObjCMethodDecl *getterMethod = prop->getGetterMethodDecl(); 794 795 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 796 797 // Pick an implementation strategy. 798 PropertyImplStrategy strategy(CGM, propImpl); 799 switch (strategy.getKind()) { 800 case PropertyImplStrategy::Native: { 801 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); 802 803 // Currently, all atomic accesses have to be through integer 804 // types, so there's no point in trying to pick a prettier type. 805 llvm::Type *bitcastType = 806 llvm::Type::getIntNTy(getLLVMContext(), 807 getContext().toBits(strategy.getIvarSize())); 808 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay 809 810 // Perform an atomic load. This does not impose ordering constraints. 811 llvm::Value *ivarAddr = LV.getAddress(); 812 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType); 813 llvm::LoadInst *load = Builder.CreateLoad(ivarAddr, "load"); 814 load->setAlignment(strategy.getIvarAlignment().getQuantity()); 815 load->setAtomic(llvm::Unordered); 816 817 // Store that value into the return address. Doing this with a 818 // bitcast is likely to produce some pretty ugly IR, but it's not 819 // the *most* terrible thing in the world. 820 Builder.CreateStore(load, Builder.CreateBitCast(ReturnValue, bitcastType)); 821 822 // Make sure we don't do an autorelease. 823 AutoreleaseResult = false; 824 return; 825 } 826 827 case PropertyImplStrategy::GetSetProperty: { 828 llvm::Value *getPropertyFn = 829 CGM.getObjCRuntime().GetPropertyGetFunction(); 830 if (!getPropertyFn) { 831 CGM.ErrorUnsupported(propImpl, "Obj-C getter requiring atomic copy"); 832 return; 833 } 834 835 // Return (ivar-type) objc_getProperty((id) self, _cmd, offset, true). 836 // FIXME: Can't this be simpler? This might even be worse than the 837 // corresponding gcc code. 838 llvm::Value *cmd = 839 Builder.CreateLoad(LocalDeclMap[getterMethod->getCmdDecl()], "cmd"); 840 llvm::Value *self = Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); 841 llvm::Value *ivarOffset = 842 EmitIvarOffset(classImpl->getClassInterface(), ivar); 843 844 CallArgList args; 845 args.add(RValue::get(self), getContext().getObjCIdType()); 846 args.add(RValue::get(cmd), getContext().getObjCSelType()); 847 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 848 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), 849 getContext().BoolTy); 850 851 // FIXME: We shouldn't need to get the function info here, the 852 // runtime already should have computed it to build the function. 853 RValue RV = EmitCall(getTypes().arrangeFunctionCall(propType, args, 854 FunctionType::ExtInfo(), 855 RequiredArgs::All), 856 getPropertyFn, ReturnValueSlot(), args); 857 858 // We need to fix the type here. Ivars with copy & retain are 859 // always objects so we don't need to worry about complex or 860 // aggregates. 861 RV = RValue::get(Builder.CreateBitCast(RV.getScalarVal(), 862 getTypes().ConvertType(propType))); 863 864 EmitReturnOfRValue(RV, propType); 865 866 // objc_getProperty does an autorelease, so we should suppress ours. 867 AutoreleaseResult = false; 868 869 return; 870 } 871 872 case PropertyImplStrategy::CopyStruct: 873 emitStructGetterCall(*this, ivar, strategy.isAtomic(), 874 strategy.hasStrongMember()); 875 return; 876 877 case PropertyImplStrategy::Expression: 878 case PropertyImplStrategy::SetPropertyAndExpressionGet: { 879 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, 0); 880 881 QualType ivarType = ivar->getType(); 882 if (ivarType->isAnyComplexType()) { 883 ComplexPairTy pair = LoadComplexFromAddr(LV.getAddress(), 884 LV.isVolatileQualified()); 885 StoreComplexToAddr(pair, ReturnValue, LV.isVolatileQualified()); 886 } else if (hasAggregateLLVMType(ivarType)) { 887 // The return value slot is guaranteed to not be aliased, but 888 // that's not necessarily the same as "on the stack", so 889 // we still potentially need objc_memmove_collectable. 890 EmitAggregateCopy(ReturnValue, LV.getAddress(), ivarType); 891 } else { 892 llvm::Value *value; 893 if (propType->isReferenceType()) { 894 value = LV.getAddress(); 895 } else { 896 // We want to load and autoreleaseReturnValue ARC __weak ivars. 897 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) { 898 value = emitARCRetainLoadOfScalar(*this, LV, ivarType); 899 900 // Otherwise we want to do a simple load, suppressing the 901 // final autorelease. 902 } else { 903 value = EmitLoadOfLValue(LV).getScalarVal(); 904 AutoreleaseResult = false; 905 } 906 907 value = Builder.CreateBitCast(value, ConvertType(propType)); 908 } 909 910 EmitReturnOfRValue(RValue::get(value), propType); 911 } 912 return; 913 } 914 915 } 916 llvm_unreachable("bad @property implementation strategy!"); 917 } 918 919 /// emitStructSetterCall - Call the runtime function to store the value 920 /// from the first formal parameter into the given ivar. 921 static void emitStructSetterCall(CodeGenFunction &CGF, ObjCMethodDecl *OMD, 922 ObjCIvarDecl *ivar) { 923 // objc_copyStruct (&structIvar, &Arg, 924 // sizeof (struct something), true, false); 925 CallArgList args; 926 927 // The first argument is the address of the ivar. 928 llvm::Value *ivarAddr = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 929 CGF.LoadObjCSelf(), ivar, 0) 930 .getAddress(); 931 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 932 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 933 934 // The second argument is the address of the parameter variable. 935 ParmVarDecl *argVar = *OMD->param_begin(); 936 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 937 VK_LValue, SourceLocation()); 938 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress(); 939 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); 940 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); 941 942 // The third argument is the sizeof the type. 943 llvm::Value *size = 944 CGF.CGM.getSize(CGF.getContext().getTypeSizeInChars(ivar->getType())); 945 args.add(RValue::get(size), CGF.getContext().getSizeType()); 946 947 // The fourth argument is the 'isAtomic' flag. 948 args.add(RValue::get(CGF.Builder.getTrue()), CGF.getContext().BoolTy); 949 950 // The fifth argument is the 'hasStrong' flag. 951 // FIXME: should this really always be false? 952 args.add(RValue::get(CGF.Builder.getFalse()), CGF.getContext().BoolTy); 953 954 llvm::Value *copyStructFn = CGF.CGM.getObjCRuntime().GetSetStructFunction(); 955 CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args, 956 FunctionType::ExtInfo(), 957 RequiredArgs::All), 958 copyStructFn, ReturnValueSlot(), args); 959 } 960 961 /// emitCPPObjectAtomicSetterCall - Call the runtime function to store 962 /// the value from the first formal parameter into the given ivar, using 963 /// the Cpp API for atomic Cpp objects with non-trivial copy assignment. 964 static void emitCPPObjectAtomicSetterCall(CodeGenFunction &CGF, 965 ObjCMethodDecl *OMD, 966 ObjCIvarDecl *ivar, 967 llvm::Constant *AtomicHelperFn) { 968 // objc_copyCppObjectAtomic (&CppObjectIvar, &Arg, 969 // AtomicHelperFn); 970 CallArgList args; 971 972 // The first argument is the address of the ivar. 973 llvm::Value *ivarAddr = 974 CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), 975 CGF.LoadObjCSelf(), ivar, 0).getAddress(); 976 ivarAddr = CGF.Builder.CreateBitCast(ivarAddr, CGF.Int8PtrTy); 977 args.add(RValue::get(ivarAddr), CGF.getContext().VoidPtrTy); 978 979 // The second argument is the address of the parameter variable. 980 ParmVarDecl *argVar = *OMD->param_begin(); 981 DeclRefExpr argRef(argVar, false, argVar->getType().getNonReferenceType(), 982 VK_LValue, SourceLocation()); 983 llvm::Value *argAddr = CGF.EmitLValue(&argRef).getAddress(); 984 argAddr = CGF.Builder.CreateBitCast(argAddr, CGF.Int8PtrTy); 985 args.add(RValue::get(argAddr), CGF.getContext().VoidPtrTy); 986 987 // Third argument is the helper function. 988 args.add(RValue::get(AtomicHelperFn), CGF.getContext().VoidPtrTy); 989 990 llvm::Value *copyCppAtomicObjectFn = 991 CGF.CGM.getObjCRuntime().GetCppAtomicObjectFunction(); 992 CGF.EmitCall(CGF.getTypes().arrangeFunctionCall(CGF.getContext().VoidTy, args, 993 FunctionType::ExtInfo(), 994 RequiredArgs::All), 995 copyCppAtomicObjectFn, ReturnValueSlot(), args); 996 997 998 } 999 1000 1001 static bool hasTrivialSetExpr(const ObjCPropertyImplDecl *PID) { 1002 Expr *setter = PID->getSetterCXXAssignment(); 1003 if (!setter) return true; 1004 1005 // Sema only makes only of these when the ivar has a C++ class type, 1006 // so the form is pretty constrained. 1007 1008 // An operator call is trivial if the function it calls is trivial. 1009 // This also implies that there's nothing non-trivial going on with 1010 // the arguments, because operator= can only be trivial if it's a 1011 // synthesized assignment operator and therefore both parameters are 1012 // references. 1013 if (CallExpr *call = dyn_cast<CallExpr>(setter)) { 1014 if (const FunctionDecl *callee 1015 = dyn_cast_or_null<FunctionDecl>(call->getCalleeDecl())) 1016 if (callee->isTrivial()) 1017 return true; 1018 return false; 1019 } 1020 1021 assert(isa<ExprWithCleanups>(setter)); 1022 return false; 1023 } 1024 1025 static bool UseOptimizedSetter(CodeGenModule &CGM) { 1026 if (CGM.getLangOpts().getGC() != LangOptions::NonGC) 1027 return false; 1028 const TargetInfo &Target = CGM.getContext().getTargetInfo(); 1029 1030 if (Target.getPlatformName() != "macosx") 1031 return false; 1032 1033 return Target.getPlatformMinVersion() >= VersionTuple(10, 8); 1034 } 1035 1036 void 1037 CodeGenFunction::generateObjCSetterBody(const ObjCImplementationDecl *classImpl, 1038 const ObjCPropertyImplDecl *propImpl, 1039 llvm::Constant *AtomicHelperFn) { 1040 const ObjCPropertyDecl *prop = propImpl->getPropertyDecl(); 1041 ObjCIvarDecl *ivar = propImpl->getPropertyIvarDecl(); 1042 ObjCMethodDecl *setterMethod = prop->getSetterMethodDecl(); 1043 1044 // Just use the setter expression if Sema gave us one and it's 1045 // non-trivial. 1046 if (!hasTrivialSetExpr(propImpl)) { 1047 if (!AtomicHelperFn) 1048 // If non-atomic, assignment is called directly. 1049 EmitStmt(propImpl->getSetterCXXAssignment()); 1050 else 1051 // If atomic, assignment is called via a locking api. 1052 emitCPPObjectAtomicSetterCall(*this, setterMethod, ivar, 1053 AtomicHelperFn); 1054 return; 1055 } 1056 1057 PropertyImplStrategy strategy(CGM, propImpl); 1058 switch (strategy.getKind()) { 1059 case PropertyImplStrategy::Native: { 1060 llvm::Value *argAddr = LocalDeclMap[*setterMethod->param_begin()]; 1061 1062 LValue ivarLValue = 1063 EmitLValueForIvar(TypeOfSelfObject(), LoadObjCSelf(), ivar, /*quals*/ 0); 1064 llvm::Value *ivarAddr = ivarLValue.getAddress(); 1065 1066 // Currently, all atomic accesses have to be through integer 1067 // types, so there's no point in trying to pick a prettier type. 1068 llvm::Type *bitcastType = 1069 llvm::Type::getIntNTy(getLLVMContext(), 1070 getContext().toBits(strategy.getIvarSize())); 1071 bitcastType = bitcastType->getPointerTo(); // addrspace 0 okay 1072 1073 // Cast both arguments to the chosen operation type. 1074 argAddr = Builder.CreateBitCast(argAddr, bitcastType); 1075 ivarAddr = Builder.CreateBitCast(ivarAddr, bitcastType); 1076 1077 // This bitcast load is likely to cause some nasty IR. 1078 llvm::Value *load = Builder.CreateLoad(argAddr); 1079 1080 // Perform an atomic store. There are no memory ordering requirements. 1081 llvm::StoreInst *store = Builder.CreateStore(load, ivarAddr); 1082 store->setAlignment(strategy.getIvarAlignment().getQuantity()); 1083 store->setAtomic(llvm::Unordered); 1084 return; 1085 } 1086 1087 case PropertyImplStrategy::GetSetProperty: 1088 case PropertyImplStrategy::SetPropertyAndExpressionGet: { 1089 1090 llvm::Value *setOptimizedPropertyFn = 0; 1091 llvm::Value *setPropertyFn = 0; 1092 if (UseOptimizedSetter(CGM)) { 1093 // 10.8 code and GC is off 1094 setOptimizedPropertyFn = 1095 CGM.getObjCRuntime() 1096 .GetOptimizedPropertySetFunction(strategy.isAtomic(), 1097 strategy.isCopy()); 1098 if (!setOptimizedPropertyFn) { 1099 CGM.ErrorUnsupported(propImpl, "Obj-C optimized setter - NYI"); 1100 return; 1101 } 1102 } 1103 else { 1104 setPropertyFn = CGM.getObjCRuntime().GetPropertySetFunction(); 1105 if (!setPropertyFn) { 1106 CGM.ErrorUnsupported(propImpl, "Obj-C setter requiring atomic copy"); 1107 return; 1108 } 1109 } 1110 1111 // Emit objc_setProperty((id) self, _cmd, offset, arg, 1112 // <is-atomic>, <is-copy>). 1113 llvm::Value *cmd = 1114 Builder.CreateLoad(LocalDeclMap[setterMethod->getCmdDecl()]); 1115 llvm::Value *self = 1116 Builder.CreateBitCast(LoadObjCSelf(), VoidPtrTy); 1117 llvm::Value *ivarOffset = 1118 EmitIvarOffset(classImpl->getClassInterface(), ivar); 1119 llvm::Value *arg = LocalDeclMap[*setterMethod->param_begin()]; 1120 arg = Builder.CreateBitCast(Builder.CreateLoad(arg, "arg"), VoidPtrTy); 1121 1122 CallArgList args; 1123 args.add(RValue::get(self), getContext().getObjCIdType()); 1124 args.add(RValue::get(cmd), getContext().getObjCSelType()); 1125 if (setOptimizedPropertyFn) { 1126 args.add(RValue::get(arg), getContext().getObjCIdType()); 1127 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 1128 EmitCall(getTypes().arrangeFunctionCall(getContext().VoidTy, args, 1129 FunctionType::ExtInfo(), 1130 RequiredArgs::All), 1131 setOptimizedPropertyFn, ReturnValueSlot(), args); 1132 } else { 1133 args.add(RValue::get(ivarOffset), getContext().getPointerDiffType()); 1134 args.add(RValue::get(arg), getContext().getObjCIdType()); 1135 args.add(RValue::get(Builder.getInt1(strategy.isAtomic())), 1136 getContext().BoolTy); 1137 args.add(RValue::get(Builder.getInt1(strategy.isCopy())), 1138 getContext().BoolTy); 1139 // FIXME: We shouldn't need to get the function info here, the runtime 1140 // already should have computed it to build the function. 1141 EmitCall(getTypes().arrangeFunctionCall(getContext().VoidTy, args, 1142 FunctionType::ExtInfo(), 1143 RequiredArgs::All), 1144 setPropertyFn, ReturnValueSlot(), args); 1145 } 1146 1147 return; 1148 } 1149 1150 case PropertyImplStrategy::CopyStruct: 1151 emitStructSetterCall(*this, setterMethod, ivar); 1152 return; 1153 1154 case PropertyImplStrategy::Expression: 1155 break; 1156 } 1157 1158 // Otherwise, fake up some ASTs and emit a normal assignment. 1159 ValueDecl *selfDecl = setterMethod->getSelfDecl(); 1160 DeclRefExpr self(selfDecl, false, selfDecl->getType(), 1161 VK_LValue, SourceLocation()); 1162 ImplicitCastExpr selfLoad(ImplicitCastExpr::OnStack, 1163 selfDecl->getType(), CK_LValueToRValue, &self, 1164 VK_RValue); 1165 ObjCIvarRefExpr ivarRef(ivar, ivar->getType().getNonReferenceType(), 1166 SourceLocation(), &selfLoad, true, true); 1167 1168 ParmVarDecl *argDecl = *setterMethod->param_begin(); 1169 QualType argType = argDecl->getType().getNonReferenceType(); 1170 DeclRefExpr arg(argDecl, false, argType, VK_LValue, SourceLocation()); 1171 ImplicitCastExpr argLoad(ImplicitCastExpr::OnStack, 1172 argType.getUnqualifiedType(), CK_LValueToRValue, 1173 &arg, VK_RValue); 1174 1175 // The property type can differ from the ivar type in some situations with 1176 // Objective-C pointer types, we can always bit cast the RHS in these cases. 1177 // The following absurdity is just to ensure well-formed IR. 1178 CastKind argCK = CK_NoOp; 1179 if (ivarRef.getType()->isObjCObjectPointerType()) { 1180 if (argLoad.getType()->isObjCObjectPointerType()) 1181 argCK = CK_BitCast; 1182 else if (argLoad.getType()->isBlockPointerType()) 1183 argCK = CK_BlockPointerToObjCPointerCast; 1184 else 1185 argCK = CK_CPointerToObjCPointerCast; 1186 } else if (ivarRef.getType()->isBlockPointerType()) { 1187 if (argLoad.getType()->isBlockPointerType()) 1188 argCK = CK_BitCast; 1189 else 1190 argCK = CK_AnyPointerToBlockPointerCast; 1191 } else if (ivarRef.getType()->isPointerType()) { 1192 argCK = CK_BitCast; 1193 } 1194 ImplicitCastExpr argCast(ImplicitCastExpr::OnStack, 1195 ivarRef.getType(), argCK, &argLoad, 1196 VK_RValue); 1197 Expr *finalArg = &argLoad; 1198 if (!getContext().hasSameUnqualifiedType(ivarRef.getType(), 1199 argLoad.getType())) 1200 finalArg = &argCast; 1201 1202 1203 BinaryOperator assign(&ivarRef, finalArg, BO_Assign, 1204 ivarRef.getType(), VK_RValue, OK_Ordinary, 1205 SourceLocation()); 1206 EmitStmt(&assign); 1207 } 1208 1209 /// GenerateObjCSetter - Generate an Objective-C property setter 1210 /// function. The given Decl must be an ObjCImplementationDecl. @synthesize 1211 /// is illegal within a category. 1212 void CodeGenFunction::GenerateObjCSetter(ObjCImplementationDecl *IMP, 1213 const ObjCPropertyImplDecl *PID) { 1214 llvm::Constant *AtomicHelperFn = 1215 GenerateObjCAtomicSetterCopyHelperFunction(PID); 1216 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 1217 ObjCMethodDecl *OMD = PD->getSetterMethodDecl(); 1218 assert(OMD && "Invalid call to generate setter (empty method)"); 1219 StartObjCMethod(OMD, IMP->getClassInterface(), OMD->getLocStart()); 1220 1221 generateObjCSetterBody(IMP, PID, AtomicHelperFn); 1222 1223 FinishFunction(); 1224 } 1225 1226 namespace { 1227 struct DestroyIvar : EHScopeStack::Cleanup { 1228 private: 1229 llvm::Value *addr; 1230 const ObjCIvarDecl *ivar; 1231 CodeGenFunction::Destroyer *destroyer; 1232 bool useEHCleanupForArray; 1233 public: 1234 DestroyIvar(llvm::Value *addr, const ObjCIvarDecl *ivar, 1235 CodeGenFunction::Destroyer *destroyer, 1236 bool useEHCleanupForArray) 1237 : addr(addr), ivar(ivar), destroyer(destroyer), 1238 useEHCleanupForArray(useEHCleanupForArray) {} 1239 1240 void Emit(CodeGenFunction &CGF, Flags flags) { 1241 LValue lvalue 1242 = CGF.EmitLValueForIvar(CGF.TypeOfSelfObject(), addr, ivar, /*CVR*/ 0); 1243 CGF.emitDestroy(lvalue.getAddress(), ivar->getType(), destroyer, 1244 flags.isForNormalCleanup() && useEHCleanupForArray); 1245 } 1246 }; 1247 } 1248 1249 /// Like CodeGenFunction::destroyARCStrong, but do it with a call. 1250 static void destroyARCStrongWithStore(CodeGenFunction &CGF, 1251 llvm::Value *addr, 1252 QualType type) { 1253 llvm::Value *null = getNullForVariable(addr); 1254 CGF.EmitARCStoreStrongCall(addr, null, /*ignored*/ true); 1255 } 1256 1257 static void emitCXXDestructMethod(CodeGenFunction &CGF, 1258 ObjCImplementationDecl *impl) { 1259 CodeGenFunction::RunCleanupsScope scope(CGF); 1260 1261 llvm::Value *self = CGF.LoadObjCSelf(); 1262 1263 const ObjCInterfaceDecl *iface = impl->getClassInterface(); 1264 for (const ObjCIvarDecl *ivar = iface->all_declared_ivar_begin(); 1265 ivar; ivar = ivar->getNextIvar()) { 1266 QualType type = ivar->getType(); 1267 1268 // Check whether the ivar is a destructible type. 1269 QualType::DestructionKind dtorKind = type.isDestructedType(); 1270 if (!dtorKind) continue; 1271 1272 CodeGenFunction::Destroyer *destroyer = 0; 1273 1274 // Use a call to objc_storeStrong to destroy strong ivars, for the 1275 // general benefit of the tools. 1276 if (dtorKind == QualType::DK_objc_strong_lifetime) { 1277 destroyer = destroyARCStrongWithStore; 1278 1279 // Otherwise use the default for the destruction kind. 1280 } else { 1281 destroyer = CGF.getDestroyer(dtorKind); 1282 } 1283 1284 CleanupKind cleanupKind = CGF.getCleanupKind(dtorKind); 1285 1286 CGF.EHStack.pushCleanup<DestroyIvar>(cleanupKind, self, ivar, destroyer, 1287 cleanupKind & EHCleanup); 1288 } 1289 1290 assert(scope.requiresCleanups() && "nothing to do in .cxx_destruct?"); 1291 } 1292 1293 void CodeGenFunction::GenerateObjCCtorDtorMethod(ObjCImplementationDecl *IMP, 1294 ObjCMethodDecl *MD, 1295 bool ctor) { 1296 MD->createImplicitParams(CGM.getContext(), IMP->getClassInterface()); 1297 StartObjCMethod(MD, IMP->getClassInterface(), MD->getLocStart()); 1298 1299 // Emit .cxx_construct. 1300 if (ctor) { 1301 // Suppress the final autorelease in ARC. 1302 AutoreleaseResult = false; 1303 1304 SmallVector<CXXCtorInitializer *, 8> IvarInitializers; 1305 for (ObjCImplementationDecl::init_const_iterator B = IMP->init_begin(), 1306 E = IMP->init_end(); B != E; ++B) { 1307 CXXCtorInitializer *IvarInit = (*B); 1308 FieldDecl *Field = IvarInit->getAnyMember(); 1309 ObjCIvarDecl *Ivar = cast<ObjCIvarDecl>(Field); 1310 LValue LV = EmitLValueForIvar(TypeOfSelfObject(), 1311 LoadObjCSelf(), Ivar, 0); 1312 EmitAggExpr(IvarInit->getInit(), 1313 AggValueSlot::forLValue(LV, AggValueSlot::IsDestructed, 1314 AggValueSlot::DoesNotNeedGCBarriers, 1315 AggValueSlot::IsNotAliased)); 1316 } 1317 // constructor returns 'self'. 1318 CodeGenTypes &Types = CGM.getTypes(); 1319 QualType IdTy(CGM.getContext().getObjCIdType()); 1320 llvm::Value *SelfAsId = 1321 Builder.CreateBitCast(LoadObjCSelf(), Types.ConvertType(IdTy)); 1322 EmitReturnOfRValue(RValue::get(SelfAsId), IdTy); 1323 1324 // Emit .cxx_destruct. 1325 } else { 1326 emitCXXDestructMethod(*this, IMP); 1327 } 1328 FinishFunction(); 1329 } 1330 1331 bool CodeGenFunction::IndirectObjCSetterArg(const CGFunctionInfo &FI) { 1332 CGFunctionInfo::const_arg_iterator it = FI.arg_begin(); 1333 it++; it++; 1334 const ABIArgInfo &AI = it->info; 1335 // FIXME. Is this sufficient check? 1336 return (AI.getKind() == ABIArgInfo::Indirect); 1337 } 1338 1339 bool CodeGenFunction::IvarTypeWithAggrGCObjects(QualType Ty) { 1340 if (CGM.getLangOpts().getGC() == LangOptions::NonGC) 1341 return false; 1342 if (const RecordType *FDTTy = Ty.getTypePtr()->getAs<RecordType>()) 1343 return FDTTy->getDecl()->hasObjectMember(); 1344 return false; 1345 } 1346 1347 llvm::Value *CodeGenFunction::LoadObjCSelf() { 1348 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); 1349 return Builder.CreateLoad(LocalDeclMap[OMD->getSelfDecl()], "self"); 1350 } 1351 1352 QualType CodeGenFunction::TypeOfSelfObject() { 1353 const ObjCMethodDecl *OMD = cast<ObjCMethodDecl>(CurFuncDecl); 1354 ImplicitParamDecl *selfDecl = OMD->getSelfDecl(); 1355 const ObjCObjectPointerType *PTy = cast<ObjCObjectPointerType>( 1356 getContext().getCanonicalType(selfDecl->getType())); 1357 return PTy->getPointeeType(); 1358 } 1359 1360 void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S){ 1361 llvm::Constant *EnumerationMutationFn = 1362 CGM.getObjCRuntime().EnumerationMutationFunction(); 1363 1364 if (!EnumerationMutationFn) { 1365 CGM.ErrorUnsupported(&S, "Obj-C fast enumeration for this runtime"); 1366 return; 1367 } 1368 1369 CGDebugInfo *DI = getDebugInfo(); 1370 if (DI) 1371 DI->EmitLexicalBlockStart(Builder, S.getSourceRange().getBegin()); 1372 1373 // The local variable comes into scope immediately. 1374 AutoVarEmission variable = AutoVarEmission::invalid(); 1375 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) 1376 variable = EmitAutoVarAlloca(*cast<VarDecl>(SD->getSingleDecl())); 1377 1378 JumpDest LoopEnd = getJumpDestInCurrentScope("forcoll.end"); 1379 1380 // Fast enumeration state. 1381 QualType StateTy = CGM.getObjCFastEnumerationStateType(); 1382 llvm::Value *StatePtr = CreateMemTemp(StateTy, "state.ptr"); 1383 EmitNullInitialization(StatePtr, StateTy); 1384 1385 // Number of elements in the items array. 1386 static const unsigned NumItems = 16; 1387 1388 // Fetch the countByEnumeratingWithState:objects:count: selector. 1389 IdentifierInfo *II[] = { 1390 &CGM.getContext().Idents.get("countByEnumeratingWithState"), 1391 &CGM.getContext().Idents.get("objects"), 1392 &CGM.getContext().Idents.get("count") 1393 }; 1394 Selector FastEnumSel = 1395 CGM.getContext().Selectors.getSelector(llvm::array_lengthof(II), &II[0]); 1396 1397 QualType ItemsTy = 1398 getContext().getConstantArrayType(getContext().getObjCIdType(), 1399 llvm::APInt(32, NumItems), 1400 ArrayType::Normal, 0); 1401 llvm::Value *ItemsPtr = CreateMemTemp(ItemsTy, "items.ptr"); 1402 1403 // Emit the collection pointer. In ARC, we do a retain. 1404 llvm::Value *Collection; 1405 if (getLangOpts().ObjCAutoRefCount) { 1406 Collection = EmitARCRetainScalarExpr(S.getCollection()); 1407 1408 // Enter a cleanup to do the release. 1409 EmitObjCConsumeObject(S.getCollection()->getType(), Collection); 1410 } else { 1411 Collection = EmitScalarExpr(S.getCollection()); 1412 } 1413 1414 // The 'continue' label needs to appear within the cleanup for the 1415 // collection object. 1416 JumpDest AfterBody = getJumpDestInCurrentScope("forcoll.next"); 1417 1418 // Send it our message: 1419 CallArgList Args; 1420 1421 // The first argument is a temporary of the enumeration-state type. 1422 Args.add(RValue::get(StatePtr), getContext().getPointerType(StateTy)); 1423 1424 // The second argument is a temporary array with space for NumItems 1425 // pointers. We'll actually be loading elements from the array 1426 // pointer written into the control state; this buffer is so that 1427 // collections that *aren't* backed by arrays can still queue up 1428 // batches of elements. 1429 Args.add(RValue::get(ItemsPtr), getContext().getPointerType(ItemsTy)); 1430 1431 // The third argument is the capacity of that temporary array. 1432 llvm::Type *UnsignedLongLTy = ConvertType(getContext().UnsignedLongTy); 1433 llvm::Constant *Count = llvm::ConstantInt::get(UnsignedLongLTy, NumItems); 1434 Args.add(RValue::get(Count), getContext().UnsignedLongTy); 1435 1436 // Start the enumeration. 1437 RValue CountRV = 1438 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 1439 getContext().UnsignedLongTy, 1440 FastEnumSel, 1441 Collection, Args); 1442 1443 // The initial number of objects that were returned in the buffer. 1444 llvm::Value *initialBufferLimit = CountRV.getScalarVal(); 1445 1446 llvm::BasicBlock *EmptyBB = createBasicBlock("forcoll.empty"); 1447 llvm::BasicBlock *LoopInitBB = createBasicBlock("forcoll.loopinit"); 1448 1449 llvm::Value *zero = llvm::Constant::getNullValue(UnsignedLongLTy); 1450 1451 // If the limit pointer was zero to begin with, the collection is 1452 // empty; skip all this. 1453 Builder.CreateCondBr(Builder.CreateICmpEQ(initialBufferLimit, zero, "iszero"), 1454 EmptyBB, LoopInitBB); 1455 1456 // Otherwise, initialize the loop. 1457 EmitBlock(LoopInitBB); 1458 1459 // Save the initial mutations value. This is the value at an 1460 // address that was written into the state object by 1461 // countByEnumeratingWithState:objects:count:. 1462 llvm::Value *StateMutationsPtrPtr = 1463 Builder.CreateStructGEP(StatePtr, 2, "mutationsptr.ptr"); 1464 llvm::Value *StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, 1465 "mutationsptr"); 1466 1467 llvm::Value *initialMutations = 1468 Builder.CreateLoad(StateMutationsPtr, "forcoll.initial-mutations"); 1469 1470 // Start looping. This is the point we return to whenever we have a 1471 // fresh, non-empty batch of objects. 1472 llvm::BasicBlock *LoopBodyBB = createBasicBlock("forcoll.loopbody"); 1473 EmitBlock(LoopBodyBB); 1474 1475 // The current index into the buffer. 1476 llvm::PHINode *index = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.index"); 1477 index->addIncoming(zero, LoopInitBB); 1478 1479 // The current buffer size. 1480 llvm::PHINode *count = Builder.CreatePHI(UnsignedLongLTy, 3, "forcoll.count"); 1481 count->addIncoming(initialBufferLimit, LoopInitBB); 1482 1483 // Check whether the mutations value has changed from where it was 1484 // at start. StateMutationsPtr should actually be invariant between 1485 // refreshes. 1486 StateMutationsPtr = Builder.CreateLoad(StateMutationsPtrPtr, "mutationsptr"); 1487 llvm::Value *currentMutations 1488 = Builder.CreateLoad(StateMutationsPtr, "statemutations"); 1489 1490 llvm::BasicBlock *WasMutatedBB = createBasicBlock("forcoll.mutated"); 1491 llvm::BasicBlock *WasNotMutatedBB = createBasicBlock("forcoll.notmutated"); 1492 1493 Builder.CreateCondBr(Builder.CreateICmpEQ(currentMutations, initialMutations), 1494 WasNotMutatedBB, WasMutatedBB); 1495 1496 // If so, call the enumeration-mutation function. 1497 EmitBlock(WasMutatedBB); 1498 llvm::Value *V = 1499 Builder.CreateBitCast(Collection, 1500 ConvertType(getContext().getObjCIdType())); 1501 CallArgList Args2; 1502 Args2.add(RValue::get(V), getContext().getObjCIdType()); 1503 // FIXME: We shouldn't need to get the function info here, the runtime already 1504 // should have computed it to build the function. 1505 EmitCall(CGM.getTypes().arrangeFunctionCall(getContext().VoidTy, Args2, 1506 FunctionType::ExtInfo(), 1507 RequiredArgs::All), 1508 EnumerationMutationFn, ReturnValueSlot(), Args2); 1509 1510 // Otherwise, or if the mutation function returns, just continue. 1511 EmitBlock(WasNotMutatedBB); 1512 1513 // Initialize the element variable. 1514 RunCleanupsScope elementVariableScope(*this); 1515 bool elementIsVariable; 1516 LValue elementLValue; 1517 QualType elementType; 1518 if (const DeclStmt *SD = dyn_cast<DeclStmt>(S.getElement())) { 1519 // Initialize the variable, in case it's a __block variable or something. 1520 EmitAutoVarInit(variable); 1521 1522 const VarDecl* D = cast<VarDecl>(SD->getSingleDecl()); 1523 DeclRefExpr tempDRE(const_cast<VarDecl*>(D), false, D->getType(), 1524 VK_LValue, SourceLocation()); 1525 elementLValue = EmitLValue(&tempDRE); 1526 elementType = D->getType(); 1527 elementIsVariable = true; 1528 1529 if (D->isARCPseudoStrong()) 1530 elementLValue.getQuals().setObjCLifetime(Qualifiers::OCL_ExplicitNone); 1531 } else { 1532 elementLValue = LValue(); // suppress warning 1533 elementType = cast<Expr>(S.getElement())->getType(); 1534 elementIsVariable = false; 1535 } 1536 llvm::Type *convertedElementType = ConvertType(elementType); 1537 1538 // Fetch the buffer out of the enumeration state. 1539 // TODO: this pointer should actually be invariant between 1540 // refreshes, which would help us do certain loop optimizations. 1541 llvm::Value *StateItemsPtr = 1542 Builder.CreateStructGEP(StatePtr, 1, "stateitems.ptr"); 1543 llvm::Value *EnumStateItems = 1544 Builder.CreateLoad(StateItemsPtr, "stateitems"); 1545 1546 // Fetch the value at the current index from the buffer. 1547 llvm::Value *CurrentItemPtr = 1548 Builder.CreateGEP(EnumStateItems, index, "currentitem.ptr"); 1549 llvm::Value *CurrentItem = Builder.CreateLoad(CurrentItemPtr); 1550 1551 // Cast that value to the right type. 1552 CurrentItem = Builder.CreateBitCast(CurrentItem, convertedElementType, 1553 "currentitem"); 1554 1555 // Make sure we have an l-value. Yes, this gets evaluated every 1556 // time through the loop. 1557 if (!elementIsVariable) { 1558 elementLValue = EmitLValue(cast<Expr>(S.getElement())); 1559 EmitStoreThroughLValue(RValue::get(CurrentItem), elementLValue); 1560 } else { 1561 EmitScalarInit(CurrentItem, elementLValue); 1562 } 1563 1564 // If we do have an element variable, this assignment is the end of 1565 // its initialization. 1566 if (elementIsVariable) 1567 EmitAutoVarCleanups(variable); 1568 1569 // Perform the loop body, setting up break and continue labels. 1570 BreakContinueStack.push_back(BreakContinue(LoopEnd, AfterBody)); 1571 { 1572 RunCleanupsScope Scope(*this); 1573 EmitStmt(S.getBody()); 1574 } 1575 BreakContinueStack.pop_back(); 1576 1577 // Destroy the element variable now. 1578 elementVariableScope.ForceCleanup(); 1579 1580 // Check whether there are more elements. 1581 EmitBlock(AfterBody.getBlock()); 1582 1583 llvm::BasicBlock *FetchMoreBB = createBasicBlock("forcoll.refetch"); 1584 1585 // First we check in the local buffer. 1586 llvm::Value *indexPlusOne 1587 = Builder.CreateAdd(index, llvm::ConstantInt::get(UnsignedLongLTy, 1)); 1588 1589 // If we haven't overrun the buffer yet, we can continue. 1590 Builder.CreateCondBr(Builder.CreateICmpULT(indexPlusOne, count), 1591 LoopBodyBB, FetchMoreBB); 1592 1593 index->addIncoming(indexPlusOne, AfterBody.getBlock()); 1594 count->addIncoming(count, AfterBody.getBlock()); 1595 1596 // Otherwise, we have to fetch more elements. 1597 EmitBlock(FetchMoreBB); 1598 1599 CountRV = 1600 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 1601 getContext().UnsignedLongTy, 1602 FastEnumSel, 1603 Collection, Args); 1604 1605 // If we got a zero count, we're done. 1606 llvm::Value *refetchCount = CountRV.getScalarVal(); 1607 1608 // (note that the message send might split FetchMoreBB) 1609 index->addIncoming(zero, Builder.GetInsertBlock()); 1610 count->addIncoming(refetchCount, Builder.GetInsertBlock()); 1611 1612 Builder.CreateCondBr(Builder.CreateICmpEQ(refetchCount, zero), 1613 EmptyBB, LoopBodyBB); 1614 1615 // No more elements. 1616 EmitBlock(EmptyBB); 1617 1618 if (!elementIsVariable) { 1619 // If the element was not a declaration, set it to be null. 1620 1621 llvm::Value *null = llvm::Constant::getNullValue(convertedElementType); 1622 elementLValue = EmitLValue(cast<Expr>(S.getElement())); 1623 EmitStoreThroughLValue(RValue::get(null), elementLValue); 1624 } 1625 1626 if (DI) 1627 DI->EmitLexicalBlockEnd(Builder, S.getSourceRange().getEnd()); 1628 1629 // Leave the cleanup we entered in ARC. 1630 if (getLangOpts().ObjCAutoRefCount) 1631 PopCleanupBlock(); 1632 1633 EmitBlock(LoopEnd.getBlock()); 1634 } 1635 1636 void CodeGenFunction::EmitObjCAtTryStmt(const ObjCAtTryStmt &S) { 1637 CGM.getObjCRuntime().EmitTryStmt(*this, S); 1638 } 1639 1640 void CodeGenFunction::EmitObjCAtThrowStmt(const ObjCAtThrowStmt &S) { 1641 CGM.getObjCRuntime().EmitThrowStmt(*this, S); 1642 } 1643 1644 void CodeGenFunction::EmitObjCAtSynchronizedStmt( 1645 const ObjCAtSynchronizedStmt &S) { 1646 CGM.getObjCRuntime().EmitSynchronizedStmt(*this, S); 1647 } 1648 1649 /// Produce the code for a CK_ARCProduceObject. Just does a 1650 /// primitive retain. 1651 llvm::Value *CodeGenFunction::EmitObjCProduceObject(QualType type, 1652 llvm::Value *value) { 1653 return EmitARCRetain(type, value); 1654 } 1655 1656 namespace { 1657 struct CallObjCRelease : EHScopeStack::Cleanup { 1658 CallObjCRelease(llvm::Value *object) : object(object) {} 1659 llvm::Value *object; 1660 1661 void Emit(CodeGenFunction &CGF, Flags flags) { 1662 CGF.EmitARCRelease(object, /*precise*/ true); 1663 } 1664 }; 1665 } 1666 1667 /// Produce the code for a CK_ARCConsumeObject. Does a primitive 1668 /// release at the end of the full-expression. 1669 llvm::Value *CodeGenFunction::EmitObjCConsumeObject(QualType type, 1670 llvm::Value *object) { 1671 // If we're in a conditional branch, we need to make the cleanup 1672 // conditional. 1673 pushFullExprCleanup<CallObjCRelease>(getARCCleanupKind(), object); 1674 return object; 1675 } 1676 1677 llvm::Value *CodeGenFunction::EmitObjCExtendObjectLifetime(QualType type, 1678 llvm::Value *value) { 1679 return EmitARCRetainAutorelease(type, value); 1680 } 1681 1682 1683 static llvm::Constant *createARCRuntimeFunction(CodeGenModule &CGM, 1684 llvm::FunctionType *type, 1685 StringRef fnName) { 1686 llvm::Constant *fn = CGM.CreateRuntimeFunction(type, fnName); 1687 1688 // In -fobjc-no-arc-runtime, emit weak references to the runtime 1689 // support library. 1690 if (!CGM.getCodeGenOpts().ObjCRuntimeHasARC) 1691 if (llvm::Function *f = dyn_cast<llvm::Function>(fn)) 1692 f->setLinkage(llvm::Function::ExternalWeakLinkage); 1693 1694 return fn; 1695 } 1696 1697 /// Perform an operation having the signature 1698 /// i8* (i8*) 1699 /// where a null input causes a no-op and returns null. 1700 static llvm::Value *emitARCValueOperation(CodeGenFunction &CGF, 1701 llvm::Value *value, 1702 llvm::Constant *&fn, 1703 StringRef fnName) { 1704 if (isa<llvm::ConstantPointerNull>(value)) return value; 1705 1706 if (!fn) { 1707 std::vector<llvm::Type*> args(1, CGF.Int8PtrTy); 1708 llvm::FunctionType *fnType = 1709 llvm::FunctionType::get(CGF.Int8PtrTy, args, false); 1710 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1711 } 1712 1713 // Cast the argument to 'id'. 1714 llvm::Type *origType = value->getType(); 1715 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy); 1716 1717 // Call the function. 1718 llvm::CallInst *call = CGF.Builder.CreateCall(fn, value); 1719 call->setDoesNotThrow(); 1720 1721 // Cast the result back to the original type. 1722 return CGF.Builder.CreateBitCast(call, origType); 1723 } 1724 1725 /// Perform an operation having the following signature: 1726 /// i8* (i8**) 1727 static llvm::Value *emitARCLoadOperation(CodeGenFunction &CGF, 1728 llvm::Value *addr, 1729 llvm::Constant *&fn, 1730 StringRef fnName) { 1731 if (!fn) { 1732 std::vector<llvm::Type*> args(1, CGF.Int8PtrPtrTy); 1733 llvm::FunctionType *fnType = 1734 llvm::FunctionType::get(CGF.Int8PtrTy, args, false); 1735 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1736 } 1737 1738 // Cast the argument to 'id*'. 1739 llvm::Type *origType = addr->getType(); 1740 addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy); 1741 1742 // Call the function. 1743 llvm::CallInst *call = CGF.Builder.CreateCall(fn, addr); 1744 call->setDoesNotThrow(); 1745 1746 // Cast the result back to a dereference of the original type. 1747 llvm::Value *result = call; 1748 if (origType != CGF.Int8PtrPtrTy) 1749 result = CGF.Builder.CreateBitCast(result, 1750 cast<llvm::PointerType>(origType)->getElementType()); 1751 1752 return result; 1753 } 1754 1755 /// Perform an operation having the following signature: 1756 /// i8* (i8**, i8*) 1757 static llvm::Value *emitARCStoreOperation(CodeGenFunction &CGF, 1758 llvm::Value *addr, 1759 llvm::Value *value, 1760 llvm::Constant *&fn, 1761 StringRef fnName, 1762 bool ignored) { 1763 assert(cast<llvm::PointerType>(addr->getType())->getElementType() 1764 == value->getType()); 1765 1766 if (!fn) { 1767 llvm::Type *argTypes[] = { CGF.Int8PtrPtrTy, CGF.Int8PtrTy }; 1768 1769 llvm::FunctionType *fnType 1770 = llvm::FunctionType::get(CGF.Int8PtrTy, argTypes, false); 1771 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1772 } 1773 1774 llvm::Type *origType = value->getType(); 1775 1776 addr = CGF.Builder.CreateBitCast(addr, CGF.Int8PtrPtrTy); 1777 value = CGF.Builder.CreateBitCast(value, CGF.Int8PtrTy); 1778 1779 llvm::CallInst *result = CGF.Builder.CreateCall2(fn, addr, value); 1780 result->setDoesNotThrow(); 1781 1782 if (ignored) return 0; 1783 1784 return CGF.Builder.CreateBitCast(result, origType); 1785 } 1786 1787 /// Perform an operation having the following signature: 1788 /// void (i8**, i8**) 1789 static void emitARCCopyOperation(CodeGenFunction &CGF, 1790 llvm::Value *dst, 1791 llvm::Value *src, 1792 llvm::Constant *&fn, 1793 StringRef fnName) { 1794 assert(dst->getType() == src->getType()); 1795 1796 if (!fn) { 1797 std::vector<llvm::Type*> argTypes(2, CGF.Int8PtrPtrTy); 1798 llvm::FunctionType *fnType 1799 = llvm::FunctionType::get(CGF.Builder.getVoidTy(), argTypes, false); 1800 fn = createARCRuntimeFunction(CGF.CGM, fnType, fnName); 1801 } 1802 1803 dst = CGF.Builder.CreateBitCast(dst, CGF.Int8PtrPtrTy); 1804 src = CGF.Builder.CreateBitCast(src, CGF.Int8PtrPtrTy); 1805 1806 llvm::CallInst *result = CGF.Builder.CreateCall2(fn, dst, src); 1807 result->setDoesNotThrow(); 1808 } 1809 1810 /// Produce the code to do a retain. Based on the type, calls one of: 1811 /// call i8* @objc_retain(i8* %value) 1812 /// call i8* @objc_retainBlock(i8* %value) 1813 llvm::Value *CodeGenFunction::EmitARCRetain(QualType type, llvm::Value *value) { 1814 if (type->isBlockPointerType()) 1815 return EmitARCRetainBlock(value, /*mandatory*/ false); 1816 else 1817 return EmitARCRetainNonBlock(value); 1818 } 1819 1820 /// Retain the given object, with normal retain semantics. 1821 /// call i8* @objc_retain(i8* %value) 1822 llvm::Value *CodeGenFunction::EmitARCRetainNonBlock(llvm::Value *value) { 1823 return emitARCValueOperation(*this, value, 1824 CGM.getARCEntrypoints().objc_retain, 1825 "objc_retain"); 1826 } 1827 1828 /// Retain the given block, with _Block_copy semantics. 1829 /// call i8* @objc_retainBlock(i8* %value) 1830 /// 1831 /// \param mandatory - If false, emit the call with metadata 1832 /// indicating that it's okay for the optimizer to eliminate this call 1833 /// if it can prove that the block never escapes except down the stack. 1834 llvm::Value *CodeGenFunction::EmitARCRetainBlock(llvm::Value *value, 1835 bool mandatory) { 1836 llvm::Value *result 1837 = emitARCValueOperation(*this, value, 1838 CGM.getARCEntrypoints().objc_retainBlock, 1839 "objc_retainBlock"); 1840 1841 // If the copy isn't mandatory, add !clang.arc.copy_on_escape to 1842 // tell the optimizer that it doesn't need to do this copy if the 1843 // block doesn't escape, where being passed as an argument doesn't 1844 // count as escaping. 1845 if (!mandatory && isa<llvm::Instruction>(result)) { 1846 llvm::CallInst *call 1847 = cast<llvm::CallInst>(result->stripPointerCasts()); 1848 assert(call->getCalledValue() == CGM.getARCEntrypoints().objc_retainBlock); 1849 1850 SmallVector<llvm::Value*,1> args; 1851 call->setMetadata("clang.arc.copy_on_escape", 1852 llvm::MDNode::get(Builder.getContext(), args)); 1853 } 1854 1855 return result; 1856 } 1857 1858 /// Retain the given object which is the result of a function call. 1859 /// call i8* @objc_retainAutoreleasedReturnValue(i8* %value) 1860 /// 1861 /// Yes, this function name is one character away from a different 1862 /// call with completely different semantics. 1863 llvm::Value * 1864 CodeGenFunction::EmitARCRetainAutoreleasedReturnValue(llvm::Value *value) { 1865 // Fetch the void(void) inline asm which marks that we're going to 1866 // retain the autoreleased return value. 1867 llvm::InlineAsm *&marker 1868 = CGM.getARCEntrypoints().retainAutoreleasedReturnValueMarker; 1869 if (!marker) { 1870 StringRef assembly 1871 = CGM.getTargetCodeGenInfo() 1872 .getARCRetainAutoreleasedReturnValueMarker(); 1873 1874 // If we have an empty assembly string, there's nothing to do. 1875 if (assembly.empty()) { 1876 1877 // Otherwise, at -O0, build an inline asm that we're going to call 1878 // in a moment. 1879 } else if (CGM.getCodeGenOpts().OptimizationLevel == 0) { 1880 llvm::FunctionType *type = 1881 llvm::FunctionType::get(VoidTy, /*variadic*/false); 1882 1883 marker = llvm::InlineAsm::get(type, assembly, "", /*sideeffects*/ true); 1884 1885 // If we're at -O1 and above, we don't want to litter the code 1886 // with this marker yet, so leave a breadcrumb for the ARC 1887 // optimizer to pick up. 1888 } else { 1889 llvm::NamedMDNode *metadata = 1890 CGM.getModule().getOrInsertNamedMetadata( 1891 "clang.arc.retainAutoreleasedReturnValueMarker"); 1892 assert(metadata->getNumOperands() <= 1); 1893 if (metadata->getNumOperands() == 0) { 1894 llvm::Value *string = llvm::MDString::get(getLLVMContext(), assembly); 1895 metadata->addOperand(llvm::MDNode::get(getLLVMContext(), string)); 1896 } 1897 } 1898 } 1899 1900 // Call the marker asm if we made one, which we do only at -O0. 1901 if (marker) Builder.CreateCall(marker); 1902 1903 return emitARCValueOperation(*this, value, 1904 CGM.getARCEntrypoints().objc_retainAutoreleasedReturnValue, 1905 "objc_retainAutoreleasedReturnValue"); 1906 } 1907 1908 /// Release the given object. 1909 /// call void @objc_release(i8* %value) 1910 void CodeGenFunction::EmitARCRelease(llvm::Value *value, bool precise) { 1911 if (isa<llvm::ConstantPointerNull>(value)) return; 1912 1913 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_release; 1914 if (!fn) { 1915 std::vector<llvm::Type*> args(1, Int8PtrTy); 1916 llvm::FunctionType *fnType = 1917 llvm::FunctionType::get(Builder.getVoidTy(), args, false); 1918 fn = createARCRuntimeFunction(CGM, fnType, "objc_release"); 1919 } 1920 1921 // Cast the argument to 'id'. 1922 value = Builder.CreateBitCast(value, Int8PtrTy); 1923 1924 // Call objc_release. 1925 llvm::CallInst *call = Builder.CreateCall(fn, value); 1926 call->setDoesNotThrow(); 1927 1928 if (!precise) { 1929 SmallVector<llvm::Value*,1> args; 1930 call->setMetadata("clang.imprecise_release", 1931 llvm::MDNode::get(Builder.getContext(), args)); 1932 } 1933 } 1934 1935 /// Store into a strong object. Always calls this: 1936 /// call void @objc_storeStrong(i8** %addr, i8* %value) 1937 llvm::Value *CodeGenFunction::EmitARCStoreStrongCall(llvm::Value *addr, 1938 llvm::Value *value, 1939 bool ignored) { 1940 assert(cast<llvm::PointerType>(addr->getType())->getElementType() 1941 == value->getType()); 1942 1943 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_storeStrong; 1944 if (!fn) { 1945 llvm::Type *argTypes[] = { Int8PtrPtrTy, Int8PtrTy }; 1946 llvm::FunctionType *fnType 1947 = llvm::FunctionType::get(Builder.getVoidTy(), argTypes, false); 1948 fn = createARCRuntimeFunction(CGM, fnType, "objc_storeStrong"); 1949 } 1950 1951 addr = Builder.CreateBitCast(addr, Int8PtrPtrTy); 1952 llvm::Value *castValue = Builder.CreateBitCast(value, Int8PtrTy); 1953 1954 Builder.CreateCall2(fn, addr, castValue)->setDoesNotThrow(); 1955 1956 if (ignored) return 0; 1957 return value; 1958 } 1959 1960 /// Store into a strong object. Sometimes calls this: 1961 /// call void @objc_storeStrong(i8** %addr, i8* %value) 1962 /// Other times, breaks it down into components. 1963 llvm::Value *CodeGenFunction::EmitARCStoreStrong(LValue dst, 1964 llvm::Value *newValue, 1965 bool ignored) { 1966 QualType type = dst.getType(); 1967 bool isBlock = type->isBlockPointerType(); 1968 1969 // Use a store barrier at -O0 unless this is a block type or the 1970 // lvalue is inadequately aligned. 1971 if (shouldUseFusedARCCalls() && 1972 !isBlock && 1973 (dst.getAlignment().isZero() || 1974 dst.getAlignment() >= CharUnits::fromQuantity(PointerAlignInBytes))) { 1975 return EmitARCStoreStrongCall(dst.getAddress(), newValue, ignored); 1976 } 1977 1978 // Otherwise, split it out. 1979 1980 // Retain the new value. 1981 newValue = EmitARCRetain(type, newValue); 1982 1983 // Read the old value. 1984 llvm::Value *oldValue = EmitLoadOfScalar(dst); 1985 1986 // Store. We do this before the release so that any deallocs won't 1987 // see the old value. 1988 EmitStoreOfScalar(newValue, dst); 1989 1990 // Finally, release the old value. 1991 EmitARCRelease(oldValue, /*precise*/ false); 1992 1993 return newValue; 1994 } 1995 1996 /// Autorelease the given object. 1997 /// call i8* @objc_autorelease(i8* %value) 1998 llvm::Value *CodeGenFunction::EmitARCAutorelease(llvm::Value *value) { 1999 return emitARCValueOperation(*this, value, 2000 CGM.getARCEntrypoints().objc_autorelease, 2001 "objc_autorelease"); 2002 } 2003 2004 /// Autorelease the given object. 2005 /// call i8* @objc_autoreleaseReturnValue(i8* %value) 2006 llvm::Value * 2007 CodeGenFunction::EmitARCAutoreleaseReturnValue(llvm::Value *value) { 2008 return emitARCValueOperation(*this, value, 2009 CGM.getARCEntrypoints().objc_autoreleaseReturnValue, 2010 "objc_autoreleaseReturnValue"); 2011 } 2012 2013 /// Do a fused retain/autorelease of the given object. 2014 /// call i8* @objc_retainAutoreleaseReturnValue(i8* %value) 2015 llvm::Value * 2016 CodeGenFunction::EmitARCRetainAutoreleaseReturnValue(llvm::Value *value) { 2017 return emitARCValueOperation(*this, value, 2018 CGM.getARCEntrypoints().objc_retainAutoreleaseReturnValue, 2019 "objc_retainAutoreleaseReturnValue"); 2020 } 2021 2022 /// Do a fused retain/autorelease of the given object. 2023 /// call i8* @objc_retainAutorelease(i8* %value) 2024 /// or 2025 /// %retain = call i8* @objc_retainBlock(i8* %value) 2026 /// call i8* @objc_autorelease(i8* %retain) 2027 llvm::Value *CodeGenFunction::EmitARCRetainAutorelease(QualType type, 2028 llvm::Value *value) { 2029 if (!type->isBlockPointerType()) 2030 return EmitARCRetainAutoreleaseNonBlock(value); 2031 2032 if (isa<llvm::ConstantPointerNull>(value)) return value; 2033 2034 llvm::Type *origType = value->getType(); 2035 value = Builder.CreateBitCast(value, Int8PtrTy); 2036 value = EmitARCRetainBlock(value, /*mandatory*/ true); 2037 value = EmitARCAutorelease(value); 2038 return Builder.CreateBitCast(value, origType); 2039 } 2040 2041 /// Do a fused retain/autorelease of the given object. 2042 /// call i8* @objc_retainAutorelease(i8* %value) 2043 llvm::Value * 2044 CodeGenFunction::EmitARCRetainAutoreleaseNonBlock(llvm::Value *value) { 2045 return emitARCValueOperation(*this, value, 2046 CGM.getARCEntrypoints().objc_retainAutorelease, 2047 "objc_retainAutorelease"); 2048 } 2049 2050 /// i8* @objc_loadWeak(i8** %addr) 2051 /// Essentially objc_autorelease(objc_loadWeakRetained(addr)). 2052 llvm::Value *CodeGenFunction::EmitARCLoadWeak(llvm::Value *addr) { 2053 return emitARCLoadOperation(*this, addr, 2054 CGM.getARCEntrypoints().objc_loadWeak, 2055 "objc_loadWeak"); 2056 } 2057 2058 /// i8* @objc_loadWeakRetained(i8** %addr) 2059 llvm::Value *CodeGenFunction::EmitARCLoadWeakRetained(llvm::Value *addr) { 2060 return emitARCLoadOperation(*this, addr, 2061 CGM.getARCEntrypoints().objc_loadWeakRetained, 2062 "objc_loadWeakRetained"); 2063 } 2064 2065 /// i8* @objc_storeWeak(i8** %addr, i8* %value) 2066 /// Returns %value. 2067 llvm::Value *CodeGenFunction::EmitARCStoreWeak(llvm::Value *addr, 2068 llvm::Value *value, 2069 bool ignored) { 2070 return emitARCStoreOperation(*this, addr, value, 2071 CGM.getARCEntrypoints().objc_storeWeak, 2072 "objc_storeWeak", ignored); 2073 } 2074 2075 /// i8* @objc_initWeak(i8** %addr, i8* %value) 2076 /// Returns %value. %addr is known to not have a current weak entry. 2077 /// Essentially equivalent to: 2078 /// *addr = nil; objc_storeWeak(addr, value); 2079 void CodeGenFunction::EmitARCInitWeak(llvm::Value *addr, llvm::Value *value) { 2080 // If we're initializing to null, just write null to memory; no need 2081 // to get the runtime involved. But don't do this if optimization 2082 // is enabled, because accounting for this would make the optimizer 2083 // much more complicated. 2084 if (isa<llvm::ConstantPointerNull>(value) && 2085 CGM.getCodeGenOpts().OptimizationLevel == 0) { 2086 Builder.CreateStore(value, addr); 2087 return; 2088 } 2089 2090 emitARCStoreOperation(*this, addr, value, 2091 CGM.getARCEntrypoints().objc_initWeak, 2092 "objc_initWeak", /*ignored*/ true); 2093 } 2094 2095 /// void @objc_destroyWeak(i8** %addr) 2096 /// Essentially objc_storeWeak(addr, nil). 2097 void CodeGenFunction::EmitARCDestroyWeak(llvm::Value *addr) { 2098 llvm::Constant *&fn = CGM.getARCEntrypoints().objc_destroyWeak; 2099 if (!fn) { 2100 std::vector<llvm::Type*> args(1, Int8PtrPtrTy); 2101 llvm::FunctionType *fnType = 2102 llvm::FunctionType::get(Builder.getVoidTy(), args, false); 2103 fn = createARCRuntimeFunction(CGM, fnType, "objc_destroyWeak"); 2104 } 2105 2106 // Cast the argument to 'id*'. 2107 addr = Builder.CreateBitCast(addr, Int8PtrPtrTy); 2108 2109 llvm::CallInst *call = Builder.CreateCall(fn, addr); 2110 call->setDoesNotThrow(); 2111 } 2112 2113 /// void @objc_moveWeak(i8** %dest, i8** %src) 2114 /// Disregards the current value in %dest. Leaves %src pointing to nothing. 2115 /// Essentially (objc_copyWeak(dest, src), objc_destroyWeak(src)). 2116 void CodeGenFunction::EmitARCMoveWeak(llvm::Value *dst, llvm::Value *src) { 2117 emitARCCopyOperation(*this, dst, src, 2118 CGM.getARCEntrypoints().objc_moveWeak, 2119 "objc_moveWeak"); 2120 } 2121 2122 /// void @objc_copyWeak(i8** %dest, i8** %src) 2123 /// Disregards the current value in %dest. Essentially 2124 /// objc_release(objc_initWeak(dest, objc_readWeakRetained(src))) 2125 void CodeGenFunction::EmitARCCopyWeak(llvm::Value *dst, llvm::Value *src) { 2126 emitARCCopyOperation(*this, dst, src, 2127 CGM.getARCEntrypoints().objc_copyWeak, 2128 "objc_copyWeak"); 2129 } 2130 2131 /// Produce the code to do a objc_autoreleasepool_push. 2132 /// call i8* @objc_autoreleasePoolPush(void) 2133 llvm::Value *CodeGenFunction::EmitObjCAutoreleasePoolPush() { 2134 llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPush; 2135 if (!fn) { 2136 llvm::FunctionType *fnType = 2137 llvm::FunctionType::get(Int8PtrTy, false); 2138 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPush"); 2139 } 2140 2141 llvm::CallInst *call = Builder.CreateCall(fn); 2142 call->setDoesNotThrow(); 2143 2144 return call; 2145 } 2146 2147 /// Produce the code to do a primitive release. 2148 /// call void @objc_autoreleasePoolPop(i8* %ptr) 2149 void CodeGenFunction::EmitObjCAutoreleasePoolPop(llvm::Value *value) { 2150 assert(value->getType() == Int8PtrTy); 2151 2152 llvm::Constant *&fn = CGM.getRREntrypoints().objc_autoreleasePoolPop; 2153 if (!fn) { 2154 std::vector<llvm::Type*> args(1, Int8PtrTy); 2155 llvm::FunctionType *fnType = 2156 llvm::FunctionType::get(Builder.getVoidTy(), args, false); 2157 2158 // We don't want to use a weak import here; instead we should not 2159 // fall into this path. 2160 fn = createARCRuntimeFunction(CGM, fnType, "objc_autoreleasePoolPop"); 2161 } 2162 2163 llvm::CallInst *call = Builder.CreateCall(fn, value); 2164 call->setDoesNotThrow(); 2165 } 2166 2167 /// Produce the code to do an MRR version objc_autoreleasepool_push. 2168 /// Which is: [[NSAutoreleasePool alloc] init]; 2169 /// Where alloc is declared as: + (id) alloc; in NSAutoreleasePool class. 2170 /// init is declared as: - (id) init; in its NSObject super class. 2171 /// 2172 llvm::Value *CodeGenFunction::EmitObjCMRRAutoreleasePoolPush() { 2173 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 2174 llvm::Value *Receiver = Runtime.EmitNSAutoreleasePoolClassRef(Builder); 2175 // [NSAutoreleasePool alloc] 2176 IdentifierInfo *II = &CGM.getContext().Idents.get("alloc"); 2177 Selector AllocSel = getContext().Selectors.getSelector(0, &II); 2178 CallArgList Args; 2179 RValue AllocRV = 2180 Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2181 getContext().getObjCIdType(), 2182 AllocSel, Receiver, Args); 2183 2184 // [Receiver init] 2185 Receiver = AllocRV.getScalarVal(); 2186 II = &CGM.getContext().Idents.get("init"); 2187 Selector InitSel = getContext().Selectors.getSelector(0, &II); 2188 RValue InitRV = 2189 Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2190 getContext().getObjCIdType(), 2191 InitSel, Receiver, Args); 2192 return InitRV.getScalarVal(); 2193 } 2194 2195 /// Produce the code to do a primitive release. 2196 /// [tmp drain]; 2197 void CodeGenFunction::EmitObjCMRRAutoreleasePoolPop(llvm::Value *Arg) { 2198 IdentifierInfo *II = &CGM.getContext().Idents.get("drain"); 2199 Selector DrainSel = getContext().Selectors.getSelector(0, &II); 2200 CallArgList Args; 2201 CGM.getObjCRuntime().GenerateMessageSend(*this, ReturnValueSlot(), 2202 getContext().VoidTy, DrainSel, Arg, Args); 2203 } 2204 2205 void CodeGenFunction::destroyARCStrongPrecise(CodeGenFunction &CGF, 2206 llvm::Value *addr, 2207 QualType type) { 2208 llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy"); 2209 CGF.EmitARCRelease(ptr, /*precise*/ true); 2210 } 2211 2212 void CodeGenFunction::destroyARCStrongImprecise(CodeGenFunction &CGF, 2213 llvm::Value *addr, 2214 QualType type) { 2215 llvm::Value *ptr = CGF.Builder.CreateLoad(addr, "strongdestroy"); 2216 CGF.EmitARCRelease(ptr, /*precise*/ false); 2217 } 2218 2219 void CodeGenFunction::destroyARCWeak(CodeGenFunction &CGF, 2220 llvm::Value *addr, 2221 QualType type) { 2222 CGF.EmitARCDestroyWeak(addr); 2223 } 2224 2225 namespace { 2226 struct CallObjCAutoreleasePoolObject : EHScopeStack::Cleanup { 2227 llvm::Value *Token; 2228 2229 CallObjCAutoreleasePoolObject(llvm::Value *token) : Token(token) {} 2230 2231 void Emit(CodeGenFunction &CGF, Flags flags) { 2232 CGF.EmitObjCAutoreleasePoolPop(Token); 2233 } 2234 }; 2235 struct CallObjCMRRAutoreleasePoolObject : EHScopeStack::Cleanup { 2236 llvm::Value *Token; 2237 2238 CallObjCMRRAutoreleasePoolObject(llvm::Value *token) : Token(token) {} 2239 2240 void Emit(CodeGenFunction &CGF, Flags flags) { 2241 CGF.EmitObjCMRRAutoreleasePoolPop(Token); 2242 } 2243 }; 2244 } 2245 2246 void CodeGenFunction::EmitObjCAutoreleasePoolCleanup(llvm::Value *Ptr) { 2247 if (CGM.getLangOpts().ObjCAutoRefCount) 2248 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, Ptr); 2249 else 2250 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, Ptr); 2251 } 2252 2253 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2254 LValue lvalue, 2255 QualType type) { 2256 switch (type.getObjCLifetime()) { 2257 case Qualifiers::OCL_None: 2258 case Qualifiers::OCL_ExplicitNone: 2259 case Qualifiers::OCL_Strong: 2260 case Qualifiers::OCL_Autoreleasing: 2261 return TryEmitResult(CGF.EmitLoadOfLValue(lvalue).getScalarVal(), 2262 false); 2263 2264 case Qualifiers::OCL_Weak: 2265 return TryEmitResult(CGF.EmitARCLoadWeakRetained(lvalue.getAddress()), 2266 true); 2267 } 2268 2269 llvm_unreachable("impossible lifetime!"); 2270 } 2271 2272 static TryEmitResult tryEmitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2273 const Expr *e) { 2274 e = e->IgnoreParens(); 2275 QualType type = e->getType(); 2276 2277 // If we're loading retained from a __strong xvalue, we can avoid 2278 // an extra retain/release pair by zeroing out the source of this 2279 // "move" operation. 2280 if (e->isXValue() && 2281 !type.isConstQualified() && 2282 type.getObjCLifetime() == Qualifiers::OCL_Strong) { 2283 // Emit the lvalue. 2284 LValue lv = CGF.EmitLValue(e); 2285 2286 // Load the object pointer. 2287 llvm::Value *result = CGF.EmitLoadOfLValue(lv).getScalarVal(); 2288 2289 // Set the source pointer to NULL. 2290 CGF.EmitStoreOfScalar(getNullForVariable(lv.getAddress()), lv); 2291 2292 return TryEmitResult(result, true); 2293 } 2294 2295 // As a very special optimization, in ARC++, if the l-value is the 2296 // result of a non-volatile assignment, do a simple retain of the 2297 // result of the call to objc_storeWeak instead of reloading. 2298 if (CGF.getLangOpts().CPlusPlus && 2299 !type.isVolatileQualified() && 2300 type.getObjCLifetime() == Qualifiers::OCL_Weak && 2301 isa<BinaryOperator>(e) && 2302 cast<BinaryOperator>(e)->getOpcode() == BO_Assign) 2303 return TryEmitResult(CGF.EmitScalarExpr(e), false); 2304 2305 return tryEmitARCRetainLoadOfScalar(CGF, CGF.EmitLValue(e), type); 2306 } 2307 2308 static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF, 2309 llvm::Value *value); 2310 2311 /// Given that the given expression is some sort of call (which does 2312 /// not return retained), emit a retain following it. 2313 static llvm::Value *emitARCRetainCall(CodeGenFunction &CGF, const Expr *e) { 2314 llvm::Value *value = CGF.EmitScalarExpr(e); 2315 return emitARCRetainAfterCall(CGF, value); 2316 } 2317 2318 static llvm::Value *emitARCRetainAfterCall(CodeGenFunction &CGF, 2319 llvm::Value *value) { 2320 if (llvm::CallInst *call = dyn_cast<llvm::CallInst>(value)) { 2321 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); 2322 2323 // Place the retain immediately following the call. 2324 CGF.Builder.SetInsertPoint(call->getParent(), 2325 ++llvm::BasicBlock::iterator(call)); 2326 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 2327 2328 CGF.Builder.restoreIP(ip); 2329 return value; 2330 } else if (llvm::InvokeInst *invoke = dyn_cast<llvm::InvokeInst>(value)) { 2331 CGBuilderTy::InsertPoint ip = CGF.Builder.saveIP(); 2332 2333 // Place the retain at the beginning of the normal destination block. 2334 llvm::BasicBlock *BB = invoke->getNormalDest(); 2335 CGF.Builder.SetInsertPoint(BB, BB->begin()); 2336 value = CGF.EmitARCRetainAutoreleasedReturnValue(value); 2337 2338 CGF.Builder.restoreIP(ip); 2339 return value; 2340 2341 // Bitcasts can arise because of related-result returns. Rewrite 2342 // the operand. 2343 } else if (llvm::BitCastInst *bitcast = dyn_cast<llvm::BitCastInst>(value)) { 2344 llvm::Value *operand = bitcast->getOperand(0); 2345 operand = emitARCRetainAfterCall(CGF, operand); 2346 bitcast->setOperand(0, operand); 2347 return bitcast; 2348 2349 // Generic fall-back case. 2350 } else { 2351 // Retain using the non-block variant: we never need to do a copy 2352 // of a block that's been returned to us. 2353 return CGF.EmitARCRetainNonBlock(value); 2354 } 2355 } 2356 2357 /// Determine whether it might be important to emit a separate 2358 /// objc_retain_block on the result of the given expression, or 2359 /// whether it's okay to just emit it in a +1 context. 2360 static bool shouldEmitSeparateBlockRetain(const Expr *e) { 2361 assert(e->getType()->isBlockPointerType()); 2362 e = e->IgnoreParens(); 2363 2364 // For future goodness, emit block expressions directly in +1 2365 // contexts if we can. 2366 if (isa<BlockExpr>(e)) 2367 return false; 2368 2369 if (const CastExpr *cast = dyn_cast<CastExpr>(e)) { 2370 switch (cast->getCastKind()) { 2371 // Emitting these operations in +1 contexts is goodness. 2372 case CK_LValueToRValue: 2373 case CK_ARCReclaimReturnedObject: 2374 case CK_ARCConsumeObject: 2375 case CK_ARCProduceObject: 2376 return false; 2377 2378 // These operations preserve a block type. 2379 case CK_NoOp: 2380 case CK_BitCast: 2381 return shouldEmitSeparateBlockRetain(cast->getSubExpr()); 2382 2383 // These operations are known to be bad (or haven't been considered). 2384 case CK_AnyPointerToBlockPointerCast: 2385 default: 2386 return true; 2387 } 2388 } 2389 2390 return true; 2391 } 2392 2393 /// Try to emit a PseudoObjectExpr at +1. 2394 /// 2395 /// This massively duplicates emitPseudoObjectRValue. 2396 static TryEmitResult tryEmitARCRetainPseudoObject(CodeGenFunction &CGF, 2397 const PseudoObjectExpr *E) { 2398 llvm::SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques; 2399 2400 // Find the result expression. 2401 const Expr *resultExpr = E->getResultExpr(); 2402 assert(resultExpr); 2403 TryEmitResult result; 2404 2405 for (PseudoObjectExpr::const_semantics_iterator 2406 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) { 2407 const Expr *semantic = *i; 2408 2409 // If this semantic expression is an opaque value, bind it 2410 // to the result of its source expression. 2411 if (const OpaqueValueExpr *ov = dyn_cast<OpaqueValueExpr>(semantic)) { 2412 typedef CodeGenFunction::OpaqueValueMappingData OVMA; 2413 OVMA opaqueData; 2414 2415 // If this semantic is the result of the pseudo-object 2416 // expression, try to evaluate the source as +1. 2417 if (ov == resultExpr) { 2418 assert(!OVMA::shouldBindAsLValue(ov)); 2419 result = tryEmitARCRetainScalarExpr(CGF, ov->getSourceExpr()); 2420 opaqueData = OVMA::bind(CGF, ov, RValue::get(result.getPointer())); 2421 2422 // Otherwise, just bind it. 2423 } else { 2424 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr()); 2425 } 2426 opaques.push_back(opaqueData); 2427 2428 // Otherwise, if the expression is the result, evaluate it 2429 // and remember the result. 2430 } else if (semantic == resultExpr) { 2431 result = tryEmitARCRetainScalarExpr(CGF, semantic); 2432 2433 // Otherwise, evaluate the expression in an ignored context. 2434 } else { 2435 CGF.EmitIgnoredExpr(semantic); 2436 } 2437 } 2438 2439 // Unbind all the opaques now. 2440 for (unsigned i = 0, e = opaques.size(); i != e; ++i) 2441 opaques[i].unbind(CGF); 2442 2443 return result; 2444 } 2445 2446 static TryEmitResult 2447 tryEmitARCRetainScalarExpr(CodeGenFunction &CGF, const Expr *e) { 2448 // Look through cleanups. 2449 if (const ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(e)) { 2450 CGF.enterFullExpression(cleanups); 2451 CodeGenFunction::RunCleanupsScope scope(CGF); 2452 return tryEmitARCRetainScalarExpr(CGF, cleanups->getSubExpr()); 2453 } 2454 2455 // The desired result type, if it differs from the type of the 2456 // ultimate opaque expression. 2457 llvm::Type *resultType = 0; 2458 2459 while (true) { 2460 e = e->IgnoreParens(); 2461 2462 // There's a break at the end of this if-chain; anything 2463 // that wants to keep looping has to explicitly continue. 2464 if (const CastExpr *ce = dyn_cast<CastExpr>(e)) { 2465 switch (ce->getCastKind()) { 2466 // No-op casts don't change the type, so we just ignore them. 2467 case CK_NoOp: 2468 e = ce->getSubExpr(); 2469 continue; 2470 2471 case CK_LValueToRValue: { 2472 TryEmitResult loadResult 2473 = tryEmitARCRetainLoadOfScalar(CGF, ce->getSubExpr()); 2474 if (resultType) { 2475 llvm::Value *value = loadResult.getPointer(); 2476 value = CGF.Builder.CreateBitCast(value, resultType); 2477 loadResult.setPointer(value); 2478 } 2479 return loadResult; 2480 } 2481 2482 // These casts can change the type, so remember that and 2483 // soldier on. We only need to remember the outermost such 2484 // cast, though. 2485 case CK_CPointerToObjCPointerCast: 2486 case CK_BlockPointerToObjCPointerCast: 2487 case CK_AnyPointerToBlockPointerCast: 2488 case CK_BitCast: 2489 if (!resultType) 2490 resultType = CGF.ConvertType(ce->getType()); 2491 e = ce->getSubExpr(); 2492 assert(e->getType()->hasPointerRepresentation()); 2493 continue; 2494 2495 // For consumptions, just emit the subexpression and thus elide 2496 // the retain/release pair. 2497 case CK_ARCConsumeObject: { 2498 llvm::Value *result = CGF.EmitScalarExpr(ce->getSubExpr()); 2499 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2500 return TryEmitResult(result, true); 2501 } 2502 2503 // Block extends are net +0. Naively, we could just recurse on 2504 // the subexpression, but actually we need to ensure that the 2505 // value is copied as a block, so there's a little filter here. 2506 case CK_ARCExtendBlockObject: { 2507 llvm::Value *result; // will be a +0 value 2508 2509 // If we can't safely assume the sub-expression will produce a 2510 // block-copied value, emit the sub-expression at +0. 2511 if (shouldEmitSeparateBlockRetain(ce->getSubExpr())) { 2512 result = CGF.EmitScalarExpr(ce->getSubExpr()); 2513 2514 // Otherwise, try to emit the sub-expression at +1 recursively. 2515 } else { 2516 TryEmitResult subresult 2517 = tryEmitARCRetainScalarExpr(CGF, ce->getSubExpr()); 2518 result = subresult.getPointer(); 2519 2520 // If that produced a retained value, just use that, 2521 // possibly casting down. 2522 if (subresult.getInt()) { 2523 if (resultType) 2524 result = CGF.Builder.CreateBitCast(result, resultType); 2525 return TryEmitResult(result, true); 2526 } 2527 2528 // Otherwise it's +0. 2529 } 2530 2531 // Retain the object as a block, then cast down. 2532 result = CGF.EmitARCRetainBlock(result, /*mandatory*/ true); 2533 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2534 return TryEmitResult(result, true); 2535 } 2536 2537 // For reclaims, emit the subexpression as a retained call and 2538 // skip the consumption. 2539 case CK_ARCReclaimReturnedObject: { 2540 llvm::Value *result = emitARCRetainCall(CGF, ce->getSubExpr()); 2541 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2542 return TryEmitResult(result, true); 2543 } 2544 2545 default: 2546 break; 2547 } 2548 2549 // Skip __extension__. 2550 } else if (const UnaryOperator *op = dyn_cast<UnaryOperator>(e)) { 2551 if (op->getOpcode() == UO_Extension) { 2552 e = op->getSubExpr(); 2553 continue; 2554 } 2555 2556 // For calls and message sends, use the retained-call logic. 2557 // Delegate inits are a special case in that they're the only 2558 // returns-retained expression that *isn't* surrounded by 2559 // a consume. 2560 } else if (isa<CallExpr>(e) || 2561 (isa<ObjCMessageExpr>(e) && 2562 !cast<ObjCMessageExpr>(e)->isDelegateInitCall())) { 2563 llvm::Value *result = emitARCRetainCall(CGF, e); 2564 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2565 return TryEmitResult(result, true); 2566 2567 // Look through pseudo-object expressions. 2568 } else if (const PseudoObjectExpr *pseudo = dyn_cast<PseudoObjectExpr>(e)) { 2569 TryEmitResult result 2570 = tryEmitARCRetainPseudoObject(CGF, pseudo); 2571 if (resultType) { 2572 llvm::Value *value = result.getPointer(); 2573 value = CGF.Builder.CreateBitCast(value, resultType); 2574 result.setPointer(value); 2575 } 2576 return result; 2577 } 2578 2579 // Conservatively halt the search at any other expression kind. 2580 break; 2581 } 2582 2583 // We didn't find an obvious production, so emit what we've got and 2584 // tell the caller that we didn't manage to retain. 2585 llvm::Value *result = CGF.EmitScalarExpr(e); 2586 if (resultType) result = CGF.Builder.CreateBitCast(result, resultType); 2587 return TryEmitResult(result, false); 2588 } 2589 2590 static llvm::Value *emitARCRetainLoadOfScalar(CodeGenFunction &CGF, 2591 LValue lvalue, 2592 QualType type) { 2593 TryEmitResult result = tryEmitARCRetainLoadOfScalar(CGF, lvalue, type); 2594 llvm::Value *value = result.getPointer(); 2595 if (!result.getInt()) 2596 value = CGF.EmitARCRetain(type, value); 2597 return value; 2598 } 2599 2600 /// EmitARCRetainScalarExpr - Semantically equivalent to 2601 /// EmitARCRetainObject(e->getType(), EmitScalarExpr(e)), but making a 2602 /// best-effort attempt to peephole expressions that naturally produce 2603 /// retained objects. 2604 llvm::Value *CodeGenFunction::EmitARCRetainScalarExpr(const Expr *e) { 2605 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); 2606 llvm::Value *value = result.getPointer(); 2607 if (!result.getInt()) 2608 value = EmitARCRetain(e->getType(), value); 2609 return value; 2610 } 2611 2612 llvm::Value * 2613 CodeGenFunction::EmitARCRetainAutoreleaseScalarExpr(const Expr *e) { 2614 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e); 2615 llvm::Value *value = result.getPointer(); 2616 if (result.getInt()) 2617 value = EmitARCAutorelease(value); 2618 else 2619 value = EmitARCRetainAutorelease(e->getType(), value); 2620 return value; 2621 } 2622 2623 llvm::Value *CodeGenFunction::EmitARCExtendBlockObject(const Expr *e) { 2624 llvm::Value *result; 2625 bool doRetain; 2626 2627 if (shouldEmitSeparateBlockRetain(e)) { 2628 result = EmitScalarExpr(e); 2629 doRetain = true; 2630 } else { 2631 TryEmitResult subresult = tryEmitARCRetainScalarExpr(*this, e); 2632 result = subresult.getPointer(); 2633 doRetain = !subresult.getInt(); 2634 } 2635 2636 if (doRetain) 2637 result = EmitARCRetainBlock(result, /*mandatory*/ true); 2638 return EmitObjCConsumeObject(e->getType(), result); 2639 } 2640 2641 llvm::Value *CodeGenFunction::EmitObjCThrowOperand(const Expr *expr) { 2642 // In ARC, retain and autorelease the expression. 2643 if (getLangOpts().ObjCAutoRefCount) { 2644 // Do so before running any cleanups for the full-expression. 2645 // tryEmitARCRetainScalarExpr does make an effort to do things 2646 // inside cleanups, but there are crazy cases like 2647 // @throw A().foo; 2648 // where a full retain+autorelease is required and would 2649 // otherwise happen after the destructor for the temporary. 2650 if (const ExprWithCleanups *ewc = dyn_cast<ExprWithCleanups>(expr)) { 2651 enterFullExpression(ewc); 2652 expr = ewc->getSubExpr(); 2653 } 2654 2655 CodeGenFunction::RunCleanupsScope cleanups(*this); 2656 return EmitARCRetainAutoreleaseScalarExpr(expr); 2657 } 2658 2659 // Otherwise, use the normal scalar-expression emission. The 2660 // exception machinery doesn't do anything special with the 2661 // exception like retaining it, so there's no safety associated with 2662 // only running cleanups after the throw has started, and when it 2663 // matters it tends to be substantially inferior code. 2664 return EmitScalarExpr(expr); 2665 } 2666 2667 std::pair<LValue,llvm::Value*> 2668 CodeGenFunction::EmitARCStoreStrong(const BinaryOperator *e, 2669 bool ignored) { 2670 // Evaluate the RHS first. 2671 TryEmitResult result = tryEmitARCRetainScalarExpr(*this, e->getRHS()); 2672 llvm::Value *value = result.getPointer(); 2673 2674 bool hasImmediateRetain = result.getInt(); 2675 2676 // If we didn't emit a retained object, and the l-value is of block 2677 // type, then we need to emit the block-retain immediately in case 2678 // it invalidates the l-value. 2679 if (!hasImmediateRetain && e->getType()->isBlockPointerType()) { 2680 value = EmitARCRetainBlock(value, /*mandatory*/ false); 2681 hasImmediateRetain = true; 2682 } 2683 2684 LValue lvalue = EmitLValue(e->getLHS()); 2685 2686 // If the RHS was emitted retained, expand this. 2687 if (hasImmediateRetain) { 2688 llvm::Value *oldValue = 2689 EmitLoadOfScalar(lvalue); 2690 EmitStoreOfScalar(value, lvalue); 2691 EmitARCRelease(oldValue, /*precise*/ false); 2692 } else { 2693 value = EmitARCStoreStrong(lvalue, value, ignored); 2694 } 2695 2696 return std::pair<LValue,llvm::Value*>(lvalue, value); 2697 } 2698 2699 std::pair<LValue,llvm::Value*> 2700 CodeGenFunction::EmitARCStoreAutoreleasing(const BinaryOperator *e) { 2701 llvm::Value *value = EmitARCRetainAutoreleaseScalarExpr(e->getRHS()); 2702 LValue lvalue = EmitLValue(e->getLHS()); 2703 2704 EmitStoreOfScalar(value, lvalue); 2705 2706 return std::pair<LValue,llvm::Value*>(lvalue, value); 2707 } 2708 2709 void CodeGenFunction::EmitObjCAutoreleasePoolStmt( 2710 const ObjCAutoreleasePoolStmt &ARPS) { 2711 const Stmt *subStmt = ARPS.getSubStmt(); 2712 const CompoundStmt &S = cast<CompoundStmt>(*subStmt); 2713 2714 CGDebugInfo *DI = getDebugInfo(); 2715 if (DI) 2716 DI->EmitLexicalBlockStart(Builder, S.getLBracLoc()); 2717 2718 // Keep track of the current cleanup stack depth. 2719 RunCleanupsScope Scope(*this); 2720 if (CGM.getCodeGenOpts().ObjCRuntimeHasARC) { 2721 llvm::Value *token = EmitObjCAutoreleasePoolPush(); 2722 EHStack.pushCleanup<CallObjCAutoreleasePoolObject>(NormalCleanup, token); 2723 } else { 2724 llvm::Value *token = EmitObjCMRRAutoreleasePoolPush(); 2725 EHStack.pushCleanup<CallObjCMRRAutoreleasePoolObject>(NormalCleanup, token); 2726 } 2727 2728 for (CompoundStmt::const_body_iterator I = S.body_begin(), 2729 E = S.body_end(); I != E; ++I) 2730 EmitStmt(*I); 2731 2732 if (DI) 2733 DI->EmitLexicalBlockEnd(Builder, S.getRBracLoc()); 2734 } 2735 2736 /// EmitExtendGCLifetime - Given a pointer to an Objective-C object, 2737 /// make sure it survives garbage collection until this point. 2738 void CodeGenFunction::EmitExtendGCLifetime(llvm::Value *object) { 2739 // We just use an inline assembly. 2740 llvm::FunctionType *extenderType 2741 = llvm::FunctionType::get(VoidTy, VoidPtrTy, RequiredArgs::All); 2742 llvm::Value *extender 2743 = llvm::InlineAsm::get(extenderType, 2744 /* assembly */ "", 2745 /* constraints */ "r", 2746 /* side effects */ true); 2747 2748 object = Builder.CreateBitCast(object, VoidPtrTy); 2749 Builder.CreateCall(extender, object)->setDoesNotThrow(); 2750 } 2751 2752 /// GenerateObjCAtomicSetterCopyHelperFunction - Given a c++ object type with 2753 /// non-trivial copy assignment function, produce following helper function. 2754 /// static void copyHelper(Ty *dest, const Ty *source) { *dest = *source; } 2755 /// 2756 llvm::Constant * 2757 CodeGenFunction::GenerateObjCAtomicSetterCopyHelperFunction( 2758 const ObjCPropertyImplDecl *PID) { 2759 // FIXME. This api is for NeXt runtime only for now. 2760 if (!getLangOpts().CPlusPlus || !getLangOpts().NeXTRuntime) 2761 return 0; 2762 QualType Ty = PID->getPropertyIvarDecl()->getType(); 2763 if (!Ty->isRecordType()) 2764 return 0; 2765 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2766 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) 2767 return 0; 2768 llvm::Constant * HelperFn = 0; 2769 if (hasTrivialSetExpr(PID)) 2770 return 0; 2771 assert(PID->getSetterCXXAssignment() && "SetterCXXAssignment - null"); 2772 if ((HelperFn = CGM.getAtomicSetterHelperFnMap(Ty))) 2773 return HelperFn; 2774 2775 ASTContext &C = getContext(); 2776 IdentifierInfo *II 2777 = &CGM.getContext().Idents.get("__assign_helper_atomic_property_"); 2778 FunctionDecl *FD = FunctionDecl::Create(C, 2779 C.getTranslationUnitDecl(), 2780 SourceLocation(), 2781 SourceLocation(), II, C.VoidTy, 0, 2782 SC_Static, 2783 SC_None, 2784 false, 2785 false); 2786 2787 QualType DestTy = C.getPointerType(Ty); 2788 QualType SrcTy = Ty; 2789 SrcTy.addConst(); 2790 SrcTy = C.getPointerType(SrcTy); 2791 2792 FunctionArgList args; 2793 ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy); 2794 args.push_back(&dstDecl); 2795 ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy); 2796 args.push_back(&srcDecl); 2797 2798 const CGFunctionInfo &FI = 2799 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 2800 FunctionType::ExtInfo(), 2801 RequiredArgs::All); 2802 2803 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 2804 2805 llvm::Function *Fn = 2806 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 2807 "__assign_helper_atomic_property_", 2808 &CGM.getModule()); 2809 2810 if (CGM.getModuleDebugInfo()) 2811 DebugInfo = CGM.getModuleDebugInfo(); 2812 2813 2814 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 2815 2816 DeclRefExpr DstExpr(&dstDecl, false, DestTy, 2817 VK_RValue, SourceLocation()); 2818 UnaryOperator DST(&DstExpr, UO_Deref, DestTy->getPointeeType(), 2819 VK_LValue, OK_Ordinary, SourceLocation()); 2820 2821 DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, 2822 VK_RValue, SourceLocation()); 2823 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), 2824 VK_LValue, OK_Ordinary, SourceLocation()); 2825 2826 Expr *Args[2] = { &DST, &SRC }; 2827 CallExpr *CalleeExp = cast<CallExpr>(PID->getSetterCXXAssignment()); 2828 CXXOperatorCallExpr TheCall(C, OO_Equal, CalleeExp->getCallee(), 2829 Args, 2, DestTy->getPointeeType(), 2830 VK_LValue, SourceLocation()); 2831 2832 EmitStmt(&TheCall); 2833 2834 FinishFunction(); 2835 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 2836 CGM.setAtomicSetterHelperFnMap(Ty, HelperFn); 2837 return HelperFn; 2838 } 2839 2840 llvm::Constant * 2841 CodeGenFunction::GenerateObjCAtomicGetterCopyHelperFunction( 2842 const ObjCPropertyImplDecl *PID) { 2843 // FIXME. This api is for NeXt runtime only for now. 2844 if (!getLangOpts().CPlusPlus || !getLangOpts().NeXTRuntime) 2845 return 0; 2846 const ObjCPropertyDecl *PD = PID->getPropertyDecl(); 2847 QualType Ty = PD->getType(); 2848 if (!Ty->isRecordType()) 2849 return 0; 2850 if ((!(PD->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_atomic))) 2851 return 0; 2852 llvm::Constant * HelperFn = 0; 2853 2854 if (hasTrivialGetExpr(PID)) 2855 return 0; 2856 assert(PID->getGetterCXXConstructor() && "getGetterCXXConstructor - null"); 2857 if ((HelperFn = CGM.getAtomicGetterHelperFnMap(Ty))) 2858 return HelperFn; 2859 2860 2861 ASTContext &C = getContext(); 2862 IdentifierInfo *II 2863 = &CGM.getContext().Idents.get("__copy_helper_atomic_property_"); 2864 FunctionDecl *FD = FunctionDecl::Create(C, 2865 C.getTranslationUnitDecl(), 2866 SourceLocation(), 2867 SourceLocation(), II, C.VoidTy, 0, 2868 SC_Static, 2869 SC_None, 2870 false, 2871 false); 2872 2873 QualType DestTy = C.getPointerType(Ty); 2874 QualType SrcTy = Ty; 2875 SrcTy.addConst(); 2876 SrcTy = C.getPointerType(SrcTy); 2877 2878 FunctionArgList args; 2879 ImplicitParamDecl dstDecl(FD, SourceLocation(), 0, DestTy); 2880 args.push_back(&dstDecl); 2881 ImplicitParamDecl srcDecl(FD, SourceLocation(), 0, SrcTy); 2882 args.push_back(&srcDecl); 2883 2884 const CGFunctionInfo &FI = 2885 CGM.getTypes().arrangeFunctionDeclaration(C.VoidTy, args, 2886 FunctionType::ExtInfo(), 2887 RequiredArgs::All); 2888 2889 llvm::FunctionType *LTy = CGM.getTypes().GetFunctionType(FI); 2890 2891 llvm::Function *Fn = 2892 llvm::Function::Create(LTy, llvm::GlobalValue::InternalLinkage, 2893 "__copy_helper_atomic_property_", &CGM.getModule()); 2894 2895 if (CGM.getModuleDebugInfo()) 2896 DebugInfo = CGM.getModuleDebugInfo(); 2897 2898 2899 StartFunction(FD, C.VoidTy, Fn, FI, args, SourceLocation()); 2900 2901 DeclRefExpr SrcExpr(&srcDecl, false, SrcTy, 2902 VK_RValue, SourceLocation()); 2903 2904 UnaryOperator SRC(&SrcExpr, UO_Deref, SrcTy->getPointeeType(), 2905 VK_LValue, OK_Ordinary, SourceLocation()); 2906 2907 CXXConstructExpr *CXXConstExpr = 2908 cast<CXXConstructExpr>(PID->getGetterCXXConstructor()); 2909 2910 SmallVector<Expr*, 4> ConstructorArgs; 2911 ConstructorArgs.push_back(&SRC); 2912 CXXConstructExpr::arg_iterator A = CXXConstExpr->arg_begin(); 2913 ++A; 2914 2915 for (CXXConstructExpr::arg_iterator AEnd = CXXConstExpr->arg_end(); 2916 A != AEnd; ++A) 2917 ConstructorArgs.push_back(*A); 2918 2919 CXXConstructExpr *TheCXXConstructExpr = 2920 CXXConstructExpr::Create(C, Ty, SourceLocation(), 2921 CXXConstExpr->getConstructor(), 2922 CXXConstExpr->isElidable(), 2923 &ConstructorArgs[0], ConstructorArgs.size(), 2924 CXXConstExpr->hadMultipleCandidates(), 2925 CXXConstExpr->isListInitialization(), 2926 CXXConstExpr->requiresZeroInitialization(), 2927 CXXConstExpr->getConstructionKind(), 2928 SourceRange()); 2929 2930 DeclRefExpr DstExpr(&dstDecl, false, DestTy, 2931 VK_RValue, SourceLocation()); 2932 2933 RValue DV = EmitAnyExpr(&DstExpr); 2934 CharUnits Alignment 2935 = getContext().getTypeAlignInChars(TheCXXConstructExpr->getType()); 2936 EmitAggExpr(TheCXXConstructExpr, 2937 AggValueSlot::forAddr(DV.getScalarVal(), Alignment, Qualifiers(), 2938 AggValueSlot::IsDestructed, 2939 AggValueSlot::DoesNotNeedGCBarriers, 2940 AggValueSlot::IsNotAliased)); 2941 2942 FinishFunction(); 2943 HelperFn = llvm::ConstantExpr::getBitCast(Fn, VoidPtrTy); 2944 CGM.setAtomicGetterHelperFnMap(Ty, HelperFn); 2945 return HelperFn; 2946 } 2947 2948 llvm::Value * 2949 CodeGenFunction::EmitBlockCopyAndAutorelease(llvm::Value *Block, QualType Ty) { 2950 // Get selectors for retain/autorelease. 2951 IdentifierInfo *CopyID = &getContext().Idents.get("copy"); 2952 Selector CopySelector = 2953 getContext().Selectors.getNullarySelector(CopyID); 2954 IdentifierInfo *AutoreleaseID = &getContext().Idents.get("autorelease"); 2955 Selector AutoreleaseSelector = 2956 getContext().Selectors.getNullarySelector(AutoreleaseID); 2957 2958 // Emit calls to retain/autorelease. 2959 CGObjCRuntime &Runtime = CGM.getObjCRuntime(); 2960 llvm::Value *Val = Block; 2961 RValue Result; 2962 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2963 Ty, CopySelector, 2964 Val, CallArgList(), 0, 0); 2965 Val = Result.getScalarVal(); 2966 Result = Runtime.GenerateMessageSend(*this, ReturnValueSlot(), 2967 Ty, AutoreleaseSelector, 2968 Val, CallArgList(), 0, 0); 2969 Val = Result.getScalarVal(); 2970 return Val; 2971 } 2972 2973 2974 CGObjCRuntime::~CGObjCRuntime() {} 2975