CGExpr.cpp revision 414ee4bb74957b4c5fe05e11848028e4701b51f7
1//===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===// 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 Expr nodes as LLVM code. 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CodeGenModule.h" 16#include "CGCall.h" 17#include "CGCXXABI.h" 18#include "CGDebugInfo.h" 19#include "CGRecordLayout.h" 20#include "CGObjCRuntime.h" 21#include "TargetInfo.h" 22#include "clang/AST/ASTContext.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/Frontend/CodeGenOptions.h" 25#include "llvm/Intrinsics.h" 26#include "llvm/Target/TargetData.h" 27using namespace clang; 28using namespace CodeGen; 29 30//===--------------------------------------------------------------------===// 31// Miscellaneous Helper Methods 32//===--------------------------------------------------------------------===// 33 34llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) { 35 unsigned addressSpace = 36 cast<llvm::PointerType>(value->getType())->getAddressSpace(); 37 38 llvm::PointerType *destType = Int8PtrTy; 39 if (addressSpace) 40 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace); 41 42 if (value->getType() == destType) return value; 43 return Builder.CreateBitCast(value, destType); 44} 45 46/// CreateTempAlloca - This creates a alloca and inserts it into the entry 47/// block. 48llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, 49 const Twine &Name) { 50 if (!Builder.isNamePreserving()) 51 return new llvm::AllocaInst(Ty, 0, "", AllocaInsertPt); 52 return new llvm::AllocaInst(Ty, 0, Name, AllocaInsertPt); 53} 54 55void CodeGenFunction::InitTempAlloca(llvm::AllocaInst *Var, 56 llvm::Value *Init) { 57 llvm::StoreInst *Store = new llvm::StoreInst(Init, Var); 58 llvm::BasicBlock *Block = AllocaInsertPt->getParent(); 59 Block->getInstList().insertAfter(&*AllocaInsertPt, Store); 60} 61 62llvm::AllocaInst *CodeGenFunction::CreateIRTemp(QualType Ty, 63 const Twine &Name) { 64 llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertType(Ty), Name); 65 // FIXME: Should we prefer the preferred type alignment here? 66 CharUnits Align = getContext().getTypeAlignInChars(Ty); 67 Alloc->setAlignment(Align.getQuantity()); 68 return Alloc; 69} 70 71llvm::AllocaInst *CodeGenFunction::CreateMemTemp(QualType Ty, 72 const Twine &Name) { 73 llvm::AllocaInst *Alloc = CreateTempAlloca(ConvertTypeForMem(Ty), Name); 74 // FIXME: Should we prefer the preferred type alignment here? 75 CharUnits Align = getContext().getTypeAlignInChars(Ty); 76 Alloc->setAlignment(Align.getQuantity()); 77 return Alloc; 78} 79 80/// EvaluateExprAsBool - Perform the usual unary conversions on the specified 81/// expression and compare the result against zero, returning an Int1Ty value. 82llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) { 83 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) { 84 llvm::Value *MemPtr = EmitScalarExpr(E); 85 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT); 86 } 87 88 QualType BoolTy = getContext().BoolTy; 89 if (!E->getType()->isAnyComplexType()) 90 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy); 91 92 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(),BoolTy); 93} 94 95/// EmitIgnoredExpr - Emit code to compute the specified expression, 96/// ignoring the result. 97void CodeGenFunction::EmitIgnoredExpr(const Expr *E) { 98 if (E->isRValue()) 99 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true); 100 101 // Just emit it as an l-value and drop the result. 102 EmitLValue(E); 103} 104 105/// EmitAnyExpr - Emit code to compute the specified expression which 106/// can have any type. The result is returned as an RValue struct. 107/// If this is an aggregate expression, AggSlot indicates where the 108/// result should be returned. 109RValue CodeGenFunction::EmitAnyExpr(const Expr *E, AggValueSlot AggSlot, 110 bool IgnoreResult) { 111 if (!hasAggregateLLVMType(E->getType())) 112 return RValue::get(EmitScalarExpr(E, IgnoreResult)); 113 else if (E->getType()->isAnyComplexType()) 114 return RValue::getComplex(EmitComplexExpr(E, IgnoreResult, IgnoreResult)); 115 116 EmitAggExpr(E, AggSlot, IgnoreResult); 117 return AggSlot.asRValue(); 118} 119 120/// EmitAnyExprToTemp - Similary to EmitAnyExpr(), however, the result will 121/// always be accessible even if no aggregate location is provided. 122RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) { 123 AggValueSlot AggSlot = AggValueSlot::ignored(); 124 125 if (hasAggregateLLVMType(E->getType()) && 126 !E->getType()->isAnyComplexType()) 127 AggSlot = CreateAggTemp(E->getType(), "agg.tmp"); 128 return EmitAnyExpr(E, AggSlot); 129} 130 131/// EmitAnyExprToMem - Evaluate an expression into a given memory 132/// location. 133void CodeGenFunction::EmitAnyExprToMem(const Expr *E, 134 llvm::Value *Location, 135 Qualifiers Quals, 136 bool IsInit) { 137 if (E->getType()->isAnyComplexType()) 138 EmitComplexExprIntoAddr(E, Location, Quals.hasVolatile()); 139 else if (hasAggregateLLVMType(E->getType())) 140 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals, 141 AggValueSlot::IsDestructed_t(IsInit), 142 AggValueSlot::DoesNotNeedGCBarriers, 143 AggValueSlot::IsAliased_t(!IsInit))); 144 else { 145 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false)); 146 LValue LV = MakeAddrLValue(Location, E->getType()); 147 EmitStoreThroughLValue(RV, LV); 148 } 149} 150 151namespace { 152/// \brief An adjustment to be made to the temporary created when emitting a 153/// reference binding, which accesses a particular subobject of that temporary. 154 struct SubobjectAdjustment { 155 enum { DerivedToBaseAdjustment, FieldAdjustment } Kind; 156 157 union { 158 struct { 159 const CastExpr *BasePath; 160 const CXXRecordDecl *DerivedClass; 161 } DerivedToBase; 162 163 FieldDecl *Field; 164 }; 165 166 SubobjectAdjustment(const CastExpr *BasePath, 167 const CXXRecordDecl *DerivedClass) 168 : Kind(DerivedToBaseAdjustment) { 169 DerivedToBase.BasePath = BasePath; 170 DerivedToBase.DerivedClass = DerivedClass; 171 } 172 173 SubobjectAdjustment(FieldDecl *Field) 174 : Kind(FieldAdjustment) { 175 this->Field = Field; 176 } 177 }; 178} 179 180static llvm::Value * 181CreateReferenceTemporary(CodeGenFunction &CGF, QualType Type, 182 const NamedDecl *InitializedDecl) { 183 if (const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl)) { 184 if (VD->hasGlobalStorage()) { 185 llvm::SmallString<256> Name; 186 llvm::raw_svector_ostream Out(Name); 187 CGF.CGM.getCXXABI().getMangleContext().mangleReferenceTemporary(VD, Out); 188 Out.flush(); 189 190 llvm::Type *RefTempTy = CGF.ConvertTypeForMem(Type); 191 192 // Create the reference temporary. 193 llvm::GlobalValue *RefTemp = 194 new llvm::GlobalVariable(CGF.CGM.getModule(), 195 RefTempTy, /*isConstant=*/false, 196 llvm::GlobalValue::InternalLinkage, 197 llvm::Constant::getNullValue(RefTempTy), 198 Name.str()); 199 return RefTemp; 200 } 201 } 202 203 return CGF.CreateMemTemp(Type, "ref.tmp"); 204} 205 206static llvm::Value * 207EmitExprForReferenceBinding(CodeGenFunction &CGF, const Expr *E, 208 llvm::Value *&ReferenceTemporary, 209 const CXXDestructorDecl *&ReferenceTemporaryDtor, 210 QualType &ObjCARCReferenceLifetimeType, 211 const NamedDecl *InitializedDecl) { 212 // Look through expressions for materialized temporaries (for now). 213 if (const MaterializeTemporaryExpr *M 214 = dyn_cast<MaterializeTemporaryExpr>(E)) { 215 // Objective-C++ ARC: 216 // If we are binding a reference to a temporary that has ownership, we 217 // need to perform retain/release operations on the temporary. 218 if (CGF.getContext().getLangOptions().ObjCAutoRefCount && 219 E->getType()->isObjCLifetimeType() && 220 (E->getType().getObjCLifetime() == Qualifiers::OCL_Strong || 221 E->getType().getObjCLifetime() == Qualifiers::OCL_Weak || 222 E->getType().getObjCLifetime() == Qualifiers::OCL_Autoreleasing)) 223 ObjCARCReferenceLifetimeType = E->getType(); 224 225 E = M->GetTemporaryExpr(); 226 } 227 228 if (const CXXDefaultArgExpr *DAE = dyn_cast<CXXDefaultArgExpr>(E)) 229 E = DAE->getExpr(); 230 231 if (const ExprWithCleanups *TE = dyn_cast<ExprWithCleanups>(E)) { 232 CodeGenFunction::RunCleanupsScope Scope(CGF); 233 234 return EmitExprForReferenceBinding(CGF, TE->getSubExpr(), 235 ReferenceTemporary, 236 ReferenceTemporaryDtor, 237 ObjCARCReferenceLifetimeType, 238 InitializedDecl); 239 } 240 241 if (const ObjCPropertyRefExpr *PRE = 242 dyn_cast<ObjCPropertyRefExpr>(E->IgnoreParenImpCasts())) 243 if (PRE->getGetterResultType()->isReferenceType()) 244 E = PRE; 245 246 RValue RV; 247 if (E->isGLValue()) { 248 // Emit the expression as an lvalue. 249 LValue LV = CGF.EmitLValue(E); 250 if (LV.isPropertyRef()) { 251 RV = CGF.EmitLoadOfPropertyRefLValue(LV); 252 return RV.getScalarVal(); 253 } 254 255 if (LV.isSimple()) 256 return LV.getAddress(); 257 258 // We have to load the lvalue. 259 RV = CGF.EmitLoadOfLValue(LV); 260 } else { 261 if (!ObjCARCReferenceLifetimeType.isNull()) { 262 ReferenceTemporary = CreateReferenceTemporary(CGF, 263 ObjCARCReferenceLifetimeType, 264 InitializedDecl); 265 266 267 LValue RefTempDst = CGF.MakeAddrLValue(ReferenceTemporary, 268 ObjCARCReferenceLifetimeType); 269 270 CGF.EmitScalarInit(E, dyn_cast_or_null<ValueDecl>(InitializedDecl), 271 RefTempDst, false); 272 273 bool ExtendsLifeOfTemporary = false; 274 if (const VarDecl *Var = dyn_cast_or_null<VarDecl>(InitializedDecl)) { 275 if (Var->extendsLifetimeOfTemporary()) 276 ExtendsLifeOfTemporary = true; 277 } else if (InitializedDecl && isa<FieldDecl>(InitializedDecl)) { 278 ExtendsLifeOfTemporary = true; 279 } 280 281 if (!ExtendsLifeOfTemporary) { 282 // Since the lifetime of this temporary isn't going to be extended, 283 // we need to clean it up ourselves at the end of the full expression. 284 switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) { 285 case Qualifiers::OCL_None: 286 case Qualifiers::OCL_ExplicitNone: 287 case Qualifiers::OCL_Autoreleasing: 288 break; 289 290 case Qualifiers::OCL_Strong: { 291 assert(!ObjCARCReferenceLifetimeType->isArrayType()); 292 CleanupKind cleanupKind = CGF.getARCCleanupKind(); 293 CGF.pushDestroy(cleanupKind, 294 ReferenceTemporary, 295 ObjCARCReferenceLifetimeType, 296 CodeGenFunction::destroyARCStrongImprecise, 297 cleanupKind & EHCleanup); 298 break; 299 } 300 301 case Qualifiers::OCL_Weak: 302 assert(!ObjCARCReferenceLifetimeType->isArrayType()); 303 CGF.pushDestroy(NormalAndEHCleanup, 304 ReferenceTemporary, 305 ObjCARCReferenceLifetimeType, 306 CodeGenFunction::destroyARCWeak, 307 /*useEHCleanupForArray*/ true); 308 break; 309 } 310 311 ObjCARCReferenceLifetimeType = QualType(); 312 } 313 314 return ReferenceTemporary; 315 } 316 317 SmallVector<SubobjectAdjustment, 2> Adjustments; 318 while (true) { 319 E = E->IgnoreParens(); 320 321 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { 322 if ((CE->getCastKind() == CK_DerivedToBase || 323 CE->getCastKind() == CK_UncheckedDerivedToBase) && 324 E->getType()->isRecordType()) { 325 E = CE->getSubExpr(); 326 CXXRecordDecl *Derived 327 = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl()); 328 Adjustments.push_back(SubobjectAdjustment(CE, Derived)); 329 continue; 330 } 331 332 if (CE->getCastKind() == CK_NoOp) { 333 E = CE->getSubExpr(); 334 continue; 335 } 336 } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) { 337 if (!ME->isArrow() && ME->getBase()->isRValue()) { 338 assert(ME->getBase()->getType()->isRecordType()); 339 if (FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl())) { 340 E = ME->getBase(); 341 Adjustments.push_back(SubobjectAdjustment(Field)); 342 continue; 343 } 344 } 345 } 346 347 if (const OpaqueValueExpr *opaque = dyn_cast<OpaqueValueExpr>(E)) 348 if (opaque->getType()->isRecordType()) 349 return CGF.EmitOpaqueValueLValue(opaque).getAddress(); 350 351 // Nothing changed. 352 break; 353 } 354 355 // Create a reference temporary if necessary. 356 AggValueSlot AggSlot = AggValueSlot::ignored(); 357 if (CGF.hasAggregateLLVMType(E->getType()) && 358 !E->getType()->isAnyComplexType()) { 359 ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), 360 InitializedDecl); 361 AggValueSlot::IsDestructed_t isDestructed 362 = AggValueSlot::IsDestructed_t(InitializedDecl != 0); 363 AggSlot = AggValueSlot::forAddr(ReferenceTemporary, Qualifiers(), 364 isDestructed, 365 AggValueSlot::DoesNotNeedGCBarriers, 366 AggValueSlot::IsNotAliased); 367 } 368 369 if (InitializedDecl) { 370 // Get the destructor for the reference temporary. 371 if (const RecordType *RT = E->getType()->getAs<RecordType>()) { 372 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(RT->getDecl()); 373 if (!ClassDecl->hasTrivialDestructor()) 374 ReferenceTemporaryDtor = ClassDecl->getDestructor(); 375 } 376 } 377 378 RV = CGF.EmitAnyExpr(E, AggSlot); 379 380 // Check if need to perform derived-to-base casts and/or field accesses, to 381 // get from the temporary object we created (and, potentially, for which we 382 // extended the lifetime) to the subobject we're binding the reference to. 383 if (!Adjustments.empty()) { 384 llvm::Value *Object = RV.getAggregateAddr(); 385 for (unsigned I = Adjustments.size(); I != 0; --I) { 386 SubobjectAdjustment &Adjustment = Adjustments[I-1]; 387 switch (Adjustment.Kind) { 388 case SubobjectAdjustment::DerivedToBaseAdjustment: 389 Object = 390 CGF.GetAddressOfBaseClass(Object, 391 Adjustment.DerivedToBase.DerivedClass, 392 Adjustment.DerivedToBase.BasePath->path_begin(), 393 Adjustment.DerivedToBase.BasePath->path_end(), 394 /*NullCheckValue=*/false); 395 break; 396 397 case SubobjectAdjustment::FieldAdjustment: { 398 LValue LV = 399 CGF.EmitLValueForField(Object, Adjustment.Field, 0); 400 if (LV.isSimple()) { 401 Object = LV.getAddress(); 402 break; 403 } 404 405 // For non-simple lvalues, we actually have to create a copy of 406 // the object we're binding to. 407 QualType T = Adjustment.Field->getType().getNonReferenceType() 408 .getUnqualifiedType(); 409 Object = CreateReferenceTemporary(CGF, T, InitializedDecl); 410 LValue TempLV = CGF.MakeAddrLValue(Object, 411 Adjustment.Field->getType()); 412 CGF.EmitStoreThroughLValue(CGF.EmitLoadOfLValue(LV), TempLV); 413 break; 414 } 415 416 } 417 } 418 419 return Object; 420 } 421 } 422 423 if (RV.isAggregate()) 424 return RV.getAggregateAddr(); 425 426 // Create a temporary variable that we can bind the reference to. 427 ReferenceTemporary = CreateReferenceTemporary(CGF, E->getType(), 428 InitializedDecl); 429 430 431 unsigned Alignment = 432 CGF.getContext().getTypeAlignInChars(E->getType()).getQuantity(); 433 if (RV.isScalar()) 434 CGF.EmitStoreOfScalar(RV.getScalarVal(), ReferenceTemporary, 435 /*Volatile=*/false, Alignment, E->getType()); 436 else 437 CGF.StoreComplexToAddr(RV.getComplexVal(), ReferenceTemporary, 438 /*Volatile=*/false); 439 return ReferenceTemporary; 440} 441 442RValue 443CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E, 444 const NamedDecl *InitializedDecl) { 445 llvm::Value *ReferenceTemporary = 0; 446 const CXXDestructorDecl *ReferenceTemporaryDtor = 0; 447 QualType ObjCARCReferenceLifetimeType; 448 llvm::Value *Value = EmitExprForReferenceBinding(*this, E, ReferenceTemporary, 449 ReferenceTemporaryDtor, 450 ObjCARCReferenceLifetimeType, 451 InitializedDecl); 452 if (!ReferenceTemporaryDtor && ObjCARCReferenceLifetimeType.isNull()) 453 return RValue::get(Value); 454 455 // Make sure to call the destructor for the reference temporary. 456 const VarDecl *VD = dyn_cast_or_null<VarDecl>(InitializedDecl); 457 if (VD && VD->hasGlobalStorage()) { 458 if (ReferenceTemporaryDtor) { 459 llvm::Constant *DtorFn = 460 CGM.GetAddrOfCXXDestructor(ReferenceTemporaryDtor, Dtor_Complete); 461 EmitCXXGlobalDtorRegistration(DtorFn, 462 cast<llvm::Constant>(ReferenceTemporary)); 463 } else { 464 assert(!ObjCARCReferenceLifetimeType.isNull()); 465 // Note: We intentionally do not register a global "destructor" to 466 // release the object. 467 } 468 469 return RValue::get(Value); 470 } 471 472 if (ReferenceTemporaryDtor) 473 PushDestructorCleanup(ReferenceTemporaryDtor, ReferenceTemporary); 474 else { 475 switch (ObjCARCReferenceLifetimeType.getObjCLifetime()) { 476 case Qualifiers::OCL_None: 477 llvm_unreachable( 478 "Not a reference temporary that needs to be deallocated"); 479 case Qualifiers::OCL_ExplicitNone: 480 case Qualifiers::OCL_Autoreleasing: 481 // Nothing to do. 482 break; 483 484 case Qualifiers::OCL_Strong: { 485 bool precise = VD && VD->hasAttr<ObjCPreciseLifetimeAttr>(); 486 CleanupKind cleanupKind = getARCCleanupKind(); 487 // This local is a GCC and MSVC compiler workaround. 488 Destroyer *destroyer = precise ? &destroyARCStrongPrecise : 489 &destroyARCStrongImprecise; 490 pushDestroy(cleanupKind, ReferenceTemporary, ObjCARCReferenceLifetimeType, 491 *destroyer, cleanupKind & EHCleanup); 492 break; 493 } 494 495 case Qualifiers::OCL_Weak: { 496 // This local is a GCC and MSVC compiler workaround. 497 Destroyer *destroyer = &destroyARCWeak; 498 // __weak objects always get EH cleanups; otherwise, exceptions 499 // could cause really nasty crashes instead of mere leaks. 500 pushDestroy(NormalAndEHCleanup, ReferenceTemporary, 501 ObjCARCReferenceLifetimeType, *destroyer, true); 502 break; 503 } 504 } 505 } 506 507 return RValue::get(Value); 508} 509 510 511/// getAccessedFieldNo - Given an encoded value and a result number, return the 512/// input field number being accessed. 513unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx, 514 const llvm::Constant *Elts) { 515 if (isa<llvm::ConstantAggregateZero>(Elts)) 516 return 0; 517 518 return cast<llvm::ConstantInt>(Elts->getOperand(Idx))->getZExtValue(); 519} 520 521void CodeGenFunction::EmitCheck(llvm::Value *Address, unsigned Size) { 522 if (!CatchUndefined) 523 return; 524 525 // This needs to be to the standard address space. 526 Address = Builder.CreateBitCast(Address, Int8PtrTy); 527 528 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, IntPtrTy); 529 530 // In time, people may want to control this and use a 1 here. 531 llvm::Value *Arg = Builder.getFalse(); 532 llvm::Value *C = Builder.CreateCall2(F, Address, Arg); 533 llvm::BasicBlock *Cont = createBasicBlock(); 534 llvm::BasicBlock *Check = createBasicBlock(); 535 llvm::Value *NegativeOne = llvm::ConstantInt::get(IntPtrTy, -1ULL); 536 Builder.CreateCondBr(Builder.CreateICmpEQ(C, NegativeOne), Cont, Check); 537 538 EmitBlock(Check); 539 Builder.CreateCondBr(Builder.CreateICmpUGE(C, 540 llvm::ConstantInt::get(IntPtrTy, Size)), 541 Cont, getTrapBB()); 542 EmitBlock(Cont); 543} 544 545 546CodeGenFunction::ComplexPairTy CodeGenFunction:: 547EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV, 548 bool isInc, bool isPre) { 549 ComplexPairTy InVal = LoadComplexFromAddr(LV.getAddress(), 550 LV.isVolatileQualified()); 551 552 llvm::Value *NextVal; 553 if (isa<llvm::IntegerType>(InVal.first->getType())) { 554 uint64_t AmountVal = isInc ? 1 : -1; 555 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true); 556 557 // Add the inc/dec to the real part. 558 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); 559 } else { 560 QualType ElemTy = E->getType()->getAs<ComplexType>()->getElementType(); 561 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1); 562 if (!isInc) 563 FVal.changeSign(); 564 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal); 565 566 // Add the inc/dec to the real part. 567 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); 568 } 569 570 ComplexPairTy IncVal(NextVal, InVal.second); 571 572 // Store the updated result through the lvalue. 573 StoreComplexToAddr(IncVal, LV.getAddress(), LV.isVolatileQualified()); 574 575 // If this is a postinc, return the value read from memory, otherwise use the 576 // updated value. 577 return isPre ? IncVal : InVal; 578} 579 580 581//===----------------------------------------------------------------------===// 582// LValue Expression Emission 583//===----------------------------------------------------------------------===// 584 585RValue CodeGenFunction::GetUndefRValue(QualType Ty) { 586 if (Ty->isVoidType()) 587 return RValue::get(0); 588 589 if (const ComplexType *CTy = Ty->getAs<ComplexType>()) { 590 llvm::Type *EltTy = ConvertType(CTy->getElementType()); 591 llvm::Value *U = llvm::UndefValue::get(EltTy); 592 return RValue::getComplex(std::make_pair(U, U)); 593 } 594 595 // If this is a use of an undefined aggregate type, the aggregate must have an 596 // identifiable address. Just because the contents of the value are undefined 597 // doesn't mean that the address can't be taken and compared. 598 if (hasAggregateLLVMType(Ty)) { 599 llvm::Value *DestPtr = CreateMemTemp(Ty, "undef.agg.tmp"); 600 return RValue::getAggregate(DestPtr); 601 } 602 603 return RValue::get(llvm::UndefValue::get(ConvertType(Ty))); 604} 605 606RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E, 607 const char *Name) { 608 ErrorUnsupported(E, Name); 609 return GetUndefRValue(E->getType()); 610} 611 612LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E, 613 const char *Name) { 614 ErrorUnsupported(E, Name); 615 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType())); 616 return MakeAddrLValue(llvm::UndefValue::get(Ty), E->getType()); 617} 618 619LValue CodeGenFunction::EmitCheckedLValue(const Expr *E) { 620 LValue LV = EmitLValue(E); 621 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) 622 EmitCheck(LV.getAddress(), 623 getContext().getTypeSizeInChars(E->getType()).getQuantity()); 624 return LV; 625} 626 627/// EmitLValue - Emit code to compute a designator that specifies the location 628/// of the expression. 629/// 630/// This can return one of two things: a simple address or a bitfield reference. 631/// In either case, the LLVM Value* in the LValue structure is guaranteed to be 632/// an LLVM pointer type. 633/// 634/// If this returns a bitfield reference, nothing about the pointee type of the 635/// LLVM value is known: For example, it may not be a pointer to an integer. 636/// 637/// If this returns a normal address, and if the lvalue's C type is fixed size, 638/// this method guarantees that the returned pointer type will point to an LLVM 639/// type of the same size of the lvalue's type. If the lvalue has a variable 640/// length type, this is not possible. 641/// 642LValue CodeGenFunction::EmitLValue(const Expr *E) { 643 switch (E->getStmtClass()) { 644 default: return EmitUnsupportedLValue(E, "l-value expression"); 645 646 case Expr::ObjCSelectorExprClass: 647 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E)); 648 case Expr::ObjCIsaExprClass: 649 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E)); 650 case Expr::BinaryOperatorClass: 651 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E)); 652 case Expr::CompoundAssignOperatorClass: 653 if (!E->getType()->isAnyComplexType()) 654 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E)); 655 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E)); 656 case Expr::CallExprClass: 657 case Expr::CXXMemberCallExprClass: 658 case Expr::CXXOperatorCallExprClass: 659 return EmitCallExprLValue(cast<CallExpr>(E)); 660 case Expr::VAArgExprClass: 661 return EmitVAArgExprLValue(cast<VAArgExpr>(E)); 662 case Expr::DeclRefExprClass: 663 return EmitDeclRefLValue(cast<DeclRefExpr>(E)); 664 case Expr::ParenExprClass: 665 return EmitLValue(cast<ParenExpr>(E)->getSubExpr()); 666 case Expr::GenericSelectionExprClass: 667 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr()); 668 case Expr::PredefinedExprClass: 669 return EmitPredefinedLValue(cast<PredefinedExpr>(E)); 670 case Expr::StringLiteralClass: 671 return EmitStringLiteralLValue(cast<StringLiteral>(E)); 672 case Expr::ObjCEncodeExprClass: 673 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E)); 674 675 case Expr::BlockDeclRefExprClass: 676 return EmitBlockDeclRefLValue(cast<BlockDeclRefExpr>(E)); 677 678 case Expr::CXXTemporaryObjectExprClass: 679 case Expr::CXXConstructExprClass: 680 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E)); 681 case Expr::CXXBindTemporaryExprClass: 682 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E)); 683 case Expr::ExprWithCleanupsClass: 684 return EmitExprWithCleanupsLValue(cast<ExprWithCleanups>(E)); 685 case Expr::CXXScalarValueInitExprClass: 686 return EmitNullInitializationLValue(cast<CXXScalarValueInitExpr>(E)); 687 case Expr::CXXDefaultArgExprClass: 688 return EmitLValue(cast<CXXDefaultArgExpr>(E)->getExpr()); 689 case Expr::CXXTypeidExprClass: 690 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E)); 691 692 case Expr::ObjCMessageExprClass: 693 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E)); 694 case Expr::ObjCIvarRefExprClass: 695 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E)); 696 case Expr::ObjCPropertyRefExprClass: 697 return EmitObjCPropertyRefLValue(cast<ObjCPropertyRefExpr>(E)); 698 case Expr::StmtExprClass: 699 return EmitStmtExprLValue(cast<StmtExpr>(E)); 700 case Expr::UnaryOperatorClass: 701 return EmitUnaryOpLValue(cast<UnaryOperator>(E)); 702 case Expr::ArraySubscriptExprClass: 703 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E)); 704 case Expr::ExtVectorElementExprClass: 705 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E)); 706 case Expr::MemberExprClass: 707 return EmitMemberExpr(cast<MemberExpr>(E)); 708 case Expr::CompoundLiteralExprClass: 709 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E)); 710 case Expr::ConditionalOperatorClass: 711 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E)); 712 case Expr::BinaryConditionalOperatorClass: 713 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E)); 714 case Expr::ChooseExprClass: 715 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr(getContext())); 716 case Expr::OpaqueValueExprClass: 717 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E)); 718 case Expr::SubstNonTypeTemplateParmExprClass: 719 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement()); 720 case Expr::ImplicitCastExprClass: 721 case Expr::CStyleCastExprClass: 722 case Expr::CXXFunctionalCastExprClass: 723 case Expr::CXXStaticCastExprClass: 724 case Expr::CXXDynamicCastExprClass: 725 case Expr::CXXReinterpretCastExprClass: 726 case Expr::CXXConstCastExprClass: 727 case Expr::ObjCBridgedCastExprClass: 728 return EmitCastLValue(cast<CastExpr>(E)); 729 730 case Expr::MaterializeTemporaryExprClass: 731 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E)); 732 } 733} 734 735llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue) { 736 return EmitLoadOfScalar(lvalue.getAddress(), lvalue.isVolatile(), 737 lvalue.getAlignment(), lvalue.getType(), 738 lvalue.getTBAAInfo()); 739} 740 741llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile, 742 unsigned Alignment, QualType Ty, 743 llvm::MDNode *TBAAInfo) { 744 llvm::LoadInst *Load = Builder.CreateLoad(Addr); 745 if (Volatile) 746 Load->setVolatile(true); 747 if (Alignment) 748 Load->setAlignment(Alignment); 749 if (TBAAInfo) 750 CGM.DecorateInstruction(Load, TBAAInfo); 751 752 return EmitFromMemory(Load, Ty); 753} 754 755static bool isBooleanUnderlyingType(QualType Ty) { 756 if (const EnumType *ET = dyn_cast<EnumType>(Ty)) 757 return ET->getDecl()->getIntegerType()->isBooleanType(); 758 return false; 759} 760 761llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) { 762 // Bool has a different representation in memory than in registers. 763 if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) { 764 // This should really always be an i1, but sometimes it's already 765 // an i8, and it's awkward to track those cases down. 766 if (Value->getType()->isIntegerTy(1)) 767 return Builder.CreateZExt(Value, Builder.getInt8Ty(), "frombool"); 768 assert(Value->getType()->isIntegerTy(8) && "value rep of bool not i1/i8"); 769 } 770 771 return Value; 772} 773 774llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) { 775 // Bool has a different representation in memory than in registers. 776 if (Ty->isBooleanType() || isBooleanUnderlyingType(Ty)) { 777 assert(Value->getType()->isIntegerTy(8) && "memory rep of bool not i8"); 778 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool"); 779 } 780 781 return Value; 782} 783 784void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr, 785 bool Volatile, unsigned Alignment, 786 QualType Ty, 787 llvm::MDNode *TBAAInfo) { 788 Value = EmitToMemory(Value, Ty); 789 790 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile); 791 if (Alignment) 792 Store->setAlignment(Alignment); 793 if (TBAAInfo) 794 CGM.DecorateInstruction(Store, TBAAInfo); 795} 796 797void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue) { 798 EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(), 799 lvalue.getAlignment(), lvalue.getType(), 800 lvalue.getTBAAInfo()); 801} 802 803/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this 804/// method emits the address of the lvalue, then loads the result as an rvalue, 805/// returning the rvalue. 806RValue CodeGenFunction::EmitLoadOfLValue(LValue LV) { 807 if (LV.isObjCWeak()) { 808 // load of a __weak object. 809 llvm::Value *AddrWeakObj = LV.getAddress(); 810 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this, 811 AddrWeakObj)); 812 } 813 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) 814 return RValue::get(EmitARCLoadWeak(LV.getAddress())); 815 816 if (LV.isSimple()) { 817 assert(!LV.getType()->isFunctionType()); 818 819 // Everything needs a load. 820 return RValue::get(EmitLoadOfScalar(LV)); 821 } 822 823 if (LV.isVectorElt()) { 824 llvm::Value *Vec = Builder.CreateLoad(LV.getVectorAddr(), 825 LV.isVolatileQualified()); 826 return RValue::get(Builder.CreateExtractElement(Vec, LV.getVectorIdx(), 827 "vecext")); 828 } 829 830 // If this is a reference to a subset of the elements of a vector, either 831 // shuffle the input or extract/insert them as appropriate. 832 if (LV.isExtVectorElt()) 833 return EmitLoadOfExtVectorElementLValue(LV); 834 835 if (LV.isBitField()) 836 return EmitLoadOfBitfieldLValue(LV); 837 838 assert(LV.isPropertyRef() && "Unknown LValue type!"); 839 return EmitLoadOfPropertyRefLValue(LV); 840} 841 842RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV) { 843 const CGBitFieldInfo &Info = LV.getBitFieldInfo(); 844 845 // Get the output type. 846 llvm::Type *ResLTy = ConvertType(LV.getType()); 847 unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy); 848 849 // Compute the result as an OR of all of the individual component accesses. 850 llvm::Value *Res = 0; 851 for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) { 852 const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i); 853 854 // Get the field pointer. 855 llvm::Value *Ptr = LV.getBitFieldBaseAddr(); 856 857 // Only offset by the field index if used, so that incoming values are not 858 // required to be structures. 859 if (AI.FieldIndex) 860 Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field"); 861 862 // Offset by the byte offset, if used. 863 if (!AI.FieldByteOffset.isZero()) { 864 Ptr = EmitCastToVoidPtr(Ptr); 865 Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(), 866 "bf.field.offs"); 867 } 868 869 // Cast to the access type. 870 llvm::Type *PTy = llvm::Type::getIntNPtrTy(getLLVMContext(), 871 AI.AccessWidth, 872 CGM.getContext().getTargetAddressSpace(LV.getType())); 873 Ptr = Builder.CreateBitCast(Ptr, PTy); 874 875 // Perform the load. 876 llvm::LoadInst *Load = Builder.CreateLoad(Ptr, LV.isVolatileQualified()); 877 if (!AI.AccessAlignment.isZero()) 878 Load->setAlignment(AI.AccessAlignment.getQuantity()); 879 880 // Shift out unused low bits and mask out unused high bits. 881 llvm::Value *Val = Load; 882 if (AI.FieldBitStart) 883 Val = Builder.CreateLShr(Load, AI.FieldBitStart); 884 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(AI.AccessWidth, 885 AI.TargetBitWidth), 886 "bf.clear"); 887 888 // Extend or truncate to the target size. 889 if (AI.AccessWidth < ResSizeInBits) 890 Val = Builder.CreateZExt(Val, ResLTy); 891 else if (AI.AccessWidth > ResSizeInBits) 892 Val = Builder.CreateTrunc(Val, ResLTy); 893 894 // Shift into place, and OR into the result. 895 if (AI.TargetBitOffset) 896 Val = Builder.CreateShl(Val, AI.TargetBitOffset); 897 Res = Res ? Builder.CreateOr(Res, Val) : Val; 898 } 899 900 // If the bit-field is signed, perform the sign-extension. 901 // 902 // FIXME: This can easily be folded into the load of the high bits, which 903 // could also eliminate the mask of high bits in some situations. 904 if (Info.isSigned()) { 905 unsigned ExtraBits = ResSizeInBits - Info.getSize(); 906 if (ExtraBits) 907 Res = Builder.CreateAShr(Builder.CreateShl(Res, ExtraBits), 908 ExtraBits, "bf.val.sext"); 909 } 910 911 return RValue::get(Res); 912} 913 914// If this is a reference to a subset of the elements of a vector, create an 915// appropriate shufflevector. 916RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) { 917 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddr(), 918 LV.isVolatileQualified()); 919 920 const llvm::Constant *Elts = LV.getExtVectorElts(); 921 922 // If the result of the expression is a non-vector type, we must be extracting 923 // a single element. Just codegen as an extractelement. 924 const VectorType *ExprVT = LV.getType()->getAs<VectorType>(); 925 if (!ExprVT) { 926 unsigned InIdx = getAccessedFieldNo(0, Elts); 927 llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx); 928 return RValue::get(Builder.CreateExtractElement(Vec, Elt)); 929 } 930 931 // Always use shuffle vector to try to retain the original program structure 932 unsigned NumResultElts = ExprVT->getNumElements(); 933 934 SmallVector<llvm::Constant*, 4> Mask; 935 for (unsigned i = 0; i != NumResultElts; ++i) { 936 unsigned InIdx = getAccessedFieldNo(i, Elts); 937 Mask.push_back(llvm::ConstantInt::get(Int32Ty, InIdx)); 938 } 939 940 llvm::Value *MaskV = llvm::ConstantVector::get(Mask); 941 Vec = Builder.CreateShuffleVector(Vec, llvm::UndefValue::get(Vec->getType()), 942 MaskV); 943 return RValue::get(Vec); 944} 945 946 947 948/// EmitStoreThroughLValue - Store the specified rvalue into the specified 949/// lvalue, where both are guaranteed to the have the same type, and that type 950/// is 'Ty'. 951void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst) { 952 if (!Dst.isSimple()) { 953 if (Dst.isVectorElt()) { 954 // Read/modify/write the vector, inserting the new element. 955 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddr(), 956 Dst.isVolatileQualified()); 957 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(), 958 Dst.getVectorIdx(), "vecins"); 959 Builder.CreateStore(Vec, Dst.getVectorAddr(),Dst.isVolatileQualified()); 960 return; 961 } 962 963 // If this is an update of extended vector elements, insert them as 964 // appropriate. 965 if (Dst.isExtVectorElt()) 966 return EmitStoreThroughExtVectorComponentLValue(Src, Dst); 967 968 if (Dst.isBitField()) 969 return EmitStoreThroughBitfieldLValue(Src, Dst); 970 971 assert(Dst.isPropertyRef() && "Unknown LValue type"); 972 return EmitStoreThroughPropertyRefLValue(Src, Dst); 973 } 974 975 // There's special magic for assigning into an ARC-qualified l-value. 976 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) { 977 switch (Lifetime) { 978 case Qualifiers::OCL_None: 979 llvm_unreachable("present but none"); 980 981 case Qualifiers::OCL_ExplicitNone: 982 // nothing special 983 break; 984 985 case Qualifiers::OCL_Strong: 986 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true); 987 return; 988 989 case Qualifiers::OCL_Weak: 990 EmitARCStoreWeak(Dst.getAddress(), Src.getScalarVal(), /*ignore*/ true); 991 return; 992 993 case Qualifiers::OCL_Autoreleasing: 994 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(), 995 Src.getScalarVal())); 996 // fall into the normal path 997 break; 998 } 999 } 1000 1001 if (Dst.isObjCWeak() && !Dst.isNonGC()) { 1002 // load of a __weak object. 1003 llvm::Value *LvalueDst = Dst.getAddress(); 1004 llvm::Value *src = Src.getScalarVal(); 1005 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst); 1006 return; 1007 } 1008 1009 if (Dst.isObjCStrong() && !Dst.isNonGC()) { 1010 // load of a __strong object. 1011 llvm::Value *LvalueDst = Dst.getAddress(); 1012 llvm::Value *src = Src.getScalarVal(); 1013 if (Dst.isObjCIvar()) { 1014 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL"); 1015 llvm::Type *ResultType = ConvertType(getContext().LongTy); 1016 llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp()); 1017 llvm::Value *dst = RHS; 1018 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 1019 llvm::Value *LHS = 1020 Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast"); 1021 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset"); 1022 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst, 1023 BytesBetween); 1024 } else if (Dst.isGlobalObjCRef()) { 1025 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst, 1026 Dst.isThreadLocalRef()); 1027 } 1028 else 1029 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst); 1030 return; 1031 } 1032 1033 assert(Src.isScalar() && "Can't emit an agg store with this method"); 1034 EmitStoreOfScalar(Src.getScalarVal(), Dst); 1035} 1036 1037void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, 1038 llvm::Value **Result) { 1039 const CGBitFieldInfo &Info = Dst.getBitFieldInfo(); 1040 1041 // Get the output type. 1042 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType()); 1043 unsigned ResSizeInBits = CGM.getTargetData().getTypeSizeInBits(ResLTy); 1044 1045 // Get the source value, truncated to the width of the bit-field. 1046 llvm::Value *SrcVal = Src.getScalarVal(); 1047 1048 if (Dst.getType()->isBooleanType()) 1049 SrcVal = Builder.CreateIntCast(SrcVal, ResLTy, /*IsSigned=*/false); 1050 1051 SrcVal = Builder.CreateAnd(SrcVal, llvm::APInt::getLowBitsSet(ResSizeInBits, 1052 Info.getSize()), 1053 "bf.value"); 1054 1055 // Return the new value of the bit-field, if requested. 1056 if (Result) { 1057 // Cast back to the proper type for result. 1058 llvm::Type *SrcTy = Src.getScalarVal()->getType(); 1059 llvm::Value *ReloadVal = Builder.CreateIntCast(SrcVal, SrcTy, false, 1060 "bf.reload.val"); 1061 1062 // Sign extend if necessary. 1063 if (Info.isSigned()) { 1064 unsigned ExtraBits = ResSizeInBits - Info.getSize(); 1065 if (ExtraBits) 1066 ReloadVal = Builder.CreateAShr(Builder.CreateShl(ReloadVal, ExtraBits), 1067 ExtraBits, "bf.reload.sext"); 1068 } 1069 1070 *Result = ReloadVal; 1071 } 1072 1073 // Iterate over the components, writing each piece to memory. 1074 for (unsigned i = 0, e = Info.getNumComponents(); i != e; ++i) { 1075 const CGBitFieldInfo::AccessInfo &AI = Info.getComponent(i); 1076 1077 // Get the field pointer. 1078 llvm::Value *Ptr = Dst.getBitFieldBaseAddr(); 1079 unsigned addressSpace = 1080 cast<llvm::PointerType>(Ptr->getType())->getAddressSpace(); 1081 1082 // Only offset by the field index if used, so that incoming values are not 1083 // required to be structures. 1084 if (AI.FieldIndex) 1085 Ptr = Builder.CreateStructGEP(Ptr, AI.FieldIndex, "bf.field"); 1086 1087 // Offset by the byte offset, if used. 1088 if (!AI.FieldByteOffset.isZero()) { 1089 Ptr = EmitCastToVoidPtr(Ptr); 1090 Ptr = Builder.CreateConstGEP1_32(Ptr, AI.FieldByteOffset.getQuantity(), 1091 "bf.field.offs"); 1092 } 1093 1094 // Cast to the access type. 1095 llvm::Type *AccessLTy = 1096 llvm::Type::getIntNTy(getLLVMContext(), AI.AccessWidth); 1097 1098 llvm::Type *PTy = AccessLTy->getPointerTo(addressSpace); 1099 Ptr = Builder.CreateBitCast(Ptr, PTy); 1100 1101 // Extract the piece of the bit-field value to write in this access, limited 1102 // to the values that are part of this access. 1103 llvm::Value *Val = SrcVal; 1104 if (AI.TargetBitOffset) 1105 Val = Builder.CreateLShr(Val, AI.TargetBitOffset); 1106 Val = Builder.CreateAnd(Val, llvm::APInt::getLowBitsSet(ResSizeInBits, 1107 AI.TargetBitWidth)); 1108 1109 // Extend or truncate to the access size. 1110 if (ResSizeInBits < AI.AccessWidth) 1111 Val = Builder.CreateZExt(Val, AccessLTy); 1112 else if (ResSizeInBits > AI.AccessWidth) 1113 Val = Builder.CreateTrunc(Val, AccessLTy); 1114 1115 // Shift into the position in memory. 1116 if (AI.FieldBitStart) 1117 Val = Builder.CreateShl(Val, AI.FieldBitStart); 1118 1119 // If necessary, load and OR in bits that are outside of the bit-field. 1120 if (AI.TargetBitWidth != AI.AccessWidth) { 1121 llvm::LoadInst *Load = Builder.CreateLoad(Ptr, Dst.isVolatileQualified()); 1122 if (!AI.AccessAlignment.isZero()) 1123 Load->setAlignment(AI.AccessAlignment.getQuantity()); 1124 1125 // Compute the mask for zeroing the bits that are part of the bit-field. 1126 llvm::APInt InvMask = 1127 ~llvm::APInt::getBitsSet(AI.AccessWidth, AI.FieldBitStart, 1128 AI.FieldBitStart + AI.TargetBitWidth); 1129 1130 // Apply the mask and OR in to the value to write. 1131 Val = Builder.CreateOr(Builder.CreateAnd(Load, InvMask), Val); 1132 } 1133 1134 // Write the value. 1135 llvm::StoreInst *Store = Builder.CreateStore(Val, Ptr, 1136 Dst.isVolatileQualified()); 1137 if (!AI.AccessAlignment.isZero()) 1138 Store->setAlignment(AI.AccessAlignment.getQuantity()); 1139 } 1140} 1141 1142void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src, 1143 LValue Dst) { 1144 // This access turns into a read/modify/write of the vector. Load the input 1145 // value now. 1146 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddr(), 1147 Dst.isVolatileQualified()); 1148 const llvm::Constant *Elts = Dst.getExtVectorElts(); 1149 1150 llvm::Value *SrcVal = Src.getScalarVal(); 1151 1152 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) { 1153 unsigned NumSrcElts = VTy->getNumElements(); 1154 unsigned NumDstElts = 1155 cast<llvm::VectorType>(Vec->getType())->getNumElements(); 1156 if (NumDstElts == NumSrcElts) { 1157 // Use shuffle vector is the src and destination are the same number of 1158 // elements and restore the vector mask since it is on the side it will be 1159 // stored. 1160 SmallVector<llvm::Constant*, 4> Mask(NumDstElts); 1161 for (unsigned i = 0; i != NumSrcElts; ++i) { 1162 unsigned InIdx = getAccessedFieldNo(i, Elts); 1163 Mask[InIdx] = llvm::ConstantInt::get(Int32Ty, i); 1164 } 1165 1166 llvm::Value *MaskV = llvm::ConstantVector::get(Mask); 1167 Vec = Builder.CreateShuffleVector(SrcVal, 1168 llvm::UndefValue::get(Vec->getType()), 1169 MaskV); 1170 } else if (NumDstElts > NumSrcElts) { 1171 // Extended the source vector to the same length and then shuffle it 1172 // into the destination. 1173 // FIXME: since we're shuffling with undef, can we just use the indices 1174 // into that? This could be simpler. 1175 SmallVector<llvm::Constant*, 4> ExtMask; 1176 unsigned i; 1177 for (i = 0; i != NumSrcElts; ++i) 1178 ExtMask.push_back(llvm::ConstantInt::get(Int32Ty, i)); 1179 for (; i != NumDstElts; ++i) 1180 ExtMask.push_back(llvm::UndefValue::get(Int32Ty)); 1181 llvm::Value *ExtMaskV = llvm::ConstantVector::get(ExtMask); 1182 llvm::Value *ExtSrcVal = 1183 Builder.CreateShuffleVector(SrcVal, 1184 llvm::UndefValue::get(SrcVal->getType()), 1185 ExtMaskV); 1186 // build identity 1187 SmallVector<llvm::Constant*, 4> Mask; 1188 for (unsigned i = 0; i != NumDstElts; ++i) 1189 Mask.push_back(llvm::ConstantInt::get(Int32Ty, i)); 1190 1191 // modify when what gets shuffled in 1192 for (unsigned i = 0; i != NumSrcElts; ++i) { 1193 unsigned Idx = getAccessedFieldNo(i, Elts); 1194 Mask[Idx] = llvm::ConstantInt::get(Int32Ty, i+NumDstElts); 1195 } 1196 llvm::Value *MaskV = llvm::ConstantVector::get(Mask); 1197 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, MaskV); 1198 } else { 1199 // We should never shorten the vector 1200 llvm_unreachable("unexpected shorten vector length"); 1201 } 1202 } else { 1203 // If the Src is a scalar (not a vector) it must be updating one element. 1204 unsigned InIdx = getAccessedFieldNo(0, Elts); 1205 llvm::Value *Elt = llvm::ConstantInt::get(Int32Ty, InIdx); 1206 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt); 1207 } 1208 1209 Builder.CreateStore(Vec, Dst.getExtVectorAddr(), Dst.isVolatileQualified()); 1210} 1211 1212// setObjCGCLValueClass - sets class of he lvalue for the purpose of 1213// generating write-barries API. It is currently a global, ivar, 1214// or neither. 1215static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E, 1216 LValue &LV) { 1217 if (Ctx.getLangOptions().getGC() == LangOptions::NonGC) 1218 return; 1219 1220 if (isa<ObjCIvarRefExpr>(E)) { 1221 LV.setObjCIvar(true); 1222 ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E)); 1223 LV.setBaseIvarExp(Exp->getBase()); 1224 LV.setObjCArray(E->getType()->isArrayType()); 1225 return; 1226 } 1227 1228 if (const DeclRefExpr *Exp = dyn_cast<DeclRefExpr>(E)) { 1229 if (const VarDecl *VD = dyn_cast<VarDecl>(Exp->getDecl())) { 1230 if (VD->hasGlobalStorage()) { 1231 LV.setGlobalObjCRef(true); 1232 LV.setThreadLocalRef(VD->isThreadSpecified()); 1233 } 1234 } 1235 LV.setObjCArray(E->getType()->isArrayType()); 1236 return; 1237 } 1238 1239 if (const UnaryOperator *Exp = dyn_cast<UnaryOperator>(E)) { 1240 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV); 1241 return; 1242 } 1243 1244 if (const ParenExpr *Exp = dyn_cast<ParenExpr>(E)) { 1245 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV); 1246 if (LV.isObjCIvar()) { 1247 // If cast is to a structure pointer, follow gcc's behavior and make it 1248 // a non-ivar write-barrier. 1249 QualType ExpTy = E->getType(); 1250 if (ExpTy->isPointerType()) 1251 ExpTy = ExpTy->getAs<PointerType>()->getPointeeType(); 1252 if (ExpTy->isRecordType()) 1253 LV.setObjCIvar(false); 1254 } 1255 return; 1256 } 1257 1258 if (const GenericSelectionExpr *Exp = dyn_cast<GenericSelectionExpr>(E)) { 1259 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV); 1260 return; 1261 } 1262 1263 if (const ImplicitCastExpr *Exp = dyn_cast<ImplicitCastExpr>(E)) { 1264 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV); 1265 return; 1266 } 1267 1268 if (const CStyleCastExpr *Exp = dyn_cast<CStyleCastExpr>(E)) { 1269 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV); 1270 return; 1271 } 1272 1273 if (const ObjCBridgedCastExpr *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) { 1274 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV); 1275 return; 1276 } 1277 1278 if (const ArraySubscriptExpr *Exp = dyn_cast<ArraySubscriptExpr>(E)) { 1279 setObjCGCLValueClass(Ctx, Exp->getBase(), LV); 1280 if (LV.isObjCIvar() && !LV.isObjCArray()) 1281 // Using array syntax to assigning to what an ivar points to is not 1282 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0; 1283 LV.setObjCIvar(false); 1284 else if (LV.isGlobalObjCRef() && !LV.isObjCArray()) 1285 // Using array syntax to assigning to what global points to is not 1286 // same as assigning to the global itself. {id *G;} G[i] = 0; 1287 LV.setGlobalObjCRef(false); 1288 return; 1289 } 1290 1291 if (const MemberExpr *Exp = dyn_cast<MemberExpr>(E)) { 1292 setObjCGCLValueClass(Ctx, Exp->getBase(), LV); 1293 // We don't know if member is an 'ivar', but this flag is looked at 1294 // only in the context of LV.isObjCIvar(). 1295 LV.setObjCArray(E->getType()->isArrayType()); 1296 return; 1297 } 1298} 1299 1300static llvm::Value * 1301EmitBitCastOfLValueToProperType(CodeGenFunction &CGF, 1302 llvm::Value *V, llvm::Type *IRType, 1303 StringRef Name = StringRef()) { 1304 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace(); 1305 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name); 1306} 1307 1308static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF, 1309 const Expr *E, const VarDecl *VD) { 1310 assert((VD->hasExternalStorage() || VD->isFileVarDecl()) && 1311 "Var decl must have external storage or be a file var decl!"); 1312 1313 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD); 1314 if (VD->getType()->isReferenceType()) 1315 V = CGF.Builder.CreateLoad(V); 1316 1317 V = EmitBitCastOfLValueToProperType(CGF, V, 1318 CGF.getTypes().ConvertTypeForMem(E->getType())); 1319 1320 unsigned Alignment = CGF.getContext().getDeclAlign(VD).getQuantity(); 1321 LValue LV = CGF.MakeAddrLValue(V, E->getType(), Alignment); 1322 setObjCGCLValueClass(CGF.getContext(), E, LV); 1323 return LV; 1324} 1325 1326static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, 1327 const Expr *E, const FunctionDecl *FD) { 1328 llvm::Value *V = CGF.CGM.GetAddrOfFunction(FD); 1329 if (!FD->hasPrototype()) { 1330 if (const FunctionProtoType *Proto = 1331 FD->getType()->getAs<FunctionProtoType>()) { 1332 // Ugly case: for a K&R-style definition, the type of the definition 1333 // isn't the same as the type of a use. Correct for this with a 1334 // bitcast. 1335 QualType NoProtoType = 1336 CGF.getContext().getFunctionNoProtoType(Proto->getResultType()); 1337 NoProtoType = CGF.getContext().getPointerType(NoProtoType); 1338 V = CGF.Builder.CreateBitCast(V, CGF.ConvertType(NoProtoType)); 1339 } 1340 } 1341 unsigned Alignment = CGF.getContext().getDeclAlign(FD).getQuantity(); 1342 return CGF.MakeAddrLValue(V, E->getType(), Alignment); 1343} 1344 1345LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) { 1346 const NamedDecl *ND = E->getDecl(); 1347 unsigned Alignment = getContext().getDeclAlign(ND).getQuantity(); 1348 1349 if (ND->hasAttr<WeakRefAttr>()) { 1350 const ValueDecl *VD = cast<ValueDecl>(ND); 1351 llvm::Constant *Aliasee = CGM.GetWeakRefReference(VD); 1352 return MakeAddrLValue(Aliasee, E->getType(), Alignment); 1353 } 1354 1355 if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) { 1356 1357 // Check if this is a global variable. 1358 if (VD->hasExternalStorage() || VD->isFileVarDecl()) 1359 return EmitGlobalVarDeclLValue(*this, E, VD); 1360 1361 bool NonGCable = VD->hasLocalStorage() && 1362 !VD->getType()->isReferenceType() && 1363 !VD->hasAttr<BlocksAttr>(); 1364 1365 llvm::Value *V = LocalDeclMap[VD]; 1366 if (!V && VD->isStaticLocal()) 1367 V = CGM.getStaticLocalDeclAddress(VD); 1368 assert(V && "DeclRefExpr not entered in LocalDeclMap?"); 1369 1370 if (VD->hasAttr<BlocksAttr>()) 1371 V = BuildBlockByrefAddress(V, VD); 1372 1373 if (VD->getType()->isReferenceType()) 1374 V = Builder.CreateLoad(V); 1375 1376 V = EmitBitCastOfLValueToProperType(*this, V, 1377 getTypes().ConvertTypeForMem(E->getType())); 1378 1379 LValue LV = MakeAddrLValue(V, E->getType(), Alignment); 1380 if (NonGCable) { 1381 LV.getQuals().removeObjCGCAttr(); 1382 LV.setNonGC(true); 1383 } 1384 setObjCGCLValueClass(getContext(), E, LV); 1385 return LV; 1386 } 1387 1388 if (const FunctionDecl *fn = dyn_cast<FunctionDecl>(ND)) 1389 return EmitFunctionDeclLValue(*this, E, fn); 1390 1391 llvm_unreachable("Unhandled DeclRefExpr"); 1392 1393 // an invalid LValue, but the assert will 1394 // ensure that this point is never reached. 1395 return LValue(); 1396} 1397 1398LValue CodeGenFunction::EmitBlockDeclRefLValue(const BlockDeclRefExpr *E) { 1399 unsigned Alignment = 1400 getContext().getDeclAlign(E->getDecl()).getQuantity(); 1401 return MakeAddrLValue(GetAddrOfBlockDecl(E), E->getType(), Alignment); 1402} 1403 1404LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) { 1405 // __extension__ doesn't affect lvalue-ness. 1406 if (E->getOpcode() == UO_Extension) 1407 return EmitLValue(E->getSubExpr()); 1408 1409 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType()); 1410 switch (E->getOpcode()) { 1411 default: llvm_unreachable("Unknown unary operator lvalue!"); 1412 case UO_Deref: { 1413 QualType T = E->getSubExpr()->getType()->getPointeeType(); 1414 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type"); 1415 1416 LValue LV = MakeAddrLValue(EmitScalarExpr(E->getSubExpr()), T); 1417 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace()); 1418 1419 // We should not generate __weak write barrier on indirect reference 1420 // of a pointer to object; as in void foo (__weak id *param); *param = 0; 1421 // But, we continue to generate __strong write barrier on indirect write 1422 // into a pointer to object. 1423 if (getContext().getLangOptions().ObjC1 && 1424 getContext().getLangOptions().getGC() != LangOptions::NonGC && 1425 LV.isObjCWeak()) 1426 LV.setNonGC(!E->isOBJCGCCandidate(getContext())); 1427 return LV; 1428 } 1429 case UO_Real: 1430 case UO_Imag: { 1431 LValue LV = EmitLValue(E->getSubExpr()); 1432 assert(LV.isSimple() && "real/imag on non-ordinary l-value"); 1433 llvm::Value *Addr = LV.getAddress(); 1434 1435 // real and imag are valid on scalars. This is a faster way of 1436 // testing that. 1437 if (!cast<llvm::PointerType>(Addr->getType()) 1438 ->getElementType()->isStructTy()) { 1439 assert(E->getSubExpr()->getType()->isArithmeticType()); 1440 return LV; 1441 } 1442 1443 assert(E->getSubExpr()->getType()->isAnyComplexType()); 1444 1445 unsigned Idx = E->getOpcode() == UO_Imag; 1446 return MakeAddrLValue(Builder.CreateStructGEP(LV.getAddress(), 1447 Idx, "idx"), 1448 ExprTy); 1449 } 1450 case UO_PreInc: 1451 case UO_PreDec: { 1452 LValue LV = EmitLValue(E->getSubExpr()); 1453 bool isInc = E->getOpcode() == UO_PreInc; 1454 1455 if (E->getType()->isAnyComplexType()) 1456 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/); 1457 else 1458 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/); 1459 return LV; 1460 } 1461 } 1462} 1463 1464LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) { 1465 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E), 1466 E->getType()); 1467} 1468 1469LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) { 1470 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E), 1471 E->getType()); 1472} 1473 1474 1475LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) { 1476 switch (E->getIdentType()) { 1477 default: 1478 return EmitUnsupportedLValue(E, "predefined expression"); 1479 1480 case PredefinedExpr::Func: 1481 case PredefinedExpr::Function: 1482 case PredefinedExpr::PrettyFunction: { 1483 unsigned Type = E->getIdentType(); 1484 std::string GlobalVarName; 1485 1486 switch (Type) { 1487 default: llvm_unreachable("Invalid type"); 1488 case PredefinedExpr::Func: 1489 GlobalVarName = "__func__."; 1490 break; 1491 case PredefinedExpr::Function: 1492 GlobalVarName = "__FUNCTION__."; 1493 break; 1494 case PredefinedExpr::PrettyFunction: 1495 GlobalVarName = "__PRETTY_FUNCTION__."; 1496 break; 1497 } 1498 1499 StringRef FnName = CurFn->getName(); 1500 if (FnName.startswith("\01")) 1501 FnName = FnName.substr(1); 1502 GlobalVarName += FnName; 1503 1504 const Decl *CurDecl = CurCodeDecl; 1505 if (CurDecl == 0) 1506 CurDecl = getContext().getTranslationUnitDecl(); 1507 1508 std::string FunctionName = 1509 (isa<BlockDecl>(CurDecl) 1510 ? FnName.str() 1511 : PredefinedExpr::ComputeName((PredefinedExpr::IdentType)Type, CurDecl)); 1512 1513 llvm::Constant *C = 1514 CGM.GetAddrOfConstantCString(FunctionName, GlobalVarName.c_str()); 1515 return MakeAddrLValue(C, E->getType()); 1516 } 1517 } 1518} 1519 1520llvm::BasicBlock *CodeGenFunction::getTrapBB() { 1521 const CodeGenOptions &GCO = CGM.getCodeGenOpts(); 1522 1523 // If we are not optimzing, don't collapse all calls to trap in the function 1524 // to the same call, that way, in the debugger they can see which operation 1525 // did in fact fail. If we are optimizing, we collapse all calls to trap down 1526 // to just one per function to save on codesize. 1527 if (GCO.OptimizationLevel && TrapBB) 1528 return TrapBB; 1529 1530 llvm::BasicBlock *Cont = 0; 1531 if (HaveInsertPoint()) { 1532 Cont = createBasicBlock("cont"); 1533 EmitBranch(Cont); 1534 } 1535 TrapBB = createBasicBlock("trap"); 1536 EmitBlock(TrapBB); 1537 1538 llvm::Value *F = CGM.getIntrinsic(llvm::Intrinsic::trap); 1539 llvm::CallInst *TrapCall = Builder.CreateCall(F); 1540 TrapCall->setDoesNotReturn(); 1541 TrapCall->setDoesNotThrow(); 1542 Builder.CreateUnreachable(); 1543 1544 if (Cont) 1545 EmitBlock(Cont); 1546 return TrapBB; 1547} 1548 1549/// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an 1550/// array to pointer, return the array subexpression. 1551static const Expr *isSimpleArrayDecayOperand(const Expr *E) { 1552 // If this isn't just an array->pointer decay, bail out. 1553 const CastExpr *CE = dyn_cast<CastExpr>(E); 1554 if (CE == 0 || CE->getCastKind() != CK_ArrayToPointerDecay) 1555 return 0; 1556 1557 // If this is a decay from variable width array, bail out. 1558 const Expr *SubExpr = CE->getSubExpr(); 1559 if (SubExpr->getType()->isVariableArrayType()) 1560 return 0; 1561 1562 return SubExpr; 1563} 1564 1565LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E) { 1566 // The index must always be an integer, which is not an aggregate. Emit it. 1567 llvm::Value *Idx = EmitScalarExpr(E->getIdx()); 1568 QualType IdxTy = E->getIdx()->getType(); 1569 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType(); 1570 1571 // If the base is a vector type, then we are forming a vector element lvalue 1572 // with this subscript. 1573 if (E->getBase()->getType()->isVectorType()) { 1574 // Emit the vector as an lvalue to get its address. 1575 LValue LHS = EmitLValue(E->getBase()); 1576 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!"); 1577 Idx = Builder.CreateIntCast(Idx, Int32Ty, IdxSigned, "vidx"); 1578 return LValue::MakeVectorElt(LHS.getAddress(), Idx, 1579 E->getBase()->getType()); 1580 } 1581 1582 // Extend or truncate the index type to 32 or 64-bits. 1583 if (Idx->getType() != IntPtrTy) 1584 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom"); 1585 1586 // FIXME: As llvm implements the object size checking, this can come out. 1587 if (CatchUndefined) { 1588 if (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E->getBase())){ 1589 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ICE->getSubExpr())) { 1590 if (ICE->getCastKind() == CK_ArrayToPointerDecay) { 1591 if (const ConstantArrayType *CAT 1592 = getContext().getAsConstantArrayType(DRE->getType())) { 1593 llvm::APInt Size = CAT->getSize(); 1594 llvm::BasicBlock *Cont = createBasicBlock("cont"); 1595 Builder.CreateCondBr(Builder.CreateICmpULE(Idx, 1596 llvm::ConstantInt::get(Idx->getType(), Size)), 1597 Cont, getTrapBB()); 1598 EmitBlock(Cont); 1599 } 1600 } 1601 } 1602 } 1603 } 1604 1605 // We know that the pointer points to a type of the correct size, unless the 1606 // size is a VLA or Objective-C interface. 1607 llvm::Value *Address = 0; 1608 unsigned ArrayAlignment = 0; 1609 if (const VariableArrayType *vla = 1610 getContext().getAsVariableArrayType(E->getType())) { 1611 // The base must be a pointer, which is not an aggregate. Emit 1612 // it. It needs to be emitted first in case it's what captures 1613 // the VLA bounds. 1614 Address = EmitScalarExpr(E->getBase()); 1615 1616 // The element count here is the total number of non-VLA elements. 1617 llvm::Value *numElements = getVLASize(vla).first; 1618 1619 // Effectively, the multiply by the VLA size is part of the GEP. 1620 // GEP indexes are signed, and scaling an index isn't permitted to 1621 // signed-overflow, so we use the same semantics for our explicit 1622 // multiply. We suppress this if overflow is not undefined behavior. 1623 if (getLangOptions().isSignedOverflowDefined()) { 1624 Idx = Builder.CreateMul(Idx, numElements); 1625 Address = Builder.CreateGEP(Address, Idx, "arrayidx"); 1626 } else { 1627 Idx = Builder.CreateNSWMul(Idx, numElements); 1628 Address = Builder.CreateInBoundsGEP(Address, Idx, "arrayidx"); 1629 } 1630 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){ 1631 // Indexing over an interface, as in "NSString *P; P[4];" 1632 llvm::Value *InterfaceSize = 1633 llvm::ConstantInt::get(Idx->getType(), 1634 getContext().getTypeSizeInChars(OIT).getQuantity()); 1635 1636 Idx = Builder.CreateMul(Idx, InterfaceSize); 1637 1638 // The base must be a pointer, which is not an aggregate. Emit it. 1639 llvm::Value *Base = EmitScalarExpr(E->getBase()); 1640 Address = EmitCastToVoidPtr(Base); 1641 Address = Builder.CreateGEP(Address, Idx, "arrayidx"); 1642 Address = Builder.CreateBitCast(Address, Base->getType()); 1643 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) { 1644 // If this is A[i] where A is an array, the frontend will have decayed the 1645 // base to be a ArrayToPointerDecay implicit cast. While correct, it is 1646 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a 1647 // "gep x, i" here. Emit one "gep A, 0, i". 1648 assert(Array->getType()->isArrayType() && 1649 "Array to pointer decay must have array source type!"); 1650 LValue ArrayLV = EmitLValue(Array); 1651 llvm::Value *ArrayPtr = ArrayLV.getAddress(); 1652 llvm::Value *Zero = llvm::ConstantInt::get(Int32Ty, 0); 1653 llvm::Value *Args[] = { Zero, Idx }; 1654 1655 // Propagate the alignment from the array itself to the result. 1656 ArrayAlignment = ArrayLV.getAlignment(); 1657 1658 if (getContext().getLangOptions().isSignedOverflowDefined()) 1659 Address = Builder.CreateGEP(ArrayPtr, Args, "arrayidx"); 1660 else 1661 Address = Builder.CreateInBoundsGEP(ArrayPtr, Args, "arrayidx"); 1662 } else { 1663 // The base must be a pointer, which is not an aggregate. Emit it. 1664 llvm::Value *Base = EmitScalarExpr(E->getBase()); 1665 if (getContext().getLangOptions().isSignedOverflowDefined()) 1666 Address = Builder.CreateGEP(Base, Idx, "arrayidx"); 1667 else 1668 Address = Builder.CreateInBoundsGEP(Base, Idx, "arrayidx"); 1669 } 1670 1671 QualType T = E->getBase()->getType()->getPointeeType(); 1672 assert(!T.isNull() && 1673 "CodeGenFunction::EmitArraySubscriptExpr(): Illegal base type"); 1674 1675 // Limit the alignment to that of the result type. 1676 if (ArrayAlignment) { 1677 unsigned Align = getContext().getTypeAlignInChars(T).getQuantity(); 1678 ArrayAlignment = std::min(Align, ArrayAlignment); 1679 } 1680 1681 LValue LV = MakeAddrLValue(Address, T, ArrayAlignment); 1682 LV.getQuals().setAddressSpace(E->getBase()->getType().getAddressSpace()); 1683 1684 if (getContext().getLangOptions().ObjC1 && 1685 getContext().getLangOptions().getGC() != LangOptions::NonGC) { 1686 LV.setNonGC(!E->isOBJCGCCandidate(getContext())); 1687 setObjCGCLValueClass(getContext(), E, LV); 1688 } 1689 return LV; 1690} 1691 1692static 1693llvm::Constant *GenerateConstantVector(llvm::LLVMContext &VMContext, 1694 SmallVector<unsigned, 4> &Elts) { 1695 SmallVector<llvm::Constant*, 4> CElts; 1696 1697 llvm::Type *Int32Ty = llvm::Type::getInt32Ty(VMContext); 1698 for (unsigned i = 0, e = Elts.size(); i != e; ++i) 1699 CElts.push_back(llvm::ConstantInt::get(Int32Ty, Elts[i])); 1700 1701 return llvm::ConstantVector::get(CElts); 1702} 1703 1704LValue CodeGenFunction:: 1705EmitExtVectorElementExpr(const ExtVectorElementExpr *E) { 1706 // Emit the base vector as an l-value. 1707 LValue Base; 1708 1709 // ExtVectorElementExpr's base can either be a vector or pointer to vector. 1710 if (E->isArrow()) { 1711 // If it is a pointer to a vector, emit the address and form an lvalue with 1712 // it. 1713 llvm::Value *Ptr = EmitScalarExpr(E->getBase()); 1714 const PointerType *PT = E->getBase()->getType()->getAs<PointerType>(); 1715 Base = MakeAddrLValue(Ptr, PT->getPointeeType()); 1716 Base.getQuals().removeObjCGCAttr(); 1717 } else if (E->getBase()->isGLValue()) { 1718 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x), 1719 // emit the base as an lvalue. 1720 assert(E->getBase()->getType()->isVectorType()); 1721 Base = EmitLValue(E->getBase()); 1722 } else { 1723 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such. 1724 assert(E->getBase()->getType()->isVectorType() && 1725 "Result must be a vector"); 1726 llvm::Value *Vec = EmitScalarExpr(E->getBase()); 1727 1728 // Store the vector to memory (because LValue wants an address). 1729 llvm::Value *VecMem = CreateMemTemp(E->getBase()->getType()); 1730 Builder.CreateStore(Vec, VecMem); 1731 Base = MakeAddrLValue(VecMem, E->getBase()->getType()); 1732 } 1733 1734 QualType type = 1735 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers()); 1736 1737 // Encode the element access list into a vector of unsigned indices. 1738 SmallVector<unsigned, 4> Indices; 1739 E->getEncodedElementAccess(Indices); 1740 1741 if (Base.isSimple()) { 1742 llvm::Constant *CV = GenerateConstantVector(getLLVMContext(), Indices); 1743 return LValue::MakeExtVectorElt(Base.getAddress(), CV, type); 1744 } 1745 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!"); 1746 1747 llvm::Constant *BaseElts = Base.getExtVectorElts(); 1748 SmallVector<llvm::Constant *, 4> CElts; 1749 1750 for (unsigned i = 0, e = Indices.size(); i != e; ++i) { 1751 if (isa<llvm::ConstantAggregateZero>(BaseElts)) 1752 CElts.push_back(llvm::ConstantInt::get(Int32Ty, 0)); 1753 else 1754 CElts.push_back(cast<llvm::Constant>(BaseElts->getOperand(Indices[i]))); 1755 } 1756 llvm::Constant *CV = llvm::ConstantVector::get(CElts); 1757 return LValue::MakeExtVectorElt(Base.getExtVectorAddr(), CV, type); 1758} 1759 1760LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) { 1761 bool isNonGC = false; 1762 Expr *BaseExpr = E->getBase(); 1763 llvm::Value *BaseValue = NULL; 1764 Qualifiers BaseQuals; 1765 1766 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. 1767 if (E->isArrow()) { 1768 BaseValue = EmitScalarExpr(BaseExpr); 1769 const PointerType *PTy = 1770 BaseExpr->getType()->getAs<PointerType>(); 1771 BaseQuals = PTy->getPointeeType().getQualifiers(); 1772 } else { 1773 LValue BaseLV = EmitLValue(BaseExpr); 1774 if (BaseLV.isNonGC()) 1775 isNonGC = true; 1776 // FIXME: this isn't right for bitfields. 1777 BaseValue = BaseLV.getAddress(); 1778 QualType BaseTy = BaseExpr->getType(); 1779 BaseQuals = BaseTy.getQualifiers(); 1780 } 1781 1782 NamedDecl *ND = E->getMemberDecl(); 1783 if (FieldDecl *Field = dyn_cast<FieldDecl>(ND)) { 1784 LValue LV = EmitLValueForField(BaseValue, Field, 1785 BaseQuals.getCVRQualifiers()); 1786 LV.setNonGC(isNonGC); 1787 setObjCGCLValueClass(getContext(), E, LV); 1788 return LV; 1789 } 1790 1791 if (VarDecl *VD = dyn_cast<VarDecl>(ND)) 1792 return EmitGlobalVarDeclLValue(*this, E, VD); 1793 1794 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) 1795 return EmitFunctionDeclLValue(*this, E, FD); 1796 1797 llvm_unreachable("Unhandled member declaration!"); 1798} 1799 1800LValue CodeGenFunction::EmitLValueForBitfield(llvm::Value *BaseValue, 1801 const FieldDecl *Field, 1802 unsigned CVRQualifiers) { 1803 const CGRecordLayout &RL = 1804 CGM.getTypes().getCGRecordLayout(Field->getParent()); 1805 const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field); 1806 return LValue::MakeBitfield(BaseValue, Info, 1807 Field->getType().withCVRQualifiers(CVRQualifiers)); 1808} 1809 1810/// EmitLValueForAnonRecordField - Given that the field is a member of 1811/// an anonymous struct or union buried inside a record, and given 1812/// that the base value is a pointer to the enclosing record, derive 1813/// an lvalue for the ultimate field. 1814LValue CodeGenFunction::EmitLValueForAnonRecordField(llvm::Value *BaseValue, 1815 const IndirectFieldDecl *Field, 1816 unsigned CVRQualifiers) { 1817 IndirectFieldDecl::chain_iterator I = Field->chain_begin(), 1818 IEnd = Field->chain_end(); 1819 while (true) { 1820 LValue LV = EmitLValueForField(BaseValue, cast<FieldDecl>(*I), 1821 CVRQualifiers); 1822 if (++I == IEnd) return LV; 1823 1824 assert(LV.isSimple()); 1825 BaseValue = LV.getAddress(); 1826 CVRQualifiers |= LV.getVRQualifiers(); 1827 } 1828} 1829 1830LValue CodeGenFunction::EmitLValueForField(llvm::Value *baseAddr, 1831 const FieldDecl *field, 1832 unsigned cvr) { 1833 if (field->isBitField()) 1834 return EmitLValueForBitfield(baseAddr, field, cvr); 1835 1836 const RecordDecl *rec = field->getParent(); 1837 QualType type = field->getType(); 1838 1839 bool mayAlias = rec->hasAttr<MayAliasAttr>(); 1840 1841 llvm::Value *addr = baseAddr; 1842 if (rec->isUnion()) { 1843 // For unions, there is no pointer adjustment. 1844 assert(!type->isReferenceType() && "union has reference member"); 1845 } else { 1846 // For structs, we GEP to the field that the record layout suggests. 1847 unsigned idx = CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field); 1848 addr = Builder.CreateStructGEP(addr, idx, field->getName()); 1849 1850 // If this is a reference field, load the reference right now. 1851 if (const ReferenceType *refType = type->getAs<ReferenceType>()) { 1852 llvm::LoadInst *load = Builder.CreateLoad(addr, "ref"); 1853 if (cvr & Qualifiers::Volatile) load->setVolatile(true); 1854 1855 if (CGM.shouldUseTBAA()) { 1856 llvm::MDNode *tbaa; 1857 if (mayAlias) 1858 tbaa = CGM.getTBAAInfo(getContext().CharTy); 1859 else 1860 tbaa = CGM.getTBAAInfo(type); 1861 CGM.DecorateInstruction(load, tbaa); 1862 } 1863 1864 addr = load; 1865 mayAlias = false; 1866 type = refType->getPointeeType(); 1867 cvr = 0; // qualifiers don't recursively apply to referencee 1868 } 1869 } 1870 1871 // Make sure that the address is pointing to the right type. This is critical 1872 // for both unions and structs. A union needs a bitcast, a struct element 1873 // will need a bitcast if the LLVM type laid out doesn't match the desired 1874 // type. 1875 addr = EmitBitCastOfLValueToProperType(*this, addr, 1876 CGM.getTypes().ConvertTypeForMem(type), 1877 field->getName()); 1878 1879 if (field->hasAttr<AnnotateAttr>()) 1880 addr = EmitFieldAnnotations(field, addr); 1881 1882 unsigned alignment = getContext().getDeclAlign(field).getQuantity(); 1883 LValue LV = MakeAddrLValue(addr, type, alignment); 1884 LV.getQuals().addCVRQualifiers(cvr); 1885 1886 // __weak attribute on a field is ignored. 1887 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak) 1888 LV.getQuals().removeObjCGCAttr(); 1889 1890 // Fields of may_alias structs act like 'char' for TBAA purposes. 1891 // FIXME: this should get propagated down through anonymous structs 1892 // and unions. 1893 if (mayAlias && LV.getTBAAInfo()) 1894 LV.setTBAAInfo(CGM.getTBAAInfo(getContext().CharTy)); 1895 1896 return LV; 1897} 1898 1899LValue 1900CodeGenFunction::EmitLValueForFieldInitialization(llvm::Value *BaseValue, 1901 const FieldDecl *Field, 1902 unsigned CVRQualifiers) { 1903 QualType FieldType = Field->getType(); 1904 1905 if (!FieldType->isReferenceType()) 1906 return EmitLValueForField(BaseValue, Field, CVRQualifiers); 1907 1908 const CGRecordLayout &RL = 1909 CGM.getTypes().getCGRecordLayout(Field->getParent()); 1910 unsigned idx = RL.getLLVMFieldNo(Field); 1911 llvm::Value *V = Builder.CreateStructGEP(BaseValue, idx); 1912 assert(!FieldType.getObjCGCAttr() && "fields cannot have GC attrs"); 1913 1914 1915 // Make sure that the address is pointing to the right type. This is critical 1916 // for both unions and structs. A union needs a bitcast, a struct element 1917 // will need a bitcast if the LLVM type laid out doesn't match the desired 1918 // type. 1919 llvm::Type *llvmType = ConvertTypeForMem(FieldType); 1920 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace(); 1921 V = Builder.CreateBitCast(V, llvmType->getPointerTo(AS)); 1922 1923 unsigned Alignment = getContext().getDeclAlign(Field).getQuantity(); 1924 return MakeAddrLValue(V, FieldType, Alignment); 1925} 1926 1927LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){ 1928 llvm::Value *DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral"); 1929 const Expr *InitExpr = E->getInitializer(); 1930 LValue Result = MakeAddrLValue(DeclPtr, E->getType()); 1931 1932 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(), 1933 /*Init*/ true); 1934 1935 return Result; 1936} 1937 1938LValue CodeGenFunction:: 1939EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) { 1940 if (!expr->isGLValue()) { 1941 // ?: here should be an aggregate. 1942 assert((hasAggregateLLVMType(expr->getType()) && 1943 !expr->getType()->isAnyComplexType()) && 1944 "Unexpected conditional operator!"); 1945 return EmitAggExprToLValue(expr); 1946 } 1947 1948 const Expr *condExpr = expr->getCond(); 1949 bool CondExprBool; 1950 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 1951 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr(); 1952 if (!CondExprBool) std::swap(live, dead); 1953 1954 if (!ContainsLabel(dead)) 1955 return EmitLValue(live); 1956 } 1957 1958 OpaqueValueMapping binding(*this, expr); 1959 1960 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true"); 1961 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false"); 1962 llvm::BasicBlock *contBlock = createBasicBlock("cond.end"); 1963 1964 ConditionalEvaluation eval(*this); 1965 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock); 1966 1967 // Any temporaries created here are conditional. 1968 EmitBlock(lhsBlock); 1969 eval.begin(*this); 1970 LValue lhs = EmitLValue(expr->getTrueExpr()); 1971 eval.end(*this); 1972 1973 if (!lhs.isSimple()) 1974 return EmitUnsupportedLValue(expr, "conditional operator"); 1975 1976 lhsBlock = Builder.GetInsertBlock(); 1977 Builder.CreateBr(contBlock); 1978 1979 // Any temporaries created here are conditional. 1980 EmitBlock(rhsBlock); 1981 eval.begin(*this); 1982 LValue rhs = EmitLValue(expr->getFalseExpr()); 1983 eval.end(*this); 1984 if (!rhs.isSimple()) 1985 return EmitUnsupportedLValue(expr, "conditional operator"); 1986 rhsBlock = Builder.GetInsertBlock(); 1987 1988 EmitBlock(contBlock); 1989 1990 llvm::PHINode *phi = Builder.CreatePHI(lhs.getAddress()->getType(), 2, 1991 "cond-lvalue"); 1992 phi->addIncoming(lhs.getAddress(), lhsBlock); 1993 phi->addIncoming(rhs.getAddress(), rhsBlock); 1994 return MakeAddrLValue(phi, expr->getType()); 1995} 1996 1997/// EmitCastLValue - Casts are never lvalues unless that cast is a dynamic_cast. 1998/// If the cast is a dynamic_cast, we can have the usual lvalue result, 1999/// otherwise if a cast is needed by the code generator in an lvalue context, 2000/// then it must mean that we need the address of an aggregate in order to 2001/// access one of its fields. This can happen for all the reasons that casts 2002/// are permitted with aggregate result, including noop aggregate casts, and 2003/// cast from scalar to union. 2004LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) { 2005 switch (E->getCastKind()) { 2006 case CK_ToVoid: 2007 return EmitUnsupportedLValue(E, "unexpected cast lvalue"); 2008 2009 case CK_Dependent: 2010 llvm_unreachable("dependent cast kind in IR gen!"); 2011 2012 case CK_GetObjCProperty: { 2013 LValue LV = EmitLValue(E->getSubExpr()); 2014 assert(LV.isPropertyRef()); 2015 RValue RV = EmitLoadOfPropertyRefLValue(LV); 2016 2017 // Property is an aggregate r-value. 2018 if (RV.isAggregate()) { 2019 return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); 2020 } 2021 2022 // Implicit property returns an l-value. 2023 assert(RV.isScalar()); 2024 return MakeAddrLValue(RV.getScalarVal(), E->getSubExpr()->getType()); 2025 } 2026 2027 case CK_NoOp: 2028 case CK_LValueToRValue: 2029 if (!E->getSubExpr()->Classify(getContext()).isPRValue() 2030 || E->getType()->isRecordType()) 2031 return EmitLValue(E->getSubExpr()); 2032 // Fall through to synthesize a temporary. 2033 2034 case CK_BitCast: 2035 case CK_ArrayToPointerDecay: 2036 case CK_FunctionToPointerDecay: 2037 case CK_NullToMemberPointer: 2038 case CK_NullToPointer: 2039 case CK_IntegralToPointer: 2040 case CK_PointerToIntegral: 2041 case CK_PointerToBoolean: 2042 case CK_VectorSplat: 2043 case CK_IntegralCast: 2044 case CK_IntegralToBoolean: 2045 case CK_IntegralToFloating: 2046 case CK_FloatingToIntegral: 2047 case CK_FloatingToBoolean: 2048 case CK_FloatingCast: 2049 case CK_FloatingRealToComplex: 2050 case CK_FloatingComplexToReal: 2051 case CK_FloatingComplexToBoolean: 2052 case CK_FloatingComplexCast: 2053 case CK_FloatingComplexToIntegralComplex: 2054 case CK_IntegralRealToComplex: 2055 case CK_IntegralComplexToReal: 2056 case CK_IntegralComplexToBoolean: 2057 case CK_IntegralComplexCast: 2058 case CK_IntegralComplexToFloatingComplex: 2059 case CK_DerivedToBaseMemberPointer: 2060 case CK_BaseToDerivedMemberPointer: 2061 case CK_MemberPointerToBoolean: 2062 case CK_AnyPointerToBlockPointerCast: 2063 case CK_ARCProduceObject: 2064 case CK_ARCConsumeObject: 2065 case CK_ARCReclaimReturnedObject: 2066 case CK_ARCExtendBlockObject: { 2067 // These casts only produce lvalues when we're binding a reference to a 2068 // temporary realized from a (converted) pure rvalue. Emit the expression 2069 // as a value, copy it into a temporary, and return an lvalue referring to 2070 // that temporary. 2071 llvm::Value *V = CreateMemTemp(E->getType(), "ref.temp"); 2072 EmitAnyExprToMem(E, V, E->getType().getQualifiers(), false); 2073 return MakeAddrLValue(V, E->getType()); 2074 } 2075 2076 case CK_Dynamic: { 2077 LValue LV = EmitLValue(E->getSubExpr()); 2078 llvm::Value *V = LV.getAddress(); 2079 const CXXDynamicCastExpr *DCE = cast<CXXDynamicCastExpr>(E); 2080 return MakeAddrLValue(EmitDynamicCast(V, DCE), E->getType()); 2081 } 2082 2083 case CK_ConstructorConversion: 2084 case CK_UserDefinedConversion: 2085 case CK_CPointerToObjCPointerCast: 2086 case CK_BlockPointerToObjCPointerCast: 2087 return EmitLValue(E->getSubExpr()); 2088 2089 case CK_UncheckedDerivedToBase: 2090 case CK_DerivedToBase: { 2091 const RecordType *DerivedClassTy = 2092 E->getSubExpr()->getType()->getAs<RecordType>(); 2093 CXXRecordDecl *DerivedClassDecl = 2094 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 2095 2096 LValue LV = EmitLValue(E->getSubExpr()); 2097 llvm::Value *This = LV.getAddress(); 2098 2099 // Perform the derived-to-base conversion 2100 llvm::Value *Base = 2101 GetAddressOfBaseClass(This, DerivedClassDecl, 2102 E->path_begin(), E->path_end(), 2103 /*NullCheckValue=*/false); 2104 2105 return MakeAddrLValue(Base, E->getType()); 2106 } 2107 case CK_ToUnion: 2108 return EmitAggExprToLValue(E); 2109 case CK_BaseToDerived: { 2110 const RecordType *DerivedClassTy = E->getType()->getAs<RecordType>(); 2111 CXXRecordDecl *DerivedClassDecl = 2112 cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 2113 2114 LValue LV = EmitLValue(E->getSubExpr()); 2115 2116 // Perform the base-to-derived conversion 2117 llvm::Value *Derived = 2118 GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl, 2119 E->path_begin(), E->path_end(), 2120 /*NullCheckValue=*/false); 2121 2122 return MakeAddrLValue(Derived, E->getType()); 2123 } 2124 case CK_LValueBitCast: { 2125 // This must be a reinterpret_cast (or c-style equivalent). 2126 const ExplicitCastExpr *CE = cast<ExplicitCastExpr>(E); 2127 2128 LValue LV = EmitLValue(E->getSubExpr()); 2129 llvm::Value *V = Builder.CreateBitCast(LV.getAddress(), 2130 ConvertType(CE->getTypeAsWritten())); 2131 return MakeAddrLValue(V, E->getType()); 2132 } 2133 case CK_ObjCObjectLValueCast: { 2134 LValue LV = EmitLValue(E->getSubExpr()); 2135 QualType ToType = getContext().getLValueReferenceType(E->getType()); 2136 llvm::Value *V = Builder.CreateBitCast(LV.getAddress(), 2137 ConvertType(ToType)); 2138 return MakeAddrLValue(V, E->getType()); 2139 } 2140 } 2141 2142 llvm_unreachable("Unhandled lvalue cast kind?"); 2143} 2144 2145LValue CodeGenFunction::EmitNullInitializationLValue( 2146 const CXXScalarValueInitExpr *E) { 2147 QualType Ty = E->getType(); 2148 LValue LV = MakeAddrLValue(CreateMemTemp(Ty), Ty); 2149 EmitNullInitialization(LV.getAddress(), Ty); 2150 return LV; 2151} 2152 2153LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) { 2154 assert(e->isGLValue() || e->getType()->isRecordType()); 2155 return getOpaqueLValueMapping(e); 2156} 2157 2158LValue CodeGenFunction::EmitMaterializeTemporaryExpr( 2159 const MaterializeTemporaryExpr *E) { 2160 RValue RV = EmitReferenceBindingToExpr(E, /*InitializedDecl=*/0); 2161 return MakeAddrLValue(RV.getScalarVal(), E->getType()); 2162} 2163 2164 2165//===--------------------------------------------------------------------===// 2166// Expression Emission 2167//===--------------------------------------------------------------------===// 2168 2169RValue CodeGenFunction::EmitCallExpr(const CallExpr *E, 2170 ReturnValueSlot ReturnValue) { 2171 if (CGDebugInfo *DI = getDebugInfo()) { 2172 DI->setLocation(E->getLocStart()); 2173 DI->EmitStopPoint(Builder); 2174 } 2175 2176 // Builtins never have block type. 2177 if (E->getCallee()->getType()->isBlockPointerType()) 2178 return EmitBlockCallExpr(E, ReturnValue); 2179 2180 if (const CXXMemberCallExpr *CE = dyn_cast<CXXMemberCallExpr>(E)) 2181 return EmitCXXMemberCallExpr(CE, ReturnValue); 2182 2183 const Decl *TargetDecl = E->getCalleeDecl(); 2184 if (const FunctionDecl *FD = dyn_cast_or_null<FunctionDecl>(TargetDecl)) { 2185 if (unsigned builtinID = FD->getBuiltinID()) 2186 return EmitBuiltinExpr(FD, builtinID, E); 2187 } 2188 2189 if (const CXXOperatorCallExpr *CE = dyn_cast<CXXOperatorCallExpr>(E)) 2190 if (const CXXMethodDecl *MD = dyn_cast_or_null<CXXMethodDecl>(TargetDecl)) 2191 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue); 2192 2193 if (const CXXPseudoDestructorExpr *PseudoDtor 2194 = dyn_cast<CXXPseudoDestructorExpr>(E->getCallee()->IgnoreParens())) { 2195 QualType DestroyedType = PseudoDtor->getDestroyedType(); 2196 if (getContext().getLangOptions().ObjCAutoRefCount && 2197 DestroyedType->isObjCLifetimeType() && 2198 (DestroyedType.getObjCLifetime() == Qualifiers::OCL_Strong || 2199 DestroyedType.getObjCLifetime() == Qualifiers::OCL_Weak)) { 2200 // Automatic Reference Counting: 2201 // If the pseudo-expression names a retainable object with weak or 2202 // strong lifetime, the object shall be released. 2203 Expr *BaseExpr = PseudoDtor->getBase(); 2204 llvm::Value *BaseValue = NULL; 2205 Qualifiers BaseQuals; 2206 2207 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. 2208 if (PseudoDtor->isArrow()) { 2209 BaseValue = EmitScalarExpr(BaseExpr); 2210 const PointerType *PTy = BaseExpr->getType()->getAs<PointerType>(); 2211 BaseQuals = PTy->getPointeeType().getQualifiers(); 2212 } else { 2213 LValue BaseLV = EmitLValue(BaseExpr); 2214 BaseValue = BaseLV.getAddress(); 2215 QualType BaseTy = BaseExpr->getType(); 2216 BaseQuals = BaseTy.getQualifiers(); 2217 } 2218 2219 switch (PseudoDtor->getDestroyedType().getObjCLifetime()) { 2220 case Qualifiers::OCL_None: 2221 case Qualifiers::OCL_ExplicitNone: 2222 case Qualifiers::OCL_Autoreleasing: 2223 break; 2224 2225 case Qualifiers::OCL_Strong: 2226 EmitARCRelease(Builder.CreateLoad(BaseValue, 2227 PseudoDtor->getDestroyedType().isVolatileQualified()), 2228 /*precise*/ true); 2229 break; 2230 2231 case Qualifiers::OCL_Weak: 2232 EmitARCDestroyWeak(BaseValue); 2233 break; 2234 } 2235 } else { 2236 // C++ [expr.pseudo]p1: 2237 // The result shall only be used as the operand for the function call 2238 // operator (), and the result of such a call has type void. The only 2239 // effect is the evaluation of the postfix-expression before the dot or 2240 // arrow. 2241 EmitScalarExpr(E->getCallee()); 2242 } 2243 2244 return RValue::get(0); 2245 } 2246 2247 llvm::Value *Callee = EmitScalarExpr(E->getCallee()); 2248 return EmitCall(E->getCallee()->getType(), Callee, ReturnValue, 2249 E->arg_begin(), E->arg_end(), TargetDecl); 2250} 2251 2252LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) { 2253 // Comma expressions just emit their LHS then their RHS as an l-value. 2254 if (E->getOpcode() == BO_Comma) { 2255 EmitIgnoredExpr(E->getLHS()); 2256 EnsureInsertPoint(); 2257 return EmitLValue(E->getRHS()); 2258 } 2259 2260 if (E->getOpcode() == BO_PtrMemD || 2261 E->getOpcode() == BO_PtrMemI) 2262 return EmitPointerToDataMemberBinaryExpr(E); 2263 2264 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value"); 2265 2266 // Note that in all of these cases, __block variables need the RHS 2267 // evaluated first just in case the variable gets moved by the RHS. 2268 2269 if (!hasAggregateLLVMType(E->getType())) { 2270 switch (E->getLHS()->getType().getObjCLifetime()) { 2271 case Qualifiers::OCL_Strong: 2272 return EmitARCStoreStrong(E, /*ignored*/ false).first; 2273 2274 case Qualifiers::OCL_Autoreleasing: 2275 return EmitARCStoreAutoreleasing(E).first; 2276 2277 // No reason to do any of these differently. 2278 case Qualifiers::OCL_None: 2279 case Qualifiers::OCL_ExplicitNone: 2280 case Qualifiers::OCL_Weak: 2281 break; 2282 } 2283 2284 RValue RV = EmitAnyExpr(E->getRHS()); 2285 LValue LV = EmitLValue(E->getLHS()); 2286 EmitStoreThroughLValue(RV, LV); 2287 return LV; 2288 } 2289 2290 if (E->getType()->isAnyComplexType()) 2291 return EmitComplexAssignmentLValue(E); 2292 2293 return EmitAggExprToLValue(E); 2294} 2295 2296LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) { 2297 RValue RV = EmitCallExpr(E); 2298 2299 if (!RV.isScalar()) 2300 return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); 2301 2302 assert(E->getCallReturnType()->isReferenceType() && 2303 "Can't have a scalar return unless the return type is a " 2304 "reference type!"); 2305 2306 return MakeAddrLValue(RV.getScalarVal(), E->getType()); 2307} 2308 2309LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) { 2310 // FIXME: This shouldn't require another copy. 2311 return EmitAggExprToLValue(E); 2312} 2313 2314LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) { 2315 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor() 2316 && "binding l-value to type which needs a temporary"); 2317 AggValueSlot Slot = CreateAggTemp(E->getType()); 2318 EmitCXXConstructExpr(E, Slot); 2319 return MakeAddrLValue(Slot.getAddr(), E->getType()); 2320} 2321 2322LValue 2323CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) { 2324 return MakeAddrLValue(EmitCXXTypeidExpr(E), E->getType()); 2325} 2326 2327LValue 2328CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) { 2329 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue"); 2330 Slot.setExternallyDestructed(); 2331 EmitAggExpr(E->getSubExpr(), Slot); 2332 EmitCXXTemporary(E->getTemporary(), Slot.getAddr()); 2333 return MakeAddrLValue(Slot.getAddr(), E->getType()); 2334} 2335 2336LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) { 2337 RValue RV = EmitObjCMessageExpr(E); 2338 2339 if (!RV.isScalar()) 2340 return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); 2341 2342 assert(E->getMethodDecl()->getResultType()->isReferenceType() && 2343 "Can't have a scalar return unless the return type is a " 2344 "reference type!"); 2345 2346 return MakeAddrLValue(RV.getScalarVal(), E->getType()); 2347} 2348 2349LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) { 2350 llvm::Value *V = 2351 CGM.getObjCRuntime().GetSelector(Builder, E->getSelector(), true); 2352 return MakeAddrLValue(V, E->getType()); 2353} 2354 2355llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface, 2356 const ObjCIvarDecl *Ivar) { 2357 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar); 2358} 2359 2360LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy, 2361 llvm::Value *BaseValue, 2362 const ObjCIvarDecl *Ivar, 2363 unsigned CVRQualifiers) { 2364 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue, 2365 Ivar, CVRQualifiers); 2366} 2367 2368LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) { 2369 // FIXME: A lot of the code below could be shared with EmitMemberExpr. 2370 llvm::Value *BaseValue = 0; 2371 const Expr *BaseExpr = E->getBase(); 2372 Qualifiers BaseQuals; 2373 QualType ObjectTy; 2374 if (E->isArrow()) { 2375 BaseValue = EmitScalarExpr(BaseExpr); 2376 ObjectTy = BaseExpr->getType()->getPointeeType(); 2377 BaseQuals = ObjectTy.getQualifiers(); 2378 } else { 2379 LValue BaseLV = EmitLValue(BaseExpr); 2380 // FIXME: this isn't right for bitfields. 2381 BaseValue = BaseLV.getAddress(); 2382 ObjectTy = BaseExpr->getType(); 2383 BaseQuals = ObjectTy.getQualifiers(); 2384 } 2385 2386 LValue LV = 2387 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(), 2388 BaseQuals.getCVRQualifiers()); 2389 setObjCGCLValueClass(getContext(), E, LV); 2390 return LV; 2391} 2392 2393LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) { 2394 // Can only get l-value for message expression returning aggregate type 2395 RValue RV = EmitAnyExprToTemp(E); 2396 return MakeAddrLValue(RV.getAggregateAddr(), E->getType()); 2397} 2398 2399RValue CodeGenFunction::EmitCall(QualType CalleeType, llvm::Value *Callee, 2400 ReturnValueSlot ReturnValue, 2401 CallExpr::const_arg_iterator ArgBeg, 2402 CallExpr::const_arg_iterator ArgEnd, 2403 const Decl *TargetDecl) { 2404 // Get the actual function type. The callee type will always be a pointer to 2405 // function type or a block pointer type. 2406 assert(CalleeType->isFunctionPointerType() && 2407 "Call must have function pointer type!"); 2408 2409 CalleeType = getContext().getCanonicalType(CalleeType); 2410 2411 const FunctionType *FnType 2412 = cast<FunctionType>(cast<PointerType>(CalleeType)->getPointeeType()); 2413 2414 CallArgList Args; 2415 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), ArgBeg, ArgEnd); 2416 2417 const CGFunctionInfo &FnInfo = CGM.getTypes().getFunctionInfo(Args, FnType); 2418 2419 // C99 6.5.2.2p6: 2420 // If the expression that denotes the called function has a type 2421 // that does not include a prototype, [the default argument 2422 // promotions are performed]. If the number of arguments does not 2423 // equal the number of parameters, the behavior is undefined. If 2424 // the function is defined with a type that includes a prototype, 2425 // and either the prototype ends with an ellipsis (, ...) or the 2426 // types of the arguments after promotion are not compatible with 2427 // the types of the parameters, the behavior is undefined. If the 2428 // function is defined with a type that does not include a 2429 // prototype, and the types of the arguments after promotion are 2430 // not compatible with those of the parameters after promotion, 2431 // the behavior is undefined [except in some trivial cases]. 2432 // That is, in the general case, we should assume that a call 2433 // through an unprototyped function type works like a *non-variadic* 2434 // call. The way we make this work is to cast to the exact type 2435 // of the promoted arguments. 2436 if (isa<FunctionNoProtoType>(FnType) && 2437 !getTargetHooks().isNoProtoCallVariadic(FnType->getCallConv())) { 2438 assert(cast<llvm::FunctionType>(Callee->getType()->getContainedType(0)) 2439 ->isVarArg()); 2440 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo, false); 2441 CalleeTy = CalleeTy->getPointerTo(); 2442 Callee = Builder.CreateBitCast(Callee, CalleeTy, "callee.knr.cast"); 2443 } 2444 2445 return EmitCall(FnInfo, Callee, ReturnValue, Args, TargetDecl); 2446} 2447 2448LValue CodeGenFunction:: 2449EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) { 2450 llvm::Value *BaseV; 2451 if (E->getOpcode() == BO_PtrMemI) 2452 BaseV = EmitScalarExpr(E->getLHS()); 2453 else 2454 BaseV = EmitLValue(E->getLHS()).getAddress(); 2455 2456 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS()); 2457 2458 const MemberPointerType *MPT 2459 = E->getRHS()->getType()->getAs<MemberPointerType>(); 2460 2461 llvm::Value *AddV = 2462 CGM.getCXXABI().EmitMemberDataPointerAddress(*this, BaseV, OffsetV, MPT); 2463 2464 return MakeAddrLValue(AddV, MPT->getPointeeType()); 2465} 2466