CGExprAgg.cpp revision 309124
1193326Sed//===--- CGExprAgg.cpp - Emit LLVM Code from Aggregate Expressions --------===// 2193326Sed// 3193326Sed// The LLVM Compiler Infrastructure 4193326Sed// 5193326Sed// This file is distributed under the University of Illinois Open Source 6193326Sed// License. See LICENSE.TXT for details. 7193326Sed// 8193326Sed//===----------------------------------------------------------------------===// 9193326Sed// 10193326Sed// This contains code to emit Aggregate Expr nodes as LLVM code. 11193326Sed// 12193326Sed//===----------------------------------------------------------------------===// 13193326Sed 14193326Sed#include "CodeGenFunction.h" 15249423Sdim#include "CGObjCRuntime.h" 16193326Sed#include "CodeGenModule.h" 17193326Sed#include "clang/AST/ASTContext.h" 18193326Sed#include "clang/AST/DeclCXX.h" 19234353Sdim#include "clang/AST/DeclTemplate.h" 20193326Sed#include "clang/AST/StmtVisitor.h" 21249423Sdim#include "llvm/IR/Constants.h" 22249423Sdim#include "llvm/IR/Function.h" 23249423Sdim#include "llvm/IR/GlobalVariable.h" 24249423Sdim#include "llvm/IR/Intrinsics.h" 25193326Sedusing namespace clang; 26193326Sedusing namespace CodeGen; 27193326Sed 28193326Sed//===----------------------------------------------------------------------===// 29193326Sed// Aggregate Expression Emitter 30193326Sed//===----------------------------------------------------------------------===// 31193326Sed 32193326Sednamespace { 33199990Srdivackyclass AggExprEmitter : public StmtVisitor<AggExprEmitter> { 34193326Sed CodeGenFunction &CGF; 35193326Sed CGBuilderTy &Builder; 36218893Sdim AggValueSlot Dest; 37288943Sdim bool IsResultUnused; 38208600Srdivacky 39226633Sdim /// We want to use 'dest' as the return slot except under two 40226633Sdim /// conditions: 41226633Sdim /// - The destination slot requires garbage collection, so we 42226633Sdim /// need to use the GC API. 43226633Sdim /// - The destination slot is potentially aliased. 44226633Sdim bool shouldUseDestForReturnSlot() const { 45226633Sdim return !(Dest.requiresGCollection() || Dest.isPotentiallyAliased()); 46226633Sdim } 47226633Sdim 48208600Srdivacky ReturnValueSlot getReturnValueSlot() const { 49226633Sdim if (!shouldUseDestForReturnSlot()) 50226633Sdim return ReturnValueSlot(); 51208600Srdivacky 52296417Sdim return ReturnValueSlot(Dest.getAddress(), Dest.isVolatile(), 53296417Sdim IsResultUnused); 54208600Srdivacky } 55208600Srdivacky 56218893Sdim AggValueSlot EnsureSlot(QualType T) { 57218893Sdim if (!Dest.isIgnored()) return Dest; 58218893Sdim return CGF.CreateAggTemp(T, "agg.tmp.ensured"); 59218893Sdim } 60239462Sdim void EnsureDest(QualType T) { 61239462Sdim if (!Dest.isIgnored()) return; 62239462Sdim Dest = CGF.CreateAggTemp(T, "agg.tmp.ensured"); 63239462Sdim } 64218893Sdim 65193326Sedpublic: 66288943Sdim AggExprEmitter(CodeGenFunction &cgf, AggValueSlot Dest, bool IsResultUnused) 67288943Sdim : CGF(cgf), Builder(CGF.Builder), Dest(Dest), 68288943Sdim IsResultUnused(IsResultUnused) { } 69193326Sed 70193326Sed //===--------------------------------------------------------------------===// 71193326Sed // Utilities 72193326Sed //===--------------------------------------------------------------------===// 73193326Sed 74193326Sed /// EmitAggLoadOfLValue - Given an expression with aggregate type that 75193326Sed /// represents a value lvalue, this method emits the address of the lvalue, 76193326Sed /// then loads the result into DestPtr. 77193326Sed void EmitAggLoadOfLValue(const Expr *E); 78193326Sed 79193326Sed /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 80239462Sdim void EmitFinalDestCopy(QualType type, const LValue &src); 81296417Sdim void EmitFinalDestCopy(QualType type, RValue src); 82239462Sdim void EmitCopy(QualType type, const AggValueSlot &dest, 83239462Sdim const AggValueSlot &src); 84193326Sed 85226633Sdim void EmitMoveFromReturnSlot(const Expr *E, RValue Src); 86208600Srdivacky 87296417Sdim void EmitArrayInit(Address DestPtr, llvm::ArrayType *AType, 88234353Sdim QualType elementType, InitListExpr *E); 89234353Sdim 90226633Sdim AggValueSlot::NeedsGCBarriers_t needsGC(QualType T) { 91234353Sdim if (CGF.getLangOpts().getGC() && TypeRequiresGCollection(T)) 92226633Sdim return AggValueSlot::NeedsGCBarriers; 93226633Sdim return AggValueSlot::DoesNotNeedGCBarriers; 94226633Sdim } 95226633Sdim 96208600Srdivacky bool TypeRequiresGCollection(QualType T); 97208600Srdivacky 98193326Sed //===--------------------------------------------------------------------===// 99193326Sed // Visitor Methods 100193326Sed //===--------------------------------------------------------------------===// 101198092Srdivacky 102288943Sdim void Visit(Expr *E) { 103288943Sdim ApplyDebugLocation DL(CGF, E); 104288943Sdim StmtVisitor<AggExprEmitter>::Visit(E); 105288943Sdim } 106288943Sdim 107193326Sed void VisitStmt(Stmt *S) { 108193326Sed CGF.ErrorUnsupported(S, "aggregate expression"); 109193326Sed } 110193326Sed void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } 111221345Sdim void VisitGenericSelectionExpr(GenericSelectionExpr *GE) { 112221345Sdim Visit(GE->getResultExpr()); 113221345Sdim } 114193326Sed void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } 115224145Sdim void VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *E) { 116224145Sdim return Visit(E->getReplacement()); 117224145Sdim } 118193326Sed 119193326Sed // l-values. 120234353Sdim void VisitDeclRefExpr(DeclRefExpr *E) { 121234353Sdim // For aggregates, we should always be able to emit the variable 122234353Sdim // as an l-value unless it's a reference. This is due to the fact 123234353Sdim // that we can't actually ever see a normal l2r conversion on an 124234353Sdim // aggregate in C++, and in C there's no language standard 125234353Sdim // actively preventing us from listing variables in the captures 126234353Sdim // list of a block. 127234353Sdim if (E->getDecl()->getType()->isReferenceType()) { 128234353Sdim if (CodeGenFunction::ConstantEmission result 129234353Sdim = CGF.tryEmitAsConstant(E)) { 130239462Sdim EmitFinalDestCopy(E->getType(), result.getReferenceLValue(CGF, E)); 131234353Sdim return; 132234353Sdim } 133234353Sdim } 134234353Sdim 135234353Sdim EmitAggLoadOfLValue(E); 136234353Sdim } 137234353Sdim 138193326Sed void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } 139193326Sed void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } 140193326Sed void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } 141224145Sdim void VisitCompoundLiteralExpr(CompoundLiteralExpr *E); 142193326Sed void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 143193326Sed EmitAggLoadOfLValue(E); 144193326Sed } 145193326Sed void VisitPredefinedExpr(const PredefinedExpr *E) { 146198092Srdivacky EmitAggLoadOfLValue(E); 147193326Sed } 148198092Srdivacky 149193326Sed // Operators. 150198092Srdivacky void VisitCastExpr(CastExpr *E); 151193326Sed void VisitCallExpr(const CallExpr *E); 152193326Sed void VisitStmtExpr(const StmtExpr *E); 153193326Sed void VisitBinaryOperator(const BinaryOperator *BO); 154198398Srdivacky void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO); 155193326Sed void VisitBinAssign(const BinaryOperator *E); 156193326Sed void VisitBinComma(const BinaryOperator *E); 157193326Sed 158193326Sed void VisitObjCMessageExpr(ObjCMessageExpr *E); 159193326Sed void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 160193326Sed EmitAggLoadOfLValue(E); 161193326Sed } 162198092Srdivacky 163288943Sdim void VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E); 164218893Sdim void VisitAbstractConditionalOperator(const AbstractConditionalOperator *CO); 165198092Srdivacky void VisitChooseExpr(const ChooseExpr *CE); 166193326Sed void VisitInitListExpr(InitListExpr *E); 167201361Srdivacky void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E); 168288943Sdim void VisitNoInitExpr(NoInitExpr *E) { } // Do nothing. 169193326Sed void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 170193326Sed Visit(DAE->getExpr()); 171193326Sed } 172251662Sdim void VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) { 173251662Sdim CodeGenFunction::CXXDefaultInitExprScope Scope(CGF); 174251662Sdim Visit(DIE->getExpr()); 175251662Sdim } 176193326Sed void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); 177193326Sed void VisitCXXConstructExpr(const CXXConstructExpr *E); 178309124Sdim void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E); 179234353Sdim void VisitLambdaExpr(LambdaExpr *E); 180261991Sdim void VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E); 181218893Sdim void VisitExprWithCleanups(ExprWithCleanups *E); 182210299Sed void VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E); 183199482Srdivacky void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); } 184224145Sdim void VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E); 185218893Sdim void VisitOpaqueValueExpr(OpaqueValueExpr *E); 186218893Sdim 187234353Sdim void VisitPseudoObjectExpr(PseudoObjectExpr *E) { 188234353Sdim if (E->isGLValue()) { 189234353Sdim LValue LV = CGF.EmitPseudoObjectLValue(E); 190239462Sdim return EmitFinalDestCopy(E->getType(), LV); 191234353Sdim } 192234353Sdim 193234353Sdim CGF.EmitPseudoObjectRValue(E, EnsureSlot(E->getType())); 194234353Sdim } 195234353Sdim 196193326Sed void VisitVAArgExpr(VAArgExpr *E); 197193326Sed 198224145Sdim void EmitInitializationToLValue(Expr *E, LValue Address); 199224145Sdim void EmitNullInitializationToLValue(LValue Address); 200193326Sed // case Expr::ChooseExprClass: 201200583Srdivacky void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); } 202226633Sdim void VisitAtomicExpr(AtomicExpr *E) { 203296417Sdim RValue Res = CGF.EmitAtomicExpr(E); 204296417Sdim EmitFinalDestCopy(E->getType(), Res); 205226633Sdim } 206193326Sed}; 207193326Sed} // end anonymous namespace. 208193326Sed 209193326Sed//===----------------------------------------------------------------------===// 210193326Sed// Utilities 211193326Sed//===----------------------------------------------------------------------===// 212193326Sed 213193326Sed/// EmitAggLoadOfLValue - Given an expression with aggregate type that 214193326Sed/// represents a value lvalue, this method emits the address of the lvalue, 215193326Sed/// then loads the result into DestPtr. 216193326Sedvoid AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { 217193326Sed LValue LV = CGF.EmitLValue(E); 218249423Sdim 219249423Sdim // If the type of the l-value is atomic, then do an atomic load. 220288943Sdim if (LV.getType()->isAtomicType() || CGF.LValueIsSuitableForInlineAtomic(LV)) { 221261991Sdim CGF.EmitAtomicLoad(LV, E->getExprLoc(), Dest); 222249423Sdim return; 223249423Sdim } 224249423Sdim 225239462Sdim EmitFinalDestCopy(E->getType(), LV); 226193326Sed} 227193326Sed 228208600Srdivacky/// \brief True if the given aggregate type requires special GC API calls. 229208600Srdivackybool AggExprEmitter::TypeRequiresGCollection(QualType T) { 230208600Srdivacky // Only record types have members that might require garbage collection. 231208600Srdivacky const RecordType *RecordTy = T->getAs<RecordType>(); 232208600Srdivacky if (!RecordTy) return false; 233208600Srdivacky 234208600Srdivacky // Don't mess with non-trivial C++ types. 235208600Srdivacky RecordDecl *Record = RecordTy->getDecl(); 236208600Srdivacky if (isa<CXXRecordDecl>(Record) && 237249423Sdim (cast<CXXRecordDecl>(Record)->hasNonTrivialCopyConstructor() || 238208600Srdivacky !cast<CXXRecordDecl>(Record)->hasTrivialDestructor())) 239208600Srdivacky return false; 240208600Srdivacky 241208600Srdivacky // Check whether the type has an object member. 242208600Srdivacky return Record->hasObjectMember(); 243208600Srdivacky} 244208600Srdivacky 245226633Sdim/// \brief Perform the final move to DestPtr if for some reason 246226633Sdim/// getReturnValueSlot() didn't use it directly. 247208600Srdivacky/// 248208600Srdivacky/// The idea is that you do something like this: 249208600Srdivacky/// RValue Result = EmitSomething(..., getReturnValueSlot()); 250226633Sdim/// EmitMoveFromReturnSlot(E, Result); 251226633Sdim/// 252226633Sdim/// If nothing interferes, this will cause the result to be emitted 253226633Sdim/// directly into the return value slot. Otherwise, a final move 254226633Sdim/// will be performed. 255239462Sdimvoid AggExprEmitter::EmitMoveFromReturnSlot(const Expr *E, RValue src) { 256226633Sdim if (shouldUseDestForReturnSlot()) { 257226633Sdim // Logically, Dest.getAddr() should equal Src.getAggregateAddr(). 258226633Sdim // The possibility of undef rvalues complicates that a lot, 259226633Sdim // though, so we can't really assert. 260226633Sdim return; 261210299Sed } 262226633Sdim 263239462Sdim // Otherwise, copy from there to the destination. 264296417Sdim assert(Dest.getPointer() != src.getAggregatePointer()); 265296417Sdim EmitFinalDestCopy(E->getType(), src); 266208600Srdivacky} 267208600Srdivacky 268193326Sed/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 269296417Sdimvoid AggExprEmitter::EmitFinalDestCopy(QualType type, RValue src) { 270239462Sdim assert(src.isAggregate() && "value must be aggregate value!"); 271296417Sdim LValue srcLV = CGF.MakeAddrLValue(src.getAggregateAddress(), type); 272239462Sdim EmitFinalDestCopy(type, srcLV); 273239462Sdim} 274193326Sed 275239462Sdim/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 276239462Sdimvoid AggExprEmitter::EmitFinalDestCopy(QualType type, const LValue &src) { 277218893Sdim // If Dest is ignored, then we're evaluating an aggregate expression 278239462Sdim // in a context that doesn't care about the result. Note that loads 279239462Sdim // from volatile l-values force the existence of a non-ignored 280239462Sdim // destination. 281239462Sdim if (Dest.isIgnored()) 282239462Sdim return; 283212904Sdim 284239462Sdim AggValueSlot srcAgg = 285239462Sdim AggValueSlot::forLValue(src, AggValueSlot::IsDestructed, 286239462Sdim needsGC(type), AggValueSlot::IsAliased); 287239462Sdim EmitCopy(type, Dest, srcAgg); 288239462Sdim} 289193326Sed 290239462Sdim/// Perform a copy from the source into the destination. 291239462Sdim/// 292239462Sdim/// \param type - the type of the aggregate being copied; qualifiers are 293239462Sdim/// ignored 294239462Sdimvoid AggExprEmitter::EmitCopy(QualType type, const AggValueSlot &dest, 295239462Sdim const AggValueSlot &src) { 296239462Sdim if (dest.requiresGCollection()) { 297239462Sdim CharUnits sz = CGF.getContext().getTypeSizeInChars(type); 298239462Sdim llvm::Value *size = llvm::ConstantInt::get(CGF.SizeTy, sz.getQuantity()); 299198092Srdivacky CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, 300296417Sdim dest.getAddress(), 301296417Sdim src.getAddress(), 302239462Sdim size); 303198092Srdivacky return; 304198092Srdivacky } 305239462Sdim 306193326Sed // If the result of the assignment is used, copy the LHS there also. 307239462Sdim // It's volatile if either side is. Use the minimum alignment of 308239462Sdim // the two sides. 309296417Sdim CGF.EmitAggregateCopy(dest.getAddress(), src.getAddress(), type, 310296417Sdim dest.isVolatile() || src.isVolatile()); 311193326Sed} 312193326Sed 313234353Sdim/// \brief Emit the initializer for a std::initializer_list initialized with a 314234353Sdim/// real initializer list. 315261991Sdimvoid 316261991SdimAggExprEmitter::VisitCXXStdInitializerListExpr(CXXStdInitializerListExpr *E) { 317261991Sdim // Emit an array containing the elements. The array is externally destructed 318261991Sdim // if the std::initializer_list object is. 319261991Sdim ASTContext &Ctx = CGF.getContext(); 320261991Sdim LValue Array = CGF.EmitLValue(E->getSubExpr()); 321261991Sdim assert(Array.isSimple() && "initializer_list array not a simple lvalue"); 322296417Sdim Address ArrayPtr = Array.getAddress(); 323234353Sdim 324261991Sdim const ConstantArrayType *ArrayType = 325261991Sdim Ctx.getAsConstantArrayType(E->getSubExpr()->getType()); 326261991Sdim assert(ArrayType && "std::initializer_list constructed from non-array"); 327234353Sdim 328261991Sdim // FIXME: Perform the checks on the field types in SemaInit. 329261991Sdim RecordDecl *Record = E->getType()->castAs<RecordType>()->getDecl(); 330261991Sdim RecordDecl::field_iterator Field = Record->field_begin(); 331261991Sdim if (Field == Record->field_end()) { 332261991Sdim CGF.ErrorUnsupported(E, "weird std::initializer_list"); 333234353Sdim return; 334234353Sdim } 335234353Sdim 336234353Sdim // Start pointer. 337261991Sdim if (!Field->getType()->isPointerType() || 338261991Sdim !Ctx.hasSameType(Field->getType()->getPointeeType(), 339261991Sdim ArrayType->getElementType())) { 340261991Sdim CGF.ErrorUnsupported(E, "weird std::initializer_list"); 341234353Sdim return; 342234353Sdim } 343234353Sdim 344261991Sdim AggValueSlot Dest = EnsureSlot(E->getType()); 345296417Sdim LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); 346261991Sdim LValue Start = CGF.EmitLValueForFieldInitialization(DestLV, *Field); 347261991Sdim llvm::Value *Zero = llvm::ConstantInt::get(CGF.PtrDiffTy, 0); 348261991Sdim llvm::Value *IdxStart[] = { Zero, Zero }; 349261991Sdim llvm::Value *ArrayStart = 350296417Sdim Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxStart, "arraystart"); 351261991Sdim CGF.EmitStoreThroughLValue(RValue::get(ArrayStart), Start); 352261991Sdim ++Field; 353261991Sdim 354261991Sdim if (Field == Record->field_end()) { 355261991Sdim CGF.ErrorUnsupported(E, "weird std::initializer_list"); 356234353Sdim return; 357234353Sdim } 358261991Sdim 359261991Sdim llvm::Value *Size = Builder.getInt(ArrayType->getSize()); 360261991Sdim LValue EndOrLength = CGF.EmitLValueForFieldInitialization(DestLV, *Field); 361261991Sdim if (Field->getType()->isPointerType() && 362261991Sdim Ctx.hasSameType(Field->getType()->getPointeeType(), 363261991Sdim ArrayType->getElementType())) { 364234353Sdim // End pointer. 365261991Sdim llvm::Value *IdxEnd[] = { Zero, Size }; 366261991Sdim llvm::Value *ArrayEnd = 367296417Sdim Builder.CreateInBoundsGEP(ArrayPtr.getPointer(), IdxEnd, "arrayend"); 368261991Sdim CGF.EmitStoreThroughLValue(RValue::get(ArrayEnd), EndOrLength); 369261991Sdim } else if (Ctx.hasSameType(Field->getType(), Ctx.getSizeType())) { 370234353Sdim // Length. 371261991Sdim CGF.EmitStoreThroughLValue(RValue::get(Size), EndOrLength); 372234353Sdim } else { 373261991Sdim CGF.ErrorUnsupported(E, "weird std::initializer_list"); 374234353Sdim return; 375234353Sdim } 376234353Sdim} 377234353Sdim 378276479Sdim/// \brief Determine if E is a trivial array filler, that is, one that is 379276479Sdim/// equivalent to zero-initialization. 380276479Sdimstatic bool isTrivialFiller(Expr *E) { 381276479Sdim if (!E) 382276479Sdim return true; 383276479Sdim 384276479Sdim if (isa<ImplicitValueInitExpr>(E)) 385276479Sdim return true; 386276479Sdim 387276479Sdim if (auto *ILE = dyn_cast<InitListExpr>(E)) { 388276479Sdim if (ILE->getNumInits()) 389276479Sdim return false; 390276479Sdim return isTrivialFiller(ILE->getArrayFiller()); 391276479Sdim } 392276479Sdim 393276479Sdim if (auto *Cons = dyn_cast_or_null<CXXConstructExpr>(E)) 394276479Sdim return Cons->getConstructor()->isDefaultConstructor() && 395276479Sdim Cons->getConstructor()->isTrivial(); 396276479Sdim 397276479Sdim // FIXME: Are there other cases where we can avoid emitting an initializer? 398276479Sdim return false; 399276479Sdim} 400276479Sdim 401234353Sdim/// \brief Emit initialization of an array from an initializer list. 402296417Sdimvoid AggExprEmitter::EmitArrayInit(Address DestPtr, llvm::ArrayType *AType, 403234353Sdim QualType elementType, InitListExpr *E) { 404234353Sdim uint64_t NumInitElements = E->getNumInits(); 405234353Sdim 406234353Sdim uint64_t NumArrayElements = AType->getNumElements(); 407234353Sdim assert(NumInitElements <= NumArrayElements); 408234353Sdim 409234353Sdim // DestPtr is an array*. Construct an elementType* by drilling 410234353Sdim // down a level. 411234353Sdim llvm::Value *zero = llvm::ConstantInt::get(CGF.SizeTy, 0); 412234353Sdim llvm::Value *indices[] = { zero, zero }; 413234353Sdim llvm::Value *begin = 414296417Sdim Builder.CreateInBoundsGEP(DestPtr.getPointer(), indices, "arrayinit.begin"); 415234353Sdim 416296417Sdim CharUnits elementSize = CGF.getContext().getTypeSizeInChars(elementType); 417296417Sdim CharUnits elementAlign = 418296417Sdim DestPtr.getAlignment().alignmentOfArrayElement(elementSize); 419296417Sdim 420234353Sdim // Exception safety requires us to destroy all the 421234353Sdim // already-constructed members if an initializer throws. 422234353Sdim // For that, we'll need an EH cleanup. 423234353Sdim QualType::DestructionKind dtorKind = elementType.isDestructedType(); 424296417Sdim Address endOfInit = Address::invalid(); 425234353Sdim EHScopeStack::stable_iterator cleanup; 426276479Sdim llvm::Instruction *cleanupDominator = nullptr; 427234353Sdim if (CGF.needsEHCleanup(dtorKind)) { 428234353Sdim // In principle we could tell the cleanup where we are more 429234353Sdim // directly, but the control flow can get so varied here that it 430234353Sdim // would actually be quite complex. Therefore we go through an 431234353Sdim // alloca. 432296417Sdim endOfInit = CGF.CreateTempAlloca(begin->getType(), CGF.getPointerAlign(), 433234353Sdim "arrayinit.endOfInit"); 434234353Sdim cleanupDominator = Builder.CreateStore(begin, endOfInit); 435234353Sdim CGF.pushIrregularPartialArrayCleanup(begin, endOfInit, elementType, 436296417Sdim elementAlign, 437234353Sdim CGF.getDestroyer(dtorKind)); 438234353Sdim cleanup = CGF.EHStack.stable_begin(); 439234353Sdim 440234353Sdim // Otherwise, remember that we didn't need a cleanup. 441234353Sdim } else { 442234353Sdim dtorKind = QualType::DK_none; 443234353Sdim } 444234353Sdim 445234353Sdim llvm::Value *one = llvm::ConstantInt::get(CGF.SizeTy, 1); 446234353Sdim 447234353Sdim // The 'current element to initialize'. The invariants on this 448234353Sdim // variable are complicated. Essentially, after each iteration of 449234353Sdim // the loop, it points to the last initialized element, except 450234353Sdim // that it points to the beginning of the array before any 451234353Sdim // elements have been initialized. 452234353Sdim llvm::Value *element = begin; 453234353Sdim 454234353Sdim // Emit the explicit initializers. 455234353Sdim for (uint64_t i = 0; i != NumInitElements; ++i) { 456234353Sdim // Advance to the next element. 457234353Sdim if (i > 0) { 458234353Sdim element = Builder.CreateInBoundsGEP(element, one, "arrayinit.element"); 459234353Sdim 460234353Sdim // Tell the cleanup that it needs to destroy up to this 461234353Sdim // element. TODO: some of these stores can be trivially 462234353Sdim // observed to be unnecessary. 463296417Sdim if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit); 464234353Sdim } 465234353Sdim 466296417Sdim LValue elementLV = 467296417Sdim CGF.MakeAddrLValue(Address(element, elementAlign), elementType); 468261991Sdim EmitInitializationToLValue(E->getInit(i), elementLV); 469234353Sdim } 470234353Sdim 471234353Sdim // Check whether there's a non-trivial array-fill expression. 472234353Sdim Expr *filler = E->getArrayFiller(); 473276479Sdim bool hasTrivialFiller = isTrivialFiller(filler); 474234353Sdim 475234353Sdim // Any remaining elements need to be zero-initialized, possibly 476234353Sdim // using the filler expression. We can skip this if the we're 477234353Sdim // emitting to zeroed memory. 478234353Sdim if (NumInitElements != NumArrayElements && 479234353Sdim !(Dest.isZeroed() && hasTrivialFiller && 480234353Sdim CGF.getTypes().isZeroInitializable(elementType))) { 481234353Sdim 482234353Sdim // Use an actual loop. This is basically 483234353Sdim // do { *array++ = filler; } while (array != end); 484234353Sdim 485234353Sdim // Advance to the start of the rest of the array. 486234353Sdim if (NumInitElements) { 487234353Sdim element = Builder.CreateInBoundsGEP(element, one, "arrayinit.start"); 488296417Sdim if (endOfInit.isValid()) Builder.CreateStore(element, endOfInit); 489234353Sdim } 490234353Sdim 491234353Sdim // Compute the end of the array. 492234353Sdim llvm::Value *end = Builder.CreateInBoundsGEP(begin, 493234353Sdim llvm::ConstantInt::get(CGF.SizeTy, NumArrayElements), 494234353Sdim "arrayinit.end"); 495234353Sdim 496234353Sdim llvm::BasicBlock *entryBB = Builder.GetInsertBlock(); 497234353Sdim llvm::BasicBlock *bodyBB = CGF.createBasicBlock("arrayinit.body"); 498234353Sdim 499234353Sdim // Jump into the body. 500234353Sdim CGF.EmitBlock(bodyBB); 501234353Sdim llvm::PHINode *currentElement = 502234353Sdim Builder.CreatePHI(element->getType(), 2, "arrayinit.cur"); 503234353Sdim currentElement->addIncoming(element, entryBB); 504234353Sdim 505234353Sdim // Emit the actual filler expression. 506296417Sdim LValue elementLV = 507296417Sdim CGF.MakeAddrLValue(Address(currentElement, elementAlign), elementType); 508234353Sdim if (filler) 509234353Sdim EmitInitializationToLValue(filler, elementLV); 510234353Sdim else 511234353Sdim EmitNullInitializationToLValue(elementLV); 512234353Sdim 513234353Sdim // Move on to the next element. 514234353Sdim llvm::Value *nextElement = 515234353Sdim Builder.CreateInBoundsGEP(currentElement, one, "arrayinit.next"); 516234353Sdim 517234353Sdim // Tell the EH cleanup that we finished with the last element. 518296417Sdim if (endOfInit.isValid()) Builder.CreateStore(nextElement, endOfInit); 519234353Sdim 520234353Sdim // Leave the loop if we're done. 521234353Sdim llvm::Value *done = Builder.CreateICmpEQ(nextElement, end, 522234353Sdim "arrayinit.done"); 523234353Sdim llvm::BasicBlock *endBB = CGF.createBasicBlock("arrayinit.end"); 524234353Sdim Builder.CreateCondBr(done, endBB, bodyBB); 525234353Sdim currentElement->addIncoming(nextElement, Builder.GetInsertBlock()); 526234353Sdim 527234353Sdim CGF.EmitBlock(endBB); 528234353Sdim } 529234353Sdim 530234353Sdim // Leave the partial-array cleanup if we entered one. 531234353Sdim if (dtorKind) CGF.DeactivateCleanupBlock(cleanup, cleanupDominator); 532234353Sdim} 533234353Sdim 534193326Sed//===----------------------------------------------------------------------===// 535193326Sed// Visitor Methods 536193326Sed//===----------------------------------------------------------------------===// 537193326Sed 538224145Sdimvoid AggExprEmitter::VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E){ 539224145Sdim Visit(E->GetTemporaryExpr()); 540224145Sdim} 541224145Sdim 542218893Sdimvoid AggExprEmitter::VisitOpaqueValueExpr(OpaqueValueExpr *e) { 543239462Sdim EmitFinalDestCopy(e->getType(), CGF.getOpaqueLValueMapping(e)); 544218893Sdim} 545218893Sdim 546224145Sdimvoid 547224145SdimAggExprEmitter::VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 548249423Sdim if (Dest.isPotentiallyAliased() && 549249423Sdim E->getType().isPODType(CGF.getContext())) { 550224145Sdim // For a POD type, just emit a load of the lvalue + a copy, because our 551224145Sdim // compound literal might alias the destination. 552224145Sdim EmitAggLoadOfLValue(E); 553224145Sdim return; 554224145Sdim } 555224145Sdim 556224145Sdim AggValueSlot Slot = EnsureSlot(E->getType()); 557224145Sdim CGF.EmitAggExpr(E->getInitializer(), Slot); 558224145Sdim} 559224145Sdim 560249423Sdim/// Attempt to look through various unimportant expressions to find a 561249423Sdim/// cast of the given kind. 562249423Sdimstatic Expr *findPeephole(Expr *op, CastKind kind) { 563249423Sdim while (true) { 564249423Sdim op = op->IgnoreParens(); 565249423Sdim if (CastExpr *castE = dyn_cast<CastExpr>(op)) { 566249423Sdim if (castE->getCastKind() == kind) 567249423Sdim return castE->getSubExpr(); 568249423Sdim if (castE->getCastKind() == CK_NoOp) 569249423Sdim continue; 570249423Sdim } 571276479Sdim return nullptr; 572249423Sdim } 573249423Sdim} 574224145Sdim 575198092Srdivackyvoid AggExprEmitter::VisitCastExpr(CastExpr *E) { 576296417Sdim if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E)) 577296417Sdim CGF.CGM.EmitExplicitCastExprType(ECE, &CGF); 578198092Srdivacky switch (E->getCastKind()) { 579212904Sdim case CK_Dynamic: { 580243830Sdim // FIXME: Can this actually happen? We have no test coverage for it. 581208600Srdivacky assert(isa<CXXDynamicCastExpr>(E) && "CK_Dynamic without a dynamic_cast?"); 582243830Sdim LValue LV = CGF.EmitCheckedLValue(E->getSubExpr(), 583243830Sdim CodeGenFunction::TCK_Load); 584208600Srdivacky // FIXME: Do we also need to handle property references here? 585208600Srdivacky if (LV.isSimple()) 586208600Srdivacky CGF.EmitDynamicCast(LV.getAddress(), cast<CXXDynamicCastExpr>(E)); 587208600Srdivacky else 588208600Srdivacky CGF.CGM.ErrorUnsupported(E, "non-simple lvalue dynamic_cast"); 589208600Srdivacky 590218893Sdim if (!Dest.isIgnored()) 591218893Sdim CGF.CGM.ErrorUnsupported(E, "lvalue dynamic_cast with a destination"); 592208600Srdivacky break; 593208600Srdivacky } 594208600Srdivacky 595212904Sdim case CK_ToUnion: { 596288943Sdim // Evaluate even if the destination is ignored. 597288943Sdim if (Dest.isIgnored()) { 598288943Sdim CGF.EmitAnyExpr(E->getSubExpr(), AggValueSlot::ignored(), 599288943Sdim /*ignoreResult=*/true); 600288943Sdim break; 601288943Sdim } 602221345Sdim 603198092Srdivacky // GCC union extension 604212904Sdim QualType Ty = E->getSubExpr()->getType(); 605296417Sdim Address CastPtr = 606296417Sdim Builder.CreateElementBitCast(Dest.getAddress(), CGF.ConvertType(Ty)); 607224145Sdim EmitInitializationToLValue(E->getSubExpr(), 608224145Sdim CGF.MakeAddrLValue(CastPtr, Ty)); 609198092Srdivacky break; 610193326Sed } 611193326Sed 612212904Sdim case CK_DerivedToBase: 613212904Sdim case CK_BaseToDerived: 614212904Sdim case CK_UncheckedDerivedToBase: { 615226633Sdim llvm_unreachable("cannot perform hierarchy conversion in EmitAggExpr: " 616208600Srdivacky "should have been unpacked before we got here"); 617208600Srdivacky } 618208600Srdivacky 619249423Sdim case CK_NonAtomicToAtomic: 620249423Sdim case CK_AtomicToNonAtomic: { 621249423Sdim bool isToAtomic = (E->getCastKind() == CK_NonAtomicToAtomic); 622249423Sdim 623249423Sdim // Determine the atomic and value types. 624249423Sdim QualType atomicType = E->getSubExpr()->getType(); 625249423Sdim QualType valueType = E->getType(); 626249423Sdim if (isToAtomic) std::swap(atomicType, valueType); 627249423Sdim 628249423Sdim assert(atomicType->isAtomicType()); 629249423Sdim assert(CGF.getContext().hasSameUnqualifiedType(valueType, 630249423Sdim atomicType->castAs<AtomicType>()->getValueType())); 631249423Sdim 632249423Sdim // Just recurse normally if we're ignoring the result or the 633249423Sdim // atomic type doesn't change representation. 634249423Sdim if (Dest.isIgnored() || !CGF.CGM.isPaddedAtomicType(atomicType)) { 635249423Sdim return Visit(E->getSubExpr()); 636249423Sdim } 637249423Sdim 638249423Sdim CastKind peepholeTarget = 639249423Sdim (isToAtomic ? CK_AtomicToNonAtomic : CK_NonAtomicToAtomic); 640249423Sdim 641249423Sdim // These two cases are reverses of each other; try to peephole them. 642249423Sdim if (Expr *op = findPeephole(E->getSubExpr(), peepholeTarget)) { 643249423Sdim assert(CGF.getContext().hasSameUnqualifiedType(op->getType(), 644249423Sdim E->getType()) && 645249423Sdim "peephole significantly changed types?"); 646249423Sdim return Visit(op); 647249423Sdim } 648249423Sdim 649249423Sdim // If we're converting an r-value of non-atomic type to an r-value 650261991Sdim // of atomic type, just emit directly into the relevant sub-object. 651249423Sdim if (isToAtomic) { 652261991Sdim AggValueSlot valueDest = Dest; 653261991Sdim if (!valueDest.isIgnored() && CGF.CGM.isPaddedAtomicType(atomicType)) { 654261991Sdim // Zero-initialize. (Strictly speaking, we only need to intialize 655261991Sdim // the padding at the end, but this is simpler.) 656261991Sdim if (!Dest.isZeroed()) 657296417Sdim CGF.EmitNullInitialization(Dest.getAddress(), atomicType); 658261991Sdim 659261991Sdim // Build a GEP to refer to the subobject. 660296417Sdim Address valueAddr = 661296417Sdim CGF.Builder.CreateStructGEP(valueDest.getAddress(), 0, 662296417Sdim CharUnits()); 663261991Sdim valueDest = AggValueSlot::forAddr(valueAddr, 664261991Sdim valueDest.getQualifiers(), 665261991Sdim valueDest.isExternallyDestructed(), 666261991Sdim valueDest.requiresGCollection(), 667261991Sdim valueDest.isPotentiallyAliased(), 668261991Sdim AggValueSlot::IsZeroed); 669261991Sdim } 670261991Sdim 671261991Sdim CGF.EmitAggExpr(E->getSubExpr(), valueDest); 672249423Sdim return; 673249423Sdim } 674249423Sdim 675249423Sdim // Otherwise, we're converting an atomic type to a non-atomic type. 676261991Sdim // Make an atomic temporary, emit into that, and then copy the value out. 677249423Sdim AggValueSlot atomicSlot = 678249423Sdim CGF.CreateAggTemp(atomicType, "atomic-to-nonatomic.temp"); 679249423Sdim CGF.EmitAggExpr(E->getSubExpr(), atomicSlot); 680249423Sdim 681296417Sdim Address valueAddr = 682296417Sdim Builder.CreateStructGEP(atomicSlot.getAddress(), 0, CharUnits()); 683249423Sdim RValue rvalue = RValue::getAggregate(valueAddr, atomicSlot.isVolatile()); 684249423Sdim return EmitFinalDestCopy(valueType, rvalue); 685249423Sdim } 686249423Sdim 687239462Sdim case CK_LValueToRValue: 688239462Sdim // If we're loading from a volatile type, force the destination 689239462Sdim // into existence. 690239462Sdim if (E->getSubExpr()->getType().isVolatileQualified()) { 691239462Sdim EnsureDest(E->getType()); 692239462Sdim return Visit(E->getSubExpr()); 693239462Sdim } 694249423Sdim 695239462Sdim // fallthrough 696239462Sdim 697212904Sdim case CK_NoOp: 698212904Sdim case CK_UserDefinedConversion: 699212904Sdim case CK_ConstructorConversion: 700198092Srdivacky assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), 701198092Srdivacky E->getType()) && 702198092Srdivacky "Implicit cast types must be compatible"); 703198092Srdivacky Visit(E->getSubExpr()); 704198092Srdivacky break; 705218893Sdim 706212904Sdim case CK_LValueBitCast: 707218893Sdim llvm_unreachable("should not be emitting lvalue bitcast as rvalue"); 708221345Sdim 709218893Sdim case CK_Dependent: 710218893Sdim case CK_BitCast: 711218893Sdim case CK_ArrayToPointerDecay: 712218893Sdim case CK_FunctionToPointerDecay: 713218893Sdim case CK_NullToPointer: 714218893Sdim case CK_NullToMemberPointer: 715218893Sdim case CK_BaseToDerivedMemberPointer: 716218893Sdim case CK_DerivedToBaseMemberPointer: 717218893Sdim case CK_MemberPointerToBoolean: 718234353Sdim case CK_ReinterpretMemberPointer: 719218893Sdim case CK_IntegralToPointer: 720218893Sdim case CK_PointerToIntegral: 721218893Sdim case CK_PointerToBoolean: 722218893Sdim case CK_ToVoid: 723218893Sdim case CK_VectorSplat: 724218893Sdim case CK_IntegralCast: 725296417Sdim case CK_BooleanToSignedIntegral: 726218893Sdim case CK_IntegralToBoolean: 727218893Sdim case CK_IntegralToFloating: 728218893Sdim case CK_FloatingToIntegral: 729218893Sdim case CK_FloatingToBoolean: 730218893Sdim case CK_FloatingCast: 731226633Sdim case CK_CPointerToObjCPointerCast: 732226633Sdim case CK_BlockPointerToObjCPointerCast: 733218893Sdim case CK_AnyPointerToBlockPointerCast: 734218893Sdim case CK_ObjCObjectLValueCast: 735218893Sdim case CK_FloatingRealToComplex: 736218893Sdim case CK_FloatingComplexToReal: 737218893Sdim case CK_FloatingComplexToBoolean: 738218893Sdim case CK_FloatingComplexCast: 739218893Sdim case CK_FloatingComplexToIntegralComplex: 740218893Sdim case CK_IntegralRealToComplex: 741218893Sdim case CK_IntegralComplexToReal: 742218893Sdim case CK_IntegralComplexToBoolean: 743218893Sdim case CK_IntegralComplexCast: 744218893Sdim case CK_IntegralComplexToFloatingComplex: 745226633Sdim case CK_ARCProduceObject: 746226633Sdim case CK_ARCConsumeObject: 747226633Sdim case CK_ARCReclaimReturnedObject: 748226633Sdim case CK_ARCExtendBlockObject: 749234353Sdim case CK_CopyAndAutoreleaseBlockObject: 750243830Sdim case CK_BuiltinFnToFnPtr: 751249423Sdim case CK_ZeroToOCLEvent: 752276479Sdim case CK_AddressSpaceConversion: 753218893Sdim llvm_unreachable("cast kind invalid for aggregate types"); 754198398Srdivacky } 755193326Sed} 756193326Sed 757193326Sedvoid AggExprEmitter::VisitCallExpr(const CallExpr *E) { 758288943Sdim if (E->getCallReturnType(CGF.getContext())->isReferenceType()) { 759193326Sed EmitAggLoadOfLValue(E); 760193326Sed return; 761193326Sed } 762198092Srdivacky 763208600Srdivacky RValue RV = CGF.EmitCallExpr(E, getReturnValueSlot()); 764226633Sdim EmitMoveFromReturnSlot(E, RV); 765193326Sed} 766193326Sed 767193326Sedvoid AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { 768208600Srdivacky RValue RV = CGF.EmitObjCMessageExpr(E, getReturnValueSlot()); 769226633Sdim EmitMoveFromReturnSlot(E, RV); 770193326Sed} 771193326Sed 772193326Sedvoid AggExprEmitter::VisitBinComma(const BinaryOperator *E) { 773218893Sdim CGF.EmitIgnoredExpr(E->getLHS()); 774218893Sdim Visit(E->getRHS()); 775193326Sed} 776193326Sed 777193326Sedvoid AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { 778218893Sdim CodeGenFunction::StmtExprEvaluation eval(CGF); 779218893Sdim CGF.EmitCompoundStmt(*E->getSubStmt(), true, Dest); 780193326Sed} 781193326Sed 782193326Sedvoid AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { 783212904Sdim if (E->getOpcode() == BO_PtrMemD || E->getOpcode() == BO_PtrMemI) 784198398Srdivacky VisitPointerToDataMemberBinaryOperator(E); 785198398Srdivacky else 786198398Srdivacky CGF.ErrorUnsupported(E, "aggregate binary expression"); 787193326Sed} 788193326Sed 789198398Srdivackyvoid AggExprEmitter::VisitPointerToDataMemberBinaryOperator( 790198398Srdivacky const BinaryOperator *E) { 791198398Srdivacky LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E); 792239462Sdim EmitFinalDestCopy(E->getType(), LV); 793198398Srdivacky} 794198398Srdivacky 795239462Sdim/// Is the value of the given expression possibly a reference to or 796239462Sdim/// into a __block variable? 797239462Sdimstatic bool isBlockVarRef(const Expr *E) { 798239462Sdim // Make sure we look through parens. 799239462Sdim E = E->IgnoreParens(); 800239462Sdim 801239462Sdim // Check for a direct reference to a __block variable. 802239462Sdim if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) { 803239462Sdim const VarDecl *var = dyn_cast<VarDecl>(DRE->getDecl()); 804239462Sdim return (var && var->hasAttr<BlocksAttr>()); 805239462Sdim } 806239462Sdim 807239462Sdim // More complicated stuff. 808239462Sdim 809239462Sdim // Binary operators. 810239462Sdim if (const BinaryOperator *op = dyn_cast<BinaryOperator>(E)) { 811239462Sdim // For an assignment or pointer-to-member operation, just care 812239462Sdim // about the LHS. 813239462Sdim if (op->isAssignmentOp() || op->isPtrMemOp()) 814239462Sdim return isBlockVarRef(op->getLHS()); 815239462Sdim 816239462Sdim // For a comma, just care about the RHS. 817239462Sdim if (op->getOpcode() == BO_Comma) 818239462Sdim return isBlockVarRef(op->getRHS()); 819239462Sdim 820239462Sdim // FIXME: pointer arithmetic? 821239462Sdim return false; 822239462Sdim 823239462Sdim // Check both sides of a conditional operator. 824239462Sdim } else if (const AbstractConditionalOperator *op 825239462Sdim = dyn_cast<AbstractConditionalOperator>(E)) { 826239462Sdim return isBlockVarRef(op->getTrueExpr()) 827239462Sdim || isBlockVarRef(op->getFalseExpr()); 828239462Sdim 829239462Sdim // OVEs are required to support BinaryConditionalOperators. 830239462Sdim } else if (const OpaqueValueExpr *op 831239462Sdim = dyn_cast<OpaqueValueExpr>(E)) { 832239462Sdim if (const Expr *src = op->getSourceExpr()) 833239462Sdim return isBlockVarRef(src); 834239462Sdim 835239462Sdim // Casts are necessary to get things like (*(int*)&var) = foo(). 836239462Sdim // We don't really care about the kind of cast here, except 837239462Sdim // we don't want to look through l2r casts, because it's okay 838239462Sdim // to get the *value* in a __block variable. 839239462Sdim } else if (const CastExpr *cast = dyn_cast<CastExpr>(E)) { 840239462Sdim if (cast->getCastKind() == CK_LValueToRValue) 841239462Sdim return false; 842239462Sdim return isBlockVarRef(cast->getSubExpr()); 843239462Sdim 844239462Sdim // Handle unary operators. Again, just aggressively look through 845239462Sdim // it, ignoring the operation. 846239462Sdim } else if (const UnaryOperator *uop = dyn_cast<UnaryOperator>(E)) { 847239462Sdim return isBlockVarRef(uop->getSubExpr()); 848239462Sdim 849239462Sdim // Look into the base of a field access. 850239462Sdim } else if (const MemberExpr *mem = dyn_cast<MemberExpr>(E)) { 851239462Sdim return isBlockVarRef(mem->getBase()); 852239462Sdim 853239462Sdim // Look into the base of a subscript. 854239462Sdim } else if (const ArraySubscriptExpr *sub = dyn_cast<ArraySubscriptExpr>(E)) { 855239462Sdim return isBlockVarRef(sub->getBase()); 856239462Sdim } 857239462Sdim 858239462Sdim return false; 859239462Sdim} 860239462Sdim 861193326Sedvoid AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { 862193326Sed // For an assignment to work, the value on the right has 863193326Sed // to be compatible with the value on the left. 864193326Sed assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), 865193326Sed E->getRHS()->getType()) 866193326Sed && "Invalid assignment"); 867218893Sdim 868239462Sdim // If the LHS might be a __block variable, and the RHS can 869239462Sdim // potentially cause a block copy, we need to evaluate the RHS first 870239462Sdim // so that the assignment goes the right place. 871239462Sdim // This is pretty semantically fragile. 872239462Sdim if (isBlockVarRef(E->getLHS()) && 873239462Sdim E->getRHS()->HasSideEffects(CGF.getContext())) { 874239462Sdim // Ensure that we have a destination, and evaluate the RHS into that. 875239462Sdim EnsureDest(E->getRHS()->getType()); 876239462Sdim Visit(E->getRHS()); 877239462Sdim 878239462Sdim // Now emit the LHS and copy into it. 879243830Sdim LValue LHS = CGF.EmitCheckedLValue(E->getLHS(), CodeGenFunction::TCK_Store); 880239462Sdim 881249423Sdim // That copy is an atomic copy if the LHS is atomic. 882288943Sdim if (LHS.getType()->isAtomicType() || 883288943Sdim CGF.LValueIsSuitableForInlineAtomic(LHS)) { 884249423Sdim CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); 885249423Sdim return; 886249423Sdim } 887249423Sdim 888239462Sdim EmitCopy(E->getLHS()->getType(), 889239462Sdim AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, 890239462Sdim needsGC(E->getLHS()->getType()), 891239462Sdim AggValueSlot::IsAliased), 892239462Sdim Dest); 893239462Sdim return; 894239462Sdim } 895221345Sdim 896193326Sed LValue LHS = CGF.EmitLValue(E->getLHS()); 897193326Sed 898249423Sdim // If we have an atomic type, evaluate into the destination and then 899249423Sdim // do an atomic copy. 900288943Sdim if (LHS.getType()->isAtomicType() || 901288943Sdim CGF.LValueIsSuitableForInlineAtomic(LHS)) { 902249423Sdim EnsureDest(E->getRHS()->getType()); 903249423Sdim Visit(E->getRHS()); 904249423Sdim CGF.EmitAtomicStore(Dest.asRValue(), LHS, /*isInit*/ false); 905249423Sdim return; 906249423Sdim } 907249423Sdim 908234353Sdim // Codegen the RHS so that it stores directly into the LHS. 909234353Sdim AggValueSlot LHSSlot = 910234353Sdim AggValueSlot::forLValue(LHS, AggValueSlot::IsDestructed, 911234353Sdim needsGC(E->getLHS()->getType()), 912234353Sdim AggValueSlot::IsAliased); 913249423Sdim // A non-volatile aggregate destination might have volatile member. 914249423Sdim if (!LHSSlot.isVolatile() && 915249423Sdim CGF.hasVolatileMember(E->getLHS()->getType())) 916249423Sdim LHSSlot.setVolatile(true); 917249423Sdim 918239462Sdim CGF.EmitAggExpr(E->getRHS(), LHSSlot); 919239462Sdim 920239462Sdim // Copy into the destination if the assignment isn't ignored. 921239462Sdim EmitFinalDestCopy(E->getType(), LHS); 922193326Sed} 923193326Sed 924218893Sdimvoid AggExprEmitter:: 925218893SdimVisitAbstractConditionalOperator(const AbstractConditionalOperator *E) { 926193326Sed llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 927193326Sed llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 928193326Sed llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 929198092Srdivacky 930218893Sdim // Bind the common expression if necessary. 931218893Sdim CodeGenFunction::OpaqueValueMapping binding(CGF, E); 932218893Sdim 933218893Sdim CodeGenFunction::ConditionalEvaluation eval(CGF); 934288943Sdim CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock, 935288943Sdim CGF.getProfileCount(E)); 936198092Srdivacky 937218893Sdim // Save whether the destination's lifetime is externally managed. 938226633Sdim bool isExternallyDestructed = Dest.isExternallyDestructed(); 939218893Sdim 940218893Sdim eval.begin(CGF); 941193326Sed CGF.EmitBlock(LHSBlock); 942288943Sdim CGF.incrementProfileCounter(E); 943218893Sdim Visit(E->getTrueExpr()); 944218893Sdim eval.end(CGF); 945198092Srdivacky 946218893Sdim assert(CGF.HaveInsertPoint() && "expression evaluation ended with no IP!"); 947218893Sdim CGF.Builder.CreateBr(ContBlock); 948193326Sed 949218893Sdim // If the result of an agg expression is unused, then the emission 950218893Sdim // of the LHS might need to create a destination slot. That's fine 951218893Sdim // with us, and we can safely emit the RHS into the same slot, but 952226633Sdim // we shouldn't claim that it's already being destructed. 953226633Sdim Dest.setExternallyDestructed(isExternallyDestructed); 954198092Srdivacky 955218893Sdim eval.begin(CGF); 956193326Sed CGF.EmitBlock(RHSBlock); 957218893Sdim Visit(E->getFalseExpr()); 958218893Sdim eval.end(CGF); 959198092Srdivacky 960193326Sed CGF.EmitBlock(ContBlock); 961193326Sed} 962193326Sed 963198092Srdivackyvoid AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { 964261991Sdim Visit(CE->getChosenSubExpr()); 965198092Srdivacky} 966198092Srdivacky 967193326Sedvoid AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 968296417Sdim Address ArgValue = Address::invalid(); 969296417Sdim Address ArgPtr = CGF.EmitVAArg(VE, ArgValue); 970193326Sed 971309124Sdim // If EmitVAArg fails, emit an error. 972296417Sdim if (!ArgPtr.isValid()) { 973309124Sdim CGF.ErrorUnsupported(VE, "aggregate va_arg expression"); 974193326Sed return; 975193326Sed } 976193326Sed 977239462Sdim EmitFinalDestCopy(VE->getType(), CGF.MakeAddrLValue(ArgPtr, VE->getType())); 978193326Sed} 979193326Sed 980193326Sedvoid AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { 981218893Sdim // Ensure that we have a slot, but if we already do, remember 982226633Sdim // whether it was externally destructed. 983226633Sdim bool wasExternallyDestructed = Dest.isExternallyDestructed(); 984239462Sdim EnsureDest(E->getType()); 985198092Srdivacky 986226633Sdim // We're going to push a destructor if there isn't already one. 987226633Sdim Dest.setExternallyDestructed(); 988226633Sdim 989218893Sdim Visit(E->getSubExpr()); 990193326Sed 991226633Sdim // Push that destructor we promised. 992226633Sdim if (!wasExternallyDestructed) 993296417Sdim CGF.EmitCXXTemporary(E->getTemporary(), E->getType(), Dest.getAddress()); 994193326Sed} 995193326Sed 996193326Sedvoid 997193326SedAggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { 998218893Sdim AggValueSlot Slot = EnsureSlot(E->getType()); 999218893Sdim CGF.EmitCXXConstructExpr(E, Slot); 1000193326Sed} 1001193326Sed 1002309124Sdimvoid AggExprEmitter::VisitCXXInheritedCtorInitExpr( 1003309124Sdim const CXXInheritedCtorInitExpr *E) { 1004309124Sdim AggValueSlot Slot = EnsureSlot(E->getType()); 1005309124Sdim CGF.EmitInheritedCXXConstructorCall( 1006309124Sdim E->getConstructor(), E->constructsVBase(), Slot.getAddress(), 1007309124Sdim E->inheritedFromVBase(), E); 1008309124Sdim} 1009309124Sdim 1010234353Sdimvoid 1011234353SdimAggExprEmitter::VisitLambdaExpr(LambdaExpr *E) { 1012234353Sdim AggValueSlot Slot = EnsureSlot(E->getType()); 1013234353Sdim CGF.EmitLambdaExpr(E, Slot); 1014234353Sdim} 1015234353Sdim 1016218893Sdimvoid AggExprEmitter::VisitExprWithCleanups(ExprWithCleanups *E) { 1017234353Sdim CGF.enterFullExpression(E); 1018234353Sdim CodeGenFunction::RunCleanupsScope cleanups(CGF); 1019234353Sdim Visit(E->getSubExpr()); 1020193326Sed} 1021193326Sed 1022210299Sedvoid AggExprEmitter::VisitCXXScalarValueInitExpr(CXXScalarValueInitExpr *E) { 1023218893Sdim QualType T = E->getType(); 1024218893Sdim AggValueSlot Slot = EnsureSlot(T); 1025296417Sdim EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T)); 1026198398Srdivacky} 1027198398Srdivacky 1028201361Srdivackyvoid AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) { 1029218893Sdim QualType T = E->getType(); 1030218893Sdim AggValueSlot Slot = EnsureSlot(T); 1031296417Sdim EmitNullInitializationToLValue(CGF.MakeAddrLValue(Slot.getAddress(), T)); 1032218893Sdim} 1033201361Srdivacky 1034218893Sdim/// isSimpleZero - If emitting this value will obviously just cause a store of 1035218893Sdim/// zero to memory, return true. This can return false if uncertain, so it just 1036218893Sdim/// handles simple cases. 1037218893Sdimstatic bool isSimpleZero(const Expr *E, CodeGenFunction &CGF) { 1038221345Sdim E = E->IgnoreParens(); 1039221345Sdim 1040218893Sdim // 0 1041218893Sdim if (const IntegerLiteral *IL = dyn_cast<IntegerLiteral>(E)) 1042218893Sdim return IL->getValue() == 0; 1043218893Sdim // +0.0 1044218893Sdim if (const FloatingLiteral *FL = dyn_cast<FloatingLiteral>(E)) 1045218893Sdim return FL->getValue().isPosZero(); 1046218893Sdim // int() 1047218893Sdim if ((isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) && 1048218893Sdim CGF.getTypes().isZeroInitializable(E->getType())) 1049218893Sdim return true; 1050218893Sdim // (int*)0 - Null pointer expressions. 1051218893Sdim if (const CastExpr *ICE = dyn_cast<CastExpr>(E)) 1052218893Sdim return ICE->getCastKind() == CK_NullToPointer; 1053218893Sdim // '\0' 1054218893Sdim if (const CharacterLiteral *CL = dyn_cast<CharacterLiteral>(E)) 1055218893Sdim return CL->getValue() == 0; 1056218893Sdim 1057218893Sdim // Otherwise, hard case: conservatively return false. 1058218893Sdim return false; 1059201361Srdivacky} 1060201361Srdivacky 1061218893Sdim 1062203955Srdivackyvoid 1063261991SdimAggExprEmitter::EmitInitializationToLValue(Expr *E, LValue LV) { 1064224145Sdim QualType type = LV.getType(); 1065193326Sed // FIXME: Ignore result? 1066193326Sed // FIXME: Are initializers affected by volatile? 1067218893Sdim if (Dest.isZeroed() && isSimpleZero(E, CGF)) { 1068218893Sdim // Storing "i32 0" to a zero'd memory location is a noop. 1069249423Sdim return; 1070249423Sdim } else if (isa<ImplicitValueInitExpr>(E) || isa<CXXScalarValueInitExpr>(E)) { 1071249423Sdim return EmitNullInitializationToLValue(LV); 1072288943Sdim } else if (isa<NoInitExpr>(E)) { 1073288943Sdim // Do nothing. 1074288943Sdim return; 1075224145Sdim } else if (type->isReferenceType()) { 1076261991Sdim RValue RV = CGF.EmitReferenceBindingToExpr(E); 1077249423Sdim return CGF.EmitStoreThroughLValue(RV, LV); 1078249423Sdim } 1079249423Sdim 1080249423Sdim switch (CGF.getEvaluationKind(type)) { 1081249423Sdim case TEK_Complex: 1082249423Sdim CGF.EmitComplexExprIntoLValue(E, LV, /*isInit*/ true); 1083249423Sdim return; 1084249423Sdim case TEK_Aggregate: 1085226633Sdim CGF.EmitAggExpr(E, AggValueSlot::forLValue(LV, 1086226633Sdim AggValueSlot::IsDestructed, 1087226633Sdim AggValueSlot::DoesNotNeedGCBarriers, 1088226633Sdim AggValueSlot::IsNotAliased, 1089224145Sdim Dest.isZeroed())); 1090249423Sdim return; 1091249423Sdim case TEK_Scalar: 1092249423Sdim if (LV.isSimple()) { 1093276479Sdim CGF.EmitScalarInit(E, /*D=*/nullptr, LV, /*Captured=*/false); 1094249423Sdim } else { 1095249423Sdim CGF.EmitStoreThroughLValue(RValue::get(CGF.EmitScalarExpr(E)), LV); 1096249423Sdim } 1097249423Sdim return; 1098193326Sed } 1099249423Sdim llvm_unreachable("bad evaluation kind"); 1100193326Sed} 1101193326Sed 1102224145Sdimvoid AggExprEmitter::EmitNullInitializationToLValue(LValue lv) { 1103224145Sdim QualType type = lv.getType(); 1104224145Sdim 1105218893Sdim // If the destination slot is already zeroed out before the aggregate is 1106218893Sdim // copied into it, we don't have to emit any zeros here. 1107224145Sdim if (Dest.isZeroed() && CGF.getTypes().isZeroInitializable(type)) 1108218893Sdim return; 1109218893Sdim 1110249423Sdim if (CGF.hasScalarEvaluationKind(type)) { 1111249423Sdim // For non-aggregates, we can store the appropriate null constant. 1112249423Sdim llvm::Value *null = CGF.CGM.EmitNullConstant(type); 1113234353Sdim // Note that the following is not equivalent to 1114234353Sdim // EmitStoreThroughBitfieldLValue for ARC types. 1115234353Sdim if (lv.isBitField()) { 1116234353Sdim CGF.EmitStoreThroughBitfieldLValue(RValue::get(null), lv); 1117234353Sdim } else { 1118234353Sdim assert(lv.isSimple()); 1119234353Sdim CGF.EmitStoreOfScalar(null, lv, /* isInitialization */ true); 1120234353Sdim } 1121193326Sed } else { 1122193326Sed // There's a potential optimization opportunity in combining 1123193326Sed // memsets; that would be easy for arrays, but relatively 1124193326Sed // difficult for structures with the current code. 1125224145Sdim CGF.EmitNullInitialization(lv.getAddress(), lv.getType()); 1126193326Sed } 1127193326Sed} 1128193326Sed 1129193326Sedvoid AggExprEmitter::VisitInitListExpr(InitListExpr *E) { 1130193326Sed#if 0 1131200583Srdivacky // FIXME: Assess perf here? Figure out what cases are worth optimizing here 1132200583Srdivacky // (Length of globals? Chunks of zeroed-out space?). 1133193326Sed // 1134193326Sed // If we can, prefer a copy from a global; this is a lot less code for long 1135193326Sed // globals, and it's easier for the current optimizers to analyze. 1136200583Srdivacky if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) { 1137193326Sed llvm::GlobalVariable* GV = 1138200583Srdivacky new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true, 1139200583Srdivacky llvm::GlobalValue::InternalLinkage, C, ""); 1140239462Sdim EmitFinalDestCopy(E->getType(), CGF.MakeAddrLValue(GV, E->getType())); 1141193326Sed return; 1142193326Sed } 1143193326Sed#endif 1144218893Sdim if (E->hadArrayRangeDesignator()) 1145193326Sed CGF.ErrorUnsupported(E, "GNU array range designator extension"); 1146193326Sed 1147261991Sdim AggValueSlot Dest = EnsureSlot(E->getType()); 1148218893Sdim 1149296417Sdim LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); 1150234353Sdim 1151193326Sed // Handle initialization of an array. 1152193326Sed if (E->getType()->isArrayType()) { 1153234982Sdim if (E->isStringLiteralInit()) 1154234982Sdim return Visit(E->getInit(0)); 1155193326Sed 1156234353Sdim QualType elementType = 1157234353Sdim CGF.getContext().getAsArrayType(E->getType())->getElementType(); 1158193326Sed 1159296417Sdim auto AType = cast<llvm::ArrayType>(Dest.getAddress().getElementType()); 1160296417Sdim EmitArrayInit(Dest.getAddress(), AType, elementType, E); 1161193326Sed return; 1162193326Sed } 1163198092Srdivacky 1164276479Sdim if (E->getType()->isAtomicType()) { 1165276479Sdim // An _Atomic(T) object can be list-initialized from an expression 1166276479Sdim // of the same type. 1167276479Sdim assert(E->getNumInits() == 1 && 1168276479Sdim CGF.getContext().hasSameUnqualifiedType(E->getInit(0)->getType(), 1169276479Sdim E->getType()) && 1170276479Sdim "unexpected list initialization for atomic object"); 1171276479Sdim return Visit(E->getInit(0)); 1172276479Sdim } 1173276479Sdim 1174193326Sed assert(E->getType()->isRecordType() && "Only support structs/unions here!"); 1175198092Srdivacky 1176193326Sed // Do struct initialization; this code just sets each individual member 1177193326Sed // to the approprate value. This makes bitfield support automatic; 1178193326Sed // the disadvantage is that the generated code is more difficult for 1179193326Sed // the optimizer, especially with bitfields. 1180193326Sed unsigned NumInitElements = E->getNumInits(); 1181224145Sdim RecordDecl *record = E->getType()->castAs<RecordType>()->getDecl(); 1182251662Sdim 1183309124Sdim // We'll need to enter cleanup scopes in case any of the element 1184309124Sdim // initializers throws an exception. 1185309124Sdim SmallVector<EHScopeStack::stable_iterator, 16> cleanups; 1186309124Sdim llvm::Instruction *cleanupDominator = nullptr; 1187309124Sdim 1188309124Sdim unsigned curInitIndex = 0; 1189309124Sdim 1190309124Sdim // Emit initialization of base classes. 1191309124Sdim if (auto *CXXRD = dyn_cast<CXXRecordDecl>(record)) { 1192309124Sdim assert(E->getNumInits() >= CXXRD->getNumBases() && 1193309124Sdim "missing initializer for base class"); 1194309124Sdim for (auto &Base : CXXRD->bases()) { 1195309124Sdim assert(!Base.isVirtual() && "should not see vbases here"); 1196309124Sdim auto *BaseRD = Base.getType()->getAsCXXRecordDecl(); 1197309124Sdim Address V = CGF.GetAddressOfDirectBaseInCompleteClass( 1198309124Sdim Dest.getAddress(), CXXRD, BaseRD, 1199309124Sdim /*isBaseVirtual*/ false); 1200309124Sdim AggValueSlot AggSlot = 1201309124Sdim AggValueSlot::forAddr(V, Qualifiers(), 1202309124Sdim AggValueSlot::IsDestructed, 1203309124Sdim AggValueSlot::DoesNotNeedGCBarriers, 1204309124Sdim AggValueSlot::IsNotAliased); 1205309124Sdim CGF.EmitAggExpr(E->getInit(curInitIndex++), AggSlot); 1206309124Sdim 1207309124Sdim if (QualType::DestructionKind dtorKind = 1208309124Sdim Base.getType().isDestructedType()) { 1209309124Sdim CGF.pushDestroy(dtorKind, V, Base.getType()); 1210309124Sdim cleanups.push_back(CGF.EHStack.stable_begin()); 1211309124Sdim } 1212309124Sdim } 1213309124Sdim } 1214309124Sdim 1215251662Sdim // Prepare a 'this' for CXXDefaultInitExprs. 1216296417Sdim CodeGenFunction::FieldConstructionScope FCS(CGF, Dest.getAddress()); 1217251662Sdim 1218224145Sdim if (record->isUnion()) { 1219193326Sed // Only initialize one field of a union. The field itself is 1220193326Sed // specified by the initializer list. 1221193326Sed if (!E->getInitializedFieldInUnion()) { 1222193326Sed // Empty union; we have nothing to do. 1223198092Srdivacky 1224193326Sed#ifndef NDEBUG 1225193326Sed // Make sure that it's really an empty and not a failure of 1226193326Sed // semantic analysis. 1227276479Sdim for (const auto *Field : record->fields()) 1228193326Sed assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); 1229193326Sed#endif 1230193326Sed return; 1231193326Sed } 1232193326Sed 1233193326Sed // FIXME: volatility 1234193326Sed FieldDecl *Field = E->getInitializedFieldInUnion(); 1235218893Sdim 1236234982Sdim LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestLV, Field); 1237193326Sed if (NumInitElements) { 1238193326Sed // Store the initializer into the field 1239224145Sdim EmitInitializationToLValue(E->getInit(0), FieldLoc); 1240193326Sed } else { 1241218893Sdim // Default-initialize to null. 1242224145Sdim EmitNullInitializationToLValue(FieldLoc); 1243193326Sed } 1244193326Sed 1245193326Sed return; 1246193326Sed } 1247198092Srdivacky 1248193326Sed // Here we iterate over the fields; this makes it simpler to both 1249193326Sed // default-initialize fields and skip over unnamed fields. 1250276479Sdim for (const auto *field : record->fields()) { 1251224145Sdim // We're done once we hit the flexible array member. 1252224145Sdim if (field->getType()->isIncompleteArrayType()) 1253193326Sed break; 1254193326Sed 1255224145Sdim // Always skip anonymous bitfields. 1256224145Sdim if (field->isUnnamedBitfield()) 1257193326Sed continue; 1258193326Sed 1259224145Sdim // We're done if we reach the end of the explicit initializers, we 1260224145Sdim // have a zeroed object, and the rest of the fields are 1261224145Sdim // zero-initializable. 1262224145Sdim if (curInitIndex == NumInitElements && Dest.isZeroed() && 1263218893Sdim CGF.getTypes().isZeroInitializable(E->getType())) 1264218893Sdim break; 1265218893Sdim 1266234982Sdim 1267276479Sdim LValue LV = CGF.EmitLValueForFieldInitialization(DestLV, field); 1268193326Sed // We never generate write-barries for initialized fields. 1269224145Sdim LV.setNonGC(true); 1270218893Sdim 1271224145Sdim if (curInitIndex < NumInitElements) { 1272204962Srdivacky // Store the initializer into the field. 1273224145Sdim EmitInitializationToLValue(E->getInit(curInitIndex++), LV); 1274193326Sed } else { 1275193326Sed // We're out of initalizers; default-initialize to null 1276224145Sdim EmitNullInitializationToLValue(LV); 1277193326Sed } 1278224145Sdim 1279224145Sdim // Push a destructor if necessary. 1280224145Sdim // FIXME: if we have an array of structures, all explicitly 1281224145Sdim // initialized, we can end up pushing a linear number of cleanups. 1282224145Sdim bool pushedCleanup = false; 1283224145Sdim if (QualType::DestructionKind dtorKind 1284224145Sdim = field->getType().isDestructedType()) { 1285224145Sdim assert(LV.isSimple()); 1286224145Sdim if (CGF.needsEHCleanup(dtorKind)) { 1287234353Sdim if (!cleanupDominator) 1288296417Sdim cleanupDominator = CGF.Builder.CreateAlignedLoad( 1289296417Sdim CGF.Int8Ty, 1290296417Sdim llvm::Constant::getNullValue(CGF.Int8PtrTy), 1291296417Sdim CharUnits::One()); // placeholder 1292234353Sdim 1293224145Sdim CGF.pushDestroy(EHCleanup, LV.getAddress(), field->getType(), 1294224145Sdim CGF.getDestroyer(dtorKind), false); 1295224145Sdim cleanups.push_back(CGF.EHStack.stable_begin()); 1296224145Sdim pushedCleanup = true; 1297224145Sdim } 1298224145Sdim } 1299218893Sdim 1300218893Sdim // If the GEP didn't get used because of a dead zero init or something 1301218893Sdim // else, clean it up for -O0 builds and general tidiness. 1302224145Sdim if (!pushedCleanup && LV.isSimple()) 1303218893Sdim if (llvm::GetElementPtrInst *GEP = 1304296417Sdim dyn_cast<llvm::GetElementPtrInst>(LV.getPointer())) 1305218893Sdim if (GEP->use_empty()) 1306218893Sdim GEP->eraseFromParent(); 1307193326Sed } 1308224145Sdim 1309224145Sdim // Deactivate all the partial cleanups in reverse order, which 1310224145Sdim // generally means popping them. 1311224145Sdim for (unsigned i = cleanups.size(); i != 0; --i) 1312234353Sdim CGF.DeactivateCleanupBlock(cleanups[i-1], cleanupDominator); 1313234353Sdim 1314234353Sdim // Destroy the placeholder if we made one. 1315234353Sdim if (cleanupDominator) 1316234353Sdim cleanupDominator->eraseFromParent(); 1317193326Sed} 1318193326Sed 1319288943Sdimvoid AggExprEmitter::VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E) { 1320288943Sdim AggValueSlot Dest = EnsureSlot(E->getType()); 1321288943Sdim 1322296417Sdim LValue DestLV = CGF.MakeAddrLValue(Dest.getAddress(), E->getType()); 1323288943Sdim EmitInitializationToLValue(E->getBase(), DestLV); 1324288943Sdim VisitInitListExpr(E->getUpdater()); 1325288943Sdim} 1326288943Sdim 1327193326Sed//===----------------------------------------------------------------------===// 1328193326Sed// Entry Points into this File 1329193326Sed//===----------------------------------------------------------------------===// 1330193326Sed 1331218893Sdim/// GetNumNonZeroBytesInInit - Get an approximate count of the number of 1332218893Sdim/// non-zero bytes that will be stored when outputting the initializer for the 1333218893Sdim/// specified initializer expression. 1334221345Sdimstatic CharUnits GetNumNonZeroBytesInInit(const Expr *E, CodeGenFunction &CGF) { 1335221345Sdim E = E->IgnoreParens(); 1336218893Sdim 1337218893Sdim // 0 and 0.0 won't require any non-zero stores! 1338221345Sdim if (isSimpleZero(E, CGF)) return CharUnits::Zero(); 1339218893Sdim 1340218893Sdim // If this is an initlist expr, sum up the size of sizes of the (present) 1341218893Sdim // elements. If this is something weird, assume the whole thing is non-zero. 1342218893Sdim const InitListExpr *ILE = dyn_cast<InitListExpr>(E); 1343276479Sdim if (!ILE || !CGF.getTypes().isZeroInitializable(ILE->getType())) 1344221345Sdim return CGF.getContext().getTypeSizeInChars(E->getType()); 1345218893Sdim 1346218893Sdim // InitListExprs for structs have to be handled carefully. If there are 1347218893Sdim // reference members, we need to consider the size of the reference, not the 1348218893Sdim // referencee. InitListExprs for unions and arrays can't have references. 1349218893Sdim if (const RecordType *RT = E->getType()->getAs<RecordType>()) { 1350218893Sdim if (!RT->isUnionType()) { 1351218893Sdim RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl(); 1352221345Sdim CharUnits NumNonZeroBytes = CharUnits::Zero(); 1353218893Sdim 1354218893Sdim unsigned ILEElement = 0; 1355309124Sdim if (auto *CXXRD = dyn_cast<CXXRecordDecl>(SD)) 1356309124Sdim while (ILEElement != CXXRD->getNumBases()) 1357309124Sdim NumNonZeroBytes += 1358309124Sdim GetNumNonZeroBytesInInit(ILE->getInit(ILEElement++), CGF); 1359276479Sdim for (const auto *Field : SD->fields()) { 1360218893Sdim // We're done once we hit the flexible array member or run out of 1361218893Sdim // InitListExpr elements. 1362218893Sdim if (Field->getType()->isIncompleteArrayType() || 1363218893Sdim ILEElement == ILE->getNumInits()) 1364218893Sdim break; 1365218893Sdim if (Field->isUnnamedBitfield()) 1366218893Sdim continue; 1367218893Sdim 1368218893Sdim const Expr *E = ILE->getInit(ILEElement++); 1369218893Sdim 1370218893Sdim // Reference values are always non-null and have the width of a pointer. 1371218893Sdim if (Field->getType()->isReferenceType()) 1372221345Sdim NumNonZeroBytes += CGF.getContext().toCharUnitsFromBits( 1373251662Sdim CGF.getTarget().getPointerWidth(0)); 1374218893Sdim else 1375218893Sdim NumNonZeroBytes += GetNumNonZeroBytesInInit(E, CGF); 1376218893Sdim } 1377218893Sdim 1378218893Sdim return NumNonZeroBytes; 1379218893Sdim } 1380218893Sdim } 1381218893Sdim 1382218893Sdim 1383221345Sdim CharUnits NumNonZeroBytes = CharUnits::Zero(); 1384218893Sdim for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) 1385218893Sdim NumNonZeroBytes += GetNumNonZeroBytesInInit(ILE->getInit(i), CGF); 1386218893Sdim return NumNonZeroBytes; 1387218893Sdim} 1388218893Sdim 1389218893Sdim/// CheckAggExprForMemSetUse - If the initializer is large and has a lot of 1390218893Sdim/// zeros in it, emit a memset and avoid storing the individual zeros. 1391218893Sdim/// 1392218893Sdimstatic void CheckAggExprForMemSetUse(AggValueSlot &Slot, const Expr *E, 1393218893Sdim CodeGenFunction &CGF) { 1394218893Sdim // If the slot is already known to be zeroed, nothing to do. Don't mess with 1395218893Sdim // volatile stores. 1396296417Sdim if (Slot.isZeroed() || Slot.isVolatile() || !Slot.getAddress().isValid()) 1397276479Sdim return; 1398221345Sdim 1399221345Sdim // C++ objects with a user-declared constructor don't need zero'ing. 1400243830Sdim if (CGF.getLangOpts().CPlusPlus) 1401221345Sdim if (const RecordType *RT = CGF.getContext() 1402221345Sdim .getBaseElementType(E->getType())->getAs<RecordType>()) { 1403221345Sdim const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 1404221345Sdim if (RD->hasUserDeclaredConstructor()) 1405221345Sdim return; 1406221345Sdim } 1407221345Sdim 1408218893Sdim // If the type is 16-bytes or smaller, prefer individual stores over memset. 1409296417Sdim CharUnits Size = CGF.getContext().getTypeSizeInChars(E->getType()); 1410296417Sdim if (Size <= CharUnits::fromQuantity(16)) 1411218893Sdim return; 1412218893Sdim 1413218893Sdim // Check to see if over 3/4 of the initializer are known to be zero. If so, 1414218893Sdim // we prefer to emit memset + individual stores for the rest. 1415221345Sdim CharUnits NumNonZeroBytes = GetNumNonZeroBytesInInit(E, CGF); 1416296417Sdim if (NumNonZeroBytes*4 > Size) 1417218893Sdim return; 1418218893Sdim 1419218893Sdim // Okay, it seems like a good idea to use an initial memset, emit the call. 1420296417Sdim llvm::Constant *SizeVal = CGF.Builder.getInt64(Size.getQuantity()); 1421218893Sdim 1422296417Sdim Address Loc = Slot.getAddress(); 1423296417Sdim Loc = CGF.Builder.CreateElementBitCast(Loc, CGF.Int8Ty); 1424296417Sdim CGF.Builder.CreateMemSet(Loc, CGF.Builder.getInt8(0), SizeVal, false); 1425218893Sdim 1426218893Sdim // Tell the AggExprEmitter that the slot is known zero. 1427218893Sdim Slot.setZeroed(); 1428218893Sdim} 1429218893Sdim 1430218893Sdim 1431218893Sdim 1432218893Sdim 1433193326Sed/// EmitAggExpr - Emit the computation of the specified expression of aggregate 1434193326Sed/// type. The result is computed into DestPtr. Note that if DestPtr is null, 1435193326Sed/// the value of the aggregate expression is not needed. If VolatileDest is 1436193326Sed/// true, DestPtr cannot be 0. 1437239462Sdimvoid CodeGenFunction::EmitAggExpr(const Expr *E, AggValueSlot Slot) { 1438249423Sdim assert(E && hasAggregateEvaluationKind(E->getType()) && 1439193326Sed "Invalid aggregate expression to emit"); 1440296417Sdim assert((Slot.getAddress().isValid() || Slot.isIgnored()) && 1441218893Sdim "slot has bits but no address"); 1442198092Srdivacky 1443218893Sdim // Optimize the slot if possible. 1444218893Sdim CheckAggExprForMemSetUse(Slot, E, *this); 1445218893Sdim 1446288943Sdim AggExprEmitter(*this, Slot, Slot.isIgnored()).Visit(const_cast<Expr*>(E)); 1447193326Sed} 1448193326Sed 1449203955SrdivackyLValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) { 1450249423Sdim assert(hasAggregateEvaluationKind(E->getType()) && "Invalid argument!"); 1451296417Sdim Address Temp = CreateMemTemp(E->getType()); 1452212904Sdim LValue LV = MakeAddrLValue(Temp, E->getType()); 1453226633Sdim EmitAggExpr(E, AggValueSlot::forLValue(LV, AggValueSlot::IsNotDestructed, 1454226633Sdim AggValueSlot::DoesNotNeedGCBarriers, 1455226633Sdim AggValueSlot::IsNotAliased)); 1456212904Sdim return LV; 1457203955Srdivacky} 1458203955Srdivacky 1459296417Sdimvoid CodeGenFunction::EmitAggregateCopy(Address DestPtr, 1460296417Sdim Address SrcPtr, QualType Ty, 1461239462Sdim bool isVolatile, 1462243830Sdim bool isAssignment) { 1463193326Sed assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); 1464198092Srdivacky 1465243830Sdim if (getLangOpts().CPlusPlus) { 1466207619Srdivacky if (const RecordType *RT = Ty->getAs<RecordType>()) { 1467208600Srdivacky CXXRecordDecl *Record = cast<CXXRecordDecl>(RT->getDecl()); 1468208600Srdivacky assert((Record->hasTrivialCopyConstructor() || 1469226633Sdim Record->hasTrivialCopyAssignment() || 1470226633Sdim Record->hasTrivialMoveConstructor() || 1471288943Sdim Record->hasTrivialMoveAssignment() || 1472288943Sdim Record->isUnion()) && 1473249423Sdim "Trying to aggregate-copy a type without a trivial copy/move " 1474208600Srdivacky "constructor or assignment operator"); 1475208600Srdivacky // Ignore empty classes in C++. 1476208600Srdivacky if (Record->isEmpty()) 1477207619Srdivacky return; 1478207619Srdivacky } 1479207619Srdivacky } 1480207619Srdivacky 1481193326Sed // Aggregate assignment turns into llvm.memcpy. This is almost valid per 1482193326Sed // C99 6.5.16.1p3, which states "If the value being stored in an object is 1483193326Sed // read from another object that overlaps in anyway the storage of the first 1484193326Sed // object, then the overlap shall be exact and the two objects shall have 1485193326Sed // qualified or unqualified versions of a compatible type." 1486193326Sed // 1487193326Sed // memcpy is not defined if the source and destination pointers are exactly 1488193326Sed // equal, but other compilers do this optimization, and almost every memcpy 1489193326Sed // implementation handles this case safely. If there is a libc that does not 1490193326Sed // safely handle this, we can add a target hook. 1491198092Srdivacky 1492296417Sdim // Get data size info for this aggregate. If this is an assignment, 1493296417Sdim // don't copy the tail padding, because we might be assigning into a 1494296417Sdim // base subobject where the tail padding is claimed. Otherwise, 1495296417Sdim // copying it is fine. 1496243830Sdim std::pair<CharUnits, CharUnits> TypeInfo; 1497243830Sdim if (isAssignment) 1498243830Sdim TypeInfo = getContext().getTypeInfoDataSizeInChars(Ty); 1499243830Sdim else 1500243830Sdim TypeInfo = getContext().getTypeInfoInChars(Ty); 1501198092Srdivacky 1502288943Sdim llvm::Value *SizeVal = nullptr; 1503288943Sdim if (TypeInfo.first.isZero()) { 1504288943Sdim // But note that getTypeInfo returns 0 for a VLA. 1505288943Sdim if (auto *VAT = dyn_cast_or_null<VariableArrayType>( 1506288943Sdim getContext().getAsArrayType(Ty))) { 1507288943Sdim QualType BaseEltTy; 1508288943Sdim SizeVal = emitArrayLength(VAT, BaseEltTy, DestPtr); 1509288943Sdim TypeInfo = getContext().getTypeInfoDataSizeInChars(BaseEltTy); 1510288943Sdim std::pair<CharUnits, CharUnits> LastElementTypeInfo; 1511288943Sdim if (!isAssignment) 1512288943Sdim LastElementTypeInfo = getContext().getTypeInfoInChars(BaseEltTy); 1513288943Sdim assert(!TypeInfo.first.isZero()); 1514288943Sdim SizeVal = Builder.CreateNUWMul( 1515288943Sdim SizeVal, 1516288943Sdim llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity())); 1517288943Sdim if (!isAssignment) { 1518288943Sdim SizeVal = Builder.CreateNUWSub( 1519288943Sdim SizeVal, 1520288943Sdim llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity())); 1521288943Sdim SizeVal = Builder.CreateNUWAdd( 1522288943Sdim SizeVal, llvm::ConstantInt::get( 1523288943Sdim SizeTy, LastElementTypeInfo.first.getQuantity())); 1524288943Sdim } 1525288943Sdim } 1526288943Sdim } 1527288943Sdim if (!SizeVal) { 1528288943Sdim SizeVal = llvm::ConstantInt::get(SizeTy, TypeInfo.first.getQuantity()); 1529288943Sdim } 1530198092Srdivacky 1531193326Sed // FIXME: If we have a volatile struct, the optimizer can remove what might 1532193326Sed // appear to be `extra' memory ops: 1533193326Sed // 1534193326Sed // volatile struct { int i; } a, b; 1535193326Sed // 1536193326Sed // int main() { 1537193326Sed // a = b; 1538193326Sed // a = b; 1539193326Sed // } 1540193326Sed // 1541206275Srdivacky // we need to use a different call here. We use isVolatile to indicate when 1542193326Sed // either the source or the destination is volatile. 1543206275Srdivacky 1544296417Sdim DestPtr = Builder.CreateElementBitCast(DestPtr, Int8Ty); 1545296417Sdim SrcPtr = Builder.CreateElementBitCast(SrcPtr, Int8Ty); 1546206275Srdivacky 1547224145Sdim // Don't do any of the memmove_collectable tests if GC isn't set. 1548234353Sdim if (CGM.getLangOpts().getGC() == LangOptions::NonGC) { 1549224145Sdim // fall through 1550224145Sdim } else if (const RecordType *RecordTy = Ty->getAs<RecordType>()) { 1551210299Sed RecordDecl *Record = RecordTy->getDecl(); 1552210299Sed if (Record->hasObjectMember()) { 1553210299Sed CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, 1554210299Sed SizeVal); 1555210299Sed return; 1556210299Sed } 1557224145Sdim } else if (Ty->isArrayType()) { 1558210299Sed QualType BaseType = getContext().getBaseElementType(Ty); 1559210299Sed if (const RecordType *RecordTy = BaseType->getAs<RecordType>()) { 1560210299Sed if (RecordTy->getDecl()->hasObjectMember()) { 1561210299Sed CGM.getObjCRuntime().EmitGCMemmoveCollectable(*this, DestPtr, SrcPtr, 1562210299Sed SizeVal); 1563210299Sed return; 1564210299Sed } 1565210299Sed } 1566210299Sed } 1567243830Sdim 1568296417Sdim auto Inst = Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, isVolatile); 1569296417Sdim 1570243830Sdim // Determine the metadata to describe the position of any padding in this 1571243830Sdim // memcpy, as well as the TBAA tags for the members of the struct, in case 1572243830Sdim // the optimizer wishes to expand it in to scalar memory operations. 1573296417Sdim if (llvm::MDNode *TBAAStructTag = CGM.getTBAAStructInfo(Ty)) 1574296417Sdim Inst->setMetadata(llvm::LLVMContext::MD_tbaa_struct, TBAAStructTag); 1575193326Sed} 1576