CGExprAgg.cpp revision 203955
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" 15193326Sed#include "CodeGenModule.h" 16198092Srdivacky#include "CGObjCRuntime.h" 17193326Sed#include "clang/AST/ASTContext.h" 18193326Sed#include "clang/AST/DeclCXX.h" 19193326Sed#include "clang/AST/StmtVisitor.h" 20193326Sed#include "llvm/Constants.h" 21193326Sed#include "llvm/Function.h" 22193326Sed#include "llvm/GlobalVariable.h" 23193326Sed#include "llvm/Intrinsics.h" 24193326Sedusing namespace clang; 25193326Sedusing namespace CodeGen; 26193326Sed 27193326Sed//===----------------------------------------------------------------------===// 28193326Sed// Aggregate Expression Emitter 29193326Sed//===----------------------------------------------------------------------===// 30193326Sed 31193326Sednamespace { 32199990Srdivackyclass AggExprEmitter : public StmtVisitor<AggExprEmitter> { 33193326Sed CodeGenFunction &CGF; 34193326Sed CGBuilderTy &Builder; 35193326Sed llvm::Value *DestPtr; 36193326Sed bool VolatileDest; 37193326Sed bool IgnoreResult; 38198092Srdivacky bool IsInitializer; 39198092Srdivacky bool RequiresGCollection; 40193326Sedpublic: 41193326Sed AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool v, 42198092Srdivacky bool ignore, bool isinit, bool requiresGCollection) 43193326Sed : CGF(cgf), Builder(CGF.Builder), 44198092Srdivacky DestPtr(destPtr), VolatileDest(v), IgnoreResult(ignore), 45198092Srdivacky IsInitializer(isinit), RequiresGCollection(requiresGCollection) { 46193326Sed } 47193326Sed 48193326Sed //===--------------------------------------------------------------------===// 49193326Sed // Utilities 50193326Sed //===--------------------------------------------------------------------===// 51193326Sed 52193326Sed /// EmitAggLoadOfLValue - Given an expression with aggregate type that 53193326Sed /// represents a value lvalue, this method emits the address of the lvalue, 54193326Sed /// then loads the result into DestPtr. 55193326Sed void EmitAggLoadOfLValue(const Expr *E); 56193326Sed 57193326Sed /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 58193326Sed void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false); 59193326Sed void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false); 60193326Sed 61193326Sed //===--------------------------------------------------------------------===// 62193326Sed // Visitor Methods 63193326Sed //===--------------------------------------------------------------------===// 64198092Srdivacky 65193326Sed void VisitStmt(Stmt *S) { 66193326Sed CGF.ErrorUnsupported(S, "aggregate expression"); 67193326Sed } 68193326Sed void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } 69193326Sed void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } 70193326Sed 71193326Sed // l-values. 72193326Sed void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); } 73193326Sed void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } 74193326Sed void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } 75193326Sed void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } 76193326Sed void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 77198092Srdivacky EmitAggLoadOfLValue(E); 78193326Sed } 79193326Sed void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 80193326Sed EmitAggLoadOfLValue(E); 81193326Sed } 82193326Sed void VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 83198092Srdivacky EmitAggLoadOfLValue(E); 84193326Sed } 85193326Sed void VisitPredefinedExpr(const PredefinedExpr *E) { 86198092Srdivacky EmitAggLoadOfLValue(E); 87193326Sed } 88198092Srdivacky 89193326Sed // Operators. 90198092Srdivacky void VisitCastExpr(CastExpr *E); 91193326Sed void VisitCallExpr(const CallExpr *E); 92193326Sed void VisitStmtExpr(const StmtExpr *E); 93193326Sed void VisitBinaryOperator(const BinaryOperator *BO); 94198398Srdivacky void VisitPointerToDataMemberBinaryOperator(const BinaryOperator *BO); 95193326Sed void VisitBinAssign(const BinaryOperator *E); 96193326Sed void VisitBinComma(const BinaryOperator *E); 97198092Srdivacky void VisitUnaryAddrOf(const UnaryOperator *E); 98193326Sed 99193326Sed void VisitObjCMessageExpr(ObjCMessageExpr *E); 100193326Sed void VisitObjCIvarRefExpr(ObjCIvarRefExpr *E) { 101193326Sed EmitAggLoadOfLValue(E); 102193326Sed } 103193326Sed void VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E); 104198092Srdivacky void VisitObjCImplicitSetterGetterRefExpr(ObjCImplicitSetterGetterRefExpr *E); 105198092Srdivacky 106193326Sed void VisitConditionalOperator(const ConditionalOperator *CO); 107198092Srdivacky void VisitChooseExpr(const ChooseExpr *CE); 108193326Sed void VisitInitListExpr(InitListExpr *E); 109201361Srdivacky void VisitImplicitValueInitExpr(ImplicitValueInitExpr *E); 110193326Sed void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 111193326Sed Visit(DAE->getExpr()); 112193326Sed } 113193326Sed void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); 114193326Sed void VisitCXXConstructExpr(const CXXConstructExpr *E); 115193326Sed void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E); 116198398Srdivacky void VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E); 117199482Srdivacky void VisitCXXTypeidExpr(CXXTypeidExpr *E) { EmitAggLoadOfLValue(E); } 118193326Sed 119193326Sed void VisitVAArgExpr(VAArgExpr *E); 120193326Sed 121203955Srdivacky void EmitInitializationToLValue(Expr *E, LValue Address, QualType T); 122193326Sed void EmitNullInitializationToLValue(LValue Address, QualType T); 123193326Sed // case Expr::ChooseExprClass: 124200583Srdivacky void VisitCXXThrowExpr(const CXXThrowExpr *E) { CGF.EmitCXXThrowExpr(E); } 125193326Sed}; 126193326Sed} // end anonymous namespace. 127193326Sed 128193326Sed//===----------------------------------------------------------------------===// 129193326Sed// Utilities 130193326Sed//===----------------------------------------------------------------------===// 131193326Sed 132193326Sed/// EmitAggLoadOfLValue - Given an expression with aggregate type that 133193326Sed/// represents a value lvalue, this method emits the address of the lvalue, 134193326Sed/// then loads the result into DestPtr. 135193326Sedvoid AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { 136193326Sed LValue LV = CGF.EmitLValue(E); 137193326Sed EmitFinalDestCopy(E, LV); 138193326Sed} 139193326Sed 140193326Sed/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 141193326Sedvoid AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) { 142193326Sed assert(Src.isAggregate() && "value must be aggregate value!"); 143193326Sed 144193326Sed // If the result is ignored, don't copy from the value. 145193326Sed if (DestPtr == 0) { 146193326Sed if (!Src.isVolatileQualified() || (IgnoreResult && Ignore)) 147193326Sed return; 148193326Sed // If the source is volatile, we must read from it; to do that, we need 149193326Sed // some place to put it. 150203955Srdivacky DestPtr = CGF.CreateMemTemp(E->getType(), "agg.tmp"); 151193326Sed } 152193326Sed 153198092Srdivacky if (RequiresGCollection) { 154198092Srdivacky CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, 155198092Srdivacky DestPtr, Src.getAggregateAddr(), 156198092Srdivacky E->getType()); 157198092Srdivacky return; 158198092Srdivacky } 159193326Sed // If the result of the assignment is used, copy the LHS there also. 160193326Sed // FIXME: Pass VolatileDest as well. I think we also need to merge volatile 161193326Sed // from the source as well, as we can't eliminate it if either operand 162193326Sed // is volatile, unless copy has volatile for both source and destination.. 163193326Sed CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(), 164193326Sed VolatileDest|Src.isVolatileQualified()); 165193326Sed} 166193326Sed 167193326Sed/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 168193326Sedvoid AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) { 169193326Sed assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc"); 170193326Sed 171193326Sed EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(), 172193326Sed Src.isVolatileQualified()), 173193326Sed Ignore); 174193326Sed} 175193326Sed 176193326Sed//===----------------------------------------------------------------------===// 177193326Sed// Visitor Methods 178193326Sed//===----------------------------------------------------------------------===// 179193326Sed 180198092Srdivackyvoid AggExprEmitter::VisitCastExpr(CastExpr *E) { 181198092Srdivacky switch (E->getCastKind()) { 182198092Srdivacky default: assert(0 && "Unhandled cast kind!"); 183198092Srdivacky 184198092Srdivacky case CastExpr::CK_ToUnion: { 185198092Srdivacky // GCC union extension 186193401Sed QualType PtrTy = 187198092Srdivacky CGF.getContext().getPointerType(E->getSubExpr()->getType()); 188193401Sed llvm::Value *CastPtr = Builder.CreateBitCast(DestPtr, 189193401Sed CGF.ConvertType(PtrTy)); 190198092Srdivacky EmitInitializationToLValue(E->getSubExpr(), 191203955Srdivacky LValue::MakeAddr(CastPtr, Qualifiers()), 192203955Srdivacky E->getType()); 193198092Srdivacky break; 194193326Sed } 195193326Sed 196198092Srdivacky // FIXME: Remove the CK_Unknown check here. 197198092Srdivacky case CastExpr::CK_Unknown: 198198092Srdivacky case CastExpr::CK_NoOp: 199198092Srdivacky case CastExpr::CK_UserDefinedConversion: 200198092Srdivacky case CastExpr::CK_ConstructorConversion: 201198092Srdivacky assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), 202198092Srdivacky E->getType()) && 203198092Srdivacky "Implicit cast types must be compatible"); 204198092Srdivacky Visit(E->getSubExpr()); 205198092Srdivacky break; 206193326Sed 207198092Srdivacky case CastExpr::CK_NullToMemberPointer: { 208198092Srdivacky const llvm::Type *PtrDiffTy = 209198092Srdivacky CGF.ConvertType(CGF.getContext().getPointerDiffType()); 210198092Srdivacky 211198092Srdivacky llvm::Value *NullValue = llvm::Constant::getNullValue(PtrDiffTy); 212198092Srdivacky llvm::Value *Ptr = Builder.CreateStructGEP(DestPtr, 0, "ptr"); 213198092Srdivacky Builder.CreateStore(NullValue, Ptr, VolatileDest); 214198092Srdivacky 215198092Srdivacky llvm::Value *Adj = Builder.CreateStructGEP(DestPtr, 1, "adj"); 216198092Srdivacky Builder.CreateStore(NullValue, Adj, VolatileDest); 217198092Srdivacky 218198092Srdivacky break; 219198092Srdivacky } 220198092Srdivacky 221198398Srdivacky case CastExpr::CK_BitCast: { 222198398Srdivacky // This must be a member function pointer cast. 223198398Srdivacky Visit(E->getSubExpr()); 224198398Srdivacky break; 225198398Srdivacky } 226198398Srdivacky 227199990Srdivacky case CastExpr::CK_DerivedToBaseMemberPointer: 228198092Srdivacky case CastExpr::CK_BaseToDerivedMemberPointer: { 229198092Srdivacky QualType SrcType = E->getSubExpr()->getType(); 230198092Srdivacky 231203955Srdivacky llvm::Value *Src = CGF.CreateMemTemp(SrcType, "tmp"); 232198092Srdivacky CGF.EmitAggExpr(E->getSubExpr(), Src, SrcType.isVolatileQualified()); 233198092Srdivacky 234198092Srdivacky llvm::Value *SrcPtr = Builder.CreateStructGEP(Src, 0, "src.ptr"); 235198092Srdivacky SrcPtr = Builder.CreateLoad(SrcPtr); 236198092Srdivacky 237198092Srdivacky llvm::Value *SrcAdj = Builder.CreateStructGEP(Src, 1, "src.adj"); 238198092Srdivacky SrcAdj = Builder.CreateLoad(SrcAdj); 239198092Srdivacky 240198092Srdivacky llvm::Value *DstPtr = Builder.CreateStructGEP(DestPtr, 0, "dst.ptr"); 241198092Srdivacky Builder.CreateStore(SrcPtr, DstPtr, VolatileDest); 242198092Srdivacky 243198092Srdivacky llvm::Value *DstAdj = Builder.CreateStructGEP(DestPtr, 1, "dst.adj"); 244198092Srdivacky 245198092Srdivacky // Now See if we need to update the adjustment. 246199990Srdivacky const CXXRecordDecl *BaseDecl = 247198092Srdivacky cast<CXXRecordDecl>(SrcType->getAs<MemberPointerType>()-> 248198092Srdivacky getClass()->getAs<RecordType>()->getDecl()); 249199990Srdivacky const CXXRecordDecl *DerivedDecl = 250198092Srdivacky cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 251198092Srdivacky getClass()->getAs<RecordType>()->getDecl()); 252199990Srdivacky if (E->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 253199990Srdivacky std::swap(DerivedDecl, BaseDecl); 254199990Srdivacky 255203955Srdivacky if (llvm::Constant *Adj = 256203955Srdivacky CGF.CGM.GetNonVirtualBaseClassOffset(DerivedDecl, BaseDecl)) { 257199990Srdivacky if (E->getCastKind() == CastExpr::CK_DerivedToBaseMemberPointer) 258199990Srdivacky SrcAdj = Builder.CreateSub(SrcAdj, Adj, "adj"); 259199990Srdivacky else 260199990Srdivacky SrcAdj = Builder.CreateAdd(SrcAdj, Adj, "adj"); 261199990Srdivacky } 262198092Srdivacky 263198092Srdivacky Builder.CreateStore(SrcAdj, DstAdj, VolatileDest); 264198092Srdivacky break; 265198092Srdivacky } 266198092Srdivacky } 267193326Sed} 268193326Sed 269193326Sedvoid AggExprEmitter::VisitCallExpr(const CallExpr *E) { 270193326Sed if (E->getCallReturnType()->isReferenceType()) { 271193326Sed EmitAggLoadOfLValue(E); 272193326Sed return; 273193326Sed } 274198092Srdivacky 275201361Srdivacky // If the struct doesn't require GC, we can just pass the destination 276201361Srdivacky // directly to EmitCall. 277201361Srdivacky if (!RequiresGCollection) { 278201361Srdivacky CGF.EmitCallExpr(E, ReturnValueSlot(DestPtr, VolatileDest)); 279201361Srdivacky return; 280201361Srdivacky } 281201361Srdivacky 282193326Sed RValue RV = CGF.EmitCallExpr(E); 283193326Sed EmitFinalDestCopy(E, RV); 284193326Sed} 285193326Sed 286193326Sedvoid AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { 287193326Sed RValue RV = CGF.EmitObjCMessageExpr(E); 288193326Sed EmitFinalDestCopy(E, RV); 289193326Sed} 290193326Sed 291193326Sedvoid AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 292193326Sed RValue RV = CGF.EmitObjCPropertyGet(E); 293193326Sed EmitFinalDestCopy(E, RV); 294193326Sed} 295193326Sed 296198092Srdivackyvoid AggExprEmitter::VisitObjCImplicitSetterGetterRefExpr( 297198092Srdivacky ObjCImplicitSetterGetterRefExpr *E) { 298193326Sed RValue RV = CGF.EmitObjCPropertyGet(E); 299193326Sed EmitFinalDestCopy(E, RV); 300193326Sed} 301193326Sed 302193326Sedvoid AggExprEmitter::VisitBinComma(const BinaryOperator *E) { 303193326Sed CGF.EmitAnyExpr(E->getLHS(), 0, false, true); 304198092Srdivacky CGF.EmitAggExpr(E->getRHS(), DestPtr, VolatileDest, 305198092Srdivacky /*IgnoreResult=*/false, IsInitializer); 306193326Sed} 307193326Sed 308198092Srdivackyvoid AggExprEmitter::VisitUnaryAddrOf(const UnaryOperator *E) { 309198092Srdivacky // We have a member function pointer. 310198092Srdivacky const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 311198398Srdivacky (void) MPT; 312198092Srdivacky assert(MPT->getPointeeType()->isFunctionProtoType() && 313198092Srdivacky "Unexpected member pointer type!"); 314198092Srdivacky 315198893Srdivacky const DeclRefExpr *DRE = cast<DeclRefExpr>(E->getSubExpr()); 316202379Srdivacky const CXXMethodDecl *MD = 317202379Srdivacky cast<CXXMethodDecl>(DRE->getDecl())->getCanonicalDecl(); 318198092Srdivacky 319198092Srdivacky const llvm::Type *PtrDiffTy = 320198092Srdivacky CGF.ConvertType(CGF.getContext().getPointerDiffType()); 321198092Srdivacky 322198092Srdivacky llvm::Value *DstPtr = Builder.CreateStructGEP(DestPtr, 0, "dst.ptr"); 323198092Srdivacky llvm::Value *FuncPtr; 324198092Srdivacky 325198092Srdivacky if (MD->isVirtual()) { 326198092Srdivacky int64_t Index = 327198092Srdivacky CGF.CGM.getVtableInfo().getMethodVtableIndex(MD); 328198092Srdivacky 329203955Srdivacky // Itanium C++ ABI 2.3: 330203955Srdivacky // For a non-virtual function, this field is a simple function pointer. 331203955Srdivacky // For a virtual function, it is 1 plus the virtual table offset 332203955Srdivacky // (in bytes) of the function, represented as a ptrdiff_t. 333203955Srdivacky FuncPtr = llvm::ConstantInt::get(PtrDiffTy, (Index * 8) + 1); 334198092Srdivacky } else { 335203955Srdivacky const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); 336203955Srdivacky const llvm::Type *Ty = 337203955Srdivacky CGF.CGM.getTypes().GetFunctionType(CGF.CGM.getTypes().getFunctionInfo(MD), 338203955Srdivacky FPT->isVariadic()); 339203955Srdivacky llvm::Constant *Fn = CGF.CGM.GetAddrOfFunction(MD, Ty); 340203955Srdivacky FuncPtr = llvm::ConstantExpr::getPtrToInt(Fn, PtrDiffTy); 341198092Srdivacky } 342198092Srdivacky Builder.CreateStore(FuncPtr, DstPtr, VolatileDest); 343198092Srdivacky 344198092Srdivacky llvm::Value *AdjPtr = Builder.CreateStructGEP(DestPtr, 1, "dst.adj"); 345198092Srdivacky 346198092Srdivacky // The adjustment will always be 0. 347198092Srdivacky Builder.CreateStore(llvm::ConstantInt::get(PtrDiffTy, 0), AdjPtr, 348198092Srdivacky VolatileDest); 349198092Srdivacky} 350198092Srdivacky 351193326Sedvoid AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { 352193326Sed CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest); 353193326Sed} 354193326Sed 355193326Sedvoid AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { 356198893Srdivacky if (E->getOpcode() == BinaryOperator::PtrMemD || 357198893Srdivacky E->getOpcode() == BinaryOperator::PtrMemI) 358198398Srdivacky VisitPointerToDataMemberBinaryOperator(E); 359198398Srdivacky else 360198398Srdivacky CGF.ErrorUnsupported(E, "aggregate binary expression"); 361193326Sed} 362193326Sed 363198398Srdivackyvoid AggExprEmitter::VisitPointerToDataMemberBinaryOperator( 364198398Srdivacky const BinaryOperator *E) { 365198398Srdivacky LValue LV = CGF.EmitPointerToDataMemberBinaryExpr(E); 366198398Srdivacky EmitFinalDestCopy(E, LV); 367198398Srdivacky} 368198398Srdivacky 369193326Sedvoid AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { 370193326Sed // For an assignment to work, the value on the right has 371193326Sed // to be compatible with the value on the left. 372193326Sed assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), 373193326Sed E->getRHS()->getType()) 374193326Sed && "Invalid assignment"); 375193326Sed LValue LHS = CGF.EmitLValue(E->getLHS()); 376193326Sed 377193326Sed // We have to special case property setters, otherwise we must have 378193326Sed // a simple lvalue (no aggregates inside vectors, bitfields). 379193326Sed if (LHS.isPropertyRef()) { 380193326Sed llvm::Value *AggLoc = DestPtr; 381193326Sed if (!AggLoc) 382203955Srdivacky AggLoc = CGF.CreateMemTemp(E->getRHS()->getType()); 383193326Sed CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest); 384198092Srdivacky CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), 385193326Sed RValue::getAggregate(AggLoc, VolatileDest)); 386198092Srdivacky } else if (LHS.isKVCRef()) { 387193326Sed llvm::Value *AggLoc = DestPtr; 388193326Sed if (!AggLoc) 389203955Srdivacky AggLoc = CGF.CreateMemTemp(E->getRHS()->getType()); 390193326Sed CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest); 391198092Srdivacky CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), 392193326Sed RValue::getAggregate(AggLoc, VolatileDest)); 393193326Sed } else { 394198092Srdivacky bool RequiresGCollection = false; 395198092Srdivacky if (CGF.getContext().getLangOptions().NeXTRuntime) { 396198092Srdivacky QualType LHSTy = E->getLHS()->getType(); 397198092Srdivacky if (const RecordType *FDTTy = LHSTy.getTypePtr()->getAs<RecordType>()) 398198092Srdivacky RequiresGCollection = FDTTy->getDecl()->hasObjectMember(); 399198092Srdivacky } 400193326Sed // Codegen the RHS so that it stores directly into the LHS. 401198092Srdivacky CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified(), 402198092Srdivacky false, false, RequiresGCollection); 403193326Sed EmitFinalDestCopy(E, LHS, true); 404193326Sed } 405193326Sed} 406193326Sed 407193326Sedvoid AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) { 408201361Srdivacky if (!E->getLHS()) { 409201361Srdivacky CGF.ErrorUnsupported(E, "conditional operator with missing LHS"); 410201361Srdivacky return; 411201361Srdivacky } 412201361Srdivacky 413193326Sed llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 414193326Sed llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 415193326Sed llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 416198092Srdivacky 417201361Srdivacky CGF.EmitBranchOnBoolExpr(E->getCond(), LHSBlock, RHSBlock); 418198092Srdivacky 419203955Srdivacky CGF.BeginConditionalBranch(); 420193326Sed CGF.EmitBlock(LHSBlock); 421198092Srdivacky 422193326Sed // Handle the GNU extension for missing LHS. 423193326Sed assert(E->getLHS() && "Must have LHS for aggregate value"); 424193326Sed 425193326Sed Visit(E->getLHS()); 426203955Srdivacky CGF.EndConditionalBranch(); 427193326Sed CGF.EmitBranch(ContBlock); 428198092Srdivacky 429203955Srdivacky CGF.BeginConditionalBranch(); 430193326Sed CGF.EmitBlock(RHSBlock); 431198092Srdivacky 432193326Sed Visit(E->getRHS()); 433203955Srdivacky CGF.EndConditionalBranch(); 434193326Sed CGF.EmitBranch(ContBlock); 435198092Srdivacky 436193326Sed CGF.EmitBlock(ContBlock); 437193326Sed} 438193326Sed 439198092Srdivackyvoid AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { 440198092Srdivacky Visit(CE->getChosenSubExpr(CGF.getContext())); 441198092Srdivacky} 442198092Srdivacky 443193326Sedvoid AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 444193326Sed llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 445193326Sed llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 446193326Sed 447193326Sed if (!ArgPtr) { 448193326Sed CGF.ErrorUnsupported(VE, "aggregate va_arg expression"); 449193326Sed return; 450193326Sed } 451193326Sed 452198092Srdivacky EmitFinalDestCopy(VE, LValue::MakeAddr(ArgPtr, Qualifiers())); 453193326Sed} 454193326Sed 455193326Sedvoid AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { 456193326Sed llvm::Value *Val = DestPtr; 457198092Srdivacky 458193326Sed if (!Val) { 459193326Sed // Create a temporary variable. 460203955Srdivacky Val = CGF.CreateMemTemp(E->getType(), "tmp"); 461193326Sed 462193326Sed // FIXME: volatile 463193326Sed CGF.EmitAggExpr(E->getSubExpr(), Val, false); 464198092Srdivacky } else 465193326Sed Visit(E->getSubExpr()); 466198092Srdivacky 467198092Srdivacky // Don't make this a live temporary if we're emitting an initializer expr. 468198092Srdivacky if (!IsInitializer) 469198092Srdivacky CGF.PushCXXTemporary(E->getTemporary(), Val); 470193326Sed} 471193326Sed 472193326Sedvoid 473193326SedAggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { 474193326Sed llvm::Value *Val = DestPtr; 475198092Srdivacky 476193326Sed if (!Val) { 477193326Sed // Create a temporary variable. 478203955Srdivacky Val = CGF.CreateMemTemp(E->getType(), "tmp"); 479193326Sed } 480193326Sed 481201361Srdivacky if (E->requiresZeroInitialization()) 482201361Srdivacky EmitNullInitializationToLValue(LValue::MakeAddr(Val, 483201361Srdivacky // FIXME: Qualifiers()? 484201361Srdivacky E->getType().getQualifiers()), 485201361Srdivacky E->getType()); 486201361Srdivacky 487193326Sed CGF.EmitCXXConstructExpr(Val, E); 488193326Sed} 489193326Sed 490193326Sedvoid AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 491201361Srdivacky llvm::Value *Val = DestPtr; 492201361Srdivacky 493201361Srdivacky if (!Val) { 494201361Srdivacky // Create a temporary variable. 495203955Srdivacky Val = CGF.CreateMemTemp(E->getType(), "tmp"); 496201361Srdivacky } 497201361Srdivacky CGF.EmitCXXExprWithTemporaries(E, Val, VolatileDest, IsInitializer); 498193326Sed} 499193326Sed 500198398Srdivackyvoid AggExprEmitter::VisitCXXZeroInitValueExpr(CXXZeroInitValueExpr *E) { 501201361Srdivacky llvm::Value *Val = DestPtr; 502201361Srdivacky 503201361Srdivacky if (!Val) { 504201361Srdivacky // Create a temporary variable. 505203955Srdivacky Val = CGF.CreateMemTemp(E->getType(), "tmp"); 506201361Srdivacky } 507201361Srdivacky LValue LV = LValue::MakeAddr(Val, Qualifiers()); 508201361Srdivacky EmitNullInitializationToLValue(LV, E->getType()); 509198398Srdivacky} 510198398Srdivacky 511201361Srdivackyvoid AggExprEmitter::VisitImplicitValueInitExpr(ImplicitValueInitExpr *E) { 512201361Srdivacky llvm::Value *Val = DestPtr; 513201361Srdivacky 514201361Srdivacky if (!Val) { 515201361Srdivacky // Create a temporary variable. 516203955Srdivacky Val = CGF.CreateMemTemp(E->getType(), "tmp"); 517201361Srdivacky } 518201361Srdivacky LValue LV = LValue::MakeAddr(Val, Qualifiers()); 519201361Srdivacky EmitNullInitializationToLValue(LV, E->getType()); 520201361Srdivacky} 521201361Srdivacky 522203955Srdivackyvoid 523203955SrdivackyAggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV, QualType T) { 524193326Sed // FIXME: Ignore result? 525193326Sed // FIXME: Are initializers affected by volatile? 526193326Sed if (isa<ImplicitValueInitExpr>(E)) { 527203955Srdivacky EmitNullInitializationToLValue(LV, T); 528203955Srdivacky } else if (T->isReferenceType()) { 529203955Srdivacky RValue RV = CGF.EmitReferenceBindingToExpr(E, /*IsInitializer=*/false); 530203955Srdivacky CGF.EmitStoreThroughLValue(RV, LV, T); 531203955Srdivacky } else if (T->isAnyComplexType()) { 532193326Sed CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false); 533203955Srdivacky } else if (CGF.hasAggregateLLVMType(T)) { 534193326Sed CGF.EmitAnyExpr(E, LV.getAddress(), false); 535193326Sed } else { 536203955Srdivacky CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, T); 537193326Sed } 538193326Sed} 539193326Sed 540193326Sedvoid AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) { 541193326Sed if (!CGF.hasAggregateLLVMType(T)) { 542193326Sed // For non-aggregates, we can store zero 543193326Sed llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T)); 544193326Sed CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T); 545193326Sed } else { 546193326Sed // Otherwise, just memset the whole thing to zero. This is legal 547193326Sed // because in LLVM, all default initializers are guaranteed to have a 548193326Sed // bit pattern of all zeros. 549193326Sed // FIXME: That isn't true for member pointers! 550193326Sed // There's a potential optimization opportunity in combining 551193326Sed // memsets; that would be easy for arrays, but relatively 552193326Sed // difficult for structures with the current code. 553193326Sed CGF.EmitMemSetToZero(LV.getAddress(), T); 554193326Sed } 555193326Sed} 556193326Sed 557193326Sedvoid AggExprEmitter::VisitInitListExpr(InitListExpr *E) { 558193326Sed#if 0 559200583Srdivacky // FIXME: Assess perf here? Figure out what cases are worth optimizing here 560200583Srdivacky // (Length of globals? Chunks of zeroed-out space?). 561193326Sed // 562193326Sed // If we can, prefer a copy from a global; this is a lot less code for long 563193326Sed // globals, and it's easier for the current optimizers to analyze. 564200583Srdivacky if (llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, E->getType(), &CGF)) { 565193326Sed llvm::GlobalVariable* GV = 566200583Srdivacky new llvm::GlobalVariable(CGF.CGM.getModule(), C->getType(), true, 567200583Srdivacky llvm::GlobalValue::InternalLinkage, C, ""); 568200583Srdivacky EmitFinalDestCopy(E, LValue::MakeAddr(GV, Qualifiers())); 569193326Sed return; 570193326Sed } 571193326Sed#endif 572193326Sed if (E->hadArrayRangeDesignator()) { 573193326Sed CGF.ErrorUnsupported(E, "GNU array range designator extension"); 574193326Sed } 575193326Sed 576193326Sed // Handle initialization of an array. 577193326Sed if (E->getType()->isArrayType()) { 578193326Sed const llvm::PointerType *APType = 579193326Sed cast<llvm::PointerType>(DestPtr->getType()); 580193326Sed const llvm::ArrayType *AType = 581193326Sed cast<llvm::ArrayType>(APType->getElementType()); 582198092Srdivacky 583193326Sed uint64_t NumInitElements = E->getNumInits(); 584193326Sed 585193326Sed if (E->getNumInits() > 0) { 586193326Sed QualType T1 = E->getType(); 587193326Sed QualType T2 = E->getInit(0)->getType(); 588193326Sed if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) { 589193326Sed EmitAggLoadOfLValue(E->getInit(0)); 590193326Sed return; 591193326Sed } 592193326Sed } 593193326Sed 594193326Sed uint64_t NumArrayElements = AType->getNumElements(); 595193326Sed QualType ElementType = CGF.getContext().getCanonicalType(E->getType()); 596193326Sed ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType(); 597193326Sed 598198092Srdivacky // FIXME: were we intentionally ignoring address spaces and GC attributes? 599198092Srdivacky Qualifiers Quals = CGF.MakeQualifiers(ElementType); 600198092Srdivacky 601193326Sed for (uint64_t i = 0; i != NumArrayElements; ++i) { 602193326Sed llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array"); 603193326Sed if (i < NumInitElements) 604193326Sed EmitInitializationToLValue(E->getInit(i), 605203955Srdivacky LValue::MakeAddr(NextVal, Quals), 606203955Srdivacky ElementType); 607193326Sed else 608198092Srdivacky EmitNullInitializationToLValue(LValue::MakeAddr(NextVal, Quals), 609193326Sed ElementType); 610193326Sed } 611193326Sed return; 612193326Sed } 613198092Srdivacky 614193326Sed assert(E->getType()->isRecordType() && "Only support structs/unions here!"); 615198092Srdivacky 616193326Sed // Do struct initialization; this code just sets each individual member 617193326Sed // to the approprate value. This makes bitfield support automatic; 618193326Sed // the disadvantage is that the generated code is more difficult for 619193326Sed // the optimizer, especially with bitfields. 620193326Sed unsigned NumInitElements = E->getNumInits(); 621198092Srdivacky RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl(); 622193326Sed unsigned CurInitVal = 0; 623193326Sed 624193326Sed if (E->getType()->isUnionType()) { 625193326Sed // Only initialize one field of a union. The field itself is 626193326Sed // specified by the initializer list. 627193326Sed if (!E->getInitializedFieldInUnion()) { 628193326Sed // Empty union; we have nothing to do. 629198092Srdivacky 630193326Sed#ifndef NDEBUG 631193326Sed // Make sure that it's really an empty and not a failure of 632193326Sed // semantic analysis. 633195341Sed for (RecordDecl::field_iterator Field = SD->field_begin(), 634195341Sed FieldEnd = SD->field_end(); 635193326Sed Field != FieldEnd; ++Field) 636193326Sed assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); 637193326Sed#endif 638193326Sed return; 639193326Sed } 640193326Sed 641193326Sed // FIXME: volatility 642193326Sed FieldDecl *Field = E->getInitializedFieldInUnion(); 643203955Srdivacky LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestPtr, Field, 0); 644193326Sed 645193326Sed if (NumInitElements) { 646193326Sed // Store the initializer into the field 647203955Srdivacky EmitInitializationToLValue(E->getInit(0), FieldLoc, Field->getType()); 648193326Sed } else { 649193326Sed // Default-initialize to null 650193326Sed EmitNullInitializationToLValue(FieldLoc, Field->getType()); 651193326Sed } 652193326Sed 653193326Sed return; 654193326Sed } 655198092Srdivacky 656193326Sed // Here we iterate over the fields; this makes it simpler to both 657193326Sed // default-initialize fields and skip over unnamed fields. 658195341Sed for (RecordDecl::field_iterator Field = SD->field_begin(), 659195341Sed FieldEnd = SD->field_end(); 660193326Sed Field != FieldEnd; ++Field) { 661193326Sed // We're done once we hit the flexible array member 662193326Sed if (Field->getType()->isIncompleteArrayType()) 663193326Sed break; 664193326Sed 665193326Sed if (Field->isUnnamedBitfield()) 666193326Sed continue; 667193326Sed 668193326Sed // FIXME: volatility 669203955Srdivacky LValue FieldLoc = CGF.EmitLValueForFieldInitialization(DestPtr, *Field, 0); 670193326Sed // We never generate write-barries for initialized fields. 671193326Sed LValue::SetObjCNonGC(FieldLoc, true); 672193326Sed if (CurInitVal < NumInitElements) { 673193326Sed // Store the initializer into the field 674203955Srdivacky EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc, 675203955Srdivacky Field->getType()); 676193326Sed } else { 677193326Sed // We're out of initalizers; default-initialize to null 678193326Sed EmitNullInitializationToLValue(FieldLoc, Field->getType()); 679193326Sed } 680193326Sed } 681193326Sed} 682193326Sed 683193326Sed//===----------------------------------------------------------------------===// 684193326Sed// Entry Points into this File 685193326Sed//===----------------------------------------------------------------------===// 686193326Sed 687193326Sed/// EmitAggExpr - Emit the computation of the specified expression of aggregate 688193326Sed/// type. The result is computed into DestPtr. Note that if DestPtr is null, 689193326Sed/// the value of the aggregate expression is not needed. If VolatileDest is 690193326Sed/// true, DestPtr cannot be 0. 691203955Srdivacky// 692203955Srdivacky// FIXME: Take Qualifiers object. 693193326Sedvoid CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr, 694198092Srdivacky bool VolatileDest, bool IgnoreResult, 695198092Srdivacky bool IsInitializer, 696198092Srdivacky bool RequiresGCollection) { 697193326Sed assert(E && hasAggregateLLVMType(E->getType()) && 698193326Sed "Invalid aggregate expression to emit"); 699193326Sed assert ((DestPtr != 0 || VolatileDest == false) 700193326Sed && "volatile aggregate can't be 0"); 701198092Srdivacky 702198092Srdivacky AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult, IsInitializer, 703198092Srdivacky RequiresGCollection) 704193326Sed .Visit(const_cast<Expr*>(E)); 705193326Sed} 706193326Sed 707203955SrdivackyLValue CodeGenFunction::EmitAggExprToLValue(const Expr *E) { 708203955Srdivacky assert(hasAggregateLLVMType(E->getType()) && "Invalid argument!"); 709203955Srdivacky Qualifiers Q = MakeQualifiers(E->getType()); 710203955Srdivacky llvm::Value *Temp = CreateMemTemp(E->getType()); 711203955Srdivacky EmitAggExpr(E, Temp, Q.hasVolatile()); 712203955Srdivacky return LValue::MakeAddr(Temp, Q); 713203955Srdivacky} 714203955Srdivacky 715193326Sedvoid CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) { 716193326Sed assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); 717193326Sed 718193326Sed EmitMemSetToZero(DestPtr, Ty); 719193326Sed} 720193326Sed 721193326Sedvoid CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr, 722193326Sed llvm::Value *SrcPtr, QualType Ty, 723193326Sed bool isVolatile) { 724193326Sed assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); 725198092Srdivacky 726193326Sed // Aggregate assignment turns into llvm.memcpy. This is almost valid per 727193326Sed // C99 6.5.16.1p3, which states "If the value being stored in an object is 728193326Sed // read from another object that overlaps in anyway the storage of the first 729193326Sed // object, then the overlap shall be exact and the two objects shall have 730193326Sed // qualified or unqualified versions of a compatible type." 731193326Sed // 732193326Sed // memcpy is not defined if the source and destination pointers are exactly 733193326Sed // equal, but other compilers do this optimization, and almost every memcpy 734193326Sed // implementation handles this case safely. If there is a libc that does not 735193326Sed // safely handle this, we can add a target hook. 736198092Srdivacky const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext); 737193326Sed if (DestPtr->getType() != BP) 738193326Sed DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp"); 739193326Sed if (SrcPtr->getType() != BP) 740193326Sed SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp"); 741198092Srdivacky 742193326Sed // Get size and alignment info for this aggregate. 743193326Sed std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty); 744198092Srdivacky 745193326Sed // FIXME: Handle variable sized types. 746198092Srdivacky const llvm::Type *IntPtr = 747198092Srdivacky llvm::IntegerType::get(VMContext, LLVMPointerWidth); 748198092Srdivacky 749193326Sed // FIXME: If we have a volatile struct, the optimizer can remove what might 750193326Sed // appear to be `extra' memory ops: 751193326Sed // 752193326Sed // volatile struct { int i; } a, b; 753193326Sed // 754193326Sed // int main() { 755193326Sed // a = b; 756193326Sed // a = b; 757193326Sed // } 758193326Sed // 759193326Sed // we need to use a differnt call here. We use isVolatile to indicate when 760193326Sed // either the source or the destination is volatile. 761193326Sed Builder.CreateCall4(CGM.getMemCpyFn(), 762193326Sed DestPtr, SrcPtr, 763193326Sed // TypeInfo.first describes size in bits. 764193326Sed llvm::ConstantInt::get(IntPtr, TypeInfo.first/8), 765198092Srdivacky llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 766193326Sed TypeInfo.second/8)); 767193326Sed} 768