CGExprAgg.cpp revision 198092
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/Support/Compiler.h" 24193326Sed#include "llvm/Intrinsics.h" 25193326Sedusing namespace clang; 26193326Sedusing namespace CodeGen; 27193326Sed 28193326Sed//===----------------------------------------------------------------------===// 29193326Sed// Aggregate Expression Emitter 30193326Sed//===----------------------------------------------------------------------===// 31193326Sed 32193326Sednamespace { 33193326Sedclass VISIBILITY_HIDDEN AggExprEmitter : public StmtVisitor<AggExprEmitter> { 34193326Sed CodeGenFunction &CGF; 35193326Sed CGBuilderTy &Builder; 36193326Sed llvm::Value *DestPtr; 37193326Sed bool VolatileDest; 38193326Sed bool IgnoreResult; 39198092Srdivacky bool IsInitializer; 40198092Srdivacky bool RequiresGCollection; 41193326Sedpublic: 42193326Sed AggExprEmitter(CodeGenFunction &cgf, llvm::Value *destPtr, bool v, 43198092Srdivacky bool ignore, bool isinit, bool requiresGCollection) 44193326Sed : CGF(cgf), Builder(CGF.Builder), 45198092Srdivacky DestPtr(destPtr), VolatileDest(v), IgnoreResult(ignore), 46198092Srdivacky IsInitializer(isinit), RequiresGCollection(requiresGCollection) { 47193326Sed } 48193326Sed 49193326Sed //===--------------------------------------------------------------------===// 50193326Sed // Utilities 51193326Sed //===--------------------------------------------------------------------===// 52193326Sed 53193326Sed /// EmitAggLoadOfLValue - Given an expression with aggregate type that 54193326Sed /// represents a value lvalue, this method emits the address of the lvalue, 55193326Sed /// then loads the result into DestPtr. 56193326Sed void EmitAggLoadOfLValue(const Expr *E); 57193326Sed 58193326Sed /// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 59193326Sed void EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore = false); 60193326Sed void EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore = false); 61193326Sed 62193326Sed //===--------------------------------------------------------------------===// 63193326Sed // Visitor Methods 64193326Sed //===--------------------------------------------------------------------===// 65198092Srdivacky 66193326Sed void VisitStmt(Stmt *S) { 67193326Sed CGF.ErrorUnsupported(S, "aggregate expression"); 68193326Sed } 69193326Sed void VisitParenExpr(ParenExpr *PE) { Visit(PE->getSubExpr()); } 70193326Sed void VisitUnaryExtension(UnaryOperator *E) { Visit(E->getSubExpr()); } 71193326Sed 72193326Sed // l-values. 73193326Sed void VisitDeclRefExpr(DeclRefExpr *DRE) { EmitAggLoadOfLValue(DRE); } 74193326Sed void VisitMemberExpr(MemberExpr *ME) { EmitAggLoadOfLValue(ME); } 75193326Sed void VisitUnaryDeref(UnaryOperator *E) { EmitAggLoadOfLValue(E); } 76193326Sed void VisitStringLiteral(StringLiteral *E) { EmitAggLoadOfLValue(E); } 77193326Sed void VisitCompoundLiteralExpr(CompoundLiteralExpr *E) { 78198092Srdivacky EmitAggLoadOfLValue(E); 79193326Sed } 80193326Sed void VisitArraySubscriptExpr(ArraySubscriptExpr *E) { 81193326Sed EmitAggLoadOfLValue(E); 82193326Sed } 83193326Sed void VisitBlockDeclRefExpr(const BlockDeclRefExpr *E) { 84198092Srdivacky EmitAggLoadOfLValue(E); 85193326Sed } 86193326Sed void VisitPredefinedExpr(const PredefinedExpr *E) { 87198092Srdivacky EmitAggLoadOfLValue(E); 88193326Sed } 89198092Srdivacky 90193326Sed // Operators. 91198092Srdivacky void VisitCastExpr(CastExpr *E); 92193326Sed void VisitCallExpr(const CallExpr *E); 93193326Sed void VisitStmtExpr(const StmtExpr *E); 94193326Sed void VisitBinaryOperator(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); 109193326Sed void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) { 110193326Sed Visit(DAE->getExpr()); 111193326Sed } 112193326Sed void VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E); 113193326Sed void VisitCXXConstructExpr(const CXXConstructExpr *E); 114193326Sed void VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E); 115193326Sed 116193326Sed void VisitVAArgExpr(VAArgExpr *E); 117193326Sed 118193326Sed void EmitInitializationToLValue(Expr *E, LValue Address); 119193326Sed void EmitNullInitializationToLValue(LValue Address, QualType T); 120193326Sed // case Expr::ChooseExprClass: 121193326Sed 122193326Sed}; 123193326Sed} // end anonymous namespace. 124193326Sed 125193326Sed//===----------------------------------------------------------------------===// 126193326Sed// Utilities 127193326Sed//===----------------------------------------------------------------------===// 128193326Sed 129193326Sed/// EmitAggLoadOfLValue - Given an expression with aggregate type that 130193326Sed/// represents a value lvalue, this method emits the address of the lvalue, 131193326Sed/// then loads the result into DestPtr. 132193326Sedvoid AggExprEmitter::EmitAggLoadOfLValue(const Expr *E) { 133193326Sed LValue LV = CGF.EmitLValue(E); 134193326Sed EmitFinalDestCopy(E, LV); 135193326Sed} 136193326Sed 137193326Sed/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 138193326Sedvoid AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) { 139193326Sed assert(Src.isAggregate() && "value must be aggregate value!"); 140193326Sed 141193326Sed // If the result is ignored, don't copy from the value. 142193326Sed if (DestPtr == 0) { 143193326Sed if (!Src.isVolatileQualified() || (IgnoreResult && Ignore)) 144193326Sed return; 145193326Sed // If the source is volatile, we must read from it; to do that, we need 146193326Sed // some place to put it. 147193326Sed DestPtr = CGF.CreateTempAlloca(CGF.ConvertType(E->getType()), "agg.tmp"); 148193326Sed } 149193326Sed 150198092Srdivacky if (RequiresGCollection) { 151198092Srdivacky CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF, 152198092Srdivacky DestPtr, Src.getAggregateAddr(), 153198092Srdivacky E->getType()); 154198092Srdivacky return; 155198092Srdivacky } 156193326Sed // If the result of the assignment is used, copy the LHS there also. 157193326Sed // FIXME: Pass VolatileDest as well. I think we also need to merge volatile 158193326Sed // from the source as well, as we can't eliminate it if either operand 159193326Sed // is volatile, unless copy has volatile for both source and destination.. 160193326Sed CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(), 161193326Sed VolatileDest|Src.isVolatileQualified()); 162193326Sed} 163193326Sed 164193326Sed/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired. 165193326Sedvoid AggExprEmitter::EmitFinalDestCopy(const Expr *E, LValue Src, bool Ignore) { 166193326Sed assert(Src.isSimple() && "Can't have aggregate bitfield, vector, etc"); 167193326Sed 168193326Sed EmitFinalDestCopy(E, RValue::getAggregate(Src.getAddress(), 169193326Sed Src.isVolatileQualified()), 170193326Sed Ignore); 171193326Sed} 172193326Sed 173193326Sed//===----------------------------------------------------------------------===// 174193326Sed// Visitor Methods 175193326Sed//===----------------------------------------------------------------------===// 176193326Sed 177198092Srdivackyvoid AggExprEmitter::VisitCastExpr(CastExpr *E) { 178198092Srdivacky switch (E->getCastKind()) { 179198092Srdivacky default: assert(0 && "Unhandled cast kind!"); 180198092Srdivacky 181198092Srdivacky case CastExpr::CK_ToUnion: { 182198092Srdivacky // GCC union extension 183193401Sed QualType PtrTy = 184198092Srdivacky CGF.getContext().getPointerType(E->getSubExpr()->getType()); 185193401Sed llvm::Value *CastPtr = Builder.CreateBitCast(DestPtr, 186193401Sed CGF.ConvertType(PtrTy)); 187198092Srdivacky EmitInitializationToLValue(E->getSubExpr(), 188198092Srdivacky LValue::MakeAddr(CastPtr, Qualifiers())); 189198092Srdivacky break; 190193326Sed } 191193326Sed 192198092Srdivacky // FIXME: Remove the CK_Unknown check here. 193198092Srdivacky case CastExpr::CK_Unknown: 194198092Srdivacky case CastExpr::CK_NoOp: 195198092Srdivacky case CastExpr::CK_UserDefinedConversion: 196198092Srdivacky case CastExpr::CK_ConstructorConversion: 197198092Srdivacky assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(), 198198092Srdivacky E->getType()) && 199198092Srdivacky "Implicit cast types must be compatible"); 200198092Srdivacky Visit(E->getSubExpr()); 201198092Srdivacky break; 202193326Sed 203198092Srdivacky case CastExpr::CK_NullToMemberPointer: { 204198092Srdivacky const llvm::Type *PtrDiffTy = 205198092Srdivacky CGF.ConvertType(CGF.getContext().getPointerDiffType()); 206198092Srdivacky 207198092Srdivacky llvm::Value *NullValue = llvm::Constant::getNullValue(PtrDiffTy); 208198092Srdivacky llvm::Value *Ptr = Builder.CreateStructGEP(DestPtr, 0, "ptr"); 209198092Srdivacky Builder.CreateStore(NullValue, Ptr, VolatileDest); 210198092Srdivacky 211198092Srdivacky llvm::Value *Adj = Builder.CreateStructGEP(DestPtr, 1, "adj"); 212198092Srdivacky Builder.CreateStore(NullValue, Adj, VolatileDest); 213198092Srdivacky 214198092Srdivacky break; 215198092Srdivacky } 216198092Srdivacky 217198092Srdivacky case CastExpr::CK_BaseToDerivedMemberPointer: { 218198092Srdivacky QualType SrcType = E->getSubExpr()->getType(); 219198092Srdivacky 220198092Srdivacky llvm::Value *Src = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(SrcType), 221198092Srdivacky "tmp"); 222198092Srdivacky CGF.EmitAggExpr(E->getSubExpr(), Src, SrcType.isVolatileQualified()); 223198092Srdivacky 224198092Srdivacky llvm::Value *SrcPtr = Builder.CreateStructGEP(Src, 0, "src.ptr"); 225198092Srdivacky SrcPtr = Builder.CreateLoad(SrcPtr); 226198092Srdivacky 227198092Srdivacky llvm::Value *SrcAdj = Builder.CreateStructGEP(Src, 1, "src.adj"); 228198092Srdivacky SrcAdj = Builder.CreateLoad(SrcAdj); 229198092Srdivacky 230198092Srdivacky llvm::Value *DstPtr = Builder.CreateStructGEP(DestPtr, 0, "dst.ptr"); 231198092Srdivacky Builder.CreateStore(SrcPtr, DstPtr, VolatileDest); 232198092Srdivacky 233198092Srdivacky llvm::Value *DstAdj = Builder.CreateStructGEP(DestPtr, 1, "dst.adj"); 234198092Srdivacky 235198092Srdivacky // Now See if we need to update the adjustment. 236198092Srdivacky const CXXRecordDecl *SrcDecl = 237198092Srdivacky cast<CXXRecordDecl>(SrcType->getAs<MemberPointerType>()-> 238198092Srdivacky getClass()->getAs<RecordType>()->getDecl()); 239198092Srdivacky const CXXRecordDecl *DstDecl = 240198092Srdivacky cast<CXXRecordDecl>(E->getType()->getAs<MemberPointerType>()-> 241198092Srdivacky getClass()->getAs<RecordType>()->getDecl()); 242198092Srdivacky 243198092Srdivacky llvm::Constant *Adj = CGF.CGM.GetCXXBaseClassOffset(DstDecl, SrcDecl); 244198092Srdivacky if (Adj) 245198092Srdivacky SrcAdj = Builder.CreateAdd(SrcAdj, Adj, "adj"); 246198092Srdivacky 247198092Srdivacky Builder.CreateStore(SrcAdj, DstAdj, VolatileDest); 248198092Srdivacky break; 249198092Srdivacky } 250198092Srdivacky } 251193326Sed} 252193326Sed 253193326Sedvoid AggExprEmitter::VisitCallExpr(const CallExpr *E) { 254193326Sed if (E->getCallReturnType()->isReferenceType()) { 255193326Sed EmitAggLoadOfLValue(E); 256193326Sed return; 257193326Sed } 258198092Srdivacky 259193326Sed RValue RV = CGF.EmitCallExpr(E); 260193326Sed EmitFinalDestCopy(E, RV); 261193326Sed} 262193326Sed 263193326Sedvoid AggExprEmitter::VisitObjCMessageExpr(ObjCMessageExpr *E) { 264193326Sed RValue RV = CGF.EmitObjCMessageExpr(E); 265193326Sed EmitFinalDestCopy(E, RV); 266193326Sed} 267193326Sed 268193326Sedvoid AggExprEmitter::VisitObjCPropertyRefExpr(ObjCPropertyRefExpr *E) { 269193326Sed RValue RV = CGF.EmitObjCPropertyGet(E); 270193326Sed EmitFinalDestCopy(E, RV); 271193326Sed} 272193326Sed 273198092Srdivackyvoid AggExprEmitter::VisitObjCImplicitSetterGetterRefExpr( 274198092Srdivacky ObjCImplicitSetterGetterRefExpr *E) { 275193326Sed RValue RV = CGF.EmitObjCPropertyGet(E); 276193326Sed EmitFinalDestCopy(E, RV); 277193326Sed} 278193326Sed 279193326Sedvoid AggExprEmitter::VisitBinComma(const BinaryOperator *E) { 280193326Sed CGF.EmitAnyExpr(E->getLHS(), 0, false, true); 281198092Srdivacky CGF.EmitAggExpr(E->getRHS(), DestPtr, VolatileDest, 282198092Srdivacky /*IgnoreResult=*/false, IsInitializer); 283193326Sed} 284193326Sed 285198092Srdivackyvoid AggExprEmitter::VisitUnaryAddrOf(const UnaryOperator *E) { 286198092Srdivacky // We have a member function pointer. 287198092Srdivacky const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>(); 288198092Srdivacky assert(MPT->getPointeeType()->isFunctionProtoType() && 289198092Srdivacky "Unexpected member pointer type!"); 290198092Srdivacky 291198092Srdivacky const QualifiedDeclRefExpr *DRE = cast<QualifiedDeclRefExpr>(E->getSubExpr()); 292198092Srdivacky const CXXMethodDecl *MD = cast<CXXMethodDecl>(DRE->getDecl()); 293198092Srdivacky 294198092Srdivacky const llvm::Type *PtrDiffTy = 295198092Srdivacky CGF.ConvertType(CGF.getContext().getPointerDiffType()); 296198092Srdivacky 297198092Srdivacky llvm::Value *DstPtr = Builder.CreateStructGEP(DestPtr, 0, "dst.ptr"); 298198092Srdivacky llvm::Value *FuncPtr; 299198092Srdivacky 300198092Srdivacky if (MD->isVirtual()) { 301198092Srdivacky int64_t Index = 302198092Srdivacky CGF.CGM.getVtableInfo().getMethodVtableIndex(MD); 303198092Srdivacky 304198092Srdivacky FuncPtr = llvm::ConstantInt::get(PtrDiffTy, Index + 1); 305198092Srdivacky } else { 306198092Srdivacky FuncPtr = llvm::ConstantExpr::getPtrToInt(CGF.CGM.GetAddrOfFunction(MD), 307198092Srdivacky PtrDiffTy); 308198092Srdivacky } 309198092Srdivacky Builder.CreateStore(FuncPtr, DstPtr, VolatileDest); 310198092Srdivacky 311198092Srdivacky llvm::Value *AdjPtr = Builder.CreateStructGEP(DestPtr, 1, "dst.adj"); 312198092Srdivacky 313198092Srdivacky // The adjustment will always be 0. 314198092Srdivacky Builder.CreateStore(llvm::ConstantInt::get(PtrDiffTy, 0), AdjPtr, 315198092Srdivacky VolatileDest); 316198092Srdivacky} 317198092Srdivacky 318193326Sedvoid AggExprEmitter::VisitStmtExpr(const StmtExpr *E) { 319193326Sed CGF.EmitCompoundStmt(*E->getSubStmt(), true, DestPtr, VolatileDest); 320193326Sed} 321193326Sed 322193326Sedvoid AggExprEmitter::VisitBinaryOperator(const BinaryOperator *E) { 323193326Sed CGF.ErrorUnsupported(E, "aggregate binary expression"); 324193326Sed} 325193326Sed 326193326Sedvoid AggExprEmitter::VisitBinAssign(const BinaryOperator *E) { 327193326Sed // For an assignment to work, the value on the right has 328193326Sed // to be compatible with the value on the left. 329193326Sed assert(CGF.getContext().hasSameUnqualifiedType(E->getLHS()->getType(), 330193326Sed E->getRHS()->getType()) 331193326Sed && "Invalid assignment"); 332193326Sed LValue LHS = CGF.EmitLValue(E->getLHS()); 333193326Sed 334193326Sed // We have to special case property setters, otherwise we must have 335193326Sed // a simple lvalue (no aggregates inside vectors, bitfields). 336193326Sed if (LHS.isPropertyRef()) { 337193326Sed llvm::Value *AggLoc = DestPtr; 338193326Sed if (!AggLoc) 339193326Sed AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType())); 340193326Sed CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest); 341198092Srdivacky CGF.EmitObjCPropertySet(LHS.getPropertyRefExpr(), 342193326Sed RValue::getAggregate(AggLoc, VolatileDest)); 343198092Srdivacky } else if (LHS.isKVCRef()) { 344193326Sed llvm::Value *AggLoc = DestPtr; 345193326Sed if (!AggLoc) 346193326Sed AggLoc = CGF.CreateTempAlloca(CGF.ConvertType(E->getRHS()->getType())); 347193326Sed CGF.EmitAggExpr(E->getRHS(), AggLoc, VolatileDest); 348198092Srdivacky CGF.EmitObjCPropertySet(LHS.getKVCRefExpr(), 349193326Sed RValue::getAggregate(AggLoc, VolatileDest)); 350193326Sed } else { 351198092Srdivacky bool RequiresGCollection = false; 352198092Srdivacky if (CGF.getContext().getLangOptions().NeXTRuntime) { 353198092Srdivacky QualType LHSTy = E->getLHS()->getType(); 354198092Srdivacky if (const RecordType *FDTTy = LHSTy.getTypePtr()->getAs<RecordType>()) 355198092Srdivacky RequiresGCollection = FDTTy->getDecl()->hasObjectMember(); 356198092Srdivacky } 357193326Sed // Codegen the RHS so that it stores directly into the LHS. 358198092Srdivacky CGF.EmitAggExpr(E->getRHS(), LHS.getAddress(), LHS.isVolatileQualified(), 359198092Srdivacky false, false, RequiresGCollection); 360193326Sed EmitFinalDestCopy(E, LHS, true); 361193326Sed } 362193326Sed} 363193326Sed 364193326Sedvoid AggExprEmitter::VisitConditionalOperator(const ConditionalOperator *E) { 365193326Sed llvm::BasicBlock *LHSBlock = CGF.createBasicBlock("cond.true"); 366193326Sed llvm::BasicBlock *RHSBlock = CGF.createBasicBlock("cond.false"); 367193326Sed llvm::BasicBlock *ContBlock = CGF.createBasicBlock("cond.end"); 368198092Srdivacky 369193326Sed llvm::Value *Cond = CGF.EvaluateExprAsBool(E->getCond()); 370193326Sed Builder.CreateCondBr(Cond, LHSBlock, RHSBlock); 371198092Srdivacky 372193576Sed CGF.PushConditionalTempDestruction(); 373193326Sed CGF.EmitBlock(LHSBlock); 374198092Srdivacky 375193326Sed // Handle the GNU extension for missing LHS. 376193326Sed assert(E->getLHS() && "Must have LHS for aggregate value"); 377193326Sed 378193326Sed Visit(E->getLHS()); 379193576Sed CGF.PopConditionalTempDestruction(); 380193326Sed CGF.EmitBranch(ContBlock); 381198092Srdivacky 382193576Sed CGF.PushConditionalTempDestruction(); 383193326Sed CGF.EmitBlock(RHSBlock); 384198092Srdivacky 385193326Sed Visit(E->getRHS()); 386193576Sed CGF.PopConditionalTempDestruction(); 387193326Sed CGF.EmitBranch(ContBlock); 388198092Srdivacky 389193326Sed CGF.EmitBlock(ContBlock); 390193326Sed} 391193326Sed 392198092Srdivackyvoid AggExprEmitter::VisitChooseExpr(const ChooseExpr *CE) { 393198092Srdivacky Visit(CE->getChosenSubExpr(CGF.getContext())); 394198092Srdivacky} 395198092Srdivacky 396193326Sedvoid AggExprEmitter::VisitVAArgExpr(VAArgExpr *VE) { 397193326Sed llvm::Value *ArgValue = CGF.EmitVAListRef(VE->getSubExpr()); 398193326Sed llvm::Value *ArgPtr = CGF.EmitVAArg(ArgValue, VE->getType()); 399193326Sed 400193326Sed if (!ArgPtr) { 401193326Sed CGF.ErrorUnsupported(VE, "aggregate va_arg expression"); 402193326Sed return; 403193326Sed } 404193326Sed 405198092Srdivacky EmitFinalDestCopy(VE, LValue::MakeAddr(ArgPtr, Qualifiers())); 406193326Sed} 407193326Sed 408193326Sedvoid AggExprEmitter::VisitCXXBindTemporaryExpr(CXXBindTemporaryExpr *E) { 409193326Sed llvm::Value *Val = DestPtr; 410198092Srdivacky 411193326Sed if (!Val) { 412193326Sed // Create a temporary variable. 413193326Sed Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp"); 414193326Sed 415193326Sed // FIXME: volatile 416193326Sed CGF.EmitAggExpr(E->getSubExpr(), Val, false); 417198092Srdivacky } else 418193326Sed Visit(E->getSubExpr()); 419198092Srdivacky 420198092Srdivacky // Don't make this a live temporary if we're emitting an initializer expr. 421198092Srdivacky if (!IsInitializer) 422198092Srdivacky CGF.PushCXXTemporary(E->getTemporary(), Val); 423193326Sed} 424193326Sed 425193326Sedvoid 426193326SedAggExprEmitter::VisitCXXConstructExpr(const CXXConstructExpr *E) { 427193326Sed llvm::Value *Val = DestPtr; 428198092Srdivacky 429193326Sed if (!Val) { 430193326Sed // Create a temporary variable. 431193326Sed Val = CGF.CreateTempAlloca(CGF.ConvertTypeForMem(E->getType()), "tmp"); 432193326Sed } 433193326Sed 434193326Sed CGF.EmitCXXConstructExpr(Val, E); 435193326Sed} 436193326Sed 437193326Sedvoid AggExprEmitter::VisitCXXExprWithTemporaries(CXXExprWithTemporaries *E) { 438198092Srdivacky CGF.EmitCXXExprWithTemporaries(E, DestPtr, VolatileDest, IsInitializer); 439193326Sed} 440193326Sed 441193326Sedvoid AggExprEmitter::EmitInitializationToLValue(Expr* E, LValue LV) { 442193326Sed // FIXME: Ignore result? 443193326Sed // FIXME: Are initializers affected by volatile? 444193326Sed if (isa<ImplicitValueInitExpr>(E)) { 445193326Sed EmitNullInitializationToLValue(LV, E->getType()); 446193326Sed } else if (E->getType()->isComplexType()) { 447193326Sed CGF.EmitComplexExprIntoAddr(E, LV.getAddress(), false); 448193326Sed } else if (CGF.hasAggregateLLVMType(E->getType())) { 449193326Sed CGF.EmitAnyExpr(E, LV.getAddress(), false); 450193326Sed } else { 451193326Sed CGF.EmitStoreThroughLValue(CGF.EmitAnyExpr(E), LV, E->getType()); 452193326Sed } 453193326Sed} 454193326Sed 455193326Sedvoid AggExprEmitter::EmitNullInitializationToLValue(LValue LV, QualType T) { 456193326Sed if (!CGF.hasAggregateLLVMType(T)) { 457193326Sed // For non-aggregates, we can store zero 458193326Sed llvm::Value *Null = llvm::Constant::getNullValue(CGF.ConvertType(T)); 459193326Sed CGF.EmitStoreThroughLValue(RValue::get(Null), LV, T); 460193326Sed } else { 461193326Sed // Otherwise, just memset the whole thing to zero. This is legal 462193326Sed // because in LLVM, all default initializers are guaranteed to have a 463193326Sed // bit pattern of all zeros. 464193326Sed // FIXME: That isn't true for member pointers! 465193326Sed // There's a potential optimization opportunity in combining 466193326Sed // memsets; that would be easy for arrays, but relatively 467193326Sed // difficult for structures with the current code. 468193326Sed CGF.EmitMemSetToZero(LV.getAddress(), T); 469193326Sed } 470193326Sed} 471193326Sed 472193326Sedvoid AggExprEmitter::VisitInitListExpr(InitListExpr *E) { 473193326Sed#if 0 474198092Srdivacky // FIXME: Disabled while we figure out what to do about 475193326Sed // test/CodeGen/bitfield.c 476193326Sed // 477193326Sed // If we can, prefer a copy from a global; this is a lot less code for long 478193326Sed // globals, and it's easier for the current optimizers to analyze. 479193326Sed // FIXME: Should we really be doing this? Should we try to avoid cases where 480193326Sed // we emit a global with a lot of zeros? Should we try to avoid short 481193326Sed // globals? 482193326Sed if (E->isConstantInitializer(CGF.getContext(), 0)) { 483193326Sed llvm::Constant* C = CGF.CGM.EmitConstantExpr(E, &CGF); 484193326Sed llvm::GlobalVariable* GV = 485193326Sed new llvm::GlobalVariable(C->getType(), true, 486193326Sed llvm::GlobalValue::InternalLinkage, 487193326Sed C, "", &CGF.CGM.getModule(), 0); 488193326Sed EmitFinalDestCopy(E, LValue::MakeAddr(GV, 0)); 489193326Sed return; 490193326Sed } 491193326Sed#endif 492193326Sed if (E->hadArrayRangeDesignator()) { 493193326Sed CGF.ErrorUnsupported(E, "GNU array range designator extension"); 494193326Sed } 495193326Sed 496193326Sed // Handle initialization of an array. 497193326Sed if (E->getType()->isArrayType()) { 498193326Sed const llvm::PointerType *APType = 499193326Sed cast<llvm::PointerType>(DestPtr->getType()); 500193326Sed const llvm::ArrayType *AType = 501193326Sed cast<llvm::ArrayType>(APType->getElementType()); 502198092Srdivacky 503193326Sed uint64_t NumInitElements = E->getNumInits(); 504193326Sed 505193326Sed if (E->getNumInits() > 0) { 506193326Sed QualType T1 = E->getType(); 507193326Sed QualType T2 = E->getInit(0)->getType(); 508193326Sed if (CGF.getContext().hasSameUnqualifiedType(T1, T2)) { 509193326Sed EmitAggLoadOfLValue(E->getInit(0)); 510193326Sed return; 511193326Sed } 512193326Sed } 513193326Sed 514193326Sed uint64_t NumArrayElements = AType->getNumElements(); 515193326Sed QualType ElementType = CGF.getContext().getCanonicalType(E->getType()); 516193326Sed ElementType = CGF.getContext().getAsArrayType(ElementType)->getElementType(); 517193326Sed 518198092Srdivacky // FIXME: were we intentionally ignoring address spaces and GC attributes? 519198092Srdivacky Qualifiers Quals = CGF.MakeQualifiers(ElementType); 520198092Srdivacky 521193326Sed for (uint64_t i = 0; i != NumArrayElements; ++i) { 522193326Sed llvm::Value *NextVal = Builder.CreateStructGEP(DestPtr, i, ".array"); 523193326Sed if (i < NumInitElements) 524193326Sed EmitInitializationToLValue(E->getInit(i), 525198092Srdivacky LValue::MakeAddr(NextVal, Quals)); 526193326Sed else 527198092Srdivacky EmitNullInitializationToLValue(LValue::MakeAddr(NextVal, Quals), 528193326Sed ElementType); 529193326Sed } 530193326Sed return; 531193326Sed } 532198092Srdivacky 533193326Sed assert(E->getType()->isRecordType() && "Only support structs/unions here!"); 534198092Srdivacky 535193326Sed // Do struct initialization; this code just sets each individual member 536193326Sed // to the approprate value. This makes bitfield support automatic; 537193326Sed // the disadvantage is that the generated code is more difficult for 538193326Sed // the optimizer, especially with bitfields. 539193326Sed unsigned NumInitElements = E->getNumInits(); 540198092Srdivacky RecordDecl *SD = E->getType()->getAs<RecordType>()->getDecl(); 541193326Sed unsigned CurInitVal = 0; 542193326Sed 543193326Sed if (E->getType()->isUnionType()) { 544193326Sed // Only initialize one field of a union. The field itself is 545193326Sed // specified by the initializer list. 546193326Sed if (!E->getInitializedFieldInUnion()) { 547193326Sed // Empty union; we have nothing to do. 548198092Srdivacky 549193326Sed#ifndef NDEBUG 550193326Sed // Make sure that it's really an empty and not a failure of 551193326Sed // semantic analysis. 552195341Sed for (RecordDecl::field_iterator Field = SD->field_begin(), 553195341Sed FieldEnd = SD->field_end(); 554193326Sed Field != FieldEnd; ++Field) 555193326Sed assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed"); 556193326Sed#endif 557193326Sed return; 558193326Sed } 559193326Sed 560193326Sed // FIXME: volatility 561193326Sed FieldDecl *Field = E->getInitializedFieldInUnion(); 562193326Sed LValue FieldLoc = CGF.EmitLValueForField(DestPtr, Field, true, 0); 563193326Sed 564193326Sed if (NumInitElements) { 565193326Sed // Store the initializer into the field 566193326Sed EmitInitializationToLValue(E->getInit(0), FieldLoc); 567193326Sed } else { 568193326Sed // Default-initialize to null 569193326Sed EmitNullInitializationToLValue(FieldLoc, Field->getType()); 570193326Sed } 571193326Sed 572193326Sed return; 573193326Sed } 574198092Srdivacky 575193326Sed // Here we iterate over the fields; this makes it simpler to both 576193326Sed // default-initialize fields and skip over unnamed fields. 577195341Sed for (RecordDecl::field_iterator Field = SD->field_begin(), 578195341Sed FieldEnd = SD->field_end(); 579193326Sed Field != FieldEnd; ++Field) { 580193326Sed // We're done once we hit the flexible array member 581193326Sed if (Field->getType()->isIncompleteArrayType()) 582193326Sed break; 583193326Sed 584193326Sed if (Field->isUnnamedBitfield()) 585193326Sed continue; 586193326Sed 587193326Sed // FIXME: volatility 588193326Sed LValue FieldLoc = CGF.EmitLValueForField(DestPtr, *Field, false, 0); 589193326Sed // We never generate write-barries for initialized fields. 590193326Sed LValue::SetObjCNonGC(FieldLoc, true); 591193326Sed if (CurInitVal < NumInitElements) { 592193326Sed // Store the initializer into the field 593193326Sed EmitInitializationToLValue(E->getInit(CurInitVal++), FieldLoc); 594193326Sed } else { 595193326Sed // We're out of initalizers; default-initialize to null 596193326Sed EmitNullInitializationToLValue(FieldLoc, Field->getType()); 597193326Sed } 598193326Sed } 599193326Sed} 600193326Sed 601193326Sed//===----------------------------------------------------------------------===// 602193326Sed// Entry Points into this File 603193326Sed//===----------------------------------------------------------------------===// 604193326Sed 605193326Sed/// EmitAggExpr - Emit the computation of the specified expression of aggregate 606193326Sed/// type. The result is computed into DestPtr. Note that if DestPtr is null, 607193326Sed/// the value of the aggregate expression is not needed. If VolatileDest is 608193326Sed/// true, DestPtr cannot be 0. 609193326Sedvoid CodeGenFunction::EmitAggExpr(const Expr *E, llvm::Value *DestPtr, 610198092Srdivacky bool VolatileDest, bool IgnoreResult, 611198092Srdivacky bool IsInitializer, 612198092Srdivacky bool RequiresGCollection) { 613193326Sed assert(E && hasAggregateLLVMType(E->getType()) && 614193326Sed "Invalid aggregate expression to emit"); 615193326Sed assert ((DestPtr != 0 || VolatileDest == false) 616193326Sed && "volatile aggregate can't be 0"); 617198092Srdivacky 618198092Srdivacky AggExprEmitter(*this, DestPtr, VolatileDest, IgnoreResult, IsInitializer, 619198092Srdivacky RequiresGCollection) 620193326Sed .Visit(const_cast<Expr*>(E)); 621193326Sed} 622193326Sed 623193326Sedvoid CodeGenFunction::EmitAggregateClear(llvm::Value *DestPtr, QualType Ty) { 624193326Sed assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); 625193326Sed 626193326Sed EmitMemSetToZero(DestPtr, Ty); 627193326Sed} 628193326Sed 629193326Sedvoid CodeGenFunction::EmitAggregateCopy(llvm::Value *DestPtr, 630193326Sed llvm::Value *SrcPtr, QualType Ty, 631193326Sed bool isVolatile) { 632193326Sed assert(!Ty->isAnyComplexType() && "Shouldn't happen for complex"); 633198092Srdivacky 634193326Sed // Aggregate assignment turns into llvm.memcpy. This is almost valid per 635193326Sed // C99 6.5.16.1p3, which states "If the value being stored in an object is 636193326Sed // read from another object that overlaps in anyway the storage of the first 637193326Sed // object, then the overlap shall be exact and the two objects shall have 638193326Sed // qualified or unqualified versions of a compatible type." 639193326Sed // 640193326Sed // memcpy is not defined if the source and destination pointers are exactly 641193326Sed // equal, but other compilers do this optimization, and almost every memcpy 642193326Sed // implementation handles this case safely. If there is a libc that does not 643193326Sed // safely handle this, we can add a target hook. 644198092Srdivacky const llvm::Type *BP = llvm::Type::getInt8PtrTy(VMContext); 645193326Sed if (DestPtr->getType() != BP) 646193326Sed DestPtr = Builder.CreateBitCast(DestPtr, BP, "tmp"); 647193326Sed if (SrcPtr->getType() != BP) 648193326Sed SrcPtr = Builder.CreateBitCast(SrcPtr, BP, "tmp"); 649198092Srdivacky 650193326Sed // Get size and alignment info for this aggregate. 651193326Sed std::pair<uint64_t, unsigned> TypeInfo = getContext().getTypeInfo(Ty); 652198092Srdivacky 653193326Sed // FIXME: Handle variable sized types. 654198092Srdivacky const llvm::Type *IntPtr = 655198092Srdivacky llvm::IntegerType::get(VMContext, LLVMPointerWidth); 656198092Srdivacky 657193326Sed // FIXME: If we have a volatile struct, the optimizer can remove what might 658193326Sed // appear to be `extra' memory ops: 659193326Sed // 660193326Sed // volatile struct { int i; } a, b; 661193326Sed // 662193326Sed // int main() { 663193326Sed // a = b; 664193326Sed // a = b; 665193326Sed // } 666193326Sed // 667193326Sed // we need to use a differnt call here. We use isVolatile to indicate when 668193326Sed // either the source or the destination is volatile. 669193326Sed Builder.CreateCall4(CGM.getMemCpyFn(), 670193326Sed DestPtr, SrcPtr, 671193326Sed // TypeInfo.first describes size in bits. 672193326Sed llvm::ConstantInt::get(IntPtr, TypeInfo.first/8), 673198092Srdivacky llvm::ConstantInt::get(llvm::Type::getInt32Ty(VMContext), 674193326Sed TypeInfo.second/8)); 675193326Sed} 676