CGExprCXX.cpp revision 1d110e05e0ff48c1c7a483d6b7fd094cdf28316a
1//===--- CGExprCXX.cpp - Emit LLVM Code for C++ expressions ---------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This contains code dealing with code generation of C++ expressions 11// 12//===----------------------------------------------------------------------===// 13 14#include "CodeGenFunction.h" 15#include "CGObjCRuntime.h" 16using namespace clang; 17using namespace CodeGen; 18 19RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, 20 llvm::Value *Callee, 21 ReturnValueSlot ReturnValue, 22 llvm::Value *This, 23 llvm::Value *VTT, 24 CallExpr::const_arg_iterator ArgBeg, 25 CallExpr::const_arg_iterator ArgEnd) { 26 assert(MD->isInstance() && 27 "Trying to emit a member call expr on a static method!"); 28 29 const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); 30 31 CallArgList Args; 32 33 // Push the this ptr. 34 Args.push_back(std::make_pair(RValue::get(This), 35 MD->getThisType(getContext()))); 36 37 // If there is a VTT parameter, emit it. 38 if (VTT) { 39 QualType T = getContext().getPointerType(getContext().VoidPtrTy); 40 Args.push_back(std::make_pair(RValue::get(VTT), T)); 41 } 42 43 // And the rest of the call args 44 EmitCallArgs(Args, FPT, ArgBeg, ArgEnd); 45 46 QualType ResultType = FPT->getResultType(); 47 return EmitCall(CGM.getTypes().getFunctionInfo(ResultType, Args, 48 FPT->getExtInfo()), 49 Callee, ReturnValue, Args, MD); 50} 51 52/// canDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given 53/// expr can be devirtualized. 54static bool canDevirtualizeMemberFunctionCalls(const Expr *Base) { 55 if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Base)) { 56 if (const VarDecl *VD = dyn_cast<VarDecl>(DRE->getDecl())) { 57 // This is a record decl. We know the type and can devirtualize it. 58 return VD->getType()->isRecordType(); 59 } 60 61 return false; 62 } 63 64 // We can always devirtualize calls on temporary object expressions. 65 if (isa<CXXConstructExpr>(Base)) 66 return true; 67 68 // And calls on bound temporaries. 69 if (isa<CXXBindTemporaryExpr>(Base)) 70 return true; 71 72 // Check if this is a call expr that returns a record type. 73 if (const CallExpr *CE = dyn_cast<CallExpr>(Base)) 74 return CE->getCallReturnType()->isRecordType(); 75 76 // We can't devirtualize the call. 77 return false; 78} 79 80RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE, 81 ReturnValueSlot ReturnValue) { 82 if (isa<BinaryOperator>(CE->getCallee()->IgnoreParens())) 83 return EmitCXXMemberPointerCallExpr(CE, ReturnValue); 84 85 const MemberExpr *ME = cast<MemberExpr>(CE->getCallee()->IgnoreParens()); 86 const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl()); 87 88 if (MD->isStatic()) { 89 // The method is static, emit it as we would a regular call. 90 llvm::Value *Callee = CGM.GetAddrOfFunction(MD); 91 return EmitCall(getContext().getPointerType(MD->getType()), Callee, 92 ReturnValue, CE->arg_begin(), CE->arg_end()); 93 } 94 95 const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); 96 97 const llvm::Type *Ty = 98 CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), 99 FPT->isVariadic()); 100 llvm::Value *This; 101 102 if (ME->isArrow()) 103 This = EmitScalarExpr(ME->getBase()); 104 else { 105 LValue BaseLV = EmitLValue(ME->getBase()); 106 This = BaseLV.getAddress(); 107 } 108 109 if (MD->isCopyAssignment() && MD->isTrivial()) { 110 // We don't like to generate the trivial copy assignment operator when 111 // it isn't necessary; just produce the proper effect here. 112 llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress(); 113 EmitAggregateCopy(This, RHS, CE->getType()); 114 return RValue::get(This); 115 } 116 117 // C++ [class.virtual]p12: 118 // Explicit qualification with the scope operator (5.1) suppresses the 119 // virtual call mechanism. 120 // 121 // We also don't emit a virtual call if the base expression has a record type 122 // because then we know what the type is. 123 llvm::Value *Callee; 124 if (const CXXDestructorDecl *Destructor 125 = dyn_cast<CXXDestructorDecl>(MD)) { 126 if (Destructor->isTrivial()) 127 return RValue::get(0); 128 if (MD->isVirtual() && !ME->hasQualifier() && 129 !canDevirtualizeMemberFunctionCalls(ME->getBase())) { 130 Callee = BuildVirtualCall(Destructor, Dtor_Complete, This, Ty); 131 } else { 132 Callee = CGM.GetAddrOfFunction(GlobalDecl(Destructor, Dtor_Complete), Ty); 133 } 134 } else if (MD->isVirtual() && !ME->hasQualifier() && 135 !canDevirtualizeMemberFunctionCalls(ME->getBase())) { 136 Callee = BuildVirtualCall(MD, This, Ty); 137 } else { 138 Callee = CGM.GetAddrOfFunction(MD, Ty); 139 } 140 141 return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0, 142 CE->arg_begin(), CE->arg_end()); 143} 144 145RValue 146CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E, 147 ReturnValueSlot ReturnValue) { 148 const BinaryOperator *BO = 149 cast<BinaryOperator>(E->getCallee()->IgnoreParens()); 150 const Expr *BaseExpr = BO->getLHS(); 151 const Expr *MemFnExpr = BO->getRHS(); 152 153 const MemberPointerType *MPT = 154 MemFnExpr->getType()->getAs<MemberPointerType>(); 155 const FunctionProtoType *FPT = 156 MPT->getPointeeType()->getAs<FunctionProtoType>(); 157 const CXXRecordDecl *RD = 158 cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl()); 159 160 const llvm::FunctionType *FTy = 161 CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(RD, FPT), 162 FPT->isVariadic()); 163 164 const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext); 165 166 // Get the member function pointer. 167 llvm::Value *MemFnPtr = CreateMemTemp(MemFnExpr->getType(), "mem.fn"); 168 EmitAggExpr(MemFnExpr, MemFnPtr, /*VolatileDest=*/false); 169 170 // Emit the 'this' pointer. 171 llvm::Value *This; 172 173 if (BO->getOpcode() == BinaryOperator::PtrMemI) 174 This = EmitScalarExpr(BaseExpr); 175 else 176 This = EmitLValue(BaseExpr).getAddress(); 177 178 // Adjust it. 179 llvm::Value *Adj = Builder.CreateStructGEP(MemFnPtr, 1); 180 Adj = Builder.CreateLoad(Adj, "mem.fn.adj"); 181 182 llvm::Value *Ptr = Builder.CreateBitCast(This, Int8PtrTy, "ptr"); 183 Ptr = Builder.CreateGEP(Ptr, Adj, "adj"); 184 185 This = Builder.CreateBitCast(Ptr, This->getType(), "this"); 186 187 llvm::Value *FnPtr = Builder.CreateStructGEP(MemFnPtr, 0, "mem.fn.ptr"); 188 189 const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType()); 190 191 llvm::Value *FnAsInt = Builder.CreateLoad(FnPtr, "fn"); 192 193 // If the LSB in the function pointer is 1, the function pointer points to 194 // a virtual function. 195 llvm::Value *IsVirtual 196 = Builder.CreateAnd(FnAsInt, llvm::ConstantInt::get(PtrDiffTy, 1), 197 "and"); 198 199 IsVirtual = Builder.CreateTrunc(IsVirtual, 200 llvm::Type::getInt1Ty(VMContext)); 201 202 llvm::BasicBlock *FnVirtual = createBasicBlock("fn.virtual"); 203 llvm::BasicBlock *FnNonVirtual = createBasicBlock("fn.nonvirtual"); 204 llvm::BasicBlock *FnEnd = createBasicBlock("fn.end"); 205 206 Builder.CreateCondBr(IsVirtual, FnVirtual, FnNonVirtual); 207 EmitBlock(FnVirtual); 208 209 const llvm::Type *VTableTy = 210 FTy->getPointerTo()->getPointerTo(); 211 212 llvm::Value *VTable = Builder.CreateBitCast(This, VTableTy->getPointerTo()); 213 VTable = Builder.CreateLoad(VTable); 214 215 VTable = Builder.CreateBitCast(VTable, Int8PtrTy); 216 llvm::Value *VTableOffset = 217 Builder.CreateSub(FnAsInt, llvm::ConstantInt::get(PtrDiffTy, 1)); 218 219 VTable = Builder.CreateGEP(VTable, VTableOffset, "fn"); 220 VTable = Builder.CreateBitCast(VTable, VTableTy); 221 222 llvm::Value *VirtualFn = Builder.CreateLoad(VTable, "virtualfn"); 223 224 EmitBranch(FnEnd); 225 EmitBlock(FnNonVirtual); 226 227 // If the function is not virtual, just load the pointer. 228 llvm::Value *NonVirtualFn = Builder.CreateLoad(FnPtr, "fn"); 229 NonVirtualFn = Builder.CreateIntToPtr(NonVirtualFn, FTy->getPointerTo()); 230 231 EmitBlock(FnEnd); 232 233 llvm::PHINode *Callee = Builder.CreatePHI(FTy->getPointerTo()); 234 Callee->reserveOperandSpace(2); 235 Callee->addIncoming(VirtualFn, FnVirtual); 236 Callee->addIncoming(NonVirtualFn, FnNonVirtual); 237 238 CallArgList Args; 239 240 QualType ThisType = 241 getContext().getPointerType(getContext().getTagDeclType(RD)); 242 243 // Push the this ptr. 244 Args.push_back(std::make_pair(RValue::get(This), ThisType)); 245 246 // And the rest of the call args 247 EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end()); 248 const FunctionType *BO_FPT = BO->getType()->getAs<FunctionProtoType>(); 249 return EmitCall(CGM.getTypes().getFunctionInfo(Args, BO_FPT), Callee, 250 ReturnValue, Args); 251} 252 253RValue 254CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E, 255 const CXXMethodDecl *MD, 256 ReturnValueSlot ReturnValue) { 257 assert(MD->isInstance() && 258 "Trying to emit a member call expr on a static method!"); 259 if (MD->isCopyAssignment()) { 260 const CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(MD->getDeclContext()); 261 if (ClassDecl->hasTrivialCopyAssignment()) { 262 assert(!ClassDecl->hasUserDeclaredCopyAssignment() && 263 "EmitCXXOperatorMemberCallExpr - user declared copy assignment"); 264 LValue LV = EmitLValue(E->getArg(0)); 265 llvm::Value *This; 266 if (LV.isPropertyRef()) { 267 llvm::Value *AggLoc = CreateMemTemp(E->getArg(1)->getType()); 268 EmitAggExpr(E->getArg(1), AggLoc, false /*VolatileDest*/); 269 EmitObjCPropertySet(LV.getPropertyRefExpr(), 270 RValue::getAggregate(AggLoc, false /*VolatileDest*/)); 271 return RValue::getAggregate(0, false); 272 } 273 else 274 This = LV.getAddress(); 275 276 llvm::Value *Src = EmitLValue(E->getArg(1)).getAddress(); 277 QualType Ty = E->getType(); 278 EmitAggregateCopy(This, Src, Ty); 279 return RValue::get(This); 280 } 281 } 282 283 const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>(); 284 const llvm::Type *Ty = 285 CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD), 286 FPT->isVariadic()); 287 LValue LV = EmitLValue(E->getArg(0)); 288 llvm::Value *This; 289 if (LV.isPropertyRef()) { 290 RValue RV = EmitLoadOfPropertyRefLValue(LV, E->getArg(0)->getType()); 291 assert (!RV.isScalar() && "EmitCXXOperatorMemberCallExpr"); 292 This = RV.getAggregateAddr(); 293 } 294 else 295 This = LV.getAddress(); 296 297 llvm::Value *Callee; 298 if (MD->isVirtual() && !canDevirtualizeMemberFunctionCalls(E->getArg(0))) 299 Callee = BuildVirtualCall(MD, This, Ty); 300 else 301 Callee = CGM.GetAddrOfFunction(MD, Ty); 302 303 return EmitCXXMemberCall(MD, Callee, ReturnValue, This, /*VTT=*/0, 304 E->arg_begin() + 1, E->arg_end()); 305} 306 307void 308CodeGenFunction::EmitCXXConstructExpr(llvm::Value *Dest, 309 const CXXConstructExpr *E) { 310 assert(Dest && "Must have a destination!"); 311 const CXXConstructorDecl *CD = E->getConstructor(); 312 const ConstantArrayType *Array = 313 getContext().getAsConstantArrayType(E->getType()); 314 // For a copy constructor, even if it is trivial, must fall thru so 315 // its argument is code-gen'ed. 316 if (!CD->isCopyConstructor()) { 317 QualType InitType = E->getType(); 318 if (Array) 319 InitType = getContext().getBaseElementType(Array); 320 const CXXRecordDecl *RD = 321 cast<CXXRecordDecl>(InitType->getAs<RecordType>()->getDecl()); 322 if (RD->hasTrivialConstructor()) 323 return; 324 } 325 // Code gen optimization to eliminate copy constructor and return 326 // its first argument instead, if in fact that argument is a temporary 327 // object. 328 if (getContext().getLangOptions().ElideConstructors && E->isElidable()) { 329 if (const Expr *Arg = E->getArg(0)->getTemporaryObject()) { 330 EmitAggExpr(Arg, Dest, false); 331 return; 332 } 333 } 334 if (Array) { 335 QualType BaseElementTy = getContext().getBaseElementType(Array); 336 const llvm::Type *BasePtr = ConvertType(BaseElementTy); 337 BasePtr = llvm::PointerType::getUnqual(BasePtr); 338 llvm::Value *BaseAddrPtr = 339 Builder.CreateBitCast(Dest, BasePtr); 340 341 EmitCXXAggrConstructorCall(CD, Array, BaseAddrPtr, 342 E->arg_begin(), E->arg_end()); 343 } 344 else { 345 CXXCtorType Type = 346 (E->getConstructionKind() == CXXConstructExpr::CK_Complete) 347 ? Ctor_Complete : Ctor_Base; 348 bool ForVirtualBase = 349 E->getConstructionKind() == CXXConstructExpr::CK_VirtualBase; 350 351 // Call the constructor. 352 EmitCXXConstructorCall(CD, Type, ForVirtualBase, Dest, 353 E->arg_begin(), E->arg_end()); 354 } 355} 356 357static CharUnits CalculateCookiePadding(ASTContext &Ctx, QualType ElementType) { 358 const RecordType *RT = ElementType->getAs<RecordType>(); 359 if (!RT) 360 return CharUnits::Zero(); 361 362 const CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl()); 363 if (!RD) 364 return CharUnits::Zero(); 365 366 // Check if the class has a trivial destructor. 367 if (RD->hasTrivialDestructor()) { 368 // Check if the usual deallocation function takes two arguments. 369 const CXXMethodDecl *UsualDeallocationFunction = 0; 370 371 DeclarationName OpName = 372 Ctx.DeclarationNames.getCXXOperatorName(OO_Array_Delete); 373 DeclContext::lookup_const_iterator Op, OpEnd; 374 for (llvm::tie(Op, OpEnd) = RD->lookup(OpName); 375 Op != OpEnd; ++Op) { 376 const CXXMethodDecl *Delete = cast<CXXMethodDecl>(*Op); 377 378 if (Delete->isUsualDeallocationFunction()) { 379 UsualDeallocationFunction = Delete; 380 break; 381 } 382 } 383 384 // No usual deallocation function, we don't need a cookie. 385 if (!UsualDeallocationFunction) 386 return CharUnits::Zero(); 387 388 // The usual deallocation function doesn't take a size_t argument, so we 389 // don't need a cookie. 390 if (UsualDeallocationFunction->getNumParams() == 1) 391 return CharUnits::Zero(); 392 393 assert(UsualDeallocationFunction->getNumParams() == 2 && 394 "Unexpected deallocation function type!"); 395 } 396 397 // Padding is the maximum of sizeof(size_t) and alignof(ElementType) 398 return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()), 399 Ctx.getTypeAlignInChars(ElementType)); 400} 401 402static CharUnits CalculateCookiePadding(ASTContext &Ctx, const CXXNewExpr *E) { 403 if (!E->isArray()) 404 return CharUnits::Zero(); 405 406 // No cookie is required if the new operator being used is 407 // ::operator new[](size_t, void*). 408 const FunctionDecl *OperatorNew = E->getOperatorNew(); 409 if (OperatorNew->getDeclContext()->getLookupContext()->isFileContext()) { 410 if (OperatorNew->getNumParams() == 2) { 411 CanQualType ParamType = 412 Ctx.getCanonicalType(OperatorNew->getParamDecl(1)->getType()); 413 414 if (ParamType == Ctx.VoidPtrTy) 415 return CharUnits::Zero(); 416 } 417 } 418 419 return CalculateCookiePadding(Ctx, E->getAllocatedType()); 420} 421 422static llvm::Value *EmitCXXNewAllocSize(ASTContext &Context, 423 CodeGenFunction &CGF, 424 const CXXNewExpr *E, 425 llvm::Value *& NumElements) { 426 QualType Type = E->getAllocatedType(); 427 CharUnits TypeSize = CGF.getContext().getTypeSizeInChars(Type); 428 const llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType()); 429 430 if (!E->isArray()) 431 return llvm::ConstantInt::get(SizeTy, TypeSize.getQuantity()); 432 433 CharUnits CookiePadding = CalculateCookiePadding(CGF.getContext(), E); 434 435 Expr::EvalResult Result; 436 if (E->getArraySize()->Evaluate(Result, CGF.getContext()) && 437 !Result.HasSideEffects && Result.Val.isInt()) { 438 439 CharUnits AllocSize = 440 Result.Val.getInt().getZExtValue() * TypeSize + CookiePadding; 441 442 NumElements = 443 llvm::ConstantInt::get(SizeTy, Result.Val.getInt().getZExtValue()); 444 while (const ArrayType *AType = Context.getAsArrayType(Type)) { 445 const llvm::ArrayType *llvmAType = 446 cast<llvm::ArrayType>(CGF.ConvertType(Type)); 447 NumElements = 448 CGF.Builder.CreateMul(NumElements, 449 llvm::ConstantInt::get( 450 SizeTy, llvmAType->getNumElements())); 451 Type = AType->getElementType(); 452 } 453 454 return llvm::ConstantInt::get(SizeTy, AllocSize.getQuantity()); 455 } 456 457 // Emit the array size expression. 458 NumElements = CGF.EmitScalarExpr(E->getArraySize()); 459 460 // Multiply with the type size. 461 llvm::Value *V = 462 CGF.Builder.CreateMul(NumElements, 463 llvm::ConstantInt::get(SizeTy, 464 TypeSize.getQuantity())); 465 466 while (const ArrayType *AType = Context.getAsArrayType(Type)) { 467 const llvm::ArrayType *llvmAType = 468 cast<llvm::ArrayType>(CGF.ConvertType(Type)); 469 NumElements = 470 CGF.Builder.CreateMul(NumElements, 471 llvm::ConstantInt::get( 472 SizeTy, llvmAType->getNumElements())); 473 Type = AType->getElementType(); 474 } 475 476 // And add the cookie padding if necessary. 477 if (!CookiePadding.isZero()) 478 V = CGF.Builder.CreateAdd(V, 479 llvm::ConstantInt::get(SizeTy, CookiePadding.getQuantity())); 480 481 return V; 482} 483 484static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const CXXNewExpr *E, 485 llvm::Value *NewPtr) { 486 487 assert(E->getNumConstructorArgs() == 1 && 488 "Can only have one argument to initializer of POD type."); 489 490 const Expr *Init = E->getConstructorArg(0); 491 QualType AllocType = E->getAllocatedType(); 492 493 if (!CGF.hasAggregateLLVMType(AllocType)) 494 CGF.EmitStoreOfScalar(CGF.EmitScalarExpr(Init), NewPtr, 495 AllocType.isVolatileQualified(), AllocType); 496 else if (AllocType->isAnyComplexType()) 497 CGF.EmitComplexExprIntoAddr(Init, NewPtr, 498 AllocType.isVolatileQualified()); 499 else 500 CGF.EmitAggExpr(Init, NewPtr, AllocType.isVolatileQualified()); 501} 502 503void 504CodeGenFunction::EmitNewArrayInitializer(const CXXNewExpr *E, 505 llvm::Value *NewPtr, 506 llvm::Value *NumElements) { 507 // We have a POD type. 508 if (E->getNumConstructorArgs() == 0) 509 return; 510 511 const llvm::Type *SizeTy = ConvertType(getContext().getSizeType()); 512 513 // Create a temporary for the loop index and initialize it with 0. 514 llvm::Value *IndexPtr = CreateTempAlloca(SizeTy, "loop.index"); 515 llvm::Value *Zero = llvm::Constant::getNullValue(SizeTy); 516 Builder.CreateStore(Zero, IndexPtr); 517 518 // Start the loop with a block that tests the condition. 519 llvm::BasicBlock *CondBlock = createBasicBlock("for.cond"); 520 llvm::BasicBlock *AfterFor = createBasicBlock("for.end"); 521 522 EmitBlock(CondBlock); 523 524 llvm::BasicBlock *ForBody = createBasicBlock("for.body"); 525 526 // Generate: if (loop-index < number-of-elements fall to the loop body, 527 // otherwise, go to the block after the for-loop. 528 llvm::Value *Counter = Builder.CreateLoad(IndexPtr); 529 llvm::Value *IsLess = Builder.CreateICmpULT(Counter, NumElements, "isless"); 530 // If the condition is true, execute the body. 531 Builder.CreateCondBr(IsLess, ForBody, AfterFor); 532 533 EmitBlock(ForBody); 534 535 llvm::BasicBlock *ContinueBlock = createBasicBlock("for.inc"); 536 // Inside the loop body, emit the constructor call on the array element. 537 Counter = Builder.CreateLoad(IndexPtr); 538 llvm::Value *Address = Builder.CreateInBoundsGEP(NewPtr, Counter, 539 "arrayidx"); 540 StoreAnyExprIntoOneUnit(*this, E, Address); 541 542 EmitBlock(ContinueBlock); 543 544 // Emit the increment of the loop counter. 545 llvm::Value *NextVal = llvm::ConstantInt::get(SizeTy, 1); 546 Counter = Builder.CreateLoad(IndexPtr); 547 NextVal = Builder.CreateAdd(Counter, NextVal, "inc"); 548 Builder.CreateStore(NextVal, IndexPtr); 549 550 // Finally, branch back up to the condition for the next iteration. 551 EmitBranch(CondBlock); 552 553 // Emit the fall-through block. 554 EmitBlock(AfterFor, true); 555} 556 557static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E, 558 llvm::Value *NewPtr, 559 llvm::Value *NumElements) { 560 if (E->isArray()) { 561 if (CXXConstructorDecl *Ctor = E->getConstructor()) { 562 if (!Ctor->getParent()->hasTrivialConstructor()) 563 CGF.EmitCXXAggrConstructorCall(Ctor, NumElements, NewPtr, 564 E->constructor_arg_begin(), 565 E->constructor_arg_end()); 566 return; 567 } 568 else { 569 CGF.EmitNewArrayInitializer(E, NewPtr, NumElements); 570 return; 571 } 572 } 573 574 if (CXXConstructorDecl *Ctor = E->getConstructor()) { 575 CGF.EmitCXXConstructorCall(Ctor, Ctor_Complete, /*ForVirtualBase=*/false, 576 NewPtr, E->constructor_arg_begin(), 577 E->constructor_arg_end()); 578 579 return; 580 } 581 // We have a POD type. 582 if (E->getNumConstructorArgs() == 0) 583 return; 584 585 StoreAnyExprIntoOneUnit(CGF, E, NewPtr); 586} 587 588llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { 589 QualType AllocType = E->getAllocatedType(); 590 FunctionDecl *NewFD = E->getOperatorNew(); 591 const FunctionProtoType *NewFTy = NewFD->getType()->getAs<FunctionProtoType>(); 592 593 CallArgList NewArgs; 594 595 // The allocation size is the first argument. 596 QualType SizeTy = getContext().getSizeType(); 597 598 llvm::Value *NumElements = 0; 599 llvm::Value *AllocSize = EmitCXXNewAllocSize(getContext(), 600 *this, E, NumElements); 601 602 NewArgs.push_back(std::make_pair(RValue::get(AllocSize), SizeTy)); 603 604 // Emit the rest of the arguments. 605 // FIXME: Ideally, this should just use EmitCallArgs. 606 CXXNewExpr::const_arg_iterator NewArg = E->placement_arg_begin(); 607 608 // First, use the types from the function type. 609 // We start at 1 here because the first argument (the allocation size) 610 // has already been emitted. 611 for (unsigned i = 1, e = NewFTy->getNumArgs(); i != e; ++i, ++NewArg) { 612 QualType ArgType = NewFTy->getArgType(i); 613 614 assert(getContext().getCanonicalType(ArgType.getNonReferenceType()). 615 getTypePtr() == 616 getContext().getCanonicalType(NewArg->getType()).getTypePtr() && 617 "type mismatch in call argument!"); 618 619 NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), 620 ArgType)); 621 622 } 623 624 // Either we've emitted all the call args, or we have a call to a 625 // variadic function. 626 assert((NewArg == E->placement_arg_end() || NewFTy->isVariadic()) && 627 "Extra arguments in non-variadic function!"); 628 629 // If we still have any arguments, emit them using the type of the argument. 630 for (CXXNewExpr::const_arg_iterator NewArgEnd = E->placement_arg_end(); 631 NewArg != NewArgEnd; ++NewArg) { 632 QualType ArgType = NewArg->getType(); 633 NewArgs.push_back(std::make_pair(EmitCallArg(*NewArg, ArgType), 634 ArgType)); 635 } 636 637 // Emit the call to new. 638 RValue RV = 639 EmitCall(CGM.getTypes().getFunctionInfo(NewArgs, NewFTy), 640 CGM.GetAddrOfFunction(NewFD), ReturnValueSlot(), NewArgs, NewFD); 641 642 // If an allocation function is declared with an empty exception specification 643 // it returns null to indicate failure to allocate storage. [expr.new]p13. 644 // (We don't need to check for null when there's no new initializer and 645 // we're allocating a POD type). 646 bool NullCheckResult = NewFTy->hasEmptyExceptionSpec() && 647 !(AllocType->isPODType() && !E->hasInitializer()); 648 649 llvm::BasicBlock *NewNull = 0; 650 llvm::BasicBlock *NewNotNull = 0; 651 llvm::BasicBlock *NewEnd = 0; 652 653 llvm::Value *NewPtr = RV.getScalarVal(); 654 655 if (NullCheckResult) { 656 NewNull = createBasicBlock("new.null"); 657 NewNotNull = createBasicBlock("new.notnull"); 658 NewEnd = createBasicBlock("new.end"); 659 660 llvm::Value *IsNull = 661 Builder.CreateICmpEQ(NewPtr, 662 llvm::Constant::getNullValue(NewPtr->getType()), 663 "isnull"); 664 665 Builder.CreateCondBr(IsNull, NewNull, NewNotNull); 666 EmitBlock(NewNotNull); 667 } 668 669 CharUnits CookiePadding = CalculateCookiePadding(getContext(), E); 670 if (!CookiePadding.isZero()) { 671 CharUnits CookieOffset = 672 CookiePadding - getContext().getTypeSizeInChars(SizeTy); 673 674 llvm::Value *NumElementsPtr = 675 Builder.CreateConstInBoundsGEP1_64(NewPtr, CookieOffset.getQuantity()); 676 677 NumElementsPtr = Builder.CreateBitCast(NumElementsPtr, 678 ConvertType(SizeTy)->getPointerTo()); 679 Builder.CreateStore(NumElements, NumElementsPtr); 680 681 // Now add the padding to the new ptr. 682 NewPtr = Builder.CreateConstInBoundsGEP1_64(NewPtr, 683 CookiePadding.getQuantity()); 684 } 685 686 if (AllocType->isArrayType()) { 687 while (const ArrayType *AType = getContext().getAsArrayType(AllocType)) 688 AllocType = AType->getElementType(); 689 NewPtr = 690 Builder.CreateBitCast(NewPtr, 691 ConvertType(getContext().getPointerType(AllocType))); 692 EmitNewInitializer(*this, E, NewPtr, NumElements); 693 NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType())); 694 } 695 else { 696 NewPtr = Builder.CreateBitCast(NewPtr, ConvertType(E->getType())); 697 EmitNewInitializer(*this, E, NewPtr, NumElements); 698 } 699 700 if (NullCheckResult) { 701 Builder.CreateBr(NewEnd); 702 NewNotNull = Builder.GetInsertBlock(); 703 EmitBlock(NewNull); 704 Builder.CreateBr(NewEnd); 705 EmitBlock(NewEnd); 706 707 llvm::PHINode *PHI = Builder.CreatePHI(NewPtr->getType()); 708 PHI->reserveOperandSpace(2); 709 PHI->addIncoming(NewPtr, NewNotNull); 710 PHI->addIncoming(llvm::Constant::getNullValue(NewPtr->getType()), NewNull); 711 712 NewPtr = PHI; 713 } 714 715 return NewPtr; 716} 717 718static std::pair<llvm::Value *, llvm::Value *> 719GetAllocatedObjectPtrAndNumElements(CodeGenFunction &CGF, 720 llvm::Value *Ptr, QualType DeleteTy) { 721 QualType SizeTy = CGF.getContext().getSizeType(); 722 const llvm::Type *SizeLTy = CGF.ConvertType(SizeTy); 723 724 CharUnits DeleteTypeAlign = CGF.getContext().getTypeAlignInChars(DeleteTy); 725 CharUnits CookiePadding = 726 std::max(CGF.getContext().getTypeSizeInChars(SizeTy), 727 DeleteTypeAlign); 728 assert(!CookiePadding.isZero() && "CookiePadding should not be 0."); 729 730 const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGF.getLLVMContext()); 731 CharUnits CookieOffset = 732 CookiePadding - CGF.getContext().getTypeSizeInChars(SizeTy); 733 734 llvm::Value *AllocatedObjectPtr = CGF.Builder.CreateBitCast(Ptr, Int8PtrTy); 735 AllocatedObjectPtr = 736 CGF.Builder.CreateConstInBoundsGEP1_64(AllocatedObjectPtr, 737 -CookiePadding.getQuantity()); 738 739 llvm::Value *NumElementsPtr = 740 CGF.Builder.CreateConstInBoundsGEP1_64(AllocatedObjectPtr, 741 CookieOffset.getQuantity()); 742 NumElementsPtr = 743 CGF.Builder.CreateBitCast(NumElementsPtr, SizeLTy->getPointerTo()); 744 745 llvm::Value *NumElements = CGF.Builder.CreateLoad(NumElementsPtr); 746 NumElements = 747 CGF.Builder.CreateIntCast(NumElements, SizeLTy, /*isSigned=*/false); 748 749 return std::make_pair(AllocatedObjectPtr, NumElements); 750} 751 752void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD, 753 llvm::Value *Ptr, 754 QualType DeleteTy) { 755 const FunctionProtoType *DeleteFTy = 756 DeleteFD->getType()->getAs<FunctionProtoType>(); 757 758 CallArgList DeleteArgs; 759 760 // Check if we need to pass the size to the delete operator. 761 llvm::Value *Size = 0; 762 QualType SizeTy; 763 if (DeleteFTy->getNumArgs() == 2) { 764 SizeTy = DeleteFTy->getArgType(1); 765 CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy); 766 Size = llvm::ConstantInt::get(ConvertType(SizeTy), 767 DeleteTypeSize.getQuantity()); 768 } 769 770 if (DeleteFD->getOverloadedOperator() == OO_Array_Delete && 771 !CalculateCookiePadding(getContext(), DeleteTy).isZero()) { 772 // We need to get the number of elements in the array from the cookie. 773 llvm::Value *AllocatedObjectPtr; 774 llvm::Value *NumElements; 775 llvm::tie(AllocatedObjectPtr, NumElements) = 776 GetAllocatedObjectPtrAndNumElements(*this, Ptr, DeleteTy); 777 778 // Multiply the size with the number of elements. 779 if (Size) 780 Size = Builder.CreateMul(NumElements, Size); 781 782 Ptr = AllocatedObjectPtr; 783 } 784 785 QualType ArgTy = DeleteFTy->getArgType(0); 786 llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy)); 787 DeleteArgs.push_back(std::make_pair(RValue::get(DeletePtr), ArgTy)); 788 789 if (Size) 790 DeleteArgs.push_back(std::make_pair(RValue::get(Size), SizeTy)); 791 792 // Emit the call to delete. 793 EmitCall(CGM.getTypes().getFunctionInfo(DeleteArgs, DeleteFTy), 794 CGM.GetAddrOfFunction(DeleteFD), ReturnValueSlot(), 795 DeleteArgs, DeleteFD); 796} 797 798void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) { 799 800 // Get at the argument before we performed the implicit conversion 801 // to void*. 802 const Expr *Arg = E->getArgument(); 803 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Arg)) { 804 if (ICE->getCastKind() != CastExpr::CK_UserDefinedConversion && 805 ICE->getType()->isVoidPointerType()) 806 Arg = ICE->getSubExpr(); 807 else 808 break; 809 } 810 811 QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType(); 812 813 llvm::Value *Ptr = EmitScalarExpr(Arg); 814 815 // Null check the pointer. 816 llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull"); 817 llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end"); 818 819 llvm::Value *IsNull = 820 Builder.CreateICmpEQ(Ptr, llvm::Constant::getNullValue(Ptr->getType()), 821 "isnull"); 822 823 Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull); 824 EmitBlock(DeleteNotNull); 825 826 bool ShouldCallDelete = true; 827 828 // Call the destructor if necessary. 829 if (const RecordType *RT = DeleteTy->getAs<RecordType>()) { 830 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) { 831 if (!RD->hasTrivialDestructor()) { 832 const CXXDestructorDecl *Dtor = RD->getDestructor(); 833 if (E->isArrayForm()) { 834 llvm::Value *AllocatedObjectPtr; 835 llvm::Value *NumElements; 836 llvm::tie(AllocatedObjectPtr, NumElements) = 837 GetAllocatedObjectPtrAndNumElements(*this, Ptr, DeleteTy); 838 839 EmitCXXAggrDestructorCall(Dtor, NumElements, Ptr); 840 } else if (Dtor->isVirtual()) { 841 const llvm::Type *Ty = 842 CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(Dtor), 843 /*isVariadic=*/false); 844 845 llvm::Value *Callee = BuildVirtualCall(Dtor, Dtor_Deleting, Ptr, Ty); 846 EmitCXXMemberCall(Dtor, Callee, ReturnValueSlot(), Ptr, /*VTT=*/0, 847 0, 0); 848 849 // The dtor took care of deleting the object. 850 ShouldCallDelete = false; 851 } else 852 EmitCXXDestructorCall(Dtor, Dtor_Complete, /*ForVirtualBase=*/false, 853 Ptr); 854 } 855 } 856 } 857 858 if (ShouldCallDelete) 859 EmitDeleteCall(E->getOperatorDelete(), Ptr, DeleteTy); 860 861 EmitBlock(DeleteEnd); 862} 863 864llvm::Value * CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) { 865 QualType Ty = E->getType(); 866 const llvm::Type *LTy = ConvertType(Ty)->getPointerTo(); 867 868 if (E->isTypeOperand()) { 869 llvm::Constant *TypeInfo = 870 CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand()); 871 return Builder.CreateBitCast(TypeInfo, LTy); 872 } 873 874 Expr *subE = E->getExprOperand(); 875 Ty = subE->getType(); 876 CanQualType CanTy = CGM.getContext().getCanonicalType(Ty); 877 Ty = CanTy.getUnqualifiedType().getNonReferenceType(); 878 if (const RecordType *RT = Ty->getAs<RecordType>()) { 879 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 880 if (RD->isPolymorphic()) { 881 // FIXME: if subE is an lvalue do 882 LValue Obj = EmitLValue(subE); 883 llvm::Value *This = Obj.getAddress(); 884 LTy = LTy->getPointerTo()->getPointerTo(); 885 llvm::Value *V = Builder.CreateBitCast(This, LTy); 886 // We need to do a zero check for *p, unless it has NonNullAttr. 887 // FIXME: PointerType->hasAttr<NonNullAttr>() 888 bool CanBeZero = false; 889 if (UnaryOperator *UO = dyn_cast<UnaryOperator>(subE->IgnoreParens())) 890 if (UO->getOpcode() == UnaryOperator::Deref) 891 CanBeZero = true; 892 if (CanBeZero) { 893 llvm::BasicBlock *NonZeroBlock = createBasicBlock(); 894 llvm::BasicBlock *ZeroBlock = createBasicBlock(); 895 896 llvm::Value *Zero = llvm::Constant::getNullValue(LTy); 897 Builder.CreateCondBr(Builder.CreateICmpNE(V, Zero), 898 NonZeroBlock, ZeroBlock); 899 EmitBlock(ZeroBlock); 900 /// Call __cxa_bad_typeid 901 const llvm::Type *ResultType = llvm::Type::getVoidTy(VMContext); 902 const llvm::FunctionType *FTy; 903 FTy = llvm::FunctionType::get(ResultType, false); 904 llvm::Value *F = CGM.CreateRuntimeFunction(FTy, "__cxa_bad_typeid"); 905 Builder.CreateCall(F)->setDoesNotReturn(); 906 Builder.CreateUnreachable(); 907 EmitBlock(NonZeroBlock); 908 } 909 V = Builder.CreateLoad(V, "vtable"); 910 V = Builder.CreateConstInBoundsGEP1_64(V, -1ULL); 911 V = Builder.CreateLoad(V); 912 return V; 913 } 914 } 915 return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(Ty), LTy); 916} 917 918llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *V, 919 const CXXDynamicCastExpr *DCE) { 920 QualType SrcTy = DCE->getSubExpr()->getType(); 921 QualType DestTy = DCE->getTypeAsWritten(); 922 QualType InnerType = DestTy->getPointeeType(); 923 924 const llvm::Type *LTy = ConvertType(DCE->getType()); 925 926 bool CanBeZero = false; 927 bool ToVoid = false; 928 bool ThrowOnBad = false; 929 if (DestTy->isPointerType()) { 930 // FIXME: if PointerType->hasAttr<NonNullAttr>(), we don't set this 931 CanBeZero = true; 932 if (InnerType->isVoidType()) 933 ToVoid = true; 934 } else { 935 LTy = LTy->getPointerTo(); 936 937 // FIXME: What if exceptions are disabled? 938 ThrowOnBad = true; 939 } 940 941 if (SrcTy->isPointerType() || SrcTy->isReferenceType()) 942 SrcTy = SrcTy->getPointeeType(); 943 SrcTy = SrcTy.getUnqualifiedType(); 944 945 if (DestTy->isPointerType() || DestTy->isReferenceType()) 946 DestTy = DestTy->getPointeeType(); 947 DestTy = DestTy.getUnqualifiedType(); 948 949 llvm::BasicBlock *ContBlock = createBasicBlock(); 950 llvm::BasicBlock *NullBlock = 0; 951 llvm::BasicBlock *NonZeroBlock = 0; 952 if (CanBeZero) { 953 NonZeroBlock = createBasicBlock(); 954 NullBlock = createBasicBlock(); 955 Builder.CreateCondBr(Builder.CreateIsNotNull(V), NonZeroBlock, NullBlock); 956 EmitBlock(NonZeroBlock); 957 } 958 959 llvm::BasicBlock *BadCastBlock = 0; 960 961 const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType()); 962 963 // See if this is a dynamic_cast(void*) 964 if (ToVoid) { 965 llvm::Value *This = V; 966 V = Builder.CreateBitCast(This, PtrDiffTy->getPointerTo()->getPointerTo()); 967 V = Builder.CreateLoad(V, "vtable"); 968 V = Builder.CreateConstInBoundsGEP1_64(V, -2ULL); 969 V = Builder.CreateLoad(V, "offset to top"); 970 This = Builder.CreateBitCast(This, llvm::Type::getInt8PtrTy(VMContext)); 971 V = Builder.CreateInBoundsGEP(This, V); 972 V = Builder.CreateBitCast(V, LTy); 973 } else { 974 /// Call __dynamic_cast 975 const llvm::Type *ResultType = llvm::Type::getInt8PtrTy(VMContext); 976 const llvm::FunctionType *FTy; 977 std::vector<const llvm::Type*> ArgTys; 978 const llvm::Type *PtrToInt8Ty 979 = llvm::Type::getInt8Ty(VMContext)->getPointerTo(); 980 ArgTys.push_back(PtrToInt8Ty); 981 ArgTys.push_back(PtrToInt8Ty); 982 ArgTys.push_back(PtrToInt8Ty); 983 ArgTys.push_back(PtrDiffTy); 984 FTy = llvm::FunctionType::get(ResultType, ArgTys, false); 985 986 // FIXME: Calculate better hint. 987 llvm::Value *hint = llvm::ConstantInt::get(PtrDiffTy, -1ULL); 988 989 assert(SrcTy->isRecordType() && "Src type must be record type!"); 990 assert(DestTy->isRecordType() && "Dest type must be record type!"); 991 992 llvm::Value *SrcArg 993 = CGM.GetAddrOfRTTIDescriptor(SrcTy.getUnqualifiedType()); 994 llvm::Value *DestArg 995 = CGM.GetAddrOfRTTIDescriptor(DestTy.getUnqualifiedType()); 996 997 V = Builder.CreateBitCast(V, PtrToInt8Ty); 998 V = Builder.CreateCall4(CGM.CreateRuntimeFunction(FTy, "__dynamic_cast"), 999 V, SrcArg, DestArg, hint); 1000 V = Builder.CreateBitCast(V, LTy); 1001 1002 if (ThrowOnBad) { 1003 BadCastBlock = createBasicBlock(); 1004 Builder.CreateCondBr(Builder.CreateIsNotNull(V), ContBlock, BadCastBlock); 1005 EmitBlock(BadCastBlock); 1006 /// Invoke __cxa_bad_cast 1007 ResultType = llvm::Type::getVoidTy(VMContext); 1008 const llvm::FunctionType *FBadTy; 1009 FBadTy = llvm::FunctionType::get(ResultType, false); 1010 llvm::Value *F = CGM.CreateRuntimeFunction(FBadTy, "__cxa_bad_cast"); 1011 if (llvm::BasicBlock *InvokeDest = getInvokeDest()) { 1012 llvm::BasicBlock *Cont = createBasicBlock("invoke.cont"); 1013 Builder.CreateInvoke(F, Cont, InvokeDest)->setDoesNotReturn(); 1014 EmitBlock(Cont); 1015 } else { 1016 // FIXME: Does this ever make sense? 1017 Builder.CreateCall(F)->setDoesNotReturn(); 1018 } 1019 Builder.CreateUnreachable(); 1020 } 1021 } 1022 1023 if (CanBeZero) { 1024 Builder.CreateBr(ContBlock); 1025 EmitBlock(NullBlock); 1026 Builder.CreateBr(ContBlock); 1027 } 1028 EmitBlock(ContBlock); 1029 if (CanBeZero) { 1030 llvm::PHINode *PHI = Builder.CreatePHI(LTy); 1031 PHI->reserveOperandSpace(2); 1032 PHI->addIncoming(V, NonZeroBlock); 1033 PHI->addIncoming(llvm::Constant::getNullValue(LTy), NullBlock); 1034 V = PHI; 1035 } 1036 1037 return V; 1038} 1039