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 "CGCUDARuntime.h" 16 #include "CGCXXABI.h" 17 #include "CGDebugInfo.h" 18 #include "CGObjCRuntime.h" 19 #include "clang/CodeGen/CGFunctionInfo.h" 20 #include "clang/Frontend/CodeGenOptions.h" 21 #include "llvm/IR/CallSite.h" 22 #include "llvm/IR/Intrinsics.h" 23 24 using namespace clang; 25 using namespace CodeGen; 26 27 RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, 28 SourceLocation CallLoc, 29 llvm::Value *Callee, 30 ReturnValueSlot ReturnValue, 31 llvm::Value *This, 32 llvm::Value *ImplicitParam, 33 QualType ImplicitParamTy, 34 CallExpr::const_arg_iterator ArgBeg, 35 CallExpr::const_arg_iterator ArgEnd) { 36 assert(MD->isInstance() && 37 "Trying to emit a member call expr on a static method!"); 38 39 // C++11 [class.mfct.non-static]p2: 40 // If a non-static member function of a class X is called for an object that 41 // is not of type X, or of a type derived from X, the behavior is undefined. 42 EmitTypeCheck(isa<CXXConstructorDecl>(MD) ? TCK_ConstructorCall 43 : TCK_MemberCall, 44 CallLoc, This, getContext().getRecordType(MD->getParent())); 45 46 CallArgList Args; 47 48 // Push the this ptr. 49 Args.add(RValue::get(This), MD->getThisType(getContext())); 50 51 // If there is an implicit parameter (e.g. VTT), emit it. 52 if (ImplicitParam) { 53 Args.add(RValue::get(ImplicitParam), ImplicitParamTy); 54 } 55 56 const FunctionProtoType *FPT = MD->getType()->castAs<FunctionProtoType>(); 57 RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, Args.size()); 58 59 // And the rest of the call args. 60 EmitCallArgs(Args, FPT, ArgBeg, ArgEnd); 61 62 return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required), 63 Callee, ReturnValue, Args, MD); 64 } 65 66 static CXXRecordDecl *getCXXRecord(const Expr *E) { 67 QualType T = E->getType(); 68 if (const PointerType *PTy = T->getAs<PointerType>()) 69 T = PTy->getPointeeType(); 70 const RecordType *Ty = T->castAs<RecordType>(); 71 return cast<CXXRecordDecl>(Ty->getDecl()); 72 } 73 74 // Note: This function also emit constructor calls to support a MSVC 75 // extensions allowing explicit constructor function call. 76 RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE, 77 ReturnValueSlot ReturnValue) { 78 const Expr *callee = CE->getCallee()->IgnoreParens(); 79 80 if (isa<BinaryOperator>(callee)) 81 return EmitCXXMemberPointerCallExpr(CE, ReturnValue); 82 83 const MemberExpr *ME = cast<MemberExpr>(callee); 84 const CXXMethodDecl *MD = cast<CXXMethodDecl>(ME->getMemberDecl()); 85 86 if (MD->isStatic()) { 87 // The method is static, emit it as we would a regular call. 88 llvm::Value *Callee = CGM.GetAddrOfFunction(MD); 89 return EmitCall(getContext().getPointerType(MD->getType()), Callee, 90 CE->getLocStart(), ReturnValue, CE->arg_begin(), 91 CE->arg_end()); 92 } 93 94 // Compute the object pointer. 95 const Expr *Base = ME->getBase(); 96 bool CanUseVirtualCall = MD->isVirtual() && !ME->hasQualifier(); 97 98 const CXXMethodDecl *DevirtualizedMethod = nullptr; 99 if (CanUseVirtualCall && CanDevirtualizeMemberFunctionCall(Base, MD)) { 100 const CXXRecordDecl *BestDynamicDecl = Base->getBestDynamicClassType(); 101 DevirtualizedMethod = MD->getCorrespondingMethodInClass(BestDynamicDecl); 102 assert(DevirtualizedMethod); 103 const CXXRecordDecl *DevirtualizedClass = DevirtualizedMethod->getParent(); 104 const Expr *Inner = Base->ignoreParenBaseCasts(); 105 if (getCXXRecord(Inner) == DevirtualizedClass) 106 // If the class of the Inner expression is where the dynamic method 107 // is defined, build the this pointer from it. 108 Base = Inner; 109 else if (getCXXRecord(Base) != DevirtualizedClass) { 110 // If the method is defined in a class that is not the best dynamic 111 // one or the one of the full expression, we would have to build 112 // a derived-to-base cast to compute the correct this pointer, but 113 // we don't have support for that yet, so do a virtual call. 114 DevirtualizedMethod = nullptr; 115 } 116 // If the return types are not the same, this might be a case where more 117 // code needs to run to compensate for it. For example, the derived 118 // method might return a type that inherits form from the return 119 // type of MD and has a prefix. 120 // For now we just avoid devirtualizing these covariant cases. 121 if (DevirtualizedMethod && 122 DevirtualizedMethod->getReturnType().getCanonicalType() != 123 MD->getReturnType().getCanonicalType()) 124 DevirtualizedMethod = nullptr; 125 } 126 127 llvm::Value *This; 128 if (ME->isArrow()) 129 This = EmitScalarExpr(Base); 130 else 131 This = EmitLValue(Base).getAddress(); 132 133 134 if (MD->isTrivial()) { 135 if (isa<CXXDestructorDecl>(MD)) return RValue::get(nullptr); 136 if (isa<CXXConstructorDecl>(MD) && 137 cast<CXXConstructorDecl>(MD)->isDefaultConstructor()) 138 return RValue::get(nullptr); 139 140 if (MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) { 141 // We don't like to generate the trivial copy/move assignment operator 142 // when it isn't necessary; just produce the proper effect here. 143 llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress(); 144 EmitAggregateAssign(This, RHS, CE->getType()); 145 return RValue::get(This); 146 } 147 148 if (isa<CXXConstructorDecl>(MD) && 149 cast<CXXConstructorDecl>(MD)->isCopyOrMoveConstructor()) { 150 // Trivial move and copy ctor are the same. 151 llvm::Value *RHS = EmitLValue(*CE->arg_begin()).getAddress(); 152 EmitSynthesizedCXXCopyCtorCall(cast<CXXConstructorDecl>(MD), This, RHS, 153 CE->arg_begin(), CE->arg_end()); 154 return RValue::get(This); 155 } 156 llvm_unreachable("unknown trivial member function"); 157 } 158 159 // Compute the function type we're calling. 160 const CXXMethodDecl *CalleeDecl = DevirtualizedMethod ? DevirtualizedMethod : MD; 161 const CGFunctionInfo *FInfo = nullptr; 162 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(CalleeDecl)) 163 FInfo = &CGM.getTypes().arrangeCXXDestructor(Dtor, 164 Dtor_Complete); 165 else if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(CalleeDecl)) 166 FInfo = &CGM.getTypes().arrangeCXXConstructorDeclaration(Ctor, 167 Ctor_Complete); 168 else 169 FInfo = &CGM.getTypes().arrangeCXXMethodDeclaration(CalleeDecl); 170 171 llvm::FunctionType *Ty = CGM.getTypes().GetFunctionType(*FInfo); 172 173 // C++ [class.virtual]p12: 174 // Explicit qualification with the scope operator (5.1) suppresses the 175 // virtual call mechanism. 176 // 177 // We also don't emit a virtual call if the base expression has a record type 178 // because then we know what the type is. 179 bool UseVirtualCall = CanUseVirtualCall && !DevirtualizedMethod; 180 llvm::Value *Callee; 181 182 if (const CXXDestructorDecl *Dtor = dyn_cast<CXXDestructorDecl>(MD)) { 183 assert(CE->arg_begin() == CE->arg_end() && 184 "Destructor shouldn't have explicit parameters"); 185 assert(ReturnValue.isNull() && "Destructor shouldn't have return value"); 186 if (UseVirtualCall) { 187 CGM.getCXXABI().EmitVirtualDestructorCall(*this, Dtor, Dtor_Complete, 188 CE->getExprLoc(), This); 189 } else { 190 if (getLangOpts().AppleKext && 191 MD->isVirtual() && 192 ME->hasQualifier()) 193 Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); 194 else if (!DevirtualizedMethod) 195 Callee = CGM.GetAddrOfCXXDestructor(Dtor, Dtor_Complete, FInfo, Ty); 196 else { 197 const CXXDestructorDecl *DDtor = 198 cast<CXXDestructorDecl>(DevirtualizedMethod); 199 Callee = CGM.GetAddrOfFunction(GlobalDecl(DDtor, Dtor_Complete), Ty); 200 } 201 EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This, 202 /*ImplicitParam=*/nullptr, QualType(), nullptr,nullptr); 203 } 204 return RValue::get(nullptr); 205 } 206 207 if (const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(MD)) { 208 Callee = CGM.GetAddrOfFunction(GlobalDecl(Ctor, Ctor_Complete), Ty); 209 } else if (UseVirtualCall) { 210 Callee = CGM.getCXXABI().getVirtualFunctionPointer(*this, MD, This, Ty); 211 } else { 212 if (getLangOpts().AppleKext && 213 MD->isVirtual() && 214 ME->hasQualifier()) 215 Callee = BuildAppleKextVirtualCall(MD, ME->getQualifier(), Ty); 216 else if (!DevirtualizedMethod) 217 Callee = CGM.GetAddrOfFunction(MD, Ty); 218 else { 219 Callee = CGM.GetAddrOfFunction(DevirtualizedMethod, Ty); 220 } 221 } 222 223 if (MD->isVirtual()) { 224 This = CGM.getCXXABI().adjustThisArgumentForVirtualFunctionCall( 225 *this, MD, This, UseVirtualCall); 226 } 227 228 return EmitCXXMemberCall(MD, CE->getExprLoc(), Callee, ReturnValue, This, 229 /*ImplicitParam=*/nullptr, QualType(), 230 CE->arg_begin(), CE->arg_end()); 231 } 232 233 RValue 234 CodeGenFunction::EmitCXXMemberPointerCallExpr(const CXXMemberCallExpr *E, 235 ReturnValueSlot ReturnValue) { 236 const BinaryOperator *BO = 237 cast<BinaryOperator>(E->getCallee()->IgnoreParens()); 238 const Expr *BaseExpr = BO->getLHS(); 239 const Expr *MemFnExpr = BO->getRHS(); 240 241 const MemberPointerType *MPT = 242 MemFnExpr->getType()->castAs<MemberPointerType>(); 243 244 const FunctionProtoType *FPT = 245 MPT->getPointeeType()->castAs<FunctionProtoType>(); 246 const CXXRecordDecl *RD = 247 cast<CXXRecordDecl>(MPT->getClass()->getAs<RecordType>()->getDecl()); 248 249 // Get the member function pointer. 250 llvm::Value *MemFnPtr = EmitScalarExpr(MemFnExpr); 251 252 // Emit the 'this' pointer. 253 llvm::Value *This; 254 255 if (BO->getOpcode() == BO_PtrMemI) 256 This = EmitScalarExpr(BaseExpr); 257 else 258 This = EmitLValue(BaseExpr).getAddress(); 259 260 EmitTypeCheck(TCK_MemberCall, E->getExprLoc(), This, 261 QualType(MPT->getClass(), 0)); 262 263 // Ask the ABI to load the callee. Note that This is modified. 264 llvm::Value *Callee = 265 CGM.getCXXABI().EmitLoadOfMemberFunctionPointer(*this, BO, This, MemFnPtr, MPT); 266 267 CallArgList Args; 268 269 QualType ThisType = 270 getContext().getPointerType(getContext().getTagDeclType(RD)); 271 272 // Push the this ptr. 273 Args.add(RValue::get(This), ThisType); 274 275 RequiredArgs required = RequiredArgs::forPrototypePlus(FPT, 1); 276 277 // And the rest of the call args 278 EmitCallArgs(Args, FPT, E->arg_begin(), E->arg_end()); 279 return EmitCall(CGM.getTypes().arrangeCXXMethodCall(Args, FPT, required), 280 Callee, ReturnValue, Args); 281 } 282 283 RValue 284 CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E, 285 const CXXMethodDecl *MD, 286 ReturnValueSlot ReturnValue) { 287 assert(MD->isInstance() && 288 "Trying to emit a member call expr on a static method!"); 289 LValue LV = EmitLValue(E->getArg(0)); 290 llvm::Value *This = LV.getAddress(); 291 292 if ((MD->isCopyAssignmentOperator() || MD->isMoveAssignmentOperator()) && 293 MD->isTrivial()) { 294 llvm::Value *Src = EmitLValue(E->getArg(1)).getAddress(); 295 QualType Ty = E->getType(); 296 EmitAggregateAssign(This, Src, Ty); 297 return RValue::get(This); 298 } 299 300 llvm::Value *Callee = EmitCXXOperatorMemberCallee(E, MD, This); 301 return EmitCXXMemberCall(MD, E->getExprLoc(), Callee, ReturnValue, This, 302 /*ImplicitParam=*/nullptr, QualType(), 303 E->arg_begin() + 1, E->arg_end()); 304 } 305 306 RValue CodeGenFunction::EmitCUDAKernelCallExpr(const CUDAKernelCallExpr *E, 307 ReturnValueSlot ReturnValue) { 308 return CGM.getCUDARuntime().EmitCUDAKernelCallExpr(*this, E, ReturnValue); 309 } 310 311 static void EmitNullBaseClassInitialization(CodeGenFunction &CGF, 312 llvm::Value *DestPtr, 313 const CXXRecordDecl *Base) { 314 if (Base->isEmpty()) 315 return; 316 317 DestPtr = CGF.EmitCastToVoidPtr(DestPtr); 318 319 const ASTRecordLayout &Layout = CGF.getContext().getASTRecordLayout(Base); 320 CharUnits Size = Layout.getNonVirtualSize(); 321 CharUnits Align = Layout.getNonVirtualAlignment(); 322 323 llvm::Value *SizeVal = CGF.CGM.getSize(Size); 324 325 // If the type contains a pointer to data member we can't memset it to zero. 326 // Instead, create a null constant and copy it to the destination. 327 // TODO: there are other patterns besides zero that we can usefully memset, 328 // like -1, which happens to be the pattern used by member-pointers. 329 // TODO: isZeroInitializable can be over-conservative in the case where a 330 // virtual base contains a member pointer. 331 if (!CGF.CGM.getTypes().isZeroInitializable(Base)) { 332 llvm::Constant *NullConstant = CGF.CGM.EmitNullConstantForBase(Base); 333 334 llvm::GlobalVariable *NullVariable = 335 new llvm::GlobalVariable(CGF.CGM.getModule(), NullConstant->getType(), 336 /*isConstant=*/true, 337 llvm::GlobalVariable::PrivateLinkage, 338 NullConstant, Twine()); 339 NullVariable->setAlignment(Align.getQuantity()); 340 llvm::Value *SrcPtr = CGF.EmitCastToVoidPtr(NullVariable); 341 342 // Get and call the appropriate llvm.memcpy overload. 343 CGF.Builder.CreateMemCpy(DestPtr, SrcPtr, SizeVal, Align.getQuantity()); 344 return; 345 } 346 347 // Otherwise, just memset the whole thing to zero. This is legal 348 // because in LLVM, all default initializers (other than the ones we just 349 // handled above) are guaranteed to have a bit pattern of all zeros. 350 CGF.Builder.CreateMemSet(DestPtr, CGF.Builder.getInt8(0), SizeVal, 351 Align.getQuantity()); 352 } 353 354 void 355 CodeGenFunction::EmitCXXConstructExpr(const CXXConstructExpr *E, 356 AggValueSlot Dest) { 357 assert(!Dest.isIgnored() && "Must have a destination!"); 358 const CXXConstructorDecl *CD = E->getConstructor(); 359 360 // If we require zero initialization before (or instead of) calling the 361 // constructor, as can be the case with a non-user-provided default 362 // constructor, emit the zero initialization now, unless destination is 363 // already zeroed. 364 if (E->requiresZeroInitialization() && !Dest.isZeroed()) { 365 switch (E->getConstructionKind()) { 366 case CXXConstructExpr::CK_Delegating: 367 case CXXConstructExpr::CK_Complete: 368 EmitNullInitialization(Dest.getAddr(), E->getType()); 369 break; 370 case CXXConstructExpr::CK_VirtualBase: 371 case CXXConstructExpr::CK_NonVirtualBase: 372 EmitNullBaseClassInitialization(*this, Dest.getAddr(), CD->getParent()); 373 break; 374 } 375 } 376 377 // If this is a call to a trivial default constructor, do nothing. 378 if (CD->isTrivial() && CD->isDefaultConstructor()) 379 return; 380 381 // Elide the constructor if we're constructing from a temporary. 382 // The temporary check is required because Sema sets this on NRVO 383 // returns. 384 if (getLangOpts().ElideConstructors && E->isElidable()) { 385 assert(getContext().hasSameUnqualifiedType(E->getType(), 386 E->getArg(0)->getType())); 387 if (E->getArg(0)->isTemporaryObject(getContext(), CD->getParent())) { 388 EmitAggExpr(E->getArg(0), Dest); 389 return; 390 } 391 } 392 393 if (const ConstantArrayType *arrayType 394 = getContext().getAsConstantArrayType(E->getType())) { 395 EmitCXXAggrConstructorCall(CD, arrayType, Dest.getAddr(), 396 E->arg_begin(), E->arg_end()); 397 } else { 398 CXXCtorType Type = Ctor_Complete; 399 bool ForVirtualBase = false; 400 bool Delegating = false; 401 402 switch (E->getConstructionKind()) { 403 case CXXConstructExpr::CK_Delegating: 404 // We should be emitting a constructor; GlobalDecl will assert this 405 Type = CurGD.getCtorType(); 406 Delegating = true; 407 break; 408 409 case CXXConstructExpr::CK_Complete: 410 Type = Ctor_Complete; 411 break; 412 413 case CXXConstructExpr::CK_VirtualBase: 414 ForVirtualBase = true; 415 // fall-through 416 417 case CXXConstructExpr::CK_NonVirtualBase: 418 Type = Ctor_Base; 419 } 420 421 // Call the constructor. 422 EmitCXXConstructorCall(CD, Type, ForVirtualBase, Delegating, Dest.getAddr(), 423 E->arg_begin(), E->arg_end()); 424 } 425 } 426 427 void 428 CodeGenFunction::EmitSynthesizedCXXCopyCtor(llvm::Value *Dest, 429 llvm::Value *Src, 430 const Expr *Exp) { 431 if (const ExprWithCleanups *E = dyn_cast<ExprWithCleanups>(Exp)) 432 Exp = E->getSubExpr(); 433 assert(isa<CXXConstructExpr>(Exp) && 434 "EmitSynthesizedCXXCopyCtor - unknown copy ctor expr"); 435 const CXXConstructExpr* E = cast<CXXConstructExpr>(Exp); 436 const CXXConstructorDecl *CD = E->getConstructor(); 437 RunCleanupsScope Scope(*this); 438 439 // If we require zero initialization before (or instead of) calling the 440 // constructor, as can be the case with a non-user-provided default 441 // constructor, emit the zero initialization now. 442 // FIXME. Do I still need this for a copy ctor synthesis? 443 if (E->requiresZeroInitialization()) 444 EmitNullInitialization(Dest, E->getType()); 445 446 assert(!getContext().getAsConstantArrayType(E->getType()) 447 && "EmitSynthesizedCXXCopyCtor - Copied-in Array"); 448 EmitSynthesizedCXXCopyCtorCall(CD, Dest, Src, E->arg_begin(), E->arg_end()); 449 } 450 451 static CharUnits CalculateCookiePadding(CodeGenFunction &CGF, 452 const CXXNewExpr *E) { 453 if (!E->isArray()) 454 return CharUnits::Zero(); 455 456 // No cookie is required if the operator new[] being used is the 457 // reserved placement operator new[]. 458 if (E->getOperatorNew()->isReservedGlobalPlacementOperator()) 459 return CharUnits::Zero(); 460 461 return CGF.CGM.getCXXABI().GetArrayCookieSize(E); 462 } 463 464 static llvm::Value *EmitCXXNewAllocSize(CodeGenFunction &CGF, 465 const CXXNewExpr *e, 466 unsigned minElements, 467 llvm::Value *&numElements, 468 llvm::Value *&sizeWithoutCookie) { 469 QualType type = e->getAllocatedType(); 470 471 if (!e->isArray()) { 472 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type); 473 sizeWithoutCookie 474 = llvm::ConstantInt::get(CGF.SizeTy, typeSize.getQuantity()); 475 return sizeWithoutCookie; 476 } 477 478 // The width of size_t. 479 unsigned sizeWidth = CGF.SizeTy->getBitWidth(); 480 481 // Figure out the cookie size. 482 llvm::APInt cookieSize(sizeWidth, 483 CalculateCookiePadding(CGF, e).getQuantity()); 484 485 // Emit the array size expression. 486 // We multiply the size of all dimensions for NumElements. 487 // e.g for 'int[2][3]', ElemType is 'int' and NumElements is 6. 488 numElements = CGF.EmitScalarExpr(e->getArraySize()); 489 assert(isa<llvm::IntegerType>(numElements->getType())); 490 491 // The number of elements can be have an arbitrary integer type; 492 // essentially, we need to multiply it by a constant factor, add a 493 // cookie size, and verify that the result is representable as a 494 // size_t. That's just a gloss, though, and it's wrong in one 495 // important way: if the count is negative, it's an error even if 496 // the cookie size would bring the total size >= 0. 497 bool isSigned 498 = e->getArraySize()->getType()->isSignedIntegerOrEnumerationType(); 499 llvm::IntegerType *numElementsType 500 = cast<llvm::IntegerType>(numElements->getType()); 501 unsigned numElementsWidth = numElementsType->getBitWidth(); 502 503 // Compute the constant factor. 504 llvm::APInt arraySizeMultiplier(sizeWidth, 1); 505 while (const ConstantArrayType *CAT 506 = CGF.getContext().getAsConstantArrayType(type)) { 507 type = CAT->getElementType(); 508 arraySizeMultiplier *= CAT->getSize(); 509 } 510 511 CharUnits typeSize = CGF.getContext().getTypeSizeInChars(type); 512 llvm::APInt typeSizeMultiplier(sizeWidth, typeSize.getQuantity()); 513 typeSizeMultiplier *= arraySizeMultiplier; 514 515 // This will be a size_t. 516 llvm::Value *size; 517 518 // If someone is doing 'new int[42]' there is no need to do a dynamic check. 519 // Don't bloat the -O0 code. 520 if (llvm::ConstantInt *numElementsC = 521 dyn_cast<llvm::ConstantInt>(numElements)) { 522 const llvm::APInt &count = numElementsC->getValue(); 523 524 bool hasAnyOverflow = false; 525 526 // If 'count' was a negative number, it's an overflow. 527 if (isSigned && count.isNegative()) 528 hasAnyOverflow = true; 529 530 // We want to do all this arithmetic in size_t. If numElements is 531 // wider than that, check whether it's already too big, and if so, 532 // overflow. 533 else if (numElementsWidth > sizeWidth && 534 numElementsWidth - sizeWidth > count.countLeadingZeros()) 535 hasAnyOverflow = true; 536 537 // Okay, compute a count at the right width. 538 llvm::APInt adjustedCount = count.zextOrTrunc(sizeWidth); 539 540 // If there is a brace-initializer, we cannot allocate fewer elements than 541 // there are initializers. If we do, that's treated like an overflow. 542 if (adjustedCount.ult(minElements)) 543 hasAnyOverflow = true; 544 545 // Scale numElements by that. This might overflow, but we don't 546 // care because it only overflows if allocationSize does, too, and 547 // if that overflows then we shouldn't use this. 548 numElements = llvm::ConstantInt::get(CGF.SizeTy, 549 adjustedCount * arraySizeMultiplier); 550 551 // Compute the size before cookie, and track whether it overflowed. 552 bool overflow; 553 llvm::APInt allocationSize 554 = adjustedCount.umul_ov(typeSizeMultiplier, overflow); 555 hasAnyOverflow |= overflow; 556 557 // Add in the cookie, and check whether it's overflowed. 558 if (cookieSize != 0) { 559 // Save the current size without a cookie. This shouldn't be 560 // used if there was overflow. 561 sizeWithoutCookie = llvm::ConstantInt::get(CGF.SizeTy, allocationSize); 562 563 allocationSize = allocationSize.uadd_ov(cookieSize, overflow); 564 hasAnyOverflow |= overflow; 565 } 566 567 // On overflow, produce a -1 so operator new will fail. 568 if (hasAnyOverflow) { 569 size = llvm::Constant::getAllOnesValue(CGF.SizeTy); 570 } else { 571 size = llvm::ConstantInt::get(CGF.SizeTy, allocationSize); 572 } 573 574 // Otherwise, we might need to use the overflow intrinsics. 575 } else { 576 // There are up to five conditions we need to test for: 577 // 1) if isSigned, we need to check whether numElements is negative; 578 // 2) if numElementsWidth > sizeWidth, we need to check whether 579 // numElements is larger than something representable in size_t; 580 // 3) if minElements > 0, we need to check whether numElements is smaller 581 // than that. 582 // 4) we need to compute 583 // sizeWithoutCookie := numElements * typeSizeMultiplier 584 // and check whether it overflows; and 585 // 5) if we need a cookie, we need to compute 586 // size := sizeWithoutCookie + cookieSize 587 // and check whether it overflows. 588 589 llvm::Value *hasOverflow = nullptr; 590 591 // If numElementsWidth > sizeWidth, then one way or another, we're 592 // going to have to do a comparison for (2), and this happens to 593 // take care of (1), too. 594 if (numElementsWidth > sizeWidth) { 595 llvm::APInt threshold(numElementsWidth, 1); 596 threshold <<= sizeWidth; 597 598 llvm::Value *thresholdV 599 = llvm::ConstantInt::get(numElementsType, threshold); 600 601 hasOverflow = CGF.Builder.CreateICmpUGE(numElements, thresholdV); 602 numElements = CGF.Builder.CreateTrunc(numElements, CGF.SizeTy); 603 604 // Otherwise, if we're signed, we want to sext up to size_t. 605 } else if (isSigned) { 606 if (numElementsWidth < sizeWidth) 607 numElements = CGF.Builder.CreateSExt(numElements, CGF.SizeTy); 608 609 // If there's a non-1 type size multiplier, then we can do the 610 // signedness check at the same time as we do the multiply 611 // because a negative number times anything will cause an 612 // unsigned overflow. Otherwise, we have to do it here. But at least 613 // in this case, we can subsume the >= minElements check. 614 if (typeSizeMultiplier == 1) 615 hasOverflow = CGF.Builder.CreateICmpSLT(numElements, 616 llvm::ConstantInt::get(CGF.SizeTy, minElements)); 617 618 // Otherwise, zext up to size_t if necessary. 619 } else if (numElementsWidth < sizeWidth) { 620 numElements = CGF.Builder.CreateZExt(numElements, CGF.SizeTy); 621 } 622 623 assert(numElements->getType() == CGF.SizeTy); 624 625 if (minElements) { 626 // Don't allow allocation of fewer elements than we have initializers. 627 if (!hasOverflow) { 628 hasOverflow = CGF.Builder.CreateICmpULT(numElements, 629 llvm::ConstantInt::get(CGF.SizeTy, minElements)); 630 } else if (numElementsWidth > sizeWidth) { 631 // The other existing overflow subsumes this check. 632 // We do an unsigned comparison, since any signed value < -1 is 633 // taken care of either above or below. 634 hasOverflow = CGF.Builder.CreateOr(hasOverflow, 635 CGF.Builder.CreateICmpULT(numElements, 636 llvm::ConstantInt::get(CGF.SizeTy, minElements))); 637 } 638 } 639 640 size = numElements; 641 642 // Multiply by the type size if necessary. This multiplier 643 // includes all the factors for nested arrays. 644 // 645 // This step also causes numElements to be scaled up by the 646 // nested-array factor if necessary. Overflow on this computation 647 // can be ignored because the result shouldn't be used if 648 // allocation fails. 649 if (typeSizeMultiplier != 1) { 650 llvm::Value *umul_with_overflow 651 = CGF.CGM.getIntrinsic(llvm::Intrinsic::umul_with_overflow, CGF.SizeTy); 652 653 llvm::Value *tsmV = 654 llvm::ConstantInt::get(CGF.SizeTy, typeSizeMultiplier); 655 llvm::Value *result = 656 CGF.Builder.CreateCall2(umul_with_overflow, size, tsmV); 657 658 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1); 659 if (hasOverflow) 660 hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed); 661 else 662 hasOverflow = overflowed; 663 664 size = CGF.Builder.CreateExtractValue(result, 0); 665 666 // Also scale up numElements by the array size multiplier. 667 if (arraySizeMultiplier != 1) { 668 // If the base element type size is 1, then we can re-use the 669 // multiply we just did. 670 if (typeSize.isOne()) { 671 assert(arraySizeMultiplier == typeSizeMultiplier); 672 numElements = size; 673 674 // Otherwise we need a separate multiply. 675 } else { 676 llvm::Value *asmV = 677 llvm::ConstantInt::get(CGF.SizeTy, arraySizeMultiplier); 678 numElements = CGF.Builder.CreateMul(numElements, asmV); 679 } 680 } 681 } else { 682 // numElements doesn't need to be scaled. 683 assert(arraySizeMultiplier == 1); 684 } 685 686 // Add in the cookie size if necessary. 687 if (cookieSize != 0) { 688 sizeWithoutCookie = size; 689 690 llvm::Value *uadd_with_overflow 691 = CGF.CGM.getIntrinsic(llvm::Intrinsic::uadd_with_overflow, CGF.SizeTy); 692 693 llvm::Value *cookieSizeV = llvm::ConstantInt::get(CGF.SizeTy, cookieSize); 694 llvm::Value *result = 695 CGF.Builder.CreateCall2(uadd_with_overflow, size, cookieSizeV); 696 697 llvm::Value *overflowed = CGF.Builder.CreateExtractValue(result, 1); 698 if (hasOverflow) 699 hasOverflow = CGF.Builder.CreateOr(hasOverflow, overflowed); 700 else 701 hasOverflow = overflowed; 702 703 size = CGF.Builder.CreateExtractValue(result, 0); 704 } 705 706 // If we had any possibility of dynamic overflow, make a select to 707 // overwrite 'size' with an all-ones value, which should cause 708 // operator new to throw. 709 if (hasOverflow) 710 size = CGF.Builder.CreateSelect(hasOverflow, 711 llvm::Constant::getAllOnesValue(CGF.SizeTy), 712 size); 713 } 714 715 if (cookieSize == 0) 716 sizeWithoutCookie = size; 717 else 718 assert(sizeWithoutCookie && "didn't set sizeWithoutCookie?"); 719 720 return size; 721 } 722 723 static void StoreAnyExprIntoOneUnit(CodeGenFunction &CGF, const Expr *Init, 724 QualType AllocType, llvm::Value *NewPtr) { 725 // FIXME: Refactor with EmitExprAsInit. 726 CharUnits Alignment = CGF.getContext().getTypeAlignInChars(AllocType); 727 switch (CGF.getEvaluationKind(AllocType)) { 728 case TEK_Scalar: 729 CGF.EmitScalarInit(Init, nullptr, CGF.MakeAddrLValue(NewPtr, AllocType, 730 Alignment), 731 false); 732 return; 733 case TEK_Complex: 734 CGF.EmitComplexExprIntoLValue(Init, CGF.MakeAddrLValue(NewPtr, AllocType, 735 Alignment), 736 /*isInit*/ true); 737 return; 738 case TEK_Aggregate: { 739 AggValueSlot Slot 740 = AggValueSlot::forAddr(NewPtr, Alignment, AllocType.getQualifiers(), 741 AggValueSlot::IsDestructed, 742 AggValueSlot::DoesNotNeedGCBarriers, 743 AggValueSlot::IsNotAliased); 744 CGF.EmitAggExpr(Init, Slot); 745 return; 746 } 747 } 748 llvm_unreachable("bad evaluation kind"); 749 } 750 751 void 752 CodeGenFunction::EmitNewArrayInitializer(const CXXNewExpr *E, 753 QualType ElementType, 754 llvm::Value *BeginPtr, 755 llvm::Value *NumElements, 756 llvm::Value *AllocSizeWithoutCookie) { 757 // If we have a type with trivial initialization and no initializer, 758 // there's nothing to do. 759 if (!E->hasInitializer()) 760 return; 761 762 llvm::Value *CurPtr = BeginPtr; 763 764 unsigned InitListElements = 0; 765 766 const Expr *Init = E->getInitializer(); 767 llvm::AllocaInst *EndOfInit = nullptr; 768 QualType::DestructionKind DtorKind = ElementType.isDestructedType(); 769 EHScopeStack::stable_iterator Cleanup; 770 llvm::Instruction *CleanupDominator = nullptr; 771 772 // If the initializer is an initializer list, first do the explicit elements. 773 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(Init)) { 774 InitListElements = ILE->getNumInits(); 775 776 // If this is a multi-dimensional array new, we will initialize multiple 777 // elements with each init list element. 778 QualType AllocType = E->getAllocatedType(); 779 if (const ConstantArrayType *CAT = dyn_cast_or_null<ConstantArrayType>( 780 AllocType->getAsArrayTypeUnsafe())) { 781 unsigned AS = CurPtr->getType()->getPointerAddressSpace(); 782 llvm::Type *AllocPtrTy = ConvertTypeForMem(AllocType)->getPointerTo(AS); 783 CurPtr = Builder.CreateBitCast(CurPtr, AllocPtrTy); 784 InitListElements *= getContext().getConstantArrayElementCount(CAT); 785 } 786 787 // Enter a partial-destruction Cleanup if necessary. 788 if (needsEHCleanup(DtorKind)) { 789 // In principle we could tell the Cleanup where we are more 790 // directly, but the control flow can get so varied here that it 791 // would actually be quite complex. Therefore we go through an 792 // alloca. 793 EndOfInit = CreateTempAlloca(BeginPtr->getType(), "array.init.end"); 794 CleanupDominator = Builder.CreateStore(BeginPtr, EndOfInit); 795 pushIrregularPartialArrayCleanup(BeginPtr, EndOfInit, ElementType, 796 getDestroyer(DtorKind)); 797 Cleanup = EHStack.stable_begin(); 798 } 799 800 for (unsigned i = 0, e = ILE->getNumInits(); i != e; ++i) { 801 // Tell the cleanup that it needs to destroy up to this 802 // element. TODO: some of these stores can be trivially 803 // observed to be unnecessary. 804 if (EndOfInit) 805 Builder.CreateStore(Builder.CreateBitCast(CurPtr, BeginPtr->getType()), 806 EndOfInit); 807 // FIXME: If the last initializer is an incomplete initializer list for 808 // an array, and we have an array filler, we can fold together the two 809 // initialization loops. 810 StoreAnyExprIntoOneUnit(*this, ILE->getInit(i), 811 ILE->getInit(i)->getType(), CurPtr); 812 CurPtr = Builder.CreateConstInBoundsGEP1_32(CurPtr, 1, "array.exp.next"); 813 } 814 815 // The remaining elements are filled with the array filler expression. 816 Init = ILE->getArrayFiller(); 817 818 // Extract the initializer for the individual array elements by pulling 819 // out the array filler from all the nested initializer lists. This avoids 820 // generating a nested loop for the initialization. 821 while (Init && Init->getType()->isConstantArrayType()) { 822 auto *SubILE = dyn_cast<InitListExpr>(Init); 823 if (!SubILE) 824 break; 825 assert(SubILE->getNumInits() == 0 && "explicit inits in array filler?"); 826 Init = SubILE->getArrayFiller(); 827 } 828 829 // Switch back to initializing one base element at a time. 830 CurPtr = Builder.CreateBitCast(CurPtr, BeginPtr->getType()); 831 } 832 833 // Attempt to perform zero-initialization using memset. 834 auto TryMemsetInitialization = [&]() -> bool { 835 // FIXME: If the type is a pointer-to-data-member under the Itanium ABI, 836 // we can initialize with a memset to -1. 837 if (!CGM.getTypes().isZeroInitializable(ElementType)) 838 return false; 839 840 // Optimization: since zero initialization will just set the memory 841 // to all zeroes, generate a single memset to do it in one shot. 842 843 // Subtract out the size of any elements we've already initialized. 844 auto *RemainingSize = AllocSizeWithoutCookie; 845 if (InitListElements) { 846 // We know this can't overflow; we check this when doing the allocation. 847 auto *InitializedSize = llvm::ConstantInt::get( 848 RemainingSize->getType(), 849 getContext().getTypeSizeInChars(ElementType).getQuantity() * 850 InitListElements); 851 RemainingSize = Builder.CreateSub(RemainingSize, InitializedSize); 852 } 853 854 // Create the memset. 855 CharUnits Alignment = getContext().getTypeAlignInChars(ElementType); 856 Builder.CreateMemSet(CurPtr, Builder.getInt8(0), RemainingSize, 857 Alignment.getQuantity(), false); 858 return true; 859 }; 860 861 // If all elements have already been initialized, skip any further 862 // initialization. 863 llvm::ConstantInt *ConstNum = dyn_cast<llvm::ConstantInt>(NumElements); 864 if (ConstNum && ConstNum->getZExtValue() <= InitListElements) { 865 // If there was a Cleanup, deactivate it. 866 if (CleanupDominator) 867 DeactivateCleanupBlock(Cleanup, CleanupDominator); 868 return; 869 } 870 871 assert(Init && "have trailing elements to initialize but no initializer"); 872 873 // If this is a constructor call, try to optimize it out, and failing that 874 // emit a single loop to initialize all remaining elements. 875 if (const CXXConstructExpr *CCE = dyn_cast<CXXConstructExpr>(Init)) { 876 CXXConstructorDecl *Ctor = CCE->getConstructor(); 877 if (Ctor->isTrivial()) { 878 // If new expression did not specify value-initialization, then there 879 // is no initialization. 880 if (!CCE->requiresZeroInitialization() || Ctor->getParent()->isEmpty()) 881 return; 882 883 if (TryMemsetInitialization()) 884 return; 885 } 886 887 // Store the new Cleanup position for irregular Cleanups. 888 // 889 // FIXME: Share this cleanup with the constructor call emission rather than 890 // having it create a cleanup of its own. 891 if (EndOfInit) Builder.CreateStore(CurPtr, EndOfInit); 892 893 // Emit a constructor call loop to initialize the remaining elements. 894 if (InitListElements) 895 NumElements = Builder.CreateSub( 896 NumElements, 897 llvm::ConstantInt::get(NumElements->getType(), InitListElements)); 898 EmitCXXAggrConstructorCall(Ctor, NumElements, CurPtr, 899 CCE->arg_begin(), CCE->arg_end(), 900 CCE->requiresZeroInitialization()); 901 return; 902 } 903 904 // If this is value-initialization, we can usually use memset. 905 ImplicitValueInitExpr IVIE(ElementType); 906 if (isa<ImplicitValueInitExpr>(Init)) { 907 if (TryMemsetInitialization()) 908 return; 909 910 // Switch to an ImplicitValueInitExpr for the element type. This handles 911 // only one case: multidimensional array new of pointers to members. In 912 // all other cases, we already have an initializer for the array element. 913 Init = &IVIE; 914 } 915 916 // At this point we should have found an initializer for the individual 917 // elements of the array. 918 assert(getContext().hasSameUnqualifiedType(ElementType, Init->getType()) && 919 "got wrong type of element to initialize"); 920 921 // If we have an empty initializer list, we can usually use memset. 922 if (auto *ILE = dyn_cast<InitListExpr>(Init)) 923 if (ILE->getNumInits() == 0 && TryMemsetInitialization()) 924 return; 925 926 // Create the loop blocks. 927 llvm::BasicBlock *EntryBB = Builder.GetInsertBlock(); 928 llvm::BasicBlock *LoopBB = createBasicBlock("new.loop"); 929 llvm::BasicBlock *ContBB = createBasicBlock("new.loop.end"); 930 931 // Find the end of the array, hoisted out of the loop. 932 llvm::Value *EndPtr = 933 Builder.CreateInBoundsGEP(BeginPtr, NumElements, "array.end"); 934 935 // If the number of elements isn't constant, we have to now check if there is 936 // anything left to initialize. 937 if (!ConstNum) { 938 llvm::Value *IsEmpty = Builder.CreateICmpEQ(CurPtr, EndPtr, 939 "array.isempty"); 940 Builder.CreateCondBr(IsEmpty, ContBB, LoopBB); 941 } 942 943 // Enter the loop. 944 EmitBlock(LoopBB); 945 946 // Set up the current-element phi. 947 llvm::PHINode *CurPtrPhi = 948 Builder.CreatePHI(CurPtr->getType(), 2, "array.cur"); 949 CurPtrPhi->addIncoming(CurPtr, EntryBB); 950 CurPtr = CurPtrPhi; 951 952 // Store the new Cleanup position for irregular Cleanups. 953 if (EndOfInit) Builder.CreateStore(CurPtr, EndOfInit); 954 955 // Enter a partial-destruction Cleanup if necessary. 956 if (!CleanupDominator && needsEHCleanup(DtorKind)) { 957 pushRegularPartialArrayCleanup(BeginPtr, CurPtr, ElementType, 958 getDestroyer(DtorKind)); 959 Cleanup = EHStack.stable_begin(); 960 CleanupDominator = Builder.CreateUnreachable(); 961 } 962 963 // Emit the initializer into this element. 964 StoreAnyExprIntoOneUnit(*this, Init, Init->getType(), CurPtr); 965 966 // Leave the Cleanup if we entered one. 967 if (CleanupDominator) { 968 DeactivateCleanupBlock(Cleanup, CleanupDominator); 969 CleanupDominator->eraseFromParent(); 970 } 971 972 // Advance to the next element by adjusting the pointer type as necessary. 973 llvm::Value *NextPtr = 974 Builder.CreateConstInBoundsGEP1_32(CurPtr, 1, "array.next"); 975 976 // Check whether we've gotten to the end of the array and, if so, 977 // exit the loop. 978 llvm::Value *IsEnd = Builder.CreateICmpEQ(NextPtr, EndPtr, "array.atend"); 979 Builder.CreateCondBr(IsEnd, ContBB, LoopBB); 980 CurPtrPhi->addIncoming(NextPtr, Builder.GetInsertBlock()); 981 982 EmitBlock(ContBB); 983 } 984 985 static void EmitNewInitializer(CodeGenFunction &CGF, const CXXNewExpr *E, 986 QualType ElementType, 987 llvm::Value *NewPtr, 988 llvm::Value *NumElements, 989 llvm::Value *AllocSizeWithoutCookie) { 990 if (E->isArray()) 991 CGF.EmitNewArrayInitializer(E, ElementType, NewPtr, NumElements, 992 AllocSizeWithoutCookie); 993 else if (const Expr *Init = E->getInitializer()) 994 StoreAnyExprIntoOneUnit(CGF, Init, E->getAllocatedType(), NewPtr); 995 } 996 997 /// Emit a call to an operator new or operator delete function, as implicitly 998 /// created by new-expressions and delete-expressions. 999 static RValue EmitNewDeleteCall(CodeGenFunction &CGF, 1000 const FunctionDecl *Callee, 1001 const FunctionProtoType *CalleeType, 1002 const CallArgList &Args) { 1003 llvm::Instruction *CallOrInvoke; 1004 llvm::Value *CalleeAddr = CGF.CGM.GetAddrOfFunction(Callee); 1005 RValue RV = 1006 CGF.EmitCall(CGF.CGM.getTypes().arrangeFreeFunctionCall(Args, CalleeType), 1007 CalleeAddr, ReturnValueSlot(), Args, 1008 Callee, &CallOrInvoke); 1009 1010 /// C++1y [expr.new]p10: 1011 /// [In a new-expression,] an implementation is allowed to omit a call 1012 /// to a replaceable global allocation function. 1013 /// 1014 /// We model such elidable calls with the 'builtin' attribute. 1015 llvm::Function *Fn = dyn_cast<llvm::Function>(CalleeAddr); 1016 if (Callee->isReplaceableGlobalAllocationFunction() && 1017 Fn && Fn->hasFnAttribute(llvm::Attribute::NoBuiltin)) { 1018 // FIXME: Add addAttribute to CallSite. 1019 if (llvm::CallInst *CI = dyn_cast<llvm::CallInst>(CallOrInvoke)) 1020 CI->addAttribute(llvm::AttributeSet::FunctionIndex, 1021 llvm::Attribute::Builtin); 1022 else if (llvm::InvokeInst *II = dyn_cast<llvm::InvokeInst>(CallOrInvoke)) 1023 II->addAttribute(llvm::AttributeSet::FunctionIndex, 1024 llvm::Attribute::Builtin); 1025 else 1026 llvm_unreachable("unexpected kind of call instruction"); 1027 } 1028 1029 return RV; 1030 } 1031 1032 RValue CodeGenFunction::EmitBuiltinNewDeleteCall(const FunctionProtoType *Type, 1033 const Expr *Arg, 1034 bool IsDelete) { 1035 CallArgList Args; 1036 const Stmt *ArgS = Arg; 1037 EmitCallArgs(Args, *Type->param_type_begin(), 1038 ConstExprIterator(&ArgS), ConstExprIterator(&ArgS + 1)); 1039 // Find the allocation or deallocation function that we're calling. 1040 ASTContext &Ctx = getContext(); 1041 DeclarationName Name = Ctx.DeclarationNames 1042 .getCXXOperatorName(IsDelete ? OO_Delete : OO_New); 1043 for (auto *Decl : Ctx.getTranslationUnitDecl()->lookup(Name)) 1044 if (auto *FD = dyn_cast<FunctionDecl>(Decl)) 1045 if (Ctx.hasSameType(FD->getType(), QualType(Type, 0))) 1046 return EmitNewDeleteCall(*this, cast<FunctionDecl>(Decl), Type, Args); 1047 llvm_unreachable("predeclared global operator new/delete is missing"); 1048 } 1049 1050 namespace { 1051 /// A cleanup to call the given 'operator delete' function upon 1052 /// abnormal exit from a new expression. 1053 class CallDeleteDuringNew : public EHScopeStack::Cleanup { 1054 size_t NumPlacementArgs; 1055 const FunctionDecl *OperatorDelete; 1056 llvm::Value *Ptr; 1057 llvm::Value *AllocSize; 1058 1059 RValue *getPlacementArgs() { return reinterpret_cast<RValue*>(this+1); } 1060 1061 public: 1062 static size_t getExtraSize(size_t NumPlacementArgs) { 1063 return NumPlacementArgs * sizeof(RValue); 1064 } 1065 1066 CallDeleteDuringNew(size_t NumPlacementArgs, 1067 const FunctionDecl *OperatorDelete, 1068 llvm::Value *Ptr, 1069 llvm::Value *AllocSize) 1070 : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete), 1071 Ptr(Ptr), AllocSize(AllocSize) {} 1072 1073 void setPlacementArg(unsigned I, RValue Arg) { 1074 assert(I < NumPlacementArgs && "index out of range"); 1075 getPlacementArgs()[I] = Arg; 1076 } 1077 1078 void Emit(CodeGenFunction &CGF, Flags flags) override { 1079 const FunctionProtoType *FPT 1080 = OperatorDelete->getType()->getAs<FunctionProtoType>(); 1081 assert(FPT->getNumParams() == NumPlacementArgs + 1 || 1082 (FPT->getNumParams() == 2 && NumPlacementArgs == 0)); 1083 1084 CallArgList DeleteArgs; 1085 1086 // The first argument is always a void*. 1087 FunctionProtoType::param_type_iterator AI = FPT->param_type_begin(); 1088 DeleteArgs.add(RValue::get(Ptr), *AI++); 1089 1090 // A member 'operator delete' can take an extra 'size_t' argument. 1091 if (FPT->getNumParams() == NumPlacementArgs + 2) 1092 DeleteArgs.add(RValue::get(AllocSize), *AI++); 1093 1094 // Pass the rest of the arguments, which must match exactly. 1095 for (unsigned I = 0; I != NumPlacementArgs; ++I) 1096 DeleteArgs.add(getPlacementArgs()[I], *AI++); 1097 1098 // Call 'operator delete'. 1099 EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs); 1100 } 1101 }; 1102 1103 /// A cleanup to call the given 'operator delete' function upon 1104 /// abnormal exit from a new expression when the new expression is 1105 /// conditional. 1106 class CallDeleteDuringConditionalNew : public EHScopeStack::Cleanup { 1107 size_t NumPlacementArgs; 1108 const FunctionDecl *OperatorDelete; 1109 DominatingValue<RValue>::saved_type Ptr; 1110 DominatingValue<RValue>::saved_type AllocSize; 1111 1112 DominatingValue<RValue>::saved_type *getPlacementArgs() { 1113 return reinterpret_cast<DominatingValue<RValue>::saved_type*>(this+1); 1114 } 1115 1116 public: 1117 static size_t getExtraSize(size_t NumPlacementArgs) { 1118 return NumPlacementArgs * sizeof(DominatingValue<RValue>::saved_type); 1119 } 1120 1121 CallDeleteDuringConditionalNew(size_t NumPlacementArgs, 1122 const FunctionDecl *OperatorDelete, 1123 DominatingValue<RValue>::saved_type Ptr, 1124 DominatingValue<RValue>::saved_type AllocSize) 1125 : NumPlacementArgs(NumPlacementArgs), OperatorDelete(OperatorDelete), 1126 Ptr(Ptr), AllocSize(AllocSize) {} 1127 1128 void setPlacementArg(unsigned I, DominatingValue<RValue>::saved_type Arg) { 1129 assert(I < NumPlacementArgs && "index out of range"); 1130 getPlacementArgs()[I] = Arg; 1131 } 1132 1133 void Emit(CodeGenFunction &CGF, Flags flags) override { 1134 const FunctionProtoType *FPT 1135 = OperatorDelete->getType()->getAs<FunctionProtoType>(); 1136 assert(FPT->getNumParams() == NumPlacementArgs + 1 || 1137 (FPT->getNumParams() == 2 && NumPlacementArgs == 0)); 1138 1139 CallArgList DeleteArgs; 1140 1141 // The first argument is always a void*. 1142 FunctionProtoType::param_type_iterator AI = FPT->param_type_begin(); 1143 DeleteArgs.add(Ptr.restore(CGF), *AI++); 1144 1145 // A member 'operator delete' can take an extra 'size_t' argument. 1146 if (FPT->getNumParams() == NumPlacementArgs + 2) { 1147 RValue RV = AllocSize.restore(CGF); 1148 DeleteArgs.add(RV, *AI++); 1149 } 1150 1151 // Pass the rest of the arguments, which must match exactly. 1152 for (unsigned I = 0; I != NumPlacementArgs; ++I) { 1153 RValue RV = getPlacementArgs()[I].restore(CGF); 1154 DeleteArgs.add(RV, *AI++); 1155 } 1156 1157 // Call 'operator delete'. 1158 EmitNewDeleteCall(CGF, OperatorDelete, FPT, DeleteArgs); 1159 } 1160 }; 1161 } 1162 1163 /// Enter a cleanup to call 'operator delete' if the initializer in a 1164 /// new-expression throws. 1165 static void EnterNewDeleteCleanup(CodeGenFunction &CGF, 1166 const CXXNewExpr *E, 1167 llvm::Value *NewPtr, 1168 llvm::Value *AllocSize, 1169 const CallArgList &NewArgs) { 1170 // If we're not inside a conditional branch, then the cleanup will 1171 // dominate and we can do the easier (and more efficient) thing. 1172 if (!CGF.isInConditionalBranch()) { 1173 CallDeleteDuringNew *Cleanup = CGF.EHStack 1174 .pushCleanupWithExtra<CallDeleteDuringNew>(EHCleanup, 1175 E->getNumPlacementArgs(), 1176 E->getOperatorDelete(), 1177 NewPtr, AllocSize); 1178 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) 1179 Cleanup->setPlacementArg(I, NewArgs[I+1].RV); 1180 1181 return; 1182 } 1183 1184 // Otherwise, we need to save all this stuff. 1185 DominatingValue<RValue>::saved_type SavedNewPtr = 1186 DominatingValue<RValue>::save(CGF, RValue::get(NewPtr)); 1187 DominatingValue<RValue>::saved_type SavedAllocSize = 1188 DominatingValue<RValue>::save(CGF, RValue::get(AllocSize)); 1189 1190 CallDeleteDuringConditionalNew *Cleanup = CGF.EHStack 1191 .pushCleanupWithExtra<CallDeleteDuringConditionalNew>(EHCleanup, 1192 E->getNumPlacementArgs(), 1193 E->getOperatorDelete(), 1194 SavedNewPtr, 1195 SavedAllocSize); 1196 for (unsigned I = 0, N = E->getNumPlacementArgs(); I != N; ++I) 1197 Cleanup->setPlacementArg(I, 1198 DominatingValue<RValue>::save(CGF, NewArgs[I+1].RV)); 1199 1200 CGF.initFullExprCleanup(); 1201 } 1202 1203 llvm::Value *CodeGenFunction::EmitCXXNewExpr(const CXXNewExpr *E) { 1204 // The element type being allocated. 1205 QualType allocType = getContext().getBaseElementType(E->getAllocatedType()); 1206 1207 // 1. Build a call to the allocation function. 1208 FunctionDecl *allocator = E->getOperatorNew(); 1209 const FunctionProtoType *allocatorType = 1210 allocator->getType()->castAs<FunctionProtoType>(); 1211 1212 CallArgList allocatorArgs; 1213 1214 // The allocation size is the first argument. 1215 QualType sizeType = getContext().getSizeType(); 1216 1217 // If there is a brace-initializer, cannot allocate fewer elements than inits. 1218 unsigned minElements = 0; 1219 if (E->isArray() && E->hasInitializer()) { 1220 if (const InitListExpr *ILE = dyn_cast<InitListExpr>(E->getInitializer())) 1221 minElements = ILE->getNumInits(); 1222 } 1223 1224 llvm::Value *numElements = nullptr; 1225 llvm::Value *allocSizeWithoutCookie = nullptr; 1226 llvm::Value *allocSize = 1227 EmitCXXNewAllocSize(*this, E, minElements, numElements, 1228 allocSizeWithoutCookie); 1229 1230 allocatorArgs.add(RValue::get(allocSize), sizeType); 1231 1232 // We start at 1 here because the first argument (the allocation size) 1233 // has already been emitted. 1234 EmitCallArgs(allocatorArgs, allocatorType->isVariadic(), 1235 allocatorType->param_type_begin() + 1, 1236 allocatorType->param_type_end(), E->placement_arg_begin(), 1237 E->placement_arg_end()); 1238 1239 // Emit the allocation call. If the allocator is a global placement 1240 // operator, just "inline" it directly. 1241 RValue RV; 1242 if (allocator->isReservedGlobalPlacementOperator()) { 1243 assert(allocatorArgs.size() == 2); 1244 RV = allocatorArgs[1].RV; 1245 // TODO: kill any unnecessary computations done for the size 1246 // argument. 1247 } else { 1248 RV = EmitNewDeleteCall(*this, allocator, allocatorType, allocatorArgs); 1249 } 1250 1251 // Emit a null check on the allocation result if the allocation 1252 // function is allowed to return null (because it has a non-throwing 1253 // exception spec; for this part, we inline 1254 // CXXNewExpr::shouldNullCheckAllocation()) and we have an 1255 // interesting initializer. 1256 bool nullCheck = allocatorType->isNothrow(getContext()) && 1257 (!allocType.isPODType(getContext()) || E->hasInitializer()); 1258 1259 llvm::BasicBlock *nullCheckBB = nullptr; 1260 llvm::BasicBlock *contBB = nullptr; 1261 1262 llvm::Value *allocation = RV.getScalarVal(); 1263 unsigned AS = allocation->getType()->getPointerAddressSpace(); 1264 1265 // The null-check means that the initializer is conditionally 1266 // evaluated. 1267 ConditionalEvaluation conditional(*this); 1268 1269 if (nullCheck) { 1270 conditional.begin(*this); 1271 1272 nullCheckBB = Builder.GetInsertBlock(); 1273 llvm::BasicBlock *notNullBB = createBasicBlock("new.notnull"); 1274 contBB = createBasicBlock("new.cont"); 1275 1276 llvm::Value *isNull = Builder.CreateIsNull(allocation, "new.isnull"); 1277 Builder.CreateCondBr(isNull, contBB, notNullBB); 1278 EmitBlock(notNullBB); 1279 } 1280 1281 // If there's an operator delete, enter a cleanup to call it if an 1282 // exception is thrown. 1283 EHScopeStack::stable_iterator operatorDeleteCleanup; 1284 llvm::Instruction *cleanupDominator = nullptr; 1285 if (E->getOperatorDelete() && 1286 !E->getOperatorDelete()->isReservedGlobalPlacementOperator()) { 1287 EnterNewDeleteCleanup(*this, E, allocation, allocSize, allocatorArgs); 1288 operatorDeleteCleanup = EHStack.stable_begin(); 1289 cleanupDominator = Builder.CreateUnreachable(); 1290 } 1291 1292 assert((allocSize == allocSizeWithoutCookie) == 1293 CalculateCookiePadding(*this, E).isZero()); 1294 if (allocSize != allocSizeWithoutCookie) { 1295 assert(E->isArray()); 1296 allocation = CGM.getCXXABI().InitializeArrayCookie(*this, allocation, 1297 numElements, 1298 E, allocType); 1299 } 1300 1301 llvm::Type *elementPtrTy 1302 = ConvertTypeForMem(allocType)->getPointerTo(AS); 1303 llvm::Value *result = Builder.CreateBitCast(allocation, elementPtrTy); 1304 1305 EmitNewInitializer(*this, E, allocType, result, numElements, 1306 allocSizeWithoutCookie); 1307 if (E->isArray()) { 1308 // NewPtr is a pointer to the base element type. If we're 1309 // allocating an array of arrays, we'll need to cast back to the 1310 // array pointer type. 1311 llvm::Type *resultType = ConvertTypeForMem(E->getType()); 1312 if (result->getType() != resultType) 1313 result = Builder.CreateBitCast(result, resultType); 1314 } 1315 1316 // Deactivate the 'operator delete' cleanup if we finished 1317 // initialization. 1318 if (operatorDeleteCleanup.isValid()) { 1319 DeactivateCleanupBlock(operatorDeleteCleanup, cleanupDominator); 1320 cleanupDominator->eraseFromParent(); 1321 } 1322 1323 if (nullCheck) { 1324 conditional.end(*this); 1325 1326 llvm::BasicBlock *notNullBB = Builder.GetInsertBlock(); 1327 EmitBlock(contBB); 1328 1329 llvm::PHINode *PHI = Builder.CreatePHI(result->getType(), 2); 1330 PHI->addIncoming(result, notNullBB); 1331 PHI->addIncoming(llvm::Constant::getNullValue(result->getType()), 1332 nullCheckBB); 1333 1334 result = PHI; 1335 } 1336 1337 return result; 1338 } 1339 1340 void CodeGenFunction::EmitDeleteCall(const FunctionDecl *DeleteFD, 1341 llvm::Value *Ptr, 1342 QualType DeleteTy) { 1343 assert(DeleteFD->getOverloadedOperator() == OO_Delete); 1344 1345 const FunctionProtoType *DeleteFTy = 1346 DeleteFD->getType()->getAs<FunctionProtoType>(); 1347 1348 CallArgList DeleteArgs; 1349 1350 // Check if we need to pass the size to the delete operator. 1351 llvm::Value *Size = nullptr; 1352 QualType SizeTy; 1353 if (DeleteFTy->getNumParams() == 2) { 1354 SizeTy = DeleteFTy->getParamType(1); 1355 CharUnits DeleteTypeSize = getContext().getTypeSizeInChars(DeleteTy); 1356 Size = llvm::ConstantInt::get(ConvertType(SizeTy), 1357 DeleteTypeSize.getQuantity()); 1358 } 1359 1360 QualType ArgTy = DeleteFTy->getParamType(0); 1361 llvm::Value *DeletePtr = Builder.CreateBitCast(Ptr, ConvertType(ArgTy)); 1362 DeleteArgs.add(RValue::get(DeletePtr), ArgTy); 1363 1364 if (Size) 1365 DeleteArgs.add(RValue::get(Size), SizeTy); 1366 1367 // Emit the call to delete. 1368 EmitNewDeleteCall(*this, DeleteFD, DeleteFTy, DeleteArgs); 1369 } 1370 1371 namespace { 1372 /// Calls the given 'operator delete' on a single object. 1373 struct CallObjectDelete : EHScopeStack::Cleanup { 1374 llvm::Value *Ptr; 1375 const FunctionDecl *OperatorDelete; 1376 QualType ElementType; 1377 1378 CallObjectDelete(llvm::Value *Ptr, 1379 const FunctionDecl *OperatorDelete, 1380 QualType ElementType) 1381 : Ptr(Ptr), OperatorDelete(OperatorDelete), ElementType(ElementType) {} 1382 1383 void Emit(CodeGenFunction &CGF, Flags flags) override { 1384 CGF.EmitDeleteCall(OperatorDelete, Ptr, ElementType); 1385 } 1386 }; 1387 } 1388 1389 /// Emit the code for deleting a single object. 1390 static void EmitObjectDelete(CodeGenFunction &CGF, 1391 const FunctionDecl *OperatorDelete, 1392 llvm::Value *Ptr, 1393 QualType ElementType, 1394 bool UseGlobalDelete) { 1395 // Find the destructor for the type, if applicable. If the 1396 // destructor is virtual, we'll just emit the vcall and return. 1397 const CXXDestructorDecl *Dtor = nullptr; 1398 if (const RecordType *RT = ElementType->getAs<RecordType>()) { 1399 CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 1400 if (RD->hasDefinition() && !RD->hasTrivialDestructor()) { 1401 Dtor = RD->getDestructor(); 1402 1403 if (Dtor->isVirtual()) { 1404 if (UseGlobalDelete) { 1405 // If we're supposed to call the global delete, make sure we do so 1406 // even if the destructor throws. 1407 1408 // Derive the complete-object pointer, which is what we need 1409 // to pass to the deallocation function. 1410 llvm::Value *completePtr = 1411 CGF.CGM.getCXXABI().adjustToCompleteObject(CGF, Ptr, ElementType); 1412 1413 CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, 1414 completePtr, OperatorDelete, 1415 ElementType); 1416 } 1417 1418 // FIXME: Provide a source location here. 1419 CXXDtorType DtorType = UseGlobalDelete ? Dtor_Complete : Dtor_Deleting; 1420 CGF.CGM.getCXXABI().EmitVirtualDestructorCall(CGF, Dtor, DtorType, 1421 SourceLocation(), Ptr); 1422 1423 if (UseGlobalDelete) { 1424 CGF.PopCleanupBlock(); 1425 } 1426 1427 return; 1428 } 1429 } 1430 } 1431 1432 // Make sure that we call delete even if the dtor throws. 1433 // This doesn't have to a conditional cleanup because we're going 1434 // to pop it off in a second. 1435 CGF.EHStack.pushCleanup<CallObjectDelete>(NormalAndEHCleanup, 1436 Ptr, OperatorDelete, ElementType); 1437 1438 if (Dtor) 1439 CGF.EmitCXXDestructorCall(Dtor, Dtor_Complete, 1440 /*ForVirtualBase=*/false, 1441 /*Delegating=*/false, 1442 Ptr); 1443 else if (CGF.getLangOpts().ObjCAutoRefCount && 1444 ElementType->isObjCLifetimeType()) { 1445 switch (ElementType.getObjCLifetime()) { 1446 case Qualifiers::OCL_None: 1447 case Qualifiers::OCL_ExplicitNone: 1448 case Qualifiers::OCL_Autoreleasing: 1449 break; 1450 1451 case Qualifiers::OCL_Strong: { 1452 // Load the pointer value. 1453 llvm::Value *PtrValue = CGF.Builder.CreateLoad(Ptr, 1454 ElementType.isVolatileQualified()); 1455 1456 CGF.EmitARCRelease(PtrValue, ARCPreciseLifetime); 1457 break; 1458 } 1459 1460 case Qualifiers::OCL_Weak: 1461 CGF.EmitARCDestroyWeak(Ptr); 1462 break; 1463 } 1464 } 1465 1466 CGF.PopCleanupBlock(); 1467 } 1468 1469 namespace { 1470 /// Calls the given 'operator delete' on an array of objects. 1471 struct CallArrayDelete : EHScopeStack::Cleanup { 1472 llvm::Value *Ptr; 1473 const FunctionDecl *OperatorDelete; 1474 llvm::Value *NumElements; 1475 QualType ElementType; 1476 CharUnits CookieSize; 1477 1478 CallArrayDelete(llvm::Value *Ptr, 1479 const FunctionDecl *OperatorDelete, 1480 llvm::Value *NumElements, 1481 QualType ElementType, 1482 CharUnits CookieSize) 1483 : Ptr(Ptr), OperatorDelete(OperatorDelete), NumElements(NumElements), 1484 ElementType(ElementType), CookieSize(CookieSize) {} 1485 1486 void Emit(CodeGenFunction &CGF, Flags flags) override { 1487 const FunctionProtoType *DeleteFTy = 1488 OperatorDelete->getType()->getAs<FunctionProtoType>(); 1489 assert(DeleteFTy->getNumParams() == 1 || DeleteFTy->getNumParams() == 2); 1490 1491 CallArgList Args; 1492 1493 // Pass the pointer as the first argument. 1494 QualType VoidPtrTy = DeleteFTy->getParamType(0); 1495 llvm::Value *DeletePtr 1496 = CGF.Builder.CreateBitCast(Ptr, CGF.ConvertType(VoidPtrTy)); 1497 Args.add(RValue::get(DeletePtr), VoidPtrTy); 1498 1499 // Pass the original requested size as the second argument. 1500 if (DeleteFTy->getNumParams() == 2) { 1501 QualType size_t = DeleteFTy->getParamType(1); 1502 llvm::IntegerType *SizeTy 1503 = cast<llvm::IntegerType>(CGF.ConvertType(size_t)); 1504 1505 CharUnits ElementTypeSize = 1506 CGF.CGM.getContext().getTypeSizeInChars(ElementType); 1507 1508 // The size of an element, multiplied by the number of elements. 1509 llvm::Value *Size 1510 = llvm::ConstantInt::get(SizeTy, ElementTypeSize.getQuantity()); 1511 Size = CGF.Builder.CreateMul(Size, NumElements); 1512 1513 // Plus the size of the cookie if applicable. 1514 if (!CookieSize.isZero()) { 1515 llvm::Value *CookieSizeV 1516 = llvm::ConstantInt::get(SizeTy, CookieSize.getQuantity()); 1517 Size = CGF.Builder.CreateAdd(Size, CookieSizeV); 1518 } 1519 1520 Args.add(RValue::get(Size), size_t); 1521 } 1522 1523 // Emit the call to delete. 1524 EmitNewDeleteCall(CGF, OperatorDelete, DeleteFTy, Args); 1525 } 1526 }; 1527 } 1528 1529 /// Emit the code for deleting an array of objects. 1530 static void EmitArrayDelete(CodeGenFunction &CGF, 1531 const CXXDeleteExpr *E, 1532 llvm::Value *deletedPtr, 1533 QualType elementType) { 1534 llvm::Value *numElements = nullptr; 1535 llvm::Value *allocatedPtr = nullptr; 1536 CharUnits cookieSize; 1537 CGF.CGM.getCXXABI().ReadArrayCookie(CGF, deletedPtr, E, elementType, 1538 numElements, allocatedPtr, cookieSize); 1539 1540 assert(allocatedPtr && "ReadArrayCookie didn't set allocated pointer"); 1541 1542 // Make sure that we call delete even if one of the dtors throws. 1543 const FunctionDecl *operatorDelete = E->getOperatorDelete(); 1544 CGF.EHStack.pushCleanup<CallArrayDelete>(NormalAndEHCleanup, 1545 allocatedPtr, operatorDelete, 1546 numElements, elementType, 1547 cookieSize); 1548 1549 // Destroy the elements. 1550 if (QualType::DestructionKind dtorKind = elementType.isDestructedType()) { 1551 assert(numElements && "no element count for a type with a destructor!"); 1552 1553 llvm::Value *arrayEnd = 1554 CGF.Builder.CreateInBoundsGEP(deletedPtr, numElements, "delete.end"); 1555 1556 // Note that it is legal to allocate a zero-length array, and we 1557 // can never fold the check away because the length should always 1558 // come from a cookie. 1559 CGF.emitArrayDestroy(deletedPtr, arrayEnd, elementType, 1560 CGF.getDestroyer(dtorKind), 1561 /*checkZeroLength*/ true, 1562 CGF.needsEHCleanup(dtorKind)); 1563 } 1564 1565 // Pop the cleanup block. 1566 CGF.PopCleanupBlock(); 1567 } 1568 1569 void CodeGenFunction::EmitCXXDeleteExpr(const CXXDeleteExpr *E) { 1570 const Expr *Arg = E->getArgument(); 1571 llvm::Value *Ptr = EmitScalarExpr(Arg); 1572 1573 // Null check the pointer. 1574 llvm::BasicBlock *DeleteNotNull = createBasicBlock("delete.notnull"); 1575 llvm::BasicBlock *DeleteEnd = createBasicBlock("delete.end"); 1576 1577 llvm::Value *IsNull = Builder.CreateIsNull(Ptr, "isnull"); 1578 1579 Builder.CreateCondBr(IsNull, DeleteEnd, DeleteNotNull); 1580 EmitBlock(DeleteNotNull); 1581 1582 // We might be deleting a pointer to array. If so, GEP down to the 1583 // first non-array element. 1584 // (this assumes that A(*)[3][7] is converted to [3 x [7 x %A]]*) 1585 QualType DeleteTy = Arg->getType()->getAs<PointerType>()->getPointeeType(); 1586 if (DeleteTy->isConstantArrayType()) { 1587 llvm::Value *Zero = Builder.getInt32(0); 1588 SmallVector<llvm::Value*,8> GEP; 1589 1590 GEP.push_back(Zero); // point at the outermost array 1591 1592 // For each layer of array type we're pointing at: 1593 while (const ConstantArrayType *Arr 1594 = getContext().getAsConstantArrayType(DeleteTy)) { 1595 // 1. Unpeel the array type. 1596 DeleteTy = Arr->getElementType(); 1597 1598 // 2. GEP to the first element of the array. 1599 GEP.push_back(Zero); 1600 } 1601 1602 Ptr = Builder.CreateInBoundsGEP(Ptr, GEP, "del.first"); 1603 } 1604 1605 assert(ConvertTypeForMem(DeleteTy) == 1606 cast<llvm::PointerType>(Ptr->getType())->getElementType()); 1607 1608 if (E->isArrayForm()) { 1609 EmitArrayDelete(*this, E, Ptr, DeleteTy); 1610 } else { 1611 EmitObjectDelete(*this, E->getOperatorDelete(), Ptr, DeleteTy, 1612 E->isGlobalDelete()); 1613 } 1614 1615 EmitBlock(DeleteEnd); 1616 } 1617 1618 static llvm::Value *EmitTypeidFromVTable(CodeGenFunction &CGF, const Expr *E, 1619 llvm::Type *StdTypeInfoPtrTy) { 1620 // Get the vtable pointer. 1621 llvm::Value *ThisPtr = CGF.EmitLValue(E).getAddress(); 1622 1623 // C++ [expr.typeid]p2: 1624 // If the glvalue expression is obtained by applying the unary * operator to 1625 // a pointer and the pointer is a null pointer value, the typeid expression 1626 // throws the std::bad_typeid exception. 1627 bool IsDeref = false; 1628 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParens())) 1629 if (UO->getOpcode() == UO_Deref) 1630 IsDeref = true; 1631 1632 QualType SrcRecordTy = E->getType(); 1633 if (CGF.CGM.getCXXABI().shouldTypeidBeNullChecked(IsDeref, SrcRecordTy)) { 1634 llvm::BasicBlock *BadTypeidBlock = 1635 CGF.createBasicBlock("typeid.bad_typeid"); 1636 llvm::BasicBlock *EndBlock = CGF.createBasicBlock("typeid.end"); 1637 1638 llvm::Value *IsNull = CGF.Builder.CreateIsNull(ThisPtr); 1639 CGF.Builder.CreateCondBr(IsNull, BadTypeidBlock, EndBlock); 1640 1641 CGF.EmitBlock(BadTypeidBlock); 1642 CGF.CGM.getCXXABI().EmitBadTypeidCall(CGF); 1643 CGF.EmitBlock(EndBlock); 1644 } 1645 1646 return CGF.CGM.getCXXABI().EmitTypeid(CGF, SrcRecordTy, ThisPtr, 1647 StdTypeInfoPtrTy); 1648 } 1649 1650 llvm::Value *CodeGenFunction::EmitCXXTypeidExpr(const CXXTypeidExpr *E) { 1651 llvm::Type *StdTypeInfoPtrTy = 1652 ConvertType(E->getType())->getPointerTo(); 1653 1654 if (E->isTypeOperand()) { 1655 llvm::Constant *TypeInfo = 1656 CGM.GetAddrOfRTTIDescriptor(E->getTypeOperand(getContext())); 1657 return Builder.CreateBitCast(TypeInfo, StdTypeInfoPtrTy); 1658 } 1659 1660 // C++ [expr.typeid]p2: 1661 // When typeid is applied to a glvalue expression whose type is a 1662 // polymorphic class type, the result refers to a std::type_info object 1663 // representing the type of the most derived object (that is, the dynamic 1664 // type) to which the glvalue refers. 1665 if (E->isPotentiallyEvaluated()) 1666 return EmitTypeidFromVTable(*this, E->getExprOperand(), 1667 StdTypeInfoPtrTy); 1668 1669 QualType OperandTy = E->getExprOperand()->getType(); 1670 return Builder.CreateBitCast(CGM.GetAddrOfRTTIDescriptor(OperandTy), 1671 StdTypeInfoPtrTy); 1672 } 1673 1674 static llvm::Value *EmitDynamicCastToNull(CodeGenFunction &CGF, 1675 QualType DestTy) { 1676 llvm::Type *DestLTy = CGF.ConvertType(DestTy); 1677 if (DestTy->isPointerType()) 1678 return llvm::Constant::getNullValue(DestLTy); 1679 1680 /// C++ [expr.dynamic.cast]p9: 1681 /// A failed cast to reference type throws std::bad_cast 1682 if (!CGF.CGM.getCXXABI().EmitBadCastCall(CGF)) 1683 return nullptr; 1684 1685 CGF.EmitBlock(CGF.createBasicBlock("dynamic_cast.end")); 1686 return llvm::UndefValue::get(DestLTy); 1687 } 1688 1689 llvm::Value *CodeGenFunction::EmitDynamicCast(llvm::Value *Value, 1690 const CXXDynamicCastExpr *DCE) { 1691 QualType DestTy = DCE->getTypeAsWritten(); 1692 1693 if (DCE->isAlwaysNull()) 1694 if (llvm::Value *T = EmitDynamicCastToNull(*this, DestTy)) 1695 return T; 1696 1697 QualType SrcTy = DCE->getSubExpr()->getType(); 1698 1699 // C++ [expr.dynamic.cast]p7: 1700 // If T is "pointer to cv void," then the result is a pointer to the most 1701 // derived object pointed to by v. 1702 const PointerType *DestPTy = DestTy->getAs<PointerType>(); 1703 1704 bool isDynamicCastToVoid; 1705 QualType SrcRecordTy; 1706 QualType DestRecordTy; 1707 if (DestPTy) { 1708 isDynamicCastToVoid = DestPTy->getPointeeType()->isVoidType(); 1709 SrcRecordTy = SrcTy->castAs<PointerType>()->getPointeeType(); 1710 DestRecordTy = DestPTy->getPointeeType(); 1711 } else { 1712 isDynamicCastToVoid = false; 1713 SrcRecordTy = SrcTy; 1714 DestRecordTy = DestTy->castAs<ReferenceType>()->getPointeeType(); 1715 } 1716 1717 assert(SrcRecordTy->isRecordType() && "source type must be a record type!"); 1718 1719 // C++ [expr.dynamic.cast]p4: 1720 // If the value of v is a null pointer value in the pointer case, the result 1721 // is the null pointer value of type T. 1722 bool ShouldNullCheckSrcValue = 1723 CGM.getCXXABI().shouldDynamicCastCallBeNullChecked(SrcTy->isPointerType(), 1724 SrcRecordTy); 1725 1726 llvm::BasicBlock *CastNull = nullptr; 1727 llvm::BasicBlock *CastNotNull = nullptr; 1728 llvm::BasicBlock *CastEnd = createBasicBlock("dynamic_cast.end"); 1729 1730 if (ShouldNullCheckSrcValue) { 1731 CastNull = createBasicBlock("dynamic_cast.null"); 1732 CastNotNull = createBasicBlock("dynamic_cast.notnull"); 1733 1734 llvm::Value *IsNull = Builder.CreateIsNull(Value); 1735 Builder.CreateCondBr(IsNull, CastNull, CastNotNull); 1736 EmitBlock(CastNotNull); 1737 } 1738 1739 if (isDynamicCastToVoid) { 1740 Value = CGM.getCXXABI().EmitDynamicCastToVoid(*this, Value, SrcRecordTy, 1741 DestTy); 1742 } else { 1743 assert(DestRecordTy->isRecordType() && 1744 "destination type must be a record type!"); 1745 Value = CGM.getCXXABI().EmitDynamicCastCall(*this, Value, SrcRecordTy, 1746 DestTy, DestRecordTy, CastEnd); 1747 } 1748 1749 if (ShouldNullCheckSrcValue) { 1750 EmitBranch(CastEnd); 1751 1752 EmitBlock(CastNull); 1753 EmitBranch(CastEnd); 1754 } 1755 1756 EmitBlock(CastEnd); 1757 1758 if (ShouldNullCheckSrcValue) { 1759 llvm::PHINode *PHI = Builder.CreatePHI(Value->getType(), 2); 1760 PHI->addIncoming(Value, CastNotNull); 1761 PHI->addIncoming(llvm::Constant::getNullValue(Value->getType()), CastNull); 1762 1763 Value = PHI; 1764 } 1765 1766 return Value; 1767 } 1768 1769 void CodeGenFunction::EmitLambdaExpr(const LambdaExpr *E, AggValueSlot Slot) { 1770 RunCleanupsScope Scope(*this); 1771 LValue SlotLV = MakeAddrLValue(Slot.getAddr(), E->getType(), 1772 Slot.getAlignment()); 1773 1774 CXXRecordDecl::field_iterator CurField = E->getLambdaClass()->field_begin(); 1775 for (LambdaExpr::capture_init_iterator i = E->capture_init_begin(), 1776 e = E->capture_init_end(); 1777 i != e; ++i, ++CurField) { 1778 // Emit initialization 1779 1780 LValue LV = EmitLValueForFieldInitialization(SlotLV, *CurField); 1781 ArrayRef<VarDecl *> ArrayIndexes; 1782 if (CurField->getType()->isArrayType()) 1783 ArrayIndexes = E->getCaptureInitIndexVars(i); 1784 EmitInitializerForField(*CurField, LV, *i, ArrayIndexes); 1785 } 1786 } 1787