1 //===--- CGExpr.cpp - Emit LLVM Code from Expressions ---------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This contains code to emit Expr nodes as LLVM code. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "CGCUDARuntime.h" 14 #include "CGCXXABI.h" 15 #include "CGCall.h" 16 #include "CGCleanup.h" 17 #include "CGDebugInfo.h" 18 #include "CGObjCRuntime.h" 19 #include "CGOpenMPRuntime.h" 20 #include "CGRecordLayout.h" 21 #include "CodeGenFunction.h" 22 #include "CodeGenModule.h" 23 #include "ConstantEmitter.h" 24 #include "TargetInfo.h" 25 #include "clang/AST/ASTContext.h" 26 #include "clang/AST/Attr.h" 27 #include "clang/AST/DeclObjC.h" 28 #include "clang/AST/NSAPI.h" 29 #include "clang/Basic/Builtins.h" 30 #include "clang/Basic/CodeGenOptions.h" 31 #include "clang/Basic/SourceManager.h" 32 #include "llvm/ADT/Hashing.h" 33 #include "llvm/ADT/StringExtras.h" 34 #include "llvm/IR/DataLayout.h" 35 #include "llvm/IR/Intrinsics.h" 36 #include "llvm/IR/LLVMContext.h" 37 #include "llvm/IR/MDBuilder.h" 38 #include "llvm/IR/MatrixBuilder.h" 39 #include "llvm/Support/ConvertUTF.h" 40 #include "llvm/Support/MathExtras.h" 41 #include "llvm/Support/Path.h" 42 #include "llvm/Support/SaveAndRestore.h" 43 #include "llvm/Transforms/Utils/SanitizerStats.h" 44 45 #include <string> 46 47 using namespace clang; 48 using namespace CodeGen; 49 50 //===--------------------------------------------------------------------===// 51 // Miscellaneous Helper Methods 52 //===--------------------------------------------------------------------===// 53 54 llvm::Value *CodeGenFunction::EmitCastToVoidPtr(llvm::Value *value) { 55 unsigned addressSpace = 56 cast<llvm::PointerType>(value->getType())->getAddressSpace(); 57 58 llvm::PointerType *destType = Int8PtrTy; 59 if (addressSpace) 60 destType = llvm::Type::getInt8PtrTy(getLLVMContext(), addressSpace); 61 62 if (value->getType() == destType) return value; 63 return Builder.CreateBitCast(value, destType); 64 } 65 66 /// CreateTempAlloca - This creates a alloca and inserts it into the entry 67 /// block. 68 Address CodeGenFunction::CreateTempAllocaWithoutCast(llvm::Type *Ty, 69 CharUnits Align, 70 const Twine &Name, 71 llvm::Value *ArraySize) { 72 auto Alloca = CreateTempAlloca(Ty, Name, ArraySize); 73 Alloca->setAlignment(Align.getAsAlign()); 74 return Address(Alloca, Ty, Align); 75 } 76 77 /// CreateTempAlloca - This creates a alloca and inserts it into the entry 78 /// block. The alloca is casted to default address space if necessary. 79 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align, 80 const Twine &Name, 81 llvm::Value *ArraySize, 82 Address *AllocaAddr) { 83 auto Alloca = CreateTempAllocaWithoutCast(Ty, Align, Name, ArraySize); 84 if (AllocaAddr) 85 *AllocaAddr = Alloca; 86 llvm::Value *V = Alloca.getPointer(); 87 // Alloca always returns a pointer in alloca address space, which may 88 // be different from the type defined by the language. For example, 89 // in C++ the auto variables are in the default address space. Therefore 90 // cast alloca to the default address space when necessary. 91 if (getASTAllocaAddressSpace() != LangAS::Default) { 92 auto DestAddrSpace = getContext().getTargetAddressSpace(LangAS::Default); 93 llvm::IRBuilderBase::InsertPointGuard IPG(Builder); 94 // When ArraySize is nullptr, alloca is inserted at AllocaInsertPt, 95 // otherwise alloca is inserted at the current insertion point of the 96 // builder. 97 if (!ArraySize) 98 Builder.SetInsertPoint(getPostAllocaInsertPoint()); 99 V = getTargetHooks().performAddrSpaceCast( 100 *this, V, getASTAllocaAddressSpace(), LangAS::Default, 101 Ty->getPointerTo(DestAddrSpace), /*non-null*/ true); 102 } 103 104 return Address(V, Ty, Align); 105 } 106 107 /// CreateTempAlloca - This creates an alloca and inserts it into the entry 108 /// block if \p ArraySize is nullptr, otherwise inserts it at the current 109 /// insertion point of the builder. 110 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, 111 const Twine &Name, 112 llvm::Value *ArraySize) { 113 if (ArraySize) 114 return Builder.CreateAlloca(Ty, ArraySize, Name); 115 return new llvm::AllocaInst(Ty, CGM.getDataLayout().getAllocaAddrSpace(), 116 ArraySize, Name, AllocaInsertPt); 117 } 118 119 /// CreateDefaultAlignTempAlloca - This creates an alloca with the 120 /// default alignment of the corresponding LLVM type, which is *not* 121 /// guaranteed to be related in any way to the expected alignment of 122 /// an AST type that might have been lowered to Ty. 123 Address CodeGenFunction::CreateDefaultAlignTempAlloca(llvm::Type *Ty, 124 const Twine &Name) { 125 CharUnits Align = 126 CharUnits::fromQuantity(CGM.getDataLayout().getPrefTypeAlignment(Ty)); 127 return CreateTempAlloca(Ty, Align, Name); 128 } 129 130 Address CodeGenFunction::CreateIRTemp(QualType Ty, const Twine &Name) { 131 CharUnits Align = getContext().getTypeAlignInChars(Ty); 132 return CreateTempAlloca(ConvertType(Ty), Align, Name); 133 } 134 135 Address CodeGenFunction::CreateMemTemp(QualType Ty, const Twine &Name, 136 Address *Alloca) { 137 // FIXME: Should we prefer the preferred type alignment here? 138 return CreateMemTemp(Ty, getContext().getTypeAlignInChars(Ty), Name, Alloca); 139 } 140 141 Address CodeGenFunction::CreateMemTemp(QualType Ty, CharUnits Align, 142 const Twine &Name, Address *Alloca) { 143 Address Result = CreateTempAlloca(ConvertTypeForMem(Ty), Align, Name, 144 /*ArraySize=*/nullptr, Alloca); 145 146 if (Ty->isConstantMatrixType()) { 147 auto *ArrayTy = cast<llvm::ArrayType>(Result.getElementType()); 148 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(), 149 ArrayTy->getNumElements()); 150 151 Result = Address( 152 Builder.CreateBitCast(Result.getPointer(), VectorTy->getPointerTo()), 153 VectorTy, Result.getAlignment()); 154 } 155 return Result; 156 } 157 158 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, CharUnits Align, 159 const Twine &Name) { 160 return CreateTempAllocaWithoutCast(ConvertTypeForMem(Ty), Align, Name); 161 } 162 163 Address CodeGenFunction::CreateMemTempWithoutCast(QualType Ty, 164 const Twine &Name) { 165 return CreateMemTempWithoutCast(Ty, getContext().getTypeAlignInChars(Ty), 166 Name); 167 } 168 169 /// EvaluateExprAsBool - Perform the usual unary conversions on the specified 170 /// expression and compare the result against zero, returning an Int1Ty value. 171 llvm::Value *CodeGenFunction::EvaluateExprAsBool(const Expr *E) { 172 PGO.setCurrentStmt(E); 173 if (const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>()) { 174 llvm::Value *MemPtr = EmitScalarExpr(E); 175 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, MemPtr, MPT); 176 } 177 178 QualType BoolTy = getContext().BoolTy; 179 SourceLocation Loc = E->getExprLoc(); 180 CGFPOptionsRAII FPOptsRAII(*this, E); 181 if (!E->getType()->isAnyComplexType()) 182 return EmitScalarConversion(EmitScalarExpr(E), E->getType(), BoolTy, Loc); 183 184 return EmitComplexToScalarConversion(EmitComplexExpr(E), E->getType(), BoolTy, 185 Loc); 186 } 187 188 /// EmitIgnoredExpr - Emit code to compute the specified expression, 189 /// ignoring the result. 190 void CodeGenFunction::EmitIgnoredExpr(const Expr *E) { 191 if (E->isPRValue()) 192 return (void) EmitAnyExpr(E, AggValueSlot::ignored(), true); 193 194 // Just emit it as an l-value and drop the result. 195 EmitLValue(E); 196 } 197 198 /// EmitAnyExpr - Emit code to compute the specified expression which 199 /// can have any type. The result is returned as an RValue struct. 200 /// If this is an aggregate expression, AggSlot indicates where the 201 /// result should be returned. 202 RValue CodeGenFunction::EmitAnyExpr(const Expr *E, 203 AggValueSlot aggSlot, 204 bool ignoreResult) { 205 switch (getEvaluationKind(E->getType())) { 206 case TEK_Scalar: 207 return RValue::get(EmitScalarExpr(E, ignoreResult)); 208 case TEK_Complex: 209 return RValue::getComplex(EmitComplexExpr(E, ignoreResult, ignoreResult)); 210 case TEK_Aggregate: 211 if (!ignoreResult && aggSlot.isIgnored()) 212 aggSlot = CreateAggTemp(E->getType(), "agg-temp"); 213 EmitAggExpr(E, aggSlot); 214 return aggSlot.asRValue(); 215 } 216 llvm_unreachable("bad evaluation kind"); 217 } 218 219 /// EmitAnyExprToTemp - Similar to EmitAnyExpr(), however, the result will 220 /// always be accessible even if no aggregate location is provided. 221 RValue CodeGenFunction::EmitAnyExprToTemp(const Expr *E) { 222 AggValueSlot AggSlot = AggValueSlot::ignored(); 223 224 if (hasAggregateEvaluationKind(E->getType())) 225 AggSlot = CreateAggTemp(E->getType(), "agg.tmp"); 226 return EmitAnyExpr(E, AggSlot); 227 } 228 229 /// EmitAnyExprToMem - Evaluate an expression into a given memory 230 /// location. 231 void CodeGenFunction::EmitAnyExprToMem(const Expr *E, 232 Address Location, 233 Qualifiers Quals, 234 bool IsInit) { 235 // FIXME: This function should take an LValue as an argument. 236 switch (getEvaluationKind(E->getType())) { 237 case TEK_Complex: 238 EmitComplexExprIntoLValue(E, MakeAddrLValue(Location, E->getType()), 239 /*isInit*/ false); 240 return; 241 242 case TEK_Aggregate: { 243 EmitAggExpr(E, AggValueSlot::forAddr(Location, Quals, 244 AggValueSlot::IsDestructed_t(IsInit), 245 AggValueSlot::DoesNotNeedGCBarriers, 246 AggValueSlot::IsAliased_t(!IsInit), 247 AggValueSlot::MayOverlap)); 248 return; 249 } 250 251 case TEK_Scalar: { 252 RValue RV = RValue::get(EmitScalarExpr(E, /*Ignore*/ false)); 253 LValue LV = MakeAddrLValue(Location, E->getType()); 254 EmitStoreThroughLValue(RV, LV); 255 return; 256 } 257 } 258 llvm_unreachable("bad evaluation kind"); 259 } 260 261 static void 262 pushTemporaryCleanup(CodeGenFunction &CGF, const MaterializeTemporaryExpr *M, 263 const Expr *E, Address ReferenceTemporary) { 264 // Objective-C++ ARC: 265 // If we are binding a reference to a temporary that has ownership, we 266 // need to perform retain/release operations on the temporary. 267 // 268 // FIXME: This should be looking at E, not M. 269 if (auto Lifetime = M->getType().getObjCLifetime()) { 270 switch (Lifetime) { 271 case Qualifiers::OCL_None: 272 case Qualifiers::OCL_ExplicitNone: 273 // Carry on to normal cleanup handling. 274 break; 275 276 case Qualifiers::OCL_Autoreleasing: 277 // Nothing to do; cleaned up by an autorelease pool. 278 return; 279 280 case Qualifiers::OCL_Strong: 281 case Qualifiers::OCL_Weak: 282 switch (StorageDuration Duration = M->getStorageDuration()) { 283 case SD_Static: 284 // Note: we intentionally do not register a cleanup to release 285 // the object on program termination. 286 return; 287 288 case SD_Thread: 289 // FIXME: We should probably register a cleanup in this case. 290 return; 291 292 case SD_Automatic: 293 case SD_FullExpression: 294 CodeGenFunction::Destroyer *Destroy; 295 CleanupKind CleanupKind; 296 if (Lifetime == Qualifiers::OCL_Strong) { 297 const ValueDecl *VD = M->getExtendingDecl(); 298 bool Precise = 299 VD && isa<VarDecl>(VD) && VD->hasAttr<ObjCPreciseLifetimeAttr>(); 300 CleanupKind = CGF.getARCCleanupKind(); 301 Destroy = Precise ? &CodeGenFunction::destroyARCStrongPrecise 302 : &CodeGenFunction::destroyARCStrongImprecise; 303 } else { 304 // __weak objects always get EH cleanups; otherwise, exceptions 305 // could cause really nasty crashes instead of mere leaks. 306 CleanupKind = NormalAndEHCleanup; 307 Destroy = &CodeGenFunction::destroyARCWeak; 308 } 309 if (Duration == SD_FullExpression) 310 CGF.pushDestroy(CleanupKind, ReferenceTemporary, 311 M->getType(), *Destroy, 312 CleanupKind & EHCleanup); 313 else 314 CGF.pushLifetimeExtendedDestroy(CleanupKind, ReferenceTemporary, 315 M->getType(), 316 *Destroy, CleanupKind & EHCleanup); 317 return; 318 319 case SD_Dynamic: 320 llvm_unreachable("temporary cannot have dynamic storage duration"); 321 } 322 llvm_unreachable("unknown storage duration"); 323 } 324 } 325 326 CXXDestructorDecl *ReferenceTemporaryDtor = nullptr; 327 if (const RecordType *RT = 328 E->getType()->getBaseElementTypeUnsafe()->getAs<RecordType>()) { 329 // Get the destructor for the reference temporary. 330 auto *ClassDecl = cast<CXXRecordDecl>(RT->getDecl()); 331 if (!ClassDecl->hasTrivialDestructor()) 332 ReferenceTemporaryDtor = ClassDecl->getDestructor(); 333 } 334 335 if (!ReferenceTemporaryDtor) 336 return; 337 338 // Call the destructor for the temporary. 339 switch (M->getStorageDuration()) { 340 case SD_Static: 341 case SD_Thread: { 342 llvm::FunctionCallee CleanupFn; 343 llvm::Constant *CleanupArg; 344 if (E->getType()->isArrayType()) { 345 CleanupFn = CodeGenFunction(CGF.CGM).generateDestroyHelper( 346 ReferenceTemporary, E->getType(), 347 CodeGenFunction::destroyCXXObject, CGF.getLangOpts().Exceptions, 348 dyn_cast_or_null<VarDecl>(M->getExtendingDecl())); 349 CleanupArg = llvm::Constant::getNullValue(CGF.Int8PtrTy); 350 } else { 351 CleanupFn = CGF.CGM.getAddrAndTypeOfCXXStructor( 352 GlobalDecl(ReferenceTemporaryDtor, Dtor_Complete)); 353 CleanupArg = cast<llvm::Constant>(ReferenceTemporary.getPointer()); 354 } 355 CGF.CGM.getCXXABI().registerGlobalDtor( 356 CGF, *cast<VarDecl>(M->getExtendingDecl()), CleanupFn, CleanupArg); 357 break; 358 } 359 360 case SD_FullExpression: 361 CGF.pushDestroy(NormalAndEHCleanup, ReferenceTemporary, E->getType(), 362 CodeGenFunction::destroyCXXObject, 363 CGF.getLangOpts().Exceptions); 364 break; 365 366 case SD_Automatic: 367 CGF.pushLifetimeExtendedDestroy(NormalAndEHCleanup, 368 ReferenceTemporary, E->getType(), 369 CodeGenFunction::destroyCXXObject, 370 CGF.getLangOpts().Exceptions); 371 break; 372 373 case SD_Dynamic: 374 llvm_unreachable("temporary cannot have dynamic storage duration"); 375 } 376 } 377 378 static Address createReferenceTemporary(CodeGenFunction &CGF, 379 const MaterializeTemporaryExpr *M, 380 const Expr *Inner, 381 Address *Alloca = nullptr) { 382 auto &TCG = CGF.getTargetHooks(); 383 switch (M->getStorageDuration()) { 384 case SD_FullExpression: 385 case SD_Automatic: { 386 // If we have a constant temporary array or record try to promote it into a 387 // constant global under the same rules a normal constant would've been 388 // promoted. This is easier on the optimizer and generally emits fewer 389 // instructions. 390 QualType Ty = Inner->getType(); 391 if (CGF.CGM.getCodeGenOpts().MergeAllConstants && 392 (Ty->isArrayType() || Ty->isRecordType()) && 393 CGF.CGM.isTypeConstant(Ty, true)) 394 if (auto Init = ConstantEmitter(CGF).tryEmitAbstract(Inner, Ty)) { 395 auto AS = CGF.CGM.GetGlobalConstantAddressSpace(); 396 auto *GV = new llvm::GlobalVariable( 397 CGF.CGM.getModule(), Init->getType(), /*isConstant=*/true, 398 llvm::GlobalValue::PrivateLinkage, Init, ".ref.tmp", nullptr, 399 llvm::GlobalValue::NotThreadLocal, 400 CGF.getContext().getTargetAddressSpace(AS)); 401 CharUnits alignment = CGF.getContext().getTypeAlignInChars(Ty); 402 GV->setAlignment(alignment.getAsAlign()); 403 llvm::Constant *C = GV; 404 if (AS != LangAS::Default) 405 C = TCG.performAddrSpaceCast( 406 CGF.CGM, GV, AS, LangAS::Default, 407 GV->getValueType()->getPointerTo( 408 CGF.getContext().getTargetAddressSpace(LangAS::Default))); 409 // FIXME: Should we put the new global into a COMDAT? 410 return Address(C, alignment); 411 } 412 return CGF.CreateMemTemp(Ty, "ref.tmp", Alloca); 413 } 414 case SD_Thread: 415 case SD_Static: 416 return CGF.CGM.GetAddrOfGlobalTemporary(M, Inner); 417 418 case SD_Dynamic: 419 llvm_unreachable("temporary can't have dynamic storage duration"); 420 } 421 llvm_unreachable("unknown storage duration"); 422 } 423 424 /// Helper method to check if the underlying ABI is AAPCS 425 static bool isAAPCS(const TargetInfo &TargetInfo) { 426 return TargetInfo.getABI().startswith("aapcs"); 427 } 428 429 LValue CodeGenFunction:: 430 EmitMaterializeTemporaryExpr(const MaterializeTemporaryExpr *M) { 431 const Expr *E = M->getSubExpr(); 432 433 assert((!M->getExtendingDecl() || !isa<VarDecl>(M->getExtendingDecl()) || 434 !cast<VarDecl>(M->getExtendingDecl())->isARCPseudoStrong()) && 435 "Reference should never be pseudo-strong!"); 436 437 // FIXME: ideally this would use EmitAnyExprToMem, however, we cannot do so 438 // as that will cause the lifetime adjustment to be lost for ARC 439 auto ownership = M->getType().getObjCLifetime(); 440 if (ownership != Qualifiers::OCL_None && 441 ownership != Qualifiers::OCL_ExplicitNone) { 442 Address Object = createReferenceTemporary(*this, M, E); 443 if (auto *Var = dyn_cast<llvm::GlobalVariable>(Object.getPointer())) { 444 Object = Address(llvm::ConstantExpr::getBitCast(Var, 445 ConvertTypeForMem(E->getType()) 446 ->getPointerTo(Object.getAddressSpace())), 447 Object.getAlignment()); 448 449 // createReferenceTemporary will promote the temporary to a global with a 450 // constant initializer if it can. It can only do this to a value of 451 // ARC-manageable type if the value is global and therefore "immune" to 452 // ref-counting operations. Therefore we have no need to emit either a 453 // dynamic initialization or a cleanup and we can just return the address 454 // of the temporary. 455 if (Var->hasInitializer()) 456 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl); 457 458 Var->setInitializer(CGM.EmitNullConstant(E->getType())); 459 } 460 LValue RefTempDst = MakeAddrLValue(Object, M->getType(), 461 AlignmentSource::Decl); 462 463 switch (getEvaluationKind(E->getType())) { 464 default: llvm_unreachable("expected scalar or aggregate expression"); 465 case TEK_Scalar: 466 EmitScalarInit(E, M->getExtendingDecl(), RefTempDst, false); 467 break; 468 case TEK_Aggregate: { 469 EmitAggExpr(E, AggValueSlot::forAddr(Object, 470 E->getType().getQualifiers(), 471 AggValueSlot::IsDestructed, 472 AggValueSlot::DoesNotNeedGCBarriers, 473 AggValueSlot::IsNotAliased, 474 AggValueSlot::DoesNotOverlap)); 475 break; 476 } 477 } 478 479 pushTemporaryCleanup(*this, M, E, Object); 480 return RefTempDst; 481 } 482 483 SmallVector<const Expr *, 2> CommaLHSs; 484 SmallVector<SubobjectAdjustment, 2> Adjustments; 485 E = E->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments); 486 487 for (const auto &Ignored : CommaLHSs) 488 EmitIgnoredExpr(Ignored); 489 490 if (const auto *opaque = dyn_cast<OpaqueValueExpr>(E)) { 491 if (opaque->getType()->isRecordType()) { 492 assert(Adjustments.empty()); 493 return EmitOpaqueValueLValue(opaque); 494 } 495 } 496 497 // Create and initialize the reference temporary. 498 Address Alloca = Address::invalid(); 499 Address Object = createReferenceTemporary(*this, M, E, &Alloca); 500 if (auto *Var = dyn_cast<llvm::GlobalVariable>( 501 Object.getPointer()->stripPointerCasts())) { 502 Object = Address(llvm::ConstantExpr::getBitCast( 503 cast<llvm::Constant>(Object.getPointer()), 504 ConvertTypeForMem(E->getType())->getPointerTo()), 505 Object.getAlignment()); 506 // If the temporary is a global and has a constant initializer or is a 507 // constant temporary that we promoted to a global, we may have already 508 // initialized it. 509 if (!Var->hasInitializer()) { 510 Var->setInitializer(CGM.EmitNullConstant(E->getType())); 511 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true); 512 } 513 } else { 514 switch (M->getStorageDuration()) { 515 case SD_Automatic: 516 if (auto *Size = EmitLifetimeStart( 517 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()), 518 Alloca.getPointer())) { 519 pushCleanupAfterFullExpr<CallLifetimeEnd>(NormalEHLifetimeMarker, 520 Alloca, Size); 521 } 522 break; 523 524 case SD_FullExpression: { 525 if (!ShouldEmitLifetimeMarkers) 526 break; 527 528 // Avoid creating a conditional cleanup just to hold an llvm.lifetime.end 529 // marker. Instead, start the lifetime of a conditional temporary earlier 530 // so that it's unconditional. Don't do this with sanitizers which need 531 // more precise lifetime marks. 532 ConditionalEvaluation *OldConditional = nullptr; 533 CGBuilderTy::InsertPoint OldIP; 534 if (isInConditionalBranch() && !E->getType().isDestructedType() && 535 !SanOpts.has(SanitizerKind::HWAddress) && 536 !SanOpts.has(SanitizerKind::Memory) && 537 !CGM.getCodeGenOpts().SanitizeAddressUseAfterScope) { 538 OldConditional = OutermostConditional; 539 OutermostConditional = nullptr; 540 541 OldIP = Builder.saveIP(); 542 llvm::BasicBlock *Block = OldConditional->getStartingBlock(); 543 Builder.restoreIP(CGBuilderTy::InsertPoint( 544 Block, llvm::BasicBlock::iterator(Block->back()))); 545 } 546 547 if (auto *Size = EmitLifetimeStart( 548 CGM.getDataLayout().getTypeAllocSize(Alloca.getElementType()), 549 Alloca.getPointer())) { 550 pushFullExprCleanup<CallLifetimeEnd>(NormalEHLifetimeMarker, Alloca, 551 Size); 552 } 553 554 if (OldConditional) { 555 OutermostConditional = OldConditional; 556 Builder.restoreIP(OldIP); 557 } 558 break; 559 } 560 561 default: 562 break; 563 } 564 EmitAnyExprToMem(E, Object, Qualifiers(), /*IsInit*/true); 565 } 566 pushTemporaryCleanup(*this, M, E, Object); 567 568 // Perform derived-to-base casts and/or field accesses, to get from the 569 // temporary object we created (and, potentially, for which we extended 570 // the lifetime) to the subobject we're binding the reference to. 571 for (SubobjectAdjustment &Adjustment : llvm::reverse(Adjustments)) { 572 switch (Adjustment.Kind) { 573 case SubobjectAdjustment::DerivedToBaseAdjustment: 574 Object = 575 GetAddressOfBaseClass(Object, Adjustment.DerivedToBase.DerivedClass, 576 Adjustment.DerivedToBase.BasePath->path_begin(), 577 Adjustment.DerivedToBase.BasePath->path_end(), 578 /*NullCheckValue=*/ false, E->getExprLoc()); 579 break; 580 581 case SubobjectAdjustment::FieldAdjustment: { 582 LValue LV = MakeAddrLValue(Object, E->getType(), AlignmentSource::Decl); 583 LV = EmitLValueForField(LV, Adjustment.Field); 584 assert(LV.isSimple() && 585 "materialized temporary field is not a simple lvalue"); 586 Object = LV.getAddress(*this); 587 break; 588 } 589 590 case SubobjectAdjustment::MemberPointerAdjustment: { 591 llvm::Value *Ptr = EmitScalarExpr(Adjustment.Ptr.RHS); 592 Object = EmitCXXMemberDataPointerAddress(E, Object, Ptr, 593 Adjustment.Ptr.MPT); 594 break; 595 } 596 } 597 } 598 599 return MakeAddrLValue(Object, M->getType(), AlignmentSource::Decl); 600 } 601 602 RValue 603 CodeGenFunction::EmitReferenceBindingToExpr(const Expr *E) { 604 // Emit the expression as an lvalue. 605 LValue LV = EmitLValue(E); 606 assert(LV.isSimple()); 607 llvm::Value *Value = LV.getPointer(*this); 608 609 if (sanitizePerformTypeCheck() && !E->getType()->isFunctionType()) { 610 // C++11 [dcl.ref]p5 (as amended by core issue 453): 611 // If a glvalue to which a reference is directly bound designates neither 612 // an existing object or function of an appropriate type nor a region of 613 // storage of suitable size and alignment to contain an object of the 614 // reference's type, the behavior is undefined. 615 QualType Ty = E->getType(); 616 EmitTypeCheck(TCK_ReferenceBinding, E->getExprLoc(), Value, Ty); 617 } 618 619 return RValue::get(Value); 620 } 621 622 623 /// getAccessedFieldNo - Given an encoded value and a result number, return the 624 /// input field number being accessed. 625 unsigned CodeGenFunction::getAccessedFieldNo(unsigned Idx, 626 const llvm::Constant *Elts) { 627 return cast<llvm::ConstantInt>(Elts->getAggregateElement(Idx)) 628 ->getZExtValue(); 629 } 630 631 /// Emit the hash_16_bytes function from include/llvm/ADT/Hashing.h. 632 static llvm::Value *emitHash16Bytes(CGBuilderTy &Builder, llvm::Value *Low, 633 llvm::Value *High) { 634 llvm::Value *KMul = Builder.getInt64(0x9ddfea08eb382d69ULL); 635 llvm::Value *K47 = Builder.getInt64(47); 636 llvm::Value *A0 = Builder.CreateMul(Builder.CreateXor(Low, High), KMul); 637 llvm::Value *A1 = Builder.CreateXor(Builder.CreateLShr(A0, K47), A0); 638 llvm::Value *B0 = Builder.CreateMul(Builder.CreateXor(High, A1), KMul); 639 llvm::Value *B1 = Builder.CreateXor(Builder.CreateLShr(B0, K47), B0); 640 return Builder.CreateMul(B1, KMul); 641 } 642 643 bool CodeGenFunction::isNullPointerAllowed(TypeCheckKind TCK) { 644 return TCK == TCK_DowncastPointer || TCK == TCK_Upcast || 645 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation; 646 } 647 648 bool CodeGenFunction::isVptrCheckRequired(TypeCheckKind TCK, QualType Ty) { 649 CXXRecordDecl *RD = Ty->getAsCXXRecordDecl(); 650 return (RD && RD->hasDefinition() && RD->isDynamicClass()) && 651 (TCK == TCK_MemberAccess || TCK == TCK_MemberCall || 652 TCK == TCK_DowncastPointer || TCK == TCK_DowncastReference || 653 TCK == TCK_UpcastToVirtualBase || TCK == TCK_DynamicOperation); 654 } 655 656 bool CodeGenFunction::sanitizePerformTypeCheck() const { 657 return SanOpts.has(SanitizerKind::Null) || 658 SanOpts.has(SanitizerKind::Alignment) || 659 SanOpts.has(SanitizerKind::ObjectSize) || 660 SanOpts.has(SanitizerKind::Vptr); 661 } 662 663 void CodeGenFunction::EmitTypeCheck(TypeCheckKind TCK, SourceLocation Loc, 664 llvm::Value *Ptr, QualType Ty, 665 CharUnits Alignment, 666 SanitizerSet SkippedChecks, 667 llvm::Value *ArraySize) { 668 if (!sanitizePerformTypeCheck()) 669 return; 670 671 // Don't check pointers outside the default address space. The null check 672 // isn't correct, the object-size check isn't supported by LLVM, and we can't 673 // communicate the addresses to the runtime handler for the vptr check. 674 if (Ptr->getType()->getPointerAddressSpace()) 675 return; 676 677 // Don't check pointers to volatile data. The behavior here is implementation- 678 // defined. 679 if (Ty.isVolatileQualified()) 680 return; 681 682 SanitizerScope SanScope(this); 683 684 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 3> Checks; 685 llvm::BasicBlock *Done = nullptr; 686 687 // Quickly determine whether we have a pointer to an alloca. It's possible 688 // to skip null checks, and some alignment checks, for these pointers. This 689 // can reduce compile-time significantly. 690 auto PtrToAlloca = dyn_cast<llvm::AllocaInst>(Ptr->stripPointerCasts()); 691 692 llvm::Value *True = llvm::ConstantInt::getTrue(getLLVMContext()); 693 llvm::Value *IsNonNull = nullptr; 694 bool IsGuaranteedNonNull = 695 SkippedChecks.has(SanitizerKind::Null) || PtrToAlloca; 696 bool AllowNullPointers = isNullPointerAllowed(TCK); 697 if ((SanOpts.has(SanitizerKind::Null) || AllowNullPointers) && 698 !IsGuaranteedNonNull) { 699 // The glvalue must not be an empty glvalue. 700 IsNonNull = Builder.CreateIsNotNull(Ptr); 701 702 // The IR builder can constant-fold the null check if the pointer points to 703 // a constant. 704 IsGuaranteedNonNull = IsNonNull == True; 705 706 // Skip the null check if the pointer is known to be non-null. 707 if (!IsGuaranteedNonNull) { 708 if (AllowNullPointers) { 709 // When performing pointer casts, it's OK if the value is null. 710 // Skip the remaining checks in that case. 711 Done = createBasicBlock("null"); 712 llvm::BasicBlock *Rest = createBasicBlock("not.null"); 713 Builder.CreateCondBr(IsNonNull, Rest, Done); 714 EmitBlock(Rest); 715 } else { 716 Checks.push_back(std::make_pair(IsNonNull, SanitizerKind::Null)); 717 } 718 } 719 } 720 721 if (SanOpts.has(SanitizerKind::ObjectSize) && 722 !SkippedChecks.has(SanitizerKind::ObjectSize) && 723 !Ty->isIncompleteType()) { 724 uint64_t TySize = CGM.getMinimumObjectSize(Ty).getQuantity(); 725 llvm::Value *Size = llvm::ConstantInt::get(IntPtrTy, TySize); 726 if (ArraySize) 727 Size = Builder.CreateMul(Size, ArraySize); 728 729 // Degenerate case: new X[0] does not need an objectsize check. 730 llvm::Constant *ConstantSize = dyn_cast<llvm::Constant>(Size); 731 if (!ConstantSize || !ConstantSize->isNullValue()) { 732 // The glvalue must refer to a large enough storage region. 733 // FIXME: If Address Sanitizer is enabled, insert dynamic instrumentation 734 // to check this. 735 // FIXME: Get object address space 736 llvm::Type *Tys[2] = { IntPtrTy, Int8PtrTy }; 737 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::objectsize, Tys); 738 llvm::Value *Min = Builder.getFalse(); 739 llvm::Value *NullIsUnknown = Builder.getFalse(); 740 llvm::Value *Dynamic = Builder.getFalse(); 741 llvm::Value *CastAddr = Builder.CreateBitCast(Ptr, Int8PtrTy); 742 llvm::Value *LargeEnough = Builder.CreateICmpUGE( 743 Builder.CreateCall(F, {CastAddr, Min, NullIsUnknown, Dynamic}), Size); 744 Checks.push_back(std::make_pair(LargeEnough, SanitizerKind::ObjectSize)); 745 } 746 } 747 748 uint64_t AlignVal = 0; 749 llvm::Value *PtrAsInt = nullptr; 750 751 if (SanOpts.has(SanitizerKind::Alignment) && 752 !SkippedChecks.has(SanitizerKind::Alignment)) { 753 AlignVal = Alignment.getQuantity(); 754 if (!Ty->isIncompleteType() && !AlignVal) 755 AlignVal = CGM.getNaturalTypeAlignment(Ty, nullptr, nullptr, 756 /*ForPointeeType=*/true) 757 .getQuantity(); 758 759 // The glvalue must be suitably aligned. 760 if (AlignVal > 1 && 761 (!PtrToAlloca || PtrToAlloca->getAlignment() < AlignVal)) { 762 PtrAsInt = Builder.CreatePtrToInt(Ptr, IntPtrTy); 763 llvm::Value *Align = Builder.CreateAnd( 764 PtrAsInt, llvm::ConstantInt::get(IntPtrTy, AlignVal - 1)); 765 llvm::Value *Aligned = 766 Builder.CreateICmpEQ(Align, llvm::ConstantInt::get(IntPtrTy, 0)); 767 if (Aligned != True) 768 Checks.push_back(std::make_pair(Aligned, SanitizerKind::Alignment)); 769 } 770 } 771 772 if (Checks.size() > 0) { 773 // Make sure we're not losing information. Alignment needs to be a power of 774 // 2 775 assert(!AlignVal || (uint64_t)1 << llvm::Log2_64(AlignVal) == AlignVal); 776 llvm::Constant *StaticData[] = { 777 EmitCheckSourceLocation(Loc), EmitCheckTypeDescriptor(Ty), 778 llvm::ConstantInt::get(Int8Ty, AlignVal ? llvm::Log2_64(AlignVal) : 1), 779 llvm::ConstantInt::get(Int8Ty, TCK)}; 780 EmitCheck(Checks, SanitizerHandler::TypeMismatch, StaticData, 781 PtrAsInt ? PtrAsInt : Ptr); 782 } 783 784 // If possible, check that the vptr indicates that there is a subobject of 785 // type Ty at offset zero within this object. 786 // 787 // C++11 [basic.life]p5,6: 788 // [For storage which does not refer to an object within its lifetime] 789 // The program has undefined behavior if: 790 // -- the [pointer or glvalue] is used to access a non-static data member 791 // or call a non-static member function 792 if (SanOpts.has(SanitizerKind::Vptr) && 793 !SkippedChecks.has(SanitizerKind::Vptr) && isVptrCheckRequired(TCK, Ty)) { 794 // Ensure that the pointer is non-null before loading it. If there is no 795 // compile-time guarantee, reuse the run-time null check or emit a new one. 796 if (!IsGuaranteedNonNull) { 797 if (!IsNonNull) 798 IsNonNull = Builder.CreateIsNotNull(Ptr); 799 if (!Done) 800 Done = createBasicBlock("vptr.null"); 801 llvm::BasicBlock *VptrNotNull = createBasicBlock("vptr.not.null"); 802 Builder.CreateCondBr(IsNonNull, VptrNotNull, Done); 803 EmitBlock(VptrNotNull); 804 } 805 806 // Compute a hash of the mangled name of the type. 807 // 808 // FIXME: This is not guaranteed to be deterministic! Move to a 809 // fingerprinting mechanism once LLVM provides one. For the time 810 // being the implementation happens to be deterministic. 811 SmallString<64> MangledName; 812 llvm::raw_svector_ostream Out(MangledName); 813 CGM.getCXXABI().getMangleContext().mangleCXXRTTI(Ty.getUnqualifiedType(), 814 Out); 815 816 // Contained in NoSanitizeList based on the mangled type. 817 if (!CGM.getContext().getNoSanitizeList().containsType(SanitizerKind::Vptr, 818 Out.str())) { 819 llvm::hash_code TypeHash = hash_value(Out.str()); 820 821 // Load the vptr, and compute hash_16_bytes(TypeHash, vptr). 822 llvm::Value *Low = llvm::ConstantInt::get(Int64Ty, TypeHash); 823 llvm::Type *VPtrTy = llvm::PointerType::get(IntPtrTy, 0); 824 Address VPtrAddr(Builder.CreateBitCast(Ptr, VPtrTy), getPointerAlign()); 825 llvm::Value *VPtrVal = Builder.CreateLoad(VPtrAddr); 826 llvm::Value *High = Builder.CreateZExt(VPtrVal, Int64Ty); 827 828 llvm::Value *Hash = emitHash16Bytes(Builder, Low, High); 829 Hash = Builder.CreateTrunc(Hash, IntPtrTy); 830 831 // Look the hash up in our cache. 832 const int CacheSize = 128; 833 llvm::Type *HashTable = llvm::ArrayType::get(IntPtrTy, CacheSize); 834 llvm::Value *Cache = CGM.CreateRuntimeVariable(HashTable, 835 "__ubsan_vptr_type_cache"); 836 llvm::Value *Slot = Builder.CreateAnd(Hash, 837 llvm::ConstantInt::get(IntPtrTy, 838 CacheSize-1)); 839 llvm::Value *Indices[] = { Builder.getInt32(0), Slot }; 840 llvm::Value *CacheVal = Builder.CreateAlignedLoad( 841 IntPtrTy, Builder.CreateInBoundsGEP(HashTable, Cache, Indices), 842 getPointerAlign()); 843 844 // If the hash isn't in the cache, call a runtime handler to perform the 845 // hard work of checking whether the vptr is for an object of the right 846 // type. This will either fill in the cache and return, or produce a 847 // diagnostic. 848 llvm::Value *EqualHash = Builder.CreateICmpEQ(CacheVal, Hash); 849 llvm::Constant *StaticData[] = { 850 EmitCheckSourceLocation(Loc), 851 EmitCheckTypeDescriptor(Ty), 852 CGM.GetAddrOfRTTIDescriptor(Ty.getUnqualifiedType()), 853 llvm::ConstantInt::get(Int8Ty, TCK) 854 }; 855 llvm::Value *DynamicData[] = { Ptr, Hash }; 856 EmitCheck(std::make_pair(EqualHash, SanitizerKind::Vptr), 857 SanitizerHandler::DynamicTypeCacheMiss, StaticData, 858 DynamicData); 859 } 860 } 861 862 if (Done) { 863 Builder.CreateBr(Done); 864 EmitBlock(Done); 865 } 866 } 867 868 /// Determine whether this expression refers to a flexible array member in a 869 /// struct. We disable array bounds checks for such members. 870 static bool isFlexibleArrayMemberExpr(const Expr *E) { 871 // For compatibility with existing code, we treat arrays of length 0 or 872 // 1 as flexible array members. 873 // FIXME: This is inconsistent with the warning code in SemaChecking. Unify 874 // the two mechanisms. 875 const ArrayType *AT = E->getType()->castAsArrayTypeUnsafe(); 876 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) { 877 // FIXME: Sema doesn't treat [1] as a flexible array member if the bound 878 // was produced by macro expansion. 879 if (CAT->getSize().ugt(1)) 880 return false; 881 } else if (!isa<IncompleteArrayType>(AT)) 882 return false; 883 884 E = E->IgnoreParens(); 885 886 // A flexible array member must be the last member in the class. 887 if (const auto *ME = dyn_cast<MemberExpr>(E)) { 888 // FIXME: If the base type of the member expr is not FD->getParent(), 889 // this should not be treated as a flexible array member access. 890 if (const auto *FD = dyn_cast<FieldDecl>(ME->getMemberDecl())) { 891 // FIXME: Sema doesn't treat a T[1] union member as a flexible array 892 // member, only a T[0] or T[] member gets that treatment. 893 if (FD->getParent()->isUnion()) 894 return true; 895 RecordDecl::field_iterator FI( 896 DeclContext::decl_iterator(const_cast<FieldDecl *>(FD))); 897 return ++FI == FD->getParent()->field_end(); 898 } 899 } else if (const auto *IRE = dyn_cast<ObjCIvarRefExpr>(E)) { 900 return IRE->getDecl()->getNextIvar() == nullptr; 901 } 902 903 return false; 904 } 905 906 llvm::Value *CodeGenFunction::LoadPassedObjectSize(const Expr *E, 907 QualType EltTy) { 908 ASTContext &C = getContext(); 909 uint64_t EltSize = C.getTypeSizeInChars(EltTy).getQuantity(); 910 if (!EltSize) 911 return nullptr; 912 913 auto *ArrayDeclRef = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()); 914 if (!ArrayDeclRef) 915 return nullptr; 916 917 auto *ParamDecl = dyn_cast<ParmVarDecl>(ArrayDeclRef->getDecl()); 918 if (!ParamDecl) 919 return nullptr; 920 921 auto *POSAttr = ParamDecl->getAttr<PassObjectSizeAttr>(); 922 if (!POSAttr) 923 return nullptr; 924 925 // Don't load the size if it's a lower bound. 926 int POSType = POSAttr->getType(); 927 if (POSType != 0 && POSType != 1) 928 return nullptr; 929 930 // Find the implicit size parameter. 931 auto PassedSizeIt = SizeArguments.find(ParamDecl); 932 if (PassedSizeIt == SizeArguments.end()) 933 return nullptr; 934 935 const ImplicitParamDecl *PassedSizeDecl = PassedSizeIt->second; 936 assert(LocalDeclMap.count(PassedSizeDecl) && "Passed size not loadable"); 937 Address AddrOfSize = LocalDeclMap.find(PassedSizeDecl)->second; 938 llvm::Value *SizeInBytes = EmitLoadOfScalar(AddrOfSize, /*Volatile=*/false, 939 C.getSizeType(), E->getExprLoc()); 940 llvm::Value *SizeOfElement = 941 llvm::ConstantInt::get(SizeInBytes->getType(), EltSize); 942 return Builder.CreateUDiv(SizeInBytes, SizeOfElement); 943 } 944 945 /// If Base is known to point to the start of an array, return the length of 946 /// that array. Return 0 if the length cannot be determined. 947 static llvm::Value *getArrayIndexingBound( 948 CodeGenFunction &CGF, const Expr *Base, QualType &IndexedType) { 949 // For the vector indexing extension, the bound is the number of elements. 950 if (const VectorType *VT = Base->getType()->getAs<VectorType>()) { 951 IndexedType = Base->getType(); 952 return CGF.Builder.getInt32(VT->getNumElements()); 953 } 954 955 Base = Base->IgnoreParens(); 956 957 if (const auto *CE = dyn_cast<CastExpr>(Base)) { 958 if (CE->getCastKind() == CK_ArrayToPointerDecay && 959 !isFlexibleArrayMemberExpr(CE->getSubExpr())) { 960 IndexedType = CE->getSubExpr()->getType(); 961 const ArrayType *AT = IndexedType->castAsArrayTypeUnsafe(); 962 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) 963 return CGF.Builder.getInt(CAT->getSize()); 964 else if (const auto *VAT = dyn_cast<VariableArrayType>(AT)) 965 return CGF.getVLASize(VAT).NumElts; 966 // Ignore pass_object_size here. It's not applicable on decayed pointers. 967 } 968 } 969 970 QualType EltTy{Base->getType()->getPointeeOrArrayElementType(), 0}; 971 if (llvm::Value *POS = CGF.LoadPassedObjectSize(Base, EltTy)) { 972 IndexedType = Base->getType(); 973 return POS; 974 } 975 976 return nullptr; 977 } 978 979 void CodeGenFunction::EmitBoundsCheck(const Expr *E, const Expr *Base, 980 llvm::Value *Index, QualType IndexType, 981 bool Accessed) { 982 assert(SanOpts.has(SanitizerKind::ArrayBounds) && 983 "should not be called unless adding bounds checks"); 984 SanitizerScope SanScope(this); 985 986 QualType IndexedType; 987 llvm::Value *Bound = getArrayIndexingBound(*this, Base, IndexedType); 988 if (!Bound) 989 return; 990 991 bool IndexSigned = IndexType->isSignedIntegerOrEnumerationType(); 992 llvm::Value *IndexVal = Builder.CreateIntCast(Index, SizeTy, IndexSigned); 993 llvm::Value *BoundVal = Builder.CreateIntCast(Bound, SizeTy, false); 994 995 llvm::Constant *StaticData[] = { 996 EmitCheckSourceLocation(E->getExprLoc()), 997 EmitCheckTypeDescriptor(IndexedType), 998 EmitCheckTypeDescriptor(IndexType) 999 }; 1000 llvm::Value *Check = Accessed ? Builder.CreateICmpULT(IndexVal, BoundVal) 1001 : Builder.CreateICmpULE(IndexVal, BoundVal); 1002 EmitCheck(std::make_pair(Check, SanitizerKind::ArrayBounds), 1003 SanitizerHandler::OutOfBounds, StaticData, Index); 1004 } 1005 1006 1007 CodeGenFunction::ComplexPairTy CodeGenFunction:: 1008 EmitComplexPrePostIncDec(const UnaryOperator *E, LValue LV, 1009 bool isInc, bool isPre) { 1010 ComplexPairTy InVal = EmitLoadOfComplex(LV, E->getExprLoc()); 1011 1012 llvm::Value *NextVal; 1013 if (isa<llvm::IntegerType>(InVal.first->getType())) { 1014 uint64_t AmountVal = isInc ? 1 : -1; 1015 NextVal = llvm::ConstantInt::get(InVal.first->getType(), AmountVal, true); 1016 1017 // Add the inc/dec to the real part. 1018 NextVal = Builder.CreateAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); 1019 } else { 1020 QualType ElemTy = E->getType()->castAs<ComplexType>()->getElementType(); 1021 llvm::APFloat FVal(getContext().getFloatTypeSemantics(ElemTy), 1); 1022 if (!isInc) 1023 FVal.changeSign(); 1024 NextVal = llvm::ConstantFP::get(getLLVMContext(), FVal); 1025 1026 // Add the inc/dec to the real part. 1027 NextVal = Builder.CreateFAdd(InVal.first, NextVal, isInc ? "inc" : "dec"); 1028 } 1029 1030 ComplexPairTy IncVal(NextVal, InVal.second); 1031 1032 // Store the updated result through the lvalue. 1033 EmitStoreOfComplex(IncVal, LV, /*init*/ false); 1034 if (getLangOpts().OpenMP) 1035 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this, 1036 E->getSubExpr()); 1037 1038 // If this is a postinc, return the value read from memory, otherwise use the 1039 // updated value. 1040 return isPre ? IncVal : InVal; 1041 } 1042 1043 void CodeGenModule::EmitExplicitCastExprType(const ExplicitCastExpr *E, 1044 CodeGenFunction *CGF) { 1045 // Bind VLAs in the cast type. 1046 if (CGF && E->getType()->isVariablyModifiedType()) 1047 CGF->EmitVariablyModifiedType(E->getType()); 1048 1049 if (CGDebugInfo *DI = getModuleDebugInfo()) 1050 DI->EmitExplicitCastType(E->getType()); 1051 } 1052 1053 //===----------------------------------------------------------------------===// 1054 // LValue Expression Emission 1055 //===----------------------------------------------------------------------===// 1056 1057 /// EmitPointerWithAlignment - Given an expression of pointer type, try to 1058 /// derive a more accurate bound on the alignment of the pointer. 1059 Address CodeGenFunction::EmitPointerWithAlignment(const Expr *E, 1060 LValueBaseInfo *BaseInfo, 1061 TBAAAccessInfo *TBAAInfo) { 1062 // We allow this with ObjC object pointers because of fragile ABIs. 1063 assert(E->getType()->isPointerType() || 1064 E->getType()->isObjCObjectPointerType()); 1065 E = E->IgnoreParens(); 1066 1067 // Casts: 1068 if (const CastExpr *CE = dyn_cast<CastExpr>(E)) { 1069 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(CE)) 1070 CGM.EmitExplicitCastExprType(ECE, this); 1071 1072 switch (CE->getCastKind()) { 1073 // Non-converting casts (but not C's implicit conversion from void*). 1074 case CK_BitCast: 1075 case CK_NoOp: 1076 case CK_AddressSpaceConversion: 1077 if (auto PtrTy = CE->getSubExpr()->getType()->getAs<PointerType>()) { 1078 if (PtrTy->getPointeeType()->isVoidType()) 1079 break; 1080 1081 LValueBaseInfo InnerBaseInfo; 1082 TBAAAccessInfo InnerTBAAInfo; 1083 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), 1084 &InnerBaseInfo, 1085 &InnerTBAAInfo); 1086 if (BaseInfo) *BaseInfo = InnerBaseInfo; 1087 if (TBAAInfo) *TBAAInfo = InnerTBAAInfo; 1088 1089 if (isa<ExplicitCastExpr>(CE)) { 1090 LValueBaseInfo TargetTypeBaseInfo; 1091 TBAAAccessInfo TargetTypeTBAAInfo; 1092 CharUnits Align = CGM.getNaturalPointeeTypeAlignment( 1093 E->getType(), &TargetTypeBaseInfo, &TargetTypeTBAAInfo); 1094 if (TBAAInfo) 1095 *TBAAInfo = CGM.mergeTBAAInfoForCast(*TBAAInfo, 1096 TargetTypeTBAAInfo); 1097 // If the source l-value is opaque, honor the alignment of the 1098 // casted-to type. 1099 if (InnerBaseInfo.getAlignmentSource() != AlignmentSource::Decl) { 1100 if (BaseInfo) 1101 BaseInfo->mergeForCast(TargetTypeBaseInfo); 1102 Addr = Address(Addr.getPointer(), Addr.getElementType(), Align); 1103 } 1104 } 1105 1106 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast) && 1107 CE->getCastKind() == CK_BitCast) { 1108 if (auto PT = E->getType()->getAs<PointerType>()) 1109 EmitVTablePtrCheckForCast(PT->getPointeeType(), Addr.getPointer(), 1110 /*MayBeNull=*/true, 1111 CodeGenFunction::CFITCK_UnrelatedCast, 1112 CE->getBeginLoc()); 1113 } 1114 1115 if (CE->getCastKind() == CK_AddressSpaceConversion) 1116 return Builder.CreateAddrSpaceCast(Addr, ConvertType(E->getType())); 1117 1118 llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType()); 1119 return Builder.CreateElementBitCast(Addr, ElemTy); 1120 } 1121 break; 1122 1123 // Array-to-pointer decay. 1124 case CK_ArrayToPointerDecay: 1125 return EmitArrayToPointerDecay(CE->getSubExpr(), BaseInfo, TBAAInfo); 1126 1127 // Derived-to-base conversions. 1128 case CK_UncheckedDerivedToBase: 1129 case CK_DerivedToBase: { 1130 // TODO: Support accesses to members of base classes in TBAA. For now, we 1131 // conservatively pretend that the complete object is of the base class 1132 // type. 1133 if (TBAAInfo) 1134 *TBAAInfo = CGM.getTBAAAccessInfo(E->getType()); 1135 Address Addr = EmitPointerWithAlignment(CE->getSubExpr(), BaseInfo); 1136 auto Derived = CE->getSubExpr()->getType()->getPointeeCXXRecordDecl(); 1137 return GetAddressOfBaseClass(Addr, Derived, 1138 CE->path_begin(), CE->path_end(), 1139 ShouldNullCheckClassCastValue(CE), 1140 CE->getExprLoc()); 1141 } 1142 1143 // TODO: Is there any reason to treat base-to-derived conversions 1144 // specially? 1145 default: 1146 break; 1147 } 1148 } 1149 1150 // Unary &. 1151 if (const UnaryOperator *UO = dyn_cast<UnaryOperator>(E)) { 1152 if (UO->getOpcode() == UO_AddrOf) { 1153 LValue LV = EmitLValue(UO->getSubExpr()); 1154 if (BaseInfo) *BaseInfo = LV.getBaseInfo(); 1155 if (TBAAInfo) *TBAAInfo = LV.getTBAAInfo(); 1156 return LV.getAddress(*this); 1157 } 1158 } 1159 1160 // TODO: conditional operators, comma. 1161 1162 // Otherwise, use the alignment of the type. 1163 CharUnits Align = 1164 CGM.getNaturalPointeeTypeAlignment(E->getType(), BaseInfo, TBAAInfo); 1165 llvm::Type *ElemTy = ConvertTypeForMem(E->getType()->getPointeeType()); 1166 return Address(EmitScalarExpr(E), ElemTy, Align); 1167 } 1168 1169 llvm::Value *CodeGenFunction::EmitNonNullRValueCheck(RValue RV, QualType T) { 1170 llvm::Value *V = RV.getScalarVal(); 1171 if (auto MPT = T->getAs<MemberPointerType>()) 1172 return CGM.getCXXABI().EmitMemberPointerIsNotNull(*this, V, MPT); 1173 return Builder.CreateICmpNE(V, llvm::Constant::getNullValue(V->getType())); 1174 } 1175 1176 RValue CodeGenFunction::GetUndefRValue(QualType Ty) { 1177 if (Ty->isVoidType()) 1178 return RValue::get(nullptr); 1179 1180 switch (getEvaluationKind(Ty)) { 1181 case TEK_Complex: { 1182 llvm::Type *EltTy = 1183 ConvertType(Ty->castAs<ComplexType>()->getElementType()); 1184 llvm::Value *U = llvm::UndefValue::get(EltTy); 1185 return RValue::getComplex(std::make_pair(U, U)); 1186 } 1187 1188 // If this is a use of an undefined aggregate type, the aggregate must have an 1189 // identifiable address. Just because the contents of the value are undefined 1190 // doesn't mean that the address can't be taken and compared. 1191 case TEK_Aggregate: { 1192 Address DestPtr = CreateMemTemp(Ty, "undef.agg.tmp"); 1193 return RValue::getAggregate(DestPtr); 1194 } 1195 1196 case TEK_Scalar: 1197 return RValue::get(llvm::UndefValue::get(ConvertType(Ty))); 1198 } 1199 llvm_unreachable("bad evaluation kind"); 1200 } 1201 1202 RValue CodeGenFunction::EmitUnsupportedRValue(const Expr *E, 1203 const char *Name) { 1204 ErrorUnsupported(E, Name); 1205 return GetUndefRValue(E->getType()); 1206 } 1207 1208 LValue CodeGenFunction::EmitUnsupportedLValue(const Expr *E, 1209 const char *Name) { 1210 ErrorUnsupported(E, Name); 1211 llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType())); 1212 return MakeAddrLValue(Address(llvm::UndefValue::get(Ty), CharUnits::One()), 1213 E->getType()); 1214 } 1215 1216 bool CodeGenFunction::IsWrappedCXXThis(const Expr *Obj) { 1217 const Expr *Base = Obj; 1218 while (!isa<CXXThisExpr>(Base)) { 1219 // The result of a dynamic_cast can be null. 1220 if (isa<CXXDynamicCastExpr>(Base)) 1221 return false; 1222 1223 if (const auto *CE = dyn_cast<CastExpr>(Base)) { 1224 Base = CE->getSubExpr(); 1225 } else if (const auto *PE = dyn_cast<ParenExpr>(Base)) { 1226 Base = PE->getSubExpr(); 1227 } else if (const auto *UO = dyn_cast<UnaryOperator>(Base)) { 1228 if (UO->getOpcode() == UO_Extension) 1229 Base = UO->getSubExpr(); 1230 else 1231 return false; 1232 } else { 1233 return false; 1234 } 1235 } 1236 return true; 1237 } 1238 1239 LValue CodeGenFunction::EmitCheckedLValue(const Expr *E, TypeCheckKind TCK) { 1240 LValue LV; 1241 if (SanOpts.has(SanitizerKind::ArrayBounds) && isa<ArraySubscriptExpr>(E)) 1242 LV = EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E), /*Accessed*/true); 1243 else 1244 LV = EmitLValue(E); 1245 if (!isa<DeclRefExpr>(E) && !LV.isBitField() && LV.isSimple()) { 1246 SanitizerSet SkippedChecks; 1247 if (const auto *ME = dyn_cast<MemberExpr>(E)) { 1248 bool IsBaseCXXThis = IsWrappedCXXThis(ME->getBase()); 1249 if (IsBaseCXXThis) 1250 SkippedChecks.set(SanitizerKind::Alignment, true); 1251 if (IsBaseCXXThis || isa<DeclRefExpr>(ME->getBase())) 1252 SkippedChecks.set(SanitizerKind::Null, true); 1253 } 1254 EmitTypeCheck(TCK, E->getExprLoc(), LV.getPointer(*this), E->getType(), 1255 LV.getAlignment(), SkippedChecks); 1256 } 1257 return LV; 1258 } 1259 1260 /// EmitLValue - Emit code to compute a designator that specifies the location 1261 /// of the expression. 1262 /// 1263 /// This can return one of two things: a simple address or a bitfield reference. 1264 /// In either case, the LLVM Value* in the LValue structure is guaranteed to be 1265 /// an LLVM pointer type. 1266 /// 1267 /// If this returns a bitfield reference, nothing about the pointee type of the 1268 /// LLVM value is known: For example, it may not be a pointer to an integer. 1269 /// 1270 /// If this returns a normal address, and if the lvalue's C type is fixed size, 1271 /// this method guarantees that the returned pointer type will point to an LLVM 1272 /// type of the same size of the lvalue's type. If the lvalue has a variable 1273 /// length type, this is not possible. 1274 /// 1275 LValue CodeGenFunction::EmitLValue(const Expr *E) { 1276 ApplyDebugLocation DL(*this, E); 1277 switch (E->getStmtClass()) { 1278 default: return EmitUnsupportedLValue(E, "l-value expression"); 1279 1280 case Expr::ObjCPropertyRefExprClass: 1281 llvm_unreachable("cannot emit a property reference directly"); 1282 1283 case Expr::ObjCSelectorExprClass: 1284 return EmitObjCSelectorLValue(cast<ObjCSelectorExpr>(E)); 1285 case Expr::ObjCIsaExprClass: 1286 return EmitObjCIsaExpr(cast<ObjCIsaExpr>(E)); 1287 case Expr::BinaryOperatorClass: 1288 return EmitBinaryOperatorLValue(cast<BinaryOperator>(E)); 1289 case Expr::CompoundAssignOperatorClass: { 1290 QualType Ty = E->getType(); 1291 if (const AtomicType *AT = Ty->getAs<AtomicType>()) 1292 Ty = AT->getValueType(); 1293 if (!Ty->isAnyComplexType()) 1294 return EmitCompoundAssignmentLValue(cast<CompoundAssignOperator>(E)); 1295 return EmitComplexCompoundAssignmentLValue(cast<CompoundAssignOperator>(E)); 1296 } 1297 case Expr::CallExprClass: 1298 case Expr::CXXMemberCallExprClass: 1299 case Expr::CXXOperatorCallExprClass: 1300 case Expr::UserDefinedLiteralClass: 1301 return EmitCallExprLValue(cast<CallExpr>(E)); 1302 case Expr::CXXRewrittenBinaryOperatorClass: 1303 return EmitLValue(cast<CXXRewrittenBinaryOperator>(E)->getSemanticForm()); 1304 case Expr::VAArgExprClass: 1305 return EmitVAArgExprLValue(cast<VAArgExpr>(E)); 1306 case Expr::DeclRefExprClass: 1307 return EmitDeclRefLValue(cast<DeclRefExpr>(E)); 1308 case Expr::ConstantExprClass: { 1309 const ConstantExpr *CE = cast<ConstantExpr>(E); 1310 if (llvm::Value *Result = ConstantEmitter(*this).tryEmitConstantExpr(CE)) { 1311 QualType RetType = cast<CallExpr>(CE->getSubExpr()->IgnoreImplicit()) 1312 ->getCallReturnType(getContext()) 1313 ->getPointeeType(); 1314 return MakeNaturalAlignAddrLValue(Result, RetType); 1315 } 1316 return EmitLValue(cast<ConstantExpr>(E)->getSubExpr()); 1317 } 1318 case Expr::ParenExprClass: 1319 return EmitLValue(cast<ParenExpr>(E)->getSubExpr()); 1320 case Expr::GenericSelectionExprClass: 1321 return EmitLValue(cast<GenericSelectionExpr>(E)->getResultExpr()); 1322 case Expr::PredefinedExprClass: 1323 return EmitPredefinedLValue(cast<PredefinedExpr>(E)); 1324 case Expr::StringLiteralClass: 1325 return EmitStringLiteralLValue(cast<StringLiteral>(E)); 1326 case Expr::ObjCEncodeExprClass: 1327 return EmitObjCEncodeExprLValue(cast<ObjCEncodeExpr>(E)); 1328 case Expr::PseudoObjectExprClass: 1329 return EmitPseudoObjectLValue(cast<PseudoObjectExpr>(E)); 1330 case Expr::InitListExprClass: 1331 return EmitInitListLValue(cast<InitListExpr>(E)); 1332 case Expr::CXXTemporaryObjectExprClass: 1333 case Expr::CXXConstructExprClass: 1334 return EmitCXXConstructLValue(cast<CXXConstructExpr>(E)); 1335 case Expr::CXXBindTemporaryExprClass: 1336 return EmitCXXBindTemporaryLValue(cast<CXXBindTemporaryExpr>(E)); 1337 case Expr::CXXUuidofExprClass: 1338 return EmitCXXUuidofLValue(cast<CXXUuidofExpr>(E)); 1339 case Expr::LambdaExprClass: 1340 return EmitAggExprToLValue(E); 1341 1342 case Expr::ExprWithCleanupsClass: { 1343 const auto *cleanups = cast<ExprWithCleanups>(E); 1344 RunCleanupsScope Scope(*this); 1345 LValue LV = EmitLValue(cleanups->getSubExpr()); 1346 if (LV.isSimple()) { 1347 // Defend against branches out of gnu statement expressions surrounded by 1348 // cleanups. 1349 Address Addr = LV.getAddress(*this); 1350 llvm::Value *V = Addr.getPointer(); 1351 Scope.ForceCleanup({&V}); 1352 return LValue::MakeAddr(Addr.withPointer(V), LV.getType(), getContext(), 1353 LV.getBaseInfo(), LV.getTBAAInfo()); 1354 } 1355 // FIXME: Is it possible to create an ExprWithCleanups that produces a 1356 // bitfield lvalue or some other non-simple lvalue? 1357 return LV; 1358 } 1359 1360 case Expr::CXXDefaultArgExprClass: { 1361 auto *DAE = cast<CXXDefaultArgExpr>(E); 1362 CXXDefaultArgExprScope Scope(*this, DAE); 1363 return EmitLValue(DAE->getExpr()); 1364 } 1365 case Expr::CXXDefaultInitExprClass: { 1366 auto *DIE = cast<CXXDefaultInitExpr>(E); 1367 CXXDefaultInitExprScope Scope(*this, DIE); 1368 return EmitLValue(DIE->getExpr()); 1369 } 1370 case Expr::CXXTypeidExprClass: 1371 return EmitCXXTypeidLValue(cast<CXXTypeidExpr>(E)); 1372 1373 case Expr::ObjCMessageExprClass: 1374 return EmitObjCMessageExprLValue(cast<ObjCMessageExpr>(E)); 1375 case Expr::ObjCIvarRefExprClass: 1376 return EmitObjCIvarRefLValue(cast<ObjCIvarRefExpr>(E)); 1377 case Expr::StmtExprClass: 1378 return EmitStmtExprLValue(cast<StmtExpr>(E)); 1379 case Expr::UnaryOperatorClass: 1380 return EmitUnaryOpLValue(cast<UnaryOperator>(E)); 1381 case Expr::ArraySubscriptExprClass: 1382 return EmitArraySubscriptExpr(cast<ArraySubscriptExpr>(E)); 1383 case Expr::MatrixSubscriptExprClass: 1384 return EmitMatrixSubscriptExpr(cast<MatrixSubscriptExpr>(E)); 1385 case Expr::OMPArraySectionExprClass: 1386 return EmitOMPArraySectionExpr(cast<OMPArraySectionExpr>(E)); 1387 case Expr::ExtVectorElementExprClass: 1388 return EmitExtVectorElementExpr(cast<ExtVectorElementExpr>(E)); 1389 case Expr::MemberExprClass: 1390 return EmitMemberExpr(cast<MemberExpr>(E)); 1391 case Expr::CompoundLiteralExprClass: 1392 return EmitCompoundLiteralLValue(cast<CompoundLiteralExpr>(E)); 1393 case Expr::ConditionalOperatorClass: 1394 return EmitConditionalOperatorLValue(cast<ConditionalOperator>(E)); 1395 case Expr::BinaryConditionalOperatorClass: 1396 return EmitConditionalOperatorLValue(cast<BinaryConditionalOperator>(E)); 1397 case Expr::ChooseExprClass: 1398 return EmitLValue(cast<ChooseExpr>(E)->getChosenSubExpr()); 1399 case Expr::OpaqueValueExprClass: 1400 return EmitOpaqueValueLValue(cast<OpaqueValueExpr>(E)); 1401 case Expr::SubstNonTypeTemplateParmExprClass: 1402 return EmitLValue(cast<SubstNonTypeTemplateParmExpr>(E)->getReplacement()); 1403 case Expr::ImplicitCastExprClass: 1404 case Expr::CStyleCastExprClass: 1405 case Expr::CXXFunctionalCastExprClass: 1406 case Expr::CXXStaticCastExprClass: 1407 case Expr::CXXDynamicCastExprClass: 1408 case Expr::CXXReinterpretCastExprClass: 1409 case Expr::CXXConstCastExprClass: 1410 case Expr::CXXAddrspaceCastExprClass: 1411 case Expr::ObjCBridgedCastExprClass: 1412 return EmitCastLValue(cast<CastExpr>(E)); 1413 1414 case Expr::MaterializeTemporaryExprClass: 1415 return EmitMaterializeTemporaryExpr(cast<MaterializeTemporaryExpr>(E)); 1416 1417 case Expr::CoawaitExprClass: 1418 return EmitCoawaitLValue(cast<CoawaitExpr>(E)); 1419 case Expr::CoyieldExprClass: 1420 return EmitCoyieldLValue(cast<CoyieldExpr>(E)); 1421 } 1422 } 1423 1424 /// Given an object of the given canonical type, can we safely copy a 1425 /// value out of it based on its initializer? 1426 static bool isConstantEmittableObjectType(QualType type) { 1427 assert(type.isCanonical()); 1428 assert(!type->isReferenceType()); 1429 1430 // Must be const-qualified but non-volatile. 1431 Qualifiers qs = type.getLocalQualifiers(); 1432 if (!qs.hasConst() || qs.hasVolatile()) return false; 1433 1434 // Otherwise, all object types satisfy this except C++ classes with 1435 // mutable subobjects or non-trivial copy/destroy behavior. 1436 if (const auto *RT = dyn_cast<RecordType>(type)) 1437 if (const auto *RD = dyn_cast<CXXRecordDecl>(RT->getDecl())) 1438 if (RD->hasMutableFields() || !RD->isTrivial()) 1439 return false; 1440 1441 return true; 1442 } 1443 1444 /// Can we constant-emit a load of a reference to a variable of the 1445 /// given type? This is different from predicates like 1446 /// Decl::mightBeUsableInConstantExpressions because we do want it to apply 1447 /// in situations that don't necessarily satisfy the language's rules 1448 /// for this (e.g. C++'s ODR-use rules). For example, we want to able 1449 /// to do this with const float variables even if those variables 1450 /// aren't marked 'constexpr'. 1451 enum ConstantEmissionKind { 1452 CEK_None, 1453 CEK_AsReferenceOnly, 1454 CEK_AsValueOrReference, 1455 CEK_AsValueOnly 1456 }; 1457 static ConstantEmissionKind checkVarTypeForConstantEmission(QualType type) { 1458 type = type.getCanonicalType(); 1459 if (const auto *ref = dyn_cast<ReferenceType>(type)) { 1460 if (isConstantEmittableObjectType(ref->getPointeeType())) 1461 return CEK_AsValueOrReference; 1462 return CEK_AsReferenceOnly; 1463 } 1464 if (isConstantEmittableObjectType(type)) 1465 return CEK_AsValueOnly; 1466 return CEK_None; 1467 } 1468 1469 /// Try to emit a reference to the given value without producing it as 1470 /// an l-value. This is just an optimization, but it avoids us needing 1471 /// to emit global copies of variables if they're named without triggering 1472 /// a formal use in a context where we can't emit a direct reference to them, 1473 /// for instance if a block or lambda or a member of a local class uses a 1474 /// const int variable or constexpr variable from an enclosing function. 1475 CodeGenFunction::ConstantEmission 1476 CodeGenFunction::tryEmitAsConstant(DeclRefExpr *refExpr) { 1477 ValueDecl *value = refExpr->getDecl(); 1478 1479 // The value needs to be an enum constant or a constant variable. 1480 ConstantEmissionKind CEK; 1481 if (isa<ParmVarDecl>(value)) { 1482 CEK = CEK_None; 1483 } else if (auto *var = dyn_cast<VarDecl>(value)) { 1484 CEK = checkVarTypeForConstantEmission(var->getType()); 1485 } else if (isa<EnumConstantDecl>(value)) { 1486 CEK = CEK_AsValueOnly; 1487 } else { 1488 CEK = CEK_None; 1489 } 1490 if (CEK == CEK_None) return ConstantEmission(); 1491 1492 Expr::EvalResult result; 1493 bool resultIsReference; 1494 QualType resultType; 1495 1496 // It's best to evaluate all the way as an r-value if that's permitted. 1497 if (CEK != CEK_AsReferenceOnly && 1498 refExpr->EvaluateAsRValue(result, getContext())) { 1499 resultIsReference = false; 1500 resultType = refExpr->getType(); 1501 1502 // Otherwise, try to evaluate as an l-value. 1503 } else if (CEK != CEK_AsValueOnly && 1504 refExpr->EvaluateAsLValue(result, getContext())) { 1505 resultIsReference = true; 1506 resultType = value->getType(); 1507 1508 // Failure. 1509 } else { 1510 return ConstantEmission(); 1511 } 1512 1513 // In any case, if the initializer has side-effects, abandon ship. 1514 if (result.HasSideEffects) 1515 return ConstantEmission(); 1516 1517 // In CUDA/HIP device compilation, a lambda may capture a reference variable 1518 // referencing a global host variable by copy. In this case the lambda should 1519 // make a copy of the value of the global host variable. The DRE of the 1520 // captured reference variable cannot be emitted as load from the host 1521 // global variable as compile time constant, since the host variable is not 1522 // accessible on device. The DRE of the captured reference variable has to be 1523 // loaded from captures. 1524 if (CGM.getLangOpts().CUDAIsDevice && result.Val.isLValue() && 1525 refExpr->refersToEnclosingVariableOrCapture()) { 1526 auto *MD = dyn_cast_or_null<CXXMethodDecl>(CurCodeDecl); 1527 if (MD && MD->getParent()->isLambda() && 1528 MD->getOverloadedOperator() == OO_Call) { 1529 const APValue::LValueBase &base = result.Val.getLValueBase(); 1530 if (const ValueDecl *D = base.dyn_cast<const ValueDecl *>()) { 1531 if (const VarDecl *VD = dyn_cast<const VarDecl>(D)) { 1532 if (!VD->hasAttr<CUDADeviceAttr>()) { 1533 return ConstantEmission(); 1534 } 1535 } 1536 } 1537 } 1538 } 1539 1540 // Emit as a constant. 1541 auto C = ConstantEmitter(*this).emitAbstract(refExpr->getLocation(), 1542 result.Val, resultType); 1543 1544 // Make sure we emit a debug reference to the global variable. 1545 // This should probably fire even for 1546 if (isa<VarDecl>(value)) { 1547 if (!getContext().DeclMustBeEmitted(cast<VarDecl>(value))) 1548 EmitDeclRefExprDbgValue(refExpr, result.Val); 1549 } else { 1550 assert(isa<EnumConstantDecl>(value)); 1551 EmitDeclRefExprDbgValue(refExpr, result.Val); 1552 } 1553 1554 // If we emitted a reference constant, we need to dereference that. 1555 if (resultIsReference) 1556 return ConstantEmission::forReference(C); 1557 1558 return ConstantEmission::forValue(C); 1559 } 1560 1561 static DeclRefExpr *tryToConvertMemberExprToDeclRefExpr(CodeGenFunction &CGF, 1562 const MemberExpr *ME) { 1563 if (auto *VD = dyn_cast<VarDecl>(ME->getMemberDecl())) { 1564 // Try to emit static variable member expressions as DREs. 1565 return DeclRefExpr::Create( 1566 CGF.getContext(), NestedNameSpecifierLoc(), SourceLocation(), VD, 1567 /*RefersToEnclosingVariableOrCapture=*/false, ME->getExprLoc(), 1568 ME->getType(), ME->getValueKind(), nullptr, nullptr, ME->isNonOdrUse()); 1569 } 1570 return nullptr; 1571 } 1572 1573 CodeGenFunction::ConstantEmission 1574 CodeGenFunction::tryEmitAsConstant(const MemberExpr *ME) { 1575 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, ME)) 1576 return tryEmitAsConstant(DRE); 1577 return ConstantEmission(); 1578 } 1579 1580 llvm::Value *CodeGenFunction::emitScalarConstant( 1581 const CodeGenFunction::ConstantEmission &Constant, Expr *E) { 1582 assert(Constant && "not a constant"); 1583 if (Constant.isReference()) 1584 return EmitLoadOfLValue(Constant.getReferenceLValue(*this, E), 1585 E->getExprLoc()) 1586 .getScalarVal(); 1587 return Constant.getValue(); 1588 } 1589 1590 llvm::Value *CodeGenFunction::EmitLoadOfScalar(LValue lvalue, 1591 SourceLocation Loc) { 1592 return EmitLoadOfScalar(lvalue.getAddress(*this), lvalue.isVolatile(), 1593 lvalue.getType(), Loc, lvalue.getBaseInfo(), 1594 lvalue.getTBAAInfo(), lvalue.isNontemporal()); 1595 } 1596 1597 static bool hasBooleanRepresentation(QualType Ty) { 1598 if (Ty->isBooleanType()) 1599 return true; 1600 1601 if (const EnumType *ET = Ty->getAs<EnumType>()) 1602 return ET->getDecl()->getIntegerType()->isBooleanType(); 1603 1604 if (const AtomicType *AT = Ty->getAs<AtomicType>()) 1605 return hasBooleanRepresentation(AT->getValueType()); 1606 1607 return false; 1608 } 1609 1610 static bool getRangeForType(CodeGenFunction &CGF, QualType Ty, 1611 llvm::APInt &Min, llvm::APInt &End, 1612 bool StrictEnums, bool IsBool) { 1613 const EnumType *ET = Ty->getAs<EnumType>(); 1614 bool IsRegularCPlusPlusEnum = CGF.getLangOpts().CPlusPlus && StrictEnums && 1615 ET && !ET->getDecl()->isFixed(); 1616 if (!IsBool && !IsRegularCPlusPlusEnum) 1617 return false; 1618 1619 if (IsBool) { 1620 Min = llvm::APInt(CGF.getContext().getTypeSize(Ty), 0); 1621 End = llvm::APInt(CGF.getContext().getTypeSize(Ty), 2); 1622 } else { 1623 const EnumDecl *ED = ET->getDecl(); 1624 llvm::Type *LTy = CGF.ConvertTypeForMem(ED->getIntegerType()); 1625 unsigned Bitwidth = LTy->getScalarSizeInBits(); 1626 unsigned NumNegativeBits = ED->getNumNegativeBits(); 1627 unsigned NumPositiveBits = ED->getNumPositiveBits(); 1628 1629 if (NumNegativeBits) { 1630 unsigned NumBits = std::max(NumNegativeBits, NumPositiveBits + 1); 1631 assert(NumBits <= Bitwidth); 1632 End = llvm::APInt(Bitwidth, 1) << (NumBits - 1); 1633 Min = -End; 1634 } else { 1635 assert(NumPositiveBits <= Bitwidth); 1636 End = llvm::APInt(Bitwidth, 1) << NumPositiveBits; 1637 Min = llvm::APInt::getZero(Bitwidth); 1638 } 1639 } 1640 return true; 1641 } 1642 1643 llvm::MDNode *CodeGenFunction::getRangeForLoadFromType(QualType Ty) { 1644 llvm::APInt Min, End; 1645 if (!getRangeForType(*this, Ty, Min, End, CGM.getCodeGenOpts().StrictEnums, 1646 hasBooleanRepresentation(Ty))) 1647 return nullptr; 1648 1649 llvm::MDBuilder MDHelper(getLLVMContext()); 1650 return MDHelper.createRange(Min, End); 1651 } 1652 1653 bool CodeGenFunction::EmitScalarRangeCheck(llvm::Value *Value, QualType Ty, 1654 SourceLocation Loc) { 1655 bool HasBoolCheck = SanOpts.has(SanitizerKind::Bool); 1656 bool HasEnumCheck = SanOpts.has(SanitizerKind::Enum); 1657 if (!HasBoolCheck && !HasEnumCheck) 1658 return false; 1659 1660 bool IsBool = hasBooleanRepresentation(Ty) || 1661 NSAPI(CGM.getContext()).isObjCBOOLType(Ty); 1662 bool NeedsBoolCheck = HasBoolCheck && IsBool; 1663 bool NeedsEnumCheck = HasEnumCheck && Ty->getAs<EnumType>(); 1664 if (!NeedsBoolCheck && !NeedsEnumCheck) 1665 return false; 1666 1667 // Single-bit booleans don't need to be checked. Special-case this to avoid 1668 // a bit width mismatch when handling bitfield values. This is handled by 1669 // EmitFromMemory for the non-bitfield case. 1670 if (IsBool && 1671 cast<llvm::IntegerType>(Value->getType())->getBitWidth() == 1) 1672 return false; 1673 1674 llvm::APInt Min, End; 1675 if (!getRangeForType(*this, Ty, Min, End, /*StrictEnums=*/true, IsBool)) 1676 return true; 1677 1678 auto &Ctx = getLLVMContext(); 1679 SanitizerScope SanScope(this); 1680 llvm::Value *Check; 1681 --End; 1682 if (!Min) { 1683 Check = Builder.CreateICmpULE(Value, llvm::ConstantInt::get(Ctx, End)); 1684 } else { 1685 llvm::Value *Upper = 1686 Builder.CreateICmpSLE(Value, llvm::ConstantInt::get(Ctx, End)); 1687 llvm::Value *Lower = 1688 Builder.CreateICmpSGE(Value, llvm::ConstantInt::get(Ctx, Min)); 1689 Check = Builder.CreateAnd(Upper, Lower); 1690 } 1691 llvm::Constant *StaticArgs[] = {EmitCheckSourceLocation(Loc), 1692 EmitCheckTypeDescriptor(Ty)}; 1693 SanitizerMask Kind = 1694 NeedsEnumCheck ? SanitizerKind::Enum : SanitizerKind::Bool; 1695 EmitCheck(std::make_pair(Check, Kind), SanitizerHandler::LoadInvalidValue, 1696 StaticArgs, EmitCheckValue(Value)); 1697 return true; 1698 } 1699 1700 llvm::Value *CodeGenFunction::EmitLoadOfScalar(Address Addr, bool Volatile, 1701 QualType Ty, 1702 SourceLocation Loc, 1703 LValueBaseInfo BaseInfo, 1704 TBAAAccessInfo TBAAInfo, 1705 bool isNontemporal) { 1706 if (!CGM.getCodeGenOpts().PreserveVec3Type) { 1707 // For better performance, handle vector loads differently. 1708 if (Ty->isVectorType()) { 1709 const llvm::Type *EltTy = Addr.getElementType(); 1710 1711 const auto *VTy = cast<llvm::FixedVectorType>(EltTy); 1712 1713 // Handle vectors of size 3 like size 4 for better performance. 1714 if (VTy->getNumElements() == 3) { 1715 1716 // Bitcast to vec4 type. 1717 auto *vec4Ty = llvm::FixedVectorType::get(VTy->getElementType(), 4); 1718 Address Cast = Builder.CreateElementBitCast(Addr, vec4Ty, "castToVec4"); 1719 // Now load value. 1720 llvm::Value *V = Builder.CreateLoad(Cast, Volatile, "loadVec4"); 1721 1722 // Shuffle vector to get vec3. 1723 V = Builder.CreateShuffleVector(V, ArrayRef<int>{0, 1, 2}, 1724 "extractVec"); 1725 return EmitFromMemory(V, Ty); 1726 } 1727 } 1728 } 1729 1730 // Atomic operations have to be done on integral types. 1731 LValue AtomicLValue = 1732 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo); 1733 if (Ty->isAtomicType() || LValueIsSuitableForInlineAtomic(AtomicLValue)) { 1734 return EmitAtomicLoad(AtomicLValue, Loc).getScalarVal(); 1735 } 1736 1737 llvm::LoadInst *Load = Builder.CreateLoad(Addr, Volatile); 1738 if (isNontemporal) { 1739 llvm::MDNode *Node = llvm::MDNode::get( 1740 Load->getContext(), llvm::ConstantAsMetadata::get(Builder.getInt32(1))); 1741 Load->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node); 1742 } 1743 1744 CGM.DecorateInstructionWithTBAA(Load, TBAAInfo); 1745 1746 if (EmitScalarRangeCheck(Load, Ty, Loc)) { 1747 // In order to prevent the optimizer from throwing away the check, don't 1748 // attach range metadata to the load. 1749 } else if (CGM.getCodeGenOpts().OptimizationLevel > 0) 1750 if (llvm::MDNode *RangeInfo = getRangeForLoadFromType(Ty)) 1751 Load->setMetadata(llvm::LLVMContext::MD_range, RangeInfo); 1752 1753 return EmitFromMemory(Load, Ty); 1754 } 1755 1756 llvm::Value *CodeGenFunction::EmitToMemory(llvm::Value *Value, QualType Ty) { 1757 // Bool has a different representation in memory than in registers. 1758 if (hasBooleanRepresentation(Ty)) { 1759 // This should really always be an i1, but sometimes it's already 1760 // an i8, and it's awkward to track those cases down. 1761 if (Value->getType()->isIntegerTy(1)) 1762 return Builder.CreateZExt(Value, ConvertTypeForMem(Ty), "frombool"); 1763 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) && 1764 "wrong value rep of bool"); 1765 } 1766 1767 return Value; 1768 } 1769 1770 llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) { 1771 // Bool has a different representation in memory than in registers. 1772 if (hasBooleanRepresentation(Ty)) { 1773 assert(Value->getType()->isIntegerTy(getContext().getTypeSize(Ty)) && 1774 "wrong value rep of bool"); 1775 return Builder.CreateTrunc(Value, Builder.getInt1Ty(), "tobool"); 1776 } 1777 1778 return Value; 1779 } 1780 1781 // Convert the pointer of \p Addr to a pointer to a vector (the value type of 1782 // MatrixType), if it points to a array (the memory type of MatrixType). 1783 static Address MaybeConvertMatrixAddress(Address Addr, CodeGenFunction &CGF, 1784 bool IsVector = true) { 1785 auto *ArrayTy = dyn_cast<llvm::ArrayType>(Addr.getElementType()); 1786 if (ArrayTy && IsVector) { 1787 auto *VectorTy = llvm::FixedVectorType::get(ArrayTy->getElementType(), 1788 ArrayTy->getNumElements()); 1789 1790 return Address(CGF.Builder.CreateElementBitCast(Addr, VectorTy)); 1791 } 1792 auto *VectorTy = dyn_cast<llvm::VectorType>(Addr.getElementType()); 1793 if (VectorTy && !IsVector) { 1794 auto *ArrayTy = llvm::ArrayType::get( 1795 VectorTy->getElementType(), 1796 cast<llvm::FixedVectorType>(VectorTy)->getNumElements()); 1797 1798 return Address(CGF.Builder.CreateElementBitCast(Addr, ArrayTy)); 1799 } 1800 1801 return Addr; 1802 } 1803 1804 // Emit a store of a matrix LValue. This may require casting the original 1805 // pointer to memory address (ArrayType) to a pointer to the value type 1806 // (VectorType). 1807 static void EmitStoreOfMatrixScalar(llvm::Value *value, LValue lvalue, 1808 bool isInit, CodeGenFunction &CGF) { 1809 Address Addr = MaybeConvertMatrixAddress(lvalue.getAddress(CGF), CGF, 1810 value->getType()->isVectorTy()); 1811 CGF.EmitStoreOfScalar(value, Addr, lvalue.isVolatile(), lvalue.getType(), 1812 lvalue.getBaseInfo(), lvalue.getTBAAInfo(), isInit, 1813 lvalue.isNontemporal()); 1814 } 1815 1816 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, Address Addr, 1817 bool Volatile, QualType Ty, 1818 LValueBaseInfo BaseInfo, 1819 TBAAAccessInfo TBAAInfo, 1820 bool isInit, bool isNontemporal) { 1821 if (!CGM.getCodeGenOpts().PreserveVec3Type) { 1822 // Handle vectors differently to get better performance. 1823 if (Ty->isVectorType()) { 1824 llvm::Type *SrcTy = Value->getType(); 1825 auto *VecTy = dyn_cast<llvm::VectorType>(SrcTy); 1826 // Handle vec3 special. 1827 if (VecTy && cast<llvm::FixedVectorType>(VecTy)->getNumElements() == 3) { 1828 // Our source is a vec3, do a shuffle vector to make it a vec4. 1829 Value = Builder.CreateShuffleVector(Value, ArrayRef<int>{0, 1, 2, -1}, 1830 "extractVec"); 1831 SrcTy = llvm::FixedVectorType::get(VecTy->getElementType(), 4); 1832 } 1833 if (Addr.getElementType() != SrcTy) { 1834 Addr = Builder.CreateElementBitCast(Addr, SrcTy, "storetmp"); 1835 } 1836 } 1837 } 1838 1839 Value = EmitToMemory(Value, Ty); 1840 1841 LValue AtomicLValue = 1842 LValue::MakeAddr(Addr, Ty, getContext(), BaseInfo, TBAAInfo); 1843 if (Ty->isAtomicType() || 1844 (!isInit && LValueIsSuitableForInlineAtomic(AtomicLValue))) { 1845 EmitAtomicStore(RValue::get(Value), AtomicLValue, isInit); 1846 return; 1847 } 1848 1849 llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile); 1850 if (isNontemporal) { 1851 llvm::MDNode *Node = 1852 llvm::MDNode::get(Store->getContext(), 1853 llvm::ConstantAsMetadata::get(Builder.getInt32(1))); 1854 Store->setMetadata(CGM.getModule().getMDKindID("nontemporal"), Node); 1855 } 1856 1857 CGM.DecorateInstructionWithTBAA(Store, TBAAInfo); 1858 } 1859 1860 void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue, 1861 bool isInit) { 1862 if (lvalue.getType()->isConstantMatrixType()) { 1863 EmitStoreOfMatrixScalar(value, lvalue, isInit, *this); 1864 return; 1865 } 1866 1867 EmitStoreOfScalar(value, lvalue.getAddress(*this), lvalue.isVolatile(), 1868 lvalue.getType(), lvalue.getBaseInfo(), 1869 lvalue.getTBAAInfo(), isInit, lvalue.isNontemporal()); 1870 } 1871 1872 // Emit a load of a LValue of matrix type. This may require casting the pointer 1873 // to memory address (ArrayType) to a pointer to the value type (VectorType). 1874 static RValue EmitLoadOfMatrixLValue(LValue LV, SourceLocation Loc, 1875 CodeGenFunction &CGF) { 1876 assert(LV.getType()->isConstantMatrixType()); 1877 Address Addr = MaybeConvertMatrixAddress(LV.getAddress(CGF), CGF); 1878 LV.setAddress(Addr); 1879 return RValue::get(CGF.EmitLoadOfScalar(LV, Loc)); 1880 } 1881 1882 /// EmitLoadOfLValue - Given an expression that represents a value lvalue, this 1883 /// method emits the address of the lvalue, then loads the result as an rvalue, 1884 /// returning the rvalue. 1885 RValue CodeGenFunction::EmitLoadOfLValue(LValue LV, SourceLocation Loc) { 1886 if (LV.isObjCWeak()) { 1887 // load of a __weak object. 1888 Address AddrWeakObj = LV.getAddress(*this); 1889 return RValue::get(CGM.getObjCRuntime().EmitObjCWeakRead(*this, 1890 AddrWeakObj)); 1891 } 1892 if (LV.getQuals().getObjCLifetime() == Qualifiers::OCL_Weak) { 1893 // In MRC mode, we do a load+autorelease. 1894 if (!getLangOpts().ObjCAutoRefCount) { 1895 return RValue::get(EmitARCLoadWeak(LV.getAddress(*this))); 1896 } 1897 1898 // In ARC mode, we load retained and then consume the value. 1899 llvm::Value *Object = EmitARCLoadWeakRetained(LV.getAddress(*this)); 1900 Object = EmitObjCConsumeObject(LV.getType(), Object); 1901 return RValue::get(Object); 1902 } 1903 1904 if (LV.isSimple()) { 1905 assert(!LV.getType()->isFunctionType()); 1906 1907 if (LV.getType()->isConstantMatrixType()) 1908 return EmitLoadOfMatrixLValue(LV, Loc, *this); 1909 1910 // Everything needs a load. 1911 return RValue::get(EmitLoadOfScalar(LV, Loc)); 1912 } 1913 1914 if (LV.isVectorElt()) { 1915 llvm::LoadInst *Load = Builder.CreateLoad(LV.getVectorAddress(), 1916 LV.isVolatileQualified()); 1917 return RValue::get(Builder.CreateExtractElement(Load, LV.getVectorIdx(), 1918 "vecext")); 1919 } 1920 1921 // If this is a reference to a subset of the elements of a vector, either 1922 // shuffle the input or extract/insert them as appropriate. 1923 if (LV.isExtVectorElt()) { 1924 return EmitLoadOfExtVectorElementLValue(LV); 1925 } 1926 1927 // Global Register variables always invoke intrinsics 1928 if (LV.isGlobalReg()) 1929 return EmitLoadOfGlobalRegLValue(LV); 1930 1931 if (LV.isMatrixElt()) { 1932 llvm::Value *Idx = LV.getMatrixIdx(); 1933 if (CGM.getCodeGenOpts().OptimizationLevel > 0) { 1934 const auto *const MatTy = LV.getType()->castAs<ConstantMatrixType>(); 1935 llvm::MatrixBuilder<CGBuilderTy> MB(Builder); 1936 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened()); 1937 } 1938 llvm::LoadInst *Load = 1939 Builder.CreateLoad(LV.getMatrixAddress(), LV.isVolatileQualified()); 1940 return RValue::get(Builder.CreateExtractElement(Load, Idx, "matrixext")); 1941 } 1942 1943 assert(LV.isBitField() && "Unknown LValue type!"); 1944 return EmitLoadOfBitfieldLValue(LV, Loc); 1945 } 1946 1947 RValue CodeGenFunction::EmitLoadOfBitfieldLValue(LValue LV, 1948 SourceLocation Loc) { 1949 const CGBitFieldInfo &Info = LV.getBitFieldInfo(); 1950 1951 // Get the output type. 1952 llvm::Type *ResLTy = ConvertType(LV.getType()); 1953 1954 Address Ptr = LV.getBitFieldAddress(); 1955 llvm::Value *Val = 1956 Builder.CreateLoad(Ptr, LV.isVolatileQualified(), "bf.load"); 1957 1958 bool UseVolatile = LV.isVolatileQualified() && 1959 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget()); 1960 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset; 1961 const unsigned StorageSize = 1962 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize; 1963 if (Info.IsSigned) { 1964 assert(static_cast<unsigned>(Offset + Info.Size) <= StorageSize); 1965 unsigned HighBits = StorageSize - Offset - Info.Size; 1966 if (HighBits) 1967 Val = Builder.CreateShl(Val, HighBits, "bf.shl"); 1968 if (Offset + HighBits) 1969 Val = Builder.CreateAShr(Val, Offset + HighBits, "bf.ashr"); 1970 } else { 1971 if (Offset) 1972 Val = Builder.CreateLShr(Val, Offset, "bf.lshr"); 1973 if (static_cast<unsigned>(Offset) + Info.Size < StorageSize) 1974 Val = Builder.CreateAnd( 1975 Val, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), "bf.clear"); 1976 } 1977 Val = Builder.CreateIntCast(Val, ResLTy, Info.IsSigned, "bf.cast"); 1978 EmitScalarRangeCheck(Val, LV.getType(), Loc); 1979 return RValue::get(Val); 1980 } 1981 1982 // If this is a reference to a subset of the elements of a vector, create an 1983 // appropriate shufflevector. 1984 RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) { 1985 llvm::Value *Vec = Builder.CreateLoad(LV.getExtVectorAddress(), 1986 LV.isVolatileQualified()); 1987 1988 const llvm::Constant *Elts = LV.getExtVectorElts(); 1989 1990 // If the result of the expression is a non-vector type, we must be extracting 1991 // a single element. Just codegen as an extractelement. 1992 const VectorType *ExprVT = LV.getType()->getAs<VectorType>(); 1993 if (!ExprVT) { 1994 unsigned InIdx = getAccessedFieldNo(0, Elts); 1995 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx); 1996 return RValue::get(Builder.CreateExtractElement(Vec, Elt)); 1997 } 1998 1999 // Always use shuffle vector to try to retain the original program structure 2000 unsigned NumResultElts = ExprVT->getNumElements(); 2001 2002 SmallVector<int, 4> Mask; 2003 for (unsigned i = 0; i != NumResultElts; ++i) 2004 Mask.push_back(getAccessedFieldNo(i, Elts)); 2005 2006 Vec = Builder.CreateShuffleVector(Vec, Mask); 2007 return RValue::get(Vec); 2008 } 2009 2010 /// Generates lvalue for partial ext_vector access. 2011 Address CodeGenFunction::EmitExtVectorElementLValue(LValue LV) { 2012 Address VectorAddress = LV.getExtVectorAddress(); 2013 QualType EQT = LV.getType()->castAs<VectorType>()->getElementType(); 2014 llvm::Type *VectorElementTy = CGM.getTypes().ConvertType(EQT); 2015 2016 Address CastToPointerElement = 2017 Builder.CreateElementBitCast(VectorAddress, VectorElementTy, 2018 "conv.ptr.element"); 2019 2020 const llvm::Constant *Elts = LV.getExtVectorElts(); 2021 unsigned ix = getAccessedFieldNo(0, Elts); 2022 2023 Address VectorBasePtrPlusIx = 2024 Builder.CreateConstInBoundsGEP(CastToPointerElement, ix, 2025 "vector.elt"); 2026 2027 return VectorBasePtrPlusIx; 2028 } 2029 2030 /// Load of global gamed gegisters are always calls to intrinsics. 2031 RValue CodeGenFunction::EmitLoadOfGlobalRegLValue(LValue LV) { 2032 assert((LV.getType()->isIntegerType() || LV.getType()->isPointerType()) && 2033 "Bad type for register variable"); 2034 llvm::MDNode *RegName = cast<llvm::MDNode>( 2035 cast<llvm::MetadataAsValue>(LV.getGlobalReg())->getMetadata()); 2036 2037 // We accept integer and pointer types only 2038 llvm::Type *OrigTy = CGM.getTypes().ConvertType(LV.getType()); 2039 llvm::Type *Ty = OrigTy; 2040 if (OrigTy->isPointerTy()) 2041 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy); 2042 llvm::Type *Types[] = { Ty }; 2043 2044 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::read_register, Types); 2045 llvm::Value *Call = Builder.CreateCall( 2046 F, llvm::MetadataAsValue::get(Ty->getContext(), RegName)); 2047 if (OrigTy->isPointerTy()) 2048 Call = Builder.CreateIntToPtr(Call, OrigTy); 2049 return RValue::get(Call); 2050 } 2051 2052 /// EmitStoreThroughLValue - Store the specified rvalue into the specified 2053 /// lvalue, where both are guaranteed to the have the same type, and that type 2054 /// is 'Ty'. 2055 void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst, 2056 bool isInit) { 2057 if (!Dst.isSimple()) { 2058 if (Dst.isVectorElt()) { 2059 // Read/modify/write the vector, inserting the new element. 2060 llvm::Value *Vec = Builder.CreateLoad(Dst.getVectorAddress(), 2061 Dst.isVolatileQualified()); 2062 Vec = Builder.CreateInsertElement(Vec, Src.getScalarVal(), 2063 Dst.getVectorIdx(), "vecins"); 2064 Builder.CreateStore(Vec, Dst.getVectorAddress(), 2065 Dst.isVolatileQualified()); 2066 return; 2067 } 2068 2069 // If this is an update of extended vector elements, insert them as 2070 // appropriate. 2071 if (Dst.isExtVectorElt()) 2072 return EmitStoreThroughExtVectorComponentLValue(Src, Dst); 2073 2074 if (Dst.isGlobalReg()) 2075 return EmitStoreThroughGlobalRegLValue(Src, Dst); 2076 2077 if (Dst.isMatrixElt()) { 2078 llvm::Value *Idx = Dst.getMatrixIdx(); 2079 if (CGM.getCodeGenOpts().OptimizationLevel > 0) { 2080 const auto *const MatTy = Dst.getType()->castAs<ConstantMatrixType>(); 2081 llvm::MatrixBuilder<CGBuilderTy> MB(Builder); 2082 MB.CreateIndexAssumption(Idx, MatTy->getNumElementsFlattened()); 2083 } 2084 llvm::Instruction *Load = Builder.CreateLoad(Dst.getMatrixAddress()); 2085 llvm::Value *Vec = 2086 Builder.CreateInsertElement(Load, Src.getScalarVal(), Idx, "matins"); 2087 Builder.CreateStore(Vec, Dst.getMatrixAddress(), 2088 Dst.isVolatileQualified()); 2089 return; 2090 } 2091 2092 assert(Dst.isBitField() && "Unknown LValue type"); 2093 return EmitStoreThroughBitfieldLValue(Src, Dst); 2094 } 2095 2096 // There's special magic for assigning into an ARC-qualified l-value. 2097 if (Qualifiers::ObjCLifetime Lifetime = Dst.getQuals().getObjCLifetime()) { 2098 switch (Lifetime) { 2099 case Qualifiers::OCL_None: 2100 llvm_unreachable("present but none"); 2101 2102 case Qualifiers::OCL_ExplicitNone: 2103 // nothing special 2104 break; 2105 2106 case Qualifiers::OCL_Strong: 2107 if (isInit) { 2108 Src = RValue::get(EmitARCRetain(Dst.getType(), Src.getScalarVal())); 2109 break; 2110 } 2111 EmitARCStoreStrong(Dst, Src.getScalarVal(), /*ignore*/ true); 2112 return; 2113 2114 case Qualifiers::OCL_Weak: 2115 if (isInit) 2116 // Initialize and then skip the primitive store. 2117 EmitARCInitWeak(Dst.getAddress(*this), Src.getScalarVal()); 2118 else 2119 EmitARCStoreWeak(Dst.getAddress(*this), Src.getScalarVal(), 2120 /*ignore*/ true); 2121 return; 2122 2123 case Qualifiers::OCL_Autoreleasing: 2124 Src = RValue::get(EmitObjCExtendObjectLifetime(Dst.getType(), 2125 Src.getScalarVal())); 2126 // fall into the normal path 2127 break; 2128 } 2129 } 2130 2131 if (Dst.isObjCWeak() && !Dst.isNonGC()) { 2132 // load of a __weak object. 2133 Address LvalueDst = Dst.getAddress(*this); 2134 llvm::Value *src = Src.getScalarVal(); 2135 CGM.getObjCRuntime().EmitObjCWeakAssign(*this, src, LvalueDst); 2136 return; 2137 } 2138 2139 if (Dst.isObjCStrong() && !Dst.isNonGC()) { 2140 // load of a __strong object. 2141 Address LvalueDst = Dst.getAddress(*this); 2142 llvm::Value *src = Src.getScalarVal(); 2143 if (Dst.isObjCIvar()) { 2144 assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL"); 2145 llvm::Type *ResultType = IntPtrTy; 2146 Address dst = EmitPointerWithAlignment(Dst.getBaseIvarExp()); 2147 llvm::Value *RHS = dst.getPointer(); 2148 RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast"); 2149 llvm::Value *LHS = 2150 Builder.CreatePtrToInt(LvalueDst.getPointer(), ResultType, 2151 "sub.ptr.lhs.cast"); 2152 llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset"); 2153 CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, dst, 2154 BytesBetween); 2155 } else if (Dst.isGlobalObjCRef()) { 2156 CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst, 2157 Dst.isThreadLocalRef()); 2158 } 2159 else 2160 CGM.getObjCRuntime().EmitObjCStrongCastAssign(*this, src, LvalueDst); 2161 return; 2162 } 2163 2164 assert(Src.isScalar() && "Can't emit an agg store with this method"); 2165 EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit); 2166 } 2167 2168 void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst, 2169 llvm::Value **Result) { 2170 const CGBitFieldInfo &Info = Dst.getBitFieldInfo(); 2171 llvm::Type *ResLTy = ConvertTypeForMem(Dst.getType()); 2172 Address Ptr = Dst.getBitFieldAddress(); 2173 2174 // Get the source value, truncated to the width of the bit-field. 2175 llvm::Value *SrcVal = Src.getScalarVal(); 2176 2177 // Cast the source to the storage type and shift it into place. 2178 SrcVal = Builder.CreateIntCast(SrcVal, Ptr.getElementType(), 2179 /*isSigned=*/false); 2180 llvm::Value *MaskedVal = SrcVal; 2181 2182 const bool UseVolatile = 2183 CGM.getCodeGenOpts().AAPCSBitfieldWidth && Dst.isVolatileQualified() && 2184 Info.VolatileStorageSize != 0 && isAAPCS(CGM.getTarget()); 2185 const unsigned StorageSize = 2186 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize; 2187 const unsigned Offset = UseVolatile ? Info.VolatileOffset : Info.Offset; 2188 // See if there are other bits in the bitfield's storage we'll need to load 2189 // and mask together with source before storing. 2190 if (StorageSize != Info.Size) { 2191 assert(StorageSize > Info.Size && "Invalid bitfield size."); 2192 llvm::Value *Val = 2193 Builder.CreateLoad(Ptr, Dst.isVolatileQualified(), "bf.load"); 2194 2195 // Mask the source value as needed. 2196 if (!hasBooleanRepresentation(Dst.getType())) 2197 SrcVal = Builder.CreateAnd( 2198 SrcVal, llvm::APInt::getLowBitsSet(StorageSize, Info.Size), 2199 "bf.value"); 2200 MaskedVal = SrcVal; 2201 if (Offset) 2202 SrcVal = Builder.CreateShl(SrcVal, Offset, "bf.shl"); 2203 2204 // Mask out the original value. 2205 Val = Builder.CreateAnd( 2206 Val, ~llvm::APInt::getBitsSet(StorageSize, Offset, Offset + Info.Size), 2207 "bf.clear"); 2208 2209 // Or together the unchanged values and the source value. 2210 SrcVal = Builder.CreateOr(Val, SrcVal, "bf.set"); 2211 } else { 2212 assert(Offset == 0); 2213 // According to the AACPS: 2214 // When a volatile bit-field is written, and its container does not overlap 2215 // with any non-bit-field member, its container must be read exactly once 2216 // and written exactly once using the access width appropriate to the type 2217 // of the container. The two accesses are not atomic. 2218 if (Dst.isVolatileQualified() && isAAPCS(CGM.getTarget()) && 2219 CGM.getCodeGenOpts().ForceAAPCSBitfieldLoad) 2220 Builder.CreateLoad(Ptr, true, "bf.load"); 2221 } 2222 2223 // Write the new value back out. 2224 Builder.CreateStore(SrcVal, Ptr, Dst.isVolatileQualified()); 2225 2226 // Return the new value of the bit-field, if requested. 2227 if (Result) { 2228 llvm::Value *ResultVal = MaskedVal; 2229 2230 // Sign extend the value if needed. 2231 if (Info.IsSigned) { 2232 assert(Info.Size <= StorageSize); 2233 unsigned HighBits = StorageSize - Info.Size; 2234 if (HighBits) { 2235 ResultVal = Builder.CreateShl(ResultVal, HighBits, "bf.result.shl"); 2236 ResultVal = Builder.CreateAShr(ResultVal, HighBits, "bf.result.ashr"); 2237 } 2238 } 2239 2240 ResultVal = Builder.CreateIntCast(ResultVal, ResLTy, Info.IsSigned, 2241 "bf.result.cast"); 2242 *Result = EmitFromMemory(ResultVal, Dst.getType()); 2243 } 2244 } 2245 2246 void CodeGenFunction::EmitStoreThroughExtVectorComponentLValue(RValue Src, 2247 LValue Dst) { 2248 // This access turns into a read/modify/write of the vector. Load the input 2249 // value now. 2250 llvm::Value *Vec = Builder.CreateLoad(Dst.getExtVectorAddress(), 2251 Dst.isVolatileQualified()); 2252 const llvm::Constant *Elts = Dst.getExtVectorElts(); 2253 2254 llvm::Value *SrcVal = Src.getScalarVal(); 2255 2256 if (const VectorType *VTy = Dst.getType()->getAs<VectorType>()) { 2257 unsigned NumSrcElts = VTy->getNumElements(); 2258 unsigned NumDstElts = 2259 cast<llvm::FixedVectorType>(Vec->getType())->getNumElements(); 2260 if (NumDstElts == NumSrcElts) { 2261 // Use shuffle vector is the src and destination are the same number of 2262 // elements and restore the vector mask since it is on the side it will be 2263 // stored. 2264 SmallVector<int, 4> Mask(NumDstElts); 2265 for (unsigned i = 0; i != NumSrcElts; ++i) 2266 Mask[getAccessedFieldNo(i, Elts)] = i; 2267 2268 Vec = Builder.CreateShuffleVector(SrcVal, Mask); 2269 } else if (NumDstElts > NumSrcElts) { 2270 // Extended the source vector to the same length and then shuffle it 2271 // into the destination. 2272 // FIXME: since we're shuffling with undef, can we just use the indices 2273 // into that? This could be simpler. 2274 SmallVector<int, 4> ExtMask; 2275 for (unsigned i = 0; i != NumSrcElts; ++i) 2276 ExtMask.push_back(i); 2277 ExtMask.resize(NumDstElts, -1); 2278 llvm::Value *ExtSrcVal = Builder.CreateShuffleVector(SrcVal, ExtMask); 2279 // build identity 2280 SmallVector<int, 4> Mask; 2281 for (unsigned i = 0; i != NumDstElts; ++i) 2282 Mask.push_back(i); 2283 2284 // When the vector size is odd and .odd or .hi is used, the last element 2285 // of the Elts constant array will be one past the size of the vector. 2286 // Ignore the last element here, if it is greater than the mask size. 2287 if (getAccessedFieldNo(NumSrcElts - 1, Elts) == Mask.size()) 2288 NumSrcElts--; 2289 2290 // modify when what gets shuffled in 2291 for (unsigned i = 0; i != NumSrcElts; ++i) 2292 Mask[getAccessedFieldNo(i, Elts)] = i + NumDstElts; 2293 Vec = Builder.CreateShuffleVector(Vec, ExtSrcVal, Mask); 2294 } else { 2295 // We should never shorten the vector 2296 llvm_unreachable("unexpected shorten vector length"); 2297 } 2298 } else { 2299 // If the Src is a scalar (not a vector) it must be updating one element. 2300 unsigned InIdx = getAccessedFieldNo(0, Elts); 2301 llvm::Value *Elt = llvm::ConstantInt::get(SizeTy, InIdx); 2302 Vec = Builder.CreateInsertElement(Vec, SrcVal, Elt); 2303 } 2304 2305 Builder.CreateStore(Vec, Dst.getExtVectorAddress(), 2306 Dst.isVolatileQualified()); 2307 } 2308 2309 /// Store of global named registers are always calls to intrinsics. 2310 void CodeGenFunction::EmitStoreThroughGlobalRegLValue(RValue Src, LValue Dst) { 2311 assert((Dst.getType()->isIntegerType() || Dst.getType()->isPointerType()) && 2312 "Bad type for register variable"); 2313 llvm::MDNode *RegName = cast<llvm::MDNode>( 2314 cast<llvm::MetadataAsValue>(Dst.getGlobalReg())->getMetadata()); 2315 assert(RegName && "Register LValue is not metadata"); 2316 2317 // We accept integer and pointer types only 2318 llvm::Type *OrigTy = CGM.getTypes().ConvertType(Dst.getType()); 2319 llvm::Type *Ty = OrigTy; 2320 if (OrigTy->isPointerTy()) 2321 Ty = CGM.getTypes().getDataLayout().getIntPtrType(OrigTy); 2322 llvm::Type *Types[] = { Ty }; 2323 2324 llvm::Function *F = CGM.getIntrinsic(llvm::Intrinsic::write_register, Types); 2325 llvm::Value *Value = Src.getScalarVal(); 2326 if (OrigTy->isPointerTy()) 2327 Value = Builder.CreatePtrToInt(Value, Ty); 2328 Builder.CreateCall( 2329 F, {llvm::MetadataAsValue::get(Ty->getContext(), RegName), Value}); 2330 } 2331 2332 // setObjCGCLValueClass - sets class of the lvalue for the purpose of 2333 // generating write-barries API. It is currently a global, ivar, 2334 // or neither. 2335 static void setObjCGCLValueClass(const ASTContext &Ctx, const Expr *E, 2336 LValue &LV, 2337 bool IsMemberAccess=false) { 2338 if (Ctx.getLangOpts().getGC() == LangOptions::NonGC) 2339 return; 2340 2341 if (isa<ObjCIvarRefExpr>(E)) { 2342 QualType ExpTy = E->getType(); 2343 if (IsMemberAccess && ExpTy->isPointerType()) { 2344 // If ivar is a structure pointer, assigning to field of 2345 // this struct follows gcc's behavior and makes it a non-ivar 2346 // writer-barrier conservatively. 2347 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType(); 2348 if (ExpTy->isRecordType()) { 2349 LV.setObjCIvar(false); 2350 return; 2351 } 2352 } 2353 LV.setObjCIvar(true); 2354 auto *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr *>(E)); 2355 LV.setBaseIvarExp(Exp->getBase()); 2356 LV.setObjCArray(E->getType()->isArrayType()); 2357 return; 2358 } 2359 2360 if (const auto *Exp = dyn_cast<DeclRefExpr>(E)) { 2361 if (const auto *VD = dyn_cast<VarDecl>(Exp->getDecl())) { 2362 if (VD->hasGlobalStorage()) { 2363 LV.setGlobalObjCRef(true); 2364 LV.setThreadLocalRef(VD->getTLSKind() != VarDecl::TLS_None); 2365 } 2366 } 2367 LV.setObjCArray(E->getType()->isArrayType()); 2368 return; 2369 } 2370 2371 if (const auto *Exp = dyn_cast<UnaryOperator>(E)) { 2372 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); 2373 return; 2374 } 2375 2376 if (const auto *Exp = dyn_cast<ParenExpr>(E)) { 2377 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); 2378 if (LV.isObjCIvar()) { 2379 // If cast is to a structure pointer, follow gcc's behavior and make it 2380 // a non-ivar write-barrier. 2381 QualType ExpTy = E->getType(); 2382 if (ExpTy->isPointerType()) 2383 ExpTy = ExpTy->castAs<PointerType>()->getPointeeType(); 2384 if (ExpTy->isRecordType()) 2385 LV.setObjCIvar(false); 2386 } 2387 return; 2388 } 2389 2390 if (const auto *Exp = dyn_cast<GenericSelectionExpr>(E)) { 2391 setObjCGCLValueClass(Ctx, Exp->getResultExpr(), LV); 2392 return; 2393 } 2394 2395 if (const auto *Exp = dyn_cast<ImplicitCastExpr>(E)) { 2396 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); 2397 return; 2398 } 2399 2400 if (const auto *Exp = dyn_cast<CStyleCastExpr>(E)) { 2401 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); 2402 return; 2403 } 2404 2405 if (const auto *Exp = dyn_cast<ObjCBridgedCastExpr>(E)) { 2406 setObjCGCLValueClass(Ctx, Exp->getSubExpr(), LV, IsMemberAccess); 2407 return; 2408 } 2409 2410 if (const auto *Exp = dyn_cast<ArraySubscriptExpr>(E)) { 2411 setObjCGCLValueClass(Ctx, Exp->getBase(), LV); 2412 if (LV.isObjCIvar() && !LV.isObjCArray()) 2413 // Using array syntax to assigning to what an ivar points to is not 2414 // same as assigning to the ivar itself. {id *Names;} Names[i] = 0; 2415 LV.setObjCIvar(false); 2416 else if (LV.isGlobalObjCRef() && !LV.isObjCArray()) 2417 // Using array syntax to assigning to what global points to is not 2418 // same as assigning to the global itself. {id *G;} G[i] = 0; 2419 LV.setGlobalObjCRef(false); 2420 return; 2421 } 2422 2423 if (const auto *Exp = dyn_cast<MemberExpr>(E)) { 2424 setObjCGCLValueClass(Ctx, Exp->getBase(), LV, true); 2425 // We don't know if member is an 'ivar', but this flag is looked at 2426 // only in the context of LV.isObjCIvar(). 2427 LV.setObjCArray(E->getType()->isArrayType()); 2428 return; 2429 } 2430 } 2431 2432 static llvm::Value * 2433 EmitBitCastOfLValueToProperType(CodeGenFunction &CGF, 2434 llvm::Value *V, llvm::Type *IRType, 2435 StringRef Name = StringRef()) { 2436 unsigned AS = cast<llvm::PointerType>(V->getType())->getAddressSpace(); 2437 return CGF.Builder.CreateBitCast(V, IRType->getPointerTo(AS), Name); 2438 } 2439 2440 static LValue EmitThreadPrivateVarDeclLValue( 2441 CodeGenFunction &CGF, const VarDecl *VD, QualType T, Address Addr, 2442 llvm::Type *RealVarTy, SourceLocation Loc) { 2443 if (CGF.CGM.getLangOpts().OpenMPIRBuilder) 2444 Addr = CodeGenFunction::OMPBuilderCBHelpers::getAddrOfThreadPrivate( 2445 CGF, VD, Addr, Loc); 2446 else 2447 Addr = 2448 CGF.CGM.getOpenMPRuntime().getAddrOfThreadPrivate(CGF, VD, Addr, Loc); 2449 2450 Addr = CGF.Builder.CreateElementBitCast(Addr, RealVarTy); 2451 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl); 2452 } 2453 2454 static Address emitDeclTargetVarDeclLValue(CodeGenFunction &CGF, 2455 const VarDecl *VD, QualType T) { 2456 llvm::Optional<OMPDeclareTargetDeclAttr::MapTypeTy> Res = 2457 OMPDeclareTargetDeclAttr::isDeclareTargetDeclaration(VD); 2458 // Return an invalid address if variable is MT_To and unified 2459 // memory is not enabled. For all other cases: MT_Link and 2460 // MT_To with unified memory, return a valid address. 2461 if (!Res || (*Res == OMPDeclareTargetDeclAttr::MT_To && 2462 !CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) 2463 return Address::invalid(); 2464 assert(((*Res == OMPDeclareTargetDeclAttr::MT_Link) || 2465 (*Res == OMPDeclareTargetDeclAttr::MT_To && 2466 CGF.CGM.getOpenMPRuntime().hasRequiresUnifiedSharedMemory())) && 2467 "Expected link clause OR to clause with unified memory enabled."); 2468 QualType PtrTy = CGF.getContext().getPointerType(VD->getType()); 2469 Address Addr = CGF.CGM.getOpenMPRuntime().getAddrOfDeclareTargetVar(VD); 2470 return CGF.EmitLoadOfPointer(Addr, PtrTy->castAs<PointerType>()); 2471 } 2472 2473 Address 2474 CodeGenFunction::EmitLoadOfReference(LValue RefLVal, 2475 LValueBaseInfo *PointeeBaseInfo, 2476 TBAAAccessInfo *PointeeTBAAInfo) { 2477 llvm::LoadInst *Load = 2478 Builder.CreateLoad(RefLVal.getAddress(*this), RefLVal.isVolatile()); 2479 CGM.DecorateInstructionWithTBAA(Load, RefLVal.getTBAAInfo()); 2480 2481 QualType PointeeType = RefLVal.getType()->getPointeeType(); 2482 CharUnits Align = CGM.getNaturalTypeAlignment( 2483 PointeeType, PointeeBaseInfo, PointeeTBAAInfo, 2484 /* forPointeeType= */ true); 2485 return Address(Load, ConvertTypeForMem(PointeeType), Align); 2486 } 2487 2488 LValue CodeGenFunction::EmitLoadOfReferenceLValue(LValue RefLVal) { 2489 LValueBaseInfo PointeeBaseInfo; 2490 TBAAAccessInfo PointeeTBAAInfo; 2491 Address PointeeAddr = EmitLoadOfReference(RefLVal, &PointeeBaseInfo, 2492 &PointeeTBAAInfo); 2493 return MakeAddrLValue(PointeeAddr, RefLVal.getType()->getPointeeType(), 2494 PointeeBaseInfo, PointeeTBAAInfo); 2495 } 2496 2497 Address CodeGenFunction::EmitLoadOfPointer(Address Ptr, 2498 const PointerType *PtrTy, 2499 LValueBaseInfo *BaseInfo, 2500 TBAAAccessInfo *TBAAInfo) { 2501 llvm::Value *Addr = Builder.CreateLoad(Ptr); 2502 return Address(Addr, CGM.getNaturalTypeAlignment(PtrTy->getPointeeType(), 2503 BaseInfo, TBAAInfo, 2504 /*forPointeeType=*/true)); 2505 } 2506 2507 LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr, 2508 const PointerType *PtrTy) { 2509 LValueBaseInfo BaseInfo; 2510 TBAAAccessInfo TBAAInfo; 2511 Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &BaseInfo, &TBAAInfo); 2512 return MakeAddrLValue(Addr, PtrTy->getPointeeType(), BaseInfo, TBAAInfo); 2513 } 2514 2515 static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF, 2516 const Expr *E, const VarDecl *VD) { 2517 QualType T = E->getType(); 2518 2519 // If it's thread_local, emit a call to its wrapper function instead. 2520 if (VD->getTLSKind() == VarDecl::TLS_Dynamic && 2521 CGF.CGM.getCXXABI().usesThreadWrapperFunction(VD)) 2522 return CGF.CGM.getCXXABI().EmitThreadLocalVarDeclLValue(CGF, VD, T); 2523 // Check if the variable is marked as declare target with link clause in 2524 // device codegen. 2525 if (CGF.getLangOpts().OpenMPIsDevice) { 2526 Address Addr = emitDeclTargetVarDeclLValue(CGF, VD, T); 2527 if (Addr.isValid()) 2528 return CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl); 2529 } 2530 2531 llvm::Value *V = CGF.CGM.GetAddrOfGlobalVar(VD); 2532 llvm::Type *RealVarTy = CGF.getTypes().ConvertTypeForMem(VD->getType()); 2533 V = EmitBitCastOfLValueToProperType(CGF, V, RealVarTy); 2534 CharUnits Alignment = CGF.getContext().getDeclAlign(VD); 2535 Address Addr(V, RealVarTy, Alignment); 2536 // Emit reference to the private copy of the variable if it is an OpenMP 2537 // threadprivate variable. 2538 if (CGF.getLangOpts().OpenMP && !CGF.getLangOpts().OpenMPSimd && 2539 VD->hasAttr<OMPThreadPrivateDeclAttr>()) { 2540 return EmitThreadPrivateVarDeclLValue(CGF, VD, T, Addr, RealVarTy, 2541 E->getExprLoc()); 2542 } 2543 LValue LV = VD->getType()->isReferenceType() ? 2544 CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(), 2545 AlignmentSource::Decl) : 2546 CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl); 2547 setObjCGCLValueClass(CGF.getContext(), E, LV); 2548 return LV; 2549 } 2550 2551 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM, 2552 GlobalDecl GD) { 2553 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 2554 if (FD->hasAttr<WeakRefAttr>()) { 2555 ConstantAddress aliasee = CGM.GetWeakRefReference(FD); 2556 return aliasee.getPointer(); 2557 } 2558 2559 llvm::Constant *V = CGM.GetAddrOfFunction(GD); 2560 if (!FD->hasPrototype()) { 2561 if (const FunctionProtoType *Proto = 2562 FD->getType()->getAs<FunctionProtoType>()) { 2563 // Ugly case: for a K&R-style definition, the type of the definition 2564 // isn't the same as the type of a use. Correct for this with a 2565 // bitcast. 2566 QualType NoProtoType = 2567 CGM.getContext().getFunctionNoProtoType(Proto->getReturnType()); 2568 NoProtoType = CGM.getContext().getPointerType(NoProtoType); 2569 V = llvm::ConstantExpr::getBitCast(V, 2570 CGM.getTypes().ConvertType(NoProtoType)); 2571 } 2572 } 2573 return V; 2574 } 2575 2576 static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E, 2577 GlobalDecl GD) { 2578 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 2579 llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, GD); 2580 CharUnits Alignment = CGF.getContext().getDeclAlign(FD); 2581 return CGF.MakeAddrLValue(V, E->getType(), Alignment, 2582 AlignmentSource::Decl); 2583 } 2584 2585 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD, 2586 llvm::Value *ThisValue) { 2587 QualType TagType = CGF.getContext().getTagDeclType(FD->getParent()); 2588 LValue LV = CGF.MakeNaturalAlignAddrLValue(ThisValue, TagType); 2589 return CGF.EmitLValueForField(LV, FD); 2590 } 2591 2592 /// Named Registers are named metadata pointing to the register name 2593 /// which will be read from/written to as an argument to the intrinsic 2594 /// @llvm.read/write_register. 2595 /// So far, only the name is being passed down, but other options such as 2596 /// register type, allocation type or even optimization options could be 2597 /// passed down via the metadata node. 2598 static LValue EmitGlobalNamedRegister(const VarDecl *VD, CodeGenModule &CGM) { 2599 SmallString<64> Name("llvm.named.register."); 2600 AsmLabelAttr *Asm = VD->getAttr<AsmLabelAttr>(); 2601 assert(Asm->getLabel().size() < 64-Name.size() && 2602 "Register name too big"); 2603 Name.append(Asm->getLabel()); 2604 llvm::NamedMDNode *M = 2605 CGM.getModule().getOrInsertNamedMetadata(Name); 2606 if (M->getNumOperands() == 0) { 2607 llvm::MDString *Str = llvm::MDString::get(CGM.getLLVMContext(), 2608 Asm->getLabel()); 2609 llvm::Metadata *Ops[] = {Str}; 2610 M->addOperand(llvm::MDNode::get(CGM.getLLVMContext(), Ops)); 2611 } 2612 2613 CharUnits Alignment = CGM.getContext().getDeclAlign(VD); 2614 2615 llvm::Value *Ptr = 2616 llvm::MetadataAsValue::get(CGM.getLLVMContext(), M->getOperand(0)); 2617 return LValue::MakeGlobalReg(Ptr, Alignment, VD->getType()); 2618 } 2619 2620 /// Determine whether we can emit a reference to \p VD from the current 2621 /// context, despite not necessarily having seen an odr-use of the variable in 2622 /// this context. 2623 static bool canEmitSpuriousReferenceToVariable(CodeGenFunction &CGF, 2624 const DeclRefExpr *E, 2625 const VarDecl *VD, 2626 bool IsConstant) { 2627 // For a variable declared in an enclosing scope, do not emit a spurious 2628 // reference even if we have a capture, as that will emit an unwarranted 2629 // reference to our capture state, and will likely generate worse code than 2630 // emitting a local copy. 2631 if (E->refersToEnclosingVariableOrCapture()) 2632 return false; 2633 2634 // For a local declaration declared in this function, we can always reference 2635 // it even if we don't have an odr-use. 2636 if (VD->hasLocalStorage()) { 2637 return VD->getDeclContext() == 2638 dyn_cast_or_null<DeclContext>(CGF.CurCodeDecl); 2639 } 2640 2641 // For a global declaration, we can emit a reference to it if we know 2642 // for sure that we are able to emit a definition of it. 2643 VD = VD->getDefinition(CGF.getContext()); 2644 if (!VD) 2645 return false; 2646 2647 // Don't emit a spurious reference if it might be to a variable that only 2648 // exists on a different device / target. 2649 // FIXME: This is unnecessarily broad. Check whether this would actually be a 2650 // cross-target reference. 2651 if (CGF.getLangOpts().OpenMP || CGF.getLangOpts().CUDA || 2652 CGF.getLangOpts().OpenCL) { 2653 return false; 2654 } 2655 2656 // We can emit a spurious reference only if the linkage implies that we'll 2657 // be emitting a non-interposable symbol that will be retained until link 2658 // time. 2659 switch (CGF.CGM.getLLVMLinkageVarDefinition(VD, IsConstant)) { 2660 case llvm::GlobalValue::ExternalLinkage: 2661 case llvm::GlobalValue::LinkOnceODRLinkage: 2662 case llvm::GlobalValue::WeakODRLinkage: 2663 case llvm::GlobalValue::InternalLinkage: 2664 case llvm::GlobalValue::PrivateLinkage: 2665 return true; 2666 default: 2667 return false; 2668 } 2669 } 2670 2671 LValue CodeGenFunction::EmitDeclRefLValue(const DeclRefExpr *E) { 2672 const NamedDecl *ND = E->getDecl(); 2673 QualType T = E->getType(); 2674 2675 assert(E->isNonOdrUse() != NOUR_Unevaluated && 2676 "should not emit an unevaluated operand"); 2677 2678 if (const auto *VD = dyn_cast<VarDecl>(ND)) { 2679 // Global Named registers access via intrinsics only 2680 if (VD->getStorageClass() == SC_Register && 2681 VD->hasAttr<AsmLabelAttr>() && !VD->isLocalVarDecl()) 2682 return EmitGlobalNamedRegister(VD, CGM); 2683 2684 // If this DeclRefExpr does not constitute an odr-use of the variable, 2685 // we're not permitted to emit a reference to it in general, and it might 2686 // not be captured if capture would be necessary for a use. Emit the 2687 // constant value directly instead. 2688 if (E->isNonOdrUse() == NOUR_Constant && 2689 (VD->getType()->isReferenceType() || 2690 !canEmitSpuriousReferenceToVariable(*this, E, VD, true))) { 2691 VD->getAnyInitializer(VD); 2692 llvm::Constant *Val = ConstantEmitter(*this).emitAbstract( 2693 E->getLocation(), *VD->evaluateValue(), VD->getType()); 2694 assert(Val && "failed to emit constant expression"); 2695 2696 Address Addr = Address::invalid(); 2697 if (!VD->getType()->isReferenceType()) { 2698 // Spill the constant value to a global. 2699 Addr = CGM.createUnnamedGlobalFrom(*VD, Val, 2700 getContext().getDeclAlign(VD)); 2701 llvm::Type *VarTy = getTypes().ConvertTypeForMem(VD->getType()); 2702 auto *PTy = llvm::PointerType::get( 2703 VarTy, getContext().getTargetAddressSpace(VD->getType())); 2704 if (PTy != Addr.getType()) 2705 Addr = Builder.CreatePointerBitCastOrAddrSpaceCast(Addr, PTy); 2706 } else { 2707 // Should we be using the alignment of the constant pointer we emitted? 2708 CharUnits Alignment = 2709 CGM.getNaturalTypeAlignment(E->getType(), 2710 /* BaseInfo= */ nullptr, 2711 /* TBAAInfo= */ nullptr, 2712 /* forPointeeType= */ true); 2713 Addr = Address(Val, ConvertTypeForMem(E->getType()), Alignment); 2714 } 2715 return MakeAddrLValue(Addr, T, AlignmentSource::Decl); 2716 } 2717 2718 // FIXME: Handle other kinds of non-odr-use DeclRefExprs. 2719 2720 // Check for captured variables. 2721 if (E->refersToEnclosingVariableOrCapture()) { 2722 VD = VD->getCanonicalDecl(); 2723 if (auto *FD = LambdaCaptureFields.lookup(VD)) 2724 return EmitCapturedFieldLValue(*this, FD, CXXABIThisValue); 2725 if (CapturedStmtInfo) { 2726 auto I = LocalDeclMap.find(VD); 2727 if (I != LocalDeclMap.end()) { 2728 LValue CapLVal; 2729 if (VD->getType()->isReferenceType()) 2730 CapLVal = EmitLoadOfReferenceLValue(I->second, VD->getType(), 2731 AlignmentSource::Decl); 2732 else 2733 CapLVal = MakeAddrLValue(I->second, T); 2734 // Mark lvalue as nontemporal if the variable is marked as nontemporal 2735 // in simd context. 2736 if (getLangOpts().OpenMP && 2737 CGM.getOpenMPRuntime().isNontemporalDecl(VD)) 2738 CapLVal.setNontemporal(/*Value=*/true); 2739 return CapLVal; 2740 } 2741 LValue CapLVal = 2742 EmitCapturedFieldLValue(*this, CapturedStmtInfo->lookup(VD), 2743 CapturedStmtInfo->getContextValue()); 2744 CapLVal = MakeAddrLValue( 2745 Address(CapLVal.getPointer(*this), getContext().getDeclAlign(VD)), 2746 CapLVal.getType(), LValueBaseInfo(AlignmentSource::Decl), 2747 CapLVal.getTBAAInfo()); 2748 // Mark lvalue as nontemporal if the variable is marked as nontemporal 2749 // in simd context. 2750 if (getLangOpts().OpenMP && 2751 CGM.getOpenMPRuntime().isNontemporalDecl(VD)) 2752 CapLVal.setNontemporal(/*Value=*/true); 2753 return CapLVal; 2754 } 2755 2756 assert(isa<BlockDecl>(CurCodeDecl)); 2757 Address addr = GetAddrOfBlockDecl(VD); 2758 return MakeAddrLValue(addr, T, AlignmentSource::Decl); 2759 } 2760 } 2761 2762 // FIXME: We should be able to assert this for FunctionDecls as well! 2763 // FIXME: We should be able to assert this for all DeclRefExprs, not just 2764 // those with a valid source location. 2765 assert((ND->isUsed(false) || !isa<VarDecl>(ND) || E->isNonOdrUse() || 2766 !E->getLocation().isValid()) && 2767 "Should not use decl without marking it used!"); 2768 2769 if (ND->hasAttr<WeakRefAttr>()) { 2770 const auto *VD = cast<ValueDecl>(ND); 2771 ConstantAddress Aliasee = CGM.GetWeakRefReference(VD); 2772 return MakeAddrLValue(Aliasee, T, AlignmentSource::Decl); 2773 } 2774 2775 if (const auto *VD = dyn_cast<VarDecl>(ND)) { 2776 // Check if this is a global variable. 2777 if (VD->hasLinkage() || VD->isStaticDataMember()) 2778 return EmitGlobalVarDeclLValue(*this, E, VD); 2779 2780 Address addr = Address::invalid(); 2781 2782 // The variable should generally be present in the local decl map. 2783 auto iter = LocalDeclMap.find(VD); 2784 if (iter != LocalDeclMap.end()) { 2785 addr = iter->second; 2786 2787 // Otherwise, it might be static local we haven't emitted yet for 2788 // some reason; most likely, because it's in an outer function. 2789 } else if (VD->isStaticLocal()) { 2790 llvm::Constant *var = CGM.getOrCreateStaticVarDecl( 2791 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false)); 2792 addr = Address( 2793 var, ConvertTypeForMem(VD->getType()), getContext().getDeclAlign(VD)); 2794 2795 // No other cases for now. 2796 } else { 2797 llvm_unreachable("DeclRefExpr for Decl not entered in LocalDeclMap?"); 2798 } 2799 2800 2801 // Check for OpenMP threadprivate variables. 2802 if (getLangOpts().OpenMP && !getLangOpts().OpenMPSimd && 2803 VD->hasAttr<OMPThreadPrivateDeclAttr>()) { 2804 return EmitThreadPrivateVarDeclLValue( 2805 *this, VD, T, addr, getTypes().ConvertTypeForMem(VD->getType()), 2806 E->getExprLoc()); 2807 } 2808 2809 // Drill into block byref variables. 2810 bool isBlockByref = VD->isEscapingByref(); 2811 if (isBlockByref) { 2812 addr = emitBlockByrefAddress(addr, VD); 2813 } 2814 2815 // Drill into reference types. 2816 LValue LV = VD->getType()->isReferenceType() ? 2817 EmitLoadOfReferenceLValue(addr, VD->getType(), AlignmentSource::Decl) : 2818 MakeAddrLValue(addr, T, AlignmentSource::Decl); 2819 2820 bool isLocalStorage = VD->hasLocalStorage(); 2821 2822 bool NonGCable = isLocalStorage && 2823 !VD->getType()->isReferenceType() && 2824 !isBlockByref; 2825 if (NonGCable) { 2826 LV.getQuals().removeObjCGCAttr(); 2827 LV.setNonGC(true); 2828 } 2829 2830 bool isImpreciseLifetime = 2831 (isLocalStorage && !VD->hasAttr<ObjCPreciseLifetimeAttr>()); 2832 if (isImpreciseLifetime) 2833 LV.setARCPreciseLifetime(ARCImpreciseLifetime); 2834 setObjCGCLValueClass(getContext(), E, LV); 2835 return LV; 2836 } 2837 2838 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) { 2839 LValue LV = EmitFunctionDeclLValue(*this, E, FD); 2840 2841 // Emit debuginfo for the function declaration if the target wants to. 2842 if (getContext().getTargetInfo().allowDebugInfoForExternalRef()) { 2843 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) { 2844 auto *Fn = 2845 cast<llvm::Function>(LV.getPointer(*this)->stripPointerCasts()); 2846 if (!Fn->getSubprogram()) 2847 DI->EmitFunctionDecl(FD, FD->getLocation(), T, Fn); 2848 } 2849 } 2850 2851 return LV; 2852 } 2853 2854 // FIXME: While we're emitting a binding from an enclosing scope, all other 2855 // DeclRefExprs we see should be implicitly treated as if they also refer to 2856 // an enclosing scope. 2857 if (const auto *BD = dyn_cast<BindingDecl>(ND)) 2858 return EmitLValue(BD->getBinding()); 2859 2860 // We can form DeclRefExprs naming GUID declarations when reconstituting 2861 // non-type template parameters into expressions. 2862 if (const auto *GD = dyn_cast<MSGuidDecl>(ND)) 2863 return MakeAddrLValue(CGM.GetAddrOfMSGuidDecl(GD), T, 2864 AlignmentSource::Decl); 2865 2866 if (const auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) 2867 return MakeAddrLValue(CGM.GetAddrOfTemplateParamObject(TPO), T, 2868 AlignmentSource::Decl); 2869 2870 llvm_unreachable("Unhandled DeclRefExpr"); 2871 } 2872 2873 LValue CodeGenFunction::EmitUnaryOpLValue(const UnaryOperator *E) { 2874 // __extension__ doesn't affect lvalue-ness. 2875 if (E->getOpcode() == UO_Extension) 2876 return EmitLValue(E->getSubExpr()); 2877 2878 QualType ExprTy = getContext().getCanonicalType(E->getSubExpr()->getType()); 2879 switch (E->getOpcode()) { 2880 default: llvm_unreachable("Unknown unary operator lvalue!"); 2881 case UO_Deref: { 2882 QualType T = E->getSubExpr()->getType()->getPointeeType(); 2883 assert(!T.isNull() && "CodeGenFunction::EmitUnaryOpLValue: Illegal type"); 2884 2885 LValueBaseInfo BaseInfo; 2886 TBAAAccessInfo TBAAInfo; 2887 Address Addr = EmitPointerWithAlignment(E->getSubExpr(), &BaseInfo, 2888 &TBAAInfo); 2889 LValue LV = MakeAddrLValue(Addr, T, BaseInfo, TBAAInfo); 2890 LV.getQuals().setAddressSpace(ExprTy.getAddressSpace()); 2891 2892 // We should not generate __weak write barrier on indirect reference 2893 // of a pointer to object; as in void foo (__weak id *param); *param = 0; 2894 // But, we continue to generate __strong write barrier on indirect write 2895 // into a pointer to object. 2896 if (getLangOpts().ObjC && 2897 getLangOpts().getGC() != LangOptions::NonGC && 2898 LV.isObjCWeak()) 2899 LV.setNonGC(!E->isOBJCGCCandidate(getContext())); 2900 return LV; 2901 } 2902 case UO_Real: 2903 case UO_Imag: { 2904 LValue LV = EmitLValue(E->getSubExpr()); 2905 assert(LV.isSimple() && "real/imag on non-ordinary l-value"); 2906 2907 // __real is valid on scalars. This is a faster way of testing that. 2908 // __imag can only produce an rvalue on scalars. 2909 if (E->getOpcode() == UO_Real && 2910 !LV.getAddress(*this).getElementType()->isStructTy()) { 2911 assert(E->getSubExpr()->getType()->isArithmeticType()); 2912 return LV; 2913 } 2914 2915 QualType T = ExprTy->castAs<ComplexType>()->getElementType(); 2916 2917 Address Component = 2918 (E->getOpcode() == UO_Real 2919 ? emitAddrOfRealComponent(LV.getAddress(*this), LV.getType()) 2920 : emitAddrOfImagComponent(LV.getAddress(*this), LV.getType())); 2921 LValue ElemLV = MakeAddrLValue(Component, T, LV.getBaseInfo(), 2922 CGM.getTBAAInfoForSubobject(LV, T)); 2923 ElemLV.getQuals().addQualifiers(LV.getQuals()); 2924 return ElemLV; 2925 } 2926 case UO_PreInc: 2927 case UO_PreDec: { 2928 LValue LV = EmitLValue(E->getSubExpr()); 2929 bool isInc = E->getOpcode() == UO_PreInc; 2930 2931 if (E->getType()->isAnyComplexType()) 2932 EmitComplexPrePostIncDec(E, LV, isInc, true/*isPre*/); 2933 else 2934 EmitScalarPrePostIncDec(E, LV, isInc, true/*isPre*/); 2935 return LV; 2936 } 2937 } 2938 } 2939 2940 LValue CodeGenFunction::EmitStringLiteralLValue(const StringLiteral *E) { 2941 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromLiteral(E), 2942 E->getType(), AlignmentSource::Decl); 2943 } 2944 2945 LValue CodeGenFunction::EmitObjCEncodeExprLValue(const ObjCEncodeExpr *E) { 2946 return MakeAddrLValue(CGM.GetAddrOfConstantStringFromObjCEncode(E), 2947 E->getType(), AlignmentSource::Decl); 2948 } 2949 2950 LValue CodeGenFunction::EmitPredefinedLValue(const PredefinedExpr *E) { 2951 auto SL = E->getFunctionName(); 2952 assert(SL != nullptr && "No StringLiteral name in PredefinedExpr"); 2953 StringRef FnName = CurFn->getName(); 2954 if (FnName.startswith("\01")) 2955 FnName = FnName.substr(1); 2956 StringRef NameItems[] = { 2957 PredefinedExpr::getIdentKindName(E->getIdentKind()), FnName}; 2958 std::string GVName = llvm::join(NameItems, NameItems + 2, "."); 2959 if (auto *BD = dyn_cast_or_null<BlockDecl>(CurCodeDecl)) { 2960 std::string Name = std::string(SL->getString()); 2961 if (!Name.empty()) { 2962 unsigned Discriminator = 2963 CGM.getCXXABI().getMangleContext().getBlockId(BD, true); 2964 if (Discriminator) 2965 Name += "_" + Twine(Discriminator + 1).str(); 2966 auto C = CGM.GetAddrOfConstantCString(Name, GVName.c_str()); 2967 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl); 2968 } else { 2969 auto C = 2970 CGM.GetAddrOfConstantCString(std::string(FnName), GVName.c_str()); 2971 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl); 2972 } 2973 } 2974 auto C = CGM.GetAddrOfConstantStringFromLiteral(SL, GVName); 2975 return MakeAddrLValue(C, E->getType(), AlignmentSource::Decl); 2976 } 2977 2978 /// Emit a type description suitable for use by a runtime sanitizer library. The 2979 /// format of a type descriptor is 2980 /// 2981 /// \code 2982 /// { i16 TypeKind, i16 TypeInfo } 2983 /// \endcode 2984 /// 2985 /// followed by an array of i8 containing the type name. TypeKind is 0 for an 2986 /// integer, 1 for a floating point value, and -1 for anything else. 2987 llvm::Constant *CodeGenFunction::EmitCheckTypeDescriptor(QualType T) { 2988 // Only emit each type's descriptor once. 2989 if (llvm::Constant *C = CGM.getTypeDescriptorFromMap(T)) 2990 return C; 2991 2992 uint16_t TypeKind = -1; 2993 uint16_t TypeInfo = 0; 2994 2995 if (T->isIntegerType()) { 2996 TypeKind = 0; 2997 TypeInfo = (llvm::Log2_32(getContext().getTypeSize(T)) << 1) | 2998 (T->isSignedIntegerType() ? 1 : 0); 2999 } else if (T->isFloatingType()) { 3000 TypeKind = 1; 3001 TypeInfo = getContext().getTypeSize(T); 3002 } 3003 3004 // Format the type name as if for a diagnostic, including quotes and 3005 // optionally an 'aka'. 3006 SmallString<32> Buffer; 3007 CGM.getDiags().ConvertArgToString(DiagnosticsEngine::ak_qualtype, 3008 (intptr_t)T.getAsOpaquePtr(), 3009 StringRef(), StringRef(), None, Buffer, 3010 None); 3011 3012 llvm::Constant *Components[] = { 3013 Builder.getInt16(TypeKind), Builder.getInt16(TypeInfo), 3014 llvm::ConstantDataArray::getString(getLLVMContext(), Buffer) 3015 }; 3016 llvm::Constant *Descriptor = llvm::ConstantStruct::getAnon(Components); 3017 3018 auto *GV = new llvm::GlobalVariable( 3019 CGM.getModule(), Descriptor->getType(), 3020 /*isConstant=*/true, llvm::GlobalVariable::PrivateLinkage, Descriptor); 3021 GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 3022 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(GV); 3023 3024 // Remember the descriptor for this type. 3025 CGM.setTypeDescriptorInMap(T, GV); 3026 3027 return GV; 3028 } 3029 3030 llvm::Value *CodeGenFunction::EmitCheckValue(llvm::Value *V) { 3031 llvm::Type *TargetTy = IntPtrTy; 3032 3033 if (V->getType() == TargetTy) 3034 return V; 3035 3036 // Floating-point types which fit into intptr_t are bitcast to integers 3037 // and then passed directly (after zero-extension, if necessary). 3038 if (V->getType()->isFloatingPointTy()) { 3039 unsigned Bits = V->getType()->getPrimitiveSizeInBits().getFixedSize(); 3040 if (Bits <= TargetTy->getIntegerBitWidth()) 3041 V = Builder.CreateBitCast(V, llvm::Type::getIntNTy(getLLVMContext(), 3042 Bits)); 3043 } 3044 3045 // Integers which fit in intptr_t are zero-extended and passed directly. 3046 if (V->getType()->isIntegerTy() && 3047 V->getType()->getIntegerBitWidth() <= TargetTy->getIntegerBitWidth()) 3048 return Builder.CreateZExt(V, TargetTy); 3049 3050 // Pointers are passed directly, everything else is passed by address. 3051 if (!V->getType()->isPointerTy()) { 3052 Address Ptr = CreateDefaultAlignTempAlloca(V->getType()); 3053 Builder.CreateStore(V, Ptr); 3054 V = Ptr.getPointer(); 3055 } 3056 return Builder.CreatePtrToInt(V, TargetTy); 3057 } 3058 3059 /// Emit a representation of a SourceLocation for passing to a handler 3060 /// in a sanitizer runtime library. The format for this data is: 3061 /// \code 3062 /// struct SourceLocation { 3063 /// const char *Filename; 3064 /// int32_t Line, Column; 3065 /// }; 3066 /// \endcode 3067 /// For an invalid SourceLocation, the Filename pointer is null. 3068 llvm::Constant *CodeGenFunction::EmitCheckSourceLocation(SourceLocation Loc) { 3069 llvm::Constant *Filename; 3070 int Line, Column; 3071 3072 PresumedLoc PLoc = getContext().getSourceManager().getPresumedLoc(Loc); 3073 if (PLoc.isValid()) { 3074 StringRef FilenameString = PLoc.getFilename(); 3075 3076 int PathComponentsToStrip = 3077 CGM.getCodeGenOpts().EmitCheckPathComponentsToStrip; 3078 if (PathComponentsToStrip < 0) { 3079 assert(PathComponentsToStrip != INT_MIN); 3080 int PathComponentsToKeep = -PathComponentsToStrip; 3081 auto I = llvm::sys::path::rbegin(FilenameString); 3082 auto E = llvm::sys::path::rend(FilenameString); 3083 while (I != E && --PathComponentsToKeep) 3084 ++I; 3085 3086 FilenameString = FilenameString.substr(I - E); 3087 } else if (PathComponentsToStrip > 0) { 3088 auto I = llvm::sys::path::begin(FilenameString); 3089 auto E = llvm::sys::path::end(FilenameString); 3090 while (I != E && PathComponentsToStrip--) 3091 ++I; 3092 3093 if (I != E) 3094 FilenameString = 3095 FilenameString.substr(I - llvm::sys::path::begin(FilenameString)); 3096 else 3097 FilenameString = llvm::sys::path::filename(FilenameString); 3098 } 3099 3100 auto FilenameGV = 3101 CGM.GetAddrOfConstantCString(std::string(FilenameString), ".src"); 3102 CGM.getSanitizerMetadata()->disableSanitizerForGlobal( 3103 cast<llvm::GlobalVariable>(FilenameGV.getPointer())); 3104 Filename = FilenameGV.getPointer(); 3105 Line = PLoc.getLine(); 3106 Column = PLoc.getColumn(); 3107 } else { 3108 Filename = llvm::Constant::getNullValue(Int8PtrTy); 3109 Line = Column = 0; 3110 } 3111 3112 llvm::Constant *Data[] = {Filename, Builder.getInt32(Line), 3113 Builder.getInt32(Column)}; 3114 3115 return llvm::ConstantStruct::getAnon(Data); 3116 } 3117 3118 namespace { 3119 /// Specify under what conditions this check can be recovered 3120 enum class CheckRecoverableKind { 3121 /// Always terminate program execution if this check fails. 3122 Unrecoverable, 3123 /// Check supports recovering, runtime has both fatal (noreturn) and 3124 /// non-fatal handlers for this check. 3125 Recoverable, 3126 /// Runtime conditionally aborts, always need to support recovery. 3127 AlwaysRecoverable 3128 }; 3129 } 3130 3131 static CheckRecoverableKind getRecoverableKind(SanitizerMask Kind) { 3132 assert(Kind.countPopulation() == 1); 3133 if (Kind == SanitizerKind::Function || Kind == SanitizerKind::Vptr) 3134 return CheckRecoverableKind::AlwaysRecoverable; 3135 else if (Kind == SanitizerKind::Return || Kind == SanitizerKind::Unreachable) 3136 return CheckRecoverableKind::Unrecoverable; 3137 else 3138 return CheckRecoverableKind::Recoverable; 3139 } 3140 3141 namespace { 3142 struct SanitizerHandlerInfo { 3143 char const *const Name; 3144 unsigned Version; 3145 }; 3146 } 3147 3148 const SanitizerHandlerInfo SanitizerHandlers[] = { 3149 #define SANITIZER_CHECK(Enum, Name, Version) {#Name, Version}, 3150 LIST_SANITIZER_CHECKS 3151 #undef SANITIZER_CHECK 3152 }; 3153 3154 static void emitCheckHandlerCall(CodeGenFunction &CGF, 3155 llvm::FunctionType *FnType, 3156 ArrayRef<llvm::Value *> FnArgs, 3157 SanitizerHandler CheckHandler, 3158 CheckRecoverableKind RecoverKind, bool IsFatal, 3159 llvm::BasicBlock *ContBB) { 3160 assert(IsFatal || RecoverKind != CheckRecoverableKind::Unrecoverable); 3161 Optional<ApplyDebugLocation> DL; 3162 if (!CGF.Builder.getCurrentDebugLocation()) { 3163 // Ensure that the call has at least an artificial debug location. 3164 DL.emplace(CGF, SourceLocation()); 3165 } 3166 bool NeedsAbortSuffix = 3167 IsFatal && RecoverKind != CheckRecoverableKind::Unrecoverable; 3168 bool MinimalRuntime = CGF.CGM.getCodeGenOpts().SanitizeMinimalRuntime; 3169 const SanitizerHandlerInfo &CheckInfo = SanitizerHandlers[CheckHandler]; 3170 const StringRef CheckName = CheckInfo.Name; 3171 std::string FnName = "__ubsan_handle_" + CheckName.str(); 3172 if (CheckInfo.Version && !MinimalRuntime) 3173 FnName += "_v" + llvm::utostr(CheckInfo.Version); 3174 if (MinimalRuntime) 3175 FnName += "_minimal"; 3176 if (NeedsAbortSuffix) 3177 FnName += "_abort"; 3178 bool MayReturn = 3179 !IsFatal || RecoverKind == CheckRecoverableKind::AlwaysRecoverable; 3180 3181 llvm::AttrBuilder B(CGF.getLLVMContext()); 3182 if (!MayReturn) { 3183 B.addAttribute(llvm::Attribute::NoReturn) 3184 .addAttribute(llvm::Attribute::NoUnwind); 3185 } 3186 B.addAttribute(llvm::Attribute::UWTable); 3187 3188 llvm::FunctionCallee Fn = CGF.CGM.CreateRuntimeFunction( 3189 FnType, FnName, 3190 llvm::AttributeList::get(CGF.getLLVMContext(), 3191 llvm::AttributeList::FunctionIndex, B), 3192 /*Local=*/true); 3193 llvm::CallInst *HandlerCall = CGF.EmitNounwindRuntimeCall(Fn, FnArgs); 3194 if (!MayReturn) { 3195 HandlerCall->setDoesNotReturn(); 3196 CGF.Builder.CreateUnreachable(); 3197 } else { 3198 CGF.Builder.CreateBr(ContBB); 3199 } 3200 } 3201 3202 void CodeGenFunction::EmitCheck( 3203 ArrayRef<std::pair<llvm::Value *, SanitizerMask>> Checked, 3204 SanitizerHandler CheckHandler, ArrayRef<llvm::Constant *> StaticArgs, 3205 ArrayRef<llvm::Value *> DynamicArgs) { 3206 assert(IsSanitizerScope); 3207 assert(Checked.size() > 0); 3208 assert(CheckHandler >= 0 && 3209 size_t(CheckHandler) < llvm::array_lengthof(SanitizerHandlers)); 3210 const StringRef CheckName = SanitizerHandlers[CheckHandler].Name; 3211 3212 llvm::Value *FatalCond = nullptr; 3213 llvm::Value *RecoverableCond = nullptr; 3214 llvm::Value *TrapCond = nullptr; 3215 for (int i = 0, n = Checked.size(); i < n; ++i) { 3216 llvm::Value *Check = Checked[i].first; 3217 // -fsanitize-trap= overrides -fsanitize-recover=. 3218 llvm::Value *&Cond = 3219 CGM.getCodeGenOpts().SanitizeTrap.has(Checked[i].second) 3220 ? TrapCond 3221 : CGM.getCodeGenOpts().SanitizeRecover.has(Checked[i].second) 3222 ? RecoverableCond 3223 : FatalCond; 3224 Cond = Cond ? Builder.CreateAnd(Cond, Check) : Check; 3225 } 3226 3227 if (TrapCond) 3228 EmitTrapCheck(TrapCond, CheckHandler); 3229 if (!FatalCond && !RecoverableCond) 3230 return; 3231 3232 llvm::Value *JointCond; 3233 if (FatalCond && RecoverableCond) 3234 JointCond = Builder.CreateAnd(FatalCond, RecoverableCond); 3235 else 3236 JointCond = FatalCond ? FatalCond : RecoverableCond; 3237 assert(JointCond); 3238 3239 CheckRecoverableKind RecoverKind = getRecoverableKind(Checked[0].second); 3240 assert(SanOpts.has(Checked[0].second)); 3241 #ifndef NDEBUG 3242 for (int i = 1, n = Checked.size(); i < n; ++i) { 3243 assert(RecoverKind == getRecoverableKind(Checked[i].second) && 3244 "All recoverable kinds in a single check must be same!"); 3245 assert(SanOpts.has(Checked[i].second)); 3246 } 3247 #endif 3248 3249 llvm::BasicBlock *Cont = createBasicBlock("cont"); 3250 llvm::BasicBlock *Handlers = createBasicBlock("handler." + CheckName); 3251 llvm::Instruction *Branch = Builder.CreateCondBr(JointCond, Cont, Handlers); 3252 // Give hint that we very much don't expect to execute the handler 3253 // Value chosen to match UR_NONTAKEN_WEIGHT, see BranchProbabilityInfo.cpp 3254 llvm::MDBuilder MDHelper(getLLVMContext()); 3255 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1); 3256 Branch->setMetadata(llvm::LLVMContext::MD_prof, Node); 3257 EmitBlock(Handlers); 3258 3259 // Handler functions take an i8* pointing to the (handler-specific) static 3260 // information block, followed by a sequence of intptr_t arguments 3261 // representing operand values. 3262 SmallVector<llvm::Value *, 4> Args; 3263 SmallVector<llvm::Type *, 4> ArgTypes; 3264 if (!CGM.getCodeGenOpts().SanitizeMinimalRuntime) { 3265 Args.reserve(DynamicArgs.size() + 1); 3266 ArgTypes.reserve(DynamicArgs.size() + 1); 3267 3268 // Emit handler arguments and create handler function type. 3269 if (!StaticArgs.empty()) { 3270 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs); 3271 auto *InfoPtr = 3272 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false, 3273 llvm::GlobalVariable::PrivateLinkage, Info); 3274 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 3275 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr); 3276 Args.push_back(Builder.CreateBitCast(InfoPtr, Int8PtrTy)); 3277 ArgTypes.push_back(Int8PtrTy); 3278 } 3279 3280 for (size_t i = 0, n = DynamicArgs.size(); i != n; ++i) { 3281 Args.push_back(EmitCheckValue(DynamicArgs[i])); 3282 ArgTypes.push_back(IntPtrTy); 3283 } 3284 } 3285 3286 llvm::FunctionType *FnType = 3287 llvm::FunctionType::get(CGM.VoidTy, ArgTypes, false); 3288 3289 if (!FatalCond || !RecoverableCond) { 3290 // Simple case: we need to generate a single handler call, either 3291 // fatal, or non-fatal. 3292 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, 3293 (FatalCond != nullptr), Cont); 3294 } else { 3295 // Emit two handler calls: first one for set of unrecoverable checks, 3296 // another one for recoverable. 3297 llvm::BasicBlock *NonFatalHandlerBB = 3298 createBasicBlock("non_fatal." + CheckName); 3299 llvm::BasicBlock *FatalHandlerBB = createBasicBlock("fatal." + CheckName); 3300 Builder.CreateCondBr(FatalCond, NonFatalHandlerBB, FatalHandlerBB); 3301 EmitBlock(FatalHandlerBB); 3302 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, true, 3303 NonFatalHandlerBB); 3304 EmitBlock(NonFatalHandlerBB); 3305 emitCheckHandlerCall(*this, FnType, Args, CheckHandler, RecoverKind, false, 3306 Cont); 3307 } 3308 3309 EmitBlock(Cont); 3310 } 3311 3312 void CodeGenFunction::EmitCfiSlowPathCheck( 3313 SanitizerMask Kind, llvm::Value *Cond, llvm::ConstantInt *TypeId, 3314 llvm::Value *Ptr, ArrayRef<llvm::Constant *> StaticArgs) { 3315 llvm::BasicBlock *Cont = createBasicBlock("cfi.cont"); 3316 3317 llvm::BasicBlock *CheckBB = createBasicBlock("cfi.slowpath"); 3318 llvm::BranchInst *BI = Builder.CreateCondBr(Cond, Cont, CheckBB); 3319 3320 llvm::MDBuilder MDHelper(getLLVMContext()); 3321 llvm::MDNode *Node = MDHelper.createBranchWeights((1U << 20) - 1, 1); 3322 BI->setMetadata(llvm::LLVMContext::MD_prof, Node); 3323 3324 EmitBlock(CheckBB); 3325 3326 bool WithDiag = !CGM.getCodeGenOpts().SanitizeTrap.has(Kind); 3327 3328 llvm::CallInst *CheckCall; 3329 llvm::FunctionCallee SlowPathFn; 3330 if (WithDiag) { 3331 llvm::Constant *Info = llvm::ConstantStruct::getAnon(StaticArgs); 3332 auto *InfoPtr = 3333 new llvm::GlobalVariable(CGM.getModule(), Info->getType(), false, 3334 llvm::GlobalVariable::PrivateLinkage, Info); 3335 InfoPtr->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global); 3336 CGM.getSanitizerMetadata()->disableSanitizerForGlobal(InfoPtr); 3337 3338 SlowPathFn = CGM.getModule().getOrInsertFunction( 3339 "__cfi_slowpath_diag", 3340 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, 3341 false)); 3342 CheckCall = Builder.CreateCall( 3343 SlowPathFn, {TypeId, Ptr, Builder.CreateBitCast(InfoPtr, Int8PtrTy)}); 3344 } else { 3345 SlowPathFn = CGM.getModule().getOrInsertFunction( 3346 "__cfi_slowpath", 3347 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy}, false)); 3348 CheckCall = Builder.CreateCall(SlowPathFn, {TypeId, Ptr}); 3349 } 3350 3351 CGM.setDSOLocal( 3352 cast<llvm::GlobalValue>(SlowPathFn.getCallee()->stripPointerCasts())); 3353 CheckCall->setDoesNotThrow(); 3354 3355 EmitBlock(Cont); 3356 } 3357 3358 // Emit a stub for __cfi_check function so that the linker knows about this 3359 // symbol in LTO mode. 3360 void CodeGenFunction::EmitCfiCheckStub() { 3361 llvm::Module *M = &CGM.getModule(); 3362 auto &Ctx = M->getContext(); 3363 llvm::Function *F = llvm::Function::Create( 3364 llvm::FunctionType::get(VoidTy, {Int64Ty, Int8PtrTy, Int8PtrTy}, false), 3365 llvm::GlobalValue::WeakAnyLinkage, "__cfi_check", M); 3366 CGM.setDSOLocal(F); 3367 llvm::BasicBlock *BB = llvm::BasicBlock::Create(Ctx, "entry", F); 3368 // FIXME: consider emitting an intrinsic call like 3369 // call void @llvm.cfi_check(i64 %0, i8* %1, i8* %2) 3370 // which can be lowered in CrossDSOCFI pass to the actual contents of 3371 // __cfi_check. This would allow inlining of __cfi_check calls. 3372 llvm::CallInst::Create( 3373 llvm::Intrinsic::getDeclaration(M, llvm::Intrinsic::trap), "", BB); 3374 llvm::ReturnInst::Create(Ctx, nullptr, BB); 3375 } 3376 3377 // This function is basically a switch over the CFI failure kind, which is 3378 // extracted from CFICheckFailData (1st function argument). Each case is either 3379 // llvm.trap or a call to one of the two runtime handlers, based on 3380 // -fsanitize-trap and -fsanitize-recover settings. Default case (invalid 3381 // failure kind) traps, but this should really never happen. CFICheckFailData 3382 // can be nullptr if the calling module has -fsanitize-trap behavior for this 3383 // check kind; in this case __cfi_check_fail traps as well. 3384 void CodeGenFunction::EmitCfiCheckFail() { 3385 SanitizerScope SanScope(this); 3386 FunctionArgList Args; 3387 ImplicitParamDecl ArgData(getContext(), getContext().VoidPtrTy, 3388 ImplicitParamDecl::Other); 3389 ImplicitParamDecl ArgAddr(getContext(), getContext().VoidPtrTy, 3390 ImplicitParamDecl::Other); 3391 Args.push_back(&ArgData); 3392 Args.push_back(&ArgAddr); 3393 3394 const CGFunctionInfo &FI = 3395 CGM.getTypes().arrangeBuiltinFunctionDeclaration(getContext().VoidTy, Args); 3396 3397 llvm::Function *F = llvm::Function::Create( 3398 llvm::FunctionType::get(VoidTy, {VoidPtrTy, VoidPtrTy}, false), 3399 llvm::GlobalValue::WeakODRLinkage, "__cfi_check_fail", &CGM.getModule()); 3400 3401 CGM.SetLLVMFunctionAttributes(GlobalDecl(), FI, F, /*IsThunk=*/false); 3402 CGM.SetLLVMFunctionAttributesForDefinition(nullptr, F); 3403 F->setVisibility(llvm::GlobalValue::HiddenVisibility); 3404 3405 StartFunction(GlobalDecl(), CGM.getContext().VoidTy, F, FI, Args, 3406 SourceLocation()); 3407 3408 // This function is not affected by NoSanitizeList. This function does 3409 // not have a source location, but "src:*" would still apply. Revert any 3410 // changes to SanOpts made in StartFunction. 3411 SanOpts = CGM.getLangOpts().Sanitize; 3412 3413 llvm::Value *Data = 3414 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgData), /*Volatile=*/false, 3415 CGM.getContext().VoidPtrTy, ArgData.getLocation()); 3416 llvm::Value *Addr = 3417 EmitLoadOfScalar(GetAddrOfLocalVar(&ArgAddr), /*Volatile=*/false, 3418 CGM.getContext().VoidPtrTy, ArgAddr.getLocation()); 3419 3420 // Data == nullptr means the calling module has trap behaviour for this check. 3421 llvm::Value *DataIsNotNullPtr = 3422 Builder.CreateICmpNE(Data, llvm::ConstantPointerNull::get(Int8PtrTy)); 3423 EmitTrapCheck(DataIsNotNullPtr, SanitizerHandler::CFICheckFail); 3424 3425 llvm::StructType *SourceLocationTy = 3426 llvm::StructType::get(VoidPtrTy, Int32Ty, Int32Ty); 3427 llvm::StructType *CfiCheckFailDataTy = 3428 llvm::StructType::get(Int8Ty, SourceLocationTy, VoidPtrTy); 3429 3430 llvm::Value *V = Builder.CreateConstGEP2_32( 3431 CfiCheckFailDataTy, 3432 Builder.CreatePointerCast(Data, CfiCheckFailDataTy->getPointerTo(0)), 0, 3433 0); 3434 Address CheckKindAddr(V, getIntAlign()); 3435 llvm::Value *CheckKind = Builder.CreateLoad(CheckKindAddr); 3436 3437 llvm::Value *AllVtables = llvm::MetadataAsValue::get( 3438 CGM.getLLVMContext(), 3439 llvm::MDString::get(CGM.getLLVMContext(), "all-vtables")); 3440 llvm::Value *ValidVtable = Builder.CreateZExt( 3441 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::type_test), 3442 {Addr, AllVtables}), 3443 IntPtrTy); 3444 3445 const std::pair<int, SanitizerMask> CheckKinds[] = { 3446 {CFITCK_VCall, SanitizerKind::CFIVCall}, 3447 {CFITCK_NVCall, SanitizerKind::CFINVCall}, 3448 {CFITCK_DerivedCast, SanitizerKind::CFIDerivedCast}, 3449 {CFITCK_UnrelatedCast, SanitizerKind::CFIUnrelatedCast}, 3450 {CFITCK_ICall, SanitizerKind::CFIICall}}; 3451 3452 SmallVector<std::pair<llvm::Value *, SanitizerMask>, 5> Checks; 3453 for (auto CheckKindMaskPair : CheckKinds) { 3454 int Kind = CheckKindMaskPair.first; 3455 SanitizerMask Mask = CheckKindMaskPair.second; 3456 llvm::Value *Cond = 3457 Builder.CreateICmpNE(CheckKind, llvm::ConstantInt::get(Int8Ty, Kind)); 3458 if (CGM.getLangOpts().Sanitize.has(Mask)) 3459 EmitCheck(std::make_pair(Cond, Mask), SanitizerHandler::CFICheckFail, {}, 3460 {Data, Addr, ValidVtable}); 3461 else 3462 EmitTrapCheck(Cond, SanitizerHandler::CFICheckFail); 3463 } 3464 3465 FinishFunction(); 3466 // The only reference to this function will be created during LTO link. 3467 // Make sure it survives until then. 3468 CGM.addUsedGlobal(F); 3469 } 3470 3471 void CodeGenFunction::EmitUnreachable(SourceLocation Loc) { 3472 if (SanOpts.has(SanitizerKind::Unreachable)) { 3473 SanitizerScope SanScope(this); 3474 EmitCheck(std::make_pair(static_cast<llvm::Value *>(Builder.getFalse()), 3475 SanitizerKind::Unreachable), 3476 SanitizerHandler::BuiltinUnreachable, 3477 EmitCheckSourceLocation(Loc), None); 3478 } 3479 Builder.CreateUnreachable(); 3480 } 3481 3482 void CodeGenFunction::EmitTrapCheck(llvm::Value *Checked, 3483 SanitizerHandler CheckHandlerID) { 3484 llvm::BasicBlock *Cont = createBasicBlock("cont"); 3485 3486 // If we're optimizing, collapse all calls to trap down to just one per 3487 // check-type per function to save on code size. 3488 if (TrapBBs.size() <= CheckHandlerID) 3489 TrapBBs.resize(CheckHandlerID + 1); 3490 llvm::BasicBlock *&TrapBB = TrapBBs[CheckHandlerID]; 3491 3492 if (!CGM.getCodeGenOpts().OptimizationLevel || !TrapBB) { 3493 TrapBB = createBasicBlock("trap"); 3494 Builder.CreateCondBr(Checked, Cont, TrapBB); 3495 EmitBlock(TrapBB); 3496 3497 llvm::CallInst *TrapCall = 3498 Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::ubsantrap), 3499 llvm::ConstantInt::get(CGM.Int8Ty, CheckHandlerID)); 3500 3501 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) { 3502 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name", 3503 CGM.getCodeGenOpts().TrapFuncName); 3504 TrapCall->addFnAttr(A); 3505 } 3506 TrapCall->setDoesNotReturn(); 3507 TrapCall->setDoesNotThrow(); 3508 Builder.CreateUnreachable(); 3509 } else { 3510 auto Call = TrapBB->begin(); 3511 assert(isa<llvm::CallInst>(Call) && "Expected call in trap BB"); 3512 3513 Call->applyMergedLocation(Call->getDebugLoc(), 3514 Builder.getCurrentDebugLocation()); 3515 Builder.CreateCondBr(Checked, Cont, TrapBB); 3516 } 3517 3518 EmitBlock(Cont); 3519 } 3520 3521 llvm::CallInst *CodeGenFunction::EmitTrapCall(llvm::Intrinsic::ID IntrID) { 3522 llvm::CallInst *TrapCall = 3523 Builder.CreateCall(CGM.getIntrinsic(IntrID)); 3524 3525 if (!CGM.getCodeGenOpts().TrapFuncName.empty()) { 3526 auto A = llvm::Attribute::get(getLLVMContext(), "trap-func-name", 3527 CGM.getCodeGenOpts().TrapFuncName); 3528 TrapCall->addFnAttr(A); 3529 } 3530 3531 return TrapCall; 3532 } 3533 3534 Address CodeGenFunction::EmitArrayToPointerDecay(const Expr *E, 3535 LValueBaseInfo *BaseInfo, 3536 TBAAAccessInfo *TBAAInfo) { 3537 assert(E->getType()->isArrayType() && 3538 "Array to pointer decay must have array source type!"); 3539 3540 // Expressions of array type can't be bitfields or vector elements. 3541 LValue LV = EmitLValue(E); 3542 Address Addr = LV.getAddress(*this); 3543 3544 // If the array type was an incomplete type, we need to make sure 3545 // the decay ends up being the right type. 3546 llvm::Type *NewTy = ConvertType(E->getType()); 3547 Addr = Builder.CreateElementBitCast(Addr, NewTy); 3548 3549 // Note that VLA pointers are always decayed, so we don't need to do 3550 // anything here. 3551 if (!E->getType()->isVariableArrayType()) { 3552 assert(isa<llvm::ArrayType>(Addr.getElementType()) && 3553 "Expected pointer to array"); 3554 Addr = Builder.CreateConstArrayGEP(Addr, 0, "arraydecay"); 3555 } 3556 3557 // The result of this decay conversion points to an array element within the 3558 // base lvalue. However, since TBAA currently does not support representing 3559 // accesses to elements of member arrays, we conservatively represent accesses 3560 // to the pointee object as if it had no any base lvalue specified. 3561 // TODO: Support TBAA for member arrays. 3562 QualType EltType = E->getType()->castAsArrayTypeUnsafe()->getElementType(); 3563 if (BaseInfo) *BaseInfo = LV.getBaseInfo(); 3564 if (TBAAInfo) *TBAAInfo = CGM.getTBAAAccessInfo(EltType); 3565 3566 return Builder.CreateElementBitCast(Addr, ConvertTypeForMem(EltType)); 3567 } 3568 3569 /// isSimpleArrayDecayOperand - If the specified expr is a simple decay from an 3570 /// array to pointer, return the array subexpression. 3571 static const Expr *isSimpleArrayDecayOperand(const Expr *E) { 3572 // If this isn't just an array->pointer decay, bail out. 3573 const auto *CE = dyn_cast<CastExpr>(E); 3574 if (!CE || CE->getCastKind() != CK_ArrayToPointerDecay) 3575 return nullptr; 3576 3577 // If this is a decay from variable width array, bail out. 3578 const Expr *SubExpr = CE->getSubExpr(); 3579 if (SubExpr->getType()->isVariableArrayType()) 3580 return nullptr; 3581 3582 return SubExpr; 3583 } 3584 3585 static llvm::Value *emitArraySubscriptGEP(CodeGenFunction &CGF, 3586 llvm::Type *elemType, 3587 llvm::Value *ptr, 3588 ArrayRef<llvm::Value*> indices, 3589 bool inbounds, 3590 bool signedIndices, 3591 SourceLocation loc, 3592 const llvm::Twine &name = "arrayidx") { 3593 if (inbounds) { 3594 return CGF.EmitCheckedInBoundsGEP(elemType, ptr, indices, signedIndices, 3595 CodeGenFunction::NotSubtraction, loc, 3596 name); 3597 } else { 3598 return CGF.Builder.CreateGEP(elemType, ptr, indices, name); 3599 } 3600 } 3601 3602 static CharUnits getArrayElementAlign(CharUnits arrayAlign, 3603 llvm::Value *idx, 3604 CharUnits eltSize) { 3605 // If we have a constant index, we can use the exact offset of the 3606 // element we're accessing. 3607 if (auto constantIdx = dyn_cast<llvm::ConstantInt>(idx)) { 3608 CharUnits offset = constantIdx->getZExtValue() * eltSize; 3609 return arrayAlign.alignmentAtOffset(offset); 3610 3611 // Otherwise, use the worst-case alignment for any element. 3612 } else { 3613 return arrayAlign.alignmentOfArrayElement(eltSize); 3614 } 3615 } 3616 3617 static QualType getFixedSizeElementType(const ASTContext &ctx, 3618 const VariableArrayType *vla) { 3619 QualType eltType; 3620 do { 3621 eltType = vla->getElementType(); 3622 } while ((vla = ctx.getAsVariableArrayType(eltType))); 3623 return eltType; 3624 } 3625 3626 /// Given an array base, check whether its member access belongs to a record 3627 /// with preserve_access_index attribute or not. 3628 static bool IsPreserveAIArrayBase(CodeGenFunction &CGF, const Expr *ArrayBase) { 3629 if (!ArrayBase || !CGF.getDebugInfo()) 3630 return false; 3631 3632 // Only support base as either a MemberExpr or DeclRefExpr. 3633 // DeclRefExpr to cover cases like: 3634 // struct s { int a; int b[10]; }; 3635 // struct s *p; 3636 // p[1].a 3637 // p[1] will generate a DeclRefExpr and p[1].a is a MemberExpr. 3638 // p->b[5] is a MemberExpr example. 3639 const Expr *E = ArrayBase->IgnoreImpCasts(); 3640 if (const auto *ME = dyn_cast<MemberExpr>(E)) 3641 return ME->getMemberDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); 3642 3643 if (const auto *DRE = dyn_cast<DeclRefExpr>(E)) { 3644 const auto *VarDef = dyn_cast<VarDecl>(DRE->getDecl()); 3645 if (!VarDef) 3646 return false; 3647 3648 const auto *PtrT = VarDef->getType()->getAs<PointerType>(); 3649 if (!PtrT) 3650 return false; 3651 3652 const auto *PointeeT = PtrT->getPointeeType() 3653 ->getUnqualifiedDesugaredType(); 3654 if (const auto *RecT = dyn_cast<RecordType>(PointeeT)) 3655 return RecT->getDecl()->hasAttr<BPFPreserveAccessIndexAttr>(); 3656 return false; 3657 } 3658 3659 return false; 3660 } 3661 3662 static Address emitArraySubscriptGEP(CodeGenFunction &CGF, Address addr, 3663 ArrayRef<llvm::Value *> indices, 3664 QualType eltType, bool inbounds, 3665 bool signedIndices, SourceLocation loc, 3666 QualType *arrayType = nullptr, 3667 const Expr *Base = nullptr, 3668 const llvm::Twine &name = "arrayidx") { 3669 // All the indices except that last must be zero. 3670 #ifndef NDEBUG 3671 for (auto idx : indices.drop_back()) 3672 assert(isa<llvm::ConstantInt>(idx) && 3673 cast<llvm::ConstantInt>(idx)->isZero()); 3674 #endif 3675 3676 // Determine the element size of the statically-sized base. This is 3677 // the thing that the indices are expressed in terms of. 3678 if (auto vla = CGF.getContext().getAsVariableArrayType(eltType)) { 3679 eltType = getFixedSizeElementType(CGF.getContext(), vla); 3680 } 3681 3682 // We can use that to compute the best alignment of the element. 3683 CharUnits eltSize = CGF.getContext().getTypeSizeInChars(eltType); 3684 CharUnits eltAlign = 3685 getArrayElementAlign(addr.getAlignment(), indices.back(), eltSize); 3686 3687 llvm::Value *eltPtr; 3688 auto LastIndex = dyn_cast<llvm::ConstantInt>(indices.back()); 3689 if (!LastIndex || 3690 (!CGF.IsInPreservedAIRegion && !IsPreserveAIArrayBase(CGF, Base))) { 3691 eltPtr = emitArraySubscriptGEP( 3692 CGF, addr.getElementType(), addr.getPointer(), indices, inbounds, 3693 signedIndices, loc, name); 3694 } else { 3695 // Remember the original array subscript for bpf target 3696 unsigned idx = LastIndex->getZExtValue(); 3697 llvm::DIType *DbgInfo = nullptr; 3698 if (arrayType) 3699 DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType(*arrayType, loc); 3700 eltPtr = CGF.Builder.CreatePreserveArrayAccessIndex(addr.getElementType(), 3701 addr.getPointer(), 3702 indices.size() - 1, 3703 idx, DbgInfo); 3704 } 3705 3706 return Address(eltPtr, CGF.ConvertTypeForMem(eltType), eltAlign); 3707 } 3708 3709 LValue CodeGenFunction::EmitArraySubscriptExpr(const ArraySubscriptExpr *E, 3710 bool Accessed) { 3711 // The index must always be an integer, which is not an aggregate. Emit it 3712 // in lexical order (this complexity is, sadly, required by C++17). 3713 llvm::Value *IdxPre = 3714 (E->getLHS() == E->getIdx()) ? EmitScalarExpr(E->getIdx()) : nullptr; 3715 bool SignedIndices = false; 3716 auto EmitIdxAfterBase = [&, IdxPre](bool Promote) -> llvm::Value * { 3717 auto *Idx = IdxPre; 3718 if (E->getLHS() != E->getIdx()) { 3719 assert(E->getRHS() == E->getIdx() && "index was neither LHS nor RHS"); 3720 Idx = EmitScalarExpr(E->getIdx()); 3721 } 3722 3723 QualType IdxTy = E->getIdx()->getType(); 3724 bool IdxSigned = IdxTy->isSignedIntegerOrEnumerationType(); 3725 SignedIndices |= IdxSigned; 3726 3727 if (SanOpts.has(SanitizerKind::ArrayBounds)) 3728 EmitBoundsCheck(E, E->getBase(), Idx, IdxTy, Accessed); 3729 3730 // Extend or truncate the index type to 32 or 64-bits. 3731 if (Promote && Idx->getType() != IntPtrTy) 3732 Idx = Builder.CreateIntCast(Idx, IntPtrTy, IdxSigned, "idxprom"); 3733 3734 return Idx; 3735 }; 3736 IdxPre = nullptr; 3737 3738 // If the base is a vector type, then we are forming a vector element lvalue 3739 // with this subscript. 3740 if (E->getBase()->getType()->isVectorType() && 3741 !isa<ExtVectorElementExpr>(E->getBase())) { 3742 // Emit the vector as an lvalue to get its address. 3743 LValue LHS = EmitLValue(E->getBase()); 3744 auto *Idx = EmitIdxAfterBase(/*Promote*/false); 3745 assert(LHS.isSimple() && "Can only subscript lvalue vectors here!"); 3746 return LValue::MakeVectorElt(LHS.getAddress(*this), Idx, 3747 E->getBase()->getType(), LHS.getBaseInfo(), 3748 TBAAAccessInfo()); 3749 } 3750 3751 // All the other cases basically behave like simple offsetting. 3752 3753 // Handle the extvector case we ignored above. 3754 if (isa<ExtVectorElementExpr>(E->getBase())) { 3755 LValue LV = EmitLValue(E->getBase()); 3756 auto *Idx = EmitIdxAfterBase(/*Promote*/true); 3757 Address Addr = EmitExtVectorElementLValue(LV); 3758 3759 QualType EltType = LV.getType()->castAs<VectorType>()->getElementType(); 3760 Addr = emitArraySubscriptGEP(*this, Addr, Idx, EltType, /*inbounds*/ true, 3761 SignedIndices, E->getExprLoc()); 3762 return MakeAddrLValue(Addr, EltType, LV.getBaseInfo(), 3763 CGM.getTBAAInfoForSubobject(LV, EltType)); 3764 } 3765 3766 LValueBaseInfo EltBaseInfo; 3767 TBAAAccessInfo EltTBAAInfo; 3768 Address Addr = Address::invalid(); 3769 if (const VariableArrayType *vla = 3770 getContext().getAsVariableArrayType(E->getType())) { 3771 // The base must be a pointer, which is not an aggregate. Emit 3772 // it. It needs to be emitted first in case it's what captures 3773 // the VLA bounds. 3774 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo); 3775 auto *Idx = EmitIdxAfterBase(/*Promote*/true); 3776 3777 // The element count here is the total number of non-VLA elements. 3778 llvm::Value *numElements = getVLASize(vla).NumElts; 3779 3780 // Effectively, the multiply by the VLA size is part of the GEP. 3781 // GEP indexes are signed, and scaling an index isn't permitted to 3782 // signed-overflow, so we use the same semantics for our explicit 3783 // multiply. We suppress this if overflow is not undefined behavior. 3784 if (getLangOpts().isSignedOverflowDefined()) { 3785 Idx = Builder.CreateMul(Idx, numElements); 3786 } else { 3787 Idx = Builder.CreateNSWMul(Idx, numElements); 3788 } 3789 3790 Addr = emitArraySubscriptGEP(*this, Addr, Idx, vla->getElementType(), 3791 !getLangOpts().isSignedOverflowDefined(), 3792 SignedIndices, E->getExprLoc()); 3793 3794 } else if (const ObjCObjectType *OIT = E->getType()->getAs<ObjCObjectType>()){ 3795 // Indexing over an interface, as in "NSString *P; P[4];" 3796 3797 // Emit the base pointer. 3798 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo); 3799 auto *Idx = EmitIdxAfterBase(/*Promote*/true); 3800 3801 CharUnits InterfaceSize = getContext().getTypeSizeInChars(OIT); 3802 llvm::Value *InterfaceSizeVal = 3803 llvm::ConstantInt::get(Idx->getType(), InterfaceSize.getQuantity()); 3804 3805 llvm::Value *ScaledIdx = Builder.CreateMul(Idx, InterfaceSizeVal); 3806 3807 // We don't necessarily build correct LLVM struct types for ObjC 3808 // interfaces, so we can't rely on GEP to do this scaling 3809 // correctly, so we need to cast to i8*. FIXME: is this actually 3810 // true? A lot of other things in the fragile ABI would break... 3811 llvm::Type *OrigBaseTy = Addr.getType(); 3812 Addr = Builder.CreateElementBitCast(Addr, Int8Ty); 3813 3814 // Do the GEP. 3815 CharUnits EltAlign = 3816 getArrayElementAlign(Addr.getAlignment(), Idx, InterfaceSize); 3817 llvm::Value *EltPtr = 3818 emitArraySubscriptGEP(*this, Addr.getElementType(), Addr.getPointer(), 3819 ScaledIdx, false, SignedIndices, E->getExprLoc()); 3820 Addr = Address(EltPtr, EltAlign); 3821 3822 // Cast back. 3823 Addr = Builder.CreateBitCast(Addr, OrigBaseTy); 3824 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) { 3825 // If this is A[i] where A is an array, the frontend will have decayed the 3826 // base to be a ArrayToPointerDecay implicit cast. While correct, it is 3827 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a 3828 // "gep x, i" here. Emit one "gep A, 0, i". 3829 assert(Array->getType()->isArrayType() && 3830 "Array to pointer decay must have array source type!"); 3831 LValue ArrayLV; 3832 // For simple multidimensional array indexing, set the 'accessed' flag for 3833 // better bounds-checking of the base expression. 3834 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array)) 3835 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true); 3836 else 3837 ArrayLV = EmitLValue(Array); 3838 auto *Idx = EmitIdxAfterBase(/*Promote*/true); 3839 3840 // Propagate the alignment from the array itself to the result. 3841 QualType arrayType = Array->getType(); 3842 Addr = emitArraySubscriptGEP( 3843 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx}, 3844 E->getType(), !getLangOpts().isSignedOverflowDefined(), SignedIndices, 3845 E->getExprLoc(), &arrayType, E->getBase()); 3846 EltBaseInfo = ArrayLV.getBaseInfo(); 3847 EltTBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, E->getType()); 3848 } else { 3849 // The base must be a pointer; emit it with an estimate of its alignment. 3850 Addr = EmitPointerWithAlignment(E->getBase(), &EltBaseInfo, &EltTBAAInfo); 3851 auto *Idx = EmitIdxAfterBase(/*Promote*/true); 3852 QualType ptrType = E->getBase()->getType(); 3853 Addr = emitArraySubscriptGEP(*this, Addr, Idx, E->getType(), 3854 !getLangOpts().isSignedOverflowDefined(), 3855 SignedIndices, E->getExprLoc(), &ptrType, 3856 E->getBase()); 3857 } 3858 3859 LValue LV = MakeAddrLValue(Addr, E->getType(), EltBaseInfo, EltTBAAInfo); 3860 3861 if (getLangOpts().ObjC && 3862 getLangOpts().getGC() != LangOptions::NonGC) { 3863 LV.setNonGC(!E->isOBJCGCCandidate(getContext())); 3864 setObjCGCLValueClass(getContext(), E, LV); 3865 } 3866 return LV; 3867 } 3868 3869 LValue CodeGenFunction::EmitMatrixSubscriptExpr(const MatrixSubscriptExpr *E) { 3870 assert( 3871 !E->isIncomplete() && 3872 "incomplete matrix subscript expressions should be rejected during Sema"); 3873 LValue Base = EmitLValue(E->getBase()); 3874 llvm::Value *RowIdx = EmitScalarExpr(E->getRowIdx()); 3875 llvm::Value *ColIdx = EmitScalarExpr(E->getColumnIdx()); 3876 llvm::Value *NumRows = Builder.getIntN( 3877 RowIdx->getType()->getScalarSizeInBits(), 3878 E->getBase()->getType()->castAs<ConstantMatrixType>()->getNumRows()); 3879 llvm::Value *FinalIdx = 3880 Builder.CreateAdd(Builder.CreateMul(ColIdx, NumRows), RowIdx); 3881 return LValue::MakeMatrixElt( 3882 MaybeConvertMatrixAddress(Base.getAddress(*this), *this), FinalIdx, 3883 E->getBase()->getType(), Base.getBaseInfo(), TBAAAccessInfo()); 3884 } 3885 3886 static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base, 3887 LValueBaseInfo &BaseInfo, 3888 TBAAAccessInfo &TBAAInfo, 3889 QualType BaseTy, QualType ElTy, 3890 bool IsLowerBound) { 3891 LValue BaseLVal; 3892 if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) { 3893 BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound); 3894 if (BaseTy->isArrayType()) { 3895 Address Addr = BaseLVal.getAddress(CGF); 3896 BaseInfo = BaseLVal.getBaseInfo(); 3897 3898 // If the array type was an incomplete type, we need to make sure 3899 // the decay ends up being the right type. 3900 llvm::Type *NewTy = CGF.ConvertType(BaseTy); 3901 Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy); 3902 3903 // Note that VLA pointers are always decayed, so we don't need to do 3904 // anything here. 3905 if (!BaseTy->isVariableArrayType()) { 3906 assert(isa<llvm::ArrayType>(Addr.getElementType()) && 3907 "Expected pointer to array"); 3908 Addr = CGF.Builder.CreateConstArrayGEP(Addr, 0, "arraydecay"); 3909 } 3910 3911 return CGF.Builder.CreateElementBitCast(Addr, 3912 CGF.ConvertTypeForMem(ElTy)); 3913 } 3914 LValueBaseInfo TypeBaseInfo; 3915 TBAAAccessInfo TypeTBAAInfo; 3916 CharUnits Align = 3917 CGF.CGM.getNaturalTypeAlignment(ElTy, &TypeBaseInfo, &TypeTBAAInfo); 3918 BaseInfo.mergeForCast(TypeBaseInfo); 3919 TBAAInfo = CGF.CGM.mergeTBAAInfoForCast(TBAAInfo, TypeTBAAInfo); 3920 return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress(CGF)), Align); 3921 } 3922 return CGF.EmitPointerWithAlignment(Base, &BaseInfo, &TBAAInfo); 3923 } 3924 3925 LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E, 3926 bool IsLowerBound) { 3927 QualType BaseTy = OMPArraySectionExpr::getBaseOriginalType(E->getBase()); 3928 QualType ResultExprTy; 3929 if (auto *AT = getContext().getAsArrayType(BaseTy)) 3930 ResultExprTy = AT->getElementType(); 3931 else 3932 ResultExprTy = BaseTy->getPointeeType(); 3933 llvm::Value *Idx = nullptr; 3934 if (IsLowerBound || E->getColonLocFirst().isInvalid()) { 3935 // Requesting lower bound or upper bound, but without provided length and 3936 // without ':' symbol for the default length -> length = 1. 3937 // Idx = LowerBound ?: 0; 3938 if (auto *LowerBound = E->getLowerBound()) { 3939 Idx = Builder.CreateIntCast( 3940 EmitScalarExpr(LowerBound), IntPtrTy, 3941 LowerBound->getType()->hasSignedIntegerRepresentation()); 3942 } else 3943 Idx = llvm::ConstantInt::getNullValue(IntPtrTy); 3944 } else { 3945 // Try to emit length or lower bound as constant. If this is possible, 1 3946 // is subtracted from constant length or lower bound. Otherwise, emit LLVM 3947 // IR (LB + Len) - 1. 3948 auto &C = CGM.getContext(); 3949 auto *Length = E->getLength(); 3950 llvm::APSInt ConstLength; 3951 if (Length) { 3952 // Idx = LowerBound + Length - 1; 3953 if (Optional<llvm::APSInt> CL = Length->getIntegerConstantExpr(C)) { 3954 ConstLength = CL->zextOrTrunc(PointerWidthInBits); 3955 Length = nullptr; 3956 } 3957 auto *LowerBound = E->getLowerBound(); 3958 llvm::APSInt ConstLowerBound(PointerWidthInBits, /*isUnsigned=*/false); 3959 if (LowerBound) { 3960 if (Optional<llvm::APSInt> LB = LowerBound->getIntegerConstantExpr(C)) { 3961 ConstLowerBound = LB->zextOrTrunc(PointerWidthInBits); 3962 LowerBound = nullptr; 3963 } 3964 } 3965 if (!Length) 3966 --ConstLength; 3967 else if (!LowerBound) 3968 --ConstLowerBound; 3969 3970 if (Length || LowerBound) { 3971 auto *LowerBoundVal = 3972 LowerBound 3973 ? Builder.CreateIntCast( 3974 EmitScalarExpr(LowerBound), IntPtrTy, 3975 LowerBound->getType()->hasSignedIntegerRepresentation()) 3976 : llvm::ConstantInt::get(IntPtrTy, ConstLowerBound); 3977 auto *LengthVal = 3978 Length 3979 ? Builder.CreateIntCast( 3980 EmitScalarExpr(Length), IntPtrTy, 3981 Length->getType()->hasSignedIntegerRepresentation()) 3982 : llvm::ConstantInt::get(IntPtrTy, ConstLength); 3983 Idx = Builder.CreateAdd(LowerBoundVal, LengthVal, "lb_add_len", 3984 /*HasNUW=*/false, 3985 !getLangOpts().isSignedOverflowDefined()); 3986 if (Length && LowerBound) { 3987 Idx = Builder.CreateSub( 3988 Idx, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "idx_sub_1", 3989 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined()); 3990 } 3991 } else 3992 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound); 3993 } else { 3994 // Idx = ArraySize - 1; 3995 QualType ArrayTy = BaseTy->isPointerType() 3996 ? E->getBase()->IgnoreParenImpCasts()->getType() 3997 : BaseTy; 3998 if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) { 3999 Length = VAT->getSizeExpr(); 4000 if (Optional<llvm::APSInt> L = Length->getIntegerConstantExpr(C)) { 4001 ConstLength = *L; 4002 Length = nullptr; 4003 } 4004 } else { 4005 auto *CAT = C.getAsConstantArrayType(ArrayTy); 4006 ConstLength = CAT->getSize(); 4007 } 4008 if (Length) { 4009 auto *LengthVal = Builder.CreateIntCast( 4010 EmitScalarExpr(Length), IntPtrTy, 4011 Length->getType()->hasSignedIntegerRepresentation()); 4012 Idx = Builder.CreateSub( 4013 LengthVal, llvm::ConstantInt::get(IntPtrTy, /*V=*/1), "len_sub_1", 4014 /*HasNUW=*/false, !getLangOpts().isSignedOverflowDefined()); 4015 } else { 4016 ConstLength = ConstLength.zextOrTrunc(PointerWidthInBits); 4017 --ConstLength; 4018 Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength); 4019 } 4020 } 4021 } 4022 assert(Idx); 4023 4024 Address EltPtr = Address::invalid(); 4025 LValueBaseInfo BaseInfo; 4026 TBAAAccessInfo TBAAInfo; 4027 if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) { 4028 // The base must be a pointer, which is not an aggregate. Emit 4029 // it. It needs to be emitted first in case it's what captures 4030 // the VLA bounds. 4031 Address Base = 4032 emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, TBAAInfo, 4033 BaseTy, VLA->getElementType(), IsLowerBound); 4034 // The element count here is the total number of non-VLA elements. 4035 llvm::Value *NumElements = getVLASize(VLA).NumElts; 4036 4037 // Effectively, the multiply by the VLA size is part of the GEP. 4038 // GEP indexes are signed, and scaling an index isn't permitted to 4039 // signed-overflow, so we use the same semantics for our explicit 4040 // multiply. We suppress this if overflow is not undefined behavior. 4041 if (getLangOpts().isSignedOverflowDefined()) 4042 Idx = Builder.CreateMul(Idx, NumElements); 4043 else 4044 Idx = Builder.CreateNSWMul(Idx, NumElements); 4045 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(), 4046 !getLangOpts().isSignedOverflowDefined(), 4047 /*signedIndices=*/false, E->getExprLoc()); 4048 } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) { 4049 // If this is A[i] where A is an array, the frontend will have decayed the 4050 // base to be a ArrayToPointerDecay implicit cast. While correct, it is 4051 // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a 4052 // "gep x, i" here. Emit one "gep A, 0, i". 4053 assert(Array->getType()->isArrayType() && 4054 "Array to pointer decay must have array source type!"); 4055 LValue ArrayLV; 4056 // For simple multidimensional array indexing, set the 'accessed' flag for 4057 // better bounds-checking of the base expression. 4058 if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array)) 4059 ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true); 4060 else 4061 ArrayLV = EmitLValue(Array); 4062 4063 // Propagate the alignment from the array itself to the result. 4064 EltPtr = emitArraySubscriptGEP( 4065 *this, ArrayLV.getAddress(*this), {CGM.getSize(CharUnits::Zero()), Idx}, 4066 ResultExprTy, !getLangOpts().isSignedOverflowDefined(), 4067 /*signedIndices=*/false, E->getExprLoc()); 4068 BaseInfo = ArrayLV.getBaseInfo(); 4069 TBAAInfo = CGM.getTBAAInfoForSubobject(ArrayLV, ResultExprTy); 4070 } else { 4071 Address Base = emitOMPArraySectionBase(*this, E->getBase(), BaseInfo, 4072 TBAAInfo, BaseTy, ResultExprTy, 4073 IsLowerBound); 4074 EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy, 4075 !getLangOpts().isSignedOverflowDefined(), 4076 /*signedIndices=*/false, E->getExprLoc()); 4077 } 4078 4079 return MakeAddrLValue(EltPtr, ResultExprTy, BaseInfo, TBAAInfo); 4080 } 4081 4082 LValue CodeGenFunction:: 4083 EmitExtVectorElementExpr(const ExtVectorElementExpr *E) { 4084 // Emit the base vector as an l-value. 4085 LValue Base; 4086 4087 // ExtVectorElementExpr's base can either be a vector or pointer to vector. 4088 if (E->isArrow()) { 4089 // If it is a pointer to a vector, emit the address and form an lvalue with 4090 // it. 4091 LValueBaseInfo BaseInfo; 4092 TBAAAccessInfo TBAAInfo; 4093 Address Ptr = EmitPointerWithAlignment(E->getBase(), &BaseInfo, &TBAAInfo); 4094 const auto *PT = E->getBase()->getType()->castAs<PointerType>(); 4095 Base = MakeAddrLValue(Ptr, PT->getPointeeType(), BaseInfo, TBAAInfo); 4096 Base.getQuals().removeObjCGCAttr(); 4097 } else if (E->getBase()->isGLValue()) { 4098 // Otherwise, if the base is an lvalue ( as in the case of foo.x.x), 4099 // emit the base as an lvalue. 4100 assert(E->getBase()->getType()->isVectorType()); 4101 Base = EmitLValue(E->getBase()); 4102 } else { 4103 // Otherwise, the base is a normal rvalue (as in (V+V).x), emit it as such. 4104 assert(E->getBase()->getType()->isVectorType() && 4105 "Result must be a vector"); 4106 llvm::Value *Vec = EmitScalarExpr(E->getBase()); 4107 4108 // Store the vector to memory (because LValue wants an address). 4109 Address VecMem = CreateMemTemp(E->getBase()->getType()); 4110 Builder.CreateStore(Vec, VecMem); 4111 Base = MakeAddrLValue(VecMem, E->getBase()->getType(), 4112 AlignmentSource::Decl); 4113 } 4114 4115 QualType type = 4116 E->getType().withCVRQualifiers(Base.getQuals().getCVRQualifiers()); 4117 4118 // Encode the element access list into a vector of unsigned indices. 4119 SmallVector<uint32_t, 4> Indices; 4120 E->getEncodedElementAccess(Indices); 4121 4122 if (Base.isSimple()) { 4123 llvm::Constant *CV = 4124 llvm::ConstantDataVector::get(getLLVMContext(), Indices); 4125 return LValue::MakeExtVectorElt(Base.getAddress(*this), CV, type, 4126 Base.getBaseInfo(), TBAAAccessInfo()); 4127 } 4128 assert(Base.isExtVectorElt() && "Can only subscript lvalue vec elts here!"); 4129 4130 llvm::Constant *BaseElts = Base.getExtVectorElts(); 4131 SmallVector<llvm::Constant *, 4> CElts; 4132 4133 for (unsigned i = 0, e = Indices.size(); i != e; ++i) 4134 CElts.push_back(BaseElts->getAggregateElement(Indices[i])); 4135 llvm::Constant *CV = llvm::ConstantVector::get(CElts); 4136 return LValue::MakeExtVectorElt(Base.getExtVectorAddress(), CV, type, 4137 Base.getBaseInfo(), TBAAAccessInfo()); 4138 } 4139 4140 LValue CodeGenFunction::EmitMemberExpr(const MemberExpr *E) { 4141 if (DeclRefExpr *DRE = tryToConvertMemberExprToDeclRefExpr(*this, E)) { 4142 EmitIgnoredExpr(E->getBase()); 4143 return EmitDeclRefLValue(DRE); 4144 } 4145 4146 Expr *BaseExpr = E->getBase(); 4147 // If this is s.x, emit s as an lvalue. If it is s->x, emit s as a scalar. 4148 LValue BaseLV; 4149 if (E->isArrow()) { 4150 LValueBaseInfo BaseInfo; 4151 TBAAAccessInfo TBAAInfo; 4152 Address Addr = EmitPointerWithAlignment(BaseExpr, &BaseInfo, &TBAAInfo); 4153 QualType PtrTy = BaseExpr->getType()->getPointeeType(); 4154 SanitizerSet SkippedChecks; 4155 bool IsBaseCXXThis = IsWrappedCXXThis(BaseExpr); 4156 if (IsBaseCXXThis) 4157 SkippedChecks.set(SanitizerKind::Alignment, true); 4158 if (IsBaseCXXThis || isa<DeclRefExpr>(BaseExpr)) 4159 SkippedChecks.set(SanitizerKind::Null, true); 4160 EmitTypeCheck(TCK_MemberAccess, E->getExprLoc(), Addr.getPointer(), PtrTy, 4161 /*Alignment=*/CharUnits::Zero(), SkippedChecks); 4162 BaseLV = MakeAddrLValue(Addr, PtrTy, BaseInfo, TBAAInfo); 4163 } else 4164 BaseLV = EmitCheckedLValue(BaseExpr, TCK_MemberAccess); 4165 4166 NamedDecl *ND = E->getMemberDecl(); 4167 if (auto *Field = dyn_cast<FieldDecl>(ND)) { 4168 LValue LV = EmitLValueForField(BaseLV, Field); 4169 setObjCGCLValueClass(getContext(), E, LV); 4170 if (getLangOpts().OpenMP) { 4171 // If the member was explicitly marked as nontemporal, mark it as 4172 // nontemporal. If the base lvalue is marked as nontemporal, mark access 4173 // to children as nontemporal too. 4174 if ((IsWrappedCXXThis(BaseExpr) && 4175 CGM.getOpenMPRuntime().isNontemporalDecl(Field)) || 4176 BaseLV.isNontemporal()) 4177 LV.setNontemporal(/*Value=*/true); 4178 } 4179 return LV; 4180 } 4181 4182 if (const auto *FD = dyn_cast<FunctionDecl>(ND)) 4183 return EmitFunctionDeclLValue(*this, E, FD); 4184 4185 llvm_unreachable("Unhandled member declaration!"); 4186 } 4187 4188 /// Given that we are currently emitting a lambda, emit an l-value for 4189 /// one of its members. 4190 LValue CodeGenFunction::EmitLValueForLambdaField(const FieldDecl *Field) { 4191 if (CurCodeDecl) { 4192 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent()->isLambda()); 4193 assert(cast<CXXMethodDecl>(CurCodeDecl)->getParent() == Field->getParent()); 4194 } 4195 QualType LambdaTagType = 4196 getContext().getTagDeclType(Field->getParent()); 4197 LValue LambdaLV = MakeNaturalAlignAddrLValue(CXXABIThisValue, LambdaTagType); 4198 return EmitLValueForField(LambdaLV, Field); 4199 } 4200 4201 /// Get the field index in the debug info. The debug info structure/union 4202 /// will ignore the unnamed bitfields. 4203 unsigned CodeGenFunction::getDebugInfoFIndex(const RecordDecl *Rec, 4204 unsigned FieldIndex) { 4205 unsigned I = 0, Skipped = 0; 4206 4207 for (auto F : Rec->getDefinition()->fields()) { 4208 if (I == FieldIndex) 4209 break; 4210 if (F->isUnnamedBitfield()) 4211 Skipped++; 4212 I++; 4213 } 4214 4215 return FieldIndex - Skipped; 4216 } 4217 4218 /// Get the address of a zero-sized field within a record. The resulting 4219 /// address doesn't necessarily have the right type. 4220 static Address emitAddrOfZeroSizeField(CodeGenFunction &CGF, Address Base, 4221 const FieldDecl *Field) { 4222 CharUnits Offset = CGF.getContext().toCharUnitsFromBits( 4223 CGF.getContext().getFieldOffset(Field)); 4224 if (Offset.isZero()) 4225 return Base; 4226 Base = CGF.Builder.CreateElementBitCast(Base, CGF.Int8Ty); 4227 return CGF.Builder.CreateConstInBoundsByteGEP(Base, Offset); 4228 } 4229 4230 /// Drill down to the storage of a field without walking into 4231 /// reference types. 4232 /// 4233 /// The resulting address doesn't necessarily have the right type. 4234 static Address emitAddrOfFieldStorage(CodeGenFunction &CGF, Address base, 4235 const FieldDecl *field) { 4236 if (field->isZeroSize(CGF.getContext())) 4237 return emitAddrOfZeroSizeField(CGF, base, field); 4238 4239 const RecordDecl *rec = field->getParent(); 4240 4241 unsigned idx = 4242 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field); 4243 4244 return CGF.Builder.CreateStructGEP(base, idx, field->getName()); 4245 } 4246 4247 static Address emitPreserveStructAccess(CodeGenFunction &CGF, LValue base, 4248 Address addr, const FieldDecl *field) { 4249 const RecordDecl *rec = field->getParent(); 4250 llvm::DIType *DbgInfo = CGF.getDebugInfo()->getOrCreateStandaloneType( 4251 base.getType(), rec->getLocation()); 4252 4253 unsigned idx = 4254 CGF.CGM.getTypes().getCGRecordLayout(rec).getLLVMFieldNo(field); 4255 4256 return CGF.Builder.CreatePreserveStructAccessIndex( 4257 addr, idx, CGF.getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo); 4258 } 4259 4260 static bool hasAnyVptr(const QualType Type, const ASTContext &Context) { 4261 const auto *RD = Type.getTypePtr()->getAsCXXRecordDecl(); 4262 if (!RD) 4263 return false; 4264 4265 if (RD->isDynamicClass()) 4266 return true; 4267 4268 for (const auto &Base : RD->bases()) 4269 if (hasAnyVptr(Base.getType(), Context)) 4270 return true; 4271 4272 for (const FieldDecl *Field : RD->fields()) 4273 if (hasAnyVptr(Field->getType(), Context)) 4274 return true; 4275 4276 return false; 4277 } 4278 4279 LValue CodeGenFunction::EmitLValueForField(LValue base, 4280 const FieldDecl *field) { 4281 LValueBaseInfo BaseInfo = base.getBaseInfo(); 4282 4283 if (field->isBitField()) { 4284 const CGRecordLayout &RL = 4285 CGM.getTypes().getCGRecordLayout(field->getParent()); 4286 const CGBitFieldInfo &Info = RL.getBitFieldInfo(field); 4287 const bool UseVolatile = isAAPCS(CGM.getTarget()) && 4288 CGM.getCodeGenOpts().AAPCSBitfieldWidth && 4289 Info.VolatileStorageSize != 0 && 4290 field->getType() 4291 .withCVRQualifiers(base.getVRQualifiers()) 4292 .isVolatileQualified(); 4293 Address Addr = base.getAddress(*this); 4294 unsigned Idx = RL.getLLVMFieldNo(field); 4295 const RecordDecl *rec = field->getParent(); 4296 if (!UseVolatile) { 4297 if (!IsInPreservedAIRegion && 4298 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) { 4299 if (Idx != 0) 4300 // For structs, we GEP to the field that the record layout suggests. 4301 Addr = Builder.CreateStructGEP(Addr, Idx, field->getName()); 4302 } else { 4303 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateRecordType( 4304 getContext().getRecordType(rec), rec->getLocation()); 4305 Addr = Builder.CreatePreserveStructAccessIndex( 4306 Addr, Idx, getDebugInfoFIndex(rec, field->getFieldIndex()), 4307 DbgInfo); 4308 } 4309 } 4310 const unsigned SS = 4311 UseVolatile ? Info.VolatileStorageSize : Info.StorageSize; 4312 // Get the access type. 4313 llvm::Type *FieldIntTy = llvm::Type::getIntNTy(getLLVMContext(), SS); 4314 if (Addr.getElementType() != FieldIntTy) 4315 Addr = Builder.CreateElementBitCast(Addr, FieldIntTy); 4316 if (UseVolatile) { 4317 const unsigned VolatileOffset = Info.VolatileStorageOffset.getQuantity(); 4318 if (VolatileOffset) 4319 Addr = Builder.CreateConstInBoundsGEP(Addr, VolatileOffset); 4320 } 4321 4322 QualType fieldType = 4323 field->getType().withCVRQualifiers(base.getVRQualifiers()); 4324 // TODO: Support TBAA for bit fields. 4325 LValueBaseInfo FieldBaseInfo(BaseInfo.getAlignmentSource()); 4326 return LValue::MakeBitfield(Addr, Info, fieldType, FieldBaseInfo, 4327 TBAAAccessInfo()); 4328 } 4329 4330 // Fields of may-alias structures are may-alias themselves. 4331 // FIXME: this should get propagated down through anonymous structs 4332 // and unions. 4333 QualType FieldType = field->getType(); 4334 const RecordDecl *rec = field->getParent(); 4335 AlignmentSource BaseAlignSource = BaseInfo.getAlignmentSource(); 4336 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(BaseAlignSource)); 4337 TBAAAccessInfo FieldTBAAInfo; 4338 if (base.getTBAAInfo().isMayAlias() || 4339 rec->hasAttr<MayAliasAttr>() || FieldType->isVectorType()) { 4340 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo(); 4341 } else if (rec->isUnion()) { 4342 // TODO: Support TBAA for unions. 4343 FieldTBAAInfo = TBAAAccessInfo::getMayAliasInfo(); 4344 } else { 4345 // If no base type been assigned for the base access, then try to generate 4346 // one for this base lvalue. 4347 FieldTBAAInfo = base.getTBAAInfo(); 4348 if (!FieldTBAAInfo.BaseType) { 4349 FieldTBAAInfo.BaseType = CGM.getTBAABaseTypeInfo(base.getType()); 4350 assert(!FieldTBAAInfo.Offset && 4351 "Nonzero offset for an access with no base type!"); 4352 } 4353 4354 // Adjust offset to be relative to the base type. 4355 const ASTRecordLayout &Layout = 4356 getContext().getASTRecordLayout(field->getParent()); 4357 unsigned CharWidth = getContext().getCharWidth(); 4358 if (FieldTBAAInfo.BaseType) 4359 FieldTBAAInfo.Offset += 4360 Layout.getFieldOffset(field->getFieldIndex()) / CharWidth; 4361 4362 // Update the final access type and size. 4363 FieldTBAAInfo.AccessType = CGM.getTBAATypeInfo(FieldType); 4364 FieldTBAAInfo.Size = 4365 getContext().getTypeSizeInChars(FieldType).getQuantity(); 4366 } 4367 4368 Address addr = base.getAddress(*this); 4369 if (auto *ClassDef = dyn_cast<CXXRecordDecl>(rec)) { 4370 if (CGM.getCodeGenOpts().StrictVTablePointers && 4371 ClassDef->isDynamicClass()) { 4372 // Getting to any field of dynamic object requires stripping dynamic 4373 // information provided by invariant.group. This is because accessing 4374 // fields may leak the real address of dynamic object, which could result 4375 // in miscompilation when leaked pointer would be compared. 4376 auto *stripped = Builder.CreateStripInvariantGroup(addr.getPointer()); 4377 addr = Address(stripped, addr.getAlignment()); 4378 } 4379 } 4380 4381 unsigned RecordCVR = base.getVRQualifiers(); 4382 if (rec->isUnion()) { 4383 // For unions, there is no pointer adjustment. 4384 if (CGM.getCodeGenOpts().StrictVTablePointers && 4385 hasAnyVptr(FieldType, getContext())) 4386 // Because unions can easily skip invariant.barriers, we need to add 4387 // a barrier every time CXXRecord field with vptr is referenced. 4388 addr = Builder.CreateLaunderInvariantGroup(addr); 4389 4390 if (IsInPreservedAIRegion || 4391 (getDebugInfo() && rec->hasAttr<BPFPreserveAccessIndexAttr>())) { 4392 // Remember the original union field index 4393 llvm::DIType *DbgInfo = getDebugInfo()->getOrCreateStandaloneType(base.getType(), 4394 rec->getLocation()); 4395 addr = Address( 4396 Builder.CreatePreserveUnionAccessIndex( 4397 addr.getPointer(), getDebugInfoFIndex(rec, field->getFieldIndex()), DbgInfo), 4398 addr.getAlignment()); 4399 } 4400 4401 if (FieldType->isReferenceType()) 4402 addr = Builder.CreateElementBitCast( 4403 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName()); 4404 } else { 4405 if (!IsInPreservedAIRegion && 4406 (!getDebugInfo() || !rec->hasAttr<BPFPreserveAccessIndexAttr>())) 4407 // For structs, we GEP to the field that the record layout suggests. 4408 addr = emitAddrOfFieldStorage(*this, addr, field); 4409 else 4410 // Remember the original struct field index 4411 addr = emitPreserveStructAccess(*this, base, addr, field); 4412 } 4413 4414 // If this is a reference field, load the reference right now. 4415 if (FieldType->isReferenceType()) { 4416 LValue RefLVal = 4417 MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo); 4418 if (RecordCVR & Qualifiers::Volatile) 4419 RefLVal.getQuals().addVolatile(); 4420 addr = EmitLoadOfReference(RefLVal, &FieldBaseInfo, &FieldTBAAInfo); 4421 4422 // Qualifiers on the struct don't apply to the referencee. 4423 RecordCVR = 0; 4424 FieldType = FieldType->getPointeeType(); 4425 } 4426 4427 // Make sure that the address is pointing to the right type. This is critical 4428 // for both unions and structs. A union needs a bitcast, a struct element 4429 // will need a bitcast if the LLVM type laid out doesn't match the desired 4430 // type. 4431 addr = Builder.CreateElementBitCast( 4432 addr, CGM.getTypes().ConvertTypeForMem(FieldType), field->getName()); 4433 4434 if (field->hasAttr<AnnotateAttr>()) 4435 addr = EmitFieldAnnotations(field, addr); 4436 4437 LValue LV = MakeAddrLValue(addr, FieldType, FieldBaseInfo, FieldTBAAInfo); 4438 LV.getQuals().addCVRQualifiers(RecordCVR); 4439 4440 // __weak attribute on a field is ignored. 4441 if (LV.getQuals().getObjCGCAttr() == Qualifiers::Weak) 4442 LV.getQuals().removeObjCGCAttr(); 4443 4444 return LV; 4445 } 4446 4447 LValue 4448 CodeGenFunction::EmitLValueForFieldInitialization(LValue Base, 4449 const FieldDecl *Field) { 4450 QualType FieldType = Field->getType(); 4451 4452 if (!FieldType->isReferenceType()) 4453 return EmitLValueForField(Base, Field); 4454 4455 Address V = emitAddrOfFieldStorage(*this, Base.getAddress(*this), Field); 4456 4457 // Make sure that the address is pointing to the right type. 4458 llvm::Type *llvmType = ConvertTypeForMem(FieldType); 4459 V = Builder.CreateElementBitCast(V, llvmType, Field->getName()); 4460 4461 // TODO: Generate TBAA information that describes this access as a structure 4462 // member access and not just an access to an object of the field's type. This 4463 // should be similar to what we do in EmitLValueForField(). 4464 LValueBaseInfo BaseInfo = Base.getBaseInfo(); 4465 AlignmentSource FieldAlignSource = BaseInfo.getAlignmentSource(); 4466 LValueBaseInfo FieldBaseInfo(getFieldAlignmentSource(FieldAlignSource)); 4467 return MakeAddrLValue(V, FieldType, FieldBaseInfo, 4468 CGM.getTBAAInfoForSubobject(Base, FieldType)); 4469 } 4470 4471 LValue CodeGenFunction::EmitCompoundLiteralLValue(const CompoundLiteralExpr *E){ 4472 if (E->isFileScope()) { 4473 ConstantAddress GlobalPtr = CGM.GetAddrOfConstantCompoundLiteral(E); 4474 return MakeAddrLValue(GlobalPtr, E->getType(), AlignmentSource::Decl); 4475 } 4476 if (E->getType()->isVariablyModifiedType()) 4477 // make sure to emit the VLA size. 4478 EmitVariablyModifiedType(E->getType()); 4479 4480 Address DeclPtr = CreateMemTemp(E->getType(), ".compoundliteral"); 4481 const Expr *InitExpr = E->getInitializer(); 4482 LValue Result = MakeAddrLValue(DeclPtr, E->getType(), AlignmentSource::Decl); 4483 4484 EmitAnyExprToMem(InitExpr, DeclPtr, E->getType().getQualifiers(), 4485 /*Init*/ true); 4486 4487 // Block-scope compound literals are destroyed at the end of the enclosing 4488 // scope in C. 4489 if (!getLangOpts().CPlusPlus) 4490 if (QualType::DestructionKind DtorKind = E->getType().isDestructedType()) 4491 pushLifetimeExtendedDestroy(getCleanupKind(DtorKind), DeclPtr, 4492 E->getType(), getDestroyer(DtorKind), 4493 DtorKind & EHCleanup); 4494 4495 return Result; 4496 } 4497 4498 LValue CodeGenFunction::EmitInitListLValue(const InitListExpr *E) { 4499 if (!E->isGLValue()) 4500 // Initializing an aggregate temporary in C++11: T{...}. 4501 return EmitAggExprToLValue(E); 4502 4503 // An lvalue initializer list must be initializing a reference. 4504 assert(E->isTransparent() && "non-transparent glvalue init list"); 4505 return EmitLValue(E->getInit(0)); 4506 } 4507 4508 /// Emit the operand of a glvalue conditional operator. This is either a glvalue 4509 /// or a (possibly-parenthesized) throw-expression. If this is a throw, no 4510 /// LValue is returned and the current block has been terminated. 4511 static Optional<LValue> EmitLValueOrThrowExpression(CodeGenFunction &CGF, 4512 const Expr *Operand) { 4513 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(Operand->IgnoreParens())) { 4514 CGF.EmitCXXThrowExpr(ThrowExpr, /*KeepInsertionPoint*/false); 4515 return None; 4516 } 4517 4518 return CGF.EmitLValue(Operand); 4519 } 4520 4521 LValue CodeGenFunction:: 4522 EmitConditionalOperatorLValue(const AbstractConditionalOperator *expr) { 4523 if (!expr->isGLValue()) { 4524 // ?: here should be an aggregate. 4525 assert(hasAggregateEvaluationKind(expr->getType()) && 4526 "Unexpected conditional operator!"); 4527 return EmitAggExprToLValue(expr); 4528 } 4529 4530 OpaqueValueMapping binding(*this, expr); 4531 4532 const Expr *condExpr = expr->getCond(); 4533 bool CondExprBool; 4534 if (ConstantFoldsToSimpleInteger(condExpr, CondExprBool)) { 4535 const Expr *live = expr->getTrueExpr(), *dead = expr->getFalseExpr(); 4536 if (!CondExprBool) std::swap(live, dead); 4537 4538 if (!ContainsLabel(dead)) { 4539 // If the true case is live, we need to track its region. 4540 if (CondExprBool) 4541 incrementProfileCounter(expr); 4542 // If a throw expression we emit it and return an undefined lvalue 4543 // because it can't be used. 4544 if (auto *ThrowExpr = dyn_cast<CXXThrowExpr>(live->IgnoreParens())) { 4545 EmitCXXThrowExpr(ThrowExpr); 4546 llvm::Type *ElemTy = ConvertType(dead->getType()); 4547 llvm::Type *Ty = llvm::PointerType::getUnqual(ElemTy); 4548 return MakeAddrLValue( 4549 Address(llvm::UndefValue::get(Ty), ElemTy, CharUnits::One()), 4550 dead->getType()); 4551 } 4552 return EmitLValue(live); 4553 } 4554 } 4555 4556 llvm::BasicBlock *lhsBlock = createBasicBlock("cond.true"); 4557 llvm::BasicBlock *rhsBlock = createBasicBlock("cond.false"); 4558 llvm::BasicBlock *contBlock = createBasicBlock("cond.end"); 4559 4560 ConditionalEvaluation eval(*this); 4561 EmitBranchOnBoolExpr(condExpr, lhsBlock, rhsBlock, getProfileCount(expr)); 4562 4563 // Any temporaries created here are conditional. 4564 EmitBlock(lhsBlock); 4565 incrementProfileCounter(expr); 4566 eval.begin(*this); 4567 Optional<LValue> lhs = 4568 EmitLValueOrThrowExpression(*this, expr->getTrueExpr()); 4569 eval.end(*this); 4570 4571 if (lhs && !lhs->isSimple()) 4572 return EmitUnsupportedLValue(expr, "conditional operator"); 4573 4574 lhsBlock = Builder.GetInsertBlock(); 4575 if (lhs) 4576 Builder.CreateBr(contBlock); 4577 4578 // Any temporaries created here are conditional. 4579 EmitBlock(rhsBlock); 4580 eval.begin(*this); 4581 Optional<LValue> rhs = 4582 EmitLValueOrThrowExpression(*this, expr->getFalseExpr()); 4583 eval.end(*this); 4584 if (rhs && !rhs->isSimple()) 4585 return EmitUnsupportedLValue(expr, "conditional operator"); 4586 rhsBlock = Builder.GetInsertBlock(); 4587 4588 EmitBlock(contBlock); 4589 4590 if (lhs && rhs) { 4591 Address lhsAddr = lhs->getAddress(*this); 4592 Address rhsAddr = rhs->getAddress(*this); 4593 llvm::PHINode *phi = Builder.CreatePHI(lhsAddr.getType(), 2, "cond-lvalue"); 4594 phi->addIncoming(lhsAddr.getPointer(), lhsBlock); 4595 phi->addIncoming(rhsAddr.getPointer(), rhsBlock); 4596 Address result(phi, lhsAddr.getElementType(), 4597 std::min(lhsAddr.getAlignment(), rhsAddr.getAlignment())); 4598 AlignmentSource alignSource = 4599 std::max(lhs->getBaseInfo().getAlignmentSource(), 4600 rhs->getBaseInfo().getAlignmentSource()); 4601 TBAAAccessInfo TBAAInfo = CGM.mergeTBAAInfoForConditionalOperator( 4602 lhs->getTBAAInfo(), rhs->getTBAAInfo()); 4603 return MakeAddrLValue(result, expr->getType(), LValueBaseInfo(alignSource), 4604 TBAAInfo); 4605 } else { 4606 assert((lhs || rhs) && 4607 "both operands of glvalue conditional are throw-expressions?"); 4608 return lhs ? *lhs : *rhs; 4609 } 4610 } 4611 4612 /// EmitCastLValue - Casts are never lvalues unless that cast is to a reference 4613 /// type. If the cast is to a reference, we can have the usual lvalue result, 4614 /// otherwise if a cast is needed by the code generator in an lvalue context, 4615 /// then it must mean that we need the address of an aggregate in order to 4616 /// access one of its members. This can happen for all the reasons that casts 4617 /// are permitted with aggregate result, including noop aggregate casts, and 4618 /// cast from scalar to union. 4619 LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) { 4620 switch (E->getCastKind()) { 4621 case CK_ToVoid: 4622 case CK_BitCast: 4623 case CK_LValueToRValueBitCast: 4624 case CK_ArrayToPointerDecay: 4625 case CK_FunctionToPointerDecay: 4626 case CK_NullToMemberPointer: 4627 case CK_NullToPointer: 4628 case CK_IntegralToPointer: 4629 case CK_PointerToIntegral: 4630 case CK_PointerToBoolean: 4631 case CK_VectorSplat: 4632 case CK_IntegralCast: 4633 case CK_BooleanToSignedIntegral: 4634 case CK_IntegralToBoolean: 4635 case CK_IntegralToFloating: 4636 case CK_FloatingToIntegral: 4637 case CK_FloatingToBoolean: 4638 case CK_FloatingCast: 4639 case CK_FloatingRealToComplex: 4640 case CK_FloatingComplexToReal: 4641 case CK_FloatingComplexToBoolean: 4642 case CK_FloatingComplexCast: 4643 case CK_FloatingComplexToIntegralComplex: 4644 case CK_IntegralRealToComplex: 4645 case CK_IntegralComplexToReal: 4646 case CK_IntegralComplexToBoolean: 4647 case CK_IntegralComplexCast: 4648 case CK_IntegralComplexToFloatingComplex: 4649 case CK_DerivedToBaseMemberPointer: 4650 case CK_BaseToDerivedMemberPointer: 4651 case CK_MemberPointerToBoolean: 4652 case CK_ReinterpretMemberPointer: 4653 case CK_AnyPointerToBlockPointerCast: 4654 case CK_ARCProduceObject: 4655 case CK_ARCConsumeObject: 4656 case CK_ARCReclaimReturnedObject: 4657 case CK_ARCExtendBlockObject: 4658 case CK_CopyAndAutoreleaseBlockObject: 4659 case CK_IntToOCLSampler: 4660 case CK_FloatingToFixedPoint: 4661 case CK_FixedPointToFloating: 4662 case CK_FixedPointCast: 4663 case CK_FixedPointToBoolean: 4664 case CK_FixedPointToIntegral: 4665 case CK_IntegralToFixedPoint: 4666 case CK_MatrixCast: 4667 return EmitUnsupportedLValue(E, "unexpected cast lvalue"); 4668 4669 case CK_Dependent: 4670 llvm_unreachable("dependent cast kind in IR gen!"); 4671 4672 case CK_BuiltinFnToFnPtr: 4673 llvm_unreachable("builtin functions are handled elsewhere"); 4674 4675 // These are never l-values; just use the aggregate emission code. 4676 case CK_NonAtomicToAtomic: 4677 case CK_AtomicToNonAtomic: 4678 return EmitAggExprToLValue(E); 4679 4680 case CK_Dynamic: { 4681 LValue LV = EmitLValue(E->getSubExpr()); 4682 Address V = LV.getAddress(*this); 4683 const auto *DCE = cast<CXXDynamicCastExpr>(E); 4684 return MakeNaturalAlignAddrLValue(EmitDynamicCast(V, DCE), E->getType()); 4685 } 4686 4687 case CK_ConstructorConversion: 4688 case CK_UserDefinedConversion: 4689 case CK_CPointerToObjCPointerCast: 4690 case CK_BlockPointerToObjCPointerCast: 4691 case CK_LValueToRValue: 4692 return EmitLValue(E->getSubExpr()); 4693 4694 case CK_NoOp: { 4695 // CK_NoOp can model a qualification conversion, which can remove an array 4696 // bound and change the IR type. 4697 // FIXME: Once pointee types are removed from IR, remove this. 4698 LValue LV = EmitLValue(E->getSubExpr()); 4699 if (LV.isSimple()) { 4700 Address V = LV.getAddress(*this); 4701 if (V.isValid()) { 4702 llvm::Type *T = ConvertTypeForMem(E->getType()); 4703 if (V.getElementType() != T) 4704 LV.setAddress(Builder.CreateElementBitCast(V, T)); 4705 } 4706 } 4707 return LV; 4708 } 4709 4710 case CK_UncheckedDerivedToBase: 4711 case CK_DerivedToBase: { 4712 const auto *DerivedClassTy = 4713 E->getSubExpr()->getType()->castAs<RecordType>(); 4714 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 4715 4716 LValue LV = EmitLValue(E->getSubExpr()); 4717 Address This = LV.getAddress(*this); 4718 4719 // Perform the derived-to-base conversion 4720 Address Base = GetAddressOfBaseClass( 4721 This, DerivedClassDecl, E->path_begin(), E->path_end(), 4722 /*NullCheckValue=*/false, E->getExprLoc()); 4723 4724 // TODO: Support accesses to members of base classes in TBAA. For now, we 4725 // conservatively pretend that the complete object is of the base class 4726 // type. 4727 return MakeAddrLValue(Base, E->getType(), LV.getBaseInfo(), 4728 CGM.getTBAAInfoForSubobject(LV, E->getType())); 4729 } 4730 case CK_ToUnion: 4731 return EmitAggExprToLValue(E); 4732 case CK_BaseToDerived: { 4733 const auto *DerivedClassTy = E->getType()->castAs<RecordType>(); 4734 auto *DerivedClassDecl = cast<CXXRecordDecl>(DerivedClassTy->getDecl()); 4735 4736 LValue LV = EmitLValue(E->getSubExpr()); 4737 4738 // Perform the base-to-derived conversion 4739 Address Derived = GetAddressOfDerivedClass( 4740 LV.getAddress(*this), DerivedClassDecl, E->path_begin(), E->path_end(), 4741 /*NullCheckValue=*/false); 4742 4743 // C++11 [expr.static.cast]p2: Behavior is undefined if a downcast is 4744 // performed and the object is not of the derived type. 4745 if (sanitizePerformTypeCheck()) 4746 EmitTypeCheck(TCK_DowncastReference, E->getExprLoc(), 4747 Derived.getPointer(), E->getType()); 4748 4749 if (SanOpts.has(SanitizerKind::CFIDerivedCast)) 4750 EmitVTablePtrCheckForCast(E->getType(), Derived.getPointer(), 4751 /*MayBeNull=*/false, CFITCK_DerivedCast, 4752 E->getBeginLoc()); 4753 4754 return MakeAddrLValue(Derived, E->getType(), LV.getBaseInfo(), 4755 CGM.getTBAAInfoForSubobject(LV, E->getType())); 4756 } 4757 case CK_LValueBitCast: { 4758 // This must be a reinterpret_cast (or c-style equivalent). 4759 const auto *CE = cast<ExplicitCastExpr>(E); 4760 4761 CGM.EmitExplicitCastExprType(CE, this); 4762 LValue LV = EmitLValue(E->getSubExpr()); 4763 Address V = Builder.CreateElementBitCast( 4764 LV.getAddress(*this), 4765 ConvertTypeForMem(CE->getTypeAsWritten()->getPointeeType())); 4766 4767 if (SanOpts.has(SanitizerKind::CFIUnrelatedCast)) 4768 EmitVTablePtrCheckForCast(E->getType(), V.getPointer(), 4769 /*MayBeNull=*/false, CFITCK_UnrelatedCast, 4770 E->getBeginLoc()); 4771 4772 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(), 4773 CGM.getTBAAInfoForSubobject(LV, E->getType())); 4774 } 4775 case CK_AddressSpaceConversion: { 4776 LValue LV = EmitLValue(E->getSubExpr()); 4777 QualType DestTy = getContext().getPointerType(E->getType()); 4778 llvm::Value *V = getTargetHooks().performAddrSpaceCast( 4779 *this, LV.getPointer(*this), 4780 E->getSubExpr()->getType().getAddressSpace(), 4781 E->getType().getAddressSpace(), ConvertType(DestTy)); 4782 return MakeAddrLValue(Address(V, LV.getAddress(*this).getAlignment()), 4783 E->getType(), LV.getBaseInfo(), LV.getTBAAInfo()); 4784 } 4785 case CK_ObjCObjectLValueCast: { 4786 LValue LV = EmitLValue(E->getSubExpr()); 4787 Address V = Builder.CreateElementBitCast(LV.getAddress(*this), 4788 ConvertType(E->getType())); 4789 return MakeAddrLValue(V, E->getType(), LV.getBaseInfo(), 4790 CGM.getTBAAInfoForSubobject(LV, E->getType())); 4791 } 4792 case CK_ZeroToOCLOpaqueType: 4793 llvm_unreachable("NULL to OpenCL opaque type lvalue cast is not valid"); 4794 } 4795 4796 llvm_unreachable("Unhandled lvalue cast kind?"); 4797 } 4798 4799 LValue CodeGenFunction::EmitOpaqueValueLValue(const OpaqueValueExpr *e) { 4800 assert(OpaqueValueMappingData::shouldBindAsLValue(e)); 4801 return getOrCreateOpaqueLValueMapping(e); 4802 } 4803 4804 LValue 4805 CodeGenFunction::getOrCreateOpaqueLValueMapping(const OpaqueValueExpr *e) { 4806 assert(OpaqueValueMapping::shouldBindAsLValue(e)); 4807 4808 llvm::DenseMap<const OpaqueValueExpr*,LValue>::iterator 4809 it = OpaqueLValues.find(e); 4810 4811 if (it != OpaqueLValues.end()) 4812 return it->second; 4813 4814 assert(e->isUnique() && "LValue for a nonunique OVE hasn't been emitted"); 4815 return EmitLValue(e->getSourceExpr()); 4816 } 4817 4818 RValue 4819 CodeGenFunction::getOrCreateOpaqueRValueMapping(const OpaqueValueExpr *e) { 4820 assert(!OpaqueValueMapping::shouldBindAsLValue(e)); 4821 4822 llvm::DenseMap<const OpaqueValueExpr*,RValue>::iterator 4823 it = OpaqueRValues.find(e); 4824 4825 if (it != OpaqueRValues.end()) 4826 return it->second; 4827 4828 assert(e->isUnique() && "RValue for a nonunique OVE hasn't been emitted"); 4829 return EmitAnyExpr(e->getSourceExpr()); 4830 } 4831 4832 RValue CodeGenFunction::EmitRValueForField(LValue LV, 4833 const FieldDecl *FD, 4834 SourceLocation Loc) { 4835 QualType FT = FD->getType(); 4836 LValue FieldLV = EmitLValueForField(LV, FD); 4837 switch (getEvaluationKind(FT)) { 4838 case TEK_Complex: 4839 return RValue::getComplex(EmitLoadOfComplex(FieldLV, Loc)); 4840 case TEK_Aggregate: 4841 return FieldLV.asAggregateRValue(*this); 4842 case TEK_Scalar: 4843 // This routine is used to load fields one-by-one to perform a copy, so 4844 // don't load reference fields. 4845 if (FD->getType()->isReferenceType()) 4846 return RValue::get(FieldLV.getPointer(*this)); 4847 // Call EmitLoadOfScalar except when the lvalue is a bitfield to emit a 4848 // primitive load. 4849 if (FieldLV.isBitField()) 4850 return EmitLoadOfLValue(FieldLV, Loc); 4851 return RValue::get(EmitLoadOfScalar(FieldLV, Loc)); 4852 } 4853 llvm_unreachable("bad evaluation kind"); 4854 } 4855 4856 //===--------------------------------------------------------------------===// 4857 // Expression Emission 4858 //===--------------------------------------------------------------------===// 4859 4860 RValue CodeGenFunction::EmitCallExpr(const CallExpr *E, 4861 ReturnValueSlot ReturnValue) { 4862 // Builtins never have block type. 4863 if (E->getCallee()->getType()->isBlockPointerType()) 4864 return EmitBlockCallExpr(E, ReturnValue); 4865 4866 if (const auto *CE = dyn_cast<CXXMemberCallExpr>(E)) 4867 return EmitCXXMemberCallExpr(CE, ReturnValue); 4868 4869 if (const auto *CE = dyn_cast<CUDAKernelCallExpr>(E)) 4870 return EmitCUDAKernelCallExpr(CE, ReturnValue); 4871 4872 if (const auto *CE = dyn_cast<CXXOperatorCallExpr>(E)) 4873 if (const CXXMethodDecl *MD = 4874 dyn_cast_or_null<CXXMethodDecl>(CE->getCalleeDecl())) 4875 return EmitCXXOperatorMemberCallExpr(CE, MD, ReturnValue); 4876 4877 CGCallee callee = EmitCallee(E->getCallee()); 4878 4879 if (callee.isBuiltin()) { 4880 return EmitBuiltinExpr(callee.getBuiltinDecl(), callee.getBuiltinID(), 4881 E, ReturnValue); 4882 } 4883 4884 if (callee.isPseudoDestructor()) { 4885 return EmitCXXPseudoDestructorExpr(callee.getPseudoDestructorExpr()); 4886 } 4887 4888 return EmitCall(E->getCallee()->getType(), callee, E, ReturnValue); 4889 } 4890 4891 /// Emit a CallExpr without considering whether it might be a subclass. 4892 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E, 4893 ReturnValueSlot ReturnValue) { 4894 CGCallee Callee = EmitCallee(E->getCallee()); 4895 return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue); 4896 } 4897 4898 // Detect the unusual situation where an inline version is shadowed by a 4899 // non-inline version. In that case we should pick the external one 4900 // everywhere. That's GCC behavior too. 4901 static bool OnlyHasInlineBuiltinDeclaration(const FunctionDecl *FD) { 4902 for (const FunctionDecl *PD = FD; PD; PD = PD->getPreviousDecl()) 4903 if (!PD->isInlineBuiltinDeclaration()) 4904 return false; 4905 return true; 4906 } 4907 4908 static CGCallee EmitDirectCallee(CodeGenFunction &CGF, GlobalDecl GD) { 4909 const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl()); 4910 4911 if (auto builtinID = FD->getBuiltinID()) { 4912 std::string FDInlineName = (FD->getName() + ".inline").str(); 4913 // When directing calling an inline builtin, call it through it's mangled 4914 // name to make it clear it's not the actual builtin. 4915 if (CGF.CurFn->getName() != FDInlineName && 4916 OnlyHasInlineBuiltinDeclaration(FD)) { 4917 llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD); 4918 llvm::Function *Fn = llvm::cast<llvm::Function>(CalleePtr); 4919 llvm::Module *M = Fn->getParent(); 4920 llvm::Function *Clone = M->getFunction(FDInlineName); 4921 if (!Clone) { 4922 Clone = llvm::Function::Create(Fn->getFunctionType(), 4923 llvm::GlobalValue::InternalLinkage, 4924 Fn->getAddressSpace(), FDInlineName, M); 4925 Clone->addFnAttr(llvm::Attribute::AlwaysInline); 4926 } 4927 return CGCallee::forDirect(Clone, GD); 4928 } 4929 4930 // Replaceable builtins provide their own implementation of a builtin. If we 4931 // are in an inline builtin implementation, avoid trivial infinite 4932 // recursion. 4933 else 4934 return CGCallee::forBuiltin(builtinID, FD); 4935 } 4936 4937 llvm::Constant *CalleePtr = EmitFunctionDeclPointer(CGF.CGM, GD); 4938 if (CGF.CGM.getLangOpts().CUDA && !CGF.CGM.getLangOpts().CUDAIsDevice && 4939 FD->hasAttr<CUDAGlobalAttr>()) 4940 CalleePtr = CGF.CGM.getCUDARuntime().getKernelStub( 4941 cast<llvm::GlobalValue>(CalleePtr->stripPointerCasts())); 4942 4943 return CGCallee::forDirect(CalleePtr, GD); 4944 } 4945 4946 CGCallee CodeGenFunction::EmitCallee(const Expr *E) { 4947 E = E->IgnoreParens(); 4948 4949 // Look through function-to-pointer decay. 4950 if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) { 4951 if (ICE->getCastKind() == CK_FunctionToPointerDecay || 4952 ICE->getCastKind() == CK_BuiltinFnToFnPtr) { 4953 return EmitCallee(ICE->getSubExpr()); 4954 } 4955 4956 // Resolve direct calls. 4957 } else if (auto DRE = dyn_cast<DeclRefExpr>(E)) { 4958 if (auto FD = dyn_cast<FunctionDecl>(DRE->getDecl())) { 4959 return EmitDirectCallee(*this, FD); 4960 } 4961 } else if (auto ME = dyn_cast<MemberExpr>(E)) { 4962 if (auto FD = dyn_cast<FunctionDecl>(ME->getMemberDecl())) { 4963 EmitIgnoredExpr(ME->getBase()); 4964 return EmitDirectCallee(*this, FD); 4965 } 4966 4967 // Look through template substitutions. 4968 } else if (auto NTTP = dyn_cast<SubstNonTypeTemplateParmExpr>(E)) { 4969 return EmitCallee(NTTP->getReplacement()); 4970 4971 // Treat pseudo-destructor calls differently. 4972 } else if (auto PDE = dyn_cast<CXXPseudoDestructorExpr>(E)) { 4973 return CGCallee::forPseudoDestructor(PDE); 4974 } 4975 4976 // Otherwise, we have an indirect reference. 4977 llvm::Value *calleePtr; 4978 QualType functionType; 4979 if (auto ptrType = E->getType()->getAs<PointerType>()) { 4980 calleePtr = EmitScalarExpr(E); 4981 functionType = ptrType->getPointeeType(); 4982 } else { 4983 functionType = E->getType(); 4984 calleePtr = EmitLValue(E).getPointer(*this); 4985 } 4986 assert(functionType->isFunctionType()); 4987 4988 GlobalDecl GD; 4989 if (const auto *VD = 4990 dyn_cast_or_null<VarDecl>(E->getReferencedDeclOfCallee())) 4991 GD = GlobalDecl(VD); 4992 4993 CGCalleeInfo calleeInfo(functionType->getAs<FunctionProtoType>(), GD); 4994 CGCallee callee(calleeInfo, calleePtr); 4995 return callee; 4996 } 4997 4998 LValue CodeGenFunction::EmitBinaryOperatorLValue(const BinaryOperator *E) { 4999 // Comma expressions just emit their LHS then their RHS as an l-value. 5000 if (E->getOpcode() == BO_Comma) { 5001 EmitIgnoredExpr(E->getLHS()); 5002 EnsureInsertPoint(); 5003 return EmitLValue(E->getRHS()); 5004 } 5005 5006 if (E->getOpcode() == BO_PtrMemD || 5007 E->getOpcode() == BO_PtrMemI) 5008 return EmitPointerToDataMemberBinaryExpr(E); 5009 5010 assert(E->getOpcode() == BO_Assign && "unexpected binary l-value"); 5011 5012 // Note that in all of these cases, __block variables need the RHS 5013 // evaluated first just in case the variable gets moved by the RHS. 5014 5015 switch (getEvaluationKind(E->getType())) { 5016 case TEK_Scalar: { 5017 switch (E->getLHS()->getType().getObjCLifetime()) { 5018 case Qualifiers::OCL_Strong: 5019 return EmitARCStoreStrong(E, /*ignored*/ false).first; 5020 5021 case Qualifiers::OCL_Autoreleasing: 5022 return EmitARCStoreAutoreleasing(E).first; 5023 5024 // No reason to do any of these differently. 5025 case Qualifiers::OCL_None: 5026 case Qualifiers::OCL_ExplicitNone: 5027 case Qualifiers::OCL_Weak: 5028 break; 5029 } 5030 5031 RValue RV = EmitAnyExpr(E->getRHS()); 5032 LValue LV = EmitCheckedLValue(E->getLHS(), TCK_Store); 5033 if (RV.isScalar()) 5034 EmitNullabilityCheck(LV, RV.getScalarVal(), E->getExprLoc()); 5035 EmitStoreThroughLValue(RV, LV); 5036 if (getLangOpts().OpenMP) 5037 CGM.getOpenMPRuntime().checkAndEmitLastprivateConditional(*this, 5038 E->getLHS()); 5039 return LV; 5040 } 5041 5042 case TEK_Complex: 5043 return EmitComplexAssignmentLValue(E); 5044 5045 case TEK_Aggregate: 5046 return EmitAggExprToLValue(E); 5047 } 5048 llvm_unreachable("bad evaluation kind"); 5049 } 5050 5051 LValue CodeGenFunction::EmitCallExprLValue(const CallExpr *E) { 5052 RValue RV = EmitCallExpr(E); 5053 5054 if (!RV.isScalar()) 5055 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(), 5056 AlignmentSource::Decl); 5057 5058 assert(E->getCallReturnType(getContext())->isReferenceType() && 5059 "Can't have a scalar return unless the return type is a " 5060 "reference type!"); 5061 5062 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType()); 5063 } 5064 5065 LValue CodeGenFunction::EmitVAArgExprLValue(const VAArgExpr *E) { 5066 // FIXME: This shouldn't require another copy. 5067 return EmitAggExprToLValue(E); 5068 } 5069 5070 LValue CodeGenFunction::EmitCXXConstructLValue(const CXXConstructExpr *E) { 5071 assert(E->getType()->getAsCXXRecordDecl()->hasTrivialDestructor() 5072 && "binding l-value to type which needs a temporary"); 5073 AggValueSlot Slot = CreateAggTemp(E->getType()); 5074 EmitCXXConstructExpr(E, Slot); 5075 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl); 5076 } 5077 5078 LValue 5079 CodeGenFunction::EmitCXXTypeidLValue(const CXXTypeidExpr *E) { 5080 return MakeNaturalAlignAddrLValue(EmitCXXTypeidExpr(E), E->getType()); 5081 } 5082 5083 Address CodeGenFunction::EmitCXXUuidofExpr(const CXXUuidofExpr *E) { 5084 return Builder.CreateElementBitCast(CGM.GetAddrOfMSGuidDecl(E->getGuidDecl()), 5085 ConvertType(E->getType())); 5086 } 5087 5088 LValue CodeGenFunction::EmitCXXUuidofLValue(const CXXUuidofExpr *E) { 5089 return MakeAddrLValue(EmitCXXUuidofExpr(E), E->getType(), 5090 AlignmentSource::Decl); 5091 } 5092 5093 LValue 5094 CodeGenFunction::EmitCXXBindTemporaryLValue(const CXXBindTemporaryExpr *E) { 5095 AggValueSlot Slot = CreateAggTemp(E->getType(), "temp.lvalue"); 5096 Slot.setExternallyDestructed(); 5097 EmitAggExpr(E->getSubExpr(), Slot); 5098 EmitCXXTemporary(E->getTemporary(), E->getType(), Slot.getAddress()); 5099 return MakeAddrLValue(Slot.getAddress(), E->getType(), AlignmentSource::Decl); 5100 } 5101 5102 LValue CodeGenFunction::EmitObjCMessageExprLValue(const ObjCMessageExpr *E) { 5103 RValue RV = EmitObjCMessageExpr(E); 5104 5105 if (!RV.isScalar()) 5106 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(), 5107 AlignmentSource::Decl); 5108 5109 assert(E->getMethodDecl()->getReturnType()->isReferenceType() && 5110 "Can't have a scalar return unless the return type is a " 5111 "reference type!"); 5112 5113 return MakeNaturalAlignPointeeAddrLValue(RV.getScalarVal(), E->getType()); 5114 } 5115 5116 LValue CodeGenFunction::EmitObjCSelectorLValue(const ObjCSelectorExpr *E) { 5117 Address V = 5118 CGM.getObjCRuntime().GetAddrOfSelector(*this, E->getSelector()); 5119 return MakeAddrLValue(V, E->getType(), AlignmentSource::Decl); 5120 } 5121 5122 llvm::Value *CodeGenFunction::EmitIvarOffset(const ObjCInterfaceDecl *Interface, 5123 const ObjCIvarDecl *Ivar) { 5124 return CGM.getObjCRuntime().EmitIvarOffset(*this, Interface, Ivar); 5125 } 5126 5127 LValue CodeGenFunction::EmitLValueForIvar(QualType ObjectTy, 5128 llvm::Value *BaseValue, 5129 const ObjCIvarDecl *Ivar, 5130 unsigned CVRQualifiers) { 5131 return CGM.getObjCRuntime().EmitObjCValueForIvar(*this, ObjectTy, BaseValue, 5132 Ivar, CVRQualifiers); 5133 } 5134 5135 LValue CodeGenFunction::EmitObjCIvarRefLValue(const ObjCIvarRefExpr *E) { 5136 // FIXME: A lot of the code below could be shared with EmitMemberExpr. 5137 llvm::Value *BaseValue = nullptr; 5138 const Expr *BaseExpr = E->getBase(); 5139 Qualifiers BaseQuals; 5140 QualType ObjectTy; 5141 if (E->isArrow()) { 5142 BaseValue = EmitScalarExpr(BaseExpr); 5143 ObjectTy = BaseExpr->getType()->getPointeeType(); 5144 BaseQuals = ObjectTy.getQualifiers(); 5145 } else { 5146 LValue BaseLV = EmitLValue(BaseExpr); 5147 BaseValue = BaseLV.getPointer(*this); 5148 ObjectTy = BaseExpr->getType(); 5149 BaseQuals = ObjectTy.getQualifiers(); 5150 } 5151 5152 LValue LV = 5153 EmitLValueForIvar(ObjectTy, BaseValue, E->getDecl(), 5154 BaseQuals.getCVRQualifiers()); 5155 setObjCGCLValueClass(getContext(), E, LV); 5156 return LV; 5157 } 5158 5159 LValue CodeGenFunction::EmitStmtExprLValue(const StmtExpr *E) { 5160 // Can only get l-value for message expression returning aggregate type 5161 RValue RV = EmitAnyExprToTemp(E); 5162 return MakeAddrLValue(RV.getAggregateAddress(), E->getType(), 5163 AlignmentSource::Decl); 5164 } 5165 5166 RValue CodeGenFunction::EmitCall(QualType CalleeType, const CGCallee &OrigCallee, 5167 const CallExpr *E, ReturnValueSlot ReturnValue, 5168 llvm::Value *Chain) { 5169 // Get the actual function type. The callee type will always be a pointer to 5170 // function type or a block pointer type. 5171 assert(CalleeType->isFunctionPointerType() && 5172 "Call must have function pointer type!"); 5173 5174 const Decl *TargetDecl = 5175 OrigCallee.getAbstractInfo().getCalleeDecl().getDecl(); 5176 5177 CalleeType = getContext().getCanonicalType(CalleeType); 5178 5179 auto PointeeType = cast<PointerType>(CalleeType)->getPointeeType(); 5180 5181 CGCallee Callee = OrigCallee; 5182 5183 if (getLangOpts().CPlusPlus && SanOpts.has(SanitizerKind::Function) && 5184 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) { 5185 if (llvm::Constant *PrefixSig = 5186 CGM.getTargetCodeGenInfo().getUBSanFunctionSignature(CGM)) { 5187 SanitizerScope SanScope(this); 5188 // Remove any (C++17) exception specifications, to allow calling e.g. a 5189 // noexcept function through a non-noexcept pointer. 5190 auto ProtoTy = 5191 getContext().getFunctionTypeWithExceptionSpec(PointeeType, EST_None); 5192 llvm::Constant *FTRTTIConst = 5193 CGM.GetAddrOfRTTIDescriptor(ProtoTy, /*ForEH=*/true); 5194 llvm::Type *PrefixSigType = PrefixSig->getType(); 5195 llvm::StructType *PrefixStructTy = llvm::StructType::get( 5196 CGM.getLLVMContext(), {PrefixSigType, Int32Ty}, /*isPacked=*/true); 5197 5198 llvm::Value *CalleePtr = Callee.getFunctionPointer(); 5199 5200 llvm::Value *CalleePrefixStruct = Builder.CreateBitCast( 5201 CalleePtr, llvm::PointerType::getUnqual(PrefixStructTy)); 5202 llvm::Value *CalleeSigPtr = 5203 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 0); 5204 llvm::Value *CalleeSig = 5205 Builder.CreateAlignedLoad(PrefixSigType, CalleeSigPtr, getIntAlign()); 5206 llvm::Value *CalleeSigMatch = Builder.CreateICmpEQ(CalleeSig, PrefixSig); 5207 5208 llvm::BasicBlock *Cont = createBasicBlock("cont"); 5209 llvm::BasicBlock *TypeCheck = createBasicBlock("typecheck"); 5210 Builder.CreateCondBr(CalleeSigMatch, TypeCheck, Cont); 5211 5212 EmitBlock(TypeCheck); 5213 llvm::Value *CalleeRTTIPtr = 5214 Builder.CreateConstGEP2_32(PrefixStructTy, CalleePrefixStruct, 0, 1); 5215 llvm::Value *CalleeRTTIEncoded = 5216 Builder.CreateAlignedLoad(Int32Ty, CalleeRTTIPtr, getPointerAlign()); 5217 llvm::Value *CalleeRTTI = 5218 DecodeAddrUsedInPrologue(CalleePtr, CalleeRTTIEncoded); 5219 llvm::Value *CalleeRTTIMatch = 5220 Builder.CreateICmpEQ(CalleeRTTI, FTRTTIConst); 5221 llvm::Constant *StaticData[] = {EmitCheckSourceLocation(E->getBeginLoc()), 5222 EmitCheckTypeDescriptor(CalleeType)}; 5223 EmitCheck(std::make_pair(CalleeRTTIMatch, SanitizerKind::Function), 5224 SanitizerHandler::FunctionTypeMismatch, StaticData, 5225 {CalleePtr, CalleeRTTI, FTRTTIConst}); 5226 5227 Builder.CreateBr(Cont); 5228 EmitBlock(Cont); 5229 } 5230 } 5231 5232 const auto *FnType = cast<FunctionType>(PointeeType); 5233 5234 // If we are checking indirect calls and this call is indirect, check that the 5235 // function pointer is a member of the bit set for the function type. 5236 if (SanOpts.has(SanitizerKind::CFIICall) && 5237 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) { 5238 SanitizerScope SanScope(this); 5239 EmitSanitizerStatReport(llvm::SanStat_CFI_ICall); 5240 5241 llvm::Metadata *MD; 5242 if (CGM.getCodeGenOpts().SanitizeCfiICallGeneralizePointers) 5243 MD = CGM.CreateMetadataIdentifierGeneralized(QualType(FnType, 0)); 5244 else 5245 MD = CGM.CreateMetadataIdentifierForType(QualType(FnType, 0)); 5246 5247 llvm::Value *TypeId = llvm::MetadataAsValue::get(getLLVMContext(), MD); 5248 5249 llvm::Value *CalleePtr = Callee.getFunctionPointer(); 5250 llvm::Value *CastedCallee = Builder.CreateBitCast(CalleePtr, Int8PtrTy); 5251 llvm::Value *TypeTest = Builder.CreateCall( 5252 CGM.getIntrinsic(llvm::Intrinsic::type_test), {CastedCallee, TypeId}); 5253 5254 auto CrossDsoTypeId = CGM.CreateCrossDsoCfiTypeId(MD); 5255 llvm::Constant *StaticData[] = { 5256 llvm::ConstantInt::get(Int8Ty, CFITCK_ICall), 5257 EmitCheckSourceLocation(E->getBeginLoc()), 5258 EmitCheckTypeDescriptor(QualType(FnType, 0)), 5259 }; 5260 if (CGM.getCodeGenOpts().SanitizeCfiCrossDso && CrossDsoTypeId) { 5261 EmitCfiSlowPathCheck(SanitizerKind::CFIICall, TypeTest, CrossDsoTypeId, 5262 CastedCallee, StaticData); 5263 } else { 5264 EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIICall), 5265 SanitizerHandler::CFICheckFail, StaticData, 5266 {CastedCallee, llvm::UndefValue::get(IntPtrTy)}); 5267 } 5268 } 5269 5270 CallArgList Args; 5271 if (Chain) 5272 Args.add(RValue::get(Builder.CreateBitCast(Chain, CGM.VoidPtrTy)), 5273 CGM.getContext().VoidPtrTy); 5274 5275 // C++17 requires that we evaluate arguments to a call using assignment syntax 5276 // right-to-left, and that we evaluate arguments to certain other operators 5277 // left-to-right. Note that we allow this to override the order dictated by 5278 // the calling convention on the MS ABI, which means that parameter 5279 // destruction order is not necessarily reverse construction order. 5280 // FIXME: Revisit this based on C++ committee response to unimplementability. 5281 EvaluationOrder Order = EvaluationOrder::Default; 5282 if (auto *OCE = dyn_cast<CXXOperatorCallExpr>(E)) { 5283 if (OCE->isAssignmentOp()) 5284 Order = EvaluationOrder::ForceRightToLeft; 5285 else { 5286 switch (OCE->getOperator()) { 5287 case OO_LessLess: 5288 case OO_GreaterGreater: 5289 case OO_AmpAmp: 5290 case OO_PipePipe: 5291 case OO_Comma: 5292 case OO_ArrowStar: 5293 Order = EvaluationOrder::ForceLeftToRight; 5294 break; 5295 default: 5296 break; 5297 } 5298 } 5299 } 5300 5301 EmitCallArgs(Args, dyn_cast<FunctionProtoType>(FnType), E->arguments(), 5302 E->getDirectCallee(), /*ParamsToSkip*/ 0, Order); 5303 5304 const CGFunctionInfo &FnInfo = CGM.getTypes().arrangeFreeFunctionCall( 5305 Args, FnType, /*ChainCall=*/Chain); 5306 5307 // C99 6.5.2.2p6: 5308 // If the expression that denotes the called function has a type 5309 // that does not include a prototype, [the default argument 5310 // promotions are performed]. If the number of arguments does not 5311 // equal the number of parameters, the behavior is undefined. If 5312 // the function is defined with a type that includes a prototype, 5313 // and either the prototype ends with an ellipsis (, ...) or the 5314 // types of the arguments after promotion are not compatible with 5315 // the types of the parameters, the behavior is undefined. If the 5316 // function is defined with a type that does not include a 5317 // prototype, and the types of the arguments after promotion are 5318 // not compatible with those of the parameters after promotion, 5319 // the behavior is undefined [except in some trivial cases]. 5320 // That is, in the general case, we should assume that a call 5321 // through an unprototyped function type works like a *non-variadic* 5322 // call. The way we make this work is to cast to the exact type 5323 // of the promoted arguments. 5324 // 5325 // Chain calls use this same code path to add the invisible chain parameter 5326 // to the function type. 5327 if (isa<FunctionNoProtoType>(FnType) || Chain) { 5328 llvm::Type *CalleeTy = getTypes().GetFunctionType(FnInfo); 5329 int AS = Callee.getFunctionPointer()->getType()->getPointerAddressSpace(); 5330 CalleeTy = CalleeTy->getPointerTo(AS); 5331 5332 llvm::Value *CalleePtr = Callee.getFunctionPointer(); 5333 CalleePtr = Builder.CreateBitCast(CalleePtr, CalleeTy, "callee.knr.cast"); 5334 Callee.setFunctionPointer(CalleePtr); 5335 } 5336 5337 // HIP function pointer contains kernel handle when it is used in triple 5338 // chevron. The kernel stub needs to be loaded from kernel handle and used 5339 // as callee. 5340 if (CGM.getLangOpts().HIP && !CGM.getLangOpts().CUDAIsDevice && 5341 isa<CUDAKernelCallExpr>(E) && 5342 (!TargetDecl || !isa<FunctionDecl>(TargetDecl))) { 5343 llvm::Value *Handle = Callee.getFunctionPointer(); 5344 auto *Cast = 5345 Builder.CreateBitCast(Handle, Handle->getType()->getPointerTo()); 5346 auto *Stub = Builder.CreateLoad(Address(Cast, CGM.getPointerAlign())); 5347 Callee.setFunctionPointer(Stub); 5348 } 5349 llvm::CallBase *CallOrInvoke = nullptr; 5350 RValue Call = EmitCall(FnInfo, Callee, ReturnValue, Args, &CallOrInvoke, 5351 E == MustTailCall, E->getExprLoc()); 5352 5353 // Generate function declaration DISuprogram in order to be used 5354 // in debug info about call sites. 5355 if (CGDebugInfo *DI = getDebugInfo()) { 5356 if (auto *CalleeDecl = dyn_cast_or_null<FunctionDecl>(TargetDecl)) { 5357 FunctionArgList Args; 5358 QualType ResTy = BuildFunctionArgList(CalleeDecl, Args); 5359 DI->EmitFuncDeclForCallSite(CallOrInvoke, 5360 DI->getFunctionType(CalleeDecl, ResTy, Args), 5361 CalleeDecl); 5362 } 5363 } 5364 5365 return Call; 5366 } 5367 5368 LValue CodeGenFunction:: 5369 EmitPointerToDataMemberBinaryExpr(const BinaryOperator *E) { 5370 Address BaseAddr = Address::invalid(); 5371 if (E->getOpcode() == BO_PtrMemI) { 5372 BaseAddr = EmitPointerWithAlignment(E->getLHS()); 5373 } else { 5374 BaseAddr = EmitLValue(E->getLHS()).getAddress(*this); 5375 } 5376 5377 llvm::Value *OffsetV = EmitScalarExpr(E->getRHS()); 5378 const auto *MPT = E->getRHS()->getType()->castAs<MemberPointerType>(); 5379 5380 LValueBaseInfo BaseInfo; 5381 TBAAAccessInfo TBAAInfo; 5382 Address MemberAddr = 5383 EmitCXXMemberDataPointerAddress(E, BaseAddr, OffsetV, MPT, &BaseInfo, 5384 &TBAAInfo); 5385 5386 return MakeAddrLValue(MemberAddr, MPT->getPointeeType(), BaseInfo, TBAAInfo); 5387 } 5388 5389 /// Given the address of a temporary variable, produce an r-value of 5390 /// its type. 5391 RValue CodeGenFunction::convertTempToRValue(Address addr, 5392 QualType type, 5393 SourceLocation loc) { 5394 LValue lvalue = MakeAddrLValue(addr, type, AlignmentSource::Decl); 5395 switch (getEvaluationKind(type)) { 5396 case TEK_Complex: 5397 return RValue::getComplex(EmitLoadOfComplex(lvalue, loc)); 5398 case TEK_Aggregate: 5399 return lvalue.asAggregateRValue(*this); 5400 case TEK_Scalar: 5401 return RValue::get(EmitLoadOfScalar(lvalue, loc)); 5402 } 5403 llvm_unreachable("bad evaluation kind"); 5404 } 5405 5406 void CodeGenFunction::SetFPAccuracy(llvm::Value *Val, float Accuracy) { 5407 assert(Val->getType()->isFPOrFPVectorTy()); 5408 if (Accuracy == 0.0 || !isa<llvm::Instruction>(Val)) 5409 return; 5410 5411 llvm::MDBuilder MDHelper(getLLVMContext()); 5412 llvm::MDNode *Node = MDHelper.createFPMath(Accuracy); 5413 5414 cast<llvm::Instruction>(Val)->setMetadata(llvm::LLVMContext::MD_fpmath, Node); 5415 } 5416 5417 namespace { 5418 struct LValueOrRValue { 5419 LValue LV; 5420 RValue RV; 5421 }; 5422 } 5423 5424 static LValueOrRValue emitPseudoObjectExpr(CodeGenFunction &CGF, 5425 const PseudoObjectExpr *E, 5426 bool forLValue, 5427 AggValueSlot slot) { 5428 SmallVector<CodeGenFunction::OpaqueValueMappingData, 4> opaques; 5429 5430 // Find the result expression, if any. 5431 const Expr *resultExpr = E->getResultExpr(); 5432 LValueOrRValue result; 5433 5434 for (PseudoObjectExpr::const_semantics_iterator 5435 i = E->semantics_begin(), e = E->semantics_end(); i != e; ++i) { 5436 const Expr *semantic = *i; 5437 5438 // If this semantic expression is an opaque value, bind it 5439 // to the result of its source expression. 5440 if (const auto *ov = dyn_cast<OpaqueValueExpr>(semantic)) { 5441 // Skip unique OVEs. 5442 if (ov->isUnique()) { 5443 assert(ov != resultExpr && 5444 "A unique OVE cannot be used as the result expression"); 5445 continue; 5446 } 5447 5448 // If this is the result expression, we may need to evaluate 5449 // directly into the slot. 5450 typedef CodeGenFunction::OpaqueValueMappingData OVMA; 5451 OVMA opaqueData; 5452 if (ov == resultExpr && ov->isPRValue() && !forLValue && 5453 CodeGenFunction::hasAggregateEvaluationKind(ov->getType())) { 5454 CGF.EmitAggExpr(ov->getSourceExpr(), slot); 5455 LValue LV = CGF.MakeAddrLValue(slot.getAddress(), ov->getType(), 5456 AlignmentSource::Decl); 5457 opaqueData = OVMA::bind(CGF, ov, LV); 5458 result.RV = slot.asRValue(); 5459 5460 // Otherwise, emit as normal. 5461 } else { 5462 opaqueData = OVMA::bind(CGF, ov, ov->getSourceExpr()); 5463 5464 // If this is the result, also evaluate the result now. 5465 if (ov == resultExpr) { 5466 if (forLValue) 5467 result.LV = CGF.EmitLValue(ov); 5468 else 5469 result.RV = CGF.EmitAnyExpr(ov, slot); 5470 } 5471 } 5472 5473 opaques.push_back(opaqueData); 5474 5475 // Otherwise, if the expression is the result, evaluate it 5476 // and remember the result. 5477 } else if (semantic == resultExpr) { 5478 if (forLValue) 5479 result.LV = CGF.EmitLValue(semantic); 5480 else 5481 result.RV = CGF.EmitAnyExpr(semantic, slot); 5482 5483 // Otherwise, evaluate the expression in an ignored context. 5484 } else { 5485 CGF.EmitIgnoredExpr(semantic); 5486 } 5487 } 5488 5489 // Unbind all the opaques now. 5490 for (unsigned i = 0, e = opaques.size(); i != e; ++i) 5491 opaques[i].unbind(CGF); 5492 5493 return result; 5494 } 5495 5496 RValue CodeGenFunction::EmitPseudoObjectRValue(const PseudoObjectExpr *E, 5497 AggValueSlot slot) { 5498 return emitPseudoObjectExpr(*this, E, false, slot).RV; 5499 } 5500 5501 LValue CodeGenFunction::EmitPseudoObjectLValue(const PseudoObjectExpr *E) { 5502 return emitPseudoObjectExpr(*this, E, true, AggValueSlot::ignored()).LV; 5503 } 5504