1 //===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This is the code that handles AST -> LLVM type lowering. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "CodeGenTypes.h" 15 #include "CGCXXABI.h" 16 #include "CGCall.h" 17 #include "CGOpenCLRuntime.h" 18 #include "CGRecordLayout.h" 19 #include "TargetInfo.h" 20 #include "clang/AST/ASTContext.h" 21 #include "clang/AST/DeclCXX.h" 22 #include "clang/AST/DeclObjC.h" 23 #include "clang/AST/Expr.h" 24 #include "clang/AST/RecordLayout.h" 25 #include "clang/CodeGen/CGFunctionInfo.h" 26 #include "llvm/IR/DataLayout.h" 27 #include "llvm/IR/DerivedTypes.h" 28 #include "llvm/IR/Module.h" 29 using namespace clang; 30 using namespace CodeGen; 31 32 CodeGenTypes::CodeGenTypes(CodeGenModule &cgm) 33 : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()), 34 Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()), 35 TheABIInfo(cgm.getTargetCodeGenInfo().getABIInfo()) { 36 SkippedLayout = false; 37 } 38 39 CodeGenTypes::~CodeGenTypes() { 40 llvm::DeleteContainerSeconds(CGRecordLayouts); 41 42 for (llvm::FoldingSet<CGFunctionInfo>::iterator 43 I = FunctionInfos.begin(), E = FunctionInfos.end(); I != E; ) 44 delete &*I++; 45 } 46 47 void CodeGenTypes::addRecordTypeName(const RecordDecl *RD, 48 llvm::StructType *Ty, 49 StringRef suffix) { 50 SmallString<256> TypeName; 51 llvm::raw_svector_ostream OS(TypeName); 52 OS << RD->getKindName() << '.'; 53 54 // Name the codegen type after the typedef name 55 // if there is no tag type name available 56 if (RD->getIdentifier()) { 57 // FIXME: We should not have to check for a null decl context here. 58 // Right now we do it because the implicit Obj-C decls don't have one. 59 if (RD->getDeclContext()) 60 RD->printQualifiedName(OS); 61 else 62 RD->printName(OS); 63 } else if (const TypedefNameDecl *TDD = RD->getTypedefNameForAnonDecl()) { 64 // FIXME: We should not have to check for a null decl context here. 65 // Right now we do it because the implicit Obj-C decls don't have one. 66 if (TDD->getDeclContext()) 67 TDD->printQualifiedName(OS); 68 else 69 TDD->printName(OS); 70 } else 71 OS << "anon"; 72 73 if (!suffix.empty()) 74 OS << suffix; 75 76 Ty->setName(OS.str()); 77 } 78 79 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 80 /// ConvertType in that it is used to convert to the memory representation for 81 /// a type. For example, the scalar representation for _Bool is i1, but the 82 /// memory representation is usually i8 or i32, depending on the target. 83 llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T) { 84 llvm::Type *R = ConvertType(T); 85 86 // If this is a non-bool type, don't map it. 87 if (!R->isIntegerTy(1)) 88 return R; 89 90 // Otherwise, return an integer of the target-specified size. 91 return llvm::IntegerType::get(getLLVMContext(), 92 (unsigned)Context.getTypeSize(T)); 93 } 94 95 96 /// isRecordLayoutComplete - Return true if the specified type is already 97 /// completely laid out. 98 bool CodeGenTypes::isRecordLayoutComplete(const Type *Ty) const { 99 llvm::DenseMap<const Type*, llvm::StructType *>::const_iterator I = 100 RecordDeclTypes.find(Ty); 101 return I != RecordDeclTypes.end() && !I->second->isOpaque(); 102 } 103 104 static bool 105 isSafeToConvert(QualType T, CodeGenTypes &CGT, 106 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked); 107 108 109 /// isSafeToConvert - Return true if it is safe to convert the specified record 110 /// decl to IR and lay it out, false if doing so would cause us to get into a 111 /// recursive compilation mess. 112 static bool 113 isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT, 114 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) { 115 // If we have already checked this type (maybe the same type is used by-value 116 // multiple times in multiple structure fields, don't check again. 117 if (!AlreadyChecked.insert(RD).second) 118 return true; 119 120 const Type *Key = CGT.getContext().getTagDeclType(RD).getTypePtr(); 121 122 // If this type is already laid out, converting it is a noop. 123 if (CGT.isRecordLayoutComplete(Key)) return true; 124 125 // If this type is currently being laid out, we can't recursively compile it. 126 if (CGT.isRecordBeingLaidOut(Key)) 127 return false; 128 129 // If this type would require laying out bases that are currently being laid 130 // out, don't do it. This includes virtual base classes which get laid out 131 // when a class is translated, even though they aren't embedded by-value into 132 // the class. 133 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 134 for (const auto &I : CRD->bases()) 135 if (!isSafeToConvert(I.getType()->getAs<RecordType>()->getDecl(), 136 CGT, AlreadyChecked)) 137 return false; 138 } 139 140 // If this type would require laying out members that are currently being laid 141 // out, don't do it. 142 for (const auto *I : RD->fields()) 143 if (!isSafeToConvert(I->getType(), CGT, AlreadyChecked)) 144 return false; 145 146 // If there are no problems, lets do it. 147 return true; 148 } 149 150 /// isSafeToConvert - Return true if it is safe to convert this field type, 151 /// which requires the structure elements contained by-value to all be 152 /// recursively safe to convert. 153 static bool 154 isSafeToConvert(QualType T, CodeGenTypes &CGT, 155 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) { 156 // Strip off atomic type sugar. 157 if (const auto *AT = T->getAs<AtomicType>()) 158 T = AT->getValueType(); 159 160 // If this is a record, check it. 161 if (const auto *RT = T->getAs<RecordType>()) 162 return isSafeToConvert(RT->getDecl(), CGT, AlreadyChecked); 163 164 // If this is an array, check the elements, which are embedded inline. 165 if (const auto *AT = CGT.getContext().getAsArrayType(T)) 166 return isSafeToConvert(AT->getElementType(), CGT, AlreadyChecked); 167 168 // Otherwise, there is no concern about transforming this. We only care about 169 // things that are contained by-value in a structure that can have another 170 // structure as a member. 171 return true; 172 } 173 174 175 /// isSafeToConvert - Return true if it is safe to convert the specified record 176 /// decl to IR and lay it out, false if doing so would cause us to get into a 177 /// recursive compilation mess. 178 static bool isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT) { 179 // If no structs are being laid out, we can certainly do this one. 180 if (CGT.noRecordsBeingLaidOut()) return true; 181 182 llvm::SmallPtrSet<const RecordDecl*, 16> AlreadyChecked; 183 return isSafeToConvert(RD, CGT, AlreadyChecked); 184 } 185 186 /// isFuncParamTypeConvertible - Return true if the specified type in a 187 /// function parameter or result position can be converted to an IR type at this 188 /// point. This boils down to being whether it is complete, as well as whether 189 /// we've temporarily deferred expanding the type because we're in a recursive 190 /// context. 191 bool CodeGenTypes::isFuncParamTypeConvertible(QualType Ty) { 192 // Some ABIs cannot have their member pointers represented in IR unless 193 // certain circumstances have been reached. 194 if (const auto *MPT = Ty->getAs<MemberPointerType>()) 195 return getCXXABI().isMemberPointerConvertible(MPT); 196 197 // If this isn't a tagged type, we can convert it! 198 const TagType *TT = Ty->getAs<TagType>(); 199 if (!TT) return true; 200 201 // Incomplete types cannot be converted. 202 if (TT->isIncompleteType()) 203 return false; 204 205 // If this is an enum, then it is always safe to convert. 206 const RecordType *RT = dyn_cast<RecordType>(TT); 207 if (!RT) return true; 208 209 // Otherwise, we have to be careful. If it is a struct that we're in the 210 // process of expanding, then we can't convert the function type. That's ok 211 // though because we must be in a pointer context under the struct, so we can 212 // just convert it to a dummy type. 213 // 214 // We decide this by checking whether ConvertRecordDeclType returns us an 215 // opaque type for a struct that we know is defined. 216 return isSafeToConvert(RT->getDecl(), *this); 217 } 218 219 220 /// Code to verify a given function type is complete, i.e. the return type 221 /// and all of the parameter types are complete. Also check to see if we are in 222 /// a RS_StructPointer context, and if so whether any struct types have been 223 /// pended. If so, we don't want to ask the ABI lowering code to handle a type 224 /// that cannot be converted to an IR type. 225 bool CodeGenTypes::isFuncTypeConvertible(const FunctionType *FT) { 226 if (!isFuncParamTypeConvertible(FT->getReturnType())) 227 return false; 228 229 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 230 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++) 231 if (!isFuncParamTypeConvertible(FPT->getParamType(i))) 232 return false; 233 234 return true; 235 } 236 237 /// UpdateCompletedType - When we find the full definition for a TagDecl, 238 /// replace the 'opaque' type we previously made for it if applicable. 239 void CodeGenTypes::UpdateCompletedType(const TagDecl *TD) { 240 // If this is an enum being completed, then we flush all non-struct types from 241 // the cache. This allows function types and other things that may be derived 242 // from the enum to be recomputed. 243 if (const EnumDecl *ED = dyn_cast<EnumDecl>(TD)) { 244 // Only flush the cache if we've actually already converted this type. 245 if (TypeCache.count(ED->getTypeForDecl())) { 246 // Okay, we formed some types based on this. We speculated that the enum 247 // would be lowered to i32, so we only need to flush the cache if this 248 // didn't happen. 249 if (!ConvertType(ED->getIntegerType())->isIntegerTy(32)) 250 TypeCache.clear(); 251 } 252 // If necessary, provide the full definition of a type only used with a 253 // declaration so far. 254 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) 255 DI->completeType(ED); 256 return; 257 } 258 259 // If we completed a RecordDecl that we previously used and converted to an 260 // anonymous type, then go ahead and complete it now. 261 const RecordDecl *RD = cast<RecordDecl>(TD); 262 if (RD->isDependentType()) return; 263 264 // Only complete it if we converted it already. If we haven't converted it 265 // yet, we'll just do it lazily. 266 if (RecordDeclTypes.count(Context.getTagDeclType(RD).getTypePtr())) 267 ConvertRecordDeclType(RD); 268 269 // If necessary, provide the full definition of a type only used with a 270 // declaration so far. 271 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) 272 DI->completeType(RD); 273 } 274 275 static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext, 276 const llvm::fltSemantics &format, 277 bool UseNativeHalf = false) { 278 if (&format == &llvm::APFloat::IEEEhalf) { 279 if (UseNativeHalf) 280 return llvm::Type::getHalfTy(VMContext); 281 else 282 return llvm::Type::getInt16Ty(VMContext); 283 } 284 if (&format == &llvm::APFloat::IEEEsingle) 285 return llvm::Type::getFloatTy(VMContext); 286 if (&format == &llvm::APFloat::IEEEdouble) 287 return llvm::Type::getDoubleTy(VMContext); 288 if (&format == &llvm::APFloat::IEEEquad) 289 return llvm::Type::getFP128Ty(VMContext); 290 if (&format == &llvm::APFloat::PPCDoubleDouble) 291 return llvm::Type::getPPC_FP128Ty(VMContext); 292 if (&format == &llvm::APFloat::x87DoubleExtended) 293 return llvm::Type::getX86_FP80Ty(VMContext); 294 llvm_unreachable("Unknown float format!"); 295 } 296 297 llvm::Type *CodeGenTypes::ConvertFunctionType(QualType QFT, 298 const FunctionDecl *FD) { 299 assert(QFT.isCanonical()); 300 const Type *Ty = QFT.getTypePtr(); 301 const FunctionType *FT = cast<FunctionType>(QFT.getTypePtr()); 302 // First, check whether we can build the full function type. If the 303 // function type depends on an incomplete type (e.g. a struct or enum), we 304 // cannot lower the function type. 305 if (!isFuncTypeConvertible(FT)) { 306 // This function's type depends on an incomplete tag type. 307 308 // Force conversion of all the relevant record types, to make sure 309 // we re-convert the FunctionType when appropriate. 310 if (const RecordType *RT = FT->getReturnType()->getAs<RecordType>()) 311 ConvertRecordDeclType(RT->getDecl()); 312 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 313 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++) 314 if (const RecordType *RT = FPT->getParamType(i)->getAs<RecordType>()) 315 ConvertRecordDeclType(RT->getDecl()); 316 317 SkippedLayout = true; 318 319 // Return a placeholder type. 320 return llvm::StructType::get(getLLVMContext()); 321 } 322 323 // While we're converting the parameter types for a function, we don't want 324 // to recursively convert any pointed-to structs. Converting directly-used 325 // structs is ok though. 326 if (!RecordsBeingLaidOut.insert(Ty).second) { 327 SkippedLayout = true; 328 return llvm::StructType::get(getLLVMContext()); 329 } 330 331 // The function type can be built; call the appropriate routines to 332 // build it. 333 const CGFunctionInfo *FI; 334 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) { 335 FI = &arrangeFreeFunctionType( 336 CanQual<FunctionProtoType>::CreateUnsafe(QualType(FPT, 0)), FD); 337 } else { 338 const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(FT); 339 FI = &arrangeFreeFunctionType( 340 CanQual<FunctionNoProtoType>::CreateUnsafe(QualType(FNPT, 0))); 341 } 342 343 llvm::Type *ResultType = nullptr; 344 // If there is something higher level prodding our CGFunctionInfo, then 345 // don't recurse into it again. 346 if (FunctionsBeingProcessed.count(FI)) { 347 348 ResultType = llvm::StructType::get(getLLVMContext()); 349 SkippedLayout = true; 350 } else { 351 352 // Otherwise, we're good to go, go ahead and convert it. 353 ResultType = GetFunctionType(*FI); 354 } 355 356 RecordsBeingLaidOut.erase(Ty); 357 358 if (SkippedLayout) 359 TypeCache.clear(); 360 361 if (RecordsBeingLaidOut.empty()) 362 while (!DeferredRecords.empty()) 363 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 364 return ResultType; 365 } 366 367 /// ConvertType - Convert the specified type to its LLVM form. 368 llvm::Type *CodeGenTypes::ConvertType(QualType T) { 369 T = Context.getCanonicalType(T); 370 371 const Type *Ty = T.getTypePtr(); 372 373 // RecordTypes are cached and processed specially. 374 if (const RecordType *RT = dyn_cast<RecordType>(Ty)) 375 return ConvertRecordDeclType(RT->getDecl()); 376 377 // See if type is already cached. 378 llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty); 379 // If type is found in map then use it. Otherwise, convert type T. 380 if (TCI != TypeCache.end()) 381 return TCI->second; 382 383 // If we don't have it in the cache, convert it now. 384 llvm::Type *ResultType = nullptr; 385 switch (Ty->getTypeClass()) { 386 case Type::Record: // Handled above. 387 #define TYPE(Class, Base) 388 #define ABSTRACT_TYPE(Class, Base) 389 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 390 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 391 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 392 #include "clang/AST/TypeNodes.def" 393 llvm_unreachable("Non-canonical or dependent types aren't possible."); 394 395 case Type::Builtin: { 396 switch (cast<BuiltinType>(Ty)->getKind()) { 397 case BuiltinType::Void: 398 case BuiltinType::ObjCId: 399 case BuiltinType::ObjCClass: 400 case BuiltinType::ObjCSel: 401 // LLVM void type can only be used as the result of a function call. Just 402 // map to the same as char. 403 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 404 break; 405 406 case BuiltinType::Bool: 407 // Note that we always return bool as i1 for use as a scalar type. 408 ResultType = llvm::Type::getInt1Ty(getLLVMContext()); 409 break; 410 411 case BuiltinType::Char_S: 412 case BuiltinType::Char_U: 413 case BuiltinType::SChar: 414 case BuiltinType::UChar: 415 case BuiltinType::Short: 416 case BuiltinType::UShort: 417 case BuiltinType::Int: 418 case BuiltinType::UInt: 419 case BuiltinType::Long: 420 case BuiltinType::ULong: 421 case BuiltinType::LongLong: 422 case BuiltinType::ULongLong: 423 case BuiltinType::WChar_S: 424 case BuiltinType::WChar_U: 425 case BuiltinType::Char16: 426 case BuiltinType::Char32: 427 ResultType = llvm::IntegerType::get(getLLVMContext(), 428 static_cast<unsigned>(Context.getTypeSize(T))); 429 break; 430 431 case BuiltinType::Half: 432 // Half FP can either be storage-only (lowered to i16) or native. 433 ResultType = 434 getTypeForFormat(getLLVMContext(), Context.getFloatTypeSemantics(T), 435 Context.getLangOpts().NativeHalfType || 436 Context.getLangOpts().HalfArgsAndReturns); 437 break; 438 case BuiltinType::Float: 439 case BuiltinType::Double: 440 case BuiltinType::LongDouble: 441 ResultType = getTypeForFormat(getLLVMContext(), 442 Context.getFloatTypeSemantics(T), 443 /* UseNativeHalf = */ false); 444 break; 445 446 case BuiltinType::NullPtr: 447 // Model std::nullptr_t as i8* 448 ResultType = llvm::Type::getInt8PtrTy(getLLVMContext()); 449 break; 450 451 case BuiltinType::UInt128: 452 case BuiltinType::Int128: 453 ResultType = llvm::IntegerType::get(getLLVMContext(), 128); 454 break; 455 456 case BuiltinType::OCLImage1d: 457 case BuiltinType::OCLImage1dArray: 458 case BuiltinType::OCLImage1dBuffer: 459 case BuiltinType::OCLImage2d: 460 case BuiltinType::OCLImage2dArray: 461 case BuiltinType::OCLImage2dDepth: 462 case BuiltinType::OCLImage2dArrayDepth: 463 case BuiltinType::OCLImage2dMSAA: 464 case BuiltinType::OCLImage2dArrayMSAA: 465 case BuiltinType::OCLImage2dMSAADepth: 466 case BuiltinType::OCLImage2dArrayMSAADepth: 467 case BuiltinType::OCLImage3d: 468 case BuiltinType::OCLSampler: 469 case BuiltinType::OCLEvent: 470 case BuiltinType::OCLClkEvent: 471 case BuiltinType::OCLQueue: 472 case BuiltinType::OCLNDRange: 473 case BuiltinType::OCLReserveID: 474 ResultType = CGM.getOpenCLRuntime().convertOpenCLSpecificType(Ty); 475 break; 476 477 case BuiltinType::Dependent: 478 #define BUILTIN_TYPE(Id, SingletonId) 479 #define PLACEHOLDER_TYPE(Id, SingletonId) \ 480 case BuiltinType::Id: 481 #include "clang/AST/BuiltinTypes.def" 482 llvm_unreachable("Unexpected placeholder builtin type!"); 483 } 484 break; 485 } 486 case Type::Auto: 487 llvm_unreachable("Unexpected undeduced auto type!"); 488 case Type::Complex: { 489 llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType()); 490 ResultType = llvm::StructType::get(EltTy, EltTy, nullptr); 491 break; 492 } 493 case Type::LValueReference: 494 case Type::RValueReference: { 495 const ReferenceType *RTy = cast<ReferenceType>(Ty); 496 QualType ETy = RTy->getPointeeType(); 497 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 498 unsigned AS = Context.getTargetAddressSpace(ETy); 499 ResultType = llvm::PointerType::get(PointeeType, AS); 500 break; 501 } 502 case Type::Pointer: { 503 const PointerType *PTy = cast<PointerType>(Ty); 504 QualType ETy = PTy->getPointeeType(); 505 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 506 if (PointeeType->isVoidTy()) 507 PointeeType = llvm::Type::getInt8Ty(getLLVMContext()); 508 unsigned AS = Context.getTargetAddressSpace(ETy); 509 ResultType = llvm::PointerType::get(PointeeType, AS); 510 break; 511 } 512 513 case Type::VariableArray: { 514 const VariableArrayType *A = cast<VariableArrayType>(Ty); 515 assert(A->getIndexTypeCVRQualifiers() == 0 && 516 "FIXME: We only handle trivial array types so far!"); 517 // VLAs resolve to the innermost element type; this matches 518 // the return of alloca, and there isn't any obviously better choice. 519 ResultType = ConvertTypeForMem(A->getElementType()); 520 break; 521 } 522 case Type::IncompleteArray: { 523 const IncompleteArrayType *A = cast<IncompleteArrayType>(Ty); 524 assert(A->getIndexTypeCVRQualifiers() == 0 && 525 "FIXME: We only handle trivial array types so far!"); 526 // int X[] -> [0 x int], unless the element type is not sized. If it is 527 // unsized (e.g. an incomplete struct) just use [0 x i8]. 528 ResultType = ConvertTypeForMem(A->getElementType()); 529 if (!ResultType->isSized()) { 530 SkippedLayout = true; 531 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 532 } 533 ResultType = llvm::ArrayType::get(ResultType, 0); 534 break; 535 } 536 case Type::ConstantArray: { 537 const ConstantArrayType *A = cast<ConstantArrayType>(Ty); 538 llvm::Type *EltTy = ConvertTypeForMem(A->getElementType()); 539 540 // Lower arrays of undefined struct type to arrays of i8 just to have a 541 // concrete type. 542 if (!EltTy->isSized()) { 543 SkippedLayout = true; 544 EltTy = llvm::Type::getInt8Ty(getLLVMContext()); 545 } 546 547 ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue()); 548 break; 549 } 550 case Type::ExtVector: 551 case Type::Vector: { 552 const VectorType *VT = cast<VectorType>(Ty); 553 ResultType = llvm::VectorType::get(ConvertType(VT->getElementType()), 554 VT->getNumElements()); 555 break; 556 } 557 case Type::FunctionNoProto: 558 case Type::FunctionProto: 559 ResultType = ConvertFunctionType(T); 560 break; 561 case Type::ObjCObject: 562 ResultType = ConvertType(cast<ObjCObjectType>(Ty)->getBaseType()); 563 break; 564 565 case Type::ObjCInterface: { 566 // Objective-C interfaces are always opaque (outside of the 567 // runtime, which can do whatever it likes); we never refine 568 // these. 569 llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(Ty)]; 570 if (!T) 571 T = llvm::StructType::create(getLLVMContext()); 572 ResultType = T; 573 break; 574 } 575 576 case Type::ObjCObjectPointer: { 577 // Protocol qualifications do not influence the LLVM type, we just return a 578 // pointer to the underlying interface type. We don't need to worry about 579 // recursive conversion. 580 llvm::Type *T = 581 ConvertTypeForMem(cast<ObjCObjectPointerType>(Ty)->getPointeeType()); 582 ResultType = T->getPointerTo(); 583 break; 584 } 585 586 case Type::Enum: { 587 const EnumDecl *ED = cast<EnumType>(Ty)->getDecl(); 588 if (ED->isCompleteDefinition() || ED->isFixed()) 589 return ConvertType(ED->getIntegerType()); 590 // Return a placeholder 'i32' type. This can be changed later when the 591 // type is defined (see UpdateCompletedType), but is likely to be the 592 // "right" answer. 593 ResultType = llvm::Type::getInt32Ty(getLLVMContext()); 594 break; 595 } 596 597 case Type::BlockPointer: { 598 const QualType FTy = cast<BlockPointerType>(Ty)->getPointeeType(); 599 llvm::Type *PointeeType = ConvertTypeForMem(FTy); 600 unsigned AS = Context.getTargetAddressSpace(FTy); 601 ResultType = llvm::PointerType::get(PointeeType, AS); 602 break; 603 } 604 605 case Type::MemberPointer: { 606 if (!getCXXABI().isMemberPointerConvertible(cast<MemberPointerType>(Ty))) 607 return llvm::StructType::create(getLLVMContext()); 608 ResultType = 609 getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty)); 610 break; 611 } 612 613 case Type::Atomic: { 614 QualType valueType = cast<AtomicType>(Ty)->getValueType(); 615 ResultType = ConvertTypeForMem(valueType); 616 617 // Pad out to the inflated size if necessary. 618 uint64_t valueSize = Context.getTypeSize(valueType); 619 uint64_t atomicSize = Context.getTypeSize(Ty); 620 if (valueSize != atomicSize) { 621 assert(valueSize < atomicSize); 622 llvm::Type *elts[] = { 623 ResultType, 624 llvm::ArrayType::get(CGM.Int8Ty, (atomicSize - valueSize) / 8) 625 }; 626 ResultType = llvm::StructType::get(getLLVMContext(), 627 llvm::makeArrayRef(elts)); 628 } 629 break; 630 } 631 } 632 633 assert(ResultType && "Didn't convert a type?"); 634 635 TypeCache[Ty] = ResultType; 636 return ResultType; 637 } 638 639 bool CodeGenModule::isPaddedAtomicType(QualType type) { 640 return isPaddedAtomicType(type->castAs<AtomicType>()); 641 } 642 643 bool CodeGenModule::isPaddedAtomicType(const AtomicType *type) { 644 return Context.getTypeSize(type) != Context.getTypeSize(type->getValueType()); 645 } 646 647 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 648 llvm::StructType *CodeGenTypes::ConvertRecordDeclType(const RecordDecl *RD) { 649 // TagDecl's are not necessarily unique, instead use the (clang) 650 // type connected to the decl. 651 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 652 653 llvm::StructType *&Entry = RecordDeclTypes[Key]; 654 655 // If we don't have a StructType at all yet, create the forward declaration. 656 if (!Entry) { 657 Entry = llvm::StructType::create(getLLVMContext()); 658 addRecordTypeName(RD, Entry, ""); 659 } 660 llvm::StructType *Ty = Entry; 661 662 // If this is still a forward declaration, or the LLVM type is already 663 // complete, there's nothing more to do. 664 RD = RD->getDefinition(); 665 if (!RD || !RD->isCompleteDefinition() || !Ty->isOpaque()) 666 return Ty; 667 668 // If converting this type would cause us to infinitely loop, don't do it! 669 if (!isSafeToConvert(RD, *this)) { 670 DeferredRecords.push_back(RD); 671 return Ty; 672 } 673 674 // Okay, this is a definition of a type. Compile the implementation now. 675 bool InsertResult = RecordsBeingLaidOut.insert(Key).second; 676 (void)InsertResult; 677 assert(InsertResult && "Recursively compiling a struct?"); 678 679 // Force conversion of non-virtual base classes recursively. 680 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 681 for (const auto &I : CRD->bases()) { 682 if (I.isVirtual()) continue; 683 684 ConvertRecordDeclType(I.getType()->getAs<RecordType>()->getDecl()); 685 } 686 } 687 688 // Layout fields. 689 CGRecordLayout *Layout = ComputeRecordLayout(RD, Ty); 690 CGRecordLayouts[Key] = Layout; 691 692 // We're done laying out this struct. 693 bool EraseResult = RecordsBeingLaidOut.erase(Key); (void)EraseResult; 694 assert(EraseResult && "struct not in RecordsBeingLaidOut set?"); 695 696 // If this struct blocked a FunctionType conversion, then recompute whatever 697 // was derived from that. 698 // FIXME: This is hugely overconservative. 699 if (SkippedLayout) 700 TypeCache.clear(); 701 702 // If we're done converting the outer-most record, then convert any deferred 703 // structs as well. 704 if (RecordsBeingLaidOut.empty()) 705 while (!DeferredRecords.empty()) 706 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 707 708 return Ty; 709 } 710 711 /// getCGRecordLayout - Return record layout info for the given record decl. 712 const CGRecordLayout & 713 CodeGenTypes::getCGRecordLayout(const RecordDecl *RD) { 714 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 715 716 const CGRecordLayout *Layout = CGRecordLayouts.lookup(Key); 717 if (!Layout) { 718 // Compute the type information. 719 ConvertRecordDeclType(RD); 720 721 // Now try again. 722 Layout = CGRecordLayouts.lookup(Key); 723 } 724 725 assert(Layout && "Unable to find record layout information for type"); 726 return *Layout; 727 } 728 729 bool CodeGenTypes::isZeroInitializable(QualType T) { 730 // No need to check for member pointers when not compiling C++. 731 if (!Context.getLangOpts().CPlusPlus) 732 return true; 733 734 if (const auto *AT = Context.getAsArrayType(T)) { 735 if (isa<IncompleteArrayType>(AT)) 736 return true; 737 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) 738 if (Context.getConstantArrayElementCount(CAT) == 0) 739 return true; 740 T = Context.getBaseElementType(T); 741 } 742 743 // Records are non-zero-initializable if they contain any 744 // non-zero-initializable subobjects. 745 if (const RecordType *RT = T->getAs<RecordType>()) { 746 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 747 return isZeroInitializable(RD); 748 } 749 750 // We have to ask the ABI about member pointers. 751 if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) 752 return getCXXABI().isZeroInitializable(MPT); 753 754 // Everything else is okay. 755 return true; 756 } 757 758 bool CodeGenTypes::isZeroInitializable(const RecordDecl *RD) { 759 return getCGRecordLayout(RD).isZeroInitializable(); 760 } 761