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