CodeGenTypes.cpp revision 251662
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 "llvm/IR/DataLayout.h" 26#include "llvm/IR/DerivedTypes.h" 27#include "llvm/IR/Module.h" 28using namespace clang; 29using namespace CodeGen; 30 31CodeGenTypes::CodeGenTypes(CodeGenModule &cgm) 32 : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()), 33 TheDataLayout(cgm.getDataLayout()), 34 Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()), 35 CodeGenOpts(cgm.getCodeGenOpts()), 36 TheABIInfo(cgm.getTargetCodeGenInfo().getABIInfo()) { 37 SkippedLayout = false; 38} 39 40CodeGenTypes::~CodeGenTypes() { 41 for (llvm::DenseMap<const Type *, CGRecordLayout *>::iterator 42 I = CGRecordLayouts.begin(), E = CGRecordLayouts.end(); 43 I != E; ++I) 44 delete I->second; 45 46 for (llvm::FoldingSet<CGFunctionInfo>::iterator 47 I = FunctionInfos.begin(), E = FunctionInfos.end(); I != E; ) 48 delete &*I++; 49} 50 51void CodeGenTypes::addRecordTypeName(const RecordDecl *RD, 52 llvm::StructType *Ty, 53 StringRef suffix) { 54 SmallString<256> TypeName; 55 llvm::raw_svector_ostream OS(TypeName); 56 OS << RD->getKindName() << '.'; 57 58 // Name the codegen type after the typedef name 59 // if there is no tag type name available 60 if (RD->getIdentifier()) { 61 // FIXME: We should not have to check for a null decl context here. 62 // Right now we do it because the implicit Obj-C decls don't have one. 63 if (RD->getDeclContext()) 64 RD->printQualifiedName(OS); 65 else 66 RD->printName(OS); 67 } else if (const TypedefNameDecl *TDD = RD->getTypedefNameForAnonDecl()) { 68 // FIXME: We should not have to check for a null decl context here. 69 // Right now we do it because the implicit Obj-C decls don't have one. 70 if (TDD->getDeclContext()) 71 TDD->printQualifiedName(OS); 72 else 73 TDD->printName(OS); 74 } else 75 OS << "anon"; 76 77 if (!suffix.empty()) 78 OS << suffix; 79 80 Ty->setName(OS.str()); 81} 82 83/// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 84/// ConvertType in that it is used to convert to the memory representation for 85/// a type. For example, the scalar representation for _Bool is i1, but the 86/// memory representation is usually i8 or i32, depending on the target. 87llvm::Type *CodeGenTypes::ConvertTypeForMem(QualType T){ 88 llvm::Type *R = ConvertType(T); 89 90 // If this is a non-bool type, don't map it. 91 if (!R->isIntegerTy(1)) 92 return R; 93 94 // Otherwise, return an integer of the target-specified size. 95 return llvm::IntegerType::get(getLLVMContext(), 96 (unsigned)Context.getTypeSize(T)); 97} 98 99 100/// isRecordLayoutComplete - Return true if the specified type is already 101/// completely laid out. 102bool CodeGenTypes::isRecordLayoutComplete(const Type *Ty) const { 103 llvm::DenseMap<const Type*, llvm::StructType *>::const_iterator I = 104 RecordDeclTypes.find(Ty); 105 return I != RecordDeclTypes.end() && !I->second->isOpaque(); 106} 107 108static bool 109isSafeToConvert(QualType T, CodeGenTypes &CGT, 110 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked); 111 112 113/// isSafeToConvert - Return true if it is safe to convert the specified record 114/// decl to IR and lay it out, false if doing so would cause us to get into a 115/// recursive compilation mess. 116static bool 117isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT, 118 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) { 119 // If we have already checked this type (maybe the same type is used by-value 120 // multiple times in multiple structure fields, don't check again. 121 if (!AlreadyChecked.insert(RD)) return true; 122 123 const Type *Key = CGT.getContext().getTagDeclType(RD).getTypePtr(); 124 125 // If this type is already laid out, converting it is a noop. 126 if (CGT.isRecordLayoutComplete(Key)) return true; 127 128 // If this type is currently being laid out, we can't recursively compile it. 129 if (CGT.isRecordBeingLaidOut(Key)) 130 return false; 131 132 // If this type would require laying out bases that are currently being laid 133 // out, don't do it. This includes virtual base classes which get laid out 134 // when a class is translated, even though they aren't embedded by-value into 135 // the class. 136 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 137 for (CXXRecordDecl::base_class_const_iterator I = CRD->bases_begin(), 138 E = CRD->bases_end(); I != E; ++I) 139 if (!isSafeToConvert(I->getType()->getAs<RecordType>()->getDecl(), 140 CGT, AlreadyChecked)) 141 return false; 142 } 143 144 // If this type would require laying out members that are currently being laid 145 // out, don't do it. 146 for (RecordDecl::field_iterator I = RD->field_begin(), 147 E = RD->field_end(); I != E; ++I) 148 if (!isSafeToConvert(I->getType(), CGT, AlreadyChecked)) 149 return false; 150 151 // If there are no problems, lets do it. 152 return true; 153} 154 155/// isSafeToConvert - Return true if it is safe to convert this field type, 156/// which requires the structure elements contained by-value to all be 157/// recursively safe to convert. 158static bool 159isSafeToConvert(QualType T, CodeGenTypes &CGT, 160 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) { 161 T = T.getCanonicalType(); 162 163 // If this is a record, check it. 164 if (const RecordType *RT = dyn_cast<RecordType>(T)) 165 return isSafeToConvert(RT->getDecl(), CGT, AlreadyChecked); 166 167 // If this is an array, check the elements, which are embedded inline. 168 if (const ArrayType *AT = dyn_cast<ArrayType>(T)) 169 return isSafeToConvert(AT->getElementType(), CGT, AlreadyChecked); 170 171 // Otherwise, there is no concern about transforming this. We only care about 172 // things that are contained by-value in a structure that can have another 173 // structure as a member. 174 return true; 175} 176 177 178/// isSafeToConvert - Return true if it is safe to convert the specified record 179/// decl to IR and lay it out, false if doing so would cause us to get into a 180/// recursive compilation mess. 181static bool isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT) { 182 // If no structs are being laid out, we can certainly do this one. 183 if (CGT.noRecordsBeingLaidOut()) return true; 184 185 llvm::SmallPtrSet<const RecordDecl*, 16> AlreadyChecked; 186 return isSafeToConvert(RD, CGT, AlreadyChecked); 187} 188 189 190/// isFuncTypeArgumentConvertible - Return true if the specified type in a 191/// function argument or result position can be converted to an IR type at this 192/// point. This boils down to being whether it is complete, as well as whether 193/// we've temporarily deferred expanding the type because we're in a recursive 194/// context. 195bool CodeGenTypes::isFuncTypeArgumentConvertible(QualType Ty) { 196 // If this isn't a tagged type, we can convert it! 197 const TagType *TT = Ty->getAs<TagType>(); 198 if (TT == 0) return true; 199 200 // Incomplete types cannot be converted. 201 if (TT->isIncompleteType()) 202 return false; 203 204 // If this is an enum, then it is always safe to convert. 205 const RecordType *RT = dyn_cast<RecordType>(TT); 206 if (RT == 0) return true; 207 208 // Otherwise, we have to be careful. If it is a struct that we're in the 209 // process of expanding, then we can't convert the function type. That's ok 210 // though because we must be in a pointer context under the struct, so we can 211 // just convert it to a dummy type. 212 // 213 // We decide this by checking whether ConvertRecordDeclType returns us an 214 // opaque type for a struct that we know is defined. 215 return isSafeToConvert(RT->getDecl(), *this); 216} 217 218 219/// Code to verify a given function type is complete, i.e. the return type 220/// and all of the argument types are complete. Also check to see if we are in 221/// a RS_StructPointer context, and if so whether any struct types have been 222/// pended. If so, we don't want to ask the ABI lowering code to handle a type 223/// that cannot be converted to an IR type. 224bool CodeGenTypes::isFuncTypeConvertible(const FunctionType *FT) { 225 if (!isFuncTypeArgumentConvertible(FT->getResultType())) 226 return false; 227 228 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 229 for (unsigned i = 0, e = FPT->getNumArgs(); i != e; i++) 230 if (!isFuncTypeArgumentConvertible(FPT->getArgType(i))) 231 return false; 232 233 return true; 234} 235 236/// UpdateCompletedType - When we find the full definition for a TagDecl, 237/// replace the 'opaque' type we previously made for it if applicable. 238void CodeGenTypes::UpdateCompletedType(const TagDecl *TD) { 239 // If this is an enum being completed, then we flush all non-struct types from 240 // the cache. This allows function types and other things that may be derived 241 // from the enum to be recomputed. 242 if (const EnumDecl *ED = dyn_cast<EnumDecl>(TD)) { 243 // Only flush the cache if we've actually already converted this type. 244 if (TypeCache.count(ED->getTypeForDecl())) { 245 // Okay, we formed some types based on this. We speculated that the enum 246 // would be lowered to i32, so we only need to flush the cache if this 247 // didn't happen. 248 if (!ConvertType(ED->getIntegerType())->isIntegerTy(32)) 249 TypeCache.clear(); 250 } 251 return; 252 } 253 254 // If we completed a RecordDecl that we previously used and converted to an 255 // anonymous type, then go ahead and complete it now. 256 const RecordDecl *RD = cast<RecordDecl>(TD); 257 if (RD->isDependentType()) return; 258 259 // Only complete it if we converted it already. If we haven't converted it 260 // yet, we'll just do it lazily. 261 if (RecordDeclTypes.count(Context.getTagDeclType(RD).getTypePtr())) 262 ConvertRecordDeclType(RD); 263} 264 265static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext, 266 const llvm::fltSemantics &format, 267 bool UseNativeHalf = false) { 268 if (&format == &llvm::APFloat::IEEEhalf) { 269 if (UseNativeHalf) 270 return llvm::Type::getHalfTy(VMContext); 271 else 272 return llvm::Type::getInt16Ty(VMContext); 273 } 274 if (&format == &llvm::APFloat::IEEEsingle) 275 return llvm::Type::getFloatTy(VMContext); 276 if (&format == &llvm::APFloat::IEEEdouble) 277 return llvm::Type::getDoubleTy(VMContext); 278 if (&format == &llvm::APFloat::IEEEquad) 279 return llvm::Type::getFP128Ty(VMContext); 280 if (&format == &llvm::APFloat::PPCDoubleDouble) 281 return llvm::Type::getPPC_FP128Ty(VMContext); 282 if (&format == &llvm::APFloat::x87DoubleExtended) 283 return llvm::Type::getX86_FP80Ty(VMContext); 284 llvm_unreachable("Unknown float format!"); 285} 286 287/// ConvertType - Convert the specified type to its LLVM form. 288llvm::Type *CodeGenTypes::ConvertType(QualType T) { 289 T = Context.getCanonicalType(T); 290 291 const Type *Ty = T.getTypePtr(); 292 293 // RecordTypes are cached and processed specially. 294 if (const RecordType *RT = dyn_cast<RecordType>(Ty)) 295 return ConvertRecordDeclType(RT->getDecl()); 296 297 // See if type is already cached. 298 llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty); 299 // If type is found in map then use it. Otherwise, convert type T. 300 if (TCI != TypeCache.end()) 301 return TCI->second; 302 303 // If we don't have it in the cache, convert it now. 304 llvm::Type *ResultType = 0; 305 switch (Ty->getTypeClass()) { 306 case Type::Record: // Handled above. 307#define TYPE(Class, Base) 308#define ABSTRACT_TYPE(Class, Base) 309#define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 310#define DEPENDENT_TYPE(Class, Base) case Type::Class: 311#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 312#include "clang/AST/TypeNodes.def" 313 llvm_unreachable("Non-canonical or dependent types aren't possible."); 314 315 case Type::Builtin: { 316 switch (cast<BuiltinType>(Ty)->getKind()) { 317 case BuiltinType::Void: 318 case BuiltinType::ObjCId: 319 case BuiltinType::ObjCClass: 320 case BuiltinType::ObjCSel: 321 // LLVM void type can only be used as the result of a function call. Just 322 // map to the same as char. 323 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 324 break; 325 326 case BuiltinType::Bool: 327 // Note that we always return bool as i1 for use as a scalar type. 328 ResultType = llvm::Type::getInt1Ty(getLLVMContext()); 329 break; 330 331 case BuiltinType::Char_S: 332 case BuiltinType::Char_U: 333 case BuiltinType::SChar: 334 case BuiltinType::UChar: 335 case BuiltinType::Short: 336 case BuiltinType::UShort: 337 case BuiltinType::Int: 338 case BuiltinType::UInt: 339 case BuiltinType::Long: 340 case BuiltinType::ULong: 341 case BuiltinType::LongLong: 342 case BuiltinType::ULongLong: 343 case BuiltinType::WChar_S: 344 case BuiltinType::WChar_U: 345 case BuiltinType::Char16: 346 case BuiltinType::Char32: 347 ResultType = llvm::IntegerType::get(getLLVMContext(), 348 static_cast<unsigned>(Context.getTypeSize(T))); 349 break; 350 351 case BuiltinType::Half: 352 // Half FP can either be storage-only (lowered to i16) or native. 353 ResultType = getTypeForFormat(getLLVMContext(), 354 Context.getFloatTypeSemantics(T), 355 Context.getLangOpts().NativeHalfType); 356 break; 357 case BuiltinType::Float: 358 case BuiltinType::Double: 359 case BuiltinType::LongDouble: 360 ResultType = getTypeForFormat(getLLVMContext(), 361 Context.getFloatTypeSemantics(T), 362 /* UseNativeHalf = */ false); 363 break; 364 365 case BuiltinType::NullPtr: 366 // Model std::nullptr_t as i8* 367 ResultType = llvm::Type::getInt8PtrTy(getLLVMContext()); 368 break; 369 370 case BuiltinType::UInt128: 371 case BuiltinType::Int128: 372 ResultType = llvm::IntegerType::get(getLLVMContext(), 128); 373 break; 374 375 case BuiltinType::OCLImage1d: 376 case BuiltinType::OCLImage1dArray: 377 case BuiltinType::OCLImage1dBuffer: 378 case BuiltinType::OCLImage2d: 379 case BuiltinType::OCLImage2dArray: 380 case BuiltinType::OCLImage3d: 381 case BuiltinType::OCLSampler: 382 case BuiltinType::OCLEvent: 383 ResultType = CGM.getOpenCLRuntime().convertOpenCLSpecificType(Ty); 384 break; 385 386 case BuiltinType::Dependent: 387#define BUILTIN_TYPE(Id, SingletonId) 388#define PLACEHOLDER_TYPE(Id, SingletonId) \ 389 case BuiltinType::Id: 390#include "clang/AST/BuiltinTypes.def" 391 llvm_unreachable("Unexpected placeholder builtin type!"); 392 } 393 break; 394 } 395 case Type::Auto: 396 llvm_unreachable("Unexpected undeduced auto type!"); 397 case Type::Complex: { 398 llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType()); 399 ResultType = llvm::StructType::get(EltTy, EltTy, NULL); 400 break; 401 } 402 case Type::LValueReference: 403 case Type::RValueReference: { 404 const ReferenceType *RTy = cast<ReferenceType>(Ty); 405 QualType ETy = RTy->getPointeeType(); 406 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 407 unsigned AS = Context.getTargetAddressSpace(ETy); 408 ResultType = llvm::PointerType::get(PointeeType, AS); 409 break; 410 } 411 case Type::Pointer: { 412 const PointerType *PTy = cast<PointerType>(Ty); 413 QualType ETy = PTy->getPointeeType(); 414 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 415 if (PointeeType->isVoidTy()) 416 PointeeType = llvm::Type::getInt8Ty(getLLVMContext()); 417 unsigned AS = Context.getTargetAddressSpace(ETy); 418 ResultType = llvm::PointerType::get(PointeeType, AS); 419 break; 420 } 421 422 case Type::VariableArray: { 423 const VariableArrayType *A = cast<VariableArrayType>(Ty); 424 assert(A->getIndexTypeCVRQualifiers() == 0 && 425 "FIXME: We only handle trivial array types so far!"); 426 // VLAs resolve to the innermost element type; this matches 427 // the return of alloca, and there isn't any obviously better choice. 428 ResultType = ConvertTypeForMem(A->getElementType()); 429 break; 430 } 431 case Type::IncompleteArray: { 432 const IncompleteArrayType *A = cast<IncompleteArrayType>(Ty); 433 assert(A->getIndexTypeCVRQualifiers() == 0 && 434 "FIXME: We only handle trivial array types so far!"); 435 // int X[] -> [0 x int], unless the element type is not sized. If it is 436 // unsized (e.g. an incomplete struct) just use [0 x i8]. 437 ResultType = ConvertTypeForMem(A->getElementType()); 438 if (!ResultType->isSized()) { 439 SkippedLayout = true; 440 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 441 } 442 ResultType = llvm::ArrayType::get(ResultType, 0); 443 break; 444 } 445 case Type::ConstantArray: { 446 const ConstantArrayType *A = cast<ConstantArrayType>(Ty); 447 llvm::Type *EltTy = ConvertTypeForMem(A->getElementType()); 448 449 // Lower arrays of undefined struct type to arrays of i8 just to have a 450 // concrete type. 451 if (!EltTy->isSized()) { 452 SkippedLayout = true; 453 EltTy = llvm::Type::getInt8Ty(getLLVMContext()); 454 } 455 456 ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue()); 457 break; 458 } 459 case Type::ExtVector: 460 case Type::Vector: { 461 const VectorType *VT = cast<VectorType>(Ty); 462 ResultType = llvm::VectorType::get(ConvertType(VT->getElementType()), 463 VT->getNumElements()); 464 break; 465 } 466 case Type::FunctionNoProto: 467 case Type::FunctionProto: { 468 const FunctionType *FT = cast<FunctionType>(Ty); 469 // First, check whether we can build the full function type. If the 470 // function type depends on an incomplete type (e.g. a struct or enum), we 471 // cannot lower the function type. 472 if (!isFuncTypeConvertible(FT)) { 473 // This function's type depends on an incomplete tag type. 474 475 // Force conversion of all the relevant record types, to make sure 476 // we re-convert the FunctionType when appropriate. 477 if (const RecordType *RT = FT->getResultType()->getAs<RecordType>()) 478 ConvertRecordDeclType(RT->getDecl()); 479 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 480 for (unsigned i = 0, e = FPT->getNumArgs(); i != e; i++) 481 if (const RecordType *RT = FPT->getArgType(i)->getAs<RecordType>()) 482 ConvertRecordDeclType(RT->getDecl()); 483 484 // Return a placeholder type. 485 ResultType = llvm::StructType::get(getLLVMContext()); 486 487 SkippedLayout = true; 488 break; 489 } 490 491 // While we're converting the argument types for a function, we don't want 492 // to recursively convert any pointed-to structs. Converting directly-used 493 // structs is ok though. 494 if (!RecordsBeingLaidOut.insert(Ty)) { 495 ResultType = llvm::StructType::get(getLLVMContext()); 496 497 SkippedLayout = true; 498 break; 499 } 500 501 // The function type can be built; call the appropriate routines to 502 // build it. 503 const CGFunctionInfo *FI; 504 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) { 505 FI = &arrangeFreeFunctionType( 506 CanQual<FunctionProtoType>::CreateUnsafe(QualType(FPT, 0))); 507 } else { 508 const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(FT); 509 FI = &arrangeFreeFunctionType( 510 CanQual<FunctionNoProtoType>::CreateUnsafe(QualType(FNPT, 0))); 511 } 512 513 // If there is something higher level prodding our CGFunctionInfo, then 514 // don't recurse into it again. 515 if (FunctionsBeingProcessed.count(FI)) { 516 517 ResultType = llvm::StructType::get(getLLVMContext()); 518 SkippedLayout = true; 519 } else { 520 521 // Otherwise, we're good to go, go ahead and convert it. 522 ResultType = GetFunctionType(*FI); 523 } 524 525 RecordsBeingLaidOut.erase(Ty); 526 527 if (SkippedLayout) 528 TypeCache.clear(); 529 530 if (RecordsBeingLaidOut.empty()) 531 while (!DeferredRecords.empty()) 532 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 533 break; 534 } 535 536 case Type::ObjCObject: 537 ResultType = ConvertType(cast<ObjCObjectType>(Ty)->getBaseType()); 538 break; 539 540 case Type::ObjCInterface: { 541 // Objective-C interfaces are always opaque (outside of the 542 // runtime, which can do whatever it likes); we never refine 543 // these. 544 llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(Ty)]; 545 if (!T) 546 T = llvm::StructType::create(getLLVMContext()); 547 ResultType = T; 548 break; 549 } 550 551 case Type::ObjCObjectPointer: { 552 // Protocol qualifications do not influence the LLVM type, we just return a 553 // pointer to the underlying interface type. We don't need to worry about 554 // recursive conversion. 555 llvm::Type *T = 556 ConvertTypeForMem(cast<ObjCObjectPointerType>(Ty)->getPointeeType()); 557 ResultType = T->getPointerTo(); 558 break; 559 } 560 561 case Type::Enum: { 562 const EnumDecl *ED = cast<EnumType>(Ty)->getDecl(); 563 if (ED->isCompleteDefinition() || ED->isFixed()) 564 return ConvertType(ED->getIntegerType()); 565 // Return a placeholder 'i32' type. This can be changed later when the 566 // type is defined (see UpdateCompletedType), but is likely to be the 567 // "right" answer. 568 ResultType = llvm::Type::getInt32Ty(getLLVMContext()); 569 break; 570 } 571 572 case Type::BlockPointer: { 573 const QualType FTy = cast<BlockPointerType>(Ty)->getPointeeType(); 574 llvm::Type *PointeeType = ConvertTypeForMem(FTy); 575 unsigned AS = Context.getTargetAddressSpace(FTy); 576 ResultType = llvm::PointerType::get(PointeeType, AS); 577 break; 578 } 579 580 case Type::MemberPointer: { 581 ResultType = 582 getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty)); 583 break; 584 } 585 586 case Type::Atomic: { 587 QualType valueType = cast<AtomicType>(Ty)->getValueType(); 588 ResultType = ConvertTypeForMem(valueType); 589 590 // Pad out to the inflated size if necessary. 591 uint64_t valueSize = Context.getTypeSize(valueType); 592 uint64_t atomicSize = Context.getTypeSize(Ty); 593 if (valueSize != atomicSize) { 594 assert(valueSize < atomicSize); 595 llvm::Type *elts[] = { 596 ResultType, 597 llvm::ArrayType::get(CGM.Int8Ty, (atomicSize - valueSize) / 8) 598 }; 599 ResultType = llvm::StructType::get(getLLVMContext(), 600 llvm::makeArrayRef(elts)); 601 } 602 break; 603 } 604 } 605 606 assert(ResultType && "Didn't convert a type?"); 607 608 TypeCache[Ty] = ResultType; 609 return ResultType; 610} 611 612bool CodeGenModule::isPaddedAtomicType(QualType type) { 613 return isPaddedAtomicType(type->castAs<AtomicType>()); 614} 615 616bool CodeGenModule::isPaddedAtomicType(const AtomicType *type) { 617 return Context.getTypeSize(type) != Context.getTypeSize(type->getValueType()); 618} 619 620/// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 621llvm::StructType *CodeGenTypes::ConvertRecordDeclType(const RecordDecl *RD) { 622 // TagDecl's are not necessarily unique, instead use the (clang) 623 // type connected to the decl. 624 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 625 626 llvm::StructType *&Entry = RecordDeclTypes[Key]; 627 628 // If we don't have a StructType at all yet, create the forward declaration. 629 if (Entry == 0) { 630 Entry = llvm::StructType::create(getLLVMContext()); 631 addRecordTypeName(RD, Entry, ""); 632 } 633 llvm::StructType *Ty = Entry; 634 635 // If this is still a forward declaration, or the LLVM type is already 636 // complete, there's nothing more to do. 637 RD = RD->getDefinition(); 638 if (RD == 0 || !RD->isCompleteDefinition() || !Ty->isOpaque()) 639 return Ty; 640 641 // If converting this type would cause us to infinitely loop, don't do it! 642 if (!isSafeToConvert(RD, *this)) { 643 DeferredRecords.push_back(RD); 644 return Ty; 645 } 646 647 // Okay, this is a definition of a type. Compile the implementation now. 648 bool InsertResult = RecordsBeingLaidOut.insert(Key); (void)InsertResult; 649 assert(InsertResult && "Recursively compiling a struct?"); 650 651 // Force conversion of non-virtual base classes recursively. 652 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 653 for (CXXRecordDecl::base_class_const_iterator i = CRD->bases_begin(), 654 e = CRD->bases_end(); i != e; ++i) { 655 if (i->isVirtual()) continue; 656 657 ConvertRecordDeclType(i->getType()->getAs<RecordType>()->getDecl()); 658 } 659 } 660 661 // Layout fields. 662 CGRecordLayout *Layout = ComputeRecordLayout(RD, Ty); 663 CGRecordLayouts[Key] = Layout; 664 665 // We're done laying out this struct. 666 bool EraseResult = RecordsBeingLaidOut.erase(Key); (void)EraseResult; 667 assert(EraseResult && "struct not in RecordsBeingLaidOut set?"); 668 669 // If this struct blocked a FunctionType conversion, then recompute whatever 670 // was derived from that. 671 // FIXME: This is hugely overconservative. 672 if (SkippedLayout) 673 TypeCache.clear(); 674 675 // If we're done converting the outer-most record, then convert any deferred 676 // structs as well. 677 if (RecordsBeingLaidOut.empty()) 678 while (!DeferredRecords.empty()) 679 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 680 681 return Ty; 682} 683 684/// getCGRecordLayout - Return record layout info for the given record decl. 685const CGRecordLayout & 686CodeGenTypes::getCGRecordLayout(const RecordDecl *RD) { 687 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 688 689 const CGRecordLayout *Layout = CGRecordLayouts.lookup(Key); 690 if (!Layout) { 691 // Compute the type information. 692 ConvertRecordDeclType(RD); 693 694 // Now try again. 695 Layout = CGRecordLayouts.lookup(Key); 696 } 697 698 assert(Layout && "Unable to find record layout information for type"); 699 return *Layout; 700} 701 702bool CodeGenTypes::isZeroInitializable(QualType T) { 703 // No need to check for member pointers when not compiling C++. 704 if (!Context.getLangOpts().CPlusPlus) 705 return true; 706 707 T = Context.getBaseElementType(T); 708 709 // Records are non-zero-initializable if they contain any 710 // non-zero-initializable subobjects. 711 if (const RecordType *RT = T->getAs<RecordType>()) { 712 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 713 return isZeroInitializable(RD); 714 } 715 716 // We have to ask the ABI about member pointers. 717 if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) 718 return getCXXABI().isZeroInitializable(MPT); 719 720 // Everything else is okay. 721 return true; 722} 723 724bool CodeGenTypes::isZeroInitializable(const CXXRecordDecl *RD) { 725 return getCGRecordLayout(RD).isZeroInitializable(); 726} 727