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).second) 119 return true; 120 121 const Type *Key = CGT.getContext().getTagDeclType(RD).getTypePtr(); 122 123 // If this type is already laid out, converting it is a noop. 124 if (CGT.isRecordLayoutComplete(Key)) return true; 125 126 // If this type is currently being laid out, we can't recursively compile it. 127 if (CGT.isRecordBeingLaidOut(Key)) 128 return false; 129 130 // If this type would require laying out bases that are currently being laid 131 // out, don't do it. This includes virtual base classes which get laid out 132 // when a class is translated, even though they aren't embedded by-value into 133 // the class. 134 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 135 for (const auto &I : CRD->bases()) 136 if (!isSafeToConvert(I.getType()->getAs<RecordType>()->getDecl(), 137 CGT, AlreadyChecked)) 138 return false; 139 } 140 141 // If this type would require laying out members that are currently being laid 142 // out, don't do it. 143 for (const auto *I : RD->fields()) 144 if (!isSafeToConvert(I->getType(), CGT, AlreadyChecked)) 145 return false; 146 147 // If there are no problems, lets do it. 148 return true; 149 } 150 151 /// isSafeToConvert - Return true if it is safe to convert this field type, 152 /// which requires the structure elements contained by-value to all be 153 /// recursively safe to convert. 154 static bool 155 isSafeToConvert(QualType T, CodeGenTypes &CGT, 156 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) { 157 T = T.getCanonicalType(); 158 159 // If this is a record, check it. 160 if (const RecordType *RT = dyn_cast<RecordType>(T)) 161 return isSafeToConvert(RT->getDecl(), CGT, AlreadyChecked); 162 163 // If this is an array, check the elements, which are embedded inline. 164 if (const ArrayType *AT = dyn_cast<ArrayType>(T)) 165 return isSafeToConvert(AT->getElementType(), CGT, AlreadyChecked); 166 167 // Otherwise, there is no concern about transforming this. We only care about 168 // things that are contained by-value in a structure that can have another 169 // structure as a member. 170 return true; 171 } 172 173 174 /// isSafeToConvert - Return true if it is safe to convert the specified record 175 /// decl to IR and lay it out, false if doing so would cause us to get into a 176 /// recursive compilation mess. 177 static bool isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT) { 178 // If no structs are being laid out, we can certainly do this one. 179 if (CGT.noRecordsBeingLaidOut()) return true; 180 181 llvm::SmallPtrSet<const RecordDecl*, 16> AlreadyChecked; 182 return isSafeToConvert(RD, CGT, AlreadyChecked); 183 } 184 185 /// isFuncParamTypeConvertible - Return true if the specified type in a 186 /// function parameter or result position can be converted to an IR type at this 187 /// point. This boils down to being whether it is complete, as well as whether 188 /// we've temporarily deferred expanding the type because we're in a recursive 189 /// context. 190 bool CodeGenTypes::isFuncParamTypeConvertible(QualType Ty) { 191 // Some ABIs cannot have their member pointers represented in IR unless 192 // certain circumstances have been reached. 193 if (const auto *MPT = Ty->getAs<MemberPointerType>()) 194 return getCXXABI().isMemberPointerConvertible(MPT); 195 196 // If this isn't a tagged type, we can convert it! 197 const TagType *TT = Ty->getAs<TagType>(); 198 if (!TT) 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) 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 parameter 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. 224 bool CodeGenTypes::isFuncTypeConvertible(const FunctionType *FT) { 225 if (!isFuncParamTypeConvertible(FT->getReturnType())) 226 return false; 227 228 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 229 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++) 230 if (!isFuncParamTypeConvertible(FPT->getParamType(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. 238 void 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 // If necessary, provide the full definition of a type only used with a 252 // declaration so far. 253 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) 254 DI->completeType(ED); 255 return; 256 } 257 258 // If we completed a RecordDecl that we previously used and converted to an 259 // anonymous type, then go ahead and complete it now. 260 const RecordDecl *RD = cast<RecordDecl>(TD); 261 if (RD->isDependentType()) return; 262 263 // Only complete it if we converted it already. If we haven't converted it 264 // yet, we'll just do it lazily. 265 if (RecordDeclTypes.count(Context.getTagDeclType(RD).getTypePtr())) 266 ConvertRecordDeclType(RD); 267 268 // If necessary, provide the full definition of a type only used with a 269 // declaration so far. 270 if (CGDebugInfo *DI = CGM.getModuleDebugInfo()) 271 DI->completeType(RD); 272 } 273 274 static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext, 275 const llvm::fltSemantics &format, 276 bool UseNativeHalf = false) { 277 if (&format == &llvm::APFloat::IEEEhalf) { 278 if (UseNativeHalf) 279 return llvm::Type::getHalfTy(VMContext); 280 else 281 return llvm::Type::getInt16Ty(VMContext); 282 } 283 if (&format == &llvm::APFloat::IEEEsingle) 284 return llvm::Type::getFloatTy(VMContext); 285 if (&format == &llvm::APFloat::IEEEdouble) 286 return llvm::Type::getDoubleTy(VMContext); 287 if (&format == &llvm::APFloat::IEEEquad) 288 return llvm::Type::getFP128Ty(VMContext); 289 if (&format == &llvm::APFloat::PPCDoubleDouble) 290 return llvm::Type::getPPC_FP128Ty(VMContext); 291 if (&format == &llvm::APFloat::x87DoubleExtended) 292 return llvm::Type::getX86_FP80Ty(VMContext); 293 llvm_unreachable("Unknown float format!"); 294 } 295 296 /// ConvertType - Convert the specified type to its LLVM form. 297 llvm::Type *CodeGenTypes::ConvertType(QualType T) { 298 T = Context.getCanonicalType(T); 299 300 const Type *Ty = T.getTypePtr(); 301 302 // RecordTypes are cached and processed specially. 303 if (const RecordType *RT = dyn_cast<RecordType>(Ty)) 304 return ConvertRecordDeclType(RT->getDecl()); 305 306 // See if type is already cached. 307 llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty); 308 // If type is found in map then use it. Otherwise, convert type T. 309 if (TCI != TypeCache.end()) 310 return TCI->second; 311 312 // If we don't have it in the cache, convert it now. 313 llvm::Type *ResultType = nullptr; 314 switch (Ty->getTypeClass()) { 315 case Type::Record: // Handled above. 316 #define TYPE(Class, Base) 317 #define ABSTRACT_TYPE(Class, Base) 318 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class: 319 #define DEPENDENT_TYPE(Class, Base) case Type::Class: 320 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class: 321 #include "clang/AST/TypeNodes.def" 322 llvm_unreachable("Non-canonical or dependent types aren't possible."); 323 324 case Type::Builtin: { 325 switch (cast<BuiltinType>(Ty)->getKind()) { 326 case BuiltinType::Void: 327 case BuiltinType::ObjCId: 328 case BuiltinType::ObjCClass: 329 case BuiltinType::ObjCSel: 330 // LLVM void type can only be used as the result of a function call. Just 331 // map to the same as char. 332 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 333 break; 334 335 case BuiltinType::Bool: 336 // Note that we always return bool as i1 for use as a scalar type. 337 ResultType = llvm::Type::getInt1Ty(getLLVMContext()); 338 break; 339 340 case BuiltinType::Char_S: 341 case BuiltinType::Char_U: 342 case BuiltinType::SChar: 343 case BuiltinType::UChar: 344 case BuiltinType::Short: 345 case BuiltinType::UShort: 346 case BuiltinType::Int: 347 case BuiltinType::UInt: 348 case BuiltinType::Long: 349 case BuiltinType::ULong: 350 case BuiltinType::LongLong: 351 case BuiltinType::ULongLong: 352 case BuiltinType::WChar_S: 353 case BuiltinType::WChar_U: 354 case BuiltinType::Char16: 355 case BuiltinType::Char32: 356 ResultType = llvm::IntegerType::get(getLLVMContext(), 357 static_cast<unsigned>(Context.getTypeSize(T))); 358 break; 359 360 case BuiltinType::Half: 361 // Half FP can either be storage-only (lowered to i16) or native. 362 ResultType = 363 getTypeForFormat(getLLVMContext(), Context.getFloatTypeSemantics(T), 364 Context.getLangOpts().NativeHalfType || 365 Context.getLangOpts().HalfArgsAndReturns); 366 break; 367 case BuiltinType::Float: 368 case BuiltinType::Double: 369 case BuiltinType::LongDouble: 370 ResultType = getTypeForFormat(getLLVMContext(), 371 Context.getFloatTypeSemantics(T), 372 /* UseNativeHalf = */ false); 373 break; 374 375 case BuiltinType::NullPtr: 376 // Model std::nullptr_t as i8* 377 ResultType = llvm::Type::getInt8PtrTy(getLLVMContext()); 378 break; 379 380 case BuiltinType::UInt128: 381 case BuiltinType::Int128: 382 ResultType = llvm::IntegerType::get(getLLVMContext(), 128); 383 break; 384 385 case BuiltinType::OCLImage1d: 386 case BuiltinType::OCLImage1dArray: 387 case BuiltinType::OCLImage1dBuffer: 388 case BuiltinType::OCLImage2d: 389 case BuiltinType::OCLImage2dArray: 390 case BuiltinType::OCLImage3d: 391 case BuiltinType::OCLSampler: 392 case BuiltinType::OCLEvent: 393 ResultType = CGM.getOpenCLRuntime().convertOpenCLSpecificType(Ty); 394 break; 395 396 case BuiltinType::Dependent: 397 #define BUILTIN_TYPE(Id, SingletonId) 398 #define PLACEHOLDER_TYPE(Id, SingletonId) \ 399 case BuiltinType::Id: 400 #include "clang/AST/BuiltinTypes.def" 401 llvm_unreachable("Unexpected placeholder builtin type!"); 402 } 403 break; 404 } 405 case Type::Auto: 406 llvm_unreachable("Unexpected undeduced auto type!"); 407 case Type::Complex: { 408 llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType()); 409 ResultType = llvm::StructType::get(EltTy, EltTy, nullptr); 410 break; 411 } 412 case Type::LValueReference: 413 case Type::RValueReference: { 414 const ReferenceType *RTy = cast<ReferenceType>(Ty); 415 QualType ETy = RTy->getPointeeType(); 416 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 417 unsigned AS = Context.getTargetAddressSpace(ETy); 418 ResultType = llvm::PointerType::get(PointeeType, AS); 419 break; 420 } 421 case Type::Pointer: { 422 const PointerType *PTy = cast<PointerType>(Ty); 423 QualType ETy = PTy->getPointeeType(); 424 llvm::Type *PointeeType = ConvertTypeForMem(ETy); 425 if (PointeeType->isVoidTy()) 426 PointeeType = llvm::Type::getInt8Ty(getLLVMContext()); 427 unsigned AS = Context.getTargetAddressSpace(ETy); 428 ResultType = llvm::PointerType::get(PointeeType, AS); 429 break; 430 } 431 432 case Type::VariableArray: { 433 const VariableArrayType *A = cast<VariableArrayType>(Ty); 434 assert(A->getIndexTypeCVRQualifiers() == 0 && 435 "FIXME: We only handle trivial array types so far!"); 436 // VLAs resolve to the innermost element type; this matches 437 // the return of alloca, and there isn't any obviously better choice. 438 ResultType = ConvertTypeForMem(A->getElementType()); 439 break; 440 } 441 case Type::IncompleteArray: { 442 const IncompleteArrayType *A = cast<IncompleteArrayType>(Ty); 443 assert(A->getIndexTypeCVRQualifiers() == 0 && 444 "FIXME: We only handle trivial array types so far!"); 445 // int X[] -> [0 x int], unless the element type is not sized. If it is 446 // unsized (e.g. an incomplete struct) just use [0 x i8]. 447 ResultType = ConvertTypeForMem(A->getElementType()); 448 if (!ResultType->isSized()) { 449 SkippedLayout = true; 450 ResultType = llvm::Type::getInt8Ty(getLLVMContext()); 451 } 452 ResultType = llvm::ArrayType::get(ResultType, 0); 453 break; 454 } 455 case Type::ConstantArray: { 456 const ConstantArrayType *A = cast<ConstantArrayType>(Ty); 457 llvm::Type *EltTy = ConvertTypeForMem(A->getElementType()); 458 459 // Lower arrays of undefined struct type to arrays of i8 just to have a 460 // concrete type. 461 if (!EltTy->isSized()) { 462 SkippedLayout = true; 463 EltTy = llvm::Type::getInt8Ty(getLLVMContext()); 464 } 465 466 ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue()); 467 break; 468 } 469 case Type::ExtVector: 470 case Type::Vector: { 471 const VectorType *VT = cast<VectorType>(Ty); 472 ResultType = llvm::VectorType::get(ConvertType(VT->getElementType()), 473 VT->getNumElements()); 474 break; 475 } 476 case Type::FunctionNoProto: 477 case Type::FunctionProto: { 478 const FunctionType *FT = cast<FunctionType>(Ty); 479 // First, check whether we can build the full function type. If the 480 // function type depends on an incomplete type (e.g. a struct or enum), we 481 // cannot lower the function type. 482 if (!isFuncTypeConvertible(FT)) { 483 // This function's type depends on an incomplete tag type. 484 485 // Force conversion of all the relevant record types, to make sure 486 // we re-convert the FunctionType when appropriate. 487 if (const RecordType *RT = FT->getReturnType()->getAs<RecordType>()) 488 ConvertRecordDeclType(RT->getDecl()); 489 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) 490 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++) 491 if (const RecordType *RT = FPT->getParamType(i)->getAs<RecordType>()) 492 ConvertRecordDeclType(RT->getDecl()); 493 494 // Return a placeholder type. 495 ResultType = llvm::StructType::get(getLLVMContext()); 496 497 SkippedLayout = true; 498 break; 499 } 500 501 // While we're converting the parameter types for a function, we don't want 502 // to recursively convert any pointed-to structs. Converting directly-used 503 // structs is ok though. 504 if (!RecordsBeingLaidOut.insert(Ty).second) { 505 ResultType = llvm::StructType::get(getLLVMContext()); 506 507 SkippedLayout = true; 508 break; 509 } 510 511 // The function type can be built; call the appropriate routines to 512 // build it. 513 const CGFunctionInfo *FI; 514 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) { 515 FI = &arrangeFreeFunctionType( 516 CanQual<FunctionProtoType>::CreateUnsafe(QualType(FPT, 0))); 517 } else { 518 const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(FT); 519 FI = &arrangeFreeFunctionType( 520 CanQual<FunctionNoProtoType>::CreateUnsafe(QualType(FNPT, 0))); 521 } 522 523 // If there is something higher level prodding our CGFunctionInfo, then 524 // don't recurse into it again. 525 if (FunctionsBeingProcessed.count(FI)) { 526 527 ResultType = llvm::StructType::get(getLLVMContext()); 528 SkippedLayout = true; 529 } else { 530 531 // Otherwise, we're good to go, go ahead and convert it. 532 ResultType = GetFunctionType(*FI); 533 } 534 535 RecordsBeingLaidOut.erase(Ty); 536 537 if (SkippedLayout) 538 TypeCache.clear(); 539 540 if (RecordsBeingLaidOut.empty()) 541 while (!DeferredRecords.empty()) 542 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 543 break; 544 } 545 546 case Type::ObjCObject: 547 ResultType = ConvertType(cast<ObjCObjectType>(Ty)->getBaseType()); 548 break; 549 550 case Type::ObjCInterface: { 551 // Objective-C interfaces are always opaque (outside of the 552 // runtime, which can do whatever it likes); we never refine 553 // these. 554 llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(Ty)]; 555 if (!T) 556 T = llvm::StructType::create(getLLVMContext()); 557 ResultType = T; 558 break; 559 } 560 561 case Type::ObjCObjectPointer: { 562 // Protocol qualifications do not influence the LLVM type, we just return a 563 // pointer to the underlying interface type. We don't need to worry about 564 // recursive conversion. 565 llvm::Type *T = 566 ConvertTypeForMem(cast<ObjCObjectPointerType>(Ty)->getPointeeType()); 567 ResultType = T->getPointerTo(); 568 break; 569 } 570 571 case Type::Enum: { 572 const EnumDecl *ED = cast<EnumType>(Ty)->getDecl(); 573 if (ED->isCompleteDefinition() || ED->isFixed()) 574 return ConvertType(ED->getIntegerType()); 575 // Return a placeholder 'i32' type. This can be changed later when the 576 // type is defined (see UpdateCompletedType), but is likely to be the 577 // "right" answer. 578 ResultType = llvm::Type::getInt32Ty(getLLVMContext()); 579 break; 580 } 581 582 case Type::BlockPointer: { 583 const QualType FTy = cast<BlockPointerType>(Ty)->getPointeeType(); 584 llvm::Type *PointeeType = ConvertTypeForMem(FTy); 585 unsigned AS = Context.getTargetAddressSpace(FTy); 586 ResultType = llvm::PointerType::get(PointeeType, AS); 587 break; 588 } 589 590 case Type::MemberPointer: { 591 if (!getCXXABI().isMemberPointerConvertible(cast<MemberPointerType>(Ty))) 592 return llvm::StructType::create(getLLVMContext()); 593 ResultType = 594 getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty)); 595 break; 596 } 597 598 case Type::Atomic: { 599 QualType valueType = cast<AtomicType>(Ty)->getValueType(); 600 ResultType = ConvertTypeForMem(valueType); 601 602 // Pad out to the inflated size if necessary. 603 uint64_t valueSize = Context.getTypeSize(valueType); 604 uint64_t atomicSize = Context.getTypeSize(Ty); 605 if (valueSize != atomicSize) { 606 assert(valueSize < atomicSize); 607 llvm::Type *elts[] = { 608 ResultType, 609 llvm::ArrayType::get(CGM.Int8Ty, (atomicSize - valueSize) / 8) 610 }; 611 ResultType = llvm::StructType::get(getLLVMContext(), 612 llvm::makeArrayRef(elts)); 613 } 614 break; 615 } 616 } 617 618 assert(ResultType && "Didn't convert a type?"); 619 620 TypeCache[Ty] = ResultType; 621 return ResultType; 622 } 623 624 bool CodeGenModule::isPaddedAtomicType(QualType type) { 625 return isPaddedAtomicType(type->castAs<AtomicType>()); 626 } 627 628 bool CodeGenModule::isPaddedAtomicType(const AtomicType *type) { 629 return Context.getTypeSize(type) != Context.getTypeSize(type->getValueType()); 630 } 631 632 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 633 llvm::StructType *CodeGenTypes::ConvertRecordDeclType(const RecordDecl *RD) { 634 // TagDecl's are not necessarily unique, instead use the (clang) 635 // type connected to the decl. 636 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 637 638 llvm::StructType *&Entry = RecordDeclTypes[Key]; 639 640 // If we don't have a StructType at all yet, create the forward declaration. 641 if (!Entry) { 642 Entry = llvm::StructType::create(getLLVMContext()); 643 addRecordTypeName(RD, Entry, ""); 644 } 645 llvm::StructType *Ty = Entry; 646 647 // If this is still a forward declaration, or the LLVM type is already 648 // complete, there's nothing more to do. 649 RD = RD->getDefinition(); 650 if (!RD || !RD->isCompleteDefinition() || !Ty->isOpaque()) 651 return Ty; 652 653 // If converting this type would cause us to infinitely loop, don't do it! 654 if (!isSafeToConvert(RD, *this)) { 655 DeferredRecords.push_back(RD); 656 return Ty; 657 } 658 659 // Okay, this is a definition of a type. Compile the implementation now. 660 bool InsertResult = RecordsBeingLaidOut.insert(Key).second; 661 (void)InsertResult; 662 assert(InsertResult && "Recursively compiling a struct?"); 663 664 // Force conversion of non-virtual base classes recursively. 665 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { 666 for (const auto &I : CRD->bases()) { 667 if (I.isVirtual()) continue; 668 669 ConvertRecordDeclType(I.getType()->getAs<RecordType>()->getDecl()); 670 } 671 } 672 673 // Layout fields. 674 CGRecordLayout *Layout = ComputeRecordLayout(RD, Ty); 675 CGRecordLayouts[Key] = Layout; 676 677 // We're done laying out this struct. 678 bool EraseResult = RecordsBeingLaidOut.erase(Key); (void)EraseResult; 679 assert(EraseResult && "struct not in RecordsBeingLaidOut set?"); 680 681 // If this struct blocked a FunctionType conversion, then recompute whatever 682 // was derived from that. 683 // FIXME: This is hugely overconservative. 684 if (SkippedLayout) 685 TypeCache.clear(); 686 687 // If we're done converting the outer-most record, then convert any deferred 688 // structs as well. 689 if (RecordsBeingLaidOut.empty()) 690 while (!DeferredRecords.empty()) 691 ConvertRecordDeclType(DeferredRecords.pop_back_val()); 692 693 return Ty; 694 } 695 696 /// getCGRecordLayout - Return record layout info for the given record decl. 697 const CGRecordLayout & 698 CodeGenTypes::getCGRecordLayout(const RecordDecl *RD) { 699 const Type *Key = Context.getTagDeclType(RD).getTypePtr(); 700 701 const CGRecordLayout *Layout = CGRecordLayouts.lookup(Key); 702 if (!Layout) { 703 // Compute the type information. 704 ConvertRecordDeclType(RD); 705 706 // Now try again. 707 Layout = CGRecordLayouts.lookup(Key); 708 } 709 710 assert(Layout && "Unable to find record layout information for type"); 711 return *Layout; 712 } 713 714 bool CodeGenTypes::isZeroInitializable(QualType T) { 715 // No need to check for member pointers when not compiling C++. 716 if (!Context.getLangOpts().CPlusPlus) 717 return true; 718 719 T = Context.getBaseElementType(T); 720 721 // Records are non-zero-initializable if they contain any 722 // non-zero-initializable subobjects. 723 if (const RecordType *RT = T->getAs<RecordType>()) { 724 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl()); 725 return isZeroInitializable(RD); 726 } 727 728 // We have to ask the ABI about member pointers. 729 if (const MemberPointerType *MPT = T->getAs<MemberPointerType>()) 730 return getCXXABI().isZeroInitializable(MPT); 731 732 // Everything else is okay. 733 return true; 734 } 735 736 bool CodeGenTypes::isZeroInitializable(const CXXRecordDecl *RD) { 737 return getCGRecordLayout(RD).isZeroInitializable(); 738 } 739