1 //===--- CodeGenTypes.cpp - Type translation for LLVM CodeGen -------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is the code that handles AST -> LLVM type lowering.
12 //===----------------------------------------------------------------------===//
14 #include "CodeGenTypes.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;
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;
40 CodeGenTypes::~CodeGenTypes() {
41 llvm::DeleteContainerSeconds(CGRecordLayouts);
43 for (llvm::FoldingSet<CGFunctionInfo>::iterator
44 I = FunctionInfos.begin(), E = FunctionInfos.end(); I != E; )
48 void CodeGenTypes::addRecordTypeName(const RecordDecl *RD,
51 SmallString<256> TypeName;
52 llvm::raw_svector_ostream OS(TypeName);
53 OS << RD->getKindName() << '.';
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);
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);
77 Ty->setName(OS.str());
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);
87 // If this is a non-bool type, don't map it.
88 if (!R->isIntegerTy(1))
91 // Otherwise, return an integer of the target-specified size.
92 return llvm::IntegerType::get(getLLVMContext(),
93 (unsigned)Context.getTypeSize(T));
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();
106 isSafeToConvert(QualType T, CodeGenTypes &CGT,
107 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked);
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.
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)
121 const Type *Key = CGT.getContext().getTagDeclType(RD).getTypePtr();
123 // If this type is already laid out, converting it is a noop.
124 if (CGT.isRecordLayoutComplete(Key)) return true;
126 // If this type is currently being laid out, we can't recursively compile it.
127 if (CGT.isRecordBeingLaidOut(Key))
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
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))
141 // If this type would require laying out members that are currently being laid
143 for (const auto *I : RD->fields())
144 if (!isSafeToConvert(I->getType(), CGT, AlreadyChecked))
147 // If there are no problems, lets do it.
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.
155 isSafeToConvert(QualType T, CodeGenTypes &CGT,
156 llvm::SmallPtrSet<const RecordDecl*, 16> &AlreadyChecked) {
157 // Strip off atomic type sugar.
158 if (const auto *AT = T->getAs<AtomicType>())
159 T = AT->getValueType();
161 // If this is a record, check it.
162 if (const auto *RT = T->getAs<RecordType>())
163 return isSafeToConvert(RT->getDecl(), CGT, AlreadyChecked);
165 // If this is an array, check the elements, which are embedded inline.
166 if (const auto *AT = CGT.getContext().getAsArrayType(T))
167 return isSafeToConvert(AT->getElementType(), CGT, AlreadyChecked);
169 // Otherwise, there is no concern about transforming this. We only care about
170 // things that are contained by-value in a structure that can have another
171 // structure as a member.
176 /// isSafeToConvert - Return true if it is safe to convert the specified record
177 /// decl to IR and lay it out, false if doing so would cause us to get into a
178 /// recursive compilation mess.
179 static bool isSafeToConvert(const RecordDecl *RD, CodeGenTypes &CGT) {
180 // If no structs are being laid out, we can certainly do this one.
181 if (CGT.noRecordsBeingLaidOut()) return true;
183 llvm::SmallPtrSet<const RecordDecl*, 16> AlreadyChecked;
184 return isSafeToConvert(RD, CGT, AlreadyChecked);
187 /// isFuncParamTypeConvertible - Return true if the specified type in a
188 /// function parameter or result position can be converted to an IR type at this
189 /// point. This boils down to being whether it is complete, as well as whether
190 /// we've temporarily deferred expanding the type because we're in a recursive
192 bool CodeGenTypes::isFuncParamTypeConvertible(QualType Ty) {
193 // Some ABIs cannot have their member pointers represented in IR unless
194 // certain circumstances have been reached.
195 if (const auto *MPT = Ty->getAs<MemberPointerType>())
196 return getCXXABI().isMemberPointerConvertible(MPT);
198 // If this isn't a tagged type, we can convert it!
199 const TagType *TT = Ty->getAs<TagType>();
200 if (!TT) return true;
202 // Incomplete types cannot be converted.
203 if (TT->isIncompleteType())
206 // If this is an enum, then it is always safe to convert.
207 const RecordType *RT = dyn_cast<RecordType>(TT);
208 if (!RT) return true;
210 // Otherwise, we have to be careful. If it is a struct that we're in the
211 // process of expanding, then we can't convert the function type. That's ok
212 // though because we must be in a pointer context under the struct, so we can
213 // just convert it to a dummy type.
215 // We decide this by checking whether ConvertRecordDeclType returns us an
216 // opaque type for a struct that we know is defined.
217 return isSafeToConvert(RT->getDecl(), *this);
221 /// Code to verify a given function type is complete, i.e. the return type
222 /// and all of the parameter types are complete. Also check to see if we are in
223 /// a RS_StructPointer context, and if so whether any struct types have been
224 /// pended. If so, we don't want to ask the ABI lowering code to handle a type
225 /// that cannot be converted to an IR type.
226 bool CodeGenTypes::isFuncTypeConvertible(const FunctionType *FT) {
227 if (!isFuncParamTypeConvertible(FT->getReturnType()))
230 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT))
231 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++)
232 if (!isFuncParamTypeConvertible(FPT->getParamType(i)))
238 /// UpdateCompletedType - When we find the full definition for a TagDecl,
239 /// replace the 'opaque' type we previously made for it if applicable.
240 void CodeGenTypes::UpdateCompletedType(const TagDecl *TD) {
241 // If this is an enum being completed, then we flush all non-struct types from
242 // the cache. This allows function types and other things that may be derived
243 // from the enum to be recomputed.
244 if (const EnumDecl *ED = dyn_cast<EnumDecl>(TD)) {
245 // Only flush the cache if we've actually already converted this type.
246 if (TypeCache.count(ED->getTypeForDecl())) {
247 // Okay, we formed some types based on this. We speculated that the enum
248 // would be lowered to i32, so we only need to flush the cache if this
250 if (!ConvertType(ED->getIntegerType())->isIntegerTy(32))
253 // If necessary, provide the full definition of a type only used with a
254 // declaration so far.
255 if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
256 DI->completeType(ED);
260 // If we completed a RecordDecl that we previously used and converted to an
261 // anonymous type, then go ahead and complete it now.
262 const RecordDecl *RD = cast<RecordDecl>(TD);
263 if (RD->isDependentType()) return;
265 // Only complete it if we converted it already. If we haven't converted it
266 // yet, we'll just do it lazily.
267 if (RecordDeclTypes.count(Context.getTagDeclType(RD).getTypePtr()))
268 ConvertRecordDeclType(RD);
270 // If necessary, provide the full definition of a type only used with a
271 // declaration so far.
272 if (CGDebugInfo *DI = CGM.getModuleDebugInfo())
273 DI->completeType(RD);
276 static llvm::Type *getTypeForFormat(llvm::LLVMContext &VMContext,
277 const llvm::fltSemantics &format,
278 bool UseNativeHalf = false) {
279 if (&format == &llvm::APFloat::IEEEhalf) {
281 return llvm::Type::getHalfTy(VMContext);
283 return llvm::Type::getInt16Ty(VMContext);
285 if (&format == &llvm::APFloat::IEEEsingle)
286 return llvm::Type::getFloatTy(VMContext);
287 if (&format == &llvm::APFloat::IEEEdouble)
288 return llvm::Type::getDoubleTy(VMContext);
289 if (&format == &llvm::APFloat::IEEEquad)
290 return llvm::Type::getFP128Ty(VMContext);
291 if (&format == &llvm::APFloat::PPCDoubleDouble)
292 return llvm::Type::getPPC_FP128Ty(VMContext);
293 if (&format == &llvm::APFloat::x87DoubleExtended)
294 return llvm::Type::getX86_FP80Ty(VMContext);
295 llvm_unreachable("Unknown float format!");
298 /// ConvertType - Convert the specified type to its LLVM form.
299 llvm::Type *CodeGenTypes::ConvertType(QualType T) {
300 T = Context.getCanonicalType(T);
302 const Type *Ty = T.getTypePtr();
304 // RecordTypes are cached and processed specially.
305 if (const RecordType *RT = dyn_cast<RecordType>(Ty))
306 return ConvertRecordDeclType(RT->getDecl());
308 // See if type is already cached.
309 llvm::DenseMap<const Type *, llvm::Type *>::iterator TCI = TypeCache.find(Ty);
310 // If type is found in map then use it. Otherwise, convert type T.
311 if (TCI != TypeCache.end())
314 // If we don't have it in the cache, convert it now.
315 llvm::Type *ResultType = nullptr;
316 switch (Ty->getTypeClass()) {
317 case Type::Record: // Handled above.
318 #define TYPE(Class, Base)
319 #define ABSTRACT_TYPE(Class, Base)
320 #define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
321 #define DEPENDENT_TYPE(Class, Base) case Type::Class:
322 #define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
323 #include "clang/AST/TypeNodes.def"
324 llvm_unreachable("Non-canonical or dependent types aren't possible.");
326 case Type::Builtin: {
327 switch (cast<BuiltinType>(Ty)->getKind()) {
328 case BuiltinType::Void:
329 case BuiltinType::ObjCId:
330 case BuiltinType::ObjCClass:
331 case BuiltinType::ObjCSel:
332 // LLVM void type can only be used as the result of a function call. Just
333 // map to the same as char.
334 ResultType = llvm::Type::getInt8Ty(getLLVMContext());
337 case BuiltinType::Bool:
338 // Note that we always return bool as i1 for use as a scalar type.
339 ResultType = llvm::Type::getInt1Ty(getLLVMContext());
342 case BuiltinType::Char_S:
343 case BuiltinType::Char_U:
344 case BuiltinType::SChar:
345 case BuiltinType::UChar:
346 case BuiltinType::Short:
347 case BuiltinType::UShort:
348 case BuiltinType::Int:
349 case BuiltinType::UInt:
350 case BuiltinType::Long:
351 case BuiltinType::ULong:
352 case BuiltinType::LongLong:
353 case BuiltinType::ULongLong:
354 case BuiltinType::WChar_S:
355 case BuiltinType::WChar_U:
356 case BuiltinType::Char16:
357 case BuiltinType::Char32:
358 ResultType = llvm::IntegerType::get(getLLVMContext(),
359 static_cast<unsigned>(Context.getTypeSize(T)));
362 case BuiltinType::Half:
363 // Half FP can either be storage-only (lowered to i16) or native.
365 getTypeForFormat(getLLVMContext(), Context.getFloatTypeSemantics(T),
366 Context.getLangOpts().NativeHalfType ||
367 Context.getLangOpts().HalfArgsAndReturns);
369 case BuiltinType::Float:
370 case BuiltinType::Double:
371 case BuiltinType::LongDouble:
372 ResultType = getTypeForFormat(getLLVMContext(),
373 Context.getFloatTypeSemantics(T),
374 /* UseNativeHalf = */ false);
377 case BuiltinType::NullPtr:
378 // Model std::nullptr_t as i8*
379 ResultType = llvm::Type::getInt8PtrTy(getLLVMContext());
382 case BuiltinType::UInt128:
383 case BuiltinType::Int128:
384 ResultType = llvm::IntegerType::get(getLLVMContext(), 128);
387 case BuiltinType::OCLImage1d:
388 case BuiltinType::OCLImage1dArray:
389 case BuiltinType::OCLImage1dBuffer:
390 case BuiltinType::OCLImage2d:
391 case BuiltinType::OCLImage2dArray:
392 case BuiltinType::OCLImage3d:
393 case BuiltinType::OCLSampler:
394 case BuiltinType::OCLEvent:
395 ResultType = CGM.getOpenCLRuntime().convertOpenCLSpecificType(Ty);
398 case BuiltinType::Dependent:
399 #define BUILTIN_TYPE(Id, SingletonId)
400 #define PLACEHOLDER_TYPE(Id, SingletonId) \
401 case BuiltinType::Id:
402 #include "clang/AST/BuiltinTypes.def"
403 llvm_unreachable("Unexpected placeholder builtin type!");
408 llvm_unreachable("Unexpected undeduced auto type!");
409 case Type::Complex: {
410 llvm::Type *EltTy = ConvertType(cast<ComplexType>(Ty)->getElementType());
411 ResultType = llvm::StructType::get(EltTy, EltTy, nullptr);
414 case Type::LValueReference:
415 case Type::RValueReference: {
416 const ReferenceType *RTy = cast<ReferenceType>(Ty);
417 QualType ETy = RTy->getPointeeType();
418 llvm::Type *PointeeType = ConvertTypeForMem(ETy);
419 unsigned AS = Context.getTargetAddressSpace(ETy);
420 ResultType = llvm::PointerType::get(PointeeType, AS);
423 case Type::Pointer: {
424 const PointerType *PTy = cast<PointerType>(Ty);
425 QualType ETy = PTy->getPointeeType();
426 llvm::Type *PointeeType = ConvertTypeForMem(ETy);
427 if (PointeeType->isVoidTy())
428 PointeeType = llvm::Type::getInt8Ty(getLLVMContext());
429 unsigned AS = Context.getTargetAddressSpace(ETy);
430 ResultType = llvm::PointerType::get(PointeeType, AS);
434 case Type::VariableArray: {
435 const VariableArrayType *A = cast<VariableArrayType>(Ty);
436 assert(A->getIndexTypeCVRQualifiers() == 0 &&
437 "FIXME: We only handle trivial array types so far!");
438 // VLAs resolve to the innermost element type; this matches
439 // the return of alloca, and there isn't any obviously better choice.
440 ResultType = ConvertTypeForMem(A->getElementType());
443 case Type::IncompleteArray: {
444 const IncompleteArrayType *A = cast<IncompleteArrayType>(Ty);
445 assert(A->getIndexTypeCVRQualifiers() == 0 &&
446 "FIXME: We only handle trivial array types so far!");
447 // int X[] -> [0 x int], unless the element type is not sized. If it is
448 // unsized (e.g. an incomplete struct) just use [0 x i8].
449 ResultType = ConvertTypeForMem(A->getElementType());
450 if (!ResultType->isSized()) {
451 SkippedLayout = true;
452 ResultType = llvm::Type::getInt8Ty(getLLVMContext());
454 ResultType = llvm::ArrayType::get(ResultType, 0);
457 case Type::ConstantArray: {
458 const ConstantArrayType *A = cast<ConstantArrayType>(Ty);
459 llvm::Type *EltTy = ConvertTypeForMem(A->getElementType());
461 // Lower arrays of undefined struct type to arrays of i8 just to have a
463 if (!EltTy->isSized()) {
464 SkippedLayout = true;
465 EltTy = llvm::Type::getInt8Ty(getLLVMContext());
468 ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue());
471 case Type::ExtVector:
473 const VectorType *VT = cast<VectorType>(Ty);
474 ResultType = llvm::VectorType::get(ConvertType(VT->getElementType()),
475 VT->getNumElements());
478 case Type::FunctionNoProto:
479 case Type::FunctionProto: {
480 const FunctionType *FT = cast<FunctionType>(Ty);
481 // First, check whether we can build the full function type. If the
482 // function type depends on an incomplete type (e.g. a struct or enum), we
483 // cannot lower the function type.
484 if (!isFuncTypeConvertible(FT)) {
485 // This function's type depends on an incomplete tag type.
487 // Force conversion of all the relevant record types, to make sure
488 // we re-convert the FunctionType when appropriate.
489 if (const RecordType *RT = FT->getReturnType()->getAs<RecordType>())
490 ConvertRecordDeclType(RT->getDecl());
491 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT))
492 for (unsigned i = 0, e = FPT->getNumParams(); i != e; i++)
493 if (const RecordType *RT = FPT->getParamType(i)->getAs<RecordType>())
494 ConvertRecordDeclType(RT->getDecl());
496 // Return a placeholder type.
497 ResultType = llvm::StructType::get(getLLVMContext());
499 SkippedLayout = true;
503 // While we're converting the parameter types for a function, we don't want
504 // to recursively convert any pointed-to structs. Converting directly-used
505 // structs is ok though.
506 if (!RecordsBeingLaidOut.insert(Ty).second) {
507 ResultType = llvm::StructType::get(getLLVMContext());
509 SkippedLayout = true;
513 // The function type can be built; call the appropriate routines to
515 const CGFunctionInfo *FI;
516 if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(FT)) {
517 FI = &arrangeFreeFunctionType(
518 CanQual<FunctionProtoType>::CreateUnsafe(QualType(FPT, 0)));
520 const FunctionNoProtoType *FNPT = cast<FunctionNoProtoType>(FT);
521 FI = &arrangeFreeFunctionType(
522 CanQual<FunctionNoProtoType>::CreateUnsafe(QualType(FNPT, 0)));
525 // If there is something higher level prodding our CGFunctionInfo, then
526 // don't recurse into it again.
527 if (FunctionsBeingProcessed.count(FI)) {
529 ResultType = llvm::StructType::get(getLLVMContext());
530 SkippedLayout = true;
533 // Otherwise, we're good to go, go ahead and convert it.
534 ResultType = GetFunctionType(*FI);
537 RecordsBeingLaidOut.erase(Ty);
542 if (RecordsBeingLaidOut.empty())
543 while (!DeferredRecords.empty())
544 ConvertRecordDeclType(DeferredRecords.pop_back_val());
548 case Type::ObjCObject:
549 ResultType = ConvertType(cast<ObjCObjectType>(Ty)->getBaseType());
552 case Type::ObjCInterface: {
553 // Objective-C interfaces are always opaque (outside of the
554 // runtime, which can do whatever it likes); we never refine
556 llvm::Type *&T = InterfaceTypes[cast<ObjCInterfaceType>(Ty)];
558 T = llvm::StructType::create(getLLVMContext());
563 case Type::ObjCObjectPointer: {
564 // Protocol qualifications do not influence the LLVM type, we just return a
565 // pointer to the underlying interface type. We don't need to worry about
566 // recursive conversion.
568 ConvertTypeForMem(cast<ObjCObjectPointerType>(Ty)->getPointeeType());
569 ResultType = T->getPointerTo();
574 const EnumDecl *ED = cast<EnumType>(Ty)->getDecl();
575 if (ED->isCompleteDefinition() || ED->isFixed())
576 return ConvertType(ED->getIntegerType());
577 // Return a placeholder 'i32' type. This can be changed later when the
578 // type is defined (see UpdateCompletedType), but is likely to be the
580 ResultType = llvm::Type::getInt32Ty(getLLVMContext());
584 case Type::BlockPointer: {
585 const QualType FTy = cast<BlockPointerType>(Ty)->getPointeeType();
586 llvm::Type *PointeeType = ConvertTypeForMem(FTy);
587 unsigned AS = Context.getTargetAddressSpace(FTy);
588 ResultType = llvm::PointerType::get(PointeeType, AS);
592 case Type::MemberPointer: {
593 if (!getCXXABI().isMemberPointerConvertible(cast<MemberPointerType>(Ty)))
594 return llvm::StructType::create(getLLVMContext());
596 getCXXABI().ConvertMemberPointerType(cast<MemberPointerType>(Ty));
601 QualType valueType = cast<AtomicType>(Ty)->getValueType();
602 ResultType = ConvertTypeForMem(valueType);
604 // Pad out to the inflated size if necessary.
605 uint64_t valueSize = Context.getTypeSize(valueType);
606 uint64_t atomicSize = Context.getTypeSize(Ty);
607 if (valueSize != atomicSize) {
608 assert(valueSize < atomicSize);
609 llvm::Type *elts[] = {
611 llvm::ArrayType::get(CGM.Int8Ty, (atomicSize - valueSize) / 8)
613 ResultType = llvm::StructType::get(getLLVMContext(),
614 llvm::makeArrayRef(elts));
620 assert(ResultType && "Didn't convert a type?");
622 TypeCache[Ty] = ResultType;
626 bool CodeGenModule::isPaddedAtomicType(QualType type) {
627 return isPaddedAtomicType(type->castAs<AtomicType>());
630 bool CodeGenModule::isPaddedAtomicType(const AtomicType *type) {
631 return Context.getTypeSize(type) != Context.getTypeSize(type->getValueType());
634 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union.
635 llvm::StructType *CodeGenTypes::ConvertRecordDeclType(const RecordDecl *RD) {
636 // TagDecl's are not necessarily unique, instead use the (clang)
637 // type connected to the decl.
638 const Type *Key = Context.getTagDeclType(RD).getTypePtr();
640 llvm::StructType *&Entry = RecordDeclTypes[Key];
642 // If we don't have a StructType at all yet, create the forward declaration.
644 Entry = llvm::StructType::create(getLLVMContext());
645 addRecordTypeName(RD, Entry, "");
647 llvm::StructType *Ty = Entry;
649 // If this is still a forward declaration, or the LLVM type is already
650 // complete, there's nothing more to do.
651 RD = RD->getDefinition();
652 if (!RD || !RD->isCompleteDefinition() || !Ty->isOpaque())
655 // If converting this type would cause us to infinitely loop, don't do it!
656 if (!isSafeToConvert(RD, *this)) {
657 DeferredRecords.push_back(RD);
661 // Okay, this is a definition of a type. Compile the implementation now.
662 bool InsertResult = RecordsBeingLaidOut.insert(Key).second;
664 assert(InsertResult && "Recursively compiling a struct?");
666 // Force conversion of non-virtual base classes recursively.
667 if (const CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) {
668 for (const auto &I : CRD->bases()) {
669 if (I.isVirtual()) continue;
671 ConvertRecordDeclType(I.getType()->getAs<RecordType>()->getDecl());
676 CGRecordLayout *Layout = ComputeRecordLayout(RD, Ty);
677 CGRecordLayouts[Key] = Layout;
679 // We're done laying out this struct.
680 bool EraseResult = RecordsBeingLaidOut.erase(Key); (void)EraseResult;
681 assert(EraseResult && "struct not in RecordsBeingLaidOut set?");
683 // If this struct blocked a FunctionType conversion, then recompute whatever
684 // was derived from that.
685 // FIXME: This is hugely overconservative.
689 // If we're done converting the outer-most record, then convert any deferred
691 if (RecordsBeingLaidOut.empty())
692 while (!DeferredRecords.empty())
693 ConvertRecordDeclType(DeferredRecords.pop_back_val());
698 /// getCGRecordLayout - Return record layout info for the given record decl.
699 const CGRecordLayout &
700 CodeGenTypes::getCGRecordLayout(const RecordDecl *RD) {
701 const Type *Key = Context.getTagDeclType(RD).getTypePtr();
703 const CGRecordLayout *Layout = CGRecordLayouts.lookup(Key);
705 // Compute the type information.
706 ConvertRecordDeclType(RD);
709 Layout = CGRecordLayouts.lookup(Key);
712 assert(Layout && "Unable to find record layout information for type");
716 bool CodeGenTypes::isZeroInitializable(QualType T) {
717 // No need to check for member pointers when not compiling C++.
718 if (!Context.getLangOpts().CPlusPlus)
721 if (const auto *AT = Context.getAsArrayType(T)) {
722 if (isa<IncompleteArrayType>(AT))
724 if (const auto *CAT = dyn_cast<ConstantArrayType>(AT))
725 if (Context.getConstantArrayElementCount(CAT) == 0)
727 T = Context.getBaseElementType(T);
730 // Records are non-zero-initializable if they contain any
731 // non-zero-initializable subobjects.
732 if (const RecordType *RT = T->getAs<RecordType>()) {
733 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
734 return isZeroInitializable(RD);
737 // We have to ask the ABI about member pointers.
738 if (const MemberPointerType *MPT = T->getAs<MemberPointerType>())
739 return getCXXABI().isZeroInitializable(MPT);
741 // Everything else is okay.
745 bool CodeGenTypes::isZeroInitializable(const RecordDecl *RD) {
746 return getCGRecordLayout(RD).isZeroInitializable();