1//==---- QualTypeMapper.cpp - Maps Clang QualType to LLVMABI Types ---------==//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8///
9/// \file
10/// Maps Clang QualType instances to corresponding LLVM ABI type
11/// representations. This mapper translates high-level type information from the
12/// AST into low-level ABI-specific types that encode size, alignment, and
13/// layout details required for code generation and cross-language
14/// interoperability.
15///
16//===----------------------------------------------------------------------===//
17#include "QualTypeMapper.h"
18#include "clang/AST/ASTContext.h"
19#include "clang/AST/ASTFwd.h"
20#include "clang/AST/Attr.h"
21#include "clang/AST/Decl.h"
22#include "clang/AST/DeclCXX.h"
23#include "clang/AST/RecordLayout.h"
24#include "clang/AST/Type.h"
25#include "clang/Basic/AddressSpaces.h"
26#include "clang/Basic/LLVM.h"
27#include "clang/Basic/TargetInfo.h"
28#include "llvm/ABI/Types.h"
29#include "llvm/Support/Alignment.h"
30#include "llvm/Support/ErrorHandling.h"
31#include "llvm/Support/TypeSize.h"
32#include <cstdint>
33
34namespace clang {
35namespace CodeGen {
36
37/// Returns true if \p BT is one of the AArch64 SVE predicate types, i.e.
38/// svbool_t or one of its tuples.
39static bool isSVEPredicateBuiltinType(const BuiltinType *BT) {
40 switch (BT->getKind()) {
41#define SVE_PREDICATE_TYPE(Name, MangledName, Id, SingletonId) \
42 case BuiltinType::Id: \
43 return true;
44#include "clang/Basic/AArch64ACLETypes.def"
45 default:
46 return false;
47 }
48}
49
50/// Maps a Clang vector kind onto the ABI library's notion of a vector flavor.
51static llvm::abi::VectorKind getABIVectorKind(clang::VectorKind Kind) {
52 switch (Kind) {
53 case clang::VectorKind::SveFixedLengthData:
54 return llvm::abi::VectorKind::SVEData;
55 case clang::VectorKind::SveFixedLengthPredicate:
56 return llvm::abi::VectorKind::SVEPredicate;
57 default:
58 return llvm::abi::VectorKind::Generic;
59 }
60}
61
62/// Main entry point for converting Clang QualType to LLVM ABI Type.
63/// This method performs type canonicalization, caching, and dispatches
64/// to specialized conversion methods based on the type kind.
65///
66/// \param QT The Clang QualType to convert
67/// \return Corresponding LLVM ABI Type representation
68const llvm::abi::Type *QualTypeMapper::convertType(QualType QT) {
69 // Canonicalize type and strip qualifiers
70 // This ensures consistent type representation across different contexts
71 //
72 // TODO: AttributedType is NeverCanonical, so aligned typedef attributes
73 // for instance, __attribute__((aligned(N))) are lost here. Capture the
74 // effective alignment from the original QT and thread it through
75 // convertTypeImpl.
76 QT = QT.getCanonicalType().getUnqualifiedType();
77
78 // Results are cached since type conversion may be expensive.
79 auto It = TypeCache.find(Val: QT);
80 if (It != TypeCache.end())
81 return It->second;
82
83 const llvm::abi::Type *Result = convertTypeImpl(QT);
84 assert(Result && "convertTypeImpl returned nullptr");
85 TypeCache[QT] = Result;
86 return Result;
87}
88
89/// Dispatches to specialized conversion methods based on the type kind.
90const llvm::abi::Type *QualTypeMapper::convertTypeImpl(QualType QT) {
91 switch (QT->getTypeClass()) {
92 // Non-canonical and dependent types should have been stripped by
93 // getCanonicalType() above or cannot appear during code generation.
94#define TYPE(Class, Base)
95#define ABSTRACT_TYPE(Class, Base)
96#define NON_CANONICAL_TYPE(Class, Base) case Type::Class:
97#define DEPENDENT_TYPE(Class, Base) case Type::Class:
98#define NON_CANONICAL_UNLESS_DEPENDENT_TYPE(Class, Base) case Type::Class:
99#include "clang/AST/TypeNodes.inc"
100 llvm::reportFatalInternalError(
101 reason: "Non-canonical or dependent types should not reach ABI lowering");
102
103 case Type::Builtin:
104 return convertBuiltinType(BT: cast<BuiltinType>(Val&: QT));
105 case Type::Pointer:
106 return createPointerTypeForPointee(PointeeType: cast<PointerType>(Val&: QT)->getPointeeType());
107 case Type::LValueReference:
108 case Type::RValueReference:
109 return createPointerTypeForPointee(
110 PointeeType: cast<ReferenceType>(Val&: QT)->getPointeeType());
111 case Type::ConstantArray:
112 case Type::ArrayParameter:
113 case Type::IncompleteArray:
114 case Type::VariableArray:
115 return convertArrayType(AT: cast<ArrayType>(Val&: QT));
116 case Type::Vector:
117 case Type::ExtVector:
118 return convertVectorType(VT: cast<VectorType>(Val&: QT));
119 case Type::Record:
120 return convertRecordType(RT: cast<RecordType>(Val&: QT));
121 case Type::Enum:
122 return convertEnumType(ET: cast<EnumType>(Val&: QT));
123 case Type::Complex:
124 return convertComplexType(CT: cast<ComplexType>(Val&: QT));
125 case Type::Atomic: {
126 const auto *AT = cast<AtomicType>(Val&: QT);
127 return Builder.getAtomicType(ValueType: convertType(QT: AT->getValueType()),
128 SizeInBits: ASTCtx.getTypeSize(T: QT), Align: getTypeAlign(QT));
129 }
130 case Type::BlockPointer:
131 case Type::Pipe:
132 return createPointerTypeForPointee(PointeeType: ASTCtx.VoidPtrTy);
133 case Type::ConstantMatrix: {
134 const auto *MT = cast<ConstantMatrixType>(Val&: QT);
135 return Builder.getArrayType(ElementType: convertType(QT: MT->getElementType()),
136 NumElements: MT->getNumRows() * MT->getNumColumns(),
137 SizeInBits: ASTCtx.getTypeSize(T: QT), /*IsMatrixType=*/true);
138 }
139 case Type::MemberPointer:
140 return convertMemberPointerType(MPT: cast<MemberPointerType>(Val&: QT));
141 case Type::BitInt: {
142 const auto *BIT = cast<BitIntType>(Val&: QT);
143 return Builder.getIntegerType(BitWidth: BIT->getNumBits(), Align: getTypeAlign(QT),
144 /*Signed=*/BIT->isSigned(),
145 /*IsBitInt=*/true);
146 }
147 case Type::ObjCObject:
148 case Type::ObjCInterface:
149 case Type::ObjCObjectPointer:
150 // Objective-C objects are represented as pointers in the ABI.
151 return Builder.getPointerType(
152 Size: ASTCtx.getTargetInfo().getPointerWidth(AddrSpace: QT.getAddressSpace()),
153 Align: llvm::Align(
154 ASTCtx.getTargetInfo().getPointerAlign(AddrSpace: QT.getAddressSpace()) / 8),
155 Addrspace: ASTCtx.getTargetInfo().getTargetAddressSpace(AS: QT.getAddressSpace()));
156 case Type::OverflowBehavior:
157 return convertType(QT: cast<OverflowBehaviorType>(Val&: QT)->getUnderlyingType());
158 case Type::Auto:
159 case Type::DeducedTemplateSpecialization:
160 case Type::FunctionProto:
161 case Type::FunctionNoProto:
162 case Type::HLSLAttributedResource:
163 case Type::HLSLInlineSpirv:
164 llvm::reportFatalInternalError(reason: "Type not supported in ABI lowering");
165 }
166 llvm_unreachable("unhandled type class in convertTypeImpl");
167}
168
169/// Converts C/C++ builtin types to LLVM ABI types.
170/// This handles all fundamental scalar types including integers, floats,
171/// and special types like void and bool.
172const llvm::abi::Type *
173QualTypeMapper::convertBuiltinType(const BuiltinType *BT) {
174 QualType QT(BT, 0);
175
176 switch (BT->getKind()) {
177 case BuiltinType::Void:
178 return Builder.getVoidType();
179
180 case BuiltinType::NullPtr:
181 return createPointerTypeForPointee(PointeeType: QT);
182
183 case BuiltinType::Bool:
184 return Builder.getIntegerType(BitWidth: 1, Align: getTypeAlign(QT), /*Signed=*/false,
185 /*IsBitInt=*/false);
186
187 case BuiltinType::Char_S:
188 case BuiltinType::Char_U:
189 case BuiltinType::SChar:
190 case BuiltinType::UChar:
191 case BuiltinType::WChar_S:
192 case BuiltinType::WChar_U:
193 case BuiltinType::Char8:
194 case BuiltinType::Char16:
195 case BuiltinType::Char32:
196 case BuiltinType::Short:
197 case BuiltinType::UShort:
198 case BuiltinType::Int:
199 case BuiltinType::UInt:
200 case BuiltinType::Long:
201 case BuiltinType::ULong:
202 case BuiltinType::LongLong:
203 case BuiltinType::ULongLong:
204 case BuiltinType::Int128:
205 case BuiltinType::UInt128:
206 return Builder.getIntegerType(BitWidth: ASTCtx.getTypeSize(T: QT), Align: getTypeAlign(QT),
207 /*Signed=*/BT->isSignedInteger(),
208 /*IsBitInt=*/false);
209
210 case BuiltinType::Half:
211 case BuiltinType::Float16:
212 case BuiltinType::BFloat16:
213 case BuiltinType::Float:
214 case BuiltinType::Double:
215 case BuiltinType::LongDouble:
216 case BuiltinType::Float128:
217 return Builder.getFloatType(Semantics: ASTCtx.getFloatTypeSemantics(T: QT),
218 Align: getTypeAlign(QT));
219
220 // TODO: IBM 128-bit extended double
221 case BuiltinType::Ibm128:
222 llvm::reportFatalInternalError(
223 reason: "IBM128 is not yet supported in the ABI lowering libary");
224
225 // TODO: Fixed-point types
226 case BuiltinType::ShortAccum:
227 case BuiltinType::Accum:
228 case BuiltinType::LongAccum:
229 case BuiltinType::UShortAccum:
230 case BuiltinType::UAccum:
231 case BuiltinType::ULongAccum:
232 case BuiltinType::ShortFract:
233 case BuiltinType::Fract:
234 case BuiltinType::LongFract:
235 case BuiltinType::UShortFract:
236 case BuiltinType::UFract:
237 case BuiltinType::ULongFract:
238 case BuiltinType::SatShortAccum:
239 case BuiltinType::SatAccum:
240 case BuiltinType::SatLongAccum:
241 case BuiltinType::SatUShortAccum:
242 case BuiltinType::SatUAccum:
243 case BuiltinType::SatULongAccum:
244 case BuiltinType::SatShortFract:
245 case BuiltinType::SatFract:
246 case BuiltinType::SatLongFract:
247 case BuiltinType::SatUShortFract:
248 case BuiltinType::SatUFract:
249 case BuiltinType::SatULongFract:
250 llvm::reportFatalInternalError(
251 reason: "Fixed Point types not yet implemented in the ABI lowering library");
252
253 // OpenCL image types are represented as opaque pointers.
254#define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix) \
255 case BuiltinType::Id:
256#include "clang/Basic/OpenCLImageTypes.def"
257 // OpenCL extension types are represented as opaque pointers.
258#define EXT_OPAQUE_TYPE(ExtType, Id, Ext) case BuiltinType::Id:
259#include "clang/Basic/OpenCLExtensionTypes.def"
260 case BuiltinType::OCLSampler:
261 case BuiltinType::OCLEvent:
262 case BuiltinType::OCLClkEvent:
263 case BuiltinType::OCLQueue:
264 case BuiltinType::OCLReserveID:
265 return createPointerTypeForPointee(PointeeType: QT);
266
267 // Objective-C builtin types are represented as opaque pointers.
268 case BuiltinType::ObjCId:
269 case BuiltinType::ObjCClass:
270 case BuiltinType::ObjCSel:
271 return createPointerTypeForPointee(PointeeType: QT);
272
273 // AArch64 SVE data and predicate types, including the x2/x3/x4 tuples.
274#define SVE_VECTOR_TYPE(Name, MangledName, Id, SingletonId) \
275 case BuiltinType::Id:
276#define SVE_PREDICATE_TYPE(Name, MangledName, Id, SingletonId) \
277 case BuiltinType::Id:
278#include "clang/Basic/AArch64ACLETypes.def"
279 return convertSVEBuiltinType(BT);
280
281 case BuiltinType::SveCount:
282 return Builder.getSVECountType(ABIAlign: getTypeAlign(QT));
283
284 // TODO: __mfp8 has no floating-point semantics of its own, so representing
285 // it needs a decision about how the ABI library should model opaque
286 // floating-point data. As an mfloat8 vector element it is treated as an
287 // 8-bit integer, but that is not right for the scalar type, which is passed
288 // in a floating-point register.
289 case BuiltinType::MFloat8:
290 llvm::reportFatalInternalError(
291 reason: "__mfp8 is not yet supported in the ABI lowering library");
292
293 // Target-specific vector/matrix types — not yet implemented.
294#define PPC_VECTOR_TYPE(Name, Id, Size) case BuiltinType::Id:
295#include "clang/Basic/PPCTypes.def"
296 llvm::reportFatalInternalError(
297 reason: "PPC MMA types not yet supported in ABI lowering library");
298#define RVV_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
299#include "clang/Basic/RISCVVTypes.def"
300 llvm::reportFatalInternalError(
301 reason: "RISC-V vector types not yet supported in ABI lowering library");
302#define WASM_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
303#include "clang/Basic/WebAssemblyReferenceTypes.def"
304 llvm::reportFatalInternalError(reason: "WebAssembly reference types not yet "
305 "supported in ABI lowering library");
306#define AMDGPU_TYPE(Name, Id, SingletonId, Width, Align) case BuiltinType::Id:
307#include "clang/Basic/AMDGPUTypes.def"
308 llvm::reportFatalInternalError(
309 reason: "AMDGPU types not yet supported in ABI lowering library");
310#define HLSL_INTANGIBLE_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
311#include "clang/Basic/HLSLIntangibleTypes.def"
312 llvm::reportFatalInternalError(
313 reason: "HLSL intangible types not yet Supported in ABI lowering library");
314#define SPIRV_TYPE(Name, Id, SingletonId) case BuiltinType::Id:
315#include "clang/Basic/SPIRVTypes.def"
316 llvm::reportFatalInternalError(
317 reason: "SPIR-V types not yet supported in ABI lowering library");
318
319 // Placeholder types should never reach ABI lowering.
320#define PLACEHOLDER_TYPE(Id, SingletonId) case BuiltinType::Id:
321#define BUILTIN_TYPE(Id, SingletonId)
322#include "clang/AST/BuiltinTypes.def"
323 llvm::reportFatalInternalError(
324 reason: "Placeholder type should not reach ABI lowering");
325
326 case BuiltinType::Dependent:
327 llvm::reportFatalInternalError(
328 reason: "Dependent builtin type should not reach ABI lowering");
329 }
330 llvm_unreachable("unhandled builtin type kind in convertBuiltinType");
331}
332
333/// Converts array types to LLVM ABI array representations.
334/// Handles different array kinds: constant arrays, incomplete arrays,
335/// and variable-length arrays.
336///
337/// \param AT The ArrayType to convert
338/// \return LLVM ABI ArrayType or PointerType
339const llvm::abi::Type *
340QualTypeMapper::convertArrayType(const clang::ArrayType *AT) {
341 const llvm::abi::Type *ElementType = convertType(QT: AT->getElementType());
342 uint64_t Size = ASTCtx.getTypeSize(T: AT);
343
344 if (const auto *CAT = dyn_cast<ConstantArrayType>(Val: AT)) {
345 auto NumElements = CAT->getZExtSize();
346 return Builder.getArrayType(ElementType, NumElements, SizeInBits: Size);
347 }
348 if (isa<IncompleteArrayType>(Val: AT))
349 return Builder.getArrayType(ElementType, NumElements: 0, SizeInBits: 0);
350 if (const auto *VAT = dyn_cast<VariableArrayType>(Val: AT))
351 return createPointerTypeForPointee(PointeeType: VAT->getPointeeType());
352 llvm::reportFatalInternalError(
353 reason: "unexpected array type in ABI lowering (dependent array types should be "
354 "resolved before reaching this point)");
355}
356
357const llvm::abi::Type *QualTypeMapper::convertVectorType(const VectorType *VT) {
358 const llvm::abi::Type *ElementType = convertType(QT: VT->getElementType());
359 QualType VectorQualType(VT, 0);
360
361 unsigned NElems = VT->getNumElements();
362 llvm::ElementCount NumElements = llvm::ElementCount::getFixed(MinVal: NElems);
363 llvm::Align VectorAlign = getTypeAlign(QT: VectorQualType);
364
365 // SveFixedLengthPredicate is tagged SVEPredicate, like sizeless svbool_t.
366 // The element type is left as the AST unsigned char (i8). The builtin path
367 // below maps sizeless predicates to i1. Both match the Clang AST, but
368 // consumers that key only off VectorKind cannot assume a 1-bit element.
369 return Builder.getVectorType(ElementType, NumElements, Align: VectorAlign,
370 VecKind: getABIVectorKind(Kind: VT->getVectorKind()));
371}
372
373/// Converts the sizeless AArch64 SVE data and predicate builtin types.
374/// Single vectors become a scalable LLVM ABI VectorType. The x2/x3/x4
375/// forms become a TupleType of that vector.
376///
377/// \param BT The SVE BuiltinType to convert
378/// \return LLVM ABI VectorType or TupleType
379const llvm::abi::Type *
380QualTypeMapper::convertSVEBuiltinType(const BuiltinType *BT) {
381 ASTContext::BuiltinVectorTypeInfo Info = ASTCtx.getBuiltinVectorTypeInfo(VecTy: BT);
382 assert(Info.NumVectors > 0 && Info.NumVectors <= 4 &&
383 "Expected 1, 2, 3 or 4 vectors!");
384
385 // __mfp8 carries no floating-point semantics, so mfloat8 vectors use an
386 // 8-bit integer element type, which is also how they are represented in
387 // LLVM IR.
388 const llvm::abi::Type *ElementType =
389 Info.ElementType->isMFloat8Type()
390 ? Builder.getIntegerType(BitWidth: 8, Align: llvm::Align(1), /*Signed=*/false)
391 : convertType(QT: Info.ElementType);
392
393 llvm::abi::VectorKind VecKind = isSVEPredicateBuiltinType(BT)
394 ? llvm::abi::VectorKind::SVEPredicate
395 : llvm::abi::VectorKind::SVEData;
396
397 const llvm::abi::VectorType *VecTy = Builder.getVectorType(
398 ElementType, NumElements: Info.EC, Align: getTypeAlign(QT: QualType(BT, 0)), VecKind);
399 if (Info.NumVectors == 1)
400 return VecTy;
401 return Builder.getTupleType(Vec: VecTy, NumVectors: Info.NumVectors);
402}
403
404/// Converts complex types to LLVM ABI complex representations.
405/// Complex types consist of two components of the element type
406/// (real and imaginary parts).
407///
408/// \param CT The ComplexType to convert
409/// \return LLVM ABI ComplexType with element type and alignment
410const llvm::abi::Type *
411QualTypeMapper::convertComplexType(const ComplexType *CT) {
412 const llvm::abi::Type *ElementType = convertType(QT: CT->getElementType());
413 llvm::Align ComplexAlign = getTypeAlign(QT: QualType(CT, 0));
414
415 return Builder.getComplexType(ElementType, Align: ComplexAlign);
416}
417
418/// Converts member pointer types to LLVM ABI representations.
419/// Member pointers have different layouts depending on whether they
420/// point to functions or data members.
421///
422/// \param MPT The MemberPointerType to convert
423/// \return LLVM ABI MemberPointerType
424const llvm::abi::Type *
425QualTypeMapper::convertMemberPointerType(const clang::MemberPointerType *MPT) {
426 QualType QT(MPT, 0);
427 uint64_t Size = ASTCtx.getTypeSize(T: QT);
428 llvm::Align Align = getTypeAlign(QT);
429
430 bool IsFunctionPointer = MPT->isMemberFunctionPointerType();
431
432 return Builder.getMemberPointerType(IsFunctionPointer, SizeInBits: Size, Align);
433}
434
435/// Converts record types (struct/class/union) to LLVM ABI representations.
436/// This is the main dispatch method that handles different record kinds
437/// and delegates to specialized converters.
438///
439/// \param RT The RecordType to convert
440/// \return LLVM ABI RecordType
441const llvm::abi::Type *QualTypeMapper::convertRecordType(const RecordType *RT) {
442 const RecordDecl *RD = RT->getDecl()->getDefinition();
443 if (!RD)
444 return Builder.getRecordType(Fields: {}, Size: llvm::TypeSize::getFixed(ExactSize: 0),
445 ABIAlign: llvm::Align(1),
446 /*UnadjustedAlign=*/llvm::Align(1));
447
448 if (RD->isUnion())
449 return convertUnionType(RD);
450
451 // Handle C++ classes with base classes
452 auto *CXXRd = dyn_cast<CXXRecordDecl>(Val: RD);
453 if (CXXRd && (CXXRd->getNumBases() > 0 || CXXRd->getNumVBases() > 0))
454 return convertCXXRecordType(RD: CXXRd);
455 return convertStructType(RD);
456}
457
458/// Converts C++ classes with inheritance to LLVM ABI struct representations.
459/// This method handles the complex layout of C++ objects including:
460/// - Virtual table pointers for polymorphic classes
461/// - Base class subobjects (both direct and virtual bases)
462/// - Member field layout with proper offsets
463///
464/// \param RD The C++ record declaration
465/// \return LLVM ABI RecordType representing the complete object layout
466const llvm::abi::RecordType *
467QualTypeMapper::convertCXXRecordType(const CXXRecordDecl *RD) {
468 const ASTRecordLayout &Layout = ASTCtx.getASTRecordLayout(D: RD);
469 SmallVector<llvm::abi::FieldInfo, 16> Fields;
470 SmallVector<llvm::abi::FieldInfo, 8> BaseClasses;
471 SmallVector<llvm::abi::FieldInfo, 8> VirtualBaseClasses;
472
473 // Add vtable pointer for polymorphic classes
474 if (RD->isPolymorphic()) {
475 const llvm::abi::Type *VtablePointer =
476 createPointerTypeForPointee(PointeeType: ASTCtx.VoidPtrTy);
477 Fields.emplace_back(Args&: VtablePointer, Args: 0);
478 }
479
480 for (const auto &Base : RD->bases()) {
481 if (Base.isVirtual())
482 continue;
483
484 const RecordType *BaseRT = Base.getType()->castAs<RecordType>();
485 const llvm::abi::Type *BaseType = convertType(QT: Base.getType());
486 uint64_t BaseOffset =
487 Layout.getBaseClassOffset(Base: BaseRT->getAsCXXRecordDecl()).getQuantity() *
488 8;
489 BaseClasses.emplace_back(Args&: BaseType, Args&: BaseOffset);
490 }
491
492 for (const auto &VBase : RD->vbases()) {
493 const RecordType *VBaseRT = VBase.getType()->castAs<RecordType>();
494 const llvm::abi::Type *VBaseType = convertType(QT: VBase.getType());
495 uint64_t VBaseOffset =
496 Layout.getVBaseClassOffset(VBase: VBaseRT->getAsCXXRecordDecl())
497 .getQuantity() *
498 8;
499 VirtualBaseClasses.emplace_back(Args&: VBaseType, Args&: VBaseOffset);
500 }
501
502 computeFieldInfo(RD, Fields, Layout);
503
504 llvm::sort(C&: Fields,
505 Comp: [](const llvm::abi::FieldInfo &A, const llvm::abi::FieldInfo &B) {
506 return A.OffsetInBits < B.OffsetInBits;
507 });
508
509 llvm::TypeSize Size =
510 llvm::TypeSize::getFixed(ExactSize: Layout.getSize().getQuantity() * 8);
511 llvm::Align Alignment = llvm::Align(Layout.getAlignment().getQuantity());
512 llvm::Align UnadjustedAlign =
513 llvm::Align(Layout.getUnadjustedAlignment().getQuantity());
514
515 llvm::abi::RecordFlags RecFlags = llvm::abi::RecordFlags::IsCXXRecord;
516 if (RD->isPolymorphic())
517 RecFlags |= llvm::abi::RecordFlags::IsPolymorphic;
518 if (RD->canPassInRegisters())
519 RecFlags |= llvm::abi::RecordFlags::CanPassInRegisters;
520 if (RD->hasFlexibleArrayMember())
521 RecFlags |= llvm::abi::RecordFlags::HasFlexibleArrayMember;
522
523 return Builder.getRecordType(Fields, Size, ABIAlign: Alignment, UnadjustedAlign,
524 Pack: llvm::abi::StructPacking::Default, BaseClasses,
525 VirtualBaseClasses, RecFlags);
526}
527
528/// Converts enumeration types to their underlying integer representations.
529/// This method handles various enum states and falls back to safe defaults
530/// when enum information is incomplete or invalid.
531///
532/// \param ET The EnumType to convert
533/// \return LLVM ABI IntegerType representing the enum's underlying type
534const llvm::abi::Type *
535QualTypeMapper::convertEnumType(const clang::EnumType *ET) {
536 const EnumDecl *ED = ET->getDecl();
537 QualType UnderlyingType = ED->getIntegerType();
538
539 if (UnderlyingType.isNull())
540 UnderlyingType = ASTCtx.IntTy;
541
542 return convertType(QT: UnderlyingType);
543}
544
545/// Converts plain C structs and C++ classes without inheritance.
546/// This handles the simpler case where we only need to layout member fields
547/// without considering base classes or virtual functions.
548///
549/// \param RD The RecordDecl to convert
550/// \return LLVM ABI RecordType
551const llvm::abi::RecordType *
552QualTypeMapper::convertStructType(const clang::RecordDecl *RD) {
553 const ASTRecordLayout &Layout = ASTCtx.getASTRecordLayout(D: RD);
554
555 bool IsCXXRecord = isa<CXXRecordDecl>(Val: RD);
556 SmallVector<llvm::abi::FieldInfo, 16> Fields;
557 computeFieldInfo(RD, Fields, Layout);
558
559 llvm::TypeSize Size =
560 llvm::TypeSize::getFixed(ExactSize: Layout.getSize().getQuantity() * 8);
561 llvm::Align Alignment = llvm::Align(Layout.getAlignment().getQuantity());
562 llvm::Align UnadjustedAlign =
563 llvm::Align(Layout.getUnadjustedAlignment().getQuantity());
564
565 llvm::abi::RecordFlags RecFlags = llvm::abi::RecordFlags::None;
566 if (IsCXXRecord)
567 RecFlags |= llvm::abi::RecordFlags::IsCXXRecord;
568 if (RD->canPassInRegisters())
569 RecFlags |= llvm::abi::RecordFlags::CanPassInRegisters;
570 if (RD->hasFlexibleArrayMember())
571 RecFlags |= llvm::abi::RecordFlags::HasFlexibleArrayMember;
572
573 return Builder.getRecordType(Fields, Size, ABIAlign: Alignment, UnadjustedAlign,
574 Pack: llvm::abi::StructPacking::Default, BaseClasses: {}, VirtualBaseClasses: {},
575 RecFlags);
576}
577
578/// Converts C union types where all fields occupy the same memory location.
579/// The union size is determined by its largest member, and all fields
580/// start at offset 0.
581///
582/// \param RD The RecordDecl representing the union
583/// \return LLVM ABI UnionType
584const llvm::abi::RecordType *
585QualTypeMapper::convertUnionType(const clang::RecordDecl *RD) {
586 const ASTRecordLayout &Layout = ASTCtx.getASTRecordLayout(D: RD);
587
588 SmallVector<llvm::abi::FieldInfo, 16> AllFields;
589 computeFieldInfo(RD, Fields&: AllFields, Layout);
590
591 llvm::TypeSize Size =
592 llvm::TypeSize::getFixed(ExactSize: Layout.getSize().getQuantity() * 8);
593 llvm::Align Alignment = llvm::Align(Layout.getAlignment().getQuantity());
594 llvm::Align UnadjustedAlign =
595 llvm::Align(Layout.getUnadjustedAlignment().getQuantity());
596
597 llvm::abi::RecordFlags RecFlags = llvm::abi::RecordFlags::None;
598 if (RD->hasAttr<TransparentUnionAttr>())
599 RecFlags |= llvm::abi::RecordFlags::IsTransparent;
600 if (RD->canPassInRegisters())
601 RecFlags |= llvm::abi::RecordFlags::CanPassInRegisters;
602 if (isa<CXXRecordDecl>(Val: RD))
603 RecFlags |= llvm::abi::RecordFlags::IsCXXRecord;
604
605 return Builder.getUnionType(Fields: AllFields, Size, ABIAlign: Alignment, UnadjustedAlign,
606 Pack: llvm::abi::StructPacking::Default, RecFlags);
607}
608
609llvm::Align QualTypeMapper::getTypeAlign(QualType QT) const {
610
611 return llvm::Align(ASTCtx.getTypeAlignInChars(T: QT).getQuantity());
612}
613
614const llvm::abi::Type *
615QualTypeMapper::createPointerTypeForPointee(QualType PointeeType) {
616 auto AddrSpace = PointeeType.getAddressSpace();
617 auto PointerSize = ASTCtx.getTargetInfo().getPointerWidth(AddrSpace);
618 llvm::Align Alignment =
619 llvm::Align(ASTCtx.getTargetInfo().getPointerAlign(AddrSpace));
620 // Function types without an explicit address space qualifier use the program
621 // address space, which may differ from the default data address space on
622 // targets like AMDGPU.
623 unsigned TargetAddrSpace =
624 PointeeType->isFunctionType() && !PointeeType.hasAddressSpace()
625 ? DL.getProgramAddressSpace()
626 : ASTCtx.getTargetInfo().getTargetAddressSpace(AS: AddrSpace);
627 return Builder.getPointerType(Size: PointerSize, Align: llvm::Align(Alignment.value() / 8),
628 Addrspace: TargetAddrSpace);
629}
630
631/// Processes the fields of a record (struct/class/union) and populates
632/// the Fields vector with FieldInfo objects containing type, offset,
633/// and bitfield information.
634///
635/// \param RD The RecordDecl whose fields to process
636/// \param Fields Output vector to populate with field information
637/// \param Layout The AST record layout containing field offset information
638void QualTypeMapper::computeFieldInfo(
639 const RecordDecl *RD, SmallVectorImpl<llvm::abi::FieldInfo> &Fields,
640 const ASTRecordLayout &Layout) {
641 unsigned FieldIndex = 0;
642
643 for (const auto *FD : RD->fields()) {
644 const llvm::abi::Type *FieldType = convertType(QT: FD->getType());
645 uint64_t OffsetInBits = Layout.getFieldOffset(FieldNo: FieldIndex);
646
647 bool IsBitField = FD->isBitField();
648 uint64_t BitFieldWidth = 0;
649 bool IsUnnamedBitField = false;
650
651 if (IsBitField) {
652 BitFieldWidth = FD->getBitWidthValue();
653 IsUnnamedBitField = FD->isUnnamedBitField();
654 }
655
656 bool HasNoUniqueAddress = FD->hasAttr<NoUniqueAddressAttr>();
657 Fields.emplace_back(Args&: FieldType, Args&: OffsetInBits, Args&: IsBitField, Args&: BitFieldWidth,
658 Args&: IsUnnamedBitField, Args&: HasNoUniqueAddress);
659 ++FieldIndex;
660 }
661}
662
663} // namespace CodeGen
664} // namespace clang
665