================ @@ -0,0 +1,404 @@ +//==---- QualTypeMapper.cpp - Maps Clang QualType to LLVMABI Types ---------==// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +/// +/// \file +/// Maps Clang QualType instances to corresponding LLVM ABI type +/// representations. This mapper translates high-level type information from the +/// AST into low-level ABI-specific types that encode size, alignment, and +/// layout details required for code generation and cross-language +/// interoperability. +/// +//===----------------------------------------------------------------------===// +#include "clang/CodeGen/QualTypeMapper.h" +#include "clang/AST/Decl.h" +#include "clang/AST/DeclCXX.h" +#include "clang/AST/RecordLayout.h" +#include "clang/AST/Type.h" +#include "clang/Basic/AddressSpaces.h" +#include "clang/Basic/LLVM.h" +#include "clang/Basic/TargetInfo.h" +#include "llvm/ABI/Types.h" +#include "llvm/Support/Alignment.h" +#include "llvm/Support/TypeSize.h" +#include "llvm/Support/raw_ostream.h" + +namespace clang { +namespace mapper { + +/// Main entry point for converting Clang QualType to LLVM ABI Type. +/// This method performs type canonicalization, caching, and dispatches +/// to specialized conversion methods based on the type kind. +/// +/// \param QT The Clang QualType to convert +/// \return Corresponding LLVM ABI Type representation, or nullptr on error +const llvm::abi::Type *QualTypeMapper::convertType(QualType QT) { + // Canonicalize type and strip qualifiers + // This ensures consistent type representation across different contexts + QT = QT.getCanonicalType().getUnqualifiedType(); + + // Results are cached since type conversion may be expensive + auto It = TypeCache.find(QT); + if (It != TypeCache.end()) + return It->second; + + const llvm::abi::Type *Result = nullptr; + if (const auto *BT = dyn_cast<BuiltinType>(QT.getTypePtr())) { + Result = convertBuiltinType(BT); + } else if (const auto *PT = dyn_cast<PointerType>(QT.getTypePtr())) { + Result = convertPointerType(PT); + } else if (const auto *RT = dyn_cast<ReferenceType>(QT.getTypePtr())) { + Result = convertReferenceType(RT); + } else if (const auto *AT = dyn_cast<ArrayType>(QT.getTypePtr())) { + Result = convertArrayType(AT); + } else if (const auto *VT = dyn_cast<VectorType>(QT.getTypePtr())) { + Result = convertVectorType(VT); + } else if (const auto *RT = dyn_cast<RecordType>(QT.getTypePtr())) { + Result = convertRecordType(RT); + } else if (const auto *ET = dyn_cast<EnumType>(QT.getTypePtr())) { + Result = convertEnumType(ET); + } else if (const auto *BIT = dyn_cast<BitIntType>(QT.getTypePtr())) { + // Handle C23 _BitInt(N) types - arbitrary precision integers + QualType QT(BIT, 0); + uint64_t NumBits = BIT->getNumBits(); + bool IsSigned = BIT->isSigned(); + llvm::Align TypeAlign = getTypeAlign(QT); + return Builder.getIntegerType(NumBits, TypeAlign, IsSigned); + } else if (isa<ObjCObjectType>(QT.getTypePtr()) || + isa<ObjCObjectPointerType>(QT.getTypePtr())) { + // Objective-C objects are represented as pointers in the ABI + auto PointerSize = ASTCtx.getTargetInfo().getPointerWidth(LangAS::Default); + llvm::Align PointerAlign = + llvm::Align(ASTCtx.getTargetInfo().getPointerAlign(LangAS::Default)); + return Builder.getPointerType(PointerSize, PointerAlign); + } else { + llvm_unreachable("Unsupported type for ABI lowering"); + } + TypeCache[QT] = Result; + return Result; +} + +/// Converts C/C++ builtin types to LLVM ABI types. +/// This handles all fundamental scalar types including integers, floats, +/// and special types like void and bool. +/// +/// \param BT The BuiltinType to convert +/// \return Corresponding LLVM ABI integer, float, or void type +const llvm::abi::Type * +QualTypeMapper::convertBuiltinType(const BuiltinType *BT) { + QualType QT(BT, 0); + + switch (BT->getKind()) { + case BuiltinType::Void: + return Builder.getVoidType(); + + case BuiltinType::Bool: + case BuiltinType::Char_S: + case BuiltinType::Char_U: + case BuiltinType::SChar: + case BuiltinType::UChar: + case BuiltinType::WChar_S: + case BuiltinType::WChar_U: + case BuiltinType::Char8: + case BuiltinType::Char16: + case BuiltinType::Char32: + case BuiltinType::Short: + case BuiltinType::UShort: + case BuiltinType::Int: + case BuiltinType::UInt: + case BuiltinType::Long: + case BuiltinType::ULong: + case BuiltinType::LongLong: + case BuiltinType::ULongLong: + case BuiltinType::Int128: + case BuiltinType::UInt128: + return Builder.getIntegerType(ASTCtx.getTypeSize(QT), getTypeAlign(QT), + BT->isSignedInteger()); + + case BuiltinType::Half: + case BuiltinType::Float16: + case BuiltinType::BFloat16: + case BuiltinType::Float: + case BuiltinType::Double: + case BuiltinType::LongDouble: + case BuiltinType::Float128: + return Builder.getFloatType(ASTCtx.getFloatTypeSemantics(QT), + getTypeAlign(QT)); + + default: + // Unhandled BuiltinTypes are treated as unsigned integers. + return Builder.getIntegerType(ASTCtx.getTypeSize(QualType(BT, 0)), + getTypeAlign(QualType(BT, 0)), false); + } +} + +/// Converts array types to LLVM ABI array representations. +/// Handles different array kinds: constant arrays, incomplete arrays, +/// and variable-length arrays. +/// +/// \param AT The ArrayType to convert +/// \return LLVM ABI ArrayType or PointerType +const llvm::abi::Type * +QualTypeMapper::convertArrayType(const clang::ArrayType *AT) { + const llvm::abi::Type *ElementType = convertType(AT->getElementType()); + + if (const auto *CAT = dyn_cast<ConstantArrayType>(AT)) { + auto NumElements = CAT->getZExtSize(); + return Builder.getArrayType(ElementType, NumElements); + } + if (const auto *IAT = dyn_cast<IncompleteArrayType>(AT)) + return Builder.getArrayType(ElementType, 0); + if (const auto *VAT = dyn_cast<VariableArrayType>(AT)) + return createPointerTypeForPointee(VAT->getPointeeType()); + // Fallback for other array types + return Builder.getArrayType(ElementType, 1); +} + +/// Converts vector types to LLVM ABI vector representations. +/// +/// \param VT The VectorType to convert +/// \return LLVM ABI VectorType with element type, count, and alignment +const llvm::abi::Type *QualTypeMapper::convertVectorType(const VectorType *VT) { + const llvm::abi::Type *ElementType = convertType(VT->getElementType()); + uint64_t NumElements = VT->getNumElements(); + + llvm::Align VectorAlign = getTypeAlign(QualType(VT, 0)); + + return Builder.getVectorType(ElementType, NumElements, VectorAlign); +} + +/// Converts record types (struct/class/union) to LLVM ABI representations. +/// This is the main dispatch method that handles different record kinds +/// and delegates to specialized converters. +/// +/// \param RT The RecordType to convert +/// \return LLVM ABI StructType or UnionType +const llvm::abi::Type *QualTypeMapper::convertRecordType(const RecordType *RT) { + const RecordDecl *RD = RT->getDecl()->getDefinition(); + if (!RD) { + SmallVector<llvm::abi::FieldInfo, 0> Fields; + return Builder.getStructType(Fields, llvm::TypeSize::getFixed(0), + llvm::Align(1)); + } + + if (RD->isUnion()) + return convertUnionType(RD); + + // Handle C++ classes with base classes + auto *const CXXRd = dyn_cast<CXXRecordDecl>(RD); + if (CXXRd && (CXXRd->getNumBases() > 0 || CXXRd->getNumVBases() > 0)) { + return convertCXXRecordType(CXXRd); + } + return convertStructType(RD); +} + +/// Converts C++ classes with inheritance to LLVM ABI struct representations. +/// This method handles the complex layout of C++ objects including: +/// - Virtual table pointers for polymorphic classes +/// - Base class subobjects (both direct and virtual bases) +/// - Member field layout with proper offsets +/// +/// \param RD The C++ record declaration +/// \return LLVM ABI StructType representing the complete object layout +const llvm::abi::StructType * +QualTypeMapper::convertCXXRecordType(const CXXRecordDecl *RD) { + const ASTRecordLayout &Layout = ASTCtx.getASTRecordLayout(RD); + SmallVector<llvm::abi::FieldInfo, 16> Fields; + + if (RD->isPolymorphic()) { + const llvm::abi::Type *VtablePointer = + createPointerTypeForPointee(ASTCtx.VoidPtrTy); + Fields.emplace_back(VtablePointer, 0); + } + + for (const auto &Base : RD->bases()) { + if (Base.isVirtual()) + continue; + + const RecordType *BaseRT = Base.getType()->castAs<RecordType>(); + + const llvm::abi::Type *BaseType = convertType(Base.getType()); + uint64_t BaseOffset = + Layout.getBaseClassOffset(BaseRT->getAsCXXRecordDecl()).getQuantity() * + 8; + + Fields.emplace_back(BaseType, BaseOffset); + } + + for (const auto &VBase : RD->vbases()) { + const RecordType *VBaseRT = VBase.getType()->getAs<RecordType>(); + if (!VBaseRT) + continue; + + const llvm::abi::Type *VBaseType = convertType(VBase.getType()); + uint64_t VBaseOffset = + Layout.getVBaseClassOffset(VBaseRT->getAsCXXRecordDecl()) + .getQuantity() * + 8; + + Fields.emplace_back(VBaseType, VBaseOffset); + } + computeFieldInfo(RD, Fields, Layout); + + llvm::sort(Fields, + [](const llvm::abi::FieldInfo &A, const llvm::abi::FieldInfo &B) { + return A.OffsetInBits < B.OffsetInBits; + }); + + llvm::TypeSize Size = + llvm::TypeSize::getFixed(Layout.getSize().getQuantity() * 8); + llvm::Align Alignment = llvm::Align(Layout.getAlignment().getQuantity()); + + return Builder.getStructType(Fields, Size, Alignment); +} + +/// Converts reference types to pointer representations in the ABI. +/// Both lvalue references (T&) and rvalue references (T&&) are represented +/// as pointers at the ABI level. +/// +/// \param RT The ReferenceType to convert +/// \return LLVM ABI PointerType +const llvm::abi::Type * +QualTypeMapper::convertReferenceType(const ReferenceType *RT) { + return createPointerTypeForPointee(RT->getPointeeType()); +} + +/// Converts pointer types to LLVM ABI pointer representations. +/// Takes into account address space information for the pointed-to type. +/// +/// \param PT The PointerType to convert +/// \return LLVM ABI PointerType with appropriate size and alignment +const llvm::abi::Type * +QualTypeMapper::convertPointerType(const clang::PointerType *PT) { + return createPointerTypeForPointee(PT->getPointeeType()); +} + +/// Converts enumeration types to their underlying integer representations. +/// This method handles various enum states and falls back to safe defaults +/// when enum information is incomplete or invalid. +/// +/// \param ET The EnumType to convert +/// \return LLVM ABI IntegerType representing the enum's underlying type +const llvm::abi::Type * +QualTypeMapper::convertEnumType(const clang::EnumType *ET) { + if (!ET) + return Builder.getIntegerType(32, llvm::Align(4), true); ---------------- nikic wrote:
As it turned out that enum types were not the problem, can we remove all these special cases now? https://github.com/llvm/llvm-project/pull/140112 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
