1//===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- C++ -*-===// 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// This is the code that handles AST -> LLVM type lowering. 10// 11//===----------------------------------------------------------------------===// 12 13#ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H 14#define LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H 15 16#include "CGCall.h" 17#include "clang/Basic/ABI.h" 18#include "clang/CodeGen/CGFunctionInfo.h" 19#include "llvm/ADT/DenseMap.h" 20#include "llvm/IR/Module.h" 21 22namespace llvm { 23class FunctionType; 24class DataLayout; 25class Type; 26class LLVMContext; 27class StructType; 28} 29 30namespace clang { 31class ASTContext; 32template <typename> class CanQual; 33class CXXConstructorDecl; 34class CXXMethodDecl; 35class CodeGenOptions; 36class FunctionProtoType; 37class QualType; 38class RecordDecl; 39class TagDecl; 40class TargetInfo; 41class Type; 42typedef CanQual<Type> CanQualType; 43class GlobalDecl; 44 45namespace CodeGen { 46class ABIInfo; 47class CGCXXABI; 48class CGRecordLayout; 49class CodeGenModule; 50class RequiredArgs; 51 52/// This class organizes the cross-module state that is used while lowering 53/// AST types to LLVM types. 54class CodeGenTypes { 55 CodeGenModule &CGM; 56 // Some of this stuff should probably be left on the CGM. 57 ASTContext &Context; 58 llvm::Module &TheModule; 59 const TargetInfo &Target; 60 CGCXXABI &TheCXXABI; 61 62 // This should not be moved earlier, since its initialization depends on some 63 // of the previous reference members being already initialized 64 const ABIInfo &TheABIInfo; 65 66 /// The opaque type map for Objective-C interfaces. All direct 67 /// manipulation is done by the runtime interfaces, which are 68 /// responsible for coercing to the appropriate type; these opaque 69 /// types are never refined. 70 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes; 71 72 /// Maps clang struct type with corresponding record layout info. 73 llvm::DenseMap<const Type*, std::unique_ptr<CGRecordLayout>> CGRecordLayouts; 74 75 /// Contains the LLVM IR type for any converted RecordDecl. 76 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes; 77 78 /// Hold memoized CGFunctionInfo results. 79 llvm::FoldingSet<CGFunctionInfo> FunctionInfos{FunctionInfosLog2InitSize}; 80 81 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed; 82 83 /// True if we didn't layout a function due to a being inside 84 /// a recursive struct conversion, set this to true. 85 bool SkippedLayout; 86 87 /// True if any instance of long double types are used. 88 bool LongDoubleReferenced; 89 90 /// This map keeps cache of llvm::Types and maps clang::Type to 91 /// corresponding llvm::Type. 92 llvm::DenseMap<const Type *, llvm::Type *> TypeCache; 93 94 llvm::DenseMap<const Type *, llvm::Type *> RecordsWithOpaqueMemberPointers; 95 96 static constexpr unsigned FunctionInfosLog2InitSize = 9; 97 /// Helper for ConvertType. 98 llvm::Type *ConvertFunctionTypeInternal(QualType FT); 99 100public: 101 CodeGenTypes(CodeGenModule &cgm); 102 ~CodeGenTypes(); 103 104 const llvm::DataLayout &getDataLayout() const { 105 return TheModule.getDataLayout(); 106 } 107 CodeGenModule &getCGM() const { return CGM; } 108 ASTContext &getContext() const { return Context; } 109 const ABIInfo &getABIInfo() const { return TheABIInfo; } 110 const TargetInfo &getTarget() const { return Target; } 111 CGCXXABI &getCXXABI() const { return TheCXXABI; } 112 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); } 113 const CodeGenOptions &getCodeGenOpts() const; 114 115 /// Convert clang calling convention to LLVM callilng convention. 116 unsigned ClangCallConvToLLVMCallConv(CallingConv CC); 117 118 /// Derives the 'this' type for codegen purposes, i.e. ignoring method CVR 119 /// qualification. 120 CanQualType DeriveThisType(const CXXRecordDecl *RD, const CXXMethodDecl *MD); 121 122 /// ConvertType - Convert type T into a llvm::Type. 123 llvm::Type *ConvertType(QualType T); 124 125 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 126 /// ConvertType in that it is used to convert to the memory representation for 127 /// a type. For example, the scalar representation for _Bool is i1, but the 128 /// memory representation is usually i8 or i32, depending on the target. 129 llvm::Type *ConvertTypeForMem(QualType T, bool ForBitField = false); 130 131 /// GetFunctionType - Get the LLVM function type for \arg Info. 132 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info); 133 134 llvm::FunctionType *GetFunctionType(GlobalDecl GD); 135 136 /// isFuncTypeConvertible - Utility to check whether a function type can 137 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag 138 /// type). 139 bool isFuncTypeConvertible(const FunctionType *FT); 140 bool isFuncParamTypeConvertible(QualType Ty); 141 142 /// Determine if a C++ inheriting constructor should have parameters matching 143 /// those of its inherited constructor. 144 bool inheritingCtorHasParams(const InheritedConstructor &Inherited, 145 CXXCtorType Type); 146 147 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable, 148 /// given a CXXMethodDecl. If the method to has an incomplete return type, 149 /// and/or incomplete argument types, this will return the opaque type. 150 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD); 151 152 const CGRecordLayout &getCGRecordLayout(const RecordDecl*); 153 154 /// UpdateCompletedType - When we find the full definition for a TagDecl, 155 /// replace the 'opaque' type we previously made for it if applicable. 156 void UpdateCompletedType(const TagDecl *TD); 157 158 /// Remove stale types from the type cache when an inheritance model 159 /// gets assigned to a class. 160 void RefreshTypeCacheForClass(const CXXRecordDecl *RD); 161 162 // The arrangement methods are split into three families: 163 // - those meant to drive the signature and prologue/epilogue 164 // of a function declaration or definition, 165 // - those meant for the computation of the LLVM type for an abstract 166 // appearance of a function, and 167 // - those meant for performing the IR-generation of a call. 168 // They differ mainly in how they deal with optional (i.e. variadic) 169 // arguments, as well as unprototyped functions. 170 // 171 // Key points: 172 // - The CGFunctionInfo for emitting a specific call site must include 173 // entries for the optional arguments. 174 // - The function type used at the call site must reflect the formal 175 // signature of the declaration being called, or else the call will 176 // go awry. 177 // - For the most part, unprototyped functions are called by casting to 178 // a formal signature inferred from the specific argument types used 179 // at the call-site. However, some targets (e.g. x86-64) screw with 180 // this for compatibility reasons. 181 182 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD); 183 184 /// Given a function info for a declaration, return the function info 185 /// for a call with the given arguments. 186 /// 187 /// Often this will be able to simply return the declaration info. 188 const CGFunctionInfo &arrangeCall(const CGFunctionInfo &declFI, 189 const CallArgList &args); 190 191 /// Free functions are functions that are compatible with an ordinary 192 /// C function pointer type. 193 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD); 194 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args, 195 const FunctionType *Ty, 196 bool ChainCall); 197 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty); 198 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty); 199 200 /// A nullary function is a freestanding function of type 'void ()'. 201 /// This method works for both calls and declarations. 202 const CGFunctionInfo &arrangeNullaryFunction(); 203 204 /// A builtin function is a freestanding function using the default 205 /// C conventions. 206 const CGFunctionInfo & 207 arrangeBuiltinFunctionDeclaration(QualType resultType, 208 const FunctionArgList &args); 209 const CGFunctionInfo & 210 arrangeBuiltinFunctionDeclaration(CanQualType resultType, 211 ArrayRef<CanQualType> argTypes); 212 const CGFunctionInfo &arrangeBuiltinFunctionCall(QualType resultType, 213 const CallArgList &args); 214 215 /// Objective-C methods are C functions with some implicit parameters. 216 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD); 217 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, 218 QualType receiverType); 219 const CGFunctionInfo &arrangeUnprototypedObjCMessageSend( 220 QualType returnType, 221 const CallArgList &args); 222 223 /// Block invocation functions are C functions with an implicit parameter. 224 const CGFunctionInfo &arrangeBlockFunctionDeclaration( 225 const FunctionProtoType *type, 226 const FunctionArgList &args); 227 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args, 228 const FunctionType *type); 229 230 /// C++ methods have some special rules and also have implicit parameters. 231 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD); 232 const CGFunctionInfo &arrangeCXXStructorDeclaration(GlobalDecl GD); 233 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args, 234 const CXXConstructorDecl *D, 235 CXXCtorType CtorKind, 236 unsigned ExtraPrefixArgs, 237 unsigned ExtraSuffixArgs, 238 bool PassProtoArgs = true); 239 240 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args, 241 const FunctionProtoType *type, 242 RequiredArgs required, 243 unsigned numPrefixArgs); 244 const CGFunctionInfo & 245 arrangeUnprototypedMustTailThunk(const CXXMethodDecl *MD); 246 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD, 247 CXXCtorType CT); 248 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD, 249 const FunctionProtoType *FTP, 250 const CXXMethodDecl *MD); 251 252 /// "Arrange" the LLVM information for a call or type with the given 253 /// signature. This is largely an internal method; other clients 254 /// should use one of the above routines, which ultimately defer to 255 /// this. 256 /// 257 /// \param argTypes - must all actually be canonical as params 258 const CGFunctionInfo &arrangeLLVMFunctionInfo( 259 CanQualType returnType, FnInfoOpts opts, ArrayRef<CanQualType> argTypes, 260 FunctionType::ExtInfo info, 261 ArrayRef<FunctionProtoType::ExtParameterInfo> paramInfos, 262 RequiredArgs args); 263 264 /// Compute a new LLVM record layout object for the given record. 265 std::unique_ptr<CGRecordLayout> ComputeRecordLayout(const RecordDecl *D, 266 llvm::StructType *Ty); 267 268 /// addRecordTypeName - Compute a name from the given record decl with an 269 /// optional suffix and name the given LLVM type using it. 270 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, 271 StringRef suffix); 272 273 274public: // These are internal details of CGT that shouldn't be used externally. 275 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 276 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD); 277 278 /// getExpandedTypes - Expand the type \arg Ty into the LLVM 279 /// argument types it would be passed as. See ABIArgInfo::Expand. 280 void getExpandedTypes(QualType Ty, 281 SmallVectorImpl<llvm::Type *>::iterator &TI); 282 283 /// IsZeroInitializable - Return whether a type can be 284 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 285 bool isZeroInitializable(QualType T); 286 287 /// Check if the pointer type can be zero-initialized (in the C++ sense) 288 /// with an LLVM zeroinitializer. 289 bool isPointerZeroInitializable(QualType T); 290 291 /// IsZeroInitializable - Return whether a record type can be 292 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 293 bool isZeroInitializable(const RecordDecl *RD); 294 295 bool isLongDoubleReferenced() const { return LongDoubleReferenced; } 296 bool isRecordLayoutComplete(const Type *Ty) const; 297 unsigned getTargetAddressSpace(QualType T) const; 298}; 299 300} // end namespace CodeGen 301} // end namespace clang 302 303#endif 304