1 //===--- CodeGenTypes.h - Type translation for LLVM CodeGen -----*- C++ -*-===// 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 #ifndef LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H 15 #define LLVM_CLANG_LIB_CODEGEN_CODEGENTYPES_H 16 17 #include "CGCall.h" 18 #include "clang/AST/GlobalDecl.h" 19 #include "clang/CodeGen/CGFunctionInfo.h" 20 #include "llvm/ADT/DenseMap.h" 21 #include "llvm/IR/Module.h" 22 #include <vector> 23 24 namespace llvm { 25 class FunctionType; 26 class Module; 27 class DataLayout; 28 class Type; 29 class LLVMContext; 30 class StructType; 31 } 32 33 namespace clang { 34 class ABIInfo; 35 class ASTContext; 36 template <typename> class CanQual; 37 class CXXConstructorDecl; 38 class CXXDestructorDecl; 39 class CXXMethodDecl; 40 class CodeGenOptions; 41 class FieldDecl; 42 class FunctionProtoType; 43 class ObjCInterfaceDecl; 44 class ObjCIvarDecl; 45 class PointerType; 46 class QualType; 47 class RecordDecl; 48 class TagDecl; 49 class TargetInfo; 50 class Type; 51 typedef CanQual<Type> CanQualType; 52 53 namespace CodeGen { 54 class CGCXXABI; 55 class CGRecordLayout; 56 class CodeGenModule; 57 class RequiredArgs; 58 59 enum class StructorType { 60 Complete, // constructor or destructor 61 Base, // constructor or destructor 62 Deleting // destructor only 63 }; 64 65 inline CXXCtorType toCXXCtorType(StructorType T) { 66 switch (T) { 67 case StructorType::Complete: 68 return Ctor_Complete; 69 case StructorType::Base: 70 return Ctor_Base; 71 case StructorType::Deleting: 72 llvm_unreachable("cannot have a deleting ctor"); 73 } 74 llvm_unreachable("not a StructorType"); 75 } 76 77 inline StructorType getFromCtorType(CXXCtorType T) { 78 switch (T) { 79 case Ctor_Complete: 80 return StructorType::Complete; 81 case Ctor_Base: 82 return StructorType::Base; 83 case Ctor_Comdat: 84 llvm_unreachable("not expecting a COMDAT"); 85 case Ctor_CopyingClosure: 86 case Ctor_DefaultClosure: 87 llvm_unreachable("not expecting a closure"); 88 } 89 llvm_unreachable("not a CXXCtorType"); 90 } 91 92 inline CXXDtorType toCXXDtorType(StructorType T) { 93 switch (T) { 94 case StructorType::Complete: 95 return Dtor_Complete; 96 case StructorType::Base: 97 return Dtor_Base; 98 case StructorType::Deleting: 99 return Dtor_Deleting; 100 } 101 llvm_unreachable("not a StructorType"); 102 } 103 104 inline StructorType getFromDtorType(CXXDtorType T) { 105 switch (T) { 106 case Dtor_Deleting: 107 return StructorType::Deleting; 108 case Dtor_Complete: 109 return StructorType::Complete; 110 case Dtor_Base: 111 return StructorType::Base; 112 case Dtor_Comdat: 113 llvm_unreachable("not expecting a COMDAT"); 114 } 115 llvm_unreachable("not a CXXDtorType"); 116 } 117 118 /// This class organizes the cross-module state that is used while lowering 119 /// AST types to LLVM types. 120 class CodeGenTypes { 121 CodeGenModule &CGM; 122 // Some of this stuff should probably be left on the CGM. 123 ASTContext &Context; 124 llvm::Module &TheModule; 125 const TargetInfo &Target; 126 CGCXXABI &TheCXXABI; 127 128 // This should not be moved earlier, since its initialization depends on some 129 // of the previous reference members being already initialized 130 const ABIInfo &TheABIInfo; 131 132 /// The opaque type map for Objective-C interfaces. All direct 133 /// manipulation is done by the runtime interfaces, which are 134 /// responsible for coercing to the appropriate type; these opaque 135 /// types are never refined. 136 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes; 137 138 /// Maps clang struct type with corresponding record layout info. 139 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts; 140 141 /// Contains the LLVM IR type for any converted RecordDecl. 142 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes; 143 144 /// Hold memoized CGFunctionInfo results. 145 llvm::FoldingSet<CGFunctionInfo> FunctionInfos; 146 147 /// This set keeps track of records that we're currently converting 148 /// to an IR type. For example, when converting: 149 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B' 150 /// types will be in this set. 151 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut; 152 153 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed; 154 155 /// True if we didn't layout a function due to a being inside 156 /// a recursive struct conversion, set this to true. 157 bool SkippedLayout; 158 159 SmallVector<const RecordDecl *, 8> DeferredRecords; 160 161 /// This map keeps cache of llvm::Types and maps clang::Type to 162 /// corresponding llvm::Type. 163 llvm::DenseMap<const Type *, llvm::Type *> TypeCache; 164 165 public: 166 CodeGenTypes(CodeGenModule &cgm); 167 ~CodeGenTypes(); 168 169 const llvm::DataLayout &getDataLayout() const { 170 return TheModule.getDataLayout(); 171 } 172 ASTContext &getContext() const { return Context; } 173 const ABIInfo &getABIInfo() const { return TheABIInfo; } 174 const TargetInfo &getTarget() const { return Target; } 175 CGCXXABI &getCXXABI() const { return TheCXXABI; } 176 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); } 177 178 /// ConvertType - Convert type T into a llvm::Type. 179 llvm::Type *ConvertType(QualType T); 180 181 /// \brief Converts the GlobalDecl into an llvm::Type. This should be used 182 /// when we know the target of the function we want to convert. This is 183 /// because some functions (explicitly, those with pass_object_size 184 /// parameters) may not have the same signature as their type portrays, and 185 /// can only be called directly. 186 llvm::Type *ConvertFunctionType(QualType FT, 187 const FunctionDecl *FD = nullptr); 188 189 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 190 /// ConvertType in that it is used to convert to the memory representation for 191 /// a type. For example, the scalar representation for _Bool is i1, but the 192 /// memory representation is usually i8 or i32, depending on the target. 193 llvm::Type *ConvertTypeForMem(QualType T); 194 195 /// GetFunctionType - Get the LLVM function type for \arg Info. 196 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info); 197 198 llvm::FunctionType *GetFunctionType(GlobalDecl GD); 199 200 /// isFuncTypeConvertible - Utility to check whether a function type can 201 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag 202 /// type). 203 bool isFuncTypeConvertible(const FunctionType *FT); 204 bool isFuncParamTypeConvertible(QualType Ty); 205 206 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable, 207 /// given a CXXMethodDecl. If the method to has an incomplete return type, 208 /// and/or incomplete argument types, this will return the opaque type. 209 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD); 210 211 const CGRecordLayout &getCGRecordLayout(const RecordDecl*); 212 213 /// UpdateCompletedType - When we find the full definition for a TagDecl, 214 /// replace the 'opaque' type we previously made for it if applicable. 215 void UpdateCompletedType(const TagDecl *TD); 216 217 /// getNullaryFunctionInfo - Get the function info for a void() 218 /// function with standard CC. 219 const CGFunctionInfo &arrangeNullaryFunction(); 220 221 // The arrangement methods are split into three families: 222 // - those meant to drive the signature and prologue/epilogue 223 // of a function declaration or definition, 224 // - those meant for the computation of the LLVM type for an abstract 225 // appearance of a function, and 226 // - those meant for performing the IR-generation of a call. 227 // They differ mainly in how they deal with optional (i.e. variadic) 228 // arguments, as well as unprototyped functions. 229 // 230 // Key points: 231 // - The CGFunctionInfo for emitting a specific call site must include 232 // entries for the optional arguments. 233 // - The function type used at the call site must reflect the formal 234 // signature of the declaration being called, or else the call will 235 // go awry. 236 // - For the most part, unprototyped functions are called by casting to 237 // a formal signature inferred from the specific argument types used 238 // at the call-site. However, some targets (e.g. x86-64) screw with 239 // this for compatibility reasons. 240 241 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD); 242 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD); 243 const CGFunctionInfo & 244 arrangeFreeFunctionDeclaration(QualType ResTy, const FunctionArgList &Args, 245 const FunctionType::ExtInfo &Info, 246 bool isVariadic); 247 248 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD); 249 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, 250 QualType receiverType); 251 252 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD); 253 const CGFunctionInfo &arrangeCXXStructorDeclaration(const CXXMethodDecl *MD, 254 StructorType Type); 255 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args, 256 const CXXConstructorDecl *D, 257 CXXCtorType CtorKind, 258 unsigned ExtraArgs); 259 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args, 260 const FunctionType *Ty, 261 bool ChainCall); 262 const CGFunctionInfo &arrangeFreeFunctionCall(QualType ResTy, 263 const CallArgList &args, 264 FunctionType::ExtInfo info, 265 RequiredArgs required); 266 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args, 267 const FunctionType *type); 268 269 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args, 270 const FunctionProtoType *type, 271 RequiredArgs required); 272 const CGFunctionInfo &arrangeMSMemberPointerThunk(const CXXMethodDecl *MD); 273 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD, 274 CXXCtorType CT); 275 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty, 276 const FunctionDecl *FD); 277 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty); 278 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD, 279 const FunctionProtoType *FTP, 280 const CXXMethodDecl *MD); 281 282 /// "Arrange" the LLVM information for a call or type with the given 283 /// signature. This is largely an internal method; other clients 284 /// should use one of the above routines, which ultimately defer to 285 /// this. 286 /// 287 /// \param argTypes - must all actually be canonical as params 288 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType, 289 bool instanceMethod, 290 bool chainCall, 291 ArrayRef<CanQualType> argTypes, 292 FunctionType::ExtInfo info, 293 RequiredArgs args); 294 295 /// \brief Compute a new LLVM record layout object for the given record. 296 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D, 297 llvm::StructType *Ty); 298 299 /// addRecordTypeName - Compute a name from the given record decl with an 300 /// optional suffix and name the given LLVM type using it. 301 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, 302 StringRef suffix); 303 304 305 public: // These are internal details of CGT that shouldn't be used externally. 306 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 307 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD); 308 309 /// getExpandedTypes - Expand the type \arg Ty into the LLVM 310 /// argument types it would be passed as. See ABIArgInfo::Expand. 311 void getExpandedTypes(QualType Ty, 312 SmallVectorImpl<llvm::Type *>::iterator &TI); 313 314 /// IsZeroInitializable - Return whether a type can be 315 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 316 bool isZeroInitializable(QualType T); 317 318 /// IsZeroInitializable - Return whether a record type can be 319 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 320 bool isZeroInitializable(const RecordDecl *RD); 321 322 bool isRecordLayoutComplete(const Type *Ty) const; 323 bool noRecordsBeingLaidOut() const { 324 return RecordsBeingLaidOut.empty(); 325 } 326 bool isRecordBeingLaidOut(const Type *Ty) const { 327 return RecordsBeingLaidOut.count(Ty); 328 } 329 330 }; 331 332 } // end namespace CodeGen 333 } // end namespace clang 334 335 #endif 336
