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 /// CodeGenTypes - This class organizes the cross-module state that is used 119 /// while lowering 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 llvm::DataLayout &TheDataLayout; 126 const TargetInfo &Target; 127 CGCXXABI &TheCXXABI; 128 129 // This should not be moved earlier, since its initialization depends on some 130 // of the previous reference members being already initialized 131 const ABIInfo &TheABIInfo; 132 133 /// The opaque type map for Objective-C interfaces. All direct 134 /// manipulation is done by the runtime interfaces, which are 135 /// responsible for coercing to the appropriate type; these opaque 136 /// types are never refined. 137 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes; 138 139 /// CGRecordLayouts - This maps llvm struct type with corresponding 140 /// record layout info. 141 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts; 142 143 /// RecordDeclTypes - This contains the LLVM IR type for any converted 144 /// RecordDecl. 145 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes; 146 147 /// FunctionInfos - Hold memoized CGFunctionInfo results. 148 llvm::FoldingSet<CGFunctionInfo> FunctionInfos; 149 150 /// RecordsBeingLaidOut - This set keeps track of records that we're currently 151 /// converting to an IR type. For example, when converting: 152 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B' 153 /// types will be in this set. 154 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut; 155 156 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed; 157 158 /// SkippedLayout - True if we didn't layout a function due to a being inside 159 /// a recursive struct conversion, set this to true. 160 bool SkippedLayout; 161 162 SmallVector<const RecordDecl *, 8> DeferredRecords; 163 164 private: 165 /// TypeCache - This map keeps cache of llvm::Types 166 /// and maps clang::Type to corresponding llvm::Type. 167 llvm::DenseMap<const Type *, llvm::Type *> TypeCache; 168 169 public: 170 CodeGenTypes(CodeGenModule &cgm); 171 ~CodeGenTypes(); 172 173 const llvm::DataLayout &getDataLayout() const { return TheDataLayout; } 174 ASTContext &getContext() const { return Context; } 175 const ABIInfo &getABIInfo() const { return TheABIInfo; } 176 const TargetInfo &getTarget() const { return Target; } 177 CGCXXABI &getCXXABI() const { return TheCXXABI; } 178 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); } 179 180 /// ConvertType - Convert type T into a llvm::Type. 181 llvm::Type *ConvertType(QualType T); 182 183 /// ConvertTypeForMem - Convert type T into a llvm::Type. This differs from 184 /// ConvertType in that it is used to convert to the memory representation for 185 /// a type. For example, the scalar representation for _Bool is i1, but the 186 /// memory representation is usually i8 or i32, depending on the target. 187 llvm::Type *ConvertTypeForMem(QualType T); 188 189 /// GetFunctionType - Get the LLVM function type for \arg Info. 190 llvm::FunctionType *GetFunctionType(const CGFunctionInfo &Info); 191 192 llvm::FunctionType *GetFunctionType(GlobalDecl GD); 193 194 /// isFuncTypeConvertible - Utility to check whether a function type can 195 /// be converted to an LLVM type (i.e. doesn't depend on an incomplete tag 196 /// type). 197 bool isFuncTypeConvertible(const FunctionType *FT); 198 bool isFuncParamTypeConvertible(QualType Ty); 199 200 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable, 201 /// given a CXXMethodDecl. If the method to has an incomplete return type, 202 /// and/or incomplete argument types, this will return the opaque type. 203 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD); 204 205 const CGRecordLayout &getCGRecordLayout(const RecordDecl*); 206 207 /// UpdateCompletedType - When we find the full definition for a TagDecl, 208 /// replace the 'opaque' type we previously made for it if applicable. 209 void UpdateCompletedType(const TagDecl *TD); 210 211 /// getNullaryFunctionInfo - Get the function info for a void() 212 /// function with standard CC. 213 const CGFunctionInfo &arrangeNullaryFunction(); 214 215 // The arrangement methods are split into three families: 216 // - those meant to drive the signature and prologue/epilogue 217 // of a function declaration or definition, 218 // - those meant for the computation of the LLVM type for an abstract 219 // appearance of a function, and 220 // - those meant for performing the IR-generation of a call. 221 // They differ mainly in how they deal with optional (i.e. variadic) 222 // arguments, as well as unprototyped functions. 223 // 224 // Key points: 225 // - The CGFunctionInfo for emitting a specific call site must include 226 // entries for the optional arguments. 227 // - The function type used at the call site must reflect the formal 228 // signature of the declaration being called, or else the call will 229 // go awry. 230 // - For the most part, unprototyped functions are called by casting to 231 // a formal signature inferred from the specific argument types used 232 // at the call-site. However, some targets (e.g. x86-64) screw with 233 // this for compatibility reasons. 234 235 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD); 236 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD); 237 const CGFunctionInfo & 238 arrangeFreeFunctionDeclaration(QualType ResTy, const FunctionArgList &Args, 239 const FunctionType::ExtInfo &Info, 240 bool isVariadic); 241 242 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD); 243 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, 244 QualType receiverType); 245 246 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD); 247 const CGFunctionInfo &arrangeCXXStructorDeclaration(const CXXMethodDecl *MD, 248 StructorType Type); 249 const CGFunctionInfo &arrangeCXXConstructorCall(const CallArgList &Args, 250 const CXXConstructorDecl *D, 251 CXXCtorType CtorKind, 252 unsigned ExtraArgs); 253 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args, 254 const FunctionType *Ty, 255 bool ChainCall); 256 const CGFunctionInfo &arrangeFreeFunctionCall(QualType ResTy, 257 const CallArgList &args, 258 FunctionType::ExtInfo info, 259 RequiredArgs required); 260 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args, 261 const FunctionType *type); 262 263 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args, 264 const FunctionProtoType *type, 265 RequiredArgs required); 266 const CGFunctionInfo &arrangeMSMemberPointerThunk(const CXXMethodDecl *MD); 267 const CGFunctionInfo &arrangeMSCtorClosure(const CXXConstructorDecl *CD, 268 CXXCtorType CT); 269 270 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty); 271 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty); 272 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD, 273 const FunctionProtoType *FTP); 274 275 /// "Arrange" the LLVM information for a call or type with the given 276 /// signature. This is largely an internal method; other clients 277 /// should use one of the above routines, which ultimately defer to 278 /// this. 279 /// 280 /// \param argTypes - must all actually be canonical as params 281 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType, 282 bool instanceMethod, 283 bool chainCall, 284 ArrayRef<CanQualType> argTypes, 285 FunctionType::ExtInfo info, 286 RequiredArgs args); 287 288 /// \brief Compute a new LLVM record layout object for the given record. 289 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D, 290 llvm::StructType *Ty); 291 292 /// addRecordTypeName - Compute a name from the given record decl with an 293 /// optional suffix and name the given LLVM type using it. 294 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, 295 StringRef suffix); 296 297 298 public: // These are internal details of CGT that shouldn't be used externally. 299 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 300 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD); 301 302 /// getExpandedTypes - Expand the type \arg Ty into the LLVM 303 /// argument types it would be passed as. See ABIArgInfo::Expand. 304 void getExpandedTypes(QualType Ty, 305 SmallVectorImpl<llvm::Type *>::iterator &TI); 306 307 /// IsZeroInitializable - Return whether a type can be 308 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 309 bool isZeroInitializable(QualType T); 310 311 /// IsZeroInitializable - Return whether a record type can be 312 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 313 bool isZeroInitializable(const CXXRecordDecl *RD); 314 315 bool isRecordLayoutComplete(const Type *Ty) const; 316 bool noRecordsBeingLaidOut() const { 317 return RecordsBeingLaidOut.empty(); 318 } 319 bool isRecordBeingLaidOut(const Type *Ty) const { 320 return RecordsBeingLaidOut.count(Ty); 321 } 322 323 }; 324 325 } // end namespace CodeGen 326 } // end namespace clang 327 328 #endif 329
