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 CLANG_CODEGEN_CODEGENTYPES_H 15 #define CLANG_CODEGEN_CODEGENTYPES_H 16 17 #include "CGCall.h" 18 #include "clang/AST/GlobalDecl.h" 19 #include "llvm/ADT/DenseMap.h" 20 #include "llvm/IR/Module.h" 21 #include <vector> 22 23 namespace llvm { 24 class FunctionType; 25 class Module; 26 class DataLayout; 27 class Type; 28 class LLVMContext; 29 class StructType; 30 } 31 32 namespace clang { 33 class ABIInfo; 34 class ASTContext; 35 template <typename> class CanQual; 36 class CXXConstructorDecl; 37 class CXXDestructorDecl; 38 class CXXMethodDecl; 39 class CodeGenOptions; 40 class FieldDecl; 41 class FunctionProtoType; 42 class ObjCInterfaceDecl; 43 class ObjCIvarDecl; 44 class PointerType; 45 class QualType; 46 class RecordDecl; 47 class TagDecl; 48 class TargetInfo; 49 class Type; 50 typedef CanQual<Type> CanQualType; 51 52 namespace CodeGen { 53 class CGCXXABI; 54 class CGRecordLayout; 55 class CodeGenModule; 56 class RequiredArgs; 57 58 /// CodeGenTypes - This class organizes the cross-module state that is used 59 /// while lowering AST types to LLVM types. 60 class CodeGenTypes { 61 CodeGenModule &CGM; 62 // Some of this stuff should probably be left on the CGM. 63 ASTContext &Context; 64 llvm::Module &TheModule; 65 const llvm::DataLayout &TheDataLayout; 66 const TargetInfo &Target; 67 CGCXXABI &TheCXXABI; 68 const CodeGenOptions &CodeGenOpts; 69 70 // This should not be moved earlier, since its initialization depends on some 71 // of the previous reference members being already initialized 72 const ABIInfo &TheABIInfo; 73 74 /// The opaque type map for Objective-C interfaces. All direct 75 /// manipulation is done by the runtime interfaces, which are 76 /// responsible for coercing to the appropriate type; these opaque 77 /// types are never refined. 78 llvm::DenseMap<const ObjCInterfaceType*, llvm::Type *> InterfaceTypes; 79 80 /// CGRecordLayouts - This maps llvm struct type with corresponding 81 /// record layout info. 82 llvm::DenseMap<const Type*, CGRecordLayout *> CGRecordLayouts; 83 84 /// RecordDeclTypes - This contains the LLVM IR type for any converted 85 /// RecordDecl. 86 llvm::DenseMap<const Type*, llvm::StructType *> RecordDeclTypes; 87 88 /// FunctionInfos - Hold memoized CGFunctionInfo results. 89 llvm::FoldingSet<CGFunctionInfo> FunctionInfos; 90 91 /// RecordsBeingLaidOut - This set keeps track of records that we're currently 92 /// converting to an IR type. For example, when converting: 93 /// struct A { struct B { int x; } } when processing 'x', the 'A' and 'B' 94 /// types will be in this set. 95 llvm::SmallPtrSet<const Type*, 4> RecordsBeingLaidOut; 96 97 llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed; 98 99 /// SkippedLayout - True if we didn't layout a function due to a being inside 100 /// a recursive struct conversion, set this to true. 101 bool SkippedLayout; 102 103 SmallVector<const RecordDecl *, 8> DeferredRecords; 104 105 private: 106 /// TypeCache - This map keeps cache of llvm::Types 107 /// and maps llvm::Types to corresponding clang::Type. 108 llvm::DenseMap<const Type *, llvm::Type *> TypeCache; 109 110 public: 111 CodeGenTypes(CodeGenModule &cgm); 112 ~CodeGenTypes(); 113 114 const llvm::DataLayout &getDataLayout() const { return TheDataLayout; } 115 ASTContext &getContext() const { return Context; } 116 const ABIInfo &getABIInfo() const { return TheABIInfo; } 117 const CodeGenOptions &getCodeGenOpts() const { return CodeGenOpts; } 118 const TargetInfo &getTarget() const { return Target; } 119 CGCXXABI &getCXXABI() const { return TheCXXABI; } 120 llvm::LLVMContext &getLLVMContext() { return TheModule.getContext(); } 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); 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 isFuncTypeArgumentConvertible(QualType Ty); 141 142 /// GetFunctionTypeForVTable - Get the LLVM function type for use in a vtable, 143 /// given a CXXMethodDecl. If the method to has an incomplete return type, 144 /// and/or incomplete argument types, this will return the opaque type. 145 llvm::Type *GetFunctionTypeForVTable(GlobalDecl GD); 146 147 const CGRecordLayout &getCGRecordLayout(const RecordDecl*); 148 149 /// UpdateCompletedType - When we find the full definition for a TagDecl, 150 /// replace the 'opaque' type we previously made for it if applicable. 151 void UpdateCompletedType(const TagDecl *TD); 152 153 /// getNullaryFunctionInfo - Get the function info for a void() 154 /// function with standard CC. 155 const CGFunctionInfo &arrangeNullaryFunction(); 156 157 // The arrangement methods are split into three families: 158 // - those meant to drive the signature and prologue/epilogue 159 // of a function declaration or definition, 160 // - those meant for the computation of the LLVM type for an abstract 161 // appearance of a function, and 162 // - those meant for performing the IR-generation of a call. 163 // They differ mainly in how they deal with optional (i.e. variadic) 164 // arguments, as well as unprototyped functions. 165 // 166 // Key points: 167 // - The CGFunctionInfo for emitting a specific call site must include 168 // entries for the optional arguments. 169 // - The function type used at the call site must reflect the formal 170 // signature of the declaration being called, or else the call will 171 // go awry. 172 // - For the most part, unprototyped functions are called by casting to 173 // a formal signature inferred from the specific argument types used 174 // at the call-site. However, some targets (e.g. x86-64) screw with 175 // this for compatibility reasons. 176 177 const CGFunctionInfo &arrangeGlobalDeclaration(GlobalDecl GD); 178 const CGFunctionInfo &arrangeFunctionDeclaration(const FunctionDecl *FD); 179 const CGFunctionInfo &arrangeFunctionDeclaration(QualType ResTy, 180 const FunctionArgList &Args, 181 const FunctionType::ExtInfo &Info, 182 bool isVariadic); 183 184 const CGFunctionInfo &arrangeObjCMethodDeclaration(const ObjCMethodDecl *MD); 185 const CGFunctionInfo &arrangeObjCMessageSendSignature(const ObjCMethodDecl *MD, 186 QualType receiverType); 187 188 const CGFunctionInfo &arrangeCXXMethodDeclaration(const CXXMethodDecl *MD); 189 const CGFunctionInfo &arrangeCXXConstructorDeclaration( 190 const CXXConstructorDecl *D, 191 CXXCtorType Type); 192 const CGFunctionInfo &arrangeCXXDestructor(const CXXDestructorDecl *D, 193 CXXDtorType Type); 194 195 const CGFunctionInfo &arrangeFreeFunctionCall(const CallArgList &Args, 196 const FunctionType *Ty); 197 const CGFunctionInfo &arrangeFreeFunctionCall(QualType ResTy, 198 const CallArgList &args, 199 FunctionType::ExtInfo info, 200 RequiredArgs required); 201 const CGFunctionInfo &arrangeBlockFunctionCall(const CallArgList &args, 202 const FunctionType *type); 203 204 const CGFunctionInfo &arrangeCXXMethodCall(const CallArgList &args, 205 const FunctionProtoType *type, 206 RequiredArgs required); 207 208 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionProtoType> Ty); 209 const CGFunctionInfo &arrangeFreeFunctionType(CanQual<FunctionNoProtoType> Ty); 210 const CGFunctionInfo &arrangeCXXMethodType(const CXXRecordDecl *RD, 211 const FunctionProtoType *FTP); 212 213 /// "Arrange" the LLVM information for a call or type with the given 214 /// signature. This is largely an internal method; other clients 215 /// should use one of the above routines, which ultimately defer to 216 /// this. 217 /// 218 /// \param argTypes - must all actually be canonical as params 219 const CGFunctionInfo &arrangeLLVMFunctionInfo(CanQualType returnType, 220 ArrayRef<CanQualType> argTypes, 221 FunctionType::ExtInfo info, 222 RequiredArgs args); 223 224 /// \brief Compute a new LLVM record layout object for the given record. 225 CGRecordLayout *ComputeRecordLayout(const RecordDecl *D, 226 llvm::StructType *Ty); 227 228 /// addRecordTypeName - Compute a name from the given record decl with an 229 /// optional suffix and name the given LLVM type using it. 230 void addRecordTypeName(const RecordDecl *RD, llvm::StructType *Ty, 231 StringRef suffix); 232 233 234 public: // These are internal details of CGT that shouldn't be used externally. 235 /// ConvertRecordDeclType - Lay out a tagged decl type like struct or union. 236 llvm::StructType *ConvertRecordDeclType(const RecordDecl *TD); 237 238 /// GetExpandedTypes - Expand the type \arg Ty into the LLVM 239 /// argument types it would be passed as on the provided vector \arg 240 /// ArgTys. See ABIArgInfo::Expand. 241 void GetExpandedTypes(QualType type, 242 SmallVectorImpl<llvm::Type*> &expanded); 243 244 /// IsZeroInitializable - Return whether a type can be 245 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 246 bool isZeroInitializable(QualType T); 247 248 /// IsZeroInitializable - Return whether a record type can be 249 /// zero-initialized (in the C++ sense) with an LLVM zeroinitializer. 250 bool isZeroInitializable(const CXXRecordDecl *RD); 251 252 bool isRecordLayoutComplete(const Type *Ty) const; 253 bool noRecordsBeingLaidOut() const { 254 return RecordsBeingLaidOut.empty(); 255 } 256 bool isRecordBeingLaidOut(const Type *Ty) const { 257 return RecordsBeingLaidOut.count(Ty); 258 } 259 260 }; 261 262 } // end namespace CodeGen 263 } // end namespace clang 264 265 #endif 266