Type.h revision 4fe16d607d11e29d742208894909733f5ad01f8f
1//===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file was developed by the LLVM research group and is distributed under 6// the University of Illinois Open Source License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10 11#ifndef LLVM_TYPE_H 12#define LLVM_TYPE_H 13 14#include "llvm/AbstractTypeUser.h" 15#include "llvm/Support/Casting.h" 16#include "llvm/Support/DataTypes.h" 17#include "llvm/Support/Streams.h" 18#include "llvm/ADT/GraphTraits.h" 19#include "llvm/ADT/iterator" 20#include <string> 21#include <vector> 22 23namespace llvm { 24 25class ArrayType; 26class DerivedType; 27class FunctionType; 28class OpaqueType; 29class PointerType; 30class StructType; 31class PackedType; 32class TypeMapBase; 33 34/// This file contains the declaration of the Type class. For more "Type" type 35/// stuff, look in DerivedTypes.h. 36/// 37/// The instances of the Type class are immutable: once they are created, 38/// they are never changed. Also note that only one instance of a particular 39/// type is ever created. Thus seeing if two types are equal is a matter of 40/// doing a trivial pointer comparison. To enforce that no two equal instances 41/// are created, Type instances can only be created via static factory methods 42/// in class Type and in derived classes. 43/// 44/// Once allocated, Types are never free'd, unless they are an abstract type 45/// that is resolved to a more concrete type. 46/// 47/// Types themself don't have a name, and can be named either by: 48/// - using SymbolTable instance, typically from some Module, 49/// - using convenience methods in the Module class (which uses module's 50/// SymbolTable too). 51/// 52/// Opaque types are simple derived types with no state. There may be many 53/// different Opaque type objects floating around, but two are only considered 54/// identical if they are pointer equals of each other. This allows us to have 55/// two opaque types that end up resolving to different concrete types later. 56/// 57/// Opaque types are also kinda weird and scary and different because they have 58/// to keep a list of uses of the type. When, through linking, parsing, or 59/// bytecode reading, they become resolved, they need to find and update all 60/// users of the unknown type, causing them to reference a new, more concrete 61/// type. Opaque types are deleted when their use list dwindles to zero users. 62/// 63/// @brief Root of type hierarchy 64class Type : public AbstractTypeUser { 65public: 66 ///===-------------------------------------------------------------------===// 67 /// Definitions of all of the base types for the Type system. Based on this 68 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h) 69 /// Note: If you add an element to this, you need to add an element to the 70 /// Type::getPrimitiveType function, or else things will break! 71 /// 72 enum TypeID { 73 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date 74 VoidTyID = 0 , Int1TyID, // 0, 1: Basics... 75 Int8TyID, // 2 : 8 bit type... 76 Int16TyID, // 3 : 16 bit type... 77 Int32TyID, // 4 : 32 bit type... 78 Int64TyID, // 5 : 64 bit type... 79 FloatTyID, DoubleTyID, // 6, 7: Floating point types... 80 LabelTyID, // 8 : Labels... 81 82 // Derived types... see DerivedTypes.h file... 83 // Make sure FirstDerivedTyID stays up to date!!! 84 FunctionTyID , StructTyID, // Functions... Structs... 85 ArrayTyID , PointerTyID, // Array... pointer... 86 OpaqueTyID, // Opaque type instances... 87 PackedTyID, // SIMD 'packed' format... 88 BC_ONLY_PackedStructTyID, // packed struct, for BC rep only 89 //... 90 91 NumTypeIDs, // Must remain as last defined ID 92 LastPrimitiveTyID = LabelTyID, 93 FirstDerivedTyID = FunctionTyID 94 }; 95 96private: 97 TypeID ID : 8; // The current base type of this type. 98 bool Abstract : 1; // True if type contains an OpaqueType 99 bool SubclassData : 1; //Space for subclasses to store a flag 100 101 /// RefCount - This counts the number of PATypeHolders that are pointing to 102 /// this type. When this number falls to zero, if the type is abstract and 103 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for 104 /// derived types. 105 /// 106 mutable unsigned RefCount; 107 108 const Type *getForwardedTypeInternal() const; 109protected: 110 Type(const char *Name, TypeID id); 111 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {} 112 virtual ~Type() { 113 assert(AbstractTypeUsers.empty()); 114 } 115 116 /// Types can become nonabstract later, if they are refined. 117 /// 118 inline void setAbstract(bool Val) { Abstract = Val; } 119 120 unsigned getRefCount() const { return RefCount; } 121 122 bool getSubclassData() const { return SubclassData; } 123 void setSubclassData(bool b) { SubclassData = b; } 124 125 /// ForwardType - This field is used to implement the union find scheme for 126 /// abstract types. When types are refined to other types, this field is set 127 /// to the more refined type. Only abstract types can be forwarded. 128 mutable const Type *ForwardType; 129 130 /// ContainedTys - The list of types contained by this one. For example, this 131 /// includes the arguments of a function type, the elements of the structure, 132 /// the pointee of a pointer, etc. Note that keeping this vector in the Type 133 /// class wastes some space for types that do not contain anything (such as 134 /// primitive types). However, keeping it here allows the subtype_* members 135 /// to be implemented MUCH more efficiently, and dynamically very few types do 136 /// not contain any elements (most are derived). 137 std::vector<PATypeHandle> ContainedTys; 138 139 /// AbstractTypeUsers - Implement a list of the users that need to be notified 140 /// if I am a type, and I get resolved into a more concrete type. 141 /// 142 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 143public: 144 void print(std::ostream &O) const; 145 void print(std::ostream *O) const { if (O) print(*O); } 146 147 /// @brief Debugging support: print to stderr 148 void dump() const; 149 150 //===--------------------------------------------------------------------===// 151 // Property accessors for dealing with types... Some of these virtual methods 152 // are defined in private classes defined in Type.cpp for primitive types. 153 // 154 155 /// getTypeID - Return the type id for the type. This will return one 156 /// of the TypeID enum elements defined above. 157 /// 158 inline TypeID getTypeID() const { return ID; } 159 160 /// getDescription - Return the string representation of the type... 161 const std::string &getDescription() const; 162 163 /// isInteger - Equivalent to isSigned() || isUnsigned() 164 /// 165 bool isInteger() const { return ID >= Int8TyID && ID <= Int64TyID; } 166 167 /// isIntegral - Returns true if this is an integral type, which is either 168 /// Int1Ty or one of the Integer types. 169 /// 170 bool isIntegral() const { return isInteger() || this == Int1Ty; } 171 172 /// isFloatingPoint - Return true if this is one of the two floating point 173 /// types 174 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; } 175 176 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types. 177 /// 178 bool isFPOrFPVector() const; 179 180 /// isAbstract - True if the type is either an Opaque type, or is a derived 181 /// type that includes an opaque type somewhere in it. 182 /// 183 inline bool isAbstract() const { return Abstract; } 184 185 /// canLosslesslyBitCastTo - Return true if this type could be converted 186 /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts 187 /// are valid for types of the same size only where no re-interpretation of 188 /// the bits is done. 189 /// @brief Determine if this type could be losslessly bitcast to Ty 190 bool canLosslesslyBitCastTo(const Type *Ty) const; 191 192 193 /// Here are some useful little methods to query what type derived types are 194 /// Note that all other types can just compare to see if this == Type::xxxTy; 195 /// 196 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 197 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 198 199 /// isFirstClassType - Return true if the value is holdable in a register. 200 /// 201 inline bool isFirstClassType() const { 202 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 203 ID == PointerTyID || ID == PackedTyID; 204 } 205 206 /// isSized - Return true if it makes sense to take the size of this type. To 207 /// get the actual size for a particular target, it is reasonable to use the 208 /// TargetData subsystem to do this. 209 /// 210 bool isSized() const { 211 // If it's a primitive, it is always sized. 212 if (ID >= Int1TyID && ID <= DoubleTyID || ID == PointerTyID) 213 return true; 214 // If it is not something that can have a size (e.g. a function or label), 215 // it doesn't have a size. 216 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID) 217 return false; 218 // If it is something that can have a size and it's concrete, it definitely 219 // has a size, otherwise we have to try harder to decide. 220 return !isAbstract() || isSizedDerivedType(); 221 } 222 223 /// getPrimitiveSize - Return the basic size of this type if it is a primitive 224 /// type. These are fixed by LLVM and are not target dependent. This will 225 /// return zero if the type does not have a size or is not a primitive type. 226 /// 227 unsigned getPrimitiveSize() const; 228 unsigned getPrimitiveSizeInBits() const; 229 230 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits 231 /// that can be set by an unsigned version of this type. This is 0xFF for 232 /// sbyte/ubyte, 0xFFFF for shorts, etc. 233 uint64_t getIntegralTypeMask() const { 234 assert(isIntegral() && "This only works for integral types!"); 235 return ~uint64_t(0UL) >> (64-getPrimitiveSizeInBits()); 236 } 237 238 /// getForwaredType - Return the type that this type has been resolved to if 239 /// it has been resolved to anything. This is used to implement the 240 /// union-find algorithm for type resolution, and shouldn't be used by general 241 /// purpose clients. 242 const Type *getForwardedType() const { 243 if (!ForwardType) return 0; 244 return getForwardedTypeInternal(); 245 } 246 247 /// getVAArgsPromotedType - Return the type an argument of this type 248 /// will be promoted to if passed through a variable argument 249 /// function. 250 const Type *getVAArgsPromotedType() const { 251 if (ID == Int1TyID || ID == Int8TyID || ID == Int16TyID) 252 return Type::Int32Ty; 253 else if (ID == FloatTyID) 254 return Type::DoubleTy; 255 else 256 return this; 257 } 258 259 //===--------------------------------------------------------------------===// 260 // Type Iteration support 261 // 262 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator; 263 subtype_iterator subtype_begin() const { return ContainedTys.begin(); } 264 subtype_iterator subtype_end() const { return ContainedTys.end(); } 265 266 /// getContainedType - This method is used to implement the type iterator 267 /// (defined a the end of the file). For derived types, this returns the 268 /// types 'contained' in the derived type. 269 /// 270 const Type *getContainedType(unsigned i) const { 271 assert(i < ContainedTys.size() && "Index out of range!"); 272 return ContainedTys[i]; 273 } 274 275 /// getNumContainedTypes - Return the number of types in the derived type. 276 /// 277 typedef std::vector<PATypeHandle>::size_type size_type; 278 size_type getNumContainedTypes() const { return ContainedTys.size(); } 279 280 //===--------------------------------------------------------------------===// 281 // Static members exported by the Type class itself. Useful for getting 282 // instances of Type. 283 // 284 285 /// getPrimitiveType - Return a type based on an identifier. 286 static const Type *getPrimitiveType(TypeID IDNumber); 287 288 //===--------------------------------------------------------------------===// 289 // These are the builtin types that are always available... 290 // 291 static Type *VoidTy , *Int1Ty; 292 static Type *Int8Ty , *Int16Ty, 293 *Int32Ty, *Int64Ty; 294 static Type *FloatTy, *DoubleTy; 295 296 static Type* LabelTy; 297 298 /// Methods for support type inquiry through isa, cast, and dyn_cast: 299 static inline bool classof(const Type *T) { return true; } 300 301 void addRef() const { 302 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 303 ++RefCount; 304 } 305 306 void dropRef() const { 307 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 308 assert(RefCount && "No objects are currently referencing this object!"); 309 310 // If this is the last PATypeHolder using this object, and there are no 311 // PATypeHandles using it, the type is dead, delete it now. 312 if (--RefCount == 0 && AbstractTypeUsers.empty()) 313 delete this; 314 } 315 316 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 317 /// it. This function is called primarily by the PATypeHandle class. 318 /// 319 void addAbstractTypeUser(AbstractTypeUser *U) const { 320 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!"); 321 AbstractTypeUsers.push_back(U); 322 } 323 324 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 325 /// no longer has a handle to the type. This function is called primarily by 326 /// the PATypeHandle class. When there are no users of the abstract type, it 327 /// is annihilated, because there is no way to get a reference to it ever 328 /// again. 329 /// 330 void removeAbstractTypeUser(AbstractTypeUser *U) const; 331 332private: 333 /// isSizedDerivedType - Derived types like structures and arrays are sized 334 /// iff all of the members of the type are sized as well. Since asking for 335 /// their size is relatively uncommon, move this operation out of line. 336 bool isSizedDerivedType() const; 337 338 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 339 virtual void typeBecameConcrete(const DerivedType *AbsTy); 340 341protected: 342 // PromoteAbstractToConcrete - This is an internal method used to calculate 343 // change "Abstract" from true to false when types are refined. 344 void PromoteAbstractToConcrete(); 345 friend class TypeMapBase; 346}; 347 348//===----------------------------------------------------------------------===// 349// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 350// These are defined here because they MUST be inlined, yet are dependent on 351// the definition of the Type class. 352// 353inline void PATypeHandle::addUser() { 354 assert(Ty && "Type Handle has a null type!"); 355 if (Ty->isAbstract()) 356 Ty->addAbstractTypeUser(User); 357} 358inline void PATypeHandle::removeUser() { 359 if (Ty->isAbstract()) 360 Ty->removeAbstractTypeUser(User); 361} 362 363// Define inline methods for PATypeHolder... 364 365inline void PATypeHolder::addRef() { 366 if (Ty->isAbstract()) 367 Ty->addRef(); 368} 369 370inline void PATypeHolder::dropRef() { 371 if (Ty->isAbstract()) 372 Ty->dropRef(); 373} 374 375 376//===----------------------------------------------------------------------===// 377// Provide specializations of GraphTraits to be able to treat a type as a 378// graph of sub types... 379 380template <> struct GraphTraits<Type*> { 381 typedef Type NodeType; 382 typedef Type::subtype_iterator ChildIteratorType; 383 384 static inline NodeType *getEntryNode(Type *T) { return T; } 385 static inline ChildIteratorType child_begin(NodeType *N) { 386 return N->subtype_begin(); 387 } 388 static inline ChildIteratorType child_end(NodeType *N) { 389 return N->subtype_end(); 390 } 391}; 392 393template <> struct GraphTraits<const Type*> { 394 typedef const Type NodeType; 395 typedef Type::subtype_iterator ChildIteratorType; 396 397 static inline NodeType *getEntryNode(const Type *T) { return T; } 398 static inline ChildIteratorType child_begin(NodeType *N) { 399 return N->subtype_begin(); 400 } 401 static inline ChildIteratorType child_end(NodeType *N) { 402 return N->subtype_end(); 403 } 404}; 405 406template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 407 return Ty.getTypeID() == Type::PointerTyID; 408} 409 410std::ostream &operator<<(std::ostream &OS, const Type &T); 411 412} // End llvm namespace 413 414#endif 415