Type.h revision b5ebf15b2b2ce8989caf1a1114b05d80b0f9bd48
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 , BoolTyID, // 0, 1: Basics... 75 UByteTyID , SByteTyID, // 2, 3: 8 bit types... 76 UShortTyID , ShortTyID, // 4, 5: 16 bit types... 77 UIntTyID , IntTyID, // 6, 7: 32 bit types... 78 ULongTyID , LongTyID, // 8, 9: 64 bit types... 79 FloatTyID , DoubleTyID, // 10,11: Floating point types... 80 LabelTyID , // 12 : 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 //... 89 90 NumTypeIDs, // Must remain as last defined ID 91 LastPrimitiveTyID = LabelTyID, 92 FirstDerivedTyID = FunctionTyID 93 }; 94 95private: 96 TypeID ID : 8; // The current base type of this type. 97 bool Abstract : 1; // True if type contains an OpaqueType 98 99 /// RefCount - This counts the number of PATypeHolders that are pointing to 100 /// this type. When this number falls to zero, if the type is abstract and 101 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for 102 /// derived types. 103 /// 104 mutable unsigned RefCount; 105 106 const Type *getForwardedTypeInternal() const; 107protected: 108 Type(const char *Name, TypeID id); 109 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {} 110 virtual ~Type() { 111 assert(AbstractTypeUsers.empty()); 112 } 113 114 /// Types can become nonabstract later, if they are refined. 115 /// 116 inline void setAbstract(bool Val) { Abstract = Val; } 117 118 unsigned getRefCount() const { return RefCount; } 119 120 /// ForwardType - This field is used to implement the union find scheme for 121 /// abstract types. When types are refined to other types, this field is set 122 /// to the more refined type. Only abstract types can be forwarded. 123 mutable const Type *ForwardType; 124 125 /// ContainedTys - The list of types contained by this one. For example, this 126 /// includes the arguments of a function type, the elements of the structure, 127 /// the pointee of a pointer, etc. Note that keeping this vector in the Type 128 /// class wastes some space for types that do not contain anything (such as 129 /// primitive types). However, keeping it here allows the subtype_* members 130 /// to be implemented MUCH more efficiently, and dynamically very few types do 131 /// not contain any elements (most are derived). 132 std::vector<PATypeHandle> ContainedTys; 133 134 /// AbstractTypeUsers - Implement a list of the users that need to be notified 135 /// if I am a type, and I get resolved into a more concrete type. 136 /// 137 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 138public: 139 void print(llvm_ostream &O) const { 140 if (O.stream()) print(*O.stream()); 141 } 142 void print(std::ostream &O) const; 143 144 /// @brief Debugging support: print to stderr 145 void dump() const; 146 147 //===--------------------------------------------------------------------===// 148 // Property accessors for dealing with types... Some of these virtual methods 149 // are defined in private classes defined in Type.cpp for primitive types. 150 // 151 152 /// getTypeID - Return the type id for the type. This will return one 153 /// of the TypeID enum elements defined above. 154 /// 155 inline TypeID getTypeID() const { return ID; } 156 157 /// getDescription - Return the string representation of the type... 158 const std::string &getDescription() const; 159 160 /// isSigned - Return whether an integral numeric type is signed. This is 161 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for 162 /// Float and Double. 163 /// 164 bool isSigned() const { 165 return ID == SByteTyID || ID == ShortTyID || 166 ID == IntTyID || ID == LongTyID; 167 } 168 169 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite 170 /// the complement of isSigned... nonnumeric types return false as they do 171 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and 172 /// ULongTy 173 /// 174 bool isUnsigned() const { 175 return ID == UByteTyID || ID == UShortTyID || 176 ID == UIntTyID || ID == ULongTyID; 177 } 178 179 /// isInteger - Equivalent to isSigned() || isUnsigned() 180 /// 181 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; } 182 183 /// isIntegral - Returns true if this is an integral type, which is either 184 /// BoolTy or one of the Integer types. 185 /// 186 bool isIntegral() const { return isInteger() || this == BoolTy; } 187 188 /// isFloatingPoint - Return true if this is one of the two floating point 189 /// types 190 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; } 191 192 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types. 193 /// 194 bool isFPOrFPVector() const; 195 196 /// isAbstract - True if the type is either an Opaque type, or is a derived 197 /// type that includes an opaque type somewhere in it. 198 /// 199 inline bool isAbstract() const { return Abstract; } 200 201 /// canLosslesslyBitCastTo - Return true if this type could be converted 202 /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts 203 /// are valid for types of the same size only where no re-interpretation of 204 /// the bits is done. 205 /// @brief Determine if this type could be losslessly bitcast to Ty 206 bool canLosslesslyBitCastTo(const Type *Ty) const; 207 208 209 /// Here are some useful little methods to query what type derived types are 210 /// Note that all other types can just compare to see if this == Type::xxxTy; 211 /// 212 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 213 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 214 215 /// isFirstClassType - Return true if the value is holdable in a register. 216 /// 217 inline bool isFirstClassType() const { 218 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 219 ID == PointerTyID || ID == PackedTyID; 220 } 221 222 /// isSized - Return true if it makes sense to take the size of this type. To 223 /// get the actual size for a particular target, it is reasonable to use the 224 /// TargetData subsystem to do this. 225 /// 226 bool isSized() const { 227 // If it's a primitive, it is always sized. 228 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID) 229 return true; 230 // If it is not something that can have a size (e.g. a function or label), 231 // it doesn't have a size. 232 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID) 233 return false; 234 // If it is something that can have a size and it's concrete, it definitely 235 // has a size, otherwise we have to try harder to decide. 236 return !isAbstract() || isSizedDerivedType(); 237 } 238 239 /// getPrimitiveSize - Return the basic size of this type if it is a primitive 240 /// type. These are fixed by LLVM and are not target dependent. This will 241 /// return zero if the type does not have a size or is not a primitive type. 242 /// 243 unsigned getPrimitiveSize() const; 244 unsigned getPrimitiveSizeInBits() const; 245 246 /// getUnsignedVersion - If this is an integer type, return the unsigned 247 /// variant of this type. For example int -> uint. 248 const Type *getUnsignedVersion() const; 249 250 /// getSignedVersion - If this is an integer type, return the signed variant 251 /// of this type. For example uint -> int. 252 const Type *getSignedVersion() const; 253 254 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits 255 /// that can be set by an unsigned version of this type. This is 0xFF for 256 /// sbyte/ubyte, 0xFFFF for shorts, etc. 257 uint64_t getIntegralTypeMask() const { 258 assert(isIntegral() && "This only works for integral types!"); 259 return ~uint64_t(0UL) >> (64-getPrimitiveSizeInBits()); 260 } 261 262 /// getForwaredType - Return the type that this type has been resolved to if 263 /// it has been resolved to anything. This is used to implement the 264 /// union-find algorithm for type resolution, and shouldn't be used by general 265 /// purpose clients. 266 const Type *getForwardedType() const { 267 if (!ForwardType) return 0; 268 return getForwardedTypeInternal(); 269 } 270 271 /// getVAArgsPromotedType - Return the type an argument of this type 272 /// will be promoted to if passed through a variable argument 273 /// function. 274 const Type *getVAArgsPromotedType() const { 275 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID) 276 return Type::UIntTy; 277 else if (ID == SByteTyID || ID == ShortTyID) 278 return Type::IntTy; 279 else if (ID == FloatTyID) 280 return Type::DoubleTy; 281 else 282 return this; 283 } 284 285 //===--------------------------------------------------------------------===// 286 // Type Iteration support 287 // 288 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator; 289 subtype_iterator subtype_begin() const { return ContainedTys.begin(); } 290 subtype_iterator subtype_end() const { return ContainedTys.end(); } 291 292 /// getContainedType - This method is used to implement the type iterator 293 /// (defined a the end of the file). For derived types, this returns the 294 /// types 'contained' in the derived type. 295 /// 296 const Type *getContainedType(unsigned i) const { 297 assert(i < ContainedTys.size() && "Index out of range!"); 298 return ContainedTys[i]; 299 } 300 301 /// getNumContainedTypes - Return the number of types in the derived type. 302 /// 303 typedef std::vector<PATypeHandle>::size_type size_type; 304 size_type getNumContainedTypes() const { return ContainedTys.size(); } 305 306 //===--------------------------------------------------------------------===// 307 // Static members exported by the Type class itself. Useful for getting 308 // instances of Type. 309 // 310 311 /// getPrimitiveType - Return a type based on an identifier. 312 static const Type *getPrimitiveType(TypeID IDNumber); 313 314 //===--------------------------------------------------------------------===// 315 // These are the builtin types that are always available... 316 // 317 static Type *VoidTy , *BoolTy; 318 static Type *SByteTy, *UByteTy, 319 *ShortTy, *UShortTy, 320 *IntTy , *UIntTy, 321 *LongTy , *ULongTy; 322 static Type *FloatTy, *DoubleTy; 323 324 static Type* LabelTy; 325 326 /// Methods for support type inquiry through isa, cast, and dyn_cast: 327 static inline bool classof(const Type *T) { return true; } 328 329 void addRef() const { 330 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 331 ++RefCount; 332 } 333 334 void dropRef() const { 335 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 336 assert(RefCount && "No objects are currently referencing this object!"); 337 338 // If this is the last PATypeHolder using this object, and there are no 339 // PATypeHandles using it, the type is dead, delete it now. 340 if (--RefCount == 0 && AbstractTypeUsers.empty()) 341 delete this; 342 } 343 344 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 345 /// it. This function is called primarily by the PATypeHandle class. 346 /// 347 void addAbstractTypeUser(AbstractTypeUser *U) const { 348 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!"); 349 AbstractTypeUsers.push_back(U); 350 } 351 352 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 353 /// no longer has a handle to the type. This function is called primarily by 354 /// the PATypeHandle class. When there are no users of the abstract type, it 355 /// is annihilated, because there is no way to get a reference to it ever 356 /// again. 357 /// 358 void removeAbstractTypeUser(AbstractTypeUser *U) const; 359 360private: 361 /// isSizedDerivedType - Derived types like structures and arrays are sized 362 /// iff all of the members of the type are sized as well. Since asking for 363 /// their size is relatively uncommon, move this operation out of line. 364 bool isSizedDerivedType() const; 365 366 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 367 virtual void typeBecameConcrete(const DerivedType *AbsTy); 368 369protected: 370 // PromoteAbstractToConcrete - This is an internal method used to calculate 371 // change "Abstract" from true to false when types are refined. 372 void PromoteAbstractToConcrete(); 373 friend class TypeMapBase; 374}; 375 376//===----------------------------------------------------------------------===// 377// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 378// These are defined here because they MUST be inlined, yet are dependent on 379// the definition of the Type class. 380// 381inline void PATypeHandle::addUser() { 382 assert(Ty && "Type Handle has a null type!"); 383 if (Ty->isAbstract()) 384 Ty->addAbstractTypeUser(User); 385} 386inline void PATypeHandle::removeUser() { 387 if (Ty->isAbstract()) 388 Ty->removeAbstractTypeUser(User); 389} 390 391// Define inline methods for PATypeHolder... 392 393inline void PATypeHolder::addRef() { 394 if (Ty->isAbstract()) 395 Ty->addRef(); 396} 397 398inline void PATypeHolder::dropRef() { 399 if (Ty->isAbstract()) 400 Ty->dropRef(); 401} 402 403 404//===----------------------------------------------------------------------===// 405// Provide specializations of GraphTraits to be able to treat a type as a 406// graph of sub types... 407 408template <> struct GraphTraits<Type*> { 409 typedef Type NodeType; 410 typedef Type::subtype_iterator ChildIteratorType; 411 412 static inline NodeType *getEntryNode(Type *T) { return T; } 413 static inline ChildIteratorType child_begin(NodeType *N) { 414 return N->subtype_begin(); 415 } 416 static inline ChildIteratorType child_end(NodeType *N) { 417 return N->subtype_end(); 418 } 419}; 420 421template <> struct GraphTraits<const Type*> { 422 typedef const Type NodeType; 423 typedef Type::subtype_iterator ChildIteratorType; 424 425 static inline NodeType *getEntryNode(const Type *T) { return T; } 426 static inline ChildIteratorType child_begin(NodeType *N) { 427 return N->subtype_begin(); 428 } 429 static inline ChildIteratorType child_end(NodeType *N) { 430 return N->subtype_end(); 431 } 432}; 433 434template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 435 return Ty.getTypeID() == Type::PointerTyID; 436} 437 438std::ostream &operator<<(std::ostream &OS, const Type &T); 439 440} // End llvm namespace 441 442#endif 443