Type.h revision e87a4b6cb000b9065c70cc40e74f89f338313f4d
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/ADT/GraphTraits.h" 18#include "llvm/ADT/iterator" 19#include <string> 20#include <vector> 21 22namespace llvm { 23 24class ArrayType; 25class DerivedType; 26class FunctionType; 27class OpaqueType; 28class PointerType; 29class StructType; 30class PackedType; 31class TypeMapBase; 32 33/// This file contains the declaration of the Type class. For more "Type" type 34/// stuff, look in DerivedTypes.h. 35/// 36/// The instances of the Type class are immutable: once they are created, 37/// they are never changed. Also note that only one instance of a particular 38/// type is ever created. Thus seeing if two types are equal is a matter of 39/// doing a trivial pointer comparison. To enforce that no two equal instances 40/// are created, Type instances can only be created via static factory methods 41/// in class Type and in derived classes. 42/// 43/// Once allocated, Types are never free'd, unless they are an abstract type 44/// that is resolved to a more concrete type. 45/// 46/// Types themself don't have a name, and can be named either by: 47/// - using SymbolTable instance, typically from some Module, 48/// - using convenience methods in the Module class (which uses module's 49/// SymbolTable too). 50/// 51/// Opaque types are simple derived types with no state. There may be many 52/// different Opaque type objects floating around, but two are only considered 53/// identical if they are pointer equals of each other. This allows us to have 54/// two opaque types that end up resolving to different concrete types later. 55/// 56/// Opaque types are also kinda weird and scary and different because they have 57/// to keep a list of uses of the type. When, through linking, parsing, or 58/// bytecode reading, they become resolved, they need to find and update all 59/// users of the unknown type, causing them to reference a new, more concrete 60/// type. Opaque types are deleted when their use list dwindles to zero users. 61/// 62/// @brief Root of type hierarchy 63class Type : public AbstractTypeUser { 64public: 65 ///===-------------------------------------------------------------------===// 66 /// Definitions of all of the base types for the Type system. Based on this 67 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h) 68 /// Note: If you add an element to this, you need to add an element to the 69 /// Type::getPrimitiveType function, or else things will break! 70 /// 71 enum TypeID { 72 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date 73 VoidTyID = 0 , BoolTyID, // 0, 1: Basics... 74 UByteTyID , SByteTyID, // 2, 3: 8 bit types... 75 UShortTyID , ShortTyID, // 4, 5: 16 bit types... 76 UIntTyID , IntTyID, // 6, 7: 32 bit types... 77 ULongTyID , LongTyID, // 8, 9: 64 bit types... 78 FloatTyID , DoubleTyID, // 10,11: Floating point types... 79 LabelTyID , // 12 : Labels... 80 81 // Derived types... see DerivedTypes.h file... 82 // Make sure FirstDerivedTyID stays up to date!!! 83 FunctionTyID , StructTyID, // Functions... Structs... 84 ArrayTyID , PointerTyID, // Array... pointer... 85 OpaqueTyID, // Opaque type instances... 86 PackedTyID, // SIMD 'packed' format... 87 //... 88 89 NumTypeIDs, // Must remain as last defined ID 90 LastPrimitiveTyID = LabelTyID, 91 FirstDerivedTyID = FunctionTyID 92 }; 93 94private: 95 TypeID ID : 8; // The current base type of this type. 96 bool Abstract : 1; // True if type contains an OpaqueType 97 98 /// RefCount - This counts the number of PATypeHolders that are pointing to 99 /// this type. When this number falls to zero, if the type is abstract and 100 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for 101 /// derived types. 102 /// 103 mutable unsigned RefCount; 104 105 const Type *getForwardedTypeInternal() const; 106protected: 107 Type(const char *Name, TypeID id); 108 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {} 109 virtual ~Type() { 110 assert(AbstractTypeUsers.empty()); 111 } 112 113 /// Types can become nonabstract later, if they are refined. 114 /// 115 inline void setAbstract(bool Val) { Abstract = Val; } 116 117 unsigned getRefCount() const { return RefCount; } 118 119 /// ForwardType - This field is used to implement the union find scheme for 120 /// abstract types. When types are refined to other types, this field is set 121 /// to the more refined type. Only abstract types can be forwarded. 122 mutable const Type *ForwardType; 123 124 /// ContainedTys - The list of types contained by this one. For example, this 125 /// includes the arguments of a function type, the elements of the structure, 126 /// the pointee of a pointer, etc. Note that keeping this vector in the Type 127 /// class wastes some space for types that do not contain anything (such as 128 /// primitive types). However, keeping it here allows the subtype_* members 129 /// to be implemented MUCH more efficiently, and dynamically very few types do 130 /// not contain any elements (most are derived). 131 std::vector<PATypeHandle> ContainedTys; 132 133 /// AbstractTypeUsers - Implement a list of the users that need to be notified 134 /// if I am a type, and I get resolved into a more concrete type. 135 /// 136 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 137public: 138 void print(std::ostream &O) const; 139 140 /// @brief Debugging support: print to stderr 141 void dump() const; 142 143 //===--------------------------------------------------------------------===// 144 // Property accessors for dealing with types... Some of these virtual methods 145 // are defined in private classes defined in Type.cpp for primitive types. 146 // 147 148 /// getTypeID - Return the type id for the type. This will return one 149 /// of the TypeID enum elements defined above. 150 /// 151 inline TypeID getTypeID() const { return ID; } 152 153 /// getDescription - Return the string representation of the type... 154 const std::string &getDescription() const; 155 156 /// isSigned - Return whether an integral numeric type is signed. This is 157 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for 158 /// Float and Double. 159 /// 160 bool isSigned() const { 161 return ID == SByteTyID || ID == ShortTyID || 162 ID == IntTyID || ID == LongTyID; 163 } 164 165 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite 166 /// the complement of isSigned... nonnumeric types return false as they do 167 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and 168 /// ULongTy 169 /// 170 bool isUnsigned() const { 171 return ID == UByteTyID || ID == UShortTyID || 172 ID == UIntTyID || ID == ULongTyID; 173 } 174 175 /// isInteger - Equivalent to isSigned() || isUnsigned() 176 /// 177 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; } 178 179 /// isIntegral - Returns true if this is an integral type, which is either 180 /// BoolTy or one of the Integer types. 181 /// 182 bool isIntegral() const { return isInteger() || this == BoolTy; } 183 184 /// isFloatingPoint - Return true if this is one of the two floating point 185 /// types 186 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; } 187 188 /// isAbstract - True if the type is either an Opaque type, or is a derived 189 /// type that includes an opaque type somewhere in it. 190 /// 191 inline bool isAbstract() const { return Abstract; } 192 193 /// isLosslesslyConvertibleTo - Return true if this type can be converted to 194 /// 'Ty' without any reinterpretation of bits. For example, uint to int. 195 /// 196 bool isLosslesslyConvertibleTo(const Type *Ty) const; 197 198 199 /// Here are some useful little methods to query what type derived types are 200 /// Note that all other types can just compare to see if this == Type::xxxTy; 201 /// 202 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 203 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 204 205 /// isFirstClassType - Return true if the value is holdable in a register. 206 /// 207 inline bool isFirstClassType() const { 208 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 209 ID == PointerTyID || ID == PackedTyID; 210 } 211 212 /// isSized - Return true if it makes sense to take the size of this type. To 213 /// get the actual size for a particular target, it is reasonable to use the 214 /// TargetData subsystem to do this. 215 /// 216 bool isSized() const { 217 // If it's a primitive, it is always sized. 218 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID) 219 return true; 220 // If it is not something that can have a size (e.g. a function or label), 221 // it doesn't have a size. 222 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID) 223 return false; 224 // If it is something that can have a size and it's concrete, it definitely 225 // has a size, otherwise we have to try harder to decide. 226 return !isAbstract() || isSizedDerivedType(); 227 } 228 229 /// getPrimitiveSize - Return the basic size of this type if it is a primitive 230 /// type. These are fixed by LLVM and are not target dependent. This will 231 /// return zero if the type does not have a size or is not a primitive type. 232 /// 233 unsigned getPrimitiveSize() const; 234 unsigned getPrimitiveSizeInBits() const; 235 236 /// getUnsignedVersion - If this is an integer type, return the unsigned 237 /// variant of this type. For example int -> uint. 238 const Type *getUnsignedVersion() const; 239 240 /// getSignedVersion - If this is an integer type, return the signed variant 241 /// of this type. For example uint -> int. 242 const Type *getSignedVersion() const; 243 244 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits 245 /// that can be set by an unsigned version of this type. This is 0xFF for 246 /// sbyte/ubyte, 0xFFFF for shorts, etc. 247 uint64_t getIntegralTypeMask() const { 248 assert(isIntegral() && "This only works for integral types!"); 249 return ~uint64_t(0UL) >> (64-getPrimitiveSizeInBits()); 250 } 251 252 /// getForwaredType - Return the type that this type has been resolved to if 253 /// it has been resolved to anything. This is used to implement the 254 /// union-find algorithm for type resolution, and shouldn't be used by general 255 /// purpose clients. 256 const Type *getForwardedType() const { 257 if (!ForwardType) return 0; 258 return getForwardedTypeInternal(); 259 } 260 261 /// getVAArgsPromotedType - Return the type an argument of this type 262 /// will be promoted to if passed through a variable argument 263 /// function. 264 const Type *getVAArgsPromotedType() const { 265 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID) 266 return Type::UIntTy; 267 else if (ID == SByteTyID || ID == ShortTyID) 268 return Type::IntTy; 269 else if (ID == FloatTyID) 270 return Type::DoubleTy; 271 else 272 return this; 273 } 274 275 //===--------------------------------------------------------------------===// 276 // Type Iteration support 277 // 278 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator; 279 subtype_iterator subtype_begin() const { return ContainedTys.begin(); } 280 subtype_iterator subtype_end() const { return ContainedTys.end(); } 281 282 /// getContainedType - This method is used to implement the type iterator 283 /// (defined a the end of the file). For derived types, this returns the 284 /// types 'contained' in the derived type. 285 /// 286 const Type *getContainedType(unsigned i) const { 287 assert(i < ContainedTys.size() && "Index out of range!"); 288 return ContainedTys[i]; 289 } 290 291 /// getNumContainedTypes - Return the number of types in the derived type. 292 /// 293 typedef std::vector<PATypeHandle>::size_type size_type; 294 size_type getNumContainedTypes() const { return ContainedTys.size(); } 295 296 //===--------------------------------------------------------------------===// 297 // Static members exported by the Type class itself. Useful for getting 298 // instances of Type. 299 // 300 301 /// getPrimitiveType - Return a type based on an identifier. 302 static const Type *getPrimitiveType(TypeID IDNumber); 303 304 //===--------------------------------------------------------------------===// 305 // These are the builtin types that are always available... 306 // 307 static Type *VoidTy , *BoolTy; 308 static Type *SByteTy, *UByteTy, 309 *ShortTy, *UShortTy, 310 *IntTy , *UIntTy, 311 *LongTy , *ULongTy; 312 static Type *FloatTy, *DoubleTy; 313 314 static Type* LabelTy; 315 316 /// Methods for support type inquiry through isa, cast, and dyn_cast: 317 static inline bool classof(const Type *T) { return true; } 318 319 void addRef() const { 320 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 321 ++RefCount; 322 } 323 324 void dropRef() const { 325 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 326 assert(RefCount && "No objects are currently referencing this object!"); 327 328 // If this is the last PATypeHolder using this object, and there are no 329 // PATypeHandles using it, the type is dead, delete it now. 330 if (--RefCount == 0 && AbstractTypeUsers.empty()) 331 delete this; 332 } 333 334 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 335 /// it. This function is called primarily by the PATypeHandle class. 336 /// 337 void addAbstractTypeUser(AbstractTypeUser *U) const { 338 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!"); 339 AbstractTypeUsers.push_back(U); 340 } 341 342 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 343 /// no longer has a handle to the type. This function is called primarily by 344 /// the PATypeHandle class. When there are no users of the abstract type, it 345 /// is annihilated, because there is no way to get a reference to it ever 346 /// again. 347 /// 348 void removeAbstractTypeUser(AbstractTypeUser *U) const; 349 350 /// clearAllTypeMaps - This method frees all internal memory used by the 351 /// type subsystem, which can be used in environments where this memory is 352 /// otherwise reported as a leak. 353 static void clearAllTypeMaps(); 354 355private: 356 /// isSizedDerivedType - Derived types like structures and arrays are sized 357 /// iff all of the members of the type are sized as well. Since asking for 358 /// their size is relatively uncommon, move this operation out of line. 359 bool isSizedDerivedType() const; 360 361 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 362 virtual void typeBecameConcrete(const DerivedType *AbsTy); 363 364protected: 365 // PromoteAbstractToConcrete - This is an internal method used to calculate 366 // change "Abstract" from true to false when types are refined. 367 void PromoteAbstractToConcrete(); 368 friend class TypeMapBase; 369}; 370 371//===----------------------------------------------------------------------===// 372// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 373// These are defined here because they MUST be inlined, yet are dependent on 374// the definition of the Type class. 375// 376inline void PATypeHandle::addUser() { 377 assert(Ty && "Type Handle has a null type!"); 378 if (Ty->isAbstract()) 379 Ty->addAbstractTypeUser(User); 380} 381inline void PATypeHandle::removeUser() { 382 if (Ty->isAbstract()) 383 Ty->removeAbstractTypeUser(User); 384} 385 386// Define inline methods for PATypeHolder... 387 388inline void PATypeHolder::addRef() { 389 if (Ty->isAbstract()) 390 Ty->addRef(); 391} 392 393inline void PATypeHolder::dropRef() { 394 if (Ty->isAbstract()) 395 Ty->dropRef(); 396} 397 398 399//===----------------------------------------------------------------------===// 400// Provide specializations of GraphTraits to be able to treat a type as a 401// graph of sub types... 402 403template <> struct GraphTraits<Type*> { 404 typedef Type NodeType; 405 typedef Type::subtype_iterator ChildIteratorType; 406 407 static inline NodeType *getEntryNode(Type *T) { return T; } 408 static inline ChildIteratorType child_begin(NodeType *N) { 409 return N->subtype_begin(); 410 } 411 static inline ChildIteratorType child_end(NodeType *N) { 412 return N->subtype_end(); 413 } 414}; 415 416template <> struct GraphTraits<const Type*> { 417 typedef const Type NodeType; 418 typedef Type::subtype_iterator ChildIteratorType; 419 420 static inline NodeType *getEntryNode(const Type *T) { return T; } 421 static inline ChildIteratorType child_begin(NodeType *N) { 422 return N->subtype_begin(); 423 } 424 static inline ChildIteratorType child_end(NodeType *N) { 425 return N->subtype_end(); 426 } 427}; 428 429template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 430 return Ty.getTypeID() == Type::PointerTyID; 431} 432 433std::ostream &operator<<(std::ostream &OS, const Type &T); 434 435} // End llvm namespace 436 437#endif 438