Type.h revision 5c7e326585f3a543388ba871c3425f7664cd9143
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 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 /// isSigned - Return whether an integral numeric type is signed. This is 164 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for 165 /// Float and Double. 166 /// 167 bool isSigned() const { 168 return ID == SByteTyID || ID == ShortTyID || 169 ID == IntTyID || ID == LongTyID; 170 } 171 172 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite 173 /// the complement of isSigned... nonnumeric types return false as they do 174 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and 175 /// ULongTy 176 /// 177 bool isUnsigned() const { 178 return ID == UByteTyID || ID == UShortTyID || 179 ID == UIntTyID || ID == ULongTyID; 180 } 181 182 /// isInteger - Equivalent to isSigned() || isUnsigned() 183 /// 184 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; } 185 186 /// isIntegral - Returns true if this is an integral type, which is either 187 /// BoolTy or one of the Integer types. 188 /// 189 bool isIntegral() const { return isInteger() || this == BoolTy; } 190 191 /// isFloatingPoint - Return true if this is one of the two floating point 192 /// types 193 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; } 194 195 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types. 196 /// 197 bool isFPOrFPVector() const; 198 199 /// isAbstract - True if the type is either an Opaque type, or is a derived 200 /// type that includes an opaque type somewhere in it. 201 /// 202 inline bool isAbstract() const { return Abstract; } 203 204 /// canLosslesslyBitCastTo - Return true if this type could be converted 205 /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts 206 /// are valid for types of the same size only where no re-interpretation of 207 /// the bits is done. 208 /// @brief Determine if this type could be losslessly bitcast to Ty 209 bool canLosslesslyBitCastTo(const Type *Ty) const; 210 211 212 /// Here are some useful little methods to query what type derived types are 213 /// Note that all other types can just compare to see if this == Type::xxxTy; 214 /// 215 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 216 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 217 218 /// isFirstClassType - Return true if the value is holdable in a register. 219 /// 220 inline bool isFirstClassType() const { 221 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 222 ID == PointerTyID || ID == PackedTyID; 223 } 224 225 /// isSized - Return true if it makes sense to take the size of this type. To 226 /// get the actual size for a particular target, it is reasonable to use the 227 /// TargetData subsystem to do this. 228 /// 229 bool isSized() const { 230 // If it's a primitive, it is always sized. 231 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID) 232 return true; 233 // If it is not something that can have a size (e.g. a function or label), 234 // it doesn't have a size. 235 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID) 236 return false; 237 // If it is something that can have a size and it's concrete, it definitely 238 // has a size, otherwise we have to try harder to decide. 239 return !isAbstract() || isSizedDerivedType(); 240 } 241 242 /// getPrimitiveSize - Return the basic size of this type if it is a primitive 243 /// type. These are fixed by LLVM and are not target dependent. This will 244 /// return zero if the type does not have a size or is not a primitive type. 245 /// 246 unsigned getPrimitiveSize() const; 247 unsigned getPrimitiveSizeInBits() const; 248 249 /// getUnsignedVersion - If this is an integer type, return the unsigned 250 /// variant of this type. For example int -> uint. 251 const Type *getUnsignedVersion() const; 252 253 /// getSignedVersion - If this is an integer type, return the signed variant 254 /// of this type. For example uint -> int. 255 const Type *getSignedVersion() const; 256 257 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits 258 /// that can be set by an unsigned version of this type. This is 0xFF for 259 /// sbyte/ubyte, 0xFFFF for shorts, etc. 260 uint64_t getIntegralTypeMask() const { 261 assert(isIntegral() && "This only works for integral types!"); 262 return ~uint64_t(0UL) >> (64-getPrimitiveSizeInBits()); 263 } 264 265 /// getForwaredType - Return the type that this type has been resolved to if 266 /// it has been resolved to anything. This is used to implement the 267 /// union-find algorithm for type resolution, and shouldn't be used by general 268 /// purpose clients. 269 const Type *getForwardedType() const { 270 if (!ForwardType) return 0; 271 return getForwardedTypeInternal(); 272 } 273 274 /// getVAArgsPromotedType - Return the type an argument of this type 275 /// will be promoted to if passed through a variable argument 276 /// function. 277 const Type *getVAArgsPromotedType() const { 278 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID) 279 return Type::UIntTy; 280 else if (ID == SByteTyID || ID == ShortTyID) 281 return Type::IntTy; 282 else if (ID == FloatTyID) 283 return Type::DoubleTy; 284 else 285 return this; 286 } 287 288 //===--------------------------------------------------------------------===// 289 // Type Iteration support 290 // 291 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator; 292 subtype_iterator subtype_begin() const { return ContainedTys.begin(); } 293 subtype_iterator subtype_end() const { return ContainedTys.end(); } 294 295 /// getContainedType - This method is used to implement the type iterator 296 /// (defined a the end of the file). For derived types, this returns the 297 /// types 'contained' in the derived type. 298 /// 299 const Type *getContainedType(unsigned i) const { 300 assert(i < ContainedTys.size() && "Index out of range!"); 301 return ContainedTys[i]; 302 } 303 304 /// getNumContainedTypes - Return the number of types in the derived type. 305 /// 306 typedef std::vector<PATypeHandle>::size_type size_type; 307 size_type getNumContainedTypes() const { return ContainedTys.size(); } 308 309 //===--------------------------------------------------------------------===// 310 // Static members exported by the Type class itself. Useful for getting 311 // instances of Type. 312 // 313 314 /// getPrimitiveType - Return a type based on an identifier. 315 static const Type *getPrimitiveType(TypeID IDNumber); 316 317 //===--------------------------------------------------------------------===// 318 // These are the builtin types that are always available... 319 // 320 static Type *VoidTy , *BoolTy; 321 static Type *SByteTy, *UByteTy, 322 *ShortTy, *UShortTy, 323 *IntTy , *UIntTy, 324 *LongTy , *ULongTy; 325 static Type *FloatTy, *DoubleTy; 326 327 static Type* LabelTy; 328 329 /// Methods for support type inquiry through isa, cast, and dyn_cast: 330 static inline bool classof(const Type *T) { return true; } 331 332 void addRef() const { 333 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 334 ++RefCount; 335 } 336 337 void dropRef() const { 338 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 339 assert(RefCount && "No objects are currently referencing this object!"); 340 341 // If this is the last PATypeHolder using this object, and there are no 342 // PATypeHandles using it, the type is dead, delete it now. 343 if (--RefCount == 0 && AbstractTypeUsers.empty()) 344 delete this; 345 } 346 347 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 348 /// it. This function is called primarily by the PATypeHandle class. 349 /// 350 void addAbstractTypeUser(AbstractTypeUser *U) const { 351 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!"); 352 AbstractTypeUsers.push_back(U); 353 } 354 355 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 356 /// no longer has a handle to the type. This function is called primarily by 357 /// the PATypeHandle class. When there are no users of the abstract type, it 358 /// is annihilated, because there is no way to get a reference to it ever 359 /// again. 360 /// 361 void removeAbstractTypeUser(AbstractTypeUser *U) const; 362 363private: 364 /// isSizedDerivedType - Derived types like structures and arrays are sized 365 /// iff all of the members of the type are sized as well. Since asking for 366 /// their size is relatively uncommon, move this operation out of line. 367 bool isSizedDerivedType() const; 368 369 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 370 virtual void typeBecameConcrete(const DerivedType *AbsTy); 371 372protected: 373 // PromoteAbstractToConcrete - This is an internal method used to calculate 374 // change "Abstract" from true to false when types are refined. 375 void PromoteAbstractToConcrete(); 376 friend class TypeMapBase; 377}; 378 379//===----------------------------------------------------------------------===// 380// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 381// These are defined here because they MUST be inlined, yet are dependent on 382// the definition of the Type class. 383// 384inline void PATypeHandle::addUser() { 385 assert(Ty && "Type Handle has a null type!"); 386 if (Ty->isAbstract()) 387 Ty->addAbstractTypeUser(User); 388} 389inline void PATypeHandle::removeUser() { 390 if (Ty->isAbstract()) 391 Ty->removeAbstractTypeUser(User); 392} 393 394// Define inline methods for PATypeHolder... 395 396inline void PATypeHolder::addRef() { 397 if (Ty->isAbstract()) 398 Ty->addRef(); 399} 400 401inline void PATypeHolder::dropRef() { 402 if (Ty->isAbstract()) 403 Ty->dropRef(); 404} 405 406 407//===----------------------------------------------------------------------===// 408// Provide specializations of GraphTraits to be able to treat a type as a 409// graph of sub types... 410 411template <> struct GraphTraits<Type*> { 412 typedef Type NodeType; 413 typedef Type::subtype_iterator ChildIteratorType; 414 415 static inline NodeType *getEntryNode(Type *T) { return T; } 416 static inline ChildIteratorType child_begin(NodeType *N) { 417 return N->subtype_begin(); 418 } 419 static inline ChildIteratorType child_end(NodeType *N) { 420 return N->subtype_end(); 421 } 422}; 423 424template <> struct GraphTraits<const Type*> { 425 typedef const Type NodeType; 426 typedef Type::subtype_iterator ChildIteratorType; 427 428 static inline NodeType *getEntryNode(const Type *T) { return T; } 429 static inline ChildIteratorType child_begin(NodeType *N) { 430 return N->subtype_begin(); 431 } 432 static inline ChildIteratorType child_end(NodeType *N) { 433 return N->subtype_end(); 434 } 435}; 436 437template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 438 return Ty.getTypeID() == Type::PointerTyID; 439} 440 441std::ostream &operator<<(std::ostream &OS, const Type &T); 442 443} // End llvm namespace 444 445#endif 446