Type.h revision 375c032468ed91991cb15edd415222815d91a3ca
1//===-- llvm/Type.h - Classes for handling data types -----------*- 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 11#ifndef LLVM_TYPE_H 12#define LLVM_TYPE_H 13 14#include "llvm/AbstractTypeUser.h" 15#include "llvm/LLVMContext.h" 16#include "llvm/Support/Casting.h" 17#include "llvm/Support/DataTypes.h" 18#include "llvm/System/Atomic.h" 19#include "llvm/ADT/GraphTraits.h" 20#include <string> 21#include <vector> 22 23namespace llvm { 24 25class DerivedType; 26class PointerType; 27class IntegerType; 28class TypeMapBase; 29class raw_ostream; 30class Module; 31 32/// This file contains the declaration of the Type class. For more "Type" type 33/// stuff, look in DerivedTypes.h. 34/// 35/// The instances of the Type class are immutable: once they are created, 36/// they are never changed. Also note that only one instance of a particular 37/// type is ever created. Thus seeing if two types are equal is a matter of 38/// doing a trivial pointer comparison. To enforce that no two equal instances 39/// are created, Type instances can only be created via static factory methods 40/// in class Type and in derived classes. 41/// 42/// Once allocated, Types are never free'd, unless they are an abstract type 43/// that is resolved to a more concrete type. 44/// 45/// Types themself don't have a name, and can be named either by: 46/// - using SymbolTable instance, typically from some Module, 47/// - using convenience methods in the Module class (which uses module's 48/// SymbolTable too). 49/// 50/// Opaque types are simple derived types with no state. There may be many 51/// different Opaque type objects floating around, but two are only considered 52/// identical if they are pointer equals of each other. This allows us to have 53/// two opaque types that end up resolving to different concrete types later. 54/// 55/// Opaque types are also kinda weird and scary and different because they have 56/// to keep a list of uses of the type. When, through linking, parsing, or 57/// bitcode reading, they become resolved, they need to find and update all 58/// users of the unknown type, causing them to reference a new, more concrete 59/// type. Opaque types are deleted when their use list dwindles to zero users. 60/// 61/// @brief Root of type hierarchy 62class Type : public AbstractTypeUser { 63public: 64 //===-------------------------------------------------------------------===// 65 /// Definitions of all of the base types for the Type system. Based on this 66 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h) 67 /// Note: If you add an element to this, you need to add an element to the 68 /// Type::getPrimitiveType function, or else things will break! 69 /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding. 70 /// 71 enum TypeID { 72 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date 73 VoidTyID = 0, ///< 0: type with no size 74 FloatTyID, ///< 1: 32 bit floating point type 75 DoubleTyID, ///< 2: 64 bit floating point type 76 X86_FP80TyID, ///< 3: 80 bit floating point type (X87) 77 FP128TyID, ///< 4: 128 bit floating point type (112-bit mantissa) 78 PPC_FP128TyID, ///< 5: 128 bit floating point type (two 64-bits) 79 LabelTyID, ///< 6: Labels 80 MetadataTyID, ///< 7: Metadata 81 82 // Derived types... see DerivedTypes.h file... 83 // Make sure FirstDerivedTyID stays up to date!!! 84 IntegerTyID, ///< 8: Arbitrary bit width integers 85 FunctionTyID, ///< 9: Functions 86 StructTyID, ///< 10: Structures 87 ArrayTyID, ///< 11: Arrays 88 PointerTyID, ///< 12: Pointers 89 OpaqueTyID, ///< 13: Opaque: type with unknown structure 90 VectorTyID, ///< 14: SIMD 'packed' format, or other vector type 91 92 NumTypeIDs, // Must remain as last defined ID 93 LastPrimitiveTyID = LabelTyID, 94 FirstDerivedTyID = IntegerTyID 95 }; 96 97private: 98 TypeID ID : 8; // The current base type of this type. 99 bool Abstract : 1; // True if type contains an OpaqueType 100 unsigned SubclassData : 23; //Space for subclasses to store data 101 102 /// RefCount - This counts the number of PATypeHolders that are pointing to 103 /// this type. When this number falls to zero, if the type is abstract and 104 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for 105 /// derived types. 106 /// 107 mutable sys::cas_flag RefCount; 108 109 /// Context - This refers to the LLVMContext in which this type was uniqued. 110 LLVMContext &Context; 111 friend class LLVMContextImpl; 112 113 const Type *getForwardedTypeInternal() const; 114 115 // Some Type instances are allocated as arrays, some aren't. So we provide 116 // this method to get the right kind of destruction for the type of Type. 117 void destroy() const; // const is a lie, this does "delete this"! 118 119protected: 120 explicit Type(LLVMContext &C, TypeID id) : 121 ID(id), Abstract(false), SubclassData(0), 122 RefCount(0), Context(C), 123 ForwardType(0), NumContainedTys(0), 124 ContainedTys(0) {} 125 virtual ~Type() { 126 assert(AbstractTypeUsers.empty() && "Abstract types remain"); 127 } 128 129 /// Types can become nonabstract later, if they are refined. 130 /// 131 inline void setAbstract(bool Val) { Abstract = Val; } 132 133 unsigned getRefCount() const { return RefCount; } 134 135 unsigned getSubclassData() const { return SubclassData; } 136 void setSubclassData(unsigned val) { SubclassData = val; } 137 138 /// ForwardType - This field is used to implement the union find scheme for 139 /// abstract types. When types are refined to other types, this field is set 140 /// to the more refined type. Only abstract types can be forwarded. 141 mutable const Type *ForwardType; 142 143 144 /// AbstractTypeUsers - Implement a list of the users that need to be notified 145 /// if I am a type, and I get resolved into a more concrete type. 146 /// 147 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 148 149 /// NumContainedTys - Keeps track of how many PATypeHandle instances there 150 /// are at the end of this type instance for the list of contained types. It 151 /// is the subclasses responsibility to set this up. Set to 0 if there are no 152 /// contained types in this type. 153 unsigned NumContainedTys; 154 155 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained 156 /// by this Type. For example, this includes the arguments of a function 157 /// type, the elements of a structure, the pointee of a pointer, the element 158 /// type of an array, etc. This pointer may be 0 for types that don't 159 /// contain other types (Integer, Double, Float). In general, the subclass 160 /// should arrange for space for the PATypeHandles to be included in the 161 /// allocation of the type object and set this pointer to the address of the 162 /// first element. This allows the Type class to manipulate the ContainedTys 163 /// without understanding the subclass's placement for this array. keeping 164 /// it here also allows the subtype_* members to be implemented MUCH more 165 /// efficiently, and dynamically very few types do not contain any elements. 166 PATypeHandle *ContainedTys; 167 168public: 169 void print(raw_ostream &O) const; 170 171 /// @brief Debugging support: print to stderr 172 void dump() const; 173 174 /// @brief Debugging support: print to stderr (use type names from context 175 /// module). 176 void dump(const Module *Context) const; 177 178 /// getContext - Fetch the LLVMContext in which this type was uniqued. 179 LLVMContext &getContext() const { return Context; } 180 181 //===--------------------------------------------------------------------===// 182 // Property accessors for dealing with types... Some of these virtual methods 183 // are defined in private classes defined in Type.cpp for primitive types. 184 // 185 186 /// getTypeID - Return the type id for the type. This will return one 187 /// of the TypeID enum elements defined above. 188 /// 189 inline TypeID getTypeID() const { return ID; } 190 191 /// getDescription - Return the string representation of the type. 192 std::string getDescription() const; 193 194 /// isInteger - True if this is an instance of IntegerType. 195 /// 196 bool isInteger() const { return ID == IntegerTyID; } 197 198 /// isIntOrIntVector - Return true if this is an integer type or a vector of 199 /// integer types. 200 /// 201 bool isIntOrIntVector() const; 202 203 /// isFloatingPoint - Return true if this is one of the five floating point 204 /// types 205 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID || 206 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; } 207 208 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type. 209 bool isFloatTy() const { return ID == FloatTyID; } 210 211 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type. 212 bool isDoubleTy() const { return ID == DoubleTyID; } 213 214 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types. 215 /// 216 bool isFPOrFPVector() const; 217 218 /// isAbstract - True if the type is either an Opaque type, or is a derived 219 /// type that includes an opaque type somewhere in it. 220 /// 221 inline bool isAbstract() const { return Abstract; } 222 223 /// canLosslesslyBitCastTo - Return true if this type could be converted 224 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts 225 /// are valid for types of the same size only where no re-interpretation of 226 /// the bits is done. 227 /// @brief Determine if this type could be losslessly bitcast to Ty 228 bool canLosslesslyBitCastTo(const Type *Ty) const; 229 230 231 /// Here are some useful little methods to query what type derived types are 232 /// Note that all other types can just compare to see if this == Type::xxxTy; 233 /// 234 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 235 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 236 237 /// isFirstClassType - Return true if the type is "first class", meaning it 238 /// is a valid type for a Value. 239 /// 240 inline bool isFirstClassType() const { 241 // There are more first-class kinds than non-first-class kinds, so a 242 // negative test is simpler than a positive one. 243 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID; 244 } 245 246 /// isSingleValueType - Return true if the type is a valid type for a 247 /// virtual register in codegen. This includes all first-class types 248 /// except struct and array types. 249 /// 250 inline bool isSingleValueType() const { 251 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 252 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID; 253 } 254 255 /// isAggregateType - Return true if the type is an aggregate type. This 256 /// means it is valid as the first operand of an insertvalue or 257 /// extractvalue instruction. This includes struct and array types, but 258 /// does not include vector types. 259 /// 260 inline bool isAggregateType() const { 261 return ID == StructTyID || ID == ArrayTyID; 262 } 263 264 /// isSized - Return true if it makes sense to take the size of this type. To 265 /// get the actual size for a particular target, it is reasonable to use the 266 /// TargetData subsystem to do this. 267 /// 268 bool isSized() const { 269 // If it's a primitive, it is always sized. 270 if (ID == IntegerTyID || isFloatingPoint() || ID == PointerTyID) 271 return true; 272 // If it is not something that can have a size (e.g. a function or label), 273 // it doesn't have a size. 274 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID) 275 return false; 276 // If it is something that can have a size and it's concrete, it definitely 277 // has a size, otherwise we have to try harder to decide. 278 return !isAbstract() || isSizedDerivedType(); 279 } 280 281 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a 282 /// primitive type. These are fixed by LLVM and are not target dependent. 283 /// This will return zero if the type does not have a size or is not a 284 /// primitive type. 285 /// 286 /// Note that this may not reflect the size of memory allocated for an 287 /// instance of the type or the number of bytes that are written when an 288 /// instance of the type is stored to memory. The TargetData class provides 289 /// additional query functions to provide this information. 290 /// 291 unsigned getPrimitiveSizeInBits() const; 292 293 /// getScalarSizeInBits - If this is a vector type, return the 294 /// getPrimitiveSizeInBits value for the element type. Otherwise return the 295 /// getPrimitiveSizeInBits value for this type. 296 unsigned getScalarSizeInBits() const; 297 298 /// getFPMantissaWidth - Return the width of the mantissa of this type. This 299 /// is only valid on floating point types. If the FP type does not 300 /// have a stable mantissa (e.g. ppc long double), this method returns -1. 301 int getFPMantissaWidth() const; 302 303 /// getForwardedType - Return the type that this type has been resolved to if 304 /// it has been resolved to anything. This is used to implement the 305 /// union-find algorithm for type resolution, and shouldn't be used by general 306 /// purpose clients. 307 const Type *getForwardedType() const { 308 if (!ForwardType) return 0; 309 return getForwardedTypeInternal(); 310 } 311 312 /// getVAArgsPromotedType - Return the type an argument of this type 313 /// will be promoted to if passed through a variable argument 314 /// function. 315 const Type *getVAArgsPromotedType(LLVMContext &C) const; 316 317 /// getScalarType - If this is a vector type, return the element type, 318 /// otherwise return this. 319 const Type *getScalarType() const; 320 321 //===--------------------------------------------------------------------===// 322 // Type Iteration support 323 // 324 typedef PATypeHandle *subtype_iterator; 325 subtype_iterator subtype_begin() const { return ContainedTys; } 326 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];} 327 328 /// getContainedType - This method is used to implement the type iterator 329 /// (defined a the end of the file). For derived types, this returns the 330 /// types 'contained' in the derived type. 331 /// 332 const Type *getContainedType(unsigned i) const { 333 assert(i < NumContainedTys && "Index out of range!"); 334 return ContainedTys[i].get(); 335 } 336 337 /// getNumContainedTypes - Return the number of types in the derived type. 338 /// 339 unsigned getNumContainedTypes() const { return NumContainedTys; } 340 341 //===--------------------------------------------------------------------===// 342 // Static members exported by the Type class itself. Useful for getting 343 // instances of Type. 344 // 345 346 /// getPrimitiveType - Return a type based on an identifier. 347 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber); 348 349 //===--------------------------------------------------------------------===// 350 // These are the builtin types that are always available... 351 // 352 static const Type *getVoidTy(LLVMContext &C); 353 static const Type *getLabelTy(LLVMContext &C); 354 static const Type *getFloatTy(LLVMContext &C); 355 static const Type *getDoubleTy(LLVMContext &C); 356 static const Type *getMetadataTy(LLVMContext &C); 357 static const Type *getX86_FP80Ty(LLVMContext &C); 358 static const Type *getFP128Ty(LLVMContext &C); 359 static const Type *getPPC_FP128Ty(LLVMContext &C); 360 static const IntegerType *getInt1Ty(LLVMContext &C); 361 static const IntegerType *getInt8Ty(LLVMContext &C); 362 static const IntegerType *getInt16Ty(LLVMContext &C); 363 static const IntegerType *getInt32Ty(LLVMContext &C); 364 static const IntegerType *getInt64Ty(LLVMContext &C); 365 366 /// Methods for support type inquiry through isa, cast, and dyn_cast: 367 static inline bool classof(const Type *) { return true; } 368 369 void addRef() const { 370 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 371 sys::AtomicIncrement(&RefCount); 372 } 373 374 void dropRef() const { 375 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 376 assert(RefCount && "No objects are currently referencing this object!"); 377 378 // If this is the last PATypeHolder using this object, and there are no 379 // PATypeHandles using it, the type is dead, delete it now. 380 sys::cas_flag OldCount = sys::AtomicDecrement(&RefCount); 381 if (OldCount == 0 && AbstractTypeUsers.empty()) 382 this->destroy(); 383 } 384 385 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 386 /// it. This function is called primarily by the PATypeHandle class. 387 /// 388 void addAbstractTypeUser(AbstractTypeUser *U) const; 389 390 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 391 /// no longer has a handle to the type. This function is called primarily by 392 /// the PATypeHandle class. When there are no users of the abstract type, it 393 /// is annihilated, because there is no way to get a reference to it ever 394 /// again. 395 /// 396 void removeAbstractTypeUser(AbstractTypeUser *U) const; 397 398 /// getPointerTo - Return a pointer to the current type. This is equivalent 399 /// to PointerType::get(Foo, AddrSpace). 400 PointerType *getPointerTo(unsigned AddrSpace = 0) const; 401 402private: 403 /// isSizedDerivedType - Derived types like structures and arrays are sized 404 /// iff all of the members of the type are sized as well. Since asking for 405 /// their size is relatively uncommon, move this operation out of line. 406 bool isSizedDerivedType() const; 407 408 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 409 virtual void typeBecameConcrete(const DerivedType *AbsTy); 410 411protected: 412 // PromoteAbstractToConcrete - This is an internal method used to calculate 413 // change "Abstract" from true to false when types are refined. 414 void PromoteAbstractToConcrete(); 415 friend class TypeMapBase; 416}; 417 418//===----------------------------------------------------------------------===// 419// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 420// These are defined here because they MUST be inlined, yet are dependent on 421// the definition of the Type class. 422// 423inline void PATypeHandle::addUser() { 424 assert(Ty && "Type Handle has a null type!"); 425 if (Ty->isAbstract()) 426 Ty->addAbstractTypeUser(User); 427} 428inline void PATypeHandle::removeUser() { 429 if (Ty->isAbstract()) 430 Ty->removeAbstractTypeUser(User); 431} 432 433// Define inline methods for PATypeHolder. 434 435/// get - This implements the forwarding part of the union-find algorithm for 436/// abstract types. Before every access to the Type*, we check to see if the 437/// type we are pointing to is forwarding to a new type. If so, we drop our 438/// reference to the type. 439/// 440inline Type* PATypeHolder::get() const { 441 const Type *NewTy = Ty->getForwardedType(); 442 if (!NewTy) return const_cast<Type*>(Ty); 443 return *const_cast<PATypeHolder*>(this) = NewTy; 444} 445 446inline void PATypeHolder::addRef() { 447 assert(Ty && "Type Holder has a null type!"); 448 if (Ty->isAbstract()) 449 Ty->addRef(); 450} 451 452inline void PATypeHolder::dropRef() { 453 if (Ty->isAbstract()) 454 Ty->dropRef(); 455} 456 457 458//===----------------------------------------------------------------------===// 459// Provide specializations of GraphTraits to be able to treat a type as a 460// graph of sub types... 461 462template <> struct GraphTraits<Type*> { 463 typedef Type NodeType; 464 typedef Type::subtype_iterator ChildIteratorType; 465 466 static inline NodeType *getEntryNode(Type *T) { return T; } 467 static inline ChildIteratorType child_begin(NodeType *N) { 468 return N->subtype_begin(); 469 } 470 static inline ChildIteratorType child_end(NodeType *N) { 471 return N->subtype_end(); 472 } 473}; 474 475template <> struct GraphTraits<const Type*> { 476 typedef const Type NodeType; 477 typedef Type::subtype_iterator ChildIteratorType; 478 479 static inline NodeType *getEntryNode(const Type *T) { return T; } 480 static inline ChildIteratorType child_begin(NodeType *N) { 481 return N->subtype_begin(); 482 } 483 static inline ChildIteratorType child_end(NodeType *N) { 484 return N->subtype_end(); 485 } 486}; 487 488template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 489 return Ty.getTypeID() == Type::PointerTyID; 490} 491 492raw_ostream &operator<<(raw_ostream &OS, const Type &T); 493 494} // End llvm namespace 495 496#endif 497