Type.h revision 47c5188789bc40671504ed1fa3a44765cefba44f
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#ifndef LLVM_TYPE_H 11#define LLVM_TYPE_H 12 13#include "llvm/AbstractTypeUser.h" 14#include "llvm/Support/Casting.h" 15#include "llvm/System/DataTypes.h" 16#include "llvm/ADT/GraphTraits.h" 17#include <string> 18#include <vector> 19 20namespace llvm { 21 22class DerivedType; 23class PointerType; 24class IntegerType; 25class TypeMapBase; 26class raw_ostream; 27class Module; 28class LLVMContext; 29 30/// This file contains the declaration of the Type class. For more "Type" type 31/// stuff, look in DerivedTypes.h. 32/// 33/// The instances of the Type class are immutable: once they are created, 34/// they are never changed. Also note that only one instance of a particular 35/// type is ever created. Thus seeing if two types are equal is a matter of 36/// doing a trivial pointer comparison. To enforce that no two equal instances 37/// are created, Type instances can only be created via static factory methods 38/// in class Type and in derived classes. 39/// 40/// Once allocated, Types are never free'd, unless they are an abstract type 41/// that is resolved to a more concrete type. 42/// 43/// Types themself don't have a name, and can be named either by: 44/// - using SymbolTable instance, typically from some Module, 45/// - using convenience methods in the Module class (which uses module's 46/// SymbolTable too). 47/// 48/// Opaque types are simple derived types with no state. There may be many 49/// different Opaque type objects floating around, but two are only considered 50/// identical if they are pointer equals of each other. This allows us to have 51/// two opaque types that end up resolving to different concrete types later. 52/// 53/// Opaque types are also kinda weird and scary and different because they have 54/// to keep a list of uses of the type. When, through linking, parsing, or 55/// bitcode reading, they become resolved, they need to find and update all 56/// users of the unknown type, causing them to reference a new, more concrete 57/// type. Opaque types are deleted when their use list dwindles to zero users. 58/// 59/// @brief Root of type hierarchy 60class Type : public AbstractTypeUser { 61public: 62 //===-------------------------------------------------------------------===// 63 /// Definitions of all of the base types for the Type system. Based on this 64 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h) 65 /// Note: If you add an element to this, you need to add an element to the 66 /// Type::getPrimitiveType function, or else things will break! 67 /// Also update LLVMTypeKind and LLVMGetTypeKind () in the C binding. 68 /// 69 enum TypeID { 70 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date 71 VoidTyID = 0, ///< 0: type with no size 72 FloatTyID, ///< 1: 32 bit floating point type 73 DoubleTyID, ///< 2: 64 bit floating point type 74 X86_FP80TyID, ///< 3: 80 bit floating point type (X87) 75 FP128TyID, ///< 4: 128 bit floating point type (112-bit mantissa) 76 PPC_FP128TyID, ///< 5: 128 bit floating point type (two 64-bits) 77 LabelTyID, ///< 6: Labels 78 MetadataTyID, ///< 7: Metadata 79 80 // Derived types... see DerivedTypes.h file... 81 // Make sure FirstDerivedTyID stays up to date!!! 82 IntegerTyID, ///< 8: Arbitrary bit width integers 83 FunctionTyID, ///< 9: Functions 84 StructTyID, ///< 10: Structures 85 UnionTyID, ///< 11: Unions 86 ArrayTyID, ///< 12: Arrays 87 PointerTyID, ///< 13: Pointers 88 OpaqueTyID, ///< 14: Opaque: type with unknown structure 89 VectorTyID, ///< 15: SIMD 'packed' format, or other vector type 90 91 NumTypeIDs, // Must remain as last defined ID 92 LastPrimitiveTyID = LabelTyID, 93 FirstDerivedTyID = IntegerTyID 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 unsigned SubclassData : 23; //Space for subclasses to store data 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 /// Context - This refers to the LLVMContext in which this type was uniqued. 109 LLVMContext &Context; 110 friend class LLVMContextImpl; 111 112 const Type *getForwardedTypeInternal() const; 113 114 // Some Type instances are allocated as arrays, some aren't. So we provide 115 // this method to get the right kind of destruction for the type of Type. 116 void destroy() const; // const is a lie, this does "delete this"! 117 118protected: 119 explicit Type(LLVMContext &C, TypeID id) : 120 ID(id), Abstract(false), SubclassData(0), 121 RefCount(0), Context(C), 122 ForwardType(0), NumContainedTys(0), 123 ContainedTys(0) {} 124 virtual ~Type() { 125 assert(AbstractTypeUsers.empty() && "Abstract types remain"); 126 } 127 128 /// Types can become nonabstract later, if they are refined. 129 /// 130 inline void setAbstract(bool Val) { Abstract = Val; } 131 132 unsigned getRefCount() const { return RefCount; } 133 134 unsigned getSubclassData() const { return SubclassData; } 135 void setSubclassData(unsigned val) { SubclassData = val; } 136 137 /// ForwardType - This field is used to implement the union find scheme for 138 /// abstract types. When types are refined to other types, this field is set 139 /// to the more refined type. Only abstract types can be forwarded. 140 mutable const Type *ForwardType; 141 142 143 /// AbstractTypeUsers - Implement a list of the users that need to be notified 144 /// if I am a type, and I get resolved into a more concrete type. 145 /// 146 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 147 148 /// NumContainedTys - Keeps track of how many PATypeHandle instances there 149 /// are at the end of this type instance for the list of contained types. It 150 /// is the subclasses responsibility to set this up. Set to 0 if there are no 151 /// contained types in this type. 152 unsigned NumContainedTys; 153 154 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained 155 /// by this Type. For example, this includes the arguments of a function 156 /// type, the elements of a structure, the pointee of a pointer, the element 157 /// type of an array, etc. This pointer may be 0 for types that don't 158 /// contain other types (Integer, Double, Float). In general, the subclass 159 /// should arrange for space for the PATypeHandles to be included in the 160 /// allocation of the type object and set this pointer to the address of the 161 /// first element. This allows the Type class to manipulate the ContainedTys 162 /// without understanding the subclass's placement for this array. keeping 163 /// it here also allows the subtype_* members to be implemented MUCH more 164 /// efficiently, and dynamically very few types do not contain any elements. 165 PATypeHandle *ContainedTys; 166 167public: 168 void print(raw_ostream &O) const; 169 170 /// @brief Debugging support: print to stderr 171 void dump() const; 172 173 /// @brief Debugging support: print to stderr (use type names from context 174 /// module). 175 void dump(const Module *Context) const; 176 177 /// getContext - Fetch the LLVMContext in which this type was uniqued. 178 LLVMContext &getContext() const { return Context; } 179 180 //===--------------------------------------------------------------------===// 181 // Property accessors for dealing with types... Some of these virtual methods 182 // are defined in private classes defined in Type.cpp for primitive types. 183 // 184 185 /// getDescription - Return the string representation of the type. 186 std::string getDescription() const; 187 188 /// getTypeID - Return the type id for the type. This will return one 189 /// of the TypeID enum elements defined above. 190 /// 191 inline TypeID getTypeID() const { return ID; } 192 193 /// isVoidTy - Return true if this is 'void'. 194 bool isVoidTy() const { return ID == VoidTyID; } 195 196 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type. 197 bool isFloatTy() const { return ID == FloatTyID; } 198 199 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type. 200 bool isDoubleTy() const { return ID == DoubleTyID; } 201 202 /// isX86_FP80Ty - Return true if this is x86 long double. 203 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; } 204 205 /// isFP128Ty - Return true if this is 'fp128'. 206 bool isFP128Ty() const { return ID == FP128TyID; } 207 208 /// isPPC_FP128Ty - Return true if this is powerpc long double. 209 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; } 210 211 /// isFloatingPointTy - Return true if this is one of the five floating point 212 /// types 213 bool isFloatingPointTy() const { return ID == FloatTyID || ID == DoubleTyID || 214 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; } 215 216 /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP. 217 /// 218 bool isFPOrFPVectorTy() const; 219 220 /// isLabelTy - Return true if this is 'label'. 221 bool isLabelTy() const { return ID == LabelTyID; } 222 223 /// isMetadataTy - Return true if this is 'metadata'. 224 bool isMetadataTy() const { return ID == MetadataTyID; } 225 226 /// isIntegerTy - True if this is an instance of IntegerType. 227 /// 228 bool isIntegerTy() const { return ID == IntegerTyID; } 229 230 /// isIntegerTy - Return true if this is an IntegerType of the given width. 231 bool isIntegerTy(unsigned Bitwidth) const; 232 233 /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of 234 /// integer types. 235 /// 236 bool isIntOrIntVectorTy() const; 237 238 /// isFunctionTy - True if this is an instance of FunctionType. 239 /// 240 bool isFunctionTy() const { return ID == FunctionTyID; } 241 242 /// isStructTy - True if this is an instance of StructType. 243 /// 244 bool isStructTy() const { return ID == StructTyID; } 245 246 /// isUnionTy - True if this is an instance of UnionType. 247 /// 248 bool isUnionTy() const { return ID == UnionTyID; } 249 250 /// isArrayTy - True if this is an instance of ArrayType. 251 /// 252 bool isArrayTy() const { return ID == ArrayTyID; } 253 254 /// isPointerTy - True if this is an instance of PointerType. 255 /// 256 bool isPointerTy() const { return ID == PointerTyID; } 257 258 /// isOpaqueTy - True if this is an instance of OpaqueType. 259 /// 260 bool isOpaqueTy() const { return ID == OpaqueTyID; } 261 262 /// isVectorTy - True if this is an instance of VectorType. 263 /// 264 bool isVectorTy() const { return ID == VectorTyID; } 265 266 /// isAbstract - True if the type is either an Opaque type, or is a derived 267 /// type that includes an opaque type somewhere in it. 268 /// 269 inline bool isAbstract() const { return Abstract; } 270 271 /// canLosslesslyBitCastTo - Return true if this type could be converted 272 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts 273 /// are valid for types of the same size only where no re-interpretation of 274 /// the bits is done. 275 /// @brief Determine if this type could be losslessly bitcast to Ty 276 bool canLosslesslyBitCastTo(const Type *Ty) const; 277 278 279 /// Here are some useful little methods to query what type derived types are 280 /// Note that all other types can just compare to see if this == Type::xxxTy; 281 /// 282 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 283 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 284 285 /// isFirstClassType - Return true if the type is "first class", meaning it 286 /// is a valid type for a Value. 287 /// 288 inline bool isFirstClassType() const { 289 // There are more first-class kinds than non-first-class kinds, so a 290 // negative test is simpler than a positive one. 291 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID; 292 } 293 294 /// isSingleValueType - Return true if the type is a valid type for a 295 /// virtual register in codegen. This includes all first-class types 296 /// except struct and array types. 297 /// 298 inline bool isSingleValueType() const { 299 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 300 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID; 301 } 302 303 /// isAggregateType - Return true if the type is an aggregate type. This 304 /// means it is valid as the first operand of an insertvalue or 305 /// extractvalue instruction. This includes struct and array types, but 306 /// does not include vector types. 307 /// 308 inline bool isAggregateType() const { 309 return ID == StructTyID || ID == ArrayTyID || ID == UnionTyID; 310 } 311 312 /// isSized - Return true if it makes sense to take the size of this type. To 313 /// get the actual size for a particular target, it is reasonable to use the 314 /// TargetData subsystem to do this. 315 /// 316 bool isSized() const { 317 // If it's a primitive, it is always sized. 318 if (ID == IntegerTyID || isFloatingPointTy() || ID == PointerTyID) 319 return true; 320 // If it is not something that can have a size (e.g. a function or label), 321 // it doesn't have a size. 322 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID && 323 ID != UnionTyID) 324 return false; 325 // If it is something that can have a size and it's concrete, it definitely 326 // has a size, otherwise we have to try harder to decide. 327 return !isAbstract() || isSizedDerivedType(); 328 } 329 330 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a 331 /// primitive type. These are fixed by LLVM and are not target dependent. 332 /// This will return zero if the type does not have a size or is not a 333 /// primitive type. 334 /// 335 /// Note that this may not reflect the size of memory allocated for an 336 /// instance of the type or the number of bytes that are written when an 337 /// instance of the type is stored to memory. The TargetData class provides 338 /// additional query functions to provide this information. 339 /// 340 unsigned getPrimitiveSizeInBits() const; 341 342 /// getScalarSizeInBits - If this is a vector type, return the 343 /// getPrimitiveSizeInBits value for the element type. Otherwise return the 344 /// getPrimitiveSizeInBits value for this type. 345 unsigned getScalarSizeInBits() const; 346 347 /// getFPMantissaWidth - Return the width of the mantissa of this type. This 348 /// is only valid on floating point types. If the FP type does not 349 /// have a stable mantissa (e.g. ppc long double), this method returns -1. 350 int getFPMantissaWidth() const; 351 352 /// getForwardedType - Return the type that this type has been resolved to if 353 /// it has been resolved to anything. This is used to implement the 354 /// union-find algorithm for type resolution, and shouldn't be used by general 355 /// purpose clients. 356 const Type *getForwardedType() const { 357 if (!ForwardType) return 0; 358 return getForwardedTypeInternal(); 359 } 360 361 /// getVAArgsPromotedType - Return the type an argument of this type 362 /// will be promoted to if passed through a variable argument 363 /// function. 364 const Type *getVAArgsPromotedType(LLVMContext &C) const; 365 366 /// getScalarType - If this is a vector type, return the element type, 367 /// otherwise return this. 368 const Type *getScalarType() const; 369 370 //===--------------------------------------------------------------------===// 371 // Type Iteration support 372 // 373 typedef PATypeHandle *subtype_iterator; 374 subtype_iterator subtype_begin() const { return ContainedTys; } 375 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];} 376 377 /// getContainedType - This method is used to implement the type iterator 378 /// (defined a the end of the file). For derived types, this returns the 379 /// types 'contained' in the derived type. 380 /// 381 const Type *getContainedType(unsigned i) const { 382 assert(i < NumContainedTys && "Index out of range!"); 383 return ContainedTys[i].get(); 384 } 385 386 /// getNumContainedTypes - Return the number of types in the derived type. 387 /// 388 unsigned getNumContainedTypes() const { return NumContainedTys; } 389 390 //===--------------------------------------------------------------------===// 391 // Static members exported by the Type class itself. Useful for getting 392 // instances of Type. 393 // 394 395 /// getPrimitiveType - Return a type based on an identifier. 396 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber); 397 398 //===--------------------------------------------------------------------===// 399 // These are the builtin types that are always available... 400 // 401 static const Type *getVoidTy(LLVMContext &C); 402 static const Type *getLabelTy(LLVMContext &C); 403 static const Type *getFloatTy(LLVMContext &C); 404 static const Type *getDoubleTy(LLVMContext &C); 405 static const Type *getMetadataTy(LLVMContext &C); 406 static const Type *getX86_FP80Ty(LLVMContext &C); 407 static const Type *getFP128Ty(LLVMContext &C); 408 static const Type *getPPC_FP128Ty(LLVMContext &C); 409 static const IntegerType *getInt1Ty(LLVMContext &C); 410 static const IntegerType *getInt8Ty(LLVMContext &C); 411 static const IntegerType *getInt16Ty(LLVMContext &C); 412 static const IntegerType *getInt32Ty(LLVMContext &C); 413 static const IntegerType *getInt64Ty(LLVMContext &C); 414 415 //===--------------------------------------------------------------------===// 416 // Convenience methods for getting pointer types with one of the above builtin 417 // types as pointee. 418 // 419 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0); 420 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0); 421 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0); 422 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0); 423 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0); 424 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0); 425 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0); 426 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0); 427 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0); 428 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0); 429 430 /// Methods for support type inquiry through isa, cast, and dyn_cast: 431 static inline bool classof(const Type *) { return true; } 432 433 void addRef() const { 434 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 435 ++RefCount; 436 } 437 438 void dropRef() const { 439 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 440 assert(RefCount && "No objects are currently referencing this object!"); 441 442 // If this is the last PATypeHolder using this object, and there are no 443 // PATypeHandles using it, the type is dead, delete it now. 444 if (--RefCount == 0 && AbstractTypeUsers.empty()) 445 this->destroy(); 446 } 447 448 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 449 /// it. This function is called primarily by the PATypeHandle class. 450 /// 451 void addAbstractTypeUser(AbstractTypeUser *U) const; 452 453 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 454 /// no longer has a handle to the type. This function is called primarily by 455 /// the PATypeHandle class. When there are no users of the abstract type, it 456 /// is annihilated, because there is no way to get a reference to it ever 457 /// again. 458 /// 459 void removeAbstractTypeUser(AbstractTypeUser *U) const; 460 461 /// getPointerTo - Return a pointer to the current type. This is equivalent 462 /// to PointerType::get(Foo, AddrSpace). 463 const PointerType *getPointerTo(unsigned AddrSpace = 0) const; 464 465private: 466 /// isSizedDerivedType - Derived types like structures and arrays are sized 467 /// iff all of the members of the type are sized as well. Since asking for 468 /// their size is relatively uncommon, move this operation out of line. 469 bool isSizedDerivedType() const; 470 471 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 472 virtual void typeBecameConcrete(const DerivedType *AbsTy); 473 474protected: 475 // PromoteAbstractToConcrete - This is an internal method used to calculate 476 // change "Abstract" from true to false when types are refined. 477 void PromoteAbstractToConcrete(); 478 friend class TypeMapBase; 479}; 480 481//===----------------------------------------------------------------------===// 482// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 483// These are defined here because they MUST be inlined, yet are dependent on 484// the definition of the Type class. 485// 486inline void PATypeHandle::addUser() { 487 assert(Ty && "Type Handle has a null type!"); 488 if (Ty->isAbstract()) 489 Ty->addAbstractTypeUser(User); 490} 491inline void PATypeHandle::removeUser() { 492 if (Ty->isAbstract()) 493 Ty->removeAbstractTypeUser(User); 494} 495 496// Define inline methods for PATypeHolder. 497 498/// get - This implements the forwarding part of the union-find algorithm for 499/// abstract types. Before every access to the Type*, we check to see if the 500/// type we are pointing to is forwarding to a new type. If so, we drop our 501/// reference to the type. 502/// 503inline Type* PATypeHolder::get() const { 504 const Type *NewTy = Ty->getForwardedType(); 505 if (!NewTy) return const_cast<Type*>(Ty); 506 return *const_cast<PATypeHolder*>(this) = NewTy; 507} 508 509inline void PATypeHolder::addRef() { 510 assert(Ty && "Type Holder has a null type!"); 511 if (Ty->isAbstract()) 512 Ty->addRef(); 513} 514 515inline void PATypeHolder::dropRef() { 516 if (Ty->isAbstract()) 517 Ty->dropRef(); 518} 519 520 521//===----------------------------------------------------------------------===// 522// Provide specializations of GraphTraits to be able to treat a type as a 523// graph of sub types... 524 525template <> struct GraphTraits<Type*> { 526 typedef Type NodeType; 527 typedef Type::subtype_iterator ChildIteratorType; 528 529 static inline NodeType *getEntryNode(Type *T) { return T; } 530 static inline ChildIteratorType child_begin(NodeType *N) { 531 return N->subtype_begin(); 532 } 533 static inline ChildIteratorType child_end(NodeType *N) { 534 return N->subtype_end(); 535 } 536}; 537 538template <> struct GraphTraits<const Type*> { 539 typedef const Type NodeType; 540 typedef Type::subtype_iterator ChildIteratorType; 541 542 static inline NodeType *getEntryNode(const Type *T) { return T; } 543 static inline ChildIteratorType child_begin(NodeType *N) { 544 return N->subtype_begin(); 545 } 546 static inline ChildIteratorType child_end(NodeType *N) { 547 return N->subtype_end(); 548 } 549}; 550 551template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) { 552 return Ty.getTypeID() == Type::PointerTyID; 553} 554 555raw_ostream &operator<<(raw_ostream &OS, const Type &T); 556 557} // End llvm namespace 558 559#endif 560