Type.h revision 61c70e98ac3c7504d31dd9bc81c4e9cb998e9984
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 ArrayTyID, ///< 11: Arrays 86 PointerTyID, ///< 12: Pointers 87 OpaqueTyID, ///< 13: Opaque: type with unknown structure 88 VectorTyID, ///< 14: SIMD 'packed' format, or other vector type 89 90 NumTypeIDs, // Must remain as last defined ID 91 LastPrimitiveTyID = MetadataTyID, 92 FirstDerivedTyID = IntegerTyID 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 unsigned SubclassData : 23; //Space for subclasses to store data 99 100 /// RefCount - This counts the number of PATypeHolders that are pointing to 101 /// this type. When this number falls to zero, if the type is abstract and 102 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for 103 /// derived types. 104 /// 105 mutable unsigned RefCount; 106 107 /// Context - This refers to the LLVMContext in which this type was uniqued. 108 LLVMContext &Context; 109 friend class LLVMContextImpl; 110 111 const Type *getForwardedTypeInternal() const; 112 113 // Some Type instances are allocated as arrays, some aren't. So we provide 114 // this method to get the right kind of destruction for the type of Type. 115 void destroy() const; // const is a lie, this does "delete this"! 116 117protected: 118 explicit Type(LLVMContext &C, TypeID id) : 119 ID(id), Abstract(false), SubclassData(0), 120 RefCount(0), Context(C), 121 ForwardType(0), NumContainedTys(0), 122 ContainedTys(0) {} 123 virtual ~Type() { 124 assert(AbstractTypeUsers.empty() && "Abstract types remain"); 125 } 126 127 /// Types can become nonabstract later, if they are refined. 128 /// 129 inline void setAbstract(bool Val) { Abstract = Val; } 130 131 unsigned getRefCount() const { return RefCount; } 132 133 unsigned getSubclassData() const { return SubclassData; } 134 void setSubclassData(unsigned val) { SubclassData = val; } 135 136 /// ForwardType - This field is used to implement the union find scheme for 137 /// abstract types. When types are refined to other types, this field is set 138 /// to the more refined type. Only abstract types can be forwarded. 139 mutable const Type *ForwardType; 140 141 142 /// AbstractTypeUsers - Implement a list of the users that need to be notified 143 /// if I am a type, and I get resolved into a more concrete type. 144 /// 145 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers; 146 147 /// NumContainedTys - Keeps track of how many PATypeHandle instances there 148 /// are at the end of this type instance for the list of contained types. It 149 /// is the subclasses responsibility to set this up. Set to 0 if there are no 150 /// contained types in this type. 151 unsigned NumContainedTys; 152 153 /// ContainedTys - A pointer to the array of Types (PATypeHandle) contained 154 /// by this Type. For example, this includes the arguments of a function 155 /// type, the elements of a structure, the pointee of a pointer, the element 156 /// type of an array, etc. This pointer may be 0 for types that don't 157 /// contain other types (Integer, Double, Float). In general, the subclass 158 /// should arrange for space for the PATypeHandles to be included in the 159 /// allocation of the type object and set this pointer to the address of the 160 /// first element. This allows the Type class to manipulate the ContainedTys 161 /// without understanding the subclass's placement for this array. keeping 162 /// it here also allows the subtype_* members to be implemented MUCH more 163 /// efficiently, and dynamically very few types do not contain any elements. 164 PATypeHandle *ContainedTys; 165 166public: 167 void print(raw_ostream &O) const; 168 169 /// @brief Debugging support: print to stderr 170 void dump() const; 171 172 /// @brief Debugging support: print to stderr (use type names from context 173 /// module). 174 void dump(const Module *Context) const; 175 176 /// getContext - Fetch the LLVMContext in which this type was uniqued. 177 LLVMContext &getContext() const { return Context; } 178 179 //===--------------------------------------------------------------------===// 180 // Property accessors for dealing with types... Some of these virtual methods 181 // are defined in private classes defined in Type.cpp for primitive types. 182 // 183 184 /// getDescription - Return the string representation of the type. 185 std::string getDescription() const; 186 187 /// getTypeID - Return the type id for the type. This will return one 188 /// of the TypeID enum elements defined above. 189 /// 190 inline TypeID getTypeID() const { return ID; } 191 192 /// isVoidTy - Return true if this is 'void'. 193 bool isVoidTy() const { return ID == VoidTyID; } 194 195 /// isFloatTy - Return true if this is 'float', a 32-bit IEEE fp type. 196 bool isFloatTy() const { return ID == FloatTyID; } 197 198 /// isDoubleTy - Return true if this is 'double', a 64-bit IEEE fp type. 199 bool isDoubleTy() const { return ID == DoubleTyID; } 200 201 /// isX86_FP80Ty - Return true if this is x86 long double. 202 bool isX86_FP80Ty() const { return ID == X86_FP80TyID; } 203 204 /// isFP128Ty - Return true if this is 'fp128'. 205 bool isFP128Ty() const { return ID == FP128TyID; } 206 207 /// isPPC_FP128Ty - Return true if this is powerpc long double. 208 bool isPPC_FP128Ty() const { return ID == PPC_FP128TyID; } 209 210 /// isFloatingPointTy - Return true if this is one of the five floating point 211 /// types 212 bool isFloatingPointTy() const { return ID == FloatTyID || ID == DoubleTyID || 213 ID == X86_FP80TyID || ID == FP128TyID || ID == PPC_FP128TyID; } 214 215 /// isFPOrFPVectorTy - Return true if this is a FP type or a vector of FP. 216 /// 217 bool isFPOrFPVectorTy() const; 218 219 /// isLabelTy - Return true if this is 'label'. 220 bool isLabelTy() const { return ID == LabelTyID; } 221 222 /// isMetadataTy - Return true if this is 'metadata'. 223 bool isMetadataTy() const { return ID == MetadataTyID; } 224 225 /// isIntegerTy - True if this is an instance of IntegerType. 226 /// 227 bool isIntegerTy() const { return ID == IntegerTyID; } 228 229 /// isIntegerTy - Return true if this is an IntegerType of the given width. 230 bool isIntegerTy(unsigned Bitwidth) const; 231 232 /// isIntOrIntVectorTy - Return true if this is an integer type or a vector of 233 /// integer types. 234 /// 235 bool isIntOrIntVectorTy() const; 236 237 /// isFunctionTy - True if this is an instance of FunctionType. 238 /// 239 bool isFunctionTy() const { return ID == FunctionTyID; } 240 241 /// isStructTy - True if this is an instance of StructType. 242 /// 243 bool isStructTy() const { return ID == StructTyID; } 244 245 /// isArrayTy - True if this is an instance of ArrayType. 246 /// 247 bool isArrayTy() const { return ID == ArrayTyID; } 248 249 /// isPointerTy - True if this is an instance of PointerType. 250 /// 251 bool isPointerTy() const { return ID == PointerTyID; } 252 253 /// isOpaqueTy - True if this is an instance of OpaqueType. 254 /// 255 bool isOpaqueTy() const { return ID == OpaqueTyID; } 256 257 /// isVectorTy - True if this is an instance of VectorType. 258 /// 259 bool isVectorTy() const { return ID == VectorTyID; } 260 261 /// isAbstract - True if the type is either an Opaque type, or is a derived 262 /// type that includes an opaque type somewhere in it. 263 /// 264 inline bool isAbstract() const { return Abstract; } 265 266 /// canLosslesslyBitCastTo - Return true if this type could be converted 267 /// with a lossless BitCast to type 'Ty'. For example, i8* to i32*. BitCasts 268 /// are valid for types of the same size only where no re-interpretation of 269 /// the bits is done. 270 /// @brief Determine if this type could be losslessly bitcast to Ty 271 bool canLosslesslyBitCastTo(const Type *Ty) const; 272 273 274 /// Here are some useful little methods to query what type derived types are 275 /// Note that all other types can just compare to see if this == Type::xxxTy; 276 /// 277 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; } 278 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; } 279 280 /// isFirstClassType - Return true if the type is "first class", meaning it 281 /// is a valid type for a Value. 282 /// 283 inline bool isFirstClassType() const { 284 // There are more first-class kinds than non-first-class kinds, so a 285 // negative test is simpler than a positive one. 286 return ID != FunctionTyID && ID != VoidTyID && ID != OpaqueTyID; 287 } 288 289 /// isSingleValueType - Return true if the type is a valid type for a 290 /// virtual register in codegen. This includes all first-class types 291 /// except struct and array types. 292 /// 293 inline bool isSingleValueType() const { 294 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || 295 ID == IntegerTyID || ID == PointerTyID || ID == VectorTyID; 296 } 297 298 /// isAggregateType - Return true if the type is an aggregate type. This 299 /// means it is valid as the first operand of an insertvalue or 300 /// extractvalue instruction. This includes struct and array types, but 301 /// does not include vector types. 302 /// 303 inline bool isAggregateType() const { 304 return ID == StructTyID || ID == ArrayTyID; 305 } 306 307 /// isSized - Return true if it makes sense to take the size of this type. To 308 /// get the actual size for a particular target, it is reasonable to use the 309 /// TargetData subsystem to do this. 310 /// 311 bool isSized() const { 312 // If it's a primitive, it is always sized. 313 if (ID == IntegerTyID || isFloatingPointTy() || ID == PointerTyID) 314 return true; 315 // If it is not something that can have a size (e.g. a function or label), 316 // it doesn't have a size. 317 if (ID != StructTyID && ID != ArrayTyID && ID != VectorTyID) 318 return false; 319 // If it is something that can have a size and it's concrete, it definitely 320 // has a size, otherwise we have to try harder to decide. 321 return !isAbstract() || isSizedDerivedType(); 322 } 323 324 /// getPrimitiveSizeInBits - Return the basic size of this type if it is a 325 /// primitive type. These are fixed by LLVM and are not target dependent. 326 /// This will return zero if the type does not have a size or is not a 327 /// primitive type. 328 /// 329 /// Note that this may not reflect the size of memory allocated for an 330 /// instance of the type or the number of bytes that are written when an 331 /// instance of the type is stored to memory. The TargetData class provides 332 /// additional query functions to provide this information. 333 /// 334 unsigned getPrimitiveSizeInBits() const; 335 336 /// getScalarSizeInBits - If this is a vector type, return the 337 /// getPrimitiveSizeInBits value for the element type. Otherwise return the 338 /// getPrimitiveSizeInBits value for this type. 339 unsigned getScalarSizeInBits() const; 340 341 /// getFPMantissaWidth - Return the width of the mantissa of this type. This 342 /// is only valid on floating point types. If the FP type does not 343 /// have a stable mantissa (e.g. ppc long double), this method returns -1. 344 int getFPMantissaWidth() const; 345 346 /// getForwardedType - Return the type that this type has been resolved to if 347 /// it has been resolved to anything. This is used to implement the 348 /// union-find algorithm for type resolution, and shouldn't be used by general 349 /// purpose clients. 350 const Type *getForwardedType() const { 351 if (!ForwardType) return 0; 352 return getForwardedTypeInternal(); 353 } 354 355 /// getVAArgsPromotedType - Return the type an argument of this type 356 /// will be promoted to if passed through a variable argument 357 /// function. 358 const Type *getVAArgsPromotedType(LLVMContext &C) const; 359 360 /// getScalarType - If this is a vector type, return the element type, 361 /// otherwise return this. 362 const Type *getScalarType() const; 363 364 //===--------------------------------------------------------------------===// 365 // Type Iteration support 366 // 367 typedef PATypeHandle *subtype_iterator; 368 subtype_iterator subtype_begin() const { return ContainedTys; } 369 subtype_iterator subtype_end() const { return &ContainedTys[NumContainedTys];} 370 371 /// getContainedType - This method is used to implement the type iterator 372 /// (defined a the end of the file). For derived types, this returns the 373 /// types 'contained' in the derived type. 374 /// 375 const Type *getContainedType(unsigned i) const { 376 assert(i < NumContainedTys && "Index out of range!"); 377 return ContainedTys[i].get(); 378 } 379 380 /// getNumContainedTypes - Return the number of types in the derived type. 381 /// 382 unsigned getNumContainedTypes() const { return NumContainedTys; } 383 384 //===--------------------------------------------------------------------===// 385 // Static members exported by the Type class itself. Useful for getting 386 // instances of Type. 387 // 388 389 /// getPrimitiveType - Return a type based on an identifier. 390 static const Type *getPrimitiveType(LLVMContext &C, TypeID IDNumber); 391 392 //===--------------------------------------------------------------------===// 393 // These are the builtin types that are always available... 394 // 395 static const Type *getVoidTy(LLVMContext &C); 396 static const Type *getLabelTy(LLVMContext &C); 397 static const Type *getFloatTy(LLVMContext &C); 398 static const Type *getDoubleTy(LLVMContext &C); 399 static const Type *getMetadataTy(LLVMContext &C); 400 static const Type *getX86_FP80Ty(LLVMContext &C); 401 static const Type *getFP128Ty(LLVMContext &C); 402 static const Type *getPPC_FP128Ty(LLVMContext &C); 403 static const IntegerType *getIntNTy(LLVMContext &C, unsigned N); 404 static const IntegerType *getInt1Ty(LLVMContext &C); 405 static const IntegerType *getInt8Ty(LLVMContext &C); 406 static const IntegerType *getInt16Ty(LLVMContext &C); 407 static const IntegerType *getInt32Ty(LLVMContext &C); 408 static const IntegerType *getInt64Ty(LLVMContext &C); 409 410 //===--------------------------------------------------------------------===// 411 // Convenience methods for getting pointer types with one of the above builtin 412 // types as pointee. 413 // 414 static const PointerType *getFloatPtrTy(LLVMContext &C, unsigned AS = 0); 415 static const PointerType *getDoublePtrTy(LLVMContext &C, unsigned AS = 0); 416 static const PointerType *getX86_FP80PtrTy(LLVMContext &C, unsigned AS = 0); 417 static const PointerType *getFP128PtrTy(LLVMContext &C, unsigned AS = 0); 418 static const PointerType *getPPC_FP128PtrTy(LLVMContext &C, unsigned AS = 0); 419 static const PointerType *getIntNPtrTy(LLVMContext &C, unsigned N, 420 unsigned AS = 0); 421 static const PointerType *getInt1PtrTy(LLVMContext &C, unsigned AS = 0); 422 static const PointerType *getInt8PtrTy(LLVMContext &C, unsigned AS = 0); 423 static const PointerType *getInt16PtrTy(LLVMContext &C, unsigned AS = 0); 424 static const PointerType *getInt32PtrTy(LLVMContext &C, unsigned AS = 0); 425 static const PointerType *getInt64PtrTy(LLVMContext &C, unsigned AS = 0); 426 427 /// Methods for support type inquiry through isa, cast, and dyn_cast: 428 static inline bool classof(const Type *) { return true; } 429 430 void addRef() const { 431 assert(isAbstract() && "Cannot add a reference to a non-abstract type!"); 432 ++RefCount; 433 } 434 435 void dropRef() const { 436 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!"); 437 assert(RefCount && "No objects are currently referencing this object!"); 438 439 // If this is the last PATypeHolder using this object, and there are no 440 // PATypeHandles using it, the type is dead, delete it now. 441 if (--RefCount == 0 && AbstractTypeUsers.empty()) 442 this->destroy(); 443 } 444 445 /// addAbstractTypeUser - Notify an abstract type that there is a new user of 446 /// it. This function is called primarily by the PATypeHandle class. 447 /// 448 void addAbstractTypeUser(AbstractTypeUser *U) const; 449 450 /// removeAbstractTypeUser - Notify an abstract type that a user of the class 451 /// no longer has a handle to the type. This function is called primarily by 452 /// the PATypeHandle class. When there are no users of the abstract type, it 453 /// is annihilated, because there is no way to get a reference to it ever 454 /// again. 455 /// 456 void removeAbstractTypeUser(AbstractTypeUser *U) const; 457 458 /// getPointerTo - Return a pointer to the current type. This is equivalent 459 /// to PointerType::get(Foo, AddrSpace). 460 const PointerType *getPointerTo(unsigned AddrSpace = 0) const; 461 462private: 463 /// isSizedDerivedType - Derived types like structures and arrays are sized 464 /// iff all of the members of the type are sized as well. Since asking for 465 /// their size is relatively uncommon, move this operation out of line. 466 bool isSizedDerivedType() const; 467 468 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy); 469 virtual void typeBecameConcrete(const DerivedType *AbsTy); 470 471protected: 472 // PromoteAbstractToConcrete - This is an internal method used to calculate 473 // change "Abstract" from true to false when types are refined. 474 void PromoteAbstractToConcrete(); 475 friend class TypeMapBase; 476}; 477 478//===----------------------------------------------------------------------===// 479// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class. 480// These are defined here because they MUST be inlined, yet are dependent on 481// the definition of the Type class. 482// 483inline void PATypeHandle::addUser() { 484 assert(Ty && "Type Handle has a null type!"); 485 if (Ty->isAbstract()) 486 Ty->addAbstractTypeUser(User); 487} 488inline void PATypeHandle::removeUser() { 489 if (Ty->isAbstract()) 490 Ty->removeAbstractTypeUser(User); 491} 492 493// Define inline methods for PATypeHolder. 494 495/// get - This implements the forwarding part of the union-find algorithm for 496/// abstract types. Before every access to the Type*, we check to see if the 497/// type we are pointing to is forwarding to a new type. If so, we drop our 498/// reference to the type. 499/// 500inline Type* PATypeHolder::get() const { 501 if (Ty == 0) return 0; 502 const Type *NewTy = Ty->getForwardedType(); 503 if (!NewTy) return const_cast<Type*>(Ty); 504 return *const_cast<PATypeHolder*>(this) = NewTy; 505} 506 507inline void PATypeHolder::addRef() { 508 if (Ty && Ty->isAbstract()) 509 Ty->addRef(); 510} 511 512inline void PATypeHolder::dropRef() { 513 if (Ty && Ty->isAbstract()) 514 Ty->dropRef(); 515} 516 517 518//===----------------------------------------------------------------------===// 519// Provide specializations of GraphTraits to be able to treat a type as a 520// graph of sub types... 521 522template <> struct GraphTraits<Type*> { 523 typedef Type NodeType; 524 typedef Type::subtype_iterator ChildIteratorType; 525 526 static inline NodeType *getEntryNode(Type *T) { return T; } 527 static inline ChildIteratorType child_begin(NodeType *N) { 528 return N->subtype_begin(); 529 } 530 static inline ChildIteratorType child_end(NodeType *N) { 531 return N->subtype_end(); 532 } 533}; 534 535template <> struct GraphTraits<const Type*> { 536 typedef const Type NodeType; 537 typedef Type::subtype_iterator ChildIteratorType; 538 539 static inline NodeType *getEntryNode(const Type *T) { return T; } 540 static inline ChildIteratorType child_begin(NodeType *N) { 541 return N->subtype_begin(); 542 } 543 static inline ChildIteratorType child_end(NodeType *N) { 544 return N->subtype_end(); 545 } 546}; 547 548template <> struct isa_impl<PointerType, Type> { 549 static inline bool doit(const Type &Ty) { 550 return Ty.getTypeID() == Type::PointerTyID; 551 } 552}; 553 554raw_ostream &operator<<(raw_ostream &OS, const Type &T); 555 556} // End llvm namespace 557 558#endif 559