1 //===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Type class. For more "Type" type
11 // stuff, look in DerivedTypes.h.
13 // Note that instances of the Type class are immutable: once they are created,
14 // they are never changed. Also note that only one instance of a particular
15 // type is ever created. Thus seeing if two types are equal is a matter of
16 // doing a trivial pointer comparison.
18 // Types, once allocated, are never free'd, unless they are an abstract type
19 // that is resolved to a more concrete type.
21 // Opaque types are simple derived types with no state. There may be many
22 // different Opaque type objects floating around, but two are only considered
23 // identical if they are pointer equals of each other. This allows us to have
24 // two opaque types that end up resolving to different concrete types later.
26 // Opaque types are also kinda weird and scary and different because they have
27 // to keep a list of uses of the type. When, through linking, parsing, or
28 // bytecode reading, they become resolved, they need to find and update all
29 // users of the unknown type, causing them to reference a new, more concrete
30 // type. Opaque types are deleted when their use list dwindles to zero users.
32 //===----------------------------------------------------------------------===//
37 #include "llvm/AbstractTypeUser.h"
38 #include "llvm/Support/Casting.h"
39 #include "llvm/Support/DataTypes.h"
40 #include "llvm/ADT/GraphTraits.h"
41 #include "llvm/ADT/iterator"
56 class Type : public AbstractTypeUser {
58 ///===-------------------------------------------------------------------===//
59 /// Definitions of all of the base types for the Type system. Based on this
60 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
61 /// Note: If you add an element to this, you need to add an element to the
62 /// Type::getPrimitiveType function, or else things will break!
65 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
66 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
67 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
68 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
69 UIntTyID , IntTyID, // 6, 7: 32 bit types...
70 ULongTyID , LongTyID, // 8, 9: 64 bit types...
71 FloatTyID , DoubleTyID, // 10,11: Floating point types...
72 LabelTyID , // 12 : Labels...
74 // Derived types... see DerivedTypes.h file...
75 // Make sure FirstDerivedTyID stays up to date!!!
76 FunctionTyID , StructTyID, // Functions... Structs...
77 ArrayTyID , PointerTyID, // Array... pointer...
78 OpaqueTyID, // Opaque type instances...
79 PackedTyID, // SIMD 'packed' format...
82 NumTypeIDs, // Must remain as last defined ID
83 LastPrimitiveTyID = LabelTyID,
84 FirstDerivedTyID = FunctionTyID
88 TypeID ID : 8; // The current base type of this type.
89 bool Abstract : 1; // True if type contains an OpaqueType
91 /// RefCount - This counts the number of PATypeHolders that are pointing to
92 /// this type. When this number falls to zero, if the type is abstract and
93 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
96 mutable unsigned RefCount;
98 const Type *getForwardedTypeInternal() const;
100 Type(const char *Name, TypeID id);
101 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {}
103 assert(AbstractTypeUsers.empty());
106 /// Types can become nonabstract later, if they are refined.
108 inline void setAbstract(bool Val) { Abstract = Val; }
110 unsigned getRefCount() const { return RefCount; }
112 /// ForwardType - This field is used to implement the union find scheme for
113 /// abstract types. When types are refined to other types, this field is set
114 /// to the more refined type. Only abstract types can be forwarded.
115 mutable const Type *ForwardType;
117 /// ContainedTys - The list of types contained by this one. For example, this
118 /// includes the arguments of a function type, the elements of the structure,
119 /// the pointee of a pointer, etc. Note that keeping this vector in the Type
120 /// class wastes some space for types that do not contain anything (such as
121 /// primitive types). However, keeping it here allows the subtype_* members
122 /// to be implemented MUCH more efficiently, and dynamically very few types do
123 /// not contain any elements (most are derived).
124 std::vector<PATypeHandle> ContainedTys;
126 /// AbstractTypeUsers - Implement a list of the users that need to be notified
127 /// if I am a type, and I get resolved into a more concrete type.
129 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
131 void print(std::ostream &O) const;
133 /// @brief Debugging support: print to stderr
136 //===--------------------------------------------------------------------===//
137 // Property accessors for dealing with types... Some of these virtual methods
138 // are defined in private classes defined in Type.cpp for primitive types.
141 /// getTypeID - Return the type id for the type. This will return one
142 /// of the TypeID enum elements defined above.
144 inline TypeID getTypeID() const { return ID; }
146 /// getDescription - Return the string representation of the type...
147 const std::string &getDescription() const;
149 /// isSigned - Return whether an integral numeric type is signed. This is
150 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
151 /// Float and Double.
153 bool isSigned() const {
154 return ID == SByteTyID || ID == ShortTyID ||
155 ID == IntTyID || ID == LongTyID;
158 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
159 /// the complement of isSigned... nonnumeric types return false as they do
160 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
163 bool isUnsigned() const {
164 return ID == UByteTyID || ID == UShortTyID ||
165 ID == UIntTyID || ID == ULongTyID;
168 /// isInteger - Equivalent to isSigned() || isUnsigned()
170 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
172 /// isIntegral - Returns true if this is an integral type, which is either
173 /// BoolTy or one of the Integer types.
175 bool isIntegral() const { return isInteger() || this == BoolTy; }
177 /// isFloatingPoint - Return true if this is one of the two floating point
179 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
181 /// isAbstract - True if the type is either an Opaque type, or is a derived
182 /// type that includes an opaque type somewhere in it.
184 inline bool isAbstract() const { return Abstract; }
186 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
187 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
189 bool isLosslesslyConvertibleTo(const Type *Ty) const;
192 /// Here are some useful little methods to query what type derived types are
193 /// Note that all other types can just compare to see if this == Type::xxxTy;
195 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
196 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
198 /// isFirstClassType - Return true if the value is holdable in a register.
200 inline bool isFirstClassType() const {
201 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
202 ID == PointerTyID || ID == PackedTyID;
205 /// isSized - Return true if it makes sense to take the size of this type. To
206 /// get the actual size for a particular target, it is reasonable to use the
207 /// TargetData subsystem to do this.
209 bool isSized() const {
210 // If it's a primitive, it is always sized.
211 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID)
213 // If it is not something that can have a size (e.g. a function or label),
214 // it doesn't have a size.
215 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID)
217 // If it is something that can have a size and it's concrete, it definitely
218 // has a size, otherwise we have to try harder to decide.
219 return !isAbstract() || isSizedDerivedType();
222 /// getPrimitiveSize - Return the basic size of this type if it is a primitive
223 /// type. These are fixed by LLVM and are not target dependent. This will
224 /// return zero if the type does not have a size or is not a primitive type.
226 unsigned getPrimitiveSize() const;
227 unsigned getPrimitiveSizeInBits() const;
229 /// getUnsignedVersion - If this is an integer type, return the unsigned
230 /// variant of this type. For example int -> uint.
231 const Type *getUnsignedVersion() const;
233 /// getSignedVersion - If this is an integer type, return the signed variant
234 /// of this type. For example uint -> int.
235 const Type *getSignedVersion() const;
237 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits
238 /// that can be set by an unsigned version of this type. This is 0xFF for
239 /// sbyte/ubyte, 0xFFFF for shorts, etc.
240 uint64_t getIntegralTypeMask() const {
241 assert(isIntegral() && "This only works for integral types!");
242 return ~0ULL >> (64-getPrimitiveSizeInBits());
245 /// getForwaredType - Return the type that this type has been resolved to if
246 /// it has been resolved to anything. This is used to implement the
247 /// union-find algorithm for type resolution, and shouldn't be used by general
249 const Type *getForwardedType() const {
250 if (!ForwardType) return 0;
251 return getForwardedTypeInternal();
254 /// getVAArgsPromotedType - Return the type an argument of this type
255 /// will be promoted to if passed through a variable argument
257 const Type *getVAArgsPromotedType() const {
258 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID)
260 else if (ID == SByteTyID || ID == ShortTyID)
262 else if (ID == FloatTyID)
263 return Type::DoubleTy;
268 //===--------------------------------------------------------------------===//
269 // Type Iteration support
271 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
272 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
273 subtype_iterator subtype_end() const { return ContainedTys.end(); }
275 /// getContainedType - This method is used to implement the type iterator
276 /// (defined a the end of the file). For derived types, this returns the
277 /// types 'contained' in the derived type.
279 const Type *getContainedType(unsigned i) const {
280 assert(i < ContainedTys.size() && "Index out of range!");
281 return ContainedTys[i];
284 /// getNumContainedTypes - Return the number of types in the derived type.
286 typedef std::vector<PATypeHandle>::size_type size_type;
287 size_type getNumContainedTypes() const { return ContainedTys.size(); }
289 //===--------------------------------------------------------------------===//
290 // Static members exported by the Type class itself. Useful for getting
291 // instances of Type.
294 /// getPrimitiveType - Return a type based on an identifier.
295 static const Type *getPrimitiveType(TypeID IDNumber);
297 //===--------------------------------------------------------------------===//
298 // These are the builtin types that are always available...
300 static Type *VoidTy , *BoolTy;
301 static Type *SByteTy, *UByteTy,
305 static Type *FloatTy, *DoubleTy;
307 static Type* LabelTy;
309 /// Methods for support type inquiry through isa, cast, and dyn_cast:
310 static inline bool classof(const Type *T) { return true; }
312 void addRef() const {
313 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
317 void dropRef() const {
318 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
319 assert(RefCount && "No objects are currently referencing this object!");
321 // If this is the last PATypeHolder using this object, and there are no
322 // PATypeHandles using it, the type is dead, delete it now.
323 if (--RefCount == 0 && AbstractTypeUsers.empty())
327 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
328 /// it. This function is called primarily by the PATypeHandle class.
330 void addAbstractTypeUser(AbstractTypeUser *U) const {
331 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
332 AbstractTypeUsers.push_back(U);
335 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
336 /// no longer has a handle to the type. This function is called primarily by
337 /// the PATypeHandle class. When there are no users of the abstract type, it
338 /// is annihilated, because there is no way to get a reference to it ever
341 void removeAbstractTypeUser(AbstractTypeUser *U) const;
343 /// clearAllTypeMaps - This method frees all internal memory used by the
344 /// type subsystem, which can be used in environments where this memory is
345 /// otherwise reported as a leak.
346 static void clearAllTypeMaps();
349 /// isSizedDerivedType - Derived types like structures and arrays are sized
350 /// iff all of the members of the type are sized as well. Since asking for
351 /// their size is relatively uncommon, move this operation out of line.
352 bool isSizedDerivedType() const;
354 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
355 virtual void typeBecameConcrete(const DerivedType *AbsTy);
358 // PromoteAbstractToConcrete - This is an internal method used to calculate
359 // change "Abstract" from true to false when types are refined.
360 void PromoteAbstractToConcrete();
361 friend class TypeMapBase;
364 //===----------------------------------------------------------------------===//
365 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
366 // These are defined here because they MUST be inlined, yet are dependent on
367 // the definition of the Type class. Of course Type derives from Value, which
368 // contains an AbstractTypeUser instance, so there is no good way to factor out
369 // the code. Hence this bit of uglyness.
371 // In the long term, Type should not derive from Value, allowing
372 // AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
373 // nastyness entirely.
375 inline void PATypeHandle::addUser() {
376 assert(Ty && "Type Handle has a null type!");
377 if (Ty->isAbstract())
378 Ty->addAbstractTypeUser(User);
380 inline void PATypeHandle::removeUser() {
381 if (Ty->isAbstract())
382 Ty->removeAbstractTypeUser(User);
385 // Define inline methods for PATypeHolder...
387 inline void PATypeHolder::addRef() {
388 if (Ty->isAbstract())
392 inline void PATypeHolder::dropRef() {
393 if (Ty->isAbstract())
397 /// get - This implements the forwarding part of the union-find algorithm for
398 /// abstract types. Before every access to the Type*, we check to see if the
399 /// type we are pointing to is forwarding to a new type. If so, we drop our
400 /// reference to the type.
402 inline Type* PATypeHolder::get() const {
403 const Type *NewTy = Ty->getForwardedType();
404 if (!NewTy) return const_cast<Type*>(Ty);
405 return *const_cast<PATypeHolder*>(this) = NewTy;
410 //===----------------------------------------------------------------------===//
411 // Provide specializations of GraphTraits to be able to treat a type as a
412 // graph of sub types...
414 template <> struct GraphTraits<Type*> {
415 typedef Type NodeType;
416 typedef Type::subtype_iterator ChildIteratorType;
418 static inline NodeType *getEntryNode(Type *T) { return T; }
419 static inline ChildIteratorType child_begin(NodeType *N) {
420 return N->subtype_begin();
422 static inline ChildIteratorType child_end(NodeType *N) {
423 return N->subtype_end();
427 template <> struct GraphTraits<const Type*> {
428 typedef const Type NodeType;
429 typedef Type::subtype_iterator ChildIteratorType;
431 static inline NodeType *getEntryNode(const Type *T) { return T; }
432 static inline ChildIteratorType child_begin(NodeType *N) {
433 return N->subtype_begin();
435 static inline ChildIteratorType child_end(NodeType *N) {
436 return N->subtype_end();
440 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
441 return Ty.getTypeID() == Type::PointerTyID;
444 std::ostream &operator<<(std::ostream &OS, const Type &T);
446 } // End llvm namespace