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 "AbstractTypeUser.h"
38 #include "llvm/Support/Casting.h"
39 #include "llvm/ADT/GraphTraits.h"
40 #include "llvm/ADT/iterator"
55 class Type : public AbstractTypeUser {
57 ///===-------------------------------------------------------------------===//
58 /// Definitions of all of the base types for the Type system. Based on this
59 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
60 /// Note: If you add an element to this, you need to add an element to the
61 /// Type::getPrimitiveType function, or else things will break!
64 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
65 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
66 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
67 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
68 UIntTyID , IntTyID, // 6, 7: 32 bit types...
69 ULongTyID , LongTyID, // 8, 9: 64 bit types...
70 FloatTyID , DoubleTyID, // 10,11: Floating point types...
71 LabelTyID , // 12 : Labels...
73 // Derived types... see DerivedTypes.h file...
74 // Make sure FirstDerivedTyID stays up to date!!!
75 FunctionTyID , StructTyID, // Functions... Structs...
76 ArrayTyID , PointerTyID, // Array... pointer...
77 OpaqueTyID, // Opaque type instances...
78 PackedTyID, // SIMD 'packed' format...
81 NumTypeIDs, // Must remain as last defined ID
82 LastPrimitiveTyID = LabelTyID,
83 FirstDerivedTyID = FunctionTyID
87 TypeID ID : 8; // The current base type of this type.
88 bool Abstract : 1; // True if type contains an OpaqueType
90 /// RefCount - This counts the number of PATypeHolders that are pointing to
91 /// this type. When this number falls to zero, if the type is abstract and
92 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
95 mutable unsigned RefCount;
97 const Type *getForwardedTypeInternal() const;
99 Type(const char *Name, TypeID id);
100 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {}
102 assert(AbstractTypeUsers.empty());
105 /// Types can become nonabstract later, if they are refined.
107 inline void setAbstract(bool Val) { Abstract = Val; }
109 unsigned getRefCount() const { return RefCount; }
111 /// ForwardType - This field is used to implement the union find scheme for
112 /// abstract types. When types are refined to other types, this field is set
113 /// to the more refined type. Only abstract types can be forwarded.
114 mutable const Type *ForwardType;
116 /// ContainedTys - The list of types contained by this one. For example, this
117 /// includes the arguments of a function type, the elements of the structure,
118 /// the pointee of a pointer, etc. Note that keeping this vector in the Type
119 /// class wastes some space for types that do not contain anything (such as
120 /// primitive types). However, keeping it here allows the subtype_* members
121 /// to be implemented MUCH more efficiently, and dynamically very few types do
122 /// not contain any elements (most are derived).
123 std::vector<PATypeHandle> ContainedTys;
125 /// AbstractTypeUsers - Implement a list of the users that need to be notified
126 /// if I am a type, and I get resolved into a more concrete type.
128 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
130 void print(std::ostream &O) const;
132 /// @brief Debugging support: print to stderr
135 //===--------------------------------------------------------------------===//
136 // Property accessors for dealing with types... Some of these virtual methods
137 // are defined in private classes defined in Type.cpp for primitive types.
140 /// getTypeID - Return the type id for the type. This will return one
141 /// of the TypeID enum elements defined above.
143 inline TypeID getTypeID() const { return ID; }
145 /// getDescription - Return the string representation of the type...
146 const std::string &getDescription() const;
148 /// isSigned - Return whether an integral numeric type is signed. This is
149 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
150 /// Float and Double.
152 bool isSigned() const {
153 return ID == SByteTyID || ID == ShortTyID ||
154 ID == IntTyID || ID == LongTyID;
157 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
158 /// the complement of isSigned... nonnumeric types return false as they do
159 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
162 bool isUnsigned() const {
163 return ID == UByteTyID || ID == UShortTyID ||
164 ID == UIntTyID || ID == ULongTyID;
167 /// isInteger - Equivalent to isSigned() || isUnsigned()
169 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
171 /// isIntegral - Returns true if this is an integral type, which is either
172 /// BoolTy or one of the Integer types.
174 bool isIntegral() const { return isInteger() || this == BoolTy; }
176 /// isFloatingPoint - Return true if this is one of the two floating point
178 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
180 /// isAbstract - True if the type is either an Opaque type, or is a derived
181 /// type that includes an opaque type somewhere in it.
183 inline bool isAbstract() const { return Abstract; }
185 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
186 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
188 bool isLosslesslyConvertibleTo(const Type *Ty) const;
191 /// Here are some useful little methods to query what type derived types are
192 /// Note that all other types can just compare to see if this == Type::xxxTy;
194 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
195 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
197 /// isFirstClassType - Return true if the value is holdable in a register.
199 inline bool isFirstClassType() const {
200 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
201 ID == PointerTyID || ID == PackedTyID;
204 /// isSized - Return true if it makes sense to take the size of this type. To
205 /// get the actual size for a particular target, it is reasonable to use the
206 /// TargetData subsystem to do this.
208 bool isSized() const {
209 // If it's a primitive, it is always sized.
210 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID)
212 // If it is not something that can have a size (e.g. a function or label),
213 // it doesn't have a size.
214 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID)
216 // If it is something that can have a size and it's concrete, it definitely
217 // has a size, otherwise we have to try harder to decide.
218 return !isAbstract() || isSizedDerivedType();
221 /// getPrimitiveSize - Return the basic size of this type if it is a primitive
222 /// type. These are fixed by LLVM and are not target dependent. This will
223 /// return zero if the type does not have a size or is not a primitive type.
225 unsigned getPrimitiveSize() const;
226 unsigned getPrimitiveSizeInBits() const;
228 /// getUnsignedVersion - If this is an integer type, return the unsigned
229 /// variant of this type. For example int -> uint.
230 const Type *getUnsignedVersion() const;
232 /// getSignedVersion - If this is an integer type, return the signed variant
233 /// of this type. For example uint -> int.
234 const Type *getSignedVersion() const;
236 /// getForwaredType - Return the type that this type has been resolved to if
237 /// it has been resolved to anything. This is used to implement the
238 /// union-find algorithm for type resolution, and shouldn't be used by general
240 const Type *getForwardedType() const {
241 if (!ForwardType) return 0;
242 return getForwardedTypeInternal();
245 /// getVAArgsPromotedType - Return the type an argument of this type
246 /// will be promoted to if passed through a variable argument
248 const Type *getVAArgsPromotedType() const {
249 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID)
251 else if (ID == SByteTyID || ID == ShortTyID)
253 else if (ID == FloatTyID)
254 return Type::DoubleTy;
259 //===--------------------------------------------------------------------===//
260 // Type Iteration support
262 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
263 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
264 subtype_iterator subtype_end() const { return ContainedTys.end(); }
266 /// getContainedType - This method is used to implement the type iterator
267 /// (defined a the end of the file). For derived types, this returns the
268 /// types 'contained' in the derived type.
270 const Type *getContainedType(unsigned i) const {
271 assert(i < ContainedTys.size() && "Index out of range!");
272 return ContainedTys[i];
275 /// getNumContainedTypes - Return the number of types in the derived type.
277 typedef std::vector<PATypeHandle>::size_type size_type;
278 size_type getNumContainedTypes() const { return ContainedTys.size(); }
280 //===--------------------------------------------------------------------===//
281 // Static members exported by the Type class itself. Useful for getting
282 // instances of Type.
285 /// getPrimitiveType - Return a type based on an identifier.
286 static const Type *getPrimitiveType(TypeID IDNumber);
288 //===--------------------------------------------------------------------===//
289 // These are the builtin types that are always available...
291 static Type *VoidTy , *BoolTy;
292 static Type *SByteTy, *UByteTy,
296 static Type *FloatTy, *DoubleTy;
298 static Type* LabelTy;
300 /// Methods for support type inquiry through isa, cast, and dyn_cast:
301 static inline bool classof(const Type *T) { return true; }
303 void addRef() const {
304 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
308 void dropRef() const {
309 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
310 assert(RefCount && "No objects are currently referencing this object!");
312 // If this is the last PATypeHolder using this object, and there are no
313 // PATypeHandles using it, the type is dead, delete it now.
314 if (--RefCount == 0 && AbstractTypeUsers.empty())
318 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
319 /// it. This function is called primarily by the PATypeHandle class.
321 void addAbstractTypeUser(AbstractTypeUser *U) const {
322 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
323 AbstractTypeUsers.push_back(U);
326 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
327 /// no longer has a handle to the type. This function is called primarily by
328 /// the PATypeHandle class. When there are no users of the abstract type, it
329 /// is annihilated, because there is no way to get a reference to it ever
332 void removeAbstractTypeUser(AbstractTypeUser *U) const;
334 /// clearAllTypeMaps - This method frees all internal memory used by the
335 /// type subsystem, which can be used in environments where this memory is
336 /// otherwise reported as a leak.
337 static void clearAllTypeMaps();
340 /// isSizedDerivedType - Derived types like structures and arrays are sized
341 /// iff all of the members of the type are sized as well. Since asking for
342 /// their size is relatively uncommon, move this operation out of line.
343 bool isSizedDerivedType() const;
345 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
346 virtual void typeBecameConcrete(const DerivedType *AbsTy);
349 // PromoteAbstractToConcrete - This is an internal method used to calculate
350 // change "Abstract" from true to false when types are refined.
351 void PromoteAbstractToConcrete();
352 friend class TypeMapBase;
355 //===----------------------------------------------------------------------===//
356 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
357 // These are defined here because they MUST be inlined, yet are dependent on
358 // the definition of the Type class. Of course Type derives from Value, which
359 // contains an AbstractTypeUser instance, so there is no good way to factor out
360 // the code. Hence this bit of uglyness.
362 // In the long term, Type should not derive from Value, allowing
363 // AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
364 // nastyness entirely.
366 inline void PATypeHandle::addUser() {
367 assert(Ty && "Type Handle has a null type!");
368 if (Ty->isAbstract())
369 Ty->addAbstractTypeUser(User);
371 inline void PATypeHandle::removeUser() {
372 if (Ty->isAbstract())
373 Ty->removeAbstractTypeUser(User);
376 // Define inline methods for PATypeHolder...
378 inline void PATypeHolder::addRef() {
379 if (Ty->isAbstract())
383 inline void PATypeHolder::dropRef() {
384 if (Ty->isAbstract())
388 /// get - This implements the forwarding part of the union-find algorithm for
389 /// abstract types. Before every access to the Type*, we check to see if the
390 /// type we are pointing to is forwarding to a new type. If so, we drop our
391 /// reference to the type.
393 inline Type* PATypeHolder::get() const {
394 const Type *NewTy = Ty->getForwardedType();
395 if (!NewTy) return const_cast<Type*>(Ty);
396 return *const_cast<PATypeHolder*>(this) = NewTy;
401 //===----------------------------------------------------------------------===//
402 // Provide specializations of GraphTraits to be able to treat a type as a
403 // graph of sub types...
405 template <> struct GraphTraits<Type*> {
406 typedef Type NodeType;
407 typedef Type::subtype_iterator ChildIteratorType;
409 static inline NodeType *getEntryNode(Type *T) { return T; }
410 static inline ChildIteratorType child_begin(NodeType *N) {
411 return N->subtype_begin();
413 static inline ChildIteratorType child_end(NodeType *N) {
414 return N->subtype_end();
418 template <> struct GraphTraits<const Type*> {
419 typedef const Type NodeType;
420 typedef Type::subtype_iterator ChildIteratorType;
422 static inline NodeType *getEntryNode(const Type *T) { return T; }
423 static inline ChildIteratorType child_begin(NodeType *N) {
424 return N->subtype_begin();
426 static inline ChildIteratorType child_end(NodeType *N) {
427 return N->subtype_end();
431 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
432 return Ty.getTypeID() == Type::PointerTyID;
435 std::ostream &operator<<(std::ostream &OS, const Type &T);
437 } // End llvm namespace