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 wierd 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 "Support/Casting.h"
39 #include "Support/GraphTraits.h"
40 #include "Support/iterator"
53 ///===-------------------------------------------------------------------===//
54 /// Definitions of all of the base types for the Type system. Based on this
55 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
56 /// Note: If you add an element to this, you need to add an element to the
57 /// Type::getPrimitiveType function, or else things will break!
60 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
61 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
62 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
63 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
64 UIntTyID , IntTyID, // 6, 7: 32 bit types...
65 ULongTyID , LongTyID, // 8, 9: 64 bit types...
66 FloatTyID , DoubleTyID, // 10,11: Floating point types...
67 LabelTyID , // 12 : Labels...
69 // Derived types... see DerivedTypes.h file...
70 // Make sure FirstDerivedTyID stays up to date!!!
71 FunctionTyID , StructTyID, // Functions... Structs...
72 ArrayTyID , PointerTyID, // Array... pointer...
73 OpaqueTyID, // Opaque type instances...
74 //PackedTyID , // SIMD 'packed' format... TODO
77 NumTypeIDs, // Must remain as last defined ID
78 LastPrimitiveTyID = LabelTyID,
79 FirstDerivedTyID = FunctionTyID,
83 TypeID ID : 8; // The current base type of this type.
84 bool Abstract; // True if type contains an OpaqueType
86 /// RefCount - This counts the number of PATypeHolders that are pointing to
87 /// this type. When this number falls to zero, if the type is abstract and
88 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
91 mutable unsigned RefCount;
93 const Type *getForwardedTypeInternal() const;
95 Type(const std::string& Name, TypeID id);
98 /// Types can become nonabstract later, if they are refined.
100 inline void setAbstract(bool Val) { Abstract = Val; }
102 /// isTypeAbstract - This method is used to calculate the Abstract bit.
104 bool isTypeAbstract();
106 unsigned getRefCount() const { return RefCount; }
108 /// ForwardType - This field is used to implement the union find scheme for
109 /// abstract types. When types are refined to other types, this field is set
110 /// to the more refined type. Only abstract types can be forwarded.
111 mutable const Type *ForwardType;
113 /// ContainedTys - The list of types contained by this one. For example, this
114 /// includes the arguments of a function type, the elements of the structure,
115 /// the pointee of a pointer, etc. Note that keeping this vector in the Type
116 /// class wastes some space for types that do not contain anything (such as
117 /// primitive types). However, keeping it here allows the subtype_* members
118 /// to be implemented MUCH more efficiently, and dynamically very few types do
119 /// not contain any elements (most are derived).
120 std::vector<PATypeHandle> ContainedTys;
123 virtual void print(std::ostream &O) const;
125 /// @brief Debugging support: print to stderr
126 virtual void dump() const;
128 //===--------------------------------------------------------------------===//
129 // Property accessors for dealing with types... Some of these virtual methods
130 // are defined in private classes defined in Type.cpp for primitive types.
133 /// getTypeID - Return the type id for the type. This will return one
134 /// of the TypeID enum elements defined above.
136 inline TypeID getTypeID() const { return ID; }
138 /// getDescription - Return the string representation of the type...
139 const std::string &getDescription() const;
141 /// isSigned - Return whether an integral numeric type is signed. This is
142 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
143 /// Float and Double.
145 bool isSigned() const {
146 return ID == SByteTyID || ID == ShortTyID ||
147 ID == IntTyID || ID == LongTyID;
150 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
151 /// the complement of isSigned... nonnumeric types return false as they do
152 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
155 bool isUnsigned() const {
156 return ID == UByteTyID || ID == UShortTyID ||
157 ID == UIntTyID || ID == ULongTyID;
160 /// isInteger - Equivalent to isSigned() || isUnsigned()
162 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
164 /// isIntegral - Returns true if this is an integral type, which is either
165 /// BoolTy or one of the Integer types.
167 bool isIntegral() const { return isInteger() || this == BoolTy; }
169 /// isFloatingPoint - Return true if this is one of the two floating point
171 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
173 /// isAbstract - True if the type is either an Opaque type, or is a derived
174 /// type that includes an opaque type somewhere in it.
176 inline bool isAbstract() const { return Abstract; }
178 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
179 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
181 bool isLosslesslyConvertibleTo(const Type *Ty) const;
184 /// Here are some useful little methods to query what type derived types are
185 /// Note that all other types can just compare to see if this == Type::xxxTy;
187 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
188 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
190 /// isFirstClassType - Return true if the value is holdable in a register.
191 inline bool isFirstClassType() const {
192 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || ID == PointerTyID;
195 /// isSized - Return true if it makes sense to take the size of this type. To
196 /// get the actual size for a particular target, it is reasonable to use the
197 /// TargetData subsystem to do this.
199 bool isSized() const {
200 return (ID >= BoolTyID && ID <= DoubleTyID) || ID == PointerTyID ||
201 isSizedDerivedType();
204 /// getPrimitiveSize - Return the basic size of this type if it is a primitive
205 /// type. These are fixed by LLVM and are not target dependent. This will
206 /// return zero if the type does not have a size or is not a primitive type.
208 unsigned getPrimitiveSize() const;
210 /// getUnsignedVersion - If this is an integer type, return the unsigned
211 /// variant of this type. For example int -> uint.
212 const Type *getUnsignedVersion() const;
214 /// getSignedVersion - If this is an integer type, return the signed variant
215 /// of this type. For example uint -> int.
216 const Type *getSignedVersion() const;
218 /// getForwaredType - Return the type that this type has been resolved to if
219 /// it has been resolved to anything. This is used to implement the
220 /// union-find algorithm for type resolution, and shouldn't be used by general
222 const Type *getForwardedType() const {
223 if (!ForwardType) return 0;
224 return getForwardedTypeInternal();
227 //===--------------------------------------------------------------------===//
228 // Type Iteration support
230 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
231 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
232 subtype_iterator subtype_end() const { return ContainedTys.end(); }
234 /// getContainedType - This method is used to implement the type iterator
235 /// (defined a the end of the file). For derived types, this returns the
236 /// types 'contained' in the derived type.
238 const Type *getContainedType(unsigned i) const {
239 assert(i < ContainedTys.size() && "Index out of range!");
240 return ContainedTys[i];
243 /// getNumContainedTypes - Return the number of types in the derived type.
245 unsigned getNumContainedTypes() const { return ContainedTys.size(); }
247 //===--------------------------------------------------------------------===//
248 // Static members exported by the Type class itself. Useful for getting
249 // instances of Type.
252 /// getPrimitiveType - Return a type based on an identifier.
253 static const Type *getPrimitiveType(TypeID IDNumber);
255 //===--------------------------------------------------------------------===//
256 // These are the builtin types that are always available...
258 static Type *VoidTy , *BoolTy;
259 static Type *SByteTy, *UByteTy,
263 static Type *FloatTy, *DoubleTy;
265 static Type* LabelTy;
267 /// Methods for support type inquiry through isa, cast, and dyn_cast:
268 static inline bool classof(const Type *T) { return true; }
270 #include "llvm/Type.def"
272 // Virtual methods used by callbacks below. These should only be implemented
273 // in the DerivedType class.
274 virtual void addAbstractTypeUser(AbstractTypeUser *U) const {
275 abort(); // Only on derived types!
277 virtual void removeAbstractTypeUser(AbstractTypeUser *U) const {
278 abort(); // Only on derived types!
281 void addRef() const {
282 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
286 void dropRef() const {
287 assert(isAbstract() && "Cannot drop a refernce to a non-abstract type!");
288 assert(RefCount && "No objects are currently referencing this object!");
290 // If this is the last PATypeHolder using this object, and there are no
291 // PATypeHandles using it, the type is dead, delete it now.
296 /// isSizedDerivedType - Derived types like structures and arrays are sized
297 /// iff all of the members of the type are sized as well. Since asking for
298 /// their size is relatively uncommon, move this operation out of line.
299 bool isSizedDerivedType() const;
301 virtual void RefCountIsZero() const {
302 abort(); // only on derived types!
307 //===----------------------------------------------------------------------===//
308 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
309 // These are defined here because they MUST be inlined, yet are dependent on
310 // the definition of the Type class. Of course Type derives from Value, which
311 // contains an AbstractTypeUser instance, so there is no good way to factor out
312 // the code. Hence this bit of uglyness.
314 // In the long term, Type should not derive from Value, allowing
315 // AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
316 // nastyness entirely.
318 inline void PATypeHandle::addUser() {
319 assert(Ty && "Type Handle has a null type!");
320 if (Ty->isAbstract())
321 Ty->addAbstractTypeUser(User);
323 inline void PATypeHandle::removeUser() {
324 if (Ty->isAbstract())
325 Ty->removeAbstractTypeUser(User);
328 inline void PATypeHandle::removeUserFromConcrete() {
329 if (!Ty->isAbstract())
330 Ty->removeAbstractTypeUser(User);
333 // Define inline methods for PATypeHolder...
335 inline void PATypeHolder::addRef() {
336 if (Ty->isAbstract())
340 inline void PATypeHolder::dropRef() {
341 if (Ty->isAbstract())
345 /// get - This implements the forwarding part of the union-find algorithm for
346 /// abstract types. Before every access to the Type*, we check to see if the
347 /// type we are pointing to is forwarding to a new type. If so, we drop our
348 /// reference to the type.
350 inline Type* PATypeHolder::get() const {
351 const Type *NewTy = Ty->getForwardedType();
352 if (!NewTy) return const_cast<Type*>(Ty);
353 return *const_cast<PATypeHolder*>(this) = NewTy;
358 //===----------------------------------------------------------------------===//
359 // Provide specializations of GraphTraits to be able to treat a type as a
360 // graph of sub types...
362 template <> struct GraphTraits<Type*> {
363 typedef Type NodeType;
364 typedef Type::subtype_iterator ChildIteratorType;
366 static inline NodeType *getEntryNode(Type *T) { return T; }
367 static inline ChildIteratorType child_begin(NodeType *N) {
368 return N->subtype_begin();
370 static inline ChildIteratorType child_end(NodeType *N) {
371 return N->subtype_end();
375 template <> struct GraphTraits<const Type*> {
376 typedef const Type NodeType;
377 typedef Type::subtype_iterator ChildIteratorType;
379 static inline NodeType *getEntryNode(const Type *T) { return T; }
380 static inline ChildIteratorType child_begin(NodeType *N) {
381 return N->subtype_begin();
383 static inline ChildIteratorType child_end(NodeType *N) {
384 return N->subtype_end();
388 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
389 return Ty.getTypeID() == Type::PointerTyID;
392 std::ostream &operator<<(std::ostream &OS, const Type &T);
394 } // End llvm namespace