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"
54 ///===-------------------------------------------------------------------===//
55 /// Definitions of all of the base types for the Type system. Based on this
56 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
57 /// Note: If you add an element to this, you need to add an element to the
58 /// Type::getPrimitiveType function, or else things will break!
61 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
62 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
63 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
64 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
65 UIntTyID , IntTyID, // 6, 7: 32 bit types...
66 ULongTyID , LongTyID, // 8, 9: 64 bit types...
67 FloatTyID , DoubleTyID, // 10,11: Floating point types...
68 LabelTyID , // 12 : Labels...
70 // Derived types... see DerivedTypes.h file...
71 // Make sure FirstDerivedTyID stays up to date!!!
72 FunctionTyID , StructTyID, // Functions... Structs...
73 ArrayTyID , PointerTyID, // Array... pointer...
74 OpaqueTyID, // Opaque type instances...
75 PackedTyID, // SIMD 'packed' format...
78 NumTypeIDs, // Must remain as last defined ID
79 LastPrimitiveTyID = LabelTyID,
80 FirstDerivedTyID = FunctionTyID,
84 TypeID ID : 8; // The current base type of this type.
85 bool Abstract; // True if type contains an OpaqueType
87 /// RefCount - This counts the number of PATypeHolders that are pointing to
88 /// this type. When this number falls to zero, if the type is abstract and
89 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
92 mutable unsigned RefCount;
94 const Type *getForwardedTypeInternal() const;
96 Type(const std::string& Name, TypeID id);
99 /// Types can become nonabstract later, if they are refined.
101 inline void setAbstract(bool Val) { Abstract = Val; }
103 /// isTypeAbstract - This method is used to calculate the Abstract bit.
105 bool isTypeAbstract();
107 unsigned getRefCount() const { return RefCount; }
109 /// ForwardType - This field is used to implement the union find scheme for
110 /// abstract types. When types are refined to other types, this field is set
111 /// to the more refined type. Only abstract types can be forwarded.
112 mutable const Type *ForwardType;
114 /// ContainedTys - The list of types contained by this one. For example, this
115 /// includes the arguments of a function type, the elements of the structure,
116 /// the pointee of a pointer, etc. Note that keeping this vector in the Type
117 /// class wastes some space for types that do not contain anything (such as
118 /// primitive types). However, keeping it here allows the subtype_* members
119 /// to be implemented MUCH more efficiently, and dynamically very few types do
120 /// not contain any elements (most are derived).
121 std::vector<PATypeHandle> ContainedTys;
124 virtual void print(std::ostream &O) const;
126 /// @brief Debugging support: print to stderr
127 virtual void dump() const;
129 //===--------------------------------------------------------------------===//
130 // Property accessors for dealing with types... Some of these virtual methods
131 // are defined in private classes defined in Type.cpp for primitive types.
134 /// getTypeID - Return the type id for the type. This will return one
135 /// of the TypeID enum elements defined above.
137 inline TypeID getTypeID() const { return ID; }
139 /// getDescription - Return the string representation of the type...
140 const std::string &getDescription() const;
142 /// isSigned - Return whether an integral numeric type is signed. This is
143 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
144 /// Float and Double.
146 bool isSigned() const {
147 return ID == SByteTyID || ID == ShortTyID ||
148 ID == IntTyID || ID == LongTyID;
151 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
152 /// the complement of isSigned... nonnumeric types return false as they do
153 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
156 bool isUnsigned() const {
157 return ID == UByteTyID || ID == UShortTyID ||
158 ID == UIntTyID || ID == ULongTyID;
161 /// isInteger - Equivalent to isSigned() || isUnsigned()
163 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
165 /// isIntegral - Returns true if this is an integral type, which is either
166 /// BoolTy or one of the Integer types.
168 bool isIntegral() const { return isInteger() || this == BoolTy; }
170 /// isFloatingPoint - Return true if this is one of the two floating point
172 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
174 /// isAbstract - True if the type is either an Opaque type, or is a derived
175 /// type that includes an opaque type somewhere in it.
177 inline bool isAbstract() const { return Abstract; }
179 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
180 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
182 bool isLosslesslyConvertibleTo(const Type *Ty) const;
185 /// Here are some useful little methods to query what type derived types are
186 /// Note that all other types can just compare to see if this == Type::xxxTy;
188 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
189 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
191 /// isFirstClassType - Return true if the value is holdable in a register.
192 inline bool isFirstClassType() const {
193 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
194 ID == PointerTyID || ID == PackedTyID;
197 /// isSized - Return true if it makes sense to take the size of this type. To
198 /// get the actual size for a particular target, it is reasonable to use the
199 /// TargetData subsystem to do this.
201 bool isSized() const {
202 return (ID >= BoolTyID && ID <= DoubleTyID) || ID == PointerTyID ||
203 isSizedDerivedType();
206 /// getPrimitiveSize - Return the basic size of this type if it is a primitive
207 /// type. These are fixed by LLVM and are not target dependent. This will
208 /// return zero if the type does not have a size or is not a primitive type.
210 unsigned getPrimitiveSize() const;
212 /// getUnsignedVersion - If this is an integer type, return the unsigned
213 /// variant of this type. For example int -> uint.
214 const Type *getUnsignedVersion() const;
216 /// getSignedVersion - If this is an integer type, return the signed variant
217 /// of this type. For example uint -> int.
218 const Type *getSignedVersion() const;
220 /// getForwaredType - Return the type that this type has been resolved to if
221 /// it has been resolved to anything. This is used to implement the
222 /// union-find algorithm for type resolution, and shouldn't be used by general
224 const Type *getForwardedType() const {
225 if (!ForwardType) return 0;
226 return getForwardedTypeInternal();
229 //===--------------------------------------------------------------------===//
230 // Type Iteration support
232 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
233 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
234 subtype_iterator subtype_end() const { return ContainedTys.end(); }
236 /// getContainedType - This method is used to implement the type iterator
237 /// (defined a the end of the file). For derived types, this returns the
238 /// types 'contained' in the derived type.
240 const Type *getContainedType(unsigned i) const {
241 assert(i < ContainedTys.size() && "Index out of range!");
242 return ContainedTys[i];
245 /// getNumContainedTypes - Return the number of types in the derived type.
247 unsigned getNumContainedTypes() const { return ContainedTys.size(); }
249 //===--------------------------------------------------------------------===//
250 // Static members exported by the Type class itself. Useful for getting
251 // instances of Type.
254 /// getPrimitiveType - Return a type based on an identifier.
255 static const Type *getPrimitiveType(TypeID IDNumber);
257 //===--------------------------------------------------------------------===//
258 // These are the builtin types that are always available...
260 static Type *VoidTy , *BoolTy;
261 static Type *SByteTy, *UByteTy,
265 static Type *FloatTy, *DoubleTy;
267 static Type* LabelTy;
269 /// Methods for support type inquiry through isa, cast, and dyn_cast:
270 static inline bool classof(const Type *T) { return true; }
272 #include "llvm/Type.def"
274 // Virtual methods used by callbacks below. These should only be implemented
275 // in the DerivedType class.
276 virtual void addAbstractTypeUser(AbstractTypeUser *U) const {
277 abort(); // Only on derived types!
279 virtual void removeAbstractTypeUser(AbstractTypeUser *U) const {
280 abort(); // Only on derived types!
283 void addRef() const {
284 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
288 void dropRef() const {
289 assert(isAbstract() && "Cannot drop a refernce to a non-abstract type!");
290 assert(RefCount && "No objects are currently referencing this object!");
292 // If this is the last PATypeHolder using this object, and there are no
293 // PATypeHandles using it, the type is dead, delete it now.
298 /// isSizedDerivedType - Derived types like structures and arrays are sized
299 /// iff all of the members of the type are sized as well. Since asking for
300 /// their size is relatively uncommon, move this operation out of line.
301 bool isSizedDerivedType() const;
303 virtual void RefCountIsZero() const {
304 abort(); // only on derived types!
309 //===----------------------------------------------------------------------===//
310 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
311 // These are defined here because they MUST be inlined, yet are dependent on
312 // the definition of the Type class. Of course Type derives from Value, which
313 // contains an AbstractTypeUser instance, so there is no good way to factor out
314 // the code. Hence this bit of uglyness.
316 // In the long term, Type should not derive from Value, allowing
317 // AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
318 // nastyness entirely.
320 inline void PATypeHandle::addUser() {
321 assert(Ty && "Type Handle has a null type!");
322 if (Ty->isAbstract())
323 Ty->addAbstractTypeUser(User);
325 inline void PATypeHandle::removeUser() {
326 if (Ty->isAbstract())
327 Ty->removeAbstractTypeUser(User);
330 inline void PATypeHandle::removeUserFromConcrete() {
331 if (!Ty->isAbstract())
332 Ty->removeAbstractTypeUser(User);
335 // Define inline methods for PATypeHolder...
337 inline void PATypeHolder::addRef() {
338 if (Ty->isAbstract())
342 inline void PATypeHolder::dropRef() {
343 if (Ty->isAbstract())
347 /// get - This implements the forwarding part of the union-find algorithm for
348 /// abstract types. Before every access to the Type*, we check to see if the
349 /// type we are pointing to is forwarding to a new type. If so, we drop our
350 /// reference to the type.
352 inline Type* PATypeHolder::get() const {
353 const Type *NewTy = Ty->getForwardedType();
354 if (!NewTy) return const_cast<Type*>(Ty);
355 return *const_cast<PATypeHolder*>(this) = NewTy;
360 //===----------------------------------------------------------------------===//
361 // Provide specializations of GraphTraits to be able to treat a type as a
362 // graph of sub types...
364 template <> struct GraphTraits<Type*> {
365 typedef Type NodeType;
366 typedef Type::subtype_iterator ChildIteratorType;
368 static inline NodeType *getEntryNode(Type *T) { return T; }
369 static inline ChildIteratorType child_begin(NodeType *N) {
370 return N->subtype_begin();
372 static inline ChildIteratorType child_end(NodeType *N) {
373 return N->subtype_end();
377 template <> struct GraphTraits<const Type*> {
378 typedef const Type NodeType;
379 typedef Type::subtype_iterator ChildIteratorType;
381 static inline NodeType *getEntryNode(const Type *T) { return T; }
382 static inline ChildIteratorType child_begin(NodeType *N) {
383 return N->subtype_begin();
385 static inline ChildIteratorType child_end(NodeType *N) {
386 return N->subtype_end();
390 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
391 return Ty.getTypeID() == Type::PointerTyID;
394 std::ostream &operator<<(std::ostream &OS, const Type &T);
396 } // End llvm namespace