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... TODO
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
86 unsigned UID; // The unique ID number for this class
88 /// RefCount - This counts the number of PATypeHolders that are pointing to
89 /// this type. When this number falls to zero, if the type is abstract and
90 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
93 mutable unsigned RefCount;
95 const Type *getForwardedTypeInternal() const;
97 Type(const std::string& Name, TypeID id);
101 /// Types can become nonabstract later, if they are refined.
103 inline void setAbstract(bool Val) { Abstract = Val; }
105 /// isTypeAbstract - This method is used to calculate the Abstract bit.
107 bool isTypeAbstract();
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;
126 virtual void print(std::ostream &O) const;
128 /// @brief Debugging support: print to stderr
129 virtual void dump() const;
131 /// setName - Associate the name with this type in the symbol table, but don't
132 /// set the local name to be equal specified name.
134 virtual void setName(const std::string &Name, SymbolTable *ST = 0);
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 /// getUniqueID - Returns the UID of the type. This can be thought of as a
147 /// small integer version of the pointer to the type class. Two types that
148 /// are structurally different have different UIDs. This can be used for
149 /// indexing types into an array.
151 inline unsigned getUniqueID() const { return UID; }
153 /// getDescription - Return the string representation of the type...
154 const std::string &getDescription() const;
156 /// isSigned - Return whether an integral numeric type is signed. This is
157 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
158 /// Float and Double.
160 bool isSigned() const {
161 return ID == SByteTyID || ID == ShortTyID ||
162 ID == IntTyID || ID == LongTyID;
165 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
166 /// the complement of isSigned... nonnumeric types return false as they do
167 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
170 bool isUnsigned() const {
171 return ID == UByteTyID || ID == UShortTyID ||
172 ID == UIntTyID || ID == ULongTyID;
175 /// isInteger - Equivalent to isSigned() || isUnsigned()
177 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
179 /// isIntegral - Returns true if this is an integral type, which is either
180 /// BoolTy or one of the Integer types.
182 bool isIntegral() const { return isInteger() || this == BoolTy; }
184 /// isFloatingPoint - Return true if this is one of the two floating point
186 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
188 /// isAbstract - True if the type is either an Opaque type, or is a derived
189 /// type that includes an opaque type somewhere in it.
191 inline bool isAbstract() const { return Abstract; }
193 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
194 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
196 bool isLosslesslyConvertibleTo(const Type *Ty) const;
199 /// Here are some useful little methods to query what type derived types are
200 /// Note that all other types can just compare to see if this == Type::xxxTy;
202 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
203 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
205 /// isFirstClassType - Return true if the value is holdable in a register.
206 inline bool isFirstClassType() const {
207 return (ID != VoidTyID && ID <= LastPrimitiveTyID) || ID == PointerTyID;
210 /// isSized - Return true if it makes sense to take the size of this type. To
211 /// get the actual size for a particular target, it is reasonable to use the
212 /// TargetData subsystem to do this.
214 bool isSized() const {
215 return (ID >= BoolTyID && ID <= DoubleTyID) || ID == PointerTyID ||
216 isSizedDerivedType();
219 /// getPrimitiveSize - Return the basic size of this type if it is a primative
220 /// type. These are fixed by LLVM and are not target dependent. This will
221 /// return zero if the type does not have a size or is not a primitive type.
223 unsigned getPrimitiveSize() const;
225 /// getUnsignedVersion - If this is an integer type, return the unsigned
226 /// variant of this type. For example int -> uint.
227 const Type *getUnsignedVersion() const;
229 /// getSignedVersion - If this is an integer type, return the signed variant
230 /// of this type. For example uint -> int.
231 const Type *getSignedVersion() const;
233 /// getForwaredType - Return the type that this type has been resolved to if
234 /// it has been resolved to anything. This is used to implement the
235 /// union-find algorithm for type resolution, and shouldn't be used by general
237 const Type *getForwardedType() const {
238 if (!ForwardType) return 0;
239 return getForwardedTypeInternal();
242 //===--------------------------------------------------------------------===//
243 // Type Iteration support
245 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
246 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
247 subtype_iterator subtype_end() const { return ContainedTys.end(); }
249 /// getContainedType - This method is used to implement the type iterator
250 /// (defined a the end of the file). For derived types, this returns the
251 /// types 'contained' in the derived type.
253 const Type *getContainedType(unsigned i) const {
254 assert(i < ContainedTys.size() && "Index out of range!");
255 return ContainedTys[i];
258 /// getNumContainedTypes - Return the number of types in the derived type.
260 unsigned getNumContainedTypes() const { return ContainedTys.size(); }
262 //===--------------------------------------------------------------------===//
263 // Static members exported by the Type class itself. Useful for getting
264 // instances of Type.
267 /// getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
268 static const Type *getPrimitiveType(TypeID IDNumber);
269 static const Type *getUniqueIDType(unsigned UID);
271 //===--------------------------------------------------------------------===//
272 // These are the builtin types that are always available...
274 static Type *VoidTy , *BoolTy;
275 static Type *SByteTy, *UByteTy,
279 static Type *FloatTy, *DoubleTy;
281 static Type* LabelTy;
283 /// Methods for support type inquiry through isa, cast, and dyn_cast:
284 static inline bool classof(const Type *T) { return true; }
286 #include "llvm/Type.def"
288 // Virtual methods used by callbacks below. These should only be implemented
289 // in the DerivedType class.
290 virtual void addAbstractTypeUser(AbstractTypeUser *U) const {
291 abort(); // Only on derived types!
293 virtual void removeAbstractTypeUser(AbstractTypeUser *U) const {
294 abort(); // Only on derived types!
297 void addRef() const {
298 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
302 void dropRef() const {
303 assert(isAbstract() && "Cannot drop a refernce to a non-abstract type!");
304 assert(RefCount && "No objects are currently referencing this object!");
306 // If this is the last PATypeHolder using this object, and there are no
307 // PATypeHandles using it, the type is dead, delete it now.
312 /// isSizedDerivedType - Derived types like structures and arrays are sized
313 /// iff all of the members of the type are sized as well. Since asking for
314 /// their size is relatively uncommon, move this operation out of line.
315 bool isSizedDerivedType() const;
317 virtual void RefCountIsZero() const {
318 abort(); // only on derived types!
323 //===----------------------------------------------------------------------===//
324 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
325 // These are defined here because they MUST be inlined, yet are dependent on
326 // the definition of the Type class. Of course Type derives from Value, which
327 // contains an AbstractTypeUser instance, so there is no good way to factor out
328 // the code. Hence this bit of uglyness.
330 // In the long term, Type should not derive from Value, allowing
331 // AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
332 // nastyness entirely.
334 inline void PATypeHandle::addUser() {
335 assert(Ty && "Type Handle has a null type!");
336 if (Ty->isAbstract())
337 Ty->addAbstractTypeUser(User);
339 inline void PATypeHandle::removeUser() {
340 if (Ty->isAbstract())
341 Ty->removeAbstractTypeUser(User);
344 inline void PATypeHandle::removeUserFromConcrete() {
345 if (!Ty->isAbstract())
346 Ty->removeAbstractTypeUser(User);
349 // Define inline methods for PATypeHolder...
351 inline void PATypeHolder::addRef() {
352 if (Ty->isAbstract())
356 inline void PATypeHolder::dropRef() {
357 if (Ty->isAbstract())
361 /// get - This implements the forwarding part of the union-find algorithm for
362 /// abstract types. Before every access to the Type*, we check to see if the
363 /// type we are pointing to is forwarding to a new type. If so, we drop our
364 /// reference to the type.
366 inline const Type* PATypeHolder::get() const {
367 const Type *NewTy = Ty->getForwardedType();
368 if (!NewTy) return Ty;
369 return *const_cast<PATypeHolder*>(this) = NewTy;
374 //===----------------------------------------------------------------------===//
375 // Provide specializations of GraphTraits to be able to treat a type as a
376 // graph of sub types...
378 template <> struct GraphTraits<Type*> {
379 typedef Type NodeType;
380 typedef Type::subtype_iterator ChildIteratorType;
382 static inline NodeType *getEntryNode(Type *T) { return T; }
383 static inline ChildIteratorType child_begin(NodeType *N) {
384 return N->subtype_begin();
386 static inline ChildIteratorType child_end(NodeType *N) {
387 return N->subtype_end();
391 template <> struct GraphTraits<const Type*> {
392 typedef const Type NodeType;
393 typedef Type::subtype_iterator ChildIteratorType;
395 static inline NodeType *getEntryNode(const Type *T) { return T; }
396 static inline ChildIteratorType child_begin(NodeType *N) {
397 return N->subtype_begin();
399 static inline ChildIteratorType child_end(NodeType *N) {
400 return N->subtype_end();
404 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
405 return Ty.getTypeID() == Type::PointerTyID;
408 std::ostream &operator<<(std::ostream &OS, const Type *T);
409 std::ostream &operator<<(std::ostream &OS, const Type &T);
411 } // End llvm namespace