1 //===-- llvm/Type.h - Classes for handling data types ------------*- C++ -*--=//
3 // This file contains the declaration of the Type class. For more "Type" type
4 // stuff, look in DerivedTypes.h and Opt/ConstantHandling.h
6 // Note that instances of the Type class are immutable: once they are created,
7 // they are never changed. Also note that only one instance of a particular
8 // type is ever created. Thus seeing if two types are equal is a matter of
9 // doing a trivial pointer comparison.
11 // Types, once allocated, are never free'd.
13 // Opaque types are simple derived types with no state. There may be many
14 // different Opaque type objects floating around, but two are only considered
15 // identical if they are pointer equals of each other. This allows us to have
16 // two opaque types that end up resolving to different concrete types later.
18 // Opaque types are also kinda wierd and scary and different because they have
19 // to keep a list of uses of the type. When, through linking, parsing, or
20 // bytecode reading, they become resolved, they need to find and update all
21 // users of the unknown type, causing them to reference a new, more concrete
22 // type. Opaque types are deleted when their use list dwindles to zero users.
24 //===----------------------------------------------------------------------===//
29 #include "llvm/Value.h"
30 #include "Support/GraphTraits.h"
39 class Type : public Value {
41 //===--------------------------------------------------------------------===//
42 // Definitions of all of the base types for the Type system. Based on this
43 // value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
44 // Note: If you add an element to this, you need to add an element to the
45 // Type::getPrimitiveType function, or else things will break!
48 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
49 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
50 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
51 UIntTyID , IntTyID, // 6, 7: 32 bit types...
52 ULongTyID , LongTyID, // 8, 9: 64 bit types...
54 FloatTyID , DoubleTyID, // 10,11: Floating point types...
56 TypeTyID, // 12 : Type definitions
57 LabelTyID , // 13 : Labels...
59 // Derived types... see DerivedTypes.h file...
60 // Make sure FirstDerivedTyID stays up to date!!!
61 FunctionTyID , StructTyID, // Functions... Structs...
62 ArrayTyID , PointerTyID, // Array... pointer...
63 OpaqueTyID, // Opaque type instances...
64 //PackedTyID , // SIMD 'packed' format... TODO
67 NumPrimitiveIDs, // Must remain as last defined ID
68 FirstDerivedTyID = FunctionTyID,
72 PrimitiveID ID; // The current base type of this type...
73 unsigned UID; // The unique ID number for this class
74 std::string Desc; // The printed name of the string...
75 bool Abstract; // True if type contains an OpaqueType
76 bool Recursive; // True if the type is recursive
79 // ctor is protected, so only subclasses can create Type objects...
80 Type(const std::string &Name, PrimitiveID id);
83 // When types are refined, they update their description to be more concrete.
85 inline void setDescription(const std::string &D) { Desc = D; }
87 // setName - Associate the name with this type in the symbol table, but don't
88 // set the local name to be equal specified name.
90 virtual void setName(const std::string &Name, SymbolTable *ST = 0);
92 // Types can become nonabstract later, if they are refined.
94 inline void setAbstract(bool Val) { Abstract = Val; }
96 // Types can become recursive later, if they are refined.
98 inline void setRecursive(bool Val) { Recursive = Val; }
102 //===--------------------------------------------------------------------===//
103 // Property accessors for dealing with types...
106 // getPrimitiveID - Return the base type of the type. This will return one
107 // of the PrimitiveID enum elements defined above.
109 inline PrimitiveID getPrimitiveID() const { return ID; }
111 // getUniqueID - Returns the UID of the type. This can be thought of as a
112 // small integer version of the pointer to the type class. Two types that are
113 // structurally different have different UIDs. This can be used for indexing
114 // types into an array.
116 inline unsigned getUniqueID() const { return UID; }
118 // getDescription - Return the string representation of the type...
119 inline const std::string &getDescription() const { return Desc; }
121 // isSigned - Return whether a numeric type is signed.
122 virtual bool isSigned() const { return 0; }
124 // isUnsigned - Return whether a numeric type is unsigned. This is not
125 // quite the complement of isSigned... nonnumeric types return false as they
128 virtual bool isUnsigned() const { return 0; }
130 // isIntegral - Equilivent to isSigned() || isUnsigned, but with only a single
131 // virtual function invocation.
133 virtual bool isIntegral() const { return 0; }
135 // isAbstract - True if the type is either an Opaque type, or is a derived
136 // type that includes an opaque type somewhere in it.
138 inline bool isAbstract() const { return Abstract; }
140 // isRecursive - True if the type graph contains a cycle.
142 inline bool isRecursive() const { return Recursive; }
144 // isLosslesslyConvertableTo - Return true if this type can be converted to
145 // 'Ty' without any reinterpretation of bits. For example, uint to int.
147 bool isLosslesslyConvertableTo(const Type *Ty) const;
149 // isSized - Return true if it makes sense to take the size of this type. To
150 // get the actual size for a particular target, it is reasonable to use the
151 // TargetData subsystem to do this.
153 bool isSized() const {
154 return ID != TypeTyID && ID != FunctionTyID && ID != OpaqueTyID;
157 //===--------------------------------------------------------------------===//
158 // Type Iteration support
161 typedef TypeIterator subtype_iterator;
162 inline subtype_iterator subtype_begin() const; // DEFINED BELOW
163 inline subtype_iterator subtype_end() const; // DEFINED BELOW
165 // getContainedType - This method is used to implement the type iterator
166 // (defined a the end of the file). For derived types, this returns the types
167 // 'contained' in the derived type, returning 0 when 'i' becomes invalid. This
168 // allows the user to iterate over the types in a struct, for example, really
171 virtual const Type *getContainedType(unsigned i) const { return 0; }
173 // getNumContainedTypes - Return the number of types in the derived type
174 virtual unsigned getNumContainedTypes() const { return 0; }
176 //===--------------------------------------------------------------------===//
177 // Static members exported by the Type class itself. Useful for getting
178 // instances of Type.
181 // getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
182 static const Type *getPrimitiveType(PrimitiveID IDNumber);
183 static const Type *getUniqueIDType(unsigned UID);
185 //===--------------------------------------------------------------------===//
186 // These are the builtin types that are always available...
188 static Type *VoidTy , *BoolTy;
189 static Type *SByteTy, *UByteTy,
193 static Type *FloatTy, *DoubleTy;
195 static Type *TypeTy , *LabelTy;
197 // Here are some useful little methods to query what type derived types are
198 // Note that all other types can just compare to see if this == Type::xxxTy;
200 inline bool isPrimitiveType() const { return ID < FirstDerivedTyID; }
201 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
203 // isFirstClassType - Return true if the value is holdable in a register.
204 inline bool isFirstClassType() const {
205 return isPrimitiveType() || ID == PointerTyID;
208 // Methods for support type inquiry through isa, cast, and dyn_cast:
209 static inline bool classof(const Type *T) { return true; }
210 static inline bool classof(const Value *V) {
211 return V->getValueType() == Value::TypeVal;
214 // Methods for determining the subtype of this Type. This section defines a
215 // family of isArrayType(), isLabelType(), etc functions...
217 #define HANDLE_PRIM_TYPE(NAME, SIZE) \
218 inline bool is##NAME##Type() const { return ID == NAME##TyID; }
219 #define HANDLE_DERV_TYPE(NAME, CLASS) \
220 inline bool is##NAME##Type() const { return ID == NAME##TyID; }
222 #include "llvm/Type.def"
225 class TypeIterator : public std::bidirectional_iterator<const Type,
227 const Type * const Ty;
230 typedef TypeIterator _Self;
232 inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
233 inline ~TypeIterator() {}
235 inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
236 inline bool operator!=(const _Self& x) const { return !operator==(x); }
238 inline pointer operator*() const { return Ty->getContainedType(Idx); }
239 inline pointer operator->() const { return operator*(); }
241 inline _Self& operator++() { ++Idx; return *this; } // Preincrement
242 inline _Self operator++(int) { // Postincrement
243 _Self tmp = *this; ++*this; return tmp;
246 inline _Self& operator--() { --Idx; return *this; } // Predecrement
247 inline _Self operator--(int) { // Postdecrement
248 _Self tmp = *this; --*this; return tmp;
253 inline Type::TypeIterator Type::subtype_begin() const {
254 return TypeIterator(this, 0);
257 inline Type::TypeIterator Type::subtype_end() const {
258 return TypeIterator(this, getNumContainedTypes());
262 // Provide specializations of GraphTraits to be able to treat a type as a
263 // graph of sub types...
265 template <> struct GraphTraits<Type*> {
266 typedef Type NodeType;
267 typedef Type::subtype_iterator ChildIteratorType;
269 static inline NodeType *getEntryNode(Type *T) { return T; }
270 static inline ChildIteratorType child_begin(NodeType *N) {
271 return N->subtype_begin();
273 static inline ChildIteratorType child_end(NodeType *N) {
274 return N->subtype_end();
278 template <> struct GraphTraits<const Type*> {
279 typedef const Type NodeType;
280 typedef Type::subtype_iterator ChildIteratorType;
282 static inline NodeType *getEntryNode(const Type *T) { return T; }
283 static inline ChildIteratorType child_begin(NodeType *N) {
284 return N->subtype_begin();
286 static inline ChildIteratorType child_end(NodeType *N) {
287 return N->subtype_end();