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.
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"
31 #include "Support/iterator"
40 class Type : public Value {
42 //===--------------------------------------------------------------------===//
43 // Definitions of all of the base types for the Type system. Based on this
44 // value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
45 // Note: If you add an element to this, you need to add an element to the
46 // Type::getPrimitiveType function, or else things will break!
49 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
50 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
51 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
52 UIntTyID , IntTyID, // 6, 7: 32 bit types...
53 ULongTyID , LongTyID, // 8, 9: 64 bit types...
55 FloatTyID , DoubleTyID, // 10,11: Floating point types...
57 TypeTyID, // 12 : Type definitions
58 LabelTyID , // 13 : Labels...
60 // Derived types... see DerivedTypes.h file...
61 // Make sure FirstDerivedTyID stays up to date!!!
62 FunctionTyID , StructTyID, // Functions... Structs...
63 ArrayTyID , PointerTyID, // Array... pointer...
64 OpaqueTyID, // Opaque type instances...
65 //PackedTyID , // SIMD 'packed' format... TODO
68 NumPrimitiveIDs, // Must remain as last defined ID
69 FirstDerivedTyID = FunctionTyID,
73 PrimitiveID ID; // The current base type of this type...
74 unsigned UID; // The unique ID number for this class
75 std::string Desc; // The printed name of the string...
76 bool Abstract; // True if type contains an OpaqueType
77 bool Recursive; // True if the type is recursive
80 // ctor is protected, so only subclasses can create Type objects...
81 Type(const std::string &Name, PrimitiveID id);
84 // When types are refined, they update their description to be more concrete.
86 inline void setDescription(const std::string &D) { Desc = D; }
88 // setName - Associate the name with this type in the symbol table, but don't
89 // set the local name to be equal specified name.
91 virtual void setName(const std::string &Name, SymbolTable *ST = 0);
93 // Types can become nonabstract later, if they are refined.
95 inline void setAbstract(bool Val) { Abstract = Val; }
97 // Types can become recursive later, if they are refined.
99 inline void setRecursive(bool Val) { Recursive = Val; }
102 virtual void print(std::ostream &O) const;
104 //===--------------------------------------------------------------------===//
105 // Property accessors for dealing with types...
108 // getPrimitiveID - Return the base type of the type. This will return one
109 // of the PrimitiveID enum elements defined above.
111 inline PrimitiveID getPrimitiveID() const { return ID; }
113 // getUniqueID - Returns the UID of the type. This can be thought of as a
114 // small integer version of the pointer to the type class. Two types that are
115 // structurally different have different UIDs. This can be used for indexing
116 // types into an array.
118 inline unsigned getUniqueID() const { return UID; }
120 // getDescription - Return the string representation of the type...
121 inline const std::string &getDescription() const { return Desc; }
123 // isSigned - Return whether a numeric type is signed.
124 virtual bool isSigned() const { return 0; }
126 // isUnsigned - Return whether a numeric type is unsigned. This is not
127 // quite the complement of isSigned... nonnumeric types return false as they
130 virtual bool isUnsigned() const { return 0; }
132 // isIntegral - Equilivent to isSigned() || isUnsigned, but with only a single
133 // virtual function invocation.
135 virtual bool isIntegral() const { return 0; }
137 // isFloatingPoint - Return true if this is one of the two floating point
139 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
141 // isAbstract - True if the type is either an Opaque type, or is a derived
142 // type that includes an opaque type somewhere in it.
144 inline bool isAbstract() const { return Abstract; }
146 // isRecursive - True if the type graph contains a cycle.
148 inline bool isRecursive() const { return Recursive; }
150 // isLosslesslyConvertableTo - Return true if this type can be converted to
151 // 'Ty' without any reinterpretation of bits. For example, uint to int.
153 bool isLosslesslyConvertableTo(const Type *Ty) const;
156 // Here are some useful little methods to query what type derived types are
157 // Note that all other types can just compare to see if this == Type::xxxTy;
159 inline bool isPrimitiveType() const { return ID < FirstDerivedTyID; }
160 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
162 // isFirstClassType - Return true if the value is holdable in a register.
163 inline bool isFirstClassType() const {
164 return isPrimitiveType() || ID == PointerTyID;
167 // isSized - Return true if it makes sense to take the size of this type. To
168 // get the actual size for a particular target, it is reasonable to use the
169 // TargetData subsystem to do this.
171 bool isSized() const {
172 return ID != VoidTyID && ID != TypeTyID &&
173 ID != FunctionTyID && ID != LabelTyID && ID != OpaqueTyID;
176 // getPrimitiveSize - Return the basic size of this type if it is a primative
177 // type. These are fixed by LLVM and are not target dependant. This will
178 // return zero if the type does not have a size or is not a primitive type.
180 unsigned getPrimitiveSize() const;
183 //===--------------------------------------------------------------------===//
184 // Type Iteration support
187 typedef TypeIterator subtype_iterator;
188 inline subtype_iterator subtype_begin() const; // DEFINED BELOW
189 inline subtype_iterator subtype_end() const; // DEFINED BELOW
191 // getContainedType - This method is used to implement the type iterator
192 // (defined a the end of the file). For derived types, this returns the types
193 // 'contained' in the derived type, returning 0 when 'i' becomes invalid. This
194 // allows the user to iterate over the types in a struct, for example, really
197 virtual const Type *getContainedType(unsigned i) const { return 0; }
199 // getNumContainedTypes - Return the number of types in the derived type
200 virtual unsigned getNumContainedTypes() const { return 0; }
202 //===--------------------------------------------------------------------===//
203 // Static members exported by the Type class itself. Useful for getting
204 // instances of Type.
207 // getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
208 static const Type *getPrimitiveType(PrimitiveID IDNumber);
209 static const Type *getUniqueIDType(unsigned UID);
211 //===--------------------------------------------------------------------===//
212 // These are the builtin types that are always available...
214 static Type *VoidTy , *BoolTy;
215 static Type *SByteTy, *UByteTy,
219 static Type *FloatTy, *DoubleTy;
221 static Type *TypeTy , *LabelTy;
223 // Methods for support type inquiry through isa, cast, and dyn_cast:
224 static inline bool classof(const Type *T) { return true; }
225 static inline bool classof(const Value *V) {
226 return V->getValueType() == Value::TypeVal;
229 #include "llvm/Type.def"
232 class TypeIterator : public bidirectional_iterator<const Type, ptrdiff_t> {
233 const Type * const Ty;
236 typedef TypeIterator _Self;
238 inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
239 inline ~TypeIterator() {}
241 inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
242 inline bool operator!=(const _Self& x) const { return !operator==(x); }
244 inline pointer operator*() const { return Ty->getContainedType(Idx); }
245 inline pointer operator->() const { return operator*(); }
247 inline _Self& operator++() { ++Idx; return *this; } // Preincrement
248 inline _Self operator++(int) { // Postincrement
249 _Self tmp = *this; ++*this; return tmp;
252 inline _Self& operator--() { --Idx; return *this; } // Predecrement
253 inline _Self operator--(int) { // Postdecrement
254 _Self tmp = *this; --*this; return tmp;
259 inline Type::TypeIterator Type::subtype_begin() const {
260 return TypeIterator(this, 0);
263 inline Type::TypeIterator Type::subtype_end() const {
264 return TypeIterator(this, getNumContainedTypes());
268 // Provide specializations of GraphTraits to be able to treat a type as a
269 // graph of sub types...
271 template <> struct GraphTraits<Type*> {
272 typedef Type NodeType;
273 typedef Type::subtype_iterator ChildIteratorType;
275 static inline NodeType *getEntryNode(Type *T) { return T; }
276 static inline ChildIteratorType child_begin(NodeType *N) {
277 return N->subtype_begin();
279 static inline ChildIteratorType child_end(NodeType *N) {
280 return N->subtype_end();
284 template <> struct GraphTraits<const Type*> {
285 typedef const Type NodeType;
286 typedef Type::subtype_iterator ChildIteratorType;
288 static inline NodeType *getEntryNode(const Type *T) { return T; }
289 static inline ChildIteratorType child_begin(NodeType *N) {
290 return N->subtype_begin();
292 static inline ChildIteratorType child_end(NodeType *N) {
293 return N->subtype_end();
297 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
298 return Ty.getPrimitiveID() == Type::PointerTyID;