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 bool Abstract; // True if type contains an OpaqueType
78 /// ctor is protected, so only subclasses can create Type objects...
79 Type(const std::string &Name, PrimitiveID id);
82 /// setName - Associate the name with this type in the symbol table, but don't
83 /// set the local name to be equal specified name.
85 virtual void setName(const std::string &Name, SymbolTable *ST = 0);
87 /// Types can become nonabstract later, if they are refined.
89 inline void setAbstract(bool Val) { Abstract = Val; }
91 /// isTypeAbstract - This method is used to calculate the Abstract bit.
93 bool isTypeAbstract();
95 virtual void print(std::ostream &O) const;
97 //===--------------------------------------------------------------------===//
98 // Property accessors for dealing with types... Some of these virtual methods
99 // are defined in private classes defined in Type.cpp for primitive types.
102 /// getPrimitiveID - Return the base type of the type. This will return one
103 /// of the PrimitiveID enum elements defined above.
105 inline PrimitiveID getPrimitiveID() const { return ID; }
107 /// getUniqueID - Returns the UID of the type. This can be thought of as a
108 /// small integer version of the pointer to the type class. Two types that
109 /// are structurally different have different UIDs. This can be used for
110 /// indexing types into an array.
112 inline unsigned getUniqueID() const { return UID; }
114 /// getDescription - Return the string representation of the type...
115 const std::string &getDescription() const;
117 /// isSigned - Return whether an integral numeric type is signed. This is
118 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
119 /// Float and Double.
121 virtual bool isSigned() const { return 0; }
123 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
124 /// the complement of isSigned... nonnumeric types return false as they do
125 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
128 virtual bool isUnsigned() const { return 0; }
130 /// isInteger - Equilivent to isSigned() || isUnsigned(), but with only a
131 /// single virtual function invocation.
133 virtual bool isInteger() const { return 0; }
135 /// isIntegral - Returns true if this is an integral type, which is either
136 /// BoolTy or one of the Integer types.
138 bool isIntegral() const { return isInteger() || this == BoolTy; }
140 /// isFloatingPoint - Return true if this is one of the two floating point
142 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
144 /// isAbstract - True if the type is either an Opaque type, or is a derived
145 /// type that includes an opaque type somewhere in it.
147 inline bool isAbstract() const { return Abstract; }
149 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
150 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
152 bool isLosslesslyConvertibleTo(const Type *Ty) const;
155 /// Here are some useful little methods to query what type derived types are
156 /// Note that all other types can just compare to see if this == Type::xxxTy;
158 inline bool isPrimitiveType() const { return ID < FirstDerivedTyID; }
159 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
161 /// isFirstClassType - Return true if the value is holdable in a register.
162 inline bool isFirstClassType() const {
163 return isPrimitiveType() || ID == PointerTyID;
166 /// isSized - Return true if it makes sense to take the size of this type. To
167 /// get the actual size for a particular target, it is reasonable to use the
168 /// TargetData subsystem to do this.
170 bool isSized() const {
171 return ID != VoidTyID && ID != TypeTyID &&
172 ID != FunctionTyID && ID != LabelTyID && ID != OpaqueTyID;
175 /// getPrimitiveSize - Return the basic size of this type if it is a primative
176 /// type. These are fixed by LLVM and are not target dependent. This will
177 /// return zero if the type does not have a size or is not a primitive type.
179 unsigned getPrimitiveSize() const;
182 //===--------------------------------------------------------------------===//
183 // Type Iteration support
186 typedef TypeIterator subtype_iterator;
187 inline subtype_iterator subtype_begin() const; // DEFINED BELOW
188 inline subtype_iterator subtype_end() const; // DEFINED BELOW
190 /// getContainedType - This method is used to implement the type iterator
191 /// (defined a the end of the file). For derived types, this returns the
192 /// types 'contained' in the derived type, returning 0 when 'i' becomes
193 /// invalid. This allows the user to iterate over the types in a struct, for
194 /// example, really easily.
196 virtual const Type *getContainedType(unsigned i) const { return 0; }
198 /// getNumContainedTypes - Return the number of types in the derived type
199 virtual unsigned getNumContainedTypes() const { return 0; }
201 //===--------------------------------------------------------------------===//
202 // Static members exported by the Type class itself. Useful for getting
203 // instances of Type.
206 /// getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
207 static const Type *getPrimitiveType(PrimitiveID IDNumber);
208 static const Type *getUniqueIDType(unsigned UID);
210 //===--------------------------------------------------------------------===//
211 // These are the builtin types that are always available...
213 static Type *VoidTy , *BoolTy;
214 static Type *SByteTy, *UByteTy,
218 static Type *FloatTy, *DoubleTy;
220 static Type *TypeTy , *LabelTy;
222 /// Methods for support type inquiry through isa, cast, and dyn_cast:
223 static inline bool classof(const Type *T) { return true; }
224 static inline bool classof(const Value *V) {
225 return V->getValueType() == Value::TypeVal;
228 #include "llvm/Type.def"
231 class TypeIterator : public bidirectional_iterator<const Type, ptrdiff_t> {
232 const Type * const Ty;
235 typedef TypeIterator _Self;
237 inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
238 inline ~TypeIterator() {}
240 inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
241 inline bool operator!=(const _Self& x) const { return !operator==(x); }
243 inline pointer operator*() const { return Ty->getContainedType(Idx); }
244 inline pointer operator->() const { return operator*(); }
246 inline _Self& operator++() { ++Idx; return *this; } // Preincrement
247 inline _Self operator++(int) { // Postincrement
248 _Self tmp = *this; ++*this; return tmp;
251 inline _Self& operator--() { --Idx; return *this; } // Predecrement
252 inline _Self operator--(int) { // Postdecrement
253 _Self tmp = *this; --*this; return tmp;
258 inline Type::TypeIterator Type::subtype_begin() const {
259 return TypeIterator(this, 0);
262 inline Type::TypeIterator Type::subtype_end() const {
263 return TypeIterator(this, getNumContainedTypes());
267 // Provide specializations of GraphTraits to be able to treat a type as a
268 // graph of sub types...
270 template <> struct GraphTraits<Type*> {
271 typedef Type NodeType;
272 typedef Type::subtype_iterator ChildIteratorType;
274 static inline NodeType *getEntryNode(Type *T) { return T; }
275 static inline ChildIteratorType child_begin(NodeType *N) {
276 return N->subtype_begin();
278 static inline ChildIteratorType child_end(NodeType *N) {
279 return N->subtype_end();
283 template <> struct GraphTraits<const Type*> {
284 typedef const Type NodeType;
285 typedef Type::subtype_iterator ChildIteratorType;
287 static inline NodeType *getEntryNode(const Type *T) { return T; }
288 static inline ChildIteratorType child_begin(NodeType *N) {
289 return N->subtype_begin();
291 static inline ChildIteratorType child_end(NodeType *N) {
292 return N->subtype_end();
296 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
297 return Ty.getPrimitiveID() == Type::PointerTyID;