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; }
92 virtual void print(std::ostream &O) const;
94 //===--------------------------------------------------------------------===//
95 // Property accessors for dealing with types... Some of these virtual methods
96 // are defined in private classes defined in Type.cpp for primitive types.
99 /// getPrimitiveID - Return the base type of the type. This will return one
100 /// of the PrimitiveID enum elements defined above.
102 inline PrimitiveID getPrimitiveID() const { return ID; }
104 /// getUniqueID - Returns the UID of the type. This can be thought of as a
105 /// small integer version of the pointer to the type class. Two types that
106 /// are structurally different have different UIDs. This can be used for
107 /// indexing types into an array.
109 inline unsigned getUniqueID() const { return UID; }
111 /// getDescription - Return the string representation of the type...
112 const std::string &getDescription() const;
114 /// isSigned - Return whether an integral numeric type is signed. This is
115 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
116 /// Float and Double.
118 virtual bool isSigned() const { return 0; }
120 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
121 /// the complement of isSigned... nonnumeric types return false as they do
122 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
125 virtual bool isUnsigned() const { return 0; }
127 /// isInteger - Equilivent to isSigned() || isUnsigned(), but with only a
128 /// single virtual function invocation.
130 virtual bool isInteger() const { return 0; }
132 /// isIntegral - Returns true if this is an integral type, which is either
133 /// BoolTy or one of the Integer types.
135 bool isIntegral() const { return isInteger() || this == BoolTy; }
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 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
147 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
149 bool isLosslesslyConvertibleTo(const Type *Ty) const;
152 /// Here are some useful little methods to query what type derived types are
153 /// Note that all other types can just compare to see if this == Type::xxxTy;
155 inline bool isPrimitiveType() const { return ID < FirstDerivedTyID; }
156 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
158 /// isFirstClassType - Return true if the value is holdable in a register.
159 inline bool isFirstClassType() const {
160 return isPrimitiveType() || ID == PointerTyID;
163 /// isSized - Return true if it makes sense to take the size of this type. To
164 /// get the actual size for a particular target, it is reasonable to use the
165 /// TargetData subsystem to do this.
167 bool isSized() const {
168 return ID != VoidTyID && ID != TypeTyID &&
169 ID != FunctionTyID && ID != LabelTyID && ID != OpaqueTyID;
172 /// getPrimitiveSize - Return the basic size of this type if it is a primative
173 /// type. These are fixed by LLVM and are not target dependent. This will
174 /// return zero if the type does not have a size or is not a primitive type.
176 unsigned getPrimitiveSize() const;
179 //===--------------------------------------------------------------------===//
180 // Type Iteration support
183 typedef TypeIterator subtype_iterator;
184 inline subtype_iterator subtype_begin() const; // DEFINED BELOW
185 inline subtype_iterator subtype_end() const; // DEFINED BELOW
187 /// getContainedType - This method is used to implement the type iterator
188 /// (defined a the end of the file). For derived types, this returns the
189 /// types 'contained' in the derived type, returning 0 when 'i' becomes
190 /// invalid. This allows the user to iterate over the types in a struct, for
191 /// example, really easily.
193 virtual const Type *getContainedType(unsigned i) const { return 0; }
195 /// getNumContainedTypes - Return the number of types in the derived type
196 virtual unsigned getNumContainedTypes() const { return 0; }
198 //===--------------------------------------------------------------------===//
199 // Static members exported by the Type class itself. Useful for getting
200 // instances of Type.
203 /// getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
204 static const Type *getPrimitiveType(PrimitiveID IDNumber);
205 static const Type *getUniqueIDType(unsigned UID);
207 //===--------------------------------------------------------------------===//
208 // These are the builtin types that are always available...
210 static Type *VoidTy , *BoolTy;
211 static Type *SByteTy, *UByteTy,
215 static Type *FloatTy, *DoubleTy;
217 static Type *TypeTy , *LabelTy;
219 /// Methods for support type inquiry through isa, cast, and dyn_cast:
220 static inline bool classof(const Type *T) { return true; }
221 static inline bool classof(const Value *V) {
222 return V->getValueType() == Value::TypeVal;
225 #include "llvm/Type.def"
228 class TypeIterator : public bidirectional_iterator<const Type, ptrdiff_t> {
229 const Type * const Ty;
232 typedef TypeIterator _Self;
234 inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
235 inline ~TypeIterator() {}
237 inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
238 inline bool operator!=(const _Self& x) const { return !operator==(x); }
240 inline pointer operator*() const { return Ty->getContainedType(Idx); }
241 inline pointer operator->() const { return operator*(); }
243 inline _Self& operator++() { ++Idx; return *this; } // Preincrement
244 inline _Self operator++(int) { // Postincrement
245 _Self tmp = *this; ++*this; return tmp;
248 inline _Self& operator--() { --Idx; return *this; } // Predecrement
249 inline _Self operator--(int) { // Postdecrement
250 _Self tmp = *this; --*this; return tmp;
255 inline Type::TypeIterator Type::subtype_begin() const {
256 return TypeIterator(this, 0);
259 inline Type::TypeIterator Type::subtype_end() const {
260 return TypeIterator(this, getNumContainedTypes());
264 // Provide specializations of GraphTraits to be able to treat a type as a
265 // graph of sub types...
267 template <> struct GraphTraits<Type*> {
268 typedef Type NodeType;
269 typedef Type::subtype_iterator ChildIteratorType;
271 static inline NodeType *getEntryNode(Type *T) { return T; }
272 static inline ChildIteratorType child_begin(NodeType *N) {
273 return N->subtype_begin();
275 static inline ChildIteratorType child_end(NodeType *N) {
276 return N->subtype_end();
280 template <> struct GraphTraits<const Type*> {
281 typedef const Type NodeType;
282 typedef Type::subtype_iterator ChildIteratorType;
284 static inline NodeType *getEntryNode(const Type *T) { return T; }
285 static inline ChildIteratorType child_begin(NodeType *N) {
286 return N->subtype_begin();
288 static inline ChildIteratorType child_end(NodeType *N) {
289 return N->subtype_end();
293 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
294 return Ty.getPrimitiveID() == Type::PointerTyID;