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 struct 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 bool Abstract; // True if type contains an OpaqueType
77 /// ctor is protected, so only subclasses can create Type objects...
78 Type(const std::string &Name, PrimitiveID id);
81 /// setName - Associate the name with this type in the symbol table, but don't
82 /// set the local name to be equal specified name.
84 virtual void setName(const std::string &Name, SymbolTable *ST = 0);
86 /// Types can become nonabstract later, if they are refined.
88 inline void setAbstract(bool Val) { Abstract = Val; }
90 /// isTypeAbstract - This method is used to calculate the Abstract bit.
92 bool isTypeAbstract();
94 virtual void print(std::ostream &O) const;
96 //===--------------------------------------------------------------------===//
97 // Property accessors for dealing with types... Some of these virtual methods
98 // are defined in private classes defined in Type.cpp for primitive types.
101 /// getPrimitiveID - Return the base type of the type. This will return one
102 /// of the PrimitiveID enum elements defined above.
104 inline PrimitiveID getPrimitiveID() const { return ID; }
106 /// getUniqueID - Returns the UID of the type. This can be thought of as a
107 /// small integer version of the pointer to the type class. Two types that
108 /// are structurally different have different UIDs. This can be used for
109 /// indexing types into an array.
111 inline unsigned getUniqueID() const { return UID; }
113 /// getDescription - Return the string representation of the type...
114 const std::string &getDescription() const;
116 /// isSigned - Return whether an integral numeric type is signed. This is
117 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
118 /// Float and Double.
120 virtual bool isSigned() const { return 0; }
122 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
123 /// the complement of isSigned... nonnumeric types return false as they do
124 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
127 virtual bool isUnsigned() const { return 0; }
129 /// isInteger - Equilivent to isSigned() || isUnsigned(), but with only a
130 /// single virtual function invocation.
132 virtual bool isInteger() const { return 0; }
134 /// isIntegral - Returns true if this is an integral type, which is either
135 /// BoolTy or one of the Integer types.
137 bool isIntegral() const { return isInteger() || this == BoolTy; }
139 /// isFloatingPoint - Return true if this is one of the two floating point
141 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
143 /// isAbstract - True if the type is either an Opaque type, or is a derived
144 /// type that includes an opaque type somewhere in it.
146 inline bool isAbstract() const { return Abstract; }
148 /// isLosslesslyConvertibleTo - Return true if this type can be converted to
149 /// 'Ty' without any reinterpretation of bits. For example, uint to int.
151 bool isLosslesslyConvertibleTo(const Type *Ty) const;
154 /// Here are some useful little methods to query what type derived types are
155 /// Note that all other types can just compare to see if this == Type::xxxTy;
157 inline bool isPrimitiveType() const { return ID < FirstDerivedTyID; }
158 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
160 /// isFirstClassType - Return true if the value is holdable in a register.
161 inline bool isFirstClassType() const {
162 return isPrimitiveType() || ID == PointerTyID;
165 /// isSized - Return true if it makes sense to take the size of this type. To
166 /// get the actual size for a particular target, it is reasonable to use the
167 /// TargetData subsystem to do this.
169 bool isSized() const {
170 return ID != VoidTyID && ID != TypeTyID &&
171 ID != FunctionTyID && ID != LabelTyID && ID != OpaqueTyID;
174 /// getPrimitiveSize - Return the basic size of this type if it is a primative
175 /// type. These are fixed by LLVM and are not target dependent. This will
176 /// return zero if the type does not have a size or is not a primitive type.
178 unsigned getPrimitiveSize() const;
181 //===--------------------------------------------------------------------===//
182 // Type Iteration support
185 typedef TypeIterator subtype_iterator;
186 inline subtype_iterator subtype_begin() const; // DEFINED BELOW
187 inline subtype_iterator subtype_end() const; // DEFINED BELOW
189 /// getContainedType - This method is used to implement the type iterator
190 /// (defined a the end of the file). For derived types, this returns the
191 /// types 'contained' in the derived type, returning 0 when 'i' becomes
192 /// invalid. This allows the user to iterate over the types in a struct, for
193 /// example, really easily.
195 virtual const Type *getContainedType(unsigned i) const { return 0; }
197 /// getNumContainedTypes - Return the number of types in the derived type
198 virtual unsigned getNumContainedTypes() const { return 0; }
200 //===--------------------------------------------------------------------===//
201 // Static members exported by the Type class itself. Useful for getting
202 // instances of Type.
205 /// getPrimitiveType/getUniqueIDType - Return a type based on an identifier.
206 static const Type *getPrimitiveType(PrimitiveID IDNumber);
207 static const Type *getUniqueIDType(unsigned UID);
209 //===--------------------------------------------------------------------===//
210 // These are the builtin types that are always available...
212 static Type *VoidTy , *BoolTy;
213 static Type *SByteTy, *UByteTy,
217 static Type *FloatTy, *DoubleTy;
219 static Type *TypeTy , *LabelTy;
221 /// Methods for support type inquiry through isa, cast, and dyn_cast:
222 static inline bool classof(const Type *T) { return true; }
223 static inline bool classof(const Value *V) {
224 return V->getValueType() == Value::TypeVal;
227 #include "llvm/Type.def"
230 class TypeIterator : public bidirectional_iterator<const Type, ptrdiff_t> {
231 const Type * const Ty;
234 typedef TypeIterator _Self;
236 inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
237 inline ~TypeIterator() {}
239 inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
240 inline bool operator!=(const _Self& x) const { return !operator==(x); }
242 inline pointer operator*() const { return Ty->getContainedType(Idx); }
243 inline pointer operator->() const { return operator*(); }
245 inline _Self& operator++() { ++Idx; return *this; } // Preincrement
246 inline _Self operator++(int) { // Postincrement
247 _Self tmp = *this; ++*this; return tmp;
250 inline _Self& operator--() { --Idx; return *this; } // Predecrement
251 inline _Self operator--(int) { // Postdecrement
252 _Self tmp = *this; --*this; return tmp;
257 inline Type::TypeIterator Type::subtype_begin() const {
258 return TypeIterator(this, 0);
261 inline Type::TypeIterator Type::subtype_end() const {
262 return TypeIterator(this, getNumContainedTypes());
266 // Provide specializations of GraphTraits to be able to treat a type as a
267 // graph of sub types...
269 template <> struct GraphTraits<Type*> {
270 typedef Type NodeType;
271 typedef Type::subtype_iterator ChildIteratorType;
273 static inline NodeType *getEntryNode(Type *T) { return T; }
274 static inline ChildIteratorType child_begin(NodeType *N) {
275 return N->subtype_begin();
277 static inline ChildIteratorType child_end(NodeType *N) {
278 return N->subtype_end();
282 template <> struct GraphTraits<const Type*> {
283 typedef const Type NodeType;
284 typedef Type::subtype_iterator ChildIteratorType;
286 static inline NodeType *getEntryNode(const Type *T) { return T; }
287 static inline ChildIteratorType child_begin(NodeType *N) {
288 return N->subtype_begin();
290 static inline ChildIteratorType child_end(NodeType *N) {
291 return N->subtype_end();
295 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
296 return Ty.getPrimitiveID() == Type::PointerTyID;