1 //===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
14 #include "llvm/AbstractTypeUser.h"
15 #include "llvm/Support/Casting.h"
16 #include "llvm/Support/DataTypes.h"
17 #include "llvm/Support/Streams.h"
18 #include "llvm/ADT/GraphTraits.h"
19 #include "llvm/ADT/iterator"
34 /// This file contains the declaration of the Type class. For more "Type" type
35 /// stuff, look in DerivedTypes.h.
37 /// The instances of the Type class are immutable: once they are created,
38 /// they are never changed. Also note that only one instance of a particular
39 /// type is ever created. Thus seeing if two types are equal is a matter of
40 /// doing a trivial pointer comparison. To enforce that no two equal instances
41 /// are created, Type instances can only be created via static factory methods
42 /// in class Type and in derived classes.
44 /// Once allocated, Types are never free'd, unless they are an abstract type
45 /// that is resolved to a more concrete type.
47 /// Types themself don't have a name, and can be named either by:
48 /// - using SymbolTable instance, typically from some Module,
49 /// - using convenience methods in the Module class (which uses module's
52 /// Opaque types are simple derived types with no state. There may be many
53 /// different Opaque type objects floating around, but two are only considered
54 /// identical if they are pointer equals of each other. This allows us to have
55 /// two opaque types that end up resolving to different concrete types later.
57 /// Opaque types are also kinda weird and scary and different because they have
58 /// to keep a list of uses of the type. When, through linking, parsing, or
59 /// bytecode reading, they become resolved, they need to find and update all
60 /// users of the unknown type, causing them to reference a new, more concrete
61 /// type. Opaque types are deleted when their use list dwindles to zero users.
63 /// @brief Root of type hierarchy
64 class Type : public AbstractTypeUser {
66 ///===-------------------------------------------------------------------===//
67 /// Definitions of all of the base types for the Type system. Based on this
68 /// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
69 /// Note: If you add an element to this, you need to add an element to the
70 /// Type::getPrimitiveType function, or else things will break!
73 // PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
74 VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
75 UByteTyID , SByteTyID, // 2, 3: 8 bit types...
76 UShortTyID , ShortTyID, // 4, 5: 16 bit types...
77 UIntTyID , IntTyID, // 6, 7: 32 bit types...
78 ULongTyID , LongTyID, // 8, 9: 64 bit types...
79 FloatTyID , DoubleTyID, // 10,11: Floating point types...
80 LabelTyID , // 12 : Labels...
82 // Derived types... see DerivedTypes.h file...
83 // Make sure FirstDerivedTyID stays up to date!!!
84 FunctionTyID , StructTyID, // Functions... Structs...
85 ArrayTyID , PointerTyID, // Array... pointer...
86 OpaqueTyID, // Opaque type instances...
87 PackedTyID, // SIMD 'packed' format...
90 NumTypeIDs, // Must remain as last defined ID
91 LastPrimitiveTyID = LabelTyID,
92 FirstDerivedTyID = FunctionTyID
96 TypeID ID : 8; // The current base type of this type.
97 bool Abstract : 1; // True if type contains an OpaqueType
99 /// RefCount - This counts the number of PATypeHolders that are pointing to
100 /// this type. When this number falls to zero, if the type is abstract and
101 /// has no AbstractTypeUsers, the type is deleted. This is only sensical for
104 mutable unsigned RefCount;
106 const Type *getForwardedTypeInternal() const;
108 Type(const char *Name, TypeID id);
109 Type(TypeID id) : ID(id), Abstract(false), RefCount(0), ForwardType(0) {}
111 assert(AbstractTypeUsers.empty());
114 /// Types can become nonabstract later, if they are refined.
116 inline void setAbstract(bool Val) { Abstract = Val; }
118 unsigned getRefCount() const { return RefCount; }
120 /// ForwardType - This field is used to implement the union find scheme for
121 /// abstract types. When types are refined to other types, this field is set
122 /// to the more refined type. Only abstract types can be forwarded.
123 mutable const Type *ForwardType;
125 /// ContainedTys - The list of types contained by this one. For example, this
126 /// includes the arguments of a function type, the elements of the structure,
127 /// the pointee of a pointer, etc. Note that keeping this vector in the Type
128 /// class wastes some space for types that do not contain anything (such as
129 /// primitive types). However, keeping it here allows the subtype_* members
130 /// to be implemented MUCH more efficiently, and dynamically very few types do
131 /// not contain any elements (most are derived).
132 std::vector<PATypeHandle> ContainedTys;
134 /// AbstractTypeUsers - Implement a list of the users that need to be notified
135 /// if I am a type, and I get resolved into a more concrete type.
137 mutable std::vector<AbstractTypeUser *> AbstractTypeUsers;
139 void print(llvm_ostream &O) const {
140 if (O.stream()) print(*O.stream());
142 void print(std::ostream &O) const;
144 /// @brief Debugging support: print to stderr
147 //===--------------------------------------------------------------------===//
148 // Property accessors for dealing with types... Some of these virtual methods
149 // are defined in private classes defined in Type.cpp for primitive types.
152 /// getTypeID - Return the type id for the type. This will return one
153 /// of the TypeID enum elements defined above.
155 inline TypeID getTypeID() const { return ID; }
157 /// getDescription - Return the string representation of the type...
158 const std::string &getDescription() const;
160 /// isSigned - Return whether an integral numeric type is signed. This is
161 /// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
162 /// Float and Double.
164 bool isSigned() const {
165 return ID == SByteTyID || ID == ShortTyID ||
166 ID == IntTyID || ID == LongTyID;
169 /// isUnsigned - Return whether a numeric type is unsigned. This is not quite
170 /// the complement of isSigned... nonnumeric types return false as they do
171 /// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
174 bool isUnsigned() const {
175 return ID == UByteTyID || ID == UShortTyID ||
176 ID == UIntTyID || ID == ULongTyID;
179 /// isInteger - Equivalent to isSigned() || isUnsigned()
181 bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
183 /// isIntegral - Returns true if this is an integral type, which is either
184 /// BoolTy or one of the Integer types.
186 bool isIntegral() const { return isInteger() || this == BoolTy; }
188 /// isFloatingPoint - Return true if this is one of the two floating point
190 bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
192 /// isFPOrFPVector - Return true if this is a FP type or a vector of FP types.
194 bool isFPOrFPVector() const;
196 /// isAbstract - True if the type is either an Opaque type, or is a derived
197 /// type that includes an opaque type somewhere in it.
199 inline bool isAbstract() const { return Abstract; }
201 /// canLosslesslyBitCastTo - Return true if this type could be converted
202 /// with a lossless BitCast to type 'Ty'. For example, uint to int. BitCasts
203 /// are valid for types of the same size only where no re-interpretation of
204 /// the bits is done.
205 /// @brief Determine if this type could be losslessly bitcast to Ty
206 bool canLosslesslyBitCastTo(const Type *Ty) const;
209 /// Here are some useful little methods to query what type derived types are
210 /// Note that all other types can just compare to see if this == Type::xxxTy;
212 inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
213 inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
215 /// isFirstClassType - Return true if the value is holdable in a register.
217 inline bool isFirstClassType() const {
218 return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
219 ID == PointerTyID || ID == PackedTyID;
222 /// isSized - Return true if it makes sense to take the size of this type. To
223 /// get the actual size for a particular target, it is reasonable to use the
224 /// TargetData subsystem to do this.
226 bool isSized() const {
227 // If it's a primitive, it is always sized.
228 if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID)
230 // If it is not something that can have a size (e.g. a function or label),
231 // it doesn't have a size.
232 if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID)
234 // If it is something that can have a size and it's concrete, it definitely
235 // has a size, otherwise we have to try harder to decide.
236 return !isAbstract() || isSizedDerivedType();
239 /// getPrimitiveSize - Return the basic size of this type if it is a primitive
240 /// type. These are fixed by LLVM and are not target dependent. This will
241 /// return zero if the type does not have a size or is not a primitive type.
243 unsigned getPrimitiveSize() const;
244 unsigned getPrimitiveSizeInBits() const;
246 /// getUnsignedVersion - If this is an integer type, return the unsigned
247 /// variant of this type. For example int -> uint.
248 const Type *getUnsignedVersion() const;
250 /// getSignedVersion - If this is an integer type, return the signed variant
251 /// of this type. For example uint -> int.
252 const Type *getSignedVersion() const;
254 /// getIntegralTypeMask - Return a bitmask with ones set for all of the bits
255 /// that can be set by an unsigned version of this type. This is 0xFF for
256 /// sbyte/ubyte, 0xFFFF for shorts, etc.
257 uint64_t getIntegralTypeMask() const {
258 assert(isIntegral() && "This only works for integral types!");
259 return ~uint64_t(0UL) >> (64-getPrimitiveSizeInBits());
262 /// getForwaredType - Return the type that this type has been resolved to if
263 /// it has been resolved to anything. This is used to implement the
264 /// union-find algorithm for type resolution, and shouldn't be used by general
266 const Type *getForwardedType() const {
267 if (!ForwardType) return 0;
268 return getForwardedTypeInternal();
271 /// getVAArgsPromotedType - Return the type an argument of this type
272 /// will be promoted to if passed through a variable argument
274 const Type *getVAArgsPromotedType() const {
275 if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID)
277 else if (ID == SByteTyID || ID == ShortTyID)
279 else if (ID == FloatTyID)
280 return Type::DoubleTy;
285 //===--------------------------------------------------------------------===//
286 // Type Iteration support
288 typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
289 subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
290 subtype_iterator subtype_end() const { return ContainedTys.end(); }
292 /// getContainedType - This method is used to implement the type iterator
293 /// (defined a the end of the file). For derived types, this returns the
294 /// types 'contained' in the derived type.
296 const Type *getContainedType(unsigned i) const {
297 assert(i < ContainedTys.size() && "Index out of range!");
298 return ContainedTys[i];
301 /// getNumContainedTypes - Return the number of types in the derived type.
303 typedef std::vector<PATypeHandle>::size_type size_type;
304 size_type getNumContainedTypes() const { return ContainedTys.size(); }
306 //===--------------------------------------------------------------------===//
307 // Static members exported by the Type class itself. Useful for getting
308 // instances of Type.
311 /// getPrimitiveType - Return a type based on an identifier.
312 static const Type *getPrimitiveType(TypeID IDNumber);
314 //===--------------------------------------------------------------------===//
315 // These are the builtin types that are always available...
317 static Type *VoidTy , *BoolTy;
318 static Type *SByteTy, *UByteTy,
322 static Type *FloatTy, *DoubleTy;
324 static Type* LabelTy;
326 /// Methods for support type inquiry through isa, cast, and dyn_cast:
327 static inline bool classof(const Type *T) { return true; }
329 void addRef() const {
330 assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
334 void dropRef() const {
335 assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
336 assert(RefCount && "No objects are currently referencing this object!");
338 // If this is the last PATypeHolder using this object, and there are no
339 // PATypeHandles using it, the type is dead, delete it now.
340 if (--RefCount == 0 && AbstractTypeUsers.empty())
344 /// addAbstractTypeUser - Notify an abstract type that there is a new user of
345 /// it. This function is called primarily by the PATypeHandle class.
347 void addAbstractTypeUser(AbstractTypeUser *U) const {
348 assert(isAbstract() && "addAbstractTypeUser: Current type not abstract!");
349 AbstractTypeUsers.push_back(U);
352 /// removeAbstractTypeUser - Notify an abstract type that a user of the class
353 /// no longer has a handle to the type. This function is called primarily by
354 /// the PATypeHandle class. When there are no users of the abstract type, it
355 /// is annihilated, because there is no way to get a reference to it ever
358 void removeAbstractTypeUser(AbstractTypeUser *U) const;
361 /// isSizedDerivedType - Derived types like structures and arrays are sized
362 /// iff all of the members of the type are sized as well. Since asking for
363 /// their size is relatively uncommon, move this operation out of line.
364 bool isSizedDerivedType() const;
366 virtual void refineAbstractType(const DerivedType *OldTy, const Type *NewTy);
367 virtual void typeBecameConcrete(const DerivedType *AbsTy);
370 // PromoteAbstractToConcrete - This is an internal method used to calculate
371 // change "Abstract" from true to false when types are refined.
372 void PromoteAbstractToConcrete();
373 friend class TypeMapBase;
376 //===----------------------------------------------------------------------===//
377 // Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
378 // These are defined here because they MUST be inlined, yet are dependent on
379 // the definition of the Type class.
381 inline void PATypeHandle::addUser() {
382 assert(Ty && "Type Handle has a null type!");
383 if (Ty->isAbstract())
384 Ty->addAbstractTypeUser(User);
386 inline void PATypeHandle::removeUser() {
387 if (Ty->isAbstract())
388 Ty->removeAbstractTypeUser(User);
391 // Define inline methods for PATypeHolder...
393 inline void PATypeHolder::addRef() {
394 if (Ty->isAbstract())
398 inline void PATypeHolder::dropRef() {
399 if (Ty->isAbstract())
404 //===----------------------------------------------------------------------===//
405 // Provide specializations of GraphTraits to be able to treat a type as a
406 // graph of sub types...
408 template <> struct GraphTraits<Type*> {
409 typedef Type NodeType;
410 typedef Type::subtype_iterator ChildIteratorType;
412 static inline NodeType *getEntryNode(Type *T) { return T; }
413 static inline ChildIteratorType child_begin(NodeType *N) {
414 return N->subtype_begin();
416 static inline ChildIteratorType child_end(NodeType *N) {
417 return N->subtype_end();
421 template <> struct GraphTraits<const Type*> {
422 typedef const Type NodeType;
423 typedef Type::subtype_iterator ChildIteratorType;
425 static inline NodeType *getEntryNode(const Type *T) { return T; }
426 static inline ChildIteratorType child_begin(NodeType *N) {
427 return N->subtype_begin();
429 static inline ChildIteratorType child_end(NodeType *N) {
430 return N->subtype_end();
434 template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
435 return Ty.getTypeID() == Type::PointerTyID;
438 std::ostream &operator<<(std::ostream &OS, const Type &T);
440 } // End llvm namespace