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//===-- llvm/Type.h - Classes for handling data types -----------*- C++ -*-===//
// The LLVM Compiler Infrastructure
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// This file contains the declaration of the Type class. For more "Type" type
// stuff, look in DerivedTypes.h.
// Note that instances of the Type class are immutable: once they are created,
// they are never changed. Also note that only one instance of a particular
// type is ever created. Thus seeing if two types are equal is a matter of
// doing a trivial pointer comparison.
// Types, once allocated, are never free'd, unless they are an abstract type
// that is resolved to a more concrete type.
// Opaque types are simple derived types with no state. There may be many
// different Opaque type objects floating around, but two are only considered
// identical if they are pointer equals of each other. This allows us to have
// two opaque types that end up resolving to different concrete types later.
// Opaque types are also kinda weird and scary and different because they have
// to keep a list of uses of the type. When, through linking, parsing, or
// bytecode reading, they become resolved, they need to find and update all
// users of the unknown type, causing them to reference a new, more concrete
// type. Opaque types are deleted when their use list dwindles to zero users.
#ifndef LLVM_TYPE_H
#define LLVM_TYPE_H
#include "AbstractTypeUser.h"
#include "llvm/Support/Casting.h"
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/iterator"
#include <vector>
namespace llvm {
class ArrayType;
class DerivedType;
class FunctionType;
class OpaqueType;
class PointerType;
class StructType;
class PackedType;
class Type {
/// Definitions of all of the base types for the Type system. Based on this
/// value, you can cast to a "DerivedType" subclass (see DerivedTypes.h)
/// Note: If you add an element to this, you need to add an element to the
/// Type::getPrimitiveType function, or else things will break!
enum TypeID {
// PrimitiveTypes .. make sure LastPrimitiveTyID stays up to date
VoidTyID = 0 , BoolTyID, // 0, 1: Basics...
UByteTyID , SByteTyID, // 2, 3: 8 bit types...
UShortTyID , ShortTyID, // 4, 5: 16 bit types...
UIntTyID , IntTyID, // 6, 7: 32 bit types...
ULongTyID , LongTyID, // 8, 9: 64 bit types...
FloatTyID , DoubleTyID, // 10,11: Floating point types...
LabelTyID , // 12 : Labels...
// Derived types... see DerivedTypes.h file...
// Make sure FirstDerivedTyID stays up to date!!!
FunctionTyID , StructTyID, // Functions... Structs...
ArrayTyID , PointerTyID, // Array... pointer...
OpaqueTyID, // Opaque type instances...
PackedTyID, // SIMD 'packed' format...
NumTypeIDs, // Must remain as last defined ID
LastPrimitiveTyID = LabelTyID,
FirstDerivedTyID = FunctionTyID
TypeID ID : 8; // The current base type of this type.
bool Abstract; // True if type contains an OpaqueType
/// RefCount - This counts the number of PATypeHolders that are pointing to
/// this type. When this number falls to zero, if the type is abstract and
/// has no AbstractTypeUsers, the type is deleted. This is only sensical for
/// derived types.
mutable unsigned RefCount;
const Type *getForwardedTypeInternal() const;
Type(const std::string& Name, TypeID id);
virtual ~Type() {}
/// Types can become nonabstract later, if they are refined.
inline void setAbstract(bool Val) { Abstract = Val; }
// PromoteAbstractToConcrete - This is an internal method used to calculate
// change "Abstract" from true to false when types are refined.
void PromoteAbstractToConcrete();
unsigned getRefCount() const { return RefCount; }
/// ForwardType - This field is used to implement the union find scheme for
/// abstract types. When types are refined to other types, this field is set
/// to the more refined type. Only abstract types can be forwarded.
mutable const Type *ForwardType;
/// ContainedTys - The list of types contained by this one. For example, this
/// includes the arguments of a function type, the elements of the structure,
/// the pointee of a pointer, etc. Note that keeping this vector in the Type
/// class wastes some space for types that do not contain anything (such as
/// primitive types). However, keeping it here allows the subtype_* members
/// to be implemented MUCH more efficiently, and dynamically very few types do
/// not contain any elements (most are derived).
std::vector<PATypeHandle> ContainedTys;
void print(std::ostream &O) const;
/// @brief Debugging support: print to stderr
void dump() const;
// Property accessors for dealing with types... Some of these virtual methods
// are defined in private classes defined in Type.cpp for primitive types.
/// getTypeID - Return the type id for the type. This will return one
/// of the TypeID enum elements defined above.
inline TypeID getTypeID() const { return ID; }
/// getDescription - Return the string representation of the type...
const std::string &getDescription() const;
/// isSigned - Return whether an integral numeric type is signed. This is
/// true for SByteTy, ShortTy, IntTy, LongTy. Note that this is not true for
/// Float and Double.
bool isSigned() const {
return ID == SByteTyID || ID == ShortTyID ||
ID == IntTyID || ID == LongTyID;
/// isUnsigned - Return whether a numeric type is unsigned. This is not quite
/// the complement of isSigned... nonnumeric types return false as they do
/// with isSigned. This returns true for UByteTy, UShortTy, UIntTy, and
/// ULongTy
bool isUnsigned() const {
return ID == UByteTyID || ID == UShortTyID ||
ID == UIntTyID || ID == ULongTyID;
/// isInteger - Equivalent to isSigned() || isUnsigned()
bool isInteger() const { return ID >= UByteTyID && ID <= LongTyID; }
/// isIntegral - Returns true if this is an integral type, which is either
/// BoolTy or one of the Integer types.
bool isIntegral() const { return isInteger() || this == BoolTy; }
/// isFloatingPoint - Return true if this is one of the two floating point
/// types
bool isFloatingPoint() const { return ID == FloatTyID || ID == DoubleTyID; }
/// isAbstract - True if the type is either an Opaque type, or is a derived
/// type that includes an opaque type somewhere in it.
inline bool isAbstract() const { return Abstract; }
/// isLosslesslyConvertibleTo - Return true if this type can be converted to
/// 'Ty' without any reinterpretation of bits. For example, uint to int.
bool isLosslesslyConvertibleTo(const Type *Ty) const;
/// Here are some useful little methods to query what type derived types are
/// Note that all other types can just compare to see if this == Type::xxxTy;
inline bool isPrimitiveType() const { return ID <= LastPrimitiveTyID; }
inline bool isDerivedType() const { return ID >= FirstDerivedTyID; }
/// isFirstClassType - Return true if the value is holdable in a register.
inline bool isFirstClassType() const {
return (ID != VoidTyID && ID <= LastPrimitiveTyID) ||
ID == PointerTyID || ID == PackedTyID;
/// isSized - Return true if it makes sense to take the size of this type. To
/// get the actual size for a particular target, it is reasonable to use the
/// TargetData subsystem to do this.
bool isSized() const {
// If it's a primitive, it is always sized.
if (ID >= BoolTyID && ID <= DoubleTyID || ID == PointerTyID)
return true;
// If it is not something that can have a size (e.g. a function or label),
// it doesn't have a size.
if (ID != StructTyID && ID != ArrayTyID && ID != PackedTyID)
return false;
// If it is something that can have a size and it's concrete, it definitely
// has a size, otherwise we have to try harder to decide.
return !isAbstract() || isSizedDerivedType();
/// getPrimitiveSize - Return the basic size of this type if it is a primitive
/// type. These are fixed by LLVM and are not target dependent. This will
/// return zero if the type does not have a size or is not a primitive type.
unsigned getPrimitiveSize() const;
unsigned getPrimitiveSizeInBits() const;
/// getUnsignedVersion - If this is an integer type, return the unsigned
/// variant of this type. For example int -> uint.
const Type *getUnsignedVersion() const;
/// getSignedVersion - If this is an integer type, return the signed variant
/// of this type. For example uint -> int.
const Type *getSignedVersion() const;
/// getForwaredType - Return the type that this type has been resolved to if
/// it has been resolved to anything. This is used to implement the
/// union-find algorithm for type resolution, and shouldn't be used by general
/// purpose clients.
const Type *getForwardedType() const {
if (!ForwardType) return 0;
return getForwardedTypeInternal();
/// getVAArgsPromotedType - Return the type an argument of this type
/// will be promoted to if passed through a variable argument
/// function.
const Type *getVAArgsPromotedType() const {
if (ID == BoolTyID || ID == UByteTyID || ID == UShortTyID)
return Type::UIntTy;
else if (ID == SByteTyID || ID == ShortTyID)
return Type::IntTy;
else if (ID == FloatTyID)
return Type::DoubleTy;
return this;
// Type Iteration support
typedef std::vector<PATypeHandle>::const_iterator subtype_iterator;
subtype_iterator subtype_begin() const { return ContainedTys.begin(); }
subtype_iterator subtype_end() const { return ContainedTys.end(); }
/// getContainedType - This method is used to implement the type iterator
/// (defined a the end of the file). For derived types, this returns the
/// types 'contained' in the derived type.
const Type *getContainedType(unsigned i) const {
assert(i < ContainedTys.size() && "Index out of range!");
return ContainedTys[i];
/// getNumContainedTypes - Return the number of types in the derived type.
typedef std::vector<PATypeHandle>::size_type size_type;
size_type getNumContainedTypes() const { return ContainedTys.size(); }
// Static members exported by the Type class itself. Useful for getting
// instances of Type.
/// getPrimitiveType - Return a type based on an identifier.
static const Type *getPrimitiveType(TypeID IDNumber);
// These are the builtin types that are always available...
static Type *VoidTy , *BoolTy;
static Type *SByteTy, *UByteTy,
*ShortTy, *UShortTy,
*IntTy , *UIntTy,
*LongTy , *ULongTy;
static Type *FloatTy, *DoubleTy;
static Type* LabelTy;
/// Methods for support type inquiry through isa, cast, and dyn_cast:
static inline bool classof(const Type *T) { return true; }
// Virtual methods used by callbacks below. These should only be implemented
// in the DerivedType class.
virtual void addAbstractTypeUser(AbstractTypeUser *U) const {
abort(); // Only on derived types!
virtual void removeAbstractTypeUser(AbstractTypeUser *U) const {
abort(); // Only on derived types!
void addRef() const {
assert(isAbstract() && "Cannot add a reference to a non-abstract type!");
void dropRef() const {
assert(isAbstract() && "Cannot drop a reference to a non-abstract type!");
assert(RefCount && "No objects are currently referencing this object!");
// If this is the last PATypeHolder using this object, and there are no
// PATypeHandles using it, the type is dead, delete it now.
if (--RefCount == 0)
/// clearAllTypeMaps - This method frees all internal memory used by the
/// type subsystem, which can be used in environments where this memory is
/// otherwise reported as a leak.
static void clearAllTypeMaps();
/// isSizedDerivedType - Derived types like structures and arrays are sized
/// iff all of the members of the type are sized as well. Since asking for
/// their size is relatively uncommon, move this operation out of line.
bool isSizedDerivedType() const;
virtual void RefCountIsZero() const {
abort(); // only on derived types!
// Define some inline methods for the AbstractTypeUser.h:PATypeHandle class.
// These are defined here because they MUST be inlined, yet are dependent on
// the definition of the Type class. Of course Type derives from Value, which
// contains an AbstractTypeUser instance, so there is no good way to factor out
// the code. Hence this bit of uglyness.
// In the long term, Type should not derive from Value, allowing
// AbstractTypeUser.h to #include Type.h, allowing us to eliminate this
// nastyness entirely.
inline void PATypeHandle::addUser() {
assert(Ty && "Type Handle has a null type!");
if (Ty->isAbstract())
inline void PATypeHandle::removeUser() {
if (Ty->isAbstract())
inline void PATypeHandle::removeUserFromConcrete() {
if (!Ty->isAbstract())
// Define inline methods for PATypeHolder...
inline void PATypeHolder::addRef() {
if (Ty->isAbstract())
inline void PATypeHolder::dropRef() {
if (Ty->isAbstract())
/// get - This implements the forwarding part of the union-find algorithm for
/// abstract types. Before every access to the Type*, we check to see if the
/// type we are pointing to is forwarding to a new type. If so, we drop our
/// reference to the type.
inline Type* PATypeHolder::get() const {
const Type *NewTy = Ty->getForwardedType();
if (!NewTy) return const_cast<Type*>(Ty);
return *const_cast<PATypeHolder*>(this) = NewTy;
// Provide specializations of GraphTraits to be able to treat a type as a
// graph of sub types...
template <> struct GraphTraits<Type*> {
typedef Type NodeType;
typedef Type::subtype_iterator ChildIteratorType;
static inline NodeType *getEntryNode(Type *T) { return T; }
static inline ChildIteratorType child_begin(NodeType *N) {
return N->subtype_begin();
static inline ChildIteratorType child_end(NodeType *N) {
return N->subtype_end();
template <> struct GraphTraits<const Type*> {
typedef const Type NodeType;
typedef Type::subtype_iterator ChildIteratorType;
static inline NodeType *getEntryNode(const Type *T) { return T; }
static inline ChildIteratorType child_begin(NodeType *N) {
return N->subtype_begin();
static inline ChildIteratorType child_end(NodeType *N) {
return N->subtype_end();
template <> inline bool isa_impl<PointerType, Type>(const Type &Ty) {
return Ty.getTypeID() == Type::PointerTyID;
std::ostream &operator<<(std::ostream &OS, const Type &T);
} // End llvm namespace