-//===-- llvm/Type.h - Classes for handling data types ------------*- C++ -*--=//
+//===-- 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.
#include "llvm/Value.h"
#include "Support/GraphTraits.h"
#include "Support/iterator"
+#include <vector>
+
+namespace llvm {
class DerivedType;
class FunctionType;
class StructType;
class OpaqueType;
-class Type : public Value {
-public:
+struct Type : public Value {
///===-------------------------------------------------------------------===//
/// 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)
unsigned UID; // The unique ID number for this class
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;
protected:
/// ctor is protected, so only subclasses can create Type objects...
Type(const std::string &Name, PrimitiveID id);
///
inline void setAbstract(bool Val) { Abstract = Val; }
+ /// isTypeAbstract - This method is used to calculate the Abstract bit.
+ ///
+ bool isTypeAbstract();
+
+ 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;
+
public:
virtual void print(std::ostream &O) 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.
- //
+ ///
virtual bool isSigned() const { return 0; }
/// isUnsigned - Return whether a numeric type is unsigned. This is not quite
/// isFirstClassType - Return true if the value is holdable in a register.
inline bool isFirstClassType() const {
- return isPrimitiveType() || ID == PointerTyID;
+ return (ID != VoidTyID && ID < TypeTyID) || ID == PointerTyID;
}
/// isSized - Return true if it makes sense to take the size of this type. To
///
unsigned getPrimitiveSize() 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.
+ const Type *getForwardedType() const {
+ if (!ForwardType) return 0;
+ return getForwardedTypeInternal();
+ }
//===--------------------------------------------------------------------===//
// Type Iteration support
//
- class TypeIterator;
- typedef TypeIterator subtype_iterator;
- inline subtype_iterator subtype_begin() const; // DEFINED BELOW
- inline subtype_iterator subtype_end() const; // DEFINED BELOW
+ 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, returning 0 when 'i' becomes
- /// invalid. This allows the user to iterate over the types in a struct, for
- /// example, really easily.
+ /// types 'contained' in the derived type.
///
- virtual const Type *getContainedType(unsigned i) const { return 0; }
+ 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
- virtual unsigned getNumContainedTypes() const { return 0; }
+ /// getNumContainedTypes - Return the number of types in the derived type.
+ ///
+ unsigned getNumContainedTypes() const { return ContainedTys.size(); }
//===--------------------------------------------------------------------===//
// Static members exported by the Type class itself. Useful for getting
#include "llvm/Type.def"
+ // 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!");
+ ++RefCount;
+ }
+
+ void dropRef() const {
+ assert(isAbstract() && "Cannot drop a refernce 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)
+ RefCountIsZero();
+ }
private:
- class TypeIterator : public bidirectional_iterator<const Type, ptrdiff_t> {
- const Type * const Ty;
- unsigned Idx;
-
- typedef TypeIterator _Self;
- public:
- inline TypeIterator(const Type *ty, unsigned idx) : Ty(ty), Idx(idx) {}
- inline ~TypeIterator() {}
-
- inline bool operator==(const _Self& x) const { return Idx == x.Idx; }
- inline bool operator!=(const _Self& x) const { return !operator==(x); }
-
- inline pointer operator*() const { return Ty->getContainedType(Idx); }
- inline pointer operator->() const { return operator*(); }
-
- inline _Self& operator++() { ++Idx; return *this; } // Preincrement
- inline _Self operator++(int) { // Postincrement
- _Self tmp = *this; ++*this; return tmp;
- }
-
- inline _Self& operator--() { --Idx; return *this; } // Predecrement
- inline _Self operator--(int) { // Postdecrement
- _Self tmp = *this; --*this; return tmp;
- }
- };
+ virtual void RefCountIsZero() const {
+ abort(); // only on derived types!
+ }
+
};
-inline Type::TypeIterator Type::subtype_begin() const {
- return TypeIterator(this, 0);
+//===----------------------------------------------------------------------===//
+// 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())
+ Ty->addAbstractTypeUser(User);
+}
+inline void PATypeHandle::removeUser() {
+ if (Ty->isAbstract())
+ Ty->removeAbstractTypeUser(User);
}
-inline Type::TypeIterator Type::subtype_end() const {
- return TypeIterator(this, getNumContainedTypes());
+inline void PATypeHandle::removeUserFromConcrete() {
+ if (!Ty->isAbstract())
+ Ty->removeAbstractTypeUser(User);
}
+// Define inline methods for PATypeHolder...
+inline void PATypeHolder::addRef() {
+ if (Ty->isAbstract())
+ Ty->addRef();
+}
+
+inline void PATypeHolder::dropRef() {
+ if (Ty->isAbstract())
+ Ty->dropRef();
+}
+
+/// 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 const Type* PATypeHolder::get() const {
+ const Type *NewTy = Ty->getForwardedType();
+ if (!NewTy) return Ty;
+ return *const_cast<PATypeHolder*>(this) = NewTy;
+}
+
+
+
+//===----------------------------------------------------------------------===//
// Provide specializations of GraphTraits to be able to treat a type as a
// graph of sub types...
return Ty.getPrimitiveID() == Type::PointerTyID;
}
+} // End llvm namespace
+
#endif