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/*****
* refaccess.h
* Andy Hammerlindl 2003/12/03
*
* An access which refers to a variable or other object in C++.
*****/
#ifndef REFACCESS_H
#define REFACCESS_H
#include "access.h"
#include "inst.h"
#include "coder.h"
#include "stack.h"
namespace trans {
// Access refers to a piece of data, represented by an item, somewhere in the
// C++ code.
class itemRefAccess : public access {
vm::item *ref;
public:
itemRefAccess(vm::item *ref)
: ref(ref) {}
void encode(action act, position pos, coder &e);
void encode(action act, position pos, coder &e, frame *);
};
// Access refers to an arbitrary piece of data of type T.
template <class T>
class refAccess : public access {
T *ref;
public:
refAccess(T *ref)
: ref(ref) {}
void encode(action act, position pos, coder &e);
void encode(action act, position pos, coder &e, frame *);
};
template <class T>
void pointerRead(vm::stack *s) {
T *ptr=vm::pop<T *>(s);
s->push(*ptr);
}
template <class T>
void pointerWrite(vm::stack *s) {
T *ptr=vm::pop<T *>(s);
T value=vm::pop<T>(s);
*ptr=value;
s->push(value);
}
template <class T>
void refAccess<T>::encode(action act, position, coder &e)
{
// You may be able to use typeid(T).name() to get a better label.
REGISTER_BLTIN((bltin) pointerRead<T>, "pointerRead");
REGISTER_BLTIN((bltin) pointerWrite<T>, "pointerWrite");
e.encode(vm::inst::constpush, (vm::item)ref);
switch (act) {
case READ:
e.encode(vm::inst::builtin, (bltin) pointerRead<T>);
break;
case WRITE:
e.encode(vm::inst::builtin, (bltin) pointerWrite<T>);
break;
case CALL:
e.encode(vm::inst::builtin, (bltin) pointerRead<T>);
e.encode(vm::inst::popcall);
break;
};
}
template <class T>
void refAccess<T>::encode(action act, position pos, coder &e, frame *)
{
// Get rid of the useless top frame.
e.encode(vm::inst::pop);
encode(act, pos, e);
}
}
#endif
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