#include "AST.h"
#include "code-util.h"
#include "clone.h"


#define DEBUG_SHARED DEBUG_PHASE_ENABLED("shared", currentFilename)

/* Recursively go through a tree, fixing all the _parent pointers.
   Returns how many it fixed. */
int TreeNode::fixParent()
{
  const int n = arity();
  int count = 0;

  for (int i = 0; i < n; i++) {
    TreeNode *c = child(i);

    if (c != NULL && !c->absent()) {
      if (c->_parent != this) {
	c->_parent = this;
	count++;
      }
      count += c->fixParent();
    }
  }

  return count;
}

/* Assumes that if the _parent pointer is incorrect that the node is
   shared.  It is recommended that one use fixSubtreeSharing(), below,
   rather than calling this method directly. */
TreeNode * TreeNode::cloneSharedSubtrees()
{
  const int n = arity();

  for (int i = 0; i < n; i++) {
    TreeNode *c = child(i);

    if (c != NULL && !c->absent()) {
      if (c->_parent != this) {
	if (DEBUG_SHARED) {
	  cout << "Shared:" << endl;
	  c->print(cout, 0);
	  cout << endl;
	}
	child(i, c = deepCloneWithCrossTreeFixup(c));
      }
      child(i, c->cloneSharedSubtrees());
    }
  }

  return this;
}

TreeNode *fixSubtreeSharing(TreeNode *t)
{
  int n;
  t->fixParent();
  t = t->cloneSharedSubtrees();
  n = t->fixParent();
  if (DEBUG_SHARED && n != 0)
    cout << "fixParent(): " << n << endl;
  return t;
}