Beispiel #1
0
static void
lower_try_catch (gimple_stmt_iterator *gsi, struct lower_data *data)
{
  bool cannot_fallthru;
  gimple stmt = gsi_stmt (*gsi);
  gimple_stmt_iterator i;

  /* We don't handle GIMPLE_TRY_FINALLY.  */
  gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH);

  lower_sequence (gimple_try_eval_ptr (stmt), data);
  cannot_fallthru = data->cannot_fallthru;

  i = gsi_start (*gimple_try_cleanup_ptr (stmt));
  switch (gimple_code (gsi_stmt (i)))
    {
    case GIMPLE_CATCH:
      /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a
	 catch expression and a body.  The whole try/catch may fall
	 through iff any of the catch bodies falls through.  */
      for (; !gsi_end_p (i); gsi_next (&i))
	{
	  data->cannot_fallthru = false;
	  lower_sequence (gimple_catch_handler_ptr (
                            as_a <gcatch *> (gsi_stmt (i))),
			  data);
	  if (!data->cannot_fallthru)
	    cannot_fallthru = false;
	}
      break;

    case GIMPLE_EH_FILTER:
      /* The exception filter expression only matters if there is an
	 exception.  If the exception does not match EH_FILTER_TYPES,
	 we will execute EH_FILTER_FAILURE, and we will fall through
	 if that falls through.  If the exception does match
	 EH_FILTER_TYPES, the stack unwinder will continue up the
	 stack, so we will not fall through.  We don't know whether we
	 will throw an exception which matches EH_FILTER_TYPES or not,
	 so we just ignore EH_FILTER_TYPES and assume that we might
	 throw an exception which doesn't match.  */
      data->cannot_fallthru = false;
      lower_sequence (gimple_eh_filter_failure_ptr (gsi_stmt (i)), data);
      if (!data->cannot_fallthru)
	cannot_fallthru = false;
      break;

    default:
      /* This case represents statements to be executed when an
	 exception occurs.  Those statements are implicitly followed
	 by a GIMPLE_RESX to resume execution after the exception.  So
	 in this case the try/catch never falls through.  */
      data->cannot_fallthru = false;
      lower_sequence (gimple_try_cleanup_ptr (stmt), data);
      break;
    }

  data->cannot_fallthru = cannot_fallthru;
  gsi_next (gsi);
}
Beispiel #2
0
tree
walk_gimple_stmt (gimple_stmt_iterator *gsi, walk_stmt_fn callback_stmt,
		  walk_tree_fn callback_op, struct walk_stmt_info *wi)
{
  gimple *ret;
  tree tree_ret;
  gimple *stmt = gsi_stmt (*gsi);

  if (wi)
    {
      wi->gsi = *gsi;
      wi->removed_stmt = false;

      if (wi->want_locations && gimple_has_location (stmt))
	input_location = gimple_location (stmt);
    }

  ret = NULL;

  /* Invoke the statement callback.  Return if the callback handled
     all of STMT operands by itself.  */
  if (callback_stmt)
    {
      bool handled_ops = false;
      tree_ret = callback_stmt (gsi, &handled_ops, wi);
      if (handled_ops)
	return tree_ret;

      /* If CALLBACK_STMT did not handle operands, it should not have
	 a value to return.  */
      gcc_assert (tree_ret == NULL);

      if (wi && wi->removed_stmt)
	return NULL;

      /* Re-read stmt in case the callback changed it.  */
      stmt = gsi_stmt (*gsi);
    }

  /* If CALLBACK_OP is defined, invoke it on every operand of STMT.  */
  if (callback_op)
    {
      tree_ret = walk_gimple_op (stmt, callback_op, wi);
      if (tree_ret)
	return tree_ret;
    }

  /* If STMT can have statements inside (e.g. GIMPLE_BIND), walk them.  */
  switch (gimple_code (stmt))
    {
    case GIMPLE_BIND:
      ret = walk_gimple_seq_mod (gimple_bind_body_ptr (as_a <gbind *> (stmt)),
				 callback_stmt, callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_CATCH:
      ret = walk_gimple_seq_mod (gimple_catch_handler_ptr (
				   as_a <gcatch *> (stmt)),
				 callback_stmt, callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_EH_FILTER:
      ret = walk_gimple_seq_mod (gimple_eh_filter_failure_ptr (stmt), callback_stmt,
		             callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_EH_ELSE:
      {
	geh_else *eh_else_stmt = as_a <geh_else *> (stmt);
	ret = walk_gimple_seq_mod (gimple_eh_else_n_body_ptr (eh_else_stmt),
				   callback_stmt, callback_op, wi);
	if (ret)
	  return wi->callback_result;
	ret = walk_gimple_seq_mod (gimple_eh_else_e_body_ptr (eh_else_stmt),
				   callback_stmt, callback_op, wi);
	if (ret)
	  return wi->callback_result;
      }
      break;

    case GIMPLE_TRY:
      ret = walk_gimple_seq_mod (gimple_try_eval_ptr (stmt), callback_stmt, callback_op,
	                     wi);
      if (ret)
	return wi->callback_result;

      ret = walk_gimple_seq_mod (gimple_try_cleanup_ptr (stmt), callback_stmt,
	                     callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_OMP_FOR:
      ret = walk_gimple_seq_mod (gimple_omp_for_pre_body_ptr (stmt), callback_stmt,
		             callback_op, wi);
      if (ret)
	return wi->callback_result;

      /* FALL THROUGH.  */
    case GIMPLE_OMP_CRITICAL:
    case GIMPLE_OMP_MASTER:
    case GIMPLE_OMP_TASKGROUP:
    case GIMPLE_OMP_ORDERED:
    case GIMPLE_OMP_SECTION:
    case GIMPLE_OMP_PARALLEL:
    case GIMPLE_OMP_TASK:
    case GIMPLE_OMP_SECTIONS:
    case GIMPLE_OMP_SINGLE:
    case GIMPLE_OMP_TARGET:
    case GIMPLE_OMP_TEAMS:
      ret = walk_gimple_seq_mod (gimple_omp_body_ptr (stmt), callback_stmt,
			     callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_WITH_CLEANUP_EXPR:
      ret = walk_gimple_seq_mod (gimple_wce_cleanup_ptr (stmt), callback_stmt,
			     callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    case GIMPLE_TRANSACTION:
      ret = walk_gimple_seq_mod (gimple_transaction_body_ptr (
				   as_a <gtransaction *> (stmt)),
			     callback_stmt, callback_op, wi);
      if (ret)
	return wi->callback_result;
      break;

    default:
      gcc_assert (!gimple_has_substatements (stmt));
      break;
    }

  return NULL;
}