text: /******************************************************************************
   *
   * Module Name: dswscope - Scope stack manipulation
   *              $Revision: 1.1.1.2 $
   *
   *****************************************************************************/
  
  /*
   *  Copyright (C) 2000, 2001 R. Byron Moore
   *
   *  This program is free software; you can redistribute it and/or modify
   *  it under the terms of the GNU General Public License as published by
   *  the Free Software Foundation; either version 2 of the License, or
   *  (at your option) any later version.
   *
   *  This program is distributed in the hope that it will be useful,
   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *  along with this program; if not, write to the Free Software
   *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   */
  
  
  #include "acpi.h"
  #include "acinterp.h"
  #include "acdispat.h"
  
  
  #define _COMPONENT          ACPI_DISPATCHER
  	 MODULE_NAME         ("dswscope")
  
  
  #define STACK_POP(head) head
  
  
  /****************************************************************************
   *
   * FUNCTION:    Acpi_ds_scope_stack_clear
   *
   * PARAMETERS:  None
   *
   * DESCRIPTION: Pop (and free) everything on the scope stack except the
   *              root scope object (which remains at the stack top.)
   *
   ***************************************************************************/
  
  void
  acpi_ds_scope_stack_clear (
  	acpi_walk_state         *walk_state)
  {
  	acpi_generic_state      *scope_info;
  
  	PROC_NAME ("Ds_scope_stack_clear");
  
  
  	while (walk_state->scope_info) {
  		/* Pop a scope off the stack */
  
  		scope_info = walk_state->scope_info;
  		walk_state->scope_info = scope_info->scope.next;
  
  		ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
  			"Popped object type %X\n", scope_info->common.value));
  		acpi_ut_delete_generic_state (scope_info);
  	}
  }
  
  
  /****************************************************************************
   *
   * FUNCTION:    Acpi_ds_scope_stack_push
   *
   * PARAMETERS:  *Node,              - Name to be made current
   *              Type,               - Type of frame being pushed
   *
   * DESCRIPTION: Push the current scope on the scope stack, and make the
   *              passed Node current.
   *
   ***************************************************************************/
  
  acpi_status
  acpi_ds_scope_stack_push (
  	acpi_namespace_node     *node,
  	acpi_object_type8       type,
  	acpi_walk_state         *walk_state)
  {
  	acpi_generic_state      *scope_info;
  
  
  	FUNCTION_TRACE ("Ds_scope_stack_push");
  
  
  	if (!node) {
  		/* Invalid scope   */
  
  		REPORT_ERROR (("Ds_scope_stack_push: null scope passed\n"));
  		return_ACPI_STATUS (AE_BAD_PARAMETER);
  	}
  
  	/* Make sure object type is valid */
  
  	if (!acpi_ex_validate_object_type (type)) {
  		REPORT_WARNING (("Ds_scope_stack_push: type code out of range\n"));
  	}
  
  
  	/* Allocate a new scope object */
  
  	scope_info = acpi_ut_create_generic_state ();
  	if (!scope_info) {
  		return_ACPI_STATUS (AE_NO_MEMORY);
  	}
  
  	/* Init new scope object */
  
  	scope_info->common.data_type = ACPI_DESC_TYPE_STATE_WSCOPE;
  	scope_info->scope.node      = node;
  	scope_info->common.value    = (u16) type;
  
  	/* Push new scope object onto stack */
  
  	acpi_ut_push_generic_state (&walk_state->scope_info, scope_info);
  
  	return_ACPI_STATUS (AE_OK);
  }
  
  
  /****************************************************************************
   *
   * FUNCTION:    Acpi_ds_scope_stack_pop
   *
   * PARAMETERS:  Type                - The type of frame to be found
   *
   * DESCRIPTION: Pop the scope stack until a frame of the requested type
   *              is found.
   *
   * RETURN:      Count of frames popped.  If no frame of the requested type
   *              was found, the count is returned as a negative number and
   *              the scope stack is emptied (which sets the current scope
   *              to the root).  If the scope stack was empty at entry, the
   *              function is a no-op and returns 0.
   *
   ***************************************************************************/
  
  acpi_status
  acpi_ds_scope_stack_pop (
  	acpi_walk_state         *walk_state)
  {
  	acpi_generic_state      *scope_info;
  
  
  	FUNCTION_TRACE ("Ds_scope_stack_pop");
  
  
  	/*
  	 * Pop scope info object off the stack.
  	 */
  	scope_info = acpi_ut_pop_generic_state (&walk_state->scope_info);
  	if (!scope_info) {
  		return_ACPI_STATUS (AE_STACK_UNDERFLOW);
  	}
  
  	ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
  		"Popped object type %X\n", scope_info->common.value));
  
  	acpi_ut_delete_generic_state (scope_info);
  
  	return_ACPI_STATUS (AE_OK);
  }
  
  
  