psscope.c

/******************************************************************************
 *
 * Module Name: psscope - Parser scope stack management routines
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2003, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */


#include <acpi/acpi.h>
#include <acpi/acparser.h>

#define _COMPONENT          ACPI_PARSER
	 ACPI_MODULE_NAME    ("psscope")


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_get_parent_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Pointer to an Op object
 *
 * DESCRIPTION: Get parent of current op being parsed
 *
 ******************************************************************************/

union acpi_parse_object *
acpi_ps_get_parent_scope (
	struct acpi_parse_state         *parser_state)
{
	return (parser_state->scope->parse_scope.op);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_has_completed_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Boolean, TRUE = scope completed.
 *
 * DESCRIPTION: Is parsing of current argument complete?  Determined by
 *              1) AML pointer is at or beyond the end of the scope
 *              2) The scope argument count has reached zero.
 *
 ******************************************************************************/

u8
acpi_ps_has_completed_scope (
	struct acpi_parse_state         *parser_state)
{
	return ((u8) ((parser_state->aml >= parser_state->scope->parse_scope.arg_end ||
			   !parser_state->scope->parse_scope.arg_count)));
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_init_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              Root                - the Root Node of this new scope
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Allocate and init a new scope object
 *
 ******************************************************************************/

acpi_status
acpi_ps_init_scope (
	struct acpi_parse_state         *parser_state,
	union acpi_parse_object         *root_op)
{
	union acpi_generic_state        *scope;


	ACPI_FUNCTION_TRACE_PTR ("ps_init_scope", root_op);


	scope = acpi_ut_create_generic_state ();
	if (!scope) {
		return_ACPI_STATUS (AE_NO_MEMORY);
	}

	scope->common.data_type     = ACPI_DESC_TYPE_STATE_RPSCOPE;
	scope->parse_scope.op       = root_op;
	scope->parse_scope.arg_count = ACPI_VAR_ARGS;
	scope->parse_scope.arg_end  = parser_state->aml_end;
	scope->parse_scope.pkg_end  = parser_state->aml_end;

	parser_state->scope         = scope;
	parser_state->start_op      = root_op;

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_push_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              Op                  - Current op to be pushed
 *              remaining_args      - List of args remaining
 *              arg_count           - Fixed or variable number of args
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Push current op to begin parsing its argument
 *
 ******************************************************************************/

acpi_status
acpi_ps_push_scope (
	struct acpi_parse_state         *parser_state,
	union acpi_parse_object         *op,
	u32                             remaining_args,
	u32                             arg_count)
{
	union acpi_generic_state        *scope;


	ACPI_FUNCTION_TRACE_PTR ("ps_push_scope", op);


	scope = acpi_ut_create_generic_state ();
	if (!scope) {
		return_ACPI_STATUS (AE_NO_MEMORY);
	}


	scope->common.data_type        = ACPI_DESC_TYPE_STATE_PSCOPE;
	scope->parse_scope.op          = op;
	scope->parse_scope.arg_list    = remaining_args;
	scope->parse_scope.arg_count   = arg_count;
	scope->parse_scope.pkg_end     = parser_state->pkg_end;

	/* Push onto scope stack */

	acpi_ut_push_generic_state (&parser_state->scope, scope);


	if (arg_count == ACPI_VAR_ARGS) {
		/* multiple arguments */

		scope->parse_scope.arg_end = parser_state->pkg_end;
	}

	else {
		/* single argument */

		scope->parse_scope.arg_end = ACPI_TO_POINTER (ACPI_MAX_PTR);
	}

	return_ACPI_STATUS (AE_OK);
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_pop_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *              Op                  - Where the popped op is returned
 *              arg_list            - Where the popped "next argument" is
 *                                    returned
 *              arg_count           - Count of objects in arg_list
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Return to parsing a previous op
 *
 ******************************************************************************/

void
acpi_ps_pop_scope (
	struct acpi_parse_state         *parser_state,
	union acpi_parse_object         **op,
	u32                             *arg_list,
	u32                             *arg_count)
{
	union acpi_generic_state        *scope = parser_state->scope;


	ACPI_FUNCTION_TRACE ("ps_pop_scope");


	/*
	 * Only pop the scope if there is in fact a next scope
	 */
	if (scope->common.next) {
		scope = acpi_ut_pop_generic_state (&parser_state->scope);

		/* return to parsing previous op */

		*op                     = scope->parse_scope.op;
		*arg_list               = scope->parse_scope.arg_list;
		*arg_count              = scope->parse_scope.arg_count;
		parser_state->pkg_end   = scope->parse_scope.pkg_end;

		/* All done with this scope state structure */

		acpi_ut_delete_generic_state (scope);
	}

	else {
		/* empty parse stack, prepare to fetch next opcode */

		*op                     = NULL;
		*arg_list               = 0;
		*arg_count              = 0;
	}


	ACPI_DEBUG_PRINT ((ACPI_DB_PARSE, "Popped Op %p Args %X\n", *op, *arg_count));
	return_VOID;
}


/*******************************************************************************
 *
 * FUNCTION:    acpi_ps_cleanup_scope
 *
 * PARAMETERS:  parser_state        - Current parser state object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Destroy available list, remaining stack levels, and return
 *              root scope
 *
 ******************************************************************************/

void
acpi_ps_cleanup_scope (
	struct acpi_parse_state         *parser_state)
{
	union acpi_generic_state        *scope;

	ACPI_FUNCTION_TRACE_PTR ("ps_cleanup_scope", parser_state);


	if (!parser_state) {
		return;
	}


	/* Delete anything on the scope stack */

	while (parser_state->scope) {
		scope = acpi_ut_pop_generic_state (&parser_state->scope);
		acpi_ut_delete_generic_state (scope);
	}

	return_VOID;
}