Subversion Repositories tendra.SVN

/*

    		 Crown Copyright (c) 1997

    This TenDRA(r) Computer Program is subject to Copyright

    owned by the United Kingdom Secretary of State for Defence

    acting through the Defence Evaluation and Research Agency

    (DERA).  It is made available to Recipients with a

    royalty-free licence for its use, reproduction, transfer

    to other parties and amendment for any purpose not excluding

    product development provided that any such use et cetera

    shall be deemed to be acceptance of the following conditions:-

        (1) Its Recipients shall ensure that this Notice is

        reproduced upon any copies or amended versions of it;

        (2) Any amended version of it shall be clearly marked to

        show both the nature of and the organisation responsible

        for the relevant amendment or amendments;

        (3) Its onward transfer from a recipient to another

        party shall be deemed to be that party's acceptance of

        these conditions;

        (4) DERA gives no warranty or assurance as to its

        quality or suitability for any purpose and DERA accepts

        no liability whatsoever in relation to any use to which

        it may be put.

*/

#include "config.h"

#include "types.h"

#include "check.h"

#include "node.h"

#include "shape.h"

#include "table.h"

#include "tdf.h"

#include "utility.h"

/*

    BASIC ALIGNMENTS

    These are the basic alignments from the TDF specification.

*/

node *al_code = null ;

node *al_frame =  null ;

node *al_alloca = null ;

node *al_var_param = null ;

node *al_top =  null ;

static node *al_offset = null ;

static node *al_pointer = null ;

static node *al_proc = null ;

/*

    FIND THE ALIGNMENT OF A SHAPE

    For the node p, representing a shape or an alignment, this returns

    the alignment of p.

*/

node *al_shape

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    node *q ;

    sortname s ;

    if ( p == null ) return ( null ) ;

    s = p->cons->sortnum ;

    if ( s == SORT_alignment ) {

	switch ( p->cons->encoding ) {

	    case ENC_alignment : {

		return ( al_shape ( p->son ) ) ;

	    }

	    case ENC_alignment_apply_token : {

		return ( al_shape ( expand_tok ( p ) ) ) ;

	    }

	}

	return ( copy_node ( p ) ) ;

    }

    if ( s == SORT_shape ) {

	switch ( p->cons->encoding ) {

	    case ENC_bottom : {

		is_fatal = 0 ;

		input_error ( "Can't have alignment of bottom in %s",

			      checking ) ;

		return ( null ) ;

	    }

	    case ENC_offset : return ( copy_node ( al_offset ) ) ;

	    case ENC_pointer : return ( copy_node ( al_pointer ) ) ;

	    case ENC_proc : return ( copy_node ( al_proc ) ) ;

	    case ENC_top : return ( copy_node ( al_top ) ) ;

	    case ENC_nof : return ( al_shape ( p->son->bro ) ) ;

	    case ENC_shape_apply_token : {

		return ( al_shape ( expand_tok ( p ) ) ) ;

	    }

	}

    }

    q = new_node () ;

    q->cons = cons_no ( SORT_alignment, ENC_alignment ) ;

    q->son = copy_node ( p ) ;

    return ( null ) ;

}

/*

    FIND WHAT A POINTER POINTS TO

    For the node p of the form ( pointer a ) this routine returns a.

*/

node *ptr_to

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    p = expand_tok ( p ) ;

    if ( p && p->cons == cons_no ( SORT_shape, ENC_pointer ) ) {

	return ( p->son ) ;

    }

    return ( null ) ;

}

/*

    FIND THE FIRST COMPONENT OF AN OFFSET

    For the node p of the form ( offset a b ) this routine returns a.

*/

node *offset_from

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    p = expand_tok ( p ) ;

    if ( p && p->cons == cons_no ( SORT_shape, ENC_offset ) ) {

	return ( p->son ) ;

    }

    return ( null ) ;

}

/*

    FIND THE SECOND COMPONENT OF AN OFFSET

    For the node p of the form ( offset a b ) this routine returns b.

*/

node *offset_to

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    p = expand_tok ( p ) ;

    if ( p && p->cons == cons_no ( SORT_shape, ENC_offset ) ) {

	return ( p->son->bro ) ;

    }

    return ( null ) ;

}

/*

    CHECK THAT TWO ALIGNMENTS ARE EQUAL

    This routine is not yet implemented.

*/

void al_equals

    PROTO_N ( ( p, q ) )

    PROTO_T ( node *p X node *q )

{

    UNUSED ( p ) ;

    UNUSED ( q ) ;

    return ;

}

/*

    CHECK THAT ONE ALIGNMENT CONTAINS ANOTHER

    This routine is not yet implemented.

*/

void al_includes

    PROTO_N ( ( p, q ) )

    PROTO_T ( node *p X node *q )

{

    UNUSED ( p ) ;

    UNUSED ( q ) ;

    return ;

}

/*

    FIND THE UNIONS OF TWO ALIGNMENTS

    The value of ( unite_alignments p q ) is returned.

*/

node *al_union

    PROTO_N ( ( p, q ) )

    PROTO_T ( node *p X node *q )

{

    if ( p == null || p->cons->sortnum != SORT_alignment ) return ( null ) ;

    if ( q == null || q->cons->sortnum != SORT_alignment ) return ( null ) ;

    if ( p->cons->encoding == ENC_alignment &&

	 p->son->cons == cons_no ( SORT_shape, ENC_top ) ) return ( q ) ;

    if ( q->cons->encoding == ENC_alignment &&

	 q->son->cons == cons_no ( SORT_shape, ENC_top ) ) return ( p ) ;

    return ( null ) ;

}

/*

    INITIALIZE BASIC ALIGNMENTS

    The basic alignments, al_top, al_offset, al_pointer and al_proc, are

    initialized.

*/

void init_alignments

    PROTO_Z ()

{

    /* Set up al_top */

    al_top =  new_node () ;

    al_top->cons = cons_no ( SORT_alignment, ENC_alignment ) ;

    al_top->son = copy_node ( sh_top ) ;

    /* Set up al_offset */

    al_offset =  new_node () ;

    al_offset->cons = cons_no ( SORT_alignment, ENC_alignment ) ;

    al_offset->son = sh_offset ( al_top, al_top ) ;

    /* Set up al_pointer */

    al_pointer =  new_node () ;

    al_pointer->cons = cons_no ( SORT_alignment, ENC_alignment ) ;

    al_pointer->son = sh_pointer ( al_top ) ;

    /* Set up al_proc */

    al_proc =  new_node () ;

    al_proc->cons = cons_no ( SORT_alignment, ENC_alignment ) ;

    al_proc->son = copy_node ( sh_proc ) ;

    return ;

}