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/*

    		 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 "de_types.h"

#include "de_capsule.h"

#include "decode.h"

#include "fetch.h"

#include "high.h"

#include "node.h"

#include "table.h"

#include "tdf.h"

#include "utility.h"

/*

    ARRAY OF ALL LABELS

    The labels in a unit are held in the table labels of size max_lab_no.

*/

static long max_lab_no = 0 ;

static construct *labels ;

/*

    SET UP LABELS

    A table of n labels is allocated and initialized.

*/

static void set_up_labels

    PROTO_N ( ( n ) )

    PROTO_T ( long n )

{

    long i ;

    static long lno = 0 ;

    max_lab_no = n ;

    labels = alloc_nof ( construct, n ) ;

    for ( i = 0 ; i < n ; i++ ) {

	char *nm = alloc_nof ( char, 32 ) ;

	IGNORE sprintf ( nm, "~~label_%ld", lno ) ;

	labels [i].sortnum = SORT_label ;

	labels [i].encoding = lno++ ;

	labels [i].name = nm ;

	labels [i].alias = null ;

	labels [i].next = null ;

	if ( add_to_var_hash ( labels + i, SORT_label ) ) {

	    input_error ( "Label %s already defined", nm ) ;

	}

    }

    return ;

}

/*

    FIND A LABEL

    The nth label in the current unit is returned.

*/

construct *find_label

    PROTO_N ( ( n ) )

    PROTO_T ( long n )

{

    if ( n < 0 || n >= max_lab_no ) {

	input_error ( "Label number %ld too big", n ) ;

	return ( null ) ;

    }

    return ( labels + n ) ;

}

/*

    DECODE A SORT NAME

    A sortname is decoded.  If expand is true the arguments of any high

    level sort will be stepped over.

*/

static sortname de_sortname

    PROTO_N ( ( expand ) )

    PROTO_T ( boolean expand )

{

    long n = de_sortname_bits () ;

    if ( n == SORT_token && expand ) {

	long i, m ;

	high_sort h, *hp ;

	static int made_up_sorts = 0 ;

	h.res = de_sortname ( 1 ) ;

	de_list_start () ;

	m = tdf_int () ;

	h.no_args = ( int ) m ;

	h.args = alloc_nof ( sortname, m ) ;

	h.name = alloc_nof ( char, 32 ) ;

	IGNORE sprintf ( h.name, "~~sort_%d", made_up_sorts++ ) ;

	for ( i = 0 ; i < m ; i++ ) {

	    h.args [i] = de_sortname ( 1 ) ;

	}

	hp = new_high_sort ( &h ) ;

	hp = unique_high_sort ( hp ) ;

	return ( hp->id ) ;

    }

    if ( n == SORT_foreign ) {

	warning ( "Foreign sorts not supported" ) ;

	IGNORE de_node ( "X" ) ;

	return ( SORT_unknown ) ;

    }

    return ( ( sortname ) n ) ;

}

/*

    DECODE AN ALIGNMENT TAG DEFINITION UNIT

    A number of alignment tag definitions are decoded.

*/

void de_aldef

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    set_up_labels ( n ) ;

    n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long t ;

	node *d ;

	construct *p ;

	al_tag_info *info ;

	/* Find the definition type */

	IGNORE de_al_tagdef_bits () ;

	/* Find the alignment tag */

	t = tdf_int () ;

	p = find_binding ( crt_binding, al_tag_var, t ) ;

	info = get_al_tag_info ( p ) ;

	/* Decode the definition (an alignment) */

	d = completion ( de_alignment () ) ;

	if ( info->def ) {

	    if ( !eq_node ( info->def, d ) ) {

		is_fatal = 0 ;

		input_error ( "Alignment tag %s defined inconsistently",

			      p->name ) ;

	    }

	    free_node ( d ) ;

	} else {

	    info->def = d ;

	}

    }

    return ;

}

/*

    DECODE A TAG DECLARATION UNIT

    A number of tag declarations are decoded.

*/

void de_tagdec

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    set_up_labels ( n ) ;

    n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long t ;

	node *d ;

	boolean is_var ;

	construct *p ;

	tag_info *info ;

	/* Find the declaration type */

	long m = de_tagdec_bits () ;

	if ( m == ENC_make_id_tagdec ) {

	    is_var = 0 ;

	} else if ( m == ENC_make_var_tagdec ) {

	    is_var = 1 ;

	} else {

	    is_var = 2 ;

	}

	/* Find the tag */

	t = tdf_int () ;

	p = find_binding ( crt_binding, tag_var, t ) ;

	set_tag_type ( p, is_var ) ;

	info = get_tag_info ( p ) ;

	/* Declaration = optional access + optional string + shape from 4.0 */

	d = completion ( de_node ( "?[u]?[X]S" ) ) ;

	info->var = is_var ;

	if ( info->dec ) {

	    if ( !eq_node ( info->dec, d ) ) {

		is_fatal = 0 ;

		input_error ( "Tag %s declared inconsistently", p->name ) ;

	    }

	    free_node ( d ) ;

	} else {

	    info->dec = d ;

	}

    }

    return ;

}

/*

    DECODE A TAG DEFINITION UNIT

    A number of tag definitions are decoded.

*/

void de_tagdef

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    set_up_labels ( n ) ;

    n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long t ;

	node *d ;

	construct *p ;

	tag_info *info ;

	boolean is_var ;

	/* Find the definition type */

	long m = de_tagdef_bits () ;

	if ( m == ENC_make_id_tagdef ) {

	    is_var = 0 ;

	} else if ( m == ENC_make_var_tagdef ) {

	    is_var = 1 ;

	} else {

	    is_var = 2 ;

	}

	/* Find the tag */

	t = tdf_int () ;

	p = find_binding ( crt_binding, tag_var, t ) ;

	info = get_tag_info ( p ) ;

	if ( info->dec == null ) {

	    input_error ( "Tag %s defined but not declared", p->name ) ;

	}

	set_tag_type ( p, is_var ) ;

	/* Added signature in 4.0 */

	d = completion ( de_node ( is_var ? "?[u]?[X]x" : "?[X]x" ) ) ;

	info->var = is_var ;

	if ( info->def ) {

	    if ( is_var == 2 ) {

		node *dp = info->def ;

		while ( dp->bro ) dp = dp->bro ;

		dp->bro = d ;

	    } else {

		if ( !eq_node ( info->def, d ) ) {

		    is_fatal = 0 ;

		    input_error ( "Tag %s defined inconsistently", p->name ) ;

		}

		free_node ( d ) ;

	    }

	} else {

	    info->def = d ;

	    if ( do_check ) check_tagdef ( p ) ;

	}

    }

    return ;

}

/*

    DECODE A TOKEN DECLARATION UNIT

    A number of token declarations are decoded.

*/

void de_tokdec

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long t ;

	node *sig ;

	char *args ;

	sortname rs ;

	construct *p ;

	tok_info *info ;

	/* Find the declaration type */

	IGNORE de_tokdec_bits () ;

	/* Find the token */

	t = tdf_int () ;

	p = find_binding ( crt_binding, tok_var, t ) ;

	info = get_tok_info ( p ) ;

	/* Deal with signature */

	sig = de_node ( "?[X]" ) ;

	/* Decode token sort */

	rs = de_sortname ( 0 ) ;

	if ( rs == SORT_token ) {

	    long m ;

	    rs = de_sortname ( 1 ) ;

	    de_list_start () ;

	    m = tdf_int () ;

	    if ( m == 0 ) {

		args = null ;

	    } else {

		long j ;

		char abuff [100], *a = abuff ;

		for ( j = 0 ; j < m ; j++ ) {

		    sortname ps = de_sortname ( 1 ) ;

		    if ( is_high ( ps ) ) {

			sprint_high_sort ( a, ps ) ;

			while ( *a ) a++ ;

		    } else {

			*( a++ ) = sort_letters [ps] ;

		    }

		}

		*a = 0 ;

		args = string_copy_aux ( abuff ) ;

	    }

	} else {

	    args = null ;

	}

	if ( is_high ( rs ) ) {

	    input_error ( "Token %s has high-level result sort", p->name ) ;

	}

	set_token_sort ( p, rs, args, sig ) ;

	info->dec = 1 ;

    }

    return ;

}

/*

    DECODE A TOKEN DEFINITION BODY

    The actual body of a token definition is decoded.

*/

void de_token_defn

    PROTO_N ( ( p, sig ) )

    PROTO_T ( construct *p X node *sig )

{

    long m ;

    node *d ;

    char *args ;

    sortname rs ;

    tok_info *info = get_tok_info ( p ) ;

    construct **old_pars = info->pars ;

    /* Find the end of the definition */

    long end_posn = tdf_int () ;

    end_posn += input_posn () ;

    /* Find the definition type */

    IGNORE de_token_defn_bits () ;

    /* Decode the token sort */

    rs = de_sortname ( 1 ) ;

    de_list_start () ;

    m = tdf_int () ;

    if ( m == 0 ) {

	args = null ;

    } else {

	long j ;

	char abuff [100], *a = abuff ;

	if ( !in_skip_pass ) {

	    info->pars = alloc_nof ( construct *, m + 1 ) ;

	}

	for ( j = 0 ; j < m ; j++ ) {

	    /* Decode the token arguments */

	    sortname ps = de_sortname ( 1 ) ;

	    long pn = tdf_int () ;

	    construct *q = find_binding ( crt_binding, tok_var, pn ) ;

	    set_token_sort ( q, ps, ( char * ) null, ( node * ) null ) ;

	    if ( is_high ( ps ) ) {

		sprint_high_sort ( a, ps ) ;

		while ( *a ) a++ ;

	    } else {

		*( a++ ) = sort_letters [ps] ;

	    }

	    if ( !in_skip_pass ) info->pars [j] = q ;

	}

	*a = 0 ;

	args = string_copy_aux ( abuff ) ;

	if ( !in_skip_pass ) info->pars [j] = null ;

    }

    if ( is_high ( rs ) ) {

	input_error ( "Token %s has high-level result sort", p->name ) ;

    }

    set_token_sort ( p, rs, args, sig ) ;

    info->dec = 1 ;

    /* Decode the actual definition */

    if ( in_skip_pass ) {

	long bits = end_posn - input_posn () ;

	input_skip ( bits ) ;

    } else {

	char buff [2] ;

	buff [0] = sort_letters [rs] ;

	buff [1] = 0 ;

	d = completion ( de_node ( buff ) ) ;

	if ( info->def ) {

	    if ( !eq_node ( info->def, d ) ) {

		is_fatal = 0 ;

		input_error ( "Token %s defined inconsistently",

			      p->name ) ;

	    }

	    free_node ( d ) ;

	    info->pars = old_pars ;

	} else {

	    info->def = d ;

	}

	if ( rs == SORT_unknown ) {

	    long bits = end_posn - input_posn () ;

	    input_skip ( bits ) ;

	}

	if ( input_posn () != end_posn ) {

	    input_error ( "Token %s definition length wrong", p->name ) ;

	}

	if ( info->pars ) {

	    /* Mark the formal arguments as unused */

	    construct **ps ;

	    for ( ps = info->pars ; *ps ; ps++ ) {

		info = get_tok_info ( *ps ) ;

		info->dec = 0 ;

	    }

	}

    }

    return ;

}

/*

    DECODE A TOKEN DEFINITION UNIT

    A number of token definitions are decoded.

*/

void de_tokdef

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    set_up_labels ( n ) ;

    n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long t ;

	node *sig ;

	construct *p ;

	/* Find the definition type */

	IGNORE de_tokdef_bits () ;

	/* Find the token */

	t = tdf_int () ;

	p = find_binding ( crt_binding, tok_var, t ) ;

	/* Deal with signature */

	sig = de_node ( "?[X]" ) ;

	/* Decode token definition */

	de_token_defn ( p, sig ) ;

    }

    return ;

}

/*

    FLAG

    Has a version number been read?

*/

int have_version = 0 ;

/*

    CHECK A VERSION NUMBER

    This routine reads and checks a version number.

*/

static void de_version_number

    PROTO_Z ()

{

    long v1 = tdf_int () ;

    long v2 = tdf_int () ;

    if ( v1 != VERSION_major || v2 > VERSION_minor ) {

	input_error ( "Illegal version number, %ld.%ld", v1, v2 ) ;

    }

    have_version = 1 ;

    return ;

}

/*

    DECODE A VERSION UNIT

    A number of TDF version numbers are decoded.  These were only

    introduced for version 2.1 of the TDF specification.

*/

void de_version

    PROTO_Z ()

{

    long i, n = tdf_int () ;

    for ( i = 0 ; i < n ; i++ ) {

	long m = de_version_bits () ;

	if ( m == ENC_make_version ) {

	    de_version_number () ;

	} else if ( m == ENC_user_info ) {

	    IGNORE de_node ( "X" ) ;

	}

    }

    return ;

}

/*

    DECODE A MAGIC NUMBER

*/

void de_magic

    PROTO_N ( ( m ) )

    PROTO_T ( char *m )

{

    int i, n = ( int ) strlen ( m ) ;

    for ( i = 0 ; i < n ; i++ ) {

	long c = fetch ( 8 ) ;

	if ( c != ( long ) m [i] ) {

	    input_error ( "Bad magic number" ) ;

	    return ;

	}

    }

    de_version_number () ;

    byte_align () ;

    return ;

}