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 "alignment.h"

#include "eval.h"

#include "node.h"

#include "read.h"

#include "shape.h"

#include "table.h"

#include "tdf.h"

#include "utility.h"

/*

    SHAPE CHECKING FLAG

    This flag is true to indicate that shape checking should be applied.

*/

boolean do_check = 0 ;

/*

    THE NAME OF THE CURRENT EXPRESSION BEING CHECKED

    The shape checking does not always take place immediately.  By

    printing the name of the expression being checked it is easier

    to find any errors.

*/

char *checking = "????" ;

/*

    SHAPE CHECKING FOR EXP_APPLY_TOKEN

    The shape checking for the exp_apply_token construct p is implemented

    by this routine.

*/

static void chk_token

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    tok_info *info = get_tok_info ( p->son->cons ) ;

    node *d = info->def ;

    if ( d ) {

	if ( d->cons->sortnum == SORT_completion ) d = d->son ;

	p->shape = normalize ( d->shape ) ;

    } else {

	p->shape = new_node () ;

	p->shape->cons = &shape_of ;

	p->shape->son = copy_node ( p->son ) ;

    }

    return ;

}

/*

    SHAPE CHECKING FOR EXP_COND

    The shape checking for the exp_cond construct p is implemented by

    this routine.  Checking that the control argument is an integer is

    carried out for all _cond constructs as part of the main reading

    and decoding routines for the decode letter '@'.

*/

static void chk_cond

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    node *s ;

    node *q1 = p->son->bro->son ;

    node *q2 = p->son->bro->bro->son ;

    node *s1 = q1->shape ;

    node *s2 = q2->shape ;

    if ( q1->cons->encoding == ENC_fail_installer ) {

	p->shape = normalize ( s2 ) ;

	return ;

    }

    if ( q2->cons->encoding == ENC_fail_installer ) {

	p->shape = normalize ( s1 ) ;

	return ;

    }

    s = lub ( s1, s2 ) ;

    if ( s == null ) {

	p->shape = null ;

    } else {

	long n = s->cons->encoding ;

	if ( n == ENC_bottom || n == ENC_top ) {

	    p->shape = null ;

	} else {

	    p->shape = normalize ( s ) ;

	}

    }

    return ;

}

/*

    SHAPE CHECKING FOR OBTAIN_TAG

    The shape checking for the obtain_tag construct p is implemented by

    this routine.  a gives the actual tag.

*/

static void chk_tag

    PROTO_N ( ( p, a, intro ) )

    PROTO_T ( node *p X node *a X int intro )

{

    if ( !intro && a->cons->encoding == ENC_make_tag ) {

	tag_info *info = get_tag_info ( a->son->cons ) ;

	node *d = info->dec ;

	if ( d && d->cons->sortnum == SORT_completion ) d = d->son ;

	if ( d ) d = d->bro ;

	if ( d ) d = d->bro ;

	switch ( info->var ) {

	    case 0 : {

		p->shape = normalize ( d ) ;

		break ;

	    }

	    case 1 :

	    case 2 : {

		p->shape = sh_pointer ( d ) ;

		break ;

	    }

	    default : {

		if ( text_input ) {

		    char *nm = a->son->cons->name ;

		    is_fatal = 0 ;

		    input_error ( "Tag %s used but not declared", nm ) ;

		}

		p->shape = null ;

		break ;

	    }

	}

    } else {

	p->shape = null ;

    }

    return ;

}

/*

    SHAPE CHECKING MACRO DEFINITIONS

    The main body of the shape checking for expressions is in the

    automatically generated file check_exp.h.  This calls a macro of

    the form check_<cons> for each construct <cons>.  The actual

    definitions of these macros (which vary between TDF specification

    releases) are in check_def.h.

*/

#include "check_def.h"

#include "check_exp.h"

/*

    SHAPE CHECK A SHAPE

    The construct compound has an exp argument which needs to be

    shape checked.

*/

void check_shape_fn

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    if ( p && p->cons->encoding == ENC_compound ) {

	if ( do_check ) {

	    checking = p->cons->name ;

	    IGNORE check1 ( ENC_offset, p->son ) ;

	}

    }

    return ;

}

/*

    SHAPE CHECK A NAT

    The construct computed_nat has an exp argument which needs to be

    shape checked.

*/

void check_nat_fn

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    if ( p && p->cons->encoding == ENC_computed_nat ) {

	if ( do_check ) {

	    checking = p->cons->name ;

	    IGNORE check1 ( ENC_integer, p->son ) ;

	}

    }

    return ;

}

/*

    SHAPE CHECK A SIGNED NAT

    The construct computed_signed_nat has an exp argument which needs

    to be shape checked.

*/

void check_snat_fn

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    if ( p && p->cons->encoding == ENC_computed_signed_nat ) {

	if ( do_check ) {

	    checking = p->cons->name ;

	    IGNORE check1 ( ENC_integer, p->son ) ;

	}

    }

    return ;

}

/*

    SHAPE CHECK AN ACCESS

    The flag intro_visible is set whenever a visible construct is

    encountered.

*/

void check_access_fn

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    if ( p && p->cons->encoding == ENC_visible ) intro_visible = 1 ;

    return ;

}

/*

    IS A SHAPE COMPLETELY KNOWN?

    This routine returns true if p is not null and does not contain

    any unknown constructs.  In encode mode we can't have any constructs

    which introduce local tags or tokens either.

*/

static boolean is_known

    PROTO_N ( ( p ) )

    PROTO_T ( node *p )

{

    if ( p == null ) return ( 0 ) ;

    while ( p ) {

	sortname s = p->cons->sortnum ;

	if ( s == SORT_unknown ) return ( 0 ) ;

	if ( !text_output && s == SORT_exp ) {

	    switch ( p->cons->encoding ) {

		case ENC_conditional : return ( 0 ) ;

		case ENC_identify : return ( 0 ) ;

		case ENC_labelled : return ( 0 ) ;

		case ENC_make_proc : return ( 0 ) ;

		case ENC_repeat : return ( 0 ) ;

		case ENC_variable : return ( 0 ) ;

	    }

	}

	if ( p->son && !is_known ( p->son ) ) return ( 0 ) ;

	p = p->bro ;

    }

    return ( 1 ) ;

}

/*

    CHECK THAT A TAG DECLARATION AND DEFINITION MATCH

    The construct p, representing a declared and defined tag, is checked

    for shape correctness.

*/

void check_tagdef

    PROTO_N ( ( p ) )

    PROTO_T ( construct *p )

{

    char *nm = p->name ;

    tag_info *info = get_tag_info ( p ) ;

    node *dc = info->dec ;

    node *df = info->def ;

    if ( df == null ) return ;

    if ( df->cons->sortnum == SORT_completion ) df = df->son ;

    if ( info->var ) df = df->bro ;

    if ( dc == null ) {

	if ( is_known ( df->shape ) ) {

	    /* Declaration = ?[u]?[X]S (from 4.0) */

	    node *q = new_node () ;

	    q->cons = &false_cons ;

	    q->bro = new_node () ;

	    q->bro->cons = &false_cons ;

	    q->bro->bro = df->shape ;

	    info->dec->bro = completion ( q ) ;

	} else {

	    is_fatal = 0 ;

	    input_error ( "Can't deduce shape of %s from definition", nm ) ;

	}

    } else {

	if ( dc->cons->sortnum == SORT_completion ) dc = dc->son ;

	/* Declaration = ?[u]?[X]S (from 4.0) */

	dc = dc->bro->bro ;

	checking = nm ;

	IGNORE check_shapes ( dc, df->shape, 1 ) ;

    }

    return ;

}