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 "ascii.h"

#include "file.h"

#include "pretty.h"

#include "tree.h"

#include "utility.h"

/*

    MACRO DEFINITIONS

    BUFFSIZE gives the size of the input buffer.  HI_MASK and LO_MASK

    are bit masks used to extract bits 8-15 and 0-7 respectively from

    an integer.

*/

#define BUFFSIZE	( ( size_t ) 1024 )

#define HI_MASK		( ( unsigned ) 0xff00 )

#define LO_MASK		( ( unsigned ) 0x00ff )

/*

    INPUT AND OUTPUT FILES AND BUFFERS

    The input TDF capsule is read from tdf_file.  The pretty-printed

    output is placed into pp_file.  The input uses the buffer

    inbuffer.

*/

FILE *pp_file ;

static FILE *tdf_file ;

static char inbuffer [ BUFFSIZE ] ;

static int ib_ptr, ib_size ;

/*

    POSITION IN INPUT FILE

    The current position in the input file is recorded by means of a

    place.

*/

place here ;

/*

    INPUT AND OUTPUT VARIABLES

    printflag is used to switch the printing on or off.  The present

    column number in the output file is given by column.  The maximum

    value attained by column is recorded in maximum.  The last character

    output is held in lastc.  The flag read_error is used to indicate

    that an error has occurred in reading the input file.

*/

int printflag = 1 ;

int column ;

int maximum ;

int lastc = 0 ;

int read_error = 0 ;

int dump = 0 ;

/*

    OPEN FILES

    The file name1 is opened for input and name2 for output.  If name2

    is the null string, the standard output is used.

*/

void open_files

    PROTO_N ( ( name1, name2 ) )

    PROTO_T ( char *name1 X char *name2 )

{

    tdf_file = fopen ( name1, "rb" ) ;

    if ( tdf_file == null ) fatal_error ( "Can't open %s", name1 ) ;

    if ( name2 == null ) dflag = 0 ;

    if ( dflag ) {

	pp_file = fopen ( name2, "w" ) ;

	if ( pp_file == null ) fatal_error ( "Can't open %s", name2 ) ;

    } else {

	pp_file = stdout ;

    }

    here.byte = 0 ;

    here.bit = 0 ;

    ib_size = 0 ;

    return ;

}

/*

    READ THE NEXT BYTE FROM THE INPUT FILE

    This routine reads the next byte from the input file, putting it

    into the worksp field of here.

*/

static void next_byte

    PROTO_Z ()

{

    if ( read_error ) {

	here.worksp = 0xff ;

    } else {

	/* refill input buffer if required */

	if ( ib_size == 0 ) {

	    ib_ptr = 0 ;

	    ib_size = ( int ) fread ( inbuffer, 1, BUFFSIZE, tdf_file ) ;

	    if ( ib_size == 0 ) {

		/* if we have reached the end of the file... */

		read_error = 1 ;

		if ( !dump ) {

		    out ( "<reading error>" ) ;

		    input_error ( "Reading error" ) ;

		}

	    }

	}

	/* get the next character */

	if ( read_error ) {

	    here.worksp = 0xff ;

	} else {

	    char c = inbuffer [ ib_ptr++ ] ;

	    here.worksp = ( unsigned ) ( c & 0xff ) ;

	    ib_size-- ;

	}

    }

    return ;

}

/*

    FETCH THE NEXT n BITS FROM THE INPUT FILE

    This routine reads the next n bits from the input file and returns

    them as an integer.  n will rarely be as much as 8, so there is

    no problem with overflow.

*/

long fetch

    PROTO_N ( ( n ) )

    PROTO_T ( int n )

{

    int m ;

    unsigned a = 0 ;

    while ( n ) {

	/* read the next byte if necessary */

	if ( here.bit == 0 ) next_byte () ;

	/* m = number of bits we need from this byte */

	m = BYTESIZE - here.bit ;

	if ( n < m ) m = n ;

	/* extract m bytes from here.worksp */

	here.worksp <<= m ;

	a = ( a << m ) + ( ( here.worksp & HI_MASK ) >> BYTESIZE ) ;

	here.worksp &= LO_MASK ;

	n -= m ;

	here.bit += m ;

	if ( here.bit == BYTESIZE ) {

	    here.bit = 0 ;

	    here.byte++ ;

	}

    }

    return ( ( long ) a ) ;

}

/*

    ALIGN INPUT FILE TO AN 8 BIT BOUNDARY

    Bits are read from the input file until it is on an 8 bit boundary.

*/

void byte_align

    PROTO_Z ()

{

    while ( !( here.bit == 0 || here.bit == BYTESIZE ) ) {

	IGNORE fetch ( 1 ) ;

    }

    return ;

}

/*

    GO TO A GIVEN PLACE IN THE INPUT FILE

    The current position is set to the position indicated by the place p.

*/

void set_place

    PROTO_N ( ( p ) )

    PROTO_T ( place *p )

{

    int s ;

    here.byte = p->byte ;

    here.bit = 0 ;

    s = fseek ( tdf_file, here.byte, SEEK_SET ) ;

    if ( s ) fatal_error ( "Internal file seek error" ) ;

    ib_size = 0 ;

    IGNORE fetch ( p->bit ) ;

    return ;

}

/*

    SKIP THE NEXT n BITS IN THE INPUT FILE

    If n is small, the next n bits are read but discarded.  Otherwise

    set_place is used.

*/

void skip_bits

    PROTO_N ( ( n ) )

    PROTO_T ( long n )

{

    if ( read_error ) return ;

    if ( n <= 4 * BYTESIZE ) {

	IGNORE fetch ( ( int ) n ) ;

    } else {

	place p ;

	long b = posn ( here ) + n ;

	p.byte = b / BYTESIZE ;

	p.bit = ( int ) ( b % BYTESIZE ) ;

	set_place ( &p ) ;

    }

    return ;

}

/*

    ARRAY OF SPACES

    The indentation spaces used during pretty-printing are stored in

    an array.

*/

static char *spaces1 ;

/*

    INITIALIZE SPACES

    This routine initializes the array of indentation spaces, spaces1.

*/

void init_spaces

    PROTO_N ( ( d ) )

    PROTO_T ( int d )

{

    int i, j ;

    if ( helpflag ) {

	spaces1 = alloc_nof ( char, 5000 ) ;

	/* every dth character should be a '.' */

	for ( i = 0, j = 0 ; i < 5000 ; i++ ) {

	    if ( ++j == d ) {

		spaces1 [i] = '.' ;

		j = 0 ;

	    } else {

		spaces1 [i] = ' ' ;

	    }

	}

    }

    return ;

}

/*

    OUTPUT n SPACES

    This routine outputs n indentation spaces, using the array spaces1

    when appropriate.

*/

void spaces

    PROTO_N ( ( n ) )

    PROTO_T ( int n )

{

    if ( n < 0 ) n = 0 ;

    if ( printflag ) {

	if ( helpflag ) {

	    if ( n ) {

		 IGNORE fwrite ( spaces1, sizeof ( char ),

				   ( size_t ) n, pp_file ) ;

	    }

	} else {

	    int i ;

	    int q = ( n / TBSIZE ) ;

	    int r = ( n % TBSIZE ) ;

	    for ( i = 0 ; i < q ; i++ ) IGNORE fputc ( TAB, pp_file ) ;

	    for ( i = 0 ; i < r ; i++ ) IGNORE fputc ( SPACE, pp_file ) ;

	}

    }

    column = n ;

    lastc = ' ' ;

    return ;

}