usr/src/usr.bin/pascal/pdx/mappings/srcfile.c

/*-
 * Copyright (c) 1980 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)srcfile.c   5.2 (Berkeley) %G%";
#endif /* not lint */

/*
 * get the source file name associated with a given address
 */

#include "defs.h"
#include "mappings.h"
#include "object.h"
#include "filetab.h"

char *srcfilename(addr)
ADDRESS addr;
{
        register ADDRESS i, j, k;
        ADDRESS a;
        FILETAB *ftp;

        if (addr < filetab[0].addr) {
                return(NIL);
        }
        i = 0;
        j = nlhdr.nfiles - 1;
        while (i < j) {
                k = (i + j) / 2;
                ftp = &filetab[k];
                if ((a = ftp->addr) == addr) {
                        return(ftp->filename);
                } else if (addr > a) {
                        i = k + 1;
                } else {
                        j = k - 1;
                }
        }
        if (addr >= filetab[i].addr) {
                return(filetab[i].filename);
        } else {
                return(filetab[i-1].filename);
        }
        /*NOTREACHED*/
}