usr/src/usr.bin/pascal/pdx/runtime/frame.rep

/*-
 * Copyright (c) 1980 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)frame.rep   5.3 (Berkeley) %G%
 */

/*
 * Definitions for accessing stack frames.
 */

#define MAINBLK         1

/*
 * Structure of an activation record's block mark.  See the
 * PX implementation notes for more details.
 */

struct frame {
        ADDRESS stackref;       /* for px self-checking */
        ADDRESS file;           /* current file information */
        ADDRESS blockp;         /* pointer to current block name */
        ADDRESS *save_loc;      /* saved local variable pointer */
        ADDRESS *save_disp;     /* saved dp contents */
        ADDRESS *save_dp;       /* saved dp */
        ADDRESS save_pc;        /* saved location counter */
        int save_lino;          /* saved source line number (never used) */
};

FRAME *curframe();              /* get the currently active frame */
FRAME *nextframe();             /* go up the stack */
FRAME *findframe();             /* find the frame for a given function */
ADDRESS entry();                /* get the entry address for a frame */
ADDRESS *dispval();             /* display associated with a given block */
ADDRESS *curdp();               /* return current display pointer */
ADDRESS *contents();            /* return the contents of display pointer */
ADDRESS stkaddr();              /* stack address associated with a frame */