BSD 4_3_Net_2 release

[unix-history] / usr / src / usr.bin / pascal / pdx / process / step.c

/*-
* Copyright (c) 1980 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
static char sccsid[] = "@(#)step.c      5.3 (Berkeley) 4/16/91";
#endif /* not lint */

/*
* Continue execution up to the next source line.
*
* We call "nextaddr" from the machine module to figure out
* what the object address is that corresponds to the next source line.
* If nextaddr returns -1, then the end of the program has been reached.
*
* There are two ways to define the next source line depending on what
* is desired when a procedure or function call is encountered.  Step
* stops at the beginning of the procedure or call; next skips over it.
*/

#include "defs.h"
#include "process.h"
#include "machine.h"
#include "breakpoint.h"
#include "source.h"
#include "mappings.h"
#include "process.rep"

/*
* Stepc is what is called when the step command is given.
* It has to play with the "isstopped" information.
*/

stepc()
{
   if (!isstopped) {
       error("can't continue execution");
   }
   isstopped = FALSE;
   dostep(FALSE);
   isstopped = TRUE;
}

next()
{
   if (!isstopped) {
       error("can't continue execution");
   }
   isstopped = FALSE;
   dostep(TRUE);
   isstopped = TRUE;
}

step()
{
   dostep(FALSE);
}

/*
* Resume execution up to the given address.  It is assumed that
* no breakpoints exist between the current address and the one
* we're stepping to.  This saves us from setting all the breakpoints.
*/

stepto(addr)
ADDRESS addr;
{
   setbp(addr);
   resume();
   unsetbp(addr);
   if (!isbperr()) {
       printstatus();
   }
}

LOCAL dostep(isnext)
BOOLEAN isnext;
{
   register ADDRESS addr;
   register LINENO line;

   addr = pc;
   do {
       addr = nextaddr(addr, isnext);
       line = linelookup(addr);
   } while (line == 0 && !ss_instructions);
   stepto(addr);
   curline = line;
}