BSD 4_4 release

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

/*-
* Copyright (c) 1980, 1993
*      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[] = "@(#)resume.c    8.1 (Berkeley) 6/6/93";
#endif /* not lint */

/*
* Resume execution, first setting appropriate registers.
*/

#include "defs.h"
#include <signal.h>
#include "process.h"
#include "machine.h"
#include "main.h"
#include "process.rep"
#include "runtime/frame.rep"

#include "machine/pxerrors.h"
#include "pxinfo.h"

/*
* Resume execution, set (get) pcode location counter before (after) resuming.
*/

resume()
{
   register PROCESS *p;

   p = process;
   do {
       if (option('e')) {
           printf("execution resumes at pc 0x%x, lc %d\n", process->pc, pc);
           fflush(stdout);
       }
       pcont(p);
       dread(&pc, PCADDR, sizeof(pc));         /* Get pcode pc */
       if (option('e')) {
           printf("execution stops at pc 0x%x, lc %d on sig %d\n",
               process->pc, pc, p->signo);
           fflush(stdout);
       }
   } while (p->signo == SIGCONT);
   if (option('r') && p->signo != 0) {
       choose();
   }

   /*
    * If px implements a breakpoint by executing a halt instruction
    * the real pc must be incremented to skip over it.
    *
    * Currently, px sends itself a signal so no incrementing is needed.
    *
       if (isbperr()) {
           p->pc++;
       }
    */
}

/*
* Under the -r option, we offer the opportunity to just get
* the px traceback and not actually enter the debugger.
*
* If the standard input is not a tty but standard error is,
* change standard input to be /dev/tty.
*/

LOCAL choose()
{
   register int c;

   if (!isterm(stdin)) {
       if (!isterm(stderr) || freopen("/dev/tty", "r", stdin) == NIL) {
           unsetsigtraces(process);
           pcont(process);
           quit(process->exitval);
           /* NOTREACHED */
       }
   }
   fprintf(stderr, "\nProgram error");
   fprintf(stderr, "\nDo you wish to enter the debugger? ");
   c = getchar();
   if (c == 'n') {
       unsetsigtraces(process);
       pcont(process);
       quit(process->exitval);
   }
   while (c != '\n' && c != EOF) {
       c = getchar();
   }
   fprintf(stderr, "\nEntering debugger ...");
   init();
   option('r') = FALSE;
   fprintf(stderr, " type 'help' for help.\n");
}