1 /*-
2  * Copyright (c) 1980 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #ifndef lint
9 static char sccsid[] = "@(#)resume.c	5.4 (Berkeley) 04/16/91";
10 #endif /* not lint */
11 
12 /*
13  * Resume execution, first setting appropriate registers.
14  */
15 
16 #include "defs.h"
17 #include <signal.h>
18 #include "process.h"
19 #include "machine.h"
20 #include "main.h"
21 #include "process.rep"
22 #include "runtime/frame.rep"
23 
24 #include "machine/pxerrors.h"
25 #include "pxinfo.h"
26 
27 /*
28  * Resume execution, set (get) pcode location counter before (after) resuming.
29  */
30 
31 resume()
32 {
33     register PROCESS *p;
34 
35     p = process;
36     do {
37 	if (option('e')) {
38 	    printf("execution resumes at pc 0x%x, lc %d\n", process->pc, pc);
39 	    fflush(stdout);
40 	}
41 	pcont(p);
42 	dread(&pc, PCADDR, sizeof(pc));		/* Get pcode pc */
43 	if (option('e')) {
44 	    printf("execution stops at pc 0x%x, lc %d on sig %d\n",
45 		process->pc, pc, p->signo);
46 	    fflush(stdout);
47 	}
48     } while (p->signo == SIGCONT);
49     if (option('r') && p->signo != 0) {
50 	choose();
51     }
52 
53     /*
54      * If px implements a breakpoint by executing a halt instruction
55      * the real pc must be incremented to skip over it.
56      *
57      * Currently, px sends itself a signal so no incrementing is needed.
58      *
59 	if (isbperr()) {
60 	    p->pc++;
61 	}
62      */
63 }
64 
65 /*
66  * Under the -r option, we offer the opportunity to just get
67  * the px traceback and not actually enter the debugger.
68  *
69  * If the standard input is not a tty but standard error is,
70  * change standard input to be /dev/tty.
71  */
72 
73 LOCAL choose()
74 {
75     register int c;
76 
77     if (!isterm(stdin)) {
78 	if (!isterm(stderr) || freopen("/dev/tty", "r", stdin) == NIL) {
79 	    unsetsigtraces(process);
80 	    pcont(process);
81 	    quit(process->exitval);
82 	    /* NOTREACHED */
83 	}
84     }
85     fprintf(stderr, "\nProgram error");
86     fprintf(stderr, "\nDo you wish to enter the debugger? ");
87     c = getchar();
88     if (c == 'n') {
89 	unsetsigtraces(process);
90 	pcont(process);
91 	quit(process->exitval);
92     }
93     while (c != '\n' && c != EOF) {
94 	c = getchar();
95     }
96     fprintf(stderr, "\nEntering debugger ...");
97     init();
98     option('r') = FALSE;
99     fprintf(stderr, " type 'help' for help.\n");
100 }
101