date and time created 82/01/18 19:20:51 by linton

SCCS-vsn: usr.bin/pascal/pdx/process/resume.c 1.1

diff --git a/usr/src/usr.bin/pascal/pdx/process/resume.c b/usr/src/usr.bin/pascal/pdx/process/resume.c
new file mode 100644 (file)
index 0000000..78b7a22
--- /dev/null
+++ b/usr/src/usr.bin/pascal/pdx/process/resume.c
@@ -0,0 +1,164 @@
+/* Copyright (c) 1982 Regents of the University of California */
+
+static char sccsid[] = "@(#)resume.c 1.1 %G%";
+
+/*
+ * 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"
+
+#      if (isvaxpx)
+#              include "machine/pxerrors.h"
+#              include "pxinfo.h"
+#      endif
+
+LOCAL ADDRESS fetchpc();
+
+/*
+ * If we hit a breakpoint, px's pc points at a halt instruction,
+ * this must be avoided when restarting.
+ */
+
+resume()
+{
+       register PROCESS *p;
+       int oldsigno;
+
+       p = process;
+       do {
+               if (option('e')) {
+                       printf("execution resumes at pc 0x%x, lc %d\n", process->pc, pc);
+                       fflush(stdout);
+               }
+               pcont(p);
+#              if (isvaxpx)
+                       if (p->status == STOPPED) {
+                               if (pcframe == NIL) {
+                                       dread(&pcframe, PCADDRP, sizeof(pcframe));
+                                       pcframe++;
+                               }
+                               if (isbperr()) {
+                                       pc = p->reg[11];
+                               } else {
+                                       pc = fetchpc(pcframe);
+                               }
+                               pc -= (sizeof(char) + ENDOFF);
+                       }
+#              else
+                       pc = process->pc;
+#              endif
+               if (option('e')) {
+                       printf("execution stops at pc 0x%x, lc %d on sig %d\n",
+                               process->pc, pc, p->signo);
+                       fflush(stdout);
+               }
+               if (p->status == STOPPED) {
+                       errnum = 0;
+               }
+       } while (p->signo == SIGCONT);
+#      if (isvaxpx)
+               oldsigno = p->signo;
+               switch (p->signo) {
+                       case SIGFPE:
+                               errnum = EOVERFLOW;
+                               p->signo = ESIGNAL;
+                               break;
+
+                       case SIGSEGV:
+                               errnum = ESTKOVER;
+                               p->signo = ESIGNAL;
+                               break;
+               }
+               if (option('r')) {
+                       p->signo = oldsigno;
+                       choose();
+                       p->signo = ESIGNAL;
+               }
+               if (isbperr()) {
+                       p->pc++;
+               }
+#      endif
+}
+
+# if (isvaxpx)
+
+/*
+ * Find the location in the Pascal object where execution was suspended.
+ */
+
+typedef struct {
+       int fr_handler;
+       unsigned int fr_psw : 16;       /* saved psw */
+       unsigned int fr_mask : 12;      /* register save mask */
+       unsigned int fr_unused : 1;
+       unsigned int fr_s : 1;          /* call was a calls, not callg */
+       unsigned int fr_spa : 2;        /* stack pointer alignment */
+       unsigned int fr_savap;          /* saved arg pointer */
+       unsigned int fr_savfp;          /* saved frame pointer */
+       int fr_savpc;                   /* saved program counter */
+} Vaxframe;
+
+LOCAL ADDRESS fetchpc(framep)
+ADDRESS *framep;
+{
+       register PROCESS *p;
+       Vaxframe vframe;
+       ADDRESS *savfp;
+       ADDRESS r;
+
+       p = process;
+       if (p->fp == (ADDRESS) framep) {
+               return(p->reg[11]);
+       }
+       savfp = (ADDRESS *) p->fp;
+       dread(&vframe, savfp, sizeof(vframe));
+       while (vframe.fr_savfp != (int) framep && vframe.fr_savfp != 0) {
+               savfp = (ADDRESS *) vframe.fr_savfp;
+               dread(&vframe, savfp, sizeof(vframe));
+       }
+       if (vframe.fr_savfp == 0) {
+               panic("resume: can't find interpreter frame 0x%x", framep);
+       }
+       if (vframe.fr_mask == 0) {
+               r = p->reg[11];
+       } else {
+               dread(&r, savfp + 5, sizeof(r));
+               r -= sizeof(char);
+       }
+       return(r);
+}
+
+/*
+ * Under the -r option, we offer the opportunity to just get
+ * the px traceback and not actually enter the debugger.
+ */
+
+LOCAL choose()
+{
+       register int c;
+
+       fprintf(stderr, "\nProgram error");
+       if (errnum != 0) {
+               fprintf(stderr, " -- %s", pxerrmsg[errnum]);
+       }
+       fprintf(stderr, "\nDo you wish to enter the debugger? ");
+       c = getchar();
+       if (c == 'n') {
+               unsetsigtraces(process);
+               pcont(process);
+               exit(0);
+       }
+       while (c != '\n') {
+               c = getchar();
+       }
+       fprintf(stderr, "\nEntering debugger, type 'help' for help\n");
+}
+
+# endif