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Annotation of 42BSD/ucb/pascal/pdx/process/resume.c, revision 1.1

1.1     ! root        1: /* Copyright (c) 1982 Regents of the University of California */
        !             2: 
        !             3: static char sccsid[] = "@(#)resume.c 1.9 2/14/83";
        !             4: 
        !             5: /*
        !             6:  * Resume execution, first setting appropriate registers.
        !             7:  */
        !             8: 
        !             9: #include "defs.h"
        !            10: #include <signal.h>
        !            11: #include "process.h"
        !            12: #include "machine.h"
        !            13: #include "main.h"
        !            14: #include "process.rep"
        !            15: #include "runtime/frame.rep"
        !            16: 
        !            17: #include "machine/pxerrors.h"
        !            18: #include "pxinfo.h"
        !            19: 
        !            20: #ifdef vax
        !            21:     LOCAL ADDRESS fetchpc();
        !            22: #endif
        !            23: 
        !            24: LOCAL ADDRESS *pcaddr;
        !            25: 
        !            26: /*
        !            27:  * Resume execution, set (get) pcode location counter before (after) resuming.
        !            28:  */
        !            29: 
        !            30: resume()
        !            31: {
        !            32:     register PROCESS *p;
        !            33:     int oldsigno;
        !            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: #       ifdef sun
        !            43:            if (pcaddr == 0) {
        !            44:                dread(&pcaddr, PCADDRP, sizeof(pcaddr));
        !            45:            }
        !            46:            dread(&pc, pcaddr, sizeof(pc));
        !            47: #       else ifdef vax
        !            48:            if (p->status == STOPPED) {
        !            49:                if (isbperr()) {
        !            50:                    pc = p->reg[11];
        !            51:                } else {
        !            52:                    dread(&pcframe, PCADDRP, sizeof(pcframe));
        !            53:                    pcframe++;
        !            54:                    pc = fetchpc(pcframe);
        !            55:                }
        !            56:                pc -= (sizeof(char) + ENDOFF);
        !            57:            }
        !            58: #       endif
        !            59:        if (option('e')) {
        !            60:            printf("execution stops at pc 0x%x, lc %d on sig %d\n",
        !            61:                process->pc, pc, p->signo);
        !            62:            fflush(stdout);
        !            63:        }
        !            64:        if (p->status == STOPPED) {
        !            65:            errnum = 0;
        !            66:        }
        !            67:     } while (p->signo == SIGCONT);
        !            68:     if (option('r') && p->signo != 0) {
        !            69:        choose();
        !            70:     }
        !            71: 
        !            72:     /*
        !            73:      * If px implements a breakpoint by executing a halt instruction
        !            74:      * the real pc must be incremented to skip over it.
        !            75:      *
        !            76:      * Currently, px sends itself a signal so no incrementing is needed.
        !            77:      *
        !            78:        if (isbperr()) {
        !            79:            p->pc++;
        !            80:        }
        !            81:      */
        !            82: }
        !            83: 
        !            84: #ifdef vax
        !            85: 
        !            86: /*
        !            87:  * Find the location in the Pascal object where execution was suspended.
        !            88:  *
        !            89:  * We basically walk back through the frames looking for saved
        !            90:  * register 11's.  Each time we find one, we remember it.  When we reach
        !            91:  * the frame associated with the interpreter procedure, the most recently
        !            92:  * saved register 11 is the one we want.
        !            93:  */
        !            94: 
        !            95: typedef struct {
        !            96:     int fr_handler;
        !            97:     unsigned int fr_psw : 16;   /* saved psw */
        !            98:     unsigned int fr_mask : 12;  /* register save mask */
        !            99:     unsigned int fr_unused : 1;
        !           100:     unsigned int fr_s : 1;      /* call was a calls, not callg */
        !           101:     unsigned int fr_spa : 2;    /* stack pointer alignment */
        !           102:     unsigned int fr_savap;      /* saved arg pointer */
        !           103:     unsigned int fr_savfp;      /* saved frame pointer */
        !           104:     int fr_savpc;           /* saved program counter */
        !           105: } Vaxframe;
        !           106: 
        !           107: #define regsaved(frame, n) ((frame.fr_mask&(1 << n)) != 0)
        !           108: 
        !           109: LOCAL ADDRESS fetchpc(framep)
        !           110: ADDRESS *framep;
        !           111: {
        !           112:     register PROCESS *p;
        !           113:     Vaxframe vframe;
        !           114:     ADDRESS *savfp;
        !           115:     ADDRESS r;
        !           116: 
        !           117:     p = process;
        !           118:     r = p->reg[11];
        !           119:     if (p->fp == (ADDRESS) framep) {
        !           120:        return r;
        !           121:     }
        !           122:     savfp = (ADDRESS *) p->fp;
        !           123:     dread(&vframe, savfp, sizeof(vframe));
        !           124:     while (vframe.fr_savfp != (int) framep && vframe.fr_savfp != 0) {
        !           125:        if (regsaved(vframe, 11)) {
        !           126:            dread(&r, savfp + 5, sizeof(r));
        !           127:            r -= sizeof(char);
        !           128:        }
        !           129:        savfp = (ADDRESS *) vframe.fr_savfp;
        !           130:        dread(&vframe, savfp, sizeof(vframe));
        !           131:     }
        !           132:     if (vframe.fr_savfp == 0) {
        !           133:        panic("resume: can't find interpreter frame 0x%x", framep);
        !           134:     }
        !           135:     if (regsaved(vframe, 11)) {
        !           136:        dread(&r, savfp + 5, sizeof(r));
        !           137:        r -= sizeof(char);
        !           138:     }
        !           139:     return(r);
        !           140: }
        !           141: 
        !           142: #endif
        !           143: 
        !           144: /*
        !           145:  * Under the -r option, we offer the opportunity to just get
        !           146:  * the px traceback and not actually enter the debugger.
        !           147:  *
        !           148:  * If the standard input is not a tty but standard error is,
        !           149:  * change standard input to be /dev/tty.
        !           150:  */
        !           151: 
        !           152: LOCAL choose()
        !           153: {
        !           154:     register int c;
        !           155: 
        !           156:     if (!isterm(stdin)) {
        !           157:        if (!isterm(stderr) || freopen("/dev/tty", "r", stdin) == NIL) {
        !           158:            unsetsigtraces(process);
        !           159:            pcont(process);
        !           160:            quit(process->exitval);
        !           161:            /* NOTREACHED */
        !           162:        }
        !           163:     }
        !           164:     fprintf(stderr, "\nProgram error");
        !           165:     if (errnum != 0) {
        !           166:        fprintf(stderr, " -- %s", pxerrmsg[errnum]);
        !           167:     }
        !           168:     fprintf(stderr, "\nDo you wish to enter the debugger? ");
        !           169:     c = getchar();
        !           170:     if (c == 'n') {
        !           171:        unsetsigtraces(process);
        !           172:        pcont(process);
        !           173:        quit(process->exitval);
        !           174:     }
        !           175:     while (c != '\n' && c != EOF) {
        !           176:        c = getchar();
        !           177:     }
        !           178:     fprintf(stderr, "\nEntering debugger ...");
        !           179:     init();
        !           180:     option('r') = FALSE;
        !           181:     fprintf(stderr, " type 'help' for help.\n");
        !           182: }

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