Commit | Line | Data |
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cd6e9098 ML |
1 | /* Copyright (c) 1982 Regents of the University of California */ |
2 | ||
3 | static char sccsid[] = "@(#)@(#)vax.c 1.1 %G%"; | |
4 | ||
5 | /* | |
6 | * Target machine dependent stuff. | |
7 | */ | |
8 | ||
9 | #include "defs.h" | |
10 | #include "machine.h" | |
11 | #include "process.h" | |
12 | #include "events.h" | |
13 | #include "main.h" | |
14 | #include "symbols.h" | |
15 | #include "source.h" | |
16 | #include "mappings.h" | |
17 | #include "object.h" | |
18 | #include "vaxops.h" | |
19 | #include <signal.h> | |
20 | ||
21 | #ifndef public | |
22 | typedef unsigned int Address; | |
23 | typedef unsigned char Byte; | |
24 | typedef unsigned int Word; | |
25 | ||
26 | #define NREG 16 | |
27 | ||
28 | #define ARGP 12 | |
29 | #define FRP 13 | |
30 | #define STKP 14 | |
31 | #define PROGCTR 15 | |
32 | ||
33 | #define BITSPERBYTE 8 | |
34 | #define BITSPERWORD (BITSPERBYTE * sizeof(Word)) | |
35 | ||
36 | #define nargspassed(frame) argn(0, frame) | |
37 | ||
38 | #include "source.h" | |
39 | #include "symbols.h" | |
40 | ||
41 | Address pc; | |
42 | Address prtaddr; | |
43 | ||
44 | #endif | |
45 | ||
46 | private Address printop(); | |
47 | ||
48 | /* | |
49 | * Decode and print the instructions within the given address range. | |
50 | */ | |
51 | ||
52 | public printinst(lowaddr, highaddr) | |
53 | Address lowaddr; | |
54 | Address highaddr; | |
55 | { | |
56 | register Address addr; | |
57 | ||
58 | for (addr = lowaddr; addr <= highaddr; ) { | |
59 | addr = printop(addr); | |
60 | } | |
61 | prtaddr = addr; | |
62 | } | |
63 | ||
64 | /* | |
65 | * Another approach: print n instructions starting at the given address. | |
66 | */ | |
67 | ||
68 | public printninst(count, addr) | |
69 | int count; | |
70 | Address addr; | |
71 | { | |
72 | register Integer i; | |
73 | register Address newaddr; | |
74 | ||
75 | if (count <= 0) { | |
76 | error("non-positive repetition count"); | |
77 | } else { | |
78 | newaddr = addr; | |
79 | for (i = 0; i < count; i++) { | |
80 | newaddr = printop(newaddr); | |
81 | } | |
82 | prtaddr = newaddr; | |
83 | } | |
84 | } | |
85 | ||
86 | /* | |
87 | * Hacked version of adb's VAX instruction decoder. | |
88 | */ | |
89 | ||
90 | private Address printop(addr) | |
91 | Address addr; | |
92 | { | |
93 | Optab op; | |
94 | VaxOpcode ins; | |
95 | unsigned char mode; | |
96 | int argtype, amode, argno, argval; | |
97 | String reg; | |
98 | Boolean indexf; | |
99 | short offset; | |
100 | ||
101 | argval = 0; | |
102 | indexf = false; | |
103 | printf("%08x ", addr); | |
104 | iread(&ins, addr, sizeof(ins)); | |
105 | addr += 1; | |
106 | op = optab[ins]; | |
107 | printf("%s", op.iname); | |
108 | for (argno = 0; argno < op.numargs; argno++) { | |
109 | if (indexf == true) { | |
110 | indexf = false; | |
111 | } else if (argno == 0) { | |
112 | printf("\t"); | |
113 | } else { | |
114 | printf(","); | |
115 | } | |
116 | argtype = op.argtype[argno]; | |
117 | if (is_branch_disp(argtype)) { | |
118 | mode = 0xAF + (typelen(argtype) << 5); | |
119 | } else { | |
120 | iread(&mode, addr, sizeof(mode)); | |
121 | addr += 1; | |
122 | } | |
123 | reg = regname[regnm(mode)]; | |
124 | amode = addrmode(mode); | |
125 | switch (amode) { | |
126 | case LITSHORT: | |
127 | case LITUPTO31: | |
128 | case LITUPTO47: | |
129 | case LITUPTO63: | |
130 | if (typelen(argtype) == TYPF || typelen(argtype) ==TYPD) | |
131 | printf("$%s", fltimm[mode]); | |
132 | else | |
133 | printf("$%x", mode); | |
134 | argval = mode; | |
135 | break; | |
136 | ||
137 | case INDEX: | |
138 | printf("[%s]", reg); | |
139 | indexf = true; | |
140 | argno--; | |
141 | break; | |
142 | ||
143 | case REG: | |
144 | printf("%s", reg); | |
145 | break; | |
146 | ||
147 | case REGDEF: | |
148 | printf("(%s)", reg); | |
149 | break; | |
150 | ||
151 | case AUTODEC: | |
152 | printf("-(%s)", reg); | |
153 | break; | |
154 | ||
155 | case AUTOINC: | |
156 | if (reg != regname[PROGCTR]) { | |
157 | printf("(%s)+", reg); | |
158 | } else { | |
159 | printf("$"); | |
160 | switch (typelen(argtype)) { | |
161 | case TYPB: | |
162 | argval = printdisp(addr, 1, reg, amode); | |
163 | addr += 1; | |
164 | break; | |
165 | ||
166 | case TYPW: | |
167 | argval = printdisp(addr, 2, reg, amode); | |
168 | addr += 2; | |
169 | break; | |
170 | ||
171 | case TYPL: | |
172 | argval = printdisp(addr, 4, reg, amode); | |
173 | addr += 4; | |
174 | break; | |
175 | ||
176 | case TYPF: | |
177 | iread(&argval, addr, sizeof(argval)); | |
178 | printf("%06x", argval); | |
179 | addr += 4; | |
180 | break; | |
181 | ||
182 | case TYPQ: | |
183 | case TYPD: | |
184 | iread(&argval, addr, sizeof(argval)); | |
185 | printf("%06x", argval); | |
186 | iread(&argval, addr+4, sizeof(argval)); | |
187 | printf("%06x", argval); | |
188 | addr += 8; | |
189 | break; | |
190 | } | |
191 | } | |
192 | break; | |
193 | ||
194 | case AUTOINCDEF: | |
195 | if (reg == regname[PROGCTR]) { | |
196 | printf("*$"); | |
197 | argval = printdisp(addr, 4, reg, amode); | |
198 | addr += 4; | |
199 | } else { | |
200 | printf("*(%s)+", reg); | |
201 | } | |
202 | break; | |
203 | ||
204 | case BYTEDISP: | |
205 | argval = printdisp(addr, 1, reg, amode); | |
206 | addr += 1; | |
207 | break; | |
208 | ||
209 | case BYTEDISPDEF: | |
210 | printf("*"); | |
211 | argval = printdisp(addr, 1, reg, amode); | |
212 | addr += 1; | |
213 | break; | |
214 | ||
215 | case WORDDISP: | |
216 | argval = printdisp(addr, 2, reg, amode); | |
217 | addr += 2; | |
218 | break; | |
219 | ||
220 | case WORDDISPDEF: | |
221 | printf("*"); | |
222 | argval = printdisp(addr, 2, reg, amode); | |
223 | addr += 2; | |
224 | break; | |
225 | ||
226 | case LONGDISP: | |
227 | argval = printdisp(addr, 4, reg, amode); | |
228 | addr += 4; | |
229 | break; | |
230 | ||
231 | case LONGDISPDEF: | |
232 | printf("*"); | |
233 | argval = printdisp(addr, 4, reg, amode); | |
234 | addr += 4; | |
235 | break; | |
236 | } | |
237 | } | |
238 | if (ins == O_CASEB || ins == O_CASEW || ins == O_CASEL) { | |
239 | for (argno = 0; argno <= argval; argno++) { | |
240 | iread(&offset, addr, sizeof(offset)); | |
241 | printf("\n\t\t%d", offset); | |
242 | addr += 2; | |
243 | } | |
244 | } | |
245 | printf("\n"); | |
246 | return addr; | |
247 | } | |
248 | ||
249 | /* | |
250 | * Print the displacement of an instruction that uses displacement | |
251 | * addressing. | |
252 | */ | |
253 | ||
254 | private int printdisp(addr, nbytes, reg, mode) | |
255 | Address addr; | |
256 | int nbytes; | |
257 | char *reg; | |
258 | int mode; | |
259 | { | |
260 | char byte; | |
261 | short hword; | |
262 | int argval; | |
263 | ||
264 | switch (nbytes) { | |
265 | case 1: | |
266 | iread(&byte, addr, sizeof(byte)); | |
267 | argval = byte; | |
268 | break; | |
269 | ||
270 | case 2: | |
271 | iread(&hword, addr, sizeof(hword)); | |
272 | argval = hword; | |
273 | break; | |
274 | ||
275 | case 4: | |
276 | iread(&argval, addr, sizeof(argval)); | |
277 | break; | |
278 | } | |
279 | if (reg == regname[PROGCTR] && mode >= BYTEDISP) { | |
280 | argval += addr + nbytes; | |
281 | } | |
282 | if (reg == regname[PROGCTR]) { | |
283 | printf("%x", argval); | |
284 | } else { | |
285 | printf("%d(%s)", argval, reg); | |
286 | } | |
287 | return argval; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Print the contents of the addresses within the given range | |
292 | * according to the given format. | |
293 | */ | |
294 | ||
295 | typedef struct { | |
296 | String name; | |
297 | String printfstring; | |
298 | int length; | |
299 | } Format; | |
300 | ||
301 | private Format fmt[] = { | |
302 | { "d", " %d", sizeof(short) }, | |
303 | { "D", " %ld", sizeof(long) }, | |
304 | { "o", " %o", sizeof(short) }, | |
305 | { "O", " %lo", sizeof(long) }, | |
306 | { "x", " %04x", sizeof(short) }, | |
307 | { "X", " %08x", sizeof(long) }, | |
308 | { "b", " \\%o", sizeof(char) }, | |
309 | { "c", " '%c'", sizeof(char) }, | |
310 | { "s", "%c", sizeof(char) }, | |
311 | { "f", " %f", sizeof(double) }, | |
312 | { "g", " %g", sizeof(double) }, | |
313 | { nil, nil, 0 } | |
314 | }; | |
315 | ||
316 | public Address printdata(lowaddr, highaddr, format) | |
317 | Address lowaddr; | |
318 | Address highaddr; | |
319 | String format; | |
320 | { | |
321 | register int n; | |
322 | register Address addr; | |
323 | register Format *f; | |
324 | int value; | |
325 | ||
326 | if (lowaddr > highaddr) { | |
327 | error("first address larger than second"); | |
328 | } | |
329 | f = &fmt[0]; | |
330 | while (f->name != nil and not streq(f->name, format)) { | |
331 | ++f; | |
332 | } | |
333 | if (f->name == nil) { | |
334 | error("bad print format \"%s\"", format); | |
335 | } | |
336 | n = 0; | |
337 | value = 0; | |
338 | for (addr = lowaddr; addr <= highaddr; addr += f->length) { | |
339 | if (n == 0) { | |
340 | printf("%08x: ", addr); | |
341 | } | |
342 | dread(&value, addr, f->length); | |
343 | printf(f->printfstring, value); | |
344 | ++n; | |
345 | if (n >= (16 div f->length)) { | |
346 | putchar('\n'); | |
347 | n = 0; | |
348 | } | |
349 | } | |
350 | if (n != 0) { | |
351 | putchar('\n'); | |
352 | } | |
353 | prtaddr = addr; | |
354 | return addr; | |
355 | } | |
356 | ||
357 | /* | |
358 | * The other approach is to print n items starting with a given address. | |
359 | */ | |
360 | ||
361 | public printndata(count, startaddr, format) | |
362 | int count; | |
363 | Address startaddr; | |
364 | String format; | |
365 | { | |
366 | register int i, n; | |
367 | register Address addr; | |
368 | register Format *f; | |
369 | register Boolean isstring; | |
370 | int value; | |
371 | ||
372 | if (count <= 0) { | |
373 | error("non-positive repetition count"); | |
374 | } | |
375 | f = &fmt[0]; | |
376 | while (f->name != nil and not streq(f->name, format)) { | |
377 | ++f; | |
378 | } | |
379 | if (f->name == nil) { | |
380 | error("bad print format \"%s\"", format); | |
381 | } | |
382 | isstring = (Boolean) streq(f->name, "s"); | |
383 | n = 0; | |
384 | addr = startaddr; | |
385 | value = 0; | |
386 | for (i = 0; i < count; i++) { | |
387 | if (n == 0) { | |
388 | printf("%08x: ", addr); | |
389 | } | |
390 | if (isstring) { | |
391 | putchar('"'); | |
392 | dread(&value, addr, sizeof(char)); | |
393 | while (value != '\0') { | |
394 | printchar((char) value); | |
395 | ++addr; | |
396 | dread(&value, addr, sizeof(char)); | |
397 | } | |
398 | putchar('"'); | |
399 | putchar('\n'); | |
400 | n = 0; | |
401 | addr += sizeof(String); | |
402 | } else { | |
403 | dread(&value, addr, f->length); | |
404 | printf(f->printfstring, value); | |
405 | ++n; | |
406 | if (n >= (16 div f->length)) { | |
407 | putchar('\n'); | |
408 | n = 0; | |
409 | } | |
410 | addr += f->length; | |
411 | } | |
412 | } | |
413 | if (n != 0) { | |
414 | putchar('\n'); | |
415 | } | |
416 | prtaddr = addr; | |
417 | } | |
418 | ||
419 | /* | |
420 | * Print out an execution time error. | |
421 | * | |
422 | * Have to check if the -r option was specified; if so then | |
423 | * the object file information hasn't been read in yet. | |
424 | */ | |
425 | ||
426 | public printerror() | |
427 | { | |
428 | extern Integer sys_nsig; | |
429 | extern String sys_siglist[]; | |
430 | String filename; | |
431 | Integer err; | |
432 | ||
433 | if (isfinished(process)) { | |
434 | printf("\"%s\" exits with code %d\n", objname, exitcode(process)); | |
435 | erecover(); | |
436 | } | |
437 | if (runfirst) { | |
438 | fprintf(stderr, "Entering debugger ..."); | |
439 | init(); | |
440 | fprintf(stderr, " type 'help' for help\n"); | |
441 | } | |
442 | curline = srcline(pc); | |
443 | curfunc = whatblock(pc); | |
444 | filename = srcfilename(pc); | |
445 | setsource(filename); | |
446 | err = errnum(process); | |
447 | if (err == SIGINT) { | |
448 | printf("\n\ninterrupt "); | |
449 | printloc(); | |
450 | } else if (err == SIGTRAP) { | |
451 | printf("\nerror "); | |
452 | printloc(); | |
453 | } else { | |
454 | if (err < 0 or err > sys_nsig) { | |
455 | printf("\nsignal %d ", err); | |
456 | } else { | |
457 | printf("\n%s ", sys_siglist[err]); | |
458 | } | |
459 | printloc(); | |
460 | } | |
461 | putchar('\n'); | |
462 | if (curline > 0) { | |
463 | printlines(curline, curline); | |
464 | } else { | |
465 | printinst(pc, pc); | |
466 | } | |
467 | erecover(); | |
468 | } | |
469 | ||
470 | private printloc() | |
471 | { | |
472 | if (curline > 0) { | |
473 | if (nlhdr.nfiles > 1) { | |
474 | printf("at line %d in file %s", curline, cursource); | |
475 | } else { | |
476 | printf("at line %d", curline); | |
477 | } | |
478 | } else { | |
479 | printf("in "); | |
480 | printname(stdout, curfunc); | |
481 | printf(" at 0x%x", pc); | |
482 | } | |
483 | } | |
484 | ||
485 | /* | |
486 | * Note the termination of the program. We do this so as to avoid | |
487 | * having the process exit, which would make the values of variables | |
488 | * inaccessible. We do want to flush all output buffers here, | |
489 | * otherwise it'll never get done. | |
490 | */ | |
491 | ||
492 | public endprogram() | |
493 | { | |
494 | Integer exitcode; | |
495 | ||
496 | stepto(nextaddr(pc, true)); | |
497 | printnews(); | |
498 | exitcode = argn(1, nil); | |
499 | printf("\nexecution completed, exit code is %d\n", exitcode); | |
500 | getsrcpos(); | |
501 | erecover(); | |
502 | } | |
503 | ||
504 | /* | |
505 | * Single step the machine a source line (or instruction if "inst_tracing" | |
506 | * is true. If "isnext" is true, skip over procedure calls. | |
507 | */ | |
508 | ||
509 | private Address getcall(); | |
510 | ||
511 | public dostep(isnext) | |
512 | Boolean isnext; | |
513 | { | |
514 | register Address addr; | |
515 | register Lineno line; | |
516 | String filename; | |
517 | ||
518 | addr = nextaddr(pc, isnext); | |
519 | if (not inst_tracing) { | |
520 | line = linelookup(addr); | |
521 | while (line == 0) { | |
522 | addr = nextaddr(addr, isnext); | |
523 | line = linelookup(addr); | |
524 | } | |
525 | } | |
526 | stepto(addr); | |
527 | curline = line; | |
528 | filename = srcfilename(addr); | |
529 | setsource(filename); | |
530 | } | |
531 | ||
532 | /* | |
533 | * Compute the next address that will be executed from the given one. | |
534 | * If "isnext" is true then consider a procedure call as straight line code. | |
535 | * | |
536 | * We must unfortunately do much of the same work that is necessary | |
537 | * to print instructions. In addition we have to deal with branches. | |
538 | * Unconditional branches we just follow, for conditional branches | |
539 | * we continue execution to the current location and then single step | |
540 | * the machine. We assume that the last argument in an instruction | |
541 | * that branches is the branch address (or relative offset). | |
542 | */ | |
543 | ||
544 | public Address nextaddr(startaddr, isnext) | |
545 | Address startaddr; | |
546 | Boolean isnext; | |
547 | { | |
548 | register Address addr; | |
549 | Optab op; | |
550 | VaxOpcode ins; | |
551 | unsigned char mode; | |
552 | int argtype, amode, argno, argval; | |
553 | String r; | |
554 | Boolean indexf; | |
555 | enum { KNOWN, SEQUENTIAL, BRANCH } addrstatus; | |
556 | ||
557 | argval = 0; | |
558 | indexf = false; | |
559 | addr = startaddr; | |
560 | iread(&ins, addr, sizeof(ins)); | |
561 | switch (ins) { | |
562 | case O_BRB: | |
563 | case O_BRW: | |
564 | case O_JMP: | |
565 | addrstatus = BRANCH; | |
566 | break; | |
567 | ||
568 | case O_BSBB: | |
569 | case O_BSBW: | |
570 | case O_JSB: | |
571 | case O_CALLG: | |
572 | case O_CALLS: | |
573 | if (isnext) { | |
574 | addrstatus = SEQUENTIAL; | |
575 | } else { | |
576 | addrstatus = KNOWN; | |
577 | stepto(addr); | |
578 | pstep(process); | |
579 | addr = reg(PROGCTR); | |
580 | pc = addr; | |
581 | callnews(/* iscall = */ true); | |
582 | if (not isbperr()) { | |
583 | printstatus(); | |
584 | } else { | |
585 | bpact(); | |
586 | } | |
587 | } | |
588 | break; | |
589 | ||
590 | case O_RSB: | |
591 | case O_RET: | |
592 | addrstatus = KNOWN; | |
593 | callnews(/* iscall = */ false); | |
594 | addr = return_addr(); | |
595 | stepto(addr); | |
596 | break; | |
597 | ||
598 | case O_BNEQ: case O_BEQL: case O_BGTR: | |
599 | case O_BLEQ: case O_BGEQ: case O_BLSS: | |
600 | case O_BGTRU: case O_BLEQU: case O_BVC: | |
601 | case O_BVS: case O_BCC: case O_BCS: | |
602 | case O_CASEB: case O_CASEW: case O_CASEL: | |
603 | case O_BBS: case O_BBC: case O_BBSS: case O_BBCS: | |
604 | case O_BBSC: case O_BBCC: case O_BBSSI: | |
605 | case O_BBCCI: case O_BLBS: case O_BLBC: | |
606 | case O_ACBL: case O_AOBLSS: case O_AOBLEQ: | |
607 | case O_SOBGEQ: case O_SOBGTR: | |
608 | addrstatus = KNOWN; | |
609 | stepto(addr); | |
610 | pstep(process); | |
611 | addr = reg(PROGCTR); | |
612 | pc = addr; | |
613 | if (not isbperr()) { | |
614 | printstatus(); | |
615 | } | |
616 | break; | |
617 | ||
618 | default: | |
619 | addrstatus = SEQUENTIAL; | |
620 | break; | |
621 | } | |
622 | if (addrstatus != KNOWN) { | |
623 | addr += 1; | |
624 | op = optab[ins]; | |
625 | for (argno = 0; argno < op.numargs; argno++) { | |
626 | if (indexf == true) { | |
627 | indexf = false; | |
628 | } | |
629 | argtype = op.argtype[argno]; | |
630 | if (is_branch_disp(argtype)) { | |
631 | mode = 0xAF + (typelen(argtype) << 5); | |
632 | } else { | |
633 | iread(&mode, addr, sizeof(mode)); | |
634 | addr += 1; | |
635 | } | |
636 | r = regname[regnm(mode)]; | |
637 | amode = addrmode(mode); | |
638 | switch (amode) { | |
639 | case LITSHORT: | |
640 | case LITUPTO31: | |
641 | case LITUPTO47: | |
642 | case LITUPTO63: | |
643 | argval = mode; | |
644 | break; | |
645 | ||
646 | case INDEX: | |
647 | indexf = true; | |
648 | --argno; | |
649 | break; | |
650 | ||
651 | case REG: | |
652 | case REGDEF: | |
653 | case AUTODEC: | |
654 | break; | |
655 | ||
656 | case AUTOINC: | |
657 | if (r == regname[PROGCTR]) { | |
658 | switch (typelen(argtype)) { | |
659 | case TYPB: | |
660 | argval = getdisp(addr, 1, r, amode); | |
661 | addr += 1; | |
662 | break; | |
663 | ||
664 | case TYPW: | |
665 | argval = getdisp(addr, 2, r, amode); | |
666 | addr += 2; | |
667 | break; | |
668 | ||
669 | case TYPL: | |
670 | argval = getdisp(addr, 4, r, amode); | |
671 | addr += 4; | |
672 | break; | |
673 | ||
674 | case TYPF: | |
675 | iread(&argval, addr, sizeof(argval)); | |
676 | addr += 4; | |
677 | break; | |
678 | ||
679 | case TYPQ: | |
680 | case TYPD: | |
681 | iread(&argval, addr+4, sizeof(argval)); | |
682 | addr += 8; | |
683 | break; | |
684 | } | |
685 | } | |
686 | break; | |
687 | ||
688 | case AUTOINCDEF: | |
689 | if (r == regname[PROGCTR]) { | |
690 | argval = getdisp(addr, 4, r, amode); | |
691 | addr += 4; | |
692 | } | |
693 | break; | |
694 | ||
695 | case BYTEDISP: | |
696 | case BYTEDISPDEF: | |
697 | argval = getdisp(addr, 1, r, amode); | |
698 | addr += 1; | |
699 | break; | |
700 | ||
701 | case WORDDISP: | |
702 | case WORDDISPDEF: | |
703 | argval = getdisp(addr, 2, r, amode); | |
704 | addr += 2; | |
705 | break; | |
706 | ||
707 | case LONGDISP: | |
708 | case LONGDISPDEF: | |
709 | argval = getdisp(addr, 4, r, amode); | |
710 | addr += 4; | |
711 | break; | |
712 | } | |
713 | } | |
714 | if (ins == O_CALLS or ins == O_CALLG) { | |
715 | argval += 2; | |
716 | } | |
717 | if (addrstatus == BRANCH) { | |
718 | addr = argval; | |
719 | } | |
720 | } | |
721 | return addr; | |
722 | } | |
723 | ||
724 | /* | |
725 | * Get the displacement of an instruction that uses displacement addressing. | |
726 | */ | |
727 | ||
728 | private int getdisp(addr, nbytes, reg, mode) | |
729 | Address addr; | |
730 | int nbytes; | |
731 | String reg; | |
732 | int mode; | |
733 | { | |
734 | char byte; | |
735 | short hword; | |
736 | int argval; | |
737 | ||
738 | switch (nbytes) { | |
739 | case 1: | |
740 | iread(&byte, addr, sizeof(byte)); | |
741 | argval = byte; | |
742 | break; | |
743 | ||
744 | case 2: | |
745 | iread(&hword, addr, sizeof(hword)); | |
746 | argval = hword; | |
747 | break; | |
748 | ||
749 | case 4: | |
750 | iread(&argval, addr, sizeof(argval)); | |
751 | break; | |
752 | } | |
753 | if (reg == regname[PROGCTR] && mode >= BYTEDISP) { | |
754 | argval += addr + nbytes; | |
755 | } | |
756 | return argval; | |
757 | } | |
758 | ||
759 | #define BP_OP O_BPT /* breakpoint trap */ | |
760 | #define BP_ERRNO SIGTRAP /* signal received at a breakpoint */ | |
761 | ||
762 | /* | |
763 | * Setting a breakpoint at a location consists of saving | |
764 | * the word at the location and poking a BP_OP there. | |
765 | * | |
766 | * We save the locations and words on a list for use in unsetting. | |
767 | */ | |
768 | ||
769 | typedef struct Savelist *Savelist; | |
770 | ||
771 | struct Savelist { | |
772 | Address location; | |
773 | Byte save; | |
774 | Byte refcount; | |
775 | Savelist link; | |
776 | }; | |
777 | ||
778 | private Savelist savelist; | |
779 | ||
780 | /* | |
781 | * Set a breakpoint at the given address. Only save the word there | |
782 | * if it's not already a breakpoint. | |
783 | */ | |
784 | ||
785 | public setbp(addr) | |
786 | Address addr; | |
787 | { | |
788 | Byte w; | |
789 | Byte save; | |
790 | register Savelist newsave, s; | |
791 | ||
792 | for (s = savelist; s != nil; s = s->link) { | |
793 | if (s->location == addr) { | |
794 | s->refcount++; | |
795 | return; | |
796 | } | |
797 | } | |
798 | iread(&save, addr, sizeof(addr)); | |
799 | newsave = new(Savelist); | |
800 | newsave->location = addr; | |
801 | newsave->save = save; | |
802 | newsave->refcount = 1; | |
803 | newsave->link = savelist; | |
804 | savelist = newsave; | |
805 | w = BP_OP; | |
806 | iwrite(&w, addr, sizeof(w)); | |
807 | } | |
808 | ||
809 | /* | |
810 | * Unset a breakpoint; unfortunately we have to search the SAVELIST | |
811 | * to find the saved value. The assumption is that the SAVELIST will | |
812 | * usually be quite small. | |
813 | */ | |
814 | ||
815 | public unsetbp(addr) | |
816 | Address addr; | |
817 | { | |
818 | register Savelist s, prev; | |
819 | ||
820 | prev = nil; | |
821 | for (s = savelist; s != nil; s = s->link) { | |
822 | if (s->location == addr) { | |
823 | iwrite(&s->save, addr, sizeof(s->save)); | |
824 | s->refcount--; | |
825 | if (s->refcount == 0) { | |
826 | if (prev == nil) { | |
827 | savelist = s->link; | |
828 | } else { | |
829 | prev->link = s->link; | |
830 | } | |
831 | dispose(s); | |
832 | } | |
833 | return; | |
834 | } | |
835 | prev = s; | |
836 | } | |
837 | panic("unsetbp: couldn't find address %d", addr); | |
838 | } | |
839 | ||
840 | /* | |
841 | * Predicate to test if the reason the process stopped was because | |
842 | * of a breakpoint. | |
843 | */ | |
844 | ||
845 | public Boolean isbperr() | |
846 | { | |
847 | return (Boolean) (not isfinished(process) and errnum(process) == SIGTRAP); | |
848 | } | |
849 | ||
850 | /* | |
851 | * Enter a procedure by creating and executing a call instruction. | |
852 | */ | |
853 | ||
854 | #define CALLSIZE 7 /* size of call instruction */ | |
855 | ||
856 | public beginproc(p, argc) | |
857 | Symbol p; | |
858 | Integer argc; | |
859 | { | |
860 | char save[CALLSIZE]; | |
861 | struct { | |
862 | VaxOpcode op; | |
863 | unsigned char numargs; | |
864 | unsigned char mode; | |
865 | char addr[sizeof(long)]; /* unaligned long */ | |
866 | } call; | |
867 | long dest; | |
868 | ||
869 | pc = 2; | |
870 | iread(save, pc, sizeof(save)); | |
871 | call.op = O_CALLS; | |
872 | call.numargs = argc; | |
873 | call.mode = 0xef; | |
874 | dest = codeloc(p) - 2 - (pc + 7); | |
875 | mov(&dest, call.addr, sizeof(call.addr)); | |
876 | iwrite(&call, pc, sizeof(call)); | |
877 | setreg(PROGCTR, pc); | |
878 | pstep(process); | |
879 | iwrite(save, pc, sizeof(save)); | |
880 | pc = reg(PROGCTR); | |
881 | if (not isbperr()) { | |
882 | printstatus(); | |
883 | } | |
884 | } |