Commit | Line | Data |
---|---|---|
381c0f0e | 1 | |
52646e6f ML |
2 | /* Copyright (c) 1982 Regents of the University of California */ |
3 | ||
316d2228 | 4 | static char sccsid[] = "@(#)runtime.c 1.7 %G%"; |
52646e6f ML |
5 | |
6 | /* | |
7 | * Runtime organization dependent routines, mostly dealing with | |
8 | * activation records. | |
9 | */ | |
10 | ||
11 | #include "defs.h" | |
12 | #include "runtime.h" | |
13 | #include "process.h" | |
14 | #include "machine.h" | |
15 | #include "events.h" | |
16 | #include "mappings.h" | |
17 | #include "symbols.h" | |
18 | #include "tree.h" | |
19 | #include "eval.h" | |
20 | #include "operators.h" | |
21 | #include "object.h" | |
381c0f0e | 22 | #include <sys/param.h> |
52646e6f ML |
23 | |
24 | #ifndef public | |
25 | typedef struct Frame *Frame; | |
26 | ||
27 | #include "machine.h" | |
28 | #endif | |
29 | ||
30 | #define NSAVEREG 12 | |
31 | ||
32 | struct Frame { | |
33 | Integer condition_handler; | |
34 | Integer mask; | |
35 | Address save_ap; /* argument pointer */ | |
36 | Address save_fp; /* frame pointer */ | |
37 | Address save_pc; /* program counter */ | |
38 | Word save_reg[NSAVEREG]; /* not necessarily there */ | |
39 | }; | |
40 | ||
41 | private Boolean walkingstack = false; | |
42 | ||
43 | /* | |
44 | * Set a frame to the current activation record. | |
45 | */ | |
46 | ||
47 | private getcurframe(frp) | |
48 | register Frame frp; | |
49 | { | |
50 | register int i; | |
51 | ||
52 | checkref(frp); | |
53 | frp->mask = reg(NREG); | |
54 | frp->save_ap = reg(ARGP); | |
55 | frp->save_fp = reg(FRP); | |
551efd5b | 56 | frp->save_pc = reg(PROGCTR) + 1; |
52646e6f ML |
57 | for (i = 0; i < NSAVEREG; i++) { |
58 | frp->save_reg[i] = reg(i); | |
59 | } | |
60 | } | |
61 | ||
62 | /* | |
63 | * Return a pointer to the next activation record up the stack. | |
64 | * Return nil if there is none. | |
65 | * Writes over space pointed to by given argument. | |
66 | */ | |
67 | ||
68 | #define bis(b, n) ((b & (1 << (n))) != 0) | |
69 | ||
70 | private Frame nextframe(frp) | |
71 | Frame frp; | |
72 | { | |
73 | register Frame newfrp; | |
74 | struct Frame frame; | |
75 | register Integer i, j, mask; | |
381c0f0e | 76 | Address prev_frame, callpc; |
316d2228 | 77 | static Integer ntramp = 0; |
52646e6f ML |
78 | |
79 | newfrp = frp; | |
381c0f0e AF |
80 | prev_frame = frp->save_fp; |
81 | ||
316d2228 ML |
82 | /* |
83 | * The check for interrupt generated frames is taken from adb with only | |
84 | * partial understanding. If you're in "sub" and on a sigxxx "sigsub" | |
85 | * gets control, then the stack does NOT look like <main, sub, sigsub>. | |
381c0f0e AF |
86 | * |
87 | * As best I can make out it looks like: | |
316d2228 ML |
88 | * |
89 | * <main, (machine check exception block + sub), sysframe, sigsub>. | |
90 | * | |
91 | * When the signal occurs an exception block and a frame for the routine | |
92 | * in which it occured are pushed on the user stack. Then another frame | |
93 | * is pushed corresponding to a call from the kernel to sigsub. | |
381c0f0e AF |
94 | * |
95 | * The addr in sub at which the exception occured is not in sub.save_pc | |
316d2228 ML |
96 | * but in the machine check exception block. It is at the magic address |
97 | * fp + 76. | |
381c0f0e AF |
98 | * |
99 | * The current approach ignores the sys_frame (what adb reports as sigtramp) | |
316d2228 ML |
100 | * and takes the pc for sub from the exception block. This allows the |
101 | * "where" command to report <main, sub, sigsub>, which seems reasonable. | |
381c0f0e | 102 | */ |
381c0f0e | 103 | |
316d2228 ML |
104 | nextf: |
105 | dread(&frame, prev_frame, sizeof(struct Frame)); | |
106 | if (ntramp == 1) { | |
107 | dread(&callpc, prev_frame + 76, sizeof(callpc)); | |
108 | } else { | |
109 | callpc = frame.save_pc; | |
110 | } | |
52646e6f ML |
111 | if (frame.save_fp == nil) { |
112 | newfrp = nil; | |
316d2228 | 113 | } else if (callpc > 0x80000000 - 0x200 * UPAGES ) { |
381c0f0e AF |
114 | ntramp++; |
115 | prev_frame = frame.save_fp; | |
116 | goto nextf; | |
316d2228 | 117 | } else { |
381c0f0e | 118 | frame.save_pc = callpc; |
316d2228 | 119 | ntramp = 0; |
52646e6f ML |
120 | mask = ((frame.mask >> 16) & 0x0fff); |
121 | j = 0; | |
122 | for (i = 0; i < NSAVEREG; i++) { | |
123 | if (bis(mask, i)) { | |
124 | newfrp->save_reg[i] = frame.save_reg[j]; | |
125 | ++j; | |
126 | } | |
127 | } | |
128 | newfrp->condition_handler = frame.condition_handler; | |
129 | newfrp->mask = mask; | |
130 | newfrp->save_ap = frame.save_ap; | |
131 | newfrp->save_fp = frame.save_fp; | |
132 | newfrp->save_pc = frame.save_pc; | |
133 | } | |
134 | return newfrp; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Return the frame associated with the given function. | |
139 | * If the function is nil, return the most recently activated frame. | |
140 | * | |
141 | * Static allocation for the frame. | |
142 | */ | |
143 | ||
144 | public Frame findframe(f) | |
145 | Symbol f; | |
146 | { | |
147 | register Frame frp; | |
148 | static struct Frame frame; | |
4fd956ac ML |
149 | Symbol p; |
150 | Boolean done; | |
52646e6f ML |
151 | |
152 | frp = &frame; | |
153 | getcurframe(frp); | |
154 | if (f != nil) { | |
4fd956ac ML |
155 | done = false; |
156 | do { | |
157 | p = whatblock(frp->save_pc); | |
158 | if (p == f) { | |
159 | done = true; | |
160 | } else if (p == program) { | |
161 | done = true; | |
162 | frp = nil; | |
163 | } else { | |
164 | frp = nextframe(frp); | |
165 | if (frp == nil) { | |
166 | done = true; | |
167 | } | |
168 | } | |
169 | } while (not done); | |
52646e6f ML |
170 | } |
171 | return frp; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Find the return address of the current procedure/function. | |
176 | */ | |
177 | ||
178 | public Address return_addr() | |
179 | { | |
180 | Frame frp; | |
181 | Address addr; | |
182 | struct Frame frame; | |
183 | ||
184 | frp = &frame; | |
185 | getcurframe(frp); | |
186 | frp = nextframe(frp); | |
187 | if (frp == nil) { | |
188 | addr = 0; | |
189 | } else { | |
190 | addr = frp->save_pc; | |
191 | } | |
192 | return addr; | |
193 | } | |
194 | ||
195 | /* | |
196 | * Push the value associated with the current function. | |
197 | */ | |
198 | ||
199 | public pushretval(len, isindirect) | |
200 | Integer len; | |
201 | Boolean isindirect; | |
202 | { | |
203 | Word r0; | |
204 | ||
205 | r0 = reg(0); | |
206 | if (isindirect) { | |
207 | rpush((Address) r0, len); | |
208 | } else { | |
209 | switch (len) { | |
210 | case sizeof(char): | |
211 | push(char, r0); | |
212 | break; | |
213 | ||
214 | case sizeof(short): | |
215 | push(short, r0); | |
216 | break; | |
217 | ||
218 | default: | |
219 | if (len == sizeof(Word)) { | |
220 | push(Word, r0); | |
221 | } else if (len == 2*sizeof(Word)) { | |
222 | push(Word, r0); | |
223 | push(Word, reg(1)); | |
224 | } else { | |
225 | panic("not indirect in pushretval?"); | |
226 | } | |
227 | break; | |
228 | } | |
229 | } | |
230 | } | |
231 | ||
232 | /* | |
233 | * Return the base address for locals in the given frame. | |
234 | */ | |
235 | ||
236 | public Address locals_base(frp) | |
237 | register Frame frp; | |
238 | { | |
239 | return (frp == nil) ? reg(FRP) : frp->save_fp; | |
240 | } | |
241 | ||
242 | /* | |
243 | * Return the base address for arguments in the given frame. | |
244 | */ | |
245 | ||
246 | public Address args_base(frp) | |
247 | register Frame frp; | |
248 | { | |
249 | return (frp == nil) ? reg(ARGP) : frp->save_ap; | |
250 | } | |
251 | ||
252 | /* | |
253 | * Return saved register n from the given frame. | |
254 | */ | |
255 | ||
256 | public Word savereg(n, frp) | |
257 | register Integer n; | |
258 | register Frame frp; | |
259 | { | |
260 | register Word w; | |
261 | ||
262 | if (frp == nil) { | |
263 | w = reg(n); | |
264 | } else { | |
265 | switch (n) { | |
266 | case ARGP: | |
267 | w = frp->save_ap; | |
268 | break; | |
269 | ||
270 | case FRP: | |
271 | w = frp->save_fp; | |
272 | break; | |
273 | ||
274 | case STKP: | |
275 | w = reg(STKP); | |
276 | break; | |
277 | ||
278 | case PROGCTR: | |
279 | w = frp->save_pc; | |
280 | break; | |
281 | ||
282 | default: | |
283 | assert(n >= 0 and n < NSAVEREG); | |
284 | w = frp->save_reg[n]; | |
285 | break; | |
286 | } | |
287 | } | |
288 | return w; | |
289 | } | |
290 | ||
291 | /* | |
292 | * Return the nth argument to the current procedure. | |
293 | */ | |
294 | ||
295 | public Word argn(n, frp) | |
296 | Integer n; | |
297 | Frame frp; | |
298 | { | |
299 | Word w; | |
300 | ||
301 | dread(&w, args_base(frp) + (n * sizeof(Word)), sizeof(w)); | |
302 | return w; | |
303 | } | |
304 | ||
305 | /* | |
306 | * Calculate the entry address for a procedure or function parameter, | |
307 | * given the address of the descriptor. | |
308 | */ | |
309 | ||
310 | public Address fparamaddr(a) | |
311 | Address a; | |
312 | { | |
313 | Address r; | |
314 | ||
315 | dread(&r, a, sizeof(r)); | |
316 | return r; | |
317 | } | |
318 | ||
319 | /* | |
320 | * Print a list of currently active blocks starting with most recent. | |
321 | */ | |
322 | ||
323 | public wherecmd() | |
324 | { | |
325 | walkstack(false); | |
326 | } | |
327 | ||
328 | /* | |
329 | * Dump the world to the given file. | |
330 | * Like "where", but variables are dumped also. | |
331 | */ | |
332 | ||
333 | public dump() | |
334 | { | |
335 | walkstack(true); | |
336 | } | |
337 | ||
338 | /* | |
339 | * Walk the stack of active procedures printing information | |
340 | * about each active procedure. | |
341 | */ | |
342 | ||
52646e6f ML |
343 | private walkstack(dumpvariables) |
344 | Boolean dumpvariables; | |
345 | { | |
346 | register Frame frp; | |
347 | register Symbol f; | |
348 | register Boolean save; | |
349 | register Lineno line; | |
350 | struct Frame frame; | |
351 | ||
352 | if (notstarted(process)) { | |
353 | error("program is not active"); | |
354 | } else { | |
355 | save = walkingstack; | |
356 | walkingstack = true; | |
357 | frp = &frame; | |
358 | getcurframe(frp); | |
359 | f = whatblock(frp->save_pc); | |
360 | do { | |
361 | printf("%s", symname(f)); | |
362 | printparams(f, frp); | |
91df78fa | 363 | line = srcline(frp->save_pc - 1); |
52646e6f ML |
364 | if (line != 0) { |
365 | printf(", line %d", line); | |
91df78fa | 366 | printf(" in \"%s\"\n", srcfilename(frp->save_pc - 1)); |
52646e6f ML |
367 | } else { |
368 | printf(" at 0x%x\n", frp->save_pc); | |
369 | } | |
370 | if (dumpvariables) { | |
371 | dumpvars(f, frp); | |
372 | putchar('\n'); | |
373 | } | |
374 | frp = nextframe(frp); | |
375 | if (frp != nil) { | |
376 | f = whatblock(frp->save_pc); | |
377 | } | |
4fd956ac | 378 | } while (frp != nil and f != program); |
52646e6f ML |
379 | if (dumpvariables) { |
380 | printf("in \"%s\":\n", symname(program)); | |
381 | dumpvars(program, nil); | |
382 | putchar('\n'); | |
383 | } | |
384 | walkingstack = save; | |
385 | } | |
386 | } | |
387 | ||
388 | /* | |
389 | * Find the entry point of a procedure or function. | |
390 | */ | |
391 | ||
392 | public findbeginning(f) | |
393 | Symbol f; | |
394 | { | |
395 | f->symvalue.funcv.beginaddr += 2; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Return the address corresponding to the first line in a function. | |
400 | */ | |
401 | ||
402 | public Address firstline(f) | |
403 | Symbol f; | |
404 | { | |
405 | Address addr; | |
406 | ||
407 | addr = codeloc(f); | |
408 | while (linelookup(addr) == 0 and addr < objsize) { | |
409 | ++addr; | |
410 | } | |
411 | if (addr == objsize) { | |
412 | addr = -1; | |
413 | } | |
414 | return addr; | |
415 | } | |
416 | ||
417 | /* | |
418 | * Catcher drops strike three ... | |
419 | */ | |
420 | ||
421 | public runtofirst() | |
422 | { | |
423 | Address addr; | |
424 | ||
425 | addr = pc; | |
426 | while (linelookup(addr) == 0 and addr < objsize) { | |
427 | ++addr; | |
428 | } | |
429 | if (addr < objsize) { | |
430 | stepto(addr); | |
431 | } | |
432 | } | |
433 | ||
434 | /* | |
435 | * Return the address corresponding to the end of the program. | |
436 | * | |
437 | * We look for the entry to "exit". | |
438 | */ | |
439 | ||
440 | public Address lastaddr() | |
441 | { | |
442 | register Symbol s; | |
443 | ||
444 | s = lookup(identname("exit", true)); | |
445 | if (s == nil) { | |
446 | panic("can't find exit"); | |
447 | } | |
448 | return codeloc(s); | |
449 | } | |
450 | ||
451 | /* | |
452 | * Decide if the given function is currently active. | |
453 | * | |
454 | * We avoid calls to "findframe" during a stack trace for efficiency. | |
455 | * Presumably information evaluated while walking the stack is active. | |
456 | */ | |
457 | ||
458 | public Boolean isactive(f) | |
459 | Symbol f; | |
460 | { | |
461 | register Boolean b; | |
462 | ||
463 | if (isfinished(process)) { | |
464 | b = false; | |
465 | } else { | |
466 | if (walkingstack or f == program or | |
467 | (ismodule(f) and isactive(container(f)))) { | |
468 | b = true; | |
469 | } else { | |
470 | b = (Boolean) (findframe(f) != nil); | |
471 | } | |
472 | } | |
473 | return b; | |
474 | } | |
475 | ||
476 | /* | |
477 | * Evaluate a call to a procedure. | |
478 | */ | |
479 | ||
480 | public callproc(procnode, arglist) | |
481 | Node procnode; | |
482 | Node arglist; | |
483 | { | |
484 | Symbol proc; | |
485 | Integer argc; | |
486 | ||
487 | if (procnode->op != O_SYM) { | |
488 | beginerrmsg(); | |
489 | fprintf(stderr, "can't call \""); | |
490 | prtree(stderr, procnode); | |
491 | fprintf(stderr, "\""); | |
492 | enderrmsg(); | |
493 | } | |
494 | assert(procnode->op == O_SYM); | |
495 | proc = procnode->value.sym; | |
496 | if (not isblock(proc)) { | |
497 | error("\"%s\" is not a procedure or function", symname(proc)); | |
498 | } | |
499 | pushenv(); | |
500 | pc = codeloc(proc); | |
501 | argc = pushargs(proc, arglist); | |
502 | beginproc(proc, argc); | |
503 | isstopped = true; | |
504 | event_once(build(O_EQ, build(O_SYM, pcsym), build(O_SYM, retaddrsym)), | |
505 | buildcmdlist(build(O_PROCRTN, proc))); | |
506 | cont(); | |
507 | /* NOTREACHED */ | |
508 | } | |
509 | ||
510 | /* | |
511 | * Push the arguments on the process' stack. We do this by first | |
512 | * evaluating them on the "eval" stack, then copying into the process' | |
513 | * space. | |
514 | */ | |
515 | ||
516 | private Integer pushargs(proc, arglist) | |
517 | Symbol proc; | |
518 | Node arglist; | |
519 | { | |
520 | Stack *savesp; | |
521 | int argc, args_size; | |
522 | ||
523 | savesp = sp; | |
524 | argc = evalargs(proc, arglist); | |
525 | args_size = sp - savesp; | |
526 | setreg(STKP, reg(STKP) - args_size); | |
527 | dwrite(savesp, reg(STKP), args_size); | |
528 | sp = savesp; | |
529 | return argc; | |
530 | } | |
531 | ||
532 | /* | |
533 | * Evaluate arguments left-to-right. | |
534 | */ | |
535 | ||
536 | private Integer evalargs(proc, arglist) | |
537 | Symbol proc; | |
538 | Node arglist; | |
539 | { | |
540 | Node p, exp; | |
541 | Symbol arg; | |
542 | Stack *savesp; | |
543 | Address addr; | |
544 | Integer count; | |
545 | ||
546 | savesp = sp; | |
547 | count = 0; | |
548 | arg = proc->chain; | |
549 | for (p = arglist; p != nil; p = p->value.arg[1]) { | |
550 | if (p->op != O_COMMA) { | |
551 | panic("evalargs: arglist missing comma"); | |
552 | } | |
553 | if (arg == nil) { | |
554 | sp = savesp; | |
555 | error("too many parameters to %s", symname(proc)); | |
556 | } | |
557 | exp = p->value.arg[0]; | |
558 | if (not compatible(arg->type, exp->nodetype)) { | |
559 | sp = savesp; | |
560 | error("expression for parameter %s is of wrong type", symname(arg)); | |
561 | } | |
562 | if (arg->class == REF) { | |
563 | if (exp->op != O_RVAL) { | |
564 | sp = savesp; | |
565 | error("variable expected for parameter \"%s\"", symname(arg)); | |
566 | } | |
567 | addr = lval(exp->value.arg[0]); | |
568 | push(Address, addr); | |
569 | } else { | |
570 | eval(exp); | |
571 | } | |
572 | arg = arg->chain; | |
573 | ++count; | |
574 | } | |
575 | if (arg != nil) { | |
576 | sp = savesp; | |
577 | error("not enough parameters to %s", symname(proc)); | |
578 | } | |
579 | return count; | |
580 | } | |
581 | ||
582 | public procreturn(f) | |
583 | Symbol f; | |
584 | { | |
585 | flushoutput(); | |
586 | putchar('\n'); | |
587 | printname(stdout, f); | |
588 | printf(" returns successfully\n", symname(f)); | |
589 | popenv(); | |
590 | erecover(); | |
591 | } | |
592 | ||
593 | /* | |
594 | * Push the current environment. | |
595 | */ | |
596 | ||
597 | private pushenv() | |
598 | { | |
599 | push(Address, pc); | |
600 | push(Lineno, curline); | |
601 | push(String, cursource); | |
602 | push(Boolean, isstopped); | |
603 | push(Symbol, curfunc); | |
604 | push(Word, reg(PROGCTR)); | |
605 | push(Word, reg(STKP)); | |
606 | } | |
607 | ||
608 | /* | |
609 | * Pop back to the real world. | |
610 | */ | |
611 | ||
612 | public popenv() | |
613 | { | |
614 | register String filename; | |
615 | ||
616 | setreg(STKP, pop(Word)); | |
617 | setreg(PROGCTR, pop(Word)); | |
618 | curfunc = pop(Symbol); | |
619 | isstopped = pop(Boolean); | |
620 | filename = pop(String); | |
621 | curline = pop(Lineno); | |
622 | pc = pop(Address); | |
623 | setsource(filename); | |
624 | } | |
625 | ||
626 | /* | |
627 | * Flush the debuggee's standard output. | |
628 | * | |
629 | * This is VERY dependent on the use of stdio. | |
630 | */ | |
631 | ||
632 | public flushoutput() | |
633 | { | |
634 | register Symbol p, iob; | |
635 | register Stack *savesp; | |
636 | ||
637 | p = lookup(identname("fflush", true)); | |
638 | while (p != nil and not isblock(p)) { | |
639 | p = p->next_sym; | |
640 | } | |
641 | if (p != nil) { | |
642 | iob = lookup(identname("_iob", true)); | |
643 | if (iob != nil) { | |
644 | pushenv(); | |
645 | pc = codeloc(p); | |
646 | savesp = sp; | |
647 | push(long, address(iob, nil) + sizeof(struct _iobuf)); | |
648 | setreg(STKP, reg(STKP) - sizeof(long)); | |
649 | dwrite(savesp, reg(STKP), sizeof(long)); | |
650 | sp = savesp; | |
651 | beginproc(p, 1); | |
652 | stepto(return_addr()); | |
653 | popenv(); | |
654 | } | |
655 | } | |
656 | } |