Commit | Line | Data |
---|---|---|
381c0f0e | 1 | |
52646e6f ML |
2 | /* Copyright (c) 1982 Regents of the University of California */ |
3 | ||
912533aa | 4 | static char sccsid[] = "@(#)runtime.c 1.10 %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 | 96 | * but in the machine check exception block. It is at the magic address |
8d44f3a5 | 97 | * fp + 84. |
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) { | |
8d44f3a5 | 107 | dread(&callpc, prev_frame + 84, sizeof(callpc)); |
316d2228 ML |
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 | 149 | Symbol p; |
52646e6f ML |
150 | |
151 | frp = &frame; | |
152 | getcurframe(frp); | |
912533aa SL |
153 | if (f == nil) |
154 | return (frp); | |
155 | /* | |
156 | * Starting at the current stack frame, | |
157 | * walk backwards looking for a symbol | |
158 | * match. Beware of local blocks which | |
159 | * have a back pointer but no stack frame. | |
160 | */ | |
161 | p = whatblock(frp->save_pc); | |
162 | while (p != f) { | |
163 | if (p == program) { | |
164 | frp = nil; | |
165 | break; | |
166 | } | |
167 | if (isinline(p)) { | |
168 | p = container(p); | |
169 | continue; | |
170 | } | |
171 | frp = nextframe(frp); | |
172 | if (frp == nil) | |
173 | break; | |
174 | p = whatblock(frp->save_pc); | |
52646e6f | 175 | } |
912533aa | 176 | return (frp); |
52646e6f ML |
177 | } |
178 | ||
179 | /* | |
180 | * Find the return address of the current procedure/function. | |
181 | */ | |
182 | ||
183 | public Address return_addr() | |
184 | { | |
185 | Frame frp; | |
186 | Address addr; | |
187 | struct Frame frame; | |
188 | ||
189 | frp = &frame; | |
190 | getcurframe(frp); | |
191 | frp = nextframe(frp); | |
192 | if (frp == nil) { | |
193 | addr = 0; | |
194 | } else { | |
195 | addr = frp->save_pc; | |
196 | } | |
197 | return addr; | |
198 | } | |
199 | ||
200 | /* | |
201 | * Push the value associated with the current function. | |
202 | */ | |
203 | ||
204 | public pushretval(len, isindirect) | |
205 | Integer len; | |
206 | Boolean isindirect; | |
207 | { | |
208 | Word r0; | |
209 | ||
210 | r0 = reg(0); | |
211 | if (isindirect) { | |
212 | rpush((Address) r0, len); | |
213 | } else { | |
214 | switch (len) { | |
215 | case sizeof(char): | |
216 | push(char, r0); | |
217 | break; | |
218 | ||
219 | case sizeof(short): | |
220 | push(short, r0); | |
221 | break; | |
222 | ||
223 | default: | |
224 | if (len == sizeof(Word)) { | |
225 | push(Word, r0); | |
226 | } else if (len == 2*sizeof(Word)) { | |
227 | push(Word, r0); | |
228 | push(Word, reg(1)); | |
229 | } else { | |
230 | panic("not indirect in pushretval?"); | |
231 | } | |
232 | break; | |
233 | } | |
234 | } | |
235 | } | |
236 | ||
237 | /* | |
238 | * Return the base address for locals in the given frame. | |
239 | */ | |
240 | ||
241 | public Address locals_base(frp) | |
242 | register Frame frp; | |
243 | { | |
244 | return (frp == nil) ? reg(FRP) : frp->save_fp; | |
245 | } | |
246 | ||
247 | /* | |
248 | * Return the base address for arguments in the given frame. | |
249 | */ | |
250 | ||
251 | public Address args_base(frp) | |
252 | register Frame frp; | |
253 | { | |
254 | return (frp == nil) ? reg(ARGP) : frp->save_ap; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Return saved register n from the given frame. | |
259 | */ | |
260 | ||
261 | public Word savereg(n, frp) | |
262 | register Integer n; | |
263 | register Frame frp; | |
264 | { | |
265 | register Word w; | |
266 | ||
267 | if (frp == nil) { | |
268 | w = reg(n); | |
269 | } else { | |
270 | switch (n) { | |
271 | case ARGP: | |
272 | w = frp->save_ap; | |
273 | break; | |
274 | ||
275 | case FRP: | |
276 | w = frp->save_fp; | |
277 | break; | |
278 | ||
279 | case STKP: | |
280 | w = reg(STKP); | |
281 | break; | |
282 | ||
283 | case PROGCTR: | |
284 | w = frp->save_pc; | |
285 | break; | |
286 | ||
287 | default: | |
288 | assert(n >= 0 and n < NSAVEREG); | |
289 | w = frp->save_reg[n]; | |
290 | break; | |
291 | } | |
292 | } | |
293 | return w; | |
294 | } | |
295 | ||
296 | /* | |
297 | * Return the nth argument to the current procedure. | |
298 | */ | |
299 | ||
300 | public Word argn(n, frp) | |
301 | Integer n; | |
302 | Frame frp; | |
303 | { | |
304 | Word w; | |
305 | ||
306 | dread(&w, args_base(frp) + (n * sizeof(Word)), sizeof(w)); | |
307 | return w; | |
308 | } | |
309 | ||
310 | /* | |
311 | * Calculate the entry address for a procedure or function parameter, | |
312 | * given the address of the descriptor. | |
313 | */ | |
314 | ||
315 | public Address fparamaddr(a) | |
316 | Address a; | |
317 | { | |
318 | Address r; | |
319 | ||
320 | dread(&r, a, sizeof(r)); | |
321 | return r; | |
322 | } | |
323 | ||
324 | /* | |
325 | * Print a list of currently active blocks starting with most recent. | |
326 | */ | |
327 | ||
328 | public wherecmd() | |
329 | { | |
330 | walkstack(false); | |
331 | } | |
332 | ||
333 | /* | |
334 | * Dump the world to the given file. | |
335 | * Like "where", but variables are dumped also. | |
336 | */ | |
337 | ||
338 | public dump() | |
339 | { | |
340 | walkstack(true); | |
341 | } | |
342 | ||
343 | /* | |
344 | * Walk the stack of active procedures printing information | |
345 | * about each active procedure. | |
346 | */ | |
347 | ||
52646e6f ML |
348 | private walkstack(dumpvariables) |
349 | Boolean dumpvariables; | |
350 | { | |
351 | register Frame frp; | |
352 | register Symbol f; | |
353 | register Boolean save; | |
354 | register Lineno line; | |
355 | struct Frame frame; | |
356 | ||
357 | if (notstarted(process)) { | |
358 | error("program is not active"); | |
359 | } else { | |
360 | save = walkingstack; | |
361 | walkingstack = true; | |
362 | frp = &frame; | |
363 | getcurframe(frp); | |
364 | f = whatblock(frp->save_pc); | |
365 | do { | |
366 | printf("%s", symname(f)); | |
92167553 ML |
367 | if (not isinline(f)) { |
368 | printparams(f, frp); | |
369 | } | |
91df78fa | 370 | line = srcline(frp->save_pc - 1); |
52646e6f ML |
371 | if (line != 0) { |
372 | printf(", line %d", line); | |
91df78fa | 373 | printf(" in \"%s\"\n", srcfilename(frp->save_pc - 1)); |
52646e6f ML |
374 | } else { |
375 | printf(" at 0x%x\n", frp->save_pc); | |
376 | } | |
377 | if (dumpvariables) { | |
378 | dumpvars(f, frp); | |
379 | putchar('\n'); | |
380 | } | |
92167553 ML |
381 | if (isinline(f)) { |
382 | f = container(f); | |
383 | } else { | |
384 | frp = nextframe(frp); | |
385 | if (frp != nil) { | |
386 | f = whatblock(frp->save_pc); | |
387 | } | |
52646e6f | 388 | } |
4fd956ac | 389 | } while (frp != nil and f != program); |
52646e6f ML |
390 | if (dumpvariables) { |
391 | printf("in \"%s\":\n", symname(program)); | |
392 | dumpvars(program, nil); | |
393 | putchar('\n'); | |
394 | } | |
395 | walkingstack = save; | |
396 | } | |
397 | } | |
398 | ||
399 | /* | |
400 | * Find the entry point of a procedure or function. | |
401 | */ | |
402 | ||
403 | public findbeginning(f) | |
404 | Symbol f; | |
405 | { | |
406 | f->symvalue.funcv.beginaddr += 2; | |
407 | } | |
408 | ||
409 | /* | |
410 | * Return the address corresponding to the first line in a function. | |
411 | */ | |
412 | ||
413 | public Address firstline(f) | |
414 | Symbol f; | |
415 | { | |
416 | Address addr; | |
417 | ||
418 | addr = codeloc(f); | |
419 | while (linelookup(addr) == 0 and addr < objsize) { | |
420 | ++addr; | |
421 | } | |
422 | if (addr == objsize) { | |
423 | addr = -1; | |
424 | } | |
425 | return addr; | |
426 | } | |
427 | ||
428 | /* | |
429 | * Catcher drops strike three ... | |
430 | */ | |
431 | ||
432 | public runtofirst() | |
433 | { | |
434 | Address addr; | |
435 | ||
436 | addr = pc; | |
437 | while (linelookup(addr) == 0 and addr < objsize) { | |
438 | ++addr; | |
439 | } | |
440 | if (addr < objsize) { | |
441 | stepto(addr); | |
442 | } | |
443 | } | |
444 | ||
445 | /* | |
446 | * Return the address corresponding to the end of the program. | |
447 | * | |
448 | * We look for the entry to "exit". | |
449 | */ | |
450 | ||
451 | public Address lastaddr() | |
452 | { | |
453 | register Symbol s; | |
454 | ||
455 | s = lookup(identname("exit", true)); | |
456 | if (s == nil) { | |
457 | panic("can't find exit"); | |
458 | } | |
459 | return codeloc(s); | |
460 | } | |
461 | ||
462 | /* | |
463 | * Decide if the given function is currently active. | |
464 | * | |
465 | * We avoid calls to "findframe" during a stack trace for efficiency. | |
466 | * Presumably information evaluated while walking the stack is active. | |
467 | */ | |
468 | ||
469 | public Boolean isactive(f) | |
470 | Symbol f; | |
471 | { | |
472 | register Boolean b; | |
473 | ||
474 | if (isfinished(process)) { | |
475 | b = false; | |
476 | } else { | |
477 | if (walkingstack or f == program or | |
478 | (ismodule(f) and isactive(container(f)))) { | |
479 | b = true; | |
480 | } else { | |
481 | b = (Boolean) (findframe(f) != nil); | |
482 | } | |
483 | } | |
484 | return b; | |
485 | } | |
486 | ||
487 | /* | |
488 | * Evaluate a call to a procedure. | |
489 | */ | |
490 | ||
491 | public callproc(procnode, arglist) | |
492 | Node procnode; | |
493 | Node arglist; | |
494 | { | |
495 | Symbol proc; | |
496 | Integer argc; | |
497 | ||
498 | if (procnode->op != O_SYM) { | |
499 | beginerrmsg(); | |
500 | fprintf(stderr, "can't call \""); | |
501 | prtree(stderr, procnode); | |
502 | fprintf(stderr, "\""); | |
503 | enderrmsg(); | |
504 | } | |
505 | assert(procnode->op == O_SYM); | |
506 | proc = procnode->value.sym; | |
507 | if (not isblock(proc)) { | |
508 | error("\"%s\" is not a procedure or function", symname(proc)); | |
509 | } | |
510 | pushenv(); | |
511 | pc = codeloc(proc); | |
512 | argc = pushargs(proc, arglist); | |
513 | beginproc(proc, argc); | |
514 | isstopped = true; | |
515 | event_once(build(O_EQ, build(O_SYM, pcsym), build(O_SYM, retaddrsym)), | |
516 | buildcmdlist(build(O_PROCRTN, proc))); | |
517 | cont(); | |
518 | /* NOTREACHED */ | |
519 | } | |
520 | ||
521 | /* | |
522 | * Push the arguments on the process' stack. We do this by first | |
523 | * evaluating them on the "eval" stack, then copying into the process' | |
524 | * space. | |
525 | */ | |
526 | ||
527 | private Integer pushargs(proc, arglist) | |
528 | Symbol proc; | |
529 | Node arglist; | |
530 | { | |
531 | Stack *savesp; | |
532 | int argc, args_size; | |
533 | ||
534 | savesp = sp; | |
535 | argc = evalargs(proc, arglist); | |
536 | args_size = sp - savesp; | |
537 | setreg(STKP, reg(STKP) - args_size); | |
538 | dwrite(savesp, reg(STKP), args_size); | |
539 | sp = savesp; | |
540 | return argc; | |
541 | } | |
542 | ||
543 | /* | |
544 | * Evaluate arguments left-to-right. | |
545 | */ | |
546 | ||
547 | private Integer evalargs(proc, arglist) | |
548 | Symbol proc; | |
549 | Node arglist; | |
550 | { | |
551 | Node p, exp; | |
552 | Symbol arg; | |
553 | Stack *savesp; | |
554 | Address addr; | |
555 | Integer count; | |
556 | ||
557 | savesp = sp; | |
558 | count = 0; | |
559 | arg = proc->chain; | |
560 | for (p = arglist; p != nil; p = p->value.arg[1]) { | |
561 | if (p->op != O_COMMA) { | |
562 | panic("evalargs: arglist missing comma"); | |
563 | } | |
564 | if (arg == nil) { | |
565 | sp = savesp; | |
566 | error("too many parameters to %s", symname(proc)); | |
567 | } | |
568 | exp = p->value.arg[0]; | |
569 | if (not compatible(arg->type, exp->nodetype)) { | |
570 | sp = savesp; | |
571 | error("expression for parameter %s is of wrong type", symname(arg)); | |
572 | } | |
573 | if (arg->class == REF) { | |
574 | if (exp->op != O_RVAL) { | |
575 | sp = savesp; | |
576 | error("variable expected for parameter \"%s\"", symname(arg)); | |
577 | } | |
578 | addr = lval(exp->value.arg[0]); | |
579 | push(Address, addr); | |
580 | } else { | |
581 | eval(exp); | |
582 | } | |
583 | arg = arg->chain; | |
584 | ++count; | |
585 | } | |
586 | if (arg != nil) { | |
587 | sp = savesp; | |
588 | error("not enough parameters to %s", symname(proc)); | |
589 | } | |
590 | return count; | |
591 | } | |
592 | ||
593 | public procreturn(f) | |
594 | Symbol f; | |
595 | { | |
596 | flushoutput(); | |
597 | putchar('\n'); | |
598 | printname(stdout, f); | |
599 | printf(" returns successfully\n", symname(f)); | |
600 | popenv(); | |
601 | erecover(); | |
602 | } | |
603 | ||
604 | /* | |
605 | * Push the current environment. | |
606 | */ | |
607 | ||
608 | private pushenv() | |
609 | { | |
610 | push(Address, pc); | |
611 | push(Lineno, curline); | |
612 | push(String, cursource); | |
613 | push(Boolean, isstopped); | |
614 | push(Symbol, curfunc); | |
615 | push(Word, reg(PROGCTR)); | |
616 | push(Word, reg(STKP)); | |
617 | } | |
618 | ||
619 | /* | |
620 | * Pop back to the real world. | |
621 | */ | |
622 | ||
623 | public popenv() | |
624 | { | |
625 | register String filename; | |
626 | ||
627 | setreg(STKP, pop(Word)); | |
628 | setreg(PROGCTR, pop(Word)); | |
629 | curfunc = pop(Symbol); | |
630 | isstopped = pop(Boolean); | |
631 | filename = pop(String); | |
632 | curline = pop(Lineno); | |
633 | pc = pop(Address); | |
634 | setsource(filename); | |
635 | } | |
636 | ||
637 | /* | |
638 | * Flush the debuggee's standard output. | |
639 | * | |
640 | * This is VERY dependent on the use of stdio. | |
641 | */ | |
642 | ||
643 | public flushoutput() | |
644 | { | |
645 | register Symbol p, iob; | |
646 | register Stack *savesp; | |
647 | ||
648 | p = lookup(identname("fflush", true)); | |
649 | while (p != nil and not isblock(p)) { | |
650 | p = p->next_sym; | |
651 | } | |
652 | if (p != nil) { | |
653 | iob = lookup(identname("_iob", true)); | |
654 | if (iob != nil) { | |
655 | pushenv(); | |
656 | pc = codeloc(p); | |
657 | savesp = sp; | |
658 | push(long, address(iob, nil) + sizeof(struct _iobuf)); | |
659 | setreg(STKP, reg(STKP) - sizeof(long)); | |
660 | dwrite(savesp, reg(STKP), sizeof(long)); | |
661 | sp = savesp; | |
662 | beginproc(p, 1); | |
663 | stepto(return_addr()); | |
664 | popenv(); | |
665 | } | |
666 | } | |
667 | } |