Commit | Line | Data |
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52646e6f ML |
1 | /* Copyright (c) 1982 Regents of the University of California */ |
2 | ||
551efd5b | 3 | static char sccsid[] = "@(#)runtime.vax.c 1.5 %G%"; |
52646e6f ML |
4 | |
5 | /* | |
6 | * Runtime organization dependent routines, mostly dealing with | |
7 | * activation records. | |
8 | */ | |
9 | ||
10 | #include "defs.h" | |
11 | #include "runtime.h" | |
12 | #include "process.h" | |
13 | #include "machine.h" | |
14 | #include "events.h" | |
15 | #include "mappings.h" | |
16 | #include "symbols.h" | |
17 | #include "tree.h" | |
18 | #include "eval.h" | |
19 | #include "operators.h" | |
20 | #include "object.h" | |
21 | ||
22 | #ifndef public | |
23 | typedef struct Frame *Frame; | |
24 | ||
25 | #include "machine.h" | |
26 | #endif | |
27 | ||
28 | #define NSAVEREG 12 | |
29 | ||
30 | struct Frame { | |
31 | Integer condition_handler; | |
32 | Integer mask; | |
33 | Address save_ap; /* argument pointer */ | |
34 | Address save_fp; /* frame pointer */ | |
35 | Address save_pc; /* program counter */ | |
36 | Word save_reg[NSAVEREG]; /* not necessarily there */ | |
37 | }; | |
38 | ||
39 | private Boolean walkingstack = false; | |
40 | ||
41 | /* | |
42 | * Set a frame to the current activation record. | |
43 | */ | |
44 | ||
45 | private getcurframe(frp) | |
46 | register Frame frp; | |
47 | { | |
48 | register int i; | |
49 | ||
50 | checkref(frp); | |
51 | frp->mask = reg(NREG); | |
52 | frp->save_ap = reg(ARGP); | |
53 | frp->save_fp = reg(FRP); | |
551efd5b | 54 | frp->save_pc = reg(PROGCTR) + 1; |
52646e6f ML |
55 | for (i = 0; i < NSAVEREG; i++) { |
56 | frp->save_reg[i] = reg(i); | |
57 | } | |
58 | } | |
59 | ||
60 | /* | |
61 | * Return a pointer to the next activation record up the stack. | |
62 | * Return nil if there is none. | |
63 | * Writes over space pointed to by given argument. | |
64 | */ | |
65 | ||
66 | #define bis(b, n) ((b & (1 << (n))) != 0) | |
67 | ||
68 | private Frame nextframe(frp) | |
69 | Frame frp; | |
70 | { | |
71 | register Frame newfrp; | |
72 | struct Frame frame; | |
73 | register Integer i, j, mask; | |
74 | ||
75 | newfrp = frp; | |
76 | dread(&frame, newfrp->save_fp, sizeof(struct Frame)); | |
77 | if (frame.save_fp == nil) { | |
78 | newfrp = nil; | |
79 | } else { | |
80 | mask = ((frame.mask >> 16) & 0x0fff); | |
81 | j = 0; | |
82 | for (i = 0; i < NSAVEREG; i++) { | |
83 | if (bis(mask, i)) { | |
84 | newfrp->save_reg[i] = frame.save_reg[j]; | |
85 | ++j; | |
86 | } | |
87 | } | |
88 | newfrp->condition_handler = frame.condition_handler; | |
89 | newfrp->mask = mask; | |
90 | newfrp->save_ap = frame.save_ap; | |
91 | newfrp->save_fp = frame.save_fp; | |
92 | newfrp->save_pc = frame.save_pc; | |
93 | } | |
94 | return newfrp; | |
95 | } | |
96 | ||
97 | /* | |
98 | * Return the frame associated with the given function. | |
99 | * If the function is nil, return the most recently activated frame. | |
100 | * | |
101 | * Static allocation for the frame. | |
102 | */ | |
103 | ||
104 | public Frame findframe(f) | |
105 | Symbol f; | |
106 | { | |
107 | register Frame frp; | |
108 | static struct Frame frame; | |
4fd956ac ML |
109 | Symbol p; |
110 | Boolean done; | |
52646e6f ML |
111 | |
112 | frp = &frame; | |
113 | getcurframe(frp); | |
114 | if (f != nil) { | |
4fd956ac ML |
115 | done = false; |
116 | do { | |
117 | p = whatblock(frp->save_pc); | |
118 | if (p == f) { | |
119 | done = true; | |
120 | } else if (p == program) { | |
121 | done = true; | |
122 | frp = nil; | |
123 | } else { | |
124 | frp = nextframe(frp); | |
125 | if (frp == nil) { | |
126 | done = true; | |
127 | } | |
128 | } | |
129 | } while (not done); | |
52646e6f ML |
130 | } |
131 | return frp; | |
132 | } | |
133 | ||
134 | /* | |
135 | * Find the return address of the current procedure/function. | |
136 | */ | |
137 | ||
138 | public Address return_addr() | |
139 | { | |
140 | Frame frp; | |
141 | Address addr; | |
142 | struct Frame frame; | |
143 | ||
144 | frp = &frame; | |
145 | getcurframe(frp); | |
146 | frp = nextframe(frp); | |
147 | if (frp == nil) { | |
148 | addr = 0; | |
149 | } else { | |
150 | addr = frp->save_pc; | |
151 | } | |
152 | return addr; | |
153 | } | |
154 | ||
155 | /* | |
156 | * Push the value associated with the current function. | |
157 | */ | |
158 | ||
159 | public pushretval(len, isindirect) | |
160 | Integer len; | |
161 | Boolean isindirect; | |
162 | { | |
163 | Word r0; | |
164 | ||
165 | r0 = reg(0); | |
166 | if (isindirect) { | |
167 | rpush((Address) r0, len); | |
168 | } else { | |
169 | switch (len) { | |
170 | case sizeof(char): | |
171 | push(char, r0); | |
172 | break; | |
173 | ||
174 | case sizeof(short): | |
175 | push(short, r0); | |
176 | break; | |
177 | ||
178 | default: | |
179 | if (len == sizeof(Word)) { | |
180 | push(Word, r0); | |
181 | } else if (len == 2*sizeof(Word)) { | |
182 | push(Word, r0); | |
183 | push(Word, reg(1)); | |
184 | } else { | |
185 | panic("not indirect in pushretval?"); | |
186 | } | |
187 | break; | |
188 | } | |
189 | } | |
190 | } | |
191 | ||
192 | /* | |
193 | * Return the base address for locals in the given frame. | |
194 | */ | |
195 | ||
196 | public Address locals_base(frp) | |
197 | register Frame frp; | |
198 | { | |
199 | return (frp == nil) ? reg(FRP) : frp->save_fp; | |
200 | } | |
201 | ||
202 | /* | |
203 | * Return the base address for arguments in the given frame. | |
204 | */ | |
205 | ||
206 | public Address args_base(frp) | |
207 | register Frame frp; | |
208 | { | |
209 | return (frp == nil) ? reg(ARGP) : frp->save_ap; | |
210 | } | |
211 | ||
212 | /* | |
213 | * Return saved register n from the given frame. | |
214 | */ | |
215 | ||
216 | public Word savereg(n, frp) | |
217 | register Integer n; | |
218 | register Frame frp; | |
219 | { | |
220 | register Word w; | |
221 | ||
222 | if (frp == nil) { | |
223 | w = reg(n); | |
224 | } else { | |
225 | switch (n) { | |
226 | case ARGP: | |
227 | w = frp->save_ap; | |
228 | break; | |
229 | ||
230 | case FRP: | |
231 | w = frp->save_fp; | |
232 | break; | |
233 | ||
234 | case STKP: | |
235 | w = reg(STKP); | |
236 | break; | |
237 | ||
238 | case PROGCTR: | |
239 | w = frp->save_pc; | |
240 | break; | |
241 | ||
242 | default: | |
243 | assert(n >= 0 and n < NSAVEREG); | |
244 | w = frp->save_reg[n]; | |
245 | break; | |
246 | } | |
247 | } | |
248 | return w; | |
249 | } | |
250 | ||
251 | /* | |
252 | * Return the nth argument to the current procedure. | |
253 | */ | |
254 | ||
255 | public Word argn(n, frp) | |
256 | Integer n; | |
257 | Frame frp; | |
258 | { | |
259 | Word w; | |
260 | ||
261 | dread(&w, args_base(frp) + (n * sizeof(Word)), sizeof(w)); | |
262 | return w; | |
263 | } | |
264 | ||
265 | /* | |
266 | * Calculate the entry address for a procedure or function parameter, | |
267 | * given the address of the descriptor. | |
268 | */ | |
269 | ||
270 | public Address fparamaddr(a) | |
271 | Address a; | |
272 | { | |
273 | Address r; | |
274 | ||
275 | dread(&r, a, sizeof(r)); | |
276 | return r; | |
277 | } | |
278 | ||
279 | /* | |
280 | * Print a list of currently active blocks starting with most recent. | |
281 | */ | |
282 | ||
283 | public wherecmd() | |
284 | { | |
285 | walkstack(false); | |
286 | } | |
287 | ||
288 | /* | |
289 | * Dump the world to the given file. | |
290 | * Like "where", but variables are dumped also. | |
291 | */ | |
292 | ||
293 | public dump() | |
294 | { | |
295 | walkstack(true); | |
296 | } | |
297 | ||
298 | /* | |
299 | * Walk the stack of active procedures printing information | |
300 | * about each active procedure. | |
301 | */ | |
302 | ||
52646e6f ML |
303 | private walkstack(dumpvariables) |
304 | Boolean dumpvariables; | |
305 | { | |
306 | register Frame frp; | |
307 | register Symbol f; | |
308 | register Boolean save; | |
309 | register Lineno line; | |
310 | struct Frame frame; | |
311 | ||
312 | if (notstarted(process)) { | |
313 | error("program is not active"); | |
314 | } else { | |
315 | save = walkingstack; | |
316 | walkingstack = true; | |
317 | frp = &frame; | |
318 | getcurframe(frp); | |
319 | f = whatblock(frp->save_pc); | |
320 | do { | |
321 | printf("%s", symname(f)); | |
322 | printparams(f, frp); | |
91df78fa | 323 | line = srcline(frp->save_pc - 1); |
52646e6f ML |
324 | if (line != 0) { |
325 | printf(", line %d", line); | |
91df78fa | 326 | printf(" in \"%s\"\n", srcfilename(frp->save_pc - 1)); |
52646e6f ML |
327 | } else { |
328 | printf(" at 0x%x\n", frp->save_pc); | |
329 | } | |
330 | if (dumpvariables) { | |
331 | dumpvars(f, frp); | |
332 | putchar('\n'); | |
333 | } | |
334 | frp = nextframe(frp); | |
335 | if (frp != nil) { | |
336 | f = whatblock(frp->save_pc); | |
337 | } | |
4fd956ac | 338 | } while (frp != nil and f != program); |
52646e6f ML |
339 | if (dumpvariables) { |
340 | printf("in \"%s\":\n", symname(program)); | |
341 | dumpvars(program, nil); | |
342 | putchar('\n'); | |
343 | } | |
344 | walkingstack = save; | |
345 | } | |
346 | } | |
347 | ||
348 | /* | |
349 | * Find the entry point of a procedure or function. | |
350 | */ | |
351 | ||
352 | public findbeginning(f) | |
353 | Symbol f; | |
354 | { | |
355 | f->symvalue.funcv.beginaddr += 2; | |
356 | } | |
357 | ||
358 | /* | |
359 | * Return the address corresponding to the first line in a function. | |
360 | */ | |
361 | ||
362 | public Address firstline(f) | |
363 | Symbol f; | |
364 | { | |
365 | Address addr; | |
366 | ||
367 | addr = codeloc(f); | |
368 | while (linelookup(addr) == 0 and addr < objsize) { | |
369 | ++addr; | |
370 | } | |
371 | if (addr == objsize) { | |
372 | addr = -1; | |
373 | } | |
374 | return addr; | |
375 | } | |
376 | ||
377 | /* | |
378 | * Catcher drops strike three ... | |
379 | */ | |
380 | ||
381 | public runtofirst() | |
382 | { | |
383 | Address addr; | |
384 | ||
385 | addr = pc; | |
386 | while (linelookup(addr) == 0 and addr < objsize) { | |
387 | ++addr; | |
388 | } | |
389 | if (addr < objsize) { | |
390 | stepto(addr); | |
391 | } | |
392 | } | |
393 | ||
394 | /* | |
395 | * Return the address corresponding to the end of the program. | |
396 | * | |
397 | * We look for the entry to "exit". | |
398 | */ | |
399 | ||
400 | public Address lastaddr() | |
401 | { | |
402 | register Symbol s; | |
403 | ||
404 | s = lookup(identname("exit", true)); | |
405 | if (s == nil) { | |
406 | panic("can't find exit"); | |
407 | } | |
408 | return codeloc(s); | |
409 | } | |
410 | ||
411 | /* | |
412 | * Decide if the given function is currently active. | |
413 | * | |
414 | * We avoid calls to "findframe" during a stack trace for efficiency. | |
415 | * Presumably information evaluated while walking the stack is active. | |
416 | */ | |
417 | ||
418 | public Boolean isactive(f) | |
419 | Symbol f; | |
420 | { | |
421 | register Boolean b; | |
422 | ||
423 | if (isfinished(process)) { | |
424 | b = false; | |
425 | } else { | |
426 | if (walkingstack or f == program or | |
427 | (ismodule(f) and isactive(container(f)))) { | |
428 | b = true; | |
429 | } else { | |
430 | b = (Boolean) (findframe(f) != nil); | |
431 | } | |
432 | } | |
433 | return b; | |
434 | } | |
435 | ||
436 | /* | |
437 | * Evaluate a call to a procedure. | |
438 | */ | |
439 | ||
440 | public callproc(procnode, arglist) | |
441 | Node procnode; | |
442 | Node arglist; | |
443 | { | |
444 | Symbol proc; | |
445 | Integer argc; | |
446 | ||
447 | if (procnode->op != O_SYM) { | |
448 | beginerrmsg(); | |
449 | fprintf(stderr, "can't call \""); | |
450 | prtree(stderr, procnode); | |
451 | fprintf(stderr, "\""); | |
452 | enderrmsg(); | |
453 | } | |
454 | assert(procnode->op == O_SYM); | |
455 | proc = procnode->value.sym; | |
456 | if (not isblock(proc)) { | |
457 | error("\"%s\" is not a procedure or function", symname(proc)); | |
458 | } | |
459 | pushenv(); | |
460 | pc = codeloc(proc); | |
461 | argc = pushargs(proc, arglist); | |
462 | beginproc(proc, argc); | |
463 | isstopped = true; | |
464 | event_once(build(O_EQ, build(O_SYM, pcsym), build(O_SYM, retaddrsym)), | |
465 | buildcmdlist(build(O_PROCRTN, proc))); | |
466 | cont(); | |
467 | /* NOTREACHED */ | |
468 | } | |
469 | ||
470 | /* | |
471 | * Push the arguments on the process' stack. We do this by first | |
472 | * evaluating them on the "eval" stack, then copying into the process' | |
473 | * space. | |
474 | */ | |
475 | ||
476 | private Integer pushargs(proc, arglist) | |
477 | Symbol proc; | |
478 | Node arglist; | |
479 | { | |
480 | Stack *savesp; | |
481 | int argc, args_size; | |
482 | ||
483 | savesp = sp; | |
484 | argc = evalargs(proc, arglist); | |
485 | args_size = sp - savesp; | |
486 | setreg(STKP, reg(STKP) - args_size); | |
487 | dwrite(savesp, reg(STKP), args_size); | |
488 | sp = savesp; | |
489 | return argc; | |
490 | } | |
491 | ||
492 | /* | |
493 | * Evaluate arguments left-to-right. | |
494 | */ | |
495 | ||
496 | private Integer evalargs(proc, arglist) | |
497 | Symbol proc; | |
498 | Node arglist; | |
499 | { | |
500 | Node p, exp; | |
501 | Symbol arg; | |
502 | Stack *savesp; | |
503 | Address addr; | |
504 | Integer count; | |
505 | ||
506 | savesp = sp; | |
507 | count = 0; | |
508 | arg = proc->chain; | |
509 | for (p = arglist; p != nil; p = p->value.arg[1]) { | |
510 | if (p->op != O_COMMA) { | |
511 | panic("evalargs: arglist missing comma"); | |
512 | } | |
513 | if (arg == nil) { | |
514 | sp = savesp; | |
515 | error("too many parameters to %s", symname(proc)); | |
516 | } | |
517 | exp = p->value.arg[0]; | |
518 | if (not compatible(arg->type, exp->nodetype)) { | |
519 | sp = savesp; | |
520 | error("expression for parameter %s is of wrong type", symname(arg)); | |
521 | } | |
522 | if (arg->class == REF) { | |
523 | if (exp->op != O_RVAL) { | |
524 | sp = savesp; | |
525 | error("variable expected for parameter \"%s\"", symname(arg)); | |
526 | } | |
527 | addr = lval(exp->value.arg[0]); | |
528 | push(Address, addr); | |
529 | } else { | |
530 | eval(exp); | |
531 | } | |
532 | arg = arg->chain; | |
533 | ++count; | |
534 | } | |
535 | if (arg != nil) { | |
536 | sp = savesp; | |
537 | error("not enough parameters to %s", symname(proc)); | |
538 | } | |
539 | return count; | |
540 | } | |
541 | ||
542 | public procreturn(f) | |
543 | Symbol f; | |
544 | { | |
545 | flushoutput(); | |
546 | putchar('\n'); | |
547 | printname(stdout, f); | |
548 | printf(" returns successfully\n", symname(f)); | |
549 | popenv(); | |
550 | erecover(); | |
551 | } | |
552 | ||
553 | /* | |
554 | * Push the current environment. | |
555 | */ | |
556 | ||
557 | private pushenv() | |
558 | { | |
559 | push(Address, pc); | |
560 | push(Lineno, curline); | |
561 | push(String, cursource); | |
562 | push(Boolean, isstopped); | |
563 | push(Symbol, curfunc); | |
564 | push(Word, reg(PROGCTR)); | |
565 | push(Word, reg(STKP)); | |
566 | } | |
567 | ||
568 | /* | |
569 | * Pop back to the real world. | |
570 | */ | |
571 | ||
572 | public popenv() | |
573 | { | |
574 | register String filename; | |
575 | ||
576 | setreg(STKP, pop(Word)); | |
577 | setreg(PROGCTR, pop(Word)); | |
578 | curfunc = pop(Symbol); | |
579 | isstopped = pop(Boolean); | |
580 | filename = pop(String); | |
581 | curline = pop(Lineno); | |
582 | pc = pop(Address); | |
583 | setsource(filename); | |
584 | } | |
585 | ||
586 | /* | |
587 | * Flush the debuggee's standard output. | |
588 | * | |
589 | * This is VERY dependent on the use of stdio. | |
590 | */ | |
591 | ||
592 | public flushoutput() | |
593 | { | |
594 | register Symbol p, iob; | |
595 | register Stack *savesp; | |
596 | ||
597 | p = lookup(identname("fflush", true)); | |
598 | while (p != nil and not isblock(p)) { | |
599 | p = p->next_sym; | |
600 | } | |
601 | if (p != nil) { | |
602 | iob = lookup(identname("_iob", true)); | |
603 | if (iob != nil) { | |
604 | pushenv(); | |
605 | pc = codeloc(p); | |
606 | savesp = sp; | |
607 | push(long, address(iob, nil) + sizeof(struct _iobuf)); | |
608 | setreg(STKP, reg(STKP) - sizeof(long)); | |
609 | dwrite(savesp, reg(STKP), sizeof(long)); | |
610 | sp = savesp; | |
611 | beginproc(p, 1); | |
612 | stepto(return_addr()); | |
613 | popenv(); | |
614 | } | |
615 | } | |
616 | } |