| 1 | /* |
| 2 | * Copyright (c) 1985 Regents of the University of California. |
| 3 | * All rights reserved. The Berkeley software License Agreement |
| 4 | * specifies the terms and conditions for redistribution. |
| 5 | */ |
| 6 | |
| 7 | #ifndef lint |
| 8 | static char sccsid[] = "@(#)runtime.tahoe.c 5.3 (Berkeley) %G%"; |
| 9 | #endif not lint |
| 10 | |
| 11 | static char rcsid[] = "$Header: runtime.tahoe.c,v 1.6 88/01/11 21:26:56 donn Exp $"; |
| 12 | |
| 13 | /* |
| 14 | * Runtime organization dependent routines, mostly dealing with |
| 15 | * activation records. |
| 16 | */ |
| 17 | |
| 18 | #include "defs.h" |
| 19 | #include "runtime.h" |
| 20 | #include "process.h" |
| 21 | #include "machine.h" |
| 22 | #include "events.h" |
| 23 | #include "mappings.h" |
| 24 | #include "symbols.h" |
| 25 | #include "tree.h" |
| 26 | #include "eval.h" |
| 27 | #include "operators.h" |
| 28 | #include "object.h" |
| 29 | |
| 30 | #ifndef public |
| 31 | #include "machine.h" |
| 32 | |
| 33 | typedef struct Frame { |
| 34 | Address save_pc; /* program counter */ |
| 35 | integer mask:16; /* register save mask */ |
| 36 | integer removed:16; /* 4*number of arguments + 4 */ |
| 37 | Address save_fp; /* frame pointer */ |
| 38 | #define NSAVEREG 13 |
| 39 | Word save_reg[NSAVEREG]; /* not necessarily there */ |
| 40 | } *Frame; |
| 41 | #endif |
| 42 | |
| 43 | private Frame curframe = nil; |
| 44 | private struct Frame curframerec; |
| 45 | private Boolean walkingstack = false; |
| 46 | |
| 47 | #define frameeq(f1, f2) ((f1)->save_fp == (f2)->save_fp) |
| 48 | |
| 49 | #define inSignalHandler(addr) \ |
| 50 | (((addr) < 0xc0000000) and ((addr) > 0xc0000000 - 0x400 * UPAGES)) |
| 51 | |
| 52 | typedef struct { |
| 53 | Node callnode; |
| 54 | Node cmdnode; |
| 55 | boolean isfunc; |
| 56 | } CallEnv; |
| 57 | |
| 58 | private CallEnv endproc; |
| 59 | |
| 60 | /* |
| 61 | * Set a frame to the current activation record. |
| 62 | */ |
| 63 | |
| 64 | private getcurframe(frp) |
| 65 | Frame frp; |
| 66 | { |
| 67 | register int i; |
| 68 | long x; |
| 69 | |
| 70 | checkref(frp); |
| 71 | frp->save_fp = reg(FRP); |
| 72 | dread(&x, frp->save_fp-4, 4); |
| 73 | frp->mask = x >> 16; |
| 74 | frp->removed = x & 0xffff; |
| 75 | frp->save_pc = reg(PROGCTR); |
| 76 | for (i = 0; i < NSAVEREG; i++) { |
| 77 | frp->save_reg[i] = reg(i); |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | /* |
| 82 | * Get the saved registers from one frame to another |
| 83 | * given mask specifying which registers were actually saved. |
| 84 | */ |
| 85 | |
| 86 | #define bis(b, n) ((b & (1 << (n))) != 0) |
| 87 | |
| 88 | private getsaveregs (newfrp, frp, mask) |
| 89 | Frame newfrp, frp; |
| 90 | integer mask; |
| 91 | { |
| 92 | integer i, j; |
| 93 | |
| 94 | j = 0; |
| 95 | for (i = 0; i < NSAVEREG; i++) { |
| 96 | if (bis(mask, i)) { |
| 97 | newfrp->save_reg[i] = frp->save_reg[j]; |
| 98 | ++j; |
| 99 | } |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /* |
| 104 | * Return a pointer to the next activation record up the stack. |
| 105 | * Return nil if there is none. |
| 106 | * Writes over space pointed to by given argument. |
| 107 | */ |
| 108 | |
| 109 | private Frame nextframe(frp) |
| 110 | Frame frp; |
| 111 | { |
| 112 | Frame newfrp; |
| 113 | struct Frame frame; |
| 114 | long x; |
| 115 | Address prev_frame, callpc; |
| 116 | static integer ntramp = 0; |
| 117 | |
| 118 | newfrp = frp; |
| 119 | prev_frame = frp->save_fp; |
| 120 | |
| 121 | /* |
| 122 | * The check for interrupt generated frames is taken from adb with only |
| 123 | * partial understanding. If you're in "sub" and on a sigxxx "sigsub" |
| 124 | * gets control, then the stack does NOT look like <main, sub, sigsub>. |
| 125 | * |
| 126 | * As best I can make out it looks like: |
| 127 | * |
| 128 | * <main, (machine check exception block + sub), sysframe, sigsub>. |
| 129 | * |
| 130 | * When the signal occurs an exception block and a frame for the routine |
| 131 | * in which it occured are pushed on the user stack. Then another frame |
| 132 | * is pushed corresponding to a call from the kernel to sigsub. |
| 133 | * |
| 134 | * The addr in sub at which the exception occured is not in sub.save_pc |
| 135 | * but in the machine check exception block. It is at the magic address |
| 136 | * fp + 84. |
| 137 | * |
| 138 | * The current approach ignores the sys_frame (what adb reports as sigtramp) |
| 139 | * and takes the pc for sub from the exception block. This allows the |
| 140 | * "where" command to report <main, sub, sigsub>, which seems reasonable. |
| 141 | */ |
| 142 | |
| 143 | nextf: |
| 144 | dread(&frame, prev_frame-8, sizeof(struct Frame)); |
| 145 | if (ntramp == 1) { |
| 146 | dread(&callpc, prev_frame+44, sizeof(callpc)); |
| 147 | } else { |
| 148 | callpc = frame.save_pc; |
| 149 | } |
| 150 | if (frame.save_fp == nil or frame.save_pc == (Address) -1) { |
| 151 | newfrp = nil; |
| 152 | } else if (inSignalHandler(callpc)) { |
| 153 | ntramp++; |
| 154 | prev_frame = frame.save_fp; |
| 155 | goto nextf; |
| 156 | } else { |
| 157 | ntramp = 0; |
| 158 | getsaveregs(newfrp, &frame, frame.mask); |
| 159 | dread(&x, frame.save_fp-4, sizeof (x)); |
| 160 | newfrp->mask = x >> 16; |
| 161 | newfrp->removed = x & 0xffff; |
| 162 | newfrp->save_fp = frame.save_fp; |
| 163 | newfrp->save_pc = callpc; |
| 164 | } |
| 165 | return newfrp; |
| 166 | } |
| 167 | |
| 168 | /* |
| 169 | * Get the current frame information in the given Frame and store the |
| 170 | * associated function in the given value-result parameter. |
| 171 | */ |
| 172 | |
| 173 | private getcurfunc (frp, fp) |
| 174 | Frame frp; |
| 175 | Symbol *fp; |
| 176 | { |
| 177 | getcurframe(frp); |
| 178 | *fp = whatblock(frp->save_pc); |
| 179 | } |
| 180 | |
| 181 | /* |
| 182 | * Return the frame associated with the next function up the call stack, or |
| 183 | * nil if there is none. The function is returned in a value-result parameter. |
| 184 | * For "inline" functions the statically outer function and same frame |
| 185 | * are returned. |
| 186 | */ |
| 187 | |
| 188 | public Frame nextfunc (frp, fp) |
| 189 | Frame frp; |
| 190 | Symbol *fp; |
| 191 | { |
| 192 | Symbol t; |
| 193 | Frame nfrp; |
| 194 | |
| 195 | t = *fp; |
| 196 | checkref(t); |
| 197 | if (isinline(t)) { |
| 198 | t = container(t); |
| 199 | nfrp = frp; |
| 200 | } else { |
| 201 | nfrp = nextframe(frp); |
| 202 | if (nfrp == nil) { |
| 203 | t = nil; |
| 204 | } else { |
| 205 | t = whatblock(nfrp->save_pc); |
| 206 | } |
| 207 | } |
| 208 | *fp = t; |
| 209 | return nfrp; |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * Return the frame associated with the given function. |
| 214 | * If the function is nil, return the most recently activated frame. |
| 215 | * |
| 216 | * Static allocation for the frame. |
| 217 | */ |
| 218 | |
| 219 | public Frame findframe(f) |
| 220 | Symbol f; |
| 221 | { |
| 222 | Frame frp; |
| 223 | static struct Frame frame; |
| 224 | Symbol p; |
| 225 | Boolean done; |
| 226 | |
| 227 | frp = &frame; |
| 228 | getcurframe(frp); |
| 229 | if (f != nil) { |
| 230 | if (f == curfunc and curframe != nil) { |
| 231 | *frp = *curframe; |
| 232 | } else { |
| 233 | done = false; |
| 234 | p = whatblock(frp->save_pc); |
| 235 | do { |
| 236 | if (p == f) { |
| 237 | done = true; |
| 238 | } else if (p == program) { |
| 239 | done = true; |
| 240 | frp = nil; |
| 241 | } else { |
| 242 | frp = nextfunc(frp, &p); |
| 243 | if (frp == nil) { |
| 244 | done = true; |
| 245 | } |
| 246 | } |
| 247 | } while (not done); |
| 248 | } |
| 249 | } |
| 250 | return frp; |
| 251 | } |
| 252 | |
| 253 | /* |
| 254 | * Set the registers according to the given frame pointer. |
| 255 | */ |
| 256 | |
| 257 | public getnewregs (addr) |
| 258 | Address addr; |
| 259 | { |
| 260 | struct Frame frame; |
| 261 | integer i, j, mask; |
| 262 | |
| 263 | dread(&frame, addr-8, sizeof(frame)); |
| 264 | setreg(FRP, frame.save_fp); |
| 265 | setreg(PROGCTR, frame.save_pc); |
| 266 | mask = frame.mask; |
| 267 | j = 0; |
| 268 | for (i = 0; i < NSAVEREG; i++) { |
| 269 | if (bis(mask, i)) { |
| 270 | setreg(i, frame.save_reg[j]); |
| 271 | ++j; |
| 272 | } |
| 273 | } |
| 274 | pc = frame.save_pc; |
| 275 | setcurfunc(whatblock(pc)); |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Find the return address of the current procedure/function. |
| 280 | */ |
| 281 | |
| 282 | public Address return_addr() |
| 283 | { |
| 284 | Frame frp; |
| 285 | Address addr; |
| 286 | struct Frame frame; |
| 287 | |
| 288 | frp = &frame; |
| 289 | getcurframe(frp); |
| 290 | frp = nextframe(frp); |
| 291 | if (frp == nil) { |
| 292 | addr = 0; |
| 293 | } else { |
| 294 | addr = frp->save_pc; |
| 295 | } |
| 296 | return addr; |
| 297 | } |
| 298 | |
| 299 | /* |
| 300 | * Push the value associated with the current function. |
| 301 | */ |
| 302 | |
| 303 | public pushretval(len, isindirect) |
| 304 | integer len; |
| 305 | boolean isindirect; |
| 306 | { |
| 307 | Word r0; |
| 308 | |
| 309 | r0 = reg(0); |
| 310 | if (isindirect) { |
| 311 | rpush((Address) r0, len); |
| 312 | } else { |
| 313 | switch (len) { |
| 314 | case sizeof(char): |
| 315 | push(char, r0); |
| 316 | break; |
| 317 | |
| 318 | case sizeof(short): |
| 319 | push(short, r0); |
| 320 | break; |
| 321 | |
| 322 | default: |
| 323 | if (len == sizeof(Word)) { |
| 324 | push(Word, r0); |
| 325 | } else if (len == 2*sizeof(Word)) { |
| 326 | push(Word, r0); |
| 327 | push(Word, reg(1)); |
| 328 | } else { |
| 329 | error("[internal error: bad size %d in pushretval]", len); |
| 330 | } |
| 331 | break; |
| 332 | } |
| 333 | } |
| 334 | } |
| 335 | |
| 336 | /* |
| 337 | * Return the base address for locals in the given frame. |
| 338 | */ |
| 339 | |
| 340 | public Address locals_base(frp) |
| 341 | Frame frp; |
| 342 | { |
| 343 | return (frp == nil ? reg(FRP) : frp->save_fp); |
| 344 | } |
| 345 | |
| 346 | /* |
| 347 | * Return the base address for arguments in the given frame. |
| 348 | */ |
| 349 | |
| 350 | public Address args_base(frp) |
| 351 | Frame frp; |
| 352 | { |
| 353 | return (frp == nil ? reg(FRP) : frp->save_fp); |
| 354 | } |
| 355 | |
| 356 | /* |
| 357 | * Return saved register n from the given frame. |
| 358 | */ |
| 359 | |
| 360 | public Word savereg(n, frp) |
| 361 | integer n; |
| 362 | Frame frp; |
| 363 | { |
| 364 | Word w; |
| 365 | |
| 366 | if (frp == nil) { |
| 367 | w = reg(n); |
| 368 | } else { |
| 369 | switch (n) { |
| 370 | |
| 371 | case FRP: |
| 372 | w = frp->save_fp; |
| 373 | break; |
| 374 | |
| 375 | case STKP: |
| 376 | w = reg(STKP); |
| 377 | break; |
| 378 | |
| 379 | case PROGCTR: |
| 380 | w = frp->save_pc; |
| 381 | break; |
| 382 | |
| 383 | default: |
| 384 | assert(n >= 0 and n < NSAVEREG); |
| 385 | w = frp->save_reg[n]; |
| 386 | break; |
| 387 | } |
| 388 | } |
| 389 | return w; |
| 390 | } |
| 391 | |
| 392 | /* |
| 393 | * Return the nth argument to the current procedure. |
| 394 | */ |
| 395 | |
| 396 | public Word argn(n, frp) |
| 397 | integer n; |
| 398 | Frame frp; |
| 399 | { |
| 400 | Address argaddr; |
| 401 | Word w; |
| 402 | |
| 403 | argaddr = args_base(frp) + (n * sizeof(Word)); |
| 404 | dread(&w, argaddr, sizeof(w)); |
| 405 | return w; |
| 406 | } |
| 407 | |
| 408 | /* |
| 409 | * Print a list of currently active blocks starting with most recent. |
| 410 | */ |
| 411 | |
| 412 | public wherecmd() |
| 413 | { |
| 414 | walkstack(false); |
| 415 | } |
| 416 | |
| 417 | /* |
| 418 | * Print the variables in the given frame or the current one if nil. |
| 419 | */ |
| 420 | |
| 421 | public dump (func) |
| 422 | Symbol func; |
| 423 | { |
| 424 | Symbol f; |
| 425 | Frame frp; |
| 426 | |
| 427 | if (func == nil) { |
| 428 | f = curfunc; |
| 429 | if (curframe != nil) { |
| 430 | frp = curframe; |
| 431 | } else { |
| 432 | frp = findframe(f); |
| 433 | } |
| 434 | } else { |
| 435 | f = func; |
| 436 | frp = findframe(f); |
| 437 | } |
| 438 | showaggrs = true; |
| 439 | printcallinfo(f, frp); |
| 440 | dumpvars(f, frp); |
| 441 | } |
| 442 | |
| 443 | /* |
| 444 | * Dump all values. |
| 445 | */ |
| 446 | |
| 447 | public dumpall () |
| 448 | { |
| 449 | walkstack(true); |
| 450 | } |
| 451 | |
| 452 | /* |
| 453 | * Walk the stack of active procedures printing information |
| 454 | * about each active procedure. |
| 455 | */ |
| 456 | |
| 457 | private walkstack(dumpvariables) |
| 458 | Boolean dumpvariables; |
| 459 | { |
| 460 | Frame frp; |
| 461 | boolean save; |
| 462 | Symbol f; |
| 463 | struct Frame frame; |
| 464 | |
| 465 | if (notstarted(process) or isfinished(process)) { |
| 466 | error("program is not active"); |
| 467 | } else { |
| 468 | save = walkingstack; |
| 469 | walkingstack = true; |
| 470 | showaggrs = dumpvariables; |
| 471 | frp = &frame; |
| 472 | getcurfunc(frp, &f); |
| 473 | for (;;) { |
| 474 | printcallinfo(f, frp); |
| 475 | if (dumpvariables) { |
| 476 | dumpvars(f, frp); |
| 477 | putchar('\n'); |
| 478 | } |
| 479 | frp = nextfunc(frp, &f); |
| 480 | if (frp == nil or f == program) { |
| 481 | break; |
| 482 | } |
| 483 | } |
| 484 | if (dumpvariables) { |
| 485 | printf("in \"%s\":\n", symname(program)); |
| 486 | dumpvars(program, nil); |
| 487 | putchar('\n'); |
| 488 | } |
| 489 | walkingstack = save; |
| 490 | } |
| 491 | } |
| 492 | |
| 493 | /* |
| 494 | * Print out the information about a call, i.e., |
| 495 | * routine name, parameter values, and source location. |
| 496 | */ |
| 497 | |
| 498 | private printcallinfo (f, frp) |
| 499 | Symbol f; |
| 500 | Frame frp; |
| 501 | { |
| 502 | Lineno line; |
| 503 | Address savepc; |
| 504 | |
| 505 | savepc = frp->save_pc; |
| 506 | if (frp->save_fp != reg(FRP)) { |
| 507 | savepc -= 1; |
| 508 | } |
| 509 | printname(stdout, f); |
| 510 | if (not isinline(f)) { |
| 511 | printparams(f, frp); |
| 512 | } |
| 513 | line = srcline(savepc); |
| 514 | if (line != 0) { |
| 515 | printf(", line %d", line); |
| 516 | printf(" in \"%s\"\n", srcfilename(savepc)); |
| 517 | } else { |
| 518 | printf(" at 0x%x\n", savepc); |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | /* |
| 523 | * Set the current function to the given symbol. |
| 524 | * We must adjust "curframe" so that subsequent operations are |
| 525 | * not confused; for simplicity we simply clear it. |
| 526 | */ |
| 527 | |
| 528 | public setcurfunc (f) |
| 529 | Symbol f; |
| 530 | { |
| 531 | curfunc = f; |
| 532 | curframe = nil; |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * Return the frame for the current function. |
| 537 | * The space for the frame is allocated statically. |
| 538 | */ |
| 539 | |
| 540 | public Frame curfuncframe () |
| 541 | { |
| 542 | static struct Frame frame; |
| 543 | Frame frp; |
| 544 | |
| 545 | if (curframe == nil) { |
| 546 | frp = findframe(curfunc); |
| 547 | curframe = &curframerec; |
| 548 | *curframe = *frp; |
| 549 | } else { |
| 550 | frp = &frame; |
| 551 | *frp = *curframe; |
| 552 | } |
| 553 | return frp; |
| 554 | } |
| 555 | |
| 556 | /* |
| 557 | * Set curfunc to be N up/down the stack from its current value. |
| 558 | */ |
| 559 | |
| 560 | public up (n) |
| 561 | integer n; |
| 562 | { |
| 563 | integer i; |
| 564 | Symbol f; |
| 565 | Frame frp; |
| 566 | boolean done; |
| 567 | |
| 568 | if (not isactive(program)) { |
| 569 | error("program is not active"); |
| 570 | } else if (curfunc == nil) { |
| 571 | error("no current function"); |
| 572 | } else { |
| 573 | i = 0; |
| 574 | f = curfunc; |
| 575 | frp = curfuncframe(); |
| 576 | done = false; |
| 577 | do { |
| 578 | if (frp == nil) { |
| 579 | done = true; |
| 580 | error("not that many levels"); |
| 581 | } else if (i >= n) { |
| 582 | done = true; |
| 583 | curfunc = f; |
| 584 | curframe = &curframerec; |
| 585 | *curframe = *frp; |
| 586 | showaggrs = false; |
| 587 | printcallinfo(curfunc, curframe); |
| 588 | } else if (f == program) { |
| 589 | done = true; |
| 590 | error("not that many levels"); |
| 591 | } else { |
| 592 | frp = nextfunc(frp, &f); |
| 593 | } |
| 594 | ++i; |
| 595 | } while (not done); |
| 596 | } |
| 597 | } |
| 598 | |
| 599 | public down (n) |
| 600 | integer n; |
| 601 | { |
| 602 | integer i, depth; |
| 603 | Frame frp, curfrp; |
| 604 | Symbol f; |
| 605 | struct Frame frame; |
| 606 | |
| 607 | if (not isactive(program)) { |
| 608 | error("program is not active"); |
| 609 | } else if (curfunc == nil) { |
| 610 | error("no current function"); |
| 611 | } else { |
| 612 | depth = 0; |
| 613 | frp = &frame; |
| 614 | getcurfunc(frp, &f); |
| 615 | if (curframe == nil) { |
| 616 | curfrp = findframe(curfunc); |
| 617 | curframe = &curframerec; |
| 618 | *curframe = *curfrp; |
| 619 | } |
| 620 | while ((f != curfunc or !frameeq(frp, curframe)) and f != nil) { |
| 621 | frp = nextfunc(frp, &f); |
| 622 | ++depth; |
| 623 | } |
| 624 | if (f == nil or n > depth) { |
| 625 | error("not that many levels"); |
| 626 | } else { |
| 627 | depth -= n; |
| 628 | frp = &frame; |
| 629 | getcurfunc(frp, &f); |
| 630 | for (i = 0; i < depth; i++) { |
| 631 | frp = nextfunc(frp, &f); |
| 632 | assert(frp != nil); |
| 633 | } |
| 634 | curfunc = f; |
| 635 | *curframe = *frp; |
| 636 | showaggrs = false; |
| 637 | printcallinfo(curfunc, curframe); |
| 638 | } |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | /* |
| 643 | * Find the entry point of a procedure or function. |
| 644 | */ |
| 645 | |
| 646 | public findbeginning (f) |
| 647 | Symbol f; |
| 648 | { |
| 649 | if (isinternal(f)) { |
| 650 | f->symvalue.funcv.beginaddr += 15; |
| 651 | } else { |
| 652 | f->symvalue.funcv.beginaddr += FUNCOFFSET; |
| 653 | } |
| 654 | } |
| 655 | |
| 656 | /* |
| 657 | * Return the address corresponding to the first line in a function. |
| 658 | */ |
| 659 | |
| 660 | public Address firstline(f) |
| 661 | Symbol f; |
| 662 | { |
| 663 | Address addr; |
| 664 | |
| 665 | addr = codeloc(f); |
| 666 | while (linelookup(addr) == 0 and addr < objsize) { |
| 667 | ++addr; |
| 668 | } |
| 669 | if (addr == objsize) { |
| 670 | addr = -1; |
| 671 | } |
| 672 | return addr; |
| 673 | } |
| 674 | |
| 675 | /* |
| 676 | * Catcher drops strike three ... |
| 677 | */ |
| 678 | |
| 679 | public runtofirst() |
| 680 | { |
| 681 | Address addr, endaddr; |
| 682 | |
| 683 | addr = pc; |
| 684 | endaddr = objsize + CODESTART; |
| 685 | while (linelookup(addr) == 0 and addr < endaddr) { |
| 686 | ++addr; |
| 687 | } |
| 688 | if (addr < endaddr) { |
| 689 | stepto(addr); |
| 690 | } |
| 691 | } |
| 692 | |
| 693 | /* |
| 694 | * Return the address corresponding to the end of the program. |
| 695 | * |
| 696 | * We look for the entry to "exit". |
| 697 | */ |
| 698 | |
| 699 | public Address lastaddr() |
| 700 | { |
| 701 | Symbol s; |
| 702 | |
| 703 | s = lookup(identname("exit", true)); |
| 704 | if (s == nil) { |
| 705 | panic("can't find exit"); |
| 706 | } |
| 707 | return codeloc(s); |
| 708 | } |
| 709 | |
| 710 | /* |
| 711 | * Decide if the given function is currently active. |
| 712 | * |
| 713 | * We avoid calls to "findframe" during a stack trace for efficiency. |
| 714 | * Presumably information evaluated while walking the stack is active. |
| 715 | */ |
| 716 | |
| 717 | public Boolean isactive (f) |
| 718 | Symbol f; |
| 719 | { |
| 720 | Boolean b; |
| 721 | |
| 722 | if (isfinished(process)) { |
| 723 | b = false; |
| 724 | } else { |
| 725 | if (walkingstack or f == program or f == nil or |
| 726 | (ismodule(f) and isactive(container(f)))) { |
| 727 | b = true; |
| 728 | } else { |
| 729 | b = (Boolean) (findframe(f) != nil); |
| 730 | } |
| 731 | } |
| 732 | return b; |
| 733 | } |
| 734 | |
| 735 | /* |
| 736 | * Evaluate a call to a procedure. |
| 737 | */ |
| 738 | |
| 739 | public callproc(exprnode, isfunc) |
| 740 | Node exprnode; |
| 741 | boolean isfunc; |
| 742 | { |
| 743 | Node procnode, arglist; |
| 744 | Symbol proc; |
| 745 | integer argc; |
| 746 | |
| 747 | procnode = exprnode->value.arg[0]; |
| 748 | arglist = exprnode->value.arg[1]; |
| 749 | if (procnode->op != O_SYM) { |
| 750 | beginerrmsg(); |
| 751 | fprintf(stderr, "can't call \""); |
| 752 | prtree(stderr, procnode); |
| 753 | fprintf(stderr, "\""); |
| 754 | enderrmsg(); |
| 755 | } |
| 756 | assert(procnode->op == O_SYM); |
| 757 | proc = procnode->value.sym; |
| 758 | if (not isblock(proc)) { |
| 759 | error("\"%s\" is not a procedure or function", symname(proc)); |
| 760 | } |
| 761 | endproc.isfunc = isfunc; |
| 762 | endproc.callnode = exprnode; |
| 763 | endproc.cmdnode = topnode; |
| 764 | pushenv(); |
| 765 | pc = codeloc(proc); |
| 766 | argc = pushargs(proc, arglist); |
| 767 | setreg(FRP, 1); /* have to ensure it's non-zero for return_addr() */ |
| 768 | beginproc(proc, argc); |
| 769 | event_once( |
| 770 | build(O_EQ, build(O_SYM, pcsym), build(O_SYM, retaddrsym)), |
| 771 | buildcmdlist(build(O_PROCRTN, proc)) |
| 772 | ); |
| 773 | isstopped = false; |
| 774 | if (not bpact()) { |
| 775 | isstopped = true; |
| 776 | cont(0); |
| 777 | } |
| 778 | /* |
| 779 | * bpact() won't return true, it will call printstatus() and go back |
| 780 | * to command input if a breakpoint is found. |
| 781 | */ |
| 782 | /* NOTREACHED */ |
| 783 | } |
| 784 | |
| 785 | /* |
| 786 | * Push the arguments on the process' stack. We do this by first |
| 787 | * evaluating them on the "eval" stack, then copying into the process' |
| 788 | * space. |
| 789 | */ |
| 790 | |
| 791 | private integer pushargs(proc, arglist) |
| 792 | Symbol proc; |
| 793 | Node arglist; |
| 794 | { |
| 795 | Stack *savesp; |
| 796 | int argc, args_size; |
| 797 | |
| 798 | savesp = sp; |
| 799 | argc = evalargs(proc, arglist); |
| 800 | args_size = sp - savesp; |
| 801 | setreg(STKP, reg(STKP) - args_size); |
| 802 | dwrite(savesp, reg(STKP), args_size); |
| 803 | sp = savesp; |
| 804 | return argc; |
| 805 | } |
| 806 | |
| 807 | /* |
| 808 | * Check to see if an expression is correct for a given parameter. |
| 809 | * If the given parameter is false, don't worry about type inconsistencies. |
| 810 | * |
| 811 | * Return whether or not it is ok. |
| 812 | */ |
| 813 | |
| 814 | private boolean chkparam (actual, formal, chk) |
| 815 | Node actual; |
| 816 | Symbol formal; |
| 817 | boolean chk; |
| 818 | { |
| 819 | boolean b; |
| 820 | |
| 821 | b = true; |
| 822 | if (chk) { |
| 823 | if (formal == nil) { |
| 824 | beginerrmsg(); |
| 825 | fprintf(stderr, "too many parameters"); |
| 826 | b = false; |
| 827 | } else if (not compatible(formal->type, actual->nodetype)) { |
| 828 | beginerrmsg(); |
| 829 | fprintf(stderr, "type mismatch for %s", symname(formal)); |
| 830 | b = false; |
| 831 | } |
| 832 | } |
| 833 | if (b and formal != nil and |
| 834 | isvarparam(formal) and not isopenarray(formal->type) and |
| 835 | not ( |
| 836 | actual->op == O_RVAL or actual->nodetype == t_addr or |
| 837 | ( |
| 838 | actual->op == O_TYPERENAME and |
| 839 | ( |
| 840 | actual->value.arg[0]->op == O_RVAL or |
| 841 | actual->value.arg[0]->nodetype == t_addr |
| 842 | ) |
| 843 | ) |
| 844 | ) |
| 845 | ) { |
| 846 | beginerrmsg(); |
| 847 | fprintf(stderr, "expected variable, found \""); |
| 848 | prtree(stderr, actual); |
| 849 | fprintf(stderr, "\""); |
| 850 | b = false; |
| 851 | } |
| 852 | return b; |
| 853 | } |
| 854 | |
| 855 | /* |
| 856 | * Pass an expression to a particular parameter. |
| 857 | * |
| 858 | * Normally we pass either the address or value, but in some cases |
| 859 | * (such as C strings) we want to copy the value onto the stack and |
| 860 | * pass its address. |
| 861 | * |
| 862 | * Another special case raised by strings is the possibility that |
| 863 | * the actual parameter will be larger than the formal, even with |
| 864 | * appropriate type-checking. This occurs because we assume during |
| 865 | * evaluation that strings are null-terminated, whereas some languages, |
| 866 | * notably Pascal, do not work under that assumption. |
| 867 | */ |
| 868 | |
| 869 | private passparam (actual, formal) |
| 870 | Node actual; |
| 871 | Symbol formal; |
| 872 | { |
| 873 | boolean b; |
| 874 | Address addr; |
| 875 | Stack *savesp; |
| 876 | integer actsize, formsize; |
| 877 | |
| 878 | if (formal != nil and isvarparam(formal) and |
| 879 | (not isopenarray(formal->type)) |
| 880 | ) { |
| 881 | addr = lval(actual->value.arg[0]); |
| 882 | push(Address, addr); |
| 883 | } else if (passaddr(formal, actual->nodetype)) { |
| 884 | savesp = sp; |
| 885 | eval(actual); |
| 886 | actsize = sp - savesp; |
| 887 | setreg(STKP, reg(STKP) - roundup(actsize, sizeof (Word))); |
| 888 | dwrite(savesp, reg(STKP), actsize); |
| 889 | sp = savesp; |
| 890 | push(Address, reg(STKP)); |
| 891 | if (formal != nil and isopenarray(formal->type)) { |
| 892 | push(integer, actsize div size(formal->type->type)); |
| 893 | } |
| 894 | } else if (formal != nil) { |
| 895 | formsize = size(formal); |
| 896 | savesp = sp; |
| 897 | eval(actual); |
| 898 | actsize = sp - savesp; |
| 899 | if (actsize > formsize) { |
| 900 | sp -= (actsize - formsize); |
| 901 | } |
| 902 | } else { |
| 903 | eval(actual); |
| 904 | } |
| 905 | } |
| 906 | |
| 907 | /* |
| 908 | * Evaluate an argument list left-to-right. |
| 909 | */ |
| 910 | |
| 911 | private integer evalargs(proc, arglist) |
| 912 | Symbol proc; |
| 913 | Node arglist; |
| 914 | { |
| 915 | Node p, actual; |
| 916 | Symbol formal; |
| 917 | Stack *savesp; |
| 918 | integer count; |
| 919 | boolean chk; |
| 920 | |
| 921 | savesp = sp; |
| 922 | count = 0; |
| 923 | formal = proc->chain; |
| 924 | chk = (boolean) (not nosource(proc)); |
| 925 | for (p = arglist; p != nil; p = p->value.arg[1]) { |
| 926 | assert(p->op == O_COMMA); |
| 927 | actual = p->value.arg[0]; |
| 928 | if (not chkparam(actual, formal, chk)) { |
| 929 | fprintf(stderr, " in call to %s", symname(proc)); |
| 930 | sp = savesp; |
| 931 | enderrmsg(); |
| 932 | } |
| 933 | passparam(actual, formal); |
| 934 | if (formal != nil) { |
| 935 | formal = formal->chain; |
| 936 | } |
| 937 | ++count; |
| 938 | } |
| 939 | if (chk) { |
| 940 | if (formal != nil) { |
| 941 | sp = savesp; |
| 942 | error("not enough parameters to %s", symname(proc)); |
| 943 | } |
| 944 | } |
| 945 | return count; |
| 946 | } |
| 947 | |
| 948 | /* |
| 949 | * Evaluate an argument list without any type checking. |
| 950 | * This is only useful for procedures with a varying number of |
| 951 | * arguments that are compiled -g. |
| 952 | */ |
| 953 | |
| 954 | private integer unsafe_evalargs (proc, arglist) |
| 955 | Symbol proc; |
| 956 | Node arglist; |
| 957 | { |
| 958 | Node p; |
| 959 | integer count; |
| 960 | |
| 961 | count = 0; |
| 962 | for (p = arglist; p != nil; p = p->value.arg[1]) { |
| 963 | assert(p->op == O_COMMA); |
| 964 | eval(p->value.arg[0]); |
| 965 | ++count; |
| 966 | } |
| 967 | return count; |
| 968 | } |
| 969 | |
| 970 | public procreturn(f) |
| 971 | Symbol f; |
| 972 | { |
| 973 | integer retvalsize; |
| 974 | Node tmp; |
| 975 | char *copy; |
| 976 | |
| 977 | flushoutput(); |
| 978 | popenv(); |
| 979 | if (endproc.isfunc) { |
| 980 | retvalsize = size(f->type); |
| 981 | if (retvalsize > sizeof(long)) { |
| 982 | pushretval(retvalsize, true); |
| 983 | copy = newarr(char, retvalsize); |
| 984 | popn(retvalsize, copy); |
| 985 | tmp = build(O_SCON, copy); |
| 986 | } else { |
| 987 | tmp = build(O_LCON, (long) (reg(0))); |
| 988 | } |
| 989 | tmp->nodetype = f->type; |
| 990 | tfree(endproc.callnode); |
| 991 | *(endproc.callnode) = *(tmp); |
| 992 | dispose(tmp); |
| 993 | eval(endproc.cmdnode); |
| 994 | } else { |
| 995 | putchar('\n'); |
| 996 | printname(stdout, f); |
| 997 | printf(" returns successfully\n"); |
| 998 | } |
| 999 | erecover(); |
| 1000 | } |
| 1001 | |
| 1002 | /* |
| 1003 | * Push the current environment. |
| 1004 | */ |
| 1005 | |
| 1006 | private pushenv() |
| 1007 | { |
| 1008 | push(Address, pc); |
| 1009 | push(Lineno, curline); |
| 1010 | push(String, cursource); |
| 1011 | push(Boolean, isstopped); |
| 1012 | push(Symbol, curfunc); |
| 1013 | push(Frame, curframe); |
| 1014 | push(struct Frame, curframerec); |
| 1015 | push(CallEnv, endproc); |
| 1016 | push(Word, reg(PROGCTR)); |
| 1017 | push(Word, reg(STKP)); |
| 1018 | } |
| 1019 | |
| 1020 | /* |
| 1021 | * Pop back to the real world. |
| 1022 | */ |
| 1023 | |
| 1024 | public popenv() |
| 1025 | { |
| 1026 | String filename; |
| 1027 | |
| 1028 | setreg(STKP, pop(Word)); |
| 1029 | setreg(PROGCTR, pop(Word)); |
| 1030 | endproc = pop(CallEnv); |
| 1031 | curframerec = pop(struct Frame); |
| 1032 | curframe = pop(Frame); |
| 1033 | curfunc = pop(Symbol); |
| 1034 | isstopped = pop(Boolean); |
| 1035 | filename = pop(String); |
| 1036 | curline = pop(Lineno); |
| 1037 | pc = pop(Address); |
| 1038 | setsource(filename); |
| 1039 | } |
| 1040 | |
| 1041 | /* |
| 1042 | * Flush the debuggee's standard output. |
| 1043 | * |
| 1044 | * This is VERY dependent on the use of stdio. |
| 1045 | */ |
| 1046 | |
| 1047 | public flushoutput() |
| 1048 | { |
| 1049 | Symbol p, iob; |
| 1050 | Stack *savesp; |
| 1051 | |
| 1052 | p = lookup(identname("fflush", true)); |
| 1053 | while (p != nil and not isblock(p)) { |
| 1054 | p = p->next_sym; |
| 1055 | } |
| 1056 | if (p != nil) { |
| 1057 | iob = lookup(identname("_iob", true)); |
| 1058 | if (iob != nil) { |
| 1059 | pushenv(); |
| 1060 | pc = codeloc(p); |
| 1061 | savesp = sp; |
| 1062 | push(long, address(iob, nil) + sizeof(struct _iobuf)); |
| 1063 | setreg(STKP, reg(STKP) - sizeof(long)); |
| 1064 | dwrite(savesp, reg(STKP), sizeof(long)); |
| 1065 | sp = savesp; |
| 1066 | beginproc(p, 1); |
| 1067 | stepto(return_addr()); |
| 1068 | popenv(); |
| 1069 | } |
| 1070 | } |
| 1071 | } |