| 1 | /* Copyright (c) 1982 Regents of the University of California */ |
| 2 | |
| 3 | static char sccsid[] = "@(#)eval.c 1.10 %G%"; |
| 4 | |
| 5 | /* |
| 6 | * Tree evaluation. |
| 7 | */ |
| 8 | |
| 9 | #include "defs.h" |
| 10 | #include "tree.h" |
| 11 | #include "operators.h" |
| 12 | #include "eval.h" |
| 13 | #include "events.h" |
| 14 | #include "symbols.h" |
| 15 | #include "scanner.h" |
| 16 | #include "source.h" |
| 17 | #include "object.h" |
| 18 | #include "mappings.h" |
| 19 | #include "process.h" |
| 20 | #include "machine.h" |
| 21 | #include <signal.h> |
| 22 | |
| 23 | #ifndef public |
| 24 | |
| 25 | #include "machine.h" |
| 26 | |
| 27 | #define STACKSIZE 20000 |
| 28 | |
| 29 | typedef Char Stack; |
| 30 | |
| 31 | #define push(type, value) { \ |
| 32 | ((type *) (sp += sizeof(type)))[-1] = (value); \ |
| 33 | } |
| 34 | |
| 35 | #define pop(type) ( \ |
| 36 | (*((type *) (sp -= sizeof(type)))) \ |
| 37 | ) |
| 38 | |
| 39 | #define alignstack() { \ |
| 40 | sp = (Stack *) (( ((int) sp) + sizeof(int) - 1)&~(sizeof(int) - 1)); \ |
| 41 | } |
| 42 | |
| 43 | #endif |
| 44 | |
| 45 | public Stack stack[STACKSIZE]; |
| 46 | public Stack *sp = &stack[0]; |
| 47 | public Boolean useInstLoc = false; |
| 48 | |
| 49 | #define chksp() \ |
| 50 | { \ |
| 51 | if (sp < &stack[0]) { \ |
| 52 | panic("stack underflow"); \ |
| 53 | } \ |
| 54 | } |
| 55 | |
| 56 | #define poparg(n, r, fr) { \ |
| 57 | eval(p->value.arg[n]); \ |
| 58 | if (isreal(p->op)) { \ |
| 59 | fr = pop(double); \ |
| 60 | } else if (isint(p->op)) { \ |
| 61 | r = popsmall(p->value.arg[n]->nodetype); \ |
| 62 | } \ |
| 63 | } |
| 64 | |
| 65 | #define Boolrep char /* underlying representation type for booleans */ |
| 66 | |
| 67 | /* |
| 68 | * Evaluate a parse tree leaving the value on the top of the stack. |
| 69 | */ |
| 70 | |
| 71 | public eval(p) |
| 72 | register Node p; |
| 73 | { |
| 74 | long r0, r1; |
| 75 | double fr0, fr1; |
| 76 | Address addr; |
| 77 | long i, n; |
| 78 | int len; |
| 79 | Symbol s, f; |
| 80 | Node n1, n2; |
| 81 | Boolean b; |
| 82 | File file; |
| 83 | |
| 84 | checkref(p); |
| 85 | if (debug_flag[2]) { |
| 86 | fprintf(stderr," evaluating %s \n",showoperator(p->op)); |
| 87 | } |
| 88 | switch (degree(p->op)) { |
| 89 | case BINARY: |
| 90 | poparg(1, r1, fr1); |
| 91 | poparg(0, r0, fr0); |
| 92 | break; |
| 93 | |
| 94 | case UNARY: |
| 95 | poparg(0, r0, fr0); |
| 96 | break; |
| 97 | |
| 98 | default: |
| 99 | /* do nothing */; |
| 100 | } |
| 101 | switch (p->op) { |
| 102 | case O_SYM: |
| 103 | s = p->value.sym; |
| 104 | if (s == retaddrsym) { |
| 105 | push(long, return_addr()); |
| 106 | } else { |
| 107 | if (isvariable(s)) { |
| 108 | if (s != program and not isactive(container(s))) { |
| 109 | error("\"%s\" is not active", symname(s)); |
| 110 | } |
| 111 | push(long, address(s, nil)); |
| 112 | } else if (isblock(s)) { |
| 113 | push(Symbol, s); |
| 114 | } else { |
| 115 | error("can't evaluate a %s", classname(s)); |
| 116 | } |
| 117 | } |
| 118 | break; |
| 119 | |
| 120 | case O_LCON: |
| 121 | r0 = p->value.lcon; |
| 122 | pushsmall(p->nodetype, r0); |
| 123 | break; |
| 124 | |
| 125 | case O_FCON: |
| 126 | push(double, p->value.fcon); |
| 127 | break; |
| 128 | |
| 129 | case O_SCON: |
| 130 | len = size(p->nodetype); |
| 131 | mov(p->value.scon, sp, len); |
| 132 | sp += len; |
| 133 | break; |
| 134 | |
| 135 | case O_INDEX: |
| 136 | n = pop(long); |
| 137 | i = evalindex(p->value.arg[0]->nodetype, |
| 138 | popsmall(p->value.arg[1]->nodetype)); |
| 139 | push(long, n + i*size(p->nodetype)); |
| 140 | break; |
| 141 | |
| 142 | case O_DOT: |
| 143 | s = p->value.arg[1]->value.sym; |
| 144 | n = lval(p->value.arg[0]); |
| 145 | push(long, n + (s->symvalue.field.offset div 8)); |
| 146 | break; |
| 147 | |
| 148 | /* |
| 149 | * Get the value of the expression addressed by the top of the stack. |
| 150 | * Push the result back on the stack. |
| 151 | */ |
| 152 | |
| 153 | case O_INDIR: |
| 154 | case O_RVAL: |
| 155 | addr = pop(long); |
| 156 | if (addr == 0) { |
| 157 | error("reference through nil pointer"); |
| 158 | } |
| 159 | if (p->op == O_INDIR) { |
| 160 | len = sizeof(long); |
| 161 | } else { |
| 162 | len = size(p->nodetype); |
| 163 | } |
| 164 | rpush(addr, len); |
| 165 | addr = pop(long); |
| 166 | push(long, addr); |
| 167 | break; |
| 168 | |
| 169 | /* |
| 170 | * Effectively, we want to pop n bytes off for the evaluated subtree |
| 171 | * and push len bytes on for the new type of the same tree. |
| 172 | */ |
| 173 | case O_TYPERENAME: |
| 174 | n = size(p->value.arg[0]->nodetype); |
| 175 | len = size(p->nodetype); |
| 176 | sp = sp - n + len; |
| 177 | break; |
| 178 | |
| 179 | case O_COMMA: |
| 180 | break; |
| 181 | |
| 182 | case O_ITOF: |
| 183 | push(double, (double) r0); |
| 184 | break; |
| 185 | |
| 186 | case O_ADD: |
| 187 | push(long, r0+r1); |
| 188 | break; |
| 189 | |
| 190 | case O_ADDF: |
| 191 | push(double, fr0+fr1); |
| 192 | break; |
| 193 | |
| 194 | case O_SUB: |
| 195 | push(long, r0-r1); |
| 196 | break; |
| 197 | |
| 198 | case O_SUBF: |
| 199 | push(double, fr0-fr1); |
| 200 | break; |
| 201 | |
| 202 | case O_NEG: |
| 203 | push(long, -r0); |
| 204 | break; |
| 205 | |
| 206 | case O_NEGF: |
| 207 | push(double, -fr0); |
| 208 | break; |
| 209 | |
| 210 | case O_MUL: |
| 211 | push(long, r0*r1); |
| 212 | break; |
| 213 | |
| 214 | case O_MULF: |
| 215 | push(double, fr0*fr1); |
| 216 | break; |
| 217 | |
| 218 | case O_DIVF: |
| 219 | if (fr1 == 0) { |
| 220 | error("error: division by 0"); |
| 221 | } |
| 222 | push(double, fr0 / fr1); |
| 223 | break; |
| 224 | |
| 225 | case O_DIV: |
| 226 | if (r1 == 0) { |
| 227 | error("error: div by 0"); |
| 228 | } |
| 229 | push(long, r0 div r1); |
| 230 | break; |
| 231 | |
| 232 | case O_MOD: |
| 233 | if (r1 == 0) { |
| 234 | error("error: mod by 0"); |
| 235 | } |
| 236 | push(long, r0 mod r1); |
| 237 | break; |
| 238 | |
| 239 | case O_LT: |
| 240 | push(Boolrep, r0 < r1); |
| 241 | break; |
| 242 | |
| 243 | case O_LTF: |
| 244 | push(Boolrep, fr0 < fr1); |
| 245 | break; |
| 246 | |
| 247 | case O_LE: |
| 248 | push(Boolrep, r0 <= r1); |
| 249 | break; |
| 250 | |
| 251 | case O_LEF: |
| 252 | push(Boolrep, fr0 <= fr1); |
| 253 | break; |
| 254 | |
| 255 | case O_GT: |
| 256 | push(Boolrep, r0 > r1); |
| 257 | break; |
| 258 | |
| 259 | case O_GTF: |
| 260 | push(Boolrep, fr0 > fr1); |
| 261 | break; |
| 262 | |
| 263 | case O_EQ: |
| 264 | push(Boolrep, r0 == r1); |
| 265 | break; |
| 266 | |
| 267 | case O_EQF: |
| 268 | push(Boolrep, fr0 == fr1); |
| 269 | break; |
| 270 | |
| 271 | case O_NE: |
| 272 | push(Boolrep, r0 != r1); |
| 273 | break; |
| 274 | |
| 275 | case O_NEF: |
| 276 | push(Boolrep, fr0 != fr1); |
| 277 | break; |
| 278 | |
| 279 | case O_AND: |
| 280 | push(Boolrep, r0 and r1); |
| 281 | break; |
| 282 | |
| 283 | case O_OR: |
| 284 | push(Boolrep, r0 or r1); |
| 285 | break; |
| 286 | |
| 287 | case O_ASSIGN: |
| 288 | assign(p->value.arg[0], p->value.arg[1]); |
| 289 | break; |
| 290 | |
| 291 | case O_CHFILE: |
| 292 | if (p->value.scon == nil) { |
| 293 | printf("%s\n", cursource); |
| 294 | } else { |
| 295 | file = opensource(p->value.scon); |
| 296 | if (file == nil) { |
| 297 | error("can't read \"%s\"", p->value.scon); |
| 298 | } else { |
| 299 | fclose(file); |
| 300 | setsource(p->value.scon); |
| 301 | } |
| 302 | } |
| 303 | break; |
| 304 | |
| 305 | case O_CONT: |
| 306 | cont(p->value.lcon); |
| 307 | printnews(); |
| 308 | break; |
| 309 | |
| 310 | case O_LIST: |
| 311 | if (p->value.arg[0]->op == O_SYM) { |
| 312 | f = p->value.arg[0]->value.sym; |
| 313 | addr = firstline(f); |
| 314 | if (addr == NOADDR) { |
| 315 | error("no source lines for \"%s\"", symname(f)); |
| 316 | } |
| 317 | setsource(srcfilename(addr)); |
| 318 | r0 = srcline(addr) - 5; |
| 319 | r1 = r0 + 10; |
| 320 | if (r0 < 1) { |
| 321 | r0 = 1; |
| 322 | } |
| 323 | } else { |
| 324 | eval(p->value.arg[0]); |
| 325 | r0 = pop(long); |
| 326 | eval(p->value.arg[1]); |
| 327 | r1 = pop(long); |
| 328 | } |
| 329 | printlines((Lineno) r0, (Lineno) r1); |
| 330 | break; |
| 331 | |
| 332 | case O_FUNC: |
| 333 | if (p->value.arg[0] == nil) { |
| 334 | printname(stdout, curfunc); |
| 335 | putchar('\n'); |
| 336 | } else { |
| 337 | s = p->value.arg[0]->value.sym; |
| 338 | find(f, s->name) where |
| 339 | f->class == FUNC or f->class == PROC |
| 340 | endfind(f); |
| 341 | if (f == nil) { |
| 342 | error("%s is not a procedure or function", symname(s)); |
| 343 | } |
| 344 | curfunc = f; |
| 345 | addr = codeloc(curfunc); |
| 346 | if (addr != NOADDR) { |
| 347 | setsource(srcfilename(addr)); |
| 348 | cursrcline = srcline(addr) - 5; |
| 349 | if (cursrcline < 1) { |
| 350 | cursrcline = 1; |
| 351 | } |
| 352 | } |
| 353 | } |
| 354 | break; |
| 355 | |
| 356 | case O_EXAMINE: |
| 357 | eval(p->value.examine.beginaddr); |
| 358 | r0 = pop(long); |
| 359 | if (p->value.examine.endaddr == nil) { |
| 360 | n = p->value.examine.count; |
| 361 | if (n == 0) { |
| 362 | printvalue(r0, p->value.examine.mode); |
| 363 | } else if (streq(p->value.examine.mode, "i")) { |
| 364 | printninst(n, (Address) r0); |
| 365 | } else { |
| 366 | printndata(n, (Address) r0, p->value.examine.mode); |
| 367 | } |
| 368 | } else { |
| 369 | eval(p->value.examine.endaddr); |
| 370 | r1 = pop(long); |
| 371 | if (streq(p->value.examine.mode, "i")) { |
| 372 | printinst((Address)r0, (Address)r1); |
| 373 | } else { |
| 374 | printdata((Address)r0, (Address)r1, p->value.examine.mode); |
| 375 | } |
| 376 | } |
| 377 | break; |
| 378 | |
| 379 | case O_PRINT: |
| 380 | for (n1 = p->value.arg[0]; n1 != nil; n1 = n1->value.arg[1]) { |
| 381 | eval(n1->value.arg[0]); |
| 382 | printval(n1->value.arg[0]->nodetype); |
| 383 | putchar(' '); |
| 384 | } |
| 385 | putchar('\n'); |
| 386 | break; |
| 387 | |
| 388 | case O_PSYM: |
| 389 | if (p->value.arg[0]->op == O_SYM) { |
| 390 | psym(p->value.arg[0]->value.sym); |
| 391 | } else { |
| 392 | psym(p->value.arg[0]->nodetype); |
| 393 | } |
| 394 | break; |
| 395 | |
| 396 | case O_QLINE: |
| 397 | eval(p->value.arg[1]); |
| 398 | break; |
| 399 | |
| 400 | case O_STEP: |
| 401 | b = inst_tracing; |
| 402 | inst_tracing = (Boolean) (not p->value.step.source); |
| 403 | if (p->value.step.skipcalls) { |
| 404 | next(); |
| 405 | } else { |
| 406 | stepc(); |
| 407 | } |
| 408 | inst_tracing = b; |
| 409 | useInstLoc = (Boolean) (not p->value.step.source); |
| 410 | printnews(); |
| 411 | break; |
| 412 | |
| 413 | case O_WHATIS: |
| 414 | if (p->value.arg[0]->op == O_SYM) { |
| 415 | printdecl(p->value.arg[0]->value.sym); |
| 416 | } else { |
| 417 | printdecl(p->value.arg[0]->nodetype); |
| 418 | } |
| 419 | break; |
| 420 | |
| 421 | case O_WHERE: |
| 422 | wherecmd(); |
| 423 | break; |
| 424 | |
| 425 | case O_WHEREIS: |
| 426 | if (p->value.arg[0]->op == O_SYM) { |
| 427 | printwhereis(stdout,p->value.arg[0]->value.sym); |
| 428 | } else { |
| 429 | printwhereis(stdout,p->value.arg[0]->nodetype); |
| 430 | } |
| 431 | break; |
| 432 | |
| 433 | case O_WHICH: |
| 434 | if (p->value.arg[0]->op == O_SYM) { |
| 435 | printwhich(stdout,p->value.arg[0]->value.sym); |
| 436 | } else { |
| 437 | printwhich(stdout,p->value.arg[0]->nodetype); |
| 438 | } |
| 439 | putchar('\n'); |
| 440 | break; |
| 441 | |
| 442 | case O_ALIAS: |
| 443 | n1 = p->value.arg[0]; |
| 444 | n2 = p->value.arg[1]; |
| 445 | if (n1 == nil) { |
| 446 | print_alias(nil); |
| 447 | } else if (n2 == nil) { |
| 448 | print_alias(n1->value.name); |
| 449 | } else { |
| 450 | enter_alias(n1->value.name, n2->value.name); |
| 451 | } |
| 452 | break; |
| 453 | |
| 454 | case O_CALL: |
| 455 | callproc(p->value.arg[0], p->value.arg[1]); |
| 456 | break; |
| 457 | |
| 458 | case O_CATCH: |
| 459 | psigtrace(process, p->value.lcon, true); |
| 460 | break; |
| 461 | |
| 462 | case O_EDIT: |
| 463 | edit(p->value.scon); |
| 464 | break; |
| 465 | |
| 466 | case O_DEBUG: |
| 467 | debug(p); |
| 468 | break; |
| 469 | |
| 470 | case O_DUMP: |
| 471 | dump(); |
| 472 | break; |
| 473 | |
| 474 | case O_GRIPE: |
| 475 | gripe(); |
| 476 | break; |
| 477 | |
| 478 | case O_HELP: |
| 479 | help(); |
| 480 | break; |
| 481 | |
| 482 | case O_IGNORE: |
| 483 | psigtrace(process, p->value.lcon, false); |
| 484 | break; |
| 485 | |
| 486 | case O_RUN: |
| 487 | run(); |
| 488 | break; |
| 489 | |
| 490 | case O_SOURCE: |
| 491 | setinput(p->value.scon); |
| 492 | break; |
| 493 | |
| 494 | case O_STATUS: |
| 495 | status(); |
| 496 | break; |
| 497 | |
| 498 | case O_TRACE: |
| 499 | case O_TRACEI: |
| 500 | trace(p); |
| 501 | break; |
| 502 | |
| 503 | case O_STOP: |
| 504 | case O_STOPI: |
| 505 | stop(p); |
| 506 | break; |
| 507 | |
| 508 | case O_ADDEVENT: |
| 509 | addevent(p->value.event.cond, p->value.event.actions); |
| 510 | break; |
| 511 | |
| 512 | case O_DELETE: |
| 513 | delevent((unsigned int) p->value.lcon); |
| 514 | break; |
| 515 | |
| 516 | case O_ENDX: |
| 517 | endprogram(); |
| 518 | break; |
| 519 | |
| 520 | case O_IF: |
| 521 | if (cond(p->value.event.cond)) { |
| 522 | evalcmdlist(p->value.event.actions); |
| 523 | } |
| 524 | break; |
| 525 | |
| 526 | case O_ONCE: |
| 527 | event_once(p->value.event.cond, p->value.event.actions); |
| 528 | break; |
| 529 | |
| 530 | case O_PRINTCALL: |
| 531 | printcall(p->value.sym, whatblock(return_addr())); |
| 532 | break; |
| 533 | |
| 534 | case O_PRINTIFCHANGED: |
| 535 | printifchanged(p->value.arg[0]); |
| 536 | break; |
| 537 | |
| 538 | case O_PRINTRTN: |
| 539 | printrtn(p->value.sym); |
| 540 | break; |
| 541 | |
| 542 | case O_PRINTSRCPOS: |
| 543 | getsrcpos(); |
| 544 | if (p->value.arg[0] == nil) { |
| 545 | printsrcpos(); |
| 546 | putchar('\n'); |
| 547 | printlines(curline, curline); |
| 548 | } else if (p->value.arg[0]->op == O_QLINE) { |
| 549 | if (p->value.arg[0]->value.arg[1]->value.lcon == 0) { |
| 550 | printf("tracei: "); |
| 551 | printinst(pc, pc); |
| 552 | } else { |
| 553 | printf("trace: "); |
| 554 | printlines(curline, curline); |
| 555 | } |
| 556 | } else { |
| 557 | printsrcpos(); |
| 558 | printf(": "); |
| 559 | eval(p->value.arg[0]); |
| 560 | prtree(stdout, p->value.arg[0]); |
| 561 | printf(" = "); |
| 562 | printval(p->value.arg[0]->nodetype); |
| 563 | putchar('\n'); |
| 564 | } |
| 565 | break; |
| 566 | |
| 567 | case O_PROCRTN: |
| 568 | procreturn(p->value.sym); |
| 569 | break; |
| 570 | |
| 571 | case O_STOPIFCHANGED: |
| 572 | stopifchanged(p->value.arg[0]); |
| 573 | break; |
| 574 | |
| 575 | case O_STOPX: |
| 576 | isstopped = true; |
| 577 | break; |
| 578 | |
| 579 | case O_TRACEON: |
| 580 | traceon(p->value.trace.inst, p->value.trace.event, |
| 581 | p->value.trace.actions); |
| 582 | break; |
| 583 | |
| 584 | case O_TRACEOFF: |
| 585 | traceoff(p->value.lcon); |
| 586 | break; |
| 587 | |
| 588 | default: |
| 589 | panic("eval: bad op %d", p->op); |
| 590 | } |
| 591 | if(debug_flag[2]) { |
| 592 | fprintf(stderr," evaluated %s \n",showoperator(p->op)); |
| 593 | } |
| 594 | |
| 595 | } |
| 596 | |
| 597 | /* |
| 598 | * Evaluate a list of commands. |
| 599 | */ |
| 600 | |
| 601 | public evalcmdlist(cl) |
| 602 | Cmdlist cl; |
| 603 | { |
| 604 | Command c; |
| 605 | |
| 606 | foreach (Command, c, cl) |
| 607 | evalcmd(c); |
| 608 | endfor |
| 609 | } |
| 610 | |
| 611 | /* |
| 612 | * Push "len" bytes onto the expression stack from address "addr" |
| 613 | * in the process. If there isn't room on the stack, print an error message. |
| 614 | */ |
| 615 | |
| 616 | public rpush(addr, len) |
| 617 | Address addr; |
| 618 | int len; |
| 619 | { |
| 620 | if (not canpush(len)) { |
| 621 | error("expression too large to evaluate"); |
| 622 | } else { |
| 623 | chksp(); |
| 624 | dread(sp, addr, len); |
| 625 | sp += len; |
| 626 | } |
| 627 | } |
| 628 | |
| 629 | /* |
| 630 | * Check if the stack has n bytes available. |
| 631 | */ |
| 632 | |
| 633 | public Boolean canpush(n) |
| 634 | Integer n; |
| 635 | { |
| 636 | return (Boolean) (sp + n < &stack[STACKSIZE]); |
| 637 | } |
| 638 | |
| 639 | /* |
| 640 | * Push a small scalar of the given type onto the stack. |
| 641 | */ |
| 642 | |
| 643 | public pushsmall(t, v) |
| 644 | Symbol t; |
| 645 | long v; |
| 646 | { |
| 647 | register Integer s; |
| 648 | |
| 649 | s = size(t); |
| 650 | switch (s) { |
| 651 | case sizeof(char): |
| 652 | push(char, v); |
| 653 | break; |
| 654 | |
| 655 | case sizeof(short): |
| 656 | push(short, v); |
| 657 | break; |
| 658 | |
| 659 | case sizeof(long): |
| 660 | push(long, v); |
| 661 | break; |
| 662 | |
| 663 | default: |
| 664 | panic("bad size %d in popsmall", s); |
| 665 | } |
| 666 | } |
| 667 | |
| 668 | /* |
| 669 | * Pop an item of the given type which is assumed to be no larger |
| 670 | * than a long and return it expanded into a long. |
| 671 | */ |
| 672 | |
| 673 | public long popsmall(t) |
| 674 | Symbol t; |
| 675 | { |
| 676 | long r; |
| 677 | |
| 678 | switch (size(t)) { |
| 679 | case sizeof(char): |
| 680 | r = (long) pop(char); |
| 681 | break; |
| 682 | |
| 683 | case sizeof(short): |
| 684 | r = (long) pop(short); |
| 685 | break; |
| 686 | |
| 687 | case sizeof(long): |
| 688 | r = pop(long); |
| 689 | break; |
| 690 | |
| 691 | default: |
| 692 | panic("popsmall: size is %d", size(t)); |
| 693 | } |
| 694 | return r; |
| 695 | } |
| 696 | |
| 697 | /* |
| 698 | * Evaluate a conditional expression. |
| 699 | */ |
| 700 | |
| 701 | public Boolean cond(p) |
| 702 | Node p; |
| 703 | { |
| 704 | register Boolean b; |
| 705 | |
| 706 | if (p == nil) { |
| 707 | b = true; |
| 708 | } else { |
| 709 | eval(p); |
| 710 | b = (Boolean) pop(Boolrep); |
| 711 | } |
| 712 | return b; |
| 713 | } |
| 714 | |
| 715 | /* |
| 716 | * Return the address corresponding to a given tree. |
| 717 | */ |
| 718 | |
| 719 | public Address lval(p) |
| 720 | Node p; |
| 721 | { |
| 722 | if (p->op == O_RVAL) { |
| 723 | eval(p->value.arg[0]); |
| 724 | } else { |
| 725 | eval(p); |
| 726 | } |
| 727 | return (Address) (pop(long)); |
| 728 | } |
| 729 | |
| 730 | /* |
| 731 | * Process a trace command, translating into the appropriate events |
| 732 | * and associated actions. |
| 733 | */ |
| 734 | |
| 735 | public trace(p) |
| 736 | Node p; |
| 737 | { |
| 738 | Node exp, place, cond; |
| 739 | Node left; |
| 740 | |
| 741 | exp = p->value.arg[0]; |
| 742 | place = p->value.arg[1]; |
| 743 | cond = p->value.arg[2]; |
| 744 | if (exp == nil) { |
| 745 | traceall(p->op, place, cond); |
| 746 | } else if (exp->op == O_QLINE or exp->op == O_LCON) { |
| 747 | traceinst(p->op, exp, cond); |
| 748 | } else if (place != nil and place->op == O_QLINE) { |
| 749 | traceat(p->op, exp, place, cond); |
| 750 | } else { |
| 751 | left = exp; |
| 752 | if (left->op == O_RVAL or left->op == O_CALL) { |
| 753 | left = left->value.arg[0]; |
| 754 | } |
| 755 | if (left->op == O_SYM and isblock(left->value.sym)) { |
| 756 | traceproc(p->op, left->value.sym, place, cond); |
| 757 | } else { |
| 758 | tracedata(p->op, exp, place, cond); |
| 759 | } |
| 760 | } |
| 761 | } |
| 762 | |
| 763 | /* |
| 764 | * Set a breakpoint that will turn on tracing. |
| 765 | */ |
| 766 | |
| 767 | private traceall(op, place, cond) |
| 768 | Operator op; |
| 769 | Node place; |
| 770 | Node cond; |
| 771 | { |
| 772 | Symbol s; |
| 773 | Node event; |
| 774 | Command action; |
| 775 | |
| 776 | if (place == nil) { |
| 777 | s = program; |
| 778 | } else { |
| 779 | s = place->value.sym; |
| 780 | } |
| 781 | event = build(O_EQ, build(O_SYM, procsym), build(O_SYM, s)); |
| 782 | action = build(O_PRINTSRCPOS, |
| 783 | build(O_QLINE, nil, build(O_LCON, (op == O_TRACE) ? 1 : 0))); |
| 784 | if (cond != nil) { |
| 785 | action = build(O_IF, cond, buildcmdlist(action)); |
| 786 | } |
| 787 | action = build(O_TRACEON, (op == O_TRACEI), buildcmdlist(action)); |
| 788 | action->value.trace.event = addevent(event, buildcmdlist(action)); |
| 789 | if (isstdin()) { |
| 790 | printevent(action->value.trace.event); |
| 791 | } |
| 792 | } |
| 793 | |
| 794 | /* |
| 795 | * Set up the appropriate breakpoint for tracing an instruction. |
| 796 | */ |
| 797 | |
| 798 | private traceinst(op, exp, cond) |
| 799 | Operator op; |
| 800 | Node exp; |
| 801 | Node cond; |
| 802 | { |
| 803 | Node event, wh; |
| 804 | Command action; |
| 805 | Event e; |
| 806 | |
| 807 | if (exp->op == O_LCON) { |
| 808 | wh = build(O_QLINE, build(O_SCON, cursource), exp); |
| 809 | } else { |
| 810 | wh = exp; |
| 811 | } |
| 812 | if (op == O_TRACEI) { |
| 813 | event = build(O_EQ, build(O_SYM, pcsym), wh); |
| 814 | } else { |
| 815 | event = build(O_EQ, build(O_SYM, linesym), wh); |
| 816 | } |
| 817 | action = build(O_PRINTSRCPOS, wh); |
| 818 | if (cond) { |
| 819 | action = build(O_IF, cond, buildcmdlist(action)); |
| 820 | } |
| 821 | e = addevent(event, buildcmdlist(action)); |
| 822 | if (isstdin()) { |
| 823 | printevent(e); |
| 824 | } |
| 825 | } |
| 826 | |
| 827 | /* |
| 828 | * Set a breakpoint to print an expression at a given line or address. |
| 829 | */ |
| 830 | |
| 831 | private traceat(op, exp, place, cond) |
| 832 | Operator op; |
| 833 | Node exp; |
| 834 | Node place; |
| 835 | Node cond; |
| 836 | { |
| 837 | Node event; |
| 838 | Command action; |
| 839 | Event e; |
| 840 | |
| 841 | if (op == O_TRACEI) { |
| 842 | event = build(O_EQ, build(O_SYM, pcsym), place); |
| 843 | } else { |
| 844 | event = build(O_EQ, build(O_SYM, linesym), place); |
| 845 | } |
| 846 | action = build(O_PRINTSRCPOS, exp); |
| 847 | if (cond != nil) { |
| 848 | action = build(O_IF, cond, buildcmdlist(action)); |
| 849 | } |
| 850 | e = addevent(event, buildcmdlist(action)); |
| 851 | if (isstdin()) { |
| 852 | printevent(e); |
| 853 | } |
| 854 | } |
| 855 | |
| 856 | /* |
| 857 | * Construct event for tracing a procedure. |
| 858 | * |
| 859 | * What we want here is |
| 860 | * |
| 861 | * when $proc = p do |
| 862 | * if <condition> then |
| 863 | * printcall; |
| 864 | * once $pc = $retaddr do |
| 865 | * printrtn; |
| 866 | * end; |
| 867 | * end if; |
| 868 | * end; |
| 869 | * |
| 870 | * Note that "once" is like "when" except that the event |
| 871 | * deletes itself as part of its associated action. |
| 872 | */ |
| 873 | |
| 874 | private traceproc(op, p, place, cond) |
| 875 | Operator op; |
| 876 | Symbol p; |
| 877 | Node place; |
| 878 | Node cond; |
| 879 | { |
| 880 | Node event; |
| 881 | Command action; |
| 882 | Cmdlist actionlist; |
| 883 | Event e; |
| 884 | |
| 885 | action = build(O_PRINTCALL, p); |
| 886 | actionlist = list_alloc(); |
| 887 | cmdlist_append(action, actionlist); |
| 888 | event = build(O_EQ, build(O_SYM, pcsym), build(O_SYM, retaddrsym)); |
| 889 | action = build(O_ONCE, event, buildcmdlist(build(O_PRINTRTN, p))); |
| 890 | cmdlist_append(action, actionlist); |
| 891 | if (cond != nil) { |
| 892 | actionlist = buildcmdlist(build(O_IF, cond, actionlist)); |
| 893 | } |
| 894 | event = build(O_EQ, build(O_SYM, procsym), build(O_SYM, p)); |
| 895 | e = addevent(event, actionlist); |
| 896 | if (isstdin()) { |
| 897 | printevent(e); |
| 898 | } |
| 899 | } |
| 900 | |
| 901 | /* |
| 902 | * Set up breakpoint for tracing data. |
| 903 | */ |
| 904 | |
| 905 | private tracedata(op, exp, place, cond) |
| 906 | Operator op; |
| 907 | Node exp; |
| 908 | Node place; |
| 909 | Node cond; |
| 910 | { |
| 911 | Symbol p; |
| 912 | Node event; |
| 913 | Command action; |
| 914 | |
| 915 | p = (place == nil) ? tcontainer(exp) : place->value.sym; |
| 916 | if (p == nil) { |
| 917 | p = program; |
| 918 | } |
| 919 | action = build(O_PRINTIFCHANGED, exp); |
| 920 | if (cond != nil) { |
| 921 | action = build(O_IF, cond, buildcmdlist(action)); |
| 922 | } |
| 923 | action = build(O_TRACEON, (op == O_TRACEI), buildcmdlist(action)); |
| 924 | event = build(O_EQ, build(O_SYM, procsym), build(O_SYM, p)); |
| 925 | action->value.trace.event = addevent(event, buildcmdlist(action)); |
| 926 | if (isstdin()) { |
| 927 | printevent(action->value.trace.event); |
| 928 | } |
| 929 | } |
| 930 | |
| 931 | /* |
| 932 | * Setting and unsetting of stops. |
| 933 | */ |
| 934 | |
| 935 | public stop(p) |
| 936 | Node p; |
| 937 | { |
| 938 | Node exp, place, cond, t; |
| 939 | Symbol s; |
| 940 | Command action; |
| 941 | Event e; |
| 942 | |
| 943 | exp = p->value.arg[0]; |
| 944 | place = p->value.arg[1]; |
| 945 | cond = p->value.arg[2]; |
| 946 | if (exp != nil) { |
| 947 | stopvar(p->op, exp, place, cond); |
| 948 | } else { |
| 949 | action = build(O_STOPX); |
| 950 | if (cond != nil) { |
| 951 | action = build(O_IF, cond, buildcmdlist(action)); |
| 952 | } |
| 953 | if (place != nil and place->op == O_SYM) { |
| 954 | s = place->value.sym; |
| 955 | t = build(O_EQ, build(O_SYM, procsym), build(O_SYM, s)); |
| 956 | if (cond != nil) { |
| 957 | action = build(O_TRACEON, (p->op == O_STOPI), |
| 958 | buildcmdlist(action)); |
| 959 | e = addevent(t, buildcmdlist(action)); |
| 960 | action->value.trace.event = e; |
| 961 | } else { |
| 962 | e = addevent(t, buildcmdlist(action)); |
| 963 | } |
| 964 | if (isstdin()) { |
| 965 | printevent(e); |
| 966 | } |
| 967 | } else { |
| 968 | stopinst(p->op, place, cond, action); |
| 969 | } |
| 970 | } |
| 971 | } |
| 972 | |
| 973 | private stopinst(op, place, cond, action) |
| 974 | Operator op; |
| 975 | Node place; |
| 976 | Node cond; |
| 977 | Command action; |
| 978 | { |
| 979 | Node event; |
| 980 | Event e; |
| 981 | |
| 982 | if (op == O_STOP) { |
| 983 | event = build(O_EQ, build(O_SYM, linesym), place); |
| 984 | } else { |
| 985 | event = build(O_EQ, build(O_SYM, pcsym), place); |
| 986 | } |
| 987 | e = addevent(event, buildcmdlist(action)); |
| 988 | if (isstdin()) { |
| 989 | printevent(e); |
| 990 | } |
| 991 | } |
| 992 | |
| 993 | /* |
| 994 | * Implement stopping on assignment to a variable by adding it to |
| 995 | * the variable list. |
| 996 | */ |
| 997 | |
| 998 | private stopvar(op, exp, place, cond) |
| 999 | Operator op; |
| 1000 | Node exp; |
| 1001 | Node place; |
| 1002 | Node cond; |
| 1003 | { |
| 1004 | Symbol p; |
| 1005 | Node event; |
| 1006 | Command action; |
| 1007 | |
| 1008 | if (place == nil) { |
| 1009 | if (exp->op == O_LCON) { |
| 1010 | p = program; |
| 1011 | } else { |
| 1012 | p = tcontainer(exp); |
| 1013 | if (p == nil) { |
| 1014 | p = program; |
| 1015 | } |
| 1016 | } |
| 1017 | } else { |
| 1018 | p = place->value.sym; |
| 1019 | } |
| 1020 | action = build(O_STOPIFCHANGED, exp); |
| 1021 | if (cond != nil) { |
| 1022 | action = build(O_IF, cond, buildcmdlist(action)); |
| 1023 | } |
| 1024 | action = build(O_TRACEON, (op == O_STOPI), buildcmdlist(action)); |
| 1025 | event = build(O_EQ, build(O_SYM, procsym), build(O_SYM, p)); |
| 1026 | action->value.trace.event = addevent(event, buildcmdlist(action)); |
| 1027 | if (isstdin()) { |
| 1028 | printevent(action->value.trace.event); |
| 1029 | } |
| 1030 | } |
| 1031 | |
| 1032 | /* |
| 1033 | * Assign the value of an expression to a variable (or term). |
| 1034 | */ |
| 1035 | |
| 1036 | public assign(var, exp) |
| 1037 | Node var; |
| 1038 | Node exp; |
| 1039 | { |
| 1040 | Address addr; |
| 1041 | int varsize; |
| 1042 | char cvalue; |
| 1043 | short svalue; |
| 1044 | long lvalue; |
| 1045 | |
| 1046 | if (not compatible(var->nodetype, exp->nodetype)) { |
| 1047 | error("incompatible types"); |
| 1048 | } |
| 1049 | addr = lval(var); |
| 1050 | eval(exp); |
| 1051 | varsize = size(var->nodetype); |
| 1052 | if (varsize < sizeof(long)) { |
| 1053 | lvalue = pop(long); |
| 1054 | switch (varsize) { |
| 1055 | case sizeof(char): |
| 1056 | cvalue = lvalue; |
| 1057 | dwrite(&cvalue, addr, varsize); |
| 1058 | break; |
| 1059 | |
| 1060 | case sizeof(short): |
| 1061 | svalue = lvalue; |
| 1062 | dwrite(&svalue, addr, varsize); |
| 1063 | break; |
| 1064 | |
| 1065 | default: |
| 1066 | panic("bad size %d", varsize); |
| 1067 | } |
| 1068 | } else { |
| 1069 | sp -= varsize; |
| 1070 | dwrite(sp, addr, varsize); |
| 1071 | } |
| 1072 | } |
| 1073 | |
| 1074 | /* |
| 1075 | * Send some nasty mail to the current support person. |
| 1076 | */ |
| 1077 | |
| 1078 | public gripe() |
| 1079 | { |
| 1080 | typedef Operation(); |
| 1081 | Operation *old; |
| 1082 | int pid, status; |
| 1083 | |
| 1084 | char *maintainer = "linton@berkeley"; |
| 1085 | |
| 1086 | puts("Type control-D to end your message. Be sure to include"); |
| 1087 | puts("your name and the name of the file you are debugging."); |
| 1088 | putchar('\n'); |
| 1089 | old = signal(SIGINT, SIG_DFL); |
| 1090 | pid = back("Mail", stdin, stdout, "-s", "dbx gripe", maintainer, nil); |
| 1091 | signal(SIGINT, SIG_IGN); |
| 1092 | pwait(pid, &status); |
| 1093 | signal(SIGINT, old); |
| 1094 | if (status == 0) { |
| 1095 | puts("Thank you."); |
| 1096 | } else { |
| 1097 | puts("\nMail not sent."); |
| 1098 | } |
| 1099 | } |
| 1100 | |
| 1101 | /* |
| 1102 | * Give the user some help. |
| 1103 | */ |
| 1104 | |
| 1105 | public help() |
| 1106 | { |
| 1107 | puts("run - begin execution of the program"); |
| 1108 | puts("cont - continue execution"); |
| 1109 | puts("step - single step one line"); |
| 1110 | puts("next - step to next line (skip over calls)"); |
| 1111 | puts("trace <line#> - trace execution of the line"); |
| 1112 | puts("trace <proc> - trace calls to the procedure"); |
| 1113 | puts("trace <var> - trace changes to the variable"); |
| 1114 | puts("trace <exp> at <line#> - print <exp> when <line> is reached"); |
| 1115 | puts("stop at <line> - suspend execution at the line"); |
| 1116 | puts("stop in <proc> - suspend execution when <proc> is called"); |
| 1117 | puts("status - print trace/stop's in effect"); |
| 1118 | puts("delete <number> - remove trace or stop of given number"); |
| 1119 | puts("call <proc> - call the procedure"); |
| 1120 | puts("where - print currently active procedures"); |
| 1121 | puts("print <exp> - print the value of the expression"); |
| 1122 | puts("whatis <name> - print the declaration of the name"); |
| 1123 | puts("list <line>, <line> - list source lines"); |
| 1124 | puts("edit <proc> - edit file containing <proc>"); |
| 1125 | puts("gripe - send mail to the person in charge of dbx"); |
| 1126 | puts("quit - exit dbx"); |
| 1127 | } |
| 1128 | |
| 1129 | /* |
| 1130 | * Divert output to the given file name. |
| 1131 | * Cannot redirect to an existing file. |
| 1132 | */ |
| 1133 | |
| 1134 | private int so_fd; |
| 1135 | private Boolean notstdout; |
| 1136 | |
| 1137 | public setout(filename) |
| 1138 | String filename; |
| 1139 | { |
| 1140 | File f; |
| 1141 | |
| 1142 | f = fopen(filename, "r"); |
| 1143 | if (f != nil) { |
| 1144 | fclose(f); |
| 1145 | error("%s: file already exists", filename); |
| 1146 | } else { |
| 1147 | so_fd = dup(1); |
| 1148 | close(1); |
| 1149 | if (creat(filename, 0666) == nil) { |
| 1150 | unsetout(); |
| 1151 | error("can't create %s", filename); |
| 1152 | } |
| 1153 | notstdout = true; |
| 1154 | } |
| 1155 | } |
| 1156 | |
| 1157 | /* |
| 1158 | * Revert output to standard output. |
| 1159 | */ |
| 1160 | |
| 1161 | public unsetout() |
| 1162 | { |
| 1163 | fflush(stdout); |
| 1164 | close(1); |
| 1165 | if (dup(so_fd) != 1) { |
| 1166 | panic("standard out dup failed"); |
| 1167 | } |
| 1168 | close(so_fd); |
| 1169 | notstdout = false; |
| 1170 | } |
| 1171 | |
| 1172 | /* |
| 1173 | * Determine is standard output is currently being redirected |
| 1174 | * to a file (as far as we know). |
| 1175 | */ |
| 1176 | |
| 1177 | public Boolean isredirected() |
| 1178 | { |
| 1179 | return notstdout; |
| 1180 | } |