1/* $NetBSD$ */ 2 3/* 4** Id: ldebug.c,v 2.29.1.6 2008/05/08 16:56:26 roberto Exp 5** Debug Interface 6** See Copyright Notice in lua.h 7*/ 8 9 10#include <stdarg.h> 11#include <stddef.h> 12#include <string.h> 13 14 15#define ldebug_c 16#define LUA_CORE 17 18#include "lua.h" 19 20#include "lapi.h" 21#include "lcode.h" 22#include "ldebug.h" 23#include "ldo.h" 24#include "lfunc.h" 25#include "lobject.h" 26#include "lopcodes.h" 27#include "lstate.h" 28#include "lstring.h" 29#include "ltable.h" 30#include "ltm.h" 31#include "lvm.h" 32 33 34 35static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name); 36 37 38static int currentpc (lua_State *L, CallInfo *ci) { 39 if (!isLua(ci)) return -1; /* function is not a Lua function? */ 40 if (ci == L->ci) 41 ci->savedpc = L->savedpc; 42 return pcRel(ci->savedpc, ci_func(ci)->l.p); 43} 44 45 46static int currentline (lua_State *L, CallInfo *ci) { 47 int pc = currentpc(L, ci); 48 if (pc < 0) 49 return -1; /* only active lua functions have current-line information */ 50 else 51 return getline(ci_func(ci)->l.p, pc); 52} 53 54 55/* 56** this function can be called asynchronous (e.g. during a signal) 57*/ 58LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { 59 if (func == NULL || mask == 0) { /* turn off hooks? */ 60 mask = 0; 61 func = NULL; 62 } 63 L->hook = func; 64 L->basehookcount = count; 65 resethookcount(L); 66 L->hookmask = cast_byte(mask); 67 return 1; 68} 69 70 71LUA_API lua_Hook lua_gethook (lua_State *L) { 72 return L->hook; 73} 74 75 76LUA_API int lua_gethookmask (lua_State *L) { 77 return L->hookmask; 78} 79 80 81LUA_API int lua_gethookcount (lua_State *L) { 82 return L->basehookcount; 83} 84 85 86LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) { 87 int status; 88 CallInfo *ci; 89 lua_lock(L); 90 for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) { 91 level--; 92 if (f_isLua(ci)) /* Lua function? */ 93 level -= ci->tailcalls; /* skip lost tail calls */ 94 } 95 if (level == 0 && ci > L->base_ci) { /* level found? */ 96 status = 1; 97 ar->i_ci = cast_int(ci - L->base_ci); 98 } 99 else if (level < 0) { /* level is of a lost tail call? */ 100 status = 1; 101 ar->i_ci = 0; 102 } 103 else status = 0; /* no such level */ 104 lua_unlock(L); 105 return status; 106} 107 108 109static Proto *getluaproto (CallInfo *ci) { 110 return (isLua(ci) ? ci_func(ci)->l.p : NULL); 111} 112 113 114static const char *findlocal (lua_State *L, CallInfo *ci, int n) { 115 const char *name; 116 Proto *fp = getluaproto(ci); 117 if (fp && (name = luaF_getlocalname(fp, n, currentpc(L, ci))) != NULL) 118 return name; /* is a local variable in a Lua function */ 119 else { 120 StkId limit = (ci == L->ci) ? L->top : (ci+1)->func; 121 if (limit - ci->base >= n && n > 0) /* is 'n' inside 'ci' stack? */ 122 return "(*temporary)"; 123 else 124 return NULL; 125 } 126} 127 128 129LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { 130 CallInfo *ci = L->base_ci + ar->i_ci; 131 const char *name = findlocal(L, ci, n); 132 lua_lock(L); 133 if (name) 134 luaA_pushobject(L, ci->base + (n - 1)); 135 lua_unlock(L); 136 return name; 137} 138 139 140LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { 141 CallInfo *ci = L->base_ci + ar->i_ci; 142 const char *name = findlocal(L, ci, n); 143 lua_lock(L); 144 if (name) 145 setobjs2s(L, ci->base + (n - 1), L->top - 1); 146 L->top--; /* pop value */ 147 lua_unlock(L); 148 return name; 149} 150 151 152static void funcinfo (lua_Debug *ar, Closure *cl) { 153 if (cl->c.isC) { 154 ar->source = "=[C]"; 155 ar->linedefined = -1; 156 ar->lastlinedefined = -1; 157 ar->what = "C"; 158 } 159 else { 160 ar->source = getstr(cl->l.p->source); 161 ar->linedefined = cl->l.p->linedefined; 162 ar->lastlinedefined = cl->l.p->lastlinedefined; 163 ar->what = (ar->linedefined == 0) ? "main" : "Lua"; 164 } 165 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); 166} 167 168 169static void info_tailcall (lua_Debug *ar) { 170 ar->name = ar->namewhat = ""; 171 ar->what = "tail"; 172 ar->lastlinedefined = ar->linedefined = ar->currentline = -1; 173 ar->source = "=(tail call)"; 174 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); 175 ar->nups = 0; 176} 177 178 179static void collectvalidlines (lua_State *L, Closure *f) { 180 if (f == NULL || f->c.isC) { 181 setnilvalue(L->top); 182 } 183 else { 184 Table *t = luaH_new(L, 0, 0); 185 int *lineinfo = f->l.p->lineinfo; 186 int i; 187 for (i=0; i<f->l.p->sizelineinfo; i++) 188 setbvalue(luaH_setnum(L, t, lineinfo[i]), 1); 189 sethvalue(L, L->top, t); 190 } 191 incr_top(L); 192} 193 194 195static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, 196 Closure *f, CallInfo *ci) { 197 int status = 1; 198 if (f == NULL) { 199 info_tailcall(ar); 200 return status; 201 } 202 for (; *what; what++) { 203 switch (*what) { 204 case 'S': { 205 funcinfo(ar, f); 206 break; 207 } 208 case 'l': { 209 ar->currentline = (ci) ? currentline(L, ci) : -1; 210 break; 211 } 212 case 'u': { 213 ar->nups = f->c.nupvalues; 214 break; 215 } 216 case 'n': { 217 ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL; 218 if (ar->namewhat == NULL) { 219 ar->namewhat = ""; /* not found */ 220 ar->name = NULL; 221 } 222 break; 223 } 224 case 'L': 225 case 'f': /* handled by lua_getinfo */ 226 break; 227 default: status = 0; /* invalid option */ 228 } 229 } 230 return status; 231} 232 233 234LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) { 235 int status; 236 Closure *f = NULL; 237 CallInfo *ci = NULL; 238 lua_lock(L); 239 if (*what == '>') { 240 StkId func = L->top - 1; 241 luai_apicheck(L, ttisfunction(func)); 242 what++; /* skip the '>' */ 243 f = clvalue(func); 244 L->top--; /* pop function */ 245 } 246 else if (ar->i_ci != 0) { /* no tail call? */ 247 ci = L->base_ci + ar->i_ci; 248 lua_assert(ttisfunction(ci->func)); 249 f = clvalue(ci->func); 250 } 251 status = auxgetinfo(L, what, ar, f, ci); 252 if (strchr(what, 'f')) { 253 if (f == NULL) setnilvalue(L->top); 254 else setclvalue(L, L->top, f); 255 incr_top(L); 256 } 257 if (strchr(what, 'L')) 258 collectvalidlines(L, f); 259 lua_unlock(L); 260 return status; 261} 262 263 264/* 265** {====================================================== 266** Symbolic Execution and code checker 267** ======================================================= 268*/ 269 270#define check(x) if (!(x)) return 0; 271 272#define checkjump(pt,pc) check(0 <= pc && pc < pt->sizecode) 273 274#define checkreg(pt,reg) check((reg) < (pt)->maxstacksize) 275 276 277 278static int precheck (const Proto *pt) { 279 check(pt->maxstacksize <= MAXSTACK); 280 check(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize); 281 check(!(pt->is_vararg & VARARG_NEEDSARG) || 282 (pt->is_vararg & VARARG_HASARG)); 283 check(pt->sizeupvalues <= pt->nups); 284 check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0); 285 check(pt->sizecode > 0 && GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN); 286 return 1; 287} 288 289 290#define checkopenop(pt,pc) luaG_checkopenop((pt)->code[(pc)+1]) 291 292int luaG_checkopenop (Instruction i) { 293 switch (GET_OPCODE(i)) { 294 case OP_CALL: 295 case OP_TAILCALL: 296 case OP_RETURN: 297 case OP_SETLIST: { 298 check(GETARG_B(i) == 0); 299 return 1; 300 } 301 default: return 0; /* invalid instruction after an open call */ 302 } 303} 304 305 306static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) { 307 switch (mode) { 308 case OpArgN: check(r == 0); break; 309 case OpArgU: break; 310 case OpArgR: checkreg(pt, r); break; 311 case OpArgK: 312 check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize); 313 break; 314 } 315 return 1; 316} 317 318 319static Instruction symbexec (const Proto *pt, int lastpc, int reg) { 320 int pc; 321 int last; /* stores position of last instruction that changed `reg' */ 322 last = pt->sizecode-1; /* points to final return (a `neutral' instruction) */ 323 check(precheck(pt)); 324 for (pc = 0; pc < lastpc; pc++) { 325 Instruction i = pt->code[pc]; 326 OpCode op = GET_OPCODE(i); 327 int a = GETARG_A(i); 328 int b = 0; 329 int c = 0; 330 check(op < NUM_OPCODES); 331 checkreg(pt, a); 332 switch (getOpMode(op)) { 333 case iABC: { 334 b = GETARG_B(i); 335 c = GETARG_C(i); 336 check(checkArgMode(pt, b, getBMode(op))); 337 check(checkArgMode(pt, c, getCMode(op))); 338 break; 339 } 340 case iABx: { 341 b = GETARG_Bx(i); 342 if (getBMode(op) == OpArgK) check(b < pt->sizek); 343 break; 344 } 345 case iAsBx: { 346 b = GETARG_sBx(i); 347 if (getBMode(op) == OpArgR) { 348 int dest = pc+1+b; 349 check(0 <= dest && dest < pt->sizecode); 350 if (dest > 0) { 351 int j; 352 /* check that it does not jump to a setlist count; this 353 is tricky, because the count from a previous setlist may 354 have the same value of an invalid setlist; so, we must 355 go all the way back to the first of them (if any) */ 356 for (j = 0; j < dest; j++) { 357 Instruction d = pt->code[dest-1-j]; 358 if (!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0)) break; 359 } 360 /* if 'j' is even, previous value is not a setlist (even if 361 it looks like one) */ 362 check((j&1) == 0); 363 } 364 } 365 break; 366 } 367 } 368 if (testAMode(op)) { 369 if (a == reg) last = pc; /* change register `a' */ 370 } 371 if (testTMode(op)) { 372 check(pc+2 < pt->sizecode); /* check skip */ 373 check(GET_OPCODE(pt->code[pc+1]) == OP_JMP); 374 } 375 switch (op) { 376 case OP_LOADBOOL: { 377 if (c == 1) { /* does it jump? */ 378 check(pc+2 < pt->sizecode); /* check its jump */ 379 check(GET_OPCODE(pt->code[pc+1]) != OP_SETLIST || 380 GETARG_C(pt->code[pc+1]) != 0); 381 } 382 break; 383 } 384 case OP_LOADNIL: { 385 if (a <= reg && reg <= b) 386 last = pc; /* set registers from `a' to `b' */ 387 break; 388 } 389 case OP_GETUPVAL: 390 case OP_SETUPVAL: { 391 check(b < pt->nups); 392 break; 393 } 394 case OP_GETGLOBAL: 395 case OP_SETGLOBAL: { 396 check(ttisstring(&pt->k[b])); 397 break; 398 } 399 case OP_SELF: { 400 checkreg(pt, a+1); 401 if (reg == a+1) last = pc; 402 break; 403 } 404 case OP_CONCAT: { 405 check(b < c); /* at least two operands */ 406 break; 407 } 408 case OP_TFORLOOP: { 409 check(c >= 1); /* at least one result (control variable) */ 410 checkreg(pt, a+2+c); /* space for results */ 411 if (reg >= a+2) last = pc; /* affect all regs above its base */ 412 break; 413 } 414 case OP_FORLOOP: 415 case OP_FORPREP: 416 checkreg(pt, a+3); 417 /* go through */ 418 case OP_JMP: { 419 int dest = pc+1+b; 420 /* not full check and jump is forward and do not skip `lastpc'? */ 421 if (reg != NO_REG && pc < dest && dest <= lastpc) 422 pc += b; /* do the jump */ 423 break; 424 } 425 case OP_CALL: 426 case OP_TAILCALL: { 427 if (b != 0) { 428 checkreg(pt, a+b-1); 429 } 430 c--; /* c = num. returns */ 431 if (c == LUA_MULTRET) { 432 check(checkopenop(pt, pc)); 433 } 434 else if (c != 0) 435 checkreg(pt, a+c-1); 436 if (reg >= a) last = pc; /* affect all registers above base */ 437 break; 438 } 439 case OP_RETURN: { 440 b--; /* b = num. returns */ 441 if (b > 0) checkreg(pt, a+b-1); 442 break; 443 } 444 case OP_SETLIST: { 445 if (b > 0) checkreg(pt, a + b); 446 if (c == 0) { 447 pc++; 448 check(pc < pt->sizecode - 1); 449 } 450 break; 451 } 452 case OP_CLOSURE: { 453 int nup, j; 454 check(b < pt->sizep); 455 nup = pt->p[b]->nups; 456 check(pc + nup < pt->sizecode); 457 for (j = 1; j <= nup; j++) { 458 OpCode op1 = GET_OPCODE(pt->code[pc + j]); 459 check(op1 == OP_GETUPVAL || op1 == OP_MOVE); 460 } 461 if (reg != NO_REG) /* tracing? */ 462 pc += nup; /* do not 'execute' these pseudo-instructions */ 463 break; 464 } 465 case OP_VARARG: { 466 check((pt->is_vararg & VARARG_ISVARARG) && 467 !(pt->is_vararg & VARARG_NEEDSARG)); 468 b--; 469 if (b == LUA_MULTRET) check(checkopenop(pt, pc)); 470 checkreg(pt, a+b-1); 471 break; 472 } 473 default: break; 474 } 475 } 476 return pt->code[last]; 477} 478 479#undef check 480#undef checkjump 481#undef checkreg 482 483/* }====================================================== */ 484 485 486int luaG_checkcode (const Proto *pt) { 487 return (symbexec(pt, pt->sizecode, NO_REG) != 0); 488} 489 490 491static const char *kname (Proto *p, int c) { 492 if (ISK(c) && ttisstring(&p->k[INDEXK(c)])) 493 return svalue(&p->k[INDEXK(c)]); 494 else 495 return "?"; 496} 497 498 499static const char *getobjname (lua_State *L, CallInfo *ci, int stackpos, 500 const char **name) { 501 if (isLua(ci)) { /* a Lua function? */ 502 Proto *p = ci_func(ci)->l.p; 503 int pc = currentpc(L, ci); 504 Instruction i; 505 *name = luaF_getlocalname(p, stackpos+1, pc); 506 if (*name) /* is a local? */ 507 return "local"; 508 i = symbexec(p, pc, stackpos); /* try symbolic execution */ 509 lua_assert(pc != -1); 510 switch (GET_OPCODE(i)) { 511 case OP_GETGLOBAL: { 512 int g = GETARG_Bx(i); /* global index */ 513 lua_assert(ttisstring(&p->k[g])); 514 *name = svalue(&p->k[g]); 515 return "global"; 516 } 517 case OP_MOVE: { 518 int a = GETARG_A(i); 519 int b = GETARG_B(i); /* move from `b' to `a' */ 520 if (b < a) 521 return getobjname(L, ci, b, name); /* get name for `b' */ 522 break; 523 } 524 case OP_GETTABLE: { 525 int k = GETARG_C(i); /* key index */ 526 *name = kname(p, k); 527 return "field"; 528 } 529 case OP_GETUPVAL: { 530 int u = GETARG_B(i); /* upvalue index */ 531 *name = p->upvalues ? getstr(p->upvalues[u]) : "?"; 532 return "upvalue"; 533 } 534 case OP_SELF: { 535 int k = GETARG_C(i); /* key index */ 536 *name = kname(p, k); 537 return "method"; 538 } 539 default: break; 540 } 541 } 542 return NULL; /* no useful name found */ 543} 544 545 546static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { 547 Instruction i; 548 if ((isLua(ci) && ci->tailcalls > 0) || !isLua(ci - 1)) 549 return NULL; /* calling function is not Lua (or is unknown) */ 550 ci--; /* calling function */ 551 i = ci_func(ci)->l.p->code[currentpc(L, ci)]; 552 if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL || 553 GET_OPCODE(i) == OP_TFORLOOP) 554 return getobjname(L, ci, GETARG_A(i), name); 555 else 556 return NULL; /* no useful name can be found */ 557} 558 559 560/* only ANSI way to check whether a pointer points to an array */ 561static int isinstack (CallInfo *ci, const TValue *o) { 562 StkId p; 563 for (p = ci->base; p < ci->top; p++) 564 if (o == p) return 1; 565 return 0; 566} 567 568 569void luaG_typeerror (lua_State *L, const TValue *o, const char *op) { 570 const char *name = NULL; 571 const char *t = luaT_typenames[ttype(o)]; 572 const char *kind = (isinstack(L->ci, o)) ? 573 getobjname(L, L->ci, cast_int(o - L->base), &name) : 574 NULL; 575 if (kind) 576 luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)", 577 op, kind, name, t); 578 else 579 luaG_runerror(L, "attempt to %s a %s value", op, t); 580} 581 582 583void luaG_concaterror (lua_State *L, StkId p1, StkId p2) { 584 if (ttisstring(p1) || ttisnumber(p1)) p1 = p2; 585 lua_assert(!ttisstring(p1) && !ttisnumber(p1)); 586 luaG_typeerror(L, p1, "concatenate"); 587} 588 589 590void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) { 591 TValue temp; 592 if (luaV_tonumber(p1, &temp) == NULL) 593 p2 = p1; /* first operand is wrong */ 594 luaG_typeerror(L, p2, "perform arithmetic on"); 595} 596 597 598int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { 599 const char *t1 = luaT_typenames[ttype(p1)]; 600 const char *t2 = luaT_typenames[ttype(p2)]; 601 if (t1[2] == t2[2]) 602 luaG_runerror(L, "attempt to compare two %s values", t1); 603 else 604 luaG_runerror(L, "attempt to compare %s with %s", t1, t2); 605 return 0; 606} 607 608 609static void addinfo (lua_State *L, const char *msg) { 610 CallInfo *ci = L->ci; 611 if (isLua(ci)) { /* is Lua code? */ 612 char buff[LUA_IDSIZE]; /* add file:line information */ 613 int line = currentline(L, ci); 614 luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE); 615 luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); 616 } 617} 618 619 620void luaG_errormsg (lua_State *L) { 621 if (L->errfunc != 0) { /* is there an error handling function? */ 622 StkId errfunc = restorestack(L, L->errfunc); 623 if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR); 624 setobjs2s(L, L->top, L->top - 1); /* move argument */ 625 setobjs2s(L, L->top - 1, errfunc); /* push function */ 626 incr_top(L); 627 luaD_call(L, L->top - 2, 1); /* call it */ 628 } 629 luaD_throw(L, LUA_ERRRUN); 630} 631 632 633void luaG_runerror (lua_State *L, const char *fmt, ...) { 634 va_list argp; 635 va_start(argp, fmt); 636 addinfo(L, luaO_pushvfstring(L, fmt, argp)); 637 va_end(argp); 638 luaG_errormsg(L); 639} 640 641