2 ** $Id: ldebug.c,v 2.117 2015/11/02 18:48:07 roberto Exp $
4 ** See Copyright Notice in lua.h
34 #define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL)
37 /* Active Lua function (given call info) */
38 #define ci_func(ci) (clLvalue((ci)->func))
41 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
44 static int currentpc (CallInfo *ci) {
45 lua_assert(isLua(ci));
46 return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
50 static int currentline (CallInfo *ci) {
51 return getfuncline(ci_func(ci)->p, currentpc(ci));
56 ** If function yielded, its 'func' can be in the 'extra' field. The
57 ** next function restores 'func' to its correct value for debugging
58 ** purposes. (It exchanges 'func' and 'extra'; so, when called again,
59 ** after debugging, it also "re-restores" ** 'func' to its altered value.
61 static void swapextra (lua_State *L) {
62 if (L->status == LUA_YIELD) {
63 CallInfo *ci = L->ci; /* get function that yielded */
64 StkId temp = ci->func; /* exchange its 'func' and 'extra' values */
65 ci->func = restorestack(L, ci->extra);
66 ci->extra = savestack(L, temp);
72 ** this function can be called asynchronous (e.g. during a signal)
74 LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
75 if (func == NULL || mask == 0) { /* turn off hooks? */
80 L->oldpc = L->ci->u.l.savedpc;
82 L->basehookcount = count;
84 L->hookmask = cast_byte(mask);
88 LUA_API lua_Hook lua_gethook (lua_State *L) {
93 LUA_API int lua_gethookmask (lua_State *L) {
98 LUA_API int lua_gethookcount (lua_State *L) {
99 return L->basehookcount;
103 LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
106 if (level < 0) return 0; /* invalid (negative) level */
108 for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
110 if (level == 0 && ci != &L->base_ci) { /* level found? */
114 else status = 0; /* no such level */
120 static const char *upvalname (Proto *p, int uv) {
121 TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
122 if (s == NULL) return "?";
123 else return getstr(s);
127 static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
128 int nparams = clLvalue(ci->func)->p->numparams;
129 if (n >= cast_int(ci->u.l.base - ci->func) - nparams)
130 return NULL; /* no such vararg */
132 *pos = ci->func + nparams + n;
133 return "(*vararg)"; /* generic name for any vararg */
138 static const char *findlocal (lua_State *L, CallInfo *ci, int n,
140 const char *name = NULL;
143 if (n < 0) /* access to vararg values? */
144 return findvararg(ci, -n, pos);
147 name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
152 if (name == NULL) { /* no 'standard' name? */
153 StkId limit = (ci == L->ci) ? L->top : ci->next->func;
154 if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */
155 name = "(*temporary)"; /* generic name for any valid slot */
157 return NULL; /* no name */
159 *pos = base + (n - 1);
164 LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
168 if (ar == NULL) { /* information about non-active function? */
169 if (!isLfunction(L->top - 1)) /* not a Lua function? */
171 else /* consider live variables at function start (parameters) */
172 name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
174 else { /* active function; get information through 'ar' */
175 StkId pos = NULL; /* to avoid warnings */
176 name = findlocal(L, ar->i_ci, n, &pos);
178 setobj2s(L, L->top, pos);
188 LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
189 StkId pos = NULL; /* to avoid warnings */
193 name = findlocal(L, ar->i_ci, n, &pos);
195 setobjs2s(L, pos, L->top - 1);
196 L->top--; /* pop value */
204 static void funcinfo (lua_Debug *ar, Closure *cl) {
205 if (noLuaClosure(cl)) {
207 ar->linedefined = -1;
208 ar->lastlinedefined = -1;
213 ar->source = p->source ? getstr(p->source) : "=?";
214 ar->linedefined = p->linedefined;
215 ar->lastlinedefined = p->lastlinedefined;
216 ar->what = (ar->linedefined == 0) ? "main" : "Lua";
218 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
222 static void collectvalidlines (lua_State *L, Closure *f) {
223 if (noLuaClosure(f)) {
230 int *lineinfo = f->l.p->lineinfo;
231 Table *t = luaH_new(L); /* new table to store active lines */
232 sethvalue(L, L->top, t); /* push it on stack */
234 setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */
235 for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */
236 luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */
241 static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
242 Closure *f, CallInfo *ci) {
244 for (; *what; what++) {
251 ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
255 ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
256 if (noLuaClosure(f)) {
261 ar->isvararg = f->l.p->is_vararg;
262 ar->nparams = f->l.p->numparams;
267 ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
271 /* calling function is a known Lua function? */
272 if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
273 ar->namewhat = getfuncname(L, ci->previous, &ar->name);
276 if (ar->namewhat == NULL) {
277 ar->namewhat = ""; /* not found */
283 case 'f': /* handled by lua_getinfo */
285 default: status = 0; /* invalid option */
292 LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
302 api_check(L, ttisfunction(func), "function expected");
303 what++; /* skip the '>' */
304 L->top--; /* pop function */
309 lua_assert(ttisfunction(ci->func));
311 cl = ttisclosure(func) ? clvalue(func) : NULL;
312 status = auxgetinfo(L, what, ar, cl, ci);
313 if (strchr(what, 'f')) {
314 setobjs2s(L, L->top, func);
317 swapextra(L); /* correct before option 'L', which can raise a mem. error */
318 if (strchr(what, 'L'))
319 collectvalidlines(L, cl);
326 ** {======================================================
327 ** Symbolic Execution
328 ** =======================================================
331 static const char *getobjname (Proto *p, int lastpc, int reg,
336 ** find a "name" for the RK value 'c'
338 static void kname (Proto *p, int pc, int c, const char **name) {
339 if (ISK(c)) { /* is 'c' a constant? */
340 TValue *kvalue = &p->k[INDEXK(c)];
341 if (ttisstring(kvalue)) { /* literal constant? */
342 *name = svalue(kvalue); /* it is its own name */
345 /* else no reasonable name found */
347 else { /* 'c' is a register */
348 const char *what = getobjname(p, pc, c, name); /* search for 'c' */
349 if (what && *what == 'c') { /* found a constant name? */
350 return; /* 'name' already filled */
352 /* else no reasonable name found */
354 *name = "?"; /* no reasonable name found */
358 static int filterpc (int pc, int jmptarget) {
359 if (pc < jmptarget) /* is code conditional (inside a jump)? */
360 return -1; /* cannot know who sets that register */
361 else return pc; /* current position sets that register */
366 ** try to find last instruction before 'lastpc' that modified register 'reg'
368 static int findsetreg (Proto *p, int lastpc, int reg) {
370 int setreg = -1; /* keep last instruction that changed 'reg' */
371 int jmptarget = 0; /* any code before this address is conditional */
372 for (pc = 0; pc < lastpc; pc++) {
373 Instruction i = p->code[pc];
374 OpCode op = GET_OPCODE(i);
379 if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */
380 setreg = filterpc(pc, jmptarget);
384 if (reg >= a + 2) /* affect all regs above its base */
385 setreg = filterpc(pc, jmptarget);
390 if (reg >= a) /* affect all registers above base */
391 setreg = filterpc(pc, jmptarget);
395 int b = GETARG_sBx(i);
396 int dest = pc + 1 + b;
397 /* jump is forward and do not skip 'lastpc'? */
398 if (pc < dest && dest <= lastpc) {
399 if (dest > jmptarget)
400 jmptarget = dest; /* update 'jmptarget' */
405 if (testAMode(op) && reg == a) /* any instruction that set A */
406 setreg = filterpc(pc, jmptarget);
414 static const char *getobjname (Proto *p, int lastpc, int reg,
417 *name = luaF_getlocalname(p, reg + 1, lastpc);
418 if (*name) /* is a local? */
420 /* else try symbolic execution */
421 pc = findsetreg(p, lastpc, reg);
422 if (pc != -1) { /* could find instruction? */
423 Instruction i = p->code[pc];
424 OpCode op = GET_OPCODE(i);
427 int b = GETARG_B(i); /* move from 'b' to 'a' */
429 return getobjname(p, pc, b, name); /* get name for 'b' */
434 int k = GETARG_C(i); /* key index */
435 int t = GETARG_B(i); /* table index */
436 const char *vn = (op == OP_GETTABLE) /* name of indexed variable */
437 ? luaF_getlocalname(p, t + 1, pc)
439 kname(p, pc, k, name);
440 return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
443 *name = upvalname(p, GETARG_B(i));
448 int b = (op == OP_LOADK) ? GETARG_Bx(i)
449 : GETARG_Ax(p->code[pc + 1]);
450 if (ttisstring(&p->k[b])) {
451 *name = svalue(&p->k[b]);
457 int k = GETARG_C(i); /* key index */
458 kname(p, pc, k, name);
461 default: break; /* go through to return NULL */
464 return NULL; /* could not find reasonable name */
468 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
469 TMS tm = (TMS)0; /* to avoid warnings */
470 Proto *p = ci_func(ci)->p; /* calling function */
471 int pc = currentpc(ci); /* calling instruction index */
472 Instruction i = p->code[pc]; /* calling instruction */
473 if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */
477 switch (GET_OPCODE(i)) {
479 case OP_TAILCALL: /* get function name */
480 return getobjname(p, pc, GETARG_A(i), name);
481 case OP_TFORCALL: { /* for iterator */
482 *name = "for iterator";
483 return "for iterator";
485 /* all other instructions can call only through metamethods */
486 case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
489 case OP_SETTABUP: case OP_SETTABLE:
492 case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD:
493 case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND:
494 case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: {
495 int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD); /* ORDER OP */
496 tm = cast(TMS, offset + cast_int(TM_ADD)); /* ORDER TM */
499 case OP_UNM: tm = TM_UNM; break;
500 case OP_BNOT: tm = TM_BNOT; break;
501 case OP_LEN: tm = TM_LEN; break;
502 case OP_CONCAT: tm = TM_CONCAT; break;
503 case OP_EQ: tm = TM_EQ; break;
504 case OP_LT: tm = TM_LT; break;
505 case OP_LE: tm = TM_LE; break;
506 default: lua_assert(0); /* other instructions cannot call a function */
508 *name = getstr(G(L)->tmname[tm]);
512 /* }====================================================== */
517 ** The subtraction of two potentially unrelated pointers is
518 ** not ISO C, but it should not crash a program; the subsequent
519 ** checks are ISO C and ensure a correct result.
521 static int isinstack (CallInfo *ci, const TValue *o) {
522 ptrdiff_t i = o - ci->u.l.base;
523 return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o);
528 ** Checks whether value 'o' came from an upvalue. (That can only happen
529 ** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on
532 static const char *getupvalname (CallInfo *ci, const TValue *o,
534 LClosure *c = ci_func(ci);
536 for (i = 0; i < c->nupvalues; i++) {
537 if (c->upvals[i]->v == o) {
538 *name = upvalname(c->p, i);
546 static const char *varinfo (lua_State *L, const TValue *o) {
547 const char *name = NULL; /* to avoid warnings */
548 CallInfo *ci = L->ci;
549 const char *kind = NULL;
551 kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */
552 if (!kind && isinstack(ci, o)) /* no? try a register */
553 kind = getobjname(ci_func(ci)->p, currentpc(ci),
554 cast_int(o - ci->u.l.base), &name);
556 return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
560 l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
561 const char *t = objtypename(o);
562 luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
566 l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
567 if (ttisstring(p1) || cvt2str(p1)) p1 = p2;
568 luaG_typeerror(L, p1, "concatenate");
572 l_noret luaG_opinterror (lua_State *L, const TValue *p1,
573 const TValue *p2, const char *msg) {
575 if (!tonumber(p1, &temp)) /* first operand is wrong? */
576 p2 = p1; /* now second is wrong */
577 luaG_typeerror(L, p2, msg);
582 ** Error when both values are convertible to numbers, but not to integers
584 l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
586 if (!tointeger(p1, &temp))
588 luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
592 l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
593 const char *t1 = objtypename(p1);
594 const char *t2 = objtypename(p2);
596 luaG_runerror(L, "attempt to compare two %s values", t1);
598 luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
602 /* add src:line information to 'msg' */
603 const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
605 char buff[LUA_IDSIZE];
607 luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
608 else { /* no source available; use "?" instead */
609 buff[0] = '?'; buff[1] = '\0';
611 return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
615 l_noret luaG_errormsg (lua_State *L) {
616 if (L->errfunc != 0) { /* is there an error handling function? */
617 StkId errfunc = restorestack(L, L->errfunc);
618 setobjs2s(L, L->top, L->top - 1); /* move argument */
619 setobjs2s(L, L->top - 1, errfunc); /* push function */
620 L->top++; /* assume EXTRA_STACK */
621 luaD_callnoyield(L, L->top - 2, 1); /* call it */
623 luaD_throw(L, LUA_ERRRUN);
627 l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
628 CallInfo *ci = L->ci;
632 msg = luaO_pushvfstring(L, fmt, argp); /* format message */
634 if (isLua(ci)) /* if Lua function, add source:line information */
635 luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci));
640 void luaG_traceexec (lua_State *L) {
641 CallInfo *ci = L->ci;
642 lu_byte mask = L->hookmask;
643 int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
645 resethookcount(L); /* reset count */
646 else if (!(mask & LUA_MASKLINE))
647 return; /* no line hook and count != 0; nothing to be done */
648 if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */
649 ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */
650 return; /* do not call hook again (VM yielded, so it did not move) */
653 luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */
654 if (mask & LUA_MASKLINE) {
655 Proto *p = ci_func(ci)->p;
656 int npc = pcRel(ci->u.l.savedpc, p);
657 int newline = getfuncline(p, npc);
658 if (npc == 0 || /* call linehook when enter a new function, */
659 ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */
660 newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */
661 luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */
663 L->oldpc = ci->u.l.savedpc;
664 if (L->status == LUA_YIELD) { /* did hook yield? */
666 L->hookcount = 1; /* undo decrement to zero */
667 ci->u.l.savedpc--; /* undo increment (resume will increment it again) */
668 ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */
669 ci->func = L->top - 1; /* protect stack below results */
670 luaD_throw(L, LUA_YIELD);