2 ** $Id: ldebug.c,v 2.120 2016/03/31 19:01:21 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 asynchronously (e.g. during a signal).
73 ** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
74 ** 'resethookcount') are for debug only, and it is no problem if they
75 ** get arbitrary values (causes at most one wrong hook call). 'hookmask'
76 ** is an atomic value. We assume that pointers are atomic too (e.g., gcc
77 ** ensures that for all platforms where it runs). Moreover, 'hook' is
78 ** always checked before being called (see 'luaD_hook').
80 LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
81 if (func == NULL || mask == 0) { /* turn off hooks? */
86 L->oldpc = L->ci->u.l.savedpc;
88 L->basehookcount = count;
90 L->hookmask = cast_byte(mask);
94 LUA_API lua_Hook lua_gethook (lua_State *L) {
99 LUA_API int lua_gethookmask (lua_State *L) {
104 LUA_API int lua_gethookcount (lua_State *L) {
105 return L->basehookcount;
109 LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
112 if (level < 0) return 0; /* invalid (negative) level */
114 for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
116 if (level == 0 && ci != &L->base_ci) { /* level found? */
120 else status = 0; /* no such level */
126 static const char *upvalname (Proto *p, int uv) {
127 TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
128 if (s == NULL) return "?";
129 else return getstr(s);
133 static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
134 int nparams = clLvalue(ci->func)->p->numparams;
135 if (n >= cast_int(ci->u.l.base - ci->func) - nparams)
136 return NULL; /* no such vararg */
138 *pos = ci->func + nparams + n;
139 return "(*vararg)"; /* generic name for any vararg */
144 static const char *findlocal (lua_State *L, CallInfo *ci, int n,
146 const char *name = NULL;
149 if (n < 0) /* access to vararg values? */
150 return findvararg(ci, -n, pos);
153 name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
158 if (name == NULL) { /* no 'standard' name? */
159 StkId limit = (ci == L->ci) ? L->top : ci->next->func;
160 if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */
161 name = "(*temporary)"; /* generic name for any valid slot */
163 return NULL; /* no name */
165 *pos = base + (n - 1);
170 LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
174 if (ar == NULL) { /* information about non-active function? */
175 if (!isLfunction(L->top - 1)) /* not a Lua function? */
177 else /* consider live variables at function start (parameters) */
178 name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
180 else { /* active function; get information through 'ar' */
181 StkId pos = NULL; /* to avoid warnings */
182 name = findlocal(L, ar->i_ci, n, &pos);
184 setobj2s(L, L->top, pos);
194 LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
195 StkId pos = NULL; /* to avoid warnings */
199 name = findlocal(L, ar->i_ci, n, &pos);
201 setobjs2s(L, pos, L->top - 1);
202 L->top--; /* pop value */
210 static void funcinfo (lua_Debug *ar, Closure *cl) {
211 if (noLuaClosure(cl)) {
213 ar->linedefined = -1;
214 ar->lastlinedefined = -1;
219 ar->source = p->source ? getstr(p->source) : "=?";
220 ar->linedefined = p->linedefined;
221 ar->lastlinedefined = p->lastlinedefined;
222 ar->what = (ar->linedefined == 0) ? "main" : "Lua";
224 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
228 static void collectvalidlines (lua_State *L, Closure *f) {
229 if (noLuaClosure(f)) {
236 int *lineinfo = f->l.p->lineinfo;
237 Table *t = luaH_new(L); /* new table to store active lines */
238 sethvalue(L, L->top, t); /* push it on stack */
240 setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */
241 for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */
242 luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */
247 static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
248 Closure *f, CallInfo *ci) {
250 for (; *what; what++) {
257 ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
261 ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
262 if (noLuaClosure(f)) {
267 ar->isvararg = f->l.p->is_vararg;
268 ar->nparams = f->l.p->numparams;
273 ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
277 /* calling function is a known Lua function? */
278 if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
279 ar->namewhat = getfuncname(L, ci->previous, &ar->name);
282 if (ar->namewhat == NULL) {
283 ar->namewhat = ""; /* not found */
289 case 'f': /* handled by lua_getinfo */
291 default: status = 0; /* invalid option */
298 LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
308 api_check(L, ttisfunction(func), "function expected");
309 what++; /* skip the '>' */
310 L->top--; /* pop function */
315 lua_assert(ttisfunction(ci->func));
317 cl = ttisclosure(func) ? clvalue(func) : NULL;
318 status = auxgetinfo(L, what, ar, cl, ci);
319 if (strchr(what, 'f')) {
320 setobjs2s(L, L->top, func);
323 swapextra(L); /* correct before option 'L', which can raise a mem. error */
324 if (strchr(what, 'L'))
325 collectvalidlines(L, cl);
332 ** {======================================================
333 ** Symbolic Execution
334 ** =======================================================
337 static const char *getobjname (Proto *p, int lastpc, int reg,
342 ** find a "name" for the RK value 'c'
344 static void kname (Proto *p, int pc, int c, const char **name) {
345 if (ISK(c)) { /* is 'c' a constant? */
346 TValue *kvalue = &p->k[INDEXK(c)];
347 if (ttisstring(kvalue)) { /* literal constant? */
348 *name = svalue(kvalue); /* it is its own name */
351 /* else no reasonable name found */
353 else { /* 'c' is a register */
354 const char *what = getobjname(p, pc, c, name); /* search for 'c' */
355 if (what && *what == 'c') { /* found a constant name? */
356 return; /* 'name' already filled */
358 /* else no reasonable name found */
360 *name = "?"; /* no reasonable name found */
364 static int filterpc (int pc, int jmptarget) {
365 if (pc < jmptarget) /* is code conditional (inside a jump)? */
366 return -1; /* cannot know who sets that register */
367 else return pc; /* current position sets that register */
372 ** try to find last instruction before 'lastpc' that modified register 'reg'
374 static int findsetreg (Proto *p, int lastpc, int reg) {
376 int setreg = -1; /* keep last instruction that changed 'reg' */
377 int jmptarget = 0; /* any code before this address is conditional */
378 for (pc = 0; pc < lastpc; pc++) {
379 Instruction i = p->code[pc];
380 OpCode op = GET_OPCODE(i);
385 if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */
386 setreg = filterpc(pc, jmptarget);
390 if (reg >= a + 2) /* affect all regs above its base */
391 setreg = filterpc(pc, jmptarget);
396 if (reg >= a) /* affect all registers above base */
397 setreg = filterpc(pc, jmptarget);
401 int b = GETARG_sBx(i);
402 int dest = pc + 1 + b;
403 /* jump is forward and do not skip 'lastpc'? */
404 if (pc < dest && dest <= lastpc) {
405 if (dest > jmptarget)
406 jmptarget = dest; /* update 'jmptarget' */
411 if (testAMode(op) && reg == a) /* any instruction that set A */
412 setreg = filterpc(pc, jmptarget);
420 static const char *getobjname (Proto *p, int lastpc, int reg,
423 *name = luaF_getlocalname(p, reg + 1, lastpc);
424 if (*name) /* is a local? */
426 /* else try symbolic execution */
427 pc = findsetreg(p, lastpc, reg);
428 if (pc != -1) { /* could find instruction? */
429 Instruction i = p->code[pc];
430 OpCode op = GET_OPCODE(i);
433 int b = GETARG_B(i); /* move from 'b' to 'a' */
435 return getobjname(p, pc, b, name); /* get name for 'b' */
440 int k = GETARG_C(i); /* key index */
441 int t = GETARG_B(i); /* table index */
442 const char *vn = (op == OP_GETTABLE) /* name of indexed variable */
443 ? luaF_getlocalname(p, t + 1, pc)
445 kname(p, pc, k, name);
446 return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
449 *name = upvalname(p, GETARG_B(i));
454 int b = (op == OP_LOADK) ? GETARG_Bx(i)
455 : GETARG_Ax(p->code[pc + 1]);
456 if (ttisstring(&p->k[b])) {
457 *name = svalue(&p->k[b]);
463 int k = GETARG_C(i); /* key index */
464 kname(p, pc, k, name);
467 default: break; /* go through to return NULL */
470 return NULL; /* could not find reasonable name */
474 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
475 TMS tm = (TMS)0; /* to avoid warnings */
476 Proto *p = ci_func(ci)->p; /* calling function */
477 int pc = currentpc(ci); /* calling instruction index */
478 Instruction i = p->code[pc]; /* calling instruction */
479 if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */
483 switch (GET_OPCODE(i)) {
485 case OP_TAILCALL: /* get function name */
486 return getobjname(p, pc, GETARG_A(i), name);
487 case OP_TFORCALL: { /* for iterator */
488 *name = "for iterator";
489 return "for iterator";
491 /* all other instructions can call only through metamethods */
492 case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
495 case OP_SETTABUP: case OP_SETTABLE:
498 case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD:
499 case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND:
500 case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: {
501 int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD); /* ORDER OP */
502 tm = cast(TMS, offset + cast_int(TM_ADD)); /* ORDER TM */
505 case OP_UNM: tm = TM_UNM; break;
506 case OP_BNOT: tm = TM_BNOT; break;
507 case OP_LEN: tm = TM_LEN; break;
508 case OP_CONCAT: tm = TM_CONCAT; break;
509 case OP_EQ: tm = TM_EQ; break;
510 case OP_LT: tm = TM_LT; break;
511 case OP_LE: tm = TM_LE; break;
512 default: lua_assert(0); /* other instructions cannot call a function */
514 *name = getstr(G(L)->tmname[tm]);
518 /* }====================================================== */
523 ** The subtraction of two potentially unrelated pointers is
524 ** not ISO C, but it should not crash a program; the subsequent
525 ** checks are ISO C and ensure a correct result.
527 static int isinstack (CallInfo *ci, const TValue *o) {
528 ptrdiff_t i = o - ci->u.l.base;
529 return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o);
534 ** Checks whether value 'o' came from an upvalue. (That can only happen
535 ** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on
538 static const char *getupvalname (CallInfo *ci, const TValue *o,
540 LClosure *c = ci_func(ci);
542 for (i = 0; i < c->nupvalues; i++) {
543 if (c->upvals[i]->v == o) {
544 *name = upvalname(c->p, i);
552 static const char *varinfo (lua_State *L, const TValue *o) {
553 const char *name = NULL; /* to avoid warnings */
554 CallInfo *ci = L->ci;
555 const char *kind = NULL;
557 kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */
558 if (!kind && isinstack(ci, o)) /* no? try a register */
559 kind = getobjname(ci_func(ci)->p, currentpc(ci),
560 cast_int(o - ci->u.l.base), &name);
562 return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
566 l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
567 const char *t = luaT_objtypename(L, o);
568 luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
572 l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
573 if (ttisstring(p1) || cvt2str(p1)) p1 = p2;
574 luaG_typeerror(L, p1, "concatenate");
578 l_noret luaG_opinterror (lua_State *L, const TValue *p1,
579 const TValue *p2, const char *msg) {
581 if (!tonumber(p1, &temp)) /* first operand is wrong? */
582 p2 = p1; /* now second is wrong */
583 luaG_typeerror(L, p2, msg);
588 ** Error when both values are convertible to numbers, but not to integers
590 l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
592 if (!tointeger(p1, &temp))
594 luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
598 l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
599 const char *t1 = luaT_objtypename(L, p1);
600 const char *t2 = luaT_objtypename(L, p2);
601 if (strcmp(t1, t2) == 0)
602 luaG_runerror(L, "attempt to compare two %s values", t1);
604 luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
608 /* add src:line information to 'msg' */
609 const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
611 char buff[LUA_IDSIZE];
613 luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
614 else { /* no source available; use "?" instead */
615 buff[0] = '?'; buff[1] = '\0';
617 return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
621 l_noret luaG_errormsg (lua_State *L) {
622 if (L->errfunc != 0) { /* is there an error handling function? */
623 StkId errfunc = restorestack(L, L->errfunc);
624 setobjs2s(L, L->top, L->top - 1); /* move argument */
625 setobjs2s(L, L->top - 1, errfunc); /* push function */
626 L->top++; /* assume EXTRA_STACK */
627 luaD_callnoyield(L, L->top - 2, 1); /* call it */
629 luaD_throw(L, LUA_ERRRUN);
633 l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
634 CallInfo *ci = L->ci;
638 msg = luaO_pushvfstring(L, fmt, argp); /* format message */
640 if (isLua(ci)) /* if Lua function, add source:line information */
641 luaG_addinfo(L, msg, ci_func(ci)->p->source, currentline(ci));
646 void luaG_traceexec (lua_State *L) {
647 CallInfo *ci = L->ci;
648 lu_byte mask = L->hookmask;
649 int counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
651 resethookcount(L); /* reset count */
652 else if (!(mask & LUA_MASKLINE))
653 return; /* no line hook and count != 0; nothing to be done */
654 if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */
655 ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */
656 return; /* do not call hook again (VM yielded, so it did not move) */
659 luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */
660 if (mask & LUA_MASKLINE) {
661 Proto *p = ci_func(ci)->p;
662 int npc = pcRel(ci->u.l.savedpc, p);
663 int newline = getfuncline(p, npc);
664 if (npc == 0 || /* call linehook when enter a new function, */
665 ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */
666 newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */
667 luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */
669 L->oldpc = ci->u.l.savedpc;
670 if (L->status == LUA_YIELD) { /* did hook yield? */
672 L->hookcount = 1; /* undo decrement to zero */
673 ci->u.l.savedpc--; /* undo increment (resume will increment it again) */
674 ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */
675 ci->func = L->top - 1; /* protect stack below results */
676 luaD_throw(L, LUA_YIELD);