1 /*
2 ** $Id: ldebug.c,v 2.90.1.4 2015/02/19 17:05:13 roberto Exp $
3 ** Debug Interface
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <sys/zfs_context.h>
9
10 #define ldebug_c
11 #define LUA_CORE
12
13 #include "lua.h"
14
15 #include "lapi.h"
16 #include "lcode.h"
17 #include "ldebug.h"
18 #include "ldo.h"
19 #include "lfunc.h"
20 #include "lobject.h"
21 #include "lopcodes.h"
22 #include "lstate.h"
23 #include "lstring.h"
24 #include "ltable.h"
25 #include "ltm.h"
26 #include "lvm.h"
27
28
29
30 #define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL)
31
32
33 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
34
35
currentpc(CallInfo * ci)36 static int currentpc (CallInfo *ci) {
37 lua_assert(isLua(ci));
38 return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
39 }
40
41
currentline(CallInfo * ci)42 static int currentline (CallInfo *ci) {
43 return getfuncline(ci_func(ci)->p, currentpc(ci));
44 }
45
46
swapextra(lua_State * L)47 static void swapextra (lua_State *L) {
48 if (L->status == LUA_YIELD) {
49 CallInfo *ci = L->ci; /* get function that yielded */
50 StkId temp = ci->func; /* exchange its 'func' and 'extra' values */
51 ci->func = restorestack(L, ci->extra);
52 ci->extra = savestack(L, temp);
53 }
54 }
55
56
57 /*
58 ** this function can be called asynchronous (e.g. during a signal)
59 */
lua_sethook(lua_State * L,lua_Hook func,int mask,int count)60 LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
61 if (func == NULL || mask == 0) { /* turn off hooks? */
62 mask = 0;
63 func = NULL;
64 }
65 if (isLua(L->ci))
66 L->oldpc = L->ci->u.l.savedpc;
67 L->hook = func;
68 L->basehookcount = count;
69 resethookcount(L);
70 L->hookmask = cast_byte(mask);
71 return 1;
72 }
73
74
lua_gethook(lua_State * L)75 LUA_API lua_Hook lua_gethook (lua_State *L) {
76 return L->hook;
77 }
78
79
lua_gethookmask(lua_State * L)80 LUA_API int lua_gethookmask (lua_State *L) {
81 return L->hookmask;
82 }
83
84
lua_gethookcount(lua_State * L)85 LUA_API int lua_gethookcount (lua_State *L) {
86 return L->basehookcount;
87 }
88
89
lua_getstack(lua_State * L,int level,lua_Debug * ar)90 LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
91 int status;
92 CallInfo *ci;
93 if (level < 0) return 0; /* invalid (negative) level */
94 lua_lock(L);
95 for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
96 level--;
97 if (level == 0 && ci != &L->base_ci) { /* level found? */
98 status = 1;
99 ar->i_ci = ci;
100 }
101 else status = 0; /* no such level */
102 lua_unlock(L);
103 return status;
104 }
105
106
upvalname(Proto * p,int uv)107 static const char *upvalname (Proto *p, int uv) {
108 TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
109 if (s == NULL) return "?";
110 else return getstr(s);
111 }
112
113
findvararg(CallInfo * ci,int n,StkId * pos)114 static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
115 int nparams = clLvalue(ci->func)->p->numparams;
116 if (n >= ci->u.l.base - ci->func - nparams)
117 return NULL; /* no such vararg */
118 else {
119 *pos = ci->func + nparams + n;
120 return "(*vararg)"; /* generic name for any vararg */
121 }
122 }
123
124
findlocal(lua_State * L,CallInfo * ci,int n,StkId * pos)125 static const char *findlocal (lua_State *L, CallInfo *ci, int n,
126 StkId *pos) {
127 const char *name = NULL;
128 StkId base;
129 if (isLua(ci)) {
130 if (n < 0) /* access to vararg values? */
131 return findvararg(ci, -n, pos);
132 else {
133 base = ci->u.l.base;
134 name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
135 }
136 }
137 else
138 base = ci->func + 1;
139 if (name == NULL) { /* no 'standard' name? */
140 StkId limit = (ci == L->ci) ? L->top : ci->next->func;
141 if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */
142 name = "(*temporary)"; /* generic name for any valid slot */
143 else
144 return NULL; /* no name */
145 }
146 *pos = base + (n - 1);
147 return name;
148 }
149
150
lua_getlocal(lua_State * L,const lua_Debug * ar,int n)151 LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
152 const char *name;
153 lua_lock(L);
154 swapextra(L);
155 if (ar == NULL) { /* information about non-active function? */
156 if (!isLfunction(L->top - 1)) /* not a Lua function? */
157 name = NULL;
158 else /* consider live variables at function start (parameters) */
159 name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0);
160 }
161 else { /* active function; get information through 'ar' */
162 StkId pos = 0; /* to avoid warnings */
163 name = findlocal(L, ar->i_ci, n, &pos);
164 if (name) {
165 setobj2s(L, L->top, pos);
166 api_incr_top(L);
167 }
168 }
169 swapextra(L);
170 lua_unlock(L);
171 return name;
172 }
173
174
lua_setlocal(lua_State * L,const lua_Debug * ar,int n)175 LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
176 StkId pos = 0; /* to avoid warnings */
177 const char *name;
178 lua_lock(L);
179 swapextra(L);
180 name = findlocal(L, ar->i_ci, n, &pos);
181 if (name)
182 setobjs2s(L, pos, L->top - 1);
183 L->top--; /* pop value */
184 swapextra(L);
185 lua_unlock(L);
186 return name;
187 }
188
189
funcinfo(lua_Debug * ar,Closure * cl)190 static void funcinfo (lua_Debug *ar, Closure *cl) {
191 if (noLuaClosure(cl)) {
192 ar->source = "=[C]";
193 ar->linedefined = -1;
194 ar->lastlinedefined = -1;
195 ar->what = "C";
196 }
197 else {
198 Proto *p = cl->l.p;
199 ar->source = p->source ? getstr(p->source) : "=?";
200 ar->linedefined = p->linedefined;
201 ar->lastlinedefined = p->lastlinedefined;
202 ar->what = (ar->linedefined == 0) ? "main" : "Lua";
203 }
204 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
205 }
206
207
collectvalidlines(lua_State * L,Closure * f)208 static void collectvalidlines (lua_State *L, Closure *f) {
209 if (noLuaClosure(f)) {
210 setnilvalue(L->top);
211 api_incr_top(L);
212 }
213 else {
214 int i;
215 TValue v;
216 int *lineinfo = f->l.p->lineinfo;
217 Table *t = luaH_new(L); /* new table to store active lines */
218 sethvalue(L, L->top, t); /* push it on stack */
219 api_incr_top(L);
220 setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */
221 for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */
222 luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */
223 }
224 }
225
226
auxgetinfo(lua_State * L,const char * what,lua_Debug * ar,Closure * f,CallInfo * ci)227 static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
228 Closure *f, CallInfo *ci) {
229 int status = 1;
230 for (; *what; what++) {
231 switch (*what) {
232 case 'S': {
233 funcinfo(ar, f);
234 break;
235 }
236 case 'l': {
237 ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1;
238 break;
239 }
240 case 'u': {
241 ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
242 if (noLuaClosure(f)) {
243 ar->isvararg = 1;
244 ar->nparams = 0;
245 }
246 else {
247 ar->isvararg = f->l.p->is_vararg;
248 ar->nparams = f->l.p->numparams;
249 }
250 break;
251 }
252 case 't': {
253 ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
254 break;
255 }
256 case 'n': {
257 /* calling function is a known Lua function? */
258 if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
259 ar->namewhat = getfuncname(L, ci->previous, &ar->name);
260 else
261 ar->namewhat = NULL;
262 if (ar->namewhat == NULL) {
263 ar->namewhat = ""; /* not found */
264 ar->name = NULL;
265 }
266 break;
267 }
268 case 'L':
269 case 'f': /* handled by lua_getinfo */
270 break;
271 default: status = 0; /* invalid option */
272 }
273 }
274 return status;
275 }
276
277
lua_getinfo(lua_State * L,const char * what,lua_Debug * ar)278 LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
279 int status;
280 Closure *cl;
281 CallInfo *ci;
282 StkId func;
283 lua_lock(L);
284 swapextra(L);
285 if (*what == '>') {
286 ci = NULL;
287 func = L->top - 1;
288 api_check(L, ttisfunction(func), "function expected");
289 what++; /* skip the '>' */
290 L->top--; /* pop function */
291 }
292 else {
293 ci = ar->i_ci;
294 func = ci->func;
295 lua_assert(ttisfunction(ci->func));
296 }
297 cl = ttisclosure(func) ? clvalue(func) : NULL;
298 status = auxgetinfo(L, what, ar, cl, ci);
299 if (strchr(what, 'f')) {
300 setobjs2s(L, L->top, func);
301 api_incr_top(L);
302 }
303 swapextra(L);
304 if (strchr(what, 'L'))
305 collectvalidlines(L, cl);
306 lua_unlock(L);
307 return status;
308 }
309
310
311 /*
312 ** {======================================================
313 ** Symbolic Execution
314 ** =======================================================
315 */
316
317 static const char *getobjname (Proto *p, int lastpc, int reg,
318 const char **name);
319
320
321 /*
322 ** find a "name" for the RK value 'c'
323 */
kname(Proto * p,int pc,int c,const char ** name)324 static void kname (Proto *p, int pc, int c, const char **name) {
325 if (ISK(c)) { /* is 'c' a constant? */
326 TValue *kvalue = &p->k[INDEXK(c)];
327 if (ttisstring(kvalue)) { /* literal constant? */
328 *name = svalue(kvalue); /* it is its own name */
329 return;
330 }
331 /* else no reasonable name found */
332 }
333 else { /* 'c' is a register */
334 const char *what = getobjname(p, pc, c, name); /* search for 'c' */
335 if (what && *what == 'c') { /* found a constant name? */
336 return; /* 'name' already filled */
337 }
338 /* else no reasonable name found */
339 }
340 *name = "?"; /* no reasonable name found */
341 }
342
343
filterpc(int pc,int jmptarget)344 static int filterpc (int pc, int jmptarget) {
345 if (pc < jmptarget) /* is code conditional (inside a jump)? */
346 return -1; /* cannot know who sets that register */
347 else return pc; /* current position sets that register */
348 }
349
350
351 /*
352 ** try to find last instruction before 'lastpc' that modified register 'reg'
353 */
findsetreg(Proto * p,int lastpc,int reg)354 static int findsetreg (Proto *p, int lastpc, int reg) {
355 int pc;
356 int setreg = -1; /* keep last instruction that changed 'reg' */
357 int jmptarget = 0; /* any code before this address is conditional */
358 for (pc = 0; pc < lastpc; pc++) {
359 Instruction i = p->code[pc];
360 OpCode op = GET_OPCODE(i);
361 int a = GETARG_A(i);
362 switch (op) {
363 case OP_LOADNIL: {
364 int b = GETARG_B(i);
365 if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */
366 setreg = filterpc(pc, jmptarget);
367 break;
368 }
369 case OP_TFORCALL: {
370 if (reg >= a + 2) /* affect all regs above its base */
371 setreg = filterpc(pc, jmptarget);
372 break;
373 }
374 case OP_CALL:
375 case OP_TAILCALL: {
376 if (reg >= a) /* affect all registers above base */
377 setreg = filterpc(pc, jmptarget);
378 break;
379 }
380 case OP_JMP: {
381 int b = GETARG_sBx(i);
382 int dest = pc + 1 + b;
383 /* jump is forward and do not skip `lastpc'? */
384 if (pc < dest && dest <= lastpc) {
385 if (dest > jmptarget)
386 jmptarget = dest; /* update 'jmptarget' */
387 }
388 break;
389 }
390 case OP_TEST: {
391 if (reg == a) /* jumped code can change 'a' */
392 setreg = filterpc(pc, jmptarget);
393 break;
394 }
395 default:
396 if (testAMode(op) && reg == a) /* any instruction that set A */
397 setreg = filterpc(pc, jmptarget);
398 break;
399 }
400 }
401 return setreg;
402 }
403
404
getobjname(Proto * p,int lastpc,int reg,const char ** name)405 static const char *getobjname (Proto *p, int lastpc, int reg,
406 const char **name) {
407 int pc;
408 *name = luaF_getlocalname(p, reg + 1, lastpc);
409 if (*name) /* is a local? */
410 return "local";
411 /* else try symbolic execution */
412 pc = findsetreg(p, lastpc, reg);
413 if (pc != -1) { /* could find instruction? */
414 Instruction i = p->code[pc];
415 OpCode op = GET_OPCODE(i);
416 switch (op) {
417 case OP_MOVE: {
418 int b = GETARG_B(i); /* move from 'b' to 'a' */
419 if (b < GETARG_A(i))
420 return getobjname(p, pc, b, name); /* get name for 'b' */
421 break;
422 }
423 case OP_GETTABUP:
424 case OP_GETTABLE: {
425 int k = GETARG_C(i); /* key index */
426 int t = GETARG_B(i); /* table index */
427 const char *vn = (op == OP_GETTABLE) /* name of indexed variable */
428 ? luaF_getlocalname(p, t + 1, pc)
429 : upvalname(p, t);
430 kname(p, pc, k, name);
431 return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field";
432 }
433 case OP_GETUPVAL: {
434 *name = upvalname(p, GETARG_B(i));
435 return "upvalue";
436 }
437 case OP_LOADK:
438 case OP_LOADKX: {
439 int b = (op == OP_LOADK) ? GETARG_Bx(i)
440 : GETARG_Ax(p->code[pc + 1]);
441 if (ttisstring(&p->k[b])) {
442 *name = svalue(&p->k[b]);
443 return "constant";
444 }
445 break;
446 }
447 case OP_SELF: {
448 int k = GETARG_C(i); /* key index */
449 kname(p, pc, k, name);
450 return "method";
451 }
452 default: break; /* go through to return NULL */
453 }
454 }
455 return NULL; /* could not find reasonable name */
456 }
457
458
getfuncname(lua_State * L,CallInfo * ci,const char ** name)459 static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
460 TMS tm;
461 Proto *p = ci_func(ci)->p; /* calling function */
462 int pc = currentpc(ci); /* calling instruction index */
463 Instruction i = p->code[pc]; /* calling instruction */
464 switch (GET_OPCODE(i)) {
465 case OP_CALL:
466 case OP_TAILCALL: /* get function name */
467 return getobjname(p, pc, GETARG_A(i), name);
468 case OP_TFORCALL: { /* for iterator */
469 *name = "for iterator";
470 return "for iterator";
471 }
472 /* all other instructions can call only through metamethods */
473 case OP_SELF:
474 case OP_GETTABUP:
475 case OP_GETTABLE: tm = TM_INDEX; break;
476 case OP_SETTABUP:
477 case OP_SETTABLE: tm = TM_NEWINDEX; break;
478 case OP_EQ: tm = TM_EQ; break;
479 case OP_ADD: tm = TM_ADD; break;
480 case OP_SUB: tm = TM_SUB; break;
481 case OP_MUL: tm = TM_MUL; break;
482 case OP_DIV: tm = TM_DIV; break;
483 case OP_MOD: tm = TM_MOD; break;
484 case OP_POW: tm = TM_POW; break;
485 case OP_UNM: tm = TM_UNM; break;
486 case OP_LEN: tm = TM_LEN; break;
487 case OP_LT: tm = TM_LT; break;
488 case OP_LE: tm = TM_LE; break;
489 case OP_CONCAT: tm = TM_CONCAT; break;
490 default:
491 return NULL; /* else no useful name can be found */
492 }
493 *name = getstr(G(L)->tmname[tm]);
494 return "metamethod";
495 }
496
497 /* }====================================================== */
498
499
500
501 /*
502 ** only ANSI way to check whether a pointer points to an array
503 ** (used only for error messages, so efficiency is not a big concern)
504 */
isinstack(CallInfo * ci,const TValue * o)505 static int isinstack (CallInfo *ci, const TValue *o) {
506 StkId p;
507 for (p = ci->u.l.base; p < ci->top; p++)
508 if (o == p) return 1;
509 return 0;
510 }
511
512
getupvalname(CallInfo * ci,const TValue * o,const char ** name)513 static const char *getupvalname (CallInfo *ci, const TValue *o,
514 const char **name) {
515 LClosure *c = ci_func(ci);
516 int i;
517 for (i = 0; i < c->nupvalues; i++) {
518 if (c->upvals[i]->v == o) {
519 *name = upvalname(c->p, i);
520 return "upvalue";
521 }
522 }
523 return NULL;
524 }
525
526
luaG_typeerror(lua_State * L,const TValue * o,const char * op)527 l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
528 CallInfo *ci = L->ci;
529 const char *name = NULL;
530 const char *t = objtypename(o);
531 const char *kind = NULL;
532 if (isLua(ci)) {
533 kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */
534 if (!kind && isinstack(ci, o)) /* no? try a register */
535 kind = getobjname(ci_func(ci)->p, currentpc(ci),
536 cast_int(o - ci->u.l.base), &name);
537 }
538 if (kind)
539 luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)",
540 op, kind, name, t);
541 else
542 luaG_runerror(L, "attempt to %s a %s value", op, t);
543 }
544
545
luaG_concaterror(lua_State * L,StkId p1,StkId p2)546 l_noret luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
547 if (ttisstring(p1) || ttisnumber(p1)) p1 = p2;
548 lua_assert(!ttisstring(p1) && !ttisnumber(p1));
549 luaG_typeerror(L, p1, "concatenate");
550 }
551
552
luaG_aritherror(lua_State * L,const TValue * p1,const TValue * p2)553 l_noret luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
554 TValue temp;
555 if (luaV_tonumber(p1, &temp) == NULL)
556 p2 = p1; /* first operand is wrong */
557 luaG_typeerror(L, p2, "perform arithmetic on");
558 }
559
560
luaG_ordererror(lua_State * L,const TValue * p1,const TValue * p2)561 l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
562 const char *t1 = objtypename(p1);
563 const char *t2 = objtypename(p2);
564 if (t1 == t2)
565 luaG_runerror(L, "attempt to compare two %s values", t1);
566 else
567 luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
568 }
569
570
addinfo(lua_State * L,const char * msg)571 static void addinfo (lua_State *L, const char *msg) {
572 CallInfo *ci = L->ci;
573 if (isLua(ci)) { /* is Lua code? */
574 char buff[LUA_IDSIZE]; /* add file:line information */
575 int line = currentline(ci);
576 TString *src = ci_func(ci)->p->source;
577 if (src)
578 luaO_chunkid(buff, getstr(src), LUA_IDSIZE);
579 else { /* no source available; use "?" instead */
580 buff[0] = '?'; buff[1] = '\0';
581 }
582 luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
583 }
584 }
585
586
luaG_errormsg(lua_State * L)587 l_noret luaG_errormsg (lua_State *L) {
588 if (L->errfunc != 0) { /* is there an error handling function? */
589 StkId errfunc = restorestack(L, L->errfunc);
590 if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
591 setobjs2s(L, L->top, L->top - 1); /* move argument */
592 setobjs2s(L, L->top - 1, errfunc); /* push function */
593 L->top++;
594 luaD_call(L, L->top - 2, 1, 0); /* call it */
595 }
596 luaD_throw(L, LUA_ERRRUN);
597 }
598
599
luaG_runerror(lua_State * L,const char * fmt,...)600 l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
601 va_list argp;
602 va_start(argp, fmt);
603 addinfo(L, luaO_pushvfstring(L, fmt, argp));
604 va_end(argp);
605 luaG_errormsg(L);
606 }
607
608