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ba8b5c17 | 1 | /* |
2 | ** $Id: ldebug.c,v 2.90 2012/08/16 17:34:28 roberto Exp $ | |
3 | ** Debug Interface | |
4 | ** See Copyright Notice in lua.h | |
5 | */ | |
6 | ||
7 | ||
8 | #include <stdarg.h> | |
9 | #include <stddef.h> | |
10 | #include <string.h> | |
11 | ||
12 | ||
13 | #define ldebug_c | |
14 | #define LUA_CORE | |
15 | ||
16 | #include "lua.h" | |
17 | ||
18 | #include "lapi.h" | |
19 | #include "lcode.h" | |
20 | #include "ldebug.h" | |
21 | #include "ldo.h" | |
22 | #include "lfunc.h" | |
23 | #include "lobject.h" | |
24 | #include "lopcodes.h" | |
25 | #include "lstate.h" | |
26 | #include "lstring.h" | |
27 | #include "ltable.h" | |
28 | #include "ltm.h" | |
29 | #include "lvm.h" | |
30 | ||
31 | ||
32 | ||
33 | #define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL) | |
34 | ||
35 | ||
36 | static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name); | |
37 | ||
38 | ||
39 | static int currentpc (CallInfo *ci) { | |
40 | lua_assert(isLua(ci)); | |
41 | return pcRel(ci->u.l.savedpc, ci_func(ci)->p); | |
42 | } | |
43 | ||
44 | ||
45 | static int currentline (CallInfo *ci) { | |
46 | return getfuncline(ci_func(ci)->p, currentpc(ci)); | |
47 | } | |
48 | ||
49 | ||
50 | /* | |
51 | ** this function can be called asynchronous (e.g. during a signal) | |
52 | */ | |
53 | LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { | |
54 | if (func == NULL || mask == 0) { /* turn off hooks? */ | |
55 | mask = 0; | |
56 | func = NULL; | |
57 | } | |
58 | if (isLua(L->ci)) | |
59 | L->oldpc = L->ci->u.l.savedpc; | |
60 | L->hook = func; | |
61 | L->basehookcount = count; | |
62 | resethookcount(L); | |
63 | L->hookmask = cast_byte(mask); | |
64 | return 1; | |
65 | } | |
66 | ||
67 | ||
68 | LUA_API lua_Hook lua_gethook (lua_State *L) { | |
69 | return L->hook; | |
70 | } | |
71 | ||
72 | ||
73 | LUA_API int lua_gethookmask (lua_State *L) { | |
74 | return L->hookmask; | |
75 | } | |
76 | ||
77 | ||
78 | LUA_API int lua_gethookcount (lua_State *L) { | |
79 | return L->basehookcount; | |
80 | } | |
81 | ||
82 | ||
83 | LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) { | |
84 | int status; | |
85 | CallInfo *ci; | |
86 | if (level < 0) return 0; /* invalid (negative) level */ | |
87 | lua_lock(L); | |
88 | for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous) | |
89 | level--; | |
90 | if (level == 0 && ci != &L->base_ci) { /* level found? */ | |
91 | status = 1; | |
92 | ar->i_ci = ci; | |
93 | } | |
94 | else status = 0; /* no such level */ | |
95 | lua_unlock(L); | |
96 | return status; | |
97 | } | |
98 | ||
99 | ||
100 | static const char *upvalname (Proto *p, int uv) { | |
101 | TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name); | |
102 | if (s == NULL) return "?"; | |
103 | else return getstr(s); | |
104 | } | |
105 | ||
106 | ||
107 | static const char *findvararg (CallInfo *ci, int n, StkId *pos) { | |
108 | int nparams = clLvalue(ci->func)->p->numparams; | |
109 | if (n >= ci->u.l.base - ci->func - nparams) | |
110 | return NULL; /* no such vararg */ | |
111 | else { | |
112 | *pos = ci->func + nparams + n; | |
113 | return "(*vararg)"; /* generic name for any vararg */ | |
114 | } | |
115 | } | |
116 | ||
117 | ||
118 | static const char *findlocal (lua_State *L, CallInfo *ci, int n, | |
119 | StkId *pos) { | |
120 | const char *name = NULL; | |
121 | StkId base; | |
122 | if (isLua(ci)) { | |
123 | if (n < 0) /* access to vararg values? */ | |
124 | return findvararg(ci, -n, pos); | |
125 | else { | |
126 | base = ci->u.l.base; | |
127 | name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci)); | |
128 | } | |
129 | } | |
130 | else | |
131 | base = ci->func + 1; | |
132 | if (name == NULL) { /* no 'standard' name? */ | |
133 | StkId limit = (ci == L->ci) ? L->top : ci->next->func; | |
134 | if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */ | |
135 | name = "(*temporary)"; /* generic name for any valid slot */ | |
136 | else | |
137 | return NULL; /* no name */ | |
138 | } | |
139 | *pos = base + (n - 1); | |
140 | return name; | |
141 | } | |
142 | ||
143 | ||
144 | LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { | |
145 | const char *name; | |
146 | lua_lock(L); | |
147 | if (ar == NULL) { /* information about non-active function? */ | |
148 | if (!isLfunction(L->top - 1)) /* not a Lua function? */ | |
149 | name = NULL; | |
150 | else /* consider live variables at function start (parameters) */ | |
151 | name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0); | |
152 | } | |
153 | else { /* active function; get information through 'ar' */ | |
154 | StkId pos = 0; /* to avoid warnings */ | |
155 | name = findlocal(L, ar->i_ci, n, &pos); | |
156 | if (name) { | |
157 | setobj2s(L, L->top, pos); | |
158 | api_incr_top(L); | |
159 | } | |
160 | } | |
161 | lua_unlock(L); | |
162 | return name; | |
163 | } | |
164 | ||
165 | ||
166 | LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { | |
167 | StkId pos = 0; /* to avoid warnings */ | |
168 | const char *name = findlocal(L, ar->i_ci, n, &pos); | |
169 | lua_lock(L); | |
170 | if (name) | |
171 | setobjs2s(L, pos, L->top - 1); | |
172 | L->top--; /* pop value */ | |
173 | lua_unlock(L); | |
174 | return name; | |
175 | } | |
176 | ||
177 | ||
178 | static void funcinfo (lua_Debug *ar, Closure *cl) { | |
179 | if (noLuaClosure(cl)) { | |
180 | ar->source = "=[C]"; | |
181 | ar->linedefined = -1; | |
182 | ar->lastlinedefined = -1; | |
183 | ar->what = "C"; | |
184 | } | |
185 | else { | |
186 | Proto *p = cl->l.p; | |
187 | ar->source = p->source ? getstr(p->source) : "=?"; | |
188 | ar->linedefined = p->linedefined; | |
189 | ar->lastlinedefined = p->lastlinedefined; | |
190 | ar->what = (ar->linedefined == 0) ? "main" : "Lua"; | |
191 | } | |
192 | luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); | |
193 | } | |
194 | ||
195 | ||
196 | static void collectvalidlines (lua_State *L, Closure *f) { | |
197 | if (noLuaClosure(f)) { | |
198 | setnilvalue(L->top); | |
199 | api_incr_top(L); | |
200 | } | |
201 | else { | |
202 | int i; | |
203 | TValue v; | |
204 | int *lineinfo = f->l.p->lineinfo; | |
205 | Table *t = luaH_new(L); /* new table to store active lines */ | |
206 | sethvalue(L, L->top, t); /* push it on stack */ | |
207 | api_incr_top(L); | |
208 | setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */ | |
209 | for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */ | |
210 | luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */ | |
211 | } | |
212 | } | |
213 | ||
214 | ||
215 | static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, | |
216 | Closure *f, CallInfo *ci) { | |
217 | int status = 1; | |
218 | for (; *what; what++) { | |
219 | switch (*what) { | |
220 | case 'S': { | |
221 | funcinfo(ar, f); | |
222 | break; | |
223 | } | |
224 | case 'l': { | |
225 | ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1; | |
226 | break; | |
227 | } | |
228 | case 'u': { | |
229 | ar->nups = (f == NULL) ? 0 : f->c.nupvalues; | |
230 | if (noLuaClosure(f)) { | |
231 | ar->isvararg = 1; | |
232 | ar->nparams = 0; | |
233 | } | |
234 | else { | |
235 | ar->isvararg = f->l.p->is_vararg; | |
236 | ar->nparams = f->l.p->numparams; | |
237 | } | |
238 | break; | |
239 | } | |
240 | case 't': { | |
241 | ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0; | |
242 | break; | |
243 | } | |
244 | case 'n': { | |
245 | /* calling function is a known Lua function? */ | |
246 | if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous)) | |
247 | ar->namewhat = getfuncname(L, ci->previous, &ar->name); | |
248 | else | |
249 | ar->namewhat = NULL; | |
250 | if (ar->namewhat == NULL) { | |
251 | ar->namewhat = ""; /* not found */ | |
252 | ar->name = NULL; | |
253 | } | |
254 | break; | |
255 | } | |
256 | case 'L': | |
257 | case 'f': /* handled by lua_getinfo */ | |
258 | break; | |
259 | default: status = 0; /* invalid option */ | |
260 | } | |
261 | } | |
262 | return status; | |
263 | } | |
264 | ||
265 | ||
266 | LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) { | |
267 | int status; | |
268 | Closure *cl; | |
269 | CallInfo *ci; | |
270 | StkId func; | |
271 | lua_lock(L); | |
272 | if (*what == '>') { | |
273 | ci = NULL; | |
274 | func = L->top - 1; | |
275 | api_check(L, ttisfunction(func), "function expected"); | |
276 | what++; /* skip the '>' */ | |
277 | L->top--; /* pop function */ | |
278 | } | |
279 | else { | |
280 | ci = ar->i_ci; | |
281 | func = ci->func; | |
282 | lua_assert(ttisfunction(ci->func)); | |
283 | } | |
284 | cl = ttisclosure(func) ? clvalue(func) : NULL; | |
285 | status = auxgetinfo(L, what, ar, cl, ci); | |
286 | if (strchr(what, 'f')) { | |
287 | setobjs2s(L, L->top, func); | |
288 | api_incr_top(L); | |
289 | } | |
290 | if (strchr(what, 'L')) | |
291 | collectvalidlines(L, cl); | |
292 | lua_unlock(L); | |
293 | return status; | |
294 | } | |
295 | ||
296 | ||
297 | /* | |
298 | ** {====================================================== | |
299 | ** Symbolic Execution | |
300 | ** ======================================================= | |
301 | */ | |
302 | ||
303 | static const char *getobjname (Proto *p, int lastpc, int reg, | |
304 | const char **name); | |
305 | ||
306 | ||
307 | /* | |
308 | ** find a "name" for the RK value 'c' | |
309 | */ | |
310 | static void kname (Proto *p, int pc, int c, const char **name) { | |
311 | if (ISK(c)) { /* is 'c' a constant? */ | |
312 | TValue *kvalue = &p->k[INDEXK(c)]; | |
313 | if (ttisstring(kvalue)) { /* literal constant? */ | |
314 | *name = svalue(kvalue); /* it is its own name */ | |
315 | return; | |
316 | } | |
317 | /* else no reasonable name found */ | |
318 | } | |
319 | else { /* 'c' is a register */ | |
320 | const char *what = getobjname(p, pc, c, name); /* search for 'c' */ | |
321 | if (what && *what == 'c') { /* found a constant name? */ | |
322 | return; /* 'name' already filled */ | |
323 | } | |
324 | /* else no reasonable name found */ | |
325 | } | |
326 | *name = "?"; /* no reasonable name found */ | |
327 | } | |
328 | ||
329 | ||
330 | /* | |
331 | ** try to find last instruction before 'lastpc' that modified register 'reg' | |
332 | */ | |
333 | static int findsetreg (Proto *p, int lastpc, int reg) { | |
334 | int pc; | |
335 | int setreg = -1; /* keep last instruction that changed 'reg' */ | |
336 | for (pc = 0; pc < lastpc; pc++) { | |
337 | Instruction i = p->code[pc]; | |
338 | OpCode op = GET_OPCODE(i); | |
339 | int a = GETARG_A(i); | |
340 | switch (op) { | |
341 | case OP_LOADNIL: { | |
342 | int b = GETARG_B(i); | |
343 | if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */ | |
344 | setreg = pc; | |
345 | break; | |
346 | } | |
347 | case OP_TFORCALL: { | |
348 | if (reg >= a + 2) setreg = pc; /* affect all regs above its base */ | |
349 | break; | |
350 | } | |
351 | case OP_CALL: | |
352 | case OP_TAILCALL: { | |
353 | if (reg >= a) setreg = pc; /* affect all registers above base */ | |
354 | break; | |
355 | } | |
356 | case OP_JMP: { | |
357 | int b = GETARG_sBx(i); | |
358 | int dest = pc + 1 + b; | |
359 | /* jump is forward and do not skip `lastpc'? */ | |
360 | if (pc < dest && dest <= lastpc) | |
361 | pc += b; /* do the jump */ | |
362 | break; | |
363 | } | |
364 | case OP_TEST: { | |
365 | if (reg == a) setreg = pc; /* jumped code can change 'a' */ | |
366 | break; | |
367 | } | |
368 | default: | |
369 | if (testAMode(op) && reg == a) /* any instruction that set A */ | |
370 | setreg = pc; | |
371 | break; | |
372 | } | |
373 | } | |
374 | return setreg; | |
375 | } | |
376 | ||
377 | ||
378 | static const char *getobjname (Proto *p, int lastpc, int reg, | |
379 | const char **name) { | |
380 | int pc; | |
381 | *name = luaF_getlocalname(p, reg + 1, lastpc); | |
382 | if (*name) /* is a local? */ | |
383 | return "local"; | |
384 | /* else try symbolic execution */ | |
385 | pc = findsetreg(p, lastpc, reg); | |
386 | if (pc != -1) { /* could find instruction? */ | |
387 | Instruction i = p->code[pc]; | |
388 | OpCode op = GET_OPCODE(i); | |
389 | switch (op) { | |
390 | case OP_MOVE: { | |
391 | int b = GETARG_B(i); /* move from 'b' to 'a' */ | |
392 | if (b < GETARG_A(i)) | |
393 | return getobjname(p, pc, b, name); /* get name for 'b' */ | |
394 | break; | |
395 | } | |
396 | case OP_GETTABUP: | |
397 | case OP_GETTABLE: { | |
398 | int k = GETARG_C(i); /* key index */ | |
399 | int t = GETARG_B(i); /* table index */ | |
400 | const char *vn = (op == OP_GETTABLE) /* name of indexed variable */ | |
401 | ? luaF_getlocalname(p, t + 1, pc) | |
402 | : upvalname(p, t); | |
403 | kname(p, pc, k, name); | |
404 | return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field"; | |
405 | } | |
406 | case OP_GETUPVAL: { | |
407 | *name = upvalname(p, GETARG_B(i)); | |
408 | return "upvalue"; | |
409 | } | |
410 | case OP_LOADK: | |
411 | case OP_LOADKX: { | |
412 | int b = (op == OP_LOADK) ? GETARG_Bx(i) | |
413 | : GETARG_Ax(p->code[pc + 1]); | |
414 | if (ttisstring(&p->k[b])) { | |
415 | *name = svalue(&p->k[b]); | |
416 | return "constant"; | |
417 | } | |
418 | break; | |
419 | } | |
420 | case OP_SELF: { | |
421 | int k = GETARG_C(i); /* key index */ | |
422 | kname(p, pc, k, name); | |
423 | return "method"; | |
424 | } | |
425 | default: break; /* go through to return NULL */ | |
426 | } | |
427 | } | |
428 | return NULL; /* could not find reasonable name */ | |
429 | } | |
430 | ||
431 | ||
432 | static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { | |
433 | TMS tm; | |
434 | Proto *p = ci_func(ci)->p; /* calling function */ | |
435 | int pc = currentpc(ci); /* calling instruction index */ | |
436 | Instruction i = p->code[pc]; /* calling instruction */ | |
437 | switch (GET_OPCODE(i)) { | |
438 | case OP_CALL: | |
439 | case OP_TAILCALL: /* get function name */ | |
440 | return getobjname(p, pc, GETARG_A(i), name); | |
441 | case OP_TFORCALL: { /* for iterator */ | |
442 | *name = "for iterator"; | |
443 | return "for iterator"; | |
444 | } | |
445 | /* all other instructions can call only through metamethods */ | |
446 | case OP_SELF: | |
447 | case OP_GETTABUP: | |
448 | case OP_GETTABLE: tm = TM_INDEX; break; | |
449 | case OP_SETTABUP: | |
450 | case OP_SETTABLE: tm = TM_NEWINDEX; break; | |
451 | case OP_EQ: tm = TM_EQ; break; | |
452 | case OP_ADD: tm = TM_ADD; break; | |
453 | case OP_SUB: tm = TM_SUB; break; | |
454 | case OP_MUL: tm = TM_MUL; break; | |
455 | case OP_DIV: tm = TM_DIV; break; | |
456 | case OP_MOD: tm = TM_MOD; break; | |
457 | case OP_POW: tm = TM_POW; break; | |
458 | case OP_UNM: tm = TM_UNM; break; | |
459 | case OP_LEN: tm = TM_LEN; break; | |
460 | case OP_LT: tm = TM_LT; break; | |
461 | case OP_LE: tm = TM_LE; break; | |
462 | case OP_CONCAT: tm = TM_CONCAT; break; | |
463 | default: | |
464 | return NULL; /* else no useful name can be found */ | |
465 | } | |
466 | *name = getstr(G(L)->tmname[tm]); | |
467 | return "metamethod"; | |
468 | } | |
469 | ||
470 | /* }====================================================== */ | |
471 | ||
472 | ||
473 | ||
474 | /* | |
475 | ** only ANSI way to check whether a pointer points to an array | |
476 | ** (used only for error messages, so efficiency is not a big concern) | |
477 | */ | |
478 | static int isinstack (CallInfo *ci, const TValue *o) { | |
479 | StkId p; | |
480 | for (p = ci->u.l.base; p < ci->top; p++) | |
481 | if (o == p) return 1; | |
482 | return 0; | |
483 | } | |
484 | ||
485 | ||
486 | static const char *getupvalname (CallInfo *ci, const TValue *o, | |
487 | const char **name) { | |
488 | LClosure *c = ci_func(ci); | |
489 | int i; | |
490 | for (i = 0; i < c->nupvalues; i++) { | |
491 | if (c->upvals[i]->v == o) { | |
492 | *name = upvalname(c->p, i); | |
493 | return "upvalue"; | |
494 | } | |
495 | } | |
496 | return NULL; | |
497 | } | |
498 | ||
499 | ||
500 | l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) { | |
501 | CallInfo *ci = L->ci; | |
502 | const char *name = NULL; | |
503 | const char *t = objtypename(o); | |
504 | const char *kind = NULL; | |
505 | if (isLua(ci)) { | |
506 | kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */ | |
507 | if (!kind && isinstack(ci, o)) /* no? try a register */ | |
508 | kind = getobjname(ci_func(ci)->p, currentpc(ci), | |
509 | cast_int(o - ci->u.l.base), &name); | |
510 | } | |
511 | if (kind) | |
512 | luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)", | |
513 | op, kind, name, t); | |
514 | else | |
515 | luaG_runerror(L, "attempt to %s a %s value", op, t); | |
516 | } | |
517 | ||
518 | ||
519 | l_noret luaG_concaterror (lua_State *L, StkId p1, StkId p2) { | |
520 | if (ttisstring(p1) || ttisnumber(p1)) p1 = p2; | |
521 | lua_assert(!ttisstring(p1) && !ttisnumber(p2)); | |
522 | luaG_typeerror(L, p1, "concatenate"); | |
523 | } | |
524 | ||
525 | ||
526 | l_noret luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) { | |
527 | TValue temp; | |
528 | if (luaV_tonumber(p1, &temp) == NULL) | |
529 | p2 = p1; /* first operand is wrong */ | |
530 | luaG_typeerror(L, p2, "perform arithmetic on"); | |
531 | } | |
532 | ||
533 | ||
534 | l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { | |
535 | const char *t1 = objtypename(p1); | |
536 | const char *t2 = objtypename(p2); | |
537 | if (t1 == t2) | |
538 | luaG_runerror(L, "attempt to compare two %s values", t1); | |
539 | else | |
540 | luaG_runerror(L, "attempt to compare %s with %s", t1, t2); | |
541 | } | |
542 | ||
543 | ||
544 | static void addinfo (lua_State *L, const char *msg) { | |
545 | CallInfo *ci = L->ci; | |
546 | if (isLua(ci)) { /* is Lua code? */ | |
547 | char buff[LUA_IDSIZE]; /* add file:line information */ | |
548 | int line = currentline(ci); | |
549 | TString *src = ci_func(ci)->p->source; | |
550 | if (src) | |
551 | luaO_chunkid(buff, getstr(src), LUA_IDSIZE); | |
552 | else { /* no source available; use "?" instead */ | |
553 | buff[0] = '?'; buff[1] = '\0'; | |
554 | } | |
555 | luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); | |
556 | } | |
557 | } | |
558 | ||
559 | ||
560 | l_noret luaG_errormsg (lua_State *L) { | |
561 | if (L->errfunc != 0) { /* is there an error handling function? */ | |
562 | StkId errfunc = restorestack(L, L->errfunc); | |
563 | if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR); | |
564 | setobjs2s(L, L->top, L->top - 1); /* move argument */ | |
565 | setobjs2s(L, L->top - 1, errfunc); /* push function */ | |
566 | L->top++; | |
567 | luaD_call(L, L->top - 2, 1, 0); /* call it */ | |
568 | } | |
569 | luaD_throw(L, LUA_ERRRUN); | |
570 | } | |
571 | ||
572 | ||
573 | l_noret luaG_runerror (lua_State *L, const char *fmt, ...) { | |
574 | va_list argp; | |
575 | va_start(argp, fmt); | |
576 | addinfo(L, luaO_pushvfstring(L, fmt, argp)); | |
577 | va_end(argp); | |
578 | luaG_errormsg(L); | |
579 | } | |
580 |