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1/*
2** $Id: ldebug.c,v 2.29 2005/12/22 16:19:56 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
33static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name);
34
35
36static int currentpc (lua_State *L, CallInfo *ci) {
37 if (!isLua(ci)) return -1; /* function is not a Lua function? */
38 if (ci == L->ci)
39 ci->savedpc = L->savedpc;
40 return pcRel(ci->savedpc, ci_func(ci)->l.p);
41}
42
43
44static int currentline (lua_State *L, CallInfo *ci) {
45 int pc = currentpc(L, ci);
46 if (pc < 0)
47 return -1; /* only active lua functions have current-line information */
48 else
49 return getline(ci_func(ci)->l.p, pc);
50}
51
52
53/*
54** this function can be called asynchronous (e.g. during a signal)
55*/
56LUA_API int lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
57 if (func == NULL || mask == 0) { /* turn off hooks? */
58 mask = 0;
59 func = NULL;
60 }
61 L->hook = func;
62 L->basehookcount = count;
63 resethookcount(L);
64 L->hookmask = cast_byte(mask);
65 return 1;
66}
67
68
69LUA_API lua_Hook lua_gethook (lua_State *L) {
70 return L->hook;
71}
72
73
74LUA_API int lua_gethookmask (lua_State *L) {
75 return L->hookmask;
76}
77
78
79LUA_API int lua_gethookcount (lua_State *L) {
80 return L->basehookcount;
81}
82
83
84LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
85 int status;
86 CallInfo *ci;
87 lua_lock(L);
88 for (ci = L->ci; level > 0 && ci > L->base_ci; ci--) {
89 level--;
90 if (f_isLua(ci)) /* Lua function? */
91 level -= ci->tailcalls; /* skip lost tail calls */
92 }
93 if (level == 0 && ci > L->base_ci) { /* level found? */
94 status = 1;
95 ar->i_ci = cast_int(ci - L->base_ci);
96 }
97 else if (level < 0) { /* level is of a lost tail call? */
98 status = 1;
99 ar->i_ci = 0;
100 }
101 else status = 0; /* no such level */
102 lua_unlock(L);
103 return status;
104}
105
106
107static Proto *getluaproto (CallInfo *ci) {
108 return (isLua(ci) ? ci_func(ci)->l.p : NULL);
109}
110
111
112static const char *findlocal (lua_State *L, CallInfo *ci, int n) {
113 const char *name;
114 Proto *fp = getluaproto(ci);
115 if (fp && (name = luaF_getlocalname(fp, n, currentpc(L, ci))) != NULL)
116 return name; /* is a local variable in a Lua function */
117 else {
118 StkId limit = (ci == L->ci) ? L->top : (ci+1)->func;
119 if (limit - ci->base >= n && n > 0) /* is 'n' inside 'ci' stack? */
120 return "(*temporary)";
121 else
122 return NULL;
123 }
124}
125
126
127LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
128 CallInfo *ci = L->base_ci + ar->i_ci;
129 const char *name = findlocal(L, ci, n);
130 lua_lock(L);
131 if (name)
132 luaA_pushobject(L, ci->base + (n - 1));
133 lua_unlock(L);
134 return name;
135}
136
137
138LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
139 CallInfo *ci = L->base_ci + ar->i_ci;
140 const char *name = findlocal(L, ci, n);
141 lua_lock(L);
142 if (name)
143 setobjs2s(L, ci->base + (n - 1), L->top - 1);
144 L->top--; /* pop value */
145 lua_unlock(L);
146 return name;
147}
148
149
150static void funcinfo (lua_Debug *ar, Closure *cl) {
151 if (cl->c.isC) {
152 ar->source = "=[C]";
153 ar->linedefined = -1;
154 ar->lastlinedefined = -1;
155 ar->what = "C";
156 }
157 else {
158 ar->source = getstr(cl->l.p->source);
159 ar->linedefined = cl->l.p->linedefined;
160 ar->lastlinedefined = cl->l.p->lastlinedefined;
161 ar->what = (ar->linedefined == 0) ? "main" : "Lua";
162 }
163 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
164}
165
166
167static void info_tailcall (lua_Debug *ar) {
168 ar->name = ar->namewhat = "";
169 ar->what = "tail";
170 ar->lastlinedefined = ar->linedefined = ar->currentline = -1;
171 ar->source = "=(tail call)";
172 luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE);
173 ar->nups = 0;
174}
175
176
177static void collectvalidlines (lua_State *L, Closure *f) {
178 if (f == NULL || f->c.isC) {
179 setnilvalue(L->top);
180 }
181 else {
182 Table *t = luaH_new(L, 0, 0);
183 int *lineinfo = f->l.p->lineinfo;
184 int i;
185 for (i=0; i<f->l.p->sizelineinfo; i++)
186 setbvalue(luaH_setnum(L, t, lineinfo[i]), 1);
187 sethvalue(L, L->top, t);
188 }
189 incr_top(L);
190}
191
192
193static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
194 Closure *f, CallInfo *ci) {
195 int status = 1;
196 if (f == NULL) {
197 info_tailcall(ar);
198 return status;
199 }
200 for (; *what; what++) {
201 switch (*what) {
202 case 'S': {
203 funcinfo(ar, f);
204 break;
205 }
206 case 'l': {
207 ar->currentline = (ci) ? currentline(L, ci) : -1;
208 break;
209 }
210 case 'u': {
211 ar->nups = f->c.nupvalues;
212 break;
213 }
214 case 'n': {
215 ar->namewhat = (ci) ? getfuncname(L, ci, &ar->name) : NULL;
216 if (ar->namewhat == NULL) {
217 ar->namewhat = ""; /* not found */
218 ar->name = NULL;
219 }
220 break;
221 }
222 case 'L':
223 case 'f': /* handled by lua_getinfo */
224 break;
225 default: status = 0; /* invalid option */
226 }
227 }
228 return status;
229}
230
231
232LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
233 int status;
234 Closure *f = NULL;
235 CallInfo *ci = NULL;
236 lua_lock(L);
237 if (*what == '>') {
238 StkId func = L->top - 1;
239 luai_apicheck(L, ttisfunction(func));
240 what++; /* skip the '>' */
241 f = clvalue(func);
242 L->top--; /* pop function */
243 }
244 else if (ar->i_ci != 0) { /* no tail call? */
245 ci = L->base_ci + ar->i_ci;
246 lua_assert(ttisfunction(ci->func));
247 f = clvalue(ci->func);
248 }
249 status = auxgetinfo(L, what, ar, f, ci);
250 if (strchr(what, 'f')) {
251 if (f == NULL) setnilvalue(L->top);
252 else setclvalue(L, L->top, f);
253 incr_top(L);
254 }
255 if (strchr(what, 'L'))
256 collectvalidlines(L, f);
257 lua_unlock(L);
258 return status;
259}
260
261
262/*
263** {======================================================
264** Symbolic Execution and code checker
265** =======================================================
266*/
267
268#define check(x)if (!(x)) return 0;
269
270#define checkjump(pt,pc)check(0 <= pc && pc < pt->sizecode)
271
272#define checkreg(pt,reg)check((reg) < (pt)->maxstacksize)
273
274
275
276static int precheck (const Proto *pt) {
277 check(pt->maxstacksize <= MAXSTACK);
278 lua_assert(pt->numparams+(pt->is_vararg & VARARG_HASARG) <= pt->maxstacksize);
279 lua_assert(!(pt->is_vararg & VARARG_NEEDSARG) ||
280 (pt->is_vararg & VARARG_HASARG));
281 check(pt->sizeupvalues <= pt->nups);
282 check(pt->sizelineinfo == pt->sizecode || pt->sizelineinfo == 0);
283 check(GET_OPCODE(pt->code[pt->sizecode-1]) == OP_RETURN);
284 return 1;
285}
286
287
288#define checkopenop(pt,pc)luaG_checkopenop((pt)->code[(pc)+1])
289
290int luaG_checkopenop (Instruction i) {
291 switch (GET_OPCODE(i)) {
292 case OP_CALL:
293 case OP_TAILCALL:
294 case OP_RETURN:
295 case OP_SETLIST: {
296 check(GETARG_B(i) == 0);
297 return 1;
298 }
299 default: return 0; /* invalid instruction after an open call */
300 }
301}
302
303
304static int checkArgMode (const Proto *pt, int r, enum OpArgMask mode) {
305 switch (mode) {
306 case OpArgN: check(r == 0); break;
307 case OpArgU: break;
308 case OpArgR: checkreg(pt, r); break;
309 case OpArgK:
310 check(ISK(r) ? INDEXK(r) < pt->sizek : r < pt->maxstacksize);
311 break;
312 }
313 return 1;
314}
315
316
317static Instruction symbexec (const Proto *pt, int lastpc, int reg) {
318 int pc;
319 int last; /* stores position of last instruction that changed `reg' */
320 last = pt->sizecode-1; /* points to final return (a `neutral' instruction) */
321 check(precheck(pt));
322 for (pc = 0; pc < lastpc; pc++) {
323 Instruction i = pt->code[pc];
324 OpCode op = GET_OPCODE(i);
325 int a = GETARG_A(i);
326 int b = 0;
327 int c = 0;
328 check(op < NUM_OPCODES);
329 checkreg(pt, a);
330 switch (getOpMode(op)) {
331 case iABC: {
332 b = GETARG_B(i);
333 c = GETARG_C(i);
334 check(checkArgMode(pt, b, getBMode(op)));
335 check(checkArgMode(pt, c, getCMode(op)));
336 break;
337 }
338 case iABx: {
339 b = GETARG_Bx(i);
340 if (getBMode(op) == OpArgK) check(b < pt->sizek);
341 break;
342 }
343 case iAsBx: {
344 b = GETARG_sBx(i);
345 if (getBMode(op) == OpArgR) {
346 int dest = pc+1+b;
347 check(0 <= dest && dest < pt->sizecode);
348 if (dest > 0) {
349 /* cannot jump to a setlist count */
350 Instruction d = pt->code[dest-1];
351 check(!(GET_OPCODE(d) == OP_SETLIST && GETARG_C(d) == 0));
352 }
353 }
354 break;
355 }
356 }
357 if (testAMode(op)) {
358 if (a == reg) last = pc; /* change register `a' */
359 }
360 if (testTMode(op)) {
361 check(pc+2 < pt->sizecode); /* check skip */
362 check(GET_OPCODE(pt->code[pc+1]) == OP_JMP);
363 }
364 switch (op) {
365 case OP_LOADBOOL: {
366 check(c == 0 || pc+2 < pt->sizecode); /* check its jump */
367 break;
368 }
369 case OP_LOADNIL: {
370 if (a <= reg && reg <= b)
371 last = pc; /* set registers from `a' to `b' */
372 break;
373 }
374 case OP_GETUPVAL:
375 case OP_SETUPVAL: {
376 check(b < pt->nups);
377 break;
378 }
379 case OP_GETGLOBAL:
380 case OP_SETGLOBAL: {
381 check(ttisstring(&pt->k[b]));
382 break;
383 }
384 case OP_SELF: {
385 checkreg(pt, a+1);
386 if (reg == a+1) last = pc;
387 break;
388 }
389 case OP_CONCAT: {
390 check(b < c); /* at least two operands */
391 break;
392 }
393 case OP_TFORLOOP: {
394 check(c >= 1); /* at least one result (control variable) */
395 checkreg(pt, a+2+c); /* space for results */
396 if (reg >= a+2) last = pc; /* affect all regs above its base */
397 break;
398 }
399 case OP_FORLOOP:
400 case OP_FORPREP:
401 checkreg(pt, a+3);
402 /* go through */
403 case OP_JMP: {
404 int dest = pc+1+b;
405 /* not full check and jump is forward and do not skip `lastpc'? */
406 if (reg != NO_REG && pc < dest && dest <= lastpc)
407 pc += b; /* do the jump */
408 break;
409 }
410 case OP_CALL:
411 case OP_TAILCALL: {
412 if (b != 0) {
413 checkreg(pt, a+b-1);
414 }
415 c--; /* c = num. returns */
416 if (c == LUA_MULTRET) {
417 check(checkopenop(pt, pc));
418 }
419 else if (c != 0)
420 checkreg(pt, a+c-1);
421 if (reg >= a) last = pc; /* affect all registers above base */
422 break;
423 }
424 case OP_RETURN: {
425 b--; /* b = num. returns */
426 if (b > 0) checkreg(pt, a+b-1);
427 break;
428 }
429 case OP_SETLIST: {
430 if (b > 0) checkreg(pt, a + b);
431 if (c == 0) pc++;
432 break;
433 }
434 case OP_CLOSURE: {
435 int nup, j;
436 check(b < pt->sizep);
437 nup = pt->p[b]->nups;
438 check(pc + nup < pt->sizecode);
439 for (j = 1; j <= nup; ++j) {
440 OpCode op1 = GET_OPCODE(pt->code[pc + j]);
441 check(op1 == OP_GETUPVAL || op1 == OP_MOVE);
442 }
443 if (reg != NO_REG) /* tracing? */
444 pc += nup; /* do nut 'execute' these pseudo-instructions */
445 break;
446 }
447 case OP_VARARG: {
448 check((pt->is_vararg & VARARG_ISVARARG) &&
449 !(pt->is_vararg & VARARG_NEEDSARG));
450 b--;
451 if (b == LUA_MULTRET) check(checkopenop(pt, pc));
452 checkreg(pt, a+b-1);
453 break;
454 }
455 default: break;
456 }
457 }
458 return pt->code[last];
459}
460
461#undef check
462#undef checkjump
463#undef checkreg
464
465/* }====================================================== */
466
467
468int luaG_checkcode (const Proto *pt) {
469 return (symbexec(pt, pt->sizecode, NO_REG) != 0);
470}
471
472
473static const char *kname (Proto *p, int c) {
474 if (ISK(c) && ttisstring(&p->k[INDEXK(c)]))
475 return svalue(&p->k[INDEXK(c)]);
476 else
477 return "?";
478}
479
480
481static const char *getobjname (lua_State *L, CallInfo *ci, int stackpos,
482 const char **name) {
483 if (isLua(ci)) { /* a Lua function? */
484 Proto *p = ci_func(ci)->l.p;
485 int pc = currentpc(L, ci);
486 Instruction i;
487 *name = luaF_getlocalname(p, stackpos+1, pc);
488 if (*name) /* is a local? */
489 return "local";
490 i = symbexec(p, pc, stackpos); /* try symbolic execution */
491 lua_assert(pc != -1);
492 switch (GET_OPCODE(i)) {
493 case OP_GETGLOBAL: {
494 int g = GETARG_Bx(i); /* global index */
495 lua_assert(ttisstring(&p->k[g]));
496 *name = svalue(&p->k[g]);
497 return "global";
498 }
499 case OP_MOVE: {
500 int a = GETARG_A(i);
501 int b = GETARG_B(i); /* move from `b' to `a' */
502 if (b < a)
503 return getobjname(L, ci, b, name); /* get name for `b' */
504 break;
505 }
506 case OP_GETTABLE: {
507 int k = GETARG_C(i); /* key index */
508 *name = kname(p, k);
509 return "field";
510 }
511 case OP_GETUPVAL: {
512 int u = GETARG_B(i); /* upvalue index */
513 *name = p->upvalues ? getstr(p->upvalues[u]) : "?";
514 return "upvalue";
515 }
516 case OP_SELF: {
517 int k = GETARG_C(i); /* key index */
518 *name = kname(p, k);
519 return "method";
520 }
521 default: break;
522 }
523 }
524 return NULL; /* no useful name found */
525}
526
527
528static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
529 Instruction i;
530 if ((isLua(ci) && ci->tailcalls > 0) || !isLua(ci - 1))
531 return NULL; /* calling function is not Lua (or is unknown) */
532 ci--; /* calling function */
533 i = ci_func(ci)->l.p->code[currentpc(L, ci)];
534 if (GET_OPCODE(i) == OP_CALL || GET_OPCODE(i) == OP_TAILCALL ||
535 GET_OPCODE(i) == OP_TFORLOOP)
536 return getobjname(L, ci, GETARG_A(i), name);
537 else
538 return NULL; /* no useful name can be found */
539}
540
541
542/* only ANSI way to check whether a pointer points to an array */
543static int isinstack (CallInfo *ci, const TValue *o) {
544 StkId p;
545 for (p = ci->base; p < ci->top; p++)
546 if (o == p) return 1;
547 return 0;
548}
549
550
551void luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
552 const char *name = NULL;
553 const char *t = luaT_typenames[ttype(o)];
554 const char *kind = (isinstack(L->ci, o)) ?
555 getobjname(L, L->ci, cast_int(o - L->base), &name) :
556 NULL;
557 if (kind)
558 luaG_runerror(L, "attempt to %s %s " LUA_QS " (a %s value)",
559 op, kind, name, t);
560 else
561 luaG_runerror(L, "attempt to %s a %s value", op, t);
562}
563
564
565void luaG_concaterror (lua_State *L, StkId p1, StkId p2) {
566 if (ttisstring(p1)) p1 = p2;
567 lua_assert(!ttisstring(p1));
568 luaG_typeerror(L, p1, "concatenate");
569}
570
571
572void luaG_aritherror (lua_State *L, const TValue *p1, const TValue *p2) {
573 TValue temp;
574 if (luaV_tonumber(p1, &temp) == NULL)
575 p2 = p1; /* first operand is wrong */
576 luaG_typeerror(L, p2, "perform arithmetic on");
577}
578
579
580int luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
581 const char *t1 = luaT_typenames[ttype(p1)];
582 const char *t2 = luaT_typenames[ttype(p2)];
583 if (t1[2] == t2[2])
584 luaG_runerror(L, "attempt to compare two %s values", t1);
585 else
586 luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
587 return 0;
588}
589
590
591static void addinfo (lua_State *L, const char *msg) {
592 CallInfo *ci = L->ci;
593 if (isLua(ci)) { /* is Lua code? */
594 char buff[LUA_IDSIZE]; /* add file:line information */
595 int line = currentline(L, ci);
596 luaO_chunkid(buff, getstr(getluaproto(ci)->source), LUA_IDSIZE);
597 luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
598 }
599}
600
601
602void luaG_errormsg (lua_State *L) {
603 if (L->errfunc != 0) { /* is there an error handling function? */
604 StkId errfunc = restorestack(L, L->errfunc);
605 if (!ttisfunction(errfunc)) luaD_throw(L, LUA_ERRERR);
606 setobjs2s(L, L->top, L->top - 1); /* move argument */
607 setobjs2s(L, L->top - 1, errfunc); /* push function */
608 incr_top(L);
609 luaD_call(L, L->top - 2, 1); /* call it */
610 }
611 luaD_throw(L, LUA_ERRRUN);
612}
613
614
615void luaG_runerror (lua_State *L, const char *fmt, ...) {
616 va_list argp;
617 va_start(argp, fmt);
618 addinfo(L, luaO_pushvfstring(L, fmt, argp));
619 va_end(argp);
620 luaG_errormsg(L);
621}
622

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