1/*
2** $Id: ldebug.c $
3** Debug Interface
4** See Copyright Notice in lua.h
5*/
6
7#define ldebug_c
8#define LUA_CORE
9
10#include "lprefix.h"
11
12
13#include <stdarg.h>
14#include <stddef.h>
15#include <string.h>
16
17#include "lua.h"
18
19#include "lapi.h"
20#include "lcode.h"
21#include "ldebug.h"
22#include "ldo.h"
23#include "lfunc.h"
24#include "lobject.h"
25#include "lopcodes.h"
26#include "lstate.h"
27#include "lstring.h"
28#include "ltable.h"
29#include "ltm.h"
30#include "lvm.h"
31
32
33
34#define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_VCCL)
35
36
37static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
38 const char **name);
39
40
41static int currentpc (CallInfo *ci) {
42 lua_assert(isLua(ci));
43 return pcRel(ci->u.l.savedpc, ci_func(ci)->p);
44}
45
46
47/*
48** Get a "base line" to find the line corresponding to an instruction.
49** Base lines are regularly placed at MAXIWTHABS intervals, so usually
50** an integer division gets the right place. When the source file has
51** large sequences of empty/comment lines, it may need extra entries,
52** so the original estimate needs a correction.
53** If the original estimate is -1, the initial 'if' ensures that the
54** 'while' will run at least once.
55** The assertion that the estimate is a lower bound for the correct base
56** is valid as long as the debug info has been generated with the same
57** value for MAXIWTHABS or smaller. (Previous releases use a little
58** smaller value.)
59*/
60static int getbaseline (const Proto *f, int pc, int *basepc) {
61 if (f->sizeabslineinfo == 0 || pc < f->abslineinfo[0].pc) {
62 *basepc = -1; /* start from the beginning */
63 return f->linedefined;
64 }
65 else {
66 int i = cast_uint(pc) / MAXIWTHABS - 1; /* get an estimate */
67 /* estimate must be a lower bond of the correct base */
68 lua_assert(i < 0 ||
69 (i < f->sizeabslineinfo && f->abslineinfo[i].pc <= pc));
70 while (i + 1 < f->sizeabslineinfo && pc >= f->abslineinfo[i + 1].pc)
71 i++; /* low estimate; adjust it */
72 *basepc = f->abslineinfo[i].pc;
73 return f->abslineinfo[i].line;
74 }
75}
76
77
78/*
79** Get the line corresponding to instruction 'pc' in function 'f';
80** first gets a base line and from there does the increments until
81** the desired instruction.
82*/
83int luaG_getfuncline (const Proto *f, int pc) {
84 if (f->lineinfo == NULL) /* no debug information? */
85 return -1;
86 else {
87 int basepc;
88 int baseline = getbaseline(f, pc, &basepc);
89 while (basepc++ < pc) { /* walk until given instruction */
90 lua_assert(f->lineinfo[basepc] != ABSLINEINFO);
91 baseline += f->lineinfo[basepc]; /* correct line */
92 }
93 return baseline;
94 }
95}
96
97
98static int getcurrentline (CallInfo *ci) {
99 return luaG_getfuncline(ci_func(ci)->p, currentpc(ci));
100}
101
102
103/*
104** Set 'trap' for all active Lua frames.
105** This function can be called during a signal, under "reasonable"
106** assumptions. A new 'ci' is completely linked in the list before it
107** becomes part of the "active" list, and we assume that pointers are
108** atomic; see comment in next function.
109** (A compiler doing interprocedural optimizations could, theoretically,
110** reorder memory writes in such a way that the list could be
111** temporarily broken while inserting a new element. We simply assume it
112** has no good reasons to do that.)
113*/
114static void settraps (CallInfo *ci) {
115 for (; ci != NULL; ci = ci->previous)
116 if (isLua(ci))
117 ci->u.l.trap = 1;
118}
119
120
121/*
122** This function can be called during a signal, under "reasonable"
123** assumptions.
124** Fields 'basehookcount' and 'hookcount' (set by 'resethookcount')
125** are for debug only, and it is no problem if they get arbitrary
126** values (causes at most one wrong hook call). 'hookmask' is an atomic
127** value. We assume that pointers are atomic too (e.g., gcc ensures that
128** for all platforms where it runs). Moreover, 'hook' is always checked
129** before being called (see 'luaD_hook').
130*/
131LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) {
132 if (func == NULL || mask == 0) { /* turn off hooks? */
133 mask = 0;
134 func = NULL;
135 }
136 L->hook = func;
137 L->basehookcount = count;
138 resethookcount(L);
139 L->hookmask = cast_byte(mask);
140 if (mask)
141 settraps(L->ci); /* to trace inside 'luaV_execute' */
142}
143
144
145LUA_API lua_Hook lua_gethook (lua_State *L) {
146 return L->hook;
147}
148
149
150LUA_API int lua_gethookmask (lua_State *L) {
151 return L->hookmask;
152}
153
154
155LUA_API int lua_gethookcount (lua_State *L) {
156 return L->basehookcount;
157}
158
159
160LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) {
161 int status;
162 CallInfo *ci;
163 if (level < 0) return 0; /* invalid (negative) level */
164 lua_lock(L);
165 for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous)
166 level--;
167 if (level == 0 && ci != &L->base_ci) { /* level found? */
168 status = 1;
169 ar->i_ci = ci;
170 }
171 else status = 0; /* no such level */
172 lua_unlock(L);
173 return status;
174}
175
176
177static const char *upvalname (const Proto *p, int uv) {
178 TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name);
179 if (s == NULL) return "?";
180 else return getstr(s);
181}
182
183
184static const char *findvararg (CallInfo *ci, int n, StkId *pos) {
185 if (clLvalue(s2v(ci->func))->p->is_vararg) {
186 int nextra = ci->u.l.nextraargs;
187 if (n >= -nextra) { /* 'n' is negative */
188 *pos = ci->func - nextra - (n + 1);
189 return "(vararg)"; /* generic name for any vararg */
190 }
191 }
192 return NULL; /* no such vararg */
193}
194
195
196const char *luaG_findlocal (lua_State *L, CallInfo *ci, int n, StkId *pos) {
197 StkId base = ci->func + 1;
198 const char *name = NULL;
199 if (isLua(ci)) {
200 if (n < 0) /* access to vararg values? */
201 return findvararg(ci, n, pos);
202 else
203 name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci));
204 }
205 if (name == NULL) { /* no 'standard' name? */
206 StkId limit = (ci == L->ci) ? L->top : ci->next->func;
207 if (limit - base >= n && n > 0) { /* is 'n' inside 'ci' stack? */
208 /* generic name for any valid slot */
209 name = isLua(ci) ? "(temporary)" : "(C temporary)";
210 }
211 else
212 return NULL; /* no name */
213 }
214 if (pos)
215 *pos = base + (n - 1);
216 return name;
217}
218
219
220LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
221 const char *name;
222 lua_lock(L);
223 if (ar == NULL) { /* information about non-active function? */
224 if (!isLfunction(s2v(L->top - 1))) /* not a Lua function? */
225 name = NULL;
226 else /* consider live variables at function start (parameters) */
227 name = luaF_getlocalname(clLvalue(s2v(L->top - 1))->p, n, 0);
228 }
229 else { /* active function; get information through 'ar' */
230 StkId pos = NULL; /* to avoid warnings */
231 name = luaG_findlocal(L, ar->i_ci, n, &pos);
232 if (name) {
233 setobjs2s(L, L->top, pos);
234 api_incr_top(L);
235 }
236 }
237 lua_unlock(L);
238 return name;
239}
240
241
242LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
243 StkId pos = NULL; /* to avoid warnings */
244 const char *name;
245 lua_lock(L);
246 name = luaG_findlocal(L, ar->i_ci, n, &pos);
247 if (name) {
248 setobjs2s(L, pos, L->top - 1);
249 L->top--; /* pop value */
250 }
251 lua_unlock(L);
252 return name;
253}
254
255
256static void funcinfo (lua_Debug *ar, Closure *cl) {
257 if (noLuaClosure(cl)) {
258 ar->source = "=[C]";
259 ar->srclen = LL("=[C]");
260 ar->linedefined = -1;
261 ar->lastlinedefined = -1;
262 ar->what = "C";
263 }
264 else {
265 const Proto *p = cl->l.p;
266 if (p->source) {
267 ar->source = getstr(p->source);
268 ar->srclen = tsslen(p->source);
269 }
270 else {
271 ar->source = "=?";
272 ar->srclen = LL("=?");
273 }
274 ar->linedefined = p->linedefined;
275 ar->lastlinedefined = p->lastlinedefined;
276 ar->what = (ar->linedefined == 0) ? "main" : "Lua";
277 }
278 luaO_chunkid(ar->short_src, ar->source, ar->srclen);
279}
280
281
282static int nextline (const Proto *p, int currentline, int pc) {
283 if (p->lineinfo[pc] != ABSLINEINFO)
284 return currentline + p->lineinfo[pc];
285 else
286 return luaG_getfuncline(p, pc);
287}
288
289
290static void collectvalidlines (lua_State *L, Closure *f) {
291 if (noLuaClosure(f)) {
292 setnilvalue(s2v(L->top));
293 api_incr_top(L);
294 }
295 else {
296 int i;
297 TValue v;
298 const Proto *p = f->l.p;
299 int currentline = p->linedefined;
300 Table *t = luaH_new(L); /* new table to store active lines */
301 sethvalue2s(L, L->top, t); /* push it on stack */
302 api_incr_top(L);
303 setbtvalue(&v); /* boolean 'true' to be the value of all indices */
304 for (i = 0; i < p->sizelineinfo; i++) { /* for all instructions */
305 currentline = nextline(p, currentline, i); /* get its line */
306 luaH_setint(L, t, currentline, &v); /* table[line] = true */
307 }
308 }
309}
310
311
312static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) {
313 if (ci == NULL) /* no 'ci'? */
314 return NULL; /* no info */
315 else if (ci->callstatus & CIST_FIN) { /* is this a finalizer? */
316 *name = "__gc";
317 return "metamethod"; /* report it as such */
318 }
319 /* calling function is a known Lua function? */
320 else if (!(ci->callstatus & CIST_TAIL) && isLua(ci->previous))
321 return funcnamefromcode(L, ci->previous, name);
322 else return NULL; /* no way to find a name */
323}
324
325
326static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar,
327 Closure *f, CallInfo *ci) {
328 int status = 1;
329 for (; *what; what++) {
330 switch (*what) {
331 case 'S': {
332 funcinfo(ar, f);
333 break;
334 }
335 case 'l': {
336 ar->currentline = (ci && isLua(ci)) ? getcurrentline(ci) : -1;
337 break;
338 }
339 case 'u': {
340 ar->nups = (f == NULL) ? 0 : f->c.nupvalues;
341 if (noLuaClosure(f)) {
342 ar->isvararg = 1;
343 ar->nparams = 0;
344 }
345 else {
346 ar->isvararg = f->l.p->is_vararg;
347 ar->nparams = f->l.p->numparams;
348 }
349 break;
350 }
351 case 't': {
352 ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0;
353 break;
354 }
355 case 'n': {
356 ar->namewhat = getfuncname(L, ci, &ar->name);
357 if (ar->namewhat == NULL) {
358 ar->namewhat = ""; /* not found */
359 ar->name = NULL;
360 }
361 break;
362 }
363 case 'r': {
364 if (ci == NULL || !(ci->callstatus & CIST_TRAN))
365 ar->ftransfer = ar->ntransfer = 0;
366 else {
367 ar->ftransfer = ci->u2.transferinfo.ftransfer;
368 ar->ntransfer = ci->u2.transferinfo.ntransfer;
369 }
370 break;
371 }
372 case 'L':
373 case 'f': /* handled by lua_getinfo */
374 break;
375 default: status = 0; /* invalid option */
376 }
377 }
378 return status;
379}
380
381
382LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
383 int status;
384 Closure *cl;
385 CallInfo *ci;
386 TValue *func;
387 lua_lock(L);
388 if (*what == '>') {
389 ci = NULL;
390 func = s2v(L->top - 1);
391 api_check(L, ttisfunction(func), "function expected");
392 what++; /* skip the '>' */
393 L->top--; /* pop function */
394 }
395 else {
396 ci = ar->i_ci;
397 func = s2v(ci->func);
398 lua_assert(ttisfunction(func));
399 }
400 cl = ttisclosure(func) ? clvalue(func) : NULL;
401 status = auxgetinfo(L, what, ar, cl, ci);
402 if (strchr(what, 'f')) {
403 setobj2s(L, L->top, func);
404 api_incr_top(L);
405 }
406 if (strchr(what, 'L'))
407 collectvalidlines(L, cl);
408 lua_unlock(L);
409 return status;
410}
411
412
413/*
414** {======================================================
415** Symbolic Execution
416** =======================================================
417*/
418
419static const char *getobjname (const Proto *p, int lastpc, int reg,
420 const char **name);
421
422
423/*
424** Find a "name" for the constant 'c'.
425*/
426static void kname (const Proto *p, int c, const char **name) {
427 TValue *kvalue = &p->k[c];
428 *name = (ttisstring(kvalue)) ? svalue(kvalue) : "?";
429}
430
431
432/*
433** Find a "name" for the register 'c'.
434*/
435static void rname (const Proto *p, int pc, int c, const char **name) {
436 const char *what = getobjname(p, pc, c, name); /* search for 'c' */
437 if (!(what && *what == 'c')) /* did not find a constant name? */
438 *name = "?";
439}
440
441
442/*
443** Find a "name" for a 'C' value in an RK instruction.
444*/
445static void rkname (const Proto *p, int pc, Instruction i, const char **name) {
446 int c = GETARG_C(i); /* key index */
447 if (GETARG_k(i)) /* is 'c' a constant? */
448 kname(p, c, name);
449 else /* 'c' is a register */
450 rname(p, pc, c, name);
451}
452
453
454static int filterpc (int pc, int jmptarget) {
455 if (pc < jmptarget) /* is code conditional (inside a jump)? */
456 return -1; /* cannot know who sets that register */
457 else return pc; /* current position sets that register */
458}
459
460
461/*
462** Try to find last instruction before 'lastpc' that modified register 'reg'.
463*/
464static int findsetreg (const Proto *p, int lastpc, int reg) {
465 int pc;
466 int setreg = -1; /* keep last instruction that changed 'reg' */
467 int jmptarget = 0; /* any code before this address is conditional */
468 if (testMMMode(GET_OPCODE(p->code[lastpc])))
469 lastpc--; /* previous instruction was not actually executed */
470 for (pc = 0; pc < lastpc; pc++) {
471 Instruction i = p->code[pc];
472 OpCode op = GET_OPCODE(i);
473 int a = GETARG_A(i);
474 int change; /* true if current instruction changed 'reg' */
475 switch (op) {
476 case OP_LOADNIL: { /* set registers from 'a' to 'a+b' */
477 int b = GETARG_B(i);
478 change = (a <= reg && reg <= a + b);
479 break;
480 }
481 case OP_TFORCALL: { /* affect all regs above its base */
482 change = (reg >= a + 2);
483 break;
484 }
485 case OP_CALL:
486 case OP_TAILCALL: { /* affect all registers above base */
487 change = (reg >= a);
488 break;
489 }
490 case OP_JMP: { /* doesn't change registers, but changes 'jmptarget' */
491 int b = GETARG_sJ(i);
492 int dest = pc + 1 + b;
493 /* jump does not skip 'lastpc' and is larger than current one? */
494 if (dest <= lastpc && dest > jmptarget)
495 jmptarget = dest; /* update 'jmptarget' */
496 change = 0;
497 break;
498 }
499 default: /* any instruction that sets A */
500 change = (testAMode(op) && reg == a);
501 break;
502 }
503 if (change)
504 setreg = filterpc(pc, jmptarget);
505 }
506 return setreg;
507}
508
509
510/*
511** Check whether table being indexed by instruction 'i' is the
512** environment '_ENV'
513*/
514static const char *gxf (const Proto *p, int pc, Instruction i, int isup) {
515 int t = GETARG_B(i); /* table index */
516 const char *name; /* name of indexed variable */
517 if (isup) /* is an upvalue? */
518 name = upvalname(p, t);
519 else
520 getobjname(p, pc, t, &name);
521 return (name && strcmp(name, LUA_ENV) == 0) ? "global" : "field";
522}
523
524
525static const char *getobjname (const Proto *p, int lastpc, int reg,
526 const char **name) {
527 int pc;
528 *name = luaF_getlocalname(p, reg + 1, lastpc);
529 if (*name) /* is a local? */
530 return "local";
531 /* else try symbolic execution */
532 pc = findsetreg(p, lastpc, reg);
533 if (pc != -1) { /* could find instruction? */
534 Instruction i = p->code[pc];
535 OpCode op = GET_OPCODE(i);
536 switch (op) {
537 case OP_MOVE: {
538 int b = GETARG_B(i); /* move from 'b' to 'a' */
539 if (b < GETARG_A(i))
540 return getobjname(p, pc, b, name); /* get name for 'b' */
541 break;
542 }
543 case OP_GETTABUP: {
544 int k = GETARG_C(i); /* key index */
545 kname(p, k, name);
546 return gxf(p, pc, i, 1);
547 }
548 case OP_GETTABLE: {
549 int k = GETARG_C(i); /* key index */
550 rname(p, pc, k, name);
551 return gxf(p, pc, i, 0);
552 }
553 case OP_GETI: {
554 *name = "integer index";
555 return "field";
556 }
557 case OP_GETFIELD: {
558 int k = GETARG_C(i); /* key index */
559 kname(p, k, name);
560 return gxf(p, pc, i, 0);
561 }
562 case OP_GETUPVAL: {
563 *name = upvalname(p, GETARG_B(i));
564 return "upvalue";
565 }
566 case OP_LOADK:
567 case OP_LOADKX: {
568 int b = (op == OP_LOADK) ? GETARG_Bx(i)
569 : GETARG_Ax(p->code[pc + 1]);
570 if (ttisstring(&p->k[b])) {
571 *name = svalue(&p->k[b]);
572 return "constant";
573 }
574 break;
575 }
576 case OP_SELF: {
577 rkname(p, pc, i, name);
578 return "method";
579 }
580 default: break; /* go through to return NULL */
581 }
582 }
583 return NULL; /* could not find reasonable name */
584}
585
586
587/*
588** Try to find a name for a function based on the code that called it.
589** (Only works when function was called by a Lua function.)
590** Returns what the name is (e.g., "for iterator", "method",
591** "metamethod") and sets '*name' to point to the name.
592*/
593static const char *funcnamefromcode (lua_State *L, CallInfo *ci,
594 const char **name) {
595 TMS tm = (TMS)0; /* (initial value avoids warnings) */
596 const Proto *p = ci_func(ci)->p; /* calling function */
597 int pc = currentpc(ci); /* calling instruction index */
598 Instruction i = p->code[pc]; /* calling instruction */
599 if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */
600 *name = "?";
601 return "hook";
602 }
603 switch (GET_OPCODE(i)) {
604 case OP_CALL:
605 case OP_TAILCALL:
606 return getobjname(p, pc, GETARG_A(i), name); /* get function name */
607 case OP_TFORCALL: { /* for iterator */
608 *name = "for iterator";
609 return "for iterator";
610 }
611 /* other instructions can do calls through metamethods */
612 case OP_SELF: case OP_GETTABUP: case OP_GETTABLE:
613 case OP_GETI: case OP_GETFIELD:
614 tm = TM_INDEX;
615 break;
616 case OP_SETTABUP: case OP_SETTABLE: case OP_SETI: case OP_SETFIELD:
617 tm = TM_NEWINDEX;
618 break;
619 case OP_MMBIN: case OP_MMBINI: case OP_MMBINK: {
620 tm = cast(TMS, GETARG_C(i));
621 break;
622 }
623 case OP_UNM: tm = TM_UNM; break;
624 case OP_BNOT: tm = TM_BNOT; break;
625 case OP_LEN: tm = TM_LEN; break;
626 case OP_CONCAT: tm = TM_CONCAT; break;
627 case OP_EQ: tm = TM_EQ; break;
628 /* no cases for OP_EQI and OP_EQK, as they don't call metamethods */
629 case OP_LT: case OP_LTI: case OP_GTI: tm = TM_LT; break;
630 case OP_LE: case OP_LEI: case OP_GEI: tm = TM_LE; break;
631 case OP_CLOSE: case OP_RETURN: tm = TM_CLOSE; break;
632 default:
633 return NULL; /* cannot find a reasonable name */
634 }
635 *name = getstr(G(L)->tmname[tm]) + 2;
636 return "metamethod";
637}
638
639/* }====================================================== */
640
641
642
643/*
644** Check whether pointer 'o' points to some value in the stack
645** frame of the current function. Because 'o' may not point to a
646** value in this stack, we cannot compare it with the region
647** boundaries (undefined behaviour in ISO C).
648*/
649static int isinstack (CallInfo *ci, const TValue *o) {
650 StkId pos;
651 for (pos = ci->func + 1; pos < ci->top; pos++) {
652 if (o == s2v(pos))
653 return 1;
654 }
655 return 0; /* not found */
656}
657
658
659/*
660** Checks whether value 'o' came from an upvalue. (That can only happen
661** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on
662** upvalues.)
663*/
664static const char *getupvalname (CallInfo *ci, const TValue *o,
665 const char **name) {
666 LClosure *c = ci_func(ci);
667 int i;
668 for (i = 0; i < c->nupvalues; i++) {
669 if (c->upvals[i]->v == o) {
670 *name = upvalname(c->p, i);
671 return "upvalue";
672 }
673 }
674 return NULL;
675}
676
677
678static const char *varinfo (lua_State *L, const TValue *o) {
679 const char *name = NULL; /* to avoid warnings */
680 CallInfo *ci = L->ci;
681 const char *kind = NULL;
682 if (isLua(ci)) {
683 kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */
684 if (!kind && isinstack(ci, o)) /* no? try a register */
685 kind = getobjname(ci_func(ci)->p, currentpc(ci),
686 cast_int(cast(StkId, o) - (ci->func + 1)), &name);
687 }
688 return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : "";
689}
690
691
692l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) {
693 const char *t = luaT_objtypename(L, o);
694 luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o));
695}
696
697
698l_noret luaG_callerror (lua_State *L, const TValue *o) {
699 CallInfo *ci = L->ci;
700 const char *name = NULL; /* to avoid warnings */
701 const char *what = (isLua(ci)) ? funcnamefromcode(L, ci, &name) : NULL;
702 if (what != NULL) {
703 const char *t = luaT_objtypename(L, o);
704 luaG_runerror(L, "%s '%s' is not callable (a %s value)", what, name, t);
705 }
706 else
707 luaG_typeerror(L, o, "call");
708}
709
710
711l_noret luaG_forerror (lua_State *L, const TValue *o, const char *what) {
712 luaG_runerror(L, "bad 'for' %s (number expected, got %s)",
713 what, luaT_objtypename(L, o));
714}
715
716
717l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) {
718 if (ttisstring(p1) || cvt2str(p1)) p1 = p2;
719 luaG_typeerror(L, p1, "concatenate");
720}
721
722
723l_noret luaG_opinterror (lua_State *L, const TValue *p1,
724 const TValue *p2, const char *msg) {
725 if (!ttisnumber(p1)) /* first operand is wrong? */
726 p2 = p1; /* now second is wrong */
727 luaG_typeerror(L, p2, msg);
728}
729
730
731/*
732** Error when both values are convertible to numbers, but not to integers
733*/
734l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) {
735 lua_Integer temp;
736 if (!luaV_tointegerns(p1, &temp, LUA_FLOORN2I))
737 p2 = p1;
738 luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2));
739}
740
741
742l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) {
743 const char *t1 = luaT_objtypename(L, p1);
744 const char *t2 = luaT_objtypename(L, p2);
745 if (strcmp(t1, t2) == 0)
746 luaG_runerror(L, "attempt to compare two %s values", t1);
747 else
748 luaG_runerror(L, "attempt to compare %s with %s", t1, t2);
749}
750
751
752/* add src:line information to 'msg' */
753const char *luaG_addinfo (lua_State *L, const char *msg, TString *src,
754 int line) {
755 char buff[LUA_IDSIZE];
756 if (src)
757 luaO_chunkid(buff, getstr(src), tsslen(src));
758 else { /* no source available; use "?" instead */
759 buff[0] = '?'; buff[1] = '\0';
760 }
761 return luaO_pushfstring(L, "%s:%d: %s", buff, line, msg);
762}
763
764
765l_noret luaG_errormsg (lua_State *L) {
766 if (L->errfunc != 0) { /* is there an error handling function? */
767 StkId errfunc = restorestack(L, L->errfunc);
768 lua_assert(ttisfunction(s2v(errfunc)));
769 setobjs2s(L, L->top, L->top - 1); /* move argument */
770 setobjs2s(L, L->top - 1, errfunc); /* push function */
771 L->top++; /* assume EXTRA_STACK */
772 luaD_callnoyield(L, L->top - 2, 1); /* call it */
773 }
774 luaD_throw(L, LUA_ERRRUN);
775}
776
777
778l_noret luaG_runerror (lua_State *L, const char *fmt, ...) {
779 CallInfo *ci = L->ci;
780 const char *msg;
781 va_list argp;
782 luaC_checkGC(L); /* error message uses memory */
783 va_start(argp, fmt);
784 msg = luaO_pushvfstring(L, fmt, argp); /* format message */
785 va_end(argp);
786 if (isLua(ci)) /* if Lua function, add source:line information */
787 luaG_addinfo(L, msg, ci_func(ci)->p->source, getcurrentline(ci));
788 luaG_errormsg(L);
789}
790
791
792/*
793** Check whether new instruction 'newpc' is in a different line from
794** previous instruction 'oldpc'. More often than not, 'newpc' is only
795** one or a few instructions after 'oldpc' (it must be after, see
796** caller), so try to avoid calling 'luaG_getfuncline'. If they are
797** too far apart, there is a good chance of a ABSLINEINFO in the way,
798** so it goes directly to 'luaG_getfuncline'.
799*/
800static int changedline (const Proto *p, int oldpc, int newpc) {
801 if (p->lineinfo == NULL) /* no debug information? */
802 return 0;
803 if (newpc - oldpc < MAXIWTHABS / 2) { /* not too far apart? */
804 int delta = 0; /* line diference */
805 int pc = oldpc;
806 for (;;) {
807 int lineinfo = p->lineinfo[++pc];
808 if (lineinfo == ABSLINEINFO)
809 break; /* cannot compute delta; fall through */
810 delta += lineinfo;
811 if (pc == newpc)
812 return (delta != 0); /* delta computed successfully */
813 }
814 }
815 /* either instructions are too far apart or there is an absolute line
816 info in the way; compute line difference explicitly */
817 return (luaG_getfuncline(p, oldpc) != luaG_getfuncline(p, newpc));
818}
819
820
821/*
822** Traces the execution of a Lua function. Called before the execution
823** of each opcode, when debug is on. 'L->oldpc' stores the last
824** instruction traced, to detect line changes. When entering a new
825** function, 'npci' will be zero and will test as a new line whatever
826** the value of 'oldpc'. Some exceptional conditions may return to
827** a function without setting 'oldpc'. In that case, 'oldpc' may be
828** invalid; if so, use zero as a valid value. (A wrong but valid 'oldpc'
829** at most causes an extra call to a line hook.)
830** This function is not "Protected" when called, so it should correct
831** 'L->top' before calling anything that can run the GC.
832*/
833int luaG_traceexec (lua_State *L, const Instruction *pc) {
834 CallInfo *ci = L->ci;
835 lu_byte mask = L->hookmask;
836 const Proto *p = ci_func(ci)->p;
837 int counthook;
838 if (!(mask & (LUA_MASKLINE | LUA_MASKCOUNT))) { /* no hooks? */
839 ci->u.l.trap = 0; /* don't need to stop again */
840 return 0; /* turn off 'trap' */
841 }
842 pc++; /* reference is always next instruction */
843 ci->u.l.savedpc = pc; /* save 'pc' */
844 counthook = (--L->hookcount == 0 && (mask & LUA_MASKCOUNT));
845 if (counthook)
846 resethookcount(L); /* reset count */
847 else if (!(mask & LUA_MASKLINE))
848 return 1; /* no line hook and count != 0; nothing to be done now */
849 if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */
850 ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */
851 return 1; /* do not call hook again (VM yielded, so it did not move) */
852 }
853 if (!isIT(*(ci->u.l.savedpc - 1))) /* top not being used? */
854 L->top = ci->top; /* correct top */
855 if (counthook)
856 luaD_hook(L, LUA_HOOKCOUNT, -1, 0, 0); /* call count hook */
857 if (mask & LUA_MASKLINE) {
858 /* 'L->oldpc' may be invalid; use zero in this case */
859 int oldpc = (L->oldpc < p->sizecode) ? L->oldpc : 0;
860 int npci = pcRel(pc, p);
861 if (npci <= oldpc || /* call hook when jump back (loop), */
862 changedline(p, oldpc, npci)) { /* or when enter new line */
863 int newline = luaG_getfuncline(p, npci);
864 luaD_hook(L, LUA_HOOKLINE, newline, 0, 0); /* call line hook */
865 }
866 L->oldpc = npci; /* 'pc' of last call to line hook */
867 }
868 if (L->status == LUA_YIELD) { /* did hook yield? */
869 if (counthook)
870 L->hookcount = 1; /* undo decrement to zero */
871 ci->u.l.savedpc--; /* undo increment (resume will increment it again) */
872 ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */
873 luaD_throw(L, LUA_YIELD);
874 }
875 return 1; /* keep 'trap' on */
876}
877
878