1/*
2** $Id: lauxlib.c $
3** Auxiliary functions for building Lua libraries
4** See Copyright Notice in lua.h
5*/
6
7#define lauxlib_c
8#define LUA_LIB
9
10#include "lprefix.h"
11
12
13#include <errno.h>
14#include <stdarg.h>
15#include <stdio.h>
16#include <stdlib.h>
17#include <string.h>
18
19
20/*
21** This file uses only the official API of Lua.
22** Any function declared here could be written as an application function.
23*/
24
25#include "lua.h"
26
27#include "lauxlib.h"
28
29
30#if !defined(MAX_SIZET)
31/* maximum value for size_t */
32#define MAX_SIZET ((size_t)(~(size_t)0))
33#endif
34
35
36/*
37** {======================================================
38** Traceback
39** =======================================================
40*/
41
42
43#define LEVELS1 10 /* size of the first part of the stack */
44#define LEVELS2 11 /* size of the second part of the stack */
45
46
47
48/*
49** Search for 'objidx' in table at index -1. ('objidx' must be an
50** absolute index.) Return 1 + string at top if it found a good name.
51*/
52static int findfield (lua_State *L, int objidx, int level) {
53 if (level == 0 || !lua_istable(L, -1))
54 return 0; /* not found */
55 lua_pushnil(L); /* start 'next' loop */
56 while (lua_next(L, -2)) { /* for each pair in table */
57 if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */
58 if (lua_rawequal(L, objidx, -1)) { /* found object? */
59 lua_pop(L, 1); /* remove value (but keep name) */
60 return 1;
61 }
62 else if (findfield(L, objidx, level - 1)) { /* try recursively */
63 /* stack: lib_name, lib_table, field_name (top) */
64 lua_pushliteral(L, "."); /* place '.' between the two names */
65 lua_replace(L, -3); /* (in the slot occupied by table) */
66 lua_concat(L, 3); /* lib_name.field_name */
67 return 1;
68 }
69 }
70 lua_pop(L, 1); /* remove value */
71 }
72 return 0; /* not found */
73}
74
75
76/*
77** Search for a name for a function in all loaded modules
78*/
79static int pushglobalfuncname (lua_State *L, lua_Debug *ar) {
80 int top = lua_gettop(L);
81 lua_getinfo(L, "f", ar); /* push function */
82 lua_getfield(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
83 luaL_checkstack(L, 6, "not enough stack"); /* slots for 'findfield' */
84 if (findfield(L, top + 1, 2)) {
85 const char *name = lua_tostring(L, -1);
86 if (strncmp(name, LUA_GNAME ".", 3) == 0) { /* name start with '_G.'? */
87 lua_pushstring(L, name + 3); /* push name without prefix */
88 lua_remove(L, -2); /* remove original name */
89 }
90 lua_copy(L, -1, top + 1); /* copy name to proper place */
91 lua_settop(L, top + 1); /* remove table "loaded" and name copy */
92 return 1;
93 }
94 else {
95 lua_settop(L, top); /* remove function and global table */
96 return 0;
97 }
98}
99
100
101static void pushfuncname (lua_State *L, lua_Debug *ar) {
102 if (pushglobalfuncname(L, ar)) { /* try first a global name */
103 lua_pushfstring(L, "function '%s'", lua_tostring(L, -1));
104 lua_remove(L, -2); /* remove name */
105 }
106 else if (*ar->namewhat != '\0') /* is there a name from code? */
107 lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */
108 else if (*ar->what == 'm') /* main? */
109 lua_pushliteral(L, "main chunk");
110 else if (*ar->what != 'C') /* for Lua functions, use <file:line> */
111 lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined);
112 else /* nothing left... */
113 lua_pushliteral(L, "?");
114}
115
116
117static int lastlevel (lua_State *L) {
118 lua_Debug ar;
119 int li = 1, le = 1;
120 /* find an upper bound */
121 while (lua_getstack(L, le, &ar)) { li = le; le *= 2; }
122 /* do a binary search */
123 while (li < le) {
124 int m = (li + le)/2;
125 if (lua_getstack(L, m, &ar)) li = m + 1;
126 else le = m;
127 }
128 return le - 1;
129}
130
131
132LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1,
133 const char *msg, int level) {
134 luaL_Buffer b;
135 lua_Debug ar;
136 int last = lastlevel(L1);
137 int limit2show = (last - level > LEVELS1 + LEVELS2) ? LEVELS1 : -1;
138 luaL_buffinit(L, &b);
139 if (msg) {
140 luaL_addstring(&b, msg);
141 luaL_addchar(&b, '\n');
142 }
143 luaL_addstring(&b, "stack traceback:");
144 while (lua_getstack(L1, level++, &ar)) {
145 if (limit2show-- == 0) { /* too many levels? */
146 int n = last - level - LEVELS2 + 1; /* number of levels to skip */
147 lua_pushfstring(L, "\n\t...\t(skipping %d levels)", n);
148 luaL_addvalue(&b); /* add warning about skip */
149 level += n; /* and skip to last levels */
150 }
151 else {
152 lua_getinfo(L1, "Slnt", &ar);
153 if (ar.currentline <= 0)
154 lua_pushfstring(L, "\n\t%s: in ", ar.short_src);
155 else
156 lua_pushfstring(L, "\n\t%s:%d: in ", ar.short_src, ar.currentline);
157 luaL_addvalue(&b);
158 pushfuncname(L, &ar);
159 luaL_addvalue(&b);
160 if (ar.istailcall)
161 luaL_addstring(&b, "\n\t(...tail calls...)");
162 }
163 }
164 luaL_pushresult(&b);
165}
166
167/* }====================================================== */
168
169
170/*
171** {======================================================
172** Error-report functions
173** =======================================================
174*/
175
176LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) {
177 lua_Debug ar;
178 if (!lua_getstack(L, 0, &ar)) /* no stack frame? */
179 return luaL_error(L, "bad argument #%d (%s)", arg, extramsg);
180 lua_getinfo(L, "n", &ar);
181 if (strcmp(ar.namewhat, "method") == 0) {
182 arg--; /* do not count 'self' */
183 if (arg == 0) /* error is in the self argument itself? */
184 return luaL_error(L, "calling '%s' on bad self (%s)",
185 ar.name, extramsg);
186 }
187 if (ar.name == NULL)
188 ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?";
189 return luaL_error(L, "bad argument #%d to '%s' (%s)",
190 arg, ar.name, extramsg);
191}
192
193
194LUALIB_API int luaL_typeerror (lua_State *L, int arg, const char *tname) {
195 const char *msg;
196 const char *typearg; /* name for the type of the actual argument */
197 if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING)
198 typearg = lua_tostring(L, -1); /* use the given type name */
199 else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA)
200 typearg = "light userdata"; /* special name for messages */
201 else
202 typearg = luaL_typename(L, arg); /* standard name */
203 msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg);
204 return luaL_argerror(L, arg, msg);
205}
206
207
208static void tag_error (lua_State *L, int arg, int tag) {
209 luaL_typeerror(L, arg, lua_typename(L, tag));
210}
211
212
213/*
214** The use of 'lua_pushfstring' ensures this function does not
215** need reserved stack space when called.
216*/
217LUALIB_API void luaL_where (lua_State *L, int level) {
218 lua_Debug ar;
219 if (lua_getstack(L, level, &ar)) { /* check function at level */
220 lua_getinfo(L, "Sl", &ar); /* get info about it */
221 if (ar.currentline > 0) { /* is there info? */
222 lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);
223 return;
224 }
225 }
226 lua_pushfstring(L, ""); /* else, no information available... */
227}
228
229
230/*
231** Again, the use of 'lua_pushvfstring' ensures this function does
232** not need reserved stack space when called. (At worst, it generates
233** an error with "stack overflow" instead of the given message.)
234*/
235LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {
236 va_list argp;
237 va_start(argp, fmt);
238 luaL_where(L, 1);
239 lua_pushvfstring(L, fmt, argp);
240 va_end(argp);
241 lua_concat(L, 2);
242 return lua_error(L);
243}
244
245
246LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) {
247 int en = errno; /* calls to Lua API may change this value */
248 if (stat) {
249 lua_pushboolean(L, 1);
250 return 1;
251 }
252 else {
253 const char *msg;
254 luaL_pushfail(L);
255 msg = (en != 0) ? strerror(en) : "(no extra info)";
256 if (fname)
257 lua_pushfstring(L, "%s: %s", fname, msg);
258 else
259 lua_pushstring(L, msg);
260 lua_pushinteger(L, en);
261 return 3;
262 }
263}
264
265
266#if !defined(l_inspectstat) /* { */
267
268#if defined(LUA_USE_POSIX)
269
270#include <sys/wait.h>
271
272/*
273** use appropriate macros to interpret 'pclose' return status
274*/
275#define l_inspectstat(stat,what) \
276 if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \
277 else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; }
278
279#else
280
281#define l_inspectstat(stat,what) /* no op */
282
283#endif
284
285#endif /* } */
286
287
288LUALIB_API int luaL_execresult (lua_State *L, int stat) {
289 if (stat != 0 && errno != 0) /* error with an 'errno'? */
290 return luaL_fileresult(L, 0, NULL);
291 else {
292 const char *what = "exit"; /* type of termination */
293 l_inspectstat(stat, what); /* interpret result */
294 if (*what == 'e' && stat == 0) /* successful termination? */
295 lua_pushboolean(L, 1);
296 else
297 luaL_pushfail(L);
298 lua_pushstring(L, what);
299 lua_pushinteger(L, stat);
300 return 3; /* return true/fail,what,code */
301 }
302}
303
304/* }====================================================== */
305
306
307
308/*
309** {======================================================
310** Userdata's metatable manipulation
311** =======================================================
312*/
313
314LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {
315 if (luaL_getmetatable(L, tname) != LUA_TNIL) /* name already in use? */
316 return 0; /* leave previous value on top, but return 0 */
317 lua_pop(L, 1);
318 lua_createtable(L, 0, 2); /* create metatable */
319 lua_pushstring(L, tname);
320 lua_setfield(L, -2, "__name"); /* metatable.__name = tname */
321 lua_pushvalue(L, -1);
322 lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */
323 return 1;
324}
325
326
327LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) {
328 luaL_getmetatable(L, tname);
329 lua_setmetatable(L, -2);
330}
331
332
333LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) {
334 void *p = lua_touserdata(L, ud);
335 if (p != NULL) { /* value is a userdata? */
336 if (lua_getmetatable(L, ud)) { /* does it have a metatable? */
337 luaL_getmetatable(L, tname); /* get correct metatable */
338 if (!lua_rawequal(L, -1, -2)) /* not the same? */
339 p = NULL; /* value is a userdata with wrong metatable */
340 lua_pop(L, 2); /* remove both metatables */
341 return p;
342 }
343 }
344 return NULL; /* value is not a userdata with a metatable */
345}
346
347
348LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {
349 void *p = luaL_testudata(L, ud, tname);
350 luaL_argexpected(L, p != NULL, ud, tname);
351 return p;
352}
353
354/* }====================================================== */
355
356
357/*
358** {======================================================
359** Argument check functions
360** =======================================================
361*/
362
363LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def,
364 const char *const lst[]) {
365 const char *name = (def) ? luaL_optstring(L, arg, def) :
366 luaL_checkstring(L, arg);
367 int i;
368 for (i=0; lst[i]; i++)
369 if (strcmp(lst[i], name) == 0)
370 return i;
371 return luaL_argerror(L, arg,
372 lua_pushfstring(L, "invalid option '%s'", name));
373}
374
375
376/*
377** Ensures the stack has at least 'space' extra slots, raising an error
378** if it cannot fulfill the request. (The error handling needs a few
379** extra slots to format the error message. In case of an error without
380** this extra space, Lua will generate the same 'stack overflow' error,
381** but without 'msg'.)
382*/
383LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) {
384 if (l_unlikely(!lua_checkstack(L, space))) {
385 if (msg)
386 luaL_error(L, "stack overflow (%s)", msg);
387 else
388 luaL_error(L, "stack overflow");
389 }
390}
391
392
393LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) {
394 if (l_unlikely(lua_type(L, arg) != t))
395 tag_error(L, arg, t);
396}
397
398
399LUALIB_API void luaL_checkany (lua_State *L, int arg) {
400 if (l_unlikely(lua_type(L, arg) == LUA_TNONE))
401 luaL_argerror(L, arg, "value expected");
402}
403
404
405LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) {
406 const char *s = lua_tolstring(L, arg, len);
407 if (l_unlikely(!s)) tag_error(L, arg, LUA_TSTRING);
408 return s;
409}
410
411
412LUALIB_API const char *luaL_optlstring (lua_State *L, int arg,
413 const char *def, size_t *len) {
414 if (lua_isnoneornil(L, arg)) {
415 if (len)
416 *len = (def ? strlen(def) : 0);
417 return def;
418 }
419 else return luaL_checklstring(L, arg, len);
420}
421
422
423LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) {
424 int isnum;
425 lua_Number d = lua_tonumberx(L, arg, &isnum);
426 if (l_unlikely(!isnum))
427 tag_error(L, arg, LUA_TNUMBER);
428 return d;
429}
430
431
432LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) {
433 return luaL_opt(L, luaL_checknumber, arg, def);
434}
435
436
437static void interror (lua_State *L, int arg) {
438 if (lua_isnumber(L, arg))
439 luaL_argerror(L, arg, "number has no integer representation");
440 else
441 tag_error(L, arg, LUA_TNUMBER);
442}
443
444
445LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) {
446 int isnum;
447 lua_Integer d = lua_tointegerx(L, arg, &isnum);
448 if (l_unlikely(!isnum)) {
449 interror(L, arg);
450 }
451 return d;
452}
453
454
455LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg,
456 lua_Integer def) {
457 return luaL_opt(L, luaL_checkinteger, arg, def);
458}
459
460/* }====================================================== */
461
462
463/*
464** {======================================================
465** Generic Buffer manipulation
466** =======================================================
467*/
468
469/* userdata to box arbitrary data */
470typedef struct UBox {
471 void *box;
472 size_t bsize;
473} UBox;
474
475
476static void *resizebox (lua_State *L, int idx, size_t newsize) {
477 void *ud;
478 lua_Alloc allocf = lua_getallocf(L, &ud);
479 UBox *box = (UBox *)lua_touserdata(L, idx);
480 void *temp = allocf(ud, box->box, box->bsize, newsize);
481 if (l_unlikely(temp == NULL && newsize > 0)) { /* allocation error? */
482 lua_pushliteral(L, "not enough memory");
483 lua_error(L); /* raise a memory error */
484 }
485 box->box = temp;
486 box->bsize = newsize;
487 return temp;
488}
489
490
491static int boxgc (lua_State *L) {
492 resizebox(L, 1, 0);
493 return 0;
494}
495
496
497static const luaL_Reg boxmt[] = { /* box metamethods */
498 {"__gc", boxgc},
499 {"__close", boxgc},
500 {NULL, NULL}
501};
502
503
504static void newbox (lua_State *L) {
505 UBox *box = (UBox *)lua_newuserdatauv(L, sizeof(UBox), 0);
506 box->box = NULL;
507 box->bsize = 0;
508 if (luaL_newmetatable(L, "_UBOX*")) /* creating metatable? */
509 luaL_setfuncs(L, boxmt, 0); /* set its metamethods */
510 lua_setmetatable(L, -2);
511}
512
513
514/*
515** check whether buffer is using a userdata on the stack as a temporary
516** buffer
517*/
518#define buffonstack(B) ((B)->b != (B)->init.b)
519
520
521/*
522** Whenever buffer is accessed, slot 'idx' must either be a box (which
523** cannot be NULL) or it is a placeholder for the buffer.
524*/
525#define checkbufferlevel(B,idx) \
526 lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL \
527 : lua_touserdata(B->L, idx) == (void*)B)
528
529
530/*
531** Compute new size for buffer 'B', enough to accommodate extra 'sz'
532** bytes. (The test for "not big enough" also gets the case when the
533** computation of 'newsize' overflows.)
534*/
535static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
536 size_t newsize = (B->size / 2) * 3; /* buffer size * 1.5 */
537 if (l_unlikely(MAX_SIZET - sz < B->n)) /* overflow in (B->n + sz)? */
538 return luaL_error(B->L, "buffer too large");
539 if (newsize < B->n + sz) /* not big enough? */
540 newsize = B->n + sz;
541 return newsize;
542}
543
544
545/*
546** Returns a pointer to a free area with at least 'sz' bytes in buffer
547** 'B'. 'boxidx' is the relative position in the stack where is the
548** buffer's box or its placeholder.
549*/
550static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
551 checkbufferlevel(B, boxidx);
552 if (B->size - B->n >= sz) /* enough space? */
553 return B->b + B->n;
554 else {
555 lua_State *L = B->L;
556 char *newbuff;
557 size_t newsize = newbuffsize(B, sz);
558 /* create larger buffer */
559 if (buffonstack(B)) /* buffer already has a box? */
560 newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */
561 else { /* no box yet */
562 lua_remove(L, boxidx); /* remove placeholder */
563 newbox(L); /* create a new box */
564 lua_insert(L, boxidx); /* move box to its intended position */
565 lua_toclose(L, boxidx);
566 newbuff = (char *)resizebox(L, boxidx, newsize);
567 memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */
568 }
569 B->b = newbuff;
570 B->size = newsize;
571 return newbuff + B->n;
572 }
573}
574
575/*
576** returns a pointer to a free area with at least 'sz' bytes
577*/
578LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
579 return prepbuffsize(B, sz, -1);
580}
581
582
583LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
584 if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */
585 char *b = prepbuffsize(B, l, -1);
586 memcpy(b, s, l * sizeof(char));
587 luaL_addsize(B, l);
588 }
589}
590
591
592LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
593 luaL_addlstring(B, s, strlen(s));
594}
595
596
597LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
598 lua_State *L = B->L;
599 checkbufferlevel(B, -1);
600 lua_pushlstring(L, B->b, B->n);
601 if (buffonstack(B))
602 lua_closeslot(L, -2); /* close the box */
603 lua_remove(L, -2); /* remove box or placeholder from the stack */
604}
605
606
607LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
608 luaL_addsize(B, sz);
609 luaL_pushresult(B);
610}
611
612
613/*
614** 'luaL_addvalue' is the only function in the Buffer system where the
615** box (if existent) is not on the top of the stack. So, instead of
616** calling 'luaL_addlstring', it replicates the code using -2 as the
617** last argument to 'prepbuffsize', signaling that the box is (or will
618** be) below the string being added to the buffer. (Box creation can
619** trigger an emergency GC, so we should not remove the string from the
620** stack before we have the space guaranteed.)
621*/
622LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
623 lua_State *L = B->L;
624 size_t len;
625 const char *s = lua_tolstring(L, -1, &len);
626 char *b = prepbuffsize(B, len, -2);
627 memcpy(b, s, len * sizeof(char));
628 luaL_addsize(B, len);
629 lua_pop(L, 1); /* pop string */
630}
631
632
633LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
634 B->L = L;
635 B->b = B->init.b;
636 B->n = 0;
637 B->size = LUAL_BUFFERSIZE;
638 lua_pushlightuserdata(L, (void*)B); /* push placeholder */
639}
640
641
642LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
643 luaL_buffinit(L, B);
644 return prepbuffsize(B, sz, -1);
645}
646
647/* }====================================================== */
648
649
650/*
651** {======================================================
652** Reference system
653** =======================================================
654*/
655
656/* index of free-list header (after the predefined values) */
657#define freelist (LUA_RIDX_LAST + 1)
658
659/*
660** The previously freed references form a linked list:
661** t[freelist] is the index of a first free index, or zero if list is
662** empty; t[t[freelist]] is the index of the second element; etc.
663*/
664LUALIB_API int luaL_ref (lua_State *L, int t) {
665 int ref;
666 if (lua_isnil(L, -1)) {
667 lua_pop(L, 1); /* remove from stack */
668 return LUA_REFNIL; /* 'nil' has a unique fixed reference */
669 }
670 t = lua_absindex(L, t);
671 if (lua_rawgeti(L, t, freelist) == LUA_TNIL) { /* first access? */
672 ref = 0; /* list is empty */
673 lua_pushinteger(L, 0); /* initialize as an empty list */
674 lua_rawseti(L, t, freelist); /* ref = t[freelist] = 0 */
675 }
676 else { /* already initialized */
677 lua_assert(lua_isinteger(L, -1));
678 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */
679 }
680 lua_pop(L, 1); /* remove element from stack */
681 if (ref != 0) { /* any free element? */
682 lua_rawgeti(L, t, ref); /* remove it from list */
683 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */
684 }
685 else /* no free elements */
686 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */
687 lua_rawseti(L, t, ref);
688 return ref;
689}
690
691
692LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
693 if (ref >= 0) {
694 t = lua_absindex(L, t);
695 lua_rawgeti(L, t, freelist);
696 lua_assert(lua_isinteger(L, -1));
697 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */
698 lua_pushinteger(L, ref);
699 lua_rawseti(L, t, freelist); /* t[freelist] = ref */
700 }
701}
702
703/* }====================================================== */
704
705
706/*
707** {======================================================
708** Load functions
709** =======================================================
710*/
711
712typedef struct LoadF {
713 int n; /* number of pre-read characters */
714 FILE *f; /* file being read */
715 char buff[BUFSIZ]; /* area for reading file */
716} LoadF;
717
718
719static const char *getF (lua_State *L, void *ud, size_t *size) {
720 LoadF *lf = (LoadF *)ud;
721 (void)L; /* not used */
722 if (lf->n > 0) { /* are there pre-read characters to be read? */
723 *size = lf->n; /* return them (chars already in buffer) */
724 lf->n = 0; /* no more pre-read characters */
725 }
726 else { /* read a block from file */
727 /* 'fread' can return > 0 *and* set the EOF flag. If next call to
728 'getF' called 'fread', it might still wait for user input.
729 The next check avoids this problem. */
730 if (feof(lf->f)) return NULL;
731 *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */
732 }
733 return lf->buff;
734}
735
736
737static int errfile (lua_State *L, const char *what, int fnameindex) {
738 int err = errno;
739 const char *filename = lua_tostring(L, fnameindex) + 1;
740 if (err != 0)
741 lua_pushfstring(L, "cannot %s %s: %s", what, filename, strerror(err));
742 else
743 lua_pushfstring(L, "cannot %s %s", what, filename);
744 lua_remove(L, fnameindex);
745 return LUA_ERRFILE;
746}
747
748
749/*
750** Skip an optional BOM at the start of a stream. If there is an
751** incomplete BOM (the first character is correct but the rest is
752** not), returns the first character anyway to force an error
753** (as no chunk can start with 0xEF).
754*/
755static int skipBOM (FILE *f) {
756 int c = getc(f); /* read first character */
757 if (c == 0xEF && getc(f) == 0xBB && getc(f) == 0xBF) /* correct BOM? */
758 return getc(f); /* ignore BOM and return next char */
759 else /* no (valid) BOM */
760 return c; /* return first character */
761}
762
763
764/*
765** reads the first character of file 'f' and skips an optional BOM mark
766** in its beginning plus its first line if it starts with '#'. Returns
767** true if it skipped the first line. In any case, '*cp' has the
768** first "valid" character of the file (after the optional BOM and
769** a first-line comment).
770*/
771static int skipcomment (FILE *f, int *cp) {
772 int c = *cp = skipBOM(f);
773 if (c == '#') { /* first line is a comment (Unix exec. file)? */
774 do { /* skip first line */
775 c = getc(f);
776 } while (c != EOF && c != '\n');
777 *cp = getc(f); /* next character after comment, if present */
778 return 1; /* there was a comment */
779 }
780 else return 0; /* no comment */
781}
782
783
784LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
785 const char *mode) {
786 LoadF lf;
787 int status, readstatus;
788 int c;
789 int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
790 if (filename == NULL) {
791 lua_pushliteral(L, "=stdin");
792 lf.f = stdin;
793 }
794 else {
795 lua_pushfstring(L, "@%s", filename);
796 errno = 0;
797 lf.f = fopen(filename, "r");
798 if (lf.f == NULL) return errfile(L, "open", fnameindex);
799 }
800 lf.n = 0;
801 if (skipcomment(lf.f, &c)) /* read initial portion */
802 lf.buff[lf.n++] = '\n'; /* add newline to correct line numbers */
803 if (c == LUA_SIGNATURE[0]) { /* binary file? */
804 lf.n = 0; /* remove possible newline */
805 if (filename) { /* "real" file? */
806 errno = 0;
807 lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */
808 if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
809 skipcomment(lf.f, &c); /* re-read initial portion */
810 }
811 }
812 if (c != EOF)
813 lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */
814 errno = 0;
815 status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
816 readstatus = ferror(lf.f);
817 if (filename) fclose(lf.f); /* close file (even in case of errors) */
818 if (readstatus) {
819 lua_settop(L, fnameindex); /* ignore results from 'lua_load' */
820 return errfile(L, "read", fnameindex);
821 }
822 lua_remove(L, fnameindex);
823 return status;
824}
825
826
827typedef struct LoadS {
828 const char *s;
829 size_t size;
830} LoadS;
831
832
833static const char *getS (lua_State *L, void *ud, size_t *size) {
834 LoadS *ls = (LoadS *)ud;
835 (void)L; /* not used */
836 if (ls->size == 0) return NULL;
837 *size = ls->size;
838 ls->size = 0;
839 return ls->s;
840}
841
842
843LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,
844 const char *name, const char *mode) {
845 LoadS ls;
846 ls.s = buff;
847 ls.size = size;
848 return lua_load(L, getS, &ls, name, mode);
849}
850
851
852LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {
853 return luaL_loadbuffer(L, s, strlen(s), s);
854}
855
856/* }====================================================== */
857
858
859
860LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
861 if (!lua_getmetatable(L, obj)) /* no metatable? */
862 return LUA_TNIL;
863 else {
864 int tt;
865 lua_pushstring(L, event);
866 tt = lua_rawget(L, -2);
867 if (tt == LUA_TNIL) /* is metafield nil? */
868 lua_pop(L, 2); /* remove metatable and metafield */
869 else
870 lua_remove(L, -2); /* remove only metatable */
871 return tt; /* return metafield type */
872 }
873}
874
875
876LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
877 obj = lua_absindex(L, obj);
878 if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */
879 return 0;
880 lua_pushvalue(L, obj);
881 lua_call(L, 1, 1);
882 return 1;
883}
884
885
886LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
887 lua_Integer l;
888 int isnum;
889 lua_len(L, idx);
890 l = lua_tointegerx(L, -1, &isnum);
891 if (l_unlikely(!isnum))
892 luaL_error(L, "object length is not an integer");
893 lua_pop(L, 1); /* remove object */
894 return l;
895}
896
897
898LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
899 idx = lua_absindex(L,idx);
900 if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */
901 if (!lua_isstring(L, -1))
902 luaL_error(L, "'__tostring' must return a string");
903 }
904 else {
905 switch (lua_type(L, idx)) {
906 case LUA_TNUMBER: {
907 if (lua_isinteger(L, idx))
908 lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx));
909 else
910 lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx));
911 break;
912 }
913 case LUA_TSTRING:
914 lua_pushvalue(L, idx);
915 break;
916 case LUA_TBOOLEAN:
917 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));
918 break;
919 case LUA_TNIL:
920 lua_pushliteral(L, "nil");
921 break;
922 default: {
923 int tt = luaL_getmetafield(L, idx, "__name"); /* try name */
924 const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :
925 luaL_typename(L, idx);
926 lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));
927 if (tt != LUA_TNIL)
928 lua_remove(L, -2); /* remove '__name' */
929 break;
930 }
931 }
932 }
933 return lua_tolstring(L, -1, len);
934}
935
936
937/*
938** set functions from list 'l' into table at top - 'nup'; each
939** function gets the 'nup' elements at the top as upvalues.
940** Returns with only the table at the stack.
941*/
942LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
943 luaL_checkstack(L, nup, "too many upvalues");
944 for (; l->name != NULL; l++) { /* fill the table with given functions */
945 if (l->func == NULL) /* placeholder? */
946 lua_pushboolean(L, 0);
947 else {
948 int i;
949 for (i = 0; i < nup; i++) /* copy upvalues to the top */
950 lua_pushvalue(L, -nup);
951 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
952 }
953 lua_setfield(L, -(nup + 2), l->name);
954 }
955 lua_pop(L, nup); /* remove upvalues */
956}
957
958
959/*
960** ensure that stack[idx][fname] has a table and push that table
961** into the stack
962*/
963LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
964 if (lua_getfield(L, idx, fname) == LUA_TTABLE)
965 return 1; /* table already there */
966 else {
967 lua_pop(L, 1); /* remove previous result */
968 idx = lua_absindex(L, idx);
969 lua_newtable(L);
970 lua_pushvalue(L, -1); /* copy to be left at top */
971 lua_setfield(L, idx, fname); /* assign new table to field */
972 return 0; /* false, because did not find table there */
973 }
974}
975
976
977/*
978** Stripped-down 'require': After checking "loaded" table, calls 'openf'
979** to open a module, registers the result in 'package.loaded' table and,
980** if 'glb' is true, also registers the result in the global table.
981** Leaves resulting module on the top.
982*/
983LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
984 lua_CFunction openf, int glb) {
985 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
986 lua_getfield(L, -1, modname); /* LOADED[modname] */
987 if (!lua_toboolean(L, -1)) { /* package not already loaded? */
988 lua_pop(L, 1); /* remove field */
989 lua_pushcfunction(L, openf);
990 lua_pushstring(L, modname); /* argument to open function */
991 lua_call(L, 1, 1); /* call 'openf' to open module */
992 lua_pushvalue(L, -1); /* make copy of module (call result) */
993 lua_setfield(L, -3, modname); /* LOADED[modname] = module */
994 }
995 lua_remove(L, -2); /* remove LOADED table */
996 if (glb) {
997 lua_pushvalue(L, -1); /* copy of module */
998 lua_setglobal(L, modname); /* _G[modname] = module */
999 }
1000}
1001
1002
1003LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
1004 const char *p, const char *r) {
1005 const char *wild;
1006 size_t l = strlen(p);
1007 while ((wild = strstr(s, p)) != NULL) {
1008 luaL_addlstring(b, s, wild - s); /* push prefix */
1009 luaL_addstring(b, r); /* push replacement in place of pattern */
1010 s = wild + l; /* continue after 'p' */
1011 }
1012 luaL_addstring(b, s); /* push last suffix */
1013}
1014
1015
1016LUALIB_API const char *luaL_gsub (lua_State *L, const char *s,
1017 const char *p, const char *r) {
1018 luaL_Buffer b;
1019 luaL_buffinit(L, &b);
1020 luaL_addgsub(&b, s, p, r);
1021 luaL_pushresult(&b);
1022 return lua_tostring(L, -1);
1023}
1024
1025
1026static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
1027 (void)ud; (void)osize; /* not used */
1028 if (nsize == 0) {
1029 free(ptr);
1030 return NULL;
1031 }
1032 else
1033 return realloc(ptr, nsize);
1034}
1035
1036
1037/*
1038** Standard panic funcion just prints an error message. The test
1039** with 'lua_type' avoids possible memory errors in 'lua_tostring'.
1040*/
1041static int panic (lua_State *L) {
1042 const char *msg = (lua_type(L, -1) == LUA_TSTRING)
1043 ? lua_tostring(L, -1)
1044 : "error object is not a string";
1045 lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
1046 msg);
1047 return 0; /* return to Lua to abort */
1048}
1049
1050
1051/*
1052** Warning functions:
1053** warnfoff: warning system is off
1054** warnfon: ready to start a new message
1055** warnfcont: previous message is to be continued
1056*/
1057static void warnfoff (void *ud, const char *message, int tocont);
1058static void warnfon (void *ud, const char *message, int tocont);
1059static void warnfcont (void *ud, const char *message, int tocont);
1060
1061
1062/*
1063** Check whether message is a control message. If so, execute the
1064** control or ignore it if unknown.
1065*/
1066static int checkcontrol (lua_State *L, const char *message, int tocont) {
1067 if (tocont || *(message++) != '@') /* not a control message? */
1068 return 0;
1069 else {
1070 if (strcmp(message, "off") == 0)
1071 lua_setwarnf(L, warnfoff, L); /* turn warnings off */
1072 else if (strcmp(message, "on") == 0)
1073 lua_setwarnf(L, warnfon, L); /* turn warnings on */
1074 return 1; /* it was a control message */
1075 }
1076}
1077
1078
1079static void warnfoff (void *ud, const char *message, int tocont) {
1080 checkcontrol((lua_State *)ud, message, tocont);
1081}
1082
1083
1084/*
1085** Writes the message and handle 'tocont', finishing the message
1086** if needed and setting the next warn function.
1087*/
1088static void warnfcont (void *ud, const char *message, int tocont) {
1089 lua_State *L = (lua_State *)ud;
1090 lua_writestringerror("%s", message); /* write message */
1091 if (tocont) /* not the last part? */
1092 lua_setwarnf(L, warnfcont, L); /* to be continued */
1093 else { /* last part */
1094 lua_writestringerror("%s", "\n"); /* finish message with end-of-line */
1095 lua_setwarnf(L, warnfon, L); /* next call is a new message */
1096 }
1097}
1098
1099
1100static void warnfon (void *ud, const char *message, int tocont) {
1101 if (checkcontrol((lua_State *)ud, message, tocont)) /* control message? */
1102 return; /* nothing else to be done */
1103 lua_writestringerror("%s", "Lua warning: "); /* start a new warning */
1104 warnfcont(ud, message, tocont); /* finish processing */
1105}
1106
1107
1108LUALIB_API lua_State *luaL_newstate (void) {
1109 lua_State *L = lua_newstate(l_alloc, NULL);
1110 if (l_likely(L)) {
1111 lua_atpanic(L, &panic);
1112 lua_setwarnf(L, warnfoff, L); /* default is warnings off */
1113 }
1114 return L;
1115}
1116
1117
1118LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
1119 lua_Number v = lua_version(L);
1120 if (sz != LUAL_NUMSIZES) /* check numeric types */
1121 luaL_error(L, "core and library have incompatible numeric types");
1122 else if (v != ver)
1123 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
1124 (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v);
1125}
1126