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