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
193LUALIB_API int 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 if (stat != 0 && errno != 0) /* error with an 'errno'? */
287 return luaL_fileresult(L, 0, NULL);
288 else {
289 const char *what = "exit"; /* type of termination */
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 (l_unlikely(!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 (l_unlikely(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 (l_unlikely(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 (l_unlikely(!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 (l_unlikely(!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 (l_unlikely(!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 (l_unlikely(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** Whenever buffer is accessed, slot 'idx' must either be a box (which
520** cannot be NULL) or it is a placeholder for the buffer.
521*/
522#define checkbufferlevel(B,idx) \
523 lua_assert(buffonstack(B) ? lua_touserdata(B->L, idx) != NULL \
524 : lua_touserdata(B->L, idx) == (void*)B)
525
526
527/*
528** Compute new size for buffer 'B', enough to accommodate extra 'sz'
529** bytes.
530*/
531static size_t newbuffsize (luaL_Buffer *B, size_t sz) {
532 size_t newsize = B->size * 2; /* double buffer size */
533 if (l_unlikely(MAX_SIZET - sz < B->n)) /* overflow in (B->n + sz)? */
534 return luaL_error(B->L, "buffer too large");
535 if (newsize < B->n + sz) /* double is not big enough? */
536 newsize = B->n + sz;
537 return newsize;
538}
539
540
541/*
542** Returns a pointer to a free area with at least 'sz' bytes in buffer
543** 'B'. 'boxidx' is the relative position in the stack where is the
544** buffer's box or its placeholder.
545*/
546static char *prepbuffsize (luaL_Buffer *B, size_t sz, int boxidx) {
547 checkbufferlevel(B, boxidx);
548 if (B->size - B->n >= sz) /* enough space? */
549 return B->b + B->n;
550 else {
551 lua_State *L = B->L;
552 char *newbuff;
553 size_t newsize = newbuffsize(B, sz);
554 /* create larger buffer */
555 if (buffonstack(B)) /* buffer already has a box? */
556 newbuff = (char *)resizebox(L, boxidx, newsize); /* resize it */
557 else { /* no box yet */
558 lua_remove(L, boxidx); /* remove placeholder */
559 newbox(L); /* create a new box */
560 lua_insert(L, boxidx); /* move box to its intended position */
561 lua_toclose(L, boxidx);
562 newbuff = (char *)resizebox(L, boxidx, newsize);
563 memcpy(newbuff, B->b, B->n * sizeof(char)); /* copy original content */
564 }
565 B->b = newbuff;
566 B->size = newsize;
567 return newbuff + B->n;
568 }
569}
570
571/*
572** returns a pointer to a free area with at least 'sz' bytes
573*/
574LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) {
575 return prepbuffsize(B, sz, -1);
576}
577
578
579LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {
580 if (l > 0) { /* avoid 'memcpy' when 's' can be NULL */
581 char *b = prepbuffsize(B, l, -1);
582 memcpy(b, s, l * sizeof(char));
583 luaL_addsize(B, l);
584 }
585}
586
587
588LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {
589 luaL_addlstring(B, s, strlen(s));
590}
591
592
593LUALIB_API void luaL_pushresult (luaL_Buffer *B) {
594 lua_State *L = B->L;
595 checkbufferlevel(B, -1);
596 lua_pushlstring(L, B->b, B->n);
597 if (buffonstack(B))
598 lua_closeslot(L, -2); /* close the box */
599 lua_remove(L, -2); /* remove box or placeholder from the stack */
600}
601
602
603LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) {
604 luaL_addsize(B, sz);
605 luaL_pushresult(B);
606}
607
608
609/*
610** 'luaL_addvalue' is the only function in the Buffer system where the
611** box (if existent) is not on the top of the stack. So, instead of
612** calling 'luaL_addlstring', it replicates the code using -2 as the
613** last argument to 'prepbuffsize', signaling that the box is (or will
614** be) bellow the string being added to the buffer. (Box creation can
615** trigger an emergency GC, so we should not remove the string from the
616** stack before we have the space guaranteed.)
617*/
618LUALIB_API void luaL_addvalue (luaL_Buffer *B) {
619 lua_State *L = B->L;
620 size_t len;
621 const char *s = lua_tolstring(L, -1, &len);
622 char *b = prepbuffsize(B, len, -2);
623 memcpy(b, s, len * sizeof(char));
624 luaL_addsize(B, len);
625 lua_pop(L, 1); /* pop string */
626}
627
628
629LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {
630 B->L = L;
631 B->b = B->init.b;
632 B->n = 0;
633 B->size = LUAL_BUFFERSIZE;
634 lua_pushlightuserdata(L, (void*)B); /* push placeholder */
635}
636
637
638LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) {
639 luaL_buffinit(L, B);
640 return prepbuffsize(B, sz, -1);
641}
642
643/* }====================================================== */
644
645
646/*
647** {======================================================
648** Reference system
649** =======================================================
650*/
651
652/* index of free-list header (after the predefined values) */
653#define freelist (LUA_RIDX_LAST + 1)
654
655/*
656** The previously freed references form a linked list:
657** t[freelist] is the index of a first free index, or zero if list is
658** empty; t[t[freelist]] is the index of the second element; etc.
659*/
660LUALIB_API int luaL_ref (lua_State *L, int t) {
661 int ref;
662 if (lua_isnil(L, -1)) {
663 lua_pop(L, 1); /* remove from stack */
664 return LUA_REFNIL; /* 'nil' has a unique fixed reference */
665 }
666 t = lua_absindex(L, t);
667 if (lua_rawgeti(L, t, freelist) == LUA_TNIL) { /* first access? */
668 ref = 0; /* list is empty */
669 lua_pushinteger(L, 0); /* initialize as an empty list */
670 lua_rawseti(L, t, freelist); /* ref = t[freelist] = 0 */
671 }
672 else { /* already initialized */
673 lua_assert(lua_isinteger(L, -1));
674 ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */
675 }
676 lua_pop(L, 1); /* remove element from stack */
677 if (ref != 0) { /* any free element? */
678 lua_rawgeti(L, t, ref); /* remove it from list */
679 lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */
680 }
681 else /* no free elements */
682 ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */
683 lua_rawseti(L, t, ref);
684 return ref;
685}
686
687
688LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {
689 if (ref >= 0) {
690 t = lua_absindex(L, t);
691 lua_rawgeti(L, t, freelist);
692 lua_assert(lua_isinteger(L, -1));
693 lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */
694 lua_pushinteger(L, ref);
695 lua_rawseti(L, t, freelist); /* t[freelist] = ref */
696 }
697}
698
699/* }====================================================== */
700
701
702/*
703** {======================================================
704** Load functions
705** =======================================================
706*/
707
708typedef struct LoadF {
709 int n; /* number of pre-read characters */
710 FILE *f; /* file being read */
711 char buff[BUFSIZ]; /* area for reading file */
712} LoadF;
713
714
715static const char *getF (lua_State *L, void *ud, size_t *size) {
716 LoadF *lf = (LoadF *)ud;
717 (void)L; /* not used */
718 if (lf->n > 0) { /* are there pre-read characters to be read? */
719 *size = lf->n; /* return them (chars already in buffer) */
720 lf->n = 0; /* no more pre-read characters */
721 }
722 else { /* read a block from file */
723 /* 'fread' can return > 0 *and* set the EOF flag. If next call to
724 'getF' called 'fread', it might still wait for user input.
725 The next check avoids this problem. */
726 if (feof(lf->f)) return NULL;
727 *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */
728 }
729 return lf->buff;
730}
731
732
733static int errfile (lua_State *L, const char *what, int fnameindex) {
734 const char *serr = strerror(errno);
735 const char *filename = lua_tostring(L, fnameindex) + 1;
736 lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);
737 lua_remove(L, fnameindex);
738 return LUA_ERRFILE;
739}
740
741
742static int skipBOM (LoadF *lf) {
743 const char *p = "\xEF\xBB\xBF"; /* UTF-8 BOM mark */
744 int c;
745 lf->n = 0;
746 do {
747 c = getc(lf->f);
748 if (c == EOF || c != *(const unsigned char *)p++) return c;
749 lf->buff[lf->n++] = c; /* to be read by the parser */
750 } while (*p != '\0');
751 lf->n = 0; /* prefix matched; discard it */
752 return getc(lf->f); /* return next character */
753}
754
755
756/*
757** reads the first character of file 'f' and skips an optional BOM mark
758** in its beginning plus its first line if it starts with '#'. Returns
759** true if it skipped the first line. In any case, '*cp' has the
760** first "valid" character of the file (after the optional BOM and
761** a first-line comment).
762*/
763static int skipcomment (LoadF *lf, int *cp) {
764 int c = *cp = skipBOM(lf);
765 if (c == '#') { /* first line is a comment (Unix exec. file)? */
766 do { /* skip first line */
767 c = getc(lf->f);
768 } while (c != EOF && c != '\n');
769 *cp = getc(lf->f); /* skip end-of-line, if present */
770 return 1; /* there was a comment */
771 }
772 else return 0; /* no comment */
773}
774
775
776LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename,
777 const char *mode) {
778 LoadF lf;
779 int status, readstatus;
780 int c;
781 int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */
782 if (filename == NULL) {
783 lua_pushliteral(L, "=stdin");
784 lf.f = stdin;
785 }
786 else {
787 lua_pushfstring(L, "@%s", filename);
788 lf.f = fopen(filename, "r");
789 if (lf.f == NULL) return errfile(L, "open", fnameindex);
790 }
791 if (skipcomment(&lf, &c)) /* read initial portion */
792 lf.buff[lf.n++] = '\n'; /* add line to correct line numbers */
793 if (c == LUA_SIGNATURE[0] && filename) { /* binary file? */
794 lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */
795 if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
796 skipcomment(&lf, &c); /* re-read initial portion */
797 }
798 if (c != EOF)
799 lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */
800 status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode);
801 readstatus = ferror(lf.f);
802 if (filename) fclose(lf.f); /* close file (even in case of errors) */
803 if (readstatus) {
804 lua_settop(L, fnameindex); /* ignore results from 'lua_load' */
805 return errfile(L, "read", fnameindex);
806 }
807 lua_remove(L, fnameindex);
808 return status;
809}
810
811
812typedef struct LoadS {
813 const char *s;
814 size_t size;
815} LoadS;
816
817
818static const char *getS (lua_State *L, void *ud, size_t *size) {
819 LoadS *ls = (LoadS *)ud;
820 (void)L; /* not used */
821 if (ls->size == 0) return NULL;
822 *size = ls->size;
823 ls->size = 0;
824 return ls->s;
825}
826
827
828LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size,
829 const char *name, const char *mode) {
830 LoadS ls;
831 ls.s = buff;
832 ls.size = size;
833 return lua_load(L, getS, &ls, name, mode);
834}
835
836
837LUALIB_API int luaL_loadstring (lua_State *L, const char *s) {
838 return luaL_loadbuffer(L, s, strlen(s), s);
839}
840
841/* }====================================================== */
842
843
844
845LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {
846 if (!lua_getmetatable(L, obj)) /* no metatable? */
847 return LUA_TNIL;
848 else {
849 int tt;
850 lua_pushstring(L, event);
851 tt = lua_rawget(L, -2);
852 if (tt == LUA_TNIL) /* is metafield nil? */
853 lua_pop(L, 2); /* remove metatable and metafield */
854 else
855 lua_remove(L, -2); /* remove only metatable */
856 return tt; /* return metafield type */
857 }
858}
859
860
861LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {
862 obj = lua_absindex(L, obj);
863 if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */
864 return 0;
865 lua_pushvalue(L, obj);
866 lua_call(L, 1, 1);
867 return 1;
868}
869
870
871LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) {
872 lua_Integer l;
873 int isnum;
874 lua_len(L, idx);
875 l = lua_tointegerx(L, -1, &isnum);
876 if (l_unlikely(!isnum))
877 luaL_error(L, "object length is not an integer");
878 lua_pop(L, 1); /* remove object */
879 return l;
880}
881
882
883LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) {
884 if (luaL_callmeta(L, idx, "__tostring")) { /* metafield? */
885 if (!lua_isstring(L, -1))
886 luaL_error(L, "'__tostring' must return a string");
887 }
888 else {
889 switch (lua_type(L, idx)) {
890 case LUA_TNUMBER: {
891 if (lua_isinteger(L, idx))
892 lua_pushfstring(L, "%I", (LUAI_UACINT)lua_tointeger(L, idx));
893 else
894 lua_pushfstring(L, "%f", (LUAI_UACNUMBER)lua_tonumber(L, idx));
895 break;
896 }
897 case LUA_TSTRING:
898 lua_pushvalue(L, idx);
899 break;
900 case LUA_TBOOLEAN:
901 lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false"));
902 break;
903 case LUA_TNIL:
904 lua_pushliteral(L, "nil");
905 break;
906 default: {
907 int tt = luaL_getmetafield(L, idx, "__name"); /* try name */
908 const char *kind = (tt == LUA_TSTRING) ? lua_tostring(L, -1) :
909 luaL_typename(L, idx);
910 lua_pushfstring(L, "%s: %p", kind, lua_topointer(L, idx));
911 if (tt != LUA_TNIL)
912 lua_remove(L, -2); /* remove '__name' */
913 break;
914 }
915 }
916 }
917 return lua_tolstring(L, -1, len);
918}
919
920
921/*
922** set functions from list 'l' into table at top - 'nup'; each
923** function gets the 'nup' elements at the top as upvalues.
924** Returns with only the table at the stack.
925*/
926LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) {
927 luaL_checkstack(L, nup, "too many upvalues");
928 for (; l->name != NULL; l++) { /* fill the table with given functions */
929 if (l->func == NULL) /* place holder? */
930 lua_pushboolean(L, 0);
931 else {
932 int i;
933 for (i = 0; i < nup; i++) /* copy upvalues to the top */
934 lua_pushvalue(L, -nup);
935 lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */
936 }
937 lua_setfield(L, -(nup + 2), l->name);
938 }
939 lua_pop(L, nup); /* remove upvalues */
940}
941
942
943/*
944** ensure that stack[idx][fname] has a table and push that table
945** into the stack
946*/
947LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) {
948 if (lua_getfield(L, idx, fname) == LUA_TTABLE)
949 return 1; /* table already there */
950 else {
951 lua_pop(L, 1); /* remove previous result */
952 idx = lua_absindex(L, idx);
953 lua_newtable(L);
954 lua_pushvalue(L, -1); /* copy to be left at top */
955 lua_setfield(L, idx, fname); /* assign new table to field */
956 return 0; /* false, because did not find table there */
957 }
958}
959
960
961/*
962** Stripped-down 'require': After checking "loaded" table, calls 'openf'
963** to open a module, registers the result in 'package.loaded' table and,
964** if 'glb' is true, also registers the result in the global table.
965** Leaves resulting module on the top.
966*/
967LUALIB_API void luaL_requiref (lua_State *L, const char *modname,
968 lua_CFunction openf, int glb) {
969 luaL_getsubtable(L, LUA_REGISTRYINDEX, LUA_LOADED_TABLE);
970 lua_getfield(L, -1, modname); /* LOADED[modname] */
971 if (!lua_toboolean(L, -1)) { /* package not already loaded? */
972 lua_pop(L, 1); /* remove field */
973 lua_pushcfunction(L, openf);
974 lua_pushstring(L, modname); /* argument to open function */
975 lua_call(L, 1, 1); /* call 'openf' to open module */
976 lua_pushvalue(L, -1); /* make copy of module (call result) */
977 lua_setfield(L, -3, modname); /* LOADED[modname] = module */
978 }
979 lua_remove(L, -2); /* remove LOADED table */
980 if (glb) {
981 lua_pushvalue(L, -1); /* copy of module */
982 lua_setglobal(L, modname); /* _G[modname] = module */
983 }
984}
985
986
987LUALIB_API void luaL_addgsub (luaL_Buffer *b, const char *s,
988 const char *p, const char *r) {
989 const char *wild;
990 size_t l = strlen(p);
991 while ((wild = strstr(s, p)) != NULL) {
992 luaL_addlstring(b, s, wild - s); /* push prefix */
993 luaL_addstring(b, r); /* push replacement in place of pattern */
994 s = wild + l; /* continue after 'p' */
995 }
996 luaL_addstring(b, s); /* push last suffix */
997}
998
999
1000LUALIB_API const char *luaL_gsub (lua_State *L, const char *s,
1001 const char *p, const char *r) {
1002 luaL_Buffer b;
1003 luaL_buffinit(L, &b);
1004 luaL_addgsub(&b, s, p, r);
1005 luaL_pushresult(&b);
1006 return lua_tostring(L, -1);
1007}
1008
1009
1010static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {
1011 (void)ud; (void)osize; /* not used */
1012 if (nsize == 0) {
1013 free(ptr);
1014 return NULL;
1015 }
1016 else
1017 return realloc(ptr, nsize);
1018}
1019
1020
1021static int panic (lua_State *L) {
1022 const char *msg = lua_tostring(L, -1);
1023 if (msg == NULL) msg = "error object is not a string";
1024 lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n",
1025 msg);
1026 return 0; /* return to Lua to abort */
1027}
1028
1029
1030/*
1031** Warning functions:
1032** warnfoff: warning system is off
1033** warnfon: ready to start a new message
1034** warnfcont: previous message is to be continued
1035*/
1036static void warnfoff (void *ud, const char *message, int tocont);
1037static void warnfon (void *ud, const char *message, int tocont);
1038static void warnfcont (void *ud, const char *message, int tocont);
1039
1040
1041/*
1042** Check whether message is a control message. If so, execute the
1043** control or ignore it if unknown.
1044*/
1045static int checkcontrol (lua_State *L, const char *message, int tocont) {
1046 if (tocont || *(message++) != '@') /* not a control message? */
1047 return 0;
1048 else {
1049 if (strcmp(message, "off") == 0)
1050 lua_setwarnf(L, warnfoff, L); /* turn warnings off */
1051 else if (strcmp(message, "on") == 0)
1052 lua_setwarnf(L, warnfon, L); /* turn warnings on */
1053 return 1; /* it was a control message */
1054 }
1055}
1056
1057
1058static void warnfoff (void *ud, const char *message, int tocont) {
1059 checkcontrol((lua_State *)ud, message, tocont);
1060}
1061
1062
1063/*
1064** Writes the message and handle 'tocont', finishing the message
1065** if needed and setting the next warn function.
1066*/
1067static void warnfcont (void *ud, const char *message, int tocont) {
1068 lua_State *L = (lua_State *)ud;
1069 lua_writestringerror("%s", message); /* write message */
1070 if (tocont) /* not the last part? */
1071 lua_setwarnf(L, warnfcont, L); /* to be continued */
1072 else { /* last part */
1073 lua_writestringerror("%s", "\n"); /* finish message with end-of-line */
1074 lua_setwarnf(L, warnfon, L); /* next call is a new message */
1075 }
1076}
1077
1078
1079static void warnfon (void *ud, const char *message, int tocont) {
1080 if (checkcontrol((lua_State *)ud, message, tocont)) /* control message? */
1081 return; /* nothing else to be done */
1082 lua_writestringerror("%s", "Lua warning: "); /* start a new warning */
1083 warnfcont(ud, message, tocont); /* finish processing */
1084}
1085
1086
1087LUALIB_API lua_State *luaL_newstate (void) {
1088 lua_State *L = lua_newstate(l_alloc, NULL);
1089 if (l_likely(L)) {
1090 lua_atpanic(L, &panic);
1091 lua_setwarnf(L, warnfoff, L); /* default is warnings off */
1092 }
1093 return L;
1094}
1095
1096
1097LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) {
1098 lua_Number v = lua_version(L);
1099 if (sz != LUAL_NUMSIZES) /* check numeric types */
1100 luaL_error(L, "core and library have incompatible numeric types");
1101 else if (v != ver)
1102 luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f",
1103 (LUAI_UACNUMBER)ver, (LUAI_UACNUMBER)v);
1104}
1105
1106