1 /*
2 ** $Id: lbaselib.c $
3 ** Basic library
4 ** See Copyright Notice in lua.h
5 */
6
7 #define lbaselib_c
8 #define LUA_LIB
9
10 #include "lprefix.h"
11
12
13 #include <ctype.h>
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17
18 #include "lua.h"
19
20 #include "lauxlib.h"
21 #include "lualib.h"
22
23
luaB_print(lua_State * L)24 static int luaB_print (lua_State *L) {
25 int n = lua_gettop(L); /* number of arguments */
26 int i;
27 for (i = 1; i <= n; i++) { /* for each argument */
28 size_t l;
29 const char *s = luaL_tolstring(L, i, &l); /* convert it to string */
30 if (i > 1) /* not the first element? */
31 lua_writestring("\t", 1); /* add a tab before it */
32 lua_writestring(s, l); /* print it */
33 lua_pop(L, 1); /* pop result */
34 }
35 lua_writeline();
36 return 0;
37 }
38
39
40 /*
41 ** Creates a warning with all given arguments.
42 ** Check first for errors; otherwise an error may interrupt
43 ** the composition of a warning, leaving it unfinished.
44 */
luaB_warn(lua_State * L)45 static int luaB_warn (lua_State *L) {
46 int n = lua_gettop(L); /* number of arguments */
47 int i;
48 luaL_checkstring(L, 1); /* at least one argument */
49 for (i = 2; i <= n; i++)
50 luaL_checkstring(L, i); /* make sure all arguments are strings */
51 for (i = 1; i < n; i++) /* compose warning */
52 lua_warning(L, lua_tostring(L, i), 1);
53 lua_warning(L, lua_tostring(L, n), 0); /* close warning */
54 return 0;
55 }
56
57
58 #define SPACECHARS " \f\n\r\t\v"
59
b_str2int(const char * s,int base,lua_Integer * pn)60 static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
61 lua_Unsigned n = 0;
62 int neg = 0;
63 s += strspn(s, SPACECHARS); /* skip initial spaces */
64 if (*s == '-') { s++; neg = 1; } /* handle sign */
65 else if (*s == '+') s++;
66 if (!isalnum((unsigned char)*s)) /* no digit? */
67 return NULL;
68 do {
69 int digit = (isdigit((unsigned char)*s)) ? *s - '0'
70 : (toupper((unsigned char)*s) - 'A') + 10;
71 if (digit >= base) return NULL; /* invalid numeral */
72 n = n * base + digit;
73 s++;
74 } while (isalnum((unsigned char)*s));
75 s += strspn(s, SPACECHARS); /* skip trailing spaces */
76 *pn = (lua_Integer)((neg) ? (0u - n) : n);
77 return s;
78 }
79
80
luaB_tonumber(lua_State * L)81 static int luaB_tonumber (lua_State *L) {
82 if (lua_isnoneornil(L, 2)) { /* standard conversion? */
83 if (lua_type(L, 1) == LUA_TNUMBER) { /* already a number? */
84 lua_settop(L, 1); /* yes; return it */
85 return 1;
86 }
87 else {
88 size_t l;
89 const char *s = lua_tolstring(L, 1, &l);
90 if (s != NULL && lua_stringtonumber(L, s) == l + 1)
91 return 1; /* successful conversion to number */
92 /* else not a number */
93 luaL_checkany(L, 1); /* (but there must be some parameter) */
94 }
95 }
96 else {
97 size_t l;
98 const char *s;
99 lua_Integer n = 0; /* to avoid warnings */
100 lua_Integer base = luaL_checkinteger(L, 2);
101 luaL_checktype(L, 1, LUA_TSTRING); /* no numbers as strings */
102 s = lua_tolstring(L, 1, &l);
103 luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
104 if (b_str2int(s, (int)base, &n) == s + l) {
105 lua_pushinteger(L, n);
106 return 1;
107 } /* else not a number */
108 } /* else not a number */
109 luaL_pushfail(L); /* not a number */
110 return 1;
111 }
112
113
luaB_error(lua_State * L)114 static int luaB_error (lua_State *L) {
115 int level = (int)luaL_optinteger(L, 2, 1);
116 lua_settop(L, 1);
117 if (lua_type(L, 1) == LUA_TSTRING && level > 0) {
118 luaL_where(L, level); /* add extra information */
119 lua_pushvalue(L, 1);
120 lua_concat(L, 2);
121 }
122 return lua_error(L);
123 }
124
125
luaB_getmetatable(lua_State * L)126 static int luaB_getmetatable (lua_State *L) {
127 luaL_checkany(L, 1);
128 if (!lua_getmetatable(L, 1)) {
129 lua_pushnil(L);
130 return 1; /* no metatable */
131 }
132 luaL_getmetafield(L, 1, "__metatable");
133 return 1; /* returns either __metatable field (if present) or metatable */
134 }
135
136
luaB_setmetatable(lua_State * L)137 static int luaB_setmetatable (lua_State *L) {
138 int t = lua_type(L, 2);
139 luaL_checktype(L, 1, LUA_TTABLE);
140 luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
141 if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL))
142 return luaL_error(L, "cannot change a protected metatable");
143 lua_settop(L, 2);
144 lua_setmetatable(L, 1);
145 return 1;
146 }
147
148
luaB_rawequal(lua_State * L)149 static int luaB_rawequal (lua_State *L) {
150 luaL_checkany(L, 1);
151 luaL_checkany(L, 2);
152 lua_pushboolean(L, lua_rawequal(L, 1, 2));
153 return 1;
154 }
155
156
luaB_rawlen(lua_State * L)157 static int luaB_rawlen (lua_State *L) {
158 int t = lua_type(L, 1);
159 luaL_argexpected(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
160 "table or string");
161 lua_pushinteger(L, lua_rawlen(L, 1));
162 return 1;
163 }
164
165
luaB_rawget(lua_State * L)166 static int luaB_rawget (lua_State *L) {
167 luaL_checktype(L, 1, LUA_TTABLE);
168 luaL_checkany(L, 2);
169 lua_settop(L, 2);
170 lua_rawget(L, 1);
171 return 1;
172 }
173
luaB_rawset(lua_State * L)174 static int luaB_rawset (lua_State *L) {
175 luaL_checktype(L, 1, LUA_TTABLE);
176 luaL_checkany(L, 2);
177 luaL_checkany(L, 3);
178 lua_settop(L, 3);
179 lua_rawset(L, 1);
180 return 1;
181 }
182
183
pushmode(lua_State * L,int oldmode)184 static int pushmode (lua_State *L, int oldmode) {
185 if (oldmode == -1)
186 luaL_pushfail(L); /* invalid call to 'lua_gc' */
187 else
188 lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"
189 : "generational");
190 return 1;
191 }
192
193
194 /*
195 ** check whether call to 'lua_gc' was valid (not inside a finalizer)
196 */
197 #define checkvalres(res) { if (res == -1) break; }
198
luaB_collectgarbage(lua_State * L)199 static int luaB_collectgarbage (lua_State *L) {
200 static const char *const opts[] = {"stop", "restart", "collect",
201 "count", "step", "setpause", "setstepmul",
202 "isrunning", "generational", "incremental", NULL};
203 static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
204 LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
205 LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
206 int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
207 switch (o) {
208 case LUA_GCCOUNT: {
209 int k = lua_gc(L, o);
210 int b = lua_gc(L, LUA_GCCOUNTB);
211 checkvalres(k);
212 lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
213 return 1;
214 }
215 case LUA_GCSTEP: {
216 int step = (int)luaL_optinteger(L, 2, 0);
217 int res = lua_gc(L, o, step);
218 checkvalres(res);
219 lua_pushboolean(L, res);
220 return 1;
221 }
222 case LUA_GCSETPAUSE:
223 case LUA_GCSETSTEPMUL: {
224 int p = (int)luaL_optinteger(L, 2, 0);
225 int previous = lua_gc(L, o, p);
226 checkvalres(previous);
227 lua_pushinteger(L, previous);
228 return 1;
229 }
230 case LUA_GCISRUNNING: {
231 int res = lua_gc(L, o);
232 checkvalres(res);
233 lua_pushboolean(L, res);
234 return 1;
235 }
236 case LUA_GCGEN: {
237 int minormul = (int)luaL_optinteger(L, 2, 0);
238 int majormul = (int)luaL_optinteger(L, 3, 0);
239 return pushmode(L, lua_gc(L, o, minormul, majormul));
240 }
241 case LUA_GCINC: {
242 int pause = (int)luaL_optinteger(L, 2, 0);
243 int stepmul = (int)luaL_optinteger(L, 3, 0);
244 int stepsize = (int)luaL_optinteger(L, 4, 0);
245 return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize));
246 }
247 default: {
248 int res = lua_gc(L, o);
249 checkvalres(res);
250 lua_pushinteger(L, res);
251 return 1;
252 }
253 }
254 luaL_pushfail(L); /* invalid call (inside a finalizer) */
255 return 1;
256 }
257
258
luaB_type(lua_State * L)259 static int luaB_type (lua_State *L) {
260 int t = lua_type(L, 1);
261 luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
262 lua_pushstring(L, lua_typename(L, t));
263 return 1;
264 }
265
266
luaB_next(lua_State * L)267 static int luaB_next (lua_State *L) {
268 luaL_checktype(L, 1, LUA_TTABLE);
269 lua_settop(L, 2); /* create a 2nd argument if there isn't one */
270 if (lua_next(L, 1))
271 return 2;
272 else {
273 lua_pushnil(L);
274 return 1;
275 }
276 }
277
278
pairscont(lua_State * L,int status,lua_KContext k)279 static int pairscont (lua_State *L, int status, lua_KContext k) {
280 (void)L; (void)status; (void)k; /* unused */
281 return 3;
282 }
283
luaB_pairs(lua_State * L)284 static int luaB_pairs (lua_State *L) {
285 luaL_checkany(L, 1);
286 if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) { /* no metamethod? */
287 lua_pushcfunction(L, luaB_next); /* will return generator, */
288 lua_pushvalue(L, 1); /* state, */
289 lua_pushnil(L); /* and initial value */
290 }
291 else {
292 lua_pushvalue(L, 1); /* argument 'self' to metamethod */
293 lua_callk(L, 1, 3, 0, pairscont); /* get 3 values from metamethod */
294 }
295 return 3;
296 }
297
298
299 /*
300 ** Traversal function for 'ipairs'
301 */
ipairsaux(lua_State * L)302 static int ipairsaux (lua_State *L) {
303 lua_Integer i = luaL_checkinteger(L, 2);
304 i = luaL_intop(+, i, 1);
305 lua_pushinteger(L, i);
306 return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
307 }
308
309
310 /*
311 ** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
312 ** (The given "table" may not be a table.)
313 */
luaB_ipairs(lua_State * L)314 static int luaB_ipairs (lua_State *L) {
315 luaL_checkany(L, 1);
316 lua_pushcfunction(L, ipairsaux); /* iteration function */
317 lua_pushvalue(L, 1); /* state */
318 lua_pushinteger(L, 0); /* initial value */
319 return 3;
320 }
321
322
load_aux(lua_State * L,int status,int envidx)323 static int load_aux (lua_State *L, int status, int envidx) {
324 if (l_likely(status == LUA_OK)) {
325 if (envidx != 0) { /* 'env' parameter? */
326 lua_pushvalue(L, envidx); /* environment for loaded function */
327 if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
328 lua_pop(L, 1); /* remove 'env' if not used by previous call */
329 }
330 return 1;
331 }
332 else { /* error (message is on top of the stack) */
333 luaL_pushfail(L);
334 lua_insert(L, -2); /* put before error message */
335 return 2; /* return fail plus error message */
336 }
337 }
338
339
luaB_loadfile(lua_State * L)340 static int luaB_loadfile (lua_State *L) {
341 const char *fname = luaL_optstring(L, 1, NULL);
342 const char *mode = luaL_optstring(L, 2, NULL);
343 int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
344 int status = luaL_loadfilex(L, fname, mode);
345 return load_aux(L, status, env);
346 }
347
348
349 /*
350 ** {======================================================
351 ** Generic Read function
352 ** =======================================================
353 */
354
355
356 /*
357 ** reserved slot, above all arguments, to hold a copy of the returned
358 ** string to avoid it being collected while parsed. 'load' has four
359 ** optional arguments (chunk, source name, mode, and environment).
360 */
361 #define RESERVEDSLOT 5
362
363
364 /*
365 ** Reader for generic 'load' function: 'lua_load' uses the
366 ** stack for internal stuff, so the reader cannot change the
367 ** stack top. Instead, it keeps its resulting string in a
368 ** reserved slot inside the stack.
369 */
generic_reader(lua_State * L,void * ud,size_t * size)370 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
371 (void)(ud); /* not used */
372 luaL_checkstack(L, 2, "too many nested functions");
373 lua_pushvalue(L, 1); /* get function */
374 lua_call(L, 0, 1); /* call it */
375 if (lua_isnil(L, -1)) {
376 lua_pop(L, 1); /* pop result */
377 *size = 0;
378 return NULL;
379 }
380 else if (l_unlikely(!lua_isstring(L, -1)))
381 luaL_error(L, "reader function must return a string");
382 lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
383 return lua_tolstring(L, RESERVEDSLOT, size);
384 }
385
386
luaB_load(lua_State * L)387 static int luaB_load (lua_State *L) {
388 int status;
389 size_t l;
390 const char *s = lua_tolstring(L, 1, &l);
391 const char *mode = luaL_optstring(L, 3, "bt");
392 int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
393 if (s != NULL) { /* loading a string? */
394 const char *chunkname = luaL_optstring(L, 2, s);
395 status = luaL_loadbufferx(L, s, l, chunkname, mode);
396 }
397 else { /* loading from a reader function */
398 const char *chunkname = luaL_optstring(L, 2, "=(load)");
399 luaL_checktype(L, 1, LUA_TFUNCTION);
400 lua_settop(L, RESERVEDSLOT); /* create reserved slot */
401 status = lua_load(L, generic_reader, NULL, chunkname, mode);
402 }
403 return load_aux(L, status, env);
404 }
405
406 /* }====================================================== */
407
408
dofilecont(lua_State * L,int d1,lua_KContext d2)409 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
410 (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */
411 return lua_gettop(L) - 1;
412 }
413
414
luaB_dofile(lua_State * L)415 static int luaB_dofile (lua_State *L) {
416 const char *fname = luaL_optstring(L, 1, NULL);
417 lua_settop(L, 1);
418 if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))
419 return lua_error(L);
420 lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
421 return dofilecont(L, 0, 0);
422 }
423
424
luaB_assert(lua_State * L)425 static int luaB_assert (lua_State *L) {
426 if (l_likely(lua_toboolean(L, 1))) /* condition is true? */
427 return lua_gettop(L); /* return all arguments */
428 else { /* error */
429 luaL_checkany(L, 1); /* there must be a condition */
430 lua_remove(L, 1); /* remove it */
431 lua_pushliteral(L, "assertion failed!"); /* default message */
432 lua_settop(L, 1); /* leave only message (default if no other one) */
433 return luaB_error(L); /* call 'error' */
434 }
435 }
436
437
luaB_select(lua_State * L)438 static int luaB_select (lua_State *L) {
439 int n = lua_gettop(L);
440 if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
441 lua_pushinteger(L, n-1);
442 return 1;
443 }
444 else {
445 lua_Integer i = luaL_checkinteger(L, 1);
446 if (i < 0) i = n + i;
447 else if (i > n) i = n;
448 luaL_argcheck(L, 1 <= i, 1, "index out of range");
449 return n - (int)i;
450 }
451 }
452
453
454 /*
455 ** Continuation function for 'pcall' and 'xpcall'. Both functions
456 ** already pushed a 'true' before doing the call, so in case of success
457 ** 'finishpcall' only has to return everything in the stack minus
458 ** 'extra' values (where 'extra' is exactly the number of items to be
459 ** ignored).
460 */
finishpcall(lua_State * L,int status,lua_KContext extra)461 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
462 if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) { /* error? */
463 lua_pushboolean(L, 0); /* first result (false) */
464 lua_pushvalue(L, -2); /* error message */
465 return 2; /* return false, msg */
466 }
467 else
468 return lua_gettop(L) - (int)extra; /* return all results */
469 }
470
471
luaB_pcall(lua_State * L)472 static int luaB_pcall (lua_State *L) {
473 int status;
474 luaL_checkany(L, 1);
475 lua_pushboolean(L, 1); /* first result if no errors */
476 lua_insert(L, 1); /* put it in place */
477 status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
478 return finishpcall(L, status, 0);
479 }
480
481
482 /*
483 ** Do a protected call with error handling. After 'lua_rotate', the
484 ** stack will have <f, err, true, f, [args...]>; so, the function passes
485 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
486 */
luaB_xpcall(lua_State * L)487 static int luaB_xpcall (lua_State *L) {
488 int status;
489 int n = lua_gettop(L);
490 luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */
491 lua_pushboolean(L, 1); /* first result */
492 lua_pushvalue(L, 1); /* function */
493 lua_rotate(L, 3, 2); /* move them below function's arguments */
494 status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
495 return finishpcall(L, status, 2);
496 }
497
498
luaB_tostring(lua_State * L)499 static int luaB_tostring (lua_State *L) {
500 luaL_checkany(L, 1);
501 luaL_tolstring(L, 1, NULL);
502 return 1;
503 }
504
505
506 static const luaL_Reg base_funcs[] = {
507 {"assert", luaB_assert},
508 {"collectgarbage", luaB_collectgarbage},
509 {"dofile", luaB_dofile},
510 {"error", luaB_error},
511 {"getmetatable", luaB_getmetatable},
512 {"ipairs", luaB_ipairs},
513 {"loadfile", luaB_loadfile},
514 {"load", luaB_load},
515 {"next", luaB_next},
516 {"pairs", luaB_pairs},
517 {"pcall", luaB_pcall},
518 {"print", luaB_print},
519 {"warn", luaB_warn},
520 {"rawequal", luaB_rawequal},
521 {"rawlen", luaB_rawlen},
522 {"rawget", luaB_rawget},
523 {"rawset", luaB_rawset},
524 {"select", luaB_select},
525 {"setmetatable", luaB_setmetatable},
526 {"tonumber", luaB_tonumber},
527 {"tostring", luaB_tostring},
528 {"type", luaB_type},
529 {"xpcall", luaB_xpcall},
530 /* placeholders */
531 {LUA_GNAME, NULL},
532 {"_VERSION", NULL},
533 {NULL, NULL}
534 };
535
536
luaopen_base(lua_State * L)537 LUAMOD_API int luaopen_base (lua_State *L) {
538 /* open lib into global table */
539 lua_pushglobaltable(L);
540 luaL_setfuncs(L, base_funcs, 0);
541 /* set global _G */
542 lua_pushvalue(L, -1);
543 lua_setfield(L, -2, LUA_GNAME);
544 /* set global _VERSION */
545 lua_pushliteral(L, LUA_VERSION);
546 lua_setfield(L, -2, "_VERSION");
547 return 1;
548 }
549
550