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 lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"
186 : "generational");
187 return 1;
188 }
189
190
luaB_collectgarbage(lua_State * L)191 static int luaB_collectgarbage (lua_State *L) {
192 static const char *const opts[] = {"stop", "restart", "collect",
193 "count", "step", "setpause", "setstepmul",
194 "isrunning", "generational", "incremental", NULL};
195 static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
196 LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
197 LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
198 int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
199 switch (o) {
200 case LUA_GCCOUNT: {
201 int k = lua_gc(L, o);
202 int b = lua_gc(L, LUA_GCCOUNTB);
203 lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
204 return 1;
205 }
206 case LUA_GCSTEP: {
207 int step = (int)luaL_optinteger(L, 2, 0);
208 int res = lua_gc(L, o, step);
209 lua_pushboolean(L, res);
210 return 1;
211 }
212 case LUA_GCSETPAUSE:
213 case LUA_GCSETSTEPMUL: {
214 int p = (int)luaL_optinteger(L, 2, 0);
215 int previous = lua_gc(L, o, p);
216 lua_pushinteger(L, previous);
217 return 1;
218 }
219 case LUA_GCISRUNNING: {
220 int res = lua_gc(L, o);
221 lua_pushboolean(L, res);
222 return 1;
223 }
224 case LUA_GCGEN: {
225 int minormul = (int)luaL_optinteger(L, 2, 0);
226 int majormul = (int)luaL_optinteger(L, 3, 0);
227 return pushmode(L, lua_gc(L, o, minormul, majormul));
228 }
229 case LUA_GCINC: {
230 int pause = (int)luaL_optinteger(L, 2, 0);
231 int stepmul = (int)luaL_optinteger(L, 3, 0);
232 int stepsize = (int)luaL_optinteger(L, 4, 0);
233 return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize));
234 }
235 default: {
236 int res = lua_gc(L, o);
237 lua_pushinteger(L, res);
238 return 1;
239 }
240 }
241 }
242
243
luaB_type(lua_State * L)244 static int luaB_type (lua_State *L) {
245 int t = lua_type(L, 1);
246 luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
247 lua_pushstring(L, lua_typename(L, t));
248 return 1;
249 }
250
251
luaB_next(lua_State * L)252 static int luaB_next (lua_State *L) {
253 luaL_checktype(L, 1, LUA_TTABLE);
254 lua_settop(L, 2); /* create a 2nd argument if there isn't one */
255 if (lua_next(L, 1))
256 return 2;
257 else {
258 lua_pushnil(L);
259 return 1;
260 }
261 }
262
263
luaB_pairs(lua_State * L)264 static int luaB_pairs (lua_State *L) {
265 luaL_checkany(L, 1);
266 if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) { /* no metamethod? */
267 lua_pushcfunction(L, luaB_next); /* will return generator, */
268 lua_pushvalue(L, 1); /* state, */
269 lua_pushnil(L); /* and initial value */
270 }
271 else {
272 lua_pushvalue(L, 1); /* argument 'self' to metamethod */
273 lua_call(L, 1, 3); /* get 3 values from metamethod */
274 }
275 return 3;
276 }
277
278
279 /*
280 ** Traversal function for 'ipairs'
281 */
ipairsaux(lua_State * L)282 static int ipairsaux (lua_State *L) {
283 lua_Integer i = luaL_checkinteger(L, 2) + 1;
284 lua_pushinteger(L, i);
285 return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
286 }
287
288
289 /*
290 ** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
291 ** (The given "table" may not be a table.)
292 */
luaB_ipairs(lua_State * L)293 static int luaB_ipairs (lua_State *L) {
294 luaL_checkany(L, 1);
295 lua_pushcfunction(L, ipairsaux); /* iteration function */
296 lua_pushvalue(L, 1); /* state */
297 lua_pushinteger(L, 0); /* initial value */
298 return 3;
299 }
300
301
load_aux(lua_State * L,int status,int envidx)302 static int load_aux (lua_State *L, int status, int envidx) {
303 if (l_likely(status == LUA_OK)) {
304 if (envidx != 0) { /* 'env' parameter? */
305 lua_pushvalue(L, envidx); /* environment for loaded function */
306 if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
307 lua_pop(L, 1); /* remove 'env' if not used by previous call */
308 }
309 return 1;
310 }
311 else { /* error (message is on top of the stack) */
312 luaL_pushfail(L);
313 lua_insert(L, -2); /* put before error message */
314 return 2; /* return fail plus error message */
315 }
316 }
317
318
luaB_loadfile(lua_State * L)319 static int luaB_loadfile (lua_State *L) {
320 const char *fname = luaL_optstring(L, 1, NULL);
321 const char *mode = luaL_optstring(L, 2, NULL);
322 int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
323 int status = luaL_loadfilex(L, fname, mode);
324 return load_aux(L, status, env);
325 }
326
327
328 /*
329 ** {======================================================
330 ** Generic Read function
331 ** =======================================================
332 */
333
334
335 /*
336 ** reserved slot, above all arguments, to hold a copy of the returned
337 ** string to avoid it being collected while parsed. 'load' has four
338 ** optional arguments (chunk, source name, mode, and environment).
339 */
340 #define RESERVEDSLOT 5
341
342
343 /*
344 ** Reader for generic 'load' function: 'lua_load' uses the
345 ** stack for internal stuff, so the reader cannot change the
346 ** stack top. Instead, it keeps its resulting string in a
347 ** reserved slot inside the stack.
348 */
generic_reader(lua_State * L,void * ud,size_t * size)349 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
350 (void)(ud); /* not used */
351 luaL_checkstack(L, 2, "too many nested functions");
352 lua_pushvalue(L, 1); /* get function */
353 lua_call(L, 0, 1); /* call it */
354 if (lua_isnil(L, -1)) {
355 lua_pop(L, 1); /* pop result */
356 *size = 0;
357 return NULL;
358 }
359 else if (l_unlikely(!lua_isstring(L, -1)))
360 luaL_error(L, "reader function must return a string");
361 lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
362 return lua_tolstring(L, RESERVEDSLOT, size);
363 }
364
365
luaB_load(lua_State * L)366 static int luaB_load (lua_State *L) {
367 int status;
368 size_t l;
369 const char *s = lua_tolstring(L, 1, &l);
370 const char *mode = luaL_optstring(L, 3, "bt");
371 int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
372 if (s != NULL) { /* loading a string? */
373 const char *chunkname = luaL_optstring(L, 2, s);
374 status = luaL_loadbufferx(L, s, l, chunkname, mode);
375 }
376 else { /* loading from a reader function */
377 const char *chunkname = luaL_optstring(L, 2, "=(load)");
378 luaL_checktype(L, 1, LUA_TFUNCTION);
379 lua_settop(L, RESERVEDSLOT); /* create reserved slot */
380 status = lua_load(L, generic_reader, NULL, chunkname, mode);
381 }
382 return load_aux(L, status, env);
383 }
384
385 /* }====================================================== */
386
387
dofilecont(lua_State * L,int d1,lua_KContext d2)388 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
389 (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */
390 return lua_gettop(L) - 1;
391 }
392
393
luaB_dofile(lua_State * L)394 static int luaB_dofile (lua_State *L) {
395 const char *fname = luaL_optstring(L, 1, NULL);
396 lua_settop(L, 1);
397 if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))
398 return lua_error(L);
399 lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
400 return dofilecont(L, 0, 0);
401 }
402
403
luaB_assert(lua_State * L)404 static int luaB_assert (lua_State *L) {
405 if (l_likely(lua_toboolean(L, 1))) /* condition is true? */
406 return lua_gettop(L); /* return all arguments */
407 else { /* error */
408 luaL_checkany(L, 1); /* there must be a condition */
409 lua_remove(L, 1); /* remove it */
410 lua_pushliteral(L, "assertion failed!"); /* default message */
411 lua_settop(L, 1); /* leave only message (default if no other one) */
412 return luaB_error(L); /* call 'error' */
413 }
414 }
415
416
luaB_select(lua_State * L)417 static int luaB_select (lua_State *L) {
418 int n = lua_gettop(L);
419 if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
420 lua_pushinteger(L, n-1);
421 return 1;
422 }
423 else {
424 lua_Integer i = luaL_checkinteger(L, 1);
425 if (i < 0) i = n + i;
426 else if (i > n) i = n;
427 luaL_argcheck(L, 1 <= i, 1, "index out of range");
428 return n - (int)i;
429 }
430 }
431
432
433 /*
434 ** Continuation function for 'pcall' and 'xpcall'. Both functions
435 ** already pushed a 'true' before doing the call, so in case of success
436 ** 'finishpcall' only has to return everything in the stack minus
437 ** 'extra' values (where 'extra' is exactly the number of items to be
438 ** ignored).
439 */
finishpcall(lua_State * L,int status,lua_KContext extra)440 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
441 if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) { /* error? */
442 lua_pushboolean(L, 0); /* first result (false) */
443 lua_pushvalue(L, -2); /* error message */
444 return 2; /* return false, msg */
445 }
446 else
447 return lua_gettop(L) - (int)extra; /* return all results */
448 }
449
450
luaB_pcall(lua_State * L)451 static int luaB_pcall (lua_State *L) {
452 int status;
453 luaL_checkany(L, 1);
454 lua_pushboolean(L, 1); /* first result if no errors */
455 lua_insert(L, 1); /* put it in place */
456 status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
457 return finishpcall(L, status, 0);
458 }
459
460
461 /*
462 ** Do a protected call with error handling. After 'lua_rotate', the
463 ** stack will have <f, err, true, f, [args...]>; so, the function passes
464 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
465 */
luaB_xpcall(lua_State * L)466 static int luaB_xpcall (lua_State *L) {
467 int status;
468 int n = lua_gettop(L);
469 luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */
470 lua_pushboolean(L, 1); /* first result */
471 lua_pushvalue(L, 1); /* function */
472 lua_rotate(L, 3, 2); /* move them below function's arguments */
473 status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
474 return finishpcall(L, status, 2);
475 }
476
477
luaB_tostring(lua_State * L)478 static int luaB_tostring (lua_State *L) {
479 luaL_checkany(L, 1);
480 luaL_tolstring(L, 1, NULL);
481 return 1;
482 }
483
484
485 static const luaL_Reg base_funcs[] = {
486 {"assert", luaB_assert},
487 {"collectgarbage", luaB_collectgarbage},
488 {"dofile", luaB_dofile},
489 {"error", luaB_error},
490 {"getmetatable", luaB_getmetatable},
491 {"ipairs", luaB_ipairs},
492 {"loadfile", luaB_loadfile},
493 {"load", luaB_load},
494 {"next", luaB_next},
495 {"pairs", luaB_pairs},
496 {"pcall", luaB_pcall},
497 {"print", luaB_print},
498 {"warn", luaB_warn},
499 {"rawequal", luaB_rawequal},
500 {"rawlen", luaB_rawlen},
501 {"rawget", luaB_rawget},
502 {"rawset", luaB_rawset},
503 {"select", luaB_select},
504 {"setmetatable", luaB_setmetatable},
505 {"tonumber", luaB_tonumber},
506 {"tostring", luaB_tostring},
507 {"type", luaB_type},
508 {"xpcall", luaB_xpcall},
509 /* placeholders */
510 {LUA_GNAME, NULL},
511 {"_VERSION", NULL},
512 {NULL, NULL}
513 };
514
515
luaopen_base(lua_State * L)516 LUAMOD_API int luaopen_base (lua_State *L) {
517 /* open lib into global table */
518 lua_pushglobaltable(L);
519 luaL_setfuncs(L, base_funcs, 0);
520 /* set global _G */
521 lua_pushvalue(L, -1);
522 lua_setfield(L, -2, LUA_GNAME);
523 /* set global _VERSION */
524 lua_pushliteral(L, LUA_VERSION);
525 lua_setfield(L, -2, "_VERSION");
526 return 1;
527 }
528
529