1 /*
2 ** $Id: lbaselib.c,v 1.312 2015/10/29 15:21:04 roberto Exp $
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
24 static int luaB_print (lua_State *L) {
25 int n = lua_gettop(L); /* number of arguments */
26 int i;
27 lua_getglobal(L, "tostring");
28 for (i=1; i<=n; i++) {
29 const char *s;
30 size_t l;
31 lua_pushvalue(L, -1); /* function to be called */
32 lua_pushvalue(L, i); /* value to print */
33 lua_call(L, 1, 1);
34 s = lua_tolstring(L, -1, &l); /* get result */
35 if (s == NULL)
36 return luaL_error(L, "'tostring' must return a string to 'print'");
37 if (i>1) lua_writestring("\t", 1);
38 lua_writestring(s, l);
39 lua_pop(L, 1); /* pop result */
40 }
41 lua_writeline();
42 return 0;
43 }
44
45
46 #define SPACECHARS " \f\n\r\t\v"
47
48 static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
49 lua_Unsigned n = 0;
50 int neg = 0;
51 s += strspn(s, SPACECHARS); /* skip initial spaces */
52 if (*s == '-') { s++; neg = 1; } /* handle signal */
53 else if (*s == '+') s++;
54 if (!isalnum((unsigned char)*s)) /* no digit? */
55 return NULL;
56 do {
57 int digit = (isdigit((unsigned char)*s)) ? *s - '0'
58 : (toupper((unsigned char)*s) - 'A') + 10;
59 if (digit >= base) return NULL; /* invalid numeral */
60 n = n * base + digit;
61 s++;
62 } while (isalnum((unsigned char)*s));
63 s += strspn(s, SPACECHARS); /* skip trailing spaces */
64 *pn = (lua_Integer)((neg) ? (0u - n) : n);
65 return s;
66 }
67
68
69 static int luaB_tonumber (lua_State *L) {
70 if (lua_isnoneornil(L, 2)) { /* standard conversion? */
71 luaL_checkany(L, 1);
72 if (lua_type(L, 1) == LUA_TNUMBER) { /* already a number? */
73 lua_settop(L, 1); /* yes; return it */
74 return 1;
75 }
76 else {
77 size_t l;
78 const char *s = lua_tolstring(L, 1, &l);
79 if (s != NULL && lua_stringtonumber(L, s) == l + 1)
80 return 1; /* successful conversion to number */
81 /* else not a number */
82 }
83 }
84 else {
85 size_t l;
86 const char *s;
87 lua_Integer n = 0; /* to avoid warnings */
88 lua_Integer base = luaL_checkinteger(L, 2);
89 luaL_checktype(L, 1, LUA_TSTRING); /* no numbers as strings */
90 s = lua_tolstring(L, 1, &l);
91 luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
92 if (b_str2int(s, (int)base, &n) == s + l) {
93 lua_pushinteger(L, n);
94 return 1;
95 } /* else not a number */
96 } /* else not a number */
97 lua_pushnil(L); /* not a number */
98 return 1;
99 }
100
101
102 static int luaB_error (lua_State *L) {
103 int level = (int)luaL_optinteger(L, 2, 1);
104 lua_settop(L, 1);
105 if (lua_isstring(L, 1) && level > 0) { /* add extra information? */
106 luaL_where(L, level);
107 lua_pushvalue(L, 1);
108 lua_concat(L, 2);
109 }
110 return lua_error(L);
111 }
112
113
114 static int luaB_getmetatable (lua_State *L) {
115 luaL_checkany(L, 1);
|
(1) Event cond_false: |
Condition "!lua_getmetatable(L, 1)", taking false branch. |
116 if (!lua_getmetatable(L, 1)) {
117 lua_pushnil(L);
118 return 1; /* no metatable */
|
(2) Event if_end: |
End of if statement. |
119 }
120 luaL_getmetafield(L, 1, "__metatable");
121 return 1; /* returns either __metatable field (if present) or metatable */
122 }
123
124
125 static int luaB_setmetatable (lua_State *L) {
126 int t = lua_type(L, 2);
127 luaL_checktype(L, 1, LUA_TTABLE);
128 luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
129 "nil or table expected");
130 if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
131 return luaL_error(L, "cannot change a protected metatable");
132 lua_settop(L, 2);
133 lua_setmetatable(L, 1);
134 return 1;
135 }
136
137
138 static int luaB_rawequal (lua_State *L) {
139 luaL_checkany(L, 1);
140 luaL_checkany(L, 2);
141 lua_pushboolean(L, lua_rawequal(L, 1, 2));
142 return 1;
143 }
144
145
146 static int luaB_rawlen (lua_State *L) {
147 int t = lua_type(L, 1);
148 luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
149 "table or string expected");
150 lua_pushinteger(L, lua_rawlen(L, 1));
151 return 1;
152 }
153
154
155 static int luaB_rawget (lua_State *L) {
156 luaL_checktype(L, 1, LUA_TTABLE);
157 luaL_checkany(L, 2);
158 lua_settop(L, 2);
159 lua_rawget(L, 1);
160 return 1;
161 }
162
163 static int luaB_rawset (lua_State *L) {
164 luaL_checktype(L, 1, LUA_TTABLE);
165 luaL_checkany(L, 2);
166 luaL_checkany(L, 3);
167 lua_settop(L, 3);
168 lua_rawset(L, 1);
169 return 1;
170 }
171
172
173 static int luaB_collectgarbage (lua_State *L) {
174 static const char *const opts[] = {"stop", "restart", "collect",
175 "count", "step", "setpause", "setstepmul",
176 "isrunning", NULL};
177 static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
178 LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
179 LUA_GCISRUNNING};
180 int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
181 int ex = (int)luaL_optinteger(L, 2, 0);
182 int res = lua_gc(L, o, ex);
183 switch (o) {
184 case LUA_GCCOUNT: {
185 int b = lua_gc(L, LUA_GCCOUNTB, 0);
186 lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024));
187 return 1;
188 }
189 case LUA_GCSTEP: case LUA_GCISRUNNING: {
190 lua_pushboolean(L, res);
191 return 1;
192 }
193 default: {
194 lua_pushinteger(L, res);
195 return 1;
196 }
197 }
198 }
199
200
201 static int luaB_type (lua_State *L) {
202 int t = lua_type(L, 1);
203 luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
204 lua_pushstring(L, lua_typename(L, t));
205 return 1;
206 }
207
208
209 static int pairsmeta (lua_State *L, const char *method, int iszero,
210 lua_CFunction iter) {
211 if (luaL_getmetafield(L, 1, method) == LUA_TNIL) { /* no metamethod? */
212 luaL_checktype(L, 1, LUA_TTABLE); /* argument must be a table */
213 lua_pushcfunction(L, iter); /* will return generator, */
214 lua_pushvalue(L, 1); /* state, */
215 if (iszero) lua_pushinteger(L, 0); /* and initial value */
216 else lua_pushnil(L);
217 }
218 else {
219 lua_pushvalue(L, 1); /* argument 'self' to metamethod */
220 lua_call(L, 1, 3); /* get 3 values from metamethod */
221 }
222 return 3;
223 }
224
225
226 static int luaB_next (lua_State *L) {
227 luaL_checktype(L, 1, LUA_TTABLE);
228 lua_settop(L, 2); /* create a 2nd argument if there isn't one */
229 if (lua_next(L, 1))
230 return 2;
231 else {
232 lua_pushnil(L);
233 return 1;
234 }
235 }
236
237
238 static int luaB_pairs (lua_State *L) {
239 return pairsmeta(L, "__pairs", 0, luaB_next);
240 }
241
242
243 /*
244 ** Traversal function for 'ipairs'
245 */
246 static int ipairsaux (lua_State *L) {
247 lua_Integer i = luaL_checkinteger(L, 2) + 1;
248 lua_pushinteger(L, i);
249 return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
250 }
251
252
253 /*
254 ** This function will use either 'ipairsaux' or 'ipairsaux_raw' to
255 ** traverse a table, depending on whether the table has metamethods
256 ** that can affect the traversal.
257 */
258 static int luaB_ipairs (lua_State *L) {
259 #if defined(LUA_COMPAT_IPAIRS)
260 return pairsmeta(L, "__ipairs", 1, ipairsaux);
261 #else
262 luaL_checkany(L, 1);
263 lua_pushcfunction(L, ipairsaux); /* iteration function */
264 lua_pushvalue(L, 1); /* state */
265 lua_pushinteger(L, 0); /* initial value */
266 return 3;
267 #endif
268 }
269
270
271 static int load_aux (lua_State *L, int status, int envidx) {
272 if (status == LUA_OK) {
273 if (envidx != 0) { /* 'env' parameter? */
274 lua_pushvalue(L, envidx); /* environment for loaded function */
275 if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
276 lua_pop(L, 1); /* remove 'env' if not used by previous call */
277 }
278 return 1;
279 }
280 else { /* error (message is on top of the stack) */
281 lua_pushnil(L);
282 lua_insert(L, -2); /* put before error message */
283 return 2; /* return nil plus error message */
284 }
285 }
286
287
288 static int luaB_loadfile (lua_State *L) {
289 const char *fname = luaL_optstring(L, 1, NULL);
290 const char *mode = luaL_optstring(L, 2, NULL);
291 int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
292 int status = luaL_loadfilex(L, fname, mode);
293 return load_aux(L, status, env);
294 }
295
296
297 /*
298 ** {======================================================
299 ** Generic Read function
300 ** =======================================================
301 */
302
303
304 /*
305 ** reserved slot, above all arguments, to hold a copy of the returned
306 ** string to avoid it being collected while parsed. 'load' has four
307 ** optional arguments (chunk, source name, mode, and environment).
308 */
309 #define RESERVEDSLOT 5
310
311
312 /*
313 ** Reader for generic 'load' function: 'lua_load' uses the
314 ** stack for internal stuff, so the reader cannot change the
315 ** stack top. Instead, it keeps its resulting string in a
316 ** reserved slot inside the stack.
317 */
318 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
319 (void)(ud); /* not used */
320 luaL_checkstack(L, 2, "too many nested functions");
321 lua_pushvalue(L, 1); /* get function */
322 lua_call(L, 0, 1); /* call it */
323 if (lua_isnil(L, -1)) {
324 lua_pop(L, 1); /* pop result */
325 *size = 0;
326 return NULL;
327 }
328 else if (!lua_isstring(L, -1))
329 luaL_error(L, "reader function must return a string");
330 lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
331 return lua_tolstring(L, RESERVEDSLOT, size);
332 }
333
334
335 static int luaB_load (lua_State *L) {
336 int status;
337 size_t l;
338 const char *s = lua_tolstring(L, 1, &l);
339 const char *mode = luaL_optstring(L, 3, "bt");
340 int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
341 if (s != NULL) { /* loading a string? */
342 const char *chunkname = luaL_optstring(L, 2, s);
343 status = luaL_loadbufferx(L, s, l, chunkname, mode);
344 }
345 else { /* loading from a reader function */
346 const char *chunkname = luaL_optstring(L, 2, "=(load)");
347 luaL_checktype(L, 1, LUA_TFUNCTION);
348 lua_settop(L, RESERVEDSLOT); /* create reserved slot */
349 status = lua_load(L, generic_reader, NULL, chunkname, mode);
350 }
351 return load_aux(L, status, env);
352 }
353
354 /* }====================================================== */
355
356
357 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
358 (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */
359 return lua_gettop(L) - 1;
360 }
361
362
363 static int luaB_dofile (lua_State *L) {
364 const char *fname = luaL_optstring(L, 1, NULL);
365 lua_settop(L, 1);
366 if (luaL_loadfile(L, fname) != LUA_OK)
367 return lua_error(L);
368 lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
369 return dofilecont(L, 0, 0);
370 }
371
372
373 static int luaB_assert (lua_State *L) {
374 if (lua_toboolean(L, 1)) /* condition is true? */
375 return lua_gettop(L); /* return all arguments */
376 else { /* error */
377 luaL_checkany(L, 1); /* there must be a condition */
378 lua_remove(L, 1); /* remove it */
379 lua_pushliteral(L, "assertion failed!"); /* default message */
380 lua_settop(L, 1); /* leave only message (default if no other one) */
381 return luaB_error(L); /* call 'error' */
382 }
383 }
384
385
386 static int luaB_select (lua_State *L) {
387 int n = lua_gettop(L);
388 if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
389 lua_pushinteger(L, n-1);
390 return 1;
391 }
392 else {
393 lua_Integer i = luaL_checkinteger(L, 1);
394 if (i < 0) i = n + i;
395 else if (i > n) i = n;
396 luaL_argcheck(L, 1 <= i, 1, "index out of range");
397 return n - (int)i;
398 }
399 }
400
401
402 /*
403 ** Continuation function for 'pcall' and 'xpcall'. Both functions
404 ** already pushed a 'true' before doing the call, so in case of success
405 ** 'finishpcall' only has to return everything in the stack minus
406 ** 'extra' values (where 'extra' is exactly the number of items to be
407 ** ignored).
408 */
409 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
410 if (status != LUA_OK && status != LUA_YIELD) { /* error? */
411 lua_pushboolean(L, 0); /* first result (false) */
412 lua_pushvalue(L, -2); /* error message */
413 return 2; /* return false, msg */
414 }
415 else
416 return lua_gettop(L) - (int)extra; /* return all results */
417 }
418
419
420 static int luaB_pcall (lua_State *L) {
421 int status;
422 luaL_checkany(L, 1);
423 lua_pushboolean(L, 1); /* first result if no errors */
424 lua_insert(L, 1); /* put it in place */
425 status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
426 return finishpcall(L, status, 0);
427 }
428
429
430 /*
431 ** Do a protected call with error handling. After 'lua_rotate', the
432 ** stack will have <f, err, true, f, [args...]>; so, the function passes
433 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
434 */
435 static int luaB_xpcall (lua_State *L) {
436 int status;
437 int n = lua_gettop(L);
438 luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */
439 lua_pushboolean(L, 1); /* first result */
440 lua_pushvalue(L, 1); /* function */
441 lua_rotate(L, 3, 2); /* move them below function's arguments */
442 status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
443 return finishpcall(L, status, 2);
444 }
445
446
447 static int luaB_tostring (lua_State *L) {
448 luaL_checkany(L, 1);
449 luaL_tolstring(L, 1, NULL);
450 return 1;
451 }
452
453
454 static const luaL_Reg base_funcs[] = {
455 {"assert", luaB_assert},
456 {"collectgarbage", luaB_collectgarbage},
457 {"dofile", luaB_dofile},
458 {"error", luaB_error},
459 {"getmetatable", luaB_getmetatable},
460 {"ipairs", luaB_ipairs},
461 {"loadfile", luaB_loadfile},
462 {"load", luaB_load},
463 #if defined(LUA_COMPAT_LOADSTRING)
464 {"loadstring", luaB_load},
465 #endif
466 {"next", luaB_next},
467 {"pairs", luaB_pairs},
468 {"pcall", luaB_pcall},
469 {"print", luaB_print},
470 {"rawequal", luaB_rawequal},
471 {"rawlen", luaB_rawlen},
472 {"rawget", luaB_rawget},
473 {"rawset", luaB_rawset},
474 {"select", luaB_select},
475 {"setmetatable", luaB_setmetatable},
476 {"tonumber", luaB_tonumber},
477 {"tostring", luaB_tostring},
478 {"type", luaB_type},
479 {"xpcall", luaB_xpcall},
480 /* placeholders */
481 {"_G", NULL},
482 {"_VERSION", NULL},
483 {NULL, NULL}
484 };
485
486
487 LUAMOD_API int luaopen_base (lua_State *L) {
488 /* open lib into global table */
489 lua_pushglobaltable(L);
490 luaL_setfuncs(L, base_funcs, 0);
491 /* set global _G */
492 lua_pushvalue(L, -1);
493 lua_setfield(L, -2, "_G");
494 /* set global _VERSION */
495 lua_pushliteral(L, LUA_VERSION);
496 lua_setfield(L, -2, "_VERSION");
497 return 1;
498 }
499
500