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
24static 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*/
45static 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
60static 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
81static 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
114static 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
126static 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
137static 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 (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
149static 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
157static 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
166static 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
174static 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
184static int pushmode (lua_State *L, int oldmode) {
185 lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental" : "generational");
186 return 1;
187}
188
189
190static int luaB_collectgarbage (lua_State *L) {
191 static const char *const opts[] = {"stop", "restart", "collect",
192 "count", "step", "setpause", "setstepmul",
193 "isrunning", "generational", "incremental", NULL};
194 static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
195 LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
196 LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
197 int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
198 switch (o) {
199 case LUA_GCCOUNT: {
200 int k = lua_gc(L, o);
201 int b = lua_gc(L, LUA_GCCOUNTB);
202 lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
203 return 1;
204 }
205 case LUA_GCSTEP: {
206 int step = (int)luaL_optinteger(L, 2, 0);
207 int res = lua_gc(L, o, step);
208 lua_pushboolean(L, res);
209 return 1;
210 }
211 case LUA_GCSETPAUSE:
212 case LUA_GCSETSTEPMUL: {
213 int p = (int)luaL_optinteger(L, 2, 0);
214 int previous = lua_gc(L, o, p);
215 lua_pushinteger(L, previous);
216 return 1;
217 }
218 case LUA_GCISRUNNING: {
219 int res = lua_gc(L, o);
220 lua_pushboolean(L, res);
221 return 1;
222 }
223 case LUA_GCGEN: {
224 int minormul = (int)luaL_optinteger(L, 2, 0);
225 int majormul = (int)luaL_optinteger(L, 3, 0);
226 return pushmode(L, lua_gc(L, o, minormul, majormul));
227 }
228 case LUA_GCINC: {
229 int pause = (int)luaL_optinteger(L, 2, 0);
230 int stepmul = (int)luaL_optinteger(L, 3, 0);
231 int stepsize = (int)luaL_optinteger(L, 4, 0);
232 return pushmode(L, lua_gc(L, o, pause, stepmul, stepsize));
233 }
234 default: {
235 int res = lua_gc(L, o);
236 lua_pushinteger(L, res);
237 return 1;
238 }
239 }
240}
241
242
243static int luaB_type (lua_State *L) {
244 int t = lua_type(L, 1);
245 luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
246 lua_pushstring(L, lua_typename(L, t));
247 return 1;
248}
249
250
251static int luaB_next (lua_State *L) {
252 luaL_checktype(L, 1, LUA_TTABLE);
253 lua_settop(L, 2); /* create a 2nd argument if there isn't one */
254 if (lua_next(L, 1))
255 return 2;
256 else {
257 lua_pushnil(L);
258 return 1;
259 }
260}
261
262
263static int luaB_pairs (lua_State *L) {
264 luaL_checkany(L, 1);
265 if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) { /* no metamethod? */
266 lua_pushcfunction(L, luaB_next); /* will return generator, */
267 lua_pushvalue(L, 1); /* state, */
268 lua_pushnil(L); /* and initial value */
269 }
270 else {
271 lua_pushvalue(L, 1); /* argument 'self' to metamethod */
272 lua_call(L, 1, 3); /* get 3 values from metamethod */
273 }
274 return 3;
275}
276
277
278/*
279** Traversal function for 'ipairs'
280*/
281static int ipairsaux (lua_State *L) {
282 lua_Integer i = luaL_checkinteger(L, 2) + 1;
283 lua_pushinteger(L, i);
284 return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
285}
286
287
288/*
289** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
290** (The given "table" may not be a table.)
291*/
292static int luaB_ipairs (lua_State *L) {
293 luaL_checkany(L, 1);
294 lua_pushcfunction(L, ipairsaux); /* iteration function */
295 lua_pushvalue(L, 1); /* state */
296 lua_pushinteger(L, 0); /* initial value */
297 return 3;
298}
299
300
301static int load_aux (lua_State *L, int status, int envidx) {
302 if (status == LUA_OK) {
303 if (envidx != 0) { /* 'env' parameter? */
304 lua_pushvalue(L, envidx); /* environment for loaded function */
305 if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */
306 lua_pop(L, 1); /* remove 'env' if not used by previous call */
307 }
308 return 1;
309 }
310 else { /* error (message is on top of the stack) */
311 luaL_pushfail(L);
312 lua_insert(L, -2); /* put before error message */
313 return 2; /* return fail plus error message */
314 }
315}
316
317
318static int luaB_loadfile (lua_State *L) {
319 const char *fname = luaL_optstring(L, 1, NULL);
320 const char *mode = luaL_optstring(L, 2, NULL);
321 int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */
322 int status = luaL_loadfilex(L, fname, mode);
323 return load_aux(L, status, env);
324}
325
326
327/*
328** {======================================================
329** Generic Read function
330** =======================================================
331*/
332
333
334/*
335** reserved slot, above all arguments, to hold a copy of the returned
336** string to avoid it being collected while parsed. 'load' has four
337** optional arguments (chunk, source name, mode, and environment).
338*/
339#define RESERVEDSLOT 5
340
341
342/*
343** Reader for generic 'load' function: 'lua_load' uses the
344** stack for internal stuff, so the reader cannot change the
345** stack top. Instead, it keeps its resulting string in a
346** reserved slot inside the stack.
347*/
348static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
349 (void)(ud); /* not used */
350 luaL_checkstack(L, 2, "too many nested functions");
351 lua_pushvalue(L, 1); /* get function */
352 lua_call(L, 0, 1); /* call it */
353 if (lua_isnil(L, -1)) {
354 lua_pop(L, 1); /* pop result */
355 *size = 0;
356 return NULL;
357 }
358 else if (!lua_isstring(L, -1))
359 luaL_error(L, "reader function must return a string");
360 lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */
361 return lua_tolstring(L, RESERVEDSLOT, size);
362}
363
364
365static int luaB_load (lua_State *L) {
366 int status;
367 size_t l;
368 const char *s = lua_tolstring(L, 1, &l);
369 const char *mode = luaL_optstring(L, 3, "bt");
370 int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */
371 if (s != NULL) { /* loading a string? */
372 const char *chunkname = luaL_optstring(L, 2, s);
373 status = luaL_loadbufferx(L, s, l, chunkname, mode);
374 }
375 else { /* loading from a reader function */
376 const char *chunkname = luaL_optstring(L, 2, "=(load)");
377 luaL_checktype(L, 1, LUA_TFUNCTION);
378 lua_settop(L, RESERVEDSLOT); /* create reserved slot */
379 status = lua_load(L, generic_reader, NULL, chunkname, mode);
380 }
381 return load_aux(L, status, env);
382}
383
384/* }====================================================== */
385
386
387static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
388 (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */
389 return lua_gettop(L) - 1;
390}
391
392
393static int luaB_dofile (lua_State *L) {
394 const char *fname = luaL_optstring(L, 1, NULL);
395 lua_settop(L, 1);
396 if (luaL_loadfile(L, fname) != LUA_OK)
397 return lua_error(L);
398 lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
399 return dofilecont(L, 0, 0);
400}
401
402
403static int luaB_assert (lua_State *L) {
404 if (lua_toboolean(L, 1)) /* condition is true? */
405 return lua_gettop(L); /* return all arguments */
406 else { /* error */
407 luaL_checkany(L, 1); /* there must be a condition */
408 lua_remove(L, 1); /* remove it */
409 lua_pushliteral(L, "assertion failed!"); /* default message */
410 lua_settop(L, 1); /* leave only message (default if no other one) */
411 return luaB_error(L); /* call 'error' */
412 }
413}
414
415
416static int luaB_select (lua_State *L) {
417 int n = lua_gettop(L);
418 if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
419 lua_pushinteger(L, n-1);
420 return 1;
421 }
422 else {
423 lua_Integer i = luaL_checkinteger(L, 1);
424 if (i < 0) i = n + i;
425 else if (i > n) i = n;
426 luaL_argcheck(L, 1 <= i, 1, "index out of range");
427 return n - (int)i;
428 }
429}
430
431
432/*
433** Continuation function for 'pcall' and 'xpcall'. Both functions
434** already pushed a 'true' before doing the call, so in case of success
435** 'finishpcall' only has to return everything in the stack minus
436** 'extra' values (where 'extra' is exactly the number of items to be
437** ignored).
438*/
439static int finishpcall (lua_State *L, int status, lua_KContext extra) {
440 if (status != LUA_OK && status != LUA_YIELD) { /* error? */
441 lua_pushboolean(L, 0); /* first result (false) */
442 lua_pushvalue(L, -2); /* error message */
443 return 2; /* return false, msg */
444 }
445 else
446 return lua_gettop(L) - (int)extra; /* return all results */
447}
448
449
450static int luaB_pcall (lua_State *L) {
451 int status;
452 luaL_checkany(L, 1);
453 lua_pushboolean(L, 1); /* first result if no errors */
454 lua_insert(L, 1); /* put it in place */
455 status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
456 return finishpcall(L, status, 0);
457}
458
459
460/*
461** Do a protected call with error handling. After 'lua_rotate', the
462** stack will have <f, err, true, f, [args...]>; so, the function passes
463** 2 to 'finishpcall' to skip the 2 first values when returning results.
464*/
465static int luaB_xpcall (lua_State *L) {
466 int status;
467 int n = lua_gettop(L);
468 luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */
469 lua_pushboolean(L, 1); /* first result */
470 lua_pushvalue(L, 1); /* function */
471 lua_rotate(L, 3, 2); /* move them below function's arguments */
472 status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
473 return finishpcall(L, status, 2);
474}
475
476
477static int luaB_tostring (lua_State *L) {
478 luaL_checkany(L, 1);
479 luaL_tolstring(L, 1, NULL);
480 return 1;
481}
482
483
484static const luaL_Reg base_funcs[] = {
485 {"assert", luaB_assert},
486 {"collectgarbage", luaB_collectgarbage},
487 {"dofile", luaB_dofile},
488 {"error", luaB_error},
489 {"getmetatable", luaB_getmetatable},
490 {"ipairs", luaB_ipairs},
491 {"loadfile", luaB_loadfile},
492 {"load", luaB_load},
493 {"next", luaB_next},
494 {"pairs", luaB_pairs},
495 {"pcall", luaB_pcall},
496 {"print", luaB_print},
497 {"warn", luaB_warn},
498 {"rawequal", luaB_rawequal},
499 {"rawlen", luaB_rawlen},
500 {"rawget", luaB_rawget},
501 {"rawset", luaB_rawset},
502 {"select", luaB_select},
503 {"setmetatable", luaB_setmetatable},
504 {"tonumber", luaB_tonumber},
505 {"tostring", luaB_tostring},
506 {"type", luaB_type},
507 {"xpcall", luaB_xpcall},
508 /* placeholders */
509 {LUA_GNAME, NULL},
510 {"_VERSION", NULL},
511 {NULL, NULL}
512};
513
514
515LUAMOD_API int luaopen_base (lua_State *L) {
516 /* open lib into global table */
517 lua_pushglobaltable(L);
518 luaL_setfuncs(L, base_funcs, 0);
519 /* set global _G */
520 lua_pushvalue(L, -1);
521 lua_setfield(L, -2, LUA_GNAME);
522 /* set global _VERSION */
523 lua_pushliteral(L, LUA_VERSION);
524 lua_setfield(L, -2, "_VERSION");
525 return 1;
526}
527
528