xref: /netbsd-src/external/mit/lua/dist/src/lbaselib.c (revision fdd524d4ccd2bb0c6f67401e938dabf773eb0372)
1 /*	$NetBSD: lbaselib.c,v 1.6 2016/01/28 14:41:39 lneto Exp $	*/
2 
3 /*
4 ** Id: lbaselib.c,v 1.312 2015/10/29 15:21:04 roberto Exp
5 ** Basic library
6 ** See Copyright Notice in lua.h
7 */
8 
9 #define lbaselib_c
10 #define LUA_LIB
11 
12 #include "lprefix.h"
13 
14 
15 #ifndef _KERNEL
16 #include <ctype.h>
17 #include <stdio.h>
18 #include <stdlib.h>
19 #include <string.h>
20 #endif /* _KERNEL */
21 
22 #include "lua.h"
23 
24 #include "lauxlib.h"
25 #include "lualib.h"
26 
27 
28 static int luaB_print (lua_State *L) {
29   int n = lua_gettop(L);  /* number of arguments */
30   int i;
31   lua_getglobal(L, "tostring");
32   for (i=1; i<=n; i++) {
33     const char *s;
34     size_t l;
35     lua_pushvalue(L, -1);  /* function to be called */
36     lua_pushvalue(L, i);   /* value to print */
37     lua_call(L, 1, 1);
38     s = lua_tolstring(L, -1, &l);  /* get result */
39     if (s == NULL)
40       return luaL_error(L, "'tostring' must return a string to 'print'");
41     if (i>1) lua_writestring("\t", 1);
42     lua_writestring(s, l);
43     lua_pop(L, 1);  /* pop result */
44   }
45   lua_writeline();
46   return 0;
47 }
48 
49 
50 #define SPACECHARS	" \f\n\r\t\v"
51 
52 static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
53   lua_Unsigned n = 0;
54   int neg = 0;
55   s += strspn(s, SPACECHARS);  /* skip initial spaces */
56   if (*s == '-') { s++; neg = 1; }  /* handle signal */
57   else if (*s == '+') s++;
58   if (!isalnum((unsigned char)*s))  /* no digit? */
59     return NULL;
60   do {
61     int digit = (isdigit((unsigned char)*s)) ? *s - '0'
62                    : (toupper((unsigned char)*s) - 'A') + 10;
63     if (digit >= base) return NULL;  /* invalid numeral */
64     n = n * base + digit;
65     s++;
66   } while (isalnum((unsigned char)*s));
67   s += strspn(s, SPACECHARS);  /* skip trailing spaces */
68   *pn = (lua_Integer)((neg) ? (0u - n) : n);
69   return s;
70 }
71 
72 
73 static int luaB_tonumber (lua_State *L) {
74   if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
75     luaL_checkany(L, 1);
76     if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
77       lua_settop(L, 1);  /* yes; return it */
78       return 1;
79     }
80     else {
81       size_t l;
82       const char *s = lua_tolstring(L, 1, &l);
83       if (s != NULL && lua_stringtonumber(L, s) == l + 1)
84         return 1;  /* successful conversion to number */
85       /* else not a number */
86     }
87   }
88   else {
89     size_t l;
90     const char *s;
91     lua_Integer n = 0;  /* to avoid warnings */
92     lua_Integer base = luaL_checkinteger(L, 2);
93     luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */
94     s = lua_tolstring(L, 1, &l);
95     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
96     if (b_str2int(s, (int)base, &n) == s + l) {
97       lua_pushinteger(L, n);
98       return 1;
99     }  /* else not a number */
100   }  /* else not a number */
101   lua_pushnil(L);  /* not a number */
102   return 1;
103 }
104 
105 
106 static int luaB_error (lua_State *L) {
107   int level = (int)luaL_optinteger(L, 2, 1);
108   lua_settop(L, 1);
109   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
110     luaL_where(L, level);
111     lua_pushvalue(L, 1);
112     lua_concat(L, 2);
113   }
114   return lua_error(L);
115 }
116 
117 
118 static int luaB_getmetatable (lua_State *L) {
119   luaL_checkany(L, 1);
120   if (!lua_getmetatable(L, 1)) {
121     lua_pushnil(L);
122     return 1;  /* no metatable */
123   }
124   luaL_getmetafield(L, 1, "__metatable");
125   return 1;  /* returns either __metatable field (if present) or metatable */
126 }
127 
128 
129 static int luaB_setmetatable (lua_State *L) {
130   int t = lua_type(L, 2);
131   luaL_checktype(L, 1, LUA_TTABLE);
132   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
133                     "nil or table expected");
134   if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL)
135     return luaL_error(L, "cannot change a protected metatable");
136   lua_settop(L, 2);
137   lua_setmetatable(L, 1);
138   return 1;
139 }
140 
141 
142 static int luaB_rawequal (lua_State *L) {
143   luaL_checkany(L, 1);
144   luaL_checkany(L, 2);
145   lua_pushboolean(L, lua_rawequal(L, 1, 2));
146   return 1;
147 }
148 
149 
150 static int luaB_rawlen (lua_State *L) {
151   int t = lua_type(L, 1);
152   luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
153                    "table or string expected");
154   lua_pushinteger(L, lua_rawlen(L, 1));
155   return 1;
156 }
157 
158 
159 static int luaB_rawget (lua_State *L) {
160   luaL_checktype(L, 1, LUA_TTABLE);
161   luaL_checkany(L, 2);
162   lua_settop(L, 2);
163   lua_rawget(L, 1);
164   return 1;
165 }
166 
167 static int luaB_rawset (lua_State *L) {
168   luaL_checktype(L, 1, LUA_TTABLE);
169   luaL_checkany(L, 2);
170   luaL_checkany(L, 3);
171   lua_settop(L, 3);
172   lua_rawset(L, 1);
173   return 1;
174 }
175 
176 
177 static int luaB_collectgarbage (lua_State *L) {
178   static const char *const opts[] = {"stop", "restart", "collect",
179     "count", "step", "setpause", "setstepmul",
180     "isrunning", NULL};
181   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
182     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
183     LUA_GCISRUNNING};
184   int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
185   int ex = (int)luaL_optinteger(L, 2, 0);
186   int res = lua_gc(L, o, ex);
187   switch (o) {
188     case LUA_GCCOUNT: {
189       int b = lua_gc(L, LUA_GCCOUNTB, 0);
190       lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024));
191       return 1;
192     }
193     case LUA_GCSTEP: case LUA_GCISRUNNING: {
194       lua_pushboolean(L, res);
195       return 1;
196     }
197     default: {
198       lua_pushinteger(L, res);
199       return 1;
200     }
201   }
202 }
203 
204 
205 static int luaB_type (lua_State *L) {
206   int t = lua_type(L, 1);
207   luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
208   lua_pushstring(L, lua_typename(L, t));
209   return 1;
210 }
211 
212 
213 static int pairsmeta (lua_State *L, const char *method, int iszero,
214                       lua_CFunction iter) {
215   if (luaL_getmetafield(L, 1, method) == LUA_TNIL) {  /* no metamethod? */
216     luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
217     lua_pushcfunction(L, iter);  /* will return generator, */
218     lua_pushvalue(L, 1);  /* state, */
219     if (iszero) lua_pushinteger(L, 0);  /* and initial value */
220     else lua_pushnil(L);
221   }
222   else {
223     lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
224     lua_call(L, 1, 3);  /* get 3 values from metamethod */
225   }
226   return 3;
227 }
228 
229 
230 static int luaB_next (lua_State *L) {
231   luaL_checktype(L, 1, LUA_TTABLE);
232   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
233   if (lua_next(L, 1))
234     return 2;
235   else {
236     lua_pushnil(L);
237     return 1;
238   }
239 }
240 
241 
242 static int luaB_pairs (lua_State *L) {
243   return pairsmeta(L, "__pairs", 0, luaB_next);
244 }
245 
246 
247 /*
248 ** Traversal function for 'ipairs'
249 */
250 static int ipairsaux (lua_State *L) {
251   lua_Integer i = luaL_checkinteger(L, 2) + 1;
252   lua_pushinteger(L, i);
253   return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
254 }
255 
256 
257 /*
258 ** This function will use either 'ipairsaux' or 'ipairsaux_raw' to
259 ** traverse a table, depending on whether the table has metamethods
260 ** that can affect the traversal.
261 */
262 static int luaB_ipairs (lua_State *L) {
263 #if defined(LUA_COMPAT_IPAIRS)
264   return pairsmeta(L, "__ipairs", 1, ipairsaux);
265 #else
266   luaL_checkany(L, 1);
267   lua_pushcfunction(L, ipairsaux);  /* iteration function */
268   lua_pushvalue(L, 1);  /* state */
269   lua_pushinteger(L, 0);  /* initial value */
270   return 3;
271 #endif
272 }
273 
274 
275 static int load_aux (lua_State *L, int status, int envidx) {
276   if (status == LUA_OK) {
277     if (envidx != 0) {  /* 'env' parameter? */
278       lua_pushvalue(L, envidx);  /* environment for loaded function */
279       if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
280         lua_pop(L, 1);  /* remove 'env' if not used by previous call */
281     }
282     return 1;
283   }
284   else {  /* error (message is on top of the stack) */
285     lua_pushnil(L);
286     lua_insert(L, -2);  /* put before error message */
287     return 2;  /* return nil plus error message */
288   }
289 }
290 
291 
292 #ifndef _KERNEL
293 static int luaB_loadfile (lua_State *L) {
294   const char *fname = luaL_optstring(L, 1, NULL);
295   const char *mode = luaL_optstring(L, 2, NULL);
296   int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
297   int status = luaL_loadfilex(L, fname, mode);
298   return load_aux(L, status, env);
299 }
300 #endif /* _KERNEL */
301 
302 
303 /*
304 ** {======================================================
305 ** Generic Read function
306 ** =======================================================
307 */
308 
309 
310 /*
311 ** reserved slot, above all arguments, to hold a copy of the returned
312 ** string to avoid it being collected while parsed. 'load' has four
313 ** optional arguments (chunk, source name, mode, and environment).
314 */
315 #define RESERVEDSLOT	5
316 
317 
318 /*
319 ** Reader for generic 'load' function: 'lua_load' uses the
320 ** stack for internal stuff, so the reader cannot change the
321 ** stack top. Instead, it keeps its resulting string in a
322 ** reserved slot inside the stack.
323 */
324 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
325   (void)(ud);  /* not used */
326   luaL_checkstack(L, 2, "too many nested functions");
327   lua_pushvalue(L, 1);  /* get function */
328   lua_call(L, 0, 1);  /* call it */
329   if (lua_isnil(L, -1)) {
330     lua_pop(L, 1);  /* pop result */
331     *size = 0;
332     return NULL;
333   }
334   else if (!lua_isstring(L, -1))
335     luaL_error(L, "reader function must return a string");
336   lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
337   return lua_tolstring(L, RESERVEDSLOT, size);
338 }
339 
340 
341 static int luaB_load (lua_State *L) {
342   int status;
343   size_t l;
344   const char *s = lua_tolstring(L, 1, &l);
345   const char *mode = luaL_optstring(L, 3, "bt");
346   int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
347   if (s != NULL) {  /* loading a string? */
348     const char *chunkname = luaL_optstring(L, 2, s);
349     status = luaL_loadbufferx(L, s, l, chunkname, mode);
350   }
351   else {  /* loading from a reader function */
352     const char *chunkname = luaL_optstring(L, 2, "=(load)");
353     luaL_checktype(L, 1, LUA_TFUNCTION);
354     lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
355     status = lua_load(L, generic_reader, NULL, chunkname, mode);
356   }
357   return load_aux(L, status, env);
358 }
359 
360 /* }====================================================== */
361 
362 
363 #ifndef _KERNEL
364 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
365   (void)d1;  (void)d2;  /* only to match 'lua_Kfunction' prototype */
366   return lua_gettop(L) - 1;
367 }
368 
369 
370 static int luaB_dofile (lua_State *L) {
371   const char *fname = luaL_optstring(L, 1, NULL);
372   lua_settop(L, 1);
373   if (luaL_loadfile(L, fname) != LUA_OK)
374     return lua_error(L);
375   lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
376   return dofilecont(L, 0, 0);
377 }
378 #endif /* _KERNEL */
379 
380 
381 static int luaB_assert (lua_State *L) {
382   if (lua_toboolean(L, 1))  /* condition is true? */
383     return lua_gettop(L);  /* return all arguments */
384   else {  /* error */
385     luaL_checkany(L, 1);  /* there must be a condition */
386     lua_remove(L, 1);  /* remove it */
387     lua_pushliteral(L, "assertion failed!");  /* default message */
388     lua_settop(L, 1);  /* leave only message (default if no other one) */
389     return luaB_error(L);  /* call 'error' */
390   }
391 }
392 
393 
394 static int luaB_select (lua_State *L) {
395   int n = lua_gettop(L);
396   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
397     lua_pushinteger(L, n-1);
398     return 1;
399   }
400   else {
401     lua_Integer i = luaL_checkinteger(L, 1);
402     if (i < 0) i = n + i;
403     else if (i > n) i = n;
404     luaL_argcheck(L, 1 <= i, 1, "index out of range");
405     return n - (int)i;
406   }
407 }
408 
409 
410 /*
411 ** Continuation function for 'pcall' and 'xpcall'. Both functions
412 ** already pushed a 'true' before doing the call, so in case of success
413 ** 'finishpcall' only has to return everything in the stack minus
414 ** 'extra' values (where 'extra' is exactly the number of items to be
415 ** ignored).
416 */
417 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
418   if (status != LUA_OK && status != LUA_YIELD) {  /* error? */
419     lua_pushboolean(L, 0);  /* first result (false) */
420     lua_pushvalue(L, -2);  /* error message */
421     return 2;  /* return false, msg */
422   }
423   else
424     return lua_gettop(L) - (int)extra;  /* return all results */
425 }
426 
427 
428 static int luaB_pcall (lua_State *L) {
429   int status;
430   luaL_checkany(L, 1);
431   lua_pushboolean(L, 1);  /* first result if no errors */
432   lua_insert(L, 1);  /* put it in place */
433   status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
434   return finishpcall(L, status, 0);
435 }
436 
437 
438 /*
439 ** Do a protected call with error handling. After 'lua_rotate', the
440 ** stack will have <f, err, true, f, [args...]>; so, the function passes
441 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
442 */
443 static int luaB_xpcall (lua_State *L) {
444   int status;
445   int n = lua_gettop(L);
446   luaL_checktype(L, 2, LUA_TFUNCTION);  /* check error function */
447   lua_pushboolean(L, 1);  /* first result */
448   lua_pushvalue(L, 1);  /* function */
449   lua_rotate(L, 3, 2);  /* move them below function's arguments */
450   status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
451   return finishpcall(L, status, 2);
452 }
453 
454 
455 static int luaB_tostring (lua_State *L) {
456   luaL_checkany(L, 1);
457   luaL_tolstring(L, 1, NULL);
458   return 1;
459 }
460 
461 
462 static const luaL_Reg base_funcs[] = {
463   {"assert", luaB_assert},
464   {"collectgarbage", luaB_collectgarbage},
465 #ifndef _KERNEL
466   {"dofile", luaB_dofile},
467 #endif /* _KERNEL */
468   {"error", luaB_error},
469   {"getmetatable", luaB_getmetatable},
470   {"ipairs", luaB_ipairs},
471 #ifndef _KERNEL
472   {"loadfile", luaB_loadfile},
473 #endif /* _KERNEL */
474   {"load", luaB_load},
475 #if defined(LUA_COMPAT_LOADSTRING)
476   {"loadstring", luaB_load},
477 #endif
478   {"next", luaB_next},
479   {"pairs", luaB_pairs},
480   {"pcall", luaB_pcall},
481   {"print", luaB_print},
482   {"rawequal", luaB_rawequal},
483   {"rawlen", luaB_rawlen},
484   {"rawget", luaB_rawget},
485   {"rawset", luaB_rawset},
486   {"select", luaB_select},
487   {"setmetatable", luaB_setmetatable},
488   {"tonumber", luaB_tonumber},
489   {"tostring", luaB_tostring},
490   {"type", luaB_type},
491   {"xpcall", luaB_xpcall},
492   /* placeholders */
493   {"_G", NULL},
494   {"_VERSION", NULL},
495   {NULL, NULL}
496 };
497 
498 
499 LUAMOD_API int luaopen_base (lua_State *L) {
500   /* open lib into global table */
501   lua_pushglobaltable(L);
502   luaL_setfuncs(L, base_funcs, 0);
503   /* set global _G */
504   lua_pushvalue(L, -1);
505   lua_setfield(L, -2, "_G");
506   /* set global _VERSION */
507   lua_pushliteral(L, LUA_VERSION);
508   lua_setfield(L, -2, "_VERSION");
509   return 1;
510 }
511 
512