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      1 /*
      2 ** $Id: lbaselib.c,v 1.276 2013/02/21 13:44:53 roberto Exp $
      3 ** Basic library
      4 ** See Copyright Notice in lua.h
      5 */
      6 
      7 
      8 
      9 #include <ctype.h>
     10 #include <stdio.h>
     11 #include <stdlib.h>
     12 #include <string.h>
     13 
     14 #define lbaselib_c
     15 #define LUA_LIB
     16 
     17 #include "lua.h"
     18 
     19 #include "lauxlib.h"
     20 #include "lualib.h"
     21 
     22 
     23 static int luaB_print (lua_State *L) {
     24   int n = lua_gettop(L);  /* number of arguments */
     25   int i;
     26   lua_getglobal(L, "tostring");
     27   for (i=1; i<=n; i++) {
     28     const char *s;
     29     size_t l;
     30     lua_pushvalue(L, -1);  /* function to be called */
     31     lua_pushvalue(L, i);   /* value to print */
     32     lua_call(L, 1, 1);
     33     s = lua_tolstring(L, -1, &l);  /* get result */
     34     if (s == NULL)
     35       return luaL_error(L,
     36          LUA_QL("tostring") " must return a string to " LUA_QL("print"));
     37     if (i>1) luai_writestring("\t", 1);
     38     luai_writestring(s, l);
     39     lua_pop(L, 1);  /* pop result */
     40   }
     41   luai_writeline();
     42   return 0;
     43 }
     44 
     45 
     46 #define SPACECHARS	" \f\n\r\t\v"
     47 
     48 static int luaB_tonumber (lua_State *L) {
     49   if (lua_isnoneornil(L, 2)) {  /* standard conversion */
     50     int isnum;
     51     lua_Number n = lua_tonumberx(L, 1, &isnum);
     52     if (isnum) {
     53       lua_pushnumber(L, n);
     54       return 1;
     55     }  /* else not a number; must be something */
     56     luaL_checkany(L, 1);
     57   }
     58   else {
     59     size_t l;
     60     const char *s = luaL_checklstring(L, 1, &l);
     61     const char *e = s + l;  /* end point for 's' */
     62     int base = luaL_checkint(L, 2);
     63     int neg = 0;
     64     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
     65     s += strspn(s, SPACECHARS);  /* skip initial spaces */
     66     if (*s == '-') { s++; neg = 1; }  /* handle signal */
     67     else if (*s == '+') s++;
     68     if (isalnum((unsigned char)*s)) {
     69       lua_Number n = 0;
     70       do {
     71         int digit = (isdigit((unsigned char)*s)) ? *s - '0'
     72                        : toupper((unsigned char)*s) - 'A' + 10;
     73         if (digit >= base) break;  /* invalid numeral; force a fail */
     74         n = n * (lua_Number)base + (lua_Number)digit;
     75         s++;
     76       } while (isalnum((unsigned char)*s));
     77       s += strspn(s, SPACECHARS);  /* skip trailing spaces */
     78       if (s == e) {  /* no invalid trailing characters? */
     79         lua_pushnumber(L, (neg) ? -n : n);
     80         return 1;
     81       }  /* else not a number */
     82     }  /* else not a number */
     83   }
     84   lua_pushnil(L);  /* not a number */
     85   return 1;
     86 }
     87 
     88 
     89 static int luaB_error (lua_State *L) {
     90   int level = luaL_optint(L, 2, 1);
     91   lua_settop(L, 1);
     92   if (lua_isstring(L, 1) && level > 0) {  /* add extra information? */
     93     luaL_where(L, level);
     94     lua_pushvalue(L, 1);
     95     lua_concat(L, 2);
     96   }
     97   return lua_error(L);
     98 }
     99 
    100 
    101 static int luaB_getmetatable (lua_State *L) {
    102   luaL_checkany(L, 1);
    103   if (!lua_getmetatable(L, 1)) {
    104     lua_pushnil(L);
    105     return 1;  /* no metatable */
    106   }
    107   luaL_getmetafield(L, 1, "__metatable");
    108   return 1;  /* returns either __metatable field (if present) or metatable */
    109 }
    110 
    111 
    112 static int luaB_setmetatable (lua_State *L) {
    113   int t = lua_type(L, 2);
    114   luaL_checktype(L, 1, LUA_TTABLE);
    115   luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2,
    116                     "nil or table expected");
    117   if (luaL_getmetafield(L, 1, "__metatable"))
    118     return luaL_error(L, "cannot change a protected metatable");
    119   lua_settop(L, 2);
    120   lua_setmetatable(L, 1);
    121   return 1;
    122 }
    123 
    124 
    125 static int luaB_rawequal (lua_State *L) {
    126   luaL_checkany(L, 1);
    127   luaL_checkany(L, 2);
    128   lua_pushboolean(L, lua_rawequal(L, 1, 2));
    129   return 1;
    130 }
    131 
    132 
    133 static int luaB_rawlen (lua_State *L) {
    134   int t = lua_type(L, 1);
    135   luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
    136                    "table or string expected");
    137   lua_pushinteger(L, lua_rawlen(L, 1));
    138   return 1;
    139 }
    140 
    141 
    142 static int luaB_rawget (lua_State *L) {
    143   luaL_checktype(L, 1, LUA_TTABLE);
    144   luaL_checkany(L, 2);
    145   lua_settop(L, 2);
    146   lua_rawget(L, 1);
    147   return 1;
    148 }
    149 
    150 static int luaB_rawset (lua_State *L) {
    151   luaL_checktype(L, 1, LUA_TTABLE);
    152   luaL_checkany(L, 2);
    153   luaL_checkany(L, 3);
    154   lua_settop(L, 3);
    155   lua_rawset(L, 1);
    156   return 1;
    157 }
    158 
    159 
    160 static int luaB_collectgarbage (lua_State *L) {
    161   static const char *const opts[] = {"stop", "restart", "collect",
    162     "count", "step", "setpause", "setstepmul",
    163     "setmajorinc", "isrunning", "generational", "incremental", NULL};
    164   static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
    165     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL,
    166     LUA_GCSETMAJORINC, LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC};
    167   int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
    168   int ex = luaL_optint(L, 2, 0);
    169   int res = lua_gc(L, o, ex);
    170   switch (o) {
    171     case LUA_GCCOUNT: {
    172       int b = lua_gc(L, LUA_GCCOUNTB, 0);
    173       lua_pushnumber(L, res + ((lua_Number)b/1024));
    174       lua_pushinteger(L, b);
    175       return 2;
    176     }
    177     case LUA_GCSTEP: case LUA_GCISRUNNING: {
    178       lua_pushboolean(L, res);
    179       return 1;
    180     }
    181     default: {
    182       lua_pushinteger(L, res);
    183       return 1;
    184     }
    185   }
    186 }
    187 
    188 
    189 static int luaB_type (lua_State *L) {
    190   luaL_checkany(L, 1);
    191   lua_pushstring(L, luaL_typename(L, 1));
    192   return 1;
    193 }
    194 
    195 
    196 static int pairsmeta (lua_State *L, const char *method, int iszero,
    197                       lua_CFunction iter) {
    198   if (!luaL_getmetafield(L, 1, method)) {  /* no metamethod? */
    199     luaL_checktype(L, 1, LUA_TTABLE);  /* argument must be a table */
    200     lua_pushcfunction(L, iter);  /* will return generator, */
    201     lua_pushvalue(L, 1);  /* state, */
    202     if (iszero) lua_pushinteger(L, 0);  /* and initial value */
    203     else lua_pushnil(L);
    204   }
    205   else {
    206     lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
    207     lua_call(L, 1, 3);  /* get 3 values from metamethod */
    208   }
    209   return 3;
    210 }
    211 
    212 
    213 static int luaB_next (lua_State *L) {
    214   luaL_checktype(L, 1, LUA_TTABLE);
    215   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
    216   if (lua_next(L, 1))
    217     return 2;
    218   else {
    219     lua_pushnil(L);
    220     return 1;
    221   }
    222 }
    223 
    224 
    225 static int luaB_pairs (lua_State *L) {
    226   return pairsmeta(L, "__pairs", 0, luaB_next);
    227 }
    228 
    229 
    230 static int ipairsaux (lua_State *L) {
    231   int i = luaL_checkint(L, 2);
    232   luaL_checktype(L, 1, LUA_TTABLE);
    233   i++;  /* next value */
    234   lua_pushinteger(L, i);
    235   lua_rawgeti(L, 1, i);
    236   return (lua_isnil(L, -1)) ? 1 : 2;
    237 }
    238 
    239 
    240 static int luaB_ipairs (lua_State *L) {
    241   return pairsmeta(L, "__ipairs", 1, ipairsaux);
    242 }
    243 
    244 
    245 static int load_aux (lua_State *L, int status, int envidx) {
    246   if (status == LUA_OK) {
    247     if (envidx != 0) {  /* 'env' parameter? */
    248       lua_pushvalue(L, envidx);  /* environment for loaded function */
    249       if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
    250         lua_pop(L, 1);  /* remove 'env' if not used by previous call */
    251     }
    252     return 1;
    253   }
    254   else {  /* error (message is on top of the stack) */
    255     lua_pushnil(L);
    256     lua_insert(L, -2);  /* put before error message */
    257     return 2;  /* return nil plus error message */
    258   }
    259 }
    260 
    261 
    262 static int luaB_loadfile (lua_State *L) {
    263   const char *fname = luaL_optstring(L, 1, NULL);
    264   const char *mode = luaL_optstring(L, 2, NULL);
    265   int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
    266   int status = luaL_loadfilex(L, fname, mode);
    267   return load_aux(L, status, env);
    268 }
    269 
    270 
    271 /*
    272 ** {======================================================
    273 ** Generic Read function
    274 ** =======================================================
    275 */
    276 
    277 
    278 /*
    279 ** reserved slot, above all arguments, to hold a copy of the returned
    280 ** string to avoid it being collected while parsed. 'load' has four
    281 ** optional arguments (chunk, source name, mode, and environment).
    282 */
    283 #define RESERVEDSLOT	5
    284 
    285 
    286 /*
    287 ** Reader for generic `load' function: `lua_load' uses the
    288 ** stack for internal stuff, so the reader cannot change the
    289 ** stack top. Instead, it keeps its resulting string in a
    290 ** reserved slot inside the stack.
    291 */
    292 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
    293   (void)(ud);  /* not used */
    294   luaL_checkstack(L, 2, "too many nested functions");
    295   lua_pushvalue(L, 1);  /* get function */
    296   lua_call(L, 0, 1);  /* call it */
    297   if (lua_isnil(L, -1)) {
    298     lua_pop(L, 1);  /* pop result */
    299     *size = 0;
    300     return NULL;
    301   }
    302   else if (!lua_isstring(L, -1))
    303     luaL_error(L, "reader function must return a string");
    304   lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
    305   return lua_tolstring(L, RESERVEDSLOT, size);
    306 }
    307 
    308 
    309 static int luaB_load (lua_State *L) {
    310   int status;
    311   size_t l;
    312   const char *s = lua_tolstring(L, 1, &l);
    313   const char *mode = luaL_optstring(L, 3, "bt");
    314   int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
    315   if (s != NULL) {  /* loading a string? */
    316     const char *chunkname = luaL_optstring(L, 2, s);
    317     status = luaL_loadbufferx(L, s, l, chunkname, mode);
    318   }
    319   else {  /* loading from a reader function */
    320     const char *chunkname = luaL_optstring(L, 2, "=(load)");
    321     luaL_checktype(L, 1, LUA_TFUNCTION);
    322     lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
    323     status = lua_load(L, generic_reader, NULL, chunkname, mode);
    324   }
    325   return load_aux(L, status, env);
    326 }
    327 
    328 /* }====================================================== */
    329 
    330 
    331 static int dofilecont (lua_State *L) {
    332   return lua_gettop(L) - 1;
    333 }
    334 
    335 
    336 static int luaB_dofile (lua_State *L) {
    337   const char *fname = luaL_optstring(L, 1, NULL);
    338   lua_settop(L, 1);
    339   if (luaL_loadfile(L, fname) != LUA_OK)
    340     return lua_error(L);
    341   lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
    342   return dofilecont(L);
    343 }
    344 
    345 
    346 static int luaB_assert (lua_State *L) {
    347   if (!lua_toboolean(L, 1))
    348     return luaL_error(L, "%s", luaL_optstring(L, 2, "assertion failed!"));
    349   return lua_gettop(L);
    350 }
    351 
    352 
    353 static int luaB_select (lua_State *L) {
    354   int n = lua_gettop(L);
    355   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
    356     lua_pushinteger(L, n-1);
    357     return 1;
    358   }
    359   else {
    360     int i = luaL_checkint(L, 1);
    361     if (i < 0) i = n + i;
    362     else if (i > n) i = n;
    363     luaL_argcheck(L, 1 <= i, 1, "index out of range");
    364     return n - i;
    365   }
    366 }
    367 
    368 
    369 static int finishpcall (lua_State *L, int status) {
    370   if (!lua_checkstack(L, 1)) {  /* no space for extra boolean? */
    371     lua_settop(L, 0);  /* create space for return values */
    372     lua_pushboolean(L, 0);
    373     lua_pushstring(L, "stack overflow");
    374     return 2;  /* return false, msg */
    375   }
    376   lua_pushboolean(L, status);  /* first result (status) */
    377   lua_replace(L, 1);  /* put first result in first slot */
    378   return lua_gettop(L);
    379 }
    380 
    381 
    382 static int pcallcont (lua_State *L) {
    383   int status = lua_getctx(L, NULL);
    384   return finishpcall(L, (status == LUA_YIELD));
    385 }
    386 
    387 
    388 static int luaB_pcall (lua_State *L) {
    389   int status;
    390   luaL_checkany(L, 1);
    391   lua_pushnil(L);
    392   lua_insert(L, 1);  /* create space for status result */
    393   status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, pcallcont);
    394   return finishpcall(L, (status == LUA_OK));
    395 }
    396 
    397 
    398 static int luaB_xpcall (lua_State *L) {
    399   int status;
    400   int n = lua_gettop(L);
    401   luaL_argcheck(L, n >= 2, 2, "value expected");
    402   lua_pushvalue(L, 1);  /* exchange function... */
    403   lua_copy(L, 2, 1);  /* ...and error handler */
    404   lua_replace(L, 2);
    405   status = lua_pcallk(L, n - 2, LUA_MULTRET, 1, 0, pcallcont);
    406   return finishpcall(L, (status == LUA_OK));
    407 }
    408 
    409 
    410 static int luaB_tostring (lua_State *L) {
    411   luaL_checkany(L, 1);
    412   luaL_tolstring(L, 1, NULL);
    413   return 1;
    414 }
    415 
    416 
    417 static const luaL_Reg base_funcs[] = {
    418   {"assert", luaB_assert},
    419   {"collectgarbage", luaB_collectgarbage},
    420   {"dofile", luaB_dofile},
    421   {"error", luaB_error},
    422   {"getmetatable", luaB_getmetatable},
    423   {"ipairs", luaB_ipairs},
    424   {"loadfile", luaB_loadfile},
    425   {"load", luaB_load},
    426 #if defined(LUA_COMPAT_LOADSTRING)
    427   {"loadstring", luaB_load},
    428 #endif
    429   {"next", luaB_next},
    430   {"pairs", luaB_pairs},
    431   {"pcall", luaB_pcall},
    432   {"print", luaB_print},
    433   {"rawequal", luaB_rawequal},
    434   {"rawlen", luaB_rawlen},
    435   {"rawget", luaB_rawget},
    436   {"rawset", luaB_rawset},
    437   {"select", luaB_select},
    438   {"setmetatable", luaB_setmetatable},
    439   {"tonumber", luaB_tonumber},
    440   {"tostring", luaB_tostring},
    441   {"type", luaB_type},
    442   {"xpcall", luaB_xpcall},
    443   {NULL, NULL}
    444 };
    445 
    446 
    447 LUAMOD_API int luaopen_base (lua_State *L) {
    448   /* set global _G */
    449   lua_pushglobaltable(L);
    450   lua_pushglobaltable(L);
    451   lua_setfield(L, -2, "_G");
    452   /* open lib into global table */
    453   luaL_setfuncs(L, base_funcs, 0);
    454   lua_pushliteral(L, LUA_VERSION);
    455   lua_setfield(L, -2, "_VERSION");  /* set global _VERSION */
    456   return 1;
    457 }
    458 
    459