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lbaselib.c (15731B)


      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 #include "llimits.h"
     23 
     24 
     25 static int luaB_print (lua_State *L) {
     26   int n = lua_gettop(L);  /* number of arguments */
     27   int i;
     28   for (i = 1; i <= n; i++) {  /* for each argument */
     29     size_t l;
     30     const char *s = luaL_tolstring(L, i, &l);  /* convert it to string */
     31     if (i > 1)  /* not the first element? */
     32       lua_writestring("\t", 1);  /* add a tab before it */
     33     lua_writestring(s, l);  /* print it */
     34     lua_pop(L, 1);  /* pop result */
     35   }
     36   lua_writeline();
     37   return 0;
     38 }
     39 
     40 
     41 /*
     42 ** Creates a warning with all given arguments.
     43 ** Check first for errors; otherwise an error may interrupt
     44 ** the composition of a warning, leaving it unfinished.
     45 */
     46 static int luaB_warn (lua_State *L) {
     47   int n = lua_gettop(L);  /* number of arguments */
     48   int i;
     49   luaL_checkstring(L, 1);  /* at least one argument */
     50   for (i = 2; i <= n; i++)
     51     luaL_checkstring(L, i);  /* make sure all arguments are strings */
     52   for (i = 1; i < n; i++)  /* compose warning */
     53     lua_warning(L, lua_tostring(L, i), 1);
     54   lua_warning(L, lua_tostring(L, n), 0);  /* close warning */
     55   return 0;
     56 }
     57 
     58 
     59 #define SPACECHARS	" \f\n\r\t\v"
     60 
     61 static const char *b_str2int (const char *s, unsigned base, lua_Integer *pn) {
     62   lua_Unsigned n = 0;
     63   int neg = 0;
     64   s += strspn(s, SPACECHARS);  /* skip initial spaces */
     65   if (*s == '-') { s++; neg = 1; }  /* handle sign */
     66   else if (*s == '+') s++;
     67   if (!isalnum(cast_uchar(*s)))  /* no digit? */
     68     return NULL;
     69   do {
     70     unsigned digit = cast_uint(isdigit(cast_uchar(*s))
     71                                ? *s - '0'
     72                                : (toupper(cast_uchar(*s)) - 'A') + 10);
     73     if (digit >= base) return NULL;  /* invalid numeral */
     74     n = n * base + digit;
     75     s++;
     76   } while (isalnum(cast_uchar(*s)));
     77   s += strspn(s, SPACECHARS);  /* skip trailing spaces */
     78   *pn = (lua_Integer)((neg) ? (0u - n) : n);
     79   return s;
     80 }
     81 
     82 
     83 static int luaB_tonumber (lua_State *L) {
     84   if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
     85     if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
     86       lua_settop(L, 1);  /* yes; return it */
     87       return 1;
     88     }
     89     else {
     90       size_t l;
     91       const char *s = lua_tolstring(L, 1, &l);
     92       if (s != NULL && lua_stringtonumber(L, s) == l + 1)
     93         return 1;  /* successful conversion to number */
     94       /* else not a number */
     95       luaL_checkany(L, 1);  /* (but there must be some parameter) */
     96     }
     97   }
     98   else {
     99     size_t l;
    100     const char *s;
    101     lua_Integer n = 0;  /* to avoid warnings */
    102     lua_Integer base = luaL_checkinteger(L, 2);
    103     luaL_checktype(L, 1, LUA_TSTRING);  /* no numbers as strings */
    104     s = lua_tolstring(L, 1, &l);
    105     luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range");
    106     if (b_str2int(s, cast_uint(base), &n) == s + l) {
    107       lua_pushinteger(L, n);
    108       return 1;
    109     }  /* else not a number */
    110   }  /* else not a number */
    111   luaL_pushfail(L);  /* not a number */
    112   return 1;
    113 }
    114 
    115 
    116 static int luaB_error (lua_State *L) {
    117   int level = (int)luaL_optinteger(L, 2, 1);
    118   lua_settop(L, 1);
    119   if (lua_type(L, 1) == LUA_TSTRING && level > 0) {
    120     luaL_where(L, level);   /* add extra information */
    121     lua_pushvalue(L, 1);
    122     lua_concat(L, 2);
    123   }
    124   return lua_error(L);
    125 }
    126 
    127 
    128 static int luaB_getmetatable (lua_State *L) {
    129   luaL_checkany(L, 1);
    130   if (!lua_getmetatable(L, 1)) {
    131     lua_pushnil(L);
    132     return 1;  /* no metatable */
    133   }
    134   luaL_getmetafield(L, 1, "__metatable");
    135   return 1;  /* returns either __metatable field (if present) or metatable */
    136 }
    137 
    138 
    139 static int luaB_setmetatable (lua_State *L) {
    140   int t = lua_type(L, 2);
    141   luaL_checktype(L, 1, LUA_TTABLE);
    142   luaL_argexpected(L, t == LUA_TNIL || t == LUA_TTABLE, 2, "nil or table");
    143   if (l_unlikely(luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL))
    144     return luaL_error(L, "cannot change a protected metatable");
    145   lua_settop(L, 2);
    146   lua_setmetatable(L, 1);
    147   return 1;
    148 }
    149 
    150 
    151 static int luaB_rawequal (lua_State *L) {
    152   luaL_checkany(L, 1);
    153   luaL_checkany(L, 2);
    154   lua_pushboolean(L, lua_rawequal(L, 1, 2));
    155   return 1;
    156 }
    157 
    158 
    159 static int luaB_rawlen (lua_State *L) {
    160   int t = lua_type(L, 1);
    161   luaL_argexpected(L, t == LUA_TTABLE || t == LUA_TSTRING, 1,
    162                       "table or string");
    163   lua_pushinteger(L, l_castU2S(lua_rawlen(L, 1)));
    164   return 1;
    165 }
    166 
    167 
    168 static int luaB_rawget (lua_State *L) {
    169   luaL_checktype(L, 1, LUA_TTABLE);
    170   luaL_checkany(L, 2);
    171   lua_settop(L, 2);
    172   lua_rawget(L, 1);
    173   return 1;
    174 }
    175 
    176 static int luaB_rawset (lua_State *L) {
    177   luaL_checktype(L, 1, LUA_TTABLE);
    178   luaL_checkany(L, 2);
    179   luaL_checkany(L, 3);
    180   lua_settop(L, 3);
    181   lua_rawset(L, 1);
    182   return 1;
    183 }
    184 
    185 
    186 static int pushmode (lua_State *L, int oldmode) {
    187   if (oldmode == -1)
    188     luaL_pushfail(L);  /* invalid call to 'lua_gc' */
    189   else
    190     lua_pushstring(L, (oldmode == LUA_GCINC) ? "incremental"
    191                                              : "generational");
    192   return 1;
    193 }
    194 
    195 
    196 /*
    197 ** check whether call to 'lua_gc' was valid (not inside a finalizer)
    198 */
    199 #define checkvalres(res) { if (res == -1) break; }
    200 
    201 static int luaB_collectgarbage (lua_State *L) {
    202   static const char *const opts[] = {"stop", "restart", "collect",
    203     "count", "step", "isrunning", "generational", "incremental",
    204     "param", NULL};
    205   static const char optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT,
    206     LUA_GCCOUNT, LUA_GCSTEP, LUA_GCISRUNNING, LUA_GCGEN, LUA_GCINC,
    207     LUA_GCPARAM};
    208   int o = optsnum[luaL_checkoption(L, 1, "collect", opts)];
    209   switch (o) {
    210     case LUA_GCCOUNT: {
    211       int k = lua_gc(L, o);
    212       int b = lua_gc(L, LUA_GCCOUNTB);
    213       checkvalres(k);
    214       lua_pushnumber(L, (lua_Number)k + ((lua_Number)b/1024));
    215       return 1;
    216     }
    217     case LUA_GCSTEP: {
    218       lua_Integer n = luaL_optinteger(L, 2, 0);
    219       int res = lua_gc(L, o, cast_sizet(n));
    220       checkvalres(res);
    221       lua_pushboolean(L, res);
    222       return 1;
    223     }
    224     case LUA_GCISRUNNING: {
    225       int res = lua_gc(L, o);
    226       checkvalres(res);
    227       lua_pushboolean(L, res);
    228       return 1;
    229     }
    230     case LUA_GCGEN: {
    231       return pushmode(L, lua_gc(L, o));
    232     }
    233     case LUA_GCINC: {
    234       return pushmode(L, lua_gc(L, o));
    235     }
    236     case LUA_GCPARAM: {
    237       static const char *const params[] = {
    238         "minormul", "majorminor", "minormajor",
    239         "pause", "stepmul", "stepsize", NULL};
    240       static const char pnum[] = {
    241         LUA_GCPMINORMUL, LUA_GCPMAJORMINOR, LUA_GCPMINORMAJOR,
    242         LUA_GCPPAUSE, LUA_GCPSTEPMUL, LUA_GCPSTEPSIZE};
    243       int p = pnum[luaL_checkoption(L, 2, NULL, params)];
    244       lua_Integer value = luaL_optinteger(L, 3, -1);
    245       lua_pushinteger(L, lua_gc(L, o, p, (int)value));
    246       return 1;
    247     }
    248     default: {
    249       int res = lua_gc(L, o);
    250       checkvalres(res);
    251       lua_pushinteger(L, res);
    252       return 1;
    253     }
    254   }
    255   luaL_pushfail(L);  /* invalid call (inside a finalizer) */
    256   return 1;
    257 }
    258 
    259 
    260 static int luaB_type (lua_State *L) {
    261   int t = lua_type(L, 1);
    262   luaL_argcheck(L, t != LUA_TNONE, 1, "value expected");
    263   lua_pushstring(L, lua_typename(L, t));
    264   return 1;
    265 }
    266 
    267 
    268 static int luaB_next (lua_State *L) {
    269   luaL_checktype(L, 1, LUA_TTABLE);
    270   lua_settop(L, 2);  /* create a 2nd argument if there isn't one */
    271   if (lua_next(L, 1))
    272     return 2;
    273   else {
    274     lua_pushnil(L);
    275     return 1;
    276   }
    277 }
    278 
    279 
    280 static int pairscont (lua_State *L, int status, lua_KContext k) {
    281   (void)L; (void)status; (void)k;  /* unused */
    282   return 3;
    283 }
    284 
    285 static int luaB_pairs (lua_State *L) {
    286   luaL_checkany(L, 1);
    287   if (luaL_getmetafield(L, 1, "__pairs") == LUA_TNIL) {  /* no metamethod? */
    288     lua_pushcfunction(L, luaB_next);  /* will return generator, */
    289     lua_pushvalue(L, 1);  /* state, */
    290     lua_pushnil(L);  /* and initial value */
    291   }
    292   else {
    293     lua_pushvalue(L, 1);  /* argument 'self' to metamethod */
    294     lua_callk(L, 1, 3, 0, pairscont);  /* get 3 values from metamethod */
    295   }
    296   return 3;
    297 }
    298 
    299 
    300 /*
    301 ** Traversal function for 'ipairs'
    302 */
    303 static int ipairsaux (lua_State *L) {
    304   lua_Integer i = luaL_checkinteger(L, 2);
    305   i = luaL_intop(+, i, 1);
    306   lua_pushinteger(L, i);
    307   return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2;
    308 }
    309 
    310 
    311 /*
    312 ** 'ipairs' function. Returns 'ipairsaux', given "table", 0.
    313 ** (The given "table" may not be a table.)
    314 */
    315 static int luaB_ipairs (lua_State *L) {
    316   luaL_checkany(L, 1);
    317   lua_pushcfunction(L, ipairsaux);  /* iteration function */
    318   lua_pushvalue(L, 1);  /* state */
    319   lua_pushinteger(L, 0);  /* initial value */
    320   return 3;
    321 }
    322 
    323 
    324 static int load_aux (lua_State *L, int status, int envidx) {
    325   if (l_likely(status == LUA_OK)) {
    326     if (envidx != 0) {  /* 'env' parameter? */
    327       lua_pushvalue(L, envidx);  /* environment for loaded function */
    328       if (!lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
    329         lua_pop(L, 1);  /* remove 'env' if not used by previous call */
    330     }
    331     return 1;
    332   }
    333   else {  /* error (message is on top of the stack) */
    334     luaL_pushfail(L);
    335     lua_insert(L, -2);  /* put before error message */
    336     return 2;  /* return fail plus error message */
    337   }
    338 }
    339 
    340 
    341 static const char *getMode (lua_State *L, int idx) {
    342   const char *mode = luaL_optstring(L, idx, "bt");
    343   if (strchr(mode, 'B') != NULL)  /* Lua code cannot use fixed buffers */
    344     luaL_argerror(L, idx, "invalid mode");
    345   return mode;
    346 }
    347 
    348 
    349 static int luaB_loadfile (lua_State *L) {
    350   const char *fname = luaL_optstring(L, 1, NULL);
    351   const char *mode = getMode(L, 2);
    352   int env = (!lua_isnone(L, 3) ? 3 : 0);  /* 'env' index or 0 if no 'env' */
    353   int status = luaL_loadfilex(L, fname, mode);
    354   return load_aux(L, status, env);
    355 }
    356 
    357 
    358 /*
    359 ** {======================================================
    360 ** Generic Read function
    361 ** =======================================================
    362 */
    363 
    364 
    365 /*
    366 ** reserved slot, above all arguments, to hold a copy of the returned
    367 ** string to avoid it being collected while parsed. 'load' has four
    368 ** optional arguments (chunk, source name, mode, and environment).
    369 */
    370 #define RESERVEDSLOT	5
    371 
    372 
    373 /*
    374 ** Reader for generic 'load' function: 'lua_load' uses the
    375 ** stack for internal stuff, so the reader cannot change the
    376 ** stack top. Instead, it keeps its resulting string in a
    377 ** reserved slot inside the stack.
    378 */
    379 static const char *generic_reader (lua_State *L, void *ud, size_t *size) {
    380   (void)(ud);  /* not used */
    381   luaL_checkstack(L, 2, "too many nested functions");
    382   lua_pushvalue(L, 1);  /* get function */
    383   lua_call(L, 0, 1);  /* call it */
    384   if (lua_isnil(L, -1)) {
    385     lua_pop(L, 1);  /* pop result */
    386     *size = 0;
    387     return NULL;
    388   }
    389   else if (l_unlikely(!lua_isstring(L, -1)))
    390     luaL_error(L, "reader function must return a string");
    391   lua_replace(L, RESERVEDSLOT);  /* save string in reserved slot */
    392   return lua_tolstring(L, RESERVEDSLOT, size);
    393 }
    394 
    395 
    396 static int luaB_load (lua_State *L) {
    397   int status;
    398   size_t l;
    399   const char *s = lua_tolstring(L, 1, &l);
    400   const char *mode = getMode(L, 3);
    401   int env = (!lua_isnone(L, 4) ? 4 : 0);  /* 'env' index or 0 if no 'env' */
    402   if (s != NULL) {  /* loading a string? */
    403     const char *chunkname = luaL_optstring(L, 2, s);
    404     status = luaL_loadbufferx(L, s, l, chunkname, mode);
    405   }
    406   else {  /* loading from a reader function */
    407     const char *chunkname = luaL_optstring(L, 2, "=(load)");
    408     luaL_checktype(L, 1, LUA_TFUNCTION);
    409     lua_settop(L, RESERVEDSLOT);  /* create reserved slot */
    410     status = lua_load(L, generic_reader, NULL, chunkname, mode);
    411   }
    412   return load_aux(L, status, env);
    413 }
    414 
    415 /* }====================================================== */
    416 
    417 
    418 static int dofilecont (lua_State *L, int d1, lua_KContext d2) {
    419   (void)d1;  (void)d2;  /* only to match 'lua_Kfunction' prototype */
    420   return lua_gettop(L) - 1;
    421 }
    422 
    423 
    424 static int luaB_dofile (lua_State *L) {
    425   const char *fname = luaL_optstring(L, 1, NULL);
    426   lua_settop(L, 1);
    427   if (l_unlikely(luaL_loadfile(L, fname) != LUA_OK))
    428     return lua_error(L);
    429   lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
    430   return dofilecont(L, 0, 0);
    431 }
    432 
    433 
    434 static int luaB_assert (lua_State *L) {
    435   if (l_likely(lua_toboolean(L, 1)))  /* condition is true? */
    436     return lua_gettop(L);  /* return all arguments */
    437   else {  /* error */
    438     luaL_checkany(L, 1);  /* there must be a condition */
    439     lua_remove(L, 1);  /* remove it */
    440     lua_pushliteral(L, "assertion failed!");  /* default message */
    441     lua_settop(L, 1);  /* leave only message (default if no other one) */
    442     return luaB_error(L);  /* call 'error' */
    443   }
    444 }
    445 
    446 
    447 static int luaB_select (lua_State *L) {
    448   int n = lua_gettop(L);
    449   if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') {
    450     lua_pushinteger(L, n-1);
    451     return 1;
    452   }
    453   else {
    454     lua_Integer i = luaL_checkinteger(L, 1);
    455     if (i < 0) i = n + i;
    456     else if (i > n) i = n;
    457     luaL_argcheck(L, 1 <= i, 1, "index out of range");
    458     return n - (int)i;
    459   }
    460 }
    461 
    462 
    463 /*
    464 ** Continuation function for 'pcall' and 'xpcall'. Both functions
    465 ** already pushed a 'true' before doing the call, so in case of success
    466 ** 'finishpcall' only has to return everything in the stack minus
    467 ** 'extra' values (where 'extra' is exactly the number of items to be
    468 ** ignored).
    469 */
    470 static int finishpcall (lua_State *L, int status, lua_KContext extra) {
    471   if (l_unlikely(status != LUA_OK && status != LUA_YIELD)) {  /* error? */
    472     lua_pushboolean(L, 0);  /* first result (false) */
    473     lua_pushvalue(L, -2);  /* error message */
    474     return 2;  /* return false, msg */
    475   }
    476   else
    477     return lua_gettop(L) - (int)extra;  /* return all results */
    478 }
    479 
    480 
    481 static int luaB_pcall (lua_State *L) {
    482   int status;
    483   luaL_checkany(L, 1);
    484   lua_pushboolean(L, 1);  /* first result if no errors */
    485   lua_insert(L, 1);  /* put it in place */
    486   status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall);
    487   return finishpcall(L, status, 0);
    488 }
    489 
    490 
    491 /*
    492 ** Do a protected call with error handling. After 'lua_rotate', the
    493 ** stack will have <f, err, true, f, [args...]>; so, the function passes
    494 ** 2 to 'finishpcall' to skip the 2 first values when returning results.
    495 */
    496 static int luaB_xpcall (lua_State *L) {
    497   int status;
    498   int n = lua_gettop(L);
    499   luaL_checktype(L, 2, LUA_TFUNCTION);  /* check error function */
    500   lua_pushboolean(L, 1);  /* first result */
    501   lua_pushvalue(L, 1);  /* function */
    502   lua_rotate(L, 3, 2);  /* move them below function's arguments */
    503   status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall);
    504   return finishpcall(L, status, 2);
    505 }
    506 
    507 
    508 static int luaB_tostring (lua_State *L) {
    509   luaL_checkany(L, 1);
    510   luaL_tolstring(L, 1, NULL);
    511   return 1;
    512 }
    513 
    514 
    515 static const luaL_Reg base_funcs[] = {
    516   {"assert", luaB_assert},
    517   {"collectgarbage", luaB_collectgarbage},
    518   {"dofile", luaB_dofile},
    519   {"error", luaB_error},
    520   {"getmetatable", luaB_getmetatable},
    521   {"ipairs", luaB_ipairs},
    522   {"loadfile", luaB_loadfile},
    523   {"load", luaB_load},
    524   {"next", luaB_next},
    525   {"pairs", luaB_pairs},
    526   {"pcall", luaB_pcall},
    527   {"print", luaB_print},
    528   {"warn", luaB_warn},
    529   {"rawequal", luaB_rawequal},
    530   {"rawlen", luaB_rawlen},
    531   {"rawget", luaB_rawget},
    532   {"rawset", luaB_rawset},
    533   {"select", luaB_select},
    534   {"setmetatable", luaB_setmetatable},
    535   {"tonumber", luaB_tonumber},
    536   {"tostring", luaB_tostring},
    537   {"type", luaB_type},
    538   {"xpcall", luaB_xpcall},
    539   /* placeholders */
    540   {LUA_GNAME, NULL},
    541   {"_VERSION", NULL},
    542   {NULL, NULL}
    543 };
    544 
    545 
    546 LUAMOD_API int luaopen_base (lua_State *L) {
    547   /* open lib into global table */
    548   lua_pushglobaltable(L);
    549   luaL_setfuncs(L, base_funcs, 0);
    550   /* set global _G */
    551   lua_pushvalue(L, -1);
    552   lua_setfield(L, -2, LUA_GNAME);
    553   /* set global _VERSION */
    554   lua_pushliteral(L, LUA_VERSION);
    555   lua_setfield(L, -2, "_VERSION");
    556   return 1;
    557 }
    558