/*

 ** $Id: lauxlib.c,v 1.159.1.3 2008/01/21 13:20:51 roberto Exp $

 ** Auxiliary functions for building Lua libraries

 ** See Copyright Notice in lua.h

 */

 

 

 #include <ctype.h>

 #include <errno.h>

 #include <stdarg.h>

 #include <stdio.h>

 #include <stdlib.h>

 #include <string.h>

 

 

 /* This file uses only the official API of Lua.

 ** Any function declared here could be written as an application function.

 */

 

 #define lauxlib_c

 #define LUA_LIB

 

 #include "lua.h"

 

 #include "lauxlib.h"

 

 

 #define FREELIST_REF	0	/* free list of references */

 

 

 /* convert a stack index to positive */

 #define abs_index(L, i)		((i) > 0 || (i) <= LUA_REGISTRYINDEX ? (i) : \

 					lua_gettop(L) + (i) + 1)

 

 

 /*

 ** {======================================================

 ** Error-report functions

 ** =======================================================

 */

 

 

 LUALIB_API int luaL_argerror (lua_State *L, int narg, const char *extramsg) {

   lua_Debug ar;

   if (!lua_getstack(L, 0, &ar))  /* no stack frame? */

     return luaL_error(L, "bad argument #%d (%s)", narg, extramsg);

   lua_getinfo(L, "n", &ar);

   if (strcmp(ar.namewhat, "method") == 0) {

     narg--;  /* do not count `self' */

     if (narg == 0)  /* error is in the self argument itself? */

       return luaL_error(L, "calling " LUA_QS " on bad self (%s)",

                            ar.name, extramsg);

   }

   if (ar.name == NULL)

     ar.name = "?";

   return luaL_error(L, "bad argument #%d to " LUA_QS " (%s)",

                         narg, ar.name, extramsg);

 }

 

 

 LUALIB_API int luaL_typerror (lua_State *L, int narg, const char *tname) {

   const char *msg = lua_pushfstring(L, "%s expected, got %s",

                                     tname, luaL_typename(L, narg));

   return luaL_argerror(L, narg, msg);

 }

 

 

 static void tag_error (lua_State *L, int narg, int tag) {

   luaL_typerror(L, narg, lua_typename(L, tag));

 }

 

 

 LUALIB_API void luaL_where (lua_State *L, int level) {

   lua_Debug ar;

   if (lua_getstack(L, level, &ar)) {  /* check function at level */

     lua_getinfo(L, "Sl", &ar);  /* get info about it */

     if (ar.currentline > 0) {  /* is there info? */

       lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline);

       return;

     }

   }

   lua_pushliteral(L, "");  /* else, no information available... */

 }

 

 

 LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) {

   va_list argp;

   va_start(argp, fmt);

   luaL_where(L, 1);

   lua_pushvfstring(L, fmt, argp);

   va_end(argp);

   lua_concat(L, 2);

   return lua_error(L);

 }

 

 /* }====================================================== */

 

 

 LUALIB_API int luaL_checkoption (lua_State *L, int narg, const char *def,

                                  const char *const lst[]) {

   const char *name = (def) ? luaL_optstring(L, narg, def) :

                              luaL_checkstring(L, narg);

   int i;

   for (i=0; lst[i]; i++)

     if (strcmp(lst[i], name) == 0)

       return i;

   return luaL_argerror(L, narg,

                        lua_pushfstring(L, "invalid option " LUA_QS, name));

 }

 

 

 LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) {

   lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get registry.name */

   if (!lua_isnil(L, -1))  /* name already in use? */

     return 0;  /* leave previous value on top, but return 0 */

   lua_pop(L, 1);

   lua_newtable(L);  /* create metatable */

   lua_pushvalue(L, -1);

   lua_setfield(L, LUA_REGISTRYINDEX, tname);  /* registry.name = metatable */

   return 1;

 }

 

 

 LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) {

   void *p = lua_touserdata(L, ud);

   if (p != NULL) {  /* value is a userdata? */

     if (lua_getmetatable(L, ud)) {  /* does it have a metatable? */

       lua_getfield(L, LUA_REGISTRYINDEX, tname);  /* get correct metatable */

       if (lua_rawequal(L, -1, -2)) {  /* does it have the correct mt? */

         lua_pop(L, 2);  /* remove both metatables */

         return p;

       }

     }

   }

   luaL_typerror(L, ud, tname);  /* else error */

   return NULL;  /* to avoid warnings */

 }

 

 

 LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *mes) {

   if (!lua_checkstack(L, space))

     luaL_error(L, "stack overflow (%s)", mes);

 }

 

 

 LUALIB_API void luaL_checktype (lua_State *L, int narg, int t) {

   if (lua_type(L, narg) != t)

     tag_error(L, narg, t);

 }

 

 

 LUALIB_API void luaL_checkany (lua_State *L, int narg) {

   if (lua_type(L, narg) == LUA_TNONE)

     luaL_argerror(L, narg, "value expected");

 }

 

 

 LUALIB_API const char *luaL_checklstring (lua_State *L, int narg, size_t *len) {

   const char *s = lua_tolstring(L, narg, len);

   if (!s) tag_error(L, narg, LUA_TSTRING);

   return s;

 }

 

 

 LUALIB_API const char *luaL_optlstring (lua_State *L, int narg,

                                         const char *def, size_t *len) {

   if (lua_isnoneornil(L, narg)) {

     if (len)

       *len = (def ? strlen(def) : 0);

     return def;

   }

   else return luaL_checklstring(L, narg, len);

 }

 

 

 LUALIB_API lua_Number luaL_checknumber (lua_State *L, int narg) {

   lua_Number d = lua_tonumber(L, narg);

   if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */

     tag_error(L, narg, LUA_TNUMBER);

   return d;

 }

 

 

 LUALIB_API lua_Number luaL_optnumber (lua_State *L, int narg, lua_Number def) {

   return luaL_opt(L, luaL_checknumber, narg, def);

 }

 

 

 LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int narg) {

   lua_Integer d = lua_tointeger(L, narg);

   if (d == 0 && !lua_isnumber(L, narg))  /* avoid extra test when d is not 0 */

     tag_error(L, narg, LUA_TNUMBER);

   return d;

 }

 

 

 LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int narg,

                                                       lua_Integer def) {

   return luaL_opt(L, luaL_checkinteger, narg, def);

 }

 

 

 LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) {

   if (!lua_getmetatable(L, obj))  /* no metatable? */

     return 0;

   lua_pushstring(L, event);

   lua_rawget(L, -2);

   if (lua_isnil(L, -1)) {

     lua_pop(L, 2);  /* remove metatable and metafield */

     return 0;

   }

   else {

     lua_remove(L, -2);  /* remove only metatable */

     return 1;

   }

 }

 

 

 LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) {

   obj = abs_index(L, obj);

   if (!luaL_getmetafield(L, obj, event))  /* no metafield? */

     return 0;

   lua_pushvalue(L, obj);

   lua_call(L, 1, 1);

   return 1;

 }

 

 

 LUALIB_API void (luaL_register) (lua_State *L, const char *libname,

                                 const luaL_Reg *l) {

   luaI_openlib(L, libname, l, 0);

 }

 

 

 static int libsize (const luaL_Reg *l) {

   int size = 0;

   for (; l->name; l++) size++;

   return size;

 }

 

 

 LUALIB_API void luaI_openlib (lua_State *L, const char *libname,

                               const luaL_Reg *l, int nup) {

   if (libname) {

     int size = libsize(l);

     /* check whether lib already exists */

     luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1);

     lua_getfield(L, -1, libname);  /* get _LOADED[libname] */

     if (!lua_istable(L, -1)) {  /* not found? */

       lua_pop(L, 1);  /* remove previous result */

       /* try global variable (and create one if it does not exist) */

       if (luaL_findtable(L, LUA_GLOBALSINDEX, libname, size) != NULL)

         luaL_error(L, "name conflict for module " LUA_QS, libname);

       lua_pushvalue(L, -1);

       lua_setfield(L, -3, libname);  /* _LOADED[libname] = new table */

     }

     lua_remove(L, -2);  /* remove _LOADED table */

     lua_insert(L, -(nup+1));  /* move library table to below upvalues */

   }

   for (; l->name; l++) {

     int i;

     for (i=0; i<nup; i++)  /* copy upvalues to the top */

       lua_pushvalue(L, -nup);

     lua_pushcclosure(L, l->func, nup);

     lua_setfield(L, -(nup+2), l->name);

   }

   lua_pop(L, nup);  /* remove upvalues */

 }

 

 

 

 /*

 ** {======================================================

 ** getn-setn: size for arrays

 ** =======================================================

 */

 

 #if defined(LUA_COMPAT_GETN)

 

 static int checkint (lua_State *L, int topop) {

   int n = (lua_type(L, -1) == LUA_TNUMBER) ? lua_tointeger(L, -1) : -1;

   lua_pop(L, topop);

   return n;

 }

 

 

 static void getsizes (lua_State *L) {

   lua_getfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");

   if (lua_isnil(L, -1)) {  /* no `size' table? */

     lua_pop(L, 1);  /* remove nil */

     lua_newtable(L);  /* create it */

     lua_pushvalue(L, -1);  /* `size' will be its own metatable */

     lua_setmetatable(L, -2);

     lua_pushliteral(L, "kv");

     lua_setfield(L, -2, "__mode");  /* metatable(N).__mode = "kv" */

     lua_pushvalue(L, -1);

     lua_setfield(L, LUA_REGISTRYINDEX, "LUA_SIZES");  /* store in register */

   }

 }

 

 

 LUALIB_API void luaL_setn (lua_State *L, int t, int n) {

   t = abs_index(L, t);

   lua_pushliteral(L, "n");

   lua_rawget(L, t);

   if (checkint(L, 1) >= 0) {  /* is there a numeric field `n'? */

     lua_pushliteral(L, "n");  /* use it */

     lua_pushinteger(L, n);

     lua_rawset(L, t);

   }

   else {  /* use `sizes' */

     getsizes(L);

     lua_pushvalue(L, t);

     lua_pushinteger(L, n);

     lua_rawset(L, -3);  /* sizes[t] = n */

     lua_pop(L, 1);  /* remove `sizes' */

   }

 }

 

 

 LUALIB_API int luaL_getn (lua_State *L, int t) {

   int n;

   t = abs_index(L, t);

   lua_pushliteral(L, "n");  /* try t.n */

   lua_rawget(L, t);

   if ((n = checkint(L, 1)) >= 0) return n;

   getsizes(L);  /* else try sizes[t] */

   lua_pushvalue(L, t);

   lua_rawget(L, -2);

   if ((n = checkint(L, 2)) >= 0) return n;

   return (int)lua_objlen(L, t);

 }

 

 #endif

 

 /* }====================================================== */

 

 

 

 LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p,

                                                                const char *r) {

   const char *wild;

   size_t l = strlen(p);

   luaL_Buffer b;

   luaL_buffinit(L, &b);

   while ((wild = strstr(s, p)) != NULL) {

     luaL_addlstring(&b, s, wild - s);  /* push prefix */

     luaL_addstring(&b, r);  /* push replacement in place of pattern */

     s = wild + l;  /* continue after `p' */

   }

   luaL_addstring(&b, s);  /* push last suffix */

   luaL_pushresult(&b);

   return lua_tostring(L, -1);

 }

 

 

 LUALIB_API const char *luaL_findtable (lua_State *L, int idx,

                                        const char *fname, int szhint) {

   const char *e;

   lua_pushvalue(L, idx);

   do {

     e = strchr(fname, '.');

     if (e == NULL) e = fname + strlen(fname);

     lua_pushlstring(L, fname, e - fname);

     lua_rawget(L, -2);

     if (lua_isnil(L, -1)) {  /* no such field? */

       lua_pop(L, 1);  /* remove this nil */

       lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */

       lua_pushlstring(L, fname, e - fname);

       lua_pushvalue(L, -2);

       lua_settable(L, -4);  /* set new table into field */

     }

     else if (!lua_istable(L, -1)) {  /* field has a non-table value? */

       lua_pop(L, 2);  /* remove table and value */

       return fname;  /* return problematic part of the name */

     }

     lua_remove(L, -2);  /* remove previous table */

     fname = e + 1;

   } while (*e == '.');

   return NULL;

 }

 

 

 

 /*

 ** {======================================================

 ** Generic Buffer manipulation

 ** =======================================================

 */

 

 

 #define bufflen(B)	((B)->p - (B)->buffer)

 #define bufffree(B)	((size_t)(LUAL_BUFFERSIZE - bufflen(B)))

 

 #define LIMIT	(LUA_MINSTACK/2)

 

 

 static int emptybuffer (luaL_Buffer *B) {

   size_t l = bufflen(B);

   if (l == 0) return 0;  /* put nothing on stack */

   else {

     lua_pushlstring(B->L, B->buffer, l);

     B->p = B->buffer;

     B->lvl++;

     return 1;

   }

 }

 

 

 static void adjuststack (luaL_Buffer *B) {

   if (B->lvl > 1) {

     lua_State *L = B->L;

     int toget = 1;  /* number of levels to concat */

     size_t toplen = lua_strlen(L, -1);

     do {

       size_t l = lua_strlen(L, -(toget+1));

       if (B->lvl - toget + 1 >= LIMIT || toplen > l) {

         toplen += l;

         toget++;

       }

       else break;

     } while (toget < B->lvl);

     lua_concat(L, toget);

     B->lvl = B->lvl - toget + 1;

   }

 }

 

 

 LUALIB_API char *luaL_prepbuffer (luaL_Buffer *B) {

   if (emptybuffer(B))

     adjuststack(B);

   return B->buffer;

 }

 

 

 LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) {

   while (l--)

     luaL_addchar(B, *s++);

 }

 

 

 LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) {

   luaL_addlstring(B, s, strlen(s));

 }

 

 

 LUALIB_API void luaL_pushresult (luaL_Buffer *B) {

   emptybuffer(B);

   lua_concat(B->L, B->lvl);

   B->lvl = 1;

 }

 

 

 LUALIB_API void luaL_addvalue (luaL_Buffer *B) {

   lua_State *L = B->L;

   size_t vl;

   const char *s = lua_tolstring(L, -1, &vl);

   if (vl <= bufffree(B)) {  /* fit into buffer? */

     memcpy(B->p, s, vl);  /* put it there */

     B->p += vl;

     lua_pop(L, 1);  /* remove from stack */

   }

   else {

     if (emptybuffer(B))

       lua_insert(L, -2);  /* put buffer before new value */

     B->lvl++;  /* add new value into B stack */

     adjuststack(B);

   }

 }

 

 

 LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) {

   B->L = L;

   B->p = B->buffer;

   B->lvl = 0;

 }

 

 /* }====================================================== */

 

 

 LUALIB_API int luaL_ref (lua_State *L, int t) {

   int ref;

   t = abs_index(L, t);

   if (lua_isnil(L, -1)) {

     lua_pop(L, 1);  /* remove from stack */

     return LUA_REFNIL;  /* `nil' has a unique fixed reference */

   }

   lua_rawgeti(L, t, FREELIST_REF);  /* get first free element */

   ref = (int)lua_tointeger(L, -1);  /* ref = t[FREELIST_REF] */

   lua_pop(L, 1);  /* remove it from stack */

   if (ref != 0) {  /* any free element? */

     lua_rawgeti(L, t, ref);  /* remove it from list */

     lua_rawseti(L, t, FREELIST_REF);  /* (t[FREELIST_REF] = t[ref]) */

   }

   else {  /* no free elements */

     ref = (int)lua_objlen(L, t);

     ref++;  /* create new reference */

   }

   lua_rawseti(L, t, ref);

   return ref;

 }

 

 

 LUALIB_API void luaL_unref (lua_State *L, int t, int ref) {

   if (ref >= 0) {

     t = abs_index(L, t);

     lua_rawgeti(L, t, FREELIST_REF);

     lua_rawseti(L, t, ref);  /* t[ref] = t[FREELIST_REF] */

     lua_pushinteger(L, ref);

     lua_rawseti(L, t, FREELIST_REF);  /* t[FREELIST_REF] = ref */

   }

 }

 

 

 

 /*

 ** {======================================================

 ** Load functions

 ** =======================================================

 */

 

 typedef struct LoadF {

   int extraline;

   FILE *f;

   char buff[LUAL_BUFFERSIZE];

 } LoadF;

 

 

 static const char *getF (lua_State *L, void *ud, size_t *size) {

   LoadF *lf = (LoadF *)ud;

   (void)L;

   if (lf->extraline) {

     lf->extraline = 0;

     *size = 1;

     return "\n";

   }

   if (feof(lf->f)) return NULL;

   *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f);

   return (*size > 0) ? lf->buff : NULL;

 }

 

 

 static int errfile (lua_State *L, const char *what, int fnameindex) {

   const char *serr = strerror(errno);

   const char *filename = lua_tostring(L, fnameindex) + 1;

   lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr);

   lua_remove(L, fnameindex);

   return LUA_ERRFILE;

 }

 

 

 LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {

   LoadF lf;

   int status, readstatus;

   int c;

   int fnameindex = lua_gettop(L) + 1;  /* index of filename on the stack */

   lf.extraline = 0;

   if (filename == NULL) {

     lua_pushliteral(L, "=stdin");

     lf.f = stdin;

   }

   else {

     lua_pushfstring(L, "@%s", filename);

     lf.f = fopen(filename, "r");

     if (lf.f == NULL) return errfile(L, "open", fnameindex);

   }

   c = getc(lf.f);

   if (c == '#') {  /* Unix exec. file? */

     lf.extraline = 1;

     while ((c = getc(lf.f)) != EOF && c != '\n') ;  /* skip first line */

     if (c == '\n') c = getc(lf.f);

   }

   if (c == LUA_SIGNATURE[0] && filename) {  /* binary file? */

     lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */

     if (lf.f == NULL) return errfile(L, "reopen", fnameindex);

     /* skip eventual `#!...' */

    while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;

     lf.extraline = 0;

   }

   ungetc(c, lf.f);

   status = lua_load(L, getF, &lf, lua_tostring(L, -1));

   readstatus = ferror(lf.f);

   if (filename) fclose(lf.f);  /* close file (even in case of errors) */

   if (readstatus) {

     lua_settop(L, fnameindex);  /* ignore results from `lua_load' */

     return errfile(L, "read", fnameindex);

   }

   lua_remove(L, fnameindex);

   return status;

 }

 

 

 typedef struct LoadS {

   const char *s;

   size_t size;

 } LoadS;

 

 

 static const char *getS (lua_State *L, void *ud, size_t *size) {

   LoadS *ls = (LoadS *)ud;

   (void)L;

   if (ls->size == 0) return NULL;

   *size = ls->size;

   ls->size = 0;

   return ls->s;

 }

 

 

 LUALIB_API int luaL_loadbuffer (lua_State *L, const char *buff, size_t size,

                                 const char *name) {

   LoadS ls;

   ls.s = buff;

   ls.size = size;

   return lua_load(L, getS, &ls, name);

 }

 

 

 LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s) {

   return luaL_loadbuffer(L, s, strlen(s), s);

 }

 

 

 

 /* }====================================================== */

 

 

 static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) {

   (void)ud;

   (void)osize;

   if (nsize == 0) {

     free(ptr);

     return NULL;

   }

   else

     return realloc(ptr, nsize);

 }

 

 

 static int panic (lua_State *L) {

   (void)L;  /* to avoid warnings */

   fprintf(stderr, "PANIC: unprotected error in call to Lua API (%s)\n",

                    lua_tostring(L, -1));

   return 0;

 }

 

 

 LUALIB_API lua_State *luaL_newstate (void) {

   lua_State *L = lua_newstate(l_alloc, NULL);

   if (L) lua_atpanic(L, &panic);

   return L;

 }