1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/lua/src/loadlib.c	Sat Mar 03 10:31:27 2012 -0600
     1.3 @@ -0,0 +1,666 @@
     1.4 +/*
     1.5 +** $Id: loadlib.c,v 1.52.1.3 2008/08/06 13:29:28 roberto Exp $
     1.6 +** Dynamic library loader for Lua
     1.7 +** See Copyright Notice in lua.h
     1.8 +**
     1.9 +** This module contains an implementation of loadlib for Unix systems
    1.10 +** that have dlfcn, an implementation for Darwin (Mac OS X), an
    1.11 +** implementation for Windows, and a stub for other systems.
    1.12 +*/
    1.13 +
    1.14 +
    1.15 +#include <stdlib.h>
    1.16 +#include <string.h>
    1.17 +
    1.18 +
    1.19 +#define loadlib_c
    1.20 +#define LUA_LIB
    1.21 +
    1.22 +#include "lua.h"
    1.23 +
    1.24 +#include "lauxlib.h"
    1.25 +#include "lualib.h"
    1.26 +
    1.27 +
    1.28 +/* prefix for open functions in C libraries */
    1.29 +#define LUA_POF		"luaopen_"
    1.30 +
    1.31 +/* separator for open functions in C libraries */
    1.32 +#define LUA_OFSEP	"_"
    1.33 +
    1.34 +
    1.35 +#define LIBPREFIX	"LOADLIB: "
    1.36 +
    1.37 +#define POF		LUA_POF
    1.38 +#define LIB_FAIL	"open"
    1.39 +
    1.40 +
    1.41 +/* error codes for ll_loadfunc */
    1.42 +#define ERRLIB		1
    1.43 +#define ERRFUNC		2
    1.44 +
    1.45 +#define setprogdir(L)		((void)0)
    1.46 +
    1.47 +
    1.48 +static void ll_unloadlib (void *lib);
    1.49 +static void *ll_load (lua_State *L, const char *path);
    1.50 +static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
    1.51 +
    1.52 +
    1.53 +
    1.54 +#if defined(LUA_DL_DLOPEN)
    1.55 +/*
    1.56 +** {========================================================================
    1.57 +** This is an implementation of loadlib based on the dlfcn interface.
    1.58 +** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD,
    1.59 +** NetBSD, AIX 4.2, HPUX 11, and  probably most other Unix flavors, at least
    1.60 +** as an emulation layer on top of native functions.
    1.61 +** =========================================================================
    1.62 +*/
    1.63 +
    1.64 +#include <dlfcn.h>
    1.65 +
    1.66 +static void ll_unloadlib (void *lib) {
    1.67 +  dlclose(lib);
    1.68 +}
    1.69 +
    1.70 +
    1.71 +static void *ll_load (lua_State *L, const char *path) {
    1.72 +  void *lib = dlopen(path, RTLD_NOW);
    1.73 +  if (lib == NULL) lua_pushstring(L, dlerror());
    1.74 +  return lib;
    1.75 +}
    1.76 +
    1.77 +
    1.78 +static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
    1.79 +  lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
    1.80 +  if (f == NULL) lua_pushstring(L, dlerror());
    1.81 +  return f;
    1.82 +}
    1.83 +
    1.84 +/* }====================================================== */
    1.85 +
    1.86 +
    1.87 +
    1.88 +#elif defined(LUA_DL_DLL)
    1.89 +/*
    1.90 +** {======================================================================
    1.91 +** This is an implementation of loadlib for Windows using native functions.
    1.92 +** =======================================================================
    1.93 +*/
    1.94 +
    1.95 +#include <windows.h>
    1.96 +
    1.97 +
    1.98 +#undef setprogdir
    1.99 +
   1.100 +static void setprogdir (lua_State *L) {
   1.101 +  char buff[MAX_PATH + 1];
   1.102 +  char *lb;
   1.103 +  DWORD nsize = sizeof(buff)/sizeof(char);
   1.104 +  DWORD n = GetModuleFileNameA(NULL, buff, nsize);
   1.105 +  if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL)
   1.106 +    luaL_error(L, "unable to get ModuleFileName");
   1.107 +  else {
   1.108 +    *lb = '\0';
   1.109 +    luaL_gsub(L, lua_tostring(L, -1), LUA_EXECDIR, buff);
   1.110 +    lua_remove(L, -2);  /* remove original string */
   1.111 +  }
   1.112 +}
   1.113 +
   1.114 +
   1.115 +static void pusherror (lua_State *L) {
   1.116 +  int error = GetLastError();
   1.117 +  char buffer[128];
   1.118 +  if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
   1.119 +      NULL, error, 0, buffer, sizeof(buffer), NULL))
   1.120 +    lua_pushstring(L, buffer);
   1.121 +  else
   1.122 +    lua_pushfstring(L, "system error %d\n", error);
   1.123 +}
   1.124 +
   1.125 +static void ll_unloadlib (void *lib) {
   1.126 +  FreeLibrary((HINSTANCE)lib);
   1.127 +}
   1.128 +
   1.129 +
   1.130 +static void *ll_load (lua_State *L, const char *path) {
   1.131 +  HINSTANCE lib = LoadLibraryA(path);
   1.132 +  if (lib == NULL) pusherror(L);
   1.133 +  return lib;
   1.134 +}
   1.135 +
   1.136 +
   1.137 +static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
   1.138 +  lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym);
   1.139 +  if (f == NULL) pusherror(L);
   1.140 +  return f;
   1.141 +}
   1.142 +
   1.143 +/* }====================================================== */
   1.144 +
   1.145 +
   1.146 +
   1.147 +#elif defined(LUA_DL_DYLD)
   1.148 +/*
   1.149 +** {======================================================================
   1.150 +** Native Mac OS X / Darwin Implementation
   1.151 +** =======================================================================
   1.152 +*/
   1.153 +
   1.154 +#include <mach-o/dyld.h>
   1.155 +
   1.156 +
   1.157 +/* Mac appends a `_' before C function names */
   1.158 +#undef POF
   1.159 +#define POF	"_" LUA_POF
   1.160 +
   1.161 +
   1.162 +static void pusherror (lua_State *L) {
   1.163 +  const char *err_str;
   1.164 +  const char *err_file;
   1.165 +  NSLinkEditErrors err;
   1.166 +  int err_num;
   1.167 +  NSLinkEditError(&err, &err_num, &err_file, &err_str);
   1.168 +  lua_pushstring(L, err_str);
   1.169 +}
   1.170 +
   1.171 +
   1.172 +static const char *errorfromcode (NSObjectFileImageReturnCode ret) {
   1.173 +  switch (ret) {
   1.174 +    case NSObjectFileImageInappropriateFile:
   1.175 +      return "file is not a bundle";
   1.176 +    case NSObjectFileImageArch:
   1.177 +      return "library is for wrong CPU type";
   1.178 +    case NSObjectFileImageFormat:
   1.179 +      return "bad format";
   1.180 +    case NSObjectFileImageAccess:
   1.181 +      return "cannot access file";
   1.182 +    case NSObjectFileImageFailure:
   1.183 +    default:
   1.184 +      return "unable to load library";
   1.185 +  }
   1.186 +}
   1.187 +
   1.188 +
   1.189 +static void ll_unloadlib (void *lib) {
   1.190 +  NSUnLinkModule((NSModule)lib, NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES);
   1.191 +}
   1.192 +
   1.193 +
   1.194 +static void *ll_load (lua_State *L, const char *path) {
   1.195 +  NSObjectFileImage img;
   1.196 +  NSObjectFileImageReturnCode ret;
   1.197 +  /* this would be a rare case, but prevents crashing if it happens */
   1.198 +  if(!_dyld_present()) {
   1.199 +    lua_pushliteral(L, "dyld not present");
   1.200 +    return NULL;
   1.201 +  }
   1.202 +  ret = NSCreateObjectFileImageFromFile(path, &img);
   1.203 +  if (ret == NSObjectFileImageSuccess) {
   1.204 +    NSModule mod = NSLinkModule(img, path, NSLINKMODULE_OPTION_PRIVATE |
   1.205 +                       NSLINKMODULE_OPTION_RETURN_ON_ERROR);
   1.206 +    NSDestroyObjectFileImage(img);
   1.207 +    if (mod == NULL) pusherror(L);
   1.208 +    return mod;
   1.209 +  }
   1.210 +  lua_pushstring(L, errorfromcode(ret));
   1.211 +  return NULL;
   1.212 +}
   1.213 +
   1.214 +
   1.215 +static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
   1.216 +  NSSymbol nss = NSLookupSymbolInModule((NSModule)lib, sym);
   1.217 +  if (nss == NULL) {
   1.218 +    lua_pushfstring(L, "symbol " LUA_QS " not found", sym);
   1.219 +    return NULL;
   1.220 +  }
   1.221 +  return (lua_CFunction)NSAddressOfSymbol(nss);
   1.222 +}
   1.223 +
   1.224 +/* }====================================================== */
   1.225 +
   1.226 +
   1.227 +
   1.228 +#else
   1.229 +/*
   1.230 +** {======================================================
   1.231 +** Fallback for other systems
   1.232 +** =======================================================
   1.233 +*/
   1.234 +
   1.235 +#undef LIB_FAIL
   1.236 +#define LIB_FAIL	"absent"
   1.237 +
   1.238 +
   1.239 +#define DLMSG	"dynamic libraries not enabled; check your Lua installation"
   1.240 +
   1.241 +
   1.242 +static void ll_unloadlib (void *lib) {
   1.243 +  (void)lib;  /* to avoid warnings */
   1.244 +}
   1.245 +
   1.246 +
   1.247 +static void *ll_load (lua_State *L, const char *path) {
   1.248 +  (void)path;  /* to avoid warnings */
   1.249 +  lua_pushliteral(L, DLMSG);
   1.250 +  return NULL;
   1.251 +}
   1.252 +
   1.253 +
   1.254 +static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
   1.255 +  (void)lib; (void)sym;  /* to avoid warnings */
   1.256 +  lua_pushliteral(L, DLMSG);
   1.257 +  return NULL;
   1.258 +}
   1.259 +
   1.260 +/* }====================================================== */
   1.261 +#endif
   1.262 +
   1.263 +
   1.264 +
   1.265 +static void **ll_register (lua_State *L, const char *path) {
   1.266 +  void **plib;
   1.267 +  lua_pushfstring(L, "%s%s", LIBPREFIX, path);
   1.268 +  lua_gettable(L, LUA_REGISTRYINDEX);  /* check library in registry? */
   1.269 +  if (!lua_isnil(L, -1))  /* is there an entry? */
   1.270 +    plib = (void **)lua_touserdata(L, -1);
   1.271 +  else {  /* no entry yet; create one */
   1.272 +    lua_pop(L, 1);
   1.273 +    plib = (void **)lua_newuserdata(L, sizeof(const void *));
   1.274 +    *plib = NULL;
   1.275 +    luaL_getmetatable(L, "_LOADLIB");
   1.276 +    lua_setmetatable(L, -2);
   1.277 +    lua_pushfstring(L, "%s%s", LIBPREFIX, path);
   1.278 +    lua_pushvalue(L, -2);
   1.279 +    lua_settable(L, LUA_REGISTRYINDEX);
   1.280 +  }
   1.281 +  return plib;
   1.282 +}
   1.283 +
   1.284 +
   1.285 +/*
   1.286 +** __gc tag method: calls library's `ll_unloadlib' function with the lib
   1.287 +** handle
   1.288 +*/
   1.289 +static int gctm (lua_State *L) {
   1.290 +  void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
   1.291 +  if (*lib) ll_unloadlib(*lib);
   1.292 +  *lib = NULL;  /* mark library as closed */
   1.293 +  return 0;
   1.294 +}
   1.295 +
   1.296 +
   1.297 +static int ll_loadfunc (lua_State *L, const char *path, const char *sym) {
   1.298 +  void **reg = ll_register(L, path);
   1.299 +  if (*reg == NULL) *reg = ll_load(L, path);
   1.300 +  if (*reg == NULL)
   1.301 +    return ERRLIB;  /* unable to load library */
   1.302 +  else {
   1.303 +    lua_CFunction f = ll_sym(L, *reg, sym);
   1.304 +    if (f == NULL)
   1.305 +      return ERRFUNC;  /* unable to find function */
   1.306 +    lua_pushcfunction(L, f);
   1.307 +    return 0;  /* return function */
   1.308 +  }
   1.309 +}
   1.310 +
   1.311 +
   1.312 +static int ll_loadlib (lua_State *L) {
   1.313 +  const char *path = luaL_checkstring(L, 1);
   1.314 +  const char *init = luaL_checkstring(L, 2);
   1.315 +  int stat = ll_loadfunc(L, path, init);
   1.316 +  if (stat == 0)  /* no errors? */
   1.317 +    return 1;  /* return the loaded function */
   1.318 +  else {  /* error; error message is on stack top */
   1.319 +    lua_pushnil(L);
   1.320 +    lua_insert(L, -2);
   1.321 +    lua_pushstring(L, (stat == ERRLIB) ?  LIB_FAIL : "init");
   1.322 +    return 3;  /* return nil, error message, and where */
   1.323 +  }
   1.324 +}
   1.325 +
   1.326 +
   1.327 +
   1.328 +/*
   1.329 +** {======================================================
   1.330 +** 'require' function
   1.331 +** =======================================================
   1.332 +*/
   1.333 +
   1.334 +
   1.335 +static int readable (const char *filename) {
   1.336 +  FILE *f = fopen(filename, "r");  /* try to open file */
   1.337 +  if (f == NULL) return 0;  /* open failed */
   1.338 +  fclose(f);
   1.339 +  return 1;
   1.340 +}
   1.341 +
   1.342 +
   1.343 +static const char *pushnexttemplate (lua_State *L, const char *path) {
   1.344 +  const char *l;
   1.345 +  while (*path == *LUA_PATHSEP) path++;  /* skip separators */
   1.346 +  if (*path == '\0') return NULL;  /* no more templates */
   1.347 +  l = strchr(path, *LUA_PATHSEP);  /* find next separator */
   1.348 +  if (l == NULL) l = path + strlen(path);
   1.349 +  lua_pushlstring(L, path, l - path);  /* template */
   1.350 +  return l;
   1.351 +}
   1.352 +
   1.353 +
   1.354 +static const char *findfile (lua_State *L, const char *name,
   1.355 +                                           const char *pname) {
   1.356 +  const char *path;
   1.357 +  name = luaL_gsub(L, name, ".", LUA_DIRSEP);
   1.358 +  lua_getfield(L, LUA_ENVIRONINDEX, pname);
   1.359 +  path = lua_tostring(L, -1);
   1.360 +  if (path == NULL)
   1.361 +    luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
   1.362 +  lua_pushliteral(L, "");  /* error accumulator */
   1.363 +  while ((path = pushnexttemplate(L, path)) != NULL) {
   1.364 +    const char *filename;
   1.365 +    filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name);
   1.366 +    lua_remove(L, -2);  /* remove path template */
   1.367 +    if (readable(filename))  /* does file exist and is readable? */
   1.368 +      return filename;  /* return that file name */
   1.369 +    lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
   1.370 +    lua_remove(L, -2);  /* remove file name */
   1.371 +    lua_concat(L, 2);  /* add entry to possible error message */
   1.372 +  }
   1.373 +  return NULL;  /* not found */
   1.374 +}
   1.375 +
   1.376 +
   1.377 +static void loaderror (lua_State *L, const char *filename) {
   1.378 +  luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s",
   1.379 +                lua_tostring(L, 1), filename, lua_tostring(L, -1));
   1.380 +}
   1.381 +
   1.382 +
   1.383 +static int loader_Lua (lua_State *L) {
   1.384 +  const char *filename;
   1.385 +  const char *name = luaL_checkstring(L, 1);
   1.386 +  filename = findfile(L, name, "path");
   1.387 +  if (filename == NULL) return 1;  /* library not found in this path */
   1.388 +  if (luaL_loadfile(L, filename) != 0)
   1.389 +    loaderror(L, filename);
   1.390 +  return 1;  /* library loaded successfully */
   1.391 +}
   1.392 +
   1.393 +
   1.394 +static const char *mkfuncname (lua_State *L, const char *modname) {
   1.395 +  const char *funcname;
   1.396 +  const char *mark = strchr(modname, *LUA_IGMARK);
   1.397 +  if (mark) modname = mark + 1;
   1.398 +  funcname = luaL_gsub(L, modname, ".", LUA_OFSEP);
   1.399 +  funcname = lua_pushfstring(L, POF"%s", funcname);
   1.400 +  lua_remove(L, -2);  /* remove 'gsub' result */
   1.401 +  return funcname;
   1.402 +}
   1.403 +
   1.404 +
   1.405 +static int loader_C (lua_State *L) {
   1.406 +  const char *funcname;
   1.407 +  const char *name = luaL_checkstring(L, 1);
   1.408 +  const char *filename = findfile(L, name, "cpath");
   1.409 +  if (filename == NULL) return 1;  /* library not found in this path */
   1.410 +  funcname = mkfuncname(L, name);
   1.411 +  if (ll_loadfunc(L, filename, funcname) != 0)
   1.412 +    loaderror(L, filename);
   1.413 +  return 1;  /* library loaded successfully */
   1.414 +}
   1.415 +
   1.416 +
   1.417 +static int loader_Croot (lua_State *L) {
   1.418 +  const char *funcname;
   1.419 +  const char *filename;
   1.420 +  const char *name = luaL_checkstring(L, 1);
   1.421 +  const char *p = strchr(name, '.');
   1.422 +  int stat;
   1.423 +  if (p == NULL) return 0;  /* is root */
   1.424 +  lua_pushlstring(L, name, p - name);
   1.425 +  filename = findfile(L, lua_tostring(L, -1), "cpath");
   1.426 +  if (filename == NULL) return 1;  /* root not found */
   1.427 +  funcname = mkfuncname(L, name);
   1.428 +  if ((stat = ll_loadfunc(L, filename, funcname)) != 0) {
   1.429 +    if (stat != ERRFUNC) loaderror(L, filename);  /* real error */
   1.430 +    lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
   1.431 +                       name, filename);
   1.432 +    return 1;  /* function not found */
   1.433 +  }
   1.434 +  return 1;
   1.435 +}
   1.436 +
   1.437 +
   1.438 +static int loader_preload (lua_State *L) {
   1.439 +  const char *name = luaL_checkstring(L, 1);
   1.440 +  lua_getfield(L, LUA_ENVIRONINDEX, "preload");
   1.441 +  if (!lua_istable(L, -1))
   1.442 +    luaL_error(L, LUA_QL("package.preload") " must be a table");
   1.443 +  lua_getfield(L, -1, name);
   1.444 +  if (lua_isnil(L, -1))  /* not found? */
   1.445 +    lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
   1.446 +  return 1;
   1.447 +}
   1.448 +
   1.449 +
   1.450 +static const int sentinel_ = 0;
   1.451 +#define sentinel	((void *)&sentinel_)
   1.452 +
   1.453 +
   1.454 +static int ll_require (lua_State *L) {
   1.455 +  const char *name = luaL_checkstring(L, 1);
   1.456 +  int i;
   1.457 +  lua_settop(L, 1);  /* _LOADED table will be at index 2 */
   1.458 +  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
   1.459 +  lua_getfield(L, 2, name);
   1.460 +  if (lua_toboolean(L, -1)) {  /* is it there? */
   1.461 +    if (lua_touserdata(L, -1) == sentinel)  /* check loops */
   1.462 +      luaL_error(L, "loop or previous error loading module " LUA_QS, name);
   1.463 +    return 1;  /* package is already loaded */
   1.464 +  }
   1.465 +  /* else must load it; iterate over available loaders */
   1.466 +  lua_getfield(L, LUA_ENVIRONINDEX, "loaders");
   1.467 +  if (!lua_istable(L, -1))
   1.468 +    luaL_error(L, LUA_QL("package.loaders") " must be a table");
   1.469 +  lua_pushliteral(L, "");  /* error message accumulator */
   1.470 +  for (i=1; ; i++) {
   1.471 +    lua_rawgeti(L, -2, i);  /* get a loader */
   1.472 +    if (lua_isnil(L, -1))
   1.473 +      luaL_error(L, "module " LUA_QS " not found:%s",
   1.474 +                    name, lua_tostring(L, -2));
   1.475 +    lua_pushstring(L, name);
   1.476 +    lua_call(L, 1, 1);  /* call it */
   1.477 +    if (lua_isfunction(L, -1))  /* did it find module? */
   1.478 +      break;  /* module loaded successfully */
   1.479 +    else if (lua_isstring(L, -1))  /* loader returned error message? */
   1.480 +      lua_concat(L, 2);  /* accumulate it */
   1.481 +    else
   1.482 +      lua_pop(L, 1);
   1.483 +  }
   1.484 +  lua_pushlightuserdata(L, sentinel);
   1.485 +  lua_setfield(L, 2, name);  /* _LOADED[name] = sentinel */
   1.486 +  lua_pushstring(L, name);  /* pass name as argument to module */
   1.487 +  lua_call(L, 1, 1);  /* run loaded module */
   1.488 +  if (!lua_isnil(L, -1))  /* non-nil return? */
   1.489 +    lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
   1.490 +  lua_getfield(L, 2, name);
   1.491 +  if (lua_touserdata(L, -1) == sentinel) {   /* module did not set a value? */
   1.492 +    lua_pushboolean(L, 1);  /* use true as result */
   1.493 +    lua_pushvalue(L, -1);  /* extra copy to be returned */
   1.494 +    lua_setfield(L, 2, name);  /* _LOADED[name] = true */
   1.495 +  }
   1.496 +  return 1;
   1.497 +}
   1.498 +
   1.499 +/* }====================================================== */
   1.500 +
   1.501 +
   1.502 +
   1.503 +/*
   1.504 +** {======================================================
   1.505 +** 'module' function
   1.506 +** =======================================================
   1.507 +*/
   1.508 +  
   1.509 +
   1.510 +static void setfenv (lua_State *L) {
   1.511 +  lua_Debug ar;
   1.512 +  if (lua_getstack(L, 1, &ar) == 0 ||
   1.513 +      lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
   1.514 +      lua_iscfunction(L, -1))
   1.515 +    luaL_error(L, LUA_QL("module") " not called from a Lua function");
   1.516 +  lua_pushvalue(L, -2);
   1.517 +  lua_setfenv(L, -2);
   1.518 +  lua_pop(L, 1);
   1.519 +}
   1.520 +
   1.521 +
   1.522 +static void dooptions (lua_State *L, int n) {
   1.523 +  int i;
   1.524 +  for (i = 2; i <= n; i++) {
   1.525 +    lua_pushvalue(L, i);  /* get option (a function) */
   1.526 +    lua_pushvalue(L, -2);  /* module */
   1.527 +    lua_call(L, 1, 0);
   1.528 +  }
   1.529 +}
   1.530 +
   1.531 +
   1.532 +static void modinit (lua_State *L, const char *modname) {
   1.533 +  const char *dot;
   1.534 +  lua_pushvalue(L, -1);
   1.535 +  lua_setfield(L, -2, "_M");  /* module._M = module */
   1.536 +  lua_pushstring(L, modname);
   1.537 +  lua_setfield(L, -2, "_NAME");
   1.538 +  dot = strrchr(modname, '.');  /* look for last dot in module name */
   1.539 +  if (dot == NULL) dot = modname;
   1.540 +  else dot++;
   1.541 +  /* set _PACKAGE as package name (full module name minus last part) */
   1.542 +  lua_pushlstring(L, modname, dot - modname);
   1.543 +  lua_setfield(L, -2, "_PACKAGE");
   1.544 +}
   1.545 +
   1.546 +
   1.547 +static int ll_module (lua_State *L) {
   1.548 +  const char *modname = luaL_checkstring(L, 1);
   1.549 +  int loaded = lua_gettop(L) + 1;  /* index of _LOADED table */
   1.550 +  lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
   1.551 +  lua_getfield(L, loaded, modname);  /* get _LOADED[modname] */
   1.552 +  if (!lua_istable(L, -1)) {  /* not found? */
   1.553 +    lua_pop(L, 1);  /* remove previous result */
   1.554 +    /* try global variable (and create one if it does not exist) */
   1.555 +    if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, 1) != NULL)
   1.556 +      return luaL_error(L, "name conflict for module " LUA_QS, modname);
   1.557 +    lua_pushvalue(L, -1);
   1.558 +    lua_setfield(L, loaded, modname);  /* _LOADED[modname] = new table */
   1.559 +  }
   1.560 +  /* check whether table already has a _NAME field */
   1.561 +  lua_getfield(L, -1, "_NAME");
   1.562 +  if (!lua_isnil(L, -1))  /* is table an initialized module? */
   1.563 +    lua_pop(L, 1);
   1.564 +  else {  /* no; initialize it */
   1.565 +    lua_pop(L, 1);
   1.566 +    modinit(L, modname);
   1.567 +  }
   1.568 +  lua_pushvalue(L, -1);
   1.569 +  setfenv(L);
   1.570 +  dooptions(L, loaded - 1);
   1.571 +  return 0;
   1.572 +}
   1.573 +
   1.574 +
   1.575 +static int ll_seeall (lua_State *L) {
   1.576 +  luaL_checktype(L, 1, LUA_TTABLE);
   1.577 +  if (!lua_getmetatable(L, 1)) {
   1.578 +    lua_createtable(L, 0, 1); /* create new metatable */
   1.579 +    lua_pushvalue(L, -1);
   1.580 +    lua_setmetatable(L, 1);
   1.581 +  }
   1.582 +  lua_pushvalue(L, LUA_GLOBALSINDEX);
   1.583 +  lua_setfield(L, -2, "__index");  /* mt.__index = _G */
   1.584 +  return 0;
   1.585 +}
   1.586 +
   1.587 +
   1.588 +/* }====================================================== */
   1.589 +
   1.590 +
   1.591 +
   1.592 +/* auxiliary mark (for internal use) */
   1.593 +#define AUXMARK		"\1"
   1.594 +
   1.595 +static void setpath (lua_State *L, const char *fieldname, const char *envname,
   1.596 +                                   const char *def) {
   1.597 +  const char *path = getenv(envname);
   1.598 +  if (path == NULL)  /* no environment variable? */
   1.599 +    lua_pushstring(L, def);  /* use default */
   1.600 +  else {
   1.601 +    /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
   1.602 +    path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP,
   1.603 +                              LUA_PATHSEP AUXMARK LUA_PATHSEP);
   1.604 +    luaL_gsub(L, path, AUXMARK, def);
   1.605 +    lua_remove(L, -2);
   1.606 +  }
   1.607 +  setprogdir(L);
   1.608 +  lua_setfield(L, -2, fieldname);
   1.609 +}
   1.610 +
   1.611 +
   1.612 +static const luaL_Reg pk_funcs[] = {
   1.613 +  {"loadlib", ll_loadlib},
   1.614 +  {"seeall", ll_seeall},
   1.615 +  {NULL, NULL}
   1.616 +};
   1.617 +
   1.618 +
   1.619 +static const luaL_Reg ll_funcs[] = {
   1.620 +  {"module", ll_module},
   1.621 +  {"require", ll_require},
   1.622 +  {NULL, NULL}
   1.623 +};
   1.624 +
   1.625 +
   1.626 +static const lua_CFunction loaders[] =
   1.627 +  {loader_preload, loader_Lua, loader_C, loader_Croot, NULL};
   1.628 +
   1.629 +
   1.630 +LUALIB_API int luaopen_package (lua_State *L) {
   1.631 +  int i;
   1.632 +  /* create new type _LOADLIB */
   1.633 +  luaL_newmetatable(L, "_LOADLIB");
   1.634 +  lua_pushcfunction(L, gctm);
   1.635 +  lua_setfield(L, -2, "__gc");
   1.636 +  /* create `package' table */
   1.637 +  luaL_register(L, LUA_LOADLIBNAME, pk_funcs);
   1.638 +#if defined(LUA_COMPAT_LOADLIB) 
   1.639 +  lua_getfield(L, -1, "loadlib");
   1.640 +  lua_setfield(L, LUA_GLOBALSINDEX, "loadlib");
   1.641 +#endif
   1.642 +  lua_pushvalue(L, -1);
   1.643 +  lua_replace(L, LUA_ENVIRONINDEX);
   1.644 +  /* create `loaders' table */
   1.645 +  lua_createtable(L, 0, sizeof(loaders)/sizeof(loaders[0]) - 1);
   1.646 +  /* fill it with pre-defined loaders */
   1.647 +  for (i=0; loaders[i] != NULL; i++) {
   1.648 +    lua_pushcfunction(L, loaders[i]);
   1.649 +    lua_rawseti(L, -2, i+1);
   1.650 +  }
   1.651 +  lua_setfield(L, -2, "loaders");  /* put it in field `loaders' */
   1.652 +  setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT);  /* set field `path' */
   1.653 +  setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT); /* set field `cpath' */
   1.654 +  /* store config information */
   1.655 +  lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATHSEP "\n" LUA_PATH_MARK "\n"
   1.656 +                     LUA_EXECDIR "\n" LUA_IGMARK);
   1.657 +  lua_setfield(L, -2, "config");
   1.658 +  /* set field `loaded' */
   1.659 +  luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 2);
   1.660 +  lua_setfield(L, -2, "loaded");
   1.661 +  /* set field `preload' */
   1.662 +  lua_newtable(L);
   1.663 +  lua_setfield(L, -2, "preload");
   1.664 +  lua_pushvalue(L, LUA_GLOBALSINDEX);
   1.665 +  luaL_register(L, NULL, ll_funcs);  /* open lib into global table */
   1.666 +  lua_pop(L, 1);
   1.667 +  return 1;  /* return 'package' table */
   1.668 +}
   1.669 +