src/lib_package.c

   1 /*
   2 ** Package library.
   3 ** Copyright (C) 2005-2011 Mike Pall. See Copyright Notice in luajit.h
   4 **
   5 ** Major portions taken verbatim or adapted from the Lua interpreter.
   6 ** Copyright (C) 1994-2011 Lua.org, PUC-Rio. See Copyright Notice in lua.h
   7 */
   8
   9 #define lib_package_c
  10 #define LUA_LIB
  11
  12 #include "lua.h"
  13 #include "lauxlib.h"
  14 #include "lualib.h"
  15
  16 #include "lj_obj.h"
  17 #include "lj_err.h"
  18 #include "lj_lib.h"
  19
  20 /* ------------------------------------------------------------------------ */
  21
  22 /* Error codes for ll_loadfunc. */
  23 #define PACKAGE_ERR_LIB         1
  24 #define PACKAGE_ERR_FUNC        2
  25
  26 /* Redefined in platform specific part. */
  27 #define PACKAGE_LIB_FAIL        "open"
  28 #define setprogdir(L)           ((void)0)
  29
  30 #if LJ_TARGET_DLOPEN
  31
  32 #include <dlfcn.h>
  33
  34 static void ll_unloadlib(void *lib)
  35 {
  36   dlclose(lib);
  37 }
  38
  39 static void *ll_load(lua_State *L, const char *path)
  40 {
  41   void *lib = dlopen(path, RTLD_NOW);
  42   if (lib == NULL) lua_pushstring(L, dlerror());
  43   return lib;
  44 }
  45
  46 static lua_CFunction ll_sym(lua_State *L, void *lib, const char *sym)
  47 {
  48   lua_CFunction f = (lua_CFunction)dlsym(lib, sym);
  49   if (f == NULL) lua_pushstring(L, dlerror());
  50   return f;
  51 }
  52
  53 #elif LJ_TARGET_WINDOWS
  54
  55 #define WIN32_LEAN_AND_MEAN
  56 #include <windows.h>
  57
  58 #undef setprogdir
  59
  60 static void setprogdir(lua_State *L)
  61 {
  62   char buff[MAX_PATH + 1];
  63   char *lb;
  64   DWORD nsize = sizeof(buff);
  65   DWORD n = GetModuleFileNameA(NULL, buff, nsize);
  66   if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) {
  67     luaL_error(L, "unable to get ModuleFileName");
  68   } else {
  69     *lb = '\0';
  70     luaL_gsub(L, lua_tostring(L, -1), LUA_EXECDIR, buff);
  71     lua_remove(L, -2);  /* remove original string */
  72   }
  73 }
  74
  75 static void pusherror(lua_State *L)
  76 {
  77   DWORD error = GetLastError();
  78   char buffer[128];
  79   if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM,
  80       NULL, error, 0, buffer, sizeof(buffer), NULL))
  81     lua_pushstring(L, buffer);
  82   else
  83     lua_pushfstring(L, "system error %d\n", error);
  84 }
  85
  86 static void ll_unloadlib(void *lib)
  87 {
  88   FreeLibrary((HINSTANCE)lib);
  89 }
  90
  91 static void *ll_load(lua_State *L, const char *path)
  92 {
  93   HINSTANCE lib = LoadLibraryA(path);
  94   if (lib == NULL) pusherror(L);
  95   return lib;
  96 }
  97
  98 static lua_CFunction ll_sym(lua_State *L, void *lib, const char *sym)
  99 {
 100   lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym);
 101   if (f == NULL) pusherror(L);
 102   return f;
 103 }
 104
 105 #else
 106
 107 #undef PACKAGE_LIB_FAIL
 108 #define PACKAGE_LIB_FAIL        "absent"
 109
 110 #define DLMSG   "dynamic libraries not enabled; no support for target OS"
 111
 112 static void ll_unloadlib(void *lib)
 113 {
 114   (void)lib;
 115 }
 116
 117 static void *ll_load(lua_State *L, const char *path)
 118 {
 119   (void)path;
 120   lua_pushliteral(L, DLMSG);
 121   return NULL;
 122 }
 123
 124 static lua_CFunction ll_sym(lua_State *L, void *lib, const char *sym)
 125 {
 126   (void)lib; (void)sym;
 127   lua_pushliteral(L, DLMSG);
 128   return NULL;
 129 }
 130 #endif
 131
 132 /* ------------------------------------------------------------------------ */
 133
 134 static void **ll_register(lua_State *L, const char *path)
 135 {
 136   void **plib;
 137   lua_pushfstring(L, "LOADLIB: %s", path);
 138   lua_gettable(L, LUA_REGISTRYINDEX);  /* check library in registry? */
 139   if (!lua_isnil(L, -1)) {  /* is there an entry? */
 140     plib = (void **)lua_touserdata(L, -1);
 141   } else {  /* no entry yet; create one */
 142     lua_pop(L, 1);
 143     plib = (void **)lua_newuserdata(L, sizeof(void *));
 144     *plib = NULL;
 145     luaL_getmetatable(L, "_LOADLIB");
 146     lua_setmetatable(L, -2);
 147     lua_pushfstring(L, "LOADLIB: %s", path);
 148     lua_pushvalue(L, -2);
 149     lua_settable(L, LUA_REGISTRYINDEX);
 150   }
 151   return plib;
 152 }
 153
 154 static int ll_loadfunc(lua_State *L, const char *path, const char *sym)
 155 {
 156   void **reg = ll_register(L, path);
 157   if (*reg == NULL) *reg = ll_load(L, path);
 158   if (*reg == NULL) {
 159     return PACKAGE_ERR_LIB;  /* unable to load library */
 160   } else {
 161     lua_CFunction f = ll_sym(L, *reg, sym);
 162     if (f == NULL)
 163       return PACKAGE_ERR_FUNC;  /* unable to find function */
 164     lua_pushcfunction(L, f);
 165     return 0;  /* return function */
 166   }
 167 }
 168
 169 static int lj_cf_package_loadlib(lua_State *L)
 170 {
 171   const char *path = luaL_checkstring(L, 1);
 172   const char *init = luaL_checkstring(L, 2);
 173   int st = ll_loadfunc(L, path, init);
 174   if (st == 0) {  /* no errors? */
 175     return 1;  /* return the loaded function */
 176   } else {  /* error; error message is on stack top */
 177     lua_pushnil(L);
 178     lua_insert(L, -2);
 179     lua_pushstring(L, (st == PACKAGE_ERR_LIB) ?  PACKAGE_LIB_FAIL : "init");
 180     return 3;  /* return nil, error message, and where */
 181   }
 182 }
 183
 184 static int lj_cf_package_unloadlib(lua_State *L)
 185 {
 186   void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB");
 187   if (*lib) ll_unloadlib(*lib);
 188   *lib = NULL;  /* mark library as closed */
 189   return 0;
 190 }
 191
 192 /* ------------------------------------------------------------------------ */
 193
 194 static int readable(const char *filename)
 195 {
 196   FILE *f = fopen(filename, "r");  /* try to open file */
 197   if (f == NULL) return 0;  /* open failed */
 198   fclose(f);
 199   return 1;
 200 }
 201
 202 static const char *pushnexttemplate(lua_State *L, const char *path)
 203 {
 204   const char *l;
 205   while (*path == *LUA_PATHSEP) path++;  /* skip separators */
 206   if (*path == '\0') return NULL;  /* no more templates */
 207   l = strchr(path, *LUA_PATHSEP);  /* find next separator */
 208   if (l == NULL) l = path + strlen(path);
 209   lua_pushlstring(L, path, (size_t)(l - path));  /* template */
 210   return l;
 211 }
 212
 213 static const char *searchpath (lua_State *L, const char *name,
 214                                const char *path)
 215 {
 216   name = luaL_gsub(L, name, ".", LUA_DIRSEP);
 217   lua_pushliteral(L, "");  /* error accumulator */
 218   while ((path = pushnexttemplate(L, path)) != NULL) {
 219     const char *filename = luaL_gsub(L, lua_tostring(L, -1),
 220                                      LUA_PATH_MARK, name);
 221     lua_remove(L, -2);  /* remove path template */
 222     if (readable(filename))  /* does file exist and is readable? */
 223       return filename;  /* return that file name */
 224     lua_pushfstring(L, "\n\tno file " LUA_QS, filename);
 225     lua_remove(L, -2);  /* remove file name */
 226     lua_concat(L, 2);  /* add entry to possible error message */
 227   }
 228   return NULL;  /* not found */
 229 }
 230
 231 static int lj_cf_package_searchpath(lua_State *L)
 232 {
 233   const char *f = searchpath(L, luaL_checkstring(L, 1), luaL_checkstring(L, 2));
 234   if (f != NULL) {
 235     return 1;
 236   } else {  /* error message is on top of the stack */
 237     lua_pushnil(L);
 238     lua_insert(L, -2);
 239     return 2;  /* return nil + error message */
 240   }
 241 }
 242
 243 static const char *findfile(lua_State *L, const char *name,
 244                             const char *pname)
 245 {
 246   const char *path;
 247   lua_getfield(L, LUA_ENVIRONINDEX, pname);
 248   path = lua_tostring(L, -1);
 249   if (path == NULL)
 250     luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
 251   return searchpath(L, name, path);
 252 }
 253
 254 static void loaderror(lua_State *L, const char *filename)
 255 {
 256   luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s",
 257              lua_tostring(L, 1), filename, lua_tostring(L, -1));
 258 }
 259
 260 static int lj_cf_package_loader_lua(lua_State *L)
 261 {
 262   const char *filename;
 263   const char *name = luaL_checkstring(L, 1);
 264   filename = findfile(L, name, "path");
 265   if (filename == NULL) return 1;  /* library not found in this path */
 266   if (luaL_loadfile(L, filename) != 0)
 267     loaderror(L, filename);
 268   return 1;  /* library loaded successfully */
 269 }
 270
 271 static const char *mkfuncname(lua_State *L, const char *modname)
 272 {
 273   const char *funcname;
 274   const char *mark = strchr(modname, *LUA_IGMARK);
 275   if (mark) modname = mark + 1;
 276   funcname = luaL_gsub(L, modname, ".", "_");
 277   funcname = lua_pushfstring(L, "luaopen_%s", funcname);
 278   lua_remove(L, -2);  /* remove 'gsub' result */
 279   return funcname;
 280 }
 281
 282 static int lj_cf_package_loader_c(lua_State *L)
 283 {
 284   const char *funcname;
 285   const char *name = luaL_checkstring(L, 1);
 286   const char *filename = findfile(L, name, "cpath");
 287   if (filename == NULL) return 1;  /* library not found in this path */
 288   funcname = mkfuncname(L, name);
 289   if (ll_loadfunc(L, filename, funcname) != 0)
 290     loaderror(L, filename);
 291   return 1;  /* library loaded successfully */
 292 }
 293
 294 static int lj_cf_package_loader_croot(lua_State *L)
 295 {
 296   const char *funcname;
 297   const char *filename;
 298   const char *name = luaL_checkstring(L, 1);
 299   const char *p = strchr(name, '.');
 300   int st;
 301   if (p == NULL) return 0;  /* is root */
 302   lua_pushlstring(L, name, (size_t)(p - name));
 303   filename = findfile(L, lua_tostring(L, -1), "cpath");
 304   if (filename == NULL) return 1;  /* root not found */
 305   funcname = mkfuncname(L, name);
 306   if ((st = ll_loadfunc(L, filename, funcname)) != 0) {
 307     if (st != PACKAGE_ERR_FUNC) loaderror(L, filename);  /* real error */
 308     lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
 309                     name, filename);
 310     return 1;  /* function not found */
 311   }
 312   return 1;
 313 }
 314
 315 static int lj_cf_package_loader_preload(lua_State *L)
 316 {
 317   const char *name = luaL_checkstring(L, 1);
 318   lua_getfield(L, LUA_ENVIRONINDEX, "preload");
 319   if (!lua_istable(L, -1))
 320     luaL_error(L, LUA_QL("package.preload") " must be a table");
 321   lua_getfield(L, -1, name);
 322   if (lua_isnil(L, -1))  /* not found? */
 323     lua_pushfstring(L, "\n\tno field package.preload['%s']", name);
 324   return 1;
 325 }
 326
 327 /* ------------------------------------------------------------------------ */
 328
 329 static const int sentinel_ = 0;
 330 #define sentinel        ((void *)&sentinel_)
 331
 332 static int lj_cf_package_require(lua_State *L)
 333 {
 334   const char *name = luaL_checkstring(L, 1);
 335   int i;
 336   lua_settop(L, 1);  /* _LOADED table will be at index 2 */
 337   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
 338   lua_getfield(L, 2, name);
 339   if (lua_toboolean(L, -1)) {  /* is it there? */
 340     if (lua_touserdata(L, -1) == sentinel)  /* check loops */
 341       luaL_error(L, "loop or previous error loading module " LUA_QS, name);
 342     return 1;  /* package is already loaded */
 343   }
 344   /* else must load it; iterate over available loaders */
 345   lua_getfield(L, LUA_ENVIRONINDEX, "loaders");
 346   if (!lua_istable(L, -1))
 347     luaL_error(L, LUA_QL("package.loaders") " must be a table");
 348   lua_pushliteral(L, "");  /* error message accumulator */
 349   for (i = 1; ; i++) {
 350     lua_rawgeti(L, -2, i);  /* get a loader */
 351     if (lua_isnil(L, -1))
 352       luaL_error(L, "module " LUA_QS " not found:%s",
 353                  name, lua_tostring(L, -2));
 354     lua_pushstring(L, name);
 355     lua_call(L, 1, 1);  /* call it */
 356     if (lua_isfunction(L, -1))  /* did it find module? */
 357       break;  /* module loaded successfully */
 358     else if (lua_isstring(L, -1))  /* loader returned error message? */
 359       lua_concat(L, 2);  /* accumulate it */
 360     else
 361       lua_pop(L, 1);
 362   }
 363   lua_pushlightuserdata(L, sentinel);
 364   lua_setfield(L, 2, name);  /* _LOADED[name] = sentinel */
 365   lua_pushstring(L, name);  /* pass name as argument to module */
 366   lua_call(L, 1, 1);  /* run loaded module */
 367   if (!lua_isnil(L, -1))  /* non-nil return? */
 368     lua_setfield(L, 2, name);  /* _LOADED[name] = returned value */
 369   lua_getfield(L, 2, name);
 370   if (lua_touserdata(L, -1) == sentinel) {   /* module did not set a value? */
 371     lua_pushboolean(L, 1);  /* use true as result */
 372     lua_pushvalue(L, -1);  /* extra copy to be returned */
 373     lua_setfield(L, 2, name);  /* _LOADED[name] = true */
 374   }
 375   lj_lib_checkfpu(L);
 376   return 1;
 377 }
 378
 379 /* ------------------------------------------------------------------------ */
 380
 381 static void setfenv(lua_State *L)
 382 {
 383   lua_Debug ar;
 384   if (lua_getstack(L, 1, &ar) == 0 ||
 385       lua_getinfo(L, "f", &ar) == 0 ||  /* get calling function */
 386       lua_iscfunction(L, -1))
 387     luaL_error(L, LUA_QL("module") " not called from a Lua function");
 388   lua_pushvalue(L, -2);
 389   lua_setfenv(L, -2);
 390   lua_pop(L, 1);
 391 }
 392
 393 static void dooptions(lua_State *L, int n)
 394 {
 395   int i;
 396   for (i = 2; i <= n; i++) {
 397     lua_pushvalue(L, i);  /* get option (a function) */
 398     lua_pushvalue(L, -2);  /* module */
 399     lua_call(L, 1, 0);
 400   }
 401 }
 402
 403 static void modinit(lua_State *L, const char *modname)
 404 {
 405   const char *dot;
 406   lua_pushvalue(L, -1);
 407   lua_setfield(L, -2, "_M");  /* module._M = module */
 408   lua_pushstring(L, modname);
 409   lua_setfield(L, -2, "_NAME");
 410   dot = strrchr(modname, '.');  /* look for last dot in module name */
 411   if (dot == NULL) dot = modname; else dot++;
 412   /* set _PACKAGE as package name (full module name minus last part) */
 413   lua_pushlstring(L, modname, (size_t)(dot - modname));
 414   lua_setfield(L, -2, "_PACKAGE");
 415 }
 416
 417 static int lj_cf_package_module(lua_State *L)
 418 {
 419   const char *modname = luaL_checkstring(L, 1);
 420   int loaded = lua_gettop(L) + 1;  /* index of _LOADED table */
 421   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
 422   lua_getfield(L, loaded, modname);  /* get _LOADED[modname] */
 423   if (!lua_istable(L, -1)) {  /* not found? */
 424     lua_pop(L, 1);  /* remove previous result */
 425     /* try global variable (and create one if it does not exist) */
 426     if (luaL_findtable(L, LUA_GLOBALSINDEX, modname, 1) != NULL)
 427       lj_err_callerv(L, LJ_ERR_BADMODN, modname);
 428     lua_pushvalue(L, -1);
 429     lua_setfield(L, loaded, modname);  /* _LOADED[modname] = new table */
 430   }
 431   /* check whether table already has a _NAME field */
 432   lua_getfield(L, -1, "_NAME");
 433   if (!lua_isnil(L, -1)) {  /* is table an initialized module? */
 434     lua_pop(L, 1);
 435   } else {  /* no; initialize it */
 436     lua_pop(L, 1);
 437     modinit(L, modname);
 438   }
 439   lua_pushvalue(L, -1);
 440   setfenv(L);
 441   dooptions(L, loaded - 1);
 442   return 0;
 443 }
 444
 445 static int lj_cf_package_seeall(lua_State *L)
 446 {
 447   luaL_checktype(L, 1, LUA_TTABLE);
 448   if (!lua_getmetatable(L, 1)) {
 449     lua_createtable(L, 0, 1); /* create new metatable */
 450     lua_pushvalue(L, -1);
 451     lua_setmetatable(L, 1);
 452   }
 453   lua_pushvalue(L, LUA_GLOBALSINDEX);
 454   lua_setfield(L, -2, "__index");  /* mt.__index = _G */
 455   return 0;
 456 }
 457
 458 /* ------------------------------------------------------------------------ */
 459
 460 #define AUXMARK         "\1"
 461
 462 static void setpath(lua_State *L, const char *fieldname, const char *envname,
 463                     const char *def)
 464 {
 465   const char *path = getenv(envname);
 466   if (path == NULL) {
 467     lua_pushstring(L, def);
 468   } else {
 469     path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP,
 470                               LUA_PATHSEP AUXMARK LUA_PATHSEP);
 471     luaL_gsub(L, path, AUXMARK, def);
 472     lua_remove(L, -2);
 473   }
 474   setprogdir(L);
 475   lua_setfield(L, -2, fieldname);
 476 }
 477
 478 static const luaL_Reg package_lib[] = {
 479   { "loadlib",  lj_cf_package_loadlib },
 480   { "searchpath",  lj_cf_package_searchpath },
 481   { "seeall",   lj_cf_package_seeall },
 482   { NULL, NULL }
 483 };
 484
 485 static const luaL_Reg package_global[] = {
 486   { "module",   lj_cf_package_module },
 487   { "require",  lj_cf_package_require },
 488   { NULL, NULL }
 489 };
 490
 491 static const lua_CFunction package_loaders[] =
 492 {
 493   lj_cf_package_loader_preload,
 494   lj_cf_package_loader_lua,
 495   lj_cf_package_loader_c,
 496   lj_cf_package_loader_croot,
 497   NULL
 498 };
 499
 500 LUALIB_API int luaopen_package(lua_State *L)
 501 {
 502   int i;
 503   luaL_newmetatable(L, "_LOADLIB");
 504   lj_lib_pushcf(L, lj_cf_package_unloadlib, 1);
 505   lua_setfield(L, -2, "__gc");
 506   luaL_register(L, LUA_LOADLIBNAME, package_lib);
 507   lua_pushvalue(L, -1);
 508   lua_replace(L, LUA_ENVIRONINDEX);
 509   lua_createtable(L, sizeof(package_loaders)/sizeof(package_loaders[0])-1, 0);
 510   for (i = 0; package_loaders[i] != NULL; i++) {
 511     lj_lib_pushcf(L, package_loaders[i], 1);
 512     lua_rawseti(L, -2, i+1);
 513   }
 514   lua_setfield(L, -2, "loaders");
 515   setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT);
 516   setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT);
 517   lua_pushliteral(L, LUA_PATH_CONFIG);
 518   lua_setfield(L, -2, "config");
 519   luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 16);
 520   lua_setfield(L, -2, "loaded");
 521   luaL_findtable(L, LUA_REGISTRYINDEX, "_PRELOAD", 4);
 522   lua_setfield(L, -2, "preload");
 523   lua_pushvalue(L, LUA_GLOBALSINDEX);
 524   luaL_register(L, NULL, package_global);
 525   lua_pop(L, 1);
 526   return 1;
 527 }
 528