/* ** $Id: loadlib.c,v 1.52.1.3 2008/08/06 13:29:28 roberto Exp $ ** Dynamic library loader for Lua ** See Copyright Notice in lua.h ** ** This module contains an implementation of loadlib for Unix systems ** that have dlfcn, an implementation for Darwin (Mac OS X), an ** implementation for Windows, and a stub for other systems. */ #include <stdlib.h> #include <string.h> #define loadlib_c #define LUA_LIB #include "lua.h" #include "lauxlib.h" #include "lualib.h" /* prefix for open functions in C libraries */ #define LUA_POF "luaopen_" /* separator for open functions in C libraries */ #define LUA_OFSEP "_" #define LIBPREFIX "LOADLIB: " #define POF LUA_POF #define LIB_FAIL "open" /* error codes for ll_loadfunc */ #define ERRLIB 1 #define ERRFUNC 2 #define setprogdir(L) ((void)0) static void ll_unloadlib (void *lib); static void *ll_load (lua_State *L, const char *path); static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym); #if defined(LUA_DL_DLOPEN) /* ** {======================================================================== ** This is an implementation of loadlib based on the dlfcn interface. ** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD, ** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least ** as an emulation layer on top of native functions. ** ========================================================================= */ #include <dlfcn.h> static void ll_unloadlib (void *lib) { dlclose(lib); } static void *ll_load (lua_State *L, const char *path) { void *lib = dlopen(path, RTLD_NOW); if (lib == NULL) lua_pushstring(L, dlerror()); return lib; } static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) { lua_CFunction f = (lua_CFunction)dlsym(lib, sym); if (f == NULL) lua_pushstring(L, dlerror()); return f; } /* }====================================================== */ #elif defined(LUA_DL_DLL) /* ** {====================================================================== ** This is an implementation of loadlib for Windows using native functions. ** ======================================================================= */ #include <windows.h> #undef setprogdir static void setprogdir (lua_State *L) { char buff[MAX_PATH + 1]; char *lb; DWORD nsize = sizeof(buff)/sizeof(char); DWORD n = GetModuleFileNameA(NULL, buff, nsize); if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) luaL_error(L, "unable to get ModuleFileName"); else { *lb = '\0'; luaL_gsub(L, lua_tostring(L, -1), LUA_EXECDIR, buff); lua_remove(L, -2); /* remove original string */ } } static void pusherror (lua_State *L) { int error = GetLastError(); char buffer[128]; if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, buffer, sizeof(buffer), NULL)) lua_pushstring(L, buffer); else lua_pushfstring(L, "system error %d\n", error); } static void ll_unloadlib (void *lib) { FreeLibrary((HINSTANCE)lib); } static void *ll_load (lua_State *L, const char *path) { HINSTANCE lib = LoadLibraryA(path); if (lib == NULL) pusherror(L); return lib; } static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) { lua_CFunction f = (lua_CFunction)GetProcAddress((HINSTANCE)lib, sym); if (f == NULL) pusherror(L); return f; } /* }====================================================== */ #elif defined(LUA_DL_DYLD) /* ** {====================================================================== ** Native Mac OS X / Darwin Implementation ** ======================================================================= */ #include <mach-o/dyld.h> /* Mac appends a `_' before C function names */ #undef POF #define POF "_" LUA_POF static void pusherror (lua_State *L) { const char *err_str; const char *err_file; NSLinkEditErrors err; int err_num; NSLinkEditError(&err, &err_num, &err_file, &err_str); lua_pushstring(L, err_str); } static const char *errorfromcode (NSObjectFileImageReturnCode ret) { switch (ret) { case NSObjectFileImageInappropriateFile: return "file is not a bundle"; case NSObjectFileImageArch: return "library is for wrong CPU type"; case NSObjectFileImageFormat: return "bad format"; case NSObjectFileImageAccess: return "cannot access file"; case NSObjectFileImageFailure: default: return "unable to load library"; } } static void ll_unloadlib (void *lib) { NSUnLinkModule((NSModule)lib, NSUNLINKMODULE_OPTION_RESET_LAZY_REFERENCES); } static void *ll_load (lua_State *L, const char *path) { NSObjectFileImage img; NSObjectFileImageReturnCode ret; /* this would be a rare case, but prevents crashing if it happens */ if(!_dyld_present()) { lua_pushliteral(L, "dyld not present"); return NULL; } ret = NSCreateObjectFileImageFromFile(path, &img); if (ret == NSObjectFileImageSuccess) { NSModule mod = NSLinkModule(img, path, NSLINKMODULE_OPTION_PRIVATE | NSLINKMODULE_OPTION_RETURN_ON_ERROR); NSDestroyObjectFileImage(img); if (mod == NULL) pusherror(L); return mod; } lua_pushstring(L, errorfromcode(ret)); return NULL; } static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) { NSSymbol nss = NSLookupSymbolInModule((NSModule)lib, sym); if (nss == NULL) { lua_pushfstring(L, "symbol " LUA_QS " not found", sym); return NULL; } return (lua_CFunction)NSAddressOfSymbol(nss); } /* }====================================================== */ #else /* ** {====================================================== ** Fallback for other systems ** ======================================================= */ #undef LIB_FAIL #define LIB_FAIL "absent" #define DLMSG "dynamic libraries not enabled; check your Lua installation" static void ll_unloadlib (void *lib) { (void)lib; /* to avoid warnings */ } static void *ll_load (lua_State *L, const char *path) { (void)path; /* to avoid warnings */ lua_pushliteral(L, DLMSG); return NULL; } static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) { (void)lib; (void)sym; /* to avoid warnings */ lua_pushliteral(L, DLMSG); return NULL; } /* }====================================================== */ #endif static void **ll_register (lua_State *L, const char *path) { void **plib; lua_pushfstring(L, "%s%s", LIBPREFIX, path); lua_gettable(L, LUA_REGISTRYINDEX); /* check library in registry? */ if (!lua_isnil(L, -1)) /* is there an entry? */ plib = (void **)lua_touserdata(L, -1); else { /* no entry yet; create one */ lua_pop(L, 1); plib = (void **)lua_newuserdata(L, sizeof(const void *)); *plib = NULL; luaL_getmetatable(L, "_LOADLIB"); lua_setmetatable(L, -2); lua_pushfstring(L, "%s%s", LIBPREFIX, path); lua_pushvalue(L, -2); lua_settable(L, LUA_REGISTRYINDEX); } return plib; } /* ** __gc tag method: calls library's `ll_unloadlib' function with the lib ** handle */ static int gctm (lua_State *L) { void **lib = (void **)luaL_checkudata(L, 1, "_LOADLIB"); if (*lib) ll_unloadlib(*lib); *lib = NULL; /* mark library as closed */ return 0; } static int ll_loadfunc (lua_State *L, const char *path, const char *sym) { void **reg = ll_register(L, path); if (*reg == NULL) *reg = ll_load(L, path); if (*reg == NULL) return ERRLIB; /* unable to load library */ else { lua_CFunction f = ll_sym(L, *reg, sym); if (f == NULL) return ERRFUNC; /* unable to find function */ lua_pushcfunction(L, f); return 0; /* return function */ } } static int ll_loadlib (lua_State *L) { const char *path = luaL_checkstring(L, 1); const char *init = luaL_checkstring(L, 2); int stat = ll_loadfunc(L, path, init); if (stat == 0) /* no errors? */ return 1; /* return the loaded function */ else { /* error; error message is on stack top */ lua_pushnil(L); lua_insert(L, -2); lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init"); return 3; /* return nil, error message, and where */ } } /* ** {====================================================== ** 'require' function ** ======================================================= */ static int readable (const char *filename) { FILE *f = fopen(filename, "r"); /* try to open file */ if (f == NULL) return 0; /* open failed */ fclose(f); return 1; } static const char *pushnexttemplate (lua_State *L, const char *path) { const char *l; while (*path == *LUA_PATHSEP) path++; /* skip separators */ if (*path == '\0') return NULL; /* no more templates */ l = strchr(path, *LUA_PATHSEP); /* find next separator */ if (l == NULL) l = path + strlen(path); lua_pushlstring(L, path, l - path); /* template */ return l; } static const char *findfile (lua_State *L, const char *name, const char *pname) { const char *path; name = luaL_gsub(L, name, ".", LUA_DIRSEP); lua_getfield(L, LUA_ENVIRONINDEX, pname); path = lua_tostring(L, -1); if (path == NULL) luaL_error(L, LUA_QL("package.%s") " must be a string", pname); lua_pushliteral(L, ""); /* error accumulator */ while ((path = pushnexttemplate(L, path)) != NULL) { const char *filename; filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name); lua_remove(L, -2); /* remove path template */ if (readable(filename)) /* does file exist and is readable? */ return filename; /* return that file name */ lua_pushfstring(L, "\n\tno file " LUA_QS, filename); lua_remove(L, -2); /* remove file name */ lua_concat(L, 2); /* add entry to possible error message */ } return NULL; /* not found */ } static void loaderror (lua_State *L, const char *filename) { luaL_error(L, "error loading module " LUA_QS " from file " LUA_QS ":\n\t%s", lua_tostring(L, 1), filename, lua_tostring(L, -1)); } static int loader_Lua (lua_State *L) { const char *filename; const char *name = luaL_checkstring(L, 1); filename = findfile(L, name, "path"); if (filename == NULL) return 1; /* library not found in this path */ if (luaL_loadfile(L, filename) != 0) loaderror(L, filename); return 1; /* library loaded successfully */ } static const char *mkfuncname (lua_State *L, const char *modname) { const char *funcname; const char *mark = strchr(modname, *LUA_IGMARK); if (mark) modname = mark + 1; funcname = luaL_gsub(L, modname, ".", LUA_OFSEP); funcname = lua_pushfstring(L, POF"%s", funcname); lua_remove(L, -2); /* remove 'gsub' result */ return funcname; } static int loader_C (lua_State *L) { const char *funcname; const char *name = luaL_checkstring(L, 1); const char *filename = findfile(L, name, "cpath"); if (filename == NULL) return 1; /* library not found in this path */ funcname = mkfuncname(L, name); if (ll_loadfunc(L, filename, funcname) != 0) loaderror(L, filename); return 1; /* library loaded successfully */ } static int loader_Croot (lua_State *L) { const char *funcname; const char *filename; const char *name = luaL_checkstring(L, 1); const char *p = strchr(name, '.'); int stat; if (p == NULL) return 0; /* is root */ lua_pushlstring(L, name, p - name); filename = findfile(L, lua_tostring(L, -1), "cpath"); if (filename == NULL) return 1; /* root not found */ funcname = mkfuncname(L, name); if ((stat = ll_loadfunc(L, filename, funcname)) != 0) { if (stat != ERRFUNC) loaderror(L, filename); /* real error */ lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS, name, filename); return 1; /* function not found */ } return 1; } static int loader_preload (lua_State *L) { const char *name = luaL_checkstring(L, 1); lua_getfield(L, LUA_ENVIRONINDEX, "preload"); if (!lua_istable(L, -1)) luaL_error(L, LUA_QL("package.preload") " must be a table"); lua_getfield(L, -1, name); if (lua_isnil(L, -1)) /* not found? */ lua_pushfstring(L, "\n\tno field package.preload['%s']", name); return 1; } static const int sentinel_ = 0; #define sentinel ((void *)&sentinel_) static int ll_require (lua_State *L) { const char *name = luaL_checkstring(L, 1); int i; lua_settop(L, 1); /* _LOADED table will be at index 2 */ lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED"); lua_getfield(L, 2, name); if (lua_toboolean(L, -1)) { /* is it there? */ if (lua_touserdata(L, -1) == sentinel) /* check loops */ luaL_error(L, "loop or previous error loading module " LUA_QS, name); return 1; /* package is already loaded */ } /* else must load it; iterate over available loaders */ lua_getfield(L, LUA_ENVIRONINDEX, "loaders"); if (!lua_istable(L, -1)) luaL_error(L, LUA_QL("package.loaders") " must be a table"); lua_pushliteral(L, ""); /* error message accumulator */ for (i=1; ; i++) { lua_rawgeti(L, -2, i); /* get a loader */ if (lua_isnil(L, -1)) luaL_error(L, "module " LUA_QS " not found:%s", name, lua_tostring(L, -2)); lua_pushstring(L, name); lua_call(L, 1, 1); /* call it */ if (lua_isfunction(L, -1)) /* did it find module? */ break; /* module loaded successfully */ else if (lua_isstring(L, -1)) /* loader returned error message? */ lua_concat(L, 2); /* accumulate it */ else lua_pop(L, 1); } lua_pushlightuserdata(L, sentinel); lua_setfield(L, 2, name); /* _LOADED[name] = sentinel */ lua_pushstring(L, name); /* pass name as argument to module */ lua_call(L, 1, 1); /* run loaded module */ if (!lua_isnil(L, -1)) /* non-nil return? */ lua_setfield(L, 2, name); /* _LOADED[name] = returned value */ lua_getfield(L, 2, name); if (lua_touserdata(L, -1) == sentinel) { /* module did not set a value? */ lua_pushboolean(L, 1); /* use true as result */ lua_pushvalue(L, -1); /* extra copy to be returned */ lua_setfield(L, 2, name); /* _LOADED[name] = true */ } return 1; } /* }====================================================== */ /* ** {====================================================== ** 'module' function ** ======================================================= */ static void setfenv (lua_State *L) { lua_Debug ar; if (lua_getstack(L, 1, &ar) == 0 || lua_getinfo(L, "f", &ar) == 0 || /* get calling function */ lua_iscfunction(L, -1)) luaL_error(L, LUA_QL("module") " not called from a Lua function"); lua_pushvalue(L, -2); lua_setfenv(L, -2); lua_pop(L, 1); } static void dooptions (lua_State *L, int n) { int i; for (i = 2; i <= n; i++) { lua_pushvalue(L, i); /* get option (a function) */ lua_pushvalue(L, -2); /* module */ lua_call(L, 1, 0); } } static void modinit (lua_State *L, const char *modname) { const char *dot; lua_pushvalue(L, -1); lua_setfield(L, -2, "_M"); /* module._M = module */ lua_pushstring(L, modname); lua_setfield(L, -2, "_NAME"); dot = strrchr(modname, '.'); /* look for last dot in module name */ if (dot == NULL) dot = modname; else dot++; /* set _PACKAGE as package name (full module name minus last part) */ lua_pushlstring(L, modname, dot - modname); lua_setfield(L, -2, "_PACKAGE"); } static int ll_module (lua_State *L) { const char *modname = luaL_checkstring(L, 1); int loaded = lua_gettop(L) + 1; /* index of _LOADED table */ lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED"); lua_getfield(L, loaded, modname); /* get _LOADED[modname] */ 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, modname, 1) != NULL) return luaL_error(L, "name conflict for module " LUA_QS, modname); lua_pushvalue(L, -1); lua_setfield(L, loaded, modname); /* _LOADED[modname] = new table */ } /* check whether table already has a _NAME field */ lua_getfield(L, -1, "_NAME"); if (!lua_isnil(L, -1)) /* is table an initialized module? */ lua_pop(L, 1); else { /* no; initialize it */ lua_pop(L, 1); modinit(L, modname); } lua_pushvalue(L, -1); setfenv(L); dooptions(L, loaded - 1); return 0; } static int ll_seeall (lua_State *L) { luaL_checktype(L, 1, LUA_TTABLE); if (!lua_getmetatable(L, 1)) { lua_createtable(L, 0, 1); /* create new metatable */ lua_pushvalue(L, -1); lua_setmetatable(L, 1); } lua_pushvalue(L, LUA_GLOBALSINDEX); lua_setfield(L, -2, "__index"); /* mt.__index = _G */ return 0; } /* }====================================================== */ /* auxiliary mark (for internal use) */ #define AUXMARK "\1" static void setpath (lua_State *L, const char *fieldname, const char *envname, const char *def) { const char *path = getenv(envname); if (path == NULL) /* no environment variable? */ lua_pushstring(L, def); /* use default */ else { /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */ path = luaL_gsub(L, path, LUA_PATHSEP LUA_PATHSEP, LUA_PATHSEP AUXMARK LUA_PATHSEP); luaL_gsub(L, path, AUXMARK, def); lua_remove(L, -2); } setprogdir(L); lua_setfield(L, -2, fieldname); } static const luaL_Reg pk_funcs[] = { {"loadlib", ll_loadlib}, {"seeall", ll_seeall}, {NULL, NULL} }; static const luaL_Reg ll_funcs[] = { {"module", ll_module}, {"require", ll_require}, {NULL, NULL} }; static const lua_CFunction loaders[] = {loader_preload, loader_Lua, loader_C, loader_Croot, NULL}; LUALIB_API int luaopen_package (lua_State *L) { int i; /* create new type _LOADLIB */ luaL_newmetatable(L, "_LOADLIB"); lua_pushcfunction(L, gctm); lua_setfield(L, -2, "__gc"); /* create `package' table */ luaL_register(L, LUA_LOADLIBNAME, pk_funcs); #if defined(LUA_COMPAT_LOADLIB) lua_getfield(L, -1, "loadlib"); lua_setfield(L, LUA_GLOBALSINDEX, "loadlib"); #endif lua_pushvalue(L, -1); lua_replace(L, LUA_ENVIRONINDEX); /* create `loaders' table */ lua_createtable(L, 0, sizeof(loaders)/sizeof(loaders[0]) - 1); /* fill it with pre-defined loaders */ for (i=0; loaders[i] != NULL; i++) { lua_pushcfunction(L, loaders[i]); lua_rawseti(L, -2, i+1); } lua_setfield(L, -2, "loaders"); /* put it in field `loaders' */ setpath(L, "path", LUA_PATH, LUA_PATH_DEFAULT); /* set field `path' */ setpath(L, "cpath", LUA_CPATH, LUA_CPATH_DEFAULT); /* set field `cpath' */ /* store config information */ lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATHSEP "\n" LUA_PATH_MARK "\n" LUA_EXECDIR "\n" LUA_IGMARK); lua_setfield(L, -2, "config"); /* set field `loaded' */ luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 2); lua_setfield(L, -2, "loaded"); /* set field `preload' */ lua_newtable(L); lua_setfield(L, -2, "preload"); lua_pushvalue(L, LUA_GLOBALSINDEX); luaL_register(L, NULL, ll_funcs); /* open lib into global table */ lua_pop(L, 1); return 1; /* return 'package' table */ }