ref: 7caf0e1b5286fc68229f60749d12e6ad28b3e01c
dir: /lua/src/loadlib.c/
/*
** $Id: loadlib.c,v 1.1 2006/12/23 01:55:12 rrt 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 "lauxlib.h"
#include "lobject.h"
#include "lua.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 = GetModuleFileName(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 (FormatMessage(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 = LoadLibrary(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_pushstring(L, ""); /* error accumulator */
while ((path = pushnexttemplate(L, path)) != NULL) {
const char *filename;
filename = luaL_gsub(L, lua_tostring(L, -1), LUA_PATH_MARK, name);
if (readable(filename)) /* does file exist and is readable? */
return filename; /* return that file name */
lua_pop(L, 2); /* remove path template and file name */
luaO_pushfstring(L, "\n\tno file " LUA_QS, filename);
lua_concat(L, 2);
}
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 */
luaO_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? */
luaO_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_pushstring(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;
lua_getstack(L, 1, &ar);
lua_getinfo(L, "f", &ar);
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_pushstring(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 */
}