blob: f2d7fe3c42aab54326140c4fab5498dddff1e704 [file] [log] [blame]
/*
** $Id: loadlib.c,v 1.107 2011/11/30 12:58:57 roberto Exp roberto $
** 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 Windows, and a stub for other
** systems.
*/
/*
** if needed, includes windows header before everything else
*/
#if defined(_WIN32)
#include <windows.h>
#endif
#include <stdlib.h>
#include <string.h>
#define loadlib_c
#define LUA_LIB
#include "lua.h"
#include "lauxlib.h"
#include "lualib.h"
/*
** LUA_PATH and LUA_CPATH are the names of the environment
** variables that Lua check to set its paths.
*/
#if !defined(LUA_PATH)
#define LUA_PATH "LUA_PATH"
#endif
#if !defined(LUA_CPATH)
#define LUA_CPATH "LUA_CPATH"
#endif
#define LUA_PATHSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
#define LUA_PATHVERSION LUA_PATH LUA_PATHSUFFIX
#define LUA_CPATHVERSION LUA_CPATH LUA_PATHSUFFIX
/*
** LUA_PATH_SEP is the character that separates templates in a path.
** LUA_PATH_MARK is the string that marks the substitution points in a
** template.
** LUA_EXEC_DIR in a Windows path is replaced by the executable's
** directory.
** LUA_IGMARK is a mark to ignore all before it when building the
** luaopen_ function name.
*/
#if !defined (LUA_PATH_SEP)
#define LUA_PATH_SEP ";"
#endif
#if !defined (LUA_PATH_MARK)
#define LUA_PATH_MARK "?"
#endif
#if !defined (LUA_EXEC_DIR)
#define LUA_EXEC_DIR "!"
#endif
#if !defined (LUA_IGMARK)
#define LUA_IGMARK "-"
#endif
/*
** LUA_CSUBSEP is the character that replaces dots in submodule names
** when searching for a C loader.
** LUA_LSUBSEP is the character that replaces dots in submodule names
** when searching for a Lua loader.
*/
#if !defined(LUA_CSUBSEP)
#define LUA_CSUBSEP LUA_DIRSEP
#endif
#if !defined(LUA_LSUBSEP)
#define LUA_LSUBSEP LUA_DIRSEP
#endif
/* 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)
/*
** system-dependent functions
*/
static void ll_unloadlib (void *lib);
static void *ll_load (lua_State *L, const char *path, int seeglb);
static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym);
#if defined(LUA_USE_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, int seeglb) {
void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL));
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.
** =======================================================================
*/
#undef setprogdir
/*
** optional flags for LoadLibraryEx
*/
#if !defined(LUA_LLE_FLAGS)
#define LUA_LLE_FLAGS 0
#endif
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_EXEC_DIR, 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)/sizeof(char), NULL))
lua_pushstring(L, buffer);
else
lua_pushfstring(L, "system error %d\n", error);
}
static void ll_unloadlib (void *lib) {
FreeLibrary((HMODULE)lib);
}
static void *ll_load (lua_State *L, const char *path, int seeglb) {
HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS);
(void)(seeglb); /* not used: symbols are 'global' by default */
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((HMODULE)lib, sym);
if (f == NULL) pusherror(L);
return f;
}
/* }====================================================== */
#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); /* not used */
}
static void *ll_load (lua_State *L, const char *path, int seeglb) {
(void)(path); (void)(seeglb); /* not used */
lua_pushliteral(L, DLMSG);
return NULL;
}
static lua_CFunction ll_sym (lua_State *L, void *lib, const char *sym) {
(void)(lib); (void)(sym); /* not used */
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); /* remove result from gettable */
plib = (void **)lua_newuserdata(L, sizeof(const void *));
*plib = NULL;
luaL_setmetatable(L, "_LOADLIB");
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, *sym == '*');
if (*reg == NULL) return ERRLIB; /* unable to load library */
if (*sym == '*') { /* loading only library (no function)? */
lua_pushboolean(L, 1); /* return 'true' */
return 0; /* no errors */
}
else {
lua_CFunction f = ll_sym(L, *reg, sym);
if (f == NULL)
return ERRFUNC; /* unable to find function */
lua_pushcfunction(L, f); /* else create new function */
return 0; /* no errors */
}
}
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_PATH_SEP) path++; /* skip separators */
if (*path == '\0') return NULL; /* no more templates */
l = strchr(path, *LUA_PATH_SEP); /* find next separator */
if (l == NULL) l = path + strlen(path);
lua_pushlstring(L, path, l - path); /* template */
return l;
}
static const char *searchpath (lua_State *L, const char *name,
const char *path,
const char *sep,
const char *dirsep) {
luaL_Buffer msg; /* to build error message */
luaL_buffinit(L, &msg);
if (*sep != '\0') /* non-empty separator? */
name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
while ((path = pushnexttemplate(L, path)) != NULL) {
const char *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 */
luaL_addvalue(&msg); /* concatenate error msg. entry */
}
luaL_pushresult(&msg); /* create error message */
return NULL; /* not found */
}
static int ll_searchpath (lua_State *L) {
const char *f = searchpath(L, luaL_checkstring(L, 1),
luaL_checkstring(L, 2),
luaL_optstring(L, 3, "."),
luaL_optstring(L, 4, LUA_DIRSEP));
if (f != NULL) return 1;
else { /* error message is on top of the stack */
lua_pushnil(L);
lua_insert(L, -2);
return 2; /* return nil + error message */
}
}
static const char *findfile (lua_State *L, const char *name,
const char *pname,
const char *dirsep) {
const char *path;
lua_getfield(L, lua_upvalueindex(1), pname);
path = lua_tostring(L, -1);
if (path == NULL)
luaL_error(L, LUA_QL("package.%s") " must be a string", pname);
return searchpath(L, name, path, ".", dirsep);
}
static int checkload (lua_State *L, int stat, const char *filename) {
if (stat) { /* module loaded successfully? */
lua_pushstring(L, filename); /* will be 2nd argument to module */
return 2; /* return open function and file name */
}
else
return 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 searcher_Lua (lua_State *L) {
const char *filename;
const char *name = luaL_checkstring(L, 1);
filename = findfile(L, name, "path", LUA_LSUBSEP);
if (filename == NULL) return 1; /* module not found in this path */
return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename);
}
static int loadfunc (lua_State *L, const char *filename, const char *modname) {
const char *funcname;
const char *mark;
modname = luaL_gsub(L, modname, ".", LUA_OFSEP);
mark = strchr(modname, *LUA_IGMARK);
if (mark) {
int stat;
funcname = lua_pushlstring(L, modname, mark - modname);
funcname = lua_pushfstring(L, POF"%s", funcname);
stat = ll_loadfunc(L, filename, funcname);
if (stat != ERRFUNC) return stat;
modname = mark + 1; /* else go ahead and try old-style name */
}
funcname = lua_pushfstring(L, POF"%s", modname);
return ll_loadfunc(L, filename, funcname);
}
static int searcher_C (lua_State *L) {
const char *name = luaL_checkstring(L, 1);
const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP);
if (filename == NULL) return 1; /* module not found in this path */
return checkload(L, (loadfunc(L, filename, name) == 0), filename);
}
static int searcher_Croot (lua_State *L) {
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", LUA_CSUBSEP);
if (filename == NULL) return 1; /* root not found */
if ((stat = loadfunc(L, filename, name)) != 0) {
if (stat != ERRFUNC)
return checkload(L, 0, filename); /* real error */
else { /* open function not found */
lua_pushfstring(L, "\n\tno module " LUA_QS " in file " LUA_QS,
name, filename);
return 1;
}
}
lua_pushstring(L, filename); /* will be 2nd argument to module */
return 2;
}
static int searcher_preload (lua_State *L) {
const char *name = luaL_checkstring(L, 1);
lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD");
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 void findloader (lua_State *L, const char *name) {
int i;
luaL_Buffer msg; /* to build error message */
luaL_buffinit(L, &msg);
lua_getfield(L, lua_upvalueindex(1), "searchers"); /* will be at index 3 */
if (!lua_istable(L, 3))
luaL_error(L, LUA_QL("package.searchers") " must be a table");
/* iterate over available seachers to find a loader */
for (i = 1; ; i++) {
lua_rawgeti(L, 3, i); /* get a seacher */
if (lua_isnil(L, -1)) { /* no more searchers? */
lua_pop(L, 1); /* remove nil */
luaL_pushresult(&msg); /* create error message */
luaL_error(L, "module " LUA_QS " not found:%s",
name, lua_tostring(L, -1));
}
lua_pushstring(L, name);
lua_call(L, 1, 2); /* call it */
if (lua_isfunction(L, -2)) /* did it find a loader? */
return; /* module loader found */
else if (lua_isstring(L, -2)) { /* searcher returned error message? */
lua_pop(L, 1); /* remove extra return */
luaL_addvalue(&msg); /* concatenate error message */
}
else
lua_pop(L, 2); /* remove both returns */
}
}
static int ll_require (lua_State *L) {
const char *name = luaL_checkstring(L, 1);
lua_settop(L, 1); /* _LOADED table will be at index 2 */
lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
lua_getfield(L, 2, name); /* _LOADED[name] */
if (lua_toboolean(L, -1)) /* is it there? */
return 1; /* package is already loaded */
/* else must load package */
lua_pop(L, 1); /* remove 'getfield' result */
findloader(L, name);
lua_pushstring(L, name); /* pass name as argument to module loader */
lua_insert(L, -2); /* name is 1st argument (before search data) */
lua_call(L, 2, 1); /* run loader to load 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_isnil(L, -1)) { /* 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
** =======================================================
*/
#if defined(LUA_COMPAT_MODULE)
/*
** changes the environment variable of calling function
*/
static void set_env (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); /* copy new environment table to top */
lua_setupvalue(L, -2, 1);
lua_pop(L, 1); /* remove function */
}
static void dooptions (lua_State *L, int n) {
int i;
for (i = 2; i <= n; i++) {
if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */
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 lastarg = lua_gettop(L); /* last parameter */
luaL_pushmodule(L, modname, 1); /* get/create module 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);
set_env(L);
dooptions(L, lastarg);
return 1;
}
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_pushglobaltable(L);
lua_setfield(L, -2, "__index"); /* mt.__index = _G */
return 0;
}
#endif
/* }====================================================== */
/* auxiliary mark (for internal use) */
#define AUXMARK "\1"
/*
** return registry.LUA_NOENV as a boolean
*/
static int noenv (lua_State *L) {
int b;
lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
b = lua_toboolean(L, -1);
lua_pop(L, 1); /* remove value */
return b;
}
static void setpath (lua_State *L, const char *fieldname, const char *envname1,
const char *envname2, const char *def) {
const char *path = getenv(envname1);
if (path == NULL) /* no environment variable? */
path = getenv(envname2); /* try alternative name */
if (path == NULL || noenv(L)) /* 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_PATH_SEP LUA_PATH_SEP,
LUA_PATH_SEP AUXMARK LUA_PATH_SEP);
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},
{"searchpath", ll_searchpath},
#if defined(LUA_COMPAT_MODULE)
{"seeall", ll_seeall},
#endif
{NULL, NULL}
};
static const luaL_Reg ll_funcs[] = {
#if defined(LUA_COMPAT_MODULE)
{"module", ll_module},
#endif
{"require", ll_require},
{NULL, NULL}
};
static const lua_CFunction searchers[] =
{searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL};
LUAMOD_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_newlib(L, pk_funcs);
/* create 'searchers' table */
lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0);
/* fill it with pre-defined searchers */
for (i=0; searchers[i] != NULL; i++) {
lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
lua_pushcclosure(L, searchers[i], 1);
lua_rawseti(L, -2, i+1);
}
#if defined(LUA_COMPAT_LOADERS)
lua_pushvalue(L, -1); /* make a copy of 'searchers' table */
lua_setfield(L, -3, "loaders"); /* put it in field `loaders' */
#endif
lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */
/* set field 'path' */
setpath(L, "path", LUA_PATHVERSION, LUA_PATH, LUA_PATH_DEFAULT);
/* set field 'cpath' */
setpath(L, "cpath", LUA_CPATHVERSION, LUA_CPATH, LUA_CPATH_DEFAULT);
/* store config information */
lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n"
LUA_EXEC_DIR "\n" LUA_IGMARK "\n");
lua_setfield(L, -2, "config");
/* set field `loaded' */
luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
lua_setfield(L, -2, "loaded");
/* set field `preload' */
luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD");
lua_setfield(L, -2, "preload");
lua_pushglobaltable(L);
lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
lua_pop(L, 1); /* pop global table */
return 1; /* return 'package' table */
}