diff options
Diffstat (limited to 'common/lua/loadlib.cpp')
| -rw-r--r-- | common/lua/loadlib.cpp | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/common/lua/loadlib.cpp b/common/lua/loadlib.cpp new file mode 100644 index 0000000000..599e07f6c6 --- /dev/null +++ b/common/lua/loadlib.cpp @@ -0,0 +1,331 @@ +/* +** $Id$ +** 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. +*/ + + +#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" + + +/* +** {====================================================== +** Fallback for other systems +** ======================================================= +*/ + +#undef LIB_FAIL +#define LIB_FAIL "absent" + + +#define DLMSG "dynamic libraries not enabled; check your Lua installation" + + +/* }====================================================== */ + + + +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"); + *lib = NULL; /* mark library as closed */ + return 0; +} + + +/* error codes for ll_loadfunc */ +#define ERRLIB 1 +#define ERRFUNC 2 + + +static int ll_loadlib (lua_State *L) { + const char *path = luaL_checkstring(L, 1); +// const char *init = luaL_checkstring(L, 2); + int stat; + void **reg = ll_register(L, path); + if (*reg == NULL) { + stat = ERRLIB; /* unable to load library */ + } else { + stat = ERRFUNC; /* unable to find function */ + } + lua_pushliteral(L, DLMSG); + + /* 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 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; + 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; +} + + +/* }====================================================== */ + + + +static void setpath (lua_State *L, const char *fieldname, const char *envname, + const char *def) { + // no environment variable -> use default + lua_pushstring(L, def); + 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, 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 */ +} |