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authorBenoit Giannangeli <giann008@gmail.com>2017-05-02 15:01:54 +0200
committerBenoit Giannangeli <giann008@gmail.com>2017-05-03 13:28:11 +0200
commitd231ed14d0816eb26856e948a9ab72f64d46c1eb (patch)
tree4e85b5237878770195aedb362b6bd446f7f2596c /src/loadlib.js
parent5ac211f983cd628dfb95a6add7e5386071f4dada (diff)
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loadlib.js
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+"use strict";
+
+const lua = require('./lua.js');
+const lauxlib = require('./lauxlib.js');
+
+const fs = require('fs');
+
+
+const LUA_IGMARK = ["-".charCodeAt(0)];
+
+const CLIBS = lua.to_luastring("__CLIBS__", true);
+const LUA_PATH_VAR = "LUA_PATH";
+const LUA_CPATH_VAR = "LUA_CPATH";
+
+/*
+** 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.
+*/
+const LUA_CSUBSEP = lua.LUA_DIRSEP;
+const LUA_LSUBSEP = lua.LUA_DIRSEP;
+
+/* prefix for open functions in C libraries */
+const LUA_POF = "luaopen_";
+
+/* separator for open functions in C libraries */
+const LUA_OFSEP = "_";
+// const LIB_FAIL = "open";
+
+const AUXMARK = [1];
+
+
+const LIB_FAIL = "absent";
+const DLMSG = "dynamic libraries not enabled; check your Lua installation";
+
+
+const lsys_unloadlib = function(lib) {
+};
+
+
+const lsys_load = function(L, path, seeglb) {
+ lua.lua_pushliteral(L, DLMSG);
+ return null;
+};
+
+
+const lsys_sym = function(L, lib, sym) {
+ lua.lua_pushliteral(L, DLMSG);
+ return null;
+};
+
+/*
+** return registry.LUA_NOENV as a boolean
+*/
+const noenv = function(L) {
+ lua.lua_getfield(L, lua.LUA_REGISTRYINDEX, "LUA_NOENV");
+ let b = lua.lua_toboolean(L, -1);
+ lua.lua_pop(L, 1); /* remove value */
+ return b;
+};
+
+const readable = function(filename) {
+ try {
+ fs.openSync(lua.to_jsstring(filename), 'r');
+ } catch (e) {
+ return false;
+ }
+
+ return true;
+};
+
+/* error codes for 'lookforfunc' */
+const ERRLIB = 1;
+const ERRFUNC = 2;
+
+/*
+** Look for a C function named 'sym' in a dynamically loaded library
+** 'path'.
+** First, check whether the library is already loaded; if not, try
+** to load it.
+** Then, if 'sym' is '*', return true (as library has been loaded).
+** Otherwise, look for symbol 'sym' in the library and push a
+** C function with that symbol.
+** Return 0 and 'true' or a function in the stack; in case of
+** errors, return an error code and an error message in the stack.
+*/
+const lookforfunc = function(L, path, sym) {
+ let reg = checkclib(L, path); /* check loaded C libraries */
+ if (reg === null) { /* must load library? */
+ reg = lsys_load(L, path, sym[0] === '*'.charCodeAt(0)); /* a global symbols if 'sym'=='*' */
+ if (reg === null) return ERRLIB; /* unable to load library */
+ addtoclib(L, path, reg);
+ }
+ if (sym[0] === '*'.charCodeAt(0)) { /* loading only library (no function)? */
+ lua.lua_pushboolean(L, 1); /* return 'true' */
+ return 0; /* no errors */
+ }
+ else {
+ let f = lsys_sym(L, reg, sym);
+ if (f === null)
+ return ERRFUNC; /* unable to find function */
+ lua.lua_pushcfunction(L, f); /* else create new function */
+ return 0; /* no errors */
+ }
+};
+
+/*
+** Set a path
+*/
+const setpath = function(L, fieldname, envname, dft) {
+ let nver = lua.lua_pushstring(L, lua.to_luastring(`${envname}${lua.LUA_VERSUFFIX}`, true));
+ let path = process.env[nver]; /* use versioned name */
+ if (path === undefined) /* no environment variable? */
+ path = process.env[envname]; /* try unversioned name */
+ if (path === undefined || noenv(L)) /* no environment variable? */
+ lua.lua_pushstring(L, lua.to_luastring(dft, true)); /* use default */
+ else {
+ /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */
+ path = lauxlib.luaL_gsub(
+ L,
+ lua.to_luastring(path),
+ lua.to_luastring(lua.LUA_PATH_SEP + lua.LUA_PATH_SEP, true),
+ lua.to_luastring(lua.LUA_PATH_SEP, true)
+ .concat(AUXMARK)
+ .concat(lua.to_luastring(lua.LUA_PATH_SEP, true))
+ );
+ lauxlib.luaL_gsub(L, path, AUXMARK, dft);
+ lua.lua_remove(L, -2); /* remove result from 1st 'gsub' */
+ }
+ lua.lua_setfield(L, -3, fieldname); /* package[fieldname] = path value */
+ lua.lua_pop(L, 1); /* pop versioned variable name */
+};
+
+/*
+** return registry.CLIBS[path]
+*/
+const checkclib = function(L, path) {
+ lua.lua_rawgetp(L, lua.LUA_REGISTRYINDEX, CLIBS);
+ lua.lua_getfield(L, -1, path);
+ let plib = lua.lua_touserdata(L, -1); /* plib = CLIBS[path] */
+ lua.lua_pop(L, 2); /* pop CLIBS table and 'plib' */
+ return plib;
+};
+
+/*
+** registry.CLIBS[path] = plib -- for queries
+** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries
+*/
+const addtoclib = function(L, path, plib) {
+ lua.lua_rawgetp(L, lua.LUA_REGISTRYINDEX, CLIBS);
+ lua.lua_pushlightuserdata(L, plib);
+ lua.lua_pushvalue(L, -1);
+ lua.lua_setfield(L, -3, path); /* CLIBS[path] = plib */
+ lua.lua_rawseti(L, -2, lauxlib.luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */
+ lua.lua_pop(L, 1); /* pop CLIBS table */
+};
+
+const pushnexttemplate = function(L, path) {
+ while (path[0] === lua.LUA_PATH_SEP.charCodeAt[0]) path = path.slice(1); /* skip separators */
+ if (path.length === 0) return null; /* no more templates */
+ let l = path.indexOf(lua.LUA_PATH_SEP.charCodeAt(0)); /* find next separator */
+ if (l < 0) l = path.length;
+ lua.lua_pushlstring(L, path, l); /* template */
+ return l;
+};
+
+const searchpath = function(L, name, path, sep, dirsep) {
+ let msg = []; /* to build error message */
+ if (sep[0] !== 0) /* non-empty separator? */
+ name = lauxlib.luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */
+ while ((path = pushnexttemplate(L, path)) !== null) {
+ let filename = lauxlib.luaL_gsub(L, lua.lua_tostring(L, -1), lua.LUA_PATH_MARK, name);
+ lua.lua_remove(L, -2); /* remove path template */
+ if (readable(filename)) /* does file exist and is readable? */
+ return filename; /* return that file name */
+ lua.lua_remove(L, -1); /* remove file name */
+ msg.push(...lua.to_luastring(`\n\tno file '${lua.to_jsstring(filename)}'`));
+ }
+ lua.lua_pushstring(msg); /* create error message */
+ return null; /* not found */
+};
+
+const findfile = function(L, name, pname, dirsep) {
+ lua.lua_getfield(L, lua.lua_upvalueindex(1), pname);
+ let path = lua.lua_tostring(L, -1);
+ if (path === null)
+ lauxlib.luaL_error(L, `'package.${lua.to_jsstring(pname)}' must be a string`);
+ return searchpath(L, name, path, ['.'.charCodeAt(0)], dirsep);
+};
+
+const checkload = function(L, stat, filename) {
+ if (stat) { /* module loaded successfully? */
+ lua.lua_pushstring(L, filename); /* will be 2nd argument to module */
+ return 2; /* return open function and file name */
+ } else
+ return lauxlib.luaL_error(L, lua.to_luastring(`error loading module '${lua.lua_tojsstring(L, 1)}' from file '${lua.to_jsstring(filename)}':\n\t${lua.lua_tojsstring(L, 1)}`));
+};
+
+const searcher_Lua = function(L) {
+ let name = lauxlib.luaL_checkstring(L, 1);
+ let filename = findfile(L, name, lua.to_luastring("path", true), LUA_LSUBSEP);
+ if (filename === null) return 1; /* module not found in this path */
+ return checkload(L, lauxlib.luaL_loadfile(L, filename) === lua.LUA_OK, filename);
+};
+
+/*
+** Try to find a load function for module 'modname' at file 'filename'.
+** First, change '.' to '_' in 'modname'; then, if 'modname' has
+** the form X-Y (that is, it has an "ignore mark"), build a function
+** name "luaopen_X" and look for it. (For compatibility, if that
+** fails, it also tries "luaopen_Y".) If there is no ignore mark,
+** look for a function named "luaopen_modname".
+*/
+const loadfunc = function(L, filename, modname) {
+ let openfunc;
+ modname = lauxlib.luaL_gsub(L, modname, [".".charCodeAt(0)], LUA_OFSEP);
+ let mark = modname.indexOf(LUA_IGMARK[0]);
+ if (mark >= 0) {
+ openfunc = lua.lua_pushlstring(L, modname, mark);
+ openfunc = lua.lua_pushstring(L, lua.to_luastring(`${LUA_POF}${openfunc}`));
+ let stat = lookforfunc(L, filename, openfunc);
+ if (stat !== ERRFUNC) return stat;
+ modname = mark + 1; /* else go ahead and try old-style name */
+ }
+ openfunc = lua.lua_pushstring(L, lua.to_luastring(`${LUA_POF}${modname}`));
+ return lookforfunc(L, filename, openfunc);
+};
+
+const searcher_C = function(L) {
+ let name = lauxlib.luaL_checkstring(L, 1);
+ let filename = findfile(L, name, "cpath", LUA_CSUBSEP);
+ if (filename === null) return 1; /* module not found in this path */
+ return checkload(L, (loadfunc(L, filename, name) === 0), filename);
+};
+
+const searcher_Croot = function(L) {
+ let name = lauxlib.luaL_checkstring(L, 1);
+ let p = name.indexOf('.'.charCodeAt(0));
+ let stat;
+ if (p < 0) return 0; /* is root */
+ lua.lua_pushlstring(L, name, p);
+ let filename = findfile(L, lua.lua_tostring(L, -1), lua.to_luastring("cpath", true), LUA_CSUBSEP);
+ if (filename === null) return 1; /* root not found */
+ if ((stat = loadfunc(L, filename, name)) !== 0) {
+ if (stat != ERRFUNC)
+ return checkload(L, 0, filename); /* real error */
+ else { /* open function not found */
+ lua.lua_pushstring(L, lua.to_luastring(`\n\tno module '${lua.to_jsstring(name)}' in file '${lua.to_jsstring(filename)}'`));
+ return 1;
+ }
+ }
+ lua.lua_pushstring(L, filename); /* will be 2nd argument to module */
+ return 2;
+};
+
+const searcher_preload = function(L) {
+ let name = lauxlib.luaL_checkstring(L, 1);
+ lua.lua_getfield(L, lua.LUA_REGISTRYINDEX, lauxlib.LUA_PRELOAD_TABLE);
+ if (lua.lua_getfield(L, -1, name) === lua.LUA_TNIL) /* not found? */
+ lua.lua_pushliteral(L, `\n\tno field package.preload['${lua.to_jsstring(name)}']`);
+ return 1;
+};
+
+const pk_funcs = {};
+
+const ll_funcs = {};
+
+const createsearcherstable = function(L) {
+ let searchers = {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, null};
+ /* create 'searchers' table */
+ lua.lua_createtable(L);
+ /* fill it with predefined searchers */
+ for (let i = 0; searchers[i]; i++) {
+ lua.lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */
+ lua.lua_pushcclosure(L, searchers[i], 1);
+ lua.lua_rawseti(L, -2, i+1);
+ }
+ lua.lua_setfield(L, -2, lua.to_luastring("searchers", true)); /* put it in field 'searchers' */
+};
+
+/*
+** create table CLIBS to keep track of loaded C libraries,
+** setting a finalizer to close all libraries when closing state.
+*/
+const createclibstable = function(L) {
+ lua.lua_newtable(L); /* create CLIBS table */
+ lua.lua_createtable(L, 0, 1); /* create metatable for CLIBS */
+ lua.lua_setmetatable(L, -2);
+ lua.lua_rawsetp(L, lua.LUA_REGISTRYINDEX, CLIBS); /* set CLIBS table in registry */
+};
+
+const luaopen_package = function(L) {
+ createclibstable(L);
+ lauxlib.luaL_newlib(L, pk_funcs); /* create 'package' table */
+ createsearcherstable(L);
+ /* set paths */
+ setpath(L, lua.to_luastring("path", true), LUA_PATH_VAR, lua.LUA_PATH_DEFAULT);
+ setpath(L, lua.to_luastring("cpath", true), LUA_CPATH_VAR, lua.LUA_CPATH_DEFAULT);
+ /* store config information */
+ lua.lua_pushliteral(L, lua.LUA_DIRSEP + "\n" + lua.LUA_PATH_SEP + "\n" + lua.LUA_PATH_MARK + "\n" +
+ lua.LUA_EXEC_DIR + "\n" + LUA_IGMARK + "\n");
+ lua.lua_setfield(L, -2, lua.to_luastring("config", true));
+ /* set field 'loaded' */
+ lauxlib.luaL_getsubtable(L, lua.LUA_REGISTRYINDEX, lua.to_luastring(lauxlib.LUA_LOADED_TABLE, true));
+ lua.lua_setfield(L, -2, lua.to_luastring("loaded", true));
+ /* set field 'preload' */
+ lauxlib.luaL_getsubtable(L, lua.LUA_REGISTRYINDEX, lua.to_luastring(lauxlib.LUA_PRELOAD_TABLE, true));
+ lua.lua_setfield(L, -2, lua.to_luastring("preload", true));
+ lua.lua_pushglobaltable(L);
+ lua.lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */
+ lauxlib.luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */
+ lua.lua_pop(L, 1); /* pop global table */
+ return 1; /* return 'package' table */
+};
+
+module.exports.luaopen_package = luaopen_package;