interp_lua.c

/*-
 * Copyright (c) 2011 Wojciech A. Koszek <[email protected]>
 * Copyright (c) 2014 Pedro Souza <[email protected]>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stand.h>
#include "bootstrap.h"

#define lua_c

#include "lstd.h"

#include <lua.h>
#include <ldebug.h>
#include <lauxlib.h>
#include <lualib.h>

#include <lerrno.h>
#include <lfs.h>
#include <lutils.h>

struct interp_lua_softc {
	lua_State	*luap;
};

static struct interp_lua_softc lua_softc;

#ifdef LUA_DEBUG
#define	LDBG(...)	do {			\
	printf("%s(%d): ", __func__, __LINE__);	\
	printf(__VA_ARGS__);			\
	printf("\n");				\
} while (0)
#else
#define	LDBG(...)
#endif

#define	LOADER_LUA	LUA_PATH "/loader.lua"

INTERP_DEFINE("lua");

static void *
interp_lua_realloc(void *ud __unused, void *ptr, size_t osize __unused, size_t nsize)
{

	if (nsize == 0) {
		free(ptr);
		return NULL;
	}
	return realloc(ptr, nsize);
}

/*
 * The libraries commented out below either lack the proper
 * support from libsa, or they are unlikely to be useful
 * in the bootloader, so have been commented out.
 */
static const luaL_Reg loadedlibs[] = {
  {"_G", luaopen_base},
  {LUA_LOADLIBNAME, luaopen_package},
//  {LUA_COLIBNAME, luaopen_coroutine},
//  {LUA_TABLIBNAME, luaopen_table},
  {LUA_STRLIBNAME, luaopen_string},
//  {LUA_IOLIBNAME, luaopen_io},
//  {LUA_OSLIBNAME, luaopen_os},
//  {LUA_MATHLIBNAME, luaopen_math},
//  {LUA_UTF8LIBNAME, luaopen_utf8},
//  {LUA_DBLIBNAME, luaopen_debug},
  {"errno", luaopen_errno},
  {"io", luaopen_io},
  {"lfs", luaopen_lfs},
  {"loader", luaopen_loader},
  {"pager", luaopen_pager},
  {NULL, NULL}
};

static bool preinit_done = false;

void
interp_preinit(void)
{
	lua_State *luap;
	struct interp_lua_softc	*softc = &lua_softc;
	const luaL_Reg *lib;
	lua_init_md_t **fnpp;

	TSENTER();

	if (preinit_done)
		return;

	setenv("script.lang", "lua", 1);
	LDBG("creating context");

	luap = lua_newstate(interp_lua_realloc, NULL);
	if (luap == NULL) {
		printf("problem initializing the Lua interpreter\n");
		abort();
	}
	softc->luap = luap;

	/* "require" functions from 'loadedlibs' and set results to global table */
	for (lib = loadedlibs; lib->func; lib++) {
		luaL_requiref(luap, lib->name, lib->func, 1);
		lua_pop(luap, 1);  /* remove lib */
	}

	LUA_FOREACH_SET(fnpp)
	    (*fnpp)(luap);

	preinit_done = true;

	TSEXIT();
}

void
interp_init(void)
{
	lua_State *luap;
	struct interp_lua_softc	*softc = &lua_softc;
	const char *filename;

	TSENTER();

	luap = softc->luap;
	filename = getenv("loader_lua");
	if (filename == NULL)
		filename = LOADER_LUA;
	if (interp_include(filename) != 0) {
		const char *errstr = lua_tostring(luap, -1);
		errstr = errstr == NULL ? "unknown" : errstr;
		printf("ERROR: %s.\n", errstr);
		lua_pop(luap, 1);
		setenv("autoboot_delay", "NO", 1);
	}

	TSEXIT();
}

int
interp_run(const char *line)
{
	int	argc, nargc;
	char	**argv;
	lua_State *luap;
	struct interp_lua_softc	*softc = &lua_softc;
	int status, ret;

	TSENTER();
	luap = softc->luap;
	LDBG("executing line...");
	if ((status = luaL_dostring(luap, line)) != 0) {
		lua_pop(luap, 1);
		/*
		 * The line wasn't executable as lua; run it through parse to
		 * to get consistent parsing of command line arguments, then
		 * run it through cli_execute. If that fails, then we'll try it
		 * as a builtin.
		 */
		command_errmsg = NULL;
		if (parse(&argc, &argv, line) == 0) {
			lua_getglobal(luap, "cli_execute");
			for (nargc = 0; nargc < argc; ++nargc) {
				lua_pushstring(luap, argv[nargc]);
			}
			status = lua_pcall(luap, argc, 1, 0);
			ret = lua_tointeger(luap, 1);
			lua_pop(luap, 1);
			if (status != 0 || ret != 0) {
				/*
				 * Lua cli_execute will pass the function back
				 * through loader.command, which is a proxy to
				 * interp_builtin_cmd. If we failed to interpret
				 * the command, though, then there's a chance
				 * that didn't happen. Call interp_builtin_cmd
				 * directly if our lua_pcall was not successful.
				 */
				status = interp_builtin_cmd(argc, argv);
			}
			if (status != 0) {
				if (command_errmsg != NULL)
					printf("%s\n", command_errmsg);
				else
					printf("Command failed\n");
				status = CMD_ERROR;
			}
			free(argv);
		} else {
			printf("Failed to parse \'%s\'\n", line);
			status = CMD_ERROR;
		}
	}

	TSEXIT();
	return (status == 0 ? CMD_OK : CMD_ERROR);
}

int
interp_include(const char *filename)
{
	struct interp_lua_softc	*softc = &lua_softc;

	LDBG("loading file %s", filename);

	return (luaL_dofile(softc->luap, filename));
}