Subversion Repositories WoWGM

/*

** $Id: lua.c,v 1.160 2006/06/02 15:34:00 roberto Exp $

** Lua stand-alone interpreter

** See Copyright Notice in lua.h

*/

#include <signal.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#define lua_c

#include "lua.h"

#include "lauxlib.h"

#include "lualib.h"

static lua_State *globalL = NULL;

static const char *progname = LUA_PROGNAME;

static void lstop (lua_State *L, lua_Debug *ar) {

  (void)ar;  /* unused arg. */

  lua_sethook(L, NULL, 0, 0);

  luaL_error(L, "interrupted!");

}

static void laction (int i) {

  signal(i, SIG_DFL); /* if another SIGINT happens before lstop,

                              terminate process (default action) */

  lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);

}

static void print_usage (void) {

  fprintf(stderr,

  "usage: %s [options] [script [args]].\n"

  "Available options are:\n"

  "  -e stat  execute string " LUA_QL("stat") "\n"

  "  -l name  require library " LUA_QL("name") "\n"

  "  -i       enter interactive mode after executing " LUA_QL("script") "\n"

  "  -v       show version information\n"

  "  --       stop handling options\n"

  "  -        execute stdin and stop handling options\n"

  ,

  progname);

  fflush(stderr);

}

static void l_message (const char *pname, const char *msg) {

  if (pname) fprintf(stderr, "%s: ", pname);

  fprintf(stderr, "%s\n", msg);

  fflush(stderr);

}

static int report (lua_State *L, int status) {

  if (status && !lua_isnil(L, -1)) {

    const char *msg = lua_tostring(L, -1);

    if (msg == NULL) msg = "(error object is not a string)";

    l_message(progname, msg);

    lua_pop(L, 1);

  }

  return status;

}

static int traceback (lua_State *L) {

  lua_getfield(L, LUA_GLOBALSINDEX, "debug");

  if (!lua_istable(L, -1)) {

    lua_pop(L, 1);

    return 1;

  }

  lua_getfield(L, -1, "traceback");

  if (!lua_isfunction(L, -1)) {

    lua_pop(L, 2);

    return 1;

  }

  lua_pushvalue(L, 1);  /* pass error message */

  lua_pushinteger(L, 2);  /* skip this function and traceback */

  lua_call(L, 2, 1);  /* call debug.traceback */

  return 1;

}

static int docall (lua_State *L, int narg, int clear) {

  int status;

  int base = lua_gettop(L) - narg;  /* function index */

  lua_pushcfunction(L, traceback);  /* push traceback function */

  lua_insert(L, base);  /* put it under chunk and args */

  signal(SIGINT, laction);

  status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);

  signal(SIGINT, SIG_DFL);

  lua_remove(L, base);  /* remove traceback function */

  /* force a complete garbage collection in case of errors */

  if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);

  return status;

}

static void print_version (void) {

  l_message(NULL, LUA_RELEASE "  " LUA_COPYRIGHT);

}

static int getargs (lua_State *L, char **argv, int n) {

  int narg;

  int i;

  int argc = 0;

  while (argv[argc]) argc++;  /* count total number of arguments */

  narg = argc - (n + 1);  /* number of arguments to the script */

  luaL_checkstack(L, narg + 3, "too many arguments to script");

  for (i=n+1; i < argc; i++)

    lua_pushstring(L, argv[i]);

  lua_createtable(L, narg, n + 1);

  for (i=0; i < argc; i++) {

    lua_pushstring(L, argv[i]);

    lua_rawseti(L, -2, i - n);

  }

  return narg;

}

static int dofile (lua_State *L, const char *name) {

  int status = luaL_loadfile(L, name) || docall(L, 0, 1);

  return report(L, status);

}

static int dostring (lua_State *L, const char *s, const char *name) {

  int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1);

  return report(L, status);

}

static int dolibrary (lua_State *L, const char *name) {

  lua_getglobal(L, "require");

  lua_pushstring(L, name);

  return report(L, lua_pcall(L, 1, 0, 0));

}

static const char *get_prompt (lua_State *L, int firstline) {

  const char *p;

  lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");

  p = lua_tostring(L, -1);

  if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);

  lua_pop(L, 1);  /* remove global */

  return p;

}

static int incomplete (lua_State *L, int status) {

  if (status == LUA_ERRSYNTAX) {

    size_t lmsg;

    const char *msg = lua_tolstring(L, -1, &lmsg);

    const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);

    if (strstr(msg, LUA_QL("<eof>")) == tp) {

      lua_pop(L, 1);

      return 1;

    }

  }

  return 0;  /* else... */

}

static int pushline (lua_State *L, int firstline) {

  char buffer[LUA_MAXINPUT];

  char *b = buffer;

  size_t l;

  const char *prmt = get_prompt(L, firstline);

  if (lua_readline(L, b, prmt) == 0)

    return 0;  /* no input */

  l = strlen(b);

  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */

    b[l-1] = '\0';  /* remove it */

  if (firstline && b[0] == '=')  /* first line starts with `=' ? */

    lua_pushfstring(L, "return %s", b+1);  /* change it to `return' */

  else

    lua_pushstring(L, b);

  lua_freeline(L, b);

  return 1;

}

static int loadline (lua_State *L) {

  int status;

  lua_settop(L, 0);

  if (!pushline(L, 1))

    return -1;  /* no input */

  for (;;) {  /* repeat until gets a complete line */

    status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");

    if (!incomplete(L, status)) break;  /* cannot try to add lines? */

    if (!pushline(L, 0))  /* no more input? */

      return -1;

    lua_pushliteral(L, "\n");  /* add a new line... */

    lua_insert(L, -2);  /* ...between the two lines */

    lua_concat(L, 3);  /* join them */

  }

  lua_saveline(L, 1);

  lua_remove(L, 1);  /* remove line */

  return status;

}

static void dotty (lua_State *L) {

  int status;

  const char *oldprogname = progname;

  progname = NULL;

  while ((status = loadline(L)) != -1) {

    if (status == 0) status = docall(L, 0, 0);

    report(L, status);

    if (status == 0 && lua_gettop(L) > 0) {  /* any result to print? */

      lua_getglobal(L, "print");

      lua_insert(L, 1);

      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)

        l_message(progname, lua_pushfstring(L,

                               "error calling " LUA_QL("print") " (%s)",

                               lua_tostring(L, -1)));

    }

  }

  lua_settop(L, 0);  /* clear stack */

  fputs("\n", stdout);

  fflush(stdout);

  progname = oldprogname;

}

static int handle_script (lua_State *L, char **argv, int n) {

  int status;

  const char *fname;

  int narg = getargs(L, argv, n);  /* collect arguments */

  lua_setglobal(L, "arg");

  fname = argv[n];

  if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0) 

    fname = NULL;  /* stdin */

  status = luaL_loadfile(L, fname);

  lua_insert(L, -(narg+1));

  if (status == 0)

    status = docall(L, narg, 0);

  else

    lua_pop(L, narg);      

  return report(L, status);

}

/* check that argument has no extra characters at the end */

#define notail(x)	{if ((x)[2] != '\0') return -1;}

static int collectargs (char **argv, int *pi, int *pv, int *pe) {

  int i;

  for (i = 1; argv[i] != NULL; i++) {

    if (argv[i][0] != '-')  /* not an option? */

        return i;

    switch (argv[i][1]) {  /* option */

      case '-':

        notail(argv[i]);

        return (argv[i+1] != NULL ? i+1 : 0);

      case '\0':

        return i;

      case 'i':

        notail(argv[i]);

        *pi = 1;  /* go through */

      case 'v':

        notail(argv[i]);

        *pv = 1;

        break;

      case 'e':

        *pe = 1;  /* go through */

      case 'l':

        if (argv[i][2] == '\0') {

          i++;

          if (argv[i] == NULL) return -1;

        }

        break;

      default: return -1;  /* invalid option */

    }

  }

  return 0;

}

static int runargs (lua_State *L, char **argv, int n) {

  int i;

  for (i = 1; i < n; i++) {

    if (argv[i] == NULL) continue;

    lua_assert(argv[i][0] == '-');

    switch (argv[i][1]) {  /* option */

      case 'e': {

        const char *chunk = argv[i] + 2;

        if (*chunk == '\0') chunk = argv[++i];

        lua_assert(chunk != NULL);

        if (dostring(L, chunk, "=(command line)") != 0)

          return 1;

        break;

      }

      case 'l': {

        const char *filename = argv[i] + 2;

        if (*filename == '\0') filename = argv[++i];

        lua_assert(filename != NULL);

        if (dolibrary(L, filename))

          return 1;  /* stop if file fails */

        break;

      }

      default: break;

    }

  }

  return 0;

}

static int handle_luainit (lua_State *L) {

  const char *init = getenv(LUA_INIT);

  if (init == NULL) return 0;  /* status OK */

  else if (init[0] == '@')

    return dofile(L, init+1);

  else

    return dostring(L, init, "=" LUA_INIT);

}

struct Smain {

  int argc;

  char **argv;

  int status;

};

static int pmain (lua_State *L) {

  struct Smain *s = (struct Smain *)lua_touserdata(L, 1);

  char **argv = s->argv;

  int script;

  int has_i = 0, has_v = 0, has_e = 0;

  globalL = L;

  if (argv[0] && argv[0][0]) progname = argv[0];

  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */

  luaL_openlibs(L);  /* open libraries */

  lua_gc(L, LUA_GCRESTART, 0);

  s->status = handle_luainit(L);

  if (s->status != 0) return 0;

  script = collectargs(argv, &has_i, &has_v, &has_e);

  if (script < 0) {  /* invalid args? */

    print_usage();

    s->status = 1;

    return 0;

  }

  if (has_v) print_version();

  s->status = runargs(L, argv, (script > 0) ? script : s->argc);

  if (s->status != 0) return 0;

  if (script)

    s->status = handle_script(L, argv, script);

  if (s->status != 0) return 0;

  if (has_i)

    dotty(L);

  else if (script == 0 && !has_e && !has_v) {

    if (lua_stdin_is_tty()) {

      print_version();

      dotty(L);

    }

    else dofile(L, NULL);  /* executes stdin as a file */

  }

  return 0;

}

int main (int argc, char **argv) {

  int status;

  struct Smain s;

  lua_State *L = lua_open();  /* create state */

  if (L == NULL) {

    l_message(argv[0], "cannot create state: not enough memory");

    return EXIT_FAILURE;

  }

  s.argc = argc;

  s.argv = argv;

  status = lua_cpcall(L, &pmain, &s);

  report(L, status);

  lua_close(L);

  return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;

}