client/deps/liblua/lua.c

   1 /*
   2 ** $Id: lua.c,v 1.206 2012/09/29 20:07:06 roberto Exp $
   3 ** Lua stand-alone interpreter
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7
   8 #include <signal.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #define lua_c
  14
  15 #include "lua.h"
  16
  17 #include "lauxlib.h"
  18 #include "lualib.h"
  19
  20
  21 #if !defined(LUA_PROMPT)
  22 #define LUA_PROMPT  "> "
  23 #define LUA_PROMPT2 ">> "
  24 #endif
  25
  26 #if !defined(LUA_PROGNAME)
  27 #define LUA_PROGNAME "lua"
  28 #endif
  29
  30 #if !defined(LUA_MAXINPUT)
  31 #define LUA_MAXINPUT 512
  32 #endif
  33
  34 #if !defined(LUA_INIT)
  35 #define LUA_INIT "LUA_INIT"
  36 #endif
  37
  38 #define LUA_INITVERSION  \
  39     LUA_INIT "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR
  40
  41
  42 /*
  43 ** lua_stdin_is_tty detects whether the standard input is a 'tty' (that
  44 ** is, whether we're running lua interactively).
  45 */
  46 #if defined(LUA_USE_ISATTY)
  47 #include <unistd.h>
  48 #define lua_stdin_is_tty() isatty(0)
  49 #elif defined(LUA_WIN)
  50 #include <io.h>
  51 #include <stdio.h>
  52 #define lua_stdin_is_tty() _isatty(_fileno(stdin))
  53 #else
  54 #define lua_stdin_is_tty() 1  /* assume stdin is a tty */
  55 #endif
  56
  57
  58 /*
  59 ** lua_readline defines how to show a prompt and then read a line from
  60 ** the standard input.
  61 ** lua_saveline defines how to "save" a read line in a "history".
  62 ** lua_freeline defines how to free a line read by lua_readline.
  63 */
  64 #if defined(LUA_USE_READLINE)
  65
  66 #include <stdio.h>
  67 #include <readline/readline.h>
  68 #include <readline/history.h>
  69 #define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL)
  70 #define lua_saveline(L,idx) \
  71     if (lua_rawlen(L,idx) > 0)  /* non-empty line? */ \
  72         add_history(lua_tostring(L, idx));  /* add it to history */
  73 #define lua_freeline(L,b) ((void)L, free(b))
  74
  75 #elif !defined(lua_readline)
  76
  77 #define lua_readline(L,b,p) \
  78     ((void)L, fputs(p, stdout), fflush(stdout),  /* show prompt */ \
  79      fgets(b, LUA_MAXINPUT, stdin) != NULL)  /* get line */
  80 #define lua_saveline(L,idx) { (void)L; (void)idx; }
  81 #define lua_freeline(L,b) { (void)L; (void)b; }
  82
  83 #endif
  84
  85
  86
  87
  88 static lua_State *globalL = NULL;
  89
  90 static const char *progname = LUA_PROGNAME;
  91
  92
  93
  94 static void lstop(lua_State *L, lua_Debug *ar) {
  95     (void)ar;  /* unused arg. */
  96     lua_sethook(L, NULL, 0, 0);
  97     luaL_error(L, "interrupted!");
  98 }
  99
 100
 101 static void laction(int i) {
 102     signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
 103                               terminate process (default action) */
 104     lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
 105 }
 106
 107
 108 static void print_usage(const char *badoption) {
 109     luai_writestringerror("%s: ", progname);
 110     if (badoption[1] == 'e' || badoption[1] == 'l')
 111         luai_writestringerror("'%s' needs argument\n", badoption);
 112     else
 113         luai_writestringerror("unrecognized option '%s'\n", badoption);
 114     luai_writestringerror(
 115         "usage: %s [options] [script [args]]\n"
 116         "Available options are:\n"
 117         "  -e stat  execute string " LUA_QL("stat") "\n"
 118         "  -i       enter interactive mode after executing " LUA_QL("script") "\n"
 119         "  -l name  require library " LUA_QL("name") "\n"
 120         "  -v       show version information\n"
 121         "  -E       ignore environment variables\n"
 122         "  --       stop handling options\n"
 123         "  -        stop handling options and execute stdin\n"
 124         ,
 125         progname);
 126 }
 127
 128
 129 static void l_message(const char *pname, const char *msg) {
 130     if (pname) luai_writestringerror("%s: ", pname);
 131     luai_writestringerror("%s\n", msg);
 132 }
 133
 134
 135 static int report(lua_State *L, int status) {
 136     if (status != LUA_OK && !lua_isnil(L, -1)) {
 137         const char *msg = lua_tostring(L, -1);
 138         if (msg == NULL) msg = "(error object is not a string)";
 139         l_message(progname, msg);
 140         lua_pop(L, 1);
 141         /* force a complete garbage collection in case of errors */
 142         lua_gc(L, LUA_GCCOLLECT, 0);
 143     }
 144     return status;
 145 }
 146
 147
 148 /* the next function is called unprotected, so it must avoid errors */
 149 static void finalreport(lua_State *L, int status) {
 150     if (status != LUA_OK) {
 151         const char *msg = (lua_type(L, -1) == LUA_TSTRING) ? lua_tostring(L, -1)
 152                           : NULL;
 153         if (msg == NULL) msg = "(error object is not a string)";
 154         l_message(progname, msg);
 155         lua_pop(L, 1);
 156     }
 157 }
 158
 159
 160 static int traceback(lua_State *L) {
 161     const char *msg = lua_tostring(L, 1);
 162     if (msg)
 163         luaL_traceback(L, L, msg, 1);
 164     else if (!lua_isnoneornil(L, 1)) {  /* is there an error object? */
 165         if (!luaL_callmeta(L, 1, "__tostring"))  /* try its 'tostring' metamethod */
 166             lua_pushliteral(L, "(no error message)");
 167     }
 168     return 1;
 169 }
 170
 171
 172 static int docall(lua_State *L, int narg, int nres) {
 173     int status;
 174     int base = lua_gettop(L) - narg;  /* function index */
 175     lua_pushcfunction(L, traceback);  /* push traceback function */
 176     lua_insert(L, base);  /* put it under chunk and args */
 177     globalL = L;  /* to be available to 'laction' */
 178     signal(SIGINT, laction);
 179     status = lua_pcall(L, narg, nres, base);
 180     signal(SIGINT, SIG_DFL);
 181     lua_remove(L, base);  /* remove traceback function */
 182     return status;
 183 }
 184
 185
 186 static void print_version(void) {
 187     luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
 188     luai_writeline();
 189 }
 190
 191
 192 static int getargs(lua_State *L, char **argv, int n) {
 193     int narg;
 194     int i;
 195     int argc = 0;
 196     while (argv[argc]) argc++;  /* count total number of arguments */
 197     narg = argc - (n + 1);  /* number of arguments to the script */
 198     luaL_checkstack(L, narg + 3, "too many arguments to script");
 199     for (i = n + 1; i < argc; i++)
 200         lua_pushstring(L, argv[i]);
 201     lua_createtable(L, narg, n + 1);
 202     for (i = 0; i < argc; i++) {
 203         lua_pushstring(L, argv[i]);
 204         lua_rawseti(L, -2, i - n);
 205     }
 206     return narg;
 207 }
 208
 209
 210 static int dofile(lua_State *L, const char *name) {
 211     int status = luaL_loadfile(L, name);
 212     if (status == LUA_OK) status = docall(L, 0, 0);
 213     return report(L, status);
 214 }
 215
 216
 217 static int dostring(lua_State *L, const char *s, const char *name) {
 218     int status = luaL_loadbuffer(L, s, strlen(s), name);
 219     if (status == LUA_OK) status = docall(L, 0, 0);
 220     return report(L, status);
 221 }
 222
 223
 224 static int dolibrary(lua_State *L, const char *name) {
 225     int status;
 226     lua_getglobal(L, "require");
 227     lua_pushstring(L, name);
 228     status = docall(L, 1, 1);  /* call 'require(name)' */
 229     if (status == LUA_OK)
 230         lua_setglobal(L, name);  /* global[name] = require return */
 231     return report(L, status);
 232 }
 233
 234
 235 static const char *get_prompt(lua_State *L, int firstline) {
 236     const char *p;
 237     lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2");
 238     p = lua_tostring(L, -1);
 239     if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
 240     return p;
 241 }
 242
 243 /* mark in error messages for incomplete statements */
 244 #define EOFMARK "<eof>"
 245 #define marklen (sizeof(EOFMARK)/sizeof(char) - 1)
 246
 247 static int incomplete(lua_State *L, int status) {
 248     if (status == LUA_ERRSYNTAX) {
 249         size_t lmsg;
 250         const char *msg = lua_tolstring(L, -1, &lmsg);
 251         if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) {
 252             lua_pop(L, 1);
 253             return 1;
 254         }
 255     }
 256     return 0;  /* else... */
 257 }
 258
 259
 260 static int pushline(lua_State *L, int firstline) {
 261     char buffer[LUA_MAXINPUT];
 262     char *b = buffer;
 263     size_t l;
 264     const char *prmt = get_prompt(L, firstline);
 265     int readstatus = lua_readline(L, b, prmt);
 266     lua_pop(L, 1);  /* remove result from 'get_prompt' */
 267     if (readstatus == 0)
 268         return 0;  /* no input */
 269     l = strlen(b);
 270     if (l > 0 && b[l - 1] == '\n') /* line ends with newline? */
 271         b[l - 1] = '\0'; /* remove it */
 272     if (firstline && b[0] == '=')  /* first line starts with `=' ? */
 273         lua_pushfstring(L, "return %s", b + 1); /* change it to `return' */
 274     else
 275         lua_pushstring(L, b);
 276     lua_freeline(L, b);
 277     return 1;
 278 }
 279
 280
 281 static int loadline(lua_State *L) {
 282     int status;
 283     lua_settop(L, 0);
 284     if (!pushline(L, 1))
 285         return -1;  /* no input */
 286     for (;;) {  /* repeat until gets a complete line */
 287         size_t l;
 288         const char *line = lua_tolstring(L, 1, &l);
 289         status = luaL_loadbuffer(L, line, l, "=stdin");
 290         if (!incomplete(L, status)) break;  /* cannot try to add lines? */
 291         if (!pushline(L, 0))  /* no more input? */
 292             return -1;
 293         lua_pushliteral(L, "\n");  /* add a new line... */
 294         lua_insert(L, -2);  /* ...between the two lines */
 295         lua_concat(L, 3);  /* join them */
 296     }
 297     lua_saveline(L, 1);
 298     lua_remove(L, 1);  /* remove line */
 299     return status;
 300 }
 301
 302
 303 static void dotty(lua_State *L) {
 304     int status;
 305     const char *oldprogname = progname;
 306     progname = NULL;
 307     while ((status = loadline(L)) != -1) {
 308         if (status == LUA_OK) status = docall(L, 0, LUA_MULTRET);
 309         report(L, status);
 310         if (status == LUA_OK && lua_gettop(L) > 0) {  /* any result to print? */
 311             luaL_checkstack(L, LUA_MINSTACK, "too many results to print");
 312             lua_getglobal(L, "print");
 313             lua_insert(L, 1);
 314             if (lua_pcall(L, lua_gettop(L) - 1, 0, 0) != LUA_OK)
 315                 l_message(progname, lua_pushfstring(L,
 316                                                     "error calling " LUA_QL("print") " (%s)",
 317                                                     lua_tostring(L, -1)));
 318         }
 319     }
 320     lua_settop(L, 0);  /* clear stack */
 321     luai_writeline();
 322     progname = oldprogname;
 323 }
 324
 325
 326 static int handle_script(lua_State *L, char **argv, int n) {
 327     int status;
 328     const char *fname;
 329     int narg = getargs(L, argv, n);  /* collect arguments */
 330     lua_setglobal(L, "arg");
 331     fname = argv[n];
 332     if (strcmp(fname, "-") == 0 && strcmp(argv[n - 1], "--") != 0)
 333         fname = NULL;  /* stdin */
 334     status = luaL_loadfile(L, fname);
 335     lua_insert(L, -(narg + 1));
 336     if (status == LUA_OK)
 337         status = docall(L, narg, LUA_MULTRET);
 338     else
 339         lua_pop(L, narg);
 340     return report(L, status);
 341 }
 342
 343
 344 /* check that argument has no extra characters at the end */
 345 #define noextrachars(x) {if ((x)[2] != '\0') return -1;}
 346
 347
 348 /* indices of various argument indicators in array args */
 349 #define has_i 0 /* -i */
 350 #define has_v 1 /* -v */
 351 #define has_e 2 /* -e */
 352 #define has_E 3 /* -E */
 353
 354 #define num_has 4 /* number of 'has_*' */
 355
 356
 357 static int collectargs(char **argv, int *args) {
 358     int i;
 359     for (i = 1; argv[i] != NULL; i++) {
 360         if (argv[i][0] != '-')  /* not an option? */
 361             return i;
 362         switch (argv[i][1]) {  /* option */
 363             case '-':
 364                 noextrachars(argv[i]);
 365                 return (argv[i + 1] != NULL ? i + 1 : 0);
 366             case '\0':
 367                 return i;
 368             case 'E':
 369                 args[has_E] = 1;
 370                 break;
 371             case 'i':
 372                 noextrachars(argv[i]);
 373                 args[has_i] = 1;  /* go through */
 374             case 'v':
 375                 noextrachars(argv[i]);
 376                 args[has_v] = 1;
 377                 break;
 378             case 'e':
 379                 args[has_e] = 1;  /* go through */
 380             case 'l':  /* both options need an argument */
 381                 if (argv[i][2] == '\0') {  /* no concatenated argument? */
 382                     i++;  /* try next 'argv' */
 383                     if (argv[i] == NULL || argv[i][0] == '-')
 384                         return -(i - 1);  /* no next argument or it is another option */
 385                 }
 386                 break;
 387             default:  /* invalid option; return its index... */
 388                 return -i;  /* ...as a negative value */
 389         }
 390     }
 391     return 0;
 392 }
 393
 394
 395 static int runargs(lua_State *L, char **argv, int n) {
 396     int i;
 397     for (i = 1; i < n; i++) {
 398         lua_assert(argv[i][0] == '-');
 399         switch (argv[i][1]) {  /* option */
 400             case 'e': {
 401                 const char *chunk = argv[i] + 2;
 402                 if (*chunk == '\0') chunk = argv[++i];
 403                 lua_assert(chunk != NULL);
 404                 if (dostring(L, chunk, "=(command line)") != LUA_OK)
 405                     return 0;
 406                 break;
 407             }
 408             case 'l': {
 409                 const char *filename = argv[i] + 2;
 410                 if (*filename == '\0') filename = argv[++i];
 411                 lua_assert(filename != NULL);
 412                 if (dolibrary(L, filename) != LUA_OK)
 413                     return 0;  /* stop if file fails */
 414                 break;
 415             }
 416             default:
 417                 break;
 418         }
 419     }
 420     return 1;
 421 }
 422
 423
 424 static int handle_luainit(lua_State *L) {
 425     const char *name = "=" LUA_INITVERSION;
 426     const char *init = getenv(name + 1);
 427     if (init == NULL) {
 428         name = "=" LUA_INIT;
 429         init = getenv(name + 1);  /* try alternative name */
 430     }
 431     if (init == NULL) return LUA_OK;
 432     else if (init[0] == '@')
 433         return dofile(L, init + 1);
 434     else
 435         return dostring(L, init, name);
 436 }
 437
 438
 439 static int pmain(lua_State *L) {
 440     int argc = (int)lua_tointeger(L, 1);
 441     char **argv = (char **)lua_touserdata(L, 2);
 442     int script;
 443     int args[num_has];
 444     args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0;
 445     if (argv[0] && argv[0][0]) progname = argv[0];
 446     script = collectargs(argv, args);
 447     if (script < 0) {  /* invalid arg? */
 448         print_usage(argv[-script]);
 449         return 0;
 450     }
 451     if (args[has_v]) print_version();
 452     if (args[has_E]) {  /* option '-E'? */
 453         lua_pushboolean(L, 1);  /* signal for libraries to ignore env. vars. */
 454         lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
 455     }
 456     /* open standard libraries */
 457     luaL_checkversion(L);
 458     lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */
 459     luaL_openlibs(L);  /* open libraries */
 460     lua_gc(L, LUA_GCRESTART, 0);
 461     if (!args[has_E] && handle_luainit(L) != LUA_OK)
 462         return 0;  /* error running LUA_INIT */
 463     /* execute arguments -e and -l */
 464     if (!runargs(L, argv, (script > 0) ? script : argc)) return 0;
 465     /* execute main script (if there is one) */
 466     if (script && handle_script(L, argv, script) != LUA_OK) return 0;
 467     if (args[has_i])  /* -i option? */
 468         dotty(L);
 469     else if (script == 0 && !args[has_e] && !args[has_v]) {  /* no arguments? */
 470         if (lua_stdin_is_tty()) {
 471             print_version();
 472             dotty(L);
 473         } else dofile(L, NULL); /* executes stdin as a file */
 474     }
 475     lua_pushboolean(L, 1);  /* signal no errors */
 476     return 1;
 477 }
 478
 479
 480 int main(int argc, char **argv) {
 481     int status, result;
 482     lua_State *L = luaL_newstate();  /* create state */
 483     if (L == NULL) {
 484         l_message(argv[0], "cannot create state: not enough memory");
 485         return EXIT_FAILURE;
 486     }
 487     /* call 'pmain' in protected mode */
 488     lua_pushcfunction(L, &pmain);
 489     lua_pushinteger(L, argc);  /* 1st argument */
 490     lua_pushlightuserdata(L, argv); /* 2nd argument */
 491     status = lua_pcall(L, 2, 1, 0);
 492     result = lua_toboolean(L, -1);  /* get result */
 493     finalreport(L, status);
 494     lua_close(L);
 495     return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;
 496 }
 497