source: trunk/src/lua/lua.c @ 2540

Last change on this file since 2540 was 2540, checked in by sam, 10 years ago

core: import pristine lua 5.2.1 in the engine code.

File size: 13.6 KB
Line 
1/*
2** $Id: lua.c,v 1.205 2012/05/23 15:37:09 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
88static lua_State *globalL = NULL;
89
90static const char *progname = LUA_PROGNAME;
91
92
93
94static 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
101static 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
108static 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
129static 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
135static 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 */
149static 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
160static 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
172static 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
186static void print_version (void) {
187  luai_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT));
188  luai_writeline();
189}
190
191
192static 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
210static 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
217static 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
224static 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
235static 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  lua_pop(L, 1);  /* remove global */
241  return p;
242}
243
244/* mark in error messages for incomplete statements */
245#define EOFMARK         "<eof>"
246#define marklen         (sizeof(EOFMARK)/sizeof(char) - 1)
247
248static int incomplete (lua_State *L, int status) {
249  if (status == LUA_ERRSYNTAX) {
250    size_t lmsg;
251    const char *msg = lua_tolstring(L, -1, &lmsg);
252    if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) {
253      lua_pop(L, 1);
254      return 1;
255    }
256  }
257  return 0;  /* else... */
258}
259
260
261static int pushline (lua_State *L, int firstline) {
262  char buffer[LUA_MAXINPUT];
263  char *b = buffer;
264  size_t l;
265  const char *prmt = get_prompt(L, firstline);
266  if (lua_readline(L, b, prmt) == 0)
267    return 0;  /* no input */
268  l = strlen(b);
269  if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
270    b[l-1] = '\0';  /* remove it */
271  if (firstline && b[0] == '=')  /* first line starts with `=' ? */
272    lua_pushfstring(L, "return %s", b+1);  /* change it to `return' */
273  else
274    lua_pushstring(L, b);
275  lua_freeline(L, b);
276  return 1;
277}
278
279
280static int loadline (lua_State *L) {
281  int status;
282  lua_settop(L, 0);
283  if (!pushline(L, 1))
284    return -1;  /* no input */
285  for (;;) {  /* repeat until gets a complete line */
286    size_t l;
287    const char *line = lua_tolstring(L, 1, &l);
288    status = luaL_loadbuffer(L, line, l, "=stdin");
289    if (!incomplete(L, status)) break;  /* cannot try to add lines? */
290    if (!pushline(L, 0))  /* no more input? */
291      return -1;
292    lua_pushliteral(L, "\n");  /* add a new line... */
293    lua_insert(L, -2);  /* ...between the two lines */
294    lua_concat(L, 3);  /* join them */
295  }
296  lua_saveline(L, 1);
297  lua_remove(L, 1);  /* remove line */
298  return status;
299}
300
301
302static void dotty (lua_State *L) {
303  int status;
304  const char *oldprogname = progname;
305  progname = NULL;
306  while ((status = loadline(L)) != -1) {
307    if (status == LUA_OK) status = docall(L, 0, LUA_MULTRET);
308    report(L, status);
309    if (status == LUA_OK && lua_gettop(L) > 0) {  /* any result to print? */
310      luaL_checkstack(L, LUA_MINSTACK, "too many results to print");
311      lua_getglobal(L, "print");
312      lua_insert(L, 1);
313      if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != LUA_OK)
314        l_message(progname, lua_pushfstring(L,
315                               "error calling " LUA_QL("print") " (%s)",
316                               lua_tostring(L, -1)));
317    }
318  }
319  lua_settop(L, 0);  /* clear stack */
320  luai_writeline();
321  progname = oldprogname;
322}
323
324
325static int handle_script (lua_State *L, char **argv, int n) {
326  int status;
327  const char *fname;
328  int narg = getargs(L, argv, n);  /* collect arguments */
329  lua_setglobal(L, "arg");
330  fname = argv[n];
331  if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0)
332    fname = NULL;  /* stdin */
333  status = luaL_loadfile(L, fname);
334  lua_insert(L, -(narg+1));
335  if (status == LUA_OK)
336    status = docall(L, narg, LUA_MULTRET);
337  else
338    lua_pop(L, narg);
339  return report(L, status);
340}
341
342
343/* check that argument has no extra characters at the end */
344#define noextrachars(x)         {if ((x)[2] != '\0') return -1;}
345
346
347/* indices of various argument indicators in array args */
348#define has_i           0       /* -i */
349#define has_v           1       /* -v */
350#define has_e           2       /* -e */
351#define has_E           3       /* -E */
352
353#define num_has         4       /* number of 'has_*' */
354
355
356static int collectargs (char **argv, int *args) {
357  int i;
358  for (i = 1; argv[i] != NULL; i++) {
359    if (argv[i][0] != '-')  /* not an option? */
360        return i;
361    switch (argv[i][1]) {  /* option */
362      case '-':
363        noextrachars(argv[i]);
364        return (argv[i+1] != NULL ? i+1 : 0);
365      case '\0':
366        return i;
367      case 'E':
368        args[has_E] = 1;
369        break;
370      case 'i':
371        noextrachars(argv[i]);
372        args[has_i] = 1;  /* go through */
373      case 'v':
374        noextrachars(argv[i]);
375        args[has_v] = 1;
376        break;
377      case 'e':
378        args[has_e] = 1;  /* go through */
379      case 'l':  /* both options need an argument */
380        if (argv[i][2] == '\0') {  /* no concatenated argument? */
381          i++;  /* try next 'argv' */
382          if (argv[i] == NULL || argv[i][0] == '-')
383            return -(i - 1);  /* no next argument or it is another option */
384        }
385        break;
386      default:  /* invalid option; return its index... */
387        return -i;  /* ...as a negative value */
388    }
389  }
390  return 0;
391}
392
393
394static int runargs (lua_State *L, char **argv, int n) {
395  int i;
396  for (i = 1; i < n; i++) {
397    lua_assert(argv[i][0] == '-');
398    switch (argv[i][1]) {  /* option */
399      case 'e': {
400        const char *chunk = argv[i] + 2;
401        if (*chunk == '\0') chunk = argv[++i];
402        lua_assert(chunk != NULL);
403        if (dostring(L, chunk, "=(command line)") != LUA_OK)
404          return 0;
405        break;
406      }
407      case 'l': {
408        const char *filename = argv[i] + 2;
409        if (*filename == '\0') filename = argv[++i];
410        lua_assert(filename != NULL);
411        if (dolibrary(L, filename) != LUA_OK)
412          return 0;  /* stop if file fails */
413        break;
414      }
415      default: break;
416    }
417  }
418  return 1;
419}
420
421
422static int handle_luainit (lua_State *L) {
423  const char *name = "=" LUA_INITVERSION;
424  const char *init = getenv(name + 1);
425  if (init == NULL) {
426    name = "=" LUA_INIT;
427    init = getenv(name + 1);  /* try alternative name */
428  }
429  if (init == NULL) return LUA_OK;
430  else if (init[0] == '@')
431    return dofile(L, init+1);
432  else
433    return dostring(L, init, name);
434}
435
436
437static int pmain (lua_State *L) {
438  int argc = (int)lua_tointeger(L, 1);
439  char **argv = (char **)lua_touserdata(L, 2);
440  int script;
441  int args[num_has];
442  args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0;
443  if (argv[0] && argv[0][0]) progname = argv[0];
444  script = collectargs(argv, args);
445  if (script < 0) {  /* invalid arg? */
446    print_usage(argv[-script]);
447    return 0;
448  }
449  if (args[has_v]) print_version();
450  if (args[has_E]) {  /* option '-E'? */
451    lua_pushboolean(L, 1);  /* signal for libraries to ignore env. vars. */
452    lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
453  }
454  /* open standard libraries */
455  luaL_checkversion(L);
456  lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */
457  luaL_openlibs(L);  /* open libraries */
458  lua_gc(L, LUA_GCRESTART, 0);
459  if (!args[has_E] && handle_luainit(L) != LUA_OK)
460    return 0;  /* error running LUA_INIT */
461  /* execute arguments -e and -l */
462  if (!runargs(L, argv, (script > 0) ? script : argc)) return 0;
463  /* execute main script (if there is one) */
464  if (script && handle_script(L, argv, script) != LUA_OK) return 0;
465  if (args[has_i])  /* -i option? */
466    dotty(L);
467  else if (script == 0 && !args[has_e] && !args[has_v]) {  /* no arguments? */
468    if (lua_stdin_is_tty()) {
469      print_version();
470      dotty(L);
471    }
472    else dofile(L, NULL);  /* executes stdin as a file */
473  }
474  lua_pushboolean(L, 1);  /* signal no errors */
475  return 1;
476}
477
478
479int main (int argc, char **argv) {
480  int status, result;
481  lua_State *L = luaL_newstate();  /* create state */
482  if (L == NULL) {
483    l_message(argv[0], "cannot create state: not enough memory");
484    return EXIT_FAILURE;
485  }
486  /* call 'pmain' in protected mode */
487  lua_pushcfunction(L, &pmain);
488  lua_pushinteger(L, argc);  /* 1st argument */
489  lua_pushlightuserdata(L, argv); /* 2nd argument */
490  status = lua_pcall(L, 2, 1, 0);
491  result = lua_toboolean(L, -1);  /* get result */
492  finalreport(L, status);
493  lua_close(L);
494  return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE;
495}
496
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