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author | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2013-04-12 15:48:47 -0300 |
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committer | Roberto Ierusalimschy <roberto@inf.puc-rio.br> | 2013-04-12 15:48:47 -0300 |
commit | 2ca518141350667e38941eac35b76980095d2fdc (patch) | |
tree | 82595f0dfd57df5782905621298c8aae68b46389 /lua.c | |
parent | f5ae26ec6c2eb69f03f316e59c1e1977c52c7c23 (diff) | |
download | lua-2ca518141350667e38941eac35b76980095d2fdc.tar.gz lua-2ca518141350667e38941eac35b76980095d2fdc.tar.bz2 lua-2ca518141350667e38941eac35b76980095d2fdc.zip |
Branch 5.2 - new releases for 5.2 go from here, main trunk goes
for next version
Diffstat (limited to 'lua.c')
-rw-r--r-- | lua.c | 497 |
1 files changed, 497 insertions, 0 deletions
@@ -0,0 +1,497 @@ | |||
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: break; | ||
417 | } | ||
418 | } | ||
419 | return 1; | ||
420 | } | ||
421 | |||
422 | |||
423 | static int handle_luainit (lua_State *L) { | ||
424 | const char *name = "=" LUA_INITVERSION; | ||
425 | const char *init = getenv(name + 1); | ||
426 | if (init == NULL) { | ||
427 | name = "=" LUA_INIT; | ||
428 | init = getenv(name + 1); /* try alternative name */ | ||
429 | } | ||
430 | if (init == NULL) return LUA_OK; | ||
431 | else if (init[0] == '@') | ||
432 | return dofile(L, init+1); | ||
433 | else | ||
434 | return dostring(L, init, name); | ||
435 | } | ||
436 | |||
437 | |||
438 | static int pmain (lua_State *L) { | ||
439 | int argc = (int)lua_tointeger(L, 1); | ||
440 | char **argv = (char **)lua_touserdata(L, 2); | ||
441 | int script; | ||
442 | int args[num_has]; | ||
443 | args[has_i] = args[has_v] = args[has_e] = args[has_E] = 0; | ||
444 | if (argv[0] && argv[0][0]) progname = argv[0]; | ||
445 | script = collectargs(argv, args); | ||
446 | if (script < 0) { /* invalid arg? */ | ||
447 | print_usage(argv[-script]); | ||
448 | return 0; | ||
449 | } | ||
450 | if (args[has_v]) print_version(); | ||
451 | if (args[has_E]) { /* option '-E'? */ | ||
452 | lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */ | ||
453 | lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); | ||
454 | } | ||
455 | /* open standard libraries */ | ||
456 | luaL_checkversion(L); | ||
457 | lua_gc(L, LUA_GCSTOP, 0); /* stop collector during initialization */ | ||
458 | luaL_openlibs(L); /* open libraries */ | ||
459 | lua_gc(L, LUA_GCRESTART, 0); | ||
460 | if (!args[has_E] && handle_luainit(L) != LUA_OK) | ||
461 | return 0; /* error running LUA_INIT */ | ||
462 | /* execute arguments -e and -l */ | ||
463 | if (!runargs(L, argv, (script > 0) ? script : argc)) return 0; | ||
464 | /* execute main script (if there is one) */ | ||
465 | if (script && handle_script(L, argv, script) != LUA_OK) return 0; | ||
466 | if (args[has_i]) /* -i option? */ | ||
467 | dotty(L); | ||
468 | else if (script == 0 && !args[has_e] && !args[has_v]) { /* no arguments? */ | ||
469 | if (lua_stdin_is_tty()) { | ||
470 | print_version(); | ||
471 | dotty(L); | ||
472 | } | ||
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 | |||