1 /*
2 ** LuaJIT frontend. Runs commands, scripts, read-eval-print (REPL) etc.
3 ** Copyright (C) 2005-2021 Mike Pall. See Copyright Notice in luajit.h
4 **
5 ** Major portions taken verbatim or adapted from the Lua interpreter.
6 ** Copyright (C) 1994-2008 Lua.org, PUC-Rio. See Copyright Notice in lua.h
7 */
8 
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 
13 #define luajit_c
14 
15 #include "lua.h"
16 #include "lauxlib.h"
17 #include "lualib.h"
18 #include "luajit.h"
19 
20 #include "lj_arch.h"
21 
22 #if LJ_TARGET_POSIX
23 #include <unistd.h>
24 #define lua_stdin_is_tty()	isatty(0)
25 #elif LJ_TARGET_WINDOWS
26 #include <io.h>
27 #ifdef __BORLANDC__
28 #define lua_stdin_is_tty()	isatty(_fileno(stdin))
29 #else
30 #define lua_stdin_is_tty()	_isatty(_fileno(stdin))
31 #endif
32 #else
33 #define lua_stdin_is_tty()	1
34 #endif
35 
36 #if !LJ_TARGET_CONSOLE
37 #include <signal.h>
38 #endif
39 
40 static lua_State *globalL = NULL;
41 static const char *progname = LUA_PROGNAME;
42 
43 #if !LJ_TARGET_CONSOLE
lstop(lua_State * L,lua_Debug * ar)44 static void lstop(lua_State *L, lua_Debug *ar)
45 {
46   (void)ar;  /* unused arg. */
47   lua_sethook(L, NULL, 0, 0);
48   /* Avoid luaL_error -- a C hook doesn't add an extra frame. */
49   luaL_where(L, 0);
50   lua_pushfstring(L, "%sinterrupted!", lua_tostring(L, -1));
51   lua_error(L);
52 }
53 
laction(int i)54 static void laction(int i)
55 {
56   signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
57 			 terminate process (default action) */
58   lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
59 }
60 #endif
61 
print_usage(void)62 static void print_usage(void)
63 {
64   fputs("usage: ", stderr);
65   fputs(progname, stderr);
66   fputs(" [options]... [script [args]...].\n"
67   "Available options are:\n"
68   "  -e chunk  Execute string " LUA_QL("chunk") ".\n"
69   "  -l name   Require library " LUA_QL("name") ".\n"
70   "  -b ...    Save or list bytecode.\n"
71   "  -j cmd    Perform LuaJIT control command.\n"
72   "  -O[opt]   Control LuaJIT optimizations.\n"
73   "  -i        Enter interactive mode after executing " LUA_QL("script") ".\n"
74   "  -v        Show version information.\n"
75   "  -E        Ignore environment variables.\n"
76   "  --        Stop handling options.\n"
77   "  -         Execute stdin and stop handling options.\n", stderr);
78   fflush(stderr);
79 }
80 
l_message(const char * pname,const char * msg)81 static void l_message(const char *pname, const char *msg)
82 {
83   if (pname) { fputs(pname, stderr); fputc(':', stderr); fputc(' ', stderr); }
84   fputs(msg, stderr); fputc('\n', stderr);
85   fflush(stderr);
86 }
87 
report(lua_State * L,int status)88 static int report(lua_State *L, int status)
89 {
90   if (status && !lua_isnil(L, -1)) {
91     const char *msg = lua_tostring(L, -1);
92     if (msg == NULL) msg = "(error object is not a string)";
93     l_message(progname, msg);
94     lua_pop(L, 1);
95   }
96   return status;
97 }
98 
traceback(lua_State * L)99 static int traceback(lua_State *L)
100 {
101   if (!lua_isstring(L, 1)) { /* Non-string error object? Try metamethod. */
102     if (lua_isnoneornil(L, 1) ||
103 	!luaL_callmeta(L, 1, "__tostring") ||
104 	!lua_isstring(L, -1))
105       return 1;  /* Return non-string error object. */
106     lua_remove(L, 1);  /* Replace object by result of __tostring metamethod. */
107   }
108   luaL_traceback(L, L, lua_tostring(L, 1), 1);
109   return 1;
110 }
111 
docall(lua_State * L,int narg,int clear)112 static int docall(lua_State *L, int narg, int clear)
113 {
114   int status;
115   int base = lua_gettop(L) - narg;  /* function index */
116   lua_pushcfunction(L, traceback);  /* push traceback function */
117   lua_insert(L, base);  /* put it under chunk and args */
118 #if !LJ_TARGET_CONSOLE
119   signal(SIGINT, laction);
120 #endif
121   status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
122 #if !LJ_TARGET_CONSOLE
123   signal(SIGINT, SIG_DFL);
124 #endif
125   lua_remove(L, base);  /* remove traceback function */
126   /* force a complete garbage collection in case of errors */
127   if (status != LUA_OK) lua_gc(L, LUA_GCCOLLECT, 0);
128   return status;
129 }
130 
print_version(void)131 static void print_version(void)
132 {
133   fputs(LUAJIT_VERSION " -- " LUAJIT_COPYRIGHT ". " LUAJIT_URL "\n", stdout);
134 }
135 
print_jit_status(lua_State * L)136 static void print_jit_status(lua_State *L)
137 {
138   int n;
139   const char *s;
140   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
141   lua_getfield(L, -1, "jit");  /* Get jit.* module table. */
142   lua_remove(L, -2);
143   lua_getfield(L, -1, "status");
144   lua_remove(L, -2);
145   n = lua_gettop(L);
146   lua_call(L, 0, LUA_MULTRET);
147   fputs(lua_toboolean(L, n) ? "JIT: ON" : "JIT: OFF", stdout);
148   for (n++; (s = lua_tostring(L, n)); n++) {
149     putc(' ', stdout);
150     fputs(s, stdout);
151   }
152   putc('\n', stdout);
153   lua_settop(L, 0);  /* clear stack */
154 }
155 
createargtable(lua_State * L,char ** argv,int argc,int argf)156 static void createargtable(lua_State *L, char **argv, int argc, int argf)
157 {
158   int i;
159   lua_createtable(L, argc - argf, argf);
160   for (i = 0; i < argc; i++) {
161     lua_pushstring(L, argv[i]);
162     lua_rawseti(L, -2, i - argf);
163   }
164   lua_setglobal(L, "arg");
165 }
166 
dofile(lua_State * L,const char * name)167 static int dofile(lua_State *L, const char *name)
168 {
169   int status = luaL_loadfile(L, name) || docall(L, 0, 1);
170   return report(L, status);
171 }
172 
dostring(lua_State * L,const char * s,const char * name)173 static int dostring(lua_State *L, const char *s, const char *name)
174 {
175   int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1);
176   return report(L, status);
177 }
178 
dolibrary(lua_State * L,const char * name)179 static int dolibrary(lua_State *L, const char *name)
180 {
181   lua_getglobal(L, "require");
182   lua_pushstring(L, name);
183   return report(L, docall(L, 1, 1));
184 }
185 
write_prompt(lua_State * L,int firstline)186 static void write_prompt(lua_State *L, int firstline)
187 {
188   const char *p;
189   lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");
190   p = lua_tostring(L, -1);
191   if (p == NULL) p = firstline ? LUA_PROMPT : LUA_PROMPT2;
192   fputs(p, stdout);
193   fflush(stdout);
194   lua_pop(L, 1);  /* remove global */
195 }
196 
incomplete(lua_State * L,int status)197 static int incomplete(lua_State *L, int status)
198 {
199   if (status == LUA_ERRSYNTAX) {
200     size_t lmsg;
201     const char *msg = lua_tolstring(L, -1, &lmsg);
202     const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
203     if (strstr(msg, LUA_QL("<eof>")) == tp) {
204       lua_pop(L, 1);
205       return 1;
206     }
207   }
208   return 0;  /* else... */
209 }
210 
pushline(lua_State * L,int firstline)211 static int pushline(lua_State *L, int firstline)
212 {
213   char buf[LUA_MAXINPUT];
214   write_prompt(L, firstline);
215   if (fgets(buf, LUA_MAXINPUT, stdin)) {
216     size_t len = strlen(buf);
217     if (len > 0 && buf[len-1] == '\n')
218       buf[len-1] = '\0';
219     if (firstline && buf[0] == '=')
220       lua_pushfstring(L, "return %s", buf+1);
221     else
222       lua_pushstring(L, buf);
223     return 1;
224   }
225   return 0;
226 }
227 
loadline(lua_State * L)228 static int loadline(lua_State *L)
229 {
230   int status;
231   lua_settop(L, 0);
232   if (!pushline(L, 1))
233     return -1;  /* no input */
234   for (;;) {  /* repeat until gets a complete line */
235     status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");
236     if (!incomplete(L, status)) break;  /* cannot try to add lines? */
237     if (!pushline(L, 0))  /* no more input? */
238       return -1;
239     lua_pushliteral(L, "\n");  /* add a new line... */
240     lua_insert(L, -2);  /* ...between the two lines */
241     lua_concat(L, 3);  /* join them */
242   }
243   lua_remove(L, 1);  /* remove line */
244   return status;
245 }
246 
dotty(lua_State * L)247 static void dotty(lua_State *L)
248 {
249   int status;
250   const char *oldprogname = progname;
251   progname = NULL;
252   while ((status = loadline(L)) != -1) {
253     if (status == LUA_OK) status = docall(L, 0, 0);
254     report(L, status);
255     if (status == LUA_OK && lua_gettop(L) > 0) {  /* any result to print? */
256       lua_getglobal(L, "print");
257       lua_insert(L, 1);
258       if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
259 	l_message(progname,
260 	  lua_pushfstring(L, "error calling " LUA_QL("print") " (%s)",
261 			      lua_tostring(L, -1)));
262     }
263   }
264   lua_settop(L, 0);  /* clear stack */
265   fputs("\n", stdout);
266   fflush(stdout);
267   progname = oldprogname;
268 }
269 
handle_script(lua_State * L,char ** argx)270 static int handle_script(lua_State *L, char **argx)
271 {
272   int status;
273   const char *fname = argx[0];
274   if (strcmp(fname, "-") == 0 && strcmp(argx[-1], "--") != 0)
275     fname = NULL;  /* stdin */
276   status = luaL_loadfile(L, fname);
277   if (status == LUA_OK) {
278     /* Fetch args from arg table. LUA_INIT or -e might have changed them. */
279     int narg = 0;
280     lua_getglobal(L, "arg");
281     if (lua_istable(L, -1)) {
282       do {
283 	narg++;
284 	lua_rawgeti(L, -narg, narg);
285       } while (!lua_isnil(L, -1));
286       lua_pop(L, 1);
287       lua_remove(L, -narg);
288       narg--;
289     } else {
290       lua_pop(L, 1);
291     }
292     status = docall(L, narg, 0);
293   }
294   return report(L, status);
295 }
296 
297 /* Load add-on module. */
loadjitmodule(lua_State * L)298 static int loadjitmodule(lua_State *L)
299 {
300   lua_getglobal(L, "require");
301   lua_pushliteral(L, "jit.");
302   lua_pushvalue(L, -3);
303   lua_concat(L, 2);
304   if (lua_pcall(L, 1, 1, 0)) {
305     const char *msg = lua_tostring(L, -1);
306     if (msg && !strncmp(msg, "module ", 7))
307       goto nomodule;
308     return report(L, 1);
309   }
310   lua_getfield(L, -1, "start");
311   if (lua_isnil(L, -1)) {
312   nomodule:
313     l_message(progname,
314 	      "unknown luaJIT command or jit.* modules not installed");
315     return 1;
316   }
317   lua_remove(L, -2);  /* Drop module table. */
318   return 0;
319 }
320 
321 /* Run command with options. */
runcmdopt(lua_State * L,const char * opt)322 static int runcmdopt(lua_State *L, const char *opt)
323 {
324   int narg = 0;
325   if (opt && *opt) {
326     for (;;) {  /* Split arguments. */
327       const char *p = strchr(opt, ',');
328       narg++;
329       if (!p) break;
330       if (p == opt)
331 	lua_pushnil(L);
332       else
333 	lua_pushlstring(L, opt, (size_t)(p - opt));
334       opt = p + 1;
335     }
336     if (*opt)
337       lua_pushstring(L, opt);
338     else
339       lua_pushnil(L);
340   }
341   return report(L, lua_pcall(L, narg, 0, 0));
342 }
343 
344 /* JIT engine control command: try jit library first or load add-on module. */
dojitcmd(lua_State * L,const char * cmd)345 static int dojitcmd(lua_State *L, const char *cmd)
346 {
347   const char *opt = strchr(cmd, '=');
348   lua_pushlstring(L, cmd, opt ? (size_t)(opt - cmd) : strlen(cmd));
349   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
350   lua_getfield(L, -1, "jit");  /* Get jit.* module table. */
351   lua_remove(L, -2);
352   lua_pushvalue(L, -2);
353   lua_gettable(L, -2);  /* Lookup library function. */
354   if (!lua_isfunction(L, -1)) {
355     lua_pop(L, 2);  /* Drop non-function and jit.* table, keep module name. */
356     if (loadjitmodule(L))
357       return 1;
358   } else {
359     lua_remove(L, -2);  /* Drop jit.* table. */
360   }
361   lua_remove(L, -2);  /* Drop module name. */
362   return runcmdopt(L, opt ? opt+1 : opt);
363 }
364 
365 /* Optimization flags. */
dojitopt(lua_State * L,const char * opt)366 static int dojitopt(lua_State *L, const char *opt)
367 {
368   lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED");
369   lua_getfield(L, -1, "jit.opt");  /* Get jit.opt.* module table. */
370   lua_remove(L, -2);
371   lua_getfield(L, -1, "start");
372   lua_remove(L, -2);
373   return runcmdopt(L, opt);
374 }
375 
376 /* Save or list bytecode. */
dobytecode(lua_State * L,char ** argv)377 static int dobytecode(lua_State *L, char **argv)
378 {
379   int narg = 0;
380   lua_pushliteral(L, "bcsave");
381   if (loadjitmodule(L))
382     return 1;
383   if (argv[0][2]) {
384     narg++;
385     argv[0][1] = '-';
386     lua_pushstring(L, argv[0]+1);
387   }
388   for (argv++; *argv != NULL; narg++, argv++)
389     lua_pushstring(L, *argv);
390   report(L, lua_pcall(L, narg, 0, 0));
391   return -1;
392 }
393 
394 /* check that argument has no extra characters at the end */
395 #define notail(x)	{if ((x)[2] != '\0') return -1;}
396 
397 #define FLAGS_INTERACTIVE	1
398 #define FLAGS_VERSION		2
399 #define FLAGS_EXEC		4
400 #define FLAGS_OPTION		8
401 #define FLAGS_NOENV		16
402 
collectargs(char ** argv,int * flags)403 static int collectargs(char **argv, int *flags)
404 {
405   int i;
406   for (i = 1; argv[i] != NULL; i++) {
407     if (argv[i][0] != '-')  /* Not an option? */
408       return i;
409     switch (argv[i][1]) {  /* Check option. */
410     case '-':
411       notail(argv[i]);
412       return i+1;
413     case '\0':
414       return i;
415     case 'i':
416       notail(argv[i]);
417       *flags |= FLAGS_INTERACTIVE;
418       /* fallthrough */
419     case 'v':
420       notail(argv[i]);
421       *flags |= FLAGS_VERSION;
422       break;
423     case 'e':
424       *flags |= FLAGS_EXEC;
425       /* fallthrough */
426     case 'j':  /* LuaJIT extension */
427     case 'l':
428       *flags |= FLAGS_OPTION;
429       if (argv[i][2] == '\0') {
430 	i++;
431 	if (argv[i] == NULL) return -1;
432       }
433       break;
434     case 'O': break;  /* LuaJIT extension */
435     case 'b':  /* LuaJIT extension */
436       if (*flags) return -1;
437       *flags |= FLAGS_EXEC;
438       return i+1;
439     case 'E':
440       *flags |= FLAGS_NOENV;
441       break;
442     default: return -1;  /* invalid option */
443     }
444   }
445   return i;
446 }
447 
runargs(lua_State * L,char ** argv,int argn)448 static int runargs(lua_State *L, char **argv, int argn)
449 {
450   int i;
451   for (i = 1; i < argn; i++) {
452     if (argv[i] == NULL) continue;
453     lua_assert(argv[i][0] == '-');
454     switch (argv[i][1]) {
455     case 'e': {
456       const char *chunk = argv[i] + 2;
457       if (*chunk == '\0') chunk = argv[++i];
458       lua_assert(chunk != NULL);
459       if (dostring(L, chunk, "=(command line)") != 0)
460 	return 1;
461       break;
462       }
463     case 'l': {
464       const char *filename = argv[i] + 2;
465       if (*filename == '\0') filename = argv[++i];
466       lua_assert(filename != NULL);
467       if (dolibrary(L, filename))
468 	return 1;
469       break;
470       }
471     case 'j': {  /* LuaJIT extension. */
472       const char *cmd = argv[i] + 2;
473       if (*cmd == '\0') cmd = argv[++i];
474       lua_assert(cmd != NULL);
475       if (dojitcmd(L, cmd))
476 	return 1;
477       break;
478       }
479     case 'O':  /* LuaJIT extension. */
480       if (dojitopt(L, argv[i] + 2))
481 	return 1;
482       break;
483     case 'b':  /* LuaJIT extension. */
484       return dobytecode(L, argv+i);
485     default: break;
486     }
487   }
488   return LUA_OK;
489 }
490 
handle_luainit(lua_State * L)491 static int handle_luainit(lua_State *L)
492 {
493 #if LJ_TARGET_CONSOLE
494   const char *init = NULL;
495 #else
496   const char *init = getenv(LUA_INIT);
497 #endif
498   if (init == NULL)
499     return LUA_OK;
500   else if (init[0] == '@')
501     return dofile(L, init+1);
502   else
503     return dostring(L, init, "=" LUA_INIT);
504 }
505 
506 static struct Smain {
507   char **argv;
508   int argc;
509   int status;
510 } smain;
511 
pmain(lua_State * L)512 static int pmain(lua_State *L)
513 {
514   struct Smain *s = &smain;
515   char **argv = s->argv;
516   int argn;
517   int flags = 0;
518   globalL = L;
519   if (argv[0] && argv[0][0]) progname = argv[0];
520 
521   LUAJIT_VERSION_SYM();  /* Linker-enforced version check. */
522 
523   argn = collectargs(argv, &flags);
524   if (argn < 0) {  /* Invalid args? */
525     print_usage();
526     s->status = 1;
527     return 0;
528   }
529 
530   if ((flags & FLAGS_NOENV)) {
531     lua_pushboolean(L, 1);
532     lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV");
533   }
534 
535   /* Stop collector during library initialization. */
536   lua_gc(L, LUA_GCSTOP, 0);
537   luaL_openlibs(L);
538   lua_gc(L, LUA_GCRESTART, -1);
539 
540   createargtable(L, argv, s->argc, argn);
541 
542   if (!(flags & FLAGS_NOENV)) {
543     s->status = handle_luainit(L);
544     if (s->status != LUA_OK) return 0;
545   }
546 
547   if ((flags & FLAGS_VERSION)) print_version();
548 
549   s->status = runargs(L, argv, argn);
550   if (s->status != LUA_OK) return 0;
551 
552   if (s->argc > argn) {
553     s->status = handle_script(L, argv + argn);
554     if (s->status != LUA_OK) return 0;
555   }
556 
557   if ((flags & FLAGS_INTERACTIVE)) {
558     print_jit_status(L);
559     dotty(L);
560   } else if (s->argc == argn && !(flags & (FLAGS_EXEC|FLAGS_VERSION))) {
561     if (lua_stdin_is_tty()) {
562       print_version();
563       print_jit_status(L);
564       dotty(L);
565     } else {
566       dofile(L, NULL);  /* Executes stdin as a file. */
567     }
568   }
569   return 0;
570 }
571 
main(int argc,char ** argv)572 int main(int argc, char **argv)
573 {
574   int status;
575   lua_State *L = lua_open();
576   if (L == NULL) {
577     l_message(argv[0], "cannot create state: not enough memory");
578     return EXIT_FAILURE;
579   }
580   smain.argc = argc;
581   smain.argv = argv;
582   status = lua_cpcall(L, pmain, NULL);
583   report(L, status);
584   lua_close(L);
585   return (status || smain.status > 0) ? EXIT_FAILURE : EXIT_SUCCESS;
586 }
587 
588