root/src/lua-5.1.3/src/lua.c

Revision 5c8778c4361d2ad3adc94ef98d804c6fa9e6ba7c, 9.9 kB (checked in by Theo Schlossnagle <jesus@omniti.com>, 10 years ago)

import lua... I'd like to write checkers in lua

  • Property mode set to 100644
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1 /*
2 ** $Id: lua.c,v 1.160.1.2 2007/12/28 15:32:23 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
22 static lua_State *globalL = NULL;
23
24 static const char *progname = LUA_PROGNAME;
25
26
27
28 static void lstop (lua_State *L, lua_Debug *ar) {
29   (void)ar;  /* unused arg. */
30   lua_sethook(L, NULL, 0, 0);
31   luaL_error(L, "interrupted!");
32 }
33
34
35 static void laction (int i) {
36   signal(i, SIG_DFL); /* if another SIGINT happens before lstop,
37                               terminate process (default action) */
38   lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
39 }
40
41
42 static void print_usage (void) {
43   fprintf(stderr,
44   "usage: %s [options] [script [args]].\n"
45   "Available options are:\n"
46   "  -e stat  execute string " LUA_QL("stat") "\n"
47   "  -l name  require library " LUA_QL("name") "\n"
48   "  -i       enter interactive mode after executing " LUA_QL("script") "\n"
49   "  -v       show version information\n"
50   "  --       stop handling options\n"
51   "  -        execute stdin and stop handling options\n"
52   ,
53   progname);
54   fflush(stderr);
55 }
56
57
58 static void l_message (const char *pname, const char *msg) {
59   if (pname) fprintf(stderr, "%s: ", pname);
60   fprintf(stderr, "%s\n", msg);
61   fflush(stderr);
62 }
63
64
65 static int report (lua_State *L, int status) {
66   if (status && !lua_isnil(L, -1)) {
67     const char *msg = lua_tostring(L, -1);
68     if (msg == NULL) msg = "(error object is not a string)";
69     l_message(progname, msg);
70     lua_pop(L, 1);
71   }
72   return status;
73 }
74
75
76 static int traceback (lua_State *L) {
77   if (!lua_isstring(L, 1))  /* 'message' not a string? */
78     return 1;  /* keep it intact */
79   lua_getfield(L, LUA_GLOBALSINDEX, "debug");
80   if (!lua_istable(L, -1)) {
81     lua_pop(L, 1);
82     return 1;
83   }
84   lua_getfield(L, -1, "traceback");
85   if (!lua_isfunction(L, -1)) {
86     lua_pop(L, 2);
87     return 1;
88   }
89   lua_pushvalue(L, 1);  /* pass error message */
90   lua_pushinteger(L, 2);  /* skip this function and traceback */
91   lua_call(L, 2, 1);  /* call debug.traceback */
92   return 1;
93 }
94
95
96 static int docall (lua_State *L, int narg, int clear) {
97   int status;
98   int base = lua_gettop(L) - narg;  /* function index */
99   lua_pushcfunction(L, traceback);  /* push traceback function */
100   lua_insert(L, base);  /* put it under chunk and args */
101   signal(SIGINT, laction);
102   status = lua_pcall(L, narg, (clear ? 0 : LUA_MULTRET), base);
103   signal(SIGINT, SIG_DFL);
104   lua_remove(L, base);  /* remove traceback function */
105   /* force a complete garbage collection in case of errors */
106   if (status != 0) lua_gc(L, LUA_GCCOLLECT, 0);
107   return status;
108 }
109
110
111 static void print_version (void) {
112   l_message(NULL, LUA_RELEASE "  " LUA_COPYRIGHT);
113 }
114
115
116 static int getargs (lua_State *L, char **argv, int n) {
117   int narg;
118   int i;
119   int argc = 0;
120   while (argv[argc]) argc++;  /* count total number of arguments */
121   narg = argc - (n + 1);  /* number of arguments to the script */
122   luaL_checkstack(L, narg + 3, "too many arguments to script");
123   for (i=n+1; i < argc; i++)
124     lua_pushstring(L, argv[i]);
125   lua_createtable(L, narg, n + 1);
126   for (i=0; i < argc; i++) {
127     lua_pushstring(L, argv[i]);
128     lua_rawseti(L, -2, i - n);
129   }
130   return narg;
131 }
132
133
134 static int dofile (lua_State *L, const char *name) {
135   int status = luaL_loadfile(L, name) || docall(L, 0, 1);
136   return report(L, status);
137 }
138
139
140 static int dostring (lua_State *L, const char *s, const char *name) {
141   int status = luaL_loadbuffer(L, s, strlen(s), name) || docall(L, 0, 1);
142   return report(L, status);
143 }
144
145
146 static int dolibrary (lua_State *L, const char *name) {
147   lua_getglobal(L, "require");
148   lua_pushstring(L, name);
149   return report(L, docall(L, 1, 1));
150 }
151
152
153 static const char *get_prompt (lua_State *L, int firstline) {
154   const char *p;
155   lua_getfield(L, LUA_GLOBALSINDEX, firstline ? "_PROMPT" : "_PROMPT2");
156   p = lua_tostring(L, -1);
157   if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2);
158   lua_pop(L, 1);  /* remove global */
159   return p;
160 }
161
162
163 static int incomplete (lua_State *L, int status) {
164   if (status == LUA_ERRSYNTAX) {
165     size_t lmsg;
166     const char *msg = lua_tolstring(L, -1, &lmsg);
167     const char *tp = msg + lmsg - (sizeof(LUA_QL("<eof>")) - 1);
168     if (strstr(msg, LUA_QL("<eof>")) == tp) {
169       lua_pop(L, 1);
170       return 1;
171     }
172   }
173   return 0;  /* else... */
174 }
175
176
177 static int pushline (lua_State *L, int firstline) {
178   char buffer[LUA_MAXINPUT];
179   char *b = buffer;
180   size_t l;
181   const char *prmt = get_prompt(L, firstline);
182   if (lua_readline(L, b, prmt) == 0)
183     return 0;  /* no input */
184   l = strlen(b);
185   if (l > 0 && b[l-1] == '\n')  /* line ends with newline? */
186     b[l-1] = '\0';  /* remove it */
187   if (firstline && b[0] == '=')  /* first line starts with `=' ? */
188     lua_pushfstring(L, "return %s", b+1);  /* change it to `return' */
189   else
190     lua_pushstring(L, b);
191   lua_freeline(L, b);
192   return 1;
193 }
194
195
196 static int loadline (lua_State *L) {
197   int status;
198   lua_settop(L, 0);
199   if (!pushline(L, 1))
200     return -1;  /* no input */
201   for (;;) {  /* repeat until gets a complete line */
202     status = luaL_loadbuffer(L, lua_tostring(L, 1), lua_strlen(L, 1), "=stdin");
203     if (!incomplete(L, status)) break;  /* cannot try to add lines? */
204     if (!pushline(L, 0))  /* no more input? */
205       return -1;
206     lua_pushliteral(L, "\n");  /* add a new line... */
207     lua_insert(L, -2);  /* ...between the two lines */
208     lua_concat(L, 3);  /* join them */
209   }
210   lua_saveline(L, 1);
211   lua_remove(L, 1);  /* remove line */
212   return status;
213 }
214
215
216 static void dotty (lua_State *L) {
217   int status;
218   const char *oldprogname = progname;
219   progname = NULL;
220   while ((status = loadline(L)) != -1) {
221     if (status == 0) status = docall(L, 0, 0);
222     report(L, status);
223     if (status == 0 && lua_gettop(L) > 0) {  /* any result to print? */
224       lua_getglobal(L, "print");
225       lua_insert(L, 1);
226       if (lua_pcall(L, lua_gettop(L)-1, 0, 0) != 0)
227         l_message(progname, lua_pushfstring(L,
228                                "error calling " LUA_QL("print") " (%s)",
229                                lua_tostring(L, -1)));
230     }
231   }
232   lua_settop(L, 0);  /* clear stack */
233   fputs("\n", stdout);
234   fflush(stdout);
235   progname = oldprogname;
236 }
237
238
239 static int handle_script (lua_State *L, char **argv, int n) {
240   int status;
241   const char *fname;
242   int narg = getargs(L, argv, n);  /* collect arguments */
243   lua_setglobal(L, "arg");
244   fname = argv[n];
245   if (strcmp(fname, "-") == 0 && strcmp(argv[n-1], "--") != 0)
246     fname = NULL;  /* stdin */
247   status = luaL_loadfile(L, fname);
248   lua_insert(L, -(narg+1));
249   if (status == 0)
250     status = docall(L, narg, 0);
251   else
252     lua_pop(L, narg);     
253   return report(L, status);
254 }
255
256
257 /* check that argument has no extra characters at the end */
258 #define notail(x)       {if ((x)[2] != '\0') return -1;}
259
260
261 static int collectargs (char **argv, int *pi, int *pv, int *pe) {
262   int i;
263   for (i = 1; argv[i] != NULL; i++) {
264     if (argv[i][0] != '-')  /* not an option? */
265         return i;
266     switch (argv[i][1]) {  /* option */
267       case '-':
268         notail(argv[i]);
269         return (argv[i+1] != NULL ? i+1 : 0);
270       case '\0':
271         return i;
272       case 'i':
273         notail(argv[i]);
274         *pi = 1;  /* go through */
275       case 'v':
276         notail(argv[i]);
277         *pv = 1;
278         break;
279       case 'e':
280         *pe = 1;  /* go through */
281       case 'l':
282         if (argv[i][2] == '\0') {
283           i++;
284           if (argv[i] == NULL) return -1;
285         }
286         break;
287       default: return -1;  /* invalid option */
288     }
289   }
290   return 0;
291 }
292
293
294 static int runargs (lua_State *L, char **argv, int n) {
295   int i;
296   for (i = 1; i < n; i++) {
297     if (argv[i] == NULL) continue;
298     lua_assert(argv[i][0] == '-');
299     switch (argv[i][1]) {  /* option */
300       case 'e': {
301         const char *chunk = argv[i] + 2;
302         if (*chunk == '\0') chunk = argv[++i];
303         lua_assert(chunk != NULL);
304         if (dostring(L, chunk, "=(command line)") != 0)
305           return 1;
306         break;
307       }
308       case 'l': {
309         const char *filename = argv[i] + 2;
310         if (*filename == '\0') filename = argv[++i];
311         lua_assert(filename != NULL);
312         if (dolibrary(L, filename))
313           return 1;  /* stop if file fails */
314         break;
315       }
316       default: break;
317     }
318   }
319   return 0;
320 }
321
322
323 static int handle_luainit (lua_State *L) {
324   const char *init = getenv(LUA_INIT);
325   if (init == NULL) return 0;  /* status OK */
326   else if (init[0] == '@')
327     return dofile(L, init+1);
328   else
329     return dostring(L, init, "=" LUA_INIT);
330 }
331
332
333 struct Smain {
334   int argc;
335   char **argv;
336   int status;
337 };
338
339
340 static int pmain (lua_State *L) {
341   struct Smain *s = (struct Smain *)lua_touserdata(L, 1);
342   char **argv = s->argv;
343   int script;
344   int has_i = 0, has_v = 0, has_e = 0;
345   globalL = L;
346   if (argv[0] && argv[0][0]) progname = argv[0];
347   lua_gc(L, LUA_GCSTOP, 0);  /* stop collector during initialization */
348   luaL_openlibs(L);  /* open libraries */
349   lua_gc(L, LUA_GCRESTART, 0);
350   s->status = handle_luainit(L);
351   if (s->status != 0) return 0;
352   script = collectargs(argv, &has_i, &has_v, &has_e);
353   if (script < 0) {  /* invalid args? */
354     print_usage();
355     s->status = 1;
356     return 0;
357   }
358   if (has_v) print_version();
359   s->status = runargs(L, argv, (script > 0) ? script : s->argc);
360   if (s->status != 0) return 0;
361   if (script)
362     s->status = handle_script(L, argv, script);
363   if (s->status != 0) return 0;
364   if (has_i)
365     dotty(L);
366   else if (script == 0 && !has_e && !has_v) {
367     if (lua_stdin_is_tty()) {
368       print_version();
369       dotty(L);
370     }
371     else dofile(L, NULL);  /* executes stdin as a file */
372   }
373   return 0;
374 }
375
376
377 int main (int argc, char **argv) {
378   int status;
379   struct Smain s;
380   lua_State *L = lua_open();  /* create state */
381   if (L == NULL) {
382     l_message(argv[0], "cannot create state: not enough memory");
383     return EXIT_FAILURE;
384   }
385   s.argc = argc;
386   s.argv = argv;
387   status = lua_cpcall(L, &pmain, &s);
388   report(L, status);
389   lua_close(L);
390   return (status || s.status) ? EXIT_FAILURE : EXIT_SUCCESS;
391 }
392
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