1 /*
2 ** $Id: llex.c,v 2.20.1.1 2007/12/27 13:02:25 roberto Exp $
3 ** Lexical Analyzer
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <ctype.h>
9 #include <locale.h>
10 #include <string.h>
11
12 #define llex_c
13 #define LUA_CORE
14
15 #include "lua.h"
16
17 #include "ldo.h"
18 #include "llex.h"
19 #include "lobject.h"
20 #include "lparser.h"
21 #include "lstate.h"
22 #include "lstring.h"
23 #include "ltable.h"
24 #include "lzio.h"
25
26
27
28 #define next(ls) (ls->current = zgetc(ls->z))
29
30
31
32
33 #define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r')
34
35
36 /* ORDER RESERVED */
37 const char *const luaX_tokens [] = {
38 "and", "break", "do", "else", "elseif",
39 "end", "false", "for", "function", "if",
40 "in", "local", "nil", "not", "or", "repeat",
41 "return", "then", "true", "until", "while",
42 "..", "...", "==", ">=", "<=", "~=",
43 "<number>", "<name>", "<string>", "<eof>",
44 NULL
45 };
46
47
48 #define save_and_next(ls) (save(ls, ls->current), next(ls))
49
50
save(LexState * ls,int c)51 static void save (LexState *ls, int c) {
52 Mbuffer *b = ls->buff;
53 if (b->n + 1 > b->buffsize) {
54 size_t newsize;
55 if (b->buffsize >= MAX_SIZET/2)
56 luaX_lexerror(ls, "lexical element too long", 0);
57 newsize = b->buffsize * 2;
58 luaZ_resizebuffer(ls->L, b, newsize);
59 }
60 b->buffer[b->n++] = cast(char, c);
61 }
62
63
luaX_init(lua_State * L)64 void luaX_init (lua_State *L) {
65 int i;
66 for (i=0; i<NUM_RESERVED; i++) {
67 TString *ts = luaS_new(L, luaX_tokens[i]);
68 luaS_fix(ts); /* reserved words are never collected */
69 lua_assert(strlen(luaX_tokens[i])+1 <= TOKEN_LEN);
70 ts->tsv.reserved = cast_byte(i+1); /* reserved word */
71 }
72 }
73
74
75 #define MAXSRC 80
76
77
luaX_token2str(LexState * ls,int token)78 const char *luaX_token2str (LexState *ls, int token) {
79 if (token < FIRST_RESERVED) {
80 lua_assert(token == cast(unsigned char, token));
81 return (iscntrl(token)) ? luaO_pushfstring(ls->L, "char(%d)", token) :
82 luaO_pushfstring(ls->L, "%c", token);
83 }
84 else
85 return luaX_tokens[token-FIRST_RESERVED];
86 }
87
88
txtToken(LexState * ls,int token)89 static const char *txtToken (LexState *ls, int token) {
90 switch (token) {
91 case TK_NAME:
92 case TK_STRING:
93 case TK_NUMBER:
94 save(ls, '\0');
95 return luaZ_buffer(ls->buff);
96 default:
97 return luaX_token2str(ls, token);
98 }
99 }
100
101
luaX_lexerror(LexState * ls,const char * msg,int token)102 void luaX_lexerror (LexState *ls, const char *msg, int token) {
103 char buff[MAXSRC];
104 luaO_chunkid(buff, getstr(ls->source), MAXSRC);
105 msg = luaO_pushfstring(ls->L, "%s:%d: %s", buff, ls->linenumber, msg);
106 if (token)
107 luaO_pushfstring(ls->L, "%s near " LUA_QS, msg, txtToken(ls, token));
108 luaD_throw(ls->L, LUA_ERRSYNTAX);
109 }
110
111
luaX_syntaxerror(LexState * ls,const char * msg)112 void luaX_syntaxerror (LexState *ls, const char *msg) {
113 luaX_lexerror(ls, msg, ls->t.token);
114 }
115
116
luaX_newstring(LexState * ls,const char * str,size_t l)117 TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
118 lua_State *L = ls->L;
119 TString *ts = luaS_newlstr(L, str, l);
120 TValue *o = luaH_setstr(L, ls->fs->h, ts); /* entry for `str' */
121 if (ttisnil(o))
122 setbvalue(o, 1); /* make sure `str' will not be collected */
123 return ts;
124 }
125
126
inclinenumber(LexState * ls)127 static void inclinenumber (LexState *ls) {
128 int old = ls->current;
129 lua_assert(currIsNewline(ls));
130 next(ls); /* skip `\n' or `\r' */
131 if (currIsNewline(ls) && ls->current != old)
132 next(ls); /* skip `\n\r' or `\r\n' */
133 if (++ls->linenumber >= MAX_INT)
134 luaX_syntaxerror(ls, "chunk has too many lines");
135 }
136
137
luaX_setinput(lua_State * L,LexState * ls,ZIO * z,TString * source)138 void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source) {
139 ls->decpoint = '.';
140 ls->L = L;
141 ls->lookahead.token = TK_EOS; /* no look-ahead token */
142 ls->z = z;
143 ls->fs = NULL;
144 ls->linenumber = 1;
145 ls->lastline = 1;
146 ls->source = source;
147 luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */
148 next(ls); /* read first char */
149 }
150
151
152
153 /*
154 ** =======================================================
155 ** LEXICAL ANALYZER
156 ** =======================================================
157 */
158
159
160
check_next(LexState * ls,const char * set)161 static int check_next (LexState *ls, const char *set) {
162 if (!strchr(set, ls->current))
163 return 0;
164 save_and_next(ls);
165 return 1;
166 }
167
168
buffreplace(LexState * ls,char from,char to)169 static void buffreplace (LexState *ls, char from, char to) {
170 size_t n = luaZ_bufflen(ls->buff);
171 char *p = luaZ_buffer(ls->buff);
172 while (n--)
173 if (p[n] == from) p[n] = to;
174 }
175
176
trydecpoint(LexState * ls,SemInfo * seminfo)177 static void trydecpoint (LexState *ls, SemInfo *seminfo) {
178 /* format error: try to update decimal point separator */
179 #ifndef ANDROID
180 struct lconv *cv = localeconv();
181 #endif
182 char old = ls->decpoint;
183 #ifdef ANDROID
184 ls->decpoint = '.';
185 #else
186 ls->decpoint = (cv ? cv->decimal_point[0] : '.');
187 #endif
188 buffreplace(ls, old, ls->decpoint); /* try updated decimal separator */
189 if (!luaO_str2d(luaZ_buffer(ls->buff), &seminfo->r)) {
190 /* format error with correct decimal point: no more options */
191 buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */
192 luaX_lexerror(ls, "malformed number", TK_NUMBER);
193 }
194 }
195
196
197 /* LUA_NUMBER */
read_numeral(LexState * ls,SemInfo * seminfo)198 static void read_numeral (LexState *ls, SemInfo *seminfo) {
199 lua_assert(isdigit(ls->current));
200 do {
201 save_and_next(ls);
202 } while (isdigit(ls->current) || ls->current == '.');
203 if (check_next(ls, "Ee")) /* `E'? */
204 check_next(ls, "+-"); /* optional exponent sign */
205 while (isalnum(ls->current) || ls->current == '_')
206 save_and_next(ls);
207 save(ls, '\0');
208 buffreplace(ls, '.', ls->decpoint); /* follow locale for decimal point */
209 if (!luaO_str2d(luaZ_buffer(ls->buff), &seminfo->r)) /* format error? */
210 trydecpoint(ls, seminfo); /* try to update decimal point separator */
211 }
212
213
skip_sep(LexState * ls)214 static int skip_sep (LexState *ls) {
215 int count = 0;
216 int s = ls->current;
217 lua_assert(s == '[' || s == ']');
218 save_and_next(ls);
219 while (ls->current == '=') {
220 save_and_next(ls);
221 count++;
222 }
223 return (ls->current == s) ? count : (-count) - 1;
224 }
225
226
read_long_string(LexState * ls,SemInfo * seminfo,int sep)227 static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
228 int cont = 0;
229 (void)(cont); /* avoid warnings when `cont' is not used */
230 save_and_next(ls); /* skip 2nd `[' */
231 if (currIsNewline(ls)) /* string starts with a newline? */
232 inclinenumber(ls); /* skip it */
233 for (;;) {
234 switch (ls->current) {
235 case EOZ:
236 luaX_lexerror(ls, (seminfo) ? "unfinished long string" :
237 "unfinished long comment", TK_EOS);
238 break; /* to avoid warnings */
239 #if defined(LUA_COMPAT_LSTR)
240 case '[': {
241 if (skip_sep(ls) == sep) {
242 save_and_next(ls); /* skip 2nd `[' */
243 cont++;
244 #if LUA_COMPAT_LSTR == 1
245 if (sep == 0)
246 luaX_lexerror(ls, "nesting of [[...]] is deprecated", '[');
247 #endif
248 }
249 break;
250 }
251 #endif
252 case ']': {
253 if (skip_sep(ls) == sep) {
254 save_and_next(ls); /* skip 2nd `]' */
255 #if defined(LUA_COMPAT_LSTR) && LUA_COMPAT_LSTR == 2
256 cont--;
257 if (sep == 0 && cont >= 0) break;
258 #endif
259 goto endloop;
260 }
261 break;
262 }
263 case '\n':
264 case '\r': {
265 save(ls, '\n');
266 inclinenumber(ls);
267 if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */
268 break;
269 }
270 default: {
271 if (seminfo) save_and_next(ls);
272 else next(ls);
273 }
274 }
275 } endloop:
276 if (seminfo)
277 seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),
278 luaZ_bufflen(ls->buff) - 2*(2 + sep));
279 }
280
281
read_string(LexState * ls,int del,SemInfo * seminfo)282 static void read_string (LexState *ls, int del, SemInfo *seminfo) {
283 save_and_next(ls);
284 while (ls->current != del) {
285 switch (ls->current) {
286 case EOZ:
287 luaX_lexerror(ls, "unfinished string", TK_EOS);
288 continue; /* to avoid warnings */
289 case '\n':
290 case '\r':
291 luaX_lexerror(ls, "unfinished string", TK_STRING);
292 continue; /* to avoid warnings */
293 case '\\': {
294 int c;
295 next(ls); /* do not save the `\' */
296 switch (ls->current) {
297 case 'a': c = '\a'; break;
298 case 'b': c = '\b'; break;
299 case 'f': c = '\f'; break;
300 case 'n': c = '\n'; break;
301 case 'r': c = '\r'; break;
302 case 't': c = '\t'; break;
303 case 'v': c = '\v'; break;
304 case '\n': /* go through */
305 case '\r': save(ls, '\n'); inclinenumber(ls); continue;
306 case EOZ: continue; /* will raise an error next loop */
307 default: {
308 if (!isdigit(ls->current))
309 save_and_next(ls); /* handles \\, \", \', and \? */
310 else { /* \xxx */
311 int i = 0;
312 c = 0;
313 do {
314 c = 10*c + (ls->current-'0');
315 next(ls);
316 } while (++i<3 && isdigit(ls->current));
317 if (c > UCHAR_MAX)
318 luaX_lexerror(ls, "escape sequence too large", TK_STRING);
319 save(ls, c);
320 }
321 continue;
322 }
323 }
324 save(ls, c);
325 next(ls);
326 continue;
327 }
328 default:
329 save_and_next(ls);
330 }
331 }
332 save_and_next(ls); /* skip delimiter */
333 seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1,
334 luaZ_bufflen(ls->buff) - 2);
335 }
336
337
llex(LexState * ls,SemInfo * seminfo)338 static int llex (LexState *ls, SemInfo *seminfo) {
339 luaZ_resetbuffer(ls->buff);
340 for (;;) {
341 switch (ls->current) {
342 case '\n':
343 case '\r': {
344 inclinenumber(ls);
345 continue;
346 }
347 case '-': {
348 next(ls);
349 if (ls->current != '-') return '-';
350 /* else is a comment */
351 next(ls);
352 if (ls->current == '[') {
353 int sep = skip_sep(ls);
354 luaZ_resetbuffer(ls->buff); /* `skip_sep' may dirty the buffer */
355 if (sep >= 0) {
356 read_long_string(ls, NULL, sep); /* long comment */
357 luaZ_resetbuffer(ls->buff);
358 continue;
359 }
360 }
361 /* else short comment */
362 while (!currIsNewline(ls) && ls->current != EOZ)
363 next(ls);
364 continue;
365 }
366 case '[': {
367 int sep = skip_sep(ls);
368 if (sep >= 0) {
369 read_long_string(ls, seminfo, sep);
370 return TK_STRING;
371 }
372 else if (sep == -1) return '[';
373 else luaX_lexerror(ls, "invalid long string delimiter", TK_STRING);
374 }
375 case '=': {
376 next(ls);
377 if (ls->current != '=') return '=';
378 else { next(ls); return TK_EQ; }
379 }
380 case '<': {
381 next(ls);
382 if (ls->current != '=') return '<';
383 else { next(ls); return TK_LE; }
384 }
385 case '>': {
386 next(ls);
387 if (ls->current != '=') return '>';
388 else { next(ls); return TK_GE; }
389 }
390 case '~': {
391 next(ls);
392 if (ls->current != '=') return '~';
393 else { next(ls); return TK_NE; }
394 }
395 case '"':
396 case '\'': {
397 read_string(ls, ls->current, seminfo);
398 return TK_STRING;
399 }
400 case '.': {
401 save_and_next(ls);
402 if (check_next(ls, ".")) {
403 if (check_next(ls, "."))
404 return TK_DOTS; /* ... */
405 else return TK_CONCAT; /* .. */
406 }
407 else if (!isdigit(ls->current)) return '.';
408 else {
409 read_numeral(ls, seminfo);
410 return TK_NUMBER;
411 }
412 }
413 case EOZ: {
414 return TK_EOS;
415 }
416 default: {
417 if (isspace(ls->current)) {
418 lua_assert(!currIsNewline(ls));
419 next(ls);
420 continue;
421 }
422 else if (isdigit(ls->current)) {
423 read_numeral(ls, seminfo);
424 return TK_NUMBER;
425 }
426 else if (isalpha(ls->current) || ls->current == '_') {
427 /* identifier or reserved word */
428 TString *ts;
429 do {
430 save_and_next(ls);
431 } while (isalnum(ls->current) || ls->current == '_');
432 ts = luaX_newstring(ls, luaZ_buffer(ls->buff),
433 luaZ_bufflen(ls->buff));
434 if (ts->tsv.reserved > 0) /* reserved word? */
435 return ts->tsv.reserved - 1 + FIRST_RESERVED;
436 else {
437 seminfo->ts = ts;
438 return TK_NAME;
439 }
440 }
441 else {
442 int c = ls->current;
443 next(ls);
444 return c; /* single-char tokens (+ - / ...) */
445 }
446 }
447 }
448 }
449 }
450
451
luaX_next(LexState * ls)452 void luaX_next (LexState *ls) {
453 ls->lastline = ls->linenumber;
454 if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */
455 ls->t = ls->lookahead; /* use this one */
456 ls->lookahead.token = TK_EOS; /* and discharge it */
457 }
458 else
459 ls->t.token = llex(ls, &ls->t.seminfo); /* read next token */
460 }
461
462
luaX_lookahead(LexState * ls)463 void luaX_lookahead (LexState *ls) {
464 lua_assert(ls->lookahead.token == TK_EOS);
465 ls->lookahead.token = llex(ls, &ls->lookahead.seminfo);
466 }
467
468