Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
/* BEGIN CSTYLED */
/*
** $Id: llex.c,v 2.63.1.3 2015/02/09 17:56:34 roberto Exp $
** Lexical Analyzer
** See Copyright Notice in lua.h
*/

#define llex_c
#define LUA_CORE

#include <sys/lua/lua.h>

#include "lctype.h"
#include "ldo.h"
#include "llex.h"
#include "lobject.h"
#include "lparser.h"
#include "lstate.h"
#include "lstring.h"
#include "ltable.h"
#include "lzio.h"



#define next(ls) (ls->current = zgetc(ls->z))



#define currIsNewline(ls)	(ls->current == '\n' || ls->current == '\r')


/* ORDER RESERVED */
static const char *const luaX_tokens [] = {
    "and", "break", "do", "else", "elseif",
    "end", "false", "for", "function", "goto", "if",
    "in", "local", "nil", "not", "or", "repeat",
    "return", "then", "true", "until", "while",
    "..", "...", "==", ">=", "<=", "~=", "::", "<eof>",
    "<number>", "<name>", "<string>"
};


#define save_and_next(ls) (save(ls, ls->current), next(ls))


static l_noret lexerror (LexState *ls, const char *msg, int token);


static void save (LexState *ls, int c) {
  Mbuffer *b = ls->buff;
  if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) {
    size_t newsize;
    if (luaZ_sizebuffer(b) >= MAX_SIZET/2)
      lexerror(ls, "lexical element too long", 0);
    newsize = luaZ_sizebuffer(b) * 2;
    luaZ_resizebuffer(ls->L, b, newsize);
  }
  b->buffer[luaZ_bufflen(b)++] = cast(char, c);
}


void luaX_init (lua_State *L) {
  int i;
  for (i=0; i<NUM_RESERVED; i++) {
    TString *ts = luaS_new(L, luaX_tokens[i]);
    luaS_fix(ts);  /* reserved words are never collected */
    ts->tsv.extra = cast_byte(i+1);  /* reserved word */
  }
}


const char *luaX_token2str (LexState *ls, int token) {
  if (token < FIRST_RESERVED) {  /* single-byte symbols? */
    lua_assert(token == cast(unsigned char, token));
    return (lisprint(token)) ? luaO_pushfstring(ls->L, LUA_QL("%c"), token) :
                              luaO_pushfstring(ls->L, "char(%d)", token);
  }
  else {
    const char *s = luaX_tokens[token - FIRST_RESERVED];
    if (token < TK_EOS)  /* fixed format (symbols and reserved words)? */
      return luaO_pushfstring(ls->L, LUA_QS, s);
    else  /* names, strings, and numerals */
      return s;
  }
}


static const char *txtToken (LexState *ls, int token) {
  switch (token) {
    case TK_NAME:
    case TK_STRING:
    case TK_NUMBER:
      save(ls, '\0');
      return luaO_pushfstring(ls->L, LUA_QS, luaZ_buffer(ls->buff));
    default:
      return luaX_token2str(ls, token);
  }
}


static l_noret lexerror (LexState *ls, const char *msg, int token) {
  char buff[LUA_IDSIZE];
  luaO_chunkid(buff, getstr(ls->source), LUA_IDSIZE);
  msg = luaO_pushfstring(ls->L, "%s:%d: %s", buff, ls->linenumber, msg);
  if (token)
    luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token));
  luaD_throw(ls->L, LUA_ERRSYNTAX);
}


l_noret luaX_syntaxerror (LexState *ls, const char *msg) {
  lexerror(ls, msg, ls->t.token);
}


/*
** creates a new string and anchors it in function's table so that
** it will not be collected until the end of the function's compilation
** (by that time it should be anchored in function's prototype)
*/
TString *luaX_newstring (LexState *ls, const char *str, size_t l) {
  lua_State *L = ls->L;
  TValue *o;  /* entry for `str' */
  TString *ts = luaS_newlstr(L, str, l);  /* create new string */
  setsvalue2s(L, L->top++, ts);  /* temporarily anchor it in stack */
  o = luaH_set(L, ls->fs->h, L->top - 1);
  if (ttisnil(o)) {  /* not in use yet? (see 'addK') */
    /* boolean value does not need GC barrier;
       table has no metatable, so it does not need to invalidate cache */
    setbvalue(o, 1);  /* t[string] = true */
    luaC_checkGC(L);
  }
  else {  /* string already present */
    ts = rawtsvalue(keyfromval(o));  /* re-use value previously stored */
  }
  L->top--;  /* remove string from stack */
  return ts;
}


/*
** increment line number and skips newline sequence (any of
** \n, \r, \n\r, or \r\n)
*/
static void inclinenumber (LexState *ls) {
  int old = ls->current;
  lua_assert(currIsNewline(ls));
  next(ls);  /* skip `\n' or `\r' */
  if (currIsNewline(ls) && ls->current != old)
    next(ls);  /* skip `\n\r' or `\r\n' */
  if (++ls->linenumber >= MAX_INT)
    lexerror(ls, "chunk has too many lines", 0);
}


void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source,
                    int firstchar) {
  ls->decpoint = '.';
  ls->L = L;
  ls->current = firstchar;
  ls->lookahead.token = TK_EOS;  /* no look-ahead token */
  ls->z = z;
  ls->fs = NULL;
  ls->linenumber = 1;
  ls->lastline = 1;
  ls->source = source;
  ls->envn = luaS_new(L, LUA_ENV);  /* create env name */
  luaS_fix(ls->envn);  /* never collect this name */
  luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER);  /* initialize buffer */
}



/*
** =======================================================
** LEXICAL ANALYZER
** =======================================================
*/



static int check_next (LexState *ls, const char *set) {
  if (ls->current == '\0' || !strchr(set, ls->current))
    return 0;
  save_and_next(ls);
  return 1;
}


/*
** change all characters 'from' in buffer to 'to'
*/
static void buffreplace (LexState *ls, char from, char to) {
  size_t n = luaZ_bufflen(ls->buff);
  char *p = luaZ_buffer(ls->buff);
  while (n--)
    if (p[n] == from) p[n] = to;
}


#if !defined(getlocaledecpoint)
#define getlocaledecpoint()	(localeconv()->decimal_point[0])
#endif


#define buff2d(b,e)	luaO_str2d(luaZ_buffer(b), luaZ_bufflen(b) - 1, e)

/*
** in case of format error, try to change decimal point separator to
** the one defined in the current locale and check again
*/
static void trydecpoint (LexState *ls, SemInfo *seminfo) {
  char old = ls->decpoint;
  ls->decpoint = getlocaledecpoint();
  buffreplace(ls, old, ls->decpoint);  /* try new decimal separator */
  if (!buff2d(ls->buff, &seminfo->r)) {
    /* format error with correct decimal point: no more options */
    buffreplace(ls, ls->decpoint, '.');  /* undo change (for error message) */
    lexerror(ls, "malformed number", TK_NUMBER);
  }
}


/* LUA_NUMBER */
/*
** this function is quite liberal in what it accepts, as 'luaO_str2d'
** will reject ill-formed numerals.
*/
static void read_numeral (LexState *ls, SemInfo *seminfo) {
  const char *expo = "Ee";
  int first = ls->current;
  lua_assert(lisdigit(ls->current));
  save_and_next(ls);
  if (first == '0' && check_next(ls, "Xx"))  /* hexadecimal? */
    expo = "Pp";
  for (;;) {
    if (check_next(ls, expo))  /* exponent part? */
      (void) check_next(ls, "+-");  /* optional exponent sign */
    if (lisxdigit(ls->current) || ls->current == '.')
      save_and_next(ls);
    else  break;
  }
  save(ls, '\0');
  buffreplace(ls, '.', ls->decpoint);  /* follow locale for decimal point */
  if (!buff2d(ls->buff, &seminfo->r))  /* format error? */
    trydecpoint(ls, seminfo); /* try to update decimal point separator */
}


/*
** skip a sequence '[=*[' or ']=*]' and return its number of '='s or
** -1 if sequence is malformed
*/
static int skip_sep (LexState *ls) {
  int count = 0;
  int s = ls->current;
  lua_assert(s == '[' || s == ']');
  save_and_next(ls);
  while (ls->current == '=') {
    save_and_next(ls);
    count++;
  }
  return (ls->current == s) ? count : (-count) - 1;
}


static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) {
  save_and_next(ls);  /* skip 2nd `[' */
  if (currIsNewline(ls))  /* string starts with a newline? */
    inclinenumber(ls);  /* skip it */
  for (;;) {
    switch (ls->current) {
      case EOZ:
        lexerror(ls, (seminfo) ? "unfinished long string" :
                                 "unfinished long comment", TK_EOS);
        break;  /* to avoid warnings */
      case ']': {
        if (skip_sep(ls) == sep) {
          save_and_next(ls);  /* skip 2nd `]' */
          goto endloop;
        }
        break;
      }
      case '\n': case '\r': {
        save(ls, '\n');
        inclinenumber(ls);
        if (!seminfo) luaZ_resetbuffer(ls->buff);  /* avoid wasting space */
        break;
      }
      default: {
        if (seminfo) save_and_next(ls);
        else next(ls);
      }
    }
  } endloop:
  if (seminfo)
    seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep),
                                     luaZ_bufflen(ls->buff) - 2*(2 + sep));
}


static void escerror (LexState *ls, int *c, int n, const char *msg) {
  int i;
  luaZ_resetbuffer(ls->buff);  /* prepare error message */
  save(ls, '\\');
  for (i = 0; i < n && c[i] != EOZ; i++)
    save(ls, c[i]);
  lexerror(ls, msg, TK_STRING);
}


static int readhexaesc (LexState *ls) {
  int c[3], i;  /* keep input for error message */
  int r = 0;  /* result accumulator */
  c[0] = 'x';  /* for error message */
  for (i = 1; i < 3; i++) {  /* read two hexadecimal digits */
    c[i] = next(ls);
    if (!lisxdigit(c[i]))
      escerror(ls, c, i + 1, "hexadecimal digit expected");
    r = (r << 4) + luaO_hexavalue(c[i]);
  }
  return r;
}


static int readdecesc (LexState *ls) {
  int c[3], i;
  int r = 0;  /* result accumulator */
  for (i = 0; i < 3 && lisdigit(ls->current); i++) {  /* read up to 3 digits */
    c[i] = ls->current;
    r = 10*r + c[i] - '0';
    next(ls);
  }
  if (r > UCHAR_MAX)
    escerror(ls, c, i, "decimal escape too large");
  return r;
}


static void read_string (LexState *ls, int del, SemInfo *seminfo) {
  save_and_next(ls);  /* keep delimiter (for error messages) */
  while (ls->current != del) {
    switch (ls->current) {
      case EOZ:
        lexerror(ls, "unfinished string", TK_EOS);
        break;  /* to avoid warnings */
      case '\n':
      case '\r':
        lexerror(ls, "unfinished string", TK_STRING);
        break;  /* to avoid warnings */
      case '\\': {  /* escape sequences */
        int c;  /* final character to be saved */
        next(ls);  /* do not save the `\' */
        switch (ls->current) {
          case 'a': c = '\a'; goto read_save;
          case 'b': c = '\b'; goto read_save;
          case 'f': c = '\f'; goto read_save;
          case 'n': c = '\n'; goto read_save;
          case 'r': c = '\r'; goto read_save;
          case 't': c = '\t'; goto read_save;
          case 'v': c = '\v'; goto read_save;
          case 'x': c = readhexaesc(ls); goto read_save;
          case '\n': case '\r':
            inclinenumber(ls); c = '\n'; goto only_save;
          case '\\': case '\"': case '\'':
            c = ls->current; goto read_save;
          case EOZ: goto no_save;  /* will raise an error next loop */
          case 'z': {  /* zap following span of spaces */
            next(ls);  /* skip the 'z' */
            while (lisspace(ls->current)) {
              if (currIsNewline(ls)) inclinenumber(ls);
              else next(ls);
            }
            goto no_save;
          }
          default: {
            if (!lisdigit(ls->current))
              escerror(ls, &ls->current, 1, "invalid escape sequence");
            /* digital escape \ddd */
            c = readdecesc(ls);
            goto only_save;
          }
        }
       read_save: next(ls);  /* read next character */
       only_save: save(ls, c);  /* save 'c' */
       no_save: break;
      }
      default:
        save_and_next(ls);
    }
  }
  save_and_next(ls);  /* skip delimiter */
  seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1,
                                   luaZ_bufflen(ls->buff) - 2);
}


static int llex (LexState *ls, SemInfo *seminfo) {
  luaZ_resetbuffer(ls->buff);
  for (;;) {
    switch (ls->current) {
      case '\n': case '\r': {  /* line breaks */
        inclinenumber(ls);
        break;
      }
      case ' ': case '\f': case '\t': case '\v': {  /* spaces */
        next(ls);
        break;
      }
      case '-': {  /* '-' or '--' (comment) */
        next(ls);
        if (ls->current != '-') return '-';
        /* else is a comment */
        next(ls);
        if (ls->current == '[') {  /* long comment? */
          int sep = skip_sep(ls);
          luaZ_resetbuffer(ls->buff);  /* `skip_sep' may dirty the buffer */
          if (sep >= 0) {
            read_long_string(ls, NULL, sep);  /* skip long comment */
            luaZ_resetbuffer(ls->buff);  /* previous call may dirty the buff. */
            break;
          }
        }
        /* else short comment */
        while (!currIsNewline(ls) && ls->current != EOZ)
          next(ls);  /* skip until end of line (or end of file) */
        break;
      }
      case '[': {  /* long string or simply '[' */
        int sep = skip_sep(ls);
        if (sep >= 0) {
          read_long_string(ls, seminfo, sep);
          return TK_STRING;
        } else if (sep == -1) {
		return '[';
        } else {
		lexerror(ls, "invalid long string delimiter", TK_STRING);
		break;
	}
      }
      case '=': {
        next(ls);
        if (ls->current != '=') return '=';
        else { next(ls); return TK_EQ; }
      }
      case '<': {
        next(ls);
        if (ls->current != '=') return '<';
        else { next(ls); return TK_LE; }
      }
      case '>': {
        next(ls);
        if (ls->current != '=') return '>';
        else { next(ls); return TK_GE; }
      }
      case '~': {
        next(ls);
        if (ls->current != '=') return '~';
        else { next(ls); return TK_NE; }
      }
      case ':': {
        next(ls);
        if (ls->current != ':') return ':';
        else { next(ls); return TK_DBCOLON; }
      }
      case '"': case '\'': {  /* short literal strings */
        read_string(ls, ls->current, seminfo);
        return TK_STRING;
      }
      case '.': {  /* '.', '..', '...', or number */
        save_and_next(ls);
        if (check_next(ls, ".")) {
          if (check_next(ls, "."))
            return TK_DOTS;   /* '...' */
          else return TK_CONCAT;   /* '..' */
        }
        else if (!lisdigit(ls->current)) return '.';
        /* else go through */
      }
      /* FALLTHROUGH */
      case '0': case '1': case '2': case '3': case '4':
      case '5': case '6': case '7': case '8': case '9': {
        read_numeral(ls, seminfo);
        return TK_NUMBER;
      }
      case EOZ: {
        return TK_EOS;
      }
      default: {
        if (lislalpha(ls->current)) {  /* identifier or reserved word? */
          TString *ts;
          do {
            save_and_next(ls);
          } while (lislalnum(ls->current));
          ts = luaX_newstring(ls, luaZ_buffer(ls->buff),
                                  luaZ_bufflen(ls->buff));
          seminfo->ts = ts;
          if (isreserved(ts))  /* reserved word? */
            return ts->tsv.extra - 1 + FIRST_RESERVED;
          else {
            return TK_NAME;
          }
        }
        else {  /* single-char tokens (+ - / ...) */
          int c = ls->current;
          next(ls);
          return c;
        }
      }
    }
  }
}


void luaX_next (LexState *ls) {
  ls->lastline = ls->linenumber;
  if (ls->lookahead.token != TK_EOS) {  /* is there a look-ahead token? */
    ls->t = ls->lookahead;  /* use this one */
    ls->lookahead.token = TK_EOS;  /* and discharge it */
  }
  else
    ls->t.token = llex(ls, &ls->t.seminfo);  /* read next token */
}


int luaX_lookahead (LexState *ls) {
  lua_assert(ls->lookahead.token == TK_EOS);
  ls->lookahead.token = llex(ls, &ls->lookahead.seminfo);
  return ls->lookahead.token;
}
/* END CSTYLED */