aboutsummaryrefslogblamecommitdiffstats
path: root/bruiser/lua-5.3.4/src/lobject.c
blob: 2da76899a27e10405325416095823e6221ed74d3 (plain) (tree)
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








































































































































































































































































































































































































































































































































                                                                                
/*
** $Id: lobject.c,v 2.113 2016/12/22 13:08:50 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#define lobject_c
#define LUA_CORE

#include "lprefix.h"


#include <locale.h>
#include <math.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lctype.h"
#include "ldebug.h"
#include "ldo.h"
#include "lmem.h"
#include "lobject.h"
#include "lstate.h"
#include "lstring.h"
#include "lvm.h"



LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};


/*
** converts an integer to a "floating point byte", represented as
** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
** eeeee != 0 and (xxx) otherwise.
*/
int luaO_int2fb (unsigned int x) {
  int e = 0;  /* exponent */
  if (x < 8) return x;
  while (x >= (8 << 4)) {  /* coarse steps */
    x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
    e += 4;
  }
  while (x >= (8 << 1)) {  /* fine steps */
    x = (x + 1) >> 1;  /* x = ceil(x / 2) */
    e++;
  }
  return ((e+1) << 3) | (cast_int(x) - 8);
}


/* converts back */
int luaO_fb2int (int x) {
  return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
}


/*
** Computes ceil(log2(x))
*/
int luaO_ceillog2 (unsigned int x) {
  static const lu_byte log_2[256] = {  /* log_2[i] = ceil(log2(i - 1)) */
    0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8
  };
  int l = 0;
  x--;
  while (x >= 256) { l += 8; x >>= 8; }
  return l + log_2[x];
}


static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
                                                   lua_Integer v2) {
  switch (op) {
    case LUA_OPADD: return intop(+, v1, v2);
    case LUA_OPSUB:return intop(-, v1, v2);
    case LUA_OPMUL:return intop(*, v1, v2);
    case LUA_OPMOD: return luaV_mod(L, v1, v2);
    case LUA_OPIDIV: return luaV_div(L, v1, v2);
    case LUA_OPBAND: return intop(&, v1, v2);
    case LUA_OPBOR: return intop(|, v1, v2);
    case LUA_OPBXOR: return intop(^, v1, v2);
    case LUA_OPSHL: return luaV_shiftl(v1, v2);
    case LUA_OPSHR: return luaV_shiftl(v1, -v2);
    case LUA_OPUNM: return intop(-, 0, v1);
    case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
    default: lua_assert(0); return 0;
  }
}


static lua_Number numarith (lua_State *L, int op, lua_Number v1,
                                                  lua_Number v2) {
  switch (op) {
    case LUA_OPADD: return luai_numadd(L, v1, v2);
    case LUA_OPSUB: return luai_numsub(L, v1, v2);
    case LUA_OPMUL: return luai_nummul(L, v1, v2);
    case LUA_OPDIV: return luai_numdiv(L, v1, v2);
    case LUA_OPPOW: return luai_numpow(L, v1, v2);
    case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
    case LUA_OPUNM: return luai_numunm(L, v1);
    case LUA_OPMOD: {
      lua_Number m;
      luai_nummod(L, v1, v2, m);
      return m;
    }
    default: lua_assert(0); return 0;
  }
}


void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
                 TValue *res) {
  switch (op) {
    case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
    case LUA_OPSHL: case LUA_OPSHR:
    case LUA_OPBNOT: {  /* operate only on integers */
      lua_Integer i1; lua_Integer i2;
      if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
        setivalue(res, intarith(L, op, i1, i2));
        return;
      }
      else break;  /* go to the end */
    }
    case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
      lua_Number n1; lua_Number n2;
      if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
        setfltvalue(res, numarith(L, op, n1, n2));
        return;
      }
      else break;  /* go to the end */
    }
    default: {  /* other operations */
      lua_Number n1; lua_Number n2;
      if (ttisinteger(p1) && ttisinteger(p2)) {
        setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
        return;
      }
      else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
        setfltvalue(res, numarith(L, op, n1, n2));
        return;
      }
      else break;  /* go to the end */
    }
  }
  /* could not perform raw operation; try metamethod */
  lua_assert(L != NULL);  /* should not fail when folding (compile time) */
  luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
}


int luaO_hexavalue (int c) {
  if (lisdigit(c)) return c - '0';
  else return (ltolower(c) - 'a') + 10;
}


static int isneg (const char **s) {
  if (**s == '-') { (*s)++; return 1; }
  else if (**s == '+') (*s)++;
  return 0;
}



/*
** {==================================================================
** Lua's implementation for 'lua_strx2number'
** ===================================================================
*/

#if !defined(lua_strx2number)

/* maximum number of significant digits to read (to avoid overflows
   even with single floats) */
#define MAXSIGDIG	30

/*
** convert an hexadecimal numeric string to a number, following
** C99 specification for 'strtod'
*/
static lua_Number lua_strx2number (const char *s, char **endptr) {
  int dot = lua_getlocaledecpoint();
  lua_Number r = 0.0;  /* result (accumulator) */
  int sigdig = 0;  /* number of significant digits */
  int nosigdig = 0;  /* number of non-significant digits */
  int e = 0;  /* exponent correction */
  int neg;  /* 1 if number is negative */
  int hasdot = 0;  /* true after seen a dot */
  *endptr = cast(char *, s);  /* nothing is valid yet */
  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  neg = isneg(&s);  /* check signal */
  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
    return 0.0;  /* invalid format (no '0x') */
  for (s += 2; ; s++) {  /* skip '0x' and read numeral */
    if (*s == dot) {
      if (hasdot) break;  /* second dot? stop loop */
      else hasdot = 1;
    }
    else if (lisxdigit(cast_uchar(*s))) {
      if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
        nosigdig++;
      else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
          r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
      else e++; /* too many digits; ignore, but still count for exponent */
      if (hasdot) e--;  /* decimal digit? correct exponent */
    }
    else break;  /* neither a dot nor a digit */
  }
  if (nosigdig + sigdig == 0)  /* no digits? */
    return 0.0;  /* invalid format */
  *endptr = cast(char *, s);  /* valid up to here */
  e *= 4;  /* each digit multiplies/divides value by 2^4 */
  if (*s == 'p' || *s == 'P') {  /* exponent part? */
    int exp1 = 0;  /* exponent value */
    int neg1;  /* exponent signal */
    s++;  /* skip 'p' */
    neg1 = isneg(&s);  /* signal */
    if (!lisdigit(cast_uchar(*s)))
      return 0.0;  /* invalid; must have at least one digit */
    while (lisdigit(cast_uchar(*s)))  /* read exponent */
      exp1 = exp1 * 10 + *(s++) - '0';
    if (neg1) exp1 = -exp1;
    e += exp1;
    *endptr = cast(char *, s);  /* valid up to here */
  }
  if (neg) r = -r;
  return l_mathop(ldexp)(r, e);
}

#endif
/* }====================================================== */


/* maximum length of a numeral */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM	200
#endif

static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
  char *endptr;
  *result = (mode == 'x') ? lua_strx2number(s, &endptr)  /* try to convert */
                          : lua_str2number(s, &endptr);
  if (endptr == s) return NULL;  /* nothing recognized? */
  while (lisspace(cast_uchar(*endptr))) endptr++;  /* skip trailing spaces */
  return (*endptr == '\0') ? endptr : NULL;  /* OK if no trailing characters */
}


/*
** Convert string 's' to a Lua number (put in 'result'). Return NULL
** on fail or the address of the ending '\0' on success.
** 'pmode' points to (and 'mode' contains) special things in the string:
** - 'x'/'X' means an hexadecimal numeral
** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
** - '.' just optimizes the search for the common case (nothing special)
** This function accepts both the current locale or a dot as the radix
** mark. If the convertion fails, it may mean number has a dot but
** locale accepts something else. In that case, the code copies 's'
** to a buffer (because 's' is read-only), changes the dot to the
** current locale radix mark, and tries to convert again.
*/
static const char *l_str2d (const char *s, lua_Number *result) {
  const char *endptr;
  const char *pmode = strpbrk(s, ".xXnN");
  int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
  if (mode == 'n')  /* reject 'inf' and 'nan' */
    return NULL;
  endptr = l_str2dloc(s, result, mode);  /* try to convert */
  if (endptr == NULL) {  /* failed? may be a different locale */
    char buff[L_MAXLENNUM + 1];
    const char *pdot = strchr(s, '.');
    if (strlen(s) > L_MAXLENNUM || pdot == NULL)
      return NULL;  /* string too long or no dot; fail */
    strcpy(buff, s);  /* copy string to buffer */
    buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
    endptr = l_str2dloc(buff, result, mode);  /* try again */
    if (endptr != NULL)
      endptr = s + (endptr - buff);  /* make relative to 's' */
  }
  return endptr;
}


#define MAXBY10		cast(lua_Unsigned, LUA_MAXINTEGER / 10)
#define MAXLASTD	cast_int(LUA_MAXINTEGER % 10)

static const char *l_str2int (const char *s, lua_Integer *result) {
  lua_Unsigned a = 0;
  int empty = 1;
  int neg;
  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  neg = isneg(&s);
  if (s[0] == '0' &&
      (s[1] == 'x' || s[1] == 'X')) {  /* hex? */
    s += 2;  /* skip '0x' */
    for (; lisxdigit(cast_uchar(*s)); s++) {
      a = a * 16 + luaO_hexavalue(*s);
      empty = 0;
    }
  }
  else {  /* decimal */
    for (; lisdigit(cast_uchar(*s)); s++) {
      int d = *s - '0';
      if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
        return NULL;  /* do not accept it (as integer) */
      a = a * 10 + d;
      empty = 0;
    }
  }
  while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
  if (empty || *s != '\0') return NULL;  /* something wrong in the numeral */
  else {
    *result = l_castU2S((neg) ? 0u - a : a);
    return s;
  }
}


size_t luaO_str2num (const char *s, TValue *o) {
  lua_Integer i; lua_Number n;
  const char *e;
  if ((e = l_str2int(s, &i)) != NULL) {  /* try as an integer */
    setivalue(o, i);
  }
  else if ((e = l_str2d(s, &n)) != NULL) {  /* else try as a float */
    setfltvalue(o, n);
  }
  else
    return 0;  /* conversion failed */
  return (e - s) + 1;  /* success; return string size */
}


int luaO_utf8esc (char *buff, unsigned long x) {
  int n = 1;  /* number of bytes put in buffer (backwards) */
  lua_assert(x <= 0x10FFFF);
  if (x < 0x80)  /* ascii? */
    buff[UTF8BUFFSZ - 1] = cast(char, x);
  else {  /* need continuation bytes */
    unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
    do {  /* add continuation bytes */
      buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
      x >>= 6;  /* remove added bits */
      mfb >>= 1;  /* now there is one less bit available in first byte */
    } while (x > mfb);  /* still needs continuation byte? */
    buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x);  /* add first byte */
  }
  return n;
}


/* maximum length of the conversion of a number to a string */
#define MAXNUMBER2STR	50


/*
** Convert a number object to a string
*/
void luaO_tostring (lua_State *L, StkId obj) {
  char buff[MAXNUMBER2STR];
  size_t len;
  lua_assert(ttisnumber(obj));
  if (ttisinteger(obj))
    len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
  else {
    len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
#if !defined(LUA_COMPAT_FLOATSTRING)
    if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
      buff[len++] = lua_getlocaledecpoint();
      buff[len++] = '0';  /* adds '.0' to result */
    }
#endif
  }
  setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
}


static void pushstr (lua_State *L, const char *str, size_t l) {
  setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  luaD_inctop(L);
}


/*
** this function handles only '%d', '%c', '%f', '%p', and '%s'
   conventional formats, plus Lua-specific '%I' and '%U'
*/
const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  int n = 0;
  for (;;) {
    const char *e = strchr(fmt, '%');
    if (e == NULL) break;
    pushstr(L, fmt, e - fmt);
    switch (*(e+1)) {
      case 's': {  /* zero-terminated string */
        const char *s = va_arg(argp, char *);
        if (s == NULL) s = "(null)";
        pushstr(L, s, strlen(s));
        break;
      }
      case 'c': {  /* an 'int' as a character */
        char buff = cast(char, va_arg(argp, int));
        if (lisprint(cast_uchar(buff)))
          pushstr(L, &buff, 1);
        else  /* non-printable character; print its code */
          luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
        break;
      }
      case 'd': {  /* an 'int' */
        setivalue(L->top, va_arg(argp, int));
        goto top2str;
      }
      case 'I': {  /* a 'lua_Integer' */
        setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
        goto top2str;
      }
      case 'f': {  /* a 'lua_Number' */
        setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
      top2str:  /* convert the top element to a string */
        luaD_inctop(L);
        luaO_tostring(L, L->top - 1);
        break;
      }
      case 'p': {  /* a pointer */
        char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
        int l = l_sprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
        pushstr(L, buff, l);
        break;
      }
      case 'U': {  /* an 'int' as a UTF-8 sequence */
        char buff[UTF8BUFFSZ];
        int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
        pushstr(L, buff + UTF8BUFFSZ - l, l);
        break;
      }
      case '%': {
        pushstr(L, "%", 1);
        break;
      }
      default: {
        luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
                         *(e + 1));
      }
    }
    n += 2;
    fmt = e+2;
  }
  luaD_checkstack(L, 1);
  pushstr(L, fmt, strlen(fmt));
  if (n > 0) luaV_concat(L, n + 1);
  return svalue(L->top - 1);
}


const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  const char *msg;
  va_list argp;
  va_start(argp, fmt);
  msg = luaO_pushvfstring(L, fmt, argp);
  va_end(argp);
  return msg;
}


/* number of chars of a literal string without the ending \0 */
#define LL(x)	(sizeof(x)/sizeof(char) - 1)

#define RETS	"..."
#define PRE	"[string \""
#define POS	"\"]"

#define addstr(a,b,l)	( memcpy(a,b,(l) * sizeof(char)), a += (l) )

void luaO_chunkid (char *out, const char *source, size_t bufflen) {
  size_t l = strlen(source);
  if (*source == '=') {  /* 'literal' source */
    if (l <= bufflen)  /* small enough? */
      memcpy(out, source + 1, l * sizeof(char));
    else {  /* truncate it */
      addstr(out, source + 1, bufflen - 1);
      *out = '\0';
    }
  }
  else if (*source == '@') {  /* file name */
    if (l <= bufflen)  /* small enough? */
      memcpy(out, source + 1, l * sizeof(char));
    else {  /* add '...' before rest of name */
      addstr(out, RETS, LL(RETS));
      bufflen -= LL(RETS);
      memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
    }
  }
  else {  /* string; format as [string "source"] */
    const char *nl = strchr(source, '\n');  /* find first new line (if any) */
    addstr(out, PRE, LL(PRE));  /* add prefix */
    bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
    if (l < bufflen && nl == NULL) {  /* small one-line source? */
      addstr(out, source, l);  /* keep it */
    }
    else {
      if (nl != NULL) l = nl - source;  /* stop at first newline */
      if (l > bufflen) l = bufflen;
      addstr(out, source, l);
      addstr(out, RETS, LL(RETS));
    }
    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  }
}