1/*
2** $Id: lobject.c $
3** Some generic functions over Lua objects
4** See Copyright Notice in lua.h
5*/
6
7#define lobject_c
8#define LUA_CORE
9
10#include "lprefix.h"
11
12
13#include <locale.h>
14#include <math.h>
15#include <stdarg.h>
16#include <stdio.h>
17#include <stdlib.h>
18#include <string.h>
19
20#include "lua.h"
21
22#include "lctype.h"
23#include "ldebug.h"
24#include "ldo.h"
25#include "lmem.h"
26#include "lobject.h"
27#include "lstate.h"
28#include "lstring.h"
29#include "lvm.h"
30
31
32/*
33** Computes ceil(log2(x))
34*/
35int luaO_ceillog2 (unsigned int x) {
36 static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */
37 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,
38 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,
39 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,
40 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,
41 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,
42 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,
43 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,
44 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
45 };
46 int l = 0;
47 x--;
48 while (x >= 256) { l += 8; x >>= 8; }
49 return l + log_2[x];
50}
51
52
53static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
54 lua_Integer v2) {
55 switch (op) {
56 case LUA_OPADD: return intop(+, v1, v2);
57 case LUA_OPSUB:return intop(-, v1, v2);
58 case LUA_OPMUL:return intop(*, v1, v2);
59 case LUA_OPMOD: return luaV_mod(L, v1, v2);
60 case LUA_OPIDIV: return luaV_idiv(L, v1, v2);
61 case LUA_OPBAND: return intop(&, v1, v2);
62 case LUA_OPBOR: return intop(|, v1, v2);
63 case LUA_OPBXOR: return intop(^, v1, v2);
64 case LUA_OPSHL: return luaV_shiftl(v1, v2);
65 case LUA_OPSHR: return luaV_shiftl(v1, -v2);
66 case LUA_OPUNM: return intop(-, 0, v1);
67 case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
68 default: lua_assert(0); return 0;
69 }
70}
71
72
73static lua_Number numarith (lua_State *L, int op, lua_Number v1,
74 lua_Number v2) {
75 switch (op) {
76 case LUA_OPADD: return luai_numadd(L, v1, v2);
77 case LUA_OPSUB: return luai_numsub(L, v1, v2);
78 case LUA_OPMUL: return luai_nummul(L, v1, v2);
79 case LUA_OPDIV: return luai_numdiv(L, v1, v2);
80 case LUA_OPPOW: return luai_numpow(L, v1, v2);
81 case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
82 case LUA_OPUNM: return luai_numunm(L, v1);
83 case LUA_OPMOD: return luaV_modf(L, v1, v2);
84 default: lua_assert(0); return 0;
85 }
86}
87
88
89int luaO_rawarith (lua_State *L, int op, const TValue *p1, const TValue *p2,
90 TValue *res) {
91 switch (op) {
92 case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
93 case LUA_OPSHL: case LUA_OPSHR:
94 case LUA_OPBNOT: { /* operate only on integers */
95 lua_Integer i1; lua_Integer i2;
96 if (tointegerns(p1, &i1) && tointegerns(p2, &i2)) {
97 setivalue(res, intarith(L, op, i1, i2));
98 return 1;
99 }
100 else return 0; /* fail */
101 }
102 case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
103 lua_Number n1; lua_Number n2;
104 if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
105 setfltvalue(res, numarith(L, op, n1, n2));
106 return 1;
107 }
108 else return 0; /* fail */
109 }
110 default: { /* other operations */
111 lua_Number n1; lua_Number n2;
112 if (ttisinteger(p1) && ttisinteger(p2)) {
113 setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
114 return 1;
115 }
116 else if (tonumberns(p1, n1) && tonumberns(p2, n2)) {
117 setfltvalue(res, numarith(L, op, n1, n2));
118 return 1;
119 }
120 else return 0; /* fail */
121 }
122 }
123}
124
125
126void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
127 StkId res) {
128 if (!luaO_rawarith(L, op, p1, p2, s2v(res))) {
129 /* could not perform raw operation; try metamethod */
130 luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
131 }
132}
133
134
135int luaO_hexavalue (int c) {
136 if (lisdigit(c)) return c - '0';
137 else return (ltolower(c) - 'a') + 10;
138}
139
140
141static int isneg (const char **s) {
142 if (**s == '-') { (*s)++; return 1; }
143 else if (**s == '+') (*s)++;
144 return 0;
145}
146
147
148
149/*
150** {==================================================================
151** Lua's implementation for 'lua_strx2number'
152** ===================================================================
153*/
154
155#if !defined(lua_strx2number)
156
157/* maximum number of significant digits to read (to avoid overflows
158 even with single floats) */
159#define MAXSIGDIG 30
160
161/*
162** convert a hexadecimal numeric string to a number, following
163** C99 specification for 'strtod'
164*/
165static lua_Number lua_strx2number (const char *s, char **endptr) {
166 int dot = lua_getlocaledecpoint();
167 lua_Number r = 0.0; /* result (accumulator) */
168 int sigdig = 0; /* number of significant digits */
169 int nosigdig = 0; /* number of non-significant digits */
170 int e = 0; /* exponent correction */
171 int neg; /* 1 if number is negative */
172 int hasdot = 0; /* true after seen a dot */
173 *endptr = cast_charp(s); /* nothing is valid yet */
174 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
175 neg = isneg(&s); /* check sign */
176 if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
177 return 0.0; /* invalid format (no '0x') */
178 for (s += 2; ; s++) { /* skip '0x' and read numeral */
179 if (*s == dot) {
180 if (hasdot) break; /* second dot? stop loop */
181 else hasdot = 1;
182 }
183 else if (lisxdigit(cast_uchar(*s))) {
184 if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
185 nosigdig++;
186 else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
187 r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
188 else e++; /* too many digits; ignore, but still count for exponent */
189 if (hasdot) e--; /* decimal digit? correct exponent */
190 }
191 else break; /* neither a dot nor a digit */
192 }
193 if (nosigdig + sigdig == 0) /* no digits? */
194 return 0.0; /* invalid format */
195 *endptr = cast_charp(s); /* valid up to here */
196 e *= 4; /* each digit multiplies/divides value by 2^4 */
197 if (*s == 'p' || *s == 'P') { /* exponent part? */
198 int exp1 = 0; /* exponent value */
199 int neg1; /* exponent sign */
200 s++; /* skip 'p' */
201 neg1 = isneg(&s); /* sign */
202 if (!lisdigit(cast_uchar(*s)))
203 return 0.0; /* invalid; must have at least one digit */
204 while (lisdigit(cast_uchar(*s))) /* read exponent */
205 exp1 = exp1 * 10 + *(s++) - '0';
206 if (neg1) exp1 = -exp1;
207 e += exp1;
208 *endptr = cast_charp(s); /* valid up to here */
209 }
210 if (neg) r = -r;
211 return l_mathop(ldexp)(r, e);
212}
213
214#endif
215/* }====================================================== */
216
217
218/* maximum length of a numeral to be converted to a number */
219#if !defined (L_MAXLENNUM)
220#define L_MAXLENNUM 200
221#endif
222
223/*
224** Convert string 's' to a Lua number (put in 'result'). Return NULL on
225** fail or the address of the ending '\0' on success. ('mode' == 'x')
226** means a hexadecimal numeral.
227*/
228static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
229 char *endptr;
230 *result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */
231 : lua_str2number(s, &endptr);
232 if (endptr == s) return NULL; /* nothing recognized? */
233 while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */
234 return (*endptr == '\0') ? endptr : NULL; /* OK iff no trailing chars */
235}
236
237
238/*
239** Convert string 's' to a Lua number (put in 'result') handling the
240** current locale.
241** This function accepts both the current locale or a dot as the radix
242** mark. If the conversion fails, it may mean number has a dot but
243** locale accepts something else. In that case, the code copies 's'
244** to a buffer (because 's' is read-only), changes the dot to the
245** current locale radix mark, and tries to convert again.
246** The variable 'mode' checks for special characters in the string:
247** - 'n' means 'inf' or 'nan' (which should be rejected)
248** - 'x' means a hexadecimal numeral
249** - '.' just optimizes the search for the common case (no special chars)
250*/
251static const char *l_str2d (const char *s, lua_Number *result) {
252 const char *endptr;
253 const char *pmode = strpbrk(s, ".xXnN"); /* look for special chars */
254 int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
255 if (mode == 'n') /* reject 'inf' and 'nan' */
256 return NULL;
257 endptr = l_str2dloc(s, result, mode); /* try to convert */
258 if (endptr == NULL) { /* failed? may be a different locale */
259 char buff[L_MAXLENNUM + 1];
260 const char *pdot = strchr(s, '.');
261 if (pdot == NULL || strlen(s) > L_MAXLENNUM)
262 return NULL; /* string too long or no dot; fail */
263 strcpy(buff, s); /* copy string to buffer */
264 buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */
265 endptr = l_str2dloc(buff, result, mode); /* try again */
266 if (endptr != NULL)
267 endptr = s + (endptr - buff); /* make relative to 's' */
268 }
269 return endptr;
270}
271
272
273#define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10)
274#define MAXLASTD cast_int(LUA_MAXINTEGER % 10)
275
276static const char *l_str2int (const char *s, lua_Integer *result) {
277 lua_Unsigned a = 0;
278 int empty = 1;
279 int neg;
280 while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
281 neg = isneg(&s);
282 if (s[0] == '0' &&
283 (s[1] == 'x' || s[1] == 'X')) { /* hex? */
284 s += 2; /* skip '0x' */
285 for (; lisxdigit(cast_uchar(*s)); s++) {
286 a = a * 16 + luaO_hexavalue(*s);
287 empty = 0;
288 }
289 }
290 else { /* decimal */
291 for (; lisdigit(cast_uchar(*s)); s++) {
292 int d = *s - '0';
293 if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */
294 return NULL; /* do not accept it (as integer) */
295 a = a * 10 + d;
296 empty = 0;
297 }
298 }
299 while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
300 if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
301 else {
302 *result = l_castU2S((neg) ? 0u - a : a);
303 return s;
304 }
305}
306
307
308size_t luaO_str2num (const char *s, TValue *o) {
309 lua_Integer i; lua_Number n;
310 const char *e;
311 if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
312 setivalue(o, i);
313 }
314 else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
315 setfltvalue(o, n);
316 }
317 else
318 return 0; /* conversion failed */
319 return (e - s) + 1; /* success; return string size */
320}
321
322
323int luaO_utf8esc (char *buff, unsigned long x) {
324 int n = 1; /* number of bytes put in buffer (backwards) */
325 lua_assert(x <= 0x7FFFFFFFu);
326 if (x < 0x80) /* ascii? */
327 buff[UTF8BUFFSZ - 1] = cast_char(x);
328 else { /* need continuation bytes */
329 unsigned int mfb = 0x3f; /* maximum that fits in first byte */
330 do { /* add continuation bytes */
331 buff[UTF8BUFFSZ - (n++)] = cast_char(0x80 | (x & 0x3f));
332 x >>= 6; /* remove added bits */
333 mfb >>= 1; /* now there is one less bit available in first byte */
334 } while (x > mfb); /* still needs continuation byte? */
335 buff[UTF8BUFFSZ - n] = cast_char((~mfb << 1) | x); /* add first byte */
336 }
337 return n;
338}
339
340
341/*
342** Maximum length of the conversion of a number to a string. Must be
343** enough to accommodate both LUA_INTEGER_FMT and LUA_NUMBER_FMT.
344** (For a long long int, this is 19 digits plus a sign and a final '\0',
345** adding to 21. For a long double, it can go to a sign, 33 digits,
346** the dot, an exponent letter, an exponent sign, 5 exponent digits,
347** and a final '\0', adding to 43.)
348*/
349#define MAXNUMBER2STR 44
350
351
352/*
353** Convert a number object to a string, adding it to a buffer
354*/
355static int tostringbuff (TValue *obj, char *buff) {
356 int len;
357 lua_assert(ttisnumber(obj));
358 if (ttisinteger(obj))
359 len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj));
360 else {
361 len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj));
362 if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
363 buff[len++] = lua_getlocaledecpoint();
364 buff[len++] = '0'; /* adds '.0' to result */
365 }
366 }
367 return len;
368}
369
370
371/*
372** Convert a number object to a Lua string, replacing the value at 'obj'
373*/
374void luaO_tostring (lua_State *L, TValue *obj) {
375 char buff[MAXNUMBER2STR];
376 int len = tostringbuff(obj, buff);
377 setsvalue(L, obj, luaS_newlstr(L, buff, len));
378}
379
380
381
382
383/*
384** {==================================================================
385** 'luaO_pushvfstring'
386** ===================================================================
387*/
388
389/* size for buffer space used by 'luaO_pushvfstring' */
390#define BUFVFS 200
391
392/* buffer used by 'luaO_pushvfstring' */
393typedef struct BuffFS {
394 lua_State *L;
395 int pushed; /* number of string pieces already on the stack */
396 int blen; /* length of partial string in 'space' */
397 char space[BUFVFS]; /* holds last part of the result */
398} BuffFS;
399
400
401/*
402** Push given string to the stack, as part of the buffer, and
403** join the partial strings in the stack into one.
404*/
405static void pushstr (BuffFS *buff, const char *str, size_t l) {
406 lua_State *L = buff->L;
407 setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
408 L->top++; /* may use one extra slot */
409 buff->pushed++;
410 luaV_concat(L, buff->pushed); /* join partial results into one */
411 buff->pushed = 1;
412}
413
414
415/*
416** empty the buffer space into the stack
417*/
418static void clearbuff (BuffFS *buff) {
419 pushstr(buff, buff->space, buff->blen); /* push buffer contents */
420 buff->blen = 0; /* space now is empty */
421}
422
423
424/*
425** Get a space of size 'sz' in the buffer. If buffer has not enough
426** space, empty it. 'sz' must fit in an empty buffer.
427*/
428static char *getbuff (BuffFS *buff, int sz) {
429 lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);
430 if (sz > BUFVFS - buff->blen) /* not enough space? */
431 clearbuff(buff);
432 return buff->space + buff->blen;
433}
434
435
436#define addsize(b,sz) ((b)->blen += (sz))
437
438
439/*
440** Add 'str' to the buffer. If string is larger than the buffer space,
441** push the string directly to the stack.
442*/
443static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {
444 if (slen <= BUFVFS) { /* does string fit into buffer? */
445 char *bf = getbuff(buff, cast_int(slen));
446 memcpy(bf, str, slen); /* add string to buffer */
447 addsize(buff, cast_int(slen));
448 }
449 else { /* string larger than buffer */
450 clearbuff(buff); /* string comes after buffer's content */
451 pushstr(buff, str, slen); /* push string */
452 }
453}
454
455
456/*
457** Add a number to the buffer.
458*/
459static void addnum2buff (BuffFS *buff, TValue *num) {
460 char *numbuff = getbuff(buff, MAXNUMBER2STR);
461 int len = tostringbuff(num, numbuff); /* format number into 'numbuff' */
462 addsize(buff, len);
463}
464
465
466/*
467** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%'
468 conventional formats, plus Lua-specific '%I' and '%U'
469*/
470const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
471 BuffFS buff; /* holds last part of the result */
472 const char *e; /* points to next '%' */
473 buff.pushed = buff.blen = 0;
474 buff.L = L;
475 while ((e = strchr(fmt, '%')) != NULL) {
476 addstr2buff(&buff, fmt, e - fmt); /* add 'fmt' up to '%' */
477 switch (*(e + 1)) { /* conversion specifier */
478 case 's': { /* zero-terminated string */
479 const char *s = va_arg(argp, char *);
480 if (s == NULL) s = "(null)";
481 addstr2buff(&buff, s, strlen(s));
482 break;
483 }
484 case 'c': { /* an 'int' as a character */
485 char c = cast_uchar(va_arg(argp, int));
486 addstr2buff(&buff, &c, sizeof(char));
487 break;
488 }
489 case 'd': { /* an 'int' */
490 TValue num;
491 setivalue(&num, va_arg(argp, int));
492 addnum2buff(&buff, &num);
493 break;
494 }
495 case 'I': { /* a 'lua_Integer' */
496 TValue num;
497 setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));
498 addnum2buff(&buff, &num);
499 break;
500 }
501 case 'f': { /* a 'lua_Number' */
502 TValue num;
503 setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));
504 addnum2buff(&buff, &num);
505 break;
506 }
507 case 'p': { /* a pointer */
508 const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */
509 char *bf = getbuff(&buff, sz);
510 void *p = va_arg(argp, void *);
511 int len = lua_pointer2str(bf, sz, p);
512 addsize(&buff, len);
513 break;
514 }
515 case 'U': { /* a 'long' as a UTF-8 sequence */
516 char bf[UTF8BUFFSZ];
517 int len = luaO_utf8esc(bf, va_arg(argp, long));
518 addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);
519 break;
520 }
521 case '%': {
522 addstr2buff(&buff, "%", 1);
523 break;
524 }
525 default: {
526 luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
527 *(e + 1));
528 }
529 }
530 fmt = e + 2; /* skip '%' and the specifier */
531 }
532 addstr2buff(&buff, fmt, strlen(fmt)); /* rest of 'fmt' */
533 clearbuff(&buff); /* empty buffer into the stack */
534 lua_assert(buff.pushed == 1);
535 return svalue(s2v(L->top - 1));
536}
537
538
539const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
540 const char *msg;
541 va_list argp;
542 va_start(argp, fmt);
543 msg = luaO_pushvfstring(L, fmt, argp);
544 va_end(argp);
545 return msg;
546}
547
548/* }================================================================== */
549
550
551#define RETS "..."
552#define PRE "[string \""
553#define POS "\"]"
554
555#define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
556
557void luaO_chunkid (char *out, const char *source, size_t srclen) {
558 size_t bufflen = LUA_IDSIZE; /* free space in buffer */
559 if (*source == '=') { /* 'literal' source */
560 if (srclen <= bufflen) /* small enough? */
561 memcpy(out, source + 1, srclen * sizeof(char));
562 else { /* truncate it */
563 addstr(out, source + 1, bufflen - 1);
564 *out = '\0';
565 }
566 }
567 else if (*source == '@') { /* file name */
568 if (srclen <= bufflen) /* small enough? */
569 memcpy(out, source + 1, srclen * sizeof(char));
570 else { /* add '...' before rest of name */
571 addstr(out, RETS, LL(RETS));
572 bufflen -= LL(RETS);
573 memcpy(out, source + 1 + srclen - bufflen, bufflen * sizeof(char));
574 }
575 }
576 else { /* string; format as [string "source"] */
577 const char *nl = strchr(source, '\n'); /* find first new line (if any) */
578 addstr(out, PRE, LL(PRE)); /* add prefix */
579 bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
580 if (srclen < bufflen && nl == NULL) { /* small one-line source? */
581 addstr(out, source, srclen); /* keep it */
582 }
583 else {
584 if (nl != NULL) srclen = nl - source; /* stop at first newline */
585 if (srclen > bufflen) srclen = bufflen;
586 addstr(out, source, srclen);
587 addstr(out, RETS, LL(RETS));
588 }
589 memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
590 }
591}
592
593