lobject.c 16 KB

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  1. /*
  2. ** $Id: lobject.c,v 2.113.1.1 2017/04/19 17:29:57 roberto Exp $
  3. ** Some generic functions over Lua objects
  4. ** See Copyright Notice in lua.h
  5. */
  6. #define lobject_c
  7. #define LUA_CORE
  8. #include "lprefix.h"
  9. #include <locale.h>
  10. #include <math.h>
  11. #include <stdarg.h>
  12. #include <stdio.h>
  13. #include <stdlib.h>
  14. #include <string.h>
  15. #include "lua.h"
  16. #include "lctype.h"
  17. #include "ldebug.h"
  18. #include "ldo.h"
  19. #include "lmem.h"
  20. #include "lobject.h"
  21. #include "lstate.h"
  22. #include "lstring.h"
  23. #include "lvm.h"
  24. LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
  25. /*
  26. ** converts an integer to a "floating point byte", represented as
  27. ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  28. ** eeeee != 0 and (xxx) otherwise.
  29. */
  30. int luaO_int2fb (unsigned int x) {
  31. int e = 0; /* exponent */
  32. if (x < 8) return x;
  33. while (x >= (8 << 4)) { /* coarse steps */
  34. x = (x + 0xf) >> 4; /* x = ceil(x / 16) */
  35. e += 4;
  36. }
  37. while (x >= (8 << 1)) { /* fine steps */
  38. x = (x + 1) >> 1; /* x = ceil(x / 2) */
  39. e++;
  40. }
  41. return ((e+1) << 3) | (cast_int(x) - 8);
  42. }
  43. /* converts back */
  44. int luaO_fb2int (int x) {
  45. return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
  46. }
  47. /*
  48. ** Computes ceil(log2(x))
  49. */
  50. int luaO_ceillog2 (unsigned int x) {
  51. #ifdef LUA_USE_ESP
  52. /* Use Normalization Shift Amount Unsigned: 0x1=>31 up to 0xffffffff =>0
  53. * See Xtensa Instruction Set Architecture (ISA) Refman P 462 */
  54. x--;
  55. asm volatile ("nsau %0, %1;" :"=r"(x) : "r"(x));
  56. return 32 - x;
  57. #else
  58. static const lu_byte log_2[256] = { /* log_2[i] = ceil(log2(i - 1)) */
  59. 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,
  60. 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,
  61. 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,
  62. 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,
  63. 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,
  64. 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,
  65. 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,
  66. 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
  67. };
  68. int l = 0;
  69. x--;
  70. while (x >= 256) { l += 8; x >>= 8; }
  71. return l + log_2[x];
  72. #endif
  73. }
  74. static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
  75. lua_Integer v2) {
  76. switch (op) {
  77. case LUA_OPADD: return intop(+, v1, v2);
  78. case LUA_OPSUB:return intop(-, v1, v2);
  79. case LUA_OPMUL:return intop(*, v1, v2);
  80. case LUA_OPMOD: return luaV_mod(L, v1, v2);
  81. case LUA_OPIDIV: return luaV_div(L, v1, v2);
  82. case LUA_OPBAND: return intop(&, v1, v2);
  83. case LUA_OPBOR: return intop(|, v1, v2);
  84. case LUA_OPBXOR: return intop(^, v1, v2);
  85. case LUA_OPSHL: return luaV_shiftl(v1, v2);
  86. case LUA_OPSHR: return luaV_shiftl(v1, -v2);
  87. case LUA_OPUNM: return intop(-, 0, v1);
  88. case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
  89. default: lua_assert(0); return 0;
  90. }
  91. }
  92. static lua_Number numarith (lua_State *L, int op, lua_Number v1,
  93. lua_Number v2) {
  94. switch (op) {
  95. case LUA_OPADD: return luai_numadd(L, v1, v2);
  96. case LUA_OPSUB: return luai_numsub(L, v1, v2);
  97. case LUA_OPMUL: return luai_nummul(L, v1, v2);
  98. case LUA_OPDIV: return luai_numdiv(L, v1, v2);
  99. case LUA_OPPOW: return luai_numpow(L, v1, v2);
  100. case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
  101. case LUA_OPUNM: return luai_numunm(L, v1);
  102. case LUA_OPMOD: {
  103. lua_Number m;
  104. luai_nummod(L, v1, v2, m);
  105. return m;
  106. }
  107. default: lua_assert(0); return 0;
  108. }
  109. }
  110. void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
  111. TValue *res) {
  112. switch (op) {
  113. case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
  114. case LUA_OPSHL: case LUA_OPSHR:
  115. case LUA_OPBNOT: { /* operate only on integers */
  116. lua_Integer i1; lua_Integer i2;
  117. if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
  118. setivalue(res, intarith(L, op, i1, i2));
  119. return;
  120. }
  121. else break; /* go to the end */
  122. }
  123. case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */
  124. lua_Number n1; lua_Number n2;
  125. if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
  126. setfltvalue(res, numarith(L, op, n1, n2));
  127. return;
  128. }
  129. else break; /* go to the end */
  130. }
  131. default: { /* other operations */
  132. lua_Number n1; lua_Number n2;
  133. if (ttisinteger(p1) && ttisinteger(p2)) {
  134. setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
  135. return;
  136. }
  137. else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
  138. setfltvalue(res, numarith(L, op, n1, n2));
  139. return;
  140. }
  141. else break; /* go to the end */
  142. }
  143. }
  144. /* could not perform raw operation; try metamethod */
  145. lua_assert(L != NULL); /* should not fail when folding (compile time) */
  146. luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
  147. }
  148. int luaO_hexavalue (int c) {
  149. if (lisdigit(c)) return c - '0';
  150. else return (ltolower(c) - 'a') + 10;
  151. }
  152. static int isneg (const char **s) {
  153. if (**s == '-') { (*s)++; return 1; }
  154. else if (**s == '+') (*s)++;
  155. return 0;
  156. }
  157. /*
  158. ** {==================================================================
  159. ** Lua's implementation for 'lua_strx2number'
  160. ** ===================================================================
  161. */
  162. #if !defined(lua_strx2number)
  163. /* maximum number of significant digits to read (to avoid overflows
  164. even with single floats) */
  165. #define MAXSIGDIG 30
  166. /*
  167. ** convert an hexadecimal numeric string to a number, following
  168. ** C99 specification for 'strtod'
  169. */
  170. static lua_Number lua_strx2number (const char *s, char **endptr) {
  171. int dot = lua_getlocaledecpoint();
  172. lua_Number r = 0.0; /* result (accumulator) */
  173. int sigdig = 0; /* number of significant digits */
  174. int nosigdig = 0; /* number of non-significant digits */
  175. int e = 0; /* exponent correction */
  176. int neg; /* 1 if number is negative */
  177. int hasdot = 0; /* true after seen a dot */
  178. *endptr = cast(char *, s); /* nothing is valid yet */
  179. while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
  180. neg = isneg(&s); /* check signal */
  181. if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */
  182. return 0.0; /* invalid format (no '0x') */
  183. for (s += 2; ; s++) { /* skip '0x' and read numeral */
  184. if (*s == dot) {
  185. if (hasdot) break; /* second dot? stop loop */
  186. else hasdot = 1;
  187. }
  188. else if (lisxdigit(cast_uchar(*s))) {
  189. if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */
  190. nosigdig++;
  191. else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */
  192. r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
  193. else e++; /* too many digits; ignore, but still count for exponent */
  194. if (hasdot) e--; /* decimal digit? correct exponent */
  195. }
  196. else break; /* neither a dot nor a digit */
  197. }
  198. if (nosigdig + sigdig == 0) /* no digits? */
  199. return 0.0; /* invalid format */
  200. *endptr = cast(char *, s); /* valid up to here */
  201. e *= 4; /* each digit multiplies/divides value by 2^4 */
  202. if (*s == 'p' || *s == 'P') { /* exponent part? */
  203. int exp1 = 0; /* exponent value */
  204. int neg1; /* exponent signal */
  205. s++; /* skip 'p' */
  206. neg1 = isneg(&s); /* signal */
  207. if (!lisdigit(cast_uchar(*s)))
  208. return 0.0; /* invalid; must have at least one digit */
  209. while (lisdigit(cast_uchar(*s))) /* read exponent */
  210. exp1 = exp1 * 10 + *(s++) - '0';
  211. if (neg1) exp1 = -exp1;
  212. e += exp1;
  213. *endptr = cast(char *, s); /* valid up to here */
  214. }
  215. if (neg) r = -r;
  216. return l_mathop(ldexp)(r, e);
  217. }
  218. #endif
  219. /* }====================================================== */
  220. /* maximum length of a numeral */
  221. #if !defined (L_MAXLENNUM)
  222. #define L_MAXLENNUM 200
  223. #endif
  224. static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
  225. char *endptr;
  226. *result = (mode == 'x') ? lua_strx2number(s, &endptr) /* try to convert */
  227. : lua_str2number(s, &endptr);
  228. if (endptr == s) return NULL; /* nothing recognized? */
  229. while (lisspace(cast_uchar(*endptr))) endptr++; /* skip trailing spaces */
  230. return (*endptr == '\0') ? endptr : NULL; /* OK if no trailing characters */
  231. }
  232. /*
  233. ** Convert string 's' to a Lua number (put in 'result'). Return NULL
  234. ** on fail or the address of the ending '\0' on success.
  235. ** 'pmode' points to (and 'mode' contains) special things in the string:
  236. ** - 'x'/'X' means an hexadecimal numeral
  237. ** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
  238. ** - '.' just optimizes the search for the common case (nothing special)
  239. ** This function accepts both the current locale or a dot as the radix
  240. ** mark. If the convertion fails, it may mean number has a dot but
  241. ** locale accepts something else. In that case, the code copies 's'
  242. ** to a buffer (because 's' is read-only), changes the dot to the
  243. ** current locale radix mark, and tries to convert again.
  244. */
  245. static const char *l_str2d (const char *s, lua_Number *result) {
  246. const char *endptr;
  247. const char *pmode = strpbrk(s, ".xXnN");
  248. int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
  249. if (mode == 'n') /* reject 'inf' and 'nan' */
  250. return NULL;
  251. endptr = l_str2dloc(s, result, mode); /* try to convert */
  252. if (endptr == NULL) { /* failed? may be a different locale */
  253. char buff[L_MAXLENNUM + 1];
  254. const char *pdot = strchr(s, '.');
  255. if (strlen(s) > L_MAXLENNUM || pdot == NULL)
  256. return NULL; /* string too long or no dot; fail */
  257. strcpy(buff, s); /* copy string to buffer */
  258. buff[pdot - s] = lua_getlocaledecpoint(); /* correct decimal point */
  259. endptr = l_str2dloc(buff, result, mode); /* try again */
  260. if (endptr != NULL)
  261. endptr = s + (endptr - buff); /* make relative to 's' */
  262. }
  263. return endptr;
  264. }
  265. #define MAXBY10 cast(lua_Unsigned, LUA_MAXINTEGER / 10)
  266. #define MAXLASTD cast_int(LUA_MAXINTEGER % 10)
  267. static const char *l_str2int (const char *s, lua_Integer *result) {
  268. lua_Unsigned a = 0;
  269. int empty = 1;
  270. int neg;
  271. while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */
  272. neg = isneg(&s);
  273. if (s[0] == '0' &&
  274. (s[1] == 'x' || s[1] == 'X')) { /* hex? */
  275. s += 2; /* skip '0x' */
  276. for (; lisxdigit(cast_uchar(*s)); s++) {
  277. a = a * 16 + luaO_hexavalue(*s);
  278. empty = 0;
  279. }
  280. }
  281. else { /* decimal */
  282. for (; lisdigit(cast_uchar(*s)); s++) {
  283. int d = *s - '0';
  284. if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg)) /* overflow? */
  285. return NULL; /* do not accept it (as integer) */
  286. a = a * 10 + d;
  287. empty = 0;
  288. }
  289. }
  290. while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */
  291. if (empty || *s != '\0') return NULL; /* something wrong in the numeral */
  292. else {
  293. *result = l_castU2S((neg) ? 0u - a : a);
  294. return s;
  295. }
  296. }
  297. size_t luaO_str2num (const char *s, TValue *o) {
  298. lua_Integer i; lua_Number n;
  299. const char *e;
  300. if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */
  301. setivalue(o, i);
  302. }
  303. else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */
  304. setfltvalue(o, n);
  305. }
  306. else
  307. return 0; /* conversion failed */
  308. return (e - s) + 1; /* success; return string size */
  309. }
  310. int luaO_utf8esc (char *buff, unsigned long x) {
  311. int n = 1; /* number of bytes put in buffer (backwards) */
  312. lua_assert(x <= 0x10FFFF);
  313. if (x < 0x80) /* ascii? */
  314. buff[UTF8BUFFSZ - 1] = cast(char, x);
  315. else { /* need continuation bytes */
  316. unsigned int mfb = 0x3f; /* maximum that fits in first byte */
  317. do { /* add continuation bytes */
  318. buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
  319. x >>= 6; /* remove added bits */
  320. mfb >>= 1; /* now there is one less bit available in first byte */
  321. } while (x > mfb); /* still needs continuation byte? */
  322. buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */
  323. }
  324. return n;
  325. }
  326. /* maximum length of the conversion of a number to a string */
  327. #define MAXNUMBER2STR 50
  328. /*
  329. ** Convert a number object to a string
  330. */
  331. void luaO_tostring (lua_State *L, StkId obj) {
  332. char buff[MAXNUMBER2STR];
  333. size_t len;
  334. lua_assert(ttisnumber(obj));
  335. if (ttisinteger(obj))
  336. len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
  337. else {
  338. len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
  339. #if !defined(LUA_COMPAT_FLOATSTRING)
  340. if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */
  341. buff[len++] = lua_getlocaledecpoint();
  342. buff[len++] = '0'; /* adds '.0' to result */
  343. }
  344. #endif
  345. }
  346. setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
  347. }
  348. static void pushstr (lua_State *L, const char *str, size_t l) {
  349. setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  350. luaD_inctop(L);
  351. }
  352. /*
  353. ** this function handles only '%d', '%c', '%f', '%p', and '%s'
  354. conventional formats, plus Lua-specific '%I' and '%U'
  355. */
  356. const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  357. int n = 0;
  358. for (;;) {
  359. const char *e = strchr(fmt, '%');
  360. if (e == NULL) break;
  361. pushstr(L, fmt, e - fmt);
  362. switch (*(e+1)) {
  363. case 's': { /* zero-terminated string */
  364. const char *s = va_arg(argp, char *);
  365. if (s == NULL) s = "(null)";
  366. pushstr(L, s, strlen(s));
  367. break;
  368. }
  369. case 'c': { /* an 'int' as a character */
  370. char buff = cast(char, va_arg(argp, int));
  371. if (lisprint(cast_uchar(buff)))
  372. pushstr(L, &buff, 1);
  373. else /* non-printable character; print its code */
  374. luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
  375. break;
  376. }
  377. case 'd': { /* an 'int' */
  378. setivalue(L->top, va_arg(argp, int));
  379. goto top2str;
  380. }
  381. case 'I': { /* a 'lua_Integer' */
  382. setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
  383. goto top2str;
  384. }
  385. case 'f': { /* a 'lua_Number' */
  386. setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
  387. top2str: /* convert the top element to a string */
  388. luaD_inctop(L);
  389. luaO_tostring(L, L->top - 1);
  390. break;
  391. }
  392. case 'p': { /* a pointer */
  393. char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
  394. void *p = va_arg(argp, void *);
  395. int l = lua_pointer2str(buff, sizeof(buff), p);
  396. pushstr(L, buff, l);
  397. break;
  398. }
  399. case 'U': { /* an 'int' as a UTF-8 sequence */
  400. char buff[UTF8BUFFSZ];
  401. int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
  402. pushstr(L, buff + UTF8BUFFSZ - l, l);
  403. break;
  404. }
  405. case '%': {
  406. pushstr(L, "%", 1);
  407. break;
  408. }
  409. default: {
  410. luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
  411. *(e + 1));
  412. }
  413. }
  414. n += 2;
  415. fmt = e+2;
  416. }
  417. luaD_checkstack(L, 1);
  418. pushstr(L, fmt, strlen(fmt));
  419. if (n > 0) luaV_concat(L, n + 1);
  420. return svalue(L->top - 1);
  421. }
  422. const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  423. const char *msg;
  424. va_list argp;
  425. va_start(argp, fmt);
  426. msg = luaO_pushvfstring(L, fmt, argp);
  427. va_end(argp);
  428. return msg;
  429. }
  430. /* number of chars of a literal string without the ending \0 */
  431. #define LL(x) (sizeof(x)/sizeof(char) - 1)
  432. #define RETS "..."
  433. #define PRE "[string \""
  434. #define POS "\"]"
  435. #define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
  436. void luaO_chunkid (char *out, const char *source, size_t bufflen) {
  437. size_t l = strlen(source);
  438. if (*source == '=') { /* 'literal' source */
  439. if (l <= bufflen) /* small enough? */
  440. memcpy(out, source + 1, l * sizeof(char));
  441. else { /* truncate it */
  442. addstr(out, source + 1, bufflen - 1);
  443. *out = '\0';
  444. }
  445. }
  446. else if (*source == '@') { /* file name */
  447. if (l <= bufflen) /* small enough? */
  448. memcpy(out, source + 1, l * sizeof(char));
  449. else { /* add '...' before rest of name */
  450. addstr(out, RETS, LL(RETS));
  451. bufflen -= LL(RETS);
  452. memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
  453. }
  454. }
  455. else { /* string; format as [string "source"] */
  456. const char *nl = strchr(source, '\n'); /* find first new line (if any) */
  457. addstr(out, PRE, LL(PRE)); /* add prefix */
  458. bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */
  459. if (l < bufflen && nl == NULL) { /* small one-line source? */
  460. addstr(out, source, l); /* keep it */
  461. }
  462. else {
  463. if (nl != NULL) l = nl - source; /* stop at first newline */
  464. if (l > bufflen) l = bufflen;
  465. addstr(out, source, l);
  466. addstr(out, RETS, LL(RETS));
  467. }
  468. memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  469. }
  470. }