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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.  
  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. LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT};
  34.  
  35.  
  36. /*
  37. ** converts an integer to a "floating point byte", represented as
  38. ** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if
  39. ** eeeee != 0 and (xxx) otherwise.
  40. */
  41. int luaO_int2fb (unsigned int x) {
  42.   int e = 0;  /* exponent */
  43.   if (x < 8) return x;
  44.   while (x >= (8 << 4)) {  /* coarse steps */
  45.     x = (x + 0xf) >> 4;  /* x = ceil(x / 16) */
  46.     e += 4;
  47.   }
  48.   while (x >= (8 << 1)) {  /* fine steps */
  49.     x = (x + 1) >> 1;  /* x = ceil(x / 2) */
  50.     e++;
  51.   }
  52.   return ((e+1) << 3) | (cast_int(x) - 8);
  53. }
  54.  
  55.  
  56. /* converts back */
  57. int luaO_fb2int (int x) {
  58.   return (x < 8) ? x : ((x & 7) + 8) << ((x >> 3) - 1);
  59. }
  60.  
  61.  
  62. /*
  63. ** Computes ceil(log2(x))
  64. */
  65. int luaO_ceillog2 (unsigned int x) {
  66.   static const lu_byte log_2[256] = {  /* log_2[i] = ceil(log2(i - 1)) */
  67.     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,
  68.     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,
  69.     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,
  70.     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,
  71.     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,
  72.     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,
  73.     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,
  74.     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
  75.   };
  76.   int l = 0;
  77.   x--;
  78.   while (x >= 256) { l += 8; x >>= 8; }
  79.   return l + log_2[x];
  80. }
  81.  
  82.  
  83. static lua_Integer intarith (lua_State *L, int op, lua_Integer v1,
  84.                                                    lua_Integer v2) {
  85.   switch (op) {
  86.     case LUA_OPADD: return intop(+, v1, v2);
  87.     case LUA_OPSUB:return intop(-, v1, v2);
  88.     case LUA_OPMUL:return intop(*, v1, v2);
  89.     case LUA_OPMOD: return luaV_mod(L, v1, v2);
  90.     case LUA_OPIDIV: return luaV_div(L, v1, v2);
  91.     case LUA_OPBAND: return intop(&, v1, v2);
  92.     case LUA_OPBOR: return intop(|, v1, v2);
  93.     case LUA_OPBXOR: return intop(^, v1, v2);
  94.     case LUA_OPSHL: return luaV_shiftl(v1, v2);
  95.     case LUA_OPSHR: return luaV_shiftl(v1, -v2);
  96.     case LUA_OPUNM: return intop(-, 0, v1);
  97.     case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1);
  98.     default: lua_assert(0); return 0;
  99.   }
  100. }
  101.  
  102.  
  103. static lua_Number numarith (lua_State *L, int op, lua_Number v1,
  104.                                                   lua_Number v2) {
  105.   switch (op) {
  106.     case LUA_OPADD: return luai_numadd(L, v1, v2);
  107.     case LUA_OPSUB: return luai_numsub(L, v1, v2);
  108.     case LUA_OPMUL: return luai_nummul(L, v1, v2);
  109.     case LUA_OPDIV: return luai_numdiv(L, v1, v2);
  110.     case LUA_OPPOW: return luai_numpow(L, v1, v2);
  111.     case LUA_OPIDIV: return luai_numidiv(L, v1, v2);
  112.     case LUA_OPUNM: return luai_numunm(L, v1);
  113.     case LUA_OPMOD: {
  114.       lua_Number m;
  115.       luai_nummod(L, v1, v2, m);
  116.       return m;
  117.     }
  118.     default: lua_assert(0); return 0;
  119.   }
  120. }
  121.  
  122.  
  123. void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,
  124.                  TValue *res) {
  125.   switch (op) {
  126.     case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR:
  127.     case LUA_OPSHL: case LUA_OPSHR:
  128.     case LUA_OPBNOT: {  /* operate only on integers */
  129.       lua_Integer i1; lua_Integer i2;
  130.       if (tointeger(p1, &i1) && tointeger(p2, &i2)) {
  131.         setivalue(res, intarith(L, op, i1, i2));
  132.         return;
  133.       }
  134.       else break;  /* go to the end */
  135.     }
  136.     case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */
  137.       lua_Number n1; lua_Number n2;
  138.       if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
  139.         setfltvalue(res, numarith(L, op, n1, n2));
  140.         return;
  141.       }
  142.       else break;  /* go to the end */
  143.     }
  144.     default: {  /* other operations */
  145.       lua_Number n1; lua_Number n2;
  146.       if (ttisinteger(p1) && ttisinteger(p2)) {
  147.         setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));
  148.         return;
  149.       }
  150.       else if (tonumber(p1, &n1) && tonumber(p2, &n2)) {
  151.         setfltvalue(res, numarith(L, op, n1, n2));
  152.         return;
  153.       }
  154.       else break;  /* go to the end */
  155.     }
  156.   }
  157.   /* could not perform raw operation; try metamethod */
  158.   lua_assert(L != NULL);  /* should not fail when folding (compile time) */
  159.   luaT_trybinTM(L, p1, p2, res, cast(TMS, (op - LUA_OPADD) + TM_ADD));
  160. }
  161.  
  162.  
  163. int luaO_hexavalue (int c) {
  164.   if (lisdigit(c)) return c - '0';
  165.   else return (ltolower(c) - 'a') + 10;
  166. }
  167.  
  168.  
  169. static int isneg (const char **s) {
  170.   if (**s == '-') { (*s)++; return 1; }
  171.   else if (**s == '+') (*s)++;
  172.   return 0;
  173. }
  174.  
  175.  
  176.  
  177. /*
  178. ** {==================================================================
  179. ** Lua's implementation for 'lua_strx2number'
  180. ** ===================================================================
  181. */
  182.  
  183. #if !defined(lua_strx2number)
  184.  
  185. /* maximum number of significant digits to read (to avoid overflows
  186.    even with single floats) */
  187. #define MAXSIGDIG       30
  188.  
  189. /*
  190. ** convert an hexadecimal numeric string to a number, following
  191. ** C99 specification for 'strtod'
  192. */
  193. static lua_Number lua_strx2number (const char *s, char **endptr) {
  194.   int dot = lua_getlocaledecpoint();
  195.   lua_Number r = 0.0;  /* result (accumulator) */
  196.   int sigdig = 0;  /* number of significant digits */
  197.   int nosigdig = 0;  /* number of non-significant digits */
  198.   int e = 0;  /* exponent correction */
  199.   int neg;  /* 1 if number is negative */
  200.   int hasdot = 0;  /* true after seen a dot */
  201.   *endptr = cast(char *, s);  /* nothing is valid yet */
  202.   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  203.   neg = isneg(&s);  /* check signal */
  204.   if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */
  205.     return 0.0;  /* invalid format (no '0x') */
  206.   for (s += 2; ; s++) {  /* skip '0x' and read numeral */
  207.     if (*s == dot) {
  208.       if (hasdot) break;  /* second dot? stop loop */
  209.       else hasdot = 1;
  210.     }
  211.     else if (lisxdigit(cast_uchar(*s))) {
  212.       if (sigdig == 0 && *s == '0')  /* non-significant digit (zero)? */
  213.         nosigdig++;
  214.       else if (++sigdig <= MAXSIGDIG)  /* can read it without overflow? */
  215.           r = (r * cast_num(16.0)) + luaO_hexavalue(*s);
  216.       else e++; /* too many digits; ignore, but still count for exponent */
  217.       if (hasdot) e--;  /* decimal digit? correct exponent */
  218.     }
  219.     else break;  /* neither a dot nor a digit */
  220.   }
  221.   if (nosigdig + sigdig == 0)  /* no digits? */
  222.     return 0.0;  /* invalid format */
  223.   *endptr = cast(char *, s);  /* valid up to here */
  224.   e *= 4;  /* each digit multiplies/divides value by 2^4 */
  225.   if (*s == 'p' || *s == 'P') {  /* exponent part? */
  226.     int exp1 = 0;  /* exponent value */
  227.     int neg1;  /* exponent signal */
  228.     s++;  /* skip 'p' */
  229.     neg1 = isneg(&s);  /* signal */
  230.     if (!lisdigit(cast_uchar(*s)))
  231.       return 0.0;  /* invalid; must have at least one digit */
  232.     while (lisdigit(cast_uchar(*s)))  /* read exponent */
  233.       exp1 = exp1 * 10 + *(s++) - '0';
  234.     if (neg1) exp1 = -exp1;
  235.     e += exp1;
  236.     *endptr = cast(char *, s);  /* valid up to here */
  237.   }
  238.   if (neg) r = -r;
  239.   return l_mathop(ldexp)(r, e);
  240. }
  241.  
  242. #endif
  243. /* }====================================================== */
  244.  
  245.  
  246. /* maximum length of a numeral */
  247. #if !defined (L_MAXLENNUM)
  248. #define L_MAXLENNUM     200
  249. #endif
  250.  
  251. static const char *l_str2dloc (const char *s, lua_Number *result, int mode) {
  252.   char *endptr;
  253.   *result = (mode == 'x') ? lua_strx2number(s, &endptr)  /* try to convert */
  254.                           : lua_str2number(s, &endptr);
  255.   if (endptr == s) return NULL;  /* nothing recognized? */
  256.   while (lisspace(cast_uchar(*endptr))) endptr++;  /* skip trailing spaces */
  257.   return (*endptr == '\0') ? endptr : NULL;  /* OK if no trailing characters */
  258. }
  259.  
  260.  
  261. /*
  262. ** Convert string 's' to a Lua number (put in 'result'). Return NULL
  263. ** on fail or the address of the ending '\0' on success.
  264. ** 'pmode' points to (and 'mode' contains) special things in the string:
  265. ** - 'x'/'X' means an hexadecimal numeral
  266. ** - 'n'/'N' means 'inf' or 'nan' (which should be rejected)
  267. ** - '.' just optimizes the search for the common case (nothing special)
  268. ** This function accepts both the current locale or a dot as the radix
  269. ** mark. If the conversion fails, it may mean number has a dot but
  270. ** locale accepts something else. In that case, the code copies 's'
  271. ** to a buffer (because 's' is read-only), changes the dot to the
  272. ** current locale radix mark, and tries to convert again.
  273. */
  274. static const char *l_str2d (const char *s, lua_Number *result) {
  275.   const char *endptr;
  276.   const char *pmode = strpbrk(s, ".xXnN");
  277.   int mode = pmode ? ltolower(cast_uchar(*pmode)) : 0;
  278.   if (mode == 'n')  /* reject 'inf' and 'nan' */
  279.     return NULL;
  280.   endptr = l_str2dloc(s, result, mode);  /* try to convert */
  281.   if (endptr == NULL) {  /* failed? may be a different locale */
  282.     char buff[L_MAXLENNUM + 1];
  283.     const char *pdot = strchr(s, '.');
  284.     if (strlen(s) > L_MAXLENNUM || pdot == NULL)
  285.       return NULL;  /* string too long or no dot; fail */
  286.     strcpy(buff, s);  /* copy string to buffer */
  287.     buff[pdot - s] = lua_getlocaledecpoint();  /* correct decimal point */
  288.     endptr = l_str2dloc(buff, result, mode);  /* try again */
  289.     if (endptr != NULL)
  290.       endptr = s + (endptr - buff);  /* make relative to 's' */
  291.   }
  292.   return endptr;
  293. }
  294.  
  295.  
  296. #define MAXBY10         cast(lua_Unsigned, LUA_MAXINTEGER / 10)
  297. #define MAXLASTD        cast_int(LUA_MAXINTEGER % 10)
  298.  
  299. static const char *l_str2int (const char *s, lua_Integer *result) {
  300.   lua_Unsigned a = 0;
  301.   int empty = 1;
  302.   int neg;
  303.   while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */
  304.   neg = isneg(&s);
  305.   if (s[0] == '0' &&
  306.       (s[1] == 'x' || s[1] == 'X')) {  /* hex? */
  307.     s += 2;  /* skip '0x' */
  308.     for (; lisxdigit(cast_uchar(*s)); s++) {
  309.       a = a * 16 + luaO_hexavalue(*s);
  310.       empty = 0;
  311.     }
  312.   }
  313.   else {  /* decimal */
  314.     for (; lisdigit(cast_uchar(*s)); s++) {
  315.       int d = *s - '0';
  316.       if (a >= MAXBY10 && (a > MAXBY10 || d > MAXLASTD + neg))  /* overflow? */
  317.         return NULL;  /* do not accept it (as integer) */
  318.       a = a * 10 + d;
  319.       empty = 0;
  320.     }
  321.   }
  322.   while (lisspace(cast_uchar(*s))) s++;  /* skip trailing spaces */
  323.   if (empty || *s != '\0') return NULL;  /* something wrong in the numeral */
  324.   else {
  325.     *result = l_castU2S((neg) ? 0u - a : a);
  326.     return s;
  327.   }
  328. }
  329.  
  330.  
  331. size_t luaO_str2num (const char *s, TValue *o) {
  332.   lua_Integer i; lua_Number n;
  333.   const char *e;
  334.   if ((e = l_str2int(s, &i)) != NULL) {  /* try as an integer */
  335.     setivalue(o, i);
  336.   }
  337.   else if ((e = l_str2d(s, &n)) != NULL) {  /* else try as a float */
  338.     setfltvalue(o, n);
  339.   }
  340.   else
  341.     return 0;  /* conversion failed */
  342.   return (e - s) + 1;  /* success; return string size */
  343. }
  344.  
  345.  
  346. int luaO_utf8esc (char *buff, unsigned long x) {
  347.   int n = 1;  /* number of bytes put in buffer (backwards) */
  348.   lua_assert(x <= 0x10FFFF);
  349.   if (x < 0x80)  /* ascii? */
  350.     buff[UTF8BUFFSZ - 1] = cast(char, x);
  351.   else {  /* need continuation bytes */
  352.     unsigned int mfb = 0x3f;  /* maximum that fits in first byte */
  353.     do {  /* add continuation bytes */
  354.       buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f));
  355.       x >>= 6;  /* remove added bits */
  356.       mfb >>= 1;  /* now there is one less bit available in first byte */
  357.     } while (x > mfb);  /* still needs continuation byte? */
  358.     buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x);  /* add first byte */
  359.   }
  360.   return n;
  361. }
  362.  
  363.  
  364. /* maximum length of the conversion of a number to a string */
  365. #define MAXNUMBER2STR   50
  366.  
  367.  
  368. /*
  369. ** Convert a number object to a string
  370. */
  371. void luaO_tostring (lua_State *L, StkId obj) {
  372.   char buff[MAXNUMBER2STR];
  373.   size_t len;
  374.   lua_assert(ttisnumber(obj));
  375.   if (ttisinteger(obj))
  376.     len = lua_integer2str(buff, sizeof(buff), ivalue(obj));
  377.   else {
  378.     len = lua_number2str(buff, sizeof(buff), fltvalue(obj));
  379. #if !defined(LUA_COMPAT_FLOATSTRING)
  380.     if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */
  381.       buff[len++] = lua_getlocaledecpoint();
  382.       buff[len++] = '0';  /* adds '.0' to result */
  383.     }
  384. #endif
  385.   }
  386.   setsvalue2s(L, obj, luaS_newlstr(L, buff, len));
  387. }
  388.  
  389.  
  390. static void pushstr (lua_State *L, const char *str, size_t l) {
  391.   setsvalue2s(L, L->top, luaS_newlstr(L, str, l));
  392.   luaD_inctop(L);
  393. }
  394.  
  395.  
  396. /*
  397. ** this function handles only '%d', '%c', '%f', '%p', and '%s'
  398.    conventional formats, plus Lua-specific '%I' and '%U'
  399. */
  400. const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {
  401.   int n = 0;
  402.   for (;;) {
  403.     const char *e = strchr(fmt, '%');
  404.     if (e == NULL) break;
  405.     pushstr(L, fmt, e - fmt);
  406.     switch (*(e+1)) {
  407.       case 's': {  /* zero-terminated string */
  408.         const char *s = va_arg(argp, char *);
  409.         if (s == NULL) s = "(null)";
  410.         pushstr(L, s, strlen(s));
  411.         break;
  412.       }
  413.       case 'c': {  /* an 'int' as a character */
  414.         char buff = cast(char, va_arg(argp, int));
  415.         if (lisprint(cast_uchar(buff)))
  416.           pushstr(L, &buff, 1);
  417.         else  /* non-printable character; print its code */
  418.           luaO_pushfstring(L, "<\\%d>", cast_uchar(buff));
  419.         break;
  420.       }
  421.       case 'd': {  /* an 'int' */
  422.         setivalue(L->top, va_arg(argp, int));
  423.         goto top2str;
  424.       }
  425.       case 'I': {  /* a 'lua_Integer' */
  426.         setivalue(L->top, cast(lua_Integer, va_arg(argp, l_uacInt)));
  427.         goto top2str;
  428.       }
  429.       case 'f': {  /* a 'lua_Number' */
  430.         setfltvalue(L->top, cast_num(va_arg(argp, l_uacNumber)));
  431.       top2str:  /* convert the top element to a string */
  432.         luaD_inctop(L);
  433.         luaO_tostring(L, L->top - 1);
  434.         break;
  435.       }
  436.       case 'p': {  /* a pointer */
  437.         char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */
  438.         void *p = va_arg(argp, void *);
  439.         int l = lua_pointer2str(buff, sizeof(buff), p);
  440.         pushstr(L, buff, l);
  441.         break;
  442.       }
  443.       case 'U': {  /* an 'int' as a UTF-8 sequence */
  444.         char buff[UTF8BUFFSZ];
  445.         int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long)));
  446.         pushstr(L, buff + UTF8BUFFSZ - l, l);
  447.         break;
  448.       }
  449.       case '%': {
  450.         pushstr(L, "%", 1);
  451.         break;
  452.       }
  453.       default: {
  454.         luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",
  455.                          *(e + 1));
  456.       }
  457.     }
  458.     n += 2;
  459.     fmt = e+2;
  460.   }
  461.   luaD_checkstack(L, 1);
  462.   pushstr(L, fmt, strlen(fmt));
  463.   if (n > 0) luaV_concat(L, n + 1);
  464.   return svalue(L->top - 1);
  465. }
  466.  
  467.  
  468. const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) {
  469.   const char *msg;
  470.   va_list argp;
  471.   va_start(argp, fmt);
  472.   msg = luaO_pushvfstring(L, fmt, argp);
  473.   va_end(argp);
  474.   return msg;
  475. }
  476.  
  477.  
  478. /* number of chars of a literal string without the ending \0 */
  479. #define LL(x)   (sizeof(x)/sizeof(char) - 1)
  480.  
  481. #define RETS    "..."
  482. #define PRE     "[string \""
  483. #define POS     "\"]"
  484.  
  485. #define addstr(a,b,l)   ( memcpy(a,b,(l) * sizeof(char)), a += (l) )
  486.  
  487. void luaO_chunkid (char *out, const char *source, size_t bufflen) {
  488.   size_t l = strlen(source);
  489.   if (*source == '=') {  /* 'literal' source */
  490.     if (l <= bufflen)  /* small enough? */
  491.       memcpy(out, source + 1, l * sizeof(char));
  492.     else {  /* truncate it */
  493.       addstr(out, source + 1, bufflen - 1);
  494.       *out = '\0';
  495.     }
  496.   }
  497.   else if (*source == '@') {  /* file name */
  498.     if (l <= bufflen)  /* small enough? */
  499.       memcpy(out, source + 1, l * sizeof(char));
  500.     else {  /* add '...' before rest of name */
  501.       addstr(out, RETS, LL(RETS));
  502.       bufflen -= LL(RETS);
  503.       memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char));
  504.     }
  505.   }
  506.   else {  /* string; format as [string "source"] */
  507.     const char *nl = strchr(source, '\n');  /* find first new line (if any) */
  508.     addstr(out, PRE, LL(PRE));  /* add prefix */
  509.     bufflen -= LL(PRE RETS POS) + 1;  /* save space for prefix+suffix+'\0' */
  510.     if (l < bufflen && nl == NULL) {  /* small one-line source? */
  511.       addstr(out, source, l);  /* keep it */
  512.     }
  513.     else {
  514.       if (nl != NULL) l = nl - source;  /* stop at first newline */
  515.       if (l > bufflen) l = bufflen;
  516.       addstr(out, source, l);
  517.       addstr(out, RETS, LL(RETS));
  518.     }
  519.     memcpy(out, POS, (LL(POS) + 1) * sizeof(char));
  520.   }
  521. }
  522.  
  523.