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/*** $Id: lobject.c,v 2.101 2014/12/26 14:43:45 roberto Exp $** Some generic functions over Lua objects** See Copyright Notice in lua.h*/ #define lobject_c#define LUA_CORE #include "lprefix.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 >= 0x10) {    x = (x+1) >> 1;    e++;  }  return ((e+1) << 3) | (cast_int(x) - 8);}  /* converts back */int luaO_fb2int (int x) {  int e = (x >> 3) & 0x1f;  if (e == 0) return x;  else return ((x & 7) + 8) << (e - 1);}  int luaO_ceillog2 (unsigned int x) {  static const lu_byte log_2[256] = {    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) #include <math.h> /* 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) {  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 dot = 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 == '.') {      if (dot) break;  /* second dot? stop loop */      else dot = 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 (dot) 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/* }====================================================== */  static const char *l_str2d (const char *s, lua_Number *result) {  char *endptr;  if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */    return NULL;  else if (strpbrk(s, "xX"))  /* hex? */    *result = lua_strx2number(s, &endptr);  else    *result = lua_str2number(s, &endptr);  if (endptr == s) return 0;  /* nothing recognized */  while (lisspace(cast_uchar(*endptr))) endptr++;  return (*endptr == '\0' ? endptr : NULL);  /* OK if no trailing characters */}  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++) {      a = a * 10 + *s - '0';      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, ivalue(obj));  else {    len = lua_number2str(buff, fltvalue(obj));#if !defined(LUA_COMPAT_FLOATSTRING)    if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */      buff[len++] = '.';      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));}  /* 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;    luaD_checkstack(L, 2);  /* fmt + item */    pushstr(L, fmt, e - fmt);    switch (*(e+1)) {      case 's': {        const char *s = va_arg(argp, char *);        if (s == NULL) s = "(null)";        pushstr(L, s, strlen(s));        break;      }      case 'c': {        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': {        setivalue(L->top++, va_arg(argp, int));        luaO_tostring(L, L->top - 1);        break;      }      case 'I': {        setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt)));        luaO_tostring(L, L->top - 1);        break;      }      case 'f': {        setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));        luaO_tostring(L, L->top - 1);        break;      }      case 'p': {        char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */        int l = sprintf(buff, "%p", va_arg(argp, void *));        pushstr(L, buff, l);        break;      }      case 'U': {        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));  }}