/*

** $Id: lobject.c $

** 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"

/*

** 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_idiv(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_shiftr(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: return luaV_modf(L, v1, v2);

    default: lua_assert(0); return 0;

  }

}

int luaO_rawarith (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 (tointegerns(p1, &i1) && tointegerns(p2, &i2)) {

        setivalue(res, intarith(L, op, i1, i2));

        return 1;

      }

      else return 0;  /* fail */

    }

    case LUA_OPDIV: case LUA_OPPOW: {  /* operate only on floats */

      lua_Number n1; lua_Number n2;

      if (tonumberns(p1, n1) && tonumberns(p2, n2)) {

        setfltvalue(res, numarith(L, op, n1, n2));

        return 1;

      }

      else return 0;  /* fail */

    }

    default: {  /* other operations */

      lua_Number n1; lua_Number n2;

      if (ttisinteger(p1) && ttisinteger(p2)) {

        setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2)));

        return 1;

      }

      else if (tonumberns(p1, n1) && tonumberns(p2, n2)) {

        setfltvalue(res, numarith(L, op, n1, n2));

        return 1;

      }

      else return 0;  /* fail */

    }

  }

}

void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2,

                 StkId res) {

  if (!luaO_rawarith(L, op, p1, p2, s2v(res))) {

    /* could not perform raw operation; try metamethod */

    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 a 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 = l_mathop(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_charp(s);  /* nothing is valid yet */

  while (lisspace(cast_uchar(*s))) s++;  /* skip initial spaces */

  neg = isneg(&s);  /* check sign */

  if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X')))  /* check '0x' */

    return l_mathop(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 * l_mathop(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 l_mathop(0.0);  /* invalid format */

  *endptr = cast_charp(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 sign */

    s++;  /* skip 'p' */

    neg1 = isneg(&s);  /* sign */

    if (!lisdigit(cast_uchar(*s)))

      return l_mathop(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_charp(s);  /* valid up to here */

  }

  if (neg) r = -r;

  return l_mathop(ldexp)(r, e);

}

#endif

/* }====================================================== */

/* maximum length of a numeral to be converted to a number */

#if !defined (L_MAXLENNUM)

#define L_MAXLENNUM 200

#endif

/*

** Convert string 's' to a Lua number (put in 'result'). Return NULL on

** fail or the address of the ending '\0' on success. ('mode' == 'x')

** means a hexadecimal numeral.

*/

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 iff no trailing chars */

}

/*

** Convert string 's' to a Lua number (put in 'result') handling the

** current locale.

** This function accepts both the current locale or a dot as the radix

** mark. If the conversion 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.

** The variable 'mode' checks for special characters in the string:

** - 'n' means 'inf' or 'nan' (which should be rejected)

** - 'x' means a hexadecimal numeral

** - '.' just optimizes the search for the common case (no special chars)

*/

static const char *l_str2d (const char *s, lua_Number *result) {

  const char *endptr;

  const char *pmode = strpbrk(s, ".xXnN");  /* look for special chars */

  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 (pdot == NULL || strlen(s) > L_MAXLENNUM)

      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 <= 0x7FFFFFFFu);

  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. Must be

** enough to accommodate both LUA_INTEGER_FMT and LUA_NUMBER_FMT.

** (For a long long int, this is 19 digits plus a sign and a final '\0',

** adding to 21. For a long double, it can go to a sign, 33 digits,

** the dot, an exponent letter, an exponent sign, 5 exponent digits,

** and a final '\0', adding to 43.)

*/

#define MAXNUMBER2STR 44

/*

** Convert a number object to a string, adding it to a buffer

*/

static int tostringbuff (TValue *obj, char *buff) {

  int len;

  lua_assert(ttisnumber(obj));

  if (ttisinteger(obj))

    len = lua_integer2str(buff, MAXNUMBER2STR, ivalue(obj));

  else {

    len = lua_number2str(buff, MAXNUMBER2STR, fltvalue(obj));

    if (buff[strspn(buff, "-0123456789")] == '\0') {  /* looks like an int? */

      buff[len++] = lua_getlocaledecpoint();

      buff[len++] = '0';  /* adds '.0' to result */

    }

  }

  return len;

}

/*

** Convert a number object to a Lua string, replacing the value at 'obj'

*/

void luaO_tostring (lua_State *L, TValue *obj) {

  char buff[MAXNUMBER2STR];

  int len = tostringbuff(obj, buff);

  setsvalue(L, obj, luaS_newlstr(L, buff, len));

}

/*

** {==================================================================

** 'luaO_pushvfstring'

** ===================================================================

*/

/*

** Size for buffer space used by 'luaO_pushvfstring'. It should be

** (LUA_IDSIZE + MAXNUMBER2STR) + a minimal space for basic messages,

** so that 'luaG_addinfo' can work directly on the buffer.

*/

#define BUFVFS    (LUA_IDSIZE + MAXNUMBER2STR + 95)

/* buffer used by 'luaO_pushvfstring' */

typedef struct BuffFS {

  lua_State *L;

  int pushed;  /* true if there is a part of the result on the stack */

  int blen;  /* length of partial string in 'space' */

  char space[BUFVFS];  /* holds last part of the result */

} BuffFS;

/*

** Push given string to the stack, as part of the result, and

** join it to previous partial result if there is one.

** It may call 'luaV_concat' while using one slot from EXTRA_STACK.

** This call cannot invoke metamethods, as both operands must be

** strings. It can, however, raise an error if the result is too

** long. In that case, 'luaV_concat' frees the extra slot before

** raising the error.

*/

static void pushstr (BuffFS *buff, const char *str, size_t lstr) {

  lua_State *L = buff->L;

  setsvalue2s(L, L->top.p, luaS_newlstr(L, str, lstr));

  L->top.p++;  /* may use one slot from EXTRA_STACK */

  if (!buff->pushed)  /* no previous string on the stack? */

    buff->pushed = 1;  /* now there is one */

  else  /* join previous string with new one */

    luaV_concat(L, 2);

}

/*

** empty the buffer space into the stack

*/

static void clearbuff (BuffFS *buff) {

  pushstr(buff, buff->space, buff->blen);  /* push buffer contents */

  buff->blen = 0;  /* space now is empty */

}

/*

** Get a space of size 'sz' in the buffer. If buffer has not enough

** space, empty it. 'sz' must fit in an empty buffer.

*/

static char *getbuff (BuffFS *buff, int sz) {

  lua_assert(buff->blen <= BUFVFS); lua_assert(sz <= BUFVFS);

  if (sz > BUFVFS - buff->blen)  /* not enough space? */

    clearbuff(buff);

  return buff->space + buff->blen;

}

#define addsize(b,sz) ((b)->blen += (sz))

/*

** Add 'str' to the buffer. If string is larger than the buffer space,

** push the string directly to the stack.

*/

static void addstr2buff (BuffFS *buff, const char *str, size_t slen) {

  if (slen <= BUFVFS) {  /* does string fit into buffer? */

    char *bf = getbuff(buff, cast_int(slen));

    memcpy(bf, str, slen);  /* add string to buffer */

    addsize(buff, cast_int(slen));

  }

  else {  /* string larger than buffer */

    clearbuff(buff);  /* string comes after buffer's content */

    pushstr(buff, str, slen);  /* push string */

  }

}

/*

** Add a numeral to the buffer.

*/

static void addnum2buff (BuffFS *buff, TValue *num) {

  char *numbuff = getbuff(buff, MAXNUMBER2STR);

  int len = tostringbuff(num, numbuff);  /* format number into 'numbuff' */

  addsize(buff, len);

}

/*

** this function handles only '%d', '%c', '%f', '%p', '%s', and '%%'

   conventional formats, plus Lua-specific '%I' and '%U'

*/

const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) {

  BuffFS buff;  /* holds last part of the result */

  const char *e;  /* points to next '%' */

  buff.pushed = buff.blen = 0;

  buff.L = L;

  while ((e = strchr(fmt, '%')) != NULL) {

    addstr2buff(&buff, fmt, e - fmt);  /* add 'fmt' up to '%' */

    switch (*(e + 1)) {  /* conversion specifier */

      case 's': {  /* zero-terminated string */

        const char *s = va_arg(argp, char *);

        if (s == NULL) s = "(null)";

        addstr2buff(&buff, s, strlen(s));

        break;

      }

      case 'c': {  /* an 'int' as a character */

        char c = cast_uchar(va_arg(argp, int));

        addstr2buff(&buff, &c, sizeof(char));

        break;

      }

      case 'd': {  /* an 'int' */

        TValue num;

        setivalue(&num, va_arg(argp, int));

        addnum2buff(&buff, &num);

        break;

      }

      case 'I': {  /* a 'lua_Integer' */

        TValue num;

        setivalue(&num, cast(lua_Integer, va_arg(argp, l_uacInt)));

        addnum2buff(&buff, &num);

        break;

      }

      case 'f': {  /* a 'lua_Number' */

        TValue num;

        setfltvalue(&num, cast_num(va_arg(argp, l_uacNumber)));

        addnum2buff(&buff, &num);

        break;

      }

      case 'p': {  /* a pointer */

        const int sz = 3 * sizeof(void*) + 8; /* enough space for '%p' */

        char *bf = getbuff(&buff, sz);

        void *p = va_arg(argp, void *);

        int len = lua_pointer2str(bf, sz, p);

        addsize(&buff, len);

        break;

      }

      case 'U': {  /* a 'long' as a UTF-8 sequence */

        char bf[UTF8BUFFSZ];

        int len = luaO_utf8esc(bf, va_arg(argp, long));

        addstr2buff(&buff, bf + UTF8BUFFSZ - len, len);

        break;

      }

      case '%': {

        addstr2buff(&buff, "%", 1);

        break;

      }

      default: {

        luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'",

                         *(e + 1));

      }

    }

    fmt = e + 2;  /* skip '%' and the specifier */

  }

  addstr2buff(&buff, fmt, strlen(fmt));  /* rest of 'fmt' */

  clearbuff(&buff);  /* empty buffer into the stack */

  lua_assert(buff.pushed == 1);

  return getstr(tsvalue(s2v(L->top.p - 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;

}

/* }================================================================== */

#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 srclen) {

  size_t bufflen = LUA_IDSIZE;  /* free space in buffer */

  if (*source == '=') {  /* 'literal' source */

    if (srclen <= bufflen)  /* small enough? */

      memcpy(out, source + 1, srclen * sizeof(char));

    else {  /* truncate it */

      addstr(out, source + 1, bufflen - 1);

      *out = '\0';

    }

  }

  else if (*source == '@') {  /* file name */

    if (srclen <= bufflen)  /* small enough? */

      memcpy(out, source + 1, srclen * sizeof(char));

    else {  /* add '...' before rest of name */

      addstr(out, RETS, LL(RETS));

      bufflen -= LL(RETS);

      memcpy(out, source + 1 + srclen - 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 (srclen < bufflen && nl == NULL) {  /* small one-line source? */

      addstr(out, source, srclen);  /* keep it */

    }

    else {

      if (nl != NULL) srclen = nl - source;  /* stop at first newline */

      if (srclen > bufflen) srclen = bufflen;

      addstr(out, source, srclen);

      addstr(out, RETS, LL(RETS));

    }

    memcpy(out, POS, (LL(POS) + 1) * sizeof(char));

  }

}