/*
** $Id: lobject.c,v 2.58 2013/02/20 14:08:56 roberto Exp $
** Some generic functions over Lua objects
** See Copyright Notice in lua.h
*/

#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define lobject_c
#define LUA_CORE

#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];
}


lua_Number luaO_arith(int op, lua_Number v1, lua_Number v2) {
    switch (op) {
        case LUA_OPADD:
            return luai_numadd(NULL, v1, v2);
        case LUA_OPSUB:
            return luai_numsub(NULL, v1, v2);
        case LUA_OPMUL:
            return luai_nummul(NULL, v1, v2);
        case LUA_OPDIV:
            return luai_numdiv(NULL, v1, v2);
        case LUA_OPMOD:
            return luai_nummod(NULL, v1, v2);
        case LUA_OPPOW:
            return luai_numpow(NULL, v1, v2);
        case LUA_OPUNM:
            return luai_numunm(NULL, v1);
        default:
            lua_assert(0);
            return 0;
    }
}


int luaO_hexavalue(int c) {
    if (lisdigit(c)) return c - '0';
    else return ltolower(c) - 'a' + 10;
}


#if !defined(lua_strx2number)

#include <math.h>


static int isneg(const char **s) {
    if (**s == '-') { (*s)++; return 1; }
    else if (**s == '+')(*s)++;
    return 0;
}


static lua_Number readhexa(const char **s, lua_Number r, int *count) {
    for (; lisxdigit(cast_uchar(**s)); (*s)++) {  /* read integer part */
        r = (r * cast_num(16.0)) + cast_num(luaO_hexavalue(cast_uchar(**s)));
        (*count)++;
    }
    return r;
}


/*
** 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;
    int e = 0, i = 0;
    int neg = 0;  /* 1 if number is negative */
    *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') */
    s += 2;  /* skip '0x' */
    r = readhexa(&s, r, &i);  /* read integer part */
    if (*s == '.') {
        s++;  /* skip dot */
        r = readhexa(&s, r, &e);  /* read fractional part */
    }
    if (i == 0 && e == 0)
        return 0.0;  /* invalid format (no digit) */
    e *= -4;  /* each fractional digit divides value by 2^-4 */
    *endptr = cast(char *, s);  /* valid up to here */
    if (*s == 'p' || *s == 'P') {  /* exponent part? */
        int exp1 = 0;
        int neg1;
        s++;  /* skip 'p' */
        neg1 = isneg(&s);  /* signal */
        if (!lisdigit(cast_uchar(*s)))
            goto ret;  /* 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 */
ret:
    if (neg) r = -r;
    return l_mathop(ldexp)(r, e);
}

#endif


int luaO_str2d(const char *s, size_t len, lua_Number *result) {
    char *endptr;
    if (strpbrk(s, "nN"))  /* reject 'inf' and 'nan' */
        return 0;
    else if (strpbrk(s, "xX"))  /* hexa? */
        *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 == s + len);  /* OK if no trailing characters */
}



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' formats */
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;
                buff = cast(char, va_arg(argp, int));
                pushstr(L, &buff, 1);
                break;
            }
            case 'd': {
                setnvalue(L->top++, cast_num(va_arg(argp, int)));
                break;
            }
            case 'f': {
                setnvalue(L->top++, cast_num(va_arg(argp, l_uacNumber)));
                break;
            }
            case 'p': {
                char buff[4 * sizeof(void *) + 8]; /* should be enough space for a `%p' */
                int l = snprintf(buff, sizeof(buff), "%p", va_arg(argp, void *));
                pushstr(L, buff, l);
                break;
            }
            case '%': {
                pushstr(L, "%", 1);
                break;
            }
            default: {
                luaG_runerror(L,
                              "invalid option " LUA_QL("%%%c") " to " LUA_QL("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));
    }
}

