hamachid-patcher.c

/*
 * linux> gcc -O2 -Wall -o hamachid-patcher.so -shared hamachid-patcher.c
 */

#define _GNU_SOURCE
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dlfcn.h>

#define EXTRA_SIZE 512
//#define DEBUG

#ifdef DEBUG

static void _putchar(char character)
{
    write(1, &character, 1);
}

 ///////////////////////////////////////////////////////////////////////////////
 // \author (c) Marco Paland (info@paland.com)
 //             2014-2019, PALANDesign Hannover, Germany
 //
 // \license The MIT License (MIT)
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to deal
 // in the Software without restriction, including without limitation the rights
 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 // copies of the Software, and to permit persons to whom the Software is
 // furnished to do so, subject to the following conditions:
 //
 // The above copyright notice and this permission notice shall be included in
 // all copies or substantial portions of the Software.
 //
 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 //
 // \brief Tiny printf, sprintf and (v)snprintf implementation, optimized for speed on
 //        embedded systems with a very limited resources. These routines are thread
 //        safe and reentrant!
 //        Use this instead of the bloated standard/newlib printf cause these use
 //        malloc for printf (and may not be thread safe).
 //
 ///////////////////////////////////////////////////////////////////////////////


#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
#include <stdarg.h>

// 'ntoa' conversion buffer size, this must be big enough to hold one converted
// numeric number including padded zeros (dynamically created on stack)
// default: 32 byte
#ifndef PRINTF_NTOA_BUFFER_SIZE
#define PRINTF_NTOA_BUFFER_SIZE    32U
#endif

// 'ftoa' conversion buffer size, this must be big enough to hold one converted
// float number including padded zeros (dynamically created on stack)
// default: 32 byte
#ifndef PRINTF_FTOA_BUFFER_SIZE
#define PRINTF_FTOA_BUFFER_SIZE    32U
#endif

// support for the floating point type (%f)
// default: activated
#ifndef PRINTF_DISABLE_SUPPORT_FLOAT
#define PRINTF_SUPPORT_FLOAT
#endif

// support for exponential floating point notation (%e/%g)
// default: activated
#ifndef PRINTF_DISABLE_SUPPORT_EXPONENTIAL
#define PRINTF_SUPPORT_EXPONENTIAL
#endif

// define the default floating point precision
// default: 6 digits
#ifndef PRINTF_DEFAULT_FLOAT_PRECISION
#define PRINTF_DEFAULT_FLOAT_PRECISION  6U
#endif

// define the largest float suitable to print with %f
// default: 1e9
#ifndef PRINTF_MAX_FLOAT
#define PRINTF_MAX_FLOAT  1e9
#endif

// support for the long long types (%llu or %p)
// default: activated
#ifndef PRINTF_DISABLE_SUPPORT_LONG_LONG
#define PRINTF_SUPPORT_LONG_LONG
#endif

// support for the ptrdiff_t type (%t)
// ptrdiff_t is normally defined in <stddef.h> as long or long long type
// default: activated
#ifndef PRINTF_DISABLE_SUPPORT_PTRDIFF_T
#define PRINTF_SUPPORT_PTRDIFF_T
#endif

///////////////////////////////////////////////////////////////////////////////

// internal flag definitions
#define FLAGS_ZEROPAD   (1U <<  0U)
#define FLAGS_LEFT      (1U <<  1U)
#define FLAGS_PLUS      (1U <<  2U)
#define FLAGS_SPACE     (1U <<  3U)
#define FLAGS_HASH      (1U <<  4U)
#define FLAGS_UPPERCASE (1U <<  5U)
#define FLAGS_CHAR      (1U <<  6U)
#define FLAGS_SHORT     (1U <<  7U)
#define FLAGS_LONG      (1U <<  8U)
#define FLAGS_LONG_LONG (1U <<  9U)
#define FLAGS_PRECISION (1U << 10U)
#define FLAGS_ADAPT_EXP (1U << 11U)


// import float.h for DBL_MAX
#if defined(PRINTF_SUPPORT_FLOAT)
#include <float.h>
#endif


// output function type
typedef void (*out_fct_type)(char character, void* buffer, size_t idx, size_t maxlen);


// wrapper (used as buffer) for output function type
typedef struct {
    void  (*fct)(char character, void* arg);
    void* arg;
} out_fct_wrap_type;


// internal buffer output
static inline void _out_buffer(char character, void* buffer, size_t idx, size_t maxlen)
{
    if (idx < maxlen) {
        ((char*)buffer)[idx] = character;
    }
}


// internal null output
static inline void _out_null(char character, void* buffer, size_t idx, size_t maxlen)
{
    (void)character; (void)buffer; (void)idx; (void)maxlen;
}


// internal _putchar wrapper
static inline void _out_char(char character, void* buffer, size_t idx, size_t maxlen)
{
    (void)buffer; (void)idx; (void)maxlen;
    if (character) {
        _putchar(character);
    }
}


// internal output function wrapper
static inline void _out_fct(char character, void* buffer, size_t idx, size_t maxlen)
{
    (void)idx; (void)maxlen;
    if (character) {
        // buffer is the output fct pointer
        ((out_fct_wrap_type*)buffer)->fct(character, ((out_fct_wrap_type*)buffer)->arg);
    }
}


// internal secure strlen
// \return The length of the string (excluding the terminating 0) limited by 'maxsize'
static inline unsigned int _strnlen_s(const char* str, size_t maxsize)
{
    const char* s;
    for (s = str; *s && maxsize--; ++s);
    return (unsigned int)(s - str);
}


// internal test if char is a digit (0-9)
// \return true if char is a digit
static inline bool _is_digit(char ch)
{
    return (ch >= '0') && (ch <= '9');
}


// internal ASCII string to unsigned int conversion
static unsigned int _atoi(const char** str)
{
    unsigned int i = 0U;
    while (_is_digit(**str)) {
        i = i * 10U + (unsigned int)(*((*str)++) - '0');
    }
    return i;
}


// output the specified string in reverse, taking care of any zero-padding
static size_t _out_rev(out_fct_type out, char* buffer, size_t idx, size_t maxlen, const char* buf, size_t len, unsigned int width, unsigned int flags)
{
    const size_t start_idx = idx;

    // pad spaces up to given width
    if (!(flags & FLAGS_LEFT) && !(flags & FLAGS_ZEROPAD)) {
        for (size_t i = len; i < width; i++) {
            out(' ', buffer, idx++, maxlen);
        }
    }

    // reverse string
    while (len) {
        out(buf[--len], buffer, idx++, maxlen);
    }

    // append pad spaces up to given width
    if (flags & FLAGS_LEFT) {
        while (idx - start_idx < width) {
            out(' ', buffer, idx++, maxlen);
        }
    }

    return idx;
}


// internal itoa format
static size_t _ntoa_format(out_fct_type out, char* buffer, size_t idx, size_t maxlen, char* buf, size_t len, bool negative, unsigned int base, unsigned int prec, unsigned int width, unsigned int flags)
{
    // pad leading zeros
    if (!(flags & FLAGS_LEFT)) {
        if (width && (flags & FLAGS_ZEROPAD) && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
            width--;
        }
        while ((len < prec) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
            buf[len++] = '0';
        }
        while ((flags & FLAGS_ZEROPAD) && (len < width) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
            buf[len++] = '0';
        }
    }

    // handle hash
    if (flags & FLAGS_HASH) {
        if (!(flags & FLAGS_PRECISION) && len && ((len == prec) || (len == width))) {
            len--;
            if (len && (base == 16U)) {
                len--;
            }
        }
        if ((base == 16U) && !(flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
            buf[len++] = 'x';
        }
        else if ((base == 16U) && (flags & FLAGS_UPPERCASE) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
            buf[len++] = 'X';
        }
        else if ((base == 2U) && (len < PRINTF_NTOA_BUFFER_SIZE)) {
            buf[len++] = 'b';
        }
        if (len < PRINTF_NTOA_BUFFER_SIZE) {
            buf[len++] = '0';
        }
    }

    if (len < PRINTF_NTOA_BUFFER_SIZE) {
        if (negative) {
            buf[len++] = '-';
        }
        else if (flags & FLAGS_PLUS) {
            buf[len++] = '+';  // ignore the space if the '+' exists
        }
        else if (flags & FLAGS_SPACE) {
            buf[len++] = ' ';
        }
    }

    return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
}


// internal itoa for 'long' type
static size_t _ntoa_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long value, bool negative, unsigned long base, unsigned int prec, unsigned int width, unsigned int flags)
{
    char buf[PRINTF_NTOA_BUFFER_SIZE];
    size_t len = 0U;

    // no hash for 0 values
    if (!value) {
        flags &= ~FLAGS_HASH;
    }

    // write if precision != 0 and value is != 0
    if (!(flags & FLAGS_PRECISION) || value) {
        do {
            const char digit = (char)(value % base);
            buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
            value /= base;
        } while (value && (len < PRINTF_NTOA_BUFFER_SIZE));
    }

    return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
}


// internal itoa for 'long long' type
#if defined(PRINTF_SUPPORT_LONG_LONG)
static size_t _ntoa_long_long(out_fct_type out, char* buffer, size_t idx, size_t maxlen, unsigned long long value, bool negative, unsigned long long base, unsigned int prec, unsigned int width, unsigned int flags)
{
    char buf[PRINTF_NTOA_BUFFER_SIZE];
    size_t len = 0U;

    // no hash for 0 values
    if (!value) {
        flags &= ~FLAGS_HASH;
    }

    // write if precision != 0 and value is != 0
    if (!(flags & FLAGS_PRECISION) || value) {
        do {
            const char digit = (char)(value % base);
            buf[len++] = digit < 10 ? '0' + digit : (flags & FLAGS_UPPERCASE ? 'A' : 'a') + digit - 10;
            value /= base;
        } while (value && (len < PRINTF_NTOA_BUFFER_SIZE));
    }

    return _ntoa_format(out, buffer, idx, maxlen, buf, len, negative, (unsigned int)base, prec, width, flags);
}
#endif  // PRINTF_SUPPORT_LONG_LONG


#if defined(PRINTF_SUPPORT_FLOAT)

#if defined(PRINTF_SUPPORT_EXPONENTIAL)
// forward declaration so that _ftoa can switch to exp notation for values > PRINTF_MAX_FLOAT
static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags);
#endif


// internal ftoa for fixed decimal floating point
static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
{
    char buf[PRINTF_FTOA_BUFFER_SIZE];
    size_t len = 0U;
    double diff = 0.0;

    // powers of 10
    static const double pow10[] = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000 };

    // test for special values
    if (value != value)
        return _out_rev(out, buffer, idx, maxlen, "nan", 3, width, flags);
    if (value < -DBL_MAX)
        return _out_rev(out, buffer, idx, maxlen, "fni-", 4, width, flags);
    if (value > DBL_MAX)
        return _out_rev(out, buffer, idx, maxlen, (flags & FLAGS_PLUS) ? "fni+" : "fni", (flags & FLAGS_PLUS) ? 4U : 3U, width, flags);

    // test for very large values
    // standard printf behavior is to print EVERY whole number digit -- which could be 100s of characters overflowing your buffers == bad
    if ((value > PRINTF_MAX_FLOAT) || (value < -PRINTF_MAX_FLOAT)) {
#if defined(PRINTF_SUPPORT_EXPONENTIAL)
        return _etoa(out, buffer, idx, maxlen, value, prec, width, flags);
#else
        return 0U;
#endif
    }

    // test for negative
    bool negative = false;
    if (value < 0) {
        negative = true;
        value = 0 - value;
    }

    // set default precision, if not set explicitly
    if (!(flags & FLAGS_PRECISION)) {
        prec = PRINTF_DEFAULT_FLOAT_PRECISION;
    }
    // limit precision to 9, cause a prec >= 10 can lead to overflow errors
    while ((len < PRINTF_FTOA_BUFFER_SIZE) && (prec > 9U)) {
        buf[len++] = '0';
        prec--;
    }

    int whole = (int)value;
    double tmp = (value - whole) * pow10[prec];
    unsigned long frac = (unsigned long)tmp;
    diff = tmp - frac;

    if (diff > 0.5) {
        ++frac;
        // handle rollover, e.g. case 0.99 with prec 1 is 1.0
        if (frac >= pow10[prec]) {
            frac = 0;
            ++whole;
        }
    }
    else if (diff < 0.5) {
    }
    else if ((frac == 0U) || (frac & 1U)) {
        // if halfway, round up if odd OR if last digit is 0
        ++frac;
    }

    if (prec == 0U) {
        diff = value - (double)whole;
        if ((!(diff < 0.5) || (diff > 0.5)) && (whole & 1)) {
            // exactly 0.5 and ODD, then round up
            // 1.5 -> 2, but 2.5 -> 2
            ++whole;
        }
    }
    else {
        unsigned int count = prec;
        // now do fractional part, as an unsigned number
        while (len < PRINTF_FTOA_BUFFER_SIZE) {
            --count;
            buf[len++] = (char)(48U + (frac % 10U));
            if (!(frac /= 10U)) {
                break;
            }
        }
        // add extra 0s
        while ((len < PRINTF_FTOA_BUFFER_SIZE) && (count-- > 0U)) {
            buf[len++] = '0';
        }
        if (len < PRINTF_FTOA_BUFFER_SIZE) {
            // add decimal
            buf[len++] = '.';
        }
    }

    // do whole part, number is reversed
    while (len < PRINTF_FTOA_BUFFER_SIZE) {
        buf[len++] = (char)(48 + (whole % 10));
        if (!(whole /= 10)) {
            break;
        }
    }

    // pad leading zeros
    if (!(flags & FLAGS_LEFT) && (flags & FLAGS_ZEROPAD)) {
        if (width && (negative || (flags & (FLAGS_PLUS | FLAGS_SPACE)))) {
            width--;
        }
        while ((len < width) && (len < PRINTF_FTOA_BUFFER_SIZE)) {
            buf[len++] = '0';
        }
    }

    if (len < PRINTF_FTOA_BUFFER_SIZE) {
        if (negative) {
            buf[len++] = '-';
        }
        else if (flags & FLAGS_PLUS) {
            buf[len++] = '+';  // ignore the space if the '+' exists
        }
        else if (flags & FLAGS_SPACE) {
            buf[len++] = ' ';
        }
    }

    return _out_rev(out, buffer, idx, maxlen, buf, len, width, flags);
}


#if defined(PRINTF_SUPPORT_EXPONENTIAL)
// internal ftoa variant for exponential floating-point type, contributed by Martijn Jasperse <m.jasperse@gmail.com>
static size_t _etoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, double value, unsigned int prec, unsigned int width, unsigned int flags)
{
    // check for NaN and special values
    if ((value != value) || (value > DBL_MAX) || (value < -DBL_MAX)) {
        return _ftoa(out, buffer, idx, maxlen, value, prec, width, flags);
    }

    // determine the sign
    const bool negative = value < 0;
    if (negative) {
        value = -value;
    }

    // default precision
    if (!(flags & FLAGS_PRECISION)) {
        prec = PRINTF_DEFAULT_FLOAT_PRECISION;
    }

    // determine the decimal exponent
    // based on the algorithm by David Gay (https://www.ampl.com/netlib/fp/dtoa.c)
    union {
        uint64_t U;
        double   F;
    } conv;

    conv.F = value;
    int exp2 = (int)((conv.U >> 52U) & 0x07FFU) - 1023;           // effectively log2
    conv.U = (conv.U & ((1ULL << 52U) - 1U)) | (1023ULL << 52U);  // drop the exponent so conv.F is now in [1,2)
    // now approximate log10 from the log2 integer part and an expansion of ln around 1.5
    int expval = (int)(0.1760912590558 + exp2 * 0.301029995663981 + (conv.F - 1.5) * 0.289529654602168);
    // now we want to compute 10^expval but we want to be sure it won't overflow
    exp2 = (int)(expval * 3.321928094887362 + 0.5);
    const double z = expval * 2.302585092994046 - exp2 * 0.6931471805599453;
    const double z2 = z * z;
    conv.U = (uint64_t)(exp2 + 1023) << 52U;
    // compute exp(z) using continued fractions, see https://en.wikipedia.org/wiki/Exponential_function#Continued_fractions_for_ex
    conv.F *= 1 + 2 * z / (2 - z + (z2 / (6 + (z2 / (10 + z2 / 14)))));
    // correct for rounding errors
    if (value < conv.F) {
        expval--;
        conv.F /= 10;
    }

    // the exponent format is "%+03d" and largest value is "307", so set aside 4-5 characters
    unsigned int minwidth = ((expval < 100) && (expval > -100)) ? 4U : 5U;

    // in "%g" mode, "prec" is the number of *significant figures* not decimals
    if (flags & FLAGS_ADAPT_EXP) {
        // do we want to fall-back to "%f" mode?
        if ((value >= 1e-4) && (value < 1e6)) {
            if ((int)prec > expval) {
                prec = (unsigned)((int)prec - expval - 1);
            }
            else {
                prec = 0;
            }
            flags |= FLAGS_PRECISION;   // make sure _ftoa respects precision
            // no characters in exponent
            minwidth = 0U;
            expval = 0;
        }
        else {
            // we use one sigfig for the whole part
            if ((prec > 0) && (flags & FLAGS_PRECISION)) {
                --prec;
            }
        }
    }

    // will everything fit?
    unsigned int fwidth = width;
    if (width > minwidth) {
        // we didn't fall-back so subtract the characters required for the exponent
        fwidth -= minwidth;
    }
    else {
        // not enough characters, so go back to default sizing
        fwidth = 0U;
    }
    if ((flags & FLAGS_LEFT) && minwidth) {
        // if we're padding on the right, DON'T pad the floating part
        fwidth = 0U;
    }

    // rescale the float value
    if (expval) {
        value /= conv.F;
    }

    // output the floating part
    const size_t start_idx = idx;
    idx = _ftoa(out, buffer, idx, maxlen, negative ? -value : value, prec, fwidth, flags & ~FLAGS_ADAPT_EXP);

    // output the exponent part
    if (minwidth) {
        // output the exponential symbol
        out((flags & FLAGS_UPPERCASE) ? 'E' : 'e', buffer, idx++, maxlen);
        // output the exponent value
        idx = _ntoa_long(out, buffer, idx, maxlen, (expval < 0) ? -expval : expval, expval < 0, 10, 0, minwidth - 1, FLAGS_ZEROPAD | FLAGS_PLUS);
        // might need to right-pad spaces
        if (flags & FLAGS_LEFT) {
            while (idx - start_idx < width) out(' ', buffer, idx++, maxlen);
        }
    }
    return idx;
}
#endif  // PRINTF_SUPPORT_EXPONENTIAL
#endif  // PRINTF_SUPPORT_FLOAT


// internal vsnprintf
static int _vsnprintf(out_fct_type out, char* buffer, const size_t maxlen, const char* format, va_list va)
{
    unsigned int flags, width, precision, n;
    size_t idx = 0U;

    if (!buffer) {
        // use null output function
        out = _out_null;
    }

    while (*format)
    {
        // format specifier?  %[flags][width][.precision][length]
        if (*format != '%') {
            // no
            out(*format, buffer, idx++, maxlen);
            format++;
            continue;
        }
        else {
            // yes, evaluate it
            format++;
        }

        // evaluate flags
        flags = 0U;
        do {
            switch (*format) {
            case '0': flags |= FLAGS_ZEROPAD; format++; n = 1U; break;
            case '-': flags |= FLAGS_LEFT;    format++; n = 1U; break;
            case '+': flags |= FLAGS_PLUS;    format++; n = 1U; break;
            case ' ': flags |= FLAGS_SPACE;   format++; n = 1U; break;
            case '#': flags |= FLAGS_HASH;    format++; n = 1U; break;
            default:                                   n = 0U; break;
            }
        } while (n);

        // evaluate width field
        width = 0U;
        if (_is_digit(*format)) {
            width = _atoi(&format);
        }
        else if (*format == '*') {
            const int w = va_arg(va, int);
            if (w < 0) {
                flags |= FLAGS_LEFT;    // reverse padding
                width = (unsigned int)-w;
            }
            else {
                width = (unsigned int)w;
            }
            format++;
        }

        // evaluate precision field
        precision = 0U;
        if (*format == '.') {
            flags |= FLAGS_PRECISION;
            format++;
            if (_is_digit(*format)) {
                precision = _atoi(&format);
            }
            else if (*format == '*') {
                const int prec = (int)va_arg(va, int);
                precision = prec > 0 ? (unsigned int)prec : 0U;
                format++;
            }
        }

        // evaluate length field
        switch (*format) {
        case 'l':
            flags |= FLAGS_LONG;
            format++;
            if (*format == 'l') {
                flags |= FLAGS_LONG_LONG;
                format++;
            }
            break;
        case 'h':
            flags |= FLAGS_SHORT;
            format++;
            if (*format == 'h') {
                flags |= FLAGS_CHAR;
                format++;
            }
            break;
#if defined(PRINTF_SUPPORT_PTRDIFF_T)
        case 't':
            flags |= (sizeof(ptrdiff_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
            format++;
            break;
#endif
        case 'j':
            flags |= (sizeof(intmax_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
            format++;
            break;
        case 'z':
            flags |= (sizeof(size_t) == sizeof(long) ? FLAGS_LONG : FLAGS_LONG_LONG);
            format++;
            break;
        default:
            break;
        }

        // evaluate specifier
        switch (*format) {
        case 'd':
        case 'i':
        case 'u':
        case 'x':
        case 'X':
        case 'o':
        case 'b': {
            // set the base
            unsigned int base;
            if (*format == 'x' || *format == 'X') {
                base = 16U;
            }
            else if (*format == 'o') {
                base = 8U;
            }
            else if (*format == 'b') {
                base = 2U;
            }
            else {
                base = 10U;
                flags &= ~FLAGS_HASH;   // no hash for dec format
            }
            // uppercase
            if (*format == 'X') {
                flags |= FLAGS_UPPERCASE;
            }

            // no plus or space flag for u, x, X, o, b
            if ((*format != 'i') && (*format != 'd')) {
                flags &= ~(FLAGS_PLUS | FLAGS_SPACE);
            }

            // ignore '0' flag when precision is given
            if (flags & FLAGS_PRECISION) {
                flags &= ~FLAGS_ZEROPAD;
            }

            // convert the integer
            if ((*format == 'i') || (*format == 'd')) {
                // signed
                if (flags & FLAGS_LONG_LONG) {
#if defined(PRINTF_SUPPORT_LONG_LONG)
                    const long long value = va_arg(va, long long);
                    idx = _ntoa_long_long(out, buffer, idx, maxlen, (unsigned long long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
#endif
                }
                else if (flags & FLAGS_LONG) {
                    const long value = va_arg(va, long);
                    idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
                }
                else {
                    const int value = (flags & FLAGS_CHAR) ? (char)va_arg(va, int) : (flags & FLAGS_SHORT) ? (short int)va_arg(va, int) : va_arg(va, int);
                    idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned int)(value > 0 ? value : 0 - value), value < 0, base, precision, width, flags);
                }
            }
            else {
                // unsigned
                if (flags & FLAGS_LONG_LONG) {
#if defined(PRINTF_SUPPORT_LONG_LONG)
                    idx = _ntoa_long_long(out, buffer, idx, maxlen, va_arg(va, unsigned long long), false, base, precision, width, flags);
#endif
                }
                else if (flags & FLAGS_LONG) {
                    idx = _ntoa_long(out, buffer, idx, maxlen, va_arg(va, unsigned long), false, base, precision, width, flags);
                }
                else {
                    const unsigned int value = (flags & FLAGS_CHAR) ? (unsigned char)va_arg(va, unsigned int) : (flags & FLAGS_SHORT) ? (unsigned short int)va_arg(va, unsigned int) : va_arg(va, unsigned int);
                    idx = _ntoa_long(out, buffer, idx, maxlen, value, false, base, precision, width, flags);
                }
            }
            format++;
            break;
        }
#if defined(PRINTF_SUPPORT_FLOAT)
        case 'f':
        case 'F':
            if (*format == 'F') flags |= FLAGS_UPPERCASE;
            idx = _ftoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
            format++;
            break;
#if defined(PRINTF_SUPPORT_EXPONENTIAL)
        case 'e':
        case 'E':
        case 'g':
        case 'G':
            if ((*format == 'g') || (*format == 'G')) flags |= FLAGS_ADAPT_EXP;
            if ((*format == 'E') || (*format == 'G')) flags |= FLAGS_UPPERCASE;
            idx = _etoa(out, buffer, idx, maxlen, va_arg(va, double), precision, width, flags);
            format++;
            break;
#endif  // PRINTF_SUPPORT_EXPONENTIAL
#endif  // PRINTF_SUPPORT_FLOAT
        case 'c': {
            unsigned int l = 1U;
            // pre padding
            if (!(flags & FLAGS_LEFT)) {
                while (l++ < width) {
                    out(' ', buffer, idx++, maxlen);
                }
            }
            // char output
            out((char)va_arg(va, int), buffer, idx++, maxlen);
            // post padding
            if (flags & FLAGS_LEFT) {
                while (l++ < width) {
                    out(' ', buffer, idx++, maxlen);
                }
            }
            format++;
            break;
        }

        case 's': {
            const char* p = va_arg(va, char*);
            unsigned int l = _strnlen_s(p, precision ? precision : (size_t)-1);
            // pre padding
            if (flags & FLAGS_PRECISION) {
                l = (l < precision ? l : precision);
            }
            if (!(flags & FLAGS_LEFT)) {
                while (l++ < width) {
                    out(' ', buffer, idx++, maxlen);
                }
            }
            // string output
            while ((*p != 0) && (!(flags & FLAGS_PRECISION) || precision--)) {
                out(*(p++), buffer, idx++, maxlen);
            }
            // post padding
            if (flags & FLAGS_LEFT) {
                while (l++ < width) {
                    out(' ', buffer, idx++, maxlen);
                }
            }
            format++;
            break;
        }

        case 'p': {
            width = sizeof(void*) * 2U;
            flags |= FLAGS_ZEROPAD | FLAGS_UPPERCASE;
#if defined(PRINTF_SUPPORT_LONG_LONG)
            const bool is_ll = sizeof(uintptr_t) == sizeof(long long);
            if (is_ll) {
                idx = _ntoa_long_long(out, buffer, idx, maxlen, (uintptr_t)va_arg(va, void*), false, 16U, precision, width, flags);
            }
            else {
#endif
                idx = _ntoa_long(out, buffer, idx, maxlen, (unsigned long)((uintptr_t)va_arg(va, void*)), false, 16U, precision, width, flags);
#if defined(PRINTF_SUPPORT_LONG_LONG)
            }
#endif
            format++;
            break;
        }

        case '%':
            out('%', buffer, idx++, maxlen);
            format++;
            break;

        default:
            out(*format, buffer, idx++, maxlen);
            format++;
            break;
        }
    }

    // termination
    out((char)0, buffer, idx < maxlen ? idx : maxlen - 1U, maxlen);

    // return written chars without terminating \0
    return (int)idx;
}


///////////////////////////////////////////////////////////////////////////////

int printf(const char* format, ...)
{
    va_list va;
    va_start(va, format);
    char buffer[1];
    const int ret = _vsnprintf(_out_char, buffer, (size_t)-1, format, va);
    va_end(va);
    return ret;
}

#define LOG(msg, ...) printf(msg "\n", __VA_ARGS__)

#else
#define LOG(msg,...) 
#endif


// We avoid including malloc.h for portability reasons.
// man mallinfo says the fields are "long", but the implementation uses int.
// It doesn't matter much -- we just need to make sure that the libc's mallinfo
// is not called.
struct fake_mallinfo {
    int x[10];
};

typedef void (*pfn_free_t)(void* ptr);
typedef void (*pfn_cfree_t)(void* ptr);
typedef void* (*pfn_malloc_t)(size_t size);
typedef void* (*pfn_calloc_t)(size_t nmemb, size_t size);
typedef void* (*pfn_realloc_t)(void* ptr, size_t size);
typedef void* (*pfn_memalign_t)(size_t boundary, size_t size);
typedef void* (*pfn_aligned_alloc_t)(size_t boundary, size_t size);
typedef void* (*pfn___libc_memalign_t)(size_t boundary, size_t size);
typedef size_t (*pfn_malloc_usable_size_t)(void* ptr);
typedef struct fake_mallinfo(*pfn_mallinfo_t)(void);
typedef int (*pfn_mallopt_t)(int cmd, int value);
typedef int (*pfn_posix_memalign_t)(void** memptr, size_t alignment, size_t size);
typedef void* (*pfn_valloc_t)(size_t size);
typedef void* (*pfn_pvalloc_t)(size_t size);
typedef void (*pfn_malloc_stats_t)(void);

typedef void* (*pfn_new_t)(size_t size);
typedef void (*pfn_delete_t)(void*);

static int pfn_inited = 0;
static pfn_free_t pfn_free = NULL;
static pfn_cfree_t pfn_cfree = NULL;
static pfn_malloc_t pfn_malloc = NULL;
static pfn_calloc_t pfn_calloc = NULL;
static pfn_realloc_t pfn_realloc = NULL;
static pfn_memalign_t pfn_memalign = NULL;
static pfn_aligned_alloc_t pfn_aligned_alloc = NULL;
static pfn___libc_memalign_t pfn___libc_memalign = NULL;
static pfn_malloc_usable_size_t pfn_malloc_usable_size = NULL;
static pfn_mallinfo_t pfn_mallinfo = NULL;
static pfn_mallopt_t pfn_mallopt = NULL;
static pfn_posix_memalign_t pfn_posix_memalign = NULL;
static pfn_valloc_t pfn_valloc = NULL;
static pfn_pvalloc_t pfn_pvalloc = NULL;
static pfn_malloc_stats_t pfn_malloc_stats = NULL;

// C++ runtime interception
static pfn_new_t pfn_new = NULL;
static pfn_delete_t pfn_delete = NULL;

static void init(void) {
    char* error;
	
    if (pfn_inited)
        return;

    pfn_free = (pfn_free_t) dlsym(RTLD_NEXT, "free");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_cfree = (pfn_cfree_t) dlsym(RTLD_NEXT, "cfree");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_malloc = (pfn_malloc_t) dlsym(RTLD_NEXT, "malloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_calloc = (pfn_calloc_t) dlsym(RTLD_NEXT, "calloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_realloc = (pfn_realloc_t) dlsym(RTLD_NEXT, "realloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_memalign = (pfn_memalign_t) dlsym(RTLD_NEXT, "memalign");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_aligned_alloc = (pfn_aligned_alloc_t) dlsym(RTLD_NEXT, "aligned_alloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn___libc_memalign = (pfn___libc_memalign_t) dlsym(RTLD_NEXT, "__libc_memalign");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_malloc_usable_size = (pfn_malloc_usable_size_t) dlsym(RTLD_NEXT, "malloc_usable_size");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_mallinfo = (pfn_mallinfo_t) dlsym(RTLD_NEXT, "mallinfo");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_mallopt = (pfn_mallopt_t) dlsym(RTLD_NEXT, "mallopt");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_posix_memalign = (pfn_posix_memalign_t) dlsym(RTLD_NEXT, "posix_memalign");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_valloc = (pfn_valloc_t) dlsym(RTLD_NEXT, "valloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_pvalloc = (pfn_pvalloc_t) dlsym(RTLD_NEXT, "pvalloc");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_malloc_stats = (pfn_malloc_stats_t) dlsym(RTLD_NEXT, "malloc_stats");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }

	// C++ runtime interception
    pfn_new = (pfn_new_t) dlsym(RTLD_NEXT, "_Znwm");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
    pfn_delete = (pfn_delete_t) dlsym(RTLD_NEXT, "_ZdlPv");
    if ((error = dlerror()) != NULL) {
        LOG("%s", error);
        exit(1);
    }
		
	pfn_inited = 1;
    LOG("allocation interception in place: %s","OK");
}

static size_t rndsize(size_t s) {
	// Always add the extra size 
	s += EXTRA_SIZE;
	// Round to a multiple of 256
	s = (s + 255) & (~(255));
	// Done
	return s;
}

void free(void *ptr) {
    LOG("free: p:%p", ptr);
	init();
	pfn_free(ptr);
}

void cfree(void *ptr) {
    LOG("cfree: p:%p", ptr);
    init();
    pfn_cfree(ptr);
}

void* malloc(size_t size) {
    LOG("malloc: s:%zu", size);
    init();
	size = rndsize(size);
	void *p = pfn_malloc(size);
	if (p) memset(p, 0, size);
	return p;
}

void* calloc(size_t nmemb, size_t size) {
    LOG("calloc: n:%zu, s:%zu", nmemb, size);
    if (!pfn_inited) {
        // Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
        static char calloc_memory_for_dlsym[4096];
        static size_t allocated = 0;
        void* mem = (void*)&calloc_memory_for_dlsym[allocated];
        size_t sz = ((nmemb * size) + 3) & (~3);
        allocated += sz;
        return mem;
    }
	size = rndsize(size);
    void* p = pfn_calloc(nmemb, size);
	if (p) memset(p, 0, size);
	return p;
}

void* realloc(void *ptr, size_t size) {
    LOG("realloc: p:%p, s:%zu", ptr, size);
    init();
	size = rndsize(size);
	void* p = pfn_realloc(ptr, size);
	return p;
}

void* memalign(size_t boundary, size_t size) {
    LOG("memalign: b:%zu, s:%zu", boundary, size);
    init();
	size = rndsize(size);
	void* p = pfn_memalign(boundary, size);
	if (p) memset(p, 0, size);
	return p;
}

void* aligned_alloc(size_t boundary, size_t size) {
    LOG("aligned_alloc: b:%zu, s:%zu", boundary, size);
    init();
	size = rndsize(size);
	void *p = pfn_aligned_alloc(boundary, size);
	if (p) memset(p, 0, size);
	return p;
}

void* __libc_memalign(size_t boundary, size_t size) {
    LOG("__libc_memalign: b:%zu, s:%zu", boundary, size);
    init();
	size = rndsize(size);
	void *p = pfn_memalign(boundary, size);
	if (p) memset(p, 0, size);
	return p;
}

size_t malloc_usable_size(void *ptr) {
    LOG("malloc_usable_size: p:%p", ptr);
    init();
	return pfn_malloc_usable_size(ptr);
}

struct fake_mallinfo mallinfo(void) {
    LOG("mallinfo: %d",0);
	struct fake_mallinfo res;
    init();
	memset(&res, 0, sizeof(res));
	return res;
}

int mallopt(int cmd, int value) {
    LOG("mallopt c:%d c:%d", cmd, value);
    init();
	return -1;
}

int posix_memalign(void **memptr, size_t alignment, size_t size) {
    LOG("posix_memalign p:%p a:%zu s:%zu", memptr, alignment, size);
    init();
	size = rndsize(size);
	int r = pfn_posix_memalign(memptr, alignment, size);
	if (*memptr) memset(*memptr,0,size);
	return r;
}

void* valloc(size_t size) {
    LOG("valloc: s:%zu", size);
    init();
	size = rndsize(size);
	void* p = pfn_valloc(size);
	if (p) memset(p,0,size);
	return p;
}

void* pvalloc(size_t size) {
    LOG("pvalloc: s:%zu", size);
    init();
	size = rndsize(size);
	void *p = pfn_pvalloc(size);
	if (p) memset(p,0,size);
	return p;
}

void malloc_stats(void) {
}

// C++ interception -- We know 77 bytes blocks cause trouble, so...
typedef struct blk {
	char data[124];
	int used;
} blk_t;
static blk_t blks[8192] = {{{0},0}};

static void* alloc_77_bytes(void) 
{
	int i;
	for (i = 0; i < 8192; ++i) {
		if (__sync_add_and_fetch(&blks[i].used, 1) == 1) {
			// Block was successfully reserved.
			memset(&blks[i].data,0,sizeof(blks[i].data));
			return (void*) &blks[i].data;
		} else {
			__sync_sub_and_fetch(&blks[i].used, 1);
		}
	}
	// At this point, we have no more room on our custom pool. Fallback to the new[] operator
	return pfn_new(77);
}

static int free_77_bytes(void* ptr) {
	ptrdiff_t delta = (char*)ptr - (char*)&blks[0];
	
	if (delta >= 0 && delta < sizeof(blks)) {
		// Dealing with a pointer to our private pool
		if ((delta % sizeof(blk_t)) != 0) {
			LOG("Invalid pointer: %p", ptr);
			return 0;
		}
		// Release the block.
		blk_t* blk = (blk_t*)ptr;
		memset(&blk->data,0,sizeof(blk->data));
		__sync_sub_and_fetch(&blk->used, 1);
		return 1;
	}
	return 0;
}

void* _Znwm(size_t size) {
	// void* operator new(size_t size)
    LOG("operator new: s:%zu", size);
    init();
	
	// Are we dealing with a suspicious request ?
	if (size == 77) {
		// Yes, use our private pool, so accesses after frees are valid
		return alloc_77_bytes();
	}
	
	// Otherwise, default to the normal pool
	return pfn_new(size);
}

void _ZdlPv(void* ptr) {
	// operator delete(void*)
    LOG("operator delete: p:%p", ptr);
    init();
	
	// Try to free it as if it was from our private pool
	if (!free_77_bytes(ptr)) {
		// It was not. Use the default 
		pfn_delete(ptr);
	}
}