snprintf.cpp

UPX 源代码

/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell ([e-mail])
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 */

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 *
 * More Recently:
 *  Brandon Long <[e-mail]> 9/15/96 for mutt 0.43
 *  This was ugly.  It is still ugly.  I opted out of floating point
 *  numbers, but the formatter understands just about everything
 *  from the normal C string format, at least as far as I can tell from
 *  the Solaris 2.5 printf(3S) man page.
 *
 *  Brandon Long <[e-mail]> 10/22/97 for mutt 0.87.1
 *    Ok, added some minimal floating point support, which means this
 *    probably requires libm on most operating systems.  Don't yet
 *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
 *    was pretty badly broken, it just wasn't being exercised in ways
 *    which showed it, so that's been fixed.  Also, formated the code
 *    to mutt conventions, and removed dead code left over from the
 *    original.  Also, there is now a builtin-test, just compile with:
 *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
 *    and run snprintf for results.
 *
 *  Thomas Roessler <[e-mail]> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats.
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <[e-mail]> 03/05/98 for mutt 0.90.8
 *    The original code assumed that both snprintf() and vsnprintf() were
 *    missing.  Some systems only have snprintf() but not vsnprintf(), so
 *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
 *
 *  Andrew Tridgell ([e-mail]) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 * [e-mail], [e-mail], April 2001
 *    got rid of fcvt code (twas buggy and made testing harder)
 *    added C99 semantics
 *
 * [e-mail], August 2002
 *    large modifications for use in UPX
 *
 **************************************************************/


#if 1
#include "conf.h"
#else
#include <ctype.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#undef NDEBUG
#include <assert.h>
#endif

#undef LLONG
#undef ULLONG
#if 1 && defined(acc_int64l_t)
#  define LLONG     acc_int64l_t
#  define ULLONG    acc_uint64l_t
#else
#  define LLONG     long int
#  define ULLONG    unsigned long int
#endif

#undef NO_FLOAT
#undef LDOUBLE
#if 1
#  define NO_FLOAT 1
#  if (ACC_CC_SUNPROC)
#  else
#  define float     error no_float
#  define double    error no_float
#  endif
#elif 0 || defined(HAVE_LONG_DOUBLE)
#  define LDOUBLE   long double
#else
#  define LDOUBLE   double
#endif

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS   1
#define DP_S_MIN     2
#define DP_S_DOT     3
#define DP_S_MAX     4
#define DP_S_MOD     5
#define DP_S_CONV    6
#define DP_S_DONE    7

/* format flags - Bits */
#define DP_F_MINUS  (1 << 0)
#define DP_F_PLUS   (1 << 1)
#define DP_F_SPACE  (1 << 2)
#define DP_F_NUM    (1 << 3)
#define DP_F_ZERO   (1 << 4)
#define DP_F_UP     (1 << 5)
#define DP_F_UNSIGNED   (1 << 6)

/* Conversion Flags */
#define DP_C_SHORT   1
#define DP_C_LONG    2
#define DP_C_LDOUBLE 3
#define DP_C_LLONG   4

#define char_to_int(p) ((p)- '0')
#undef MAX
#define MAX(p,q) (((p) >= (q)) ? (p) : (q))


/*************************************************************************
 //
**************************************************************************/

static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, int c)
{
    if (*currlen < maxlen)
        buffer[*currlen] = (char) c;
    *currlen += 1;
}


static void fmtstr(char *buffer, size_t *currlen, size_t maxlen,
                   const char *value, int flags, int min, int max)
{
    int padlen, strln;     /* amount to pad */
    int cnt = 0;

#ifdef DEBUG_SNPRINTF
    printf("fmtstr min=%d max=%d s=[%s]\n", min, max, value);
#endif
    if (value == NULL)
        value = "<NULL>";

    for (strln = 0; value[strln]; )     /* strlen */
        ++strln;
    padlen = min - strln;
    if (padlen < 0)
        padlen = 0;
    if (flags & DP_F_MINUS)
        padlen = -padlen; /* Left Justify */

    while ((padlen > 0) && (cnt < max)) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        --padlen;
        ++cnt;
    }
    while (*value && (cnt < max)) {
        dopr_outch (buffer, currlen, maxlen, *value++);
        ++cnt;
    }
    while ((padlen < 0) && (cnt < max)) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        ++padlen;
        ++cnt;
    }
}


/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */
static void fmtint(char *buffer, size_t *currlen, size_t maxlen,
                   LLONG value, unsigned base, int min, int max, int flags)
{
    int signvalue = 0;
    ULLONG uvalue;
    char convert[64+1];
    int place = 0;
    int spadlen = 0; /* amount to space pad */
    int zpadlen = 0; /* amount to zero pad */
    const char *digits;

    if (min < 0)
        min = 0;
    if (max < 0)
        max = 0;

    uvalue = value;
    if (!(flags & DP_F_UNSIGNED)) {
        if( value < 0 ) {
            signvalue = '-';
            uvalue = -value;
        } else {
            if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
                signvalue = '+';
            else if (flags & DP_F_SPACE)
                signvalue = ' ';
        }
    }

    digits = (flags & DP_F_UP) ? "0123456789ABCDEF" : "0123456789abcdef";
    do {
        convert[place] = digits[(unsigned) (uvalue % base)];
        uvalue /= base;
    } while (++place < (int)sizeof(convert) - 1 && uvalue);
    convert[place] = 0;

    zpadlen = max - place;
    spadlen = min - MAX (max, place) - (signvalue ? 1 : 0);
    if (zpadlen < 0) zpadlen = 0;
    if (spadlen < 0) spadlen = 0;
    if (flags & DP_F_ZERO) {
        zpadlen = MAX(zpadlen, spadlen);
        spadlen = 0;
    }
    if (flags & DP_F_MINUS)
        spadlen = -spadlen; /* Left Justifty */

#ifdef DEBUG_SNPRINTF
    printf("zpad: %d, spad: %d, min: %d, max: %d, place: %d\n",
           zpadlen, spadlen, min, max, place);
#endif

    /* Spaces */
    while (spadlen > 0) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        --spadlen;
    }

    /* Sign */
    if (signvalue)
        dopr_outch (buffer, currlen, maxlen, signvalue);

    /* Zeros */
    while (zpadlen > 0) {
        dopr_outch (buffer, currlen, maxlen, '0');
        --zpadlen;
    }

    /* Digits */
    while (place > 0)
        dopr_outch (buffer, currlen, maxlen, convert[--place]);

    /* Left Justified spaces */
    while (spadlen < 0) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        ++spadlen;
    }
}


/*************************************************************************
// floating format support
**************************************************************************/

#if !defined(NO_FLOAT)

static LDOUBLE abs_val(LDOUBLE value)
{
    LDOUBLE result = value;

    if (value < 0)
        result = -value;

    return result;
}

static LDOUBLE POW10(int exp)
{
    LDOUBLE result = 1;

    while (exp) {
        result *= 10;
        exp--;
    }

    return result;
}

static LLONG ROUND(LDOUBLE value)
{
    LLONG intpart;

    intpart = (LLONG)value;
    value = value - intpart;
    if (value >= 0.5) intpart++;

    return intpart;
}

/* a replacement for modf that doesn't need the math library. Should
   be portable, but slow */
static double my_modf(double x0, double *iptr)
{
    int i;
    long l;
    double x = x0;
    double f = 1.0;

    for (i = 0; i < 100; i++) {
        l = (long)x;
        if (l <= (x+1) && l >= (x-1)) break;
        x *= 0.1;
        f *= 10.0;
    }

    if (i == 100) {
        /* yikes! the number is beyond what we can handle. What do we do? */
        *iptr = 0.0;
        return 0;
    }

    if (i != 0) {
        double i2, ret;

        ret = my_modf(x0-l*f, &i2);
        *iptr = l*f + i2;
        return ret;
    }

    *iptr = l;
    return x - *iptr;
}


static void fmtfp (char *buffer, size_t *currlen, size_t maxlen,
                   LDOUBLE fvalue, int min, int max, int flags)
{
    /* avoid warnings with 'gcc -Wshadow' */
#undef index
#define index iindex
    int signvalue = 0;
    double ufvalue;
    char iconvert[311+1];
    char fconvert[311+1];
    int iplace = 0;
    int fplace = 0;
    int padlen = 0; /* amount to pad */
    int zpadlen = 0;
    const char *digits;
    int index;
    double intpart;
    double fracpart;
    double temp;

    /*
     * AIX manpage says the default is 0, but Solaris says the default
     * is 6, and sprintf on AIX defaults to 6
     */
    if (min < 0)
        min = 0;
    if (max < 0)
        max = 6;

    ufvalue = abs_val (fvalue);

    if (fvalue < 0) {
        signvalue = '-';
    } else {
        if (flags & DP_F_PLUS) { /* Do a sign (+/i) */
            signvalue = '+';
        } else {
            if (flags & DP_F_SPACE)
                signvalue = ' ';
        }
    }

    digits = "0123456789ABCDEF";
#if 0
    digits = (flags & DP_F_UP) ? "0123456789ABCDEF" : "0123456789abcdef";
#endif

#if 0
     if (max == 0) ufvalue += 0.5; /* if max = 0 we must round */
#endif

    /*
     * Sorry, we only support 16 digits past the decimal because of our
     * conversion method
     */
    if (max > 16)
        max = 16;

    /* We "cheat" by converting the fractional part to integer by
     * multiplying by a factor of 10
     */

    temp = ufvalue;
    my_modf(temp, &intpart);

    fracpart = ROUND((POW10(max)) * (ufvalue - intpart));

    if (fracpart >= POW10(max)) {
        intpart++;
        fracpart -= POW10(max);
    }

    /* Convert integer part */
    do {
        temp = intpart;
        my_modf(intpart*0.1, &intpart);
        temp = temp*0.1;
        index = (int) ((temp - intpart + 0.05) * 10.0);
        /* index = (int) (((double)(temp*0.1) -intpart +0.05) *10.0); */
        /* printf ("%llf, %f, %x\n", temp, intpart, index); */
        iconvert[iplace] = digits[index];
    } while (++iplace < (int)sizeof(iconvert) - 1 && intpart);
    iconvert[iplace] = 0;

    /* Convert fractional part */
    if (fracpart)
    {
        do {
            temp = fracpart;
            my_modf(fracpart*0.1, &fracpart);
            temp = temp*0.1;
            index = (int) ((temp - fracpart + 0.05) * 10.0);
            /* index = (int) ((((temp/10) -fracpart) +0.05) *10); */
            /* printf ("%lf, %lf, %ld\n", temp, fracpart, index); */
            fconvert[fplace] = digits[index];
        } while (++fplace < (int)sizeof(fconvert) - 1 && fracpart);
    }
    fconvert[fplace] = 0;

    /* -1 for decimal point, another -1 if we are printing a sign */
    padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
    zpadlen = max - fplace;
    if (zpadlen < 0) zpadlen = 0;
    if (padlen < 0)
        padlen = 0;
    if (flags & DP_F_MINUS)
        padlen = -padlen; /* Left Justifty */

    if ((flags & DP_F_ZERO) && (padlen > 0)) {
        if (signvalue) {
            dopr_outch (buffer, currlen, maxlen, signvalue);
            --padlen;
            signvalue = 0;
        }
        while (padlen > 0) {
            dopr_outch (buffer, currlen, maxlen, '0');
            --padlen;
        }
    }
    while (padlen > 0) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        --padlen;
    }
    if (signvalue)
        dopr_outch (buffer, currlen, maxlen, signvalue);

    while (iplace > 0)
        dopr_outch (buffer, currlen, maxlen, iconvert[--iplace]);

#ifdef DEBUG_SNPRINTF
    printf("fmtfp: fplace=%d zpadlen=%d\n", fplace, zpadlen);
#endif

    /*
     * Decimal point.  This should probably use locale to find the correct
     * char to print out.
     */
    if (max > 0) {
        dopr_outch (buffer, currlen, maxlen, '.');

        while (fplace > 0)
            dopr_outch (buffer, currlen, maxlen, fconvert[--fplace]);
    }

    while (zpadlen > 0) {
        dopr_outch (buffer, currlen, maxlen, '0');
        --zpadlen;
    }

    while (padlen < 0) {
        dopr_outch (buffer, currlen, maxlen, ' ');
        ++padlen;
    }
#undef index
}


#endif /* !defined(NO_FLOAT) */


/*************************************************************************
// dopr()
**************************************************************************/

static size_t dopr(char *buffer, size_t maxlen, const char *format, va_list args)
{