qemu

cutils.c (29534B)

---

 /*
  * Simple C functions to supplement the C library
  *
  * Copyright (c) 2006 Fabrice Bellard
  *
  * 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.
  */
 
 #include "qemu/osdep.h"
 #include "qemu/host-utils.h"
 #include <math.h>
 
 #ifdef __FreeBSD__
 #include <sys/sysctl.h>
 #include <sys/user.h>
 #endif
 
 #ifdef __NetBSD__
 #include <sys/sysctl.h>
 #endif
 
 #ifdef __HAIKU__
 #include <kernel/image.h>
 #endif
 
 #ifdef __APPLE__
 #include <mach-o/dyld.h>
 #endif
 
 #ifdef G_OS_WIN32
 #include <pathcch.h>
 #include <wchar.h>
 #endif
 
 #include "qemu/ctype.h"
 #include "qemu/cutils.h"
 #include "qemu/error-report.h"
 
 void strpadcpy(char *buf, int buf_size, const char *str, char pad)
 {
     int len = qemu_strnlen(str, buf_size);
     memcpy(buf, str, len);
     memset(buf + len, pad, buf_size - len);
 }
 
 void pstrcpy(char *buf, int buf_size, const char *str)
 {
     int c;
     char *q = buf;
 
     if (buf_size <= 0)
         return;
 
     for(;;) {
         c = *str++;
         if (c == 0 || q >= buf + buf_size - 1)
             break;
         *q++ = c;
     }
     *q = '\0';
 }
 
 /* strcat and truncate. */
 char *pstrcat(char *buf, int buf_size, const char *s)
 {
     int len;
     len = strlen(buf);
     if (len < buf_size)
         pstrcpy(buf + len, buf_size - len, s);
     return buf;
 }
 
 int strstart(const char *str, const char *val, const char **ptr)
 {
     const char *p, *q;
     p = str;
     q = val;
     while (*q != '\0') {
         if (*p != *q)
             return 0;
         p++;
         q++;
     }
     if (ptr)
         *ptr = p;
     return 1;
 }
 
 int stristart(const char *str, const char *val, const char **ptr)
 {
     const char *p, *q;
     p = str;
     q = val;
     while (*q != '\0') {
         if (qemu_toupper(*p) != qemu_toupper(*q))
             return 0;
         p++;
         q++;
     }
     if (ptr)
         *ptr = p;
     return 1;
 }
 
 /* XXX: use host strnlen if available ? */
 int qemu_strnlen(const char *s, int max_len)
 {
     int i;
 
     for(i = 0; i < max_len; i++) {
         if (s[i] == '\0') {
             break;
         }
     }
     return i;
 }
 
 char *qemu_strsep(char **input, const char *delim)
 {
     char *result = *input;
     if (result != NULL) {
         char *p;
 
         for (p = result; *p != '\0'; p++) {
             if (strchr(delim, *p)) {
                 break;
             }
         }
         if (*p == '\0') {
             *input = NULL;
         } else {
             *p = '\0';
             *input = p + 1;
         }
     }
     return result;
 }
 
 time_t mktimegm(struct tm *tm)
 {
     time_t t;
     int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
     if (m < 3) {
         m += 12;
         y--;
     }
     t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + 
                  y / 400 - 719469);
     t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
     return t;
 }
 
 static int64_t suffix_mul(char suffix, int64_t unit)
 {
     switch (qemu_toupper(suffix)) {
     case 'B':
         return 1;
     case 'K':
         return unit;
     case 'M':
         return unit * unit;
     case 'G':
         return unit * unit * unit;
     case 'T':
         return unit * unit * unit * unit;
     case 'P':
         return unit * unit * unit * unit * unit;
     case 'E':
         return unit * unit * unit * unit * unit * unit;
     }
     return -1;
 }
 
 /*
  * Convert size string to bytes.
  *
  * The size parsing supports the following syntaxes
  * - 12345 - decimal, scale determined by @default_suffix and @unit
  * - 12345{bBkKmMgGtTpPeE} - decimal, scale determined by suffix and @unit
  * - 12345.678{kKmMgGtTpPeE} - decimal, scale determined by suffix, and
  *   fractional portion is truncated to byte
  * - 0x7fEE - hexadecimal, unit determined by @default_suffix
  *
  * The following cause a deprecation warning, and may be removed in the future
  * - 0xabc{kKmMgGtTpP} - hex with scaling suffix
  *
  * The following are intentionally not supported
  * - octal, such as 08
  * - fractional hex, such as 0x1.8
  * - floating point exponents, such as 1e3
  *
  * The end pointer will be returned in *end, if not NULL.  If there is
  * no fraction, the input can be decimal or hexadecimal; if there is a
  * fraction, then the input must be decimal and there must be a suffix
  * (possibly by @default_suffix) larger than Byte, and the fractional
  * portion may suffer from precision loss or rounding.  The input must
  * be positive.
  *
  * Return -ERANGE on overflow (with *@end advanced), and -EINVAL on
  * other error (with *@end left unchanged).
  */
 static int do_strtosz(const char *nptr, const char **end,
                       const char default_suffix, int64_t unit,
                       uint64_t *result)
 {
     int retval;
     const char *endptr, *f;
     unsigned char c;
     bool hex = false;
     uint64_t val, valf = 0;
     int64_t mul;
 
     /* Parse integral portion as decimal. */
     retval = qemu_strtou64(nptr, &endptr, 10, &val);
     if (retval) {
         goto out;
     }
     if (memchr(nptr, '-', endptr - nptr) != NULL) {
         endptr = nptr;
         retval = -EINVAL;
         goto out;
     }
     if (val == 0 && (*endptr == 'x' || *endptr == 'X')) {
         /* Input looks like hex, reparse, and insist on no fraction. */
         retval = qemu_strtou64(nptr, &endptr, 16, &val);
         if (retval) {
             goto out;
         }
         if (*endptr == '.') {
             endptr = nptr;
             retval = -EINVAL;
             goto out;
         }
         hex = true;
     } else if (*endptr == '.') {
         /*
          * Input looks like a fraction.  Make sure even 1.k works
          * without fractional digits.  If we see an exponent, treat
          * the entire input as invalid instead.
          */
         double fraction;
 
         f = endptr;
         retval = qemu_strtod_finite(f, &endptr, &fraction);
         if (retval) {
             endptr++;
         } else if (memchr(f, 'e', endptr - f) || memchr(f, 'E', endptr - f)) {
             endptr = nptr;
             retval = -EINVAL;
             goto out;
         } else {
             /* Extract into a 64-bit fixed-point fraction. */
             valf = (uint64_t)(fraction * 0x1p64);
         }
     }
     c = *endptr;
     mul = suffix_mul(c, unit);
     if (mul > 0) {
         if (hex) {
             warn_report("Using a multiplier suffix on hex numbers "
                         "is deprecated: %s", nptr);
         }
         endptr++;
     } else {
         mul = suffix_mul(default_suffix, unit);
         assert(mul > 0);
     }
     if (mul == 1) {
         /* When a fraction is present, a scale is required. */
         if (valf != 0) {
             endptr = nptr;
             retval = -EINVAL;
             goto out;
         }
     } else {
         uint64_t valh, tmp;
 
         /* Compute exact result: 64.64 x 64.0 -> 128.64 fixed point */
         mulu64(&val, &valh, val, mul);
         mulu64(&valf, &tmp, valf, mul);
         val += tmp;
         valh += val < tmp;
 
         /* Round 0.5 upward. */
         tmp = valf >> 63;
         val += tmp;
         valh += val < tmp;
 
         /* Report overflow. */
         if (valh != 0) {
             retval = -ERANGE;
             goto out;
         }
     }
 
     retval = 0;
 
 out:
     if (end) {
         *end = endptr;
     } else if (*endptr) {
         retval = -EINVAL;
     }
     if (retval == 0) {
         *result = val;
     }
 
     return retval;
 }
 
 int qemu_strtosz(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'B', 1024, result);
 }
 
 int qemu_strtosz_MiB(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'M', 1024, result);
 }
 
 int qemu_strtosz_metric(const char *nptr, const char **end, uint64_t *result)
 {
     return do_strtosz(nptr, end, 'B', 1000, result);
 }
 
 /**
  * Helper function for error checking after strtol() and the like
  */
 static int check_strtox_error(const char *nptr, char *ep,
                               const char **endptr, bool check_zero,
                               int libc_errno)
 {
     assert(ep >= nptr);
 
     /* Windows has a bug in that it fails to parse 0 from "0x" in base 16 */
     if (check_zero && ep == nptr && libc_errno == 0) {
         char *tmp;
 
         errno = 0;
         if (strtol(nptr, &tmp, 10) == 0 && errno == 0 &&
             (*tmp == 'x' || *tmp == 'X')) {
             ep = tmp;
         }
     }
 
     if (endptr) {
         *endptr = ep;
     }
 
     /* Turn "no conversion" into an error */
     if (libc_errno == 0 && ep == nptr) {
         return -EINVAL;
     }
 
     /* Fail when we're expected to consume the string, but didn't */
     if (!endptr && *ep) {
         return -EINVAL;
     }
 
     return -libc_errno;
 }
 
 /**
  * Convert string @nptr to an integer, and store it in @result.
  *
  * This is a wrapper around strtol() that is harder to misuse.
  * Semantics of @nptr, @endptr, @base match strtol() with differences
  * noted below.
  *
  * @nptr may be null, and no conversion is performed then.
  *
  * If no conversion is performed, store @nptr in *@endptr and return
  * -EINVAL.
  *
  * If @endptr is null, and the string isn't fully converted, return
  * -EINVAL.  This is the case when the pointer that would be stored in
  * a non-null @endptr points to a character other than '\0'.
  *
  * If the conversion overflows @result, store INT_MAX in @result,
  * and return -ERANGE.
  *
  * If the conversion underflows @result, store INT_MIN in @result,
  * and return -ERANGE.
  *
  * Else store the converted value in @result, and return zero.
  */
 int qemu_strtoi(const char *nptr, const char **endptr, int base,
                 int *result)
 {
     char *ep;
     long long lresult;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     errno = 0;
     lresult = strtoll(nptr, &ep, base);
     if (lresult < INT_MIN) {
         *result = INT_MIN;
         errno = ERANGE;
     } else if (lresult > INT_MAX) {
         *result = INT_MAX;
         errno = ERANGE;
     } else {
         *result = lresult;
     }
     return check_strtox_error(nptr, ep, endptr, lresult == 0, errno);
 }
 
 /**
  * Convert string @nptr to an unsigned integer, and store it in @result.
  *
  * This is a wrapper around strtoul() that is harder to misuse.
  * Semantics of @nptr, @endptr, @base match strtoul() with differences
  * noted below.
  *
  * @nptr may be null, and no conversion is performed then.
  *
  * If no conversion is performed, store @nptr in *@endptr and return
  * -EINVAL.
  *
  * If @endptr is null, and the string isn't fully converted, return
  * -EINVAL.  This is the case when the pointer that would be stored in
  * a non-null @endptr points to a character other than '\0'.
  *
  * If the conversion overflows @result, store UINT_MAX in @result,
  * and return -ERANGE.
  *
  * Else store the converted value in @result, and return zero.
  *
  * Note that a number with a leading minus sign gets converted without
  * the minus sign, checked for overflow (see above), then negated (in
  * @result's type).  This is exactly how strtoul() works.
  */
 int qemu_strtoui(const char *nptr, const char **endptr, int base,
                  unsigned int *result)
 {
     char *ep;
     long long lresult;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     errno = 0;
     lresult = strtoull(nptr, &ep, base);
 
     /* Windows returns 1 for negative out-of-range values.  */
     if (errno == ERANGE) {
         *result = -1;
     } else {
         if (lresult > UINT_MAX) {
             *result = UINT_MAX;
             errno = ERANGE;
         } else if (lresult < INT_MIN) {
             *result = UINT_MAX;
             errno = ERANGE;
         } else {
             *result = lresult;
         }
     }
     return check_strtox_error(nptr, ep, endptr, lresult == 0, errno);
 }
 
 /**
  * Convert string @nptr to a long integer, and store it in @result.
  *
  * This is a wrapper around strtol() that is harder to misuse.
  * Semantics of @nptr, @endptr, @base match strtol() with differences
  * noted below.
  *
  * @nptr may be null, and no conversion is performed then.
  *
  * If no conversion is performed, store @nptr in *@endptr and return
  * -EINVAL.
  *
  * If @endptr is null, and the string isn't fully converted, return
  * -EINVAL.  This is the case when the pointer that would be stored in
  * a non-null @endptr points to a character other than '\0'.
  *
  * If the conversion overflows @result, store LONG_MAX in @result,
  * and return -ERANGE.
  *
  * If the conversion underflows @result, store LONG_MIN in @result,
  * and return -ERANGE.
  *
  * Else store the converted value in @result, and return zero.
  */
 int qemu_strtol(const char *nptr, const char **endptr, int base,
                 long *result)
 {
     char *ep;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     errno = 0;
     *result = strtol(nptr, &ep, base);
     return check_strtox_error(nptr, ep, endptr, *result == 0, errno);
 }
 
 /**
  * Convert string @nptr to an unsigned long, and store it in @result.
  *
  * This is a wrapper around strtoul() that is harder to misuse.
  * Semantics of @nptr, @endptr, @base match strtoul() with differences
  * noted below.
  *
  * @nptr may be null, and no conversion is performed then.
  *
  * If no conversion is performed, store @nptr in *@endptr and return
  * -EINVAL.
  *
  * If @endptr is null, and the string isn't fully converted, return
  * -EINVAL.  This is the case when the pointer that would be stored in
  * a non-null @endptr points to a character other than '\0'.
  *
  * If the conversion overflows @result, store ULONG_MAX in @result,
  * and return -ERANGE.
  *
  * Else store the converted value in @result, and return zero.
  *
  * Note that a number with a leading minus sign gets converted without
  * the minus sign, checked for overflow (see above), then negated (in
  * @result's type).  This is exactly how strtoul() works.
  */
 int qemu_strtoul(const char *nptr, const char **endptr, int base,
                  unsigned long *result)
 {
     char *ep;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     errno = 0;
     *result = strtoul(nptr, &ep, base);
     /* Windows returns 1 for negative out-of-range values.  */
     if (errno == ERANGE) {
         *result = -1;
     }
     return check_strtox_error(nptr, ep, endptr, *result == 0, errno);
 }
 
 /**
  * Convert string @nptr to an int64_t.
  *
  * Works like qemu_strtol(), except it stores INT64_MAX on overflow,
  * and INT64_MIN on underflow.
  */
 int qemu_strtoi64(const char *nptr, const char **endptr, int base,
                  int64_t *result)
 {
     char *ep;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     /* This assumes int64_t is long long TODO relax */
     QEMU_BUILD_BUG_ON(sizeof(int64_t) != sizeof(long long));
     errno = 0;
     *result = strtoll(nptr, &ep, base);
     return check_strtox_error(nptr, ep, endptr, *result == 0, errno);
 }
 
 /**
  * Convert string @nptr to an uint64_t.
  *
  * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow.
  */
 int qemu_strtou64(const char *nptr, const char **endptr, int base,
                   uint64_t *result)
 {
     char *ep;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     /* This assumes uint64_t is unsigned long long TODO relax */
     QEMU_BUILD_BUG_ON(sizeof(uint64_t) != sizeof(unsigned long long));
     errno = 0;
     *result = strtoull(nptr, &ep, base);
     /* Windows returns 1 for negative out-of-range values.  */
     if (errno == ERANGE) {
         *result = -1;
     }
     return check_strtox_error(nptr, ep, endptr, *result == 0, errno);
 }
 
 /**
  * Convert string @nptr to a double.
   *
  * This is a wrapper around strtod() that is harder to misuse.
  * Semantics of @nptr and @endptr match strtod() with differences
  * noted below.
  *
  * @nptr may be null, and no conversion is performed then.
  *
  * If no conversion is performed, store @nptr in *@endptr and return
  * -EINVAL.
  *
  * If @endptr is null, and the string isn't fully converted, return
  * -EINVAL. This is the case when the pointer that would be stored in
  * a non-null @endptr points to a character other than '\0'.
  *
  * If the conversion overflows, store +/-HUGE_VAL in @result, depending
  * on the sign, and return -ERANGE.
  *
  * If the conversion underflows, store +/-0.0 in @result, depending on the
  * sign, and return -ERANGE.
  *
  * Else store the converted value in @result, and return zero.
  */
 int qemu_strtod(const char *nptr, const char **endptr, double *result)
 {
     char *ep;
 
     if (!nptr) {
         if (endptr) {
             *endptr = nptr;
         }
         return -EINVAL;
     }
 
     errno = 0;
     *result = strtod(nptr, &ep);
     return check_strtox_error(nptr, ep, endptr, false, errno);
 }
 
 /**
  * Convert string @nptr to a finite double.
  *
  * Works like qemu_strtod(), except that "NaN" and "inf" are rejected
  * with -EINVAL and no conversion is performed.
  */
 int qemu_strtod_finite(const char *nptr, const char **endptr, double *result)
 {
     double tmp;
     int ret;
 
     ret = qemu_strtod(nptr, endptr, &tmp);
     if (!ret && !isfinite(tmp)) {
         if (endptr) {
             *endptr = nptr;
         }
         ret = -EINVAL;
     }
 
     if (ret != -EINVAL) {
         *result = tmp;
     }
     return ret;
 }
 
 /**
  * Searches for the first occurrence of 'c' in 's', and returns a pointer
  * to the trailing null byte if none was found.
  */
 #ifndef HAVE_STRCHRNUL
 const char *qemu_strchrnul(const char *s, int c)
 {
     const char *e = strchr(s, c);
     if (!e) {
         e = s + strlen(s);
     }
     return e;
 }
 #endif
 
 /**
  * parse_uint:
  *
  * @s: String to parse
  * @value: Destination for parsed integer value
  * @endptr: Destination for pointer to first character not consumed
  * @base: integer base, between 2 and 36 inclusive, or 0
  *
  * Parse unsigned integer
  *
  * Parsed syntax is like strtoull()'s: arbitrary whitespace, a single optional
  * '+' or '-', an optional "0x" if @base is 0 or 16, one or more digits.
  *
  * If @s is null, or @base is invalid, or @s doesn't start with an
  * integer in the syntax above, set *@value to 0, *@endptr to @s, and
  * return -EINVAL.
  *
  * Set *@endptr to point right beyond the parsed integer (even if the integer
  * overflows or is negative, all digits will be parsed and *@endptr will
  * point right beyond them).
  *
  * If the integer is negative, set *@value to 0, and return -ERANGE.
  *
  * If the integer overflows unsigned long long, set *@value to
  * ULLONG_MAX, and return -ERANGE.
  *
  * Else, set *@value to the parsed integer, and return 0.
  */
 int parse_uint(const char *s, unsigned long long *value, char **endptr,
                int base)
 {
     int r = 0;
     char *endp = (char *)s;
     unsigned long long val = 0;
 
     assert((unsigned) base <= 36 && base != 1);
     if (!s) {
         r = -EINVAL;
         goto out;
     }
 
     errno = 0;
     val = strtoull(s, &endp, base);
     if (errno) {
         r = -errno;
         goto out;
     }
 
     if (endp == s) {
         r = -EINVAL;
         goto out;
     }
 
     /* make sure we reject negative numbers: */
     while (qemu_isspace(*s)) {
         s++;
     }
     if (*s == '-') {
         val = 0;
         r = -ERANGE;
         goto out;
     }
 
 out:
     *value = val;
     *endptr = endp;
     return r;
 }
 
 /**
  * parse_uint_full:
  *
  * @s: String to parse
  * @value: Destination for parsed integer value
  * @base: integer base, between 2 and 36 inclusive, or 0
  *
  * Parse unsigned integer from entire string
  *
  * Have the same behavior of parse_uint(), but with an additional check
  * for additional data after the parsed number. If extra characters are present
  * after the parsed number, the function will return -EINVAL, and *@v will
  * be set to 0.
  */
 int parse_uint_full(const char *s, unsigned long long *value, int base)
 {
     char *endp;
     int r;
 
     r = parse_uint(s, value, &endp, base);
     if (r < 0) {
         return r;
     }
     if (*endp) {
         *value = 0;
         return -EINVAL;
     }
 
     return 0;
 }
 
 int qemu_parse_fd(const char *param)
 {
     long fd;
     char *endptr;
 
     errno = 0;
     fd = strtol(param, &endptr, 10);
     if (param == endptr /* no conversion performed */                    ||
         errno != 0      /* not representable as long; possibly others */ ||
         *endptr != '\0' /* final string not empty */                     ||
         fd < 0          /* invalid as file descriptor */                 ||
         fd > INT_MAX    /* not representable as int */) {
         return -1;
     }
     return fd;
 }
 
 /*
  * Implementation of  ULEB128 (http://en.wikipedia.org/wiki/LEB128)
  * Input is limited to 14-bit numbers
  */
 int uleb128_encode_small(uint8_t *out, uint32_t n)
 {
     g_assert(n <= 0x3fff);
     if (n < 0x80) {
         *out = n;
         return 1;
     } else {
         *out++ = (n & 0x7f) | 0x80;
         *out = n >> 7;
         return 2;
     }
 }
 
 int uleb128_decode_small(const uint8_t *in, uint32_t *n)
 {
     if (!(*in & 0x80)) {
         *n = *in;
         return 1;
     } else {
         *n = *in++ & 0x7f;
         /* we exceed 14 bit number */
         if (*in & 0x80) {
             return -1;
         }
         *n |= *in << 7;
         return 2;
     }
 }
 
 /*
  * helper to parse debug environment variables
  */
 int parse_debug_env(const char *name, int max, int initial)
 {
     char *debug_env = getenv(name);
     char *inv = NULL;
     long debug;
 
     if (!debug_env) {
         return initial;
     }
     errno = 0;
     debug = strtol(debug_env, &inv, 10);
     if (inv == debug_env) {
         return initial;
     }
     if (debug < 0 || debug > max || errno != 0) {
         warn_report("%s not in [0, %d]", name, max);
         return initial;
     }
     return debug;
 }
 
 const char *si_prefix(unsigned int exp10)
 {
     static const char *prefixes[] = {
         "a", "f", "p", "n", "u", "m", "", "K", "M", "G", "T", "P", "E"
     };
 
     exp10 += 18;
     assert(exp10 % 3 == 0 && exp10 / 3 < ARRAY_SIZE(prefixes));
     return prefixes[exp10 / 3];
 }
 
 const char *iec_binary_prefix(unsigned int exp2)
 {
     static const char *prefixes[] = { "", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei" };
 
     assert(exp2 % 10 == 0 && exp2 / 10 < ARRAY_SIZE(prefixes));
     return prefixes[exp2 / 10];
 }
 
 /*
  * Return human readable string for size @val.
  * @val can be anything that uint64_t allows (no more than "16 EiB").
  * Use IEC binary units like KiB, MiB, and so forth.
  * Caller is responsible for passing it to g_free().
  */
 char *size_to_str(uint64_t val)
 {
     uint64_t div;
     int i;
 
     /*
      * The exponent (returned in i) minus one gives us
      * floor(log2(val * 1024 / 1000).  The correction makes us
      * switch to the higher power when the integer part is >= 1000.
      * (see e41b509d68afb1f for more info)
      */
     frexp(val / (1000.0 / 1024.0), &i);
     i = (i - 1) / 10 * 10;
     div = 1ULL << i;
 
     return g_strdup_printf("%0.3g %sB", (double)val / div, iec_binary_prefix(i));
 }
 
 char *freq_to_str(uint64_t freq_hz)
 {
     double freq = freq_hz;
     size_t exp10 = 0;
 
     while (freq >= 1000.0) {
         freq /= 1000.0;
         exp10 += 3;
     }
 
     return g_strdup_printf("%0.3g %sHz", freq, si_prefix(exp10));
 }
 
 int qemu_pstrcmp0(const char **str1, const char **str2)
 {
     return g_strcmp0(*str1, *str2);
 }
 
 static inline bool starts_with_prefix(const char *dir)
 {
     size_t prefix_len = strlen(CONFIG_PREFIX);
     return !memcmp(dir, CONFIG_PREFIX, prefix_len) &&
         (!dir[prefix_len] || G_IS_DIR_SEPARATOR(dir[prefix_len]));
 }
 
 /* Return the next path component in dir, and store its length in *p_len.  */
 static inline const char *next_component(const char *dir, int *p_len)
 {
     int len;
     while ((*dir && G_IS_DIR_SEPARATOR(*dir)) ||
            (*dir == '.' && (G_IS_DIR_SEPARATOR(dir[1]) || dir[1] == '\0'))) {
         dir++;
     }
     len = 0;
     while (dir[len] && !G_IS_DIR_SEPARATOR(dir[len])) {
         len++;
     }
     *p_len = len;
     return dir;
 }
 
 static const char *exec_dir;
 
 void qemu_init_exec_dir(const char *argv0)
 {
 #ifdef G_OS_WIN32
     char *p;
     char buf[MAX_PATH];
     DWORD len;
 
     if (exec_dir) {
         return;
     }
 
     len = GetModuleFileName(NULL, buf, sizeof(buf) - 1);
     if (len == 0) {
         return;
     }
 
     buf[len] = 0;
     p = buf + len - 1;
     while (p != buf && *p != '\\') {
         p--;
     }
     *p = 0;
     if (access(buf, R_OK) == 0) {
         exec_dir = g_strdup(buf);
     } else {
         exec_dir = CONFIG_BINDIR;
     }
 #else
     char *p = NULL;
     char buf[PATH_MAX];
 
     if (exec_dir) {
         return;
     }
 
 #if defined(__linux__)
     {
         int len;
         len = readlink("/proc/self/exe", buf, sizeof(buf) - 1);
         if (len > 0) {
             buf[len] = 0;
             p = buf;
         }
     }
 #elif defined(__FreeBSD__) \
       || (defined(__NetBSD__) && defined(KERN_PROC_PATHNAME))
     {
 #if defined(__FreeBSD__)
         static int mib[4] = {CTL_KERN, KERN_PROC, KERN_PROC_PATHNAME, -1};
 #else
         static int mib[4] = {CTL_KERN, KERN_PROC_ARGS, -1, KERN_PROC_PATHNAME};
 #endif
         size_t len = sizeof(buf) - 1;
 
         *buf = '\0';
         if (!sysctl(mib, ARRAY_SIZE(mib), buf, &len, NULL, 0) &&
             *buf) {
             buf[sizeof(buf) - 1] = '\0';
             p = buf;
         }
     }
 #elif defined(__APPLE__)
     {
         char fpath[PATH_MAX];
         uint32_t len = sizeof(fpath);
         if (_NSGetExecutablePath(fpath, &len) == 0) {
             p = realpath(fpath, buf);
             if (!p) {
                 return;
             }
         }
     }
 #elif defined(__HAIKU__)
     {
         image_info ii;
         int32_t c = 0;
 
         *buf = '\0';
         while (get_next_image_info(0, &c, &ii) == B_OK) {
             if (ii.type == B_APP_IMAGE) {
                 strncpy(buf, ii.name, sizeof(buf));
                 buf[sizeof(buf) - 1] = 0;
                 p = buf;
                 break;
             }
         }
     }
 #endif
     /* If we don't have any way of figuring out the actual executable
        location then try argv[0].  */
     if (!p && argv0) {
         p = realpath(argv0, buf);
     }
     if (p) {
         exec_dir = g_path_get_dirname(p);
     } else {
         exec_dir = CONFIG_BINDIR;
     }
 #endif
 }
 
 const char *qemu_get_exec_dir(void)
 {
     return exec_dir;
 }
 
 char *get_relocated_path(const char *dir)
 {
     size_t prefix_len = strlen(CONFIG_PREFIX);
     const char *bindir = CONFIG_BINDIR;
     const char *exec_dir = qemu_get_exec_dir();
     GString *result;
     int len_dir, len_bindir;
 
     /* Fail if qemu_init_exec_dir was not called.  */
     assert(exec_dir[0]);
 
     result = g_string_new(exec_dir);
     g_string_append(result, "/qemu-bundle");
     if (access(result->str, R_OK) == 0) {
 #ifdef G_OS_WIN32
         size_t size = mbsrtowcs(NULL, &dir, 0, &(mbstate_t){0}) + 1;
         PWSTR wdir = g_new(WCHAR, size);
         mbsrtowcs(wdir, &dir, size, &(mbstate_t){0});
 
         PCWSTR wdir_skipped_root;
         PathCchSkipRoot(wdir, &wdir_skipped_root);
 
         size = wcsrtombs(NULL, &wdir_skipped_root, 0, &(mbstate_t){0});
         char *cursor = result->str + result->len;
         g_string_set_size(result, result->len + size);
         wcsrtombs(cursor, &wdir_skipped_root, size + 1, &(mbstate_t){0});
         g_free(wdir);
 #else
         g_string_append(result, dir);
 #endif
     } else if (!starts_with_prefix(dir) || !starts_with_prefix(bindir)) {
         g_string_assign(result, dir);
     } else {
         g_string_assign(result, exec_dir);
 
         /* Advance over common components.  */
         len_dir = len_bindir = prefix_len;
         do {
             dir += len_dir;
             bindir += len_bindir;
             dir = next_component(dir, &len_dir);
             bindir = next_component(bindir, &len_bindir);
         } while (len_dir && len_dir == len_bindir && !memcmp(dir, bindir, len_dir));
 
         /* Ascend from bindir to the common prefix with dir.  */
         while (len_bindir) {
             bindir += len_bindir;
             g_string_append(result, "/..");
             bindir = next_component(bindir, &len_bindir);
         }
 
         if (*dir) {
             assert(G_IS_DIR_SEPARATOR(dir[-1]));
             g_string_append(result, dir - 1);
         }
     }
 
     return g_string_free(result, false);
 }