Commit ca28f548 authored by David Hildenbrand's avatar David Hildenbrand Committed by Markus Armbruster
Browse files

cutils: Add qemu_strtod() and qemu_strtod_finite() 



Let's provide a wrapper for strtod().

Reviewed-by: default avatarMarkus Armbruster <armbru@redhat.com>
Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Message-Id: <20181121164421.20780-2-david@redhat.com>
Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
parent c3ec0fa1

include/qemu/cutils.h

+2 −0
Original line number Diff line number Diff line
@@ -146,6 +146,8 @@ int qemu_strtoi64(const char *nptr, const char **endptr, int base, 
                  int64_t *result);

int qemu_strtou64(const char *nptr, const char **endptr, int base,

                  uint64_t *result);

int qemu_strtod(const char *nptr, const char **endptr, double *result);

int qemu_strtod_finite(const char *nptr, const char **endptr, double *result);



int parse_uint(const char *s, unsigned long long *value, char **endptr,

               int base);

util/cutils.c

+65 −0
Original line number Diff line number Diff line
@@ -551,6 +551,71 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, 
    return check_strtox_error(nptr, ep, endptr, 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, 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.