diff options
| -rw-r--r-- | util/cutils.c | 88 |
1 files changed, 49 insertions, 39 deletions
diff --git a/util/cutils.c b/util/cutils.c index 4fefcf3be3..1ae2a0814b 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -265,9 +265,6 @@ int64_t qemu_strtosz(const char *nptr, char **end) static int check_strtox_error(const char *p, char *endptr, const char **next, int err) { - /* If no conversion was performed, prefer BSD behavior over glibc - * behavior. - */ if (err == 0 && endptr == p) { err = EINVAL; } @@ -281,30 +278,28 @@ static int check_strtox_error(const char *p, char *endptr, const char **next, } /** - * QEMU wrappers for strtol(), strtoll(), strtoul(), strotull() C functions. - * - * Convert ASCII string @nptr to a long integer value - * from the given @base. Parameters @nptr, @endptr, @base - * follows same semantics as strtol() C function. - * - * Unlike from strtol() function, if @endptr is not NULL, this - * function will return -EINVAL whenever it cannot fully convert - * the string in @nptr with given @base to a long. This function returns - * the result of the conversion only through the @result parameter. - * - * If NULL is passed in @endptr, then the whole string in @ntpr - * is a number otherwise it returns -EINVAL. - * - * RETURN VALUE - * Unlike from strtol() function, this wrapper returns either - * -EINVAL or the errno set by strtol() function (e.g -ERANGE). - * If the conversion overflows, -ERANGE is returned, and @result - * is set to the max value of the desired type - * (e.g. LONG_MAX, LLONG_MAX, ULONG_MAX, ULLONG_MAX). If the case - * of underflow, -ERANGE is returned, and @result is set to the min - * value of the desired type. For strtol(), strtoll(), @result is set to - * LONG_MIN, LLONG_MIN, respectively, and for strtoul(), strtoull() it - * is set to 0. + * 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) @@ -325,17 +320,29 @@ int qemu_strtol(const char *nptr, const char **endptr, int base, } /** - * Converts ASCII string to an unsigned long integer. + * 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 string contains a negative number, value will be converted to - * the unsigned representation of the signed value, unless the original - * (nonnegated) value would overflow, in this case, it will set @result - * to ULONG_MAX, and return ERANGE. + * If the conversion overflows @result, store ULONG_MAX in @result, + * and return -ERANGE. * - * The same behavior holds, for qemu_strtoull() but sets @result to - * ULLONG_MAX instead of ULONG_MAX. + * Else store the converted value in @result, and return zero. * - * See qemu_strtol() documentation for more info. + * 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) @@ -360,9 +367,10 @@ int qemu_strtoul(const char *nptr, const char **endptr, int base, } /** - * Converts ASCII string to a long long integer. + * Convert string @nptr to an int64_t. * - * See qemu_strtol() documentation for more info. + * Works like qemu_strtol(), except it stores INT64_MAX on overflow, + * and INT_MIN on underflow. */ int qemu_strtoll(const char *nptr, const char **endptr, int base, int64_t *result) @@ -376,6 +384,7 @@ int qemu_strtoll(const char *nptr, const char **endptr, int base, err = -EINVAL; } else { errno = 0; + /* FIXME This assumes int64_t is long long */ *result = strtoll(nptr, &p, base); err = check_strtox_error(nptr, p, endptr, errno); } @@ -383,9 +392,9 @@ int qemu_strtoll(const char *nptr, const char **endptr, int base, } /** - * Converts ASCII string to an unsigned long long integer. + * Convert string @nptr to an uint64_t. * - * See qemu_strtol() documentation for more info. + * Works like qemu_strtoul(), except it stores UINT64_MAX on overflow. */ int qemu_strtoull(const char *nptr, const char **endptr, int base, uint64_t *result) @@ -399,6 +408,7 @@ int qemu_strtoull(const char *nptr, const char **endptr, int base, err = -EINVAL; } else { errno = 0; + /* FIXME This assumes uint64_t is unsigned long long */ *result = strtoull(nptr, &p, base); /* Windows returns 1 for negative out-of-range values. */ if (errno == ERANGE) { |