On 11/20/18 3:25 AM, David Hildenbrand wrote:
Let's provide a wrapper for strtod().
Reviewed-by: Eric Blake <ebl...@redhat.com>
This changed enough from v1 that I would have dropped R-b to ensure that
reviewers notice the differences.
Signed-off-by: David Hildenbrand <da...@redhat.com>
---
include/qemu/cutils.h | 2 ++
util/cutils.c | 65 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 67 insertions(+)
+ * 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.
The use of UTF-8 ± in one place but not both is odd. I think we're at
the point where UTF-8 comments are acceptable these days, rather than
trying to keep our codebase ASCII-clean, so I don't care which way you
resolve the inconsistency.
+/**
+ * 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) {
+ return ret;
So, if we overflow, we are returning -ERANGE but with nothing stored
into *result. This is different from qemu_strtod(), where a return of
-ERANGE guarantees that *result is one of 4 values (+/- 0.0/inf). That
seems awkward.
+ } else if (!isfinite(tmp)) {
+ if (endptr) {
+ *endptr = nptr;
+ }
+ return -EINVAL;
Rewinding back to the start of "inf" is interesting, but matches your
documentation.
+ }
+
+ *result = tmp;
+ return ret;
+}
+
I think you still need to fix -ERANGE handling before I can give R-b.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
