[libvirt PATCH v4 3/8] virxml: Add virXMLPropInt

[Daniel P. Berrangé]

On Thu, Apr 08, 2021 at 10:57:05AM +0200, Tim Wiederhake wrote:
> Convenience function to return the value of an integer XML attribute.
> 
> Signed-off-by: Tim Wiederhake <twiederh at redhat.com>
> ---
>  src/libvirt_private.syms |  1 +
>  src/util/virxml.c        | 51 ++++++++++++++++++++++++++++++++++++++++
>  src/util/virxml.h        |  6 +++++
>  3 files changed, 58 insertions(+)
> 
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 776387e6b3..bdb63349ee 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -3544,6 +3544,7 @@ virXMLNodeSanitizeNamespaces;
>  virXMLNodeToString;
>  virXMLParseHelper;
>  virXMLPickShellSafeComment;
> +virXMLPropInt;
>  virXMLPropString;
>  virXMLPropStringLimit;
>  virXMLPropTristateBool;
> diff --git a/src/util/virxml.c b/src/util/virxml.c
> index f62c5c39c4..807cb7dae9 100644
> --- a/src/util/virxml.c
> +++ b/src/util/virxml.c
> @@ -656,6 +656,57 @@ virXMLPropTristateSwitch(xmlNodePtr node, const char* name,
>  }
>  
>  
> +/**
> + * virXMLPropInt:
> + * @node: XML dom node pointer
> + * @name: Name of the property (attribute) to get
> + * @base: Number base, see strtol
> + * @flags: Bitwise or of virXMLPropFlags
> + * @result: The returned value
> + *
> + * Convenience function to return value of an integer attribute.
> + *
> + * Returns 1 in case of success in which case @result is set,
> + *         or 0 if the attribute is not present,
> + *         or -1 and reports an error on failure.
> + */
> +int
> +virXMLPropInt(xmlNodePtr node, const char *name, int base,
> +              virXMLPropFlags flags, int *result)
> +{
> +    g_autofree char *tmp = NULL;
> +    int ret;
> +
> +    if (!node || !name || !result) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR,
> +                       _("Invalid argument to %s"),
> +                       __FUNCTION__);
> +        return -1;
> +    }
> +
> +    if (!(tmp = virXMLPropString(node, name))) {
> +        if ((flags & VIR_XML_PROP_REQUIRED) != VIR_XML_PROP_REQUIRED)
> +            return 0;
> +
> +        virReportError(VIR_ERR_XML_ERROR,
> +                       _("Missing required attribute '%s' in element '%s'"),
> +                       name, node->name);
> +        return -1;
> +    }
> +
> +    ret = virStrToLong_i(tmp, NULL, base, result);
> +
> +    if ((ret < 0) || ((flags & VIR_XML_PROP_NONZERO) && (*result == 0))) {
> +        virReportError(VIR_ERR_XML_ERROR,
> +                       _("Invalid value for attribute '%s' in element '%s': '%s'. Expected integer value"),
> +                       name, node->name, tmp);
> +        return -1;
> +    }

0 is an integer value, so this message is not especially helpful in
the case VIR_XML_PROP_NONZERO is set.

Separate the two tests and give them separate error messages which are
more directly relevant.

  "Unable to parse '%s' for property '%s' as an integer value"
  "Zero is not a permitted value for property '%s'"


Regards,
Daniel
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