Re: [PATCH 1/2] livepatch-build-tools: remove usage of gawk

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Fri, Nov 24, 2023 at 12:10:57PM +0000, Alejandro Vallejo wrote:
> On 24/11/2023 11:43, Ross Lagerwall wrote:
> > On Thu, Nov 23, 2023 at 4:08 PM Roger Pau Monne <roger.pau@xxxxxxxxxx>
> wrote:
> >>
> >> And instead use plain awk.
> >>
> >> There's no need to use the --non-decimal-data option for gawk, since the
> >> numbers that we want to print are already prefixed with '0x', and so
> plain awk
> >> will do the conversion from hexadecimal to decimal just fine.
> >
> > I don't think that's true (at least with gnu awk 5.1.1):
> >
> > $ echo '<e98b7>   DW_AT_byte_size   : 0x14' | awk '{printf("%d\n", $4)}'
> > 0
> >
> 
> I think it's a FreeBSD quirk. From their man page:

Seems like BusyBox inherited that behavior:

BusyBox v1.36.1 (2023-07-27 17:12:24 UTC) multi-call binary.
$ echo '<e98b7>   DW_AT_byte_size   : 0x14' | awk '{printf("%d\n", $4)}'
20

I've assumed that Busybox was the lowest common denominator, but not
in this case.

> >        Historically,  awk did not accept "0x" as a hex string. However,
> since
> >        One True Awk used strtod to convert strings to floats, and since
> "0x12"
> >        is a valid hexadecimal representation of a floating  point number,
> On
> >        FreeBSD, awk has accepted this notation as an extension since One
> True
> >        Awk was imported in FreeBSD 5.0. Upstream One True  Awk has
> restored
> >        the  historical behavior for better compatibility between the
> different
> >        awk implementations.  Both gawk and mawk already  behave similarly.
> >        Starting with FreeBSD 14.0 awk will no longer accept this
> extension.
> 
> I'm guessing the latest FreeBSD doesn't have that behaviour either?

Hm, I guess my FreeBSD world is not new enough, as the awk (version
20210724) I have does parse hex numbers:

# echo '<e98b7>   DW_AT_byte_size   : 0x14' | awk '{printf("%d\n", $4)}'
20

Will see what I can do to address this without requiring gawk if
possible.

I'm not sure if there are other issues that would prevent
livepatch-build-tools from working on FreeBSD however.

Thanks, Roger.