Re: [PATCH for-4.15] tools/configure: add bison as mandatory

[Jan Beulich <jbeulich@xxxxxxxx>]

On 05.02.2021 14:50, Andrew Cooper wrote:
> On 05/02/2021 13:39, Roger Pau Monné wrote:
>> On Fri, Feb 05, 2021 at 01:34:20PM +0000, Andrew Cooper wrote:
>>> On 05/02/2021 11:53, Roger Pau Monne wrote:
>>>> Bison is now mandatory when the pvshim build is enabled in order to
>>>> generate the Kconfig.
>>>>
>>>> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
>>>> ---
>>>> Please re-run autogen.sh after applying.
>>>>
>>>> Fallout from this patch can lead to broken configure script being
>>>> generated or bison not detected correctly, but those will be cached
>>>> quite quickly by the automated testing.
>>> I think this can be simpler.  Both flex and bison are mandatory libxlutil.
>> No, we ship the output .c and .h files so that the user only needs to
>> have bison/flex if it wants to modify the .l or .y files AFAICT?
> 
> I know that theory, but it is broken in practice because of `git
> checkout` timestamps.
> 
> Also, the Makefile explicitly enforces the checks, so they are mandatory
> in despite an attempt to ship the preprocessed form.

I don't see the Makefile enforcing anything. Upon seeing "XYZ is
needed to rebuild some libxl parsers and scanners, please install
it and rerun configure" you then have the choice of doing so or,
if you know you didn't fiddle with the sources, playing with the
time stamps.

Jan