RE: [PATCH] tools/configure: drop BASH configure variable

[Paul Durrant <xadimgnik@xxxxxxxxx>]

> -----Original Message-----
> From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Sent: 29 June 2020 14:51
> To: Ian Jackson <ian.jackson@xxxxxxxxxx>
> Cc: Xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>; Wei Liu <wl@xxxxxxx>; Daniel 
> De Graaf
> <dgdegra@xxxxxxxxxxxxx>; Paul Durrant <paul@xxxxxxx>
> Subject: Re: [PATCH] tools/configure: drop BASH configure variable
> 
> On 29/06/2020 14:34, Ian Jackson wrote:
> > Andrew Cooper writes ("[PATCH] tools/configure: drop BASH configure 
> > variable"):
> >> This is a weird variable to have in the first place.  The only user of it 
> >> is
> >> XSM's CONFIG_SHELL, which opencodes a fallback to sh, and the only two 
> >> scripts
> >> run with this are shebang sh anyway, so don't need bash in the first place.
> > Thanks for this cleanup.  I agree with the basic idea.
> >
> > However, did you run these scripts with dash, or review them, to check
> > for bashisms ?
> 
> Yes, to all of the above.
> 
> They are both very thin wrappers (doing some argument shuffling) around
> large AWK scripts.
> 
> >> Make the mkflask.sh and mkaccess_vector.sh scripts executable, drop the
> >> CONFIG_SHELL, and drop the $BASH variable to prevent further use.
> > Since the build currently uses bash for these, a more neutral change
> > would be to change to #!/bin/bash at the same time.
> 
> That will break FreeBSD, which has no `bash` in sight.
> 
> >> RFC for 4.14.  This is a cleanup to the build system.
> > I see this already has a release-ack.  However, I would not have
> > recommended granting one at least on the basis of the description
> > above.
> >
> > I agree that this is cleanup.  But the current situation is not buggy.
> > I'm not sure exactly what the release criteria are but ISTM that this
> > patch adds risk to the release rather than removing it.
> 
> I agree that the current state of play isn't a major issue, but having
> ./configure check for bash is buggy for both uses.
> 

Even if it is not buggy, it is pointless complexity since FreeBSD would clearly 
have been broken all this time had there been bash-isms in the scripts.

  Paul

> ~Andrew