Re: [Qemu-devel] [PATCH] script: git script to compile every commit in a range of commits

[Jeff Cody <jcody@redhat.com>]

On Fri, Jun 07, 2013 at 11:51:36AM -0500, Anthony Liguori wrote:
> Laszlo Ersek <lersek@redhat.com> writes:
> 
> > On 06/07/13 16:44, Jeff Cody wrote:
> >
> >> Thanks.  I can either do the above changes for a v2, or as follow on
> >> patches.
> >
> > Whichever is easier for you, certainly! I'm fine with the script
> > going-in as is.
> 
> A suggestion I'll make is to split the script into two parts.

Hi Anthony,

I'm sorry, but I'm a bit confused by your suggestion.  I think I know
what you are asking (see below), but I'm not positive.

> git-bisect run is a terribly useful command and I use a bisect script
> that looks like this:
> 
>     #!/bin/sh
> 
>     set -e
> 
>     pushd ~/build/qemu
>     make -j1 || exit 1
>     popd
> 
>     # Add right seed here
>     if test "$1"; then
>         "$@"
>     fi
> 
> I'm sure we all have bisect scripts like this.
> 
> What you're proposing is very similar to bisect but instead of doing a
> binary search, it does a linear search starting from the oldest commit.
> Basically:

I agree that git bisect is useful, but solves a slightly different
problem than what I am looking to solve.

For instance, in my working branches I have a whole stack of commits
that I will rebase and squash into a set of sane patches before
submitting.  To make sure I don't do something silly in that process,
and create a patch X that does not build without patch X+1, I want to
explicitly compile each patch, without skipping over any patches.


>     #!/bin/sh
> 
>     refspec="$1"
>     shift
> 
>     git rev-list $refspec | while read commit; do
>         git checkout $commit
>         "$@" || exit $?
>     done
> 
> And indeed, I have a local script called git-foreach to do exactly
> this.  I suspect a nicer version would make a very good addition to the
> git project.
> 
> So to bisect for a make check failure, I do:
> 
>   git bisect run bisect.sh make check
> 
> Or to bisect for a qemu-test failure:
> 
>   git bisect run bisect.sh qemu-test-regress.sh
> 
> With git-foreach, you can do:
> 
>   git-foreach bisect.sh
> 
> To do a simple build test.  Or you can do:
> 
>   git-foreach git show checkpatch-head.sh
>
> etc.

Ah!  So if I understand correctly, what you are asking is to split
the script up into two different scripts:

1.) A 'foreach' framework script to run an arbitrary command over a
range of commits, against each commit  (i.e. in the place where I run
'make clean, git checkout, configure, and make [lines 188-191], simply
do the git checkout and execute a passed script / command).

2.) A second script to perform the complication check, intended to be
called by script 1).  We could then add additional scripts to be
called by the 'foreach' framework patch as desired.

Heck, if we wanted to, we could then even create a menu-drive
meta-script to interactively run any number of tests (checkpatch,
compilation, etc..) using that framework.

> 
> Regards,
> 
> Anthony Liguori
>

Thanks,

Jeff