Re: [PATCH 3/4] perf tools: Fix check-headers.sh output file variables

[Jiri Olsa <jolsa@redhat.com>]

On Fri, Jul 20, 2018 at 06:22:49PM +0300, Alexander Kapshuk wrote:
> On Fri, Jul 20, 2018 at 6:16 PM Jiri Olsa <jolsa@redhat.com> wrote:
> >
> > On Fri, Jul 20, 2018 at 11:57:45AM -0300, Arnaldo Carvalho de Melo wrote:
> > > Em Fri, Jul 20, 2018 at 01:00:35PM +0200, Jiri Olsa escreveu:
> > > > The warning message in check_w function uses wrongly
> > > > the $file variable instead of $file1 and $file2.
> > >
> > > Humm,
> > >
> > > Before:
> > >
> > > Warning: Kernel ABI header at 'tools/arch/powerpc/include/uapi/asm/unistd.h' differs from latest version at 'arch/powerpc/include/uapi/asm/unistd.h'
> > >
> > > After:
> > >
> > > Warning: Kernel ABI header at '../arch/powerpc/include/uapi/asm/unistd.h' differs from latest version at '../../arch/powerpc/include/uapi/asm/unistd.h'
> > >
> > >
> > > The previous version is better, I can then just use:
> > >
> > > diff -u tools/arch/powerpc/include/uapi/asm/unistd.h arch/powerpc/include/uapi/asm/unistd.h
> > >
> > > and get what changed, with your change I have to go to tools/perf before
> > > doing that diff, which is an unnecessary extra step in at least my
> > > workflow.
> >
> > so all paths output based in kernel tree root then, will change
> >
> > jirka
> 
> I was going to ask about this in a separate email initially, but then
> thought I'd use this email exchange instead, as my question is about
> the code in question. Hope you don't mind.
> 
> If I'm reading this right, the intended behavoir of the block of code
> below is to test file2 for existance, and if it exists, to evaluate $cmd.
> If file1 and file2 are found to differ, print the warning.
> 
> test -f $file2 &&
>   eval $cmd || echo "Warning: Kernel ABI header at 'tools/$file'
> differs from latest version at '$file'" >&2
> 
> The '||' path of execution is however also taken if file2 doesn't exist,
> which is probably very unlikely to happen. See below.
> 
> % file1=file1; file2=file2
> % cmd="echo diff $file1 $file2"
> % test -f $file2 &&
> eval $cmd || echo "Warning: Kernel ABI header at 'tools/$file1'
> differs from latest version at '$file2'" >&2
> Warning: Kernel ABI header at 'tools/file1' differs from latest
> version at 'file2'
> 
> Is this something you would rather leave as is, or perhaps use something
> along the lines of the code below instead:
> 
> test -f $file2 && {
> eval $cmd ||
> echo "Warning: Kernel ABI header at 'tools/$file' differs from latest
> version at '$file'" >&2
> }

hi,
yea, probably..  please feel free to post a patch.. just make sure all
the displayed files paths are based on the kernel root

thanks,
jirka