Re: [PATCH v11 1/4] perf check: introduce check subcommand

[Arnaldo Carvalho de Melo <acme@kernel.org>]

On Fri, Jun 28, 2024 at 11:12:16AM -0300, Arnaldo Carvalho de Melo wrote:
> On Thu, Jun 27, 2024 at 03:36:41PM +0530, Aditya Gupta wrote:
> > Currently the presence of a feature is checked with a combination of
> > perf version --build-options and greps, such as:
> > 
> >     perf version --build-options | grep " on .* HAVE_FEATURE"
> > 
> > Instead of this, introduce a subcommand "perf check feature", with which
> > scripts can test for presence of a feature, such as:
> > 
> >     perf check feature HAVE_FEATURE
> > 
> > 'perf check feature' command is expected to have exit status of 0 if
> > feature is built-in, and 1 if it's not built-in or if feature is not known.
> > 
> > Multiple features can also be passed as a comma-separated list, in which
> > case the exit status will be 1 only if all of the passed features are
> > built-in. For example, with below command, it will have exit status of 0
> > only if both libtraceevent and bpf are enabled, else 1 in all other cases
> > 
> >     perf check feature libtraceevent,bpf
> > 
> > The arguments are case-insensitive.
> > An array 'supported_features' has also been introduced that can be used by
> > other commands like 'perf version --build-options', so that new features
> > can be added in one place, with the array

Now testing it with just this first patch applied:

⬢[acme@toolbox perf-tools-next]$ perf check feature bpf
                   bpf: [ on  ]  # HAVE_LIBBPF_SUPPORT
⬢[acme@toolbox perf-tools-next]$ echo $?
0
⬢[acme@toolbox perf-tools-next]$ perf check bpf,libtrafs

 Usage: perf check [<subcommand>] [<options>]

    -q, --quiet           do not show any warnings or messages

⬢[acme@toolbox perf-tools-next]$


I don't see a way to list what features can be tested against, would be
great to have.

Also it just says that the usage is wrong, no indication as to why, I
think this would be more informative:


⬢[acme@toolbox perf-tools-next]$ perf check bpf,libtrafs
Unkown feature 'libtrafs', please use 'perf check feature --list' to see which ones are available.

⬢[acme@toolbox perf-tools-next]$

- Arnaldo