Date: Tue, 28 Jul 2015 15:44:43 +0200
From: Jiri Olsa <jolsa@redhat.com>
To: Pawel Moll <pawel.moll@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Ingo Molnar <mingo@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tools: perf: Avoid error message when building with no
 python installed
Message-ID: <20150728134443.GB28175@krava.brq.redhat.com>
References: <1438012255-26462-1-git-send-email-pawel.moll@arm.com>
 <20150727183601.GE20509@krava.brq.redhat.com>
 <1438087752.2114.22.camel@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1438087752.2114.22.camel@arm.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 3054
Lines: 68

On Tue, Jul 28, 2015 at 01:49:12PM +0100, Pawel Moll wrote:
> On Mon, 2015-07-27 at 19:36 +0100, Jiri Olsa wrote:
> > > @@ -150,7 +150,7 @@ ifndef NO_LIBPYTHON
> > >    PYTHON2 := $(if $(call get-executable,python2),python2,python)
> > >    override PYTHON := $(call get-executable-or-default,PYTHON,$(PYTHON2))
> > >    PYTHON2_CONFIG := \
> > > -    $(if $(call get-executable,$(PYTHON)-config),$(PYTHON)-config,python-config)
> > > +    $(if $(PYTHON),$(if $(call get-executable,$(PYTHON)-config),$(PYTHON)-config,python-config))
> > >    override PYTHON_CONFIG := \
> > >      $(call get-executable-or-default,PYTHON_CONFIG,$(PYTHON2_CONFIG))
> > 
> > haven't tried, but seems like we want to add also the else part
> > to get default into PYTHON_CONFIG?
> > -    $(if $(PYTHON),$(if $(call get-executable,$(PYTHON)-config),$(PYTHON)-config,python-config))
> > +    $(if $(PYTHON),$(if $(call get-executable,$(PYTHON)-config),$(PYTHON)-config,python-config),python-config)
> 
> It's not strictly necessary, because the issue here is just executing
> "command -v -c" (followed by "onfig" :-), but of course it will still
> work.
> 
> > it fails anyway later either way, but seems like the 'python-config'
> > was the default case that was meant to fail later
> 
> Well, yes, I had the same impression. But at the same time
> get-executable-or-default is constructed in such a way that either of
> the variants must be a real executable:
> 
> --8<-----------
> # get-supplied-or-default-executable
> #
> # Usage: absolute-executable-path-or-empty = $(call get-executable-or-default,variable,default)
> #
> define get-executable-or-default
> $(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2)))
> endef
> _ge_attempt = $(if $(get-executable),$(get-executable),$(call _gea_err,$(2)))
> _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))
> --8<-----------
> 
> See? Both alternatives in the $(if $($(1)) monster do _ge_attempt... So
> one could say that the change may rather look like this (untested):
> 
> --8<-----------
> diff --git a/tools/perf/config/utilities.mak
> b/tools/perf/config/utilities.mak
> index 0ebef09..78135dc 100644
> --- a/tools/perf/config/utilities.mak
> +++ b/tools/perf/config/utilities.mak
> @@ -173,7 +173,7 @@ _ge-abspath = $(if $(is-executable),$(1))
>  # Usage: absolute-executable-path-or-empty = $(call
> get-executable-or-default,variable,default)
>  #
>  define get-executable-or-default
> -$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(call _ge_attempt,$(2)))
> +$(if $($(1)),$(call _ge_attempt,$($(1)),$(1)),$(2))
>  endef
>  _ge_attempt = $(if $(get-executable),$(get-executable),$(call _gea_err,
> $(2)))
>  _gea_err  = $(if $(1),$(error Please set '$(1)' appropriately))

hum right.. looks like pythom is the only caller, nice

jirka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/