[Buildroot] [PATCH] core: enhance printvars

[Buildroot] [PATCH] core: enhance printvars

[Yann E. MORIN]

Currently, the output of printvars copntains the name of the variable,
its expanded value and its un-expanded value.

However, most of the time, we need the actual, expanded value, so it can
be re-used from a (non-Buildroot) infrastructure script, like a
post-build script, or a build-farm driver (e.g. a Jenkins job...)

Add two options that a user may set to change the output of printvars:
  - RAW_VARS, if set, will drop the unexpanded value
  - QUOTED_VARS, if set, will quote the expanded value

So that it can be used as such:

    $ make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1
    BUSYBOX_VERSION='1.26.2'

And it is even possible to directly evaluate it in a shell script:

    eval $(make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1)

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 5e4bc92..67a9b5d 100644
--- a/Makefile
+++ b/Makefile
@@ -934,7 +934,7 @@ printvars:
 		$(sort $(if $(VARS),$(filter $(VARS),$(.VARIABLES)),$(.VARIABLES))), \
 		$(if $(filter-out environment% default automatic, \
 				$(origin $V)), \
-		$(info $V=$($V) ($(value $V)))))
+		$(info $V=$(if $(QUOTED_VARS),')$($V)$(if $(QUOTED_VARS),')$(if $(RAW_VARS),, ($(value $V))))))
 
 clean:
 	rm -rf $(TARGET_DIR) $(BINARIES_DIR) $(HOST_DIR) \
-- 
2.7.4

[Buildroot] [PATCH] core: enhance printvars

[Thomas De Schampheleire]

On Sat, Jan 28, 2017 at 11:19 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> Currently, the output of printvars copntains the name of the variable,
> its expanded value and its un-expanded value.
>
> However, most of the time, we need the actual, expanded value, so it can
> be re-used from a (non-Buildroot) infrastructure script, like a
> post-build script, or a build-farm driver (e.g. a Jenkins job...)
>
> Add two options that a user may set to change the output of printvars:
>   - RAW_VARS, if set, will drop the unexpanded value
>   - QUOTED_VARS, if set, will quote the expanded value
>
> So that it can be used as such:
>
>     $ make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1
>     BUSYBOX_VERSION='1.26.2'
>
> And it is even possible to directly evaluate it in a shell script:
>
>     eval $(make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1)
>
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> ---
>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index 5e4bc92..67a9b5d 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -934,7 +934,7 @@ printvars:
>                 $(sort $(if $(VARS),$(filter $(VARS),$(.VARIABLES)),$(.VARIABLES))), \
>                 $(if $(filter-out environment% default automatic, \
>                                 $(origin $V)), \
> -               $(info $V=$($V) ($(value $V)))))
> +               $(info $V=$(if $(QUOTED_VARS),')$($V)$(if $(QUOTED_VARS),')$(if $(RAW_VARS),, ($(value $V))))))
>
>  clean:
>         rm -rf $(TARGET_DIR) $(BINARIES_DIR) $(HOST_DIR) \
> --
> 2.7.4


Very nice, I've been needing this a few times before too.

I do think we should document the new flags QUOTED_VARS and RAW_VARS
somewhere (and in general 'printvars' itself). Perhaps here:
http://buildroot.uclibc.org/downloads/manual/manual.html#make-tips ?

Regarding naming (I realize, these are nits): RAW sounds like somehow
opposite of QUOTED. What about using PLAIN rather than RAW ?
An alternative is to change the default behavior to be raw/plain, and
add a VERBOSE option to display also the unexpanded value.

/Thomas

[Buildroot] [PATCH] core: enhance printvars

[Yann E. MORIN]

Thomas, All,

On 2017-01-31 11:12 +0100, Thomas De Schampheleire spake thusly:
> On Sat, Jan 28, 2017 at 11:19 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
> > Currently, the output of printvars copntains the name of the variable,
> > its expanded value and its un-expanded value.
> >
> > However, most of the time, we need the actual, expanded value, so it can
> > be re-used from a (non-Buildroot) infrastructure script, like a
> > post-build script, or a build-farm driver (e.g. a Jenkins job...)
> >
> > Add two options that a user may set to change the output of printvars:
> >   - RAW_VARS, if set, will drop the unexpanded value
> >   - QUOTED_VARS, if set, will quote the expanded value
> >
> > So that it can be used as such:
> >
> >     $ make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1
> >     BUSYBOX_VERSION='1.26.2'
> >
> > And it is even possible to directly evaluate it in a shell script:
> >
> >     eval $(make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1)
> >
> > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> > ---
> >  Makefile | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/Makefile b/Makefile
> > index 5e4bc92..67a9b5d 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -934,7 +934,7 @@ printvars:
> >                 $(sort $(if $(VARS),$(filter $(VARS),$(.VARIABLES)),$(.VARIABLES))), \
> >                 $(if $(filter-out environment% default automatic, \
> >                                 $(origin $V)), \
> > -               $(info $V=$($V) ($(value $V)))))
> > +               $(info $V=$(if $(QUOTED_VARS),')$($V)$(if $(QUOTED_VARS),')$(if $(RAW_VARS),, ($(value $V))))))
> >
> >  clean:
> >         rm -rf $(TARGET_DIR) $(BINARIES_DIR) $(HOST_DIR) \
> > --
> > 2.7.4
> 
> 
> Very nice, I've been needing this a few times before too.
> 
> I do think we should document the new flags QUOTED_VARS and RAW_VARS
> somewhere (and in general 'printvars' itself). Perhaps here:
> http://buildroot.uclibc.org/downloads/manual/manual.html#make-tips ?

Damned, I forgot to document it, indeed...

I was instead thinking of documenting it in the output of 'make help'.

But both there and in the manual seems OK for me. I'll do.

> Regarding naming (I realize, these are nits): RAW sounds like somehow
> opposite of QUOTED. What about using PLAIN rather than RAW ?
> An alternative is to change the default behavior to be raw/plain, and
> add a VERBOSE option to display also the unexpanded value.

Well, I prefer not to change the current behaviour.

If others prefer we change the current behaviour, so be it. I'll wait
for more feedback.

Regards,
Yann E. MORIN.

-- 
.-----------------.--------------------.------------------.--------------------.
|  Yann E. MORIN  | Real-Time Embedded | /"\ ASCII RIBBON | Erics' conspiracy: |
| +33 662 376 056 | Software  Designer | \ / CAMPAIGN     |  ___               |
| +33 223 225 172 `------------.-------:  X  AGAINST      |  \e/  There is no  |
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'------------------------------^-------^------------------^--------------------'

[Buildroot] [PATCH] core: enhance printvars

[Arnout Vandecappelle]

On 31-01-17 18:31, Yann E. MORIN wrote:
> Thomas, All,
> 
> On 2017-01-31 11:12 +0100, Thomas De Schampheleire spake thusly:
>> On Sat, Jan 28, 2017 at 11:19 PM, Yann E. MORIN <yann.morin.1998@free.fr> wrote:
>>> Currently, the output of printvars copntains the name of the variable,
>>> its expanded value and its un-expanded value.
>>>
>>> However, most of the time, we need the actual, expanded value, so it can
>>> be re-used from a (non-Buildroot) infrastructure script, like a
>>> post-build script, or a build-farm driver (e.g. a Jenkins job...)
>>>
>>> Add two options that a user may set to change the output of printvars:
>>>   - RAW_VARS, if set, will drop the unexpanded value
>>>   - QUOTED_VARS, if set, will quote the expanded value
>>>
>>> So that it can be used as such:
>>>
>>>     $ make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1
>>>     BUSYBOX_VERSION='1.26.2'
>>>
>>> And it is even possible to directly evaluate it in a shell script:
>>>
>>>     eval $(make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1)

 That one would be nice to add to the documentation! However, I think you should
document it as XXX_VARS=YES to stay consistent with the rest of Buildroot.

>>>
>>> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
>>> ---
>>>  Makefile | 2 +-
>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/Makefile b/Makefile
>>> index 5e4bc92..67a9b5d 100644
>>> --- a/Makefile
>>> +++ b/Makefile
>>> @@ -934,7 +934,7 @@ printvars:
>>>                 $(sort $(if $(VARS),$(filter $(VARS),$(.VARIABLES)),$(.VARIABLES))), \
>>>                 $(if $(filter-out environment% default automatic, \
>>>                                 $(origin $V)), \
>>> -               $(info $V=$($V) ($(value $V)))))
>>> +               $(info $V=$(if $(QUOTED_VARS),')$($V)$(if $(QUOTED_VARS),')$(if $(RAW_VARS),, ($(value $V))))))
>>>
>>>  clean:
>>>         rm -rf $(TARGET_DIR) $(BINARIES_DIR) $(HOST_DIR) \
>>> --
>>> 2.7.4
>>
>>
>> Very nice, I've been needing this a few times before too.
>>
>> I do think we should document the new flags QUOTED_VARS and RAW_VARS
>> somewhere (and in general 'printvars' itself). Perhaps here:
>> http://buildroot.uclibc.org/downloads/manual/manual.html#make-tips ?
> 
> Damned, I forgot to document it, indeed...
> 
> I was instead thinking of documenting it in the output of 'make help'.
> 
> But both there and in the manual seems OK for me. I'll do.

 IMHO 'make help' should be rather limited, the real explanation should be in
the manual.


>> Regarding naming (I realize, these are nits): RAW sounds like somehow
>> opposite of QUOTED. What about using PLAIN rather than RAW ?

 Or say it like it is: NO_UNEXPANDED_VARS.

>> An alternative is to change the default behavior to be raw/plain, and
>> add a VERBOSE option to display also the unexpanded value.
> 
> Well, I prefer not to change the current behaviour.
> 
> If others prefer we change the current behaviour, so be it. I'll wait
> for more feedback.

 I'd normally indeed prefer to not change current behaviour. However, making the
verbose one optional does make a whole lot more sense. Also, the reson to not
change current behaviour is not to break existing scripts. But using the current
output in scripts would be extremely fragile; it would require a filter that
most likely will still match (e.g. "make printvars | cut -d ' ' -f 1").

 So I'm inclined indeed to change to expanded only by default.

 Regards,
 Arnout

-- 
Arnout Vandecappelle                          arnout at mind be
Senior Embedded Software Architect            +32-16-286500
Essensium/Mind                                http://www.mind.be
G.Geenslaan 9, 3001 Leuven, Belgium           BE 872 984 063 RPR Leuven
LinkedIn profile: http://www.linkedin.com/in/arnoutvandecappelle
GPG fingerprint:  7493 020B C7E3 8618 8DEC 222C 82EB F404 F9AC 0DDF

[Buildroot] [PATCH] core: enhance printvars

[Thomas Petazzoni]

Hello,

On Sat, 28 Jan 2017 23:19:31 +0100, Yann E. MORIN wrote:
> Currently, the output of printvars copntains the name of the variable,
> its expanded value and its un-expanded value.
> 
> However, most of the time, we need the actual, expanded value, so it can
> be re-used from a (non-Buildroot) infrastructure script, like a
> post-build script, or a build-farm driver (e.g. a Jenkins job...)
> 
> Add two options that a user may set to change the output of printvars:
>   - RAW_VARS, if set, will drop the unexpanded value
>   - QUOTED_VARS, if set, will quote the expanded value
> 
> So that it can be used as such:
> 
>     $ make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1
>     BUSYBOX_VERSION='1.26.2'
> 
> And it is even possible to directly evaluate it in a shell script:
> 
>     eval $(make -s printvars VARS=BUSYBOX_VERSION RAW_VARS=1 QUOTED_VARS=1)
> 
> Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
> ---
>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Seeing the feedback from Thomas DS and Arnout, I've marked the patch as
"Changes Requested". Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com