[Buildroot] Option for debug support in DirectFB package

[Buildroot] Option for debug support in DirectFB package

[Cédric Marie]

Hi,

DirectFB provides two configure options for debug:
* --enable-debug (default is no)
* --enable-debug-support (default is yes)
The first one enables verbose mode in DirectFB, while the second one
only provide the functions to print debug information, that might be
used by an external DirectFB driver.

When these options are both disabled, the installation path is suffixed
with -pure (i.e. /usr/lib/directfb-x.y.z-pure instead of
/usr/lib/directfb-x.y.z).

Buildroot only gives the possibility to enable/disable the first one
(with BR2_PACKAGE_DIRECTFB_DEBUG).

Some external DirectFB driver, when compiled in release mode, would
expect debug support to be disabled, and would install in the -pure
suffixed directory.

Therefore it would be helpful:
- either to have another option for debug support (and debug option
   would depend on debug support option, in Config.in)
- or to disable debug support when debug is disabled: the two options
   would always be forced to have the same value.

I believe the first solution is better, but let me know what you
think... I can provide the patch if you agree with the suggestion.

That would also prevent DirectFB to compile some useless features
in release mode.

-- 
C?dric

[Buildroot] Option for debug support in DirectFB package

[Thomas Petazzoni]

Dear C?dric Marie,

On Mon, 08 Jun 2015 23:56:09 +0200, C?dric Marie wrote:

> DirectFB provides two configure options for debug:
> * --enable-debug (default is no)
> * --enable-debug-support (default is yes)
> The first one enables verbose mode in DirectFB, while the second one
> only provide the functions to print debug information, that might be
> used by an external DirectFB driver.
> 
> When these options are both disabled, the installation path is suffixed
> with -pure (i.e. /usr/lib/directfb-x.y.z-pure instead of
> /usr/lib/directfb-x.y.z).
> 
> Buildroot only gives the possibility to enable/disable the first one
> (with BR2_PACKAGE_DIRECTFB_DEBUG).
> 
> Some external DirectFB driver, when compiled in release mode, would
> expect debug support to be disabled, and would install in the -pure
> suffixed directory.
> 
> Therefore it would be helpful:
> - either to have another option for debug support (and debug option
>    would depend on debug support option, in Config.in)
> - or to disable debug support when debug is disabled: the two options
>    would always be forced to have the same value.
> 
> I believe the first solution is better, but let me know what you
> think... I can provide the patch if you agree with the suggestion.
> 
> That would also prevent DirectFB to compile some useless features
> in release mode.

I am not sure I've made up my mind yet specifically about your
question, but two informations:

 * BR2_PACKAGE_DIRECTFB_DEBUG will most likely be removed, as part of
   a patch series I have to bump the entire DirectFB stack. See:

    http://git.free-electrons.com/users/thomas-petazzoni/buildroot/log/?h=directfb-bump

 * --enable-debug / --disable-debug used to be passed to all autotools
   packages, depending on the state of the BR2_ENABLE_DEBUG option.
   This is no longer the case since commit
   http://git.buildroot.net/buildroot/commit/?id=0552a367dbdc27a211daaac3359d81dd537e384f.

Best regards,

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

[Buildroot] Option for debug support in DirectFB package

[Cédric Marie]

[Thomas Petazzoni]
> I am not sure I've made up my mind yet specifically about your
> question, but two informations:
> 
>  * BR2_PACKAGE_DIRECTFB_DEBUG will most likely be removed, as part of
>    a patch series I have to bump the entire DirectFB stack. See:
> 
> http://git.free-electrons.com/users/thomas-petazzoni/buildroot/log/?h=directfb-bump
> 
>  * --enable-debug / --disable-debug used to be passed to all autotools
>    packages, depending on the state of the BR2_ENABLE_DEBUG option.
>    This is no longer the case since commit
> 
> http://git.buildroot.net/buildroot/commit/?id=0552a367dbdc27a211daaac3359d81dd537e384f.


It sounds like a very good idea to avoid mixing two "features" in 
BR2_ENABLE_DEBUG.
We may need debugging symbols without wanting to add any overload in 
binaries.

But then, since it is already commited, is your removal of DirectFB 
specific debug option still relevant?
Or should we create another global option to enable debug (i.e. traces) 
in autotools packages (and similar things in other types of packages 
when possible)?
This is just a question, I have no personal need for this debug 
option...

[Arnout Vandecappelle]
> That indeed sounds like a good solution. As mentioned by Thomas, the
> BR2_PACKAGE_DIRECTFB_DEBUG option will go away, so I'd suggest an 
> option
> BR2_PACKAGE_DIRECTFB_DEBUG_SUPPORT that defaults to y.

It might sound strange to have an option for debug support (i.e. compile 
the functions to print debug info) and no option for debug (i.e. use 
these functions in DFB core).
Yet it seems to be the better idea, and the only way to force to compile 
with no debug feature at all and to install in -pure directory.
Waiting for Thomas feedback...

Thank you.


-- 
C?dric

[Buildroot] Option for debug support in DirectFB package

[Thomas Petazzoni]

Dear C?dric Marie,

On Tue, 09 Jun 2015 09:29:00 +0200, C?dric Marie wrote:

> But then, since it is already commited, is your removal of DirectFB 
> specific debug option still relevant?

Well, maybe no.

> Or should we create another global option to enable debug (i.e. traces) 
> in autotools packages (and similar things in other types of packages 
> when possible)?
> This is just a question, I have no personal need for this debug 
> option...

A global option is a bit problematic, because we have discovered that
--enable-debug is clearly not used for the same thing in all packages.
Some packages add -Werror, some add some other funky stuff, some simply
enable debugging symbols. --enable-debug is not a standard, formalized
option with a well-defined meaning. So I don't think a global option
that applies to all autotools packages make sense here.

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

[Buildroot] Option for debug support in DirectFB package

[Cédric Marie]

Le 2015-06-09 10:15, Thomas Petazzoni a ?crit?:
> A global option is a bit problematic, because we have discovered that
> --enable-debug is clearly not used for the same thing in all packages.
> Some packages add -Werror, some add some other funky stuff, some simply
> enable debugging symbols. --enable-debug is not a standard, formalized
> option with a well-defined meaning. So I don't think a global option
> that applies to all autotools packages make sense here.

OK, I understand.

So I will provide the patch with BR2_PACKAGE_DIRECTFB_DEBUG_SUPPORT as 
suggested by Arnout.
Since BR2_PACKAGE_DIRECTFB_DEBUG is still present, I will make it depend 
on BR2_PACKAGE_DIRECTFB_DEBUG_SUPPORT (default yes). 
(--disable-debug-support is ignored if --enable-debug is set.)
Of course it is still possible to remove BR2_PACKAGE_DIRECTFB_DEBUG 
later...

-- 
C?dric

[Buildroot] Option for debug support in DirectFB package

[Arnout Vandecappelle]

On 06/08/15 23:56, C?dric Marie wrote:
> Hi,
> 
> DirectFB provides two configure options for debug:
> * --enable-debug (default is no)
> * --enable-debug-support (default is yes)
> The first one enables verbose mode in DirectFB, while the second one
> only provide the functions to print debug information, that might be
> used by an external DirectFB driver.
> 
> When these options are both disabled, the installation path is suffixed
> with -pure (i.e. /usr/lib/directfb-x.y.z-pure instead of
> /usr/lib/directfb-x.y.z).
> 
> Buildroot only gives the possibility to enable/disable the first one
> (with BR2_PACKAGE_DIRECTFB_DEBUG).
> 
> Some external DirectFB driver, when compiled in release mode, would
> expect debug support to be disabled, and would install in the -pure
> suffixed directory.
> 
> Therefore it would be helpful:
> - either to have another option for debug support (and debug option
>   would depend on debug support option, in Config.in)
> - or to disable debug support when debug is disabled: the two options
>   would always be forced to have the same value.
> 
> I believe the first solution is better, but let me know what you
> think... I can provide the patch if you agree with the suggestion.

 That indeed sounds like a good solution. As mentioned by Thomas, the
BR2_PACKAGE_DIRECTFB_DEBUG option will go away, so I'd suggest an option
BR2_PACKAGE_DIRECTFB_DEBUG_SUPPORT that defaults to y.

 Regards,
 Arnout

> 
> That would also prevent DirectFB to compile some useless features
> in release mode.
> 


-- 
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:  7CB5 E4CC 6C2E EFD4 6E3D A754 F963 ECAB 2450 2F1F