[Buildroot] CMake and VERBOSE variable

[Cédric Marie]

Hi!

I'm getting back to working on this old subject (it was discussed in 
June).
I have proposed a first patch to fix the CMake specific problem.
See: 
http://git.buildroot.net/buildroot/commit/?id=307029867b0384446cd74b232b45a7b4f40cf0d1
VERBOSE is not exported anymore, unless V=1 in the command line.

It was suggested that I should provide a second patch, to address the 
problem globally.
I have a local patch for that, but I need some feedback before providing 
it.

The idea is to remove exported variables that come from the kernel and 
are useless in our context (KBUILD_VERBOSE and quiet), to remove 
VERBOSE, and to manage the verbosity in a specific way in each pkg-infra 
(VERBOSE=1 is understood by CMake, but might not be understood by 
another build system).

When V=1, we should export Q = (empty) and a new variable BR2_VERBOSE = 
1.
When V=0, we should export Q = @ and BR2_VERBOSE = (empty).

Q behaviour is not modified.

BR2_VERBOSE is taken into account in pkg-infra.
* In pkg-cmake.mk:
When BR2_VERBOSE=1, I add VERBOSE=1 in <PKG>_BUILD_CMDS
* In pkg-autotools.mk:
I don't know what to do. VERBOSE=1 has no effect, V=0/1 has no effect, 
--enable-silent-rules has no effect.

NB: The only verbosity setting that has an effect on autotools is "make 
-s", but it is different from "make V=0/1", and it is already taken into 
account by Buildroot (QUIET variable in root Makefile).

Globally, there is no change:
* V=1 involves VERBOSE=1 for CMake.
* V=1 already has no effect for autotools.

In fact I'm not sure about autotools. I suppose it depends on the 
version of autotools that is used by the package.
Do you know an autotools package that currently takes Buildroot's V=1 
into account?

And what about the other pkg-infra?
Does one of them take VERBOSE into account?

If we have too much doubts, we can also simply remove KBUILD_VERBOSE and 
quiet, and keep on exporting VERBOSE when not empty. I think it would 
just have been more clean to apply pkg-infra specific rules.

Let me know what you think about it...
Thank you.

Regards.

-- 
Cédric