Re: [Qemu-devel] [PATCH v1 2/2] make: fix help message reference to bogus V=0 variable

[Daniel P. Berrange]

On Tue, Jan 23, 2018 at 01:05:31PM -0600, Eric Blake wrote:
> On 01/23/2018 10:47 AM, Daniel P. Berrange wrote:
> > The make rules for building QEMU are mostly silent by default. They can
> > be made verbose by setting the variable V=1. The default state does not
> > however correspond to a V=0 setting - $(V) must be undefined / empty to
> > get the default quiet build.
> 
> Makefiles generated by automake support V=0; how hard would it be to
> instead tweak things so that 'V=' and 'V=0' have the same effect?

Well it would make the various conmditionals a bit more complex because
we'd have to check three states instead of two. I'm not really convinced
it is worth it because explicitly passing V=0 doesn't do anything useful
given that we are unconditionally silent by default.

It makes more sense with autoconf, because the default behaviour may vary
based on configure setup and/or configure args, so you can't assume that
omitting 'V=' gives you silent build like we do with QEMU.

> 
> > 
> > Signed-off-by: Daniel P. Berrange 
> > ---
> >  Makefile | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Makefile b/Makefile
> > index c263190b8d..554ba69ced 100644
> > --- a/Makefile
> > +++ b/Makefile
> > @@ -940,4 +940,5 @@ ifdef QEMU_GA_MSI_ENABLED
> >  endif
> > @echo  ''
> >  endif
> > -   @echo  '  $(MAKE) V=0|1 [targets] 0 => quiet build (default), 1 => 
> > verbose build'
> > +   @echo  '  $(MAKE) [targets]  (quiet build, default)'
> > +   @echo  '  $(MAKE) V=1 [targets]  (verbose build)'
> > 
> 
> -- 
> Eric Blake, Principal Software Engineer
> Red Hat, Inc.   +1-919-301-3266
> Virtualization:  qemu.org | libvirt.org
> 




Regards,
Daniel
-- 
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Re: [Qemu-devel] [PATCH v1 2/2] make: fix help message reference to bogus V=0 variable

[Eric Blake]

On 01/23/2018 10:47 AM, Daniel P. Berrange wrote:
> The make rules for building QEMU are mostly silent by default. They can
> be made verbose by setting the variable V=1. The default state does not
> however correspond to a V=0 setting - $(V) must be undefined / empty to
> get the default quiet build.

Makefiles generated by automake support V=0; how hard would it be to
instead tweak things so that 'V=' and 'V=0' have the same effect?

> 
> Signed-off-by: Daniel P. Berrange 
> ---
>  Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index c263190b8d..554ba69ced 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -940,4 +940,5 @@ ifdef QEMU_GA_MSI_ENABLED
>  endif
>   @echo  ''
>  endif
> - @echo  '  $(MAKE) V=0|1 [targets] 0 => quiet build (default), 1 => 
> verbose build'
> + @echo  '  $(MAKE) [targets]  (quiet build, default)'
> + @echo  '  $(MAKE) V=1 [targets]  (verbose build)'
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3266
Virtualization:  qemu.org | libvirt.org



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Re: [Qemu-devel] [PATCH v1 2/2] make: fix help message reference to bogus V=0 variable

[Marc-Andre Lureau]

On Tue, Jan 23, 2018 at 5:47 PM, Daniel P. Berrange  wrote:
> The make rules for building QEMU are mostly silent by default. They can
> be made verbose by setting the variable V=1. The default state does not
> however correspond to a V=0 setting - $(V) must be undefined / empty to
> get the default quiet build.
>
> Signed-off-by: Daniel P. Berrange 


(with that, qemu build-sys differs from automake & kernel at least)

Reviewed-by: Marc-André Lureau 


> ---
>  Makefile | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/Makefile b/Makefile
> index c263190b8d..554ba69ced 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -940,4 +940,5 @@ ifdef QEMU_GA_MSI_ENABLED
>  endif
> @echo  ''
>  endif
> -   @echo  '  $(MAKE) V=0|1 [targets] 0 => quiet build (default), 1 => 
> verbose build'
> +   @echo  '  $(MAKE) [targets]  (quiet build, default)'
> +   @echo  '  $(MAKE) V=1 [targets]  (verbose build)'
> --
> 2.14.3
>

[Qemu-devel] [PATCH v1 2/2] make: fix help message reference to bogus V=0 variable

[Daniel P. Berrange]

The make rules for building QEMU are mostly silent by default. They can
be made verbose by setting the variable V=1. The default state does not
however correspond to a V=0 setting - $(V) must be undefined / empty to
get the default quiet build.

Signed-off-by: Daniel P. Berrange 
---
 Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index c263190b8d..554ba69ced 100644
--- a/Makefile
+++ b/Makefile
@@ -940,4 +940,5 @@ ifdef QEMU_GA_MSI_ENABLED
 endif
@echo  ''
 endif
-   @echo  '  $(MAKE) V=0|1 [targets] 0 => quiet build (default), 1 => 
verbose build'
+   @echo  '  $(MAKE) [targets]  (quiet build, default)'
+   @echo  '  $(MAKE) V=1 [targets]  (verbose build)'
-- 
2.14.3