We do not need TCG and capstone all the times. In some
configuration we can leave them out.

Last patch emit a warning when a user explicitly select an
accelerator that the build with not use.

Philippe Mathieu-Daudé (3):
  configure: Do not build TCG if not necessary
  configure: Do not build/check for capstone when emulation is disabled
  configure: Emit warning when accelerator requested but not needed

 configure | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

-- 
2.26.2

On 20/01/21 16:19, Philippe Mathieu-Daudé wrote:
> We do not need TCG and capstone all the times. In some
> configuration we can leave them out.
> 
> Last patch emit a warning when a user explicitly select an
> accelerator that the build with not use.
> 
> Philippe Mathieu-Daudé (3):
>    configure: Do not build TCG if not necessary
>    configure: Do not build/check for capstone when emulation is disabled
>    configure: Emit warning when accelerator requested but not needed
> 
>   configure | 37 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 36 insertions(+), 1 deletion(-)
> 

Nice, but I have some remarks on how the patches are done. :)

For patch 1, which files are not compiled with the patch that were 
compiled without?

For patch 2, I think it's enough to add "build_by_default: false" to 
libcapstone (and while you're at it, to libslirp and libfdt).

Finally, I would prefer patch 3 to be done in Meson, right before the 
summary() call.  You can use config_all to check, like

if get_option('kvm').enabled() and not config_all.has_key('CONFIG_KVM')

etc.  This will also warn for e.g. --enable-kvm 
--target-list=sh4-softmmu, which could be considered an improvement over 
your patch.

Paolo

On 1/20/21 5:46 PM, Paolo Bonzini wrote:
> On 20/01/21 16:19, Philippe Mathieu-Daudé wrote:
>> We do not need TCG and capstone all the times. In some
>> configuration we can leave them out.
>>
>> Last patch emit a warning when a user explicitly select an
>> accelerator that the build with not use.
>>
>> Philippe Mathieu-Daudé (3):
>>    configure: Do not build TCG if not necessary
>>    configure: Do not build/check for capstone when emulation is disabled
>>    configure: Emit warning when accelerator requested but not needed
>>
>>   configure | 37 ++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 36 insertions(+), 1 deletion(-)
>>
> 
> Nice, but I have some remarks on how the patches are done. :)
> 
> For patch 1, which files are not compiled with the patch that were
> compiled without?

softfloat.

I'll mention and address Thomas and your's other comments.

Thanks,

Phil.

> 
> For patch 2, I think it's enough to add "build_by_default: false" to
> libcapstone (and while you're at it, to libslirp and libfdt).
> 
> Finally, I would prefer patch 3 to be done in Meson, right before the
> summary() call.  You can use config_all to check, like
> 
> if get_option('kvm').enabled() and not config_all.has_key('CONFIG_KVM')
> 
> etc.  This will also warn for e.g. --enable-kvm
> --target-list=sh4-softmmu, which could be considered an improvement over
> your patch.
> 
> Paolo
> 

On 20/01/21 18:02, Philippe Mathieu-Daudé wrote:
>>
>> For patch 1, which files are not compiled with the patch that were
>> compiled without?
> softfloat.

Really?  I see this:

specific_ss.add(when: 'CONFIG_TCG', if_true: files(
   'fpu/softfloat.c',
   ...))

Maybe

-subdir('fp')
+if 'CONFIG_TCG' in config_all
+  subdir('fp')
+endif

in tests/meson.build is enough?

Paolo

On 1/20/21 6:35 PM, Paolo Bonzini wrote:
> On 20/01/21 18:02, Philippe Mathieu-Daudé wrote:
>>>
>>> For patch 1, which files are not compiled with the patch that were
>>> compiled without?
>> softfloat.
> 
> Really?  I see this:
> 
> specific_ss.add(when: 'CONFIG_TCG', if_true: files(
>   'fpu/softfloat.c',
>   ...))
> 
> Maybe
> 
> -subdir('fp')
> +if 'CONFIG_TCG' in config_all
> +  subdir('fp')
> +endif
> 
> in tests/meson.build is enough?

Yes, 464 unnecessary objects removed :)