Re: [PATCH] meson: change buildtype when debug_info=no

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 4/29/21 9:33 AM, Joelle van Dyne wrote:
> On Wed, Apr 28, 2021 at 10:07 PM Philippe Mathieu-Daudé
> <philmd@redhat.com> wrote:
>>
>> On 4/28/21 9:55 PM, Joelle van Dyne wrote:
>>> Meson defaults builds to 'debugoptimized' which adds '-g -O2'
>>> to CFLAGS. If the user specifies '--disable-debug-info' we
>>> should instead build with 'release' which does not emit any
>>> debug info.
>>>
>>> Signed-off-by: Joelle van Dyne <j@getutm.app>
>>> ---
>>>  configure | 1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/configure b/configure
>>> index 4f374b4889..5c3568cbc3 100755
>>> --- a/configure
>>> +++ b/configure
>>> @@ -6398,6 +6398,7 @@ NINJA=$ninja $meson setup \
>>>          --sysconfdir "$sysconfdir" \
>>>          --localedir "$localedir" \
>>>          --localstatedir "$local_statedir" \
>>> +        --buildtype $(if test "$debug_info" = yes; then echo "debugoptimized"; else echo "release"; fi) \
>>
>> NAck. You are changing the default (which is 'debug') to 'release'.
> 
> I thought 'debugoptimized' was the default? From my build logs,
> there's always '-g -O2' which is why I needed to make this change. The
> default for 'debug_info' is yes so this keeps it on 'debugoptimized'
> and uses 'release' when explicitly disabling debug_info.

Again, I'm not concerned between 'debugoptimized' VS 'debug',
I'm worried to use 'release', because of the b_ndebug=if-release
option which disable assertions (unsupported QEMU build mode).

Also, 'release' sets optimization=3 which isn't supported neither.

Per https://mesonbuild.com/Builtin-options.html#build-type-options

  All other combinations of debug and optimization set buildtype
  to 'custom'.

So maybe this is what you want, with debug=false and optimization=2?

> 
>>
>> This should be at least mentioned in the commit description, but
>> I don't think this is what we want here. 'release' enables -O3,
>> which is certainly not supported. The 'debug' profile is what we
>> have been and are testing.
>>
>> I'd be OK if you had used "debugoptimized else debug".
>>
>> The mainstream project would rather use 'debug'/'debugoptimized', or
>> 'minsize', which are already tested. We might consider allowing forks
>> to use 'plain' profile eventually. But the 'release' type is an
>> unsupported landmine IMHO.
>>
>> If you want to use something else, it should be an explicit argument
>> to ./configure, then you are on your own IMO.
> 
> What do I need to avoid '-g'?

Why don't you simply use ./configure --extra-cflags='-g0 -O2'?

Regards,

Phil.