Re: [PATCH 00/37] accel/tcg, codebase: Build once patches

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 3/13/25 10:48, Philippe Mathieu-Daudé wrote:
> On 13/3/25 17:36, Pierrick Bouvier wrote:
>> On 3/12/25 20:44, Richard Henderson wrote:
>>> All this is working toward building accel/tcg/translator.c once,
>>> but it got late and I decided to stop at a convenient milestone.
>>>
>>> In the process, I discovered that we have already added files to
>>> common_ss which indirectly depend on CONFIG_USER_ONLY.  Sometimes
>>> this is harmless, and sometimes it really is not.  For instance,
>>> plugin/api.c is affected by different translation-block.h layout.
>>>
>>
>> Maybe it's finally a good reason to tackle user/system at the same time
>> we make the rest of the files common.
>>
>>> The only solution I can see is to poison CONFIG_USER_ONLY outside
>>> of specific contexts.  I hoisted some existing magic in tcg/ and
>>> gdbstub/ to build separate shared_libraries for user and system,
>>> as that's the only way to add extra command-line -Defines.
>>>
>>
>> It's a good approach (make common + poison is what prevent regressions
>> and ensure we progress).
>> Working on target code, I found the need to have a common-{arch} lib,
>> allowing to share code between variants of a given arch (arm vs
>> aarch64), with a specific define too.
> 
> Are really ARM & Aarch64 different architectures (QEMU wise)?
> 

Not really, but as long as we have #ifdef TARGET_AARCH64,
the cu is duplicated, and it brings a lot of issues (symbols, type 
difference, multiple board type definition, etc).