[Development] Qt Compilation Speed

[Sérgio Martins]

On 2022-01-03 08:43, Marc Mutz wrote:
> Hi,
> 
> The Qt Creator folks have noted that compilation of Qt projects
> against Qt 6.2 is sometimes almost twice as slow as it was in 5.15:
> https://bugreports.qt.io/browse/QTBUG-97601
> 
> While we have some ideas where this may come from (including more std
> headers, qmetatype compile-time typename construction, qglobal.h
> becoming larger and larger), most of these should be fixed by PCH, yet
> PCH builds are also slower.
> 
> The questions that we face now are a) do we care and b) if we do, then
> what metrics should we use to define success?


Hi Marc,


Better first check what the problem is.
You can use "clang -ftime-trace" [1] or Microsoft's own thing [2]

Both were easy to use and helped for customer project's build times.


[1] 
https://aras-p.info/blog/2019/01/16/time-trace-timeline-flame-chart-profiler-for-Clang/
[2] https://devblogs.microsoft.com/cppblog/introducing-c-build-insights/



Regards,
-- 
Sérgio Martins | sergio.martins at kdab.com | Senior Software Engineer
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel: Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
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