[Interest] building Qt 5.9 on Linux - clang or GCC?

[Thiago Macieira]

On Monday, 18 December 2017 07:32:39 PST René J. V. Bertin wrote:
> That's more or less what I expected. The only mostly systematic difference I
> see (on all platforms) is that GCC generates debug information that takes
> much more space. No idea if that means there's more information but the
> difference is large enough that I wonder if it doesn't increase load times.

It doesn't, because the debug information is not loaded in the first place. 
When using readelf, note how the "A" flag is missing for those sections.

> I know, but it still basically doubles the build time because almost
> everything is actually built a second time during the link step. A regular
> build already stresses my Linux system to a point where I can barely do
> anything else on it. And on Mac, well, using LTO means you give up
> debugging, for some reason (the information is still there AFAICT, but the
> debugger acts as if it isn't). Not that I do a lot of Qt debugging, but
> it's useful to be able to trace application crashes into Qt code, and to be
> able to inspect QObjects, QWidgets etc.

One more reason to use GCC. It only builds once, even under LTO, unless you 
specifically ask for the fat LTO objects.

	qmake -config ltcg -config fat-lto

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center