[Development] Problem loading plugins with gcc 4.9.2

[Thiago Macieira]

Em quarta-feira, 8 de março de 2017, às 12:55:58 CET, Sérgio Martins escreveu:
> On Wed, Mar 8, 2017 at 11:33 AM, Alex Blasche <alexander.blasche at qt.io> 
wrote:
> > This is an ancient thread but just to keep this in mind (it certainly cost
> > me a day re-figuring this out).
> > 
> > If you do Qt development for Android you are going to be hit by this. The
> > four most recent Android NDKs (11c, 12b, 13b & 14) are affected by this
> > bug when using Linux (not all Linux distros though but certainly Ubuntu
> > 16.04) as host platform. The only decent choice is 10e at this point in
> > time.
> > 
> > I am tempted to just submit a patch that renames the damn loader
> > variables. Any opinions?
> Hi,
> 
> Options:
> 
> - Use the latest NDKs, but with clang instead of gcc
> - Use the latest NDKs with gcc but don't compile in debug mode
> (release doesn't crash)
> - Use 10e
> 
> I prefer option 1, sooner or later that gcc will rot, since google
> stopped supporting it.

I'm with Sergio, since Clang appears to be the future direction anyway.

Speaking to Bogdan on IRC a few days ago, it turns out that we haven't been 
using Clang because it has much poorer optimisations than GCC (that's not 
news), and produces much bigger code than GCC when compiled with -Os. Size 
itself is not a big deal, but apparently it causes execution to be slower on 
ARM 32-bit -- probably due to cache limitations.

He's now testing -Oz (aggressive optimise for size) and will let us know if it 
helps. I can tell you that -Oz produces executables of comparable size with 
GCC -Os, but still bigger.

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