Re: [boost] [context] asm_context_sources breaking regression testing for WinCE

Subject: Re: [boost] [context] asm_context_sources breaking regression testing for WinCE
From: David Deakins (ddeakins_at_[hidden])
Date: 2012-12-03 11:49:27

On 12/3/2012 7:09 AM, Oliver Kowalke wrote:
>
> I'm still wondering why on of your test systems (9.0~wm5~stlport5.2 ==
> Windows CE 5 ?) gracefully fails (with message 'platform not supported')
> and the other one does fail without any information (at least at thre
> regression test page). Does bjam segfault or do you get some
> output/warnings/errors?
> I've removed an unreferenced alias from Jamfile.v2 - but it would be
> suspicious if this would have caused the error.
>

That was actually a good clue.  The 9.0~wm5~stlport5.2 platform is the 
Windows Mobile 5 ARM platform (not CE 5 on x86) and that compile on Nov 
28 was the last time that the build worked.  It appears that the changes 
you checked in on Nov 27 (and which didn't get picked up until after Nov 
28 on the regression test builds) caused things to stop working.  It 
looks like when you had the additional context_sources target with 
fcontext.cpp, then it would fail to select an alias for 
select_asm_context, but it would still see fcontext.cpp for the source 
of lib boost_context.  And so it was still happy and would compile 
fcontext.cpp and move on.  Then during the Boost.Context test builds it 
would gracefully fail with the 'platform not supported' message you see 
in the test output.  However, after the jamfile changes of Nov 27 that 
eliminated context_sources, now when it fails to match any of the 
asm_context_sources aliases, it ends up that lib boost_context has no 
sources at all for that first argument and this seems to make 
Boost.Build angry (see the argument error messages back in the 
attachment from my earlier post).

So it seems like the trouble is making sure there is at least some 
source file to build in the event that the platform is not supported and 
that no alias of asm_context_sources is matched.  Or maybe there is some 
other Boost.Build mechanism to realize that the platform is not 
supported and block it from trying to build lib boost_context at all.

Thanks,
-Dave