[Buildroot] [PATCH] autossh: honour LDFLAGS

[Waldemar Brodkorb]

Hi Thomas,
Thomas Petazzoni wrote,

> Hello,
> 
> On Fri, 25 Nov 2016 19:00:16 +0100, Waldemar Brodkorb wrote:
> > Fixes:
> >  http://autobuild.buildroot.net/results/08a458572a2e9c599dd32b837b1e5c02a6721973
> > 
> > Signed-off-by: Waldemar Brodkorb <wbx at openadk.org>
> > ---
> > It is indeed a change from uClibc-ng 1.0.18 and upward, but I think
> > it is the fault of the package not respecting LDFLAGS and so not
> > passing -static. I am unsure why it just worked in the past.
> > When it fails linker is doing following:
> > -lnsl -lgcc -lc -lgcc
> > When -static is used, following is passed:
> > -lnsl --start-group -lgcc -lc --end-group 
> 
> Applied to master.
> 
> The difference in the gcc behavior is due to gcc/config/gnu-user.h:
> 
> #define LINK_GCC_C_SEQUENCE_SPEC \
>   "%{static:--start-group} %G %L %{static:--end-group}%{!static:%G}"
> 
> So, when you're linking dynamic, you have:
> 
> 	-lgcc -lc -lgcc
> 
> And when you're linking statically, you have:
> 
> 	--start-group -lgcc -lc --end-group
> 
> The --start-group/--end-group ask the linker to loop between -lgcc and
> -lc until all unresolved symbols have been resolved. So
> dl_iterate_phdr() being defined in the C library, but used in libgcc, I
> guess the dynamic way (-lgcc -lc -lgcc) doesn't work.

But why gcc behaves different?
BR+gcc5+uClibc-ng-1.0.17 - no extra -static in LDFLAGS required
BR+gcc5+musl+static - no extra -static in LDFLAGS required
BR+gcc5+uClibc-ng-1.0.19 - extra -static required!
 
> In any case, could you try to send your patch upstream to the autossh
> developers?

Already done.

best regards
 Waldemar