Re: Unable to build with --enable-shared

[Szabolcs Nagy <nsz@port70.net>]

* Samuel Sadok <innovation-labs@appinstall.ch> [2016-10-22 22:37:46 +0200]:
> I am unable to build musl with --enable-shared. Multiple issues in
> unrelated projects (e.g. here: https://bugs.swift.org/browse/SR-1023)
> suggest that the culprit is a change in behaviour between binutils
> 2.25 and 2.26.
> 

that bug is different, that's about object symbols

(swift seems to misuse protected visibility objects,
and instead of fixing the problem they switched to the
gold linker which does not yet have the bfd linker fix,
such incompetence is frustrating..  however the issue
does not affect musl: we don't mark objects protected
to avoid issues with broken toolchains.)

> $ make
> [...]
> x86_64-pc-linux-gnu-gcc  -D_XOPEN_SOURCE=700 -I./arch/x86_64
> -I./arch/generic -Iobj/src/internal -I./src/internal -Iobj/include
> -I./include  -include vis.h -B/usr/local/bin/x86_64-pc-linux-gnu-
> -fPIC -c -o obj/src/process/posix_spawn.lo src/process/posix_spawn.c

some flags are missing here.. e.g. freestanding flags

> [...]
> x86_64-pc-linux-gnu-gcc  -D_XOPEN_SOURCE=700 -I./arch/x86_64
> -I./arch/generic -Iobj/src/internal -I./src/internal -Iobj/include
> -I./include  -include vis.h -B/usr/local/bin/x86_64-pc-linux-gnu-
> -nostdlib -shared -Wl,-e,_dlstart -o lib/libc.so obj/src/aio/aio.lo [a
> ton of objects] obj/ldso/dynlink.lo
> /usr/local/bin/x86_64-pc-linux-gnu-ld: obj/src/process/posix_spawn.lo:
> relocation R_X86_64_PC32 against protected symbol `execve' can not be
> used when making a shared object
> /usr/local/bin/x86_64-pc-linux-gnu-ld: final link failed: Bad value
> collect2: error: ld returned 1 exit status
> make: *** [lib/libc.so] Error 1
> 

execve is a protected function symbol, so it should be bound locally,
i think R_X86_64_PC32 is ok for that, so it's not clear to me what
goes wrong..