Re: musl 1.1.14 and x86_64

[Rich Felker <dalias@libc.org>]

On Tue, Feb 23, 2016 at 01:03:55PM +0100, Jens wrote:
> 
> Hello!
> 
> Since 1.1.14 I am seeing the following when compiling musl for
> x86_64 (32 bit is fine). 1.1.12 was Ok.
> 
> ../include/unistd.h:125: warning: redeclaration of 'optarg' with
> different visibility (old visibility preserved)
> ../src/internal/vis.h:23: warning: previous declaration of 'optarg'
> was here
> ../include/unistd.h:126: warning: redeclaration of 'optind' with
> different visibility (old visibility preserved)
> ../src/internal/vis.h:17: warning: previous declaration of 'optind'
> was here
> ../include/unistd.h:126: warning: redeclaration of 'opterr' with
> different visibility (old visibility preserved)
> ../src/internal/vis.h:17: warning: previous declaration of 'opterr'
> was here
> ../include/unistd.h:126: warning: redeclaration of 'optopt' with
> different visibility (old visibility preserved)
> ../src/internal/vis.h:17: warning: previous declaration of 'optopt'
> was here
> 
> Can I ignore these warnings or are they likely to break something?
> 
> I'm still building things from a pretty old environment, so that may
> be the cause of the warnings. (The base is an old uclibc buildroot).
> 
> gcc 4.1.2 and binutils-2.20.1-1.
> 
> configured with --prefix=/opt/musl --bindir=/usr/bin --disable-shared

I don't think anything will break, but this sounds like a pretty
broken toolchain, and could have other "interesting" bugs. Gregor's
musl-cross or my musl-cross-make build system should make it easy to
build a musl-targeting cross compiler, but for building musl itself
it's fine to just use a host compiler targeting glibc (except on weird
archs like powerpc where ABI issues preclude this from working).

Rich