Re: [PATCH] fix wrapper auto detection in configure

[Szabolcs Nagy <nsz@port70.net>]

* Rich Felker <dalias@libc.org> [2016-01-22 18:47:45 -0500]:
> On Fri, Jan 22, 2016 at 10:56:03PM +0100, Szabolcs Nagy wrote:
> > the libc header based test is wrong if there are no such headers on the
> > system only a free standing cc, which should be enough for a musl build.
> 
> I'm trying to understand the usage case you're concerned about. Is it
> failing to build the wrapper for a glibc-targeted toolchain that
> doesn't actually have glibc installed? Is there a reason you woul want
> the wrapper in this case?
> 

distros package libc-headers separately and
apparently one can install gcc without it
and that should be enough to build musl.

> > check for *-musl* in the target triplet instead.
> 
> I don't think we depend on the target tuple at all now except as a way
> of identifying the arch. It's only available with gcc, not other
> compilers that lack -dumpmachine. I was actually thinking about this
> issue a couple days ago and wonder if we should instead check for
> predefined macros defined in the psABI for each arch to determine the
> arch. This would also work on non-gcc compilers so you don't have to
> manually pass the target arch (or tuple) to configure for them.
> 

makes sense
but note that only gcc and clang matter here
(the wrapper will be disabled for other compilers)

> Anyway if I can understand what real problem you're trying to solve
> maybe I can come up with a better approach that doesn't expend
> dependency on having a named target tuple.
> 
> Rich