Re: compatability: heirloom-utils +.5, libarchive -1

[Rich Felker <dalias@aerifal.cx>]

On Tue, Jan 03, 2012 at 06:06:00AM -0800, Isaac Dunham wrote:
> I was building a kernel on Sabotage Linux (I'm using a rather modified
> version already...), with initramfs enabled (which Sabotage does not
> seem to support).  make would die because it couldn't find a cpio.xz
> archive, so I assumed I needed a full cpio and xz.
> That wasn't the issue, but I found some more compatability stuff:
> xz: Seems to build fine (well, selecting {en,de}coders may not work
> right, but otherwise it builds unchanged)
> heirloom-utils: They are trying to support other nonstandard linux
> libcs, so they check for __GLIBC__ | __uclibc__ to determine whether
> dirent.h is present & sufficient; if dietlibc is detected, both

This sort of test is really backwards. The correct approach is to test
conditionally for the (small, finite) set of known-broken libs (diet,
etc.) and otherwise assume a working, conformant system.

> libarchive: needs memory.h --I just dropped it, since the syntax isn't
> exactly like string.h, and there are at least two other cpio
> implementations

Yes, memory.h is purely a nonstandard alias for string.h.

> Also, could PATH_MAX be exported unconditionally, or is that
> nonstandard? Currently, defining any of the standard compatability
> macros enables it.
> This is needed for the kernel to build without defining HOSTCFLAGS,
> though it really wants -D_GNU_SOURCE

I suspect there are other warnings that should really be errors when
you try building without HOSTCFLAGS, and which might break on 64-bit
systems due to int/pointer size mismatch. You really need to define
the right feature-test macros for what it needs.

Rich