Re: Build system adjustments for subarchs

[Rich Felker <dalias@aerifal.cx>]

On Tue, Aug 13, 2013 at 09:06:17PM -0400, Rich Felker wrote:
> Another idea, using the filesystem, would be to have .sub files in the
> asm directories containing the filename of a different asm file to
> substitute. This is essentially emulating symlinks, but I don't see a
> good way to get make to do automated dependency tracking so that
> modifying the pointed-to asm file causes the object file to be
> rebuilt. I am exploring this approach further however in hopes that
> there might be a way.

Actually, this would work great if I could write an abstract rule that
says roughly: for each .o target %.o, add dependencies on %.c and
$(wildcard */%.s). This would make it so files with asm always get
rebuilt if either the base C file or any of the asm versions, for any
arch or subarch, has been modified. Obviously in some cases the
rebuild would be spurious, but such files are sufficiently small that
I don't care; the simplicity of a universal rule with no
arch-dependent dependency data to maintain is much more valuable.

Unfortunately, I don't know a way to do this with make, but I believe
there should be a way...

Rich