Re: Question on BIGGEST_ALIGNMENT in GCC on NetBSD/m68k

[Finn Thain <fthain@linux-m68k.org>]

On Sat, 7 Jun 2025, John Paul Adrian Glaubitz wrote:

> On Fri, 2025-06-06 at 20:20 +1000, Finn Thain wrote:
> > Whereas, the ability to use old binaries is proof that we care about 
> > rule #1 don't break userspace.
> 
> Who is "we"?

AFAICT, it's essentially everyone who contributes patches at the userspace 
interfaces.

> The official(!) ABI says that pointers are supposed to be aligned with 4 
> bytes, not 2 bytes. It's the current implementation that violates the 
> ABI, not what I want to achieve which is make Linux/m68k adhere to the 
> official specification.
> 

You've mistaken the flock for the shepherd. And the map for the terrain(!)

But once you've been around the block a few times, you'll come to 
understand that standards lag best practice. They don't lead.

And then maybe you'll stop moving in circles.

Also, you've misunderstood he relationship between Linux and Unix. There 
is a long and colorful history there. You should look into it. 
https://en.wikipedia.org/wiki/SVR4#SVR6_(cancelled)

> Furthermore, we're still talking about a hobbyist platform here which 
> hasn't been in production use for more than ten years. It doesn't really 
> matter whether we break the ABI or not.
> 

By the same argument, since Debian is comprised of volunteers and 
hobbyists, it can be ignored by corporate-sponsored organizations, such as 
the Rust Foundation, and by upstream maintainers employed by for-profit 
companies. Yet they don't ignore us. Why do you think that is?

> And it's not like there isn't strong case for making this change. As I 
> have tirelessly explained, the current port with 2 bytes alignment is 
> simply no longer feasible since an increasing number of packages either 
> require 4 bytes alignment or require Rust.
> 
> These include more and more fundamental packages such as coreutils, the 
> kernel or various Python packages such as python-cryptography. It's 
> simply not an option to continue on the current path as it has become a 
> dead-end.
> 

Every CPU architecture is a dead end. This observation is as old as 
Moore's Law.

> I don't see the point in maintaining something that becomes increasingly 
> useless because more and more packages are no longer buildable.

That's because you still haven't identified those packages in the Debian 
archive which actually need porting.