libdispatch for PowerPC

[barracuda156]

@iains Turned out that libdispatch builds fine with system toolchain without any need for blocks support. This is a preliminary thing, but it produces a library:
https://ports.macports.org/port/libdispatch-legacy

Question is, how could we try using it? On 10.6 it is baked into libSystem, but at the moment we can only install it as a standalone thing.
What I am not sure about is whether it is usable without blocks (and if yes then to what extent).

What do you think?

[iains]

I doubt it is going to do much without blocks support. FWIW I have made some progress in bringing the blocks support forward (at least to GCC-10) .. but limited time, as always, means it goes slowly.

[barracuda156]

@iains Is there a branch which can be tried?

(And on a general note, if we could be helpful with testing something, please let me know. Perhaps Kirill @catap may be interested too.)

[iains]

I promise to tell you folks as soon as there is - right now there's still work to do (but less than before :) )

[iains]

@iains Turned out that libdispatch builds fine with system toolchain without any need for blocks support. This is a preliminary thing, but it produces a library: https://ports.macports.org/port/libdispatch-legacy

What do you think?

Actually, I'd be more concerned that full functionality might need kernel support (for some reason, I have it in mind that was the case) - but I guess if it built OK (without warnings?) then my memory must be faulty.

[barracuda156]

Actually, I'd be more concerned that full functionality might need kernel support (for some reason, I have it in mind that was the case) - but I guess if it built OK (without warnings?) then my memory must be faulty.

By the way, what prevented us from rebuilding libSystem from sources? Lack of clear documentation and time, or it is known that something is broken beyond repair in that regard?

[iains]

"broken beyond repair" == incomplete sources, AFAIR (you'd need to check the Apple open source distributions) . We can probably build significant chunks (esp. libc) but not sure we can build all of it. Time to investigate and work around anything that's missing would, indeed, be a second factor.

[barracuda156]

@iains By the way, if you will be interested to try, this port installs libdispatch and should build on 10.5.8 and 10.6 (Tiger not been tried): https://ports.macports.org/port/libdispatch-legacy

While it uses Macports for the build, there are no dependencies besides Xcode, and it does not link to anything in Macports prefix. It installs everything into ${prefix}/libexec/dispatch, so in principle prepending ${prefix}/libexec/dispatch/usr to PATH should make it available for usage, or otherwise just manually copy libs and headers wherever desired.

[barracuda156]

@iains Just as a quick update on the matter (no action required): while I think I have built it on 10.5.8 as well, I got ICE yesterday when trying to do that.

So at the moment I can only say for the fact that it builds on 10.6 for ppc (this has been verified on two different systems).