Pass -bind_at_load on macOS

Here is a PR from a new contributor: https://github.com/torproject/tor/pull/1655

changed milestone to %Tor: 0.4.4.x-final

added component::core tor/tor macos milestone::Tor: 0.4.4.x-final priority::medium resolution::wontfix reviewer::nickm reviewer::teor severity::normal status::closed type::enhancement labels

Trac:
Status: new to needs_review

This is essentially the equivalent of passing

-Wl,-z,now

on Linux.

Trac:
Username: rex4539

What is the reason for doing this?

Replying to nickm:

What is the reason for doing this?

The original PR says that it reduces the tor binary size by about 5.5 kilobytes on macOS: https://github.com/torproject/tor/pull/1655

However, it's a risky change if we're using weak linking on macOS or iOS (which I don't think we do, but other tor packagers might). I think if we try to bind all symbols at launch, and the current macOS doesn't have an optional symbol, we'll crash at launch. (Rather than testing if the optional symbol is NULL, or if we don't test, crashing when we use that symbol.)

So if I'm figuring right, 5.5k is currently around .05% (that is, 5% of 1%) of the binary size? Right now, I don't think a savings that small is worth even a small amount of risk, if that's the only motivation.

Is there anything else going on here?

Trac:
Reviewer: N/A to teor, nickm
Keywords: N/A deleted, macos added

I've commented on the PR asking for more information.

If the small binary size reduction is not worth it, there is no other useful side effect I'm aware of.

Thanks for reviewing.

Trac:
Username: rex4539

Thanks for submitting the patch!

Sorry we weren't able to accept it.

Trac:
Status: needs_review to closed
Resolution: N/A to wontfix

closed

moved to tpo/core/tor#33092 (closed)