Add ppoll() for all unix platforms

[Susurrus]

I'm unsure of whether there is support in OS X for this, and I can't find anything online (so I'm betting there isn't), but I'm going to let this run through CI to confirm.

[rust-highfive]

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[alexcrichton]

@bors: r+

Thanks!

[bors]

📌 Commit cd84475 has been approved by alexcrichton

[bors]

⌛ Testing commit cd84475 with merge 93525ec...

[Susurrus]

I have a local fix for the styling, so I already know about that, but I also ran things through my local test suite and found some errors I'm not understanding:

cargo:warning=/home/susurrus/Projects/libc/target/debug/build/libc-test-26b349ee79642880/out/all.c: In function ‘__test_fn_ppoll’:
cargo:warning=/home/susurrus/Projects/libc/target/debug/build/libc-test-26b349ee79642880/out/all.c:2830:24: error: return from incompatible pointer type [-Werror=incompatible-pointer-types]
cargo:warning=                 return ppoll;
cargo:warning=                        ^~~~~
cargo:warning=cc1: all warnings being treated as errors

But if I look at that file that function looks correct:

int (*_test_fn_ppoll(void))(struct pollfd*, nfds_t, int, const sigset_t*) {
    return ppoll;
}

I thought maybe it was because the sigset_t struct wasn't getting a struct keyword, but sigwait doesn't seem to have that problem.

[alexcrichton]

Let's see what CI says, it may just be a const/mut or bit width thing

[Susurrus]

That same problem is occurring on Travis, so there's definitely something wrong which I can reproduce locally.

I also pushed a style fix, but it looks like that retriggered CI, so maybe I shouldn't have done that yet...

[Susurrus]

Alright, I think I got it. Had the wrong type for timeout.

[Susurrus]

So turns out this doesn't exist on Mac or NetBSD, or at least not by that name. There are similar different names for pselect() or one of the other functions. But I couldn't find anything by googling, though I did find the name ppollts() for NetBSD, but I don't know if that's right. Any suggestions for how to resolve this one way or another for those platforms?

[alexcrichton]

It's ok to just leave out this function on those platforms, you can sink the definition farther down the crate hierarchy

[Susurrus]

I just pushed it down the stack, but I'm not certain that was correct. OpenBSD and FreeBSD passed their tests, so it's just NetBSD and Mac that don't have it. Should I also expose it in /src/unix/bsd/freebsdlike/mod.rs?

[Susurrus]

Alright, looks like I finally figured it out! @alexcrichton Wanna give this a look-see?

[alexcrichton]

@bors: r+

[bors]

📌 Commit 88e37f2 has been approved by alexcrichton

[bors]

⌛ Testing commit 88e37f2 with merge b9a0a6a...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: alexcrichton
Pushing b9a0a6a to master...