[stdlib] Buildfix getting stack bounds on OpenBSD.

[3405691582]

OpenBSD doesn't have pthread_attr_get_np and expects something like
pthread_attr_getstackaddr to be used to get the initial stack size.
We need to use pthread_stackseg_np on this platform to get the
stack size and location of pthread_self.

[3405691582]

cc @grynspan

[3405691582]

FTR, the buildbreak was in Stubs.cpp in #37666.

[grynspan]

@swift-ci please test

[grynspan]

Please note swift-ci does not run tests on OpenBSD and it's not a platform actively supported by the Swift team at this time. Can you confirm:

1. You were able to build for OpenBSD with this change, and
2. The "temporary_allocation" and "TemporaryAllocation" tests ran successfully on OpenBSD with this change?

[3405691582]

You were able to build for OpenBSD with this change, and

Correct.

(I made an earlier comment about a little confused about which pointer should be which in this stub, but I deleted it since think I've sorted it out now.)

The "temporary_allocation" and "TemporaryAllocation" tests ran successfully on OpenBSD with this change?

There are a number of other unrelated issues that are currently preventing some of the automated tests from running that I need to debug and fix. However, I can extract the actual test executable build commands from test/stdlib/TemporaryAllocation.swift and run the result manually (e.g., running the result ./build/Ninja-DebugAssert/swift-openbsd-amd64/test-openbsd-amd64/stdlib/Output/TemporaryAllocation.swift.tmp/a.out). This ends in TemporaryAllocation: All tests passed.

I can't find a temporary_allocation test, but swift/test/SILGen/memberwise_init_temporary_allocations.swift passes.

[grynspan]

I can't find a temporary_allocation test, but swift/test/SILGen/memberwise_init_temporary_allocations.swift passes.

Those tests are located in swift/test/IRGen/temporary_allocation/. There are multiple test files. I do not expect them to fail if they were passing previously since the change you made should not affect SIL or IR. At least on macOS, you can run just the temporary allocation IRGen tests with this command:

utils/run-test --lit ../llvm-project/llvm/utils/lit/lit.py \
  ../build/Ninja-RelWithDebInfoAssert/swift-macosx-$(uname -m)/test-macosx-$(uname -m) \
  --filter="temporary_allocation"

I'm not certain how to modify that command to work on OpenBSD (I imagine just replacing macosx with openbsd?)

[3405691582]

Got it. Both swift/test/IRGen/temporary_allocation and swift/test/stdlib/TemporaryAllocation.swift are passing.

[swift-ci]

Build failed
Swift Test Linux Platform
Git Sha - b5135fa

[3405691582]

Test failures appear unrelated.

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - b5135fa

[grynspan]

@swift-ci please test

[lorentey]

Thank you! 👍