QNX target renaming

[jonathanpallant]

This PR renames two QNX targets:

• aarch64-unknown-nto-qnx800 becomes simply aarch64-unknown-qnx
• x86_64-pc-nto-qnx800 becomes simply x86_64-pc-qnx

In addition:

• references to QNX OS and QNX Neutrino RTOS are replaced with QNX SDP for uniformity
• the spec::base::nto_qnx module is renamed to base::spec::qnx_sdp to match the above
• the target_os of the QNX SDP 8.0 targets is changed to qnx to match the target name
• a lot of code is then touched to handle any(target_os = "nto", target_os = "qnx")

I think it's worth noting that QNX Software Development Platform is the build environment that you download and install, and you can use it to create a custom run-time environment. In SDP 7.x the run-time environment was based on QNX Neutrino 7.x, but in SDP 8.0 the run-time environment is based on QNX OS 8.0. I think it was weird to users to see the two different run-time environments in the docs, and referring to the build environment just seems to make more sense anyway because that's what users install, it's where the headers live, and ultimately it's what the toolchain will care about.

The new target names match those reported by clang running on the self-hosted QNX Developer Desktop.

$ clang --version
QNX clang version 21.1.3
Target: x86_64-pc-qnx
Thread model: posix
InstalledDir: /usr/bin

Once the compiler knows about the new target names, libc, backtrace and cc-rs can be updated to match, and then building libstd for the new targets can be fixed. This rename will cause a bit of churn, but it seemed important to get it changed before anyone tries to finish libstd support for QNX SDP 8.0 (it's currently noted as "in-progress"). It's also Tier 3 so we have fairly broad latitude to do this I think, and aligning with QNX's build of clang just makes sense.

With these changes I can run:

$ ./x build library/std --stage 2 --target x86_64-pc-nto-qnx710,aarch64-unknown-nto-qnx710,x86_64-pc-nto-qnx710_iosock,aarch64-unknown-nto-qnx710_iosock,aarch64-unknown-nto-qnx700
$ ./x build library/core --stage 1 --target x86_64-pc-qnx,aarch64-unknown-qnx

The QNX SDP 7.x targets retain their old names, and their target_os = "nto", target_env = "qnx710" configuration, to avoid breakage.

[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

miri is developed in its own repository. If possible, consider making this change to rust-lang/miri instead.

cc @rust-lang/miri

Some changes occurred in src/doc/rustc/src/platform-support

cc @Noratrieb

[rustbot]

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[jonathanpallant]

Fixing those stderr failures now.

[rustbot]

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

[workingjubilee]

Can we get a comment in some file explaining that "SDP" implies, functionally, both "the C toolchain" and "the libc"? Or a clarification on that relationship, if that's off? Perhaps one of the std::sys files or on the platform support page? I think it is implied by the current text but with more emphasis on the term it feels a bit more ambiguous, ironically, via repetition.

I skimmed over things and everything seems fine otherwise, though it may benefit from another scan. Mostly just nits and me going "that's odd... eh, doesn't matter, right?"

View changes since this review

[workingjubilee]

...shouldn't it be aarch64-blackberry-qnx...? ...Well, I'm not gonna push on that, they can pretend no one knows who they are if that's how they want to brand things. :^)

[workingjubilee]

Q?

Suggested change

	# Q
	# QNX

[workingjubilee]

A quirk of the current irregular shape is that "pairs" of OS that "resemble each other" are grouped onto the same line, so maybe "target_os = "nto" should be on the same line as target_os = "qnx"? But I don't know how intentional that is.

[workingjubilee]

there isn't a "latest version" link, is there?

[rust-bors]

☔ The latest upstream changes (presumably #158508) made this pull request unmergeable. Please resolve the merge conflicts by rebasing.

[jonathanpallant]

Can we get a comment in some file explaining that "SDP" implies, functionally, both "the C toolchain" and "the libc"? Or a clarification on that relationship, if that's off? Perhaps one of the std::sys files or on the platform support page? I think it is implied by the current text but with more emphasis on the term it feels a bit more ambiguous, ironically, via repetition.

How about if I take the text from the PR description and put it on the QNX target doc page?

But you are right, the SDP contains a C toolchain, libc, other libraries, headers - all the ingredients to build your own OS image.

[workingjubilee]

How about if I take the text from the PR description and put it on the QNX target doc page?

That is absolutely fine!

[JohnTitor]

r? workingjubilee

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