Provide optional Read/Write methods for stdio

[thaliaarchi]

Override more of the default methods for io::Read and io::Write for stdio types, when efficient to do so, and deduplicate unsupported types.

Tracked in #136756.

try-job: x86_64-msvc-1

[rustbot]

r? @Noratrieb

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[thaliaarchi]

@joboet Looks like you wrote #136780 to have minimum conflicts to this. Thanks for that. I don't mind rebasing onto that, if yours is merged first.

[Noratrieb]

r? joboet

[thaliaarchi]

I dropped a few commits from this PR:

• 5da7fbe (Fix unsafe_op_in_unsafe_fn for TEEOS), because Apply unsafe_op_in_unsafe_fn to the standard library #136986 is in the merge queue
• 1a08321 (Deduplicate unsupported fs.rs for UEFI) per Nora's note
• 1b05019 (Remove unused methods on Hermit FileDesc), because that would be a better fit for a file-focused PR.

[thaliaarchi]

Since this touches a lot of targets, I'm going to split this into multiple PRs for more target-focused review, once #136780 goes through the merge queue.

[joboet]

Since this touches a lot of targets, I'm going to split this into multiple PRs for more target-focused review, once #136780 goes through the merge queue.

That'd be great, thank you! Especially the SGX stuff would be much simpler to review as a dedicated PR.

[bors]

⌛ Trying commit 46e3e46 with merge 4fff642...

[thaliaarchi]

That's a strange failure, since this PR changes nothing for Windows and the other PRs look platform-independent. I'm curious what the try run will report.

I reviewed it again and noticed that write_fmt shouldn't be stubbed like std::io::Sink. It's not appropriate for some platforms to not expand the fmt::Arguments, so I've reverted that bit.

[thaliaarchi]

@tgross35 The try job passed

[tgross35]

Weird, nothing else in that rollup seems like it could have had an affect on those tests.

@bors r=joboet

[bors]

📌 Commit f6e90d8 has been approved by joboet

It is now in the queue for this repository.

[tgross35]

Actually, the other PRs in that rollup all merged. This wouldn't make it into a rollup for a few hours, so might as well use that time to try again on top of everything else in case it interacted with another PR somehow.

@bors r-
@bors try

[bors]

⌛ Trying commit f6e90d8 with merge 533535adca65287b0e54b123821057231cd51bc8...

[bors]

☀️ Try build successful - checks-actions
Build commit: 533535a (533535adca65287b0e54b123821057231cd51bc8)

[thaliaarchi]

Probably just a spurious failure then?

[tgross35]

I guess so, that’s just a weirdly specific failure to be spurious.

@bors r=joboet

[bors]

📌 Commit f6e90d8 has been approved by joboet

It is now in the queue for this repository.

[bors]

⌛ Testing commit f6e90d8 with merge 60a3084f64607e86dd7715d72f11764cd500c364...

[bors]

☀️ Test successful - checks-actions
Approved by: joboet
Pushing 60a3084 to master...

[github-actions]

What is this?

This is an experimental post-merge analysis report that shows differences in test outcomes between the merged PR and its parent PR.

Comparing f08d5c0 (parent) -> 60a3084 (this PR)

Test differences

Show 60 test diffs

Additionally, 60 doctest diffs were found. These are ignored, as they are noisy.

Job group index

[rust-timer]

Finished benchmarking commit (60a3084): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results (primary -3.1%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.1%	[-3.1%, -3.1%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.1%	[-3.1%, -3.1%]	1

Cycles

Results (secondary 3.7%)

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.7%	[3.7%, 3.7%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 774.928s -> 774.048s (-0.11%)
Artifact size: 365.54 MiB -> 365.55 MiB (0.00%)