Add an Mmap wrapper to rustc_data_structures

[bjorn3]

This wrapper implements StableAddress and falls back to directly reading the file on wasm32.

Taken from #83640, which I will close due to the perf regression.

[rust-highfive]

Some changes occured to rustc_codegen_cranelift

cc @bjorn3

[rust-highfive]

r? @lcnr

(rust-highfive has picked a reviewer for you, use r? to override)

[bjorn3]

I don't think this is the cause of the perf regression in #83640, but just in case.

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit 8331dbe with merge 2d883ace5ff221db332b7155122d99e1cb8a3375...

[cjgillot]

Commit 8fcd03e7358ccb8f568ab3b34f3f31fac4b6ede9 also seems interessant to keep.

[bjorn3]

It seemed to be a tiny (<0.1%) regression on the other PR. I can to benchmark after this commit.

[bors]

☀️ Try build successful - checks-actions
Build commit: 2d883ace5ff221db332b7155122d99e1cb8a3375 (2d883ace5ff221db332b7155122d99e1cb8a3375)

[rust-timer]

Queued 2d883ace5ff221db332b7155122d99e1cb8a3375 with parent 16156fb, future comparison URL.

[rust-timer]

Finished benchmarking try commit (2d883ace5ff221db332b7155122d99e1cb8a3375): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[bjorn3]

This seems to be a slight regression on a few benchmarks. Trying with a few methods inlined.

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit 5773e51 with merge d95b884a112e6be1fc0a5c178a5404c031f491a8...

[bors]

☀️ Try build successful - checks-actions
Build commit: d95b884a112e6be1fc0a5c178a5404c031f491a8 (d95b884a112e6be1fc0a5c178a5404c031f491a8)

[rust-timer]

Queued d95b884a112e6be1fc0a5c178a5404c031f491a8 with parent 6ff482b, future comparison URL.

[rust-timer]

Finished benchmarking try commit (d95b884a112e6be1fc0a5c178a5404c031f491a8): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[bjorn3]

That seems to be slightly better. Now trying with 8fcd03e7358ccb8f568ab3b34f3f31fac4b6ede9 cherry-picked.

@bors try @rust-timer queue

[rust-timer]

Awaiting bors try build completion.

@rustbot label: +S-waiting-on-perf

[bors]

⌛ Trying commit 88a7e8f2248260f4af7910a0e14e8d672afede9b with merge c6b3d6133f84d4c800af3b32f46663a91f0ab432...

[bors]

☀️ Try build successful - checks-actions
Build commit: c6b3d6133f84d4c800af3b32f46663a91f0ab432 (c6b3d6133f84d4c800af3b32f46663a91f0ab432)

[rust-timer]

Queued c6b3d6133f84d4c800af3b32f46663a91f0ab432 with parent a5029ac, future comparison URL.

[rust-timer]

Finished benchmarking try commit (c6b3d6133f84d4c800af3b32f46663a91f0ab432): comparison url.

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. Please note that if the perf results are neutral, you should likely undo the rollup=never given below by specifying rollup- to bors.

Importantly, though, if the results of this run are non-neutral do not roll this PR up -- it will mask other regressions or improvements in the roll up.

@bors rollup=never
@rustbot label: +S-waiting-on-review -S-waiting-on-perf

[bjorn3]

Nope, that is a regression. Maybe due to the double metadata call by both this code and memmap2? I reverted it again. Ready for review.

[bjorn3]

Added the safety comment.

@bors r=cjgillot

[bors]

📌 Commit bda6d1f has been approved by cjgillot

[bors]

⌛ Testing commit bda6d1f with merge 97717a5...

[bors]

☀️ Test successful - checks-actions
Approved by: cjgillot
Pushing 97717a5 to master...