Limit impl_trait_header query to only trait impls

[camsteffen]

Changes impl_trait_header to panic on inherent impls intstead of returning None. A few downstream functions are split into option and non-option returning functions. This gets rid of a lot of unwraps where we know we have a trait impl, while there are still some cases where the Option is helpful.

Summary of changes to tcx methods:

• impl_is_of_trait (new)
• impl_trait_header -> impl_trait_header/impl_opt_trait_header
• impl_trait_ref -> impl_trait_ref/impl_opt_trait_ref
• trait_id_of_impl -> impl_trait_id/impl_opt_trait_id

[rustbot]

r? @jackh726

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They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

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[rustbot]

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes occurred to the CTFE machinery

cc @RalfJung, @oli-obk, @lcnr

Some changes occurred in compiler/rustc_sanitizers

cc @rcvalle

HIR ty lowering was modified

cc @fmease

[lqd]

@bors try @rust-timer queue

[rust-bors]

⌛ Trying commit c4b4025 with merge a9207a1…

To cancel the try build, run the command @bors try cancel.

[rust-bors]

💔 Test failed (CI). Failed jobs:

• bors build finished (web logs, extended logs)
• try - dist-x86_64-linux (web logs, extended logs)

[camsteffen]

@bors try @rust-timer queue

[rust-bors]

@camsteffen: 🔑 Insufficient privileges: not in try users

[lqd]

@bors try @rust-timer queue

[rust-bors]

⌛ Trying commit 35dbd1a with merge 60b45cb…

To cancel the try build, run the command @bors try cancel.

[rust-bors]

☀️ Try build successful (CI)
Build commit: 60b45cb (60b45cbaa7a7f0ea8340063c9bbac4ed081c245a, parent: cdccba87bf9ad5d87c1417eeb8fa52a4b614bbf9)

[rust-timer]

Finished benchmarking commit (60b45cb): comparison URL.

Overall result: ❌✅ regressions and improvements - BENCHMARK(S) FAILED

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

Next Steps: If you can justify the regressions found in this try perf run, please do so in sufficient writing along with @rustbot label: +perf-regression-triaged. If not, please fix the regressions and do another perf run. If its results are neutral or positive, the label will be automatically removed.

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

❗ ❗ ❗ ❗ ❗
Warning ⚠️: The following benchmark(s) failed to build:

• eza-0.21.2
• externs
• include-blob
• clap_derive-4.5.32
• serde-1.0.219
• wg-grammar
• syn-2.0.101
• unify-linearly
• ucd
• serde_derive-1.0.219
• cranelift-codegen-0.119.0
• regression-31157
• diesel-2.2.10
• bitmaps-3.2.1
• hyper-1.6.0
• ripgrep-14.1.1
• tuple-stress
• match-stress
• ctfe-stress-5
• derive
• deeply-nested-multi
• helloworld
• unicode-normalization-0.1.24
• wf-projection-stress-65510
• coercions
• stm32f4-0.15.1
• issue-58319
• html5ever-0.31.0
• projection-caching
• token-stream-stress
• tt-muncher
• serde-1.0.219-threads4
• large-workspace
• nalgebra-0.33.0
• many-assoc-items
• issue-46449
• image-0.25.6
• cargo-0.87.1
• typenum-1.18.0
• unused-warnings
• await-call-tree
• regex-automata-0.4.8
• issue-88862
• deep-vector
• libc-0.2.172

❗ ❗ ❗ ❗ ❗

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	2.4%	[0.2%, 3.7%]	9
Regressions ❌ (secondary)	0.5%	[0.4%, 0.5%]	3
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	1
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	1
All ❌✅ (primary)	2.1%	[-0.2%, 3.7%]	10

Max RSS (memory usage)

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

Cycles

Results (secondary -2.6%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.6%	[-3.1%, -2.3%]	5
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 469.046s -> 466.887s (-0.46%)
Artifact size: 376.81 MiB -> 376.87 MiB (0.02%)

[camsteffen]

Y'all think that's funny? 😤

Fixed the rustdoc issues from above.

[rustbot]

This PR was rebased onto a different master 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.

[camsteffen]

@bors r=lcnr

[bors]

📌 Commit d9a5389 has been approved by lcnr

It is now in the queue for this repository.

[bors]

⌛ Testing commit d9a5389 with merge 2170b4d...

[bors]

☀️ Test successful - checks-actions
Approved by: lcnr
Pushing 2170b4d 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 28fad95 (parent) -> 2170b4d (this PR)

Test differences

Show 100 test diffs

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

Test dashboard

Run

cargo run --manifest-path src/ci/citool/Cargo.toml -- \
test-dashboard 2170b4da847c9d75d400b13ba53bd47f749233bd --output-dir test-dashboard

And then open test-dashboard/index.html in your browser to see an overview of all executed tests.

Job duration changes

1. pr-check-1: 1441.0s -> 1756.7s (21.9%)
2. dist-apple-various: 4004.2s -> 3440.0s (-14.1%)
3. aarch64-apple: 7459.1s -> 8256.0s (10.7%)
4. dist-s390x-linux: 4846.4s -> 5346.6s (10.3%)
5. x86_64-gnu-llvm-20: 2805.8s -> 2525.1s (-10.0%)
6. armhf-gnu: 4825.4s -> 5270.2s (9.2%)
7. x86_64-rust-for-linux: 2736.4s -> 2976.1s (8.8%)
8. aarch64-msvc-2: 5142.0s -> 4691.7s (-8.8%)
9. x86_64-gnu-miri: 4714.8s -> 4302.3s (-8.7%)
10. x86_64-gnu-debug: 6680.5s -> 7233.0s (8.3%)

How to interpret the job duration changes?

Job durations can vary a lot, based on the actual runner instance
that executed the job, system noise, invalidated caches, etc. The table above is provided
mostly for t-infra members, for simpler debugging of potential CI slow-downs.

[rust-timer]

Finished benchmarking commit (2170b4d): comparison URL.

Overall result: ❌✅ regressions and improvements - please read the text below

Our benchmarks found a performance regression caused by this PR.
This might be an actual regression, but it can also be just noise.

Next Steps:

• If the regression was expected or you think it can be justified,
  please write a comment with sufficient written justification, and add
  @rustbot label: +perf-regression-triaged to it, to mark the regression as triaged.
• If you think that you know of a way to resolve the regression, try to create
  a new PR with a fix for the regression.
• If you do not understand the regression or you think that it is just noise,
  you can ask the @rust-lang/wg-compiler-performance working group for help (members of this group
  were already notified of this PR).

@rustbot label: +perf-regression
cc @rust-lang/wg-compiler-performance

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	0.2%	[0.2%, 0.2%]	1
Regressions ❌ (secondary)	0.2%	[0.1%, 0.2%]	11
Improvements ✅ (primary)	-0.6%	[-0.8%, -0.4%]	7
Improvements ✅ (secondary)	-1.8%	[-2.6%, -0.1%]	4
All ❌✅ (primary)	-0.5%	[-0.8%, 0.2%]	8

Max RSS (memory usage)

Results (primary -0.4%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	2.9%	[2.9%, 2.9%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-2.0%	[-3.3%, -0.7%]	2
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.4%	[-3.3%, 2.9%]	3

Cycles

Results (primary 3.0%, secondary -4.0%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	3.0%	[3.0%, 3.0%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-4.0%	[-4.9%, -2.7%]	3
All ❌✅ (primary)	3.0%	[3.0%, 3.0%]	1

Binary size

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

Bootstrap: 475.32s -> 475.309s (-0.00%)
Artifact size: 390.35 MiB -> 390.33 MiB (-0.00%)

[Mark-Simulacrum]

Some regressions on smaller benchmarks. My guess is that this hurts the case where there's lots of opt function lookups for that are now two query cache hit lookups rather than just one? But that seems to generally be less likely in our benchmarks than showing an improvement, so willing to just accept the regressions.