interpret: correctly deal with repr(transparent) enums by RalfJung · Pull Request #156105 · rust-lang/rust

RalfJung · 2026-05-03T11:52:24Z

Fixes rust-lang/miri#4998

rustbot · 2026-05-03T11:52:26Z

Some changes occurred to the CTFE / Miri interpreter

cc @rust-lang/miri

The Miri subtree was changed

cc @rust-lang/miri

Some changes occurred to the CTFE machinery

cc @oli-obk, @lcnr

rustbot · 2026-05-03T11:52:28Z

r? @nikomatsakis

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lcnr · 2026-05-05T15:22:12Z

r? lcnr

@bors r+ rollup

rust-bors · 2026-05-05T15:22:15Z

📌 Commit a6d6601 has been approved by lcnr

It is now in the queue for this repository.

interpret: correctly deal with repr(transparent) enums Fixes rust-lang/miri#4998

Rollup of 12 pull requests Successful merges: - #155341 (generic_const_args: allow paths to non type consts) - #156062 (Added command-line argument support for `wasm32-wali-linux-musl`) - #156159 ([AIX] add -bdbg:namedsects:ss link arg) - #156174 (Wasm: remove implicit `__heap_base`/`__data_end` exports) - #156186 (fix: remap ci-llvm debug paths via `-ffile-prefix-map`) - #156193 (port `rustc_ast*` crates from `box_` to `deref_patterns`) - #156201 (Don't run ui-fulldeps tests twice in stage 1) - #155808 (Always use `ConstFn` context for `const` closures) - #156105 (interpret: correctly deal with repr(transparent) enums) - #156148 (Use `all_impls` instead of handrolling it) - #156156 (Adjust getMCSubtargetInfo signature for LLVM 23+) - #156205 (move generalization test)

Rollup of 15 pull requests Successful merges: - #151122 (fix: more descriptive error message for enum to integer) - #155341 (generic_const_args: allow paths to non type consts) - #156062 (Added command-line argument support for `wasm32-wali-linux-musl`) - #156159 ([AIX] add -bdbg:namedsects:ss link arg) - #156174 (Wasm: remove implicit `__heap_base`/`__data_end` exports) - #156186 (fix: remap ci-llvm debug paths via `-ffile-prefix-map`) - #156193 (port `rustc_ast*` crates from `box_` to `deref_patterns`) - #156201 (Don't run ui-fulldeps tests twice in stage 1) - #155808 (Always use `ConstFn` context for `const` closures) - #156105 (interpret: correctly deal with repr(transparent) enums) - #156148 (Use `all_impls` instead of handrolling it) - #156156 (Adjust getMCSubtargetInfo signature for LLVM 23+) - #156170 (add known-bug test for coroutine 'static-yields-non-'static unsoundness (#144442)) - #156195 (Move tests codegen) - #156205 (move generalization test)

Rollup merge of #156105 - RalfJung:transparent-enums, r=lcnr interpret: correctly deal with repr(transparent) enums Fixes rust-lang/miri#4998

Rollup of 15 pull requests Successful merges: - rust-lang/rust#151122 (fix: more descriptive error message for enum to integer) - rust-lang/rust#155341 (generic_const_args: allow paths to non type consts) - rust-lang/rust#156062 (Added command-line argument support for `wasm32-wali-linux-musl`) - rust-lang/rust#156159 ([AIX] add -bdbg:namedsects:ss link arg) - rust-lang/rust#156174 (Wasm: remove implicit `__heap_base`/`__data_end` exports) - rust-lang/rust#156186 (fix: remap ci-llvm debug paths via `-ffile-prefix-map`) - rust-lang/rust#156193 (port `rustc_ast*` crates from `box_` to `deref_patterns`) - rust-lang/rust#156201 (Don't run ui-fulldeps tests twice in stage 1) - rust-lang/rust#155808 (Always use `ConstFn` context for `const` closures) - rust-lang/rust#156105 (interpret: correctly deal with repr(transparent) enums) - rust-lang/rust#156148 (Use `all_impls` instead of handrolling it) - rust-lang/rust#156156 (Adjust getMCSubtargetInfo signature for LLVM 23+) - rust-lang/rust#156170 (add known-bug test for coroutine 'static-yields-non-'static unsoundness (rust-lang/rust#144442)) - rust-lang/rust#156195 (Move tests codegen) - rust-lang/rust#156205 (move generalization test)

Kobzol · 2026-05-12T11:53:38Z

@rust-timer build 918aaa3

Testing for #156217.

rust-timer · 2026-05-12T13:16:09Z

Finished benchmarking commit (918aaa3): comparison URL.

Overall result: ❌✅ regressions and improvements - please read:

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

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

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
Regressions ❌ (secondary)	0.7%	[0.0%, 1.0%]	8
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.1%, -0.0%]	3
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary 2.2%, secondary -0.8%)

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

	mean	range	count
Regressions ❌ (primary)	2.2%	[2.2%, 2.2%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-1.4%, -0.4%]	4
All ❌✅ (primary)	2.2%	[2.2%, 2.2%]	1

Cycles

Results (secondary 0.5%)

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)	0.8%	[0.4%, 1.1%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.4%	[-0.4%, -0.4%]	1
All ❌✅ (primary)	-	-	0

Binary size

Results (primary 0.1%, secondary 0.1%)

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

	mean	range	count
Regressions ❌ (primary)	0.1%	[0.0%, 0.1%]	31
Regressions ❌ (secondary)	0.1%	[0.0%, 0.1%]	21
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.1%	[0.0%, 0.1%]	31

Bootstrap: 493.455s -> 494.183s (0.15%)
Artifact size: 394.43 MiB -> 396.48 MiB (0.52%)

Kobzol · 2026-05-12T13:19:01Z

Huh, this seems to have the same regression as #155808.

RalfJung · 2026-05-12T13:30:31Z

Probably flaky tests that keep flipping between two states.

interpret: correctly deal with repr(transparent) enums

a6d6601

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels May 3, 2026

rustbot assigned nikomatsakis May 3, 2026

rustbot assigned lcnr and unassigned nikomatsakis May 5, 2026

rust-bors Bot added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels May 5, 2026

jhpratt added a commit to jhpratt/rust that referenced this pull request May 5, 2026

Rollup merge of rust-lang#156105 - RalfJung:transparent-enums, r=lcnr

4db4248

interpret: correctly deal with repr(transparent) enums Fixes rust-lang/miri#4998

jhpratt mentioned this pull request May 5, 2026

Rollup of 12 pull requests #156207

Closed

jhpratt added a commit to jhpratt/rust that referenced this pull request May 5, 2026

Rollup merge of rust-lang#156105 - RalfJung:transparent-enums, r=lcnr

cdf9df0

interpret: correctly deal with repr(transparent) enums Fixes rust-lang/miri#4998

jhpratt mentioned this pull request May 5, 2026

Rollup of 12 pull requests #156213

Closed

jhpratt mentioned this pull request May 6, 2026

Rollup of 15 pull requests #156217

Merged

rust-bors Bot merged commit 38bbf33 into rust-lang:main May 6, 2026
11 checks passed

rust-timer added a commit that referenced this pull request May 6, 2026

Unrolled build for #156105

918aaa3

Rollup merge of #156105 - RalfJung:transparent-enums, r=lcnr interpret: correctly deal with repr(transparent) enums Fixes rust-lang/miri#4998

RalfJung deleted the transparent-enums branch May 9, 2026 11:11

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interpret: correctly deal with repr(transparent) enums#156105

interpret: correctly deal with repr(transparent) enums#156105
rust-bors[bot] merged 1 commit into
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RalfJung:transparent-enums

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Overall result: ❌✅ regressions and improvements - please read:

Instruction count

Max RSS (memory usage)

Cycles

Binary size

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