Fix unused_assignments false positives from macros #149147

chenyukang · 2025-11-20T12:57:50Z

rustbot · 2025-11-20T12:57:53Z

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

rustbot · 2025-11-20T12:57:55Z

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compiler/rustc_mir_transform/src/liveness.rs

workingjubilee · 2025-12-03T03:54:31Z

r? compiler

JonathanBrouwer · 2025-12-03T20:28:23Z

@bors r+ rollup

bors · 2025-12-03T20:28:26Z

📌 Commit f943606 has been approved by JonathanBrouwer

It is now in the queue for this repository.

…nments-macro-gen-147648, r=JonathanBrouwer Fix unused_assignments false positives from macros Fixes rust-lang#147648

Rollup of 12 pull requests Successful merges: - #147841 (Fix ICE when applying test macro to crate root) - #149147 (Fix unused_assignments false positives from macros) - #149183 (Use `TypingMode::PostAnalysis` in `try_evaluate_const`) - #149456 (std: don't call `current_os_id` from signal handler) - #149501 (CTFE: avoid emitting a hard error on generic normalization failures) - #149528 (reword error for invalid range patterns) - #149539 (Additional test for uN::{gather,scatter}_bits) - #149549 (Regression test for system register `ttbr0_el2`) - #149550 (Disable native-lib for x check miri) - #149554 (build-manifest: generate MSI and MINGW arrays from rustc) - #149557 (c-variadic: bpf and spirv do not support c-variadic definitions) - #149569 (Fix mailmap issue) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer Fix unused_assignments false positives from macros Fixes #147648

Kobzol · 2025-12-04T12:50:37Z

@rust-timer build 4da4cc5

For #149631 (comment).

Kobzol · 2025-12-04T13:51:23Z

@rust-timer build 4da4cc5

rust-timer · 2025-12-04T16:29:23Z

Finished benchmarking commit (4da4cc5): comparison URL.

Overall result: ❌ regressions - please read the text below

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

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)	7.4%	[0.1%, 25.0%]	10
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (primary -1.0%, secondary 11.1%)

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)	14.4%	[10.4%, 19.2%]	4
Improvements ✅ (primary)	-1.0%	[-1.0%, -1.0%]	1
Improvements ✅ (secondary)	-2.2%	[-2.2%, -2.2%]	1
All ❌✅ (primary)	-1.0%	[-1.0%, -1.0%]	1

Cycles

Results (secondary 23.6%)

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)	23.6%	[4.3%, 40.2%]	4
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 468.789s -> 468.96s (0.04%)
Artifact size: 386.75 MiB -> 386.76 MiB (0.00%)

JonathanBrouwer · 2025-12-04T16:46:47Z

Oh wow I did not expect that regression from such a simple check.
Is .in_external_macro a slow check?
@chenyukang Do you have the time to look into this?

workingjubilee · 2025-12-04T18:01:39Z

I'm expecting the answer to be "no" but I want to be sure we're confirming that answer given this is a beta regression:

@rustbot label +beta-nominated

…ed_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b3, reversing changes made to 5019bda.

Kobzol · 2025-12-04T20:18:17Z

Posted a revert in #149657.

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer"

chenyukang · 2025-12-05T04:07:00Z

I'm on travel right now, will have a check it later.
seems the new testing code is on a hot path.

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b3, reversing changes made to 5019bda. Reverts #149147 due to a [perf regression](#149147 (comment)).

apiraino · 2025-12-08T10:57:56Z

Beta backport declined as per discussion on Zulip.

@rustbot label -beta-nominated

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b30d8cd379a43c3ee8d12598e89e3be0fbd, reversing changes made to 5019bdaefeebecac42b778ae98def56cab69ab30. Reverts rust-lang/rust#149147 due to a [perf regression](rust-lang/rust#149147 (comment)).

Rollup of 12 pull requests Successful merges: - rust-lang/rust#147841 (Fix ICE when applying test macro to crate root) - rust-lang/rust#149147 (Fix unused_assignments false positives from macros) - rust-lang/rust#149183 (Use `TypingMode::PostAnalysis` in `try_evaluate_const`) - rust-lang/rust#149456 (std: don't call `current_os_id` from signal handler) - rust-lang/rust#149501 (CTFE: avoid emitting a hard error on generic normalization failures) - rust-lang/rust#149528 (reword error for invalid range patterns) - rust-lang/rust#149539 (Additional test for uN::{gather,scatter}_bits) - rust-lang/rust#149549 (Regression test for system register `ttbr0_el2`) - rust-lang/rust#149550 (Disable native-lib for x check miri) - rust-lang/rust#149554 (build-manifest: generate MSI and MINGW arrays from rustc) - rust-lang/rust#149557 (c-variadic: bpf and spirv do not support c-variadic definitions) - rust-lang/rust#149569 (Fix mailmap issue) r? `@ghost` `@rustbot` modify labels: rollup

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b30d8cd379a43c3ee8d12598e89e3be0fbd, reversing changes made to 5019bdaefeebecac42b778ae98def56cab69ab30. Reverts rust-lang/rust#149147 due to a [perf regression](rust-lang/rust#149147 (comment)).

Revert "Rollup merge of rust-lang#149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b3, reversing changes made to 5019bda. Reverts rust-lang#149147 due to a [perf regression](rust-lang#149147 (comment)).

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b30d8cd379a43c3ee8d12598e89e3be0fbd, reversing changes made to 5019bdaefeebecac42b778ae98def56cab69ab30. Reverts rust-lang/rust#149147 due to a [perf regression](rust-lang/rust#149147 (comment)).

…ed_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b3, reversing changes made to 5019bda. (cherry picked from commit 7438715)

[beta] backports - Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" #149657 - Don't lint on interior mutable `const` item coming from derefs #150166 - stdarch subtree update #150639 (partial) r? cuviper

[beta] backports - Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" #149657 - Don't lint on interior mutable `const` item coming from derefs #150166 - stdarch subtree update #150639 (partial) - Update bors configuration #150308 - Update bors e-mail lookup #150783 - Make verify-channel.sh script compatible with new bors #150759 r? cuviper

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 Nov 20, 2025

rustbot assigned SparrowLii Nov 20, 2025

cjgillot reviewed Nov 21, 2025

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compiler/rustc_mir_transform/src/liveness.rs Outdated Show resolved Hide resolved

chenyukang force-pushed the yukang-fix-unused_assignments-macro-gen-147648 branch from 0f7c6a0 to c21d817 Compare November 21, 2025 03:58

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Fix unused_assignments false positives from macros

f943606

chenyukang force-pushed the yukang-fix-unused_assignments-macro-gen-147648 branch from c21d817 to f943606 Compare November 21, 2025 04:20

rustbot assigned JonathanBrouwer and unassigned SparrowLii Dec 3, 2025

workingjubilee mentioned this pull request Dec 3, 2025

rustc 1.92.0-beta3 flags unreachable code where there is none #149571

Closed

bors 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 Dec 3, 2025

Zalathar added a commit to Zalathar/rust that referenced this pull request Dec 4, 2025

Rollup merge of rust-lang#149147 - chenyukang:yukang-fix-unused_assig…

62c8df1

…nments-macro-gen-147648, r=JonathanBrouwer Fix unused_assignments false positives from macros Fixes rust-lang#147648

Zalathar added a commit to Zalathar/rust that referenced this pull request Dec 4, 2025

Rollup merge of rust-lang#149147 - chenyukang:yukang-fix-unused_assig…

24cfe98

…nments-macro-gen-147648, r=JonathanBrouwer Fix unused_assignments false positives from macros Fixes rust-lang#147648

Zalathar mentioned this pull request Dec 4, 2025

Rollup of 14 pull requests #149628

Closed

This was referenced Dec 4, 2025

Rollup of 13 pull requests #149629

Closed

Rollup of 12 pull requests #149631

Merged

bors merged commit 82a17b3 into rust-lang:main Dec 4, 2025
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rustbot added this to the 1.93.0 milestone Dec 4, 2025

rust-timer added a commit that referenced this pull request Dec 4, 2025

Unrolled build for #149147

4da4cc5

Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer Fix unused_assignments false positives from macros Fixes #147648

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rustbot added the perf-regression Performance regression. label Dec 4, 2025

rustbot added the beta-nominated Nominated for backporting to the compiler in the beta channel. label Dec 4, 2025

Kobzol mentioned this pull request Dec 4, 2025

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer" #149657

Merged

Kobzol added a commit to Kobzol/rust that referenced this pull request Dec 4, 2025

Revert "Rollup merge of rust-lang#149147 - chenyukang:yukang-fix-unus…

7438715

…ed_assignments-macro-gen-147648, r=JonathanBrouwer" This reverts commit 82a17b3, reversing changes made to 5019bda.

rust-bors bot added a commit that referenced this pull request Dec 4, 2025

Auto merge of #149657 - Kobzol:revert-149147, r=<try>

9177f5d

Revert "Rollup merge of #149147 - chenyukang:yukang-fix-unused_assignments-macro-gen-147648, r=JonathanBrouwer"

rustbot removed the beta-nominated Nominated for backporting to the compiler in the beta channel. label Dec 8, 2025

huitseeker mentioned this pull request Dec 8, 2025

Revert "chore: remove obsolete allow(unused_assignments)" 0xMiden/miden-vm#2442

Closed

traviscross mentioned this pull request Dec 12, 2025

nightly unused_assignments false positives for miette::Diagnostic fields #147648

Open

cuviper mentioned this pull request Jan 9, 2026

[beta] backports #150848

Merged

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Fix unused_assignments false positives from macros #149147

Fix unused_assignments false positives from macros #149147

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rust-timer commented Dec 4, 2025

Overall result: ❌ regressions - please read the text below

Instruction count

Max RSS (memory usage)

Cycles

Binary size

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