Various proc-macro related code cleanups by bjorn3 · Pull Request #157076 · rust-lang/rust

bjorn3 · 2026-05-28T17:03:54Z

Some are just misc cleanups. Others are to make the proc-macro ABI and RPC interface a bit less target dependent. I've got some local changes that change the ABI to what is effectively a single &[extern "C" fn(BridgeConfig<'_>) -> Buffer] export.

This makes the proc-macro RPC protocol platform independent as necessary for running proc macros and rustc on different architectures.

rustbot · 2026-05-28T17:04:00Z

r? @petrochenkov

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Owners of files modified in this PR: @petrochenkov

This shrinks the proc-macro ABI a bit. Nothing on the client side needs to allocate handles. This will share the counters between proc-macros, which may cause us to run out of handles earlier, but 4 bilion handles per process is still a lot. Rust-analyzer might run out at some point, but it can recover by restarting the proc-macro-server, and it could already run out before this change anyway,

petrochenkov · 2026-05-29T10:28:35Z

cc @cyrgani

petrochenkov · 2026-05-29T10:44:22Z

@bors r+

rust-bors · 2026-05-29T10:44:25Z

📌 Commit d31c731 has been approved by petrochenkov

It is now in the queue for this repository.

🌲 The tree is currently closed for pull requests below priority 1. This pull request will be tested once the tree is reopened.

…trochenkov Various proc-macro related code cleanups Some are just misc cleanups. Others are to make the proc-macro ABI and RPC interface a bit less target dependent. I've got some local changes that change the ABI to what is effectively a single `&[extern "C" fn(BridgeConfig<'_>) -> Buffer]` export.

…uwer Rollup of 9 pull requests Successful merges: - #156963 (definitions: remove `DefPathTable`, use `LocalDefId` instead of `DefIndex`) - #157053 (Eagerly resolve delegations in late resolution) - #157068 (NVPTX: Remove the unstable ptx linker flavor) - #157076 (Various proc-macro related code cleanups) - #157100 (Some more per owner things) - #157065 (Stabilize `Path::is_empty`) - #157070 (Remove `skip_arg` attribute from `Diagnostic` and `Subdiagnostic` proc-macros) - #157088 (Improve suggestions for malformed deprecated attribute) - #157103 (Add reproducibly failing tests for parallel frontend)

…trochenkov Various proc-macro related code cleanups Some are just misc cleanups. Others are to make the proc-macro ABI and RPC interface a bit less target dependent. I've got some local changes that change the ABI to what is effectively a single `&[extern "C" fn(BridgeConfig<'_>) -> Buffer]` export.

…uwer Rollup of 11 pull requests Successful merges: - #156960 (Some cleanups around passing extra lifetime params from the resolver to ast lowering) - #156963 (definitions: remove `DefPathTable`, use `LocalDefId` instead of `DefIndex`) - #157053 (Eagerly resolve delegations in late resolution) - #157068 (NVPTX: Remove the unstable ptx linker flavor) - #157076 (Various proc-macro related code cleanups) - #157106 (add ABI check logic for wasm) - #154835 (std::offload sharedmem) - #157065 (Stabilize `Path::is_empty`) - #157070 (Remove `skip_arg` attribute from `Diagnostic` and `Subdiagnostic` proc-macros) - #157088 (Improve suggestions for malformed deprecated attribute) - #157103 (Add reproducibly failing tests for parallel frontend) Failed merges: - #157100 (Some more per owner things)

…trochenkov Various proc-macro related code cleanups Some are just misc cleanups. Others are to make the proc-macro ABI and RPC interface a bit less target dependent. I've got some local changes that change the ABI to what is effectively a single `&[extern "C" fn(BridgeConfig<'_>) -> Buffer]` export.

…uwer Rollup of 11 pull requests Successful merges: - #149195 (resolve: Partially convert `ambiguous_glob_imports` lint into a hard error) - #156960 (Some cleanups around passing extra lifetime params from the resolver to ast lowering) - #156963 (definitions: remove `DefPathTable`, use `LocalDefId` instead of `DefIndex`) - #157053 (Eagerly resolve delegations in late resolution) - #157068 (NVPTX: Remove the unstable ptx linker flavor) - #157076 (Various proc-macro related code cleanups) - #157106 (add ABI check logic for wasm) - #154835 (std::offload sharedmem) - #157065 (Stabilize `Path::is_empty`) - #157088 (Improve suggestions for malformed deprecated attribute) - #157103 (Add reproducibly failing tests for parallel frontend) Failed merges: - #157100 (Some more per owner things)

…uwer Rollup of 16 pull requests Successful merges: - #149195 (resolve: Partially convert `ambiguous_glob_imports` lint into a hard error) - #156960 (Some cleanups around passing extra lifetime params from the resolver to ast lowering) - #156963 (definitions: remove `DefPathTable`, use `LocalDefId` instead of `DefIndex`) - #157053 (Eagerly resolve delegations in late resolution) - #157068 (NVPTX: Remove the unstable ptx linker flavor) - #157076 (Various proc-macro related code cleanups) - #157106 (add ABI check logic for wasm) - #154835 (std::offload sharedmem) - #157065 (Stabilize `Path::is_empty`) - #157088 (Improve suggestions for malformed deprecated attribute) - #157098 (Add the `clflushopt` x86 target feature) - #157103 (Add reproducibly failing tests for parallel frontend) - #157111 (Update target maintainer for x86_64-unknown-linux-none) - #157116 (rustc_public: add `with_cx()` to `CompilerInterface`) - #157119 (ast_lowering: Simplify `resolve_pin_drop_sugar_impl_item`) - #157120 (Cleanups around attribute target checking) Failed merges: - #157100 (Some more per owner things)

Rollup merge of #157076 - bjorn3:proc_macro_refactors4, r=petrochenkov Various proc-macro related code cleanups Some are just misc cleanups. Others are to make the proc-macro ABI and RPC interface a bit less target dependent. I've got some local changes that change the ABI to what is effectively a single `&[extern "C" fn(BridgeConfig<'_>) -> Buffer]` export.

JonathanBrouwer · 2026-05-30T21:51:39Z

@rust-timer build ee86314

rust-timer · 2026-05-30T23:07:23Z

Finished benchmarking commit (ee86314): comparison URL.

Overall result: ❌ regressions - 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)	0.3%	[0.3%, 0.3%]	1
Regressions ❌ (secondary)	0.6%	[0.3%, 1.0%]	8
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.0%	[-0.0%, -0.0%]	1
All ❌✅ (primary)	0.3%	[0.3%, 0.3%]	1

Max RSS (memory usage)

This perf run didn't have relevant results for this metric.

Cycles

Results (secondary 3.1%)

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)	3.1%	[2.3%, 3.9%]	2
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

Results (secondary -0.0%)

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)	-0.0%	[-0.0%, -0.0%]	7
All ❌✅ (primary)	-	-	0

Bootstrap: 511.654s -> 511.251s (-0.08%)
Artifact size: 400.70 MiB -> 400.79 MiB (0.02%)

bjorn3 added 5 commits May 28, 2026 16:17

Remove a hack introduced back when unwinding through extern "C" was UB

420566f

Implement Encode and Decode for proc_macro::TokenStream wrapper type

32615f2

Remove outdated comment

53b4acd

Remove unused proc_macro table from crate metadata

5c56e61

Use platform independent encoding for integers in proc-macro RPC

bde798a

This makes the proc-macro RPC protocol platform independent as necessary for running proc macros and rustc on different architectures.

rustbot assigned petrochenkov May 28, 2026

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 28, 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 29, 2026

JonathanBrouwer mentioned this pull request May 29, 2026

Rollup of 9 pull requests #157109

Closed

JonathanBrouwer mentioned this pull request May 29, 2026

Rollup of 11 pull requests #157113

Closed

JonathanBrouwer mentioned this pull request May 29, 2026

Rollup of 11 pull requests #157114

Closed

JonathanBrouwer mentioned this pull request May 29, 2026

Rollup of 16 pull requests #157121

Merged

rust-bors Bot merged commit 2ae7dbd into rust-lang:main May 30, 2026
12 checks passed

rustbot added this to the 1.98.0 milestone May 30, 2026

bjorn3 deleted the proc_macro_refactors4 branch May 30, 2026 12:00

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rustbot added the perf-regression Performance regression. label May 30, 2026

bjorn3 mentioned this pull request May 31, 2026

Revert "Implement Encode and Decode for proc_macro::TokenStream wrapper type" #157182

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Various proc-macro related code cleanups#157076

Various proc-macro related code cleanups#157076
rust-bors[bot] merged 6 commits into
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bjorn3:proc_macro_refactors4

bjorn3 commented May 28, 2026 •

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Overall result: ❌ regressions - please read:

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bjorn3 commented May 28, 2026 •

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