Remove `compiler-builtins-{no-asm,mangled-names}` #144471

tgross35 · 2025-07-25T22:23:59Z

Remove compiler-builtins-no-asm

This feature used to be for when Cranelift didn't support inline
assembly, but its last uses were removed in 52933e0 ("Don't disable
inline asm usage in compiler-builtins when the cranelift backend is
enabled"). and cba05a7 ("Support naked functions").

This doesn't remove the feature from the compiler-builtins crate, that
will be done separately in the subtree repo.

Remove compiler-builtins-mangled-names

This config was added in 207de01 ("libary: Forward
compiler-builtins "asm" and "mangled-names" feature") but it does not
appear this has ever been used. The PR adding it (#78472) says that
this was exposed to help with configuration and points at the Hermit
Cargo config, but as far as I can tell, this feature name has never
been mentioned in that repository's git history.

Thus, clean up a seemingly unneeded feature.

r? @Amanieu
cc @bjorn3

This feature used to be for when Cranelift didn't support inline assembly, but its last uses were removed in 52933e0 ("Don't disable inline asm usage in compiler-builtins when the cranelift backend is enabled"). and cba05a7 ("Support naked functions"). This doesn't remove the feature from the `compiler-builtins` crate, that will be done separately in the subtree repo.

Assembly-related configuration was added in 1621c6d ("Use `specialized-div-rem` 1.0.0 for division algorithms") to account for Cranelift not yet supporting assembly. This hasn't been relevant for a while so remove the unused feature here. To keep miri tests working, replace one instance of `not(feature = "no-asm")` with `not(miri)`. This is the compiler-builtins portion of rust-lang/rust#144471.

tgross35 · 2025-07-25T23:15:26Z

@bors r=Amanieu rollup

bors · 2025-07-25T23:15:29Z

📌 Commit a076bd8 has been approved by Amanieu

It is now in the queue for this repository.

Assembly-related configuration was added in 1621c6d ("Use `specialized-div-rem` 1.0.0 for division algorithms") to account for Cranelift not yet supporting assembly. This hasn't been relevant for a while, so we no longer need to gate `asm!` behind this configuration. Thus, remove `cfg(not(feature = "no-asm"))` in places where there is no generic fallback. There are other cases, however, where setting the `no-asm` configuration enables testing of generic version of builtins when there are platform- specific implementations available; these cases are left unchanged. This could be improved in the future. This is the compiler-builtins portion of rust-lang/rust#144471.

Assembly-related configuration was added in 1621c6d ("Use `specialized-div-rem` 1.0.0 for division algorithms") to account for Cranelift not yet supporting assembly. This hasn't been relevant for a while, so we no longer need to gate `asm!` behind this configuration. Thus, remove `cfg(not(feature = "no-asm"))` in places where there is no generic fallback. There are other cases, however, where setting the `no-asm` configuration enables testing of generic version of builtins when there are platform- specific implementations available; these cases are left unchanged. This could be improved in the future by exposing both versions for testing rather than using a configuration and running the entire testsuite twice. This is the compiler-builtins portion of rust-lang/rust#144471.

This config was added in 207de01 ("libary: Forward compiler-builtins "asm" and "mangled-names" feature") but it does not appear this has ever been used. The PR adding it (RUST-78472) says that this was exposed to help with configuration and points at the [Hermit Cargo config], but as far as I can tell, this feature name has never been mentioned in that repository's git history. Thus, clean up a seemingly unneeded feature. [Hermit Cargo config]: https://github.com/hermit-os/hermit-rs/blob/ab2b830930e6a9a98c8294997a8183feeabeda4a/.cargo/config

tgross35 · 2025-07-26T00:32:08Z

Added a commit to also remove compiler-builtins-mangled-names since that is also unused, rather than creating a separate PR to conflict with this one.

Amanieu · 2025-07-27T17:31:08Z

@bors r+

bors · 2025-07-27T17:31:10Z

📌 Commit 51c5f19 has been approved by Amanieu

It is now in the queue for this repository.

…Amanieu Remove `compiler-builtins-{no-asm,mangled-names}` Remove `compiler-builtins-no-asm` This feature used to be for when Cranelift didn't support inline assembly, but its last uses were removed in 52933e0 ("Don't disable inline asm usage in compiler-builtins when the cranelift backend is enabled"). and cba05a7 ("Support naked functions"). This doesn't remove the feature from the `compiler-builtins` crate, that will be done separately in the subtree repo. --- Remove `compiler-builtins-mangled-names` This config was added in 207de01 ("libary: Forward compiler-builtins "asm" and "mangled-names" feature") but it does not appear this has ever been used. The PR adding it (rust-lang#78472) says that this was exposed to help with configuration and points at the [Hermit Cargo config], but as far as I can tell, this feature name has never been mentioned in that repository's git history. Thus, clean up a seemingly unneeded feature. [Hermit Cargo config]: https://github.com/hermit-os/hermit-rs/blob/ab2b830930e6a9a98c8294997a8183feeabeda4a/.cargo/config

Assembly-related configuration was added in 1621c6d ("Use `specialized-div-rem` 1.0.0 for division algorithms") to account for Cranelift not yet supporting assembly. This hasn't been relevant for a while, so we no longer need to gate `asm!` behind this configuration. Thus, remove `cfg(not(feature = "no-asm"))` in places where there is no generic fallback. There are other cases, however, where setting the `no-asm` configuration enables testing of generic version of builtins when there are platform- specific implementations available; these cases are left unchanged. This could be improved in the future by exposing both versions for testing rather than using a configuration and running the entire testsuite twice. This is the compiler-builtins portion of rust-lang/rust#144471.

Rollup of 7 pull requests Successful merges: - #143289 (Remove `[T]::array_chunks(_mut)`) - #143607 (Port the proc macro attributes to the new attribute parsing infrastructure) - #144471 (Remove `compiler-builtins-{no-asm,mangled-names}`) - #144495 (bump cargo_metadata) - #144523 (rustdoc: save target modifiers) - #144534 (check_static_item: explain should_check_for_sync choices) - #144535 (miri: for ABI mismatch errors, say which argument is the problem) Failed merges: - #144536 (miri subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 6 pull requests Successful merges: - #143607 (Port the proc macro attributes to the new attribute parsing infrastructure) - #144471 (Remove `compiler-builtins-{no-asm,mangled-names}`) - #144495 (bump cargo_metadata) - #144523 (rustdoc: save target modifiers) - #144534 (check_static_item: explain should_check_for_sync choices) - #144535 (miri: for ABI mismatch errors, say which argument is the problem) Failed merges: - #144536 (miri subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #144471 - tgross35:compiler-builtins-asm, r=Amanieu Remove `compiler-builtins-{no-asm,mangled-names}` Remove `compiler-builtins-no-asm` This feature used to be for when Cranelift didn't support inline assembly, but its last uses were removed in 52933e0 ("Don't disable inline asm usage in compiler-builtins when the cranelift backend is enabled"). and cba05a7 ("Support naked functions"). This doesn't remove the feature from the `compiler-builtins` crate, that will be done separately in the subtree repo. --- Remove `compiler-builtins-mangled-names` This config was added in 207de01 ("libary: Forward compiler-builtins "asm" and "mangled-names" feature") but it does not appear this has ever been used. The PR adding it (#78472) says that this was exposed to help with configuration and points at the [Hermit Cargo config], but as far as I can tell, this feature name has never been mentioned in that repository's git history. Thus, clean up a seemingly unneeded feature. [Hermit Cargo config]: https://github.com/hermit-os/hermit-rs/blob/ab2b830930e6a9a98c8294997a8183feeabeda4a/.cargo/config

Rollup of 6 pull requests Successful merges: - rust-lang/rust#143607 (Port the proc macro attributes to the new attribute parsing infrastructure) - rust-lang/rust#144471 (Remove `compiler-builtins-{no-asm,mangled-names}`) - rust-lang/rust#144495 (bump cargo_metadata) - rust-lang/rust#144523 (rustdoc: save target modifiers) - rust-lang/rust#144534 (check_static_item: explain should_check_for_sync choices) - rust-lang/rust#144535 (miri: for ABI mismatch errors, say which argument is the problem) Failed merges: - rust-lang/rust#144536 (miri subtree update) r? `@ghost` `@rustbot` modify labels: rollup

…Amanieu Remove `compiler-builtins-{no-asm,mangled-names}` Remove `compiler-builtins-no-asm` This feature used to be for when Cranelift didn't support inline assembly, but its last uses were removed in 52933e0 ("Don't disable inline asm usage in compiler-builtins when the cranelift backend is enabled"). and cba05a7 ("Support naked functions"). This doesn't remove the feature from the `compiler-builtins` crate, that will be done separately in the subtree repo. --- Remove `compiler-builtins-mangled-names` This config was added in 207de01 ("libary: Forward compiler-builtins "asm" and "mangled-names" feature") but it does not appear this has ever been used. The PR adding it (rust-lang#78472) says that this was exposed to help with configuration and points at the [Hermit Cargo config], but as far as I can tell, this feature name has never been mentioned in that repository's git history. Thus, clean up a seemingly unneeded feature. [Hermit Cargo config]: https://github.com/hermit-os/hermit-rs/blob/ab2b830930e6a9a98c8294997a8183feeabeda4a/.cargo/config

…iaskrgr Rollup of 6 pull requests Successful merges: - rust-lang#143607 (Port the proc macro attributes to the new attribute parsing infrastructure) - rust-lang#144471 (Remove `compiler-builtins-{no-asm,mangled-names}`) - rust-lang#144495 (bump cargo_metadata) - rust-lang#144523 (rustdoc: save target modifiers) - rust-lang#144534 (check_static_item: explain should_check_for_sync choices) - rust-lang#144535 (miri: for ABI mismatch errors, say which argument is the problem) Failed merges: - rust-lang#144536 (miri subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 6 pull requests Successful merges: - rust-lang/rust#143607 (Port the proc macro attributes to the new attribute parsing infrastructure) - rust-lang/rust#144471 (Remove `compiler-builtins-{no-asm,mangled-names}`) - rust-lang/rust#144495 (bump cargo_metadata) - rust-lang/rust#144523 (rustdoc: save target modifiers) - rust-lang/rust#144534 (check_static_item: explain should_check_for_sync choices) - rust-lang/rust#144535 (miri: for ABI mismatch errors, say which argument is the problem) Failed merges: - rust-lang/rust#144536 (miri subtree update) r? `@ghost` `@rustbot` modify labels: rollup

Assembly-related configuration was added in 1621c6dbf9eb ("Use `specialized-div-rem` 1.0.0 for division algorithms") to account for Cranelift not yet supporting assembly. This hasn't been relevant for a while, so we no longer need to gate `asm!` behind this configuration. Thus, remove `cfg(not(feature = "no-asm"))` in places where there is no generic fallback. There are other cases, however, where setting the `no-asm` configuration enables testing of generic version of builtins when there are platform- specific implementations available; these cases are left unchanged. This could be improved in the future by exposing both versions for testing rather than using a configuration and running the entire testsuite twice. This is the compiler-builtins portion of rust-lang#144471.

rustbot assigned Amanieu Jul 25, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Jul 25, 2025

tgross35 mentioned this pull request Jul 25, 2025

Remove no-asm gating when there is no alternative implementation rust-lang/compiler-builtins#994

Merged

Amanieu approved these changes Jul 25, 2025

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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 Jul 25, 2025

tgross35 changed the title ~~Remove compiler-builtins-no-asm~~ Remove compiler-builtins-{no-asm,mangled-names} Jul 26, 2025

tgross35 requested a review from Amanieu July 26, 2025 00:32

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jul 26, 2025

bors removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Jul 27, 2025

jhpratt mentioned this pull request Jul 27, 2025

Rollup of 7 pull requests #144546

Closed

matthiaskrgr mentioned this pull request Jul 27, 2025

Rollup of 6 pull requests #144556

Merged

bors merged commit 1e888ed into rust-lang:master Jul 28, 2025
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rustbot added this to the 1.90.0 milestone Jul 28, 2025

tgross35 deleted the compiler-builtins-asm branch July 28, 2025 05:33

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Remove `compiler-builtins-{no-asm,mangled-names}` #144471

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