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Merged
merged 3 commits into from
Mar 12, 2023
Merged

Forbid the use of #[target_feature] on main #108651

merged 3 commits into from
Mar 12, 2023

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LeSeulArtichaut
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Fixes #108645.

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rustbot commented Mar 2, 2023

r? @jackh726

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@rustbot 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 Mar 2, 2023
Noratrieb
Noratrieb approved these changes Mar 2, 2023
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r? Nilstrieb
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r=me when CI is green

@rustbot rustbot assigned Noratrieb and unassigned jackh726 Mar 2, 2023
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Uh, I don't think target_feature should be an only_local attribute.... that's unsound, isn't it? When it always pretends it isn't there across crates? Sounds like we need to encode it in the metadata (which is as simple as removing the @only_local: true)

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WaffleLapkin commented Mar 2, 2023 •
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waffle rustc log analyzer

There are two failures:

  1. tests/ui/asm/x86_64/issue-89875.rs uses #[target_feature] on main (moving main's inside and #[target_feature] to a separate fn should fix the test)
  2. tests/ui/entry-point/imported_main_from_extern_crate.rs ICEs because the main function there is imported from another crate and the #[target_feature] attribute is local-only (probably an error?...)

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Hm, target_feature was made local_only in #98450 as an optimization...

Ig it is fine, actually? Maybe? If the codegen only happens inside the crate, then target_feature being local is totally fine. At least we don't have any tests that tried to access target_feature in non-local crate...

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This isn't unsound, the safeaty check probably goes through target feature queries instead of the attr.
So I guess you should try figuring out how that works and whether you can use the same way - although encoding target_feature is also a possible solution.

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the safeaty check probably goes through target feature queries instead of the attr

Yes, see

rust/compiler/rustc_mir_transform/src/check_unsafety.rs

Lines 363 to 365 in 18caf88

let callee_features = &self.tcx.codegen_fn_attrs(func_did).target_features;
// The body might be a constant, so it doesn't have codegen attributes.
let self_features = &self.tcx.body_codegen_attrs(self.body_did.to_def_id()).target_features;

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Also we need to forbid #[target_feature] on start, no?

@LeSeulArtichaut LeSeulArtichaut force-pushed the 108645-target-feature-on-main branch from 23db00f to aa67dbe Compare March 2, 2023 13:10
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Now it looks good and green 😊
@bors r+

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bors commented Mar 2, 2023

📌 Commit dc6e0d9 has been approved by Nilstrieb

It is now in the queue for this repository.

@bors 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 Mar 2, 2023
compiler-errors added a commit to compiler-errors/rust that referenced this pull request Mar 2, 2023
@compiler-errors
Rollup merge of rust-lang#108651 - LeSeulArtichaut:108645-target-feat…
b5aec1c 
…ure-on-main, r=Nilstrieb

Forbid the use of `#[target_feature]` on `main`

Fixes rust-lang#108645.
@compiler-errors compiler-errors mentioned this pull request Mar 2, 2023
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@bors r- this will fail after the revert, needs to add the unstable feature to the test

@bors bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Mar 2, 2023
@LeSeulArtichaut
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(I'll need to add the feature gates back if #108654 lands first)

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failed in a rollup

https://github.com/rust-lang-ci/rust/actions/runs/4316566308/jobs/7532513148#step:26:17181

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@bors r-

Fair chance this will land after #108654, so this needs blessing and fixing.

@LeSeulArtichaut LeSeulArtichaut force-pushed the 108645-target-feature-on-main branch 3 times, most recently from 1072bc8 to faebedf Compare March 3, 2023 07:05
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Since #[target_feature] is allowed on safe functions (on stable), I guess we should allow #[target_feature] on main/start? It's sound and it would otherwise be a breaking change.

@LeSeulArtichaut LeSeulArtichaut force-pushed the 108645-target-feature-on-main branch from a52a586 to 7841b8b Compare March 10, 2023 12:23
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rustbot commented Mar 10, 2023

Some changes occurred in src/tools/cargo

cc @ehuss

@LeSeulArtichaut LeSeulArtichaut force-pushed the 108645-target-feature-on-main branch from 7841b8b to 28dca77 Compare March 10, 2023 12:27
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(Committed a submodule change by accident, sorry for the noise)

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@bors r+

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bors commented Mar 11, 2023

📌 Commit 28dca77acf1d7280b51372abf3dd50c14616b628 has been approved by Nilstrieb

It is now in the queue for this repository.

@bors 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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Mar 11, 2023
@matthiaskrgr matthiaskrgr mentioned this pull request Mar 12, 2023
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bors commented Mar 12, 2023

☔ The latest upstream changes (presumably #108682) made this pull request unmergeable. Please resolve the merge conflicts.

@bors bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Mar 12, 2023
@LeSeulArtichaut LeSeulArtichaut force-pushed the 108645-target-feature-on-main branch from 28dca77 to 29b1789 Compare March 12, 2023 14:00
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@bors r+

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bors commented Mar 12, 2023

📌 Commit 29b1789 has been approved by Nilstrieb

It is now in the queue for this repository.

@bors 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-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Mar 12, 2023
@matthiaskrgr matthiaskrgr mentioned this pull request Mar 12, 2023
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bors added a commit to rust-lang-ci/rust that referenced this pull request Mar 12, 2023
@bors
Auto merge of rust-lang#109056 - matthiaskrgr:rollup-9trny1z, r=matth…
7b4f489 
…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#108651 (Forbid the use of `#[target_feature]` on `main`)
 - rust-lang#109009 (rustdoc: use restricted Damerau-Levenshtein distance for search)
 - rust-lang#109026 (Introduce `Rc::into_inner`, as a parallel to `Arc::into_inner`)
 - rust-lang#109029 (Gate usages of `dyn*` and const closures in macros)
 - rust-lang#109031 (Rename `config.toml.example` to `config.example.toml`)
 - rust-lang#109032 (Use `TyCtxt::trait_solver_next` in some places)
 - rust-lang#109047 (typo)
 - rust-lang#109052 (Add eslint check for rustdoc-gui tester)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup
@bors bors merged commit f41796e into rust-lang:master Mar 12, 2023
@rustbot rustbot added this to the 1.70.0 milestone Mar 12, 2023
@LeSeulArtichaut LeSeulArtichaut deleted the 108645-target-feature-on-main branch March 13, 2023 06:46
@ehuss ehuss mentioned this pull request Mar 14, 2023
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@est31 est31 mentioned this pull request Mar 20, 2023
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#[target_feature] is allowed on main
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@LeSeulArtichaut @rustbot @Noratrieb @WaffleLapkin @bors @matthiaskrgr @compiler-errors @jackh726