Unsafe extern blocks #124482

spastorino · 2024-04-28T17:07:50Z

This implements RFC 3484.

Tracking issue #123743 and RFC rust-lang/rfcs#3484

This is better reviewed commit by commit, the first 2 commits live also in a separate PR #124455.

This is a first working version that needs:

I need to review and tidy up commits
I need to extensively add tests and in particular tests about static items
Is based on Add new safety enum for inner extern items #124455, so we need to merge that one first.
Decision on the name missing_unsafe_on_extern attribute.
After the name is set I can prepare a PRs to stdarch crate and remove the commit on this PR that modifies the submodule to point to mine

rustbot · 2024-04-28T17:07:58Z

rustbot has assigned @cjgillot.
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rustbot · 2024-04-28T17:07:58Z

⚠️ Warning ⚠️

These commits modify submodules.

spastorino · 2024-04-28T17:22:34Z

⚠️ Warning ⚠️
* These commits modify **submodules**.

Ohh I forgot to mention this. I'd need to land some PRs, at least to stdarch so it doesn't warn for the usages of extern blocks without unsafe.
I was planning to do ![allow(unknown_lints)] + #![allow(missing_unsafe_on_extern)], so this doesn't warn in new versions and doesn't error in old versions for the usage of missing_unsafe_on_extern which is unknown.

bors · 2024-05-04T00:46:23Z

☔ The latest upstream changes (presumably #123602) made this pull request unmergeable. Please resolve the merge conflicts.

rustbot · 2024-05-04T02:29:55Z

The Miri subtree was changed

cc @rust-lang/miri

bors · 2024-05-05T05:26:35Z

☔ The latest upstream changes (presumably #124631) made this pull request unmergeable. Please resolve the merge conflicts.

bors · 2024-05-05T20:04:47Z

☔ The latest upstream changes (presumably #124754) made this pull request unmergeable. Please resolve the merge conflicts.

…erwards

rustbot · 2024-05-08T13:32:33Z

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

rust-log-analyzer · 2024-05-08T13:40:30Z

The job mingw-check failed! Check out the build log: (web) (plain)

Click to see the possible cause of the failure (guessed by this bot)

   Compiling basic-toml v0.1.9
   Compiling askama_derive v0.12.5
    Checking askama v0.12.1
    Checking rustdoc v0.0.0 (/checkout/src/librustdoc)
error[E0063]: missing field `safety` in initializer of `DefKind`
     |
     |
1520 |                 "static" => Kind(DefKind::Static { mutability: Mutability::Not, nested: false }),
     |                                  ^^^^^^^^^^^^^^^ missing `safety`
For more information about this error, try `rustc --explain E0063`.
error: could not compile `rustdoc` (lib) due to 1 previous error
Build completed unsuccessfully in 0:02:15
  local time: Wed May  8 13:40:20 UTC 2024

RalfJung · 2024-05-08T14:05:19Z

src/tools/miri/src/bin/miri.rs

@@ -342,6 +342,7 @@ fn jemalloc_magic() {
    // linking, so we need to explicitly depend on the function.
    #[cfg(target_os = "macos")]
    {
+        #[allow(missing_unsafe_on_extern)]


Instead of adding an enormous amount of allow, what about keeping the lint allow-by-default until the bootstrap compiler has unsafe extern, so that then we can start using it in the codebase? That avoids having to change everything twice...

Yeah, totally. I guess that depends when do we want to land this change and then how much do we want to wait but yeah :).

On old editions I think the RFC says it should be allow-by-default for now anyway?

Ohh good catch. I've implemented Felix's proposal rust-lang/rfcs#3484 (comment) which I see now is out of sync.
Going to fix this accordingly when I have some time.

bors · 2024-05-09T22:07:03Z

☔ The latest upstream changes (presumably #124934) made this pull request unmergeable. Please resolve the merge conflicts.

spastorino · 2024-05-14T17:05:15Z

This is waiting on a decision on #124455 or #125077 or any other preferred alternative.

rustbot assigned cjgillot Apr 28, 2024