Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

add missing #[repr(C)] on the Slices union #63980

Merged
merged 1 commit into from
Aug 29, 2019
Merged

add missing #[repr(C)] on the Slices union #63980

merged 1 commit into from
Aug 29, 2019

Conversation

DutchGhost
Copy link
Contributor

@DutchGhost DutchGhost commented Aug 28, 2019

Adds the #[repr(C)] attribute to the Slices union used to convert an &str into a &[u8].
Without the attribute, the union has an unspecified layout: https://doc.rust-lang.org/reference/types/union.html, so performing the 'transmute' is unsound without the attribute (as far as I understand).

The Repr union, used for converting a raw ptr + len to a slice has this attribute as well:
https://github.com/rust-lang/rust/blob/master/src/libcore/ptr/mod.rs#L211-#L216

@rust-highfive
Copy link
Collaborator

r? @cramertj

(rust_highfive has picked a reviewer for you, use r? to override)

@rust-highfive rust-highfive added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Aug 28, 2019
@cramertj
Copy link
Member

@bors r+ rollup

@bors
Copy link
Contributor

bors commented Aug 28, 2019

📌 Commit 080fdb8 has been approved by cramertj

@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 Aug 28, 2019
Centril added a commit to Centril/rust that referenced this pull request Aug 29, 2019
add missing `#[repr(C)]` on the Slices union

Adds the `#[repr(C)]` attribute to the `Slices` union used to convert an `&str` into a `&[u8]`.
Without the attribute, the union has an unspecified layout: https://doc.rust-lang.org/reference/types/union.html, so performing the 'transmute' is unsound without the attribute (as far as I understand).

The `Repr` union, used for converting a raw ptr + len to a slice has this attribute as well:
https://github.com/rust-lang/rust/blob/master/src/libcore/ptr/mod.rs#L211-#L216
bors added a commit that referenced this pull request Aug 29, 2019
Rollup of 11 pull requests

Successful merges:

 - #63811 (Correctly suggest adding bounds to `impl Trait` argument)
 - #63933 (Resolve some small issues related to #63580)
 - #63938 (or-pattern: fix typo in error message)
 - #63945 (Recover `mut $pat` and other improvements)
 - #63958 (const_prop: only call error_to_const_error if we are actually showing something)
 - #63961 (Add Option<Span> to `require_lang_item`)
 - #63963 (remove the reference to __cxa_thread_atexit_impl)
 - #63965 (Prevent syntax error in LD linker version script)
 - #63968 (rustc_apfloat: make the crate #![no_std] explicitly.)
 - #63970 (Notify me (flip1995) when Clippy toolstate changes)
 - #63980 (add missing `#[repr(C)]` on the Slices union)

Failed merges:

 - #63989 (Add Yaah to clippy toolstain notification list)

r? @ghost
@bors bors merged commit 080fdb8 into rust-lang:master Aug 29, 2019
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion.
Projects
None yet
Development

Successfully merging this pull request may close these issues.

4 participants