rustc: do not raise the alignment of optimized enums to the niche's alignment. by eddyb · Pull Request #46809 · rust-lang/rust (original) (raw)
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This is the improved fix for #46769 that does not increase the size of any types (see also #46808).
r? @estebank
(rust_highfive has picked a reviewer for you, use r? to override)
Status: Blocked on something else such as an RFC or other implementation work.
label
📌 Commit 090a192 has been approved by arielb1
(don't mind me, just Travis-cycling the PR)
bors added a commit that referenced this pull request
rustc: ensure optimized enums have a properly aligned size.
Fixes #46769 by padding the optimized enums wrapping packed data as necessary.
Note that this is not the only way to solve this - on nightly, #46436 makes it easier to fix without adding new padding because of the replacement of packed flags with a non-redundant scheme.
But because it can't be backported, the optimal fix will be in a separate nightly-only PR (#46809).
Status: This is awaiting some action (such as code changes or more information) from the author.
and removed S-blocked
Status: Blocked on something else such as an RFC or other implementation work.
labels
📌 Commit 8fc4afe has been approved by arielb1
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.
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Could you please add a test that the size of a packed enum is what it's supposed to be?
@bors r-
Something like this:
// This struct has a single niche - the dealigned pointer within. Check that // it is null-pointer-optimized correctly struct Interesting { packed: Packed<&'static ()>, other: u8 }
assert_eq!(mem::size_of::(), mem::size_of::<Option>());
📌 Commit 5c3dcfa has been approved by arielb1
kennytm added a commit to kennytm/rust that referenced this pull request
rustc: do not raise the alignment of optimized enums to the niche's alignment.
This is the improved fix for rust-lang#46769 that does not increase the size of any types (see also rust-lang#46808).
bors added a commit that referenced this pull request
Rollup of 14 pull requests
- Successful merges: #46636, #46780, #46784, #46809, #46814, #46820, #46839, #46847, #46858, #46878, #46884, #46890, #46898, #46918
- Failed merges:
Labels
Status: Waiting on bors to run and complete tests. Bors will change the label on completion.