move of packed fields might or might not occur when they actually are sufficiently aligned #63374
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
… sufficiently aligned
|
r? @cramertj (rust_highfive has picked a reviewer for you, use r? to override) |
rust-highfive
added
the
S-waiting-on-review
|
Is there a reason we don't do something similar for |
Not that I know if. Honestly I was surprised we do any magic at all even for 1-aligned types, but it makes sense of course. |
|
@bors r+ I guess? |
|
📌 Commit e82b053 has been approved by |
bors
added
S-waiting-on-bors
Whatever that means?^^ |
RalfJung
commented
Aug 8, 2019
|
Just removed that weird lead-in to the new sentence. @bors r=cramertj |
|
📌 Commit fa58c27 has been approved by |
Just that I think this is a good clarifying remark to have, but the actual behavior is somewhat strange. |
Centril
added a commit
to Centril/rust
that referenced
this pull request
Aug 8, 2019
move of packed fields might or might not occur when they actually are sufficiently aligned See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a `packed(2)` struct, we don't do something similar for 2-aligned types. The code for that is [here](/~https://github.com/rust-lang/rust/blob/db7c773a6be2f050d1d1504763819ea3916f5428/src/librustc_mir/util/alignment.rs#L7).
Centril
added a commit
to Centril/rust
that referenced
this pull request
Aug 8, 2019
move of packed fields might or might not occur when they actually are sufficiently aligned See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a `packed(2)` struct, we don't do something similar for 2-aligned types. The code for that is [here](/~https://github.com/rust-lang/rust/blob/db7c773a6be2f050d1d1504763819ea3916f5428/src/librustc_mir/util/alignment.rs#L7).
bors
added a commit
that referenced
this pull request
Aug 8, 2019
Rollup of 6 pull requests Successful merges: - #63162 (Miri tests: use xargo to build separate libstd) - #63289 (Don't recommend `extern crate` syntax) - #63373 (gitignore: add comment explaining policy) - #63374 (move of packed fields might or might not occur when they actually are sufficiently aligned) - #63381 (reduce visibility) - #63387 (Test interaction between `async { ... }` and `?`, `return`, and `break`) Failed merges: r? @ghost
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
See taiki-e/pin-project#34, where it was pointed out that we actually don't move fields of 1-aligned types when dropping a packed struct -- but e.g. in a
packed(2)struct, we don't do something similar for 2-aligned types. The code for that is here.