add_retag: ensure box-to-raw-ptr casts are preserved for Miri #122647
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
rustbot
added
S-waiting-on-review
|
Some changes occurred to MIR optimizations cc @rust-lang/wg-mir-opt The Miri subtree was changed cc @rust-lang/miri |
RalfJung
commented
Mar 17, 2024
| &elaborate_box_derefs::ElaborateBoxDerefs, | ||
| &coroutine::StateTransform, | ||
| &add_retag::AddRetag, | ||
| &Lint(known_panics_lint::KnownPanicsLint), |
There was a problem hiding this comment.
I was not sure what to do with the pass order here. AddRetag needs to be before ElaborateBoxDerefs removes all traces of primitive Box derefs. Whether they should be before or after StateTransform, I don't know. I decided to use the order which doesn't change anything on stable (where AddRetag is a NOP).
RalfJung
force-pushed
the
box-to-raw-retag
branch
from
65752d1 to
bcf8015
Compare
|
@bors r+ rollup thanks for the thorough explanations |
bors
added
S-waiting-on-bors
matthiaskrgr
added a commit
to matthiaskrgr/rust
that referenced
this pull request
Mar 18, 2024
add_retag: ensure box-to-raw-ptr casts are preserved for Miri In rust-lang#122233 I added `retag_box_to_raw` not realizing that we can already do `addr_of_mut!(*bx)` to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass. r? `@oli-obk`
This was referenced Mar 18, 2024
bors
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Mar 18, 2024
…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#122480 (Avoid various uses of `Option<Span>` in favor of using `DUMMY_SP` in the few cases that used `None`) - rust-lang#122567 (Remove fixme about LLVM basic block naming) - rust-lang#122588 (less useless filter calls in imported_source_file) - rust-lang#122647 (add_retag: ensure box-to-raw-ptr casts are preserved for Miri) - rust-lang#122649 (Update the minimum external LLVM to 17) - rust-lang#122680 (Do not eat nested expressions' results in `MayContainYieldPoint` format args visitor) - rust-lang#122683 (add missing test: expected paren or brace in macro) - rust-lang#122689 (Add missing `try_visit` calls in visitors.) r? `@ghost` `@rustbot` modify labels: rollup
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Mar 18, 2024
Rollup merge of rust-lang#122647 - RalfJung:box-to-raw-retag, r=oli-obk add_retag: ensure box-to-raw-ptr casts are preserved for Miri In rust-lang#122233 I added `retag_box_to_raw` not realizing that we can already do `addr_of_mut!(*bx)` to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass. r? ``@oli-obk``
This was referenced Apr 16, 2024
GuillaumeGomez
added a commit
to GuillaumeGomez/rust
that referenced
this pull request
Apr 16, 2024
Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes rust-lang/miri#3473.
rust-timer
added a commit
to rust-lang-ci/rust
that referenced
this pull request
Apr 17, 2024
Rollup merge of rust-lang#124013 - RalfJung:box-to-raw, r=oli-obk Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes rust-lang/miri#3473.
github-actions bot
pushed a commit
to rust-lang/miri
that referenced
this pull request
Apr 17, 2024
Box::into_raw: make Miri understand that this is a box-to-raw cast Turns out rust-lang/rust#122647 went a bit too far in cleaning up `Box`... we still need a hack in `Box::into_raw`. The nicer fix would be to make Stacked Borrows not care about reference-to-raw-pointer casts, but it's unclear whether that will ever be possible without going to full Tree Borrows. Fixes #3473.
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.
In #122233 I added
retag_box_to_rawnot realizing that we can already doaddr_of_mut!(*bx)to turn a box into a raw pointer without an intermediate reference. We just need to ensure this information is preserved past the ElaborateBoxDerefs pass.r? @oli-obk