Allow for AsIter(Mut)/AsSlice(Mut) to be implemented in safe Rust #2120
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
langston-barrett
force-pushed
the
lb/safe-map-observer
branch
4 times, most recently
from
b4be1a9
to
6f3d9e0
Compare
Towards `MapObserver`s in safe Rust.
`Self::Entry` is `Copy`, so there's not much value in returning a reference from `get()`. Futhermore, returning a reference limits the possible implementations of `MapObserver`, because it forces the borrow/reset to outlive the body of the method.
Like the previous commit, this is intended to expand the possible implementations of `MapObserver` to types with interior mutability, which can't necessarily loan out their content.
langston-barrett
force-pushed
the
lb/safe-map-observer
branch
from
6f3d9e0
to
fd76d30
Compare
|
I recognise fighting CI is no fun, so if at any point you want me to take over, let me know 🙂 |
|
@addisoncrump That'd be awesome! I'm done for the day, I can return to this on Tuesday if you don't have a minute to push it through before then. |
|
Also working on AsSlice/AsSliceMut for this pattern as well, since we very likely want to be able to use e.g. SIMD accel on the RefCell maps. |
addisoncrump
changed the title
impl MapObserver for RefCellValueObserver in safe Rust
addisoncrump
changed the title
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Outdated suggestions cannot be applied.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.
Redux of #2000.
Previously,
MapFeedbackrequired theObserverto implementAsIter, and to give out references via.getand.get_mut. This works for all the existing in-repoMapObservers, which useunsafeto pretend that they own the underlying map/vector/array. This lets them loan out items in the array with the same lifetime as&self.This wasn't previously possible for observers using
RefCell, as the loan of the content of aRefCellby definition has a shorter lifetime than theRefCellitself. With the changes here, we can have aMapObserverbuilt in safe Rust, i.e.,RefCellValueObserver<Vec<...>>MapFeedbackalready requires that all the values areCopy, and in practice, they're generally small (in fact, they're generally primitive integers, meaning copying is free). The changes in this PR take advantage of this to remove borrowing values from the interface, thus enabling implementation ofMapObservers in safe Rust.We may want to make similar changes for
AsIterMut, although it doesn't appear to be necessary for this particular use-case.These modifications to the LibAFL library were made under funding provided by the U.S. government. The work represented in this PR is provided under Distribution Statement “A” (Approved for Public Release, Distribution Unlimited.)