Use box in shadow memory test for reliable object count
#3380
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
When using stack-allocated objects, MIR is not actually introducing fresh objects in this loop. Us treating them as fresh objects is just an artifact of interpreting StorageLive as creating a fresh object. Using `box` will make sure we genuinely have independent objects.
zhassan-aws
reviewed
Jul 24, 2024
| let x = i; | ||
| assert_eq!(kani::mem::pointer_object(&x as *const usize), i + 2); | ||
| let x: Box<usize> = Box::new(i); | ||
| assert_eq!(kani::mem::pointer_object(&*x as *const usize), 2 * i + 2); |
There was a problem hiding this comment.
What is the reason for the multiplication by 2? Is there an object for the box and another for the variable x? If so, would inlining the Box:new operation in the assert remove the doubling?
|
Closing as this has been made part of #2995. |
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Outdated suggestions cannot be applied.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.
When using stack-allocated objects, MIR is not actually introducing fresh objects in this loop. Us treating them as fresh objects is just an artifact of interpreting StorageLive as creating a fresh object. Using
boxwill make sure we genuinely have independent objects.By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.