Revise for-loop inference to account for loop_isolation settings #1768
Conversation
This file contains hidden or 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
Without this fix, trying to verify a simple program like:
let m = HashSet::<u32>::new();
for k in m.iter() {}
would lead to an error:
error: loop invariant not satisfied
--> bug.rs:9:9
|
9 | for k in m.iter() {}
| ^^^^^^^^^^^^^^^^^^^^
| |
| at this loop exit
| failed this invariant
verification results:: 1 verified, 1 errors
error: aborting due to 1 previous error
but if m.iter() was instead an identifier, as in below, verification passed:
let m = HashSet::<u32>::new();
let m_iter = m.iter();
for k in m_iter {}
This commit changes the for loop macro to avoid evaluating the iterator
expression, such as m.iter() in the above example, multiple times, which
makes the first example above verify just fine.
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Outdated suggestions cannot be applied.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.
Revise #1704 (see comments there for more details)
By submitting this pull request, I confirm that my contribution is made under the terms of the MIT license.