[5.9] MoveOnlyAddressChecker: Confine analysis to current formal access. #64864
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
Code can only locally interact with a mutable memory location within a formal access, and is only responsible for maintaining its invariants during that access, so the move-only address checker does not need to, and should not, observe operations that occur outside of the access marked with the `mark_must_check` instruction. And for immutable memory locations, although there are no explicit formal accesses, that's because every access must be read-only, so although individual accesses are not delimited, they are all compatible as far as move-only checking is concerned. So we can back out the changes to SILGen to re-project a memory location from its origin on every access, a change which breaks invariants assumed by other SIL passes.
|
@swift-ci Please test |
tbkka
approved these changes
Apr 3, 2023
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Outdated suggestions cannot be applied.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.
Code can only locally interact with a mutable memory location within a formal access, and is only responsible for maintaining its invariants during that access, so the move-only address checker does not need to, and should not, observe operations that occur outside of the access marked with the
mark_must_checkinstruction. And for immutable memory locations, although there are no explicit formal accesses, that's because every access must be read-only, so although individual accesses are not delimited, they are all compatible as far as move-only checking is concerned. So we can back out the changes to SILGen to re-project a memory location from its origin on every access, a change which breaks invariants assumed by other SIL passes.Main PR: #64850
rdar://106204488