[cxx-interop] Handle Unowned values in implicit value ctors #84203
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
Xazax-hun
requested review from
egorzhdan,
fahadnayyar,
hnrklssn,
j-hui,
jckarter,
kavon,
susmonteiro and
zoecarver
as code owners
hnrklssn
reviewed
Sep 10, 2025
Xazax-hun
force-pushed
the
handle-unowned-in-impicit-value-init
branch
3 times, most recently
from
d79cf25 to
b4fb025
Compare
We usually have unowned values when dealing with foreign types. Make sure the implicit value ctors will do a +1 to balance the releases. In a release build we had a use after free over-releasing the object. In assert builds we had an assertion failure: Assertion failed: (value->getOwnershipKind() == OwnershipKind::Guaranteed), function forBorrowedObjectRValue, file ManagedValue.h, line 181. rdar://160232360
Xazax-hun
force-pushed
the
handle-unowned-in-impicit-value-init
branch
from
b4fb025 to
fe3cc6d
Compare
|
@swift-ci please test |
jckarter
approved these changes
Sep 15, 2025
Xazax-hun
added a commit
to Xazax-hun/swift
that referenced
this pull request
Sep 15, 2025
Explanation: Implicit value constructors did not account for unowned ownership resulting in unbalanced refcounts and use after free errors. This PR makes sure we +1 the unowned constructor arguments to balance out the ref counts. Issues: rdar://160232360 Original PRs: swiftlang#84203 Risk: Low, the fix is narrow to implicit value ctors taking foreign reference types and this scenario was broken before the patch. Testing: Added a compiler test. Reviewers: @egorzhdan, @jckarter
Xazax-hun
added a commit
to Xazax-hun/swift
that referenced
this pull request
Sep 25, 2025
…mpicit-value-init [cxx-interop] Handle Unowned values in implicit value ctors
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
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.
We usually have unowned values when dealing with foreign types. Make sure the implicit value ctors will do a +1 to balance the releases. In a release build we had a use after free over-releasing the object. In assert builds we had an assertion failure:
Assertion failed: (value->getOwnershipKind() == OwnershipKind::Guaranteed), function forBorrowedObjectRValue, file ManagedValue.h, line 181.
rdar://160232360