6.0: [Features] Move NoncopyableGenerics up. #73847
Merged
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
Some compilers have the NoncopyableGenerics feature enabled via interesting mechanisms but do not have ConformanceSuppression. To support such compilers, the NoncopyableGenerics feature must appear before ConformanceSuppression in the list of features. Otherwise, when parsing the portion of the swiftinterface corresponding to an entity which involves both features, the first check will be for NoncopyableGenerics (which that old compiler has) and the code inside will involve ConformanceSuppression (which that old compiler does not have). rdar://128611158
nate-chandler
force-pushed
the
cherrypick/release/6.0/rdar128611158
branch
from
e2fdfea to
0d950fd
Compare
|
@swift-ci please test |
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Outdated suggestions cannot be applied.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.
Explanation: Fix a condfail on MemoryLayout in the stdlib.
The
MemoryLayoutdeclaration involves bothNoncopyableGenerics(its generic paramter need not conform toCopyable) andConformanceSuppression(inference of conformance toBitwiseCopyableis repressed).Some compilers have
NoncopyableGenericsbut notConformanceSuppression. The declarations in Features.def need to match the order in which features appeared in compilers. This is necesary because ASTPrinting assumes that if a compiler has a declared-later feature, it has all declared-earlier features.Previously,
NoncopyableGenericswas declared afterConformanceSuppression. That resulted inASTPrintingassuming that all compilers which hadNoncopyableGenericsalso hadConformanceSuppression. That isn't the case, however--as mentioned, some compilers haveNoncopyableGenericsbut notConformanceSuppression.Here, this is fixed by declaring the
NoncopyableGenericsfeature earlier thanConformanceSuppressionin Features.def. The result is that ASTPrinting correctly assumes that if a compiler hasConformanceSuppressionit also hasNoncopyableGenerics, but not the reverse.caused by NoncopyableGenerics being newer than ConformanceSuppression.
Scope: Very narrow. Affects declarations of types involving both
NoncopyableGenericsandConformanceSuppressionin swiftinterfaces.Issue: rdar://128611158
Original PR: #73843
Risk: Very low.
Testing: Added a test which demonstrates the interface being printed as desired.
Reviewer: Allan Shortlidge ( @tshortli )