Fix desugaring of const x::T = y for complex y
#59155
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
mlechu
added
compiler:lowering
|
I am excited to revive #58187 if only to remove the lowered const/surface const confusion... |
xal-0
approved these changes
Jul 30, 2025
34 tasks
KristofferC
pushed a commit
that referenced
this pull request
Aug 6, 2025
Fix #59128 Assignment desugaring of `(const (= (|::| x T) rhs))` would pre-expand to, then re-expand `(const x ,(convert-for-type-decl rhs T))`, but two-arg (IR) const is expected to have a simple RHS---closure conversion doesn't recurse here (should it?), giving us partially-lowered IR, and hence our bug. Fix: Pre-expand to the one-arg AST const form `(const (= x ,(convert-for-type-decl rhs T)))` instead. This also gives us a `(latestworld)` we were missing before, so this lowering may have been originally intended. (cherry picked from commit 3de5b9a)
KristofferC
removed
the
backport 1.12
KristofferC
pushed a commit
that referenced
this pull request
Sep 5, 2025
Fix #59128 Assignment desugaring of `(const (= (|::| x T) rhs))` would pre-expand to, then re-expand `(const x ,(convert-for-type-decl rhs T))`, but two-arg (IR) const is expected to have a simple RHS---closure conversion doesn't recurse here (should it?), giving us partially-lowered IR, and hence our bug. Fix: Pre-expand to the one-arg AST const form `(const (= x ,(convert-for-type-decl rhs T)))` instead. This also gives us a `(latestworld)` we were missing before, so this lowering may have been originally intended. (cherry picked from commit 3de5b9a)
KristofferC
pushed a commit
that referenced
this pull request
Sep 15, 2025
Fix #59128 Assignment desugaring of `(const (= (|::| x T) rhs))` would pre-expand to, then re-expand `(const x ,(convert-for-type-decl rhs T))`, but two-arg (IR) const is expected to have a simple RHS---closure conversion doesn't recurse here (should it?), giving us partially-lowered IR, and hence our bug. Fix: Pre-expand to the one-arg AST const form `(const (= x ,(convert-for-type-decl rhs T)))` instead. This also gives us a `(latestworld)` we were missing before, so this lowering may have been originally intended. (cherry picked from commit 3de5b9a)
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
5 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.
Fix #59128
Assignment desugaring of
(const (= (|::| x T) rhs))would pre-expand to, then re-expand(const x ,(convert-for-type-decl rhs T)), but two-arg (IR) const is expected to have a simple RHS---closure conversion doesn't recurse here (should it?), giving us partially-lowered IR, and hence our bug.Fix: Pre-expand to the one-arg AST const form
(const (= x ,(convert-for-type-decl rhs T)))instead. This also gives us a(latestworld)we were missing before, so this lowering may have been originally intended.