fix #18556: avoid crash on nested void proc result assignment - #25986
Open
nimamasl114514 wants to merge 1 commit into
Open
fix #18556: avoid crash on nested void proc result assignment#25986nimamasl114514 wants to merge 1 commit into
nimamasl114514 wants to merge 1 commit into
Conversation
When 'result' inside a nested void proc is captured via closure and refers to the outer proc's resultSym, semAsgn assumed it belonged to the current proc and hit internalAssert(c.p.resultSym != nil) on the void proc which has no resultSym. Only run the return-type inference path when the result sym actually belongs to the current proc owner.
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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Summary
esult = expr\ caused compiler internal error crash instead of a friendly type error.
esult\ inside a nested void proc was captured via closure and referred to the outer proc's
esultSym, \semAsgn\ assumed it belonged to the current proc and hit \internalAssert(c.p.resultSym != nil)\ on the void proc which has no
esultSym.
Fix
Only run the return-type inference path when the result sym actually belongs to the current proc owner:
\
im
if lhs.sym.owner == c.p.owner and
c.p.owner.kind != skMacro and resultTypeIsInferrable(lhs.sym.typ):
\\
Repro
\
im
proc p(): auto =
result = proc(): auto =
result = 42 # type error: should be friendly, not crash
\\
Before: \internalError\ crash at \compiler/semexprs.nim:2125.
After: \ ype mismatch: p(): void\ friendly error.
Testing
Fixes #18556.