perf: fix quadratic scaling in unused variable linter#12843
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perf: fix quadratic scaling in unused variable linter#12843
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This PR fixes a quadratic performance issue in the unused variable linter that was exposed by a benchmark with many implicit parameters from https://github.com/JacquesCarette/BenchmarkingProofAssistants. The linter previously called `findStack?` once per variable definition, resulting in O(n·m) cost for n unused variables in a syntax tree with m leaves. This is replaced by a single batch traversal (`findStacks`) that collects all syntax stacks at once. Additionally, macro expansion info tree traversal is now skipped entirely when no macro expansions are present. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Benchmark results for f9aeed3 against 333ab1c are in! @nomeata
Small changes (44🟥) Too many entries to display here. View the full report on radar instead. |
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Overall a mild regression, and the problem this fixes (many unused implicit variables or something) is likely not relevant in practice. Closing until something shows it is. |
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This PR fixes a quadratic performance issue in the unused variable linter
that was exposed by a benchmark with many implicit parameters from
https://github.com/JacquesCarette/BenchmarkingProofAssistants. The linter
previously called
findStack?once per variable definition, resulting inO(n·m) cost for n unused variables in a syntax tree with m leaves. This is
replaced by a single batch traversal (
findStacks) that collects allsyntax stacks at once. Additionally, macro expansion info tree traversal
is now skipped entirely when no macro expansions are present.
Co-Authored-By: Claude Opus 4.6 noreply@anthropic.com