From 30fbfd5f05108d12f08711024db699e1b0632508 Mon Sep 17 00:00:00 2001 From: Ulrich Weigand Date: Wed, 21 Dec 2022 17:27:45 +0100 Subject: [PATCH] Sort lint_groups in no_lint_suggestion The no_lint_suggestion routine passes a vector of lint group names to find_best_match_for_name. That routine depends on the sort order of its input vector, which matters in case multiple inputs are at the same Levenshtein distance to the target name. However, no_lint_suggestion currently just passes lint_groups.keys() as input vector - this is sorted in hash value order, which is not guaranteed to be stable, and in fact differs between big- and little-endian host platforms, causing test failures on s390x. To fix this, always sort the lint groups before using their names as input to find_best_match_for_name. In addition, deprecated lint groups should never be suggested, so filter those out. Fixes https://github.com/rust-lang/rust/issues/105379 --- compiler/rustc_lint/src/context.rs | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs index 0417f375588..3c9ad410663 100644 --- a/compiler/rustc_lint/src/context.rs +++ b/compiler/rustc_lint/src/context.rs @@ -483,7 +483,16 @@ fn no_lint_suggestion(&self, lint_name: &str) -> CheckLintNameResult<'_> { return CheckLintNameResult::NoLint(Some(Symbol::intern(&name_lower))); } // ...if not, search for lints with a similar name - let groups = self.lint_groups.keys().copied().map(Symbol::intern); + // Note: find_best_match_for_name depends on the sort order of its input vector. + // To ensure deterministic output, sort elements of the lint_groups hash map. + // Also, never suggest deprecated lint groups. + let mut groups: Vec<_> = self + .lint_groups + .iter() + .filter_map(|(k, LintGroup { depr, .. })| if depr.is_none() { Some(k) } else { None }) + .collect(); + groups.sort(); + let groups = groups.iter().map(|k| Symbol::intern(k)); let lints = self.lints.iter().map(|l| Symbol::intern(&l.name_lower())); let names: Vec = groups.chain(lints).collect(); let suggestion = find_best_match_for_name(&names, Symbol::intern(&name_lower), None);