add find_best_match_for_names for multiple lookups

Author: chenyukang

compiler/rustc_lint/src/context.rs

@@ -33,7 +33,7 @@ use rustc_middle::ty::{self, print::Printer, GenericArg, RegisteredTools, Ty, Ty
 use rustc_session::lint::{BuiltinLintDiagnostics, LintExpectationId};
 use rustc_session::lint::{FutureIncompatibleInfo, Level, Lint, LintBuffer, LintId};
 use rustc_session::{LintStoreMarker, Session};
-use rustc_span::edit_distance::find_best_match_for_name;
+use rustc_span::edit_distance::find_best_match_for_names;
 use rustc_span::symbol::{sym, Ident, Symbol};
 use rustc_span::Span;
 use rustc_target::abi;
@@ -442,14 +442,11 @@ impl LintStore {
         let groups = groups.iter().map(|k| Symbol::intern(k));
         let lints = self.lints.iter().map(|l| Symbol::intern(&l.name_lower()));
         let names: Vec<Symbol> = groups.chain(lints).collect();
-        let mut res = find_best_match_for_name(&names, Symbol::intern(&name_lower), Some(2));
-        if res.is_none() && name_lower.contains("::") {
-            let stripped = name_lower.split("::").last().unwrap();
-            res = find_best_match_for_name(&names, Symbol::intern(stripped), Some(2));
-        }
-        if res.is_none() {
-            res = find_best_match_for_name(&names, Symbol::intern(&name_lower), None);
+        let mut lookups = vec![Symbol::intern(&name_lower)];
+        if let Some(stripped) = name_lower.split("::").last() {
+            lookups.push(Symbol::intern(stripped));
         }
+        let res = find_best_match_for_names(&names, &lookups, None);
         let is_rustc = res.map_or_else(
             || false,
             |s| name_lower.contains("::") && !s.as_str().starts_with(tool_name),

compiler/rustc_span/src/edit_distance.rs

@@ -170,6 +170,34 @@ pub fn find_best_match_for_name(
     find_best_match_for_name_impl(false, candidates, lookup, dist)
 }
 
+/// Find the best match for a give word list
+///
+/// This function is helpfull when we have multiple patterns for candidates, for example:
+///
+/// For give keyword `clippy::missing_docs`, we may have multiple candidates:
+/// - `clippy::missing_docs_in_private_items`
+/// - `clippy::erasing_op`
+/// - `missing_docs`
+///
+/// We want to find the best match for the given keyword, strip a prefix to get `missing_docs`,
+/// then call this function with `lookups` as `["clippy::missing_docs", "missing_docs"]`
+pub fn find_best_match_for_names(
+    candidates: &[Symbol],
+    lookups: &[Symbol],
+    dist: Option<usize>,
+) -> Option<Symbol> {
+    lookups
+        .iter()
+        .map(|s| (s, find_best_match_for_name_impl(false, candidates, *s, dist)))
+        .filter_map(|(s, r)| r.map(|r| (s, r)))
+        .min_by(|(s1, r1), (s2, r2)| {
+            let d1 = edit_distance(s1.as_str(), r1.as_str(), usize::MAX).unwrap();
+            let d2 = edit_distance(s2.as_str(), r2.as_str(), usize::MAX).unwrap();
+            d1.cmp(&d2)
+        })
+        .map(|(_, r)| r)
+}
+
 #[cold]
 fn find_best_match_for_name_impl(
     use_substring_score: bool,