Collect renamed lints

Author: Serial-ATA

clippy_lints/src/utils/internal_lints/metadata_collector.rs

@@ -8,6 +8,7 @@
 //! a simple mistake)
 
 use crate::utils::internal_lints::{extract_clippy_version_value, is_lint_ref_type};
+use crate::renamed_lints::RENAMED_LINTS;
 
 use clippy_utils::diagnostics::span_lint;
 use clippy_utils::ty::{match_type, walk_ptrs_ty_depth};
@@ -200,7 +201,10 @@ impl Drop for MetadataCollector {
         let mut lints = std::mem::take(&mut self.lints).into_sorted_vec();
         lints
             .iter_mut()
-            .for_each(|x| x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default()));
+            .for_each(|x| {
+                x.applicability = Some(applicability_info.remove(&x.id).unwrap_or_default());
+                x.past_names = collect_renames(&x.id);
+            });
 
         // Outputting
         if Path::new(OUTPUT_FILE).exists() {
@@ -222,6 +226,7 @@ struct LintMetadata {
     /// This field is only used in the output and will only be
     /// mapped shortly before the actual output.
     applicability: Option<ApplicabilityInfo>,
+    past_names: Option<Vec<String>>,
 }
 
 impl LintMetadata {
@@ -241,6 +246,7 @@ impl LintMetadata {
             version,
             docs,
             applicability: None,
+            past_names: None,
         }
     }
 }
@@ -643,6 +649,27 @@ fn is_deprecated_lint(cx: &LateContext<'_>, ty: &hir::Ty<'_>) -> bool {
     false
 }
 
+fn collect_renames(lint_name: &str) -> Option<Vec<String>> {
+    let collected = RENAMED_LINTS.iter().filter_map(|(k, v)| {
+        if_chain! {
+            if let Some(name) = v.strip_prefix(CLIPPY_LINT_GROUP_PREFIX);
+            if name == lint_name;
+            if let Some(past_name) = k.strip_prefix(CLIPPY_LINT_GROUP_PREFIX);
+            then {
+                Some(past_name.to_string())
+            } else {
+                None
+            }
+        }
+    }).collect::<Vec<_>>();
+
+    if collected.is_empty() {
+        None
+    } else {
+        Some(collected)
+    }
+}
+
 // ==================================================================
 // Lint emission
 // ==================================================================