Check overlapping_range lint level per arm

Author: Nadrieril

compiler/rustc_mir_build/src/thir/pattern/deconstruct_pat.rs

@@ -215,9 +215,8 @@ impl IntRange {
     pub(super) fn lint_overlapping_range_endpoints<'a, 'p: 'a, 'tcx: 'a>(
         &self,
         pcx: &PatCtxt<'_, 'p, 'tcx>,
-        pats: impl Iterator<Item = (&'a DeconstructedPat<'p, 'tcx>, bool)>,
+        pats: impl Iterator<Item = (&'a DeconstructedPat<'p, 'tcx>, bool, HirId)>,
         column_count: usize,
-        lint_root: HirId,
     ) {
         // FIXME: for now, only check for overlapping ranges on non-nested range patterns. Otherwise
         // with the current logic the following is detected as overlapping:
@@ -237,9 +236,11 @@ impl IntRange {
         let mut prefixes: SmallVec<[_; 1]> = Default::default();
         let mut suffixes: SmallVec<[_; 1]> = Default::default();
         // Iterate on rows that contained `overlap`.
-        for (range, this_span, is_under_guard) in pats.filter_map(|(pat, under_guard)| {
-            Some((pat.ctor().as_int_range()?, pat.span(), under_guard))
-        }) {
+        for (range, this_span, is_under_guard, arm_hir_id) in
+            pats.filter_map(|(pat, under_guard, arm_hir_id)| {
+                Some((pat.ctor().as_int_range()?, pat.span(), under_guard, arm_hir_id))
+            })
+        {
             if range.is_singleton() {
                 continue;
             }
@@ -268,7 +269,7 @@ impl IntRange {
                     .collect();
                 pcx.cx.tcx.emit_spanned_lint(
                     lint::builtin::OVERLAPPING_RANGE_ENDPOINTS,
-                    lint_root,
+                    arm_hir_id,
                     this_span,
                     OverlappingRangeEndpoints { overlap: overlaps, range: this_span },
                 );

compiler/rustc_mir_build/src/thir/pattern/usefulness.rs

@@ -806,12 +806,16 @@ fn compute_usefulness<'p, 'tcx>(
                 if overlap_range.is_singleton() && orig_column_count == 1 {
                     overlap_range.lint_overlapping_range_endpoints(
                         pcx,
-                        spec_matrix
-                            .rows()
-                            .map(|child_row| &matrix.rows[child_row.parent_row])
-                            .map(|parent_row| (parent_row.head(), parent_row.is_under_guard)),
+                        spec_matrix.rows().map(|child_row| &matrix.rows[child_row.parent_row]).map(
+                            |parent_row| {
+                                (
+                                    parent_row.head(),
+                                    parent_row.is_under_guard,
+                                    parent_row.arm_hir_id,
+                                )
+                            },
+                        ),
                         orig_column_count,
-                        lint_root,
                     );
                 }
             }

tests/ui/pattern/usefulness/integer-ranges/overlapping_range_endpoints.rs

@@ -42,6 +42,15 @@ fn main() {
         //~| ERROR multiple patterns overlap on their endpoints
         _ => {}
     }
+    // Selectively allow lint
+    match 0u8 {
+        0..=10 => {}
+        #[allow(overlapping_range_endpoints)]
+        10..=20 => {}
+        10..=20 => {}
+        //~^ ERROR multiple patterns overlap on their endpoints
+        _ => {}
+    }
     match 0u8 {
         0..=10 => {}
         10..=20 if true => {} //~ ERROR multiple patterns overlap on their endpoints

tests/ui/pattern/usefulness/integer-ranges/overlapping_range_endpoints.stderr

@@ -77,7 +77,18 @@ LL |         10..=20 => {}
    = note: you likely meant to write mutually exclusive ranges
 
 error: multiple patterns overlap on their endpoints
-  --> $DIR/overlapping_range_endpoints.rs:47:9
+  --> $DIR/overlapping_range_endpoints.rs:50:9
+   |
+LL |         0..=10 => {}
+   |         ------ this range overlaps on `10_u8`...
+...
+LL |         10..=20 => {}
+   |         ^^^^^^^ ... with this range
+   |
+   = note: you likely meant to write mutually exclusive ranges
+
+error: multiple patterns overlap on their endpoints
+  --> $DIR/overlapping_range_endpoints.rs:56:9
    |
 LL |         0..=10 => {}
    |         ------ this range overlaps on `10_u8`...
@@ -87,7 +98,7 @@ LL |         10..=20 if true => {}
    = note: you likely meant to write mutually exclusive ranges
 
 error: multiple patterns overlap on their endpoints
-  --> $DIR/overlapping_range_endpoints.rs:63:16
+  --> $DIR/overlapping_range_endpoints.rs:72:16
    |
 LL |         (true, 0..=10) => {}
    |                ------ this range overlaps on `10_u8`...
@@ -97,7 +108,7 @@ LL |         (true, 10..20) => {}
    = note: you likely meant to write mutually exclusive ranges
 
 error: multiple patterns overlap on their endpoints
-  --> $DIR/overlapping_range_endpoints.rs:71:13
+  --> $DIR/overlapping_range_endpoints.rs:80:13
    |
 LL |         (true, 0..=10) => {}
    |                ------ this range overlaps on `10_u8`...
@@ -108,7 +119,7 @@ LL |         (_, 10..20) => {}
    = note: you likely meant to write mutually exclusive ranges
 
 error: multiple patterns overlap on their endpoints
-  --> $DIR/overlapping_range_endpoints.rs:76:14
+  --> $DIR/overlapping_range_endpoints.rs:85:14
    |
 LL |         Some(0..=10) => {}
    |              ------ this range overlaps on `10_u8`...
@@ -117,5 +128,5 @@ LL |         Some(10..20) => {}
    |
    = note: you likely meant to write mutually exclusive ranges
 
-error: aborting due to 11 previous errors
+error: aborting due to 12 previous errors