Auto merge of #78242 - Nadrieril:rename-overlapping_endpoints-lint, r=varkor

Rename `overlapping_patterns` lint

As discussed in #65477. I also tweaked a few things along the way.

r? `@varkor`
`@rustbot` modify labels: +A-exhaustiveness-checking

Author: bors

compiler/rustc_lint/src/lib.rs

@@ -283,7 +283,6 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
         UNUSED_MUT,
         UNREACHABLE_CODE,
         UNREACHABLE_PATTERNS,
-        OVERLAPPING_PATTERNS,
         UNUSED_MUST_USE,
         UNUSED_UNSAFE,
         PATH_STATEMENTS,
@@ -335,6 +334,7 @@ fn register_builtins(store: &mut LintStore, no_interleave_lints: bool) {
     store.register_renamed("exceeding_bitshifts", "arithmetic_overflow");
     store.register_renamed("redundant_semicolon", "redundant_semicolons");
     store.register_renamed("intra_doc_link_resolution_failure", "broken_intra_doc_links");
+    store.register_renamed("overlapping_patterns", "overlapping_range_endpoints");
     store.register_removed("unknown_features", "replaced by an error");
     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
     store.register_removed("negate_unsigned", "cast a signed value instead");

compiler/rustc_lint_defs/src/builtin.rs

@@ -588,8 +588,8 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// The `overlapping_patterns` lint detects `match` arms that have
-    /// [range patterns] that overlap.
+    /// The `overlapping_range_endpoints` lint detects `match` arms that have [range patterns] that
+    /// overlap on their endpoints.
     ///
     /// [range patterns]: https://doc.rust-lang.org/nightly/reference/patterns.html#range-patterns
     ///
@@ -607,13 +607,12 @@ declare_lint! {
     ///
     /// ### Explanation
     ///
-    /// It is likely a mistake to have range patterns in a match expression
-    /// that overlap. Check that the beginning and end values are what you
-    /// expect, and keep in mind that with `..=` the left and right bounds are
-    /// inclusive.
-    pub OVERLAPPING_PATTERNS,
+    /// It is likely a mistake to have range patterns in a match expression that overlap in this
+    /// way. Check that the beginning and end values are what you expect, and keep in mind that
+    /// with `..=` the left and right bounds are inclusive.
+    pub OVERLAPPING_RANGE_ENDPOINTS,
     Warn,
-    "detects overlapping patterns"
+    "detects range patterns with overlapping endpoints"
 }
 
 declare_lint! {
@@ -2809,7 +2808,7 @@ declare_lint_pass! {
         DEAD_CODE,
         UNREACHABLE_CODE,
         UNREACHABLE_PATTERNS,
-        OVERLAPPING_PATTERNS,
+        OVERLAPPING_RANGE_ENDPOINTS,
         BINDINGS_WITH_VARIANT_NAME,
         UNUSED_MACROS,
         WARNINGS,

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

@@ -161,7 +161,7 @@ impl IntRange {
         // 2       --------   // 2 -------
         let (lo, hi) = self.boundaries();
         let (other_lo, other_hi) = other.boundaries();
-        lo == other_hi || hi == other_lo
+        (lo == other_hi || hi == other_lo) && !self.is_singleton() && !other.is_singleton()
     }
 
     fn to_pat<'tcx>(&self, tcx: TyCtxt<'tcx>, ty: Ty<'tcx>) -> Pat<'tcx> {
@@ -273,7 +273,7 @@ impl IntRange {
         let mut borders: Vec<_> = row_borders.chain(self_borders).collect();
         borders.sort_unstable();
 
-        self.lint_overlapping_patterns(pcx, hir_id, overlaps);
+        self.lint_overlapping_range_endpoints(pcx, hir_id, overlaps);
 
         // We're going to iterate through every adjacent pair of borders, making sure that
         // each represents an interval of nonnegative length, and convert each such
@@ -296,30 +296,30 @@ impl IntRange {
             .collect()
     }
 
-    fn lint_overlapping_patterns(
+    fn lint_overlapping_range_endpoints(
         &self,
         pcx: PatCtxt<'_, '_, '_>,
         hir_id: Option<HirId>,
         overlaps: Vec<(IntRange, Span)>,
     ) {
         if let (true, Some(hir_id)) = (!overlaps.is_empty(), hir_id) {
             pcx.cx.tcx.struct_span_lint_hir(
-                lint::builtin::OVERLAPPING_PATTERNS,
+                lint::builtin::OVERLAPPING_RANGE_ENDPOINTS,
                 hir_id,
                 pcx.span,
                 |lint| {
-                    let mut err = lint.build("multiple patterns covering the same range");
-                    err.span_label(pcx.span, "overlapping patterns");
+                    let mut err = lint.build("multiple patterns overlap on their endpoints");
                     for (int_range, span) in overlaps {
-                        // Use the real type for user display of the ranges:
                         err.span_label(
                             span,
                             &format!(
-                                "this range overlaps on `{}`",
-                                int_range.to_pat(pcx.cx.tcx, pcx.ty),
+                                "this range overlaps on `{}`...",
+                                int_range.to_pat(pcx.cx.tcx, pcx.ty)
                             ),
                         );
                     }
+                    err.span_label(pcx.span, "... with this range");
+                    err.note("you likely meant to write mutually exclusive ranges");
                     err.emit();
                 },
             );

src/test/ui/issues/issue-21475.rs

@@ -1,5 +1,5 @@
 // run-pass
-#![allow(unused_imports, overlapping_patterns)]
+#![allow(unused_imports, overlapping_range_endpoints)]
 // pretty-expanded FIXME #23616
 
 use m::{START, END};

src/test/ui/issues/issue-26251.rs

@@ -1,5 +1,5 @@
 // run-pass
-#![allow(overlapping_patterns)]
+#![allow(overlapping_range_endpoints)]
 
 fn main() {
     let x = 'a';

src/test/ui/pattern/usefulness/integer-ranges/exhaustiveness.rs

@@ -1,5 +1,6 @@
 #![feature(exclusive_range_pattern)]
 #![feature(assoc_char_consts)]
+#![allow(overlapping_range_endpoints)]
 #![deny(unreachable_patterns)]
 
 macro_rules! m {

src/test/ui/pattern/usefulness/integer-ranges/exhaustiveness.stderr

@@ -1,5 +1,5 @@
 error[E0004]: non-exhaustive patterns: `u8::MAX` not covered
-  --> $DIR/exhaustiveness.rs:47:8
+  --> $DIR/exhaustiveness.rs:48:8
    |
 LL |     m!(0u8, 0..255);
    |        ^^^ pattern `u8::MAX` not covered
@@ -8,7 +8,7 @@ LL |     m!(0u8, 0..255);
    = note: the matched value is of type `u8`
 
 error[E0004]: non-exhaustive patterns: `u8::MAX` not covered
-  --> $DIR/exhaustiveness.rs:48:8
+  --> $DIR/exhaustiveness.rs:49:8
    |
 LL |     m!(0u8, 0..=254);
    |        ^^^ pattern `u8::MAX` not covered
@@ -17,7 +17,7 @@ LL |     m!(0u8, 0..=254);
    = note: the matched value is of type `u8`
 
 error[E0004]: non-exhaustive patterns: `0_u8` not covered
-  --> $DIR/exhaustiveness.rs:49:8
+  --> $DIR/exhaustiveness.rs:50:8
    |
 LL |     m!(0u8, 1..=255);
    |        ^^^ pattern `0_u8` not covered
@@ -26,7 +26,7 @@ LL |     m!(0u8, 1..=255);
    = note: the matched value is of type `u8`
 
 error[E0004]: non-exhaustive patterns: `42_u8` not covered
-  --> $DIR/exhaustiveness.rs:50:8
+  --> $DIR/exhaustiveness.rs:51:8
    |
 LL |     m!(0u8, 0..42 | 43..=255);
    |        ^^^ pattern `42_u8` not covered
@@ -35,7 +35,7 @@ LL |     m!(0u8, 0..42 | 43..=255);
    = note: the matched value is of type `u8`
 
 error[E0004]: non-exhaustive patterns: `i8::MAX` not covered
-  --> $DIR/exhaustiveness.rs:51:8
+  --> $DIR/exhaustiveness.rs:52:8
    |
 LL |     m!(0i8, -128..127);
    |        ^^^ pattern `i8::MAX` not covered
@@ -44,7 +44,7 @@ LL |     m!(0i8, -128..127);
    = note: the matched value is of type `i8`
 
 error[E0004]: non-exhaustive patterns: `i8::MAX` not covered
-  --> $DIR/exhaustiveness.rs:52:8
+  --> $DIR/exhaustiveness.rs:53:8
    |
 LL |     m!(0i8, -128..=126);
    |        ^^^ pattern `i8::MAX` not covered
@@ -53,7 +53,7 @@ LL |     m!(0i8, -128..=126);
    = note: the matched value is of type `i8`
 
 error[E0004]: non-exhaustive patterns: `i8::MIN` not covered
-  --> $DIR/exhaustiveness.rs:53:8
+  --> $DIR/exhaustiveness.rs:54:8
    |
 LL |     m!(0i8, -127..=127);
    |        ^^^ pattern `i8::MIN` not covered
@@ -62,7 +62,7 @@ LL |     m!(0i8, -127..=127);
    = note: the matched value is of type `i8`
 
 error[E0004]: non-exhaustive patterns: `0_i8` not covered
-  --> $DIR/exhaustiveness.rs:54:11
+  --> $DIR/exhaustiveness.rs:55:11
    |
 LL |     match 0i8 {
    |           ^^^ pattern `0_i8` not covered
@@ -71,7 +71,7 @@ LL |     match 0i8 {
    = note: the matched value is of type `i8`
 
 error[E0004]: non-exhaustive patterns: `u128::MAX` not covered
-  --> $DIR/exhaustiveness.rs:59:8
+  --> $DIR/exhaustiveness.rs:60:8
    |
 LL |     m!(0u128, 0..=ALMOST_MAX);
    |        ^^^^^ pattern `u128::MAX` not covered
@@ -80,7 +80,7 @@ LL |     m!(0u128, 0..=ALMOST_MAX);
    = note: the matched value is of type `u128`
 
 error[E0004]: non-exhaustive patterns: `5_u128..=u128::MAX` not covered
-  --> $DIR/exhaustiveness.rs:60:8
+  --> $DIR/exhaustiveness.rs:61:8
    |
 LL |     m!(0u128, 0..=4);
    |        ^^^^^ pattern `5_u128..=u128::MAX` not covered
@@ -89,7 +89,7 @@ LL |     m!(0u128, 0..=4);
    = note: the matched value is of type `u128`
 
 error[E0004]: non-exhaustive patterns: `0_u128` not covered
-  --> $DIR/exhaustiveness.rs:61:8
+  --> $DIR/exhaustiveness.rs:62:8
    |
 LL |     m!(0u128, 1..=u128::MAX);
    |        ^^^^^ pattern `0_u128` not covered
@@ -98,7 +98,7 @@ LL |     m!(0u128, 1..=u128::MAX);
    = note: the matched value is of type `u128`
 
 error[E0004]: non-exhaustive patterns: `(126_u8..=127_u8, false)` not covered
-  --> $DIR/exhaustiveness.rs:69:11
+  --> $DIR/exhaustiveness.rs:70:11
    |
 LL |     match (0u8, true) {
    |           ^^^^^^^^^^^ pattern `(126_u8..=127_u8, false)` not covered

src/test/ui/pattern/usefulness/integer-ranges/overlapping_range_endpoints.rs

@@ -1,5 +1,5 @@
 #![feature(exclusive_range_pattern)]
-#![deny(overlapping_patterns)]
+#![deny(overlapping_range_endpoints)]
 
 macro_rules! m {
     ($s:expr, $t1:pat, $t2:pat) => {
@@ -12,27 +12,33 @@ macro_rules! m {
 }
 
 fn main() {
-    m!(0u8, 20..=30, 30..=40); //~ ERROR multiple patterns covering the same range
-    m!(0u8, 30..=40, 20..=30); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 20..=30, 30..=40); //~ ERROR multiple patterns overlap on their endpoints
+    m!(0u8, 30..=40, 20..=30); //~ ERROR multiple patterns overlap on their endpoints
     m!(0u8, 20..=30, 31..=40);
     m!(0u8, 20..=30, 29..=40);
-    m!(0u8, 20.. 30, 29..=40); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 20.. 30, 29..=40); //~ ERROR multiple patterns overlap on their endpoints
     m!(0u8, 20.. 30, 28..=40);
     m!(0u8, 20.. 30, 30..=40);
     m!(0u8, 20..=30, 30..=30);
-    m!(0u8, 20..=30, 30..=31); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 20..=30, 30..=31); //~ ERROR multiple patterns overlap on their endpoints
     m!(0u8, 20..=30, 29..=30);
     m!(0u8, 20..=30, 20..=20);
     m!(0u8, 20..=30, 20..=21);
-    m!(0u8, 20..=30, 19..=20); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 20..=30, 19..=20); //~ ERROR multiple patterns overlap on their endpoints
     m!(0u8, 20..=30, 20);
     m!(0u8, 20..=30, 25);
     m!(0u8, 20..=30, 30);
     m!(0u8, 20.. 30, 29);
-    m!(0u8, 20, 20..=30); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 20, 20..=30);
     m!(0u8, 25, 20..=30);
-    m!(0u8, 30, 20..=30); //~ ERROR multiple patterns covering the same range
+    m!(0u8, 30, 20..=30);
 
+    match 0u8 {
+        0..=10 => {}
+        20..=30 => {}
+        10..=20 => {} //~ ERROR multiple patterns overlap on their endpoints
+        _ => {}
+    }
     match (0u8, true) {
         (0..=10, true) => {}
         (10..20, true) => {} // not detected
@@ -41,13 +47,13 @@ fn main() {
     }
     match (true, 0u8) {
         (true, 0..=10) => {}
-        (true, 10..20) => {} //~ ERROR multiple patterns covering the same range
+        (true, 10..20) => {} //~ ERROR multiple patterns overlap on their endpoints
         (false, 10..20) => {}
         _ => {}
     }
     match Some(0u8) {
         Some(0..=10) => {}
-        Some(10..20) => {} //~ ERROR multiple patterns covering the same range
+        Some(10..20) => {} //~ ERROR multiple patterns overlap on their endpoints
         _ => {}
     }
 }