Add some tests

src/test/ui/or-patterns/exhaustiveness-pass.rs

@@ -6,35 +6,63 @@
 // We wrap patterns in a tuple because top-level or-patterns are special-cased for now.
 fn main() {
     // Get the fatal error out of the way
-    match (0u8,) {
+    match (0,) {
         (0 | _,) => {}
         //~^ ERROR or-patterns are not fully implemented yet
     }
 
-    match (0u8,) {
+    match (0,) {
         (1 | 2,) => {}
         _ => {}
     }
 
-    match (0u8,) {
+    match (0, 0) {
-        (1 | 1,) => {} // FIXME(or_patterns): redundancy not detected for now.
-        _ => {}
-    }
-    match (0u8, 0u8) {
         (1 | 2, 3 | 4) => {}
         (1, 2) => {}
-        (2, 1) => {}
+        (3, 1) => {}
         _ => {}
     }
     match (Some(0u8),) {
         (None | Some(0 | 1),) => {}
         (Some(2..=255),) => {}
     }
-    match ((0u8,),) {
+    match ((0,),) {
         ((0 | 1,) | (2 | 3,),) => {},
         ((_,),) => {},
     }
     match (&[0u8][..],) {
         ([] | [0 | 1..=255] | [_, ..],) => {},
     }
+
+    match ((0, 0),) {
+        ((0, 0) | (0, 1),) => {}
+        _ => {}
+    }
+    match ((0, 0),) {
+        ((0, 0) | (1, 0),) => {}
+        _ => {}
+    }
+
+     // FIXME(or_patterns): Redundancies not detected for now.
+    match (0,) {
+        (1 | 1,) => {}
+        _ => {}
+    }
+    match [0; 2] {
+        [0 | 0, 0 | 0] => {}
+        _ => {}
+    }
+    match &[][..] {
+        [0] => {}
+        [0, _] => {}
+        [0, _, _] => {}
+        [1, ..] => {}
+        [1 | 2, ..] => {}
+        _ => {}
+    }
+    match Some(0) {
+        Some(0) => {}
+        Some(0 | 1) => {}
+        _ => {}
+    }
 }

src/test/ui/pattern/usefulness/top-level-alternation.rs

@@ -0,0 +1,58 @@
+#![deny(unreachable_patterns)]
+
+fn main() {
+    while let 0..=2 | 1 = 0 {} //~ ERROR unreachable pattern
+    if let 0..=2 | 1 = 0 {} //~ WARN irrefutable if-let pattern
+    // this one ^ is incorrect
+
+    match 0u8 {
+        0
+            | 0 => {} //~ ERROR unreachable pattern
+        _ => {}
+    }
+    match Some(0u8) {
+        Some(0)
+            | Some(0) => {} //~ ERROR unreachable pattern
+        _ => {}
+    }
+    match (0u8, 0u8) {
+        (0, _) | (_, 0) => {}
+        (0, 0) => {} //~ ERROR unreachable pattern
+        (1, 1) => {}
+        _ => {}
+    }
+    match (0u8, 0u8) {
+        (0, 1) | (2, 3) => {}
+        (0, 3) => {}
+        (2, 1) => {}
+        _ => {}
+    }
+    match (0u8, 0u8) {
+        (_, 0) | (_, 1) => {}
+        _ => {}
+    }
+    match (0u8, 0u8) {
+        (0, _) | (1, _) => {}
+        _ => {}
+    }
+    match Some(0u8) {
+        None | Some(_) => {}
+        _ => {} //~ ERROR unreachable pattern
+    }
+    match Some(0u8) {
+        None | Some(_) => {}
+        Some(_) => {} //~ ERROR unreachable pattern
+        None => {} //~ ERROR unreachable pattern
+    }
+    match Some(0u8) {
+        Some(_) => {}
+        None => {}
+        None //~ ERROR unreachable pattern
+            | Some(_) => {} //~ ERROR unreachable pattern
+    }
+    match 0u8 {
+        1 | 2 => {},
+        1..=2 => {}, //~ ERROR unreachable pattern
+        _ => {},
+    }
+}

src/test/ui/pattern/usefulness/top-level-alternation.stderr

@@ -0,0 +1,76 @@
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:4:23
+   |
+LL |     while let 0..=2 | 1 = 0 {}
+   |                       ^
+   |
+note: lint level defined here
+  --> $DIR/top-level-alternation.rs:1:9
+   |
+LL | #![deny(unreachable_patterns)]
+   |         ^^^^^^^^^^^^^^^^^^^^
+
+warning: irrefutable if-let pattern
+  --> $DIR/top-level-alternation.rs:5:20
+   |
+LL |     if let 0..=2 | 1 = 0 {}
+   |                    ^
+   |
+   = note: `#[warn(irrefutable_let_patterns)]` on by default
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:10:15
+   |
+LL |             | 0 => {}
+   |               ^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:15:15
+   |
+LL |             | Some(0) => {}
+   |               ^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:20:9
+   |
+LL |         (0, 0) => {}
+   |         ^^^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:40:9
+   |
+LL |         _ => {}
+   |         ^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:44:9
+   |
+LL |         Some(_) => {}
+   |         ^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:45:9
+   |
+LL |         None => {}
+   |         ^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:50:9
+   |
+LL |         None
+   |         ^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:51:15
+   |
+LL |             | Some(_) => {}
+   |               ^^^^^^^
+
+error: unreachable pattern
+  --> $DIR/top-level-alternation.rs:55:9
+   |
+LL |         1..=2 => {},
+   |         ^^^^^
+
+error: aborting due to 10 previous errors
+