1 files changed, 157 insertions, 0 deletions
diff --git a/src/test/ui/pattern/usefulness/exhaustive_integer_patterns.rs b/src/test/ui/pattern/usefulness/exhaustive_integer_patterns.rs
new file mode 100644
index 00000000000..59f74919897
--- /dev/null
+++ b/src/test/ui/pattern/usefulness/exhaustive_integer_patterns.rs
@@ -0,0 +1,157 @@
+#![feature(precise_pointer_size_matching)]
+#![feature(exclusive_range_pattern)]
+#![deny(unreachable_patterns)]
+#![deny(overlapping_patterns)]
+
+use std::{char, u8, u16, u32, u64, u128, i8, i16, i32, i64, i128};
+
+fn main() {
+    let x: u8 = 0;
+
+    // A single range covering the entire domain.
+    match x {
+        0 ..= 255 => {} // ok
+    }
+
+    // A combination of ranges and values.
+    // These are currently allowed to be overlapping.
+    match x {
+        0 ..= 32 => {}
+        33 => {}
+        34 .. 128 => {}
+        100 ..= 200 => {}
+        200 => {} //~ ERROR unreachable pattern
+        201 ..= 255 => {}
+    }
+
+    // An incomplete set of values.
+    match x { //~ ERROR non-exhaustive patterns
+        0 .. 128 => {}
+    }
+
+    // A more incomplete set of values.
+    match x { //~ ERROR non-exhaustive patterns
+        0 ..= 10 => {}
+        20 ..= 30 => {}
+        35 => {}
+        70 .. 255 => {}
+    }
+
+    let x: i8 = 0;
+    match x { //~ ERROR non-exhaustive patterns
+        -7 => {}
+        -5..=120 => {}
+        -2..=20 => {}
+        //~^ ERROR unreachable pattern
+        125 => {}
+    }
+
+    // Let's test other types too!
+    let c: char = '\u{0}';
+    match c {
+        '\u{0}' ..= char::MAX => {} // ok
+    }
+
+    // We can actually get away with just covering the
+    // following two ranges, which correspond to all
+    // valid Unicode Scalar Values.
+    match c {
+        '\u{0000}' ..= '\u{D7FF}' => {}
+        '\u{E000}' ..= '\u{10_FFFF}' => {}
+    }
+
+    match 0u16 {
+        0 ..= u16::MAX => {} // ok
+    }
+
+    match 0u32 {
+        0 ..= u32::MAX => {} // ok
+    }
+
+    match 0u64 {
+        0 ..= u64::MAX => {} // ok
+    }
+
+    match 0u128 {
+        0 ..= u128::MAX => {} // ok
+    }
+
+    match 0i8 {
+        -128 ..= 127 => {} // ok
+    }
+
+    match 0i8 { //~ ERROR non-exhaustive patterns
+        -127 ..= 127 => {}
+    }
+
+    match 0i16 {
+        i16::MIN ..= i16::MAX => {} // ok
+    }
+
+    match 0i16 { //~ ERROR non-exhaustive patterns
+        i16::MIN ..= -1 => {}
+        1 ..= i16::MAX => {}
+    }
+
+    match 0i32 {
+        i32::MIN ..= i32::MAX => {} // ok
+    }
+
+    match 0i64 {
+        i64::MIN ..= i64::MAX => {} // ok
+    }
+
+    match 0i128 {
+        i128::MIN ..= i128::MAX => {} // ok
+    }
+
+    // Make sure that guards don't factor into the exhaustiveness checks.
+    match 0u8 { //~ ERROR non-exhaustive patterns
+        0 .. 128 => {}
+        128 ..= 255 if true => {}
+    }
+
+    match 0u8 {
+        0 .. 128 => {}
+        128 ..= 255 if false => {}
+        128 ..= 255 => {} // ok, because previous arm was guarded
+    }
+
+    // Now things start getting a bit more interesting. Testing products!
+    match (0u8, Some(())) { //~ ERROR non-exhaustive patterns
+        (1, _) => {}
+        (_, None) => {}
+    }
+
+    match (0u8, true) { //~ ERROR non-exhaustive patterns
+        (0 ..= 125, false) => {}
+        (128 ..= 255, false) => {}
+        (0 ..= 255, true) => {}
+    }
+
+    match (0u8, true) { // ok
+        (0 ..= 125, false) => {}
+        (128 ..= 255, false) => {}
+        (0 ..= 255, true) => {}
+        (125 .. 128, false) => {}
+    }
+
+    match 0u8 {
+        0 .. 2 => {}
+        1 ..= 2 => {} //~ ERROR multiple patterns covering the same range
+        _ => {}
+    }
+
+    const LIM: u128 = u128::MAX - 1;
+    match 0u128 { //~ ERROR non-exhaustive patterns
+        0 ..= LIM => {}
+    }
+
+    match 0u128 { //~ ERROR non-exhaustive patterns
+        0 ..= 4 => {}
+    }
+
+    match 0u128 { //~ ERROR non-exhaustive patterns
+        4 ..= u128::MAX => {}
+    }
+}