1 files changed, 95 insertions, 0 deletions
diff --git a/tests/ui/pattern/usefulness/empty-match.rs b/tests/ui/pattern/usefulness/empty-match.rs
new file mode 100644
index 00000000000..9cdc0413ba1
--- /dev/null
+++ b/tests/ui/pattern/usefulness/empty-match.rs
@@ -0,0 +1,95 @@
+// aux-build:empty.rs
+// revisions: normal exhaustive_patterns
+//
+// This tests a match with no arms on various types.
+#![feature(never_type)]
+#![feature(never_type_fallback)]
+#![cfg_attr(exhaustive_patterns, feature(exhaustive_patterns))]
+#![deny(unreachable_patterns)]
+
+extern crate empty;
+
+enum EmptyEnum {}
+
+struct NonEmptyStruct1;
+struct NonEmptyStruct2(bool);
+union NonEmptyUnion1 {
+    foo: (),
+}
+union NonEmptyUnion2 {
+    foo: (),
+    bar: (),
+}
+enum NonEmptyEnum1 {
+    Foo(bool),
+}
+enum NonEmptyEnum2 {
+    Foo(bool),
+    Bar,
+}
+enum NonEmptyEnum5 {
+    V1, V2, V3, V4, V5,
+}
+
+fn empty_enum(x: EmptyEnum) {
+    match x {} // ok
+    match x {
+        _ => {}, //~ ERROR unreachable pattern
+    }
+    match x {
+        _ if false => {}, //~ ERROR unreachable pattern
+    }
+}
+
+fn empty_foreign_enum(x: empty::EmptyForeignEnum) {
+    match x {} // ok
+    match x {
+        _ => {}, //~ ERROR unreachable pattern
+    }
+    match x {
+        _ if false => {}, //~ ERROR unreachable pattern
+    }
+}
+
+fn never(x: !) {
+    match x {} // ok
+    match x {
+        _ => {}, //~ ERROR unreachable pattern
+    }
+    match x {
+        _ if false => {}, //~ ERROR unreachable pattern
+    }
+}
+
+macro_rules! match_no_arms {
+    ($e:expr) => {
+        match $e {}
+    };
+}
+macro_rules! match_guarded_arm {
+    ($e:expr) => {
+        match $e {
+            _ if false => {}
+        }
+    };
+}
+
+fn main() {
+    match_no_arms!(0u8); //~ ERROR type `u8` is non-empty
+    match_no_arms!(NonEmptyStruct1); //~ ERROR type `NonEmptyStruct1` is non-empty
+    match_no_arms!(NonEmptyStruct2(true)); //~ ERROR type `NonEmptyStruct2` is non-empty
+    match_no_arms!((NonEmptyUnion1 { foo: () })); //~ ERROR type `NonEmptyUnion1` is non-empty
+    match_no_arms!((NonEmptyUnion2 { foo: () })); //~ ERROR type `NonEmptyUnion2` is non-empty
+    match_no_arms!(NonEmptyEnum1::Foo(true)); //~ ERROR `NonEmptyEnum1::Foo(_)` not covered
+    match_no_arms!(NonEmptyEnum2::Foo(true)); //~ ERROR `NonEmptyEnum2::Foo(_)` and `NonEmptyEnum2::Bar` not covered
+    match_no_arms!(NonEmptyEnum5::V1); //~ ERROR `NonEmptyEnum5::V1`, `NonEmptyEnum5::V2`, `NonEmptyEnum5::V3` and 2 more not covered
+
+    match_guarded_arm!(0u8); //~ ERROR `_` not covered
+    match_guarded_arm!(NonEmptyStruct1); //~ ERROR `NonEmptyStruct1` not covered
+    match_guarded_arm!(NonEmptyStruct2(true)); //~ ERROR `NonEmptyStruct2(_)` not covered
+    match_guarded_arm!((NonEmptyUnion1 { foo: () })); //~ ERROR `NonEmptyUnion1 { .. }` not covered
+    match_guarded_arm!((NonEmptyUnion2 { foo: () })); //~ ERROR `NonEmptyUnion2 { .. }` not covered
+    match_guarded_arm!(NonEmptyEnum1::Foo(true)); //~ ERROR `NonEmptyEnum1::Foo(_)` not covered
+    match_guarded_arm!(NonEmptyEnum2::Foo(true)); //~ ERROR `NonEmptyEnum2::Foo(_)` and `NonEmptyEnum2::Bar` not covered
+    match_guarded_arm!(NonEmptyEnum5::V1); //~ ERROR `NonEmptyEnum5::V1`, `NonEmptyEnum5::V2`, `NonEmptyEnum5::V3` and 2 more not covered
+}