Merging upstream version 1.68.2+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/tests/mir-opt/uninhabited_enum_branching.rs b/tests/mir-opt/uninhabited_enum_branching.rs
new file mode 100644
index 000000000..0ef604c30
--- /dev/null
+++ b/tests/mir-opt/uninhabited_enum_branching.rs
@@ -0,0 +1,30 @@
+enum Empty { }
+
+// test matching an enum with uninhabited variants
+enum Test1 {
+    A(Empty),
+    B(Empty),
+    C
+}
+
+// test an enum where the discriminants don't match the variant indexes
+// (the optimization should do nothing here)
+enum Test2 {
+    D = 4,
+    E = 5,
+}
+
+// EMIT_MIR uninhabited_enum_branching.main.UninhabitedEnumBranching.diff
+// EMIT_MIR uninhabited_enum_branching.main.SimplifyCfg-after-uninhabited-enum-branching.after.mir
+fn main() {
+    match Test1::C {
+        Test1::A(_) => "A(Empty)",
+        Test1::B(_) => "B(Empty)",
+        Test1::C => "C",
+    };
+
+    match Test2::D {
+        Test2::D => "D",
+        Test2::E => "E",
+    };
+}