rust: Add checking for union patterns

gcc/rust/ChangeLog:

	* typecheck/rust-hir-type-check-pattern.cc (TypeCheckPattern::visit):
		Add check for union patterns.

gcc/testsuite/ChangeLog:

	* rust/compile/match8.rs: New test.

Signed-off-by: Raiki Tamura <tamaron1203@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/gcc/testsuite/rust/compile/match8.rs b/gcc/testsuite/rust/compile/match8.rs
new file mode 100644
index 0000000..336b313
--- /dev/null
+++ b/gcc/testsuite/rust/compile/match8.rs
@@ -0,0 +1,19 @@
+union MyUnion {
+    f1: u32,
+    f2: f32,
+}
+
+fn f(u: MyUnion) -> i32 {
+    unsafe {
+        match u {
+            MyUnion { f1: 10 } => 0,
+            MyUnion { f2 } => 0,
+            MyUnion { f1: 10, f2: 10.0 } => 0, // { dg-error "union patterns should have exactly one field" "" }
+            MyUnion {} => 0, // { dg-error "union patterns should have exactly one field" "" }
+            MyUnion { f1: () } => 0, // { dg-error "expected u32, found tuple" "" }
+            _ => 1,
+        }
+    }
+}
+
+fn main() {}