Sema: properly handle noreturn fields in unions

3 files changed, 55 insertions, 2 deletions

diff --git a/test/cases/compile_errors/noreturn_struct_field.zig b/test/cases/compile_errors/noreturn_struct_field.zig
new file mode 100644
index 0000000000..90b243c31d
--- /dev/null
+++ b/test/cases/compile_errors/noreturn_struct_field.zig
@@ -0,0 +1,12 @@
+const S = struct {
+    s: noreturn,
+};
+comptime {
+    _ = @typeInfo(S);
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:5: error: struct fields cannot be 'noreturn'
diff --git a/test/cases/compile_errors/runtime_cast_to_union_which_has_non-void_fields.zig b/test/cases/compile_errors/runtime_cast_to_union_which_has_non-void_fields.zig
index c312d6db40..0142f422f4 100644
--- a/test/cases/compile_errors/runtime_cast_to_union_which_has_non-void_fields.zig
+++ b/test/cases/compile_errors/runtime_cast_to_union_which_has_non-void_fields.zig
@@ -18,6 +18,4 @@ fn foo(l: Letter) void {
 //
 // :11:20: error: runtime coercion from enum 'tmp.Letter' to union 'tmp.Value' which has non-void fields
 // :3:5: note: field 'A' has type 'i32'
-// :4:5: note: field 'B' has type 'void'
-// :5:5: note: field 'C' has type 'void'
 // :2:15: note: union declared here
diff --git a/test/cases/compile_errors/union_noreturn_field_initialized.zig b/test/cases/compile_errors/union_noreturn_field_initialized.zig
new file mode 100644
index 0000000000..66304d6a74
--- /dev/null
+++ b/test/cases/compile_errors/union_noreturn_field_initialized.zig
@@ -0,0 +1,43 @@
+pub export fn entry1() void {
+    const U = union(enum) {
+        a: u32,
+        b: noreturn,
+        fn foo(_: @This()) void {}
+        fn bar() noreturn {
+            unreachable;
+        }
+    };
+
+    var a = U{ .b = undefined };
+    _ = a;
+}
+pub export fn entry2() void {
+    const U = union(enum) {
+        a: noreturn,
+    };
+    var u: U = undefined;
+    u = .a;
+}
+pub export fn entry3() void {
+    const U = union(enum) {
+        a: noreturn,
+        b: void,
+    };
+    var e = @typeInfo(U).Union.tag_type.?.a;
+    var u: U = undefined;
+    u = e;
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :11:21: error: cannot initialize 'noreturn' field of union
+// :4:9: note: field 'b' declared here
+// :2:15: note: union declared here
+// :19:10: error: cannot initialize 'noreturn' field of union
+// :16:9: note: field 'a' declared here
+// :15:15: note: union declared here
+// :28:9: error: runtime coercion from enum '@typeInfo(tmp.entry3.U).Union.tag_type.?' to union 'tmp.entry3.U' which has a 'noreturn' field
+// :23:9: note: 'noreturn' field here
+// :22:15: note: union declared here