stage2: treat `error{}!void` as a zero-bit type

1 files changed, 30 insertions, 3 deletions

diff --git a/test/behavior/error.zig b/test/behavior/error.zig
index 4f316aeab2..312ab1524a 100644
--- a/test/behavior/error.zig
+++ b/test/behavior/error.zig
@@ -479,11 +479,38 @@ test "optional error set with only one error is the same size as bool" {
 test "optional empty error set" {
     if (builtin.zig_backend == .stage1) return error.SkipZigTest;
 
-    const T = ?error{};
-    var t: T = undefined;
-    if (t != null) {
+    comptime try expect(@sizeOf(error{}!void) == @sizeOf(void));
+    comptime try expect(@alignOf(error{}!void) == @alignOf(void));
+
+    var x: ?error{} = undefined;
+    if (x != null) {
+        @compileError("test failed");
+    }
+}
+
+test "empty error set plus zero-bit payload" {
+    if (builtin.zig_backend == .stage1) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
+
+    comptime try expect(@sizeOf(error{}!void) == @sizeOf(void));
+    comptime try expect(@alignOf(error{}!void) == @alignOf(void));
+
+    var x: error{}!void = undefined;
+    if (x) |payload| {
+        if (payload != {}) {
+            @compileError("test failed");
+        }
+    } else |_| {
         @compileError("test failed");
     }
+    const S = struct {
+        fn empty() error{}!void {}
+        fn inferred() !void {
+            return empty();
+        }
+    };
+    try S.inferred();
 }
 
 test "nested catch" {