From 616f74ba2098297fbe430651930f9e784909263f Mon Sep 17 00:00:00 2001
From: Andrew Kelley <andrew@ziglang.org>
Date: Sun, 11 Feb 2024 14:14:59 -0700
Subject: [PATCH] add behavior test for recently fixed wasm backend bug

Adds the corresponding behavior test for the fix in
320c4d68f5f40794ae31d5535de9c3a8ff5cb471.
---
 test/behavior/packed-struct.zig | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/test/behavior/packed-struct.zig b/test/behavior/packed-struct.zig
index 48e75706cd..27f460e175 100644
--- a/test/behavior/packed-struct.zig
+++ b/test/behavior/packed-struct.zig
@@ -1248,3 +1248,32 @@ test "bitcasting a packed struct at comptime and using the result" {
         _ = Struct.bitcast(@as(u64, 0)).cannotReach();
     }
 }
+
+test "2-byte packed struct argument in C calling convention" {
+    if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
+
+    const S = packed struct(u16) {
+        x: u15 = 0,
+        y: u1 = 0,
+
+        fn foo(s: @This()) callconv(.C) i32 {
+            return s.x;
+        }
+        fn bar(s: @This()) !void {
+            try expect(foo(s) == 1);
+        }
+    };
+    {
+        var s: S = .{};
+        s.x += 1;
+        try S.bar(s);
+    }
+    comptime {
+        var s: S = .{};
+        s.x += 1;
+        try S.bar(s);
+    }
+}