1 files changed, 89 insertions, 0 deletions
diff --git a/tests/run-make/extern-fn-explicit-align/test.rs b/tests/run-make/extern-fn-explicit-align/test.rs
new file mode 100644
index 000000000..846622de3
--- /dev/null
+++ b/tests/run-make/extern-fn-explicit-align/test.rs
@@ -0,0 +1,89 @@
+// Issue #80127: Passing structs via FFI should work with explicit alignment.
+
+use std::ffi::{CStr, c_char};
+use std::ptr::null_mut;
+
+#[repr(C)]
+pub struct BoolAndU32 {
+    pub a: bool,
+    pub b: u32,
+}
+
+#[repr(C)]
+#[repr(align(16))]
+pub struct TwoU64s {
+    pub a: u64,
+    pub b: u64,
+}
+
+#[repr(C)]
+pub struct WrappedU64s {
+    pub a: TwoU64s
+}
+
+#[repr(C)]
+// Even though requesting align 1 can never change the alignment, it still affects the ABI
+// on some platforms like i686-windows.
+#[repr(align(1))]
+pub struct LowerAlign {
+    pub a: u64,
+    pub b: u64,
+}
+
+#[repr(C)]
+#[repr(packed)]
+pub struct Packed {
+    pub a: u64,
+    pub b: u64,
+}
+
+#[link(name = "test", kind = "static")]
+extern "C" {
+    fn many_args(
+        a: *mut (),
+        b: *mut (),
+        c: *const c_char,
+        d: u64,
+        e: bool,
+        f: BoolAndU32,
+        g: *mut (),
+        h: TwoU64s,
+        i: *mut (),
+        j: WrappedU64s,
+        k: *mut (),
+        l: LowerAlign,
+        m: *mut (),
+        n: Packed,
+        o: *const c_char,
+    ) -> i32;
+}
+
+const STRING: &CStr = unsafe { CStr::from_bytes_with_nul_unchecked(b"Hello world\0") };
+
+fn main() {
+    let bool_and_u32 = BoolAndU32 { a: true, b: 1337 };
+    let two_u64s = TwoU64s { a: 1, b: 2 };
+    let wrapped = WrappedU64s { a: TwoU64s { a: 3, b: 4 } };
+    let lower = LowerAlign { a: 5, b: 6 };
+    let packed = Packed { a: 7, b: 8 };
+    let string = STRING;
+    unsafe {
+        many_args(
+            null_mut(),
+            null_mut(),
+            null_mut(),
+            42,
+            true,
+            bool_and_u32,
+            null_mut(),
+            two_u64s,
+            null_mut(),
+            wrapped,
+            null_mut(),
+            lower,
+            null_mut(),
+            packed,
+            string.as_ptr(),
+        );
+    }
+}