1 files changed, 38 insertions, 0 deletions
diff --git a/src/test/ui/print_type_sizes/repr-align.rs b/src/test/ui/print_type_sizes/repr-align.rs
new file mode 100644
index 000000000..07544935b
--- /dev/null
+++ b/src/test/ui/print_type_sizes/repr-align.rs
@@ -0,0 +1,38 @@
+// compile-flags: -Z print-type-sizes
+// build-pass
+// ignore-pass
+// ^-- needed because `--pass check` does not emit the output needed.
+//     FIXME: consider using an attribute instead of side-effects.
+
+// This file illustrates how padding is handled: alignment
+// requirements can lead to the introduction of padding, either before
+// fields or at the end of the structure as a whole.
+//
+// It avoids using u64/i64 because on some targets that is only 4-byte
+// aligned (while on most it is 8-byte aligned) and so the resulting
+// padding and overall computed sizes can be quite different.
+#![feature(start)]
+#![allow(dead_code)]
+
+#[repr(align(16))]
+#[derive(Default)]
+struct A(i32);
+
+enum E {
+    A(i32),
+    B(A)
+}
+
+#[derive(Default)]
+struct S {
+    a: i32,
+    b: i32,
+    c: A,
+    d: i8,
+}
+
+#[start]
+fn start(_: isize, _: *const *const u8) -> isize {
+    let _s: S = Default::default();
+    0
+}