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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:19:13 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:19:13 +0000
commit218caa410aa38c29984be31a5229b9fa717560ee (patch)
treec54bd55eeb6e4c508940a30e94c0032fbd45d677 /tests/ui/print_type_sizes/packed.rs
parentReleasing progress-linux version 1.67.1+dfsg1-1~progress7.99u1. (diff)
downloadrustc-218caa410aa38c29984be31a5229b9fa717560ee.tar.xz
rustc-218caa410aa38c29984be31a5229b9fa717560ee.zip
Merging upstream version 1.68.2+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--tests/ui/print_type_sizes/packed.rs59
1 files changed, 59 insertions, 0 deletions
diff --git a/tests/ui/print_type_sizes/packed.rs b/tests/ui/print_type_sizes/packed.rs
new file mode 100644
index 000000000..5ddfe4bf4
--- /dev/null
+++ b/tests/ui/print_type_sizes/packed.rs
@@ -0,0 +1,59 @@
+// compile-flags: -Z print-type-sizes --crate-type=lib
+// 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 packing is handled; it should cause
+// the elimination of padding that would normally be introduced
+// to satisfy alignment desirata.
+//
+// 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.
+
+#![allow(dead_code)]
+
+#[derive(Default)]
+#[repr(packed)]
+pub struct Packed1 {
+ a: u8,
+ b: u8,
+ g: i32,
+ c: u8,
+ h: i16,
+ d: u8,
+}
+
+#[derive(Default)]
+#[repr(packed(2))]
+pub struct Packed2 {
+ a: u8,
+ b: u8,
+ g: i32,
+ c: u8,
+ h: i16,
+ d: u8,
+}
+
+#[derive(Default)]
+#[repr(packed(2))]
+#[repr(C)]
+pub struct Packed2C {
+ a: u8,
+ b: u8,
+ g: i32,
+ c: u8,
+ h: i16,
+ d: u8,
+}
+
+#[derive(Default)]
+pub struct Padded {
+ a: u8,
+ b: u8,
+ g: i32,
+ c: u8,
+ h: i16,
+ d: u8,
+}