diff options
Diffstat (limited to 'src/test/codegen/box-maybe-uninit.rs')
-rw-r--r-- | src/test/codegen/box-maybe-uninit.rs | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/src/test/codegen/box-maybe-uninit.rs b/src/test/codegen/box-maybe-uninit.rs new file mode 100644 index 000000000..e105e26f1 --- /dev/null +++ b/src/test/codegen/box-maybe-uninit.rs @@ -0,0 +1,25 @@ +// compile-flags: -O +// min-llvm-version: 15.0 +#![crate_type="lib"] + +use std::mem::MaybeUninit; + +// Boxing a `MaybeUninit` value should not copy junk from the stack +#[no_mangle] +pub fn box_uninitialized() -> Box<MaybeUninit<usize>> { + // CHECK-LABEL: @box_uninitialized + // CHECK-NOT: store + // CHECK-NOT: alloca + // CHECK-NOT: memcpy + // CHECK-NOT: memset + Box::new(MaybeUninit::uninit()) +} + +// FIXME: add a test for a bigger box. Currently broken, see +// https://github.com/rust-lang/rust/issues/58201. + +// Hide the `allocalign` attribute in the declaration of __rust_alloc +// from the CHECK-NOT above, and also verify the attributes got set reasonably. +// CHECK: declare noalias ptr @__rust_alloc(i{{[0-9]+}}, i{{[0-9]+}} allocalign) unnamed_addr [[RUST_ALLOC_ATTRS:#[0-9]+]] + +// CHECK-DAG: attributes [[RUST_ALLOC_ATTRS]] = { {{.*}} allockind("alloc,uninitialized,aligned") allocsize(0) uwtable "alloc-family"="__rust_alloc" {{.*}} } |