mirror of
https://github.com/rust-lang/rust.git
synced 2024-11-01 06:51:58 +00:00
47 lines
1.5 KiB
Rust
47 lines
1.5 KiB
Rust
//@ compile-flags: -O
|
|
#![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())
|
|
}
|
|
|
|
// https://github.com/rust-lang/rust/issues/58201
|
|
#[no_mangle]
|
|
pub fn box_uninitialized2() -> Box<MaybeUninit<[usize; 1024 * 1024]>> {
|
|
// CHECK-LABEL: @box_uninitialized2
|
|
// CHECK-NOT: store
|
|
// CHECK-NOT: alloca
|
|
// CHECK-NOT: memcpy
|
|
// CHECK-NOT: memset
|
|
Box::new(MaybeUninit::uninit())
|
|
}
|
|
|
|
#[repr(align(1024))]
|
|
pub struct LotsaPadding(usize);
|
|
|
|
// Boxing a value with padding should not copy junk from the stack
|
|
#[no_mangle]
|
|
pub fn box_lotsa_padding() -> Box<LotsaPadding> {
|
|
// CHECK-LABEL: @box_lotsa_padding
|
|
// CHECK-NOT: alloca
|
|
// CHECK-NOT: getelementptr
|
|
// CHECK-NOT: memcpy
|
|
// CHECK-NOT: memset
|
|
Box::new(LotsaPadding(42))
|
|
}
|
|
|
|
// 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 {{(dso_local )?}}noalias noundef ptr @__rust_alloc(i{{[0-9]+}} noundef, i{{[0-9]+}} allocalign noundef) unnamed_addr [[RUST_ALLOC_ATTRS:#[0-9]+]]
|
|
|
|
// CHECK-DAG: attributes [[RUST_ALLOC_ATTRS]] = { {{.*}} allockind("alloc,uninitialized,aligned") allocsize(0) {{(uwtable )?}}"alloc-family"="__rust_alloc" {{.*}} }
|