pub struct AddMovesForPackedDrops;
Expand description
This pass moves values being dropped that are within a packed struct to a separate local before dropping them, to ensure that they are dropped from an aligned address.
For example, if we have something like
ⓘ
#[repr(packed)]
struct Foo {
dealign: u8,
data: Vec<u8>
}
let foo = ...;
We want to call drop_in_place::<Vec<u8>>
on data
from an aligned
address. This means we can’t simply drop foo.data
directly, because
its address is not aligned.
Instead, we move foo.data
to a local and drop that:
ⓘ
storage.live(drop_temp)
drop_temp = foo.data;
drop(drop_temp) -> next
next:
storage.dead(drop_temp)
The storage instructions are required to avoid stack space blowup.
Trait Implementations§
source§impl<'tcx> MirPass<'tcx> for AddMovesForPackedDrops
impl<'tcx> MirPass<'tcx> for AddMovesForPackedDrops
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>)
fn name(&self) -> &'static str
fn profiler_name(&self) -> &'static str
source§fn is_enabled(&self, _sess: &Session) -> bool
fn is_enabled(&self, _sess: &Session) -> bool
Returns
true
if this pass is enabled with the current combination of compiler flags.fn is_mir_dump_enabled(&self) -> bool
Auto Trait Implementations§
impl RefUnwindSafe for AddMovesForPackedDrops
impl Send for AddMovesForPackedDrops
impl Sync for AddMovesForPackedDrops
impl Unpin for AddMovesForPackedDrops
impl UnwindSafe for AddMovesForPackedDrops
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
Layout§
Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...)
attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.
Size: 0 bytes