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Make zeroed return an Option

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Rune Tynan 2023-02-28 15:39:17 -05:00
parent 936b567d2e
commit 3a87a18857
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GPG key ID: 7ECC932F8B2C731E
1 changed files with 8 additions and 13 deletions
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21
compiler/rustc_middle/src/mir/interpret/allocation.rs
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@ -42,11 +42,10 @@ pub trait AllocBytes:
/// Create a zeroed `AllocBytes` of the specified size and alignment;
/// call the callback error handler if there is an error in allocating the memory.
fn zeroed<'tcx, F: Fn() -> InterpError<'tcx>>(
fn zeroed(
size: Size,
_align: Align,
handle_alloc_fail: F,
) -> Result<Self, InterpError<'tcx>>;
) -> Option<Self>;
}
// Default `bytes` for `Allocation` is a `Box<[u8]>`.
@ -59,16 +58,14 @@ impl AllocBytes for Box<[u8]> {
Box::<[u8]>::from(slice.into())
}
fn zeroed<'tcx, F: Fn() -> InterpError<'tcx>>(
fn zeroed(
size: Size,
_align: Align,
handle_alloc_fail: F,
) -> Result<Self, InterpError<'tcx>> {
let bytes = Box::<[u8]>::try_new_zeroed_slice(size.bytes_usize())
.map_err(|_| handle_alloc_fail())?;
) -> Option<Self> {
let bytes = Box::<[u8]>::try_new_zeroed_slice(size.bytes_usize()).ok()?;
// SAFETY: the box was zero-allocated, which is a valid initial value for Box<[u8]>
let bytes = unsafe { bytes.assume_init() };
Ok(bytes)
Some(bytes)
}
}
@ -304,7 +301,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
///
/// If `panic_on_fail` is true, this will never return `Err`.
pub fn uninit<'tcx>(size: Size, align: Align, panic_on_fail: bool) -> InterpResult<'tcx, Self> {
let handle_alloc_fail = || -> InterpError<'tcx> {
let bytes = Bytes::zeroed(size, align).ok_or_else(|| {
// This results in an error that can happen non-deterministically, since the memory
// available to the compiler can change between runs. Normally queries are always
// deterministic. However, we can be non-deterministic here because all uses of const
@ -317,9 +314,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
tcx.sess.delay_span_bug(DUMMY_SP, "exhausted memory during interpretation")
});
InterpError::ResourceExhaustion(ResourceExhaustionInfo::MemoryExhausted)
};
let bytes = Bytes::zeroed(size, align, handle_alloc_fail)?;
})?;
Ok(Allocation {
bytes,