diff options
Diffstat (limited to 'compiler/rustc_middle/src/mir/interpret/allocation.rs')
-rw-r--r-- | compiler/rustc_middle/src/mir/interpret/allocation.rs | 18 |
1 files changed, 5 insertions, 13 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation.rs b/compiler/rustc_middle/src/mir/interpret/allocation.rs index c787481bf..aded3e495 100644 --- a/compiler/rustc_middle/src/mir/interpret/allocation.rs +++ b/compiler/rustc_middle/src/mir/interpret/allocation.rs @@ -32,23 +32,16 @@ pub use init_mask::{InitChunk, InitChunkIter}; pub trait AllocBytes: Clone + fmt::Debug + Eq + PartialEq + Hash + Deref<Target = [u8]> + DerefMut<Target = [u8]> { - /// Adjust the bytes to the specified alignment -- by default, this is a no-op. - fn adjust_to_align(self, _align: Align) -> Self; - /// Create an `AllocBytes` from a slice of `u8`. fn from_bytes<'a>(slice: impl Into<Cow<'a, [u8]>>, _align: Align) -> Self; - /// Create a zeroed `AllocBytes` of the specified size and alignment; - /// call the callback error handler if there is an error in allocating the memory. + /// Create a zeroed `AllocBytes` of the specified size and alignment. + /// Returns `None` if we ran out of memory on the host. fn zeroed(size: Size, _align: Align) -> Option<Self>; } // Default `bytes` for `Allocation` is a `Box<[u8]>`. impl AllocBytes for Box<[u8]> { - fn adjust_to_align(self, _align: Align) -> Self { - self - } - fn from_bytes<'a>(slice: impl Into<Cow<'a, [u8]>>, _align: Align) -> Self { Box::<[u8]>::from(slice.into()) } @@ -299,6 +292,7 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> { } fn uninit_inner<R>(size: Size, align: Align, fail: impl FnOnce() -> R) -> Result<Self, R> { + // We raise an error if we cannot create the allocation on the host. // 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 @@ -351,10 +345,8 @@ impl<Bytes: AllocBytes> Allocation<AllocId, (), Bytes> { extra: Extra, mut adjust_ptr: impl FnMut(Pointer<AllocId>) -> Result<Pointer<Prov>, Err>, ) -> Result<Allocation<Prov, Extra, Bytes>, Err> { - // Compute new pointer provenance, which also adjusts the bytes, and realign the pointer if - // necessary. - let mut bytes = self.bytes.adjust_to_align(self.align); - + let mut bytes = self.bytes; + // Adjust provenance of pointers stored in this allocation. let mut new_provenance = Vec::with_capacity(self.provenance.ptrs().len()); let ptr_size = cx.data_layout().pointer_size.bytes_usize(); let endian = cx.data_layout().endian; |