bjoernager/rust
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miri: avoid making a full copy of all new allocations

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This commit is contained in:
Ralf Jung 2024-05-27 23:28:32 +02:00
parent b0f8618938
commit 869306418d
8 changed files with 92 additions and 85 deletions
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43
compiler/rustc_middle/src/mir/interpret/allocation.rs
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@ -266,19 +266,6 @@ impl AllocRange {
// The constructors are all without extra; the extra gets added by a machine hook later.
impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
/// Creates an allocation from an existing `Bytes` value - this is needed for miri FFI support
pub fn from_raw_bytes(bytes: Bytes, align: Align, mutability: Mutability) -> Self {
let size = Size::from_bytes(bytes.len());
Self {
bytes,
provenance: ProvenanceMap::new(),
init_mask: InitMask::new(size, true),
align,
mutability,
extra: (),
}
}
/// Creates an allocation initialized by the given bytes
pub fn from_bytes<'a>(
slice: impl Into<Cow<'a, [u8]>>,
@ -342,18 +329,30 @@ impl<Prov: Provenance, Bytes: AllocBytes> Allocation<Prov, (), Bytes> {
Err(x) => x,
}
}
/// Add the extra.
pub fn with_extra<Extra>(self, extra: Extra) -> Allocation<Prov, Extra, Bytes> {
Allocation {
bytes: self.bytes,
provenance: self.provenance,
init_mask: self.init_mask,
align: self.align,
mutability: self.mutability,
extra,
}
}
}
impl Allocation {
/// Adjust allocation from the ones in `tcx` to a custom Machine instance
/// with a different `Provenance`, `Extra` and `Byte` type.
pub fn adjust_from_tcx<Prov: Provenance, Extra, Bytes: AllocBytes, Err>(
self,
/// with a different `Provenance` and `Byte` type.
pub fn adjust_from_tcx<Prov: Provenance, Bytes: AllocBytes, Err>(
&self,
cx: &impl HasDataLayout,
extra: Extra,
mut adjust_ptr: impl FnMut(Pointer<CtfeProvenance>) -> Result<Pointer<Prov>, Err>,
) -> Result<Allocation<Prov, Extra, Bytes>, Err> {
let mut bytes = self.bytes;
) -> Result<Allocation<Prov, (), Bytes>, Err> {
// Copy the data.
let mut bytes = Bytes::from_bytes(Cow::Borrowed(&*self.bytes), self.align);
// 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();
@ -369,12 +368,12 @@ impl Allocation {
}
// Create allocation.
Ok(Allocation {
bytes: AllocBytes::from_bytes(Cow::Owned(Vec::from(bytes)), self.align),
bytes,
provenance: ProvenanceMap::from_presorted_ptrs(new_provenance),
init_mask: self.init_mask,
init_mask: self.init_mask.clone(),
align: self.align,
mutability: self.mutability,
extra,
extra: self.extra,
})
}
}