bjoernager/rust
bjoernager/rust
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Make vtable_allocation always succeed

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This commit is contained in:
Smitty 2021-07-03 11:14:19 -04:00
parent e9d69d9f8e
commit b201b2f65f
4 changed files with 9 additions and 14 deletions
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11
compiler/rustc_middle/src/ty/vtable.rs
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@ -1,6 +1,6 @@
use std::convert::TryFrom;
use crate::mir::interpret::{alloc_range, AllocId, Allocation, InterpResult, Pointer, Scalar};
use crate::mir::interpret::{alloc_range, AllocId, Allocation, Pointer, Scalar};
use crate::ty::fold::TypeFoldable;
use crate::ty::{self, DefId, SubstsRef, Ty, TyCtxt};
use rustc_ast::Mutability;
@ -28,11 +28,11 @@ impl<'tcx> TyCtxt<'tcx> {
self,
ty: Ty<'tcx>,
poly_trait_ref: Option<ty::PolyExistentialTraitRef<'tcx>>,
) -> InterpResult<'tcx, AllocId> {
) -> AllocId {
let tcx = self;
let vtables_cache = tcx.vtables_cache.lock();
if let Some(alloc_id) = vtables_cache.get(&(ty, poly_trait_ref)).cloned() {
return Ok(alloc_id);
return alloc_id;
}
drop(vtables_cache);
@ -60,7 +60,8 @@ impl<'tcx> TyCtxt<'tcx> {
let ptr_align = tcx.data_layout.pointer_align.abi;
let vtable_size = ptr_size * u64::try_from(vtable_entries.len()).unwrap();
let mut vtable = Allocation::uninit(vtable_size, ptr_align, true)?;
let mut vtable =
Allocation::uninit(vtable_size, ptr_align, /* panic_on_fail */ true).unwrap();
// No need to do any alignment checks on the memory accesses below, because we know the
// allocation is correctly aligned as we created it above. Also we're only offsetting by
@ -101,6 +102,6 @@ impl<'tcx> TyCtxt<'tcx> {
let alloc_id = tcx.create_memory_alloc(tcx.intern_const_alloc(vtable));
let mut vtables_cache = self.vtables_cache.lock();
vtables_cache.insert((ty, poly_trait_ref), alloc_id);
Ok(alloc_id)
alloc_id
}
}