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Auto merge of #826 - RalfJung:uninit, r=RalfJung

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uninit intrinsic is gone

Finally. :D

However, to land this we'll need to fix the intptrcast issues that block https://github.com/rust-lang/miri/pull/803.
This commit is contained in:
bors 2019-07-06 09:40:51 +00:00
commit e4a98ea8d8
1 changed files with 0 additions and 30 deletions
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30
src/shims/intrinsics.rs
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@ -481,36 +481,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
this.write_scalar(res, dest)?;
}
"uninit" => {
// Check fast path: we don't want to force an allocation in case the destination is a simple value,
// but we also do not want to create a new allocation with 0s and then copy that over.
// FIXME: We do not properly validate in case of ZSTs and when doing it in memory!
// However, this only affects direct calls of the intrinsic; calls to the stable
// functions wrapping them do get their validation.
// FIXME: should we check alignment for ZSTs?
if !dest.layout.is_zst() {
match dest.layout.abi {
layout::Abi::Scalar(..) => {
let x = ScalarMaybeUndef::Undef;
this.write_immediate(Immediate::Scalar(x), dest)?;
}
layout::Abi::ScalarPair(..) => {
let x = ScalarMaybeUndef::Undef;
this.write_immediate(Immediate::ScalarPair(x, x), dest)?;
}
_ => {
// Do it in memory
let mplace = this.force_allocation(dest)?;
assert!(mplace.meta.is_none());
let ptr = mplace.ptr.to_ptr()?;
this.memory_mut()
.get_mut(ptr.alloc_id)?
.mark_definedness(ptr, dest.layout.size, false);
}
}
}
}
"write_bytes" => {
let ty = substs.type_at(0);
let ty_layout = this.layout_of(ty)?;