bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rollup merge of #91088 - RalfJung:revert, r=oli-obk

Browse source 
Revert "require full validity when determining the discriminant of a value"

This reverts commit 0a2b7d71d9, reversing
changes made to 47c1bd1bcc.
This caused several unforeseen problems:
- https://github.com/rust-lang/rust/issues/91029
- https://github.com/rust-lang/rust/pull/89764#issuecomment-973588007

So I think it's best to revert for now while we keep discussing the MIR semantics of getting a discriminant.

r? `@oli-obk`
This commit is contained in:
Matthias Krüger 2021-11-20 22:33:52 +01:00 • committed by GitHub
commit 83c83d4dd7
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 0 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

6
compiler/rustc_const_eval/src/interpret/intrinsics.rs
View file

@ -265,12 +265,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
}
sym::discriminant_value => {
let place = self.deref_operand(&args[0])?;
if M::enforce_validity(self) {
// This is 'using' the value, so make sure the validity invariant is satisfied.
// (Also see https://github.com/rust-lang/rust/pull/89764.)
self.validate_operand(&place.into())?;
}
let discr_val = self.read_discriminant(&place.into())?.0;
self.write_scalar(discr_val, dest)?;
}

6
compiler/rustc_const_eval/src/interpret/step.rs
View file

@ -304,12 +304,6 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
Discriminant(place) => {
let op = self.eval_place_to_op(place, None)?;
if M::enforce_validity(self) {
// This is 'using' the value, so make sure the validity invariant is satisfied.
// (Also see https://github.com/rust-lang/rust/pull/89764.)
self.validate_operand(&op)?;
}
let discr_val = self.read_discriminant(&op)?.0;
self.write_scalar(discr_val, &dest)?;
}