diff options
Diffstat (limited to 'compiler/rustc_const_eval/src')
5 files changed, 9 insertions, 25 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index 2da9123b846..d37eaeed095 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -187,9 +187,6 @@ pub enum LocalValue<Prov: Provenance = AllocId> { impl<'tcx, Prov: Provenance + 'static> LocalState<'tcx, Prov> { /// Read the local's value or error if the local is not yet live or not live anymore. - /// - /// Note: This may only be invoked from the `Machine::access_local` hook and not from - /// anywhere else. You may be invalidating machine invariants if you do! #[inline] pub fn access(&self) -> InterpResult<'tcx, &Operand<Prov>> { match &self.value { diff --git a/compiler/rustc_const_eval/src/interpret/machine.rs b/compiler/rustc_const_eval/src/interpret/machine.rs index 6bed8a7a007..b151d03681f 100644 --- a/compiler/rustc_const_eval/src/interpret/machine.rs +++ b/compiler/rustc_const_eval/src/interpret/machine.rs @@ -215,23 +215,12 @@ pub trait Machine<'mir, 'tcx>: Sized { right: &ImmTy<'tcx, Self::Provenance>, ) -> InterpResult<'tcx, (Scalar<Self::Provenance>, bool, Ty<'tcx>)>; - /// Called to read the specified `local` from the `frame`. - /// Since reading a ZST is not actually accessing memory or locals, this is never invoked - /// for ZST reads. - #[inline] - fn access_local<'a>( - frame: &'a Frame<'mir, 'tcx, Self::Provenance, Self::FrameExtra>, - local: mir::Local, - ) -> InterpResult<'tcx, &'a Operand<Self::Provenance>> - where - 'tcx: 'mir, - { - frame.locals[local].access() - } - /// Called to write the specified `local` from the `frame`. /// Since writing a ZST is not actually accessing memory or locals, this is never invoked /// for ZST reads. + /// + /// Due to borrow checker trouble, we indicate the `frame` as an index rather than an `&mut + /// Frame`. #[inline] fn access_local_mut<'a>( ecx: &'a mut InterpCx<'mir, 'tcx, Self>, diff --git a/compiler/rustc_const_eval/src/interpret/operand.rs b/compiler/rustc_const_eval/src/interpret/operand.rs index e80a82acd58..91a97fe4d4d 100644 --- a/compiler/rustc_const_eval/src/interpret/operand.rs +++ b/compiler/rustc_const_eval/src/interpret/operand.rs @@ -444,7 +444,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { } } - /// Read from a local. Will not actually access the local if reading from a ZST. + /// Read from a local. /// Will not access memory, instead an indirect `Operand` is returned. /// /// This is public because it is used by [priroda](https://github.com/oli-obk/priroda) to get an @@ -456,12 +456,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> { layout: Option<TyAndLayout<'tcx>>, ) -> InterpResult<'tcx, OpTy<'tcx, M::Provenance>> { let layout = self.layout_of_local(frame, local, layout)?; - let op = if layout.is_zst() { - // Bypass `access_local` (helps in ConstProp) - Operand::Immediate(Immediate::Uninit) - } else { - *M::access_local(frame, local)? - }; + let op = *frame.locals[local].access()?; Ok(OpTy { op, layout, align: Some(layout.align.abi) }) } diff --git a/compiler/rustc_const_eval/src/interpret/place.rs b/compiler/rustc_const_eval/src/interpret/place.rs index 7aa76fe1dae..d56323448ce 100644 --- a/compiler/rustc_const_eval/src/interpret/place.rs +++ b/compiler/rustc_const_eval/src/interpret/place.rs @@ -642,7 +642,7 @@ where // avoid force_allocation. let src = match self.read_immediate_raw(src)? { Ok(src_val) => { - assert!(!src.layout.is_unsized(), "cannot have unsized immediates"); + assert!(!src.layout.is_unsized(), "cannot copy unsized immediates"); assert!( !dest.layout.is_unsized(), "the src is sized, so the dest must also be sized" diff --git a/compiler/rustc_const_eval/src/interpret/projection.rs b/compiler/rustc_const_eval/src/interpret/projection.rs index 742339f2b0a..16ce5bc7175 100644 --- a/compiler/rustc_const_eval/src/interpret/projection.rs +++ b/compiler/rustc_const_eval/src/interpret/projection.rs @@ -100,6 +100,8 @@ where // This makes several assumptions about what layouts we will encounter; we match what // codegen does as good as we can (see `extract_field` in `rustc_codegen_ssa/src/mir/operand.rs`). let field_val: Immediate<_> = match (*base, base.layout.abi) { + // if the entire value is uninit, then so is the field (can happen in ConstProp) + (Immediate::Uninit, _) => Immediate::Uninit, // the field contains no information, can be left uninit _ if field_layout.is_zst() => Immediate::Uninit, // the field covers the entire type @@ -124,6 +126,7 @@ where b_val }) } + // everything else is a bug _ => span_bug!( self.cur_span(), "invalid field access on immediate {}, layout {:#?}", |