diff options
| -rw-r--r-- | compiler/rustc_middle/src/lib.rs | 1 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/statement.rs | 36 | ||||
| -rw-r--r-- | compiler/rustc_mir_dataflow/src/move_paths/abs_domain.rs | 38 | ||||
| -rw-r--r-- | compiler/rustc_mir_dataflow/src/move_paths/builder.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_mir_dataflow/src/move_paths/mod.rs | 17 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/gvn.rs | 62 |
6 files changed, 66 insertions, 93 deletions
diff --git a/compiler/rustc_middle/src/lib.rs b/compiler/rustc_middle/src/lib.rs index e5cc23c213d..cf0549fa668 100644 --- a/compiler/rustc_middle/src/lib.rs +++ b/compiler/rustc_middle/src/lib.rs @@ -60,6 +60,7 @@ #![feature(try_trait_v2_residual)] #![feature(try_trait_v2_yeet)] #![feature(type_alias_impl_trait)] +#![feature(unwrap_infallible)] #![feature(yeet_expr)] #![recursion_limit = "256"] // tidy-alphabetical-end diff --git a/compiler/rustc_middle/src/mir/statement.rs b/compiler/rustc_middle/src/mir/statement.rs index 683d7b48617..6e52bc775ef 100644 --- a/compiler/rustc_middle/src/mir/statement.rs +++ b/compiler/rustc_middle/src/mir/statement.rs @@ -160,7 +160,11 @@ impl<'tcx> PlaceTy<'tcx> { /// Convenience wrapper around `projection_ty_core` for `PlaceElem`, /// where we can just use the `Ty` that is already stored inline on /// field projection elems. - pub fn projection_ty(self, tcx: TyCtxt<'tcx>, elem: PlaceElem<'tcx>) -> PlaceTy<'tcx> { + pub fn projection_ty<V: ::std::fmt::Debug>( + self, + tcx: TyCtxt<'tcx>, + elem: ProjectionElem<V, Ty<'tcx>>, + ) -> PlaceTy<'tcx> { self.projection_ty_core(tcx, &elem, |ty| ty, |_, _, _, ty| ty, |ty| ty) } @@ -290,6 +294,36 @@ impl<V, T> ProjectionElem<V, T> { Self::UnwrapUnsafeBinder(..) => false, } } + + /// Returns the `ProjectionKind` associated to this projection. + pub fn kind(self) -> ProjectionKind { + self.try_map(|_| Some(()), |_| ()).unwrap() + } + + /// Apply functions to types and values in this projection and return the result. + pub fn try_map<V2, T2>( + self, + v: impl FnOnce(V) -> Option<V2>, + t: impl FnOnce(T) -> T2, + ) -> Option<ProjectionElem<V2, T2>> { + Some(match self { + ProjectionElem::Deref => ProjectionElem::Deref, + ProjectionElem::Downcast(name, read_variant) => { + ProjectionElem::Downcast(name, read_variant) + } + ProjectionElem::Field(f, ty) => ProjectionElem::Field(f, t(ty)), + ProjectionElem::ConstantIndex { offset, min_length, from_end } => { + ProjectionElem::ConstantIndex { offset, min_length, from_end } + } + ProjectionElem::Subslice { from, to, from_end } => { + ProjectionElem::Subslice { from, to, from_end } + } + ProjectionElem::OpaqueCast(ty) => ProjectionElem::OpaqueCast(t(ty)), + ProjectionElem::Subtype(ty) => ProjectionElem::Subtype(t(ty)), + ProjectionElem::UnwrapUnsafeBinder(ty) => ProjectionElem::UnwrapUnsafeBinder(t(ty)), + ProjectionElem::Index(val) => ProjectionElem::Index(v(val)?), + }) + } } /// Alias for projections as they appear in `UserTypeProjection`, where we diff --git a/compiler/rustc_mir_dataflow/src/move_paths/abs_domain.rs b/compiler/rustc_mir_dataflow/src/move_paths/abs_domain.rs deleted file mode 100644 index d056ad3d4b4..00000000000 --- a/compiler/rustc_mir_dataflow/src/move_paths/abs_domain.rs +++ /dev/null @@ -1,38 +0,0 @@ -//! The move-analysis portion of borrowck needs to work in an abstract -//! domain of lifted `Place`s. Most of the `Place` variants fall into a -//! one-to-one mapping between the concrete and abstract (e.g., a -//! field-deref on a local variable, `x.field`, has the same meaning -//! in both domains). Indexed projections are the exception: `a[x]` -//! needs to be treated as mapping to the same move path as `a[y]` as -//! well as `a[13]`, etc. So we map these `x`/`y` values to `()`. -//! -//! (In theory, the analysis could be extended to work with sets of -//! paths, so that `a[0]` and `a[13]` could be kept distinct, while -//! `a[x]` would still overlap them both. But that is not this -//! representation does today.) - -use rustc_middle::mir::{PlaceElem, ProjectionElem, ProjectionKind}; - -pub(crate) trait Lift { - fn lift(&self) -> ProjectionKind; -} - -impl<'tcx> Lift for PlaceElem<'tcx> { - fn lift(&self) -> ProjectionKind { - match *self { - ProjectionElem::Deref => ProjectionElem::Deref, - ProjectionElem::Field(f, _ty) => ProjectionElem::Field(f, ()), - ProjectionElem::OpaqueCast(_ty) => ProjectionElem::OpaqueCast(()), - ProjectionElem::Index(_i) => ProjectionElem::Index(()), - ProjectionElem::Subslice { from, to, from_end } => { - ProjectionElem::Subslice { from, to, from_end } - } - ProjectionElem::ConstantIndex { offset, min_length, from_end } => { - ProjectionElem::ConstantIndex { offset, min_length, from_end } - } - ProjectionElem::Downcast(a, u) => ProjectionElem::Downcast(a, u), - ProjectionElem::Subtype(_ty) => ProjectionElem::Subtype(()), - ProjectionElem::UnwrapUnsafeBinder(_ty) => ProjectionElem::UnwrapUnsafeBinder(()), - } - } -} diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs index 8bbc89fdcec..48718cad597 100644 --- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs +++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs @@ -7,7 +7,6 @@ use rustc_middle::{bug, span_bug}; use smallvec::{SmallVec, smallvec}; use tracing::debug; -use super::abs_domain::Lift; use super::{ Init, InitIndex, InitKind, InitLocation, LocationMap, LookupResult, MoveData, MoveOut, MoveOutIndex, MovePath, MovePathIndex, MovePathLookup, @@ -241,7 +240,7 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> { if union_path.is_none() { // inlined from add_move_path because of a borrowck conflict with the iterator base = - *data.rev_lookup.projections.entry((base, elem.lift())).or_insert_with(|| { + *data.rev_lookup.projections.entry((base, elem.kind())).or_insert_with(|| { new_move_path( &mut data.move_paths, &mut data.path_map, @@ -272,7 +271,7 @@ impl<'a, 'tcx, F: Fn(Ty<'tcx>) -> bool> MoveDataBuilder<'a, 'tcx, F> { tcx, .. } = self; - *rev_lookup.projections.entry((base, elem.lift())).or_insert_with(move || { + *rev_lookup.projections.entry((base, elem.kind())).or_insert_with(move || { new_move_path(move_paths, path_map, init_path_map, Some(base), mk_place(*tcx)) }) } diff --git a/compiler/rustc_mir_dataflow/src/move_paths/mod.rs b/compiler/rustc_mir_dataflow/src/move_paths/mod.rs index 18985ba0da2..466416d63f5 100644 --- a/compiler/rustc_mir_dataflow/src/move_paths/mod.rs +++ b/compiler/rustc_mir_dataflow/src/move_paths/mod.rs @@ -1,3 +1,15 @@ +//! The move-analysis portion of borrowck needs to work in an abstract domain of lifted `Place`s. +//! Most of the `Place` variants fall into a one-to-one mapping between the concrete and abstract +//! (e.g., a field projection on a local variable, `x.field`, has the same meaning in both +//! domains). In other words, all field projections for the same field on the same local do not +//! have meaningfully different types if ever. Indexed projections are the exception: `a[x]` needs +//! to be treated as mapping to the same move path as `a[y]` as well as `a[13]`, etc. So we map +//! these `x`/`y` values to `()`. +//! +//! (In theory, the analysis could be extended to work with sets of paths, so that `a[0]` and +//! `a[13]` could be kept distinct, while `a[x]` would still overlap them both. But that is not +//! what this representation does today.) + use std::fmt; use std::ops::{Index, IndexMut}; @@ -8,11 +20,8 @@ use rustc_middle::ty::{Ty, TyCtxt}; use rustc_span::Span; use smallvec::SmallVec; -use self::abs_domain::Lift; use crate::un_derefer::UnDerefer; -mod abs_domain; - rustc_index::newtype_index! { #[orderable] #[debug_format = "mp{}"] @@ -324,7 +333,7 @@ impl<'tcx> MovePathLookup<'tcx> { }; for (_, elem) in self.un_derefer.iter_projections(place) { - if let Some(&subpath) = self.projections.get(&(result, elem.lift())) { + if let Some(&subpath) = self.projections.get(&(result, elem.kind())) { result = subpath; } else { return LookupResult::Parent(Some(result)); diff --git a/compiler/rustc_mir_transform/src/gvn.rs b/compiler/rustc_mir_transform/src/gvn.rs index 952da2cdf72..5a13394543b 100644 --- a/compiler/rustc_mir_transform/src/gvn.rs +++ b/compiler/rustc_mir_transform/src/gvn.rs @@ -447,26 +447,9 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { Projection(base, elem) => { let base = self.evaluated[base].as_ref()?; - let elem = match elem { - ProjectionElem::Deref => ProjectionElem::Deref, - ProjectionElem::Downcast(name, read_variant) => { - ProjectionElem::Downcast(name, read_variant) - } - ProjectionElem::Field(f, ()) => ProjectionElem::Field(f, ty.ty), - ProjectionElem::ConstantIndex { offset, min_length, from_end } => { - ProjectionElem::ConstantIndex { offset, min_length, from_end } - } - ProjectionElem::Subslice { from, to, from_end } => { - ProjectionElem::Subslice { from, to, from_end } - } - ProjectionElem::OpaqueCast(()) => ProjectionElem::OpaqueCast(ty.ty), - ProjectionElem::Subtype(()) => ProjectionElem::Subtype(ty.ty), - ProjectionElem::UnwrapUnsafeBinder(()) => { - ProjectionElem::UnwrapUnsafeBinder(ty.ty) - } - // This should have been replaced by a `ConstantIndex` earlier. - ProjectionElem::Index(_) => return None, - }; + // `Index` by constants should have been replaced by `ConstantIndex` by + // `simplify_place_projection`. + let elem = elem.try_map(|_| None, |()| ty.ty)?; self.ecx.project(base, elem).discard_err()? } Address { place, kind: _, provenance: _ } => { @@ -476,13 +459,11 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { let local = self.locals[place.local]?; let pointer = self.evaluated[local].as_ref()?; let mut mplace = self.ecx.deref_pointer(pointer).discard_err()?; - for proj in place.projection.iter().skip(1) { - // We have no call stack to associate a local with a value, so we cannot - // interpret indexing. - if matches!(proj, ProjectionElem::Index(_)) { - return None; - } - mplace = self.ecx.project(&mplace, proj).discard_err()?; + for elem in place.projection.iter().skip(1) { + // `Index` by constants should have been replaced by `ConstantIndex` by + // `simplify_place_projection`. + let elem = elem.try_map(|_| None, |ty| ty)?; + mplace = self.ecx.project(&mplace, elem).discard_err()?; } let pointer = mplace.to_ref(&self.ecx); ImmTy::from_immediate(pointer, ty).into() @@ -902,27 +883,14 @@ impl<'body, 'tcx> VnState<'body, 'tcx> { proj: ProjectionElem<VnIndex, ()>, loc: Location, ) -> Option<PlaceElem<'tcx>> { - Some(match proj { - ProjectionElem::Deref => ProjectionElem::Deref, - ProjectionElem::Field(idx, ()) => ProjectionElem::Field(idx, ty), - ProjectionElem::Index(idx) => { - let Some(local) = self.try_as_local(idx, loc) else { - return None; - }; + proj.try_map( + |value| { + let local = self.try_as_local(value, loc)?; self.reused_locals.insert(local); - ProjectionElem::Index(local) - } - ProjectionElem::ConstantIndex { offset, min_length, from_end } => { - ProjectionElem::ConstantIndex { offset, min_length, from_end } - } - ProjectionElem::Subslice { from, to, from_end } => { - ProjectionElem::Subslice { from, to, from_end } - } - ProjectionElem::Downcast(symbol, idx) => ProjectionElem::Downcast(symbol, idx), - ProjectionElem::OpaqueCast(()) => ProjectionElem::OpaqueCast(ty), - ProjectionElem::Subtype(()) => ProjectionElem::Subtype(ty), - ProjectionElem::UnwrapUnsafeBinder(()) => ProjectionElem::UnwrapUnsafeBinder(ty), - }) + Some(local) + }, + |()| ty, + ) } fn simplify_aggregate_to_copy( |