diff options
Diffstat (limited to 'compiler/rustc_mir_dataflow/src/move_paths/builder.rs')
| -rw-r--r-- | compiler/rustc_mir_dataflow/src/move_paths/builder.rs | 125 |
1 files changed, 66 insertions, 59 deletions
diff --git a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs index dc7e9ab3c..5052de991 100644 --- a/compiler/rustc_mir_dataflow/src/move_paths/builder.rs +++ b/compiler/rustc_mir_dataflow/src/move_paths/builder.rs @@ -4,7 +4,6 @@ use rustc_middle::mir::*; use rustc_middle::ty::{self, TyCtxt}; use smallvec::{smallvec, SmallVec}; -use std::iter; use std::mem; use super::abs_domain::Lift; @@ -40,22 +39,22 @@ impl<'a, 'tcx> MoveDataBuilder<'a, 'tcx> { locals: body .local_decls .iter_enumerated() - .filter(|(_, l)| !l.is_deref_temp()) - .map(|(i, _)| { - ( - i, + .map(|(i, l)| { + if l.is_deref_temp() { + MovePathIndex::MAX + } else { Self::new_move_path( &mut move_paths, &mut path_map, &mut init_path_map, None, Place::from(i), - ), - ) + ) + } }) .collect(), projections: Default::default(), - derefer_sidetable: Default::default(), + un_derefer: Default::default(), }, move_paths, path_map, @@ -100,11 +99,10 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { /// /// Maybe we should have separate "borrowck" and "moveck" modes. fn move_path_for(&mut self, place: Place<'tcx>) -> Result<MovePathIndex, MoveError<'tcx>> { - let deref_chain = self.builder.data.rev_lookup.deref_chain(place.as_ref()); + let data = &mut self.builder.data; debug!("lookup({:?})", place); - let mut base = - self.builder.data.rev_lookup.find_local(deref_chain.first().unwrap_or(&place).local); + let mut base = data.rev_lookup.find_local(place.local); // The move path index of the first union that we find. Once this is // some we stop creating child move paths, since moves from unions @@ -113,55 +111,60 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { // from `*(u.f: &_)` isn't allowed. let mut union_path = None; - for place in deref_chain.into_iter().chain(iter::once(place)) { - for (place_ref, elem) in place.as_ref().iter_projections() { - let body = self.builder.body; - let tcx = self.builder.tcx; - let place_ty = place_ref.ty(body, tcx).ty; - match place_ty.kind() { - ty::Ref(..) | ty::RawPtr(..) => { - return Err(MoveError::cannot_move_out_of( - self.loc, - BorrowedContent { - target_place: place_ref.project_deeper(&[elem], tcx), - }, - )); - } - ty::Adt(adt, _) if adt.has_dtor(tcx) && !adt.is_box() => { - return Err(MoveError::cannot_move_out_of( - self.loc, - InteriorOfTypeWithDestructor { container_ty: place_ty }, - )); - } - ty::Adt(adt, _) if adt.is_union() => { - union_path.get_or_insert(base); - } - ty::Slice(_) => { + for (place_ref, elem) in data.rev_lookup.un_derefer.iter_projections(place.as_ref()) { + let body = self.builder.body; + let tcx = self.builder.tcx; + let place_ty = place_ref.ty(body, tcx).ty; + match place_ty.kind() { + ty::Ref(..) | ty::RawPtr(..) => { + return Err(MoveError::cannot_move_out_of( + self.loc, + BorrowedContent { target_place: place_ref.project_deeper(&[elem], tcx) }, + )); + } + ty::Adt(adt, _) if adt.has_dtor(tcx) && !adt.is_box() => { + return Err(MoveError::cannot_move_out_of( + self.loc, + InteriorOfTypeWithDestructor { container_ty: place_ty }, + )); + } + ty::Adt(adt, _) if adt.is_union() => { + union_path.get_or_insert(base); + } + ty::Slice(_) => { + return Err(MoveError::cannot_move_out_of( + self.loc, + InteriorOfSliceOrArray { + ty: place_ty, + is_index: matches!(elem, ProjectionElem::Index(..)), + }, + )); + } + + ty::Array(..) => { + if let ProjectionElem::Index(..) = elem { return Err(MoveError::cannot_move_out_of( self.loc, - InteriorOfSliceOrArray { - ty: place_ty, - is_index: matches!(elem, ProjectionElem::Index(..)), - }, + InteriorOfSliceOrArray { ty: place_ty, is_index: true }, )); } + } - ty::Array(..) => { - if let ProjectionElem::Index(..) = elem { - return Err(MoveError::cannot_move_out_of( - self.loc, - InteriorOfSliceOrArray { ty: place_ty, is_index: true }, - )); - } - } - - _ => {} - }; + _ => {} + }; - if union_path.is_none() { - base = self - .add_move_path(base, elem, |tcx| place_ref.project_deeper(&[elem], tcx)); - } + 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(|| { + MoveDataBuilder::new_move_path( + &mut data.move_paths, + &mut data.path_map, + &mut data.init_path_map, + Some(base), + place_ref.project_deeper(&[elem], tcx), + ) + }) } } @@ -282,10 +285,14 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { fn gather_statement(&mut self, stmt: &Statement<'tcx>) { match &stmt.kind { StatementKind::Assign(box (place, Rvalue::CopyForDeref(reffed))) => { - assert!(place.projection.is_empty()); - if self.builder.body.local_decls[place.local].is_deref_temp() { - self.builder.data.rev_lookup.derefer_sidetable.insert(place.local, *reffed); - } + let local = place.as_local().unwrap(); + assert!(self.builder.body.local_decls[local].is_deref_temp()); + + let rev_lookup = &mut self.builder.data.rev_lookup; + + rev_lookup.un_derefer.insert(local, reffed.as_ref()); + let base_local = rev_lookup.un_derefer.deref_chain(local).first().unwrap().local; + rev_lookup.locals[local] = rev_lookup.locals[base_local]; } StatementKind::Assign(box (place, rval)) => { self.create_move_path(*place); @@ -306,7 +313,7 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> { StatementKind::StorageLive(_) => {} StatementKind::StorageDead(local) => { // DerefTemp locals (results of CopyForDeref) don't actually move anything. - if !self.builder.data.rev_lookup.derefer_sidetable.contains_key(&local) { + if !self.builder.body.local_decls[*local].is_deref_temp() { self.gather_move(Place::from(*local)); } } |