Rollup merge of #115770 - ouz-a:match_elem_builder, r=lcnr

Match on elem first while building move paths

While working on https://github.com/rust-lang/rust/pull/115025 `@lcnr` and I observed "move_paths_for" function matched on the `Ty` instead of `Projection` which seems flawed as it's the `Projection`s that cause the problem not the type.

r? `@lcnr`
This commit is contained in:
Matthias Krüger 2023-09-22 23:12:34 +02:00 committed by GitHub
commit d4d0c840b3
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@ -115,44 +115,125 @@ fn move_path_for(&mut self, place: Place<'tcx>) -> Result<MovePathIndex, MoveErr
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) },
));
match elem {
ProjectionElem::Deref => 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.is_box() {
bug!("Adt should be a box type when Place is deref");
}
}
ty::Bool
| ty::Char
| ty::Int(_)
| ty::Uint(_)
| ty::Float(_)
| ty::Foreign(_)
| ty::Str
| ty::Array(_, _)
| ty::Slice(_)
| ty::FnDef(_, _)
| ty::FnPtr(_)
| ty::Dynamic(_, _, _)
| ty::Closure(_, _)
| ty::Generator(_, _, _)
| ty::GeneratorWitness(_)
| ty::GeneratorWitnessMIR(_, _)
| ty::Never
| ty::Tuple(_)
| ty::Alias(_, _)
| ty::Param(_)
| ty::Bound(_, _)
| ty::Infer(_)
| ty::Error(_)
| ty::Placeholder(_) => {
bug!("When Place is Deref it's type shouldn't be {place_ty:#?}")
}
},
ProjectionElem::Field(_, _) => match place_ty.kind() {
ty::Adt(adt, _) => {
if adt.has_dtor(tcx) {
return Err(MoveError::cannot_move_out_of(
self.loc,
InteriorOfTypeWithDestructor { container_ty: place_ty },
));
}
if adt.is_union() {
union_path.get_or_insert(base);
}
}
ty::Closure(_, _) | ty::Generator(_, _, _) | ty::Tuple(_) => (),
ty::Bool
| ty::Char
| ty::Int(_)
| ty::Uint(_)
| ty::Float(_)
| ty::Foreign(_)
| ty::Str
| ty::Array(_, _)
| ty::Slice(_)
| ty::RawPtr(_)
| ty::Ref(_, _, _)
| ty::FnDef(_, _)
| ty::FnPtr(_)
| ty::Dynamic(_, _, _)
| ty::GeneratorWitness(_)
| ty::GeneratorWitnessMIR(_, _)
| ty::Never
| ty::Alias(_, _)
| ty::Param(_)
| ty::Bound(_, _)
| ty::Infer(_)
| ty::Error(_)
| ty::Placeholder(_) => bug!(
"When Place contains ProjectionElem::Field it's type shouldn't be {place_ty:#?}"
),
},
ProjectionElem::ConstantIndex { .. } | ProjectionElem::Subslice { .. } => {
match place_ty.kind() {
ty::Slice(_) => {
return Err(MoveError::cannot_move_out_of(
self.loc,
InteriorOfSliceOrArray {
ty: place_ty,
is_index: matches!(elem, ProjectionElem::Index(..)),
},
));
}
ty::Array(_, _) => (),
_ => bug!("Unexpected type {:#?}", place_ty.is_array()),
}
}
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 {
ProjectionElem::Index(_) => match place_ty.kind() {
ty::Array(..) => {
return Err(MoveError::cannot_move_out_of(
self.loc,
InteriorOfSliceOrArray { ty: place_ty, is_index: true },
));
}
}
_ => {}
};
ty::Slice(_) => {
return Err(MoveError::cannot_move_out_of(
self.loc,
InteriorOfSliceOrArray {
ty: place_ty,
is_index: matches!(elem, ProjectionElem::Index(..)),
},
));
}
_ => bug!("Unexpected type {place_ty:#?}"),
},
// `OpaqueCast` only transmutes the type, so no moves there and
// `Downcast` only changes information about a `Place` without moving
// So it's safe to skip these.
ProjectionElem::OpaqueCast(_) | ProjectionElem::Downcast(_, _) => (),
}
if union_path.is_none() {
// inlined from add_move_path because of a borrowck conflict with the iterator
base =