bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/mir/eval.rs')
-rw-r--r--crates/hir-ty/src/mir/eval.rs101
1 files changed, 66 insertions, 35 deletions
diff --git a/crates/hir-ty/src/mir/eval.rs b/crates/hir-ty/src/mir/eval.rs
index 78961e1982..01295a9fc3 100644
--- a/crates/hir-ty/src/mir/eval.rs
+++ b/crates/hir-ty/src/mir/eval.rs
@@ -1263,50 +1263,81 @@ impl Evaluator<'_> {
current_ty: &Ty,
target_ty: &Ty,
) -> Result<IntervalOrOwned> {
- use IntervalOrOwned::*;
fn for_ptr(x: &TyKind) -> Option<Ty> {
match x {
TyKind::Raw(_, ty) | TyKind::Ref(_, _, ty) => Some(ty.clone()),
_ => None,
}
}
- Ok(match self.coerce_unsized_look_through_fields(target_ty, for_ptr)? {
- ty => match &ty.data(Interner).kind {
- TyKind::Slice(_) => {
- match self.coerce_unsized_look_through_fields(current_ty, for_ptr)? {
- ty => match &ty.data(Interner).kind {
- TyKind::Array(_, size) => {
- let len = match try_const_usize(self.db, size) {
- None => not_supported!(
- "unevaluatble len of array in coerce unsized"
- ),
- Some(x) => x as usize,
- };
- let mut r = Vec::with_capacity(16);
- let addr = addr.get(self)?;
- r.extend(addr.iter().copied());
- r.extend(len.to_le_bytes().into_iter());
- Owned(r)
- }
- t => {
- not_supported!("slice unsizing from non array type {t:?}")
- }
- },
- }
+ let target_ty = self.coerce_unsized_look_through_fields(target_ty, for_ptr)?;
+ let current_ty = self.coerce_unsized_look_through_fields(current_ty, for_ptr)?;
+
+ self.unsizing_ptr_from_addr(target_ty, current_ty, addr)
+ }
+
+ /// Adds metadata to the address and create the fat pointer result of the unsizing operation.
+ fn unsizing_ptr_from_addr(
+ &mut self,
+ target_ty: Ty,
+ current_ty: Ty,
+ addr: Interval,
+ ) -> Result<IntervalOrOwned> {
+ use IntervalOrOwned::*;
+ Ok(match &target_ty.data(Interner).kind {
+ TyKind::Slice(_) => match &current_ty.data(Interner).kind {
+ TyKind::Array(_, size) => {
+ let len = match try_const_usize(self.db, size) {
+ None => {
+ not_supported!("unevaluatble len of array in coerce unsized")
+ }
+ Some(x) => x as usize,
+ };
+ let mut r = Vec::with_capacity(16);
+ let addr = addr.get(self)?;
+ r.extend(addr.iter().copied());
+ r.extend(len.to_le_bytes().into_iter());
+ Owned(r)
}
- TyKind::Dyn(_) => match &current_ty.data(Interner).kind {
- TyKind::Raw(_, ty) | TyKind::Ref(_, _, ty) => {
- let vtable = self.vtable_map.id(ty.clone());
- let mut r = Vec::with_capacity(16);
- let addr = addr.get(self)?;
- r.extend(addr.iter().copied());
- r.extend(vtable.to_le_bytes().into_iter());
- Owned(r)
+ t => {
+ not_supported!("slice unsizing from non array type {t:?}")
+ }
+ },
+ TyKind::Dyn(_) => {
+ let vtable = self.vtable_map.id(current_ty.clone());
+ let mut r = Vec::with_capacity(16);
+ let addr = addr.get(self)?;
+ r.extend(addr.iter().copied());
+ r.extend(vtable.to_le_bytes().into_iter());
+ Owned(r)
+ }
+ TyKind::Adt(id, target_subst) => match &current_ty.data(Interner).kind {
+ TyKind::Adt(current_id, current_subst) => {
+ if id != current_id {
+ not_supported!("unsizing struct with different type");
}
- _ => not_supported!("dyn unsizing from non pointers"),
- },
- _ => not_supported!("unknown unsized cast"),
+ let id = match id.0 {
+ AdtId::StructId(s) => s,
+ AdtId::UnionId(_) => not_supported!("unsizing unions"),
+ AdtId::EnumId(_) => not_supported!("unsizing enums"),
+ };
+ let Some((last_field, _)) = self.db.struct_data(id).variant_data.fields().iter().rev().next() else {
+ not_supported!("unsizing struct without field");
+ };
+ let target_last_field = self.db.field_types(id.into())[last_field]
+ .clone()
+ .substitute(Interner, target_subst);
+ let current_last_field = self.db.field_types(id.into())[last_field]
+ .clone()
+ .substitute(Interner, current_subst);
+ return self.unsizing_ptr_from_addr(
+ target_last_field,
+ current_last_field,
+ addr,
+ );
+ }
+ _ => not_supported!("unsizing struct with non adt type"),
},
+ _ => not_supported!("unknown unsized cast"),
})
}