Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-def/src/lib.rs')
| -rw-r--r-- | crates/hir-def/src/lib.rs | 39 |
1 files changed, 32 insertions, 7 deletions
diff --git a/crates/hir-def/src/lib.rs b/crates/hir-def/src/lib.rs index 69e4afe94f..4f68093bcb 100644 --- a/crates/hir-def/src/lib.rs +++ b/crates/hir-def/src/lib.rs @@ -482,8 +482,8 @@ impl_from!( /// Id of the anonymous const block expression and patterns. This is very similar to `ClosureId` and /// shouldn't be a `DefWithBodyId` since its type inference is dependent on its parent. #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)] -pub struct AnonymousConstId(InternId); -impl_intern_key!(AnonymousConstId); +pub struct ConstBlockId(InternId); +impl_intern_key!(ConstBlockId); #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)] pub enum TypeOwnerId { @@ -563,7 +563,10 @@ impl From<GenericDefId> for TypeOwnerId { } } -/// A thing that we want to store in interned ids, but we don't know its type in `hir-def` +/// A thing that we want to store in interned ids, but we don't know its type in `hir-def`. This is +/// currently only used in `InTypeConstId` for storing the type (which has type `Ty` defined in +/// the `hir-ty` crate) of the constant in its id, which is a temporary hack so we may want +/// to remove this after removing that. pub trait OpaqueInternableThing: std::any::Any + std::fmt::Debug + Sync + Send + UnwindSafe + RefUnwindSafe { @@ -594,6 +597,28 @@ impl Clone for Box<dyn OpaqueInternableThing> { } } +// FIXME(const-generic-body): Use an stable id for in type consts. +// +// The current id uses `AstId<ast::ConstArg>` which will be changed by every change in the code. Ideally +// we should use an id which is relative to the type owner, so that every change will only invalidate the +// id if it happens inside of the type owner. +// +// The solution probably is to have some query on `TypeOwnerId` to traverse its constant children and store +// their `AstId` in a list (vector or arena), and use the index of that list in the id here. That query probably +// needs name resolution, and might go far and handles the whole path lowering or type lowering for a `TypeOwnerId`. +// +// Whatever path the solution takes, it should answer 3 questions at the same time: +// * Is the id stable enough? +// * How to find a constant id using an ast node / position in the source code? This is needed when we want to +// provide ide functionalities inside an in type const (which we currently don't support) e.g. go to definition +// for a local defined there. A complex id might have some trouble in this reverse mapping. +// * How to find the return type of a constant using its id? We have this data when we are doing type lowering +// and the name of the struct that contains this constant is resolved, so a query that only traverses the +// type owner by its syntax tree might have a hard time here. + +/// A constant in a type as a substitution for const generics (like `Foo<{ 2 + 2 }>`) or as an array +/// length (like `[u8; 2 + 2]`). These constants are body owner and are a variant of `DefWithBodyId`. These +/// are not called `AnonymousConstId` to prevent confusion with [`ConstBlockId`]. #[derive(Debug, Clone, Copy, Eq, PartialEq, Hash)] pub struct InTypeConstId(InternId); type InTypeConstLoc = (AstId<ast::ConstArg>, TypeOwnerId, Box<dyn OpaqueInternableThing>); @@ -613,17 +638,17 @@ impl InTypeConstId { #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)] pub enum GeneralConstId { ConstId(ConstId), - AnonymousConstId(AnonymousConstId), + ConstBlockId(ConstBlockId), InTypeConstId(InTypeConstId), } -impl_from!(ConstId, AnonymousConstId, InTypeConstId for GeneralConstId); +impl_from!(ConstId, ConstBlockId, InTypeConstId for GeneralConstId); impl GeneralConstId { pub fn generic_def(self, db: &dyn db::DefDatabase) -> Option<GenericDefId> { match self { GeneralConstId::ConstId(x) => Some(x.into()), - GeneralConstId::AnonymousConstId(x) => { + GeneralConstId::ConstBlockId(x) => { let (parent, _) = db.lookup_intern_anonymous_const(x); parent.as_generic_def_id() } @@ -643,7 +668,7 @@ impl GeneralConstId { .and_then(|x| x.as_str()) .unwrap_or("_") .to_owned(), - GeneralConstId::AnonymousConstId(id) => format!("{{anonymous const {id:?}}}"), + GeneralConstId::ConstBlockId(id) => format!("{{anonymous const {id:?}}}"), GeneralConstId::InTypeConstId(id) => format!("{{in type const {id:?}}}"), } } |