bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir-ty/src/next_solver/generics.rs')
-rw-r--r--crates/hir-ty/src/next_solver/generics.rs142
1 files changed, 142 insertions, 0 deletions
diff --git a/crates/hir-ty/src/next_solver/generics.rs b/crates/hir-ty/src/next_solver/generics.rs
new file mode 100644
index 0000000000..5ec9a18a6c
--- /dev/null
+++ b/crates/hir-ty/src/next_solver/generics.rs
@@ -0,0 +1,142 @@
+//! Things related to generics in the next-trait-solver.
+
+use hir_def::{
+ ConstParamId, GenericDefId, GenericParamId, ItemContainerId, LifetimeParamId, Lookup,
+ TypeOrConstParamId, TypeParamId,
+ db::DefDatabase,
+ expr_store::ExpressionStore,
+ hir::generics::{
+ GenericParamDataRef, GenericParams, LifetimeParamData, LocalLifetimeParamId,
+ LocalTypeOrConstParamId, TypeOrConstParamData, TypeParamData, TypeParamProvenance,
+ WherePredicate,
+ },
+};
+use hir_expand::name::Name;
+use intern::{Symbol, sym};
+use la_arena::Arena;
+use rustc_type_ir::inherent::Ty as _;
+use triomphe::Arc;
+
+use crate::{db::HirDatabase, generics::parent_generic_def, next_solver::Ty};
+
+use super::{Const, EarlyParamRegion, ErrorGuaranteed, ParamConst, Region, SolverDefId};
+
+use super::{DbInterner, GenericArg};
+
+pub(crate) fn generics(db: &dyn HirDatabase, def: SolverDefId) -> Generics {
+ let mk_lt = |parent, index, local_id, lt: &LifetimeParamData| {
+ let name = lt.name.symbol().clone();
+ let id = GenericParamId::LifetimeParamId(LifetimeParamId { parent, local_id });
+ GenericParamDef { name, index, id }
+ };
+ let mk_ty = |parent, index, local_id, p: &TypeOrConstParamData| {
+ let name = p.name().map(|n| n.symbol().clone()).unwrap_or_else(|| sym::MISSING_NAME);
+ let id = TypeOrConstParamId { parent, local_id };
+ let id = match p {
+ TypeOrConstParamData::TypeParamData(_) => {
+ GenericParamId::TypeParamId(TypeParamId::from_unchecked(id))
+ }
+ TypeOrConstParamData::ConstParamData(_) => {
+ GenericParamId::ConstParamId(ConstParamId::from_unchecked(id))
+ }
+ };
+ GenericParamDef { name, index, id }
+ };
+ let own_params_for_generic_params = |parent, params: &GenericParams| {
+ let mut result = Vec::with_capacity(params.len());
+ let mut type_and_consts = params.iter_type_or_consts();
+ let mut index = 0;
+ if let Some(self_param) = params.trait_self_param() {
+ result.push(mk_ty(parent, 0, self_param, &params[self_param]));
+ type_and_consts.next();
+ index += 1;
+ }
+ result.extend(params.iter_lt().map(|(local_id, data)| {
+ let lt = mk_lt(parent, index, local_id, data);
+ index += 1;
+ lt
+ }));
+ result.extend(type_and_consts.map(|(local_id, data)| {
+ let ty = mk_ty(parent, index, local_id, data);
+ index += 1;
+ ty
+ }));
+ result
+ };
+
+ let (parent, own_params) = match (def.try_into(), def) {
+ (Ok(def), _) => (
+ parent_generic_def(db, def),
+ own_params_for_generic_params(def, &db.generic_params(def)),
+ ),
+ (_, SolverDefId::InternedOpaqueTyId(id)) => {
+ match db.lookup_intern_impl_trait_id(id) {
+ crate::ImplTraitId::ReturnTypeImplTrait(function_id, _) => {
+ // The opaque type itself does not have generics - only the parent function
+ (Some(GenericDefId::FunctionId(function_id)), vec![])
+ }
+ crate::ImplTraitId::TypeAliasImplTrait(type_alias_id, _) => {
+ (Some(type_alias_id.into()), Vec::new())
+ }
+ crate::ImplTraitId::AsyncBlockTypeImplTrait(def, _) => {
+ let param = TypeOrConstParamData::TypeParamData(TypeParamData {
+ name: None,
+ default: None,
+ provenance: TypeParamProvenance::TypeParamList,
+ });
+ // Yes, there is a parent but we don't include it in the generics
+ // FIXME: It seems utterly sensitive to fake a generic param here.
+ // Also, what a horrible mess!
+ (
+ None,
+ vec![mk_ty(
+ GenericDefId::FunctionId(salsa::plumbing::FromId::from_id(unsafe {
+ salsa::Id::from_index(salsa::Id::MAX_U32 - 1)
+ })),
+ 0,
+ LocalTypeOrConstParamId::from_raw(la_arena::RawIdx::from_u32(0)),
+ &param,
+ )],
+ )
+ }
+ }
+ }
+ _ => panic!("No generics for {def:?}"),
+ };
+ let parent_generics = parent.map(|def| Box::new(generics(db, def.into())));
+
+ Generics {
+ parent,
+ parent_count: parent_generics.map_or(0, |g| g.parent_count + g.own_params.len()),
+ own_params,
+ }
+}
+
+#[derive(Debug)]
+pub struct Generics {
+ pub parent: Option<GenericDefId>,
+ pub parent_count: usize,
+ pub own_params: Vec<GenericParamDef>,
+}
+
+#[derive(Debug)]
+pub struct GenericParamDef {
+ pub(crate) name: Symbol,
+ //def_id: GenericDefId,
+ index: u32,
+ pub(crate) id: GenericParamId,
+}
+
+impl GenericParamDef {
+ /// Returns the index of the param on the self generics only
+ /// (i.e. not including parent generics)
+ pub fn index(&self) -> u32 {
+ self.index
+ }
+}
+
+impl<'db> rustc_type_ir::inherent::GenericsOf<DbInterner<'db>> for Generics {
+ fn count(&self) -> usize {
+ self.parent_count + self.own_params.len()
+ }
+}