rust-analyzer

diff --git a/crates/hir-ty/src/consteval.rs b/crates/hir-ty/src/consteval.rs
index aa7fc598b4..8b6cde975f 100644
--- a/crates/hir-ty/src/consteval.rs
+++ b/crates/hir-ty/src/consteval.rs

@@ -71,12 +71,12 @@ impl From<MirEvalError> for ConstEvalError {

}

-pub(crate) fn path_to_const(

+pub(crate) fn path_to_const<'g>(

db: &dyn HirDatabase,

resolver: &Resolver,

path: &Path,

mode: ParamLoweringMode,

- args: impl FnOnce() -> Option<Generics>,

+ args: impl FnOnce() -> Option<&'g Generics>,

debruijn: DebruijnIndex,

expected_ty: Ty,

) -> Option<Const> {

@@ -89,7 +89,7 @@ pub(crate) fn path_to_const(

}

ParamLoweringMode::Variable => {

let args = args();

- match args.as_ref().and_then(|args| args.type_or_const_param_idx(p.into())) {

+ match args.and_then(|args| args.type_or_const_param_idx(p.into())) {

Some(it) => ConstValue::BoundVar(BoundVar::new(debruijn, it)),

None => {

never!(

diff --git a/crates/hir-ty/src/infer.rs b/crates/hir-ty/src/infer.rs
index c82bac0c5c..aeb6e69ce7 100644
--- a/crates/hir-ty/src/infer.rs
+++ b/crates/hir-ty/src/infer.rs

@@ -49,6 +49,7 @@ use hir_def::{

use hir_expand::name::{name, Name};

use indexmap::IndexSet;

use la_arena::{ArenaMap, Entry};

+use once_cell::unsync::OnceCell;

use rustc_hash::{FxHashMap, FxHashSet};

use stdx::{always, never};

use triomphe::Arc;

@@ -527,6 +528,7 @@ pub(crate) struct InferenceContext<'a> {

pub(crate) owner: DefWithBodyId,

pub(crate) body: &'a Body,

pub(crate) resolver: Resolver,

+ generics: OnceCell<Option<Generics>>,

table: unify::InferenceTable<'a>,

/// The traits in scope, disregarding block modules. This is used for caching purposes.

traits_in_scope: FxHashSet<TraitId>,

@@ -612,6 +614,7 @@ impl<'a> InferenceContext<'a> {

) -> Self {

let trait_env = db.trait_environment_for_body(owner);

InferenceContext {

+ generics: OnceCell::new(),

result: InferenceResult::default(),

table: unify::InferenceTable::new(db, trait_env),

tuple_field_accesses_rev: Default::default(),

@@ -633,8 +636,14 @@ impl<'a> InferenceContext<'a> {

}

- pub(crate) fn generics(&self) -> Option<Generics> {

- Some(crate::generics::generics(self.db.upcast(), self.resolver.generic_def()?))

+ pub(crate) fn generics(&self) -> Option<&Generics> {

+ self.generics

+ .get_or_init(|| {

+ self.resolver

+ .generic_def()

+ .map(|def| crate::generics::generics(self.db.upcast(), def))

+ })

+ .as_ref()

}

// FIXME: This function should be private in module. It is currently only used in the consteval, since we need

diff --git a/crates/hir-ty/src/infer/closure.rs b/crates/hir-ty/src/infer/closure.rs
index 9f95e6edff..b7c7b66545 100644
--- a/crates/hir-ty/src/infer/closure.rs
+++ b/crates/hir-ty/src/infer/closure.rs

@@ -339,7 +339,7 @@ impl CapturedItemWithoutTy {

fn replace_placeholder_with_binder(ctx: &mut InferenceContext<'_>, ty: Ty) -> Binders<Ty> {

struct Filler<'a> {

db: &'a dyn HirDatabase,

- generics: Generics,

+ generics: &'a Generics,

}

impl FallibleTypeFolder<Interner> for Filler<'_> {

type Error = ();

@@ -382,7 +382,7 @@ impl CapturedItemWithoutTy {

};

let filler = &mut Filler { db: ctx.db, generics };

let result = ty.clone().try_fold_with(filler, DebruijnIndex::INNERMOST).unwrap_or(ty);

- make_binders(ctx.db, &filler.generics, result)

+ make_binders(ctx.db, filler.generics, result)

}

diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs
index 00b1f53857..30d6b2f664 100644
--- a/crates/hir-ty/src/lower.rs
+++ b/crates/hir-ty/src/lower.rs

@@ -45,6 +45,7 @@ use hir_def::{

use hir_expand::{name::Name, ExpandResult};

use intern::Interned;

use la_arena::{Arena, ArenaMap};

+use once_cell::unsync::OnceCell;

use rustc_hash::FxHashSet;

use smallvec::SmallVec;

use stdx::{impl_from, never};

@@ -122,6 +123,7 @@ impl ImplTraitLoweringState {

pub struct TyLoweringContext<'a> {

pub db: &'a dyn HirDatabase,

resolver: &'a Resolver,

+ generics: OnceCell<Option<Generics>>,

in_binders: DebruijnIndex,

// FIXME: Should not be an `Option` but `Resolver` currently does not return owners in all cases

// where expected

@@ -153,6 +155,7 @@ impl<'a> TyLoweringContext<'a> {

Self {

db,

resolver,

+ generics: OnceCell::new(),

owner,

in_binders,

impl_trait_mode,

@@ -175,6 +178,7 @@ impl<'a> TyLoweringContext<'a> {

impl_trait_mode,

expander: RefCell::new(expander),

unsized_types: RefCell::new(unsized_types),

+ generics: self.generics.clone(),

..*self

};

let result = f(&new_ctx);

@@ -246,8 +250,10 @@ impl<'a> TyLoweringContext<'a> {

)

}

- fn generics(&self) -> Option<Generics> {

- Some(generics(self.db.upcast(), self.resolver.generic_def()?))

+ fn generics(&self) -> Option<&Generics> {

+ self.generics

+ .get_or_init(|| self.resolver.generic_def().map(|def| generics(self.db.upcast(), def)))

+ .as_ref()

}

pub fn lower_ty_ext(&self, type_ref: &TypeRef) -> (Ty, Option<TypeNs>) {

@@ -2207,14 +2213,14 @@ pub(crate) fn generic_arg_to_chalk<'a, T>(

}

-pub(crate) fn const_or_path_to_chalk(

+pub(crate) fn const_or_path_to_chalk<'g>(

db: &dyn HirDatabase,

resolver: &Resolver,

owner: TypeOwnerId,

expected_ty: Ty,

value: &ConstRef,

mode: ParamLoweringMode,

- args: impl FnOnce() -> Option<Generics>,

+ args: impl FnOnce() -> Option<&'g Generics>,

debruijn: DebruijnIndex,

) -> Const {

match value {