rust-analyzer

diff --git a/crates/hir-def/src/hir/generics.rs b/crates/hir-def/src/hir/generics.rs
index a9a0e36312..94e683cb0f 100644
--- a/crates/hir-def/src/hir/generics.rs
+++ b/crates/hir-def/src/hir/generics.rs

@@ -331,13 +331,13 @@ impl GenericParams {

}

#[inline]

- pub fn no_predicates(&self) -> bool {

+ pub fn has_no_predicates(&self) -> bool {

self.where_predicates.is_empty()

}

#[inline]

- pub fn where_predicates(&self) -> std::slice::Iter<'_, WherePredicate> {

- self.where_predicates.iter()

+ pub fn where_predicates(&self) -> &[WherePredicate] {

+ &self.where_predicates

}

/// Iterator of type_or_consts field

diff --git a/crates/hir-ty/src/display.rs b/crates/hir-ty/src/display.rs
index 1aa7e0fcf8..e3dd74534c 100644
--- a/crates/hir-ty/src/display.rs
+++ b/crates/hir-ty/src/display.rs

@@ -2178,6 +2178,7 @@ impl HirDisplayWithExpressionStore for TypeRefId {

f.write_joined(

generic_params

.where_predicates()

+ .iter()

.filter_map(|it| match it {

WherePredicate::TypeBound { target, bound }

| WherePredicate::ForLifetime { lifetimes: _, target, bound }

diff --git a/crates/hir-ty/src/generics.rs b/crates/hir-ty/src/generics.rs
index a3ed39934c..f14872e68c 100644
--- a/crates/hir-ty/src/generics.rs
+++ b/crates/hir-ty/src/generics.rs

@@ -60,7 +60,16 @@ impl Generics {

}

pub(crate) fn where_predicates(&self) -> impl Iterator<Item = &WherePredicate> {

- self.params.where_predicates()

+ self.params.where_predicates().iter()

+ }

+ pub(crate) fn has_no_predicates(&self) -> bool {

+ self.params.has_no_predicates()

+ && self.parent_generics.as_ref().is_none_or(|g| g.params.has_no_predicates())

+ }

+ pub(crate) fn is_empty(&self) -> bool {

+ self.params.is_empty() && self.parent_generics.as_ref().is_none_or(|g| g.params.is_empty())

}

pub(crate) fn iter_id(&self) -> impl Iterator<Item = GenericParamId> + '_ {

diff --git a/crates/hir-ty/src/lower.rs b/crates/hir-ty/src/lower.rs
index 3134793054..40adfca7fc 100644
--- a/crates/hir-ty/src/lower.rs
+++ b/crates/hir-ty/src/lower.rs

@@ -884,6 +884,11 @@ pub(crate) fn field_types_with_diagnostics_query(

variant_id: VariantId,

) -> (Arc<ArenaMap<LocalFieldId, Binders<Ty>>>, Diagnostics) {

let var_data = db.variant_fields(variant_id);

+ let fields = var_data.fields();

+ if fields.is_empty() {

+ return (Arc::new(ArenaMap::default()), None);

+ }

let (resolver, def): (_, GenericDefId) = match variant_id {

VariantId::StructId(it) => (it.resolver(db), it.into()),

VariantId::UnionId(it) => (it.resolver(db), it.into()),

@@ -899,7 +904,7 @@ pub(crate) fn field_types_with_diagnostics_query(

LifetimeElisionKind::AnonymousReportError,

)

.with_type_param_mode(ParamLoweringMode::Variable);

- for (field_id, field_data) in var_data.fields().iter() {

+ for (field_id, field_data) in fields.iter() {

res.insert(field_id, make_binders(db, &generics, ctx.lower_ty(field_data.type_ref)));

}

(Arc::new(res), create_diagnostics(ctx.diagnostics))

@@ -920,6 +925,10 @@ pub(crate) fn generic_predicates_for_param_query(

assoc_name: Option<Name>,

) -> GenericPredicates {

let generics = generics(db, def);

+ if generics.has_no_predicates() && generics.is_empty() {

+ return GenericPredicates(None);

+ }

let resolver = def.resolver(db);

let mut ctx = TyLoweringContext::new(

db,

@@ -1025,6 +1034,10 @@ pub(crate) fn trait_environment_query(

def: GenericDefId,

) -> Arc<TraitEnvironment> {

let generics = generics(db, def);

+ if generics.has_no_predicates() && generics.is_empty() {

+ return TraitEnvironment::empty(def.krate(db));

+ }

let resolver = def.resolver(db);

let mut ctx = TyLoweringContext::new(

db,

@@ -1128,6 +1141,10 @@ where

F: Fn(&WherePredicate, GenericDefId) -> bool,

{

let generics = generics(db, def);

+ if generics.has_no_predicates() && generics.is_empty() {

+ return (GenericPredicates(None), None);

+ }

let resolver = def.resolver(db);

let mut ctx = TyLoweringContext::new(

db,

@@ -1154,7 +1171,7 @@ where

}

- if generics.len() > 0 {

+ if !generics.is_empty() {

let subst = generics.bound_vars_subst(db, DebruijnIndex::INNERMOST);

let explicitly_unsized_tys = ctx.unsized_types;

if let Some(implicitly_sized_predicates) =

@@ -1229,7 +1246,7 @@ pub(crate) fn generic_defaults_with_diagnostics_query(

def: GenericDefId,

) -> (GenericDefaults, Diagnostics) {

let generic_params = generics(db, def);

- if generic_params.len() == 0 {

+ if generic_params.is_empty() {

return (GenericDefaults(None), None);

}

let resolver = def.resolver(db);

diff --git a/crates/hir-ty/src/tests/incremental.rs b/crates/hir-ty/src/tests/incremental.rs
index 905fd8a3bc..692397a5a6 100644
--- a/crates/hir-ty/src/tests/incremental.rs
+++ b/crates/hir-ty/src/tests/incremental.rs

@@ -695,10 +695,8 @@ fn main() {

"return_type_impl_traits_shim",

"infer_shim",

"function_signature_with_source_map_shim",

- "trait_environment_shim",

"expr_scopes_shim",

"struct_signature_with_source_map_shim",

- "generic_predicates_shim",

"variant_fields_with_source_map_shim",

"inherent_impls_in_crate_shim",

"impl_signature_with_source_map_shim",

@@ -709,7 +707,6 @@ fn main() {

"impl_trait_with_diagnostics_shim",

"impl_self_ty_with_diagnostics_shim",

"generic_predicates_shim",

- "generic_predicates_shim",

]

"#]],

);

diff --git a/crates/hir-ty/src/utils.rs b/crates/hir-ty/src/utils.rs
index 4c8e635eff..d655320310 100644
--- a/crates/hir-ty/src/utils.rs
+++ b/crates/hir-ty/src/utils.rs

@@ -1,7 +1,7 @@

//! Helper functions for working with def, which don't need to be a separate

//! query, but can't be computed directly from `*Data` (ie, which need a `db`).

-use std::iter;

+use std::{cell::LazyCell, iter};

use base_db::Crate;

use chalk_ir::{

@@ -161,11 +161,12 @@ impl Iterator for ClauseElaborator<'_> {

}

fn direct_super_traits_cb(db: &dyn DefDatabase, trait_: TraitId, cb: impl FnMut(TraitId)) {

- let resolver = trait_.resolver(db);

+ let resolver = LazyCell::new(|| trait_.resolver(db));

let (generic_params, store) = db.generic_params_and_store(trait_.into());

let trait_self = generic_params.trait_self_param();

generic_params

.where_predicates()

+ .iter()

.filter_map(|pred| match pred {

WherePredicate::ForLifetime { target, bound, .. }

| WherePredicate::TypeBound { target, bound } => {

diff --git a/crates/hir/src/display.rs b/crates/hir/src/display.rs
index 112558bdd0..18bab7cbf9 100644
--- a/crates/hir/src/display.rs
+++ b/crates/hir/src/display.rs

@@ -633,7 +633,7 @@ fn has_disaplayable_predicates(

params: &GenericParams,

store: &ExpressionStore,

) -> bool {

- params.where_predicates().any(|pred| {

+ params.where_predicates().iter().any(|pred| {

!matches!(

pred,

WherePredicate::TypeBound { target, .. }

@@ -668,7 +668,7 @@ fn write_where_predicates(

_ => false,

};

- let mut iter = params.where_predicates().peekable();

+ let mut iter = params.where_predicates().iter().peekable();

while let Some(pred) = iter.next() {

if matches!(pred, TypeBound { target, .. } if is_unnamed_type_target(*target)) {

continue;

diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 46d2e88160..6d9f0f3a3e 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs

@@ -3667,7 +3667,7 @@ impl GenericDef {

let generics = db.generic_params(def);

- if generics.is_empty() && generics.no_predicates() {

+ if generics.is_empty() && generics.has_no_predicates() {

return;

}