Auto merge of rust-lang#17473 - Veykril:generics, r=Veykril

internal: Tidy up generics handling in hir-ty a bit

Author: bors

src/tools/rust-analyzer/crates/hir-def/src/generics.rs

@@ -11,7 +11,7 @@ use hir_expand::{
     ExpandResult,
 };
 use intern::Interned;
-use la_arena::Arena;
+use la_arena::{Arena, RawIdx};
 use once_cell::unsync::Lazy;
 use stdx::impl_from;
 use syntax::ast::{self, HasGenericParams, HasName, HasTypeBounds};
@@ -28,6 +28,9 @@ use crate::{
     LocalLifetimeParamId, LocalTypeOrConstParamId, Lookup, TypeOrConstParamId, TypeParamId,
 };
 
+const SELF_PARAM_ID_IN_SELF: la_arena::Idx<TypeOrConstParamData> =
+    LocalTypeOrConstParamId::from_raw(RawIdx::from_u32(0));
+
 /// Data about a generic type parameter (to a function, struct, impl, ...).
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
 pub struct TypeParamData {
@@ -441,22 +444,26 @@ impl GenericParamsCollector {
 
 impl GenericParams {
     /// Number of Generic parameters (type_or_consts + lifetimes)
+    #[inline]
     pub fn len(&self) -> usize {
         self.type_or_consts.len() + self.lifetimes.len()
     }
 
+    #[inline]
     pub fn is_empty(&self) -> bool {
         self.len() == 0
     }
 
     /// Iterator of type_or_consts field
+    #[inline]
     pub fn iter_type_or_consts(
         &self,
     ) -> impl DoubleEndedIterator<Item = (LocalTypeOrConstParamId, &TypeOrConstParamData)> {
         self.type_or_consts.iter()
     }
 
     /// Iterator of lifetimes field
+    #[inline]
     pub fn iter_lt(
         &self,
     ) -> impl DoubleEndedIterator<Item = (LocalLifetimeParamId, &LifetimeParamData)> {
@@ -605,17 +612,18 @@ impl GenericParams {
         })
     }
 
-    pub fn find_trait_self_param(&self) -> Option<LocalTypeOrConstParamId> {
-        self.type_or_consts.iter().find_map(|(id, p)| {
-            matches!(
-                p,
-                TypeOrConstParamData::TypeParamData(TypeParamData {
-                    provenance: TypeParamProvenance::TraitSelf,
-                    ..
-                })
-            )
-            .then(|| id)
-        })
+    pub fn trait_self_param(&self) -> Option<LocalTypeOrConstParamId> {
+        if self.type_or_consts.is_empty() {
+            return None;
+        }
+        matches!(
+            self.type_or_consts[SELF_PARAM_ID_IN_SELF],
+            TypeOrConstParamData::TypeParamData(TypeParamData {
+                provenance: TypeParamProvenance::TraitSelf,
+                ..
+            })
+        )
+        .then(|| SELF_PARAM_ID_IN_SELF)
     }
 
     pub fn find_lifetime_by_name(

src/tools/rust-analyzer/crates/hir-def/src/lib.rs

@@ -923,6 +923,7 @@ pub enum GenericDefId {
     ImplId(ImplId),
     // enum variants cannot have generics themselves, but their parent enums
     // can, and this makes some code easier to write
+    // FIXME: Try to remove this as that will reduce the amount of query slots generated per enum?
     EnumVariantId(EnumVariantId),
     // consts can have type parameters from their parents (i.e. associated consts of traits)
     ConstId(ConstId),

src/tools/rust-analyzer/crates/hir-ty/src/builder.rs

@@ -14,10 +14,10 @@ use hir_def::{
 use smallvec::SmallVec;
 
 use crate::{
-    consteval::unknown_const_as_generic, db::HirDatabase, error_lifetime,
-    infer::unify::InferenceTable, primitive, to_assoc_type_id, to_chalk_trait_id, utils::generics,
-    Binders, BoundVar, CallableSig, GenericArg, GenericArgData, Interner, ProjectionTy,
-    Substitution, TraitRef, Ty, TyDefId, TyExt, TyKind,
+    consteval::unknown_const_as_generic, db::HirDatabase, error_lifetime, generics::generics,
+    infer::unify::InferenceTable, primitive, to_assoc_type_id, to_chalk_trait_id, Binders,
+    BoundVar, CallableSig, GenericArg, GenericArgData, Interner, ProjectionTy, Substitution,
+    TraitRef, Ty, TyDefId, TyExt, TyKind,
 };
 
 #[derive(Debug, Clone, PartialEq, Eq)]

src/tools/rust-analyzer/crates/hir-ty/src/chalk_db.rs

@@ -20,13 +20,14 @@ use hir_expand::name::name;
 use crate::{
     db::{HirDatabase, InternedCoroutine},
     display::HirDisplay,
-    from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, make_binders,
-    make_single_type_binders,
+    from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
+    generics::generics,
+    make_binders, make_single_type_binders,
     mapping::{from_chalk, ToChalk, TypeAliasAsValue},
     method_resolution::{TraitImpls, TyFingerprint, ALL_FLOAT_FPS, ALL_INT_FPS},
     to_assoc_type_id, to_chalk_trait_id,
     traits::ChalkContext,
-    utils::{generics, ClosureSubst},
+    utils::ClosureSubst,
     wrap_empty_binders, AliasEq, AliasTy, BoundVar, CallableDefId, DebruijnIndex, FnDefId,
     Interner, ProjectionTy, ProjectionTyExt, QuantifiedWhereClause, Substitution, TraitRef,
     TraitRefExt, Ty, TyBuilder, TyExt, TyKind, WhereClause,

src/tools/rust-analyzer/crates/hir-ty/src/chalk_ext.rs

@@ -12,12 +12,10 @@ use hir_def::{
 };
 
 use crate::{
-    db::HirDatabase,
-    from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
-    to_chalk_trait_id,
-    utils::{generics, ClosureSubst},
-    AdtId, AliasEq, AliasTy, Binders, CallableDefId, CallableSig, Canonical, CanonicalVarKinds,
-    ClosureId, DynTy, FnPointer, ImplTraitId, InEnvironment, Interner, Lifetime, ProjectionTy,
+    db::HirDatabase, from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id,
+    from_placeholder_idx, generics::generics, to_chalk_trait_id, utils::ClosureSubst, AdtId,
+    AliasEq, AliasTy, Binders, CallableDefId, CallableSig, Canonical, CanonicalVarKinds, ClosureId,
+    DynTy, FnPointer, ImplTraitId, InEnvironment, Interner, Lifetime, ProjectionTy,
     QuantifiedWhereClause, Substitution, TraitRef, Ty, TyBuilder, TyKind, TypeFlags, WhereClause,
 };
 

src/tools/rust-analyzer/crates/hir-ty/src/consteval.rs

@@ -15,10 +15,9 @@ use stdx::never;
 use triomphe::Arc;
 
 use crate::{
-    db::HirDatabase, infer::InferenceContext, lower::ParamLoweringMode,
-    mir::monomorphize_mir_body_bad, to_placeholder_idx, utils::Generics, Const, ConstData,
-    ConstScalar, ConstValue, GenericArg, Interner, MemoryMap, Substitution, TraitEnvironment, Ty,
-    TyBuilder,
+    db::HirDatabase, generics::Generics, infer::InferenceContext, lower::ParamLoweringMode,
+    mir::monomorphize_mir_body_bad, to_placeholder_idx, Const, ConstData, ConstScalar, ConstValue,
+    GenericArg, Interner, MemoryMap, Substitution, TraitEnvironment, Ty, TyBuilder,
 };
 
 use super::mir::{interpret_mir, lower_to_mir, pad16, MirEvalError, MirLowerError};
@@ -72,12 +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> {
@@ -90,7 +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!(

src/tools/rust-analyzer/crates/hir-ty/src/display.rs

@@ -36,12 +36,13 @@ use crate::{
     consteval::try_const_usize,
     db::{HirDatabase, InternedClosure},
     from_assoc_type_id, from_foreign_def_id, from_placeholder_idx,
+    generics::generics,
     layout::Layout,
     lt_from_placeholder_idx,
     mapping::from_chalk,
     mir::pad16,
     primitive, to_assoc_type_id,
-    utils::{self, detect_variant_from_bytes, generics, ClosureSubst},
+    utils::{self, detect_variant_from_bytes, ClosureSubst},
     AdtId, AliasEq, AliasTy, Binders, CallableDefId, CallableSig, ConcreteConst, Const,
     ConstScalar, ConstValue, DomainGoal, FnAbi, GenericArg, ImplTraitId, Interner, Lifetime,
     LifetimeData, LifetimeOutlives, MemoryMap, Mutability, OpaqueTy, ProjectionTy, ProjectionTyExt,
@@ -493,7 +494,7 @@ impl HirDisplay for Const {
             ConstValue::Placeholder(idx) => {
                 let id = from_placeholder_idx(f.db, *idx);
                 let generics = generics(f.db.upcast(), id.parent);
-                let param_data = &generics.params[id.local_id];
+                let param_data = &generics[id.local_id];
                 write!(f, "{}", param_data.name().unwrap().display(f.db.upcast()))?;
                 Ok(())
             }
@@ -988,15 +989,15 @@ impl HirDisplay for Ty {
 
                 if parameters.len(Interner) > 0 {
                     let generics = generics(db.upcast(), def.into());
-                    let (parent_len, self_, type_, const_, impl_, lifetime) =
+                    let (parent_len, self_param, type_, const_, impl_, lifetime) =
                         generics.provenance_split();
                     let parameters = parameters.as_slice(Interner);
                     // We print all params except implicit impl Trait params. Still a bit weird; should we leave out parent and self?
                     if parameters.len() - impl_ > 0 {
                         // `parameters` are in the order of fn's params (including impl traits), fn's lifetimes
                         // parent's params (those from enclosing impl or trait, if any).
                         let (fn_params, other) =
-                            parameters.split_at(self_ + type_ + const_ + lifetime);
+                            parameters.split_at(self_param as usize + type_ + const_ + lifetime);
                         let (_impl, parent_params) = other.split_at(impl_);
                         debug_assert_eq!(parent_params.len(), parent_len);
 
@@ -1215,7 +1216,7 @@ impl HirDisplay for Ty {
             TyKind::Placeholder(idx) => {
                 let id = from_placeholder_idx(db, *idx);
                 let generics = generics(db.upcast(), id.parent);
-                let param_data = &generics.params[id.local_id];
+                let param_data = &generics[id.local_id];
                 match param_data {
                     TypeOrConstParamData::TypeParamData(p) => match p.provenance {
                         TypeParamProvenance::TypeParamList | TypeParamProvenance::TraitSelf => {
@@ -1797,7 +1798,7 @@ impl HirDisplay for LifetimeData {
             LifetimeData::Placeholder(idx) => {
                 let id = lt_from_placeholder_idx(f.db, *idx);
                 let generics = generics(f.db.upcast(), id.parent);
-                let param_data = &generics.params[id.local_id];
+                let param_data = &generics[id.local_id];
                 write!(f, "{}", param_data.name.display(f.db.upcast()))?;
                 Ok(())
             }