Merge #8359

8359: Add Lifetime to TyKind::Ref and DynTy r=flodiebold a=Veykril

CC #8313

Co-authored-by: Lukas Wirth <[email protected]>

12 files changed, 58 insertions, 38 deletions

diff --git a/crates/hir_ty/src/diagnostics/expr.rs b/crates/hir_ty/src/diagnostics/expr.rs
index db278d0db..d7bf9fdf7 100644
--- a/crates/hir_ty/src/diagnostics/expr.rs
+++ b/crates/hir_ty/src/diagnostics/expr.rs
@@ -315,7 +315,7 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
                 if pat_ty == match_expr_ty
                     || match_expr_ty
                         .as_reference()
-                        .map(|(match_expr_ty, _)| match_expr_ty == pat_ty)
+                        .map(|(match_expr_ty, ..)| match_expr_ty == pat_ty)
                         .unwrap_or(false)
                 {
                     // If we had a NotUsefulMatchArm diagnostic, we could
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index 4ef8024d0..22416c0cf 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -314,7 +314,7 @@ impl HirDisplay for Ty {
                 t.hir_fmt(f)?;
                 write!(f, "; _]")?;
             }
-            TyKind::Raw(m, t) | TyKind::Ref(m, t) => {
+            TyKind::Raw(m, t) | TyKind::Ref(m, _, t) => {
                 let ty_display =
                     t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
diff --git a/crates/hir_ty/src/infer/coerce.rs b/crates/hir_ty/src/infer/coerce.rs
index 32c273afc..d6c48870a 100644
--- a/crates/hir_ty/src/infer/coerce.rs
+++ b/crates/hir_ty/src/infer/coerce.rs
@@ -81,7 +81,7 @@ impl<'a> InferenceContext<'a> {
             // `&T` -> `*const T`
             // `&mut T` -> `*mut T`/`*const T`
             (TyKind::Ref(.., substs), &TyKind::Raw(m2 @ Mutability::Not, ..))
-            | (TyKind::Ref(Mutability::Mut, substs), &TyKind::Raw(m2, ..)) => {
+            | (TyKind::Ref(Mutability::Mut, _, substs), &TyKind::Raw(m2, ..)) => {
                 from_ty = TyKind::Raw(m2, substs.clone()).intern(&Interner);
             }
 
@@ -111,7 +111,9 @@ impl<'a> InferenceContext<'a> {
         // Auto Deref if cannot coerce
         match (from_ty.kind(&Interner), to_ty.kind(&Interner)) {
             // FIXME: DerefMut
-            (TyKind::Ref(_, st1), TyKind::Ref(_, st2)) => self.unify_autoderef_behind_ref(st1, st2),
+            (TyKind::Ref(.., st1), TyKind::Ref(.., st2)) => {
+                self.unify_autoderef_behind_ref(st1, st2)
+            }
 
             // Otherwise, normal unify
             _ => self.unify(&from_ty, to_ty),
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index ff564106b..796487d02 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -19,7 +19,7 @@ use crate::{
     lower::lower_to_chalk_mutability,
     method_resolution, op,
     primitive::{self, UintTy},
-    to_chalk_trait_id,
+    static_lifetime, to_chalk_trait_id,
     traits::{chalk::from_chalk, FnTrait},
     utils::{generics, variant_data, Generics},
     AdtId, Binders, CallableDefId, FnPointer, FnSig, FnSubst, InEnvironment, Interner,
@@ -527,7 +527,7 @@ impl<'a> InferenceContext<'a> {
                 let inner_ty = self.infer_expr_inner(*expr, &expectation);
                 match rawness {
                     Rawness::RawPtr => TyKind::Raw(mutability, inner_ty),
-                    Rawness::Ref => TyKind::Ref(mutability, inner_ty),
+                    Rawness::Ref => TyKind::Ref(mutability, static_lifetime(), inner_ty),
                 }
                 .intern(&Interner)
             }
@@ -731,12 +731,13 @@ impl<'a> InferenceContext<'a> {
             Expr::Literal(lit) => match lit {
                 Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner),
                 Literal::String(..) => {
-                    TyKind::Ref(Mutability::Not, TyKind::Str.intern(&Interner)).intern(&Interner)
+                    TyKind::Ref(Mutability::Not, static_lifetime(), TyKind::Str.intern(&Interner))
+                        .intern(&Interner)
                 }
                 Literal::ByteString(..) => {
                     let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner);
                     let array_type = TyKind::Array(byte_type).intern(&Interner);
-                    TyKind::Ref(Mutability::Not, array_type).intern(&Interner)
+                    TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner)
                 }
                 Literal::Char(..) => TyKind::Scalar(Scalar::Char).intern(&Interner),
                 Literal::Int(_v, ty) => match ty {
@@ -872,7 +873,9 @@ impl<'a> InferenceContext<'a> {
         // Apply autoref so the below unification works correctly
         // FIXME: return correct autorefs from lookup_method
         let actual_receiver_ty = match expected_receiver_ty.as_reference() {
-            Some((_, mutability)) => TyKind::Ref(mutability, derefed_receiver_ty).intern(&Interner),
+            Some((_, lifetime, mutability)) => {
+                TyKind::Ref(mutability, lifetime, derefed_receiver_ty).intern(&Interner)
+            }
             _ => derefed_receiver_ty,
         };
         self.unify(&expected_receiver_ty, &actual_receiver_ty);
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
index 252ae914a..2848a393c 100644
--- a/crates/hir_ty/src/infer/pat.rs
+++ b/crates/hir_ty/src/infer/pat.rs
@@ -13,8 +13,8 @@ use hir_expand::name::Name;
 
 use super::{BindingMode, Expectation, InferenceContext};
 use crate::{
-    lower::lower_to_chalk_mutability, utils::variant_data, Interner, Substitution, Ty, TyBuilder,
-    TyKind,
+    lower::lower_to_chalk_mutability, static_lifetime, utils::variant_data, Interner, Substitution,
+    Ty, TyBuilder, TyKind,
 };
 
 impl<'a> InferenceContext<'a> {
@@ -104,7 +104,7 @@ impl<'a> InferenceContext<'a> {
         let body = Arc::clone(&self.body); // avoid borrow checker problem
 
         if is_non_ref_pat(&body, pat) {
-            while let Some((inner, mutability)) = expected.as_reference() {
+            while let Some((inner, _lifetime, mutability)) = expected.as_reference() {
                 expected = inner;
                 default_bm = match default_bm {
                     BindingMode::Move => BindingMode::Ref(mutability),
@@ -162,7 +162,7 @@ impl<'a> InferenceContext<'a> {
             Pat::Ref { pat, mutability } => {
                 let mutability = lower_to_chalk_mutability(*mutability);
                 let expectation = match expected.as_reference() {
-                    Some((inner_ty, exp_mut)) => {
+                    Some((inner_ty, _lifetime, exp_mut)) => {
                         if mutability != exp_mut {
                             // FIXME: emit type error?
                         }
@@ -171,7 +171,7 @@ impl<'a> InferenceContext<'a> {
                     _ => self.result.standard_types.unknown.clone(),
                 };
                 let subty = self.infer_pat(*pat, &expectation, default_bm);
-                TyKind::Ref(mutability, subty).intern(&Interner)
+                TyKind::Ref(mutability, static_lifetime(), subty).intern(&Interner)
             }
             Pat::TupleStruct { path: p, args: subpats, ellipsis } => self.infer_tuple_struct_pat(
                 p.as_ref(),
@@ -204,7 +204,8 @@ impl<'a> InferenceContext<'a> {
 
                 let bound_ty = match mode {
                     BindingMode::Ref(mutability) => {
-                        TyKind::Ref(mutability, inner_ty.clone()).intern(&Interner)
+                        TyKind::Ref(mutability, static_lifetime(), inner_ty.clone())
+                            .intern(&Interner)
                     }
                     BindingMode::Move => inner_ty.clone(),
                 };
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index 2f9523325..c7878ebfd 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -317,7 +317,7 @@ impl InferenceTable {
                 | (TyKind::Closure(.., substs1), TyKind::Closure(.., substs2)) => {
                     self.unify_substs(substs1, substs2, depth + 1)
                 }
-                (TyKind::Ref(_, ty1), TyKind::Ref(_, ty2))
+                (TyKind::Ref(_, _, ty1), TyKind::Ref(_, _, ty2))
                 | (TyKind::Raw(_, ty1), TyKind::Raw(_, ty2))
                 | (TyKind::Array(ty1), TyKind::Array(ty2))
                 | (TyKind::Slice(ty1), TyKind::Slice(ty2)) => self.unify_inner(ty1, ty2, depth + 1),
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index c3ec12352..bccc73449 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -165,16 +165,16 @@ impl CallableSig {
 }
 
 impl Ty {
-    pub fn as_reference(&self) -> Option<(&Ty, Mutability)> {
+    pub fn as_reference(&self) -> Option<(&Ty, Lifetime, Mutability)> {
         match self.kind(&Interner) {
-            TyKind::Ref(mutability, ty) => Some((ty, *mutability)),
+            TyKind::Ref(mutability, lifetime, ty) => Some((ty, *lifetime, *mutability)),
             _ => None,
         }
     }
 
     pub fn as_reference_or_ptr(&self) -> Option<(&Ty, Rawness, Mutability)> {
         match self.kind(&Interner) {
-            TyKind::Ref(mutability, ty) => Some((ty, Rawness::Ref, *mutability)),
+            TyKind::Ref(mutability, _, ty) => Some((ty, Rawness::Ref, *mutability)),
             TyKind::Raw(mutability, ty) => Some((ty, Rawness::RawPtr, *mutability)),
             _ => None,
         }
@@ -183,7 +183,7 @@ impl Ty {
     pub fn strip_references(&self) -> &Ty {
         let mut t: &Ty = self;
 
-        while let TyKind::Ref(_mutability, ty) = t.kind(&Interner) {
+        while let TyKind::Ref(_mutability, _lifetime, ty) = t.kind(&Interner) {
             t = ty;
         }
 
@@ -495,3 +495,7 @@ pub fn to_chalk_trait_id(id: TraitId) -> ChalkTraitId {
 pub fn from_chalk_trait_id(id: ChalkTraitId) -> TraitId {
     salsa::InternKey::from_intern_id(id.0)
 }
+
+pub fn static_lifetime() -> Lifetime {
+    LifetimeData::Static.intern(&Interner)
+}
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 3cbb6ad54..df6619af3 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -27,7 +27,7 @@ use stdx::impl_from;
 
 use crate::{
     db::HirDatabase,
-    to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
+    static_lifetime, to_assoc_type_id, to_chalk_trait_id, to_placeholder_idx,
     traits::chalk::{Interner, ToChalk},
     utils::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
@@ -174,7 +174,9 @@ impl<'a> TyLoweringContext<'a> {
             }
             TypeRef::Reference(inner, _, mutability) => {
                 let inner_ty = self.lower_ty(inner);
-                TyKind::Ref(lower_to_chalk_mutability(*mutability), inner_ty).intern(&Interner)
+                let lifetime = static_lifetime();
+                TyKind::Ref(lower_to_chalk_mutability(*mutability), lifetime, inner_ty)
+                    .intern(&Interner)
             }
             TypeRef::Placeholder => TyKind::Error.intern(&Interner),
             TypeRef::Fn(params, is_varargs) => {
@@ -198,7 +200,7 @@ impl<'a> TyLoweringContext<'a> {
                     )
                 });
                 let bounds = crate::make_only_type_binders(1, bounds);
-                TyKind::Dyn(DynTy { bounds }).intern(&Interner)
+                TyKind::Dyn(DynTy { bounds, lifetime: static_lifetime() }).intern(&Interner)
             }
             TypeRef::ImplTrait(bounds) => {
                 match self.impl_trait_mode {
@@ -390,6 +392,7 @@ impl<'a> TyLoweringContext<'a> {
                                 ))),
                             ),
                         ),
+                        lifetime: static_lifetime(),
                     };
                     TyKind::Dyn(dyn_ty).intern(&Interner)
                 };
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 6d65d3eb9..436dea22b 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -19,6 +19,7 @@ use crate::{
     db::HirDatabase,
     from_foreign_def_id,
     primitive::{self, FloatTy, IntTy, UintTy},
+    static_lifetime,
     utils::all_super_traits,
     AdtId, Canonical, CanonicalVarKinds, DebruijnIndex, FnPointer, FnSig, ForeignDefId,
     InEnvironment, Interner, Scalar, Substitution, TraitEnvironment, Ty, TyBuilder, TyKind,
@@ -453,7 +454,8 @@ fn iterate_method_candidates_with_autoref(
     }
     let refed = Canonical {
         binders: deref_chain[0].binders.clone(),
-        value: TyKind::Ref(Mutability::Not, deref_chain[0].value.clone()).intern(&Interner),
+        value: TyKind::Ref(Mutability::Not, static_lifetime(), deref_chain[0].value.clone())
+            .intern(&Interner),
     };
     if iterate_method_candidates_by_receiver(
         &refed,
@@ -470,7 +472,8 @@ fn iterate_method_candidates_with_autoref(
     }
     let ref_muted = Canonical {
         binders: deref_chain[0].binders.clone(),
-        value: TyKind::Ref(Mutability::Mut, deref_chain[0].value.clone()).intern(&Interner),
+        value: TyKind::Ref(Mutability::Mut, static_lifetime(), deref_chain[0].value.clone())
+            .intern(&Interner),
     };
     if iterate_method_candidates_by_receiver(
         &ref_muted,
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 3047fbacb..9267e32b5 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -3,16 +3,16 @@
 //! Chalk (in both directions); plus some helper functions for more specialized
 //! conversions.
 
-use chalk_ir::{cast::Cast, interner::HasInterner, LifetimeData};
+use chalk_ir::{cast::Cast, interner::HasInterner};
 use chalk_solve::rust_ir;
 
 use base_db::salsa::InternKey;
 use hir_def::{GenericDefId, TypeAliasId};
 
 use crate::{
-    chalk_ext::ProjectionTyExt, db::HirDatabase, primitive::UintTy, AliasTy, CallableDefId,
-    Canonical, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy, ProjectionTy,
-    QuantifiedWhereClause, Scalar, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
+    chalk_ext::ProjectionTyExt, db::HirDatabase, primitive::UintTy, static_lifetime, AliasTy,
+    CallableDefId, Canonical, DomainGoal, FnPointer, GenericArg, InEnvironment, Lifetime, OpaqueTy,
+    ProjectionTy, QuantifiedWhereClause, Scalar, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
 };
 
 use super::interner::*;
@@ -22,7 +22,7 @@ impl ToChalk for Ty {
     type Chalk = chalk_ir::Ty<Interner>;
     fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
         match self.into_inner() {
-            TyKind::Ref(m, ty) => ref_to_chalk(db, m, ty),
+            TyKind::Ref(m, lt, ty) => ref_to_chalk(db, m, lt, ty),
             TyKind::Array(ty) => array_to_chalk(db, ty),
             TyKind::Function(FnPointer { sig, substitution: substs, .. }) => {
                 let substitution = chalk_ir::FnSubst(substs.0.to_chalk(db));
@@ -100,7 +100,7 @@ impl ToChalk for Ty {
                 );
                 let bounded_ty = chalk_ir::DynTy {
                     bounds: chalk_ir::Binders::new(binders, where_clauses),
-                    lifetime: LifetimeData::Static.intern(&Interner),
+                    lifetime: static_lifetime(),
                 };
                 chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
             }
@@ -149,6 +149,7 @@ impl ToChalk for Ty {
                         where_clauses.bounds.binders.clone(),
                         crate::QuantifiedWhereClauses::from_iter(&Interner, bounds),
                     ),
+                    lifetime: static_lifetime(),
                 })
             }
 
@@ -167,8 +168,8 @@ impl ToChalk for Ty {
             }
             chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)),
             chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)),
-            chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
-                TyKind::Ref(mutability, from_chalk(db, ty))
+            chalk_ir::TyKind::Ref(mutability, lifetime, ty) => {
+                TyKind::Ref(mutability, lifetime, from_chalk(db, ty))
             }
             chalk_ir::TyKind::Str => TyKind::Str,
             chalk_ir::TyKind::Never => TyKind::Never,
@@ -192,10 +193,11 @@ impl ToChalk for Ty {
 fn ref_to_chalk(
     db: &dyn HirDatabase,
     mutability: chalk_ir::Mutability,
+    _lifetime: Lifetime,
     ty: Ty,
 ) -> chalk_ir::Ty<Interner> {
     let arg = ty.to_chalk(db);
-    let lifetime = LifetimeData::Static.intern(&Interner);
+    let lifetime = static_lifetime();
     chalk_ir::TyKind::Ref(mutability, lifetime, arg).intern(&Interner)
 }
 
diff --git a/crates/hir_ty/src/types.rs b/crates/hir_ty/src/types.rs
index d4e07a6b8..844e57896 100644
--- a/crates/hir_ty/src/types.rs
+++ b/crates/hir_ty/src/types.rs
@@ -11,7 +11,8 @@ use smallvec::SmallVec;
 
 use crate::{
     AssocTypeId, CanonicalVarKinds, ChalkTraitId, ClosureId, FnDefId, FnSig, ForeignDefId,
-    InferenceVar, Interner, OpaqueTyId, PlaceholderIndex, TypeWalk, VariableKind, VariableKinds,
+    InferenceVar, Interner, Lifetime, OpaqueTyId, PlaceholderIndex, TypeWalk, VariableKind,
+    VariableKinds,
 };
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -39,6 +40,7 @@ impl ProjectionTy {
 pub struct DynTy {
     /// The unknown self type.
     pub bounds: Binders<QuantifiedWhereClauses>,
+    pub lifetime: Lifetime,
 }
 
 #[derive(Clone, PartialEq, Eq, Debug, Hash)]
@@ -122,7 +124,7 @@ pub enum TyKind {
 
     /// A reference; a pointer with an associated lifetime. Written as
     /// `&'a mut T` or `&'a T`.
-    Ref(Mutability, Ty),
+    Ref(Mutability, Lifetime, Ty),
 
     /// This represents a placeholder for an opaque type in situations where we
     /// don't know the hidden type (i.e. currently almost always). This is
diff --git a/crates/hir_ty/src/walk.rs b/crates/hir_ty/src/walk.rs
index e1e77ba37..4cc4e24fd 100644
--- a/crates/hir_ty/src/walk.rs
+++ b/crates/hir_ty/src/walk.rs
@@ -153,7 +153,7 @@ impl TypeWalk for Ty {
                     p.walk(f);
                 }
             }
-            TyKind::Slice(ty) | TyKind::Array(ty) | TyKind::Ref(_, ty) | TyKind::Raw(_, ty) => {
+            TyKind::Slice(ty) | TyKind::Array(ty) | TyKind::Ref(_, _, ty) | TyKind::Raw(_, ty) => {
                 ty.walk(f);
             }
             TyKind::Function(fn_pointer) => {
@@ -187,7 +187,7 @@ impl TypeWalk for Ty {
             TyKind::Alias(AliasTy::Opaque(o_ty)) => {
                 o_ty.substitution.walk_mut_binders(f, binders);
             }
-            TyKind::Slice(ty) | TyKind::Array(ty) | TyKind::Ref(_, ty) | TyKind::Raw(_, ty) => {
+            TyKind::Slice(ty) | TyKind::Array(ty) | TyKind::Ref(_, _, ty) | TyKind::Raw(_, ty) => {
                 ty.walk_mut_binders(f, binders);
             }
             TyKind::Function(fn_pointer) => {