minor: Remove frequent Arc<Body> clones in type checking

Veykril · Veykril · commit e5bf60fee2de · 2022-04-15T21:44:47.000+02:00
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
@@ -59,7 +59,8 @@ mod closure;
 pub(crate) fn infer_query(db: &dyn HirDatabase, def: DefWithBodyId) -> Arc<InferenceResult> {
     let _p = profile::span("infer_query");
     let resolver = def.resolver(db.upcast());
-    let mut ctx = InferenceContext::new(db, def, resolver);
+    let body = db.body(def);
+    let mut ctx = InferenceContext::new(db, def, &body, resolver);
 
     match def {
         DefWithBodyId::ConstId(c) => ctx.collect_const(&db.const_data(c)),
@@ -360,7 +361,7 @@ impl Index<PatId> for InferenceResult {
 pub(crate) struct InferenceContext<'a> {
     pub(crate) db: &'a dyn HirDatabase,
     pub(crate) owner: DefWithBodyId,
-    pub(crate) body: Arc<Body>,
+    pub(crate) body: &'a Body,
     pub(crate) resolver: Resolver,
     table: unify::InferenceTable<'a>,
     trait_env: Arc<TraitEnvironment>,
@@ -394,7 +395,12 @@ fn find_breakable<'c>(
 }
 
 impl<'a> InferenceContext<'a> {
-    fn new(db: &'a dyn HirDatabase, owner: DefWithBodyId, resolver: Resolver) -> Self {
+    fn new(
+        db: &'a dyn HirDatabase,
+        owner: DefWithBodyId,
+        body: &'a Body,
+        resolver: Resolver,
+    ) -> Self {
         let krate = owner.module(db.upcast()).krate();
         let trait_env = owner
             .as_generic_def_id()
@@ -406,7 +412,7 @@ impl<'a> InferenceContext<'a> {
             return_ty: TyKind::Error.intern(Interner), // set in collect_fn_signature
             db,
             owner,
-            body: db.body(owner),
+            body,
             resolver,
             diverges: Diverges::Maybe,
             breakables: Vec::new(),
@@ -452,12 +458,11 @@ impl<'a> InferenceContext<'a> {
     }
 
     fn collect_fn(&mut self, data: &FunctionData) {
-        let body = Arc::clone(&self.body); // avoid borrow checker problem
         let ctx = crate::lower::TyLoweringContext::new(self.db, &self.resolver)
             .with_impl_trait_mode(ImplTraitLoweringMode::Param);
         let param_tys =
             data.params.iter().map(|(_, type_ref)| ctx.lower_ty(type_ref)).collect::<Vec<_>>();
-        for (ty, pat) in param_tys.into_iter().zip(body.params.iter()) {
+        for (ty, pat) in param_tys.into_iter().zip(self.body.params.iter()) {
             let ty = self.insert_type_vars(ty);
             let ty = self.normalize_associated_types_in(ty);
 
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
@@ -4,7 +4,6 @@ use std::{
     collections::hash_map::Entry,
     iter::{repeat, repeat_with},
     mem,
-    sync::Arc,
 };
 
 use chalk_ir::{
@@ -80,8 +79,7 @@ impl<'a> InferenceContext<'a> {
     fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty {
         self.db.unwind_if_cancelled();
 
-        let body = Arc::clone(&self.body); // avoid borrow checker problem
-        let ty = match &body[tgt_expr] {
+        let ty = match &self.body[tgt_expr] {
             Expr::Missing => self.err_ty(),
             &Expr::If { condition, then_branch, else_branch } => {
                 self.infer_expr(
@@ -560,17 +558,7 @@ impl<'a> InferenceContext<'a> {
                 }
                 .intern(Interner)
             }
-            Expr::Box { expr } => {
-                let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
-                if let Some(box_) = self.resolve_boxed_box() {
-                    TyBuilder::adt(self.db, box_)
-                        .push(inner_ty)
-                        .fill_with_defaults(self.db, || self.table.new_type_var())
-                        .build()
-                } else {
-                    self.err_ty()
-                }
-            }
+            &Expr::Box { expr } => self.infer_expr_box(expr),
             Expr::UnaryOp { expr, op } => {
                 let inner_ty = self.infer_expr_inner(*expr, &Expectation::none());
                 let inner_ty = self.resolve_ty_shallow(&inner_ty);
@@ -798,6 +786,18 @@ impl<'a> InferenceContext<'a> {
         ty
     }
 
+    fn infer_expr_box(&mut self, inner_expr: ExprId) -> chalk_ir::Ty<Interner> {
+        let inner_ty = self.infer_expr_inner(inner_expr, &Expectation::none());
+        if let Some(box_) = self.resolve_boxed_box() {
+            TyBuilder::adt(self.db, box_)
+                .push(inner_ty)
+                .fill_with_defaults(self.db, || self.table.new_type_var())
+                .build()
+        } else {
+            self.err_ty()
+        }
+    }
+
     fn infer_overloadable_binop(
         &mut self,
         lhs: ExprId,
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
@@ -1,6 +1,6 @@
 //! Type inference for patterns.
 
-use std::{iter::repeat, sync::Arc};
+use std::iter::repeat;
 
 use chalk_ir::Mutability;
 use hir_def::{
@@ -100,10 +100,9 @@ impl<'a> InferenceContext<'a> {
         expected: &Ty,
         mut default_bm: BindingMode,
     ) -> Ty {
-        let body = Arc::clone(&self.body); // avoid borrow checker problem
         let mut expected = self.resolve_ty_shallow(expected);
 
-        if is_non_ref_pat(&body, pat) {
+        if is_non_ref_pat(&self.body, pat) {
             let mut pat_adjustments = Vec::new();
             while let Some((inner, _lifetime, mutability)) = expected.as_reference() {
                 pat_adjustments.push(Adjustment {
@@ -122,7 +121,7 @@ impl<'a> InferenceContext<'a> {
                 pat_adjustments.shrink_to_fit();
                 self.result.pat_adjustments.insert(pat, pat_adjustments);
             }
-        } else if let Pat::Ref { .. } = &body[pat] {
+        } else if let Pat::Ref { .. } = &self.body[pat] {
             cov_mark::hit!(match_ergonomics_ref);
             // When you encounter a `&pat` pattern, reset to Move.
             // This is so that `w` is by value: `let (_, &w) = &(1, &2);`
@@ -133,7 +132,7 @@ impl<'a> InferenceContext<'a> {
         let default_bm = default_bm;
         let expected = expected;
 
-        let ty = match &body[pat] {
+        let ty = match &self.body[pat] {
             Pat::Tuple { args, ellipsis } => {
                 let expectations = match expected.as_tuple() {
                     Some(parameters) => &*parameters.as_slice(Interner),
