Don't redo field resolution in the IDE

4 files changed, 26 insertions, 14 deletions

diff --git a/crates/ra_hir/src/code_model.rs b/crates/ra_hir/src/code_model.rs
index 9f06b147c..a98f2f247 100644
--- a/crates/ra_hir/src/code_model.rs
+++ b/crates/ra_hir/src/code_model.rs
@@ -510,7 +510,7 @@ impl VariantDef {
         }
     }
 
-    pub fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
+    pub(crate) fn field(self, db: &impl HirDatabase, name: &Name) -> Option<StructField> {
         match self {
             VariantDef::Struct(it) => it.field(db, name),
             VariantDef::EnumVariant(it) => it.field(db, name),
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index cfc4bd326..9e5ce5508 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -216,6 +216,11 @@ impl SourceAnalyzer {
         self.infer.as_ref()?.field_resolution(expr_id)
     }
 
+    pub fn resolve_record_field(&self, field: &ast::RecordField) -> Option<crate::StructField> {
+        let expr_id = self.expr_id(&field.expr()?)?;
+        self.infer.as_ref()?.record_field_resolution(expr_id)
+    }
+
     pub fn resolve_record_literal(&self, record_lit: &ast::RecordLit) -> Option<crate::VariantDef> {
         let expr_id = self.expr_id(&record_lit.clone().into())?;
         self.infer.as_ref()?.variant_resolution_for_expr(expr_id)
diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index 2e744e5ec..0a9a83800 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -126,6 +126,8 @@ pub struct InferenceResult {
     method_resolutions: FxHashMap<ExprId, Function>,
     /// For each field access expr, records the field it resolves to.
     field_resolutions: FxHashMap<ExprId, StructField>,
+    /// For each field in record literal, records the field it resolves to.
+    record_field_resolutions: FxHashMap<ExprId, StructField>,
     /// For each struct literal, records the variant it resolves to.
     variant_resolutions: FxHashMap<ExprOrPatId, VariantDef>,
     /// For each associated item record what it resolves to
@@ -143,6 +145,9 @@ impl InferenceResult {
     pub fn field_resolution(&self, expr: ExprId) -> Option<StructField> {
         self.field_resolutions.get(&expr).copied()
     }
+    pub fn record_field_resolution(&self, expr: ExprId) -> Option<StructField> {
+        self.record_field_resolutions.get(&expr).copied()
+    }
     pub fn variant_resolution_for_expr(&self, id: ExprId) -> Option<VariantDef> {
         self.variant_resolutions.get(&id.into()).copied()
     }
diff --git a/crates/ra_hir/src/ty/infer/expr.rs b/crates/ra_hir/src/ty/infer/expr.rs
index 20a7e9352..2996920c6 100644
--- a/crates/ra_hir/src/ty/infer/expr.rs
+++ b/crates/ra_hir/src/ty/infer/expr.rs
@@ -215,19 +215,21 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
 
                 let substs = ty.substs().unwrap_or_else(Substs::empty);
                 for (field_idx, field) in fields.iter().enumerate() {
-                    let field_ty = def_id
-                        .and_then(|it| match it.field(self.db, &field.name) {
-                            Some(field) => Some(field),
-                            None => {
-                                self.push_diagnostic(InferenceDiagnostic::NoSuchField {
-                                    expr: tgt_expr,
-                                    field: field_idx,
-                                });
-                                None
-                            }
-                        })
-                        .map_or(Ty::Unknown, |field| field.ty(self.db))
-                        .subst(&substs);
+                    let field_def = def_id.and_then(|it| match it.field(self.db, &field.name) {
+                        Some(field) => Some(field),
+                        None => {
+                            self.push_diagnostic(InferenceDiagnostic::NoSuchField {
+                                expr: tgt_expr,
+                                field: field_idx,
+                            });
+                            None
+                        }
+                    });
+                    if let Some(field_def) = field_def {
+                        self.result.record_field_resolutions.insert(field.expr, field_def);
+                    }
+                    let field_ty =
+                        field_def.map_or(Ty::Unknown, |field| field.ty(self.db)).subst(&substs);
                     self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty));
                 }
                 if let Some(expr) = spread {