4 files changed, 84 insertions, 31 deletions

diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index ec6a10353..22bbad964 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -11,7 +11,7 @@ use ra_syntax::{
 
 use crate::{
     Name, AsName, Struct, Enum, EnumVariant, Crate,
-    HirDatabase, HirFileId,
+    HirDatabase, HirFileId, StructField, FieldSource,
     type_ref::TypeRef,
 };
 
@@ -150,7 +150,7 @@ impl VariantData {
 impl VariantData {
     fn new(flavor: StructFlavor) -> Self {
         let inner = match flavor {
-            StructFlavor::Tuple(fl) => {
+            ast::StructFlavor::Tuple(fl) => {
                 let fields = fl
                     .fields()
                     .enumerate()
@@ -161,7 +161,7 @@ impl VariantData {
                     .collect();
                 VariantDataInner::Tuple(fields)
             }
-            StructFlavor::Named(fl) => {
+            ast::StructFlavor::Named(fl) => {
                 let fields = fl
                     .fields()
                     .map(|fd| StructFieldData {
@@ -171,8 +171,70 @@ impl VariantData {
                     .collect();
                 VariantDataInner::Struct(fields)
             }
-            StructFlavor::Unit => VariantDataInner::Unit,
+            ast::StructFlavor::Unit => VariantDataInner::Unit,
         };
         VariantData(inner)
     }
 }
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
+pub enum VariantDef {
+    Struct(Struct),
+    EnumVariant(EnumVariant),
+}
+impl_froms!(VariantDef: Struct, EnumVariant);
+
+impl VariantDef {
+    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),
+        }
+    }
+    pub(crate) fn variant_data(self, db: &impl HirDatabase) -> Arc<VariantData> {
+        match self {
+            VariantDef::Struct(it) => it.variant_data(db),
+            VariantDef::EnumVariant(it) => it.variant_data(db),
+        }
+    }
+}
+
+impl StructField {
+    pub(crate) fn source_impl(&self, db: &impl HirDatabase) -> (HirFileId, FieldSource) {
+        let var_data = self.parent.variant_data(db);
+        let fields = var_data.fields().unwrap();
+        let ss;
+        let es;
+        let (file_id, struct_flavor) = match self.parent {
+            VariantDef::Struct(s) => {
+                let (file_id, source) = s.source(db);
+                ss = source;
+                (file_id, ss.flavor())
+            }
+            VariantDef::EnumVariant(e) => {
+                let (file_id, source) = e.source(db);
+                es = source;
+                (file_id, es.flavor())
+            }
+        };
+
+        let field_sources = match struct_flavor {
+            ast::StructFlavor::Tuple(fl) => fl
+                .fields()
+                .map(|it| FieldSource::Pos(it.to_owned()))
+                .collect(),
+            ast::StructFlavor::Named(fl) => fl
+                .fields()
+                .map(|it| FieldSource::Named(it.to_owned()))
+                .collect(),
+            ast::StructFlavor::Unit => Vec::new(),
+        };
+        let field = field_sources
+            .into_iter()
+            .zip(fields.iter())
+            .find(|(_syntax, (id, _))| *id == self.id)
+            .unwrap()
+            .0;
+        (file_id, field)
+    }
+}
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 118562984..fdea5be57 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -10,8 +10,8 @@ use crate::{
     nameres::{ModuleScope, lower::ImportId},
     db::HirDatabase,
     expr::BodySyntaxMapping,
-    ty::{InferenceResult, VariantDef},
-    adt::{EnumVariantId, StructFieldId},
+    ty::InferenceResult,
+    adt::{EnumVariantId, StructFieldId, VariantDef},
     generics::GenericParams,
     docs::{Documentation, Docs, docs_from_ast},
     module_tree::ModuleId,
@@ -179,10 +179,16 @@ impl Module {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct StructField {
-    parent: VariantDef,
+    pub(crate) parent: VariantDef,
     pub(crate) id: StructFieldId,
 }
 
+#[derive(Debug)]
+pub enum FieldSource {
+    Named(TreeArc<ast::NamedFieldDef>),
+    Pos(TreeArc<ast::PosField>),
+}
+
 impl StructField {
     pub fn name(&self, db: &impl HirDatabase) -> Name {
         self.parent.variant_data(db).fields().unwrap()[self.id]
@@ -190,6 +196,10 @@ impl StructField {
             .clone()
     }
 
+    pub fn source(&self, db: &impl HirDatabase) -> (HirFileId, FieldSource) {
+        self.source_impl(db)
+    }
+
     pub fn ty(&self, db: &impl HirDatabase) -> Ty {
         db.type_for_field(*self)
     }
diff --git a/crates/ra_hir/src/lib.rs b/crates/ra_hir/src/lib.rs
index 596f9c38c..eaf8565ee 100644
--- a/crates/ra_hir/src/lib.rs
+++ b/crates/ra_hir/src/lib.rs
@@ -68,7 +68,7 @@ pub use self::code_model_api::{
     Module, ModuleDef, ModuleSource, Problem,
     Struct, Enum, EnumVariant,
     Function, FnSignature, ScopeEntryWithSyntax,
-    StructField,
+    StructField, FieldSource,
     Static, Const,
     Trait, Type,
 };
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 97a876da8..714eaaae5 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -38,7 +38,7 @@ use crate::{
     expr::{Body, Expr, BindingAnnotation, Literal, ExprId, Pat, PatId, UnaryOp, BinaryOp, Statement, FieldPat},
     generics::GenericParams,
     path::GenericArg,
-    adt::VariantData,
+    adt::VariantDef,
 };
 
 /// The ID of a type variable.
@@ -696,28 +696,6 @@ pub(super) fn type_for_def(db: &impl HirDatabase, def: TypableDef) -> Ty {
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
-pub enum VariantDef {
-    Struct(Struct),
-    EnumVariant(EnumVariant),
-}
-impl_froms!(VariantDef: Struct, EnumVariant);
-
-impl VariantDef {
-    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),
-        }
-    }
-    pub(crate) fn variant_data(self, db: &impl HirDatabase) -> Arc<VariantData> {
-        match self {
-            VariantDef::Struct(it) => it.variant_data(db),
-            VariantDef::EnumVariant(it) => it.variant_data(db),
-        }
-    }
-}
-
 pub(super) fn type_for_field(db: &impl HirDatabase, field: StructField) -> Ty {
     let parent_def = field.parent_def(db);
     let (generics, module) = match parent_def {
@@ -744,6 +722,9 @@ impl InferenceResult {
     pub fn method_resolution(&self, expr: ExprId) -> Option<Function> {
         self.method_resolutions.get(&expr).map(|it| *it)
     }
+    pub fn field_resolution(&self, expr: ExprId) -> Option<StructField> {
+        self.field_resolutions.get(&expr).map(|it| *it)
+    }
 }
 
 impl Index<ExprId> for InferenceResult {