Merge #7115

7115: Migrate HasSource::source to return Option r=matklad a=nick96

I've made a start on fixing #6913 based on the provided work plan, migrating `HasSource::source` to return an `Option`. The simple cases are migrated but there are a few that I'm unsure exactly how they should be handled:

- Logging the processing of functions in `AnalysisStatsCmd::run`: In verbose mode it includes the path to the module containing the function and the syntax range. I've handled this with an if-let but would it be better to blow up here with `expect`? I'm not 100% on the code paths but if we're processing a function definition then the source should exist.

I've handled `source()` in all code paths as `None` being a valid return value but are there some cases where we should just blow up? Also, all I've done is bubble up the returned `None`s, there may be some places where we can recover and still provide something.

Co-authored-by: Nick Spain <[email protected]>
Co-authored-by: Nick Spain <[email protected]>

2 files changed, 36 insertions, 43 deletions

diff --git a/crates/hir/src/code_model.rs b/crates/hir/src/code_model.rs
index 97b7a8b5f..3c83231cf 100644
--- a/crates/hir/src/code_model.rs
+++ b/crates/hir/src/code_model.rs
@@ -983,13 +983,7 @@ impl MacroDef {
 
     /// XXX: this parses the file
     pub fn name(self, db: &dyn HirDatabase) -> Option<Name> {
-        // FIXME: Currently proc-macro do not have ast-node,
-        // such that it does not have source
-        // more discussion: https://github.com/rust-analyzer/rust-analyzer/issues/6913
-        if self.is_proc_macro() {
-            return None;
-        }
-        self.source(db).value.name().map(|it| it.as_name())
+        self.source(db)?.value.name().map(|it| it.as_name())
     }
 
     /// Indicate it is a proc-macro
@@ -1378,7 +1372,7 @@ impl Impl {
     }
 
     pub fn is_builtin_derive(self, db: &dyn HirDatabase) -> Option<InFile<ast::Attr>> {
-        let src = self.source(db);
+        let src = self.source(db)?;
         let item = src.file_id.is_builtin_derive(db.upcast())?;
         let hygenic = hir_expand::hygiene::Hygiene::new(db.upcast(), item.file_id);
 
diff --git a/crates/hir/src/has_source.rs b/crates/hir/src/has_source.rs
index dd7c0c570..7c57d8378 100644
--- a/crates/hir/src/has_source.rs
+++ b/crates/hir/src/has_source.rs
@@ -16,7 +16,7 @@ use crate::{
 
 pub trait HasSource {
     type Ast;
-    fn source(self, db: &dyn HirDatabase) -> InFile<Self::Ast>;
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>>;
 }
 
 /// NB: Module is !HasSource, because it has two source nodes at the same time:
@@ -46,105 +46,104 @@ impl Module {
 
 impl HasSource for Field {
     type Ast = FieldSource;
-    fn source(self, db: &dyn HirDatabase) -> InFile<FieldSource> {
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
         let var = VariantId::from(self.parent);
         let src = var.child_source(db.upcast());
-        src.map(|it| match it[self.id].clone() {
+        let field_source = src.map(|it| match it[self.id].clone() {
             Either::Left(it) => FieldSource::Pos(it),
             Either::Right(it) => FieldSource::Named(it),
-        })
+        });
+        Some(field_source)
     }
 }
 impl HasSource for Struct {
     type Ast = ast::Struct;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Struct> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Union {
     type Ast = ast::Union;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Union> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Enum {
     type Ast = ast::Enum;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Enum> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Variant {
     type Ast = ast::Variant;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Variant> {
-        self.parent.id.child_source(db.upcast()).map(|map| map[self.id].clone())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<ast::Variant>> {
+        Some(self.parent.id.child_source(db.upcast()).map(|map| map[self.id].clone()))
     }
 }
 impl HasSource for Function {
     type Ast = ast::Fn;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Fn> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Const {
     type Ast = ast::Const;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Const> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Static {
     type Ast = ast::Static;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Static> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for Trait {
     type Ast = ast::Trait;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Trait> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for TypeAlias {
     type Ast = ast::TypeAlias;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::TypeAlias> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 impl HasSource for MacroDef {
     type Ast = ast::Macro;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Macro> {
-        InFile {
-            file_id: self.id.ast_id.expect("MacroDef without ast_id").file_id,
-            value: self.id.ast_id.expect("MacroDef without ast_id").to_node(db.upcast()),
-        }
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        let ast_id = self.id.ast_id?;
+        Some(InFile { file_id: ast_id.file_id, value: ast_id.to_node(db.upcast()) })
     }
 }
 impl HasSource for Impl {
     type Ast = ast::Impl;
-    fn source(self, db: &dyn HirDatabase) -> InFile<ast::Impl> {
-        self.id.lookup(db.upcast()).source(db.upcast())
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
+        Some(self.id.lookup(db.upcast()).source(db.upcast()))
     }
 }
 
 impl HasSource for TypeParam {
     type Ast = Either<ast::Trait, ast::TypeParam>;
-    fn source(self, db: &dyn HirDatabase) -> InFile<Self::Ast> {
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
         let child_source = self.id.parent.child_source(db.upcast());
-        child_source.map(|it| it[self.id.local_id].clone())
+        Some(child_source.map(|it| it[self.id.local_id].clone()))
     }
 }
 
 impl HasSource for LifetimeParam {
     type Ast = ast::LifetimeParam;
-    fn source(self, db: &dyn HirDatabase) -> InFile<Self::Ast> {
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
         let child_source = self.id.parent.child_source(db.upcast());
-        child_source.map(|it| it[self.id.local_id].clone())
+        Some(child_source.map(|it| it[self.id.local_id].clone()))
     }
 }
 
 impl HasSource for ConstParam {
     type Ast = ast::ConstParam;
-    fn source(self, db: &dyn HirDatabase) -> InFile<Self::Ast> {
+    fn source(self, db: &dyn HirDatabase) -> Option<InFile<Self::Ast>> {
         let child_source = self.id.parent.child_source(db.upcast());
-        child_source.map(|it| it[self.id.local_id].clone())
+        Some(child_source.map(|it| it[self.id.local_id].clone()))
     }
 }