Merge #4313

4313: refactor: use attrsOwner directly in is_cfg_enabled r=edwin0cheng a=bnjjj

As promised @edwin0cheng here is the PR to resolve the comment [here](https://github.com/rust-analyzer/rust-analyzer/pull/4285#discussion_r419200375).

Co-authored-by: Benjamin Coenen <[email protected]>

4 files changed, 15 insertions, 22 deletions

diff --git a/crates/ra_hir_def/src/adt.rs b/crates/ra_hir_def/src/adt.rs
index d0912ddaa..2bc34d449 100644
--- a/crates/ra_hir_def/src/adt.rs
+++ b/crates/ra_hir_def/src/adt.rs
@@ -118,11 +118,12 @@ fn lower_enum(
     module_id: ModuleId,
 ) {
     let expander = CfgExpander::new(db, ast.file_id, module_id.krate);
-    let variants =
-        ast.value.variant_list().into_iter().flat_map(|it| it.variants()).filter(|var| {
-            let attrs = expander.parse_attrs(var);
-            expander.is_cfg_enabled(&attrs)
-        });
+    let variants = ast
+        .value
+        .variant_list()
+        .into_iter()
+        .flat_map(|it| it.variants())
+        .filter(|var| expander.is_cfg_enabled(var));
     for var in variants {
         trace.alloc(
             || var.clone(),
@@ -215,8 +216,7 @@ fn lower_struct(
     match &ast.value {
         ast::StructKind::Tuple(fl) => {
             for (i, fd) in fl.fields().enumerate() {
-                let attrs = expander.parse_attrs(&fd);
-                if !expander.is_cfg_enabled(&attrs) {
+                if !expander.is_cfg_enabled(&fd) {
                     continue;
                 }
 
@@ -233,8 +233,7 @@ fn lower_struct(
         }
         ast::StructKind::Record(fl) => {
             for fd in fl.fields() {
-                let attrs = expander.parse_attrs(&fd);
-                if !expander.is_cfg_enabled(&attrs) {
+                if !expander.is_cfg_enabled(&fd) {
                     continue;
                 }
 
diff --git a/crates/ra_hir_def/src/body.rs b/crates/ra_hir_def/src/body.rs
index 4edaad960..f5a7305dc 100644
--- a/crates/ra_hir_def/src/body.rs
+++ b/crates/ra_hir_def/src/body.rs
@@ -60,7 +60,8 @@ impl CfgExpander {
         Attrs::new(owner, &self.hygiene)
     }
 
-    pub(crate) fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
+    pub(crate) fn is_cfg_enabled(&self, owner: &dyn ast::AttrsOwner) -> bool {
+        let attrs = self.parse_attrs(owner);
         attrs.is_cfg_enabled(&self.cfg_options)
     }
 }
@@ -141,12 +142,8 @@ impl Expander {
         InFile { file_id: self.current_file_id, value }
     }
 
-    pub(crate) fn parse_attrs(&self, owner: &dyn ast::AttrsOwner) -> Attrs {
-        self.cfg_expander.parse_attrs(owner)
-    }
-
-    pub(crate) fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
-        self.cfg_expander.is_cfg_enabled(attrs)
+    pub(crate) fn is_cfg_enabled(&self, owner: &dyn ast::AttrsOwner) -> bool {
+        self.cfg_expander.is_cfg_enabled(owner)
     }
 
     fn parse_path(&mut self, path: ast::Path) -> Option<Path> {
diff --git a/crates/ra_hir_def/src/body/lower.rs b/crates/ra_hir_def/src/body/lower.rs
index 687216dc3..8f5fa1b55 100644
--- a/crates/ra_hir_def/src/body/lower.rs
+++ b/crates/ra_hir_def/src/body/lower.rs
@@ -162,8 +162,7 @@ impl ExprCollector<'_> {
 
     fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
         let syntax_ptr = AstPtr::new(&expr);
-        let attrs = self.expander.parse_attrs(&expr);
-        if !self.expander.is_cfg_enabled(&attrs) {
+        if !self.expander.is_cfg_enabled(&expr) {
             return self.missing_expr();
         }
         match expr {
@@ -329,8 +328,7 @@ impl ExprCollector<'_> {
                         .fields()
                         .inspect(|field| field_ptrs.push(AstPtr::new(field)))
                         .filter_map(|field| {
-                            let attrs = self.expander.parse_attrs(&field);
-                            if !self.expander.is_cfg_enabled(&attrs) {
+                            if !self.expander.is_cfg_enabled(&field) {
                                 return None;
                             }
                             let name = field.field_name()?.as_name();
diff --git a/crates/ra_hir_def/src/data.rs b/crates/ra_hir_def/src/data.rs
index d4cba4d05..2dbae04d3 100644
--- a/crates/ra_hir_def/src/data.rs
+++ b/crates/ra_hir_def/src/data.rs
@@ -335,8 +335,7 @@ fn collect_items(
         .filter_map(|item_node| match item_node {
             ast::ImplItem::FnDef(it) => {
                 let name = it.name().map_or_else(Name::missing, |it| it.as_name());
-                let attrs = expander.parse_attrs(&it);
-                if !expander.is_cfg_enabled(&attrs) {
+                if !expander.is_cfg_enabled(&it) {
                     return None;
                 }
                 let def = FunctionLoc { container, ast_id: AstId::new(file_id, items.ast_id(&it)) }