From e42f9627664cc3c44094e1c4f985270fbfd592b1 Mon Sep 17 00:00:00 2001
From: Aleksey Kladov <aleksey.kladov@gmail.com>
Date: Fri, 22 Nov 2019 11:27:47 +0300
Subject: Encapsulate Attrs

---
 crates/ra_hir_def/src/attr.rs              | 36 +++++++++++++++++++++++++-----
 crates/ra_hir_def/src/nameres/collector.rs | 20 +++++++----------
 crates/ra_hir_def/src/nameres/raw.rs       | 18 ++++++---------
 3 files changed, 45 insertions(+), 29 deletions(-)

(limited to 'crates/ra_hir_def/src')

diff --git a/crates/ra_hir_def/src/attr.rs b/crates/ra_hir_def/src/attr.rs
index 0e961ca12..7a9d0fdf4 100644
--- a/crates/ra_hir_def/src/attr.rs
+++ b/crates/ra_hir_def/src/attr.rs
@@ -1,6 +1,6 @@
 //! A higher level attributes based on TokenTree, with also some shortcuts.
 
-use std::sync::Arc;
+use std::{ops, sync::Arc};
 
 use hir_expand::hygiene::Hygiene;
 use mbe::ast_to_token_tree;
@@ -13,6 +13,28 @@ use tt::Subtree;
 
 use crate::path::Path;
 
+#[derive(Default, Debug, Clone, PartialEq, Eq)]
+pub struct Attrs {
+    entries: Option<Arc<[Attr]>>,
+}
+
+impl ops::Deref for Attrs {
+    type Target = [Attr];
+
+    fn deref(&self) -> &[Attr] {
+        match &self.entries {
+            Some(it) => &*it,
+            None => &[],
+        }
+    }
+}
+
+impl Attrs {
+    pub fn has_atom(&self, atom: &str) -> bool {
+        self.iter().any(|it| it.is_simple_atom(atom))
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Attr {
     pub(crate) path: Path,
@@ -43,13 +65,15 @@ impl Attr {
         Some(Attr { path, input })
     }
 
-    pub fn from_attrs_owner(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Option<Arc<[Attr]>> {
+    pub fn from_attrs_owner(owner: &dyn AttrsOwner, hygiene: &Hygiene) -> Attrs {
         let mut attrs = owner.attrs().peekable();
-        if attrs.peek().is_none() {
+        let entries = if attrs.peek().is_none() {
             // Avoid heap allocation
-            return None;
-        }
-        Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+            None
+        } else {
+            Some(attrs.flat_map(|ast| Attr::from_src(ast, hygiene)).collect())
+        };
+        Attrs { entries }
     }
 
     pub fn is_simple_atom(&self, name: &str) -> bool {
diff --git a/crates/ra_hir_def/src/nameres/collector.rs b/crates/ra_hir_def/src/nameres/collector.rs
index aae3dcadf..7902293e8 100644
--- a/crates/ra_hir_def/src/nameres/collector.rs
+++ b/crates/ra_hir_def/src/nameres/collector.rs
@@ -12,7 +12,7 @@ use rustc_hash::FxHashMap;
 use test_utils::tested_by;
 
 use crate::{
-    attr::Attr,
+    attr::Attrs,
     db::DefDatabase2,
     nameres::{
         diagnostics::DefDiagnostic, mod_resolution::ModDir, path_resolution::ReachedFixedPoint,
@@ -549,7 +549,7 @@ where
         // `#[macro_use] extern crate` is hoisted to imports macros before collecting
         // any other items.
         for item in items {
-            if self.is_cfg_enabled(item.attrs()) {
+            if self.is_cfg_enabled(&item.attrs) {
                 if let raw::RawItemKind::Import(import_id) = item.kind {
                     let import = self.raw_items[import_id].clone();
                     if import.is_extern_crate && import.is_macro_use {
@@ -560,10 +560,10 @@ where
         }
 
         for item in items {
-            if self.is_cfg_enabled(item.attrs()) {
+            if self.is_cfg_enabled(&item.attrs) {
                 match item.kind {
                     raw::RawItemKind::Module(m) => {
-                        self.collect_module(&self.raw_items[m], item.attrs())
+                        self.collect_module(&self.raw_items[m], &item.attrs)
                     }
                     raw::RawItemKind::Import(import_id) => self
                         .def_collector
@@ -585,9 +585,9 @@ where
         }
     }
 
-    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &[Attr]) {
+    fn collect_module(&mut self, module: &raw::ModuleData, attrs: &Attrs) {
         let path_attr = self.path_attr(attrs);
-        let is_macro_use = self.is_macro_use(attrs);
+        let is_macro_use = attrs.has_atom("macro_use");
         match module {
             // inline module, just recurse
             raw::ModuleData::Definition { name, items, ast_id } => {
@@ -779,17 +779,13 @@ where
         }
     }
 
-    fn is_cfg_enabled(&self, attrs: &[Attr]) -> bool {
+    fn is_cfg_enabled(&self, attrs: &Attrs) -> bool {
         attrs.iter().all(|attr| attr.is_cfg_enabled(&self.def_collector.cfg_options) != Some(false))
     }
 
-    fn path_attr<'a>(&self, attrs: &'a [Attr]) -> Option<&'a SmolStr> {
+    fn path_attr<'a>(&self, attrs: &'a Attrs) -> Option<&'a SmolStr> {
         attrs.iter().find_map(|attr| attr.as_path())
     }
-
-    fn is_macro_use<'a>(&self, attrs: &'a [Attr]) -> bool {
-        attrs.iter().any(|attr| attr.is_simple_atom("macro_use"))
-    }
 }
 
 fn is_macro_rules(path: &Path) -> bool {
diff --git a/crates/ra_hir_def/src/nameres/raw.rs b/crates/ra_hir_def/src/nameres/raw.rs
index 7c68fd638..55a9634f8 100644
--- a/crates/ra_hir_def/src/nameres/raw.rs
+++ b/crates/ra_hir_def/src/nameres/raw.rs
@@ -16,7 +16,12 @@ use ra_syntax::{
 };
 use test_utils::tested_by;
 
-use crate::{attr::Attr, db::DefDatabase2, path::Path, FileAstId, HirFileId, ModuleSource, Source};
+use crate::{
+    attr::{Attr, Attrs},
+    db::DefDatabase2,
+    path::Path,
+    FileAstId, HirFileId, ModuleSource, Source,
+};
 
 /// `RawItems` is a set of top-level items in a file (except for impls).
 ///
@@ -129,21 +134,12 @@ impl Index<Impl> for RawItems {
     }
 }
 
-// Avoid heap allocation on items without attributes.
-type Attrs = Option<Arc<[Attr]>>;
-
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub(super) struct RawItem {
-    attrs: Attrs,
+    pub(super) attrs: Attrs,
     pub(super) kind: RawItemKind,
 }
 
-impl RawItem {
-    pub(super) fn attrs(&self) -> &[Attr] {
-        self.attrs.as_ref().map_or(&[], |it| &*it)
-    }
-}
-
 #[derive(Debug, PartialEq, Eq, Clone, Copy)]
 pub(super) enum RawItemKind {
     Module(Module),
-- 
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