From 67b8f9491c30cba0e4892f6b5b8bda8b312428da Mon Sep 17 00:00:00 2001
From: marmeladema <xademax@gmail.com>
Date: Tue, 1 Sep 2020 21:31:22 +0100
Subject: [PATCH] hir: replace `lazy_static` by `SyncLazy` from std

---
 Cargo.lock                                |  1 -
 compiler/rustc_hir/Cargo.toml             |  1 -
 compiler/rustc_hir/src/lang_items.rs      | 16 +++++++---------
 compiler/rustc_hir/src/lib.rs             |  1 +
 compiler/rustc_hir/src/weak_lang_items.rs | 14 ++++++--------
 5 files changed, 14 insertions(+), 19 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index c710bf164a8..3cc5aec6cac 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3530,7 +3530,6 @@ version = "0.0.0"
 name = "rustc_hir"
 version = "0.0.0"
 dependencies = [
- "lazy_static",
  "rustc_ast",
  "rustc_data_structures",
  "rustc_index",
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index ed295ff0058..b24c208c76a 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -15,6 +15,5 @@ rustc_index = { path = "../rustc_index" }
 rustc_span = { path = "../rustc_span" }
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_ast = { path = "../rustc_ast" }
-lazy_static = "1"
 tracing = "0.1"
 smallvec = { version = "1.0", features = ["union", "may_dangle"] }
diff --git a/compiler/rustc_hir/src/lang_items.rs b/compiler/rustc_hir/src/lang_items.rs
index acf6847c014..5e4c03bec83 100644
--- a/compiler/rustc_hir/src/lang_items.rs
+++ b/compiler/rustc_hir/src/lang_items.rs
@@ -17,7 +17,7 @@ use rustc_macros::HashStable_Generic;
 use rustc_span::symbol::{kw, sym, Symbol};
 use rustc_span::Span;
 
-use lazy_static::lazy_static;
+use std::lazy::SyncLazy;
 
 pub enum LangItemGroup {
     Op,
@@ -117,14 +117,12 @@ macro_rules! language_item_table {
             )*
         }
 
-        lazy_static! {
-            /// A mapping from the name of the lang item to its order and the form it must be of.
-            pub static ref ITEM_REFS: FxHashMap<Symbol, (usize, Target)> = {
-                let mut item_refs = FxHashMap::default();
-                $( item_refs.insert($name, (LangItem::$variant as usize, $target)); )*
-                item_refs
-            };
-        }
+        /// A mapping from the name of the lang item to its order and the form it must be of.
+        pub static ITEM_REFS: SyncLazy<FxHashMap<Symbol, (usize, Target)>> = SyncLazy::new(|| {
+            let mut item_refs = FxHashMap::default();
+            $( item_refs.insert($name, (LangItem::$variant as usize, $target)); )*
+            item_refs
+        });
 
 // End of the macro
     }
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index 19ea1de5683..c69a9b063ae 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -6,6 +6,7 @@
 #![feature(const_fn)] // For the unsizing cast on `&[]`
 #![feature(const_panic)]
 #![feature(in_band_lifetimes)]
+#![feature(once_cell)]
 #![feature(or_patterns)]
 #![recursion_limit = "256"]
 
diff --git a/compiler/rustc_hir/src/weak_lang_items.rs b/compiler/rustc_hir/src/weak_lang_items.rs
index 129eec7d29e..52f28bf8f4c 100644
--- a/compiler/rustc_hir/src/weak_lang_items.rs
+++ b/compiler/rustc_hir/src/weak_lang_items.rs
@@ -7,18 +7,16 @@ use rustc_ast as ast;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::symbol::{sym, Symbol};
 
-use lazy_static::lazy_static;
+use std::lazy::SyncLazy;
 
 macro_rules! weak_lang_items {
     ($($name:ident, $item:ident, $sym:ident;)*) => (
 
-lazy_static! {
-    pub static ref WEAK_ITEMS_REFS: FxHashMap<Symbol, LangItem> = {
-        let mut map = FxHashMap::default();
-        $(map.insert(sym::$name, LangItem::$item);)*
-        map
-    };
-}
+pub static WEAK_ITEMS_REFS: SyncLazy<FxHashMap<Symbol, LangItem>> = SyncLazy::new(|| {
+    let mut map = FxHashMap::default();
+    $(map.insert(sym::$name, LangItem::$item);)*
+    map
+});
 
 /// The `check_name` argument avoids the need for `librustc_hir` to depend on
 /// `librustc_session`.