From 1b650d0fea209e0b69407a0a1e04feeb57c4b2d4 Mon Sep 17 00:00:00 2001
From: marmeladema <xademax@gmail.com>
Date: Sun, 30 Aug 2020 11:48:50 +0100
Subject: [PATCH] datastructures: replace `lazy_static` by `SyncLazy` from std

---
 Cargo.lock                                    |  1 -
 compiler/rustc_data_structures/Cargo.toml     |  1 -
 .../rustc_data_structures/src/jobserver.rs    | 52 +++++++++----------
 3 files changed, 25 insertions(+), 29 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 3fe024ce318..c710bf164a8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3417,7 +3417,6 @@ dependencies = [
  "ena",
  "indexmap",
  "jobserver",
- "lazy_static",
  "libc",
  "measureme",
  "parking_lot 0.10.2",
diff --git a/compiler/rustc_data_structures/Cargo.toml b/compiler/rustc_data_structures/Cargo.toml
index 464f8c984dd..fcae9b936ed 100644
--- a/compiler/rustc_data_structures/Cargo.toml
+++ b/compiler/rustc_data_structures/Cargo.toml
@@ -12,7 +12,6 @@ ena = "0.14"
 indexmap = "1.5.1"
 tracing = "0.1"
 jobserver_crate = { version = "0.1.13", package = "jobserver" }
-lazy_static = "1"
 rustc_serialize = { path = "../rustc_serialize" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_graphviz = { path = "../rustc_graphviz" }
diff --git a/compiler/rustc_data_structures/src/jobserver.rs b/compiler/rustc_data_structures/src/jobserver.rs
index a811c88839d..41605afb44e 100644
--- a/compiler/rustc_data_structures/src/jobserver.rs
+++ b/compiler/rustc_data_structures/src/jobserver.rs
@@ -1,33 +1,31 @@
 pub use jobserver_crate::Client;
-use lazy_static::lazy_static;
+use std::lazy::SyncLazy;
 
-lazy_static! {
-    // We can only call `from_env` once per process
+// We can only call `from_env` once per process
 
-    // Note that this is unsafe because it may misinterpret file descriptors
-    // on Unix as jobserver file descriptors. We hopefully execute this near
-    // the beginning of the process though to ensure we don't get false
-    // positives, or in other words we try to execute this before we open
-    // any file descriptors ourselves.
-    //
-    // Pick a "reasonable maximum" if we don't otherwise have
-    // a jobserver in our environment, capping out at 32 so we
-    // don't take everything down by hogging the process run queue.
-    // The fixed number is used to have deterministic compilation
-    // across machines.
-    //
-    // Also note that we stick this in a global because there could be
-    // multiple rustc instances in this process, and the jobserver is
-    // per-process.
-    static ref GLOBAL_CLIENT: Client = unsafe {
-        Client::from_env().unwrap_or_else(|| {
-            let client = Client::new(32).expect("failed to create jobserver");
-            // Acquire a token for the main thread which we can release later
-            client.acquire_raw().ok();
-            client
-        })
-    };
-}
+// Note that this is unsafe because it may misinterpret file descriptors
+// on Unix as jobserver file descriptors. We hopefully execute this near
+// the beginning of the process though to ensure we don't get false
+// positives, or in other words we try to execute this before we open
+// any file descriptors ourselves.
+//
+// Pick a "reasonable maximum" if we don't otherwise have
+// a jobserver in our environment, capping out at 32 so we
+// don't take everything down by hogging the process run queue.
+// The fixed number is used to have deterministic compilation
+// across machines.
+//
+// Also note that we stick this in a global because there could be
+// multiple rustc instances in this process, and the jobserver is
+// per-process.
+static GLOBAL_CLIENT: SyncLazy<Client> = SyncLazy::new(|| unsafe {
+    Client::from_env().unwrap_or_else(|| {
+        let client = Client::new(32).expect("failed to create jobserver");
+        // Acquire a token for the main thread which we can release later
+        client.acquire_raw().ok();
+        client
+    })
+});
 
 pub fn client() -> Client {
     GLOBAL_CLIENT.clone()