driver: replace lazy_static by SyncLazy from std

Cargo.lock

@@ -3439,7 +3439,6 @@ dependencies = [
 name = "rustc_driver"
 version = "0.0.0"
 dependencies = [
- "lazy_static",
  "libc",
  "rustc_ast",
  "rustc_ast_pretty",

compiler/rustc_driver/Cargo.toml

@@ -8,7 +8,6 @@ edition = "2018"
 crate-type = ["dylib"]
 
 [dependencies]
-lazy_static = "1.0"
 libc = "0.2"
 tracing = { version = "0.1.18", features = ["release_max_level_info"]  }
 tracing-subscriber = { version = "0.2.10", default-features = false, features = ["fmt", "env-filter", "smallvec", "parking_lot", "ansi"] }

compiler/rustc_driver/src/lib.rs

@@ -11,8 +11,6 @@
 
 #[macro_use]
 extern crate tracing;
-#[macro_use]
-extern crate lazy_static;
 
 pub extern crate rustc_plugin_impl as plugin;
 
@@ -49,6 +47,7 @@
 use std::ffi::OsString;
 use std::fs;
 use std::io::{self, Read, Write};
+use std::lazy::SyncLazy;
 use std::mem;
 use std::panic::{self, catch_unwind};
 use std::path::PathBuf;
@@ -1142,13 +1141,12 @@ pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
     }
 }
 
-lazy_static! {
-    static ref DEFAULT_HOOK: Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static> = {
+static DEFAULT_HOOK: SyncLazy<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
+    SyncLazy::new(|| {
         let hook = panic::take_hook();
         panic::set_hook(Box::new(|info| report_ice(info, BUG_REPORT_URL)));
         hook
-    };
-}
+    });
 
 /// Prints the ICE message, including backtrace and query stack.
 ///
@@ -1223,7 +1221,7 @@ pub fn report_ice(info: &panic::PanicInfo<'_>, bug_report_url: &str) {
 ///
 /// A custom rustc driver can skip calling this to set up a custom ICE hook.
 pub fn install_ice_hook() {
-    lazy_static::initialize(&DEFAULT_HOOK);
+    SyncLazy::force(&DEFAULT_HOOK);
 }
 
 /// This allows tools to enable rust logging without having to magically match rustc's

compiler/rustc_feature/src/builtin_attrs.rs

@@ -590,12 +590,13 @@ pub fn is_builtin_attr_name(name: Symbol) -> bool {
     BUILTIN_ATTRIBUTE_MAP.get(&name).is_some()
 }
 
-pub static BUILTIN_ATTRIBUTE_MAP: SyncLazy<FxHashMap<Symbol, &'static BuiltinAttribute>> = SyncLazy::new(|| {
-    let mut map = FxHashMap::default();
-    for attr in BUILTIN_ATTRIBUTES.iter() {
-        if map.insert(attr.0, attr).is_some() {
-            panic!("duplicate builtin attribute `{}`", attr.0);
+pub static BUILTIN_ATTRIBUTE_MAP: SyncLazy<FxHashMap<Symbol, &'static BuiltinAttribute>> =
+    SyncLazy::new(|| {
+        let mut map = FxHashMap::default();
+        for attr in BUILTIN_ATTRIBUTES.iter() {
+            if map.insert(attr.0, attr).is_some() {
+                panic!("duplicate builtin attribute `{}`", attr.0);
+            }
         }
-    }
-    map
-});
+        map
+    });