Rollup merge of rust-lang#98165 - WaffleLapkin:once_things_renamings, r=m-ou-se

once cell renamings

This PR does the renamings proposed in rust-lang#74465 (comment)

- Move/rename `lazy::{OnceCell, Lazy}` to `cell::{OnceCell, LazyCell}`
- Move/rename `lazy::{SyncOnceCell, SyncLazy}` to `sync::{OnceLock, LazyLock}`

(I used `Lazy...` instead of `...Lazy` as it seems to be more consistent, easier to pronounce, etc)

`@rustbot` label +T-libs-api -T-libs

Author: matthiaskrgr

compiler/rustc_codegen_cranelift/src/driver/jit.rs

@@ -13,7 +13,7 @@ use rustc_span::Symbol;
 
 use cranelift_jit::{JITBuilder, JITModule};
 
-// FIXME use std::lazy::SyncOnceCell once it stabilizes
+// FIXME use std::sync::OnceLock once it stabilizes
 use once_cell::sync::OnceCell;
 
 use crate::{prelude::*, BackendConfig};

compiler/rustc_codegen_llvm/src/debuginfo/mod.rs

@@ -36,9 +36,9 @@ use rustc_target::abi::Size;
 
 use libc::c_uint;
 use smallvec::SmallVec;
+use std::cell::OnceCell;
 use std::cell::RefCell;
 use std::iter;
-use std::lazy::OnceCell;
 use tracing::debug;
 
 mod create_scope_map;

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -38,11 +38,11 @@ use regex::Regex;
 use tempfile::Builder as TempFileBuilder;
 
 use std::borrow::Borrow;
+use std::cell::OnceCell;
 use std::collections::BTreeSet;
 use std::ffi::OsString;
 use std::fs::{File, OpenOptions};
 use std::io::{BufWriter, Write};
-use std::lazy::OnceCell;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
 use std::process::{ExitStatus, Output, Stdio};

compiler/rustc_data_structures/src/jobserver.rs

@@ -1,5 +1,5 @@
 pub use jobserver_crate::Client;
-use std::lazy::SyncLazy;
+use std::sync::LazyLock;
 
 // We can only call `from_env` once per process
 
@@ -18,7 +18,7 @@ use std::lazy::SyncLazy;
 // 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 {
+static GLOBAL_CLIENT: LazyLock<Client> = LazyLock::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

compiler/rustc_data_structures/src/sync.rs

@@ -173,7 +173,7 @@ cfg_if! {
         pub use std::cell::RefMut as LockGuard;
         pub use std::cell::RefMut as MappedLockGuard;
 
-        pub use std::lazy::OnceCell;
+        pub use std::cell::OnceCell;
 
         use std::cell::RefCell as InnerRwLock;
         use std::cell::RefCell as InnerLock;
@@ -258,7 +258,7 @@ cfg_if! {
         pub use parking_lot::MutexGuard as LockGuard;
         pub use parking_lot::MappedMutexGuard as MappedLockGuard;
 
-        pub use std::lazy::SyncOnceCell as OnceCell;
+        pub use std::sync::OnceLock as OnceCell;
 
         pub use std::sync::atomic::{AtomicBool, AtomicUsize, AtomicU32, AtomicU64};
 

compiler/rustc_driver/src/lib.rs

@@ -47,11 +47,11 @@ use std::env;
 use std::ffi::OsString;
 use std::fs;
 use std::io::{self, Read, Write};
-use std::lazy::SyncLazy;
 use std::panic::{self, catch_unwind};
 use std::path::PathBuf;
 use std::process::{self, Command, Stdio};
 use std::str;
+use std::sync::LazyLock;
 use std::time::Instant;
 
 pub mod args;
@@ -1141,8 +1141,8 @@ pub fn catch_with_exit_code(f: impl FnOnce() -> interface::Result<()>) -> i32 {
     }
 }
 
-static DEFAULT_HOOK: SyncLazy<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
-    SyncLazy::new(|| {
+static DEFAULT_HOOK: LazyLock<Box<dyn Fn(&panic::PanicInfo<'_>) + Sync + Send + 'static>> =
+    LazyLock::new(|| {
         let hook = panic::take_hook();
         panic::set_hook(Box::new(|info| {
             // Invoke the default handler, which prints the actual panic message and optionally a backtrace
@@ -1237,7 +1237,7 @@ pub fn install_ice_hook() {
     if std::env::var("RUST_BACKTRACE").is_err() {
         std::env::set_var("RUST_BACKTRACE", "full");
     }
-    SyncLazy::force(&DEFAULT_HOOK);
+    LazyLock::force(&DEFAULT_HOOK);
 }
 
 /// This allows tools to enable rust logging without having to magically match rustc's

compiler/rustc_error_messages/src/lib.rs

@@ -18,9 +18,9 @@ use std::path::{Path, PathBuf};
 use tracing::{instrument, trace};
 
 #[cfg(not(parallel_compiler))]
-use std::lazy::Lazy;
+use std::cell::LazyCell as Lazy;
 #[cfg(parallel_compiler)]
-use std::lazy::SyncLazy as Lazy;
+use std::sync::LazyLock as Lazy;
 
 #[cfg(parallel_compiler)]
 use intl_memoizer::concurrent::IntlLangMemoizer;

compiler/rustc_feature/src/builtin_attrs.rs

@@ -9,7 +9,7 @@ use crate::{Features, Stability};
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::symbol::{sym, Symbol};
 
-use std::lazy::SyncLazy;
+use std::sync::LazyLock;
 
 type GateFn = fn(&Features) -> bool;
 
@@ -809,8 +809,8 @@ pub fn is_builtin_only_local(name: Symbol) -> bool {
     BUILTIN_ATTRIBUTE_MAP.get(&name).map_or(false, |attr| attr.only_local)
 }
 
-pub static BUILTIN_ATTRIBUTE_MAP: SyncLazy<FxHashMap<Symbol, &BuiltinAttribute>> =
-    SyncLazy::new(|| {
+pub static BUILTIN_ATTRIBUTE_MAP: LazyLock<FxHashMap<Symbol, &BuiltinAttribute>> =
+    LazyLock::new(|| {
         let mut map = FxHashMap::default();
         for attr in BUILTIN_ATTRIBUTES.iter() {
             if map.insert(attr.name, attr).is_some() {

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 std::lazy::SyncLazy;
+use std::sync::LazyLock;
 
 pub enum LangItemGroup {
     Op,
@@ -134,7 +134,7 @@ macro_rules! language_item_table {
         }
 
         /// 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(|| {
+        pub static ITEM_REFS: LazyLock<FxHashMap<Symbol, (usize, Target)>> = LazyLock::new(|| {
             let mut item_refs = FxHashMap::default();
             $( item_refs.insert($module::$name, (LangItem::$variant as usize, $target)); )*
             item_refs

compiler/rustc_hir/src/weak_lang_items.rs

@@ -7,12 +7,12 @@ use rustc_ast as ast;
 use rustc_data_structures::stable_map::StableMap;
 use rustc_span::symbol::{sym, Symbol};
 
-use std::lazy::SyncLazy;
+use std::sync::LazyLock;
 
 macro_rules! weak_lang_items {
     ($($name:ident, $item:ident, $sym:ident;)*) => (
 
-pub static WEAK_ITEMS_REFS: SyncLazy<StableMap<Symbol, LangItem>> = SyncLazy::new(|| {
+pub static WEAK_ITEMS_REFS: LazyLock<StableMap<Symbol, LangItem>> = LazyLock::new(|| {
     let mut map = StableMap::default();
     $(map.insert(sym::$name, LangItem::$item);)*
     map

compiler/rustc_interface/src/passes.rs

@@ -44,11 +44,11 @@ use std::any::Any;
 use std::cell::RefCell;
 use std::ffi::OsString;
 use std::io::{self, BufWriter, Write};
-use std::lazy::SyncLazy;
 use std::marker::PhantomPinned;
 use std::path::{Path, PathBuf};
 use std::pin::Pin;
 use std::rc::Rc;
+use std::sync::LazyLock;
 use std::{env, fs, iter};
 
 pub fn parse<'a>(sess: &'a Session, input: &Input) -> PResult<'a, ast::Crate> {
@@ -774,7 +774,7 @@ pub fn prepare_outputs(
     Ok(outputs)
 }
 
-pub static DEFAULT_QUERY_PROVIDERS: SyncLazy<Providers> = SyncLazy::new(|| {
+pub static DEFAULT_QUERY_PROVIDERS: LazyLock<Providers> = LazyLock::new(|| {
     let providers = &mut Providers::default();
     providers.analysis = analysis;
     proc_macro_decls::provide(providers);
@@ -799,7 +799,7 @@ pub static DEFAULT_QUERY_PROVIDERS: SyncLazy<Providers> = SyncLazy::new(|| {
     *providers
 });
 
-pub static DEFAULT_EXTERN_QUERY_PROVIDERS: SyncLazy<ExternProviders> = SyncLazy::new(|| {
+pub static DEFAULT_EXTERN_QUERY_PROVIDERS: LazyLock<ExternProviders> = LazyLock::new(|| {
     let mut extern_providers = ExternProviders::default();
     rustc_metadata::provide_extern(&mut extern_providers);
     rustc_codegen_ssa::provide_extern(&mut extern_providers);

compiler/rustc_interface/src/util.rs

@@ -24,12 +24,12 @@ use rustc_span::source_map::FileLoader;
 use rustc_span::symbol::{sym, Symbol};
 use std::env;
 use std::env::consts::{DLL_PREFIX, DLL_SUFFIX};
-use std::lazy::SyncOnceCell;
 use std::mem;
 #[cfg(not(parallel_compiler))]
 use std::panic;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::OnceLock;
 use std::thread;
 use tracing::info;
 
@@ -242,7 +242,7 @@ pub fn get_codegen_backend(
     maybe_sysroot: &Option<PathBuf>,
     backend_name: Option<&str>,
 ) -> Box<dyn CodegenBackend> {
-    static LOAD: SyncOnceCell<unsafe fn() -> Box<dyn CodegenBackend>> = SyncOnceCell::new();
+    static LOAD: OnceLock<unsafe fn() -> Box<dyn CodegenBackend>> = OnceLock::new();
 
     let load = LOAD.get_or_init(|| {
         let default_codegen_backend = option_env!("CFG_DEFAULT_CODEGEN_BACKEND").unwrap_or("llvm");
@@ -265,7 +265,7 @@ pub fn get_codegen_backend(
 // loading, so we leave the code here. It is potentially useful for other tools
 // that want to invoke the rustc binary while linking to rustc as well.
 pub fn rustc_path<'a>() -> Option<&'a Path> {
-    static RUSTC_PATH: SyncOnceCell<Option<PathBuf>> = SyncOnceCell::new();
+    static RUSTC_PATH: OnceLock<Option<PathBuf>> = OnceLock::new();
 
     const BIN_PATH: &str = env!("RUSTC_INSTALL_BINDIR");
 

compiler/rustc_mir_dataflow/src/framework/graphviz.rs

@@ -1,7 +1,7 @@
 //! A helpful diagram for debugging dataflow problems.
 
 use std::borrow::Cow;
-use std::lazy::SyncOnceCell;
+use std::sync::OnceLock;
 use std::{io, ops, str};
 
 use regex::Regex;
@@ -590,7 +590,7 @@ where
 
 macro_rules! regex {
     ($re:literal $(,)?) => {{
-        static RE: SyncOnceCell<regex::Regex> = SyncOnceCell::new();
+        static RE: OnceLock<regex::Regex> = OnceLock::new();
         RE.get_or_init(|| Regex::new($re).unwrap())
     }};
 }

compiler/rustc_mir_transform/src/coverage/debug.rs

@@ -123,15 +123,15 @@ use rustc_middle::ty::TyCtxt;
 use rustc_span::Span;
 
 use std::iter;
-use std::lazy::SyncOnceCell;
 use std::ops::Deref;
+use std::sync::OnceLock;
 
 pub const NESTED_INDENT: &str = "    ";
 
 const RUSTC_COVERAGE_DEBUG_OPTIONS: &str = "RUSTC_COVERAGE_DEBUG_OPTIONS";
 
 pub(super) fn debug_options<'a>() -> &'a DebugOptions {
-    static DEBUG_OPTIONS: SyncOnceCell<DebugOptions> = SyncOnceCell::new();
+    static DEBUG_OPTIONS: OnceLock<DebugOptions> = OnceLock::new();
 
     &DEBUG_OPTIONS.get_or_init(DebugOptions::from_env)
 }

compiler/rustc_typeck/src/check/wfcheck.rs

@@ -29,9 +29,9 @@ use rustc_span::{Span, DUMMY_SP};
 use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _;
 use rustc_trait_selection::traits::{self, ObligationCause, ObligationCauseCode, WellFormedLoc};
 
+use std::cell::LazyCell;
 use std::convert::TryInto;
 use std::iter;
-use std::lazy::Lazy;
 use std::ops::ControlFlow;
 
 /// Helper type of a temporary returned by `.for_item(...)`.
@@ -1728,7 +1728,7 @@ fn check_variances_for_type_defn<'tcx>(
     identify_constrained_generic_params(tcx, ty_predicates, None, &mut constrained_parameters);
 
     // Lazily calculated because it is only needed in case of an error.
-    let explicitly_bounded_params = Lazy::new(|| {
+    let explicitly_bounded_params = LazyCell::new(|| {
         let icx = crate::collect::ItemCtxt::new(tcx, item.def_id.to_def_id());
         hir_generics
             .predicates

library/core/src/cell.rs

@@ -199,6 +199,14 @@ use crate::mem;
 use crate::ops::{CoerceUnsized, Deref, DerefMut};
 use crate::ptr::{self, NonNull};
 
+mod lazy;
+mod once;
+
+#[unstable(feature = "once_cell", issue = "74465")]
+pub use lazy::LazyCell;
+#[unstable(feature = "once_cell", issue = "74465")]
+pub use once::OnceCell;
+
 /// A mutable memory location.
 ///
 /// # Examples