Initiate the inner usage of cfg_match

compiler/rustc_data_structures/src/flock.rs

@@ -4,17 +4,20 @@
 //! green/native threading. This is just a bare-bones enough solution for
 //! librustdoc, it is not production quality at all.
 
-cfg_if! {
-    if #[cfg(target_os = "linux")] {
+cfg_match! {
+    cfg(target_os = "linux") => {
         mod linux;
         use linux as imp;
-    } else if #[cfg(unix)] {
+    }
+    cfg(unix) => {
         mod unix;
         use unix as imp;
-    } else if #[cfg(windows)] {
+    }
+    cfg(windows) => {
         mod windows;
         use self::windows as imp;
-    } else {
+    }
+    _ => {
         mod unsupported;
         use unsupported as imp;
     }

compiler/rustc_data_structures/src/lib.rs

@@ -6,43 +6,44 @@
 //!
 //! This API is completely unstable and subject to change.
 
+// tidy-alphabetical-start
+#![allow(internal_features)]
+#![allow(rustc::default_hash_types)]
+#![allow(rustc::potential_query_instability)]
 #![cfg_attr(not(bootstrap), doc(rust_logo))]
 #![cfg_attr(not(bootstrap), feature(rustdoc_internals))]
+#![deny(rustc::diagnostic_outside_of_impl)]
+#![deny(rustc::untranslatable_diagnostic)]
+#![deny(unsafe_op_in_unsafe_fn)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
+#![feature(allocator_api)]
 #![feature(array_windows)]
 #![feature(auto_traits)]
 #![feature(cell_leak)]
+#![feature(cfg_match)]
 #![feature(core_intrinsics)]
 #![feature(extend_one)]
 #![feature(hash_raw_entry)]
 #![feature(hasher_prefixfree_extras)]
+#![feature(lazy_cell)]
+#![feature(lint_reasons)]
+#![feature(macro_metavar_expr)]
 #![feature(maybe_uninit_uninit_array)]
 #![feature(min_specialization)]
-#![feature(never_type)]
-#![feature(type_alias_impl_trait)]
-#![feature(lazy_cell)]
-#![feature(rustc_attrs)]
 #![feature(negative_impls)]
+#![feature(never_type)]
+#![feature(ptr_alignment_type)]
+#![feature(rustc_attrs)]
+#![feature(strict_provenance)]
 #![feature(test)]
 #![feature(thread_id_value)]
-#![feature(allocator_api)]
-#![feature(lint_reasons)]
+#![feature(type_alias_impl_trait)]
 #![feature(unwrap_infallible)]
-#![feature(strict_provenance)]
-#![feature(ptr_alignment_type)]
-#![feature(macro_metavar_expr)]
-#![allow(rustc::default_hash_types)]
-#![allow(rustc::potential_query_instability)]
-#![deny(rustc::untranslatable_diagnostic)]
-#![deny(rustc::diagnostic_outside_of_impl)]
-#![allow(internal_features)]
-#![deny(unsafe_op_in_unsafe_fn)]
+// tidy-alphabetical-end
 
 #[macro_use]
 extern crate tracing;
 #[macro_use]
-extern crate cfg_if;
-#[macro_use]
 extern crate rustc_macros;
 
 use std::fmt;

compiler/rustc_data_structures/src/marker.rs

@@ -1,11 +1,12 @@
-cfg_if!(
-    if #[cfg(not(parallel_compiler))] {
+cfg_match! {
+    cfg(not(parallel_compiler)) => {
         pub auto trait DynSend {}
         pub auto trait DynSync {}
 
         impl<T> DynSend for T {}
         impl<T> DynSync for T {}
-    } else {
+    }
+    _ => {
         #[rustc_on_unimplemented(
             message = "`{Self}` doesn't implement `DynSend`. \
             Add it to `rustc_data_structures::marker` or use `IntoDynSyncSend` if it's already `Send`"
@@ -48,13 +49,10 @@ cfg_if!(
             [std::io::StdoutLock<'_>]
             [std::io::StderrLock<'_>]
         );
-        cfg_if!(
-            // Consistent with `std`
-            // `os_imp::Env` is `!Send` in these platforms
-            if #[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))] {
-                impl !DynSend for std::env::VarsOs {}
-            }
-        );
+
+        #[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))]
+        // Consistent with `std`, `os_imp::Env` is `!Sync` in these platforms
+        impl !DynSend for std::env::VarsOs {}
 
         macro_rules! already_send {
             ($([$ty: ty])*) => {
@@ -123,13 +121,10 @@ cfg_if!(
             [std::sync::mpsc::Receiver<T> where T]
             [std::sync::mpsc::Sender<T> where T]
         );
-        cfg_if!(
-            // Consistent with `std`
-            // `os_imp::Env` is `!Sync` in these platforms
-            if #[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))] {
-                impl !DynSync for std::env::VarsOs {}
-            }
-        );
+
+        #[cfg(any(unix, target_os = "hermit", target_os = "wasi", target_os = "solid_asp3"))]
+        // Consistent with `std`, `os_imp::Env` is `!Sync` in these platforms
+        impl !DynSync for std::env::VarsOs {}
 
         macro_rules! already_sync {
             ($([$ty: ty])*) => {
@@ -183,7 +178,7 @@ cfg_if!(
             [thin_vec::ThinVec<T> where T: DynSync]
         );
     }
-);
+}
 
 pub fn assert_dyn_sync<T: ?Sized + DynSync>() {}
 pub fn assert_dyn_send<T: ?Sized + DynSend>() {}

compiler/rustc_data_structures/src/profiling.rs

@@ -859,8 +859,8 @@ fn get_thread_id() -> u32 {
 }
 
 // Memory reporting
-cfg_if! {
-    if #[cfg(windows)] {
+cfg_match! {
+    cfg(windows) => {
         pub fn get_resident_set_size() -> Option<usize> {
             use std::mem;
 
@@ -885,7 +885,8 @@ cfg_if! {
 
             Some(pmc.WorkingSetSize)
         }
-    } else if #[cfg(target_os = "macos")] {
+    }
+    cfg(target_os = "macos")  => {
         pub fn get_resident_set_size() -> Option<usize> {
             use libc::{c_int, c_void, getpid, proc_pidinfo, proc_taskinfo, PROC_PIDTASKINFO};
             use std::mem;
@@ -903,7 +904,8 @@ cfg_if! {
                 }
             }
         }
-    } else if #[cfg(unix)] {
+    }
+    cfg(unix) => {
         pub fn get_resident_set_size() -> Option<usize> {
             let field = 1;
             let contents = fs::read("/proc/self/statm").ok()?;
@@ -912,7 +914,8 @@ cfg_if! {
             let npages = s.parse::<usize>().ok()?;
             Some(npages * 4096)
         }
-    } else {
+    }
+    _ => {
         pub fn get_resident_set_size() -> Option<usize> {
             None
         }

compiler/rustc_data_structures/src/sync.rs

@@ -109,8 +109,8 @@ mod mode {
 
 pub use mode::{is_dyn_thread_safe, set_dyn_thread_safe_mode};
 
-cfg_if! {
-    if #[cfg(not(parallel_compiler))] {
+cfg_match! {
+    cfg(not(parallel_compiler)) => {
         use std::ops::Add;
         use std::cell::Cell;
 
@@ -251,7 +251,8 @@ cfg_if! {
                 MTLock(self.0.clone())
             }
         }
-    } else {
+    }
+    _ => {
         pub use std::marker::Send as Send;
         pub use std::marker::Sync as Sync;