Rename cfg_match! to cfg_select!

At [1] it was pointed out that `cfg_match!` syntax does not actually
align well with match syntax, which is a possible source of confusion.
The comment points out that usage is instead more similar to ecosystem
`select!` macros. Rename `cfg_match!` to `cfg_select!` to match this.

Tracking issue: #115585

[1]: #115585 (comment)

Author: tgross35

compiler/rustc_codegen_cranelift/patches/0027-sysroot_tests-128bit-atomic-operations.patch

@@ -17,7 +17,7 @@ index 1e336bf..35e6f54 100644
 @@ -2,5 +2,4 @@
  // tidy-alphabetical-start
 -#![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
- #![cfg_attr(test, feature(cfg_match))]
+ #![cfg_attr(test, feature(cfg_select))]
  #![feature(alloc_layout_extra)]
  #![feature(array_chunks)]
 diff --git a/coretests/tests/atomic.rs b/coretests/tests/atomic.rs

compiler/rustc_data_structures/src/flock.rs

@@ -4,7 +4,7 @@
 //! green/native threading. This is just a bare-bones enough solution for
 //! librustdoc, it is not production quality at all.
 
-cfg_match! {
+cfg_select! {
     target_os = "linux" => {
         mod linux;
         use linux as imp;

compiler/rustc_data_structures/src/lib.rs

@@ -19,7 +19,7 @@
 #![feature(ascii_char_variants)]
 #![feature(assert_matches)]
 #![feature(auto_traits)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(extend_one)]

compiler/rustc_data_structures/src/profiling.rs

@@ -860,7 +860,7 @@ fn get_thread_id() -> u32 {
 }
 
 // Memory reporting
-cfg_match! {
+cfg_select! {
     windows => {
         pub fn get_resident_set_size() -> Option<usize> {
             use windows::{

compiler/rustc_span/src/analyze_source_file.rs

@@ -29,7 +29,7 @@ pub(crate) fn analyze_source_file(src: &str) -> (Vec<RelativeBytePos>, Vec<Multi
     (lines, multi_byte_chars)
 }
 
-cfg_match! {
+cfg_select! {
     any(target_arch = "x86", target_arch = "x86_64") => {
         fn analyze_source_file_dispatch(
             src: &str,

compiler/rustc_span/src/lib.rs

@@ -20,7 +20,7 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
 #![feature(array_windows)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(core_io_borrowed_buf)]
 #![feature(hash_set_entry)]
 #![feature(if_let_guard)]

library/core/src/ffi/primitives.rs

@@ -35,7 +35,7 @@ type_alias! { "c_float.md", c_float = f32; }
 type_alias! { "c_double.md", c_double = f64; }
 
 mod c_char_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         // These are the targets on which c_char is unsigned. Usually the
         // signedness is the same for all target_os values on a given architecture
         // but there are some exceptions (see isSignedCharDefault() in clang).
@@ -133,7 +133,7 @@ mod c_char_definition {
 }
 
 mod c_long_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(
             all(target_pointer_width = "64", not(windows)),
             // wasm32 Linux ABI uses 64-bit long
@@ -172,7 +172,7 @@ pub type c_ptrdiff_t = isize;
 pub type c_ssize_t = isize;
 
 mod c_int_definition {
-    crate::cfg_match! {
+    crate::cfg_select! {
         any(target_arch = "avr", target_arch = "msp430") => {
             pub(super) type c_int = i16;
             pub(super) type c_uint = u16;

library/core/src/lib.rs

@@ -100,7 +100,7 @@
 #![feature(bigint_helper_methods)]
 #![feature(bstr)]
 #![feature(bstr_internals)]
-#![feature(cfg_match)]
+#![feature(cfg_select)]
 #![feature(cfg_target_has_reliable_f16_f128)]
 #![feature(const_carrying_mul_add)]
 #![feature(const_eval_select)]
@@ -235,8 +235,8 @@ pub mod autodiff {
 #[unstable(feature = "contracts", issue = "128044")]
 pub mod contracts;
 
-#[unstable(feature = "cfg_match", issue = "115585")]
-pub use crate::macros::cfg_match;
+#[unstable(feature = "cfg_select", issue = "115585")]
+pub use crate::macros::cfg_select;
 
 #[macro_use]
 mod internal_macros;

library/core/src/macros/mod.rs

@@ -210,9 +210,9 @@ pub macro assert_matches {
 /// # Example
 ///
 /// ```
-/// #![feature(cfg_match)]
+/// #![feature(cfg_select)]
 ///
-/// cfg_match! {
+/// cfg_select! {
 ///     unix => {
 ///         fn foo() { /* unix specific functionality */ }
 ///     }
@@ -228,19 +228,19 @@ pub macro assert_matches {
 /// If desired, it is possible to return expressions through the use of surrounding braces:
 ///
 /// ```
-/// #![feature(cfg_match)]
+/// #![feature(cfg_select)]
 ///
-/// let _some_string = cfg_match! {{
+/// let _some_string = cfg_select! {{
 ///     unix => { "With great power comes great electricity bills" }
 ///     _ => { "Behind every successful diet is an unwatched pizza" }
 /// }};
 /// ```
-#[unstable(feature = "cfg_match", issue = "115585")]
-#[rustc_diagnostic_item = "cfg_match"]
+#[unstable(feature = "cfg_select", issue = "115585")]
+#[rustc_diagnostic_item = "cfg_select"]
 #[rustc_macro_transparency = "semitransparent"]
-pub macro cfg_match {
+pub macro cfg_select {
     ({ $($tt:tt)* }) => {{
-        $crate::cfg_match! { $($tt)* }
+        $crate::cfg_select! { $($tt)* }
     }},
     (_ => { $($output:tt)* }) => {
         $($output)*
@@ -250,10 +250,10 @@ pub macro cfg_match {
         $($( $rest:tt )+)?
     ) => {
         #[cfg($cfg)]
-        $crate::cfg_match! { _ => $output }
+        $crate::cfg_select! { _ => $output }
         $(
             #[cfg(not($cfg))]
-            $crate::cfg_match! { $($rest)+ }
+            $crate::cfg_select! { $($rest)+ }
         )?
     },
 }

library/core/src/num/f32.rs

@@ -14,7 +14,7 @@
 use crate::convert::FloatToInt;
 use crate::num::{FpCategory, libm};
 use crate::panic::const_assert;
-use crate::{cfg_match, intrinsics, mem};
+use crate::{cfg_select, intrinsics, mem};
 
 /// The radix or base of the internal representation of `f32`.
 /// Use [`f32::RADIX`] instead.
@@ -990,7 +990,7 @@ impl f32 {
     #[stable(feature = "num_midpoint", since = "1.85.0")]
     #[rustc_const_stable(feature = "num_midpoint", since = "1.85.0")]
     pub const fn midpoint(self, other: f32) -> f32 {
-        cfg_match! {
+        cfg_select! {
             // Allow faster implementation that have known good 64-bit float
             // implementations. Falling back to the branchy code on targets that don't
             // have 64-bit hardware floats or buggy implementations.