Add 2027 unstable edition

Author: obeis

compiler/rustc_builtin_macros/src/standard_library_imports.rs

@@ -84,6 +84,7 @@ pub fn inject(
             Edition2018 => sym::rust_2018,
             Edition2021 => sym::rust_2021,
             Edition2024 => sym::rust_2024,
+            Edition2027 => sym::rust_2027,
         }])
         .map(|&symbol| Ident::new(symbol, span))
         .collect();

compiler/rustc_span/src/edition.rs

@@ -23,13 +23,20 @@ pub enum Edition {
     Edition2021,
     /// The 2024 edition
     Edition2024,
+    /// The 2027 edition
+    Edition2027,
 }
 
 // Must be in order from oldest to newest.
-pub const ALL_EDITIONS: &[Edition] =
-    &[Edition::Edition2015, Edition::Edition2018, Edition::Edition2021, Edition::Edition2024];
+pub const ALL_EDITIONS: &[Edition] = &[
+    Edition::Edition2015,
+    Edition::Edition2018,
+    Edition::Edition2021,
+    Edition::Edition2024,
+    Edition::Edition2027,
+];
 
-pub const EDITION_NAME_LIST: &str = "2015|2018|2021|2024";
+pub const EDITION_NAME_LIST: &str = "2015|2018|2021|2024|2027";
 
 pub const DEFAULT_EDITION: Edition = Edition::Edition2015;
 
@@ -42,6 +49,7 @@ impl fmt::Display for Edition {
             Edition::Edition2018 => "2018",
             Edition::Edition2021 => "2021",
             Edition::Edition2024 => "2024",
+            Edition::Edition2027 => "2027",
         };
         write!(f, "{s}")
     }
@@ -54,6 +62,7 @@ impl Edition {
             Edition::Edition2018 => "rust_2018_compatibility",
             Edition::Edition2021 => "rust_2021_compatibility",
             Edition::Edition2024 => "rust_2024_compatibility",
+            Edition::Edition2027 => "rust_2027_compatibility",
         }
     }
 
@@ -63,6 +72,7 @@ impl Edition {
             Edition::Edition2018 => true,
             Edition::Edition2021 => true,
             Edition::Edition2024 => true,
+            Edition::Edition2027 => false,
         }
     }
 
@@ -85,6 +95,11 @@ impl Edition {
     pub fn at_least_rust_2024(self) -> bool {
         self >= Edition::Edition2024
     }
+
+    /// Are we allowed to use features from the Rust 2027 edition?
+    pub fn at_least_rust_2027(self) -> bool {
+        self >= Edition::Edition2027
+    }
 }
 
 impl FromStr for Edition {
@@ -95,6 +110,7 @@ impl FromStr for Edition {
             "2018" => Ok(Edition::Edition2018),
             "2021" => Ok(Edition::Edition2021),
             "2024" => Ok(Edition::Edition2024),
+            "2027" => Ok(Edition::Edition2027),
             _ => Err(()),
         }
     }

compiler/rustc_span/src/lib.rs

@@ -785,6 +785,12 @@ impl Span {
         self.edition().at_least_rust_2024()
     }
 
+    /// Are we allowed to use features from the Rust 2027 edition?
+    #[inline]
+    pub fn at_least_rust_2027(self) -> bool {
+        self.edition().at_least_rust_2027()
+    }
+
     /// Returns the source callee.
     ///
     /// Returns `None` if the supplied span has no expansion trace,

compiler/rustc_span/src/symbol.rs

@@ -1681,6 +1681,7 @@ symbols! {
         rust_2018_preview,
         rust_2021,
         rust_2024,
+        rust_2027,
         rust_analyzer,
         rust_begin_unwind,
         rust_cold_cc,

library/core/src/prelude/mod.rs

@@ -88,3 +88,13 @@ pub mod rust_2024 {
     #[doc(no_inline)]
     pub use crate::future::{Future, IntoFuture};
 }
+
+/// The 2027 edition of the core prelude.
+///
+/// See the [module-level documentation](self) for more.
+#[unstable(feature = "prelude_2027", issue = "none")]
+pub mod rust_2027 {
+    #[unstable(feature = "prelude_2027", issue = "none")]
+    #[doc(no_inline)]
+    pub use super::rust_2024::*;
+}

library/std/src/lib.rs

@@ -347,6 +347,7 @@
 #![feature(pin_coerce_unsized_trait)]
 #![feature(pointer_is_aligned_to)]
 #![feature(portable_simd)]
+#![feature(prelude_2027)]
 #![feature(ptr_as_uninit)]
 #![feature(ptr_mask)]
 #![feature(random)]

library/std/src/prelude/mod.rs

@@ -178,3 +178,17 @@ pub mod rust_2024 {
     #[doc(no_inline)]
     pub use core::prelude::rust_2024::*;
 }
+
+/// The 2027 version of the prelude of The Rust Standard Library.
+///
+/// See the [module-level documentation](self) for more.
+#[unstable(feature = "prelude_2027", issue = "none")]
+pub mod rust_2027 {
+    #[unstable(feature = "prelude_2027", issue = "none")]
+    #[doc(no_inline)]
+    pub use super::v1::*;
+
+    #[unstable(feature = "prelude_2027", issue = "none")]
+    #[doc(no_inline)]
+    pub use core::prelude::rust_2027::*;
+}

src/tools/rustfmt/src/config/options.rs

@@ -443,6 +443,10 @@ pub enum Edition {
     #[doc_hint = "2024"]
     /// Edition 2024.
     Edition2024,
+    #[value = "2027"]
+    #[doc_hint = "2027"]
+    /// Edition 2027.
+    Edition2027,
 }
 
 impl Default for Edition {
@@ -458,6 +462,7 @@ impl From<Edition> for rustc_span::edition::Edition {
             Edition::Edition2018 => Self::Edition2018,
             Edition::Edition2021 => Self::Edition2021,
             Edition::Edition2024 => Self::Edition2024,
+            Edition::Edition2027 => Self::Edition2027,
         }
     }
 }
@@ -469,6 +474,7 @@ impl From<Edition> for StyleEdition {
             Edition::Edition2018 => StyleEdition::Edition2018,
             Edition::Edition2021 => StyleEdition::Edition2021,
             Edition::Edition2024 => StyleEdition::Edition2024,
+            Edition::Edition2027 => StyleEdition::Edition2027,
         }
     }
 }
@@ -513,6 +519,11 @@ pub enum StyleEdition {
     #[doc_hint = "2024"]
     /// [Edition 2024]().
     Edition2024,
+    #[value = "2027"]
+    #[doc_hint = "2027"]
+    #[unstable_variant]
+    /// [Edition 2027]().
+    Edition2027,
 }
 
 impl From<StyleEdition> for rustc_span::edition::Edition {
@@ -522,6 +533,7 @@ impl From<StyleEdition> for rustc_span::edition::Edition {
             StyleEdition::Edition2018 => Self::Edition2018,
             StyleEdition::Edition2021 => Self::Edition2021,
             StyleEdition::Edition2024 => Self::Edition2024,
+            StyleEdition::Edition2027 => Self::Edition2027,
         }
     }
 }

src/tools/rustfmt/src/config/style_edition.rs

@@ -30,7 +30,8 @@ macro_rules! style_edition_default {
                     $crate::config::StyleEdition::Edition2015
                     | $crate::config::StyleEdition::Edition2018
                     | $crate::config::StyleEdition::Edition2021 => $default_2015,
-                    $crate::config::StyleEdition::Edition2024 => $default_2024,
+                    $crate::config::StyleEdition::Edition2024
+                    | $crate::config::StyleEdition::Edition2027 => $default_2024,
                 }
             }
         }