Rollup merge of #107508 - WaffleLapkin:uneq'15, r=oli-obk

`Edition` micro refactor

r? ``@oli-obk``

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -131,7 +131,7 @@ pub fn print_crate<'a>(
 
         // Currently, in Rust 2018 we don't have `extern crate std;` at the crate
         // root, so this is not needed, and actually breaks things.
-        if edition == Edition::Edition2015 {
+        if edition.rust_2015() {
             // `#![no_std]`
             let fake_attr = attr::mk_attr_word(g, ast::AttrStyle::Inner, sym::no_std, DUMMY_SP);
             s.print_attribute(&fake_attr);

compiler/rustc_resolve/src/diagnostics.rs

@@ -1717,7 +1717,7 @@ impl<'a> Resolver<'a> {
                         Applicability::MaybeIncorrect,
                     )),
                 )
-            } else if self.session.edition() == Edition::Edition2015 {
+            } else if self.session.rust_2015() {
                 (
                     format!("maybe a missing crate `{ident}`?"),
                     Some((

compiler/rustc_resolve/src/ident.rs

@@ -7,7 +7,6 @@ use rustc_middle::ty;
 use rustc_session::lint::builtin::PROC_MACRO_DERIVE_RESOLUTION_FALLBACK;
 use rustc_session::lint::BuiltinLintDiagnostics;
 use rustc_span::def_id::LocalDefId;
-use rustc_span::edition::Edition;
 use rustc_span::hygiene::{ExpnId, ExpnKind, LocalExpnId, MacroKind, SyntaxContext};
 use rustc_span::symbol::{kw, Ident};
 use rustc_span::{Span, DUMMY_SP};
@@ -86,7 +85,7 @@ impl<'a> Resolver<'a> {
         // 4c. Standard library prelude (de-facto closed, controlled).
         // 6. Language prelude: builtin attributes (closed, controlled).
 
-        let rust_2015 = ctxt.edition() == Edition::Edition2015;
+        let rust_2015 = ctxt.edition().rust_2015();
         let (ns, macro_kind, is_absolute_path) = match scope_set {
             ScopeSet::All(ns, _) => (ns, None, false),
             ScopeSet::AbsolutePath(ns) => (ns, None, true),

compiler/rustc_session/src/session.rs

@@ -918,23 +918,24 @@ impl Session {
         ret
     }
 
+    /// Is this edition 2015?
     pub fn rust_2015(&self) -> bool {
-        self.edition() == Edition::Edition2015
+        self.edition().rust_2015()
     }
 
     /// Are we allowed to use features from the Rust 2018 edition?
     pub fn rust_2018(&self) -> bool {
-        self.edition() >= Edition::Edition2018
+        self.edition().rust_2018()
     }
 
     /// Are we allowed to use features from the Rust 2021 edition?
     pub fn rust_2021(&self) -> bool {
-        self.edition() >= Edition::Edition2021
+        self.edition().rust_2021()
     }
 
     /// Are we allowed to use features from the Rust 2024 edition?
     pub fn rust_2024(&self) -> bool {
-        self.edition() >= Edition::Edition2024
+        self.edition().rust_2024()
     }
 
     /// Returns `true` if we cannot skip the PLT for shared library calls.

compiler/rustc_span/src/edition.rs

@@ -49,8 +49,8 @@ impl fmt::Display for Edition {
 }
 
 impl Edition {
-    pub fn lint_name(&self) -> &'static str {
-        match *self {
+    pub fn lint_name(self) -> &'static str {
+        match self {
             Edition::Edition2015 => "rust_2015_compatibility",
             Edition::Edition2018 => "rust_2018_compatibility",
             Edition::Edition2021 => "rust_2021_compatibility",
@@ -58,8 +58,8 @@ impl Edition {
         }
     }
 
-    pub fn feature_name(&self) -> Symbol {
-        match *self {
+    pub fn feature_name(self) -> Symbol {
+        match self {
             Edition::Edition2015 => sym::rust_2015_preview,
             Edition::Edition2018 => sym::rust_2018_preview,
             Edition::Edition2021 => sym::rust_2021_preview,
@@ -67,8 +67,8 @@ impl Edition {
         }
     }
 
-    pub fn is_stable(&self) -> bool {
-        match *self {
+    pub fn is_stable(self) -> bool {
+        match self {
             Edition::Edition2015 => true,
             Edition::Edition2018 => true,
             Edition::Edition2021 => true,
@@ -76,23 +76,24 @@ impl Edition {
         }
     }
 
-    pub fn rust_2015(&self) -> bool {
-        *self == Edition::Edition2015
+    /// Is this edition 2015?
+    pub fn rust_2015(self) -> bool {
+        self == Edition::Edition2015
     }
 
     /// Are we allowed to use features from the Rust 2018 edition?
-    pub fn rust_2018(&self) -> bool {
-        *self >= Edition::Edition2018
+    pub fn rust_2018(self) -> bool {
+        self >= Edition::Edition2018
     }
 
     /// Are we allowed to use features from the Rust 2021 edition?
-    pub fn rust_2021(&self) -> bool {
-        *self >= Edition::Edition2021
+    pub fn rust_2021(self) -> bool {
+        self >= Edition::Edition2021
     }
 
     /// Are we allowed to use features from the Rust 2024 edition?
-    pub fn rust_2024(&self) -> bool {
-        *self >= Edition::Edition2024
+    pub fn rust_2024(self) -> bool {
+        self >= Edition::Edition2024
     }
 }
 

compiler/rustc_span/src/lib.rs

@@ -706,22 +706,22 @@ impl Span {
 
     #[inline]
     pub fn rust_2015(self) -> bool {
-        self.edition() == edition::Edition::Edition2015
+        self.edition().rust_2015()
     }
 
     #[inline]
     pub fn rust_2018(self) -> bool {
-        self.edition() >= edition::Edition::Edition2018
+        self.edition().rust_2018()
     }
 
     #[inline]
     pub fn rust_2021(self) -> bool {
-        self.edition() >= edition::Edition::Edition2021
+        self.edition().rust_2021()
     }
 
     #[inline]
     pub fn rust_2024(self) -> bool {
-        self.edition() >= edition::Edition::Edition2024
+        self.edition().rust_2024()
     }
 
     /// Returns the source callee.