Add support for edition 2021.

Cargo.toml

@@ -107,32 +107,32 @@ lazy_static = "1.0.0"
 
 [dependencies.rustc_ast]
 package = "rustc-ap-rustc_ast"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_ast_pretty]
 package = "rustc-ap-rustc_ast_pretty"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_data_structures]
 package = "rustc-ap-rustc_data_structures"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_errors]
 package = "rustc-ap-rustc_errors"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_expand]
 package = "rustc-ap-rustc_expand"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_parse]
 package = "rustc-ap-rustc_parse"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_session]
 package = "rustc-ap-rustc_session"
-version = "691.0.0"
+version = "697.0.0"
 
 [dependencies.rustc_span]
 package = "rustc-ap-rustc_span"
-version = "691.0.0"
+version = "697.0.0"

Configurations.md

@@ -569,7 +569,7 @@ fn main() {
 Specifies which edition is used by the parser.
 
 - **Default value**: `"2015"`
-- **Possible values**: `"2015"`, `"2018"`
+- **Possible values**: `"2015"`, `"2018"`, `"2021"`
 - **Stable**: Yes
 
 Rustfmt is able to pick up the edition used by reading the `Cargo.toml` file if executed

rust-toolchain

@@ -1 +1 @@
-nightly-2020-11-29
+nightly-2020-12-31

src/config/options.rs

@@ -343,6 +343,10 @@ pub enum Edition {
     #[doc_hint = "2018"]
     /// Edition 2018.
     Edition2018,
+    #[value = "2021"]
+    #[doc_hint = "2021"]
+    /// Edition 2021.
+    Edition2021,
 }
 
 impl Default for Edition {
@@ -356,10 +360,17 @@ impl From<Edition> for rustc_span::edition::Edition {
         match edition {
             Edition::Edition2015 => Self::Edition2015,
             Edition::Edition2018 => Self::Edition2018,
+            Edition::Edition2021 => Self::Edition2021,
         }
     }
 }
 
+impl PartialOrd for Edition {
+    fn partial_cmp(&self, other: &Edition) -> Option<std::cmp::Ordering> {
+        rustc_span::edition::Edition::partial_cmp(&(*self).into(), &(*other).into())
+    }
+}
+
 /// Controls how rustfmt should handle leading pipes on match arms.
 #[config_type]
 pub enum MatchArmLeadingPipe {

src/formatting/closures.rs

@@ -199,7 +199,6 @@ fn rewrite_closure_with_block(
             id: ast::NodeId::root(),
             kind: ast::StmtKind::Expr(ptr::P(body.clone())),
             span: body.span,
-            tokens: None,
         }],
         id: ast::NodeId::root(),
         rules: ast::BlockCheckMode::Default,

src/formatting/imports.rs

@@ -333,7 +333,7 @@ impl UseTree {
         };
 
         let leading_modsep =
-            context.config.edition() == Edition::Edition2018 && a.prefix.is_global();
+            context.config.edition() >= Edition::Edition2018 && a.prefix.is_global();
 
         let mut modsep = leading_modsep;
 

src/formatting/items.rs

@@ -2275,7 +2275,7 @@ pub(crate) fn span_hi_for_param(context: &RewriteContext<'_>, param: &ast::Param
 
 pub(crate) fn is_named_param(param: &ast::Param) -> bool {
     if let ast::PatKind::Ident(_, ident, _) = param.pat.kind {
-        ident.name != symbol::kw::Invalid
+        ident.name != symbol::kw::Empty
     } else {
         true
     }

src/formatting/macros.rs

@@ -157,7 +157,7 @@ fn rewrite_macro_name(
         format!("{}!", pprust::path_to_string(path))
     };
     match extra_ident {
-        Some(ident) if ident.name != kw::Invalid => format!("{} {}", name, ident),
+        Some(ident) if ident.name != kw::Empty => format!("{} {}", name, ident),
         _ => name,
     }
 }

src/formatting/spanned.rs

@@ -116,7 +116,12 @@ impl Spanned for ast::Param {
 
 impl Spanned for ast::GenericParam {
     fn span(&self) -> Span {
-        let lo = if let ast::GenericParamKind::Const { ty: _, kw_span } = self.kind {
+        let lo = if let ast::GenericParamKind::Const {
+            ty: _,
+            kw_span,
+            default: _,
+        } = self.kind
+        {
             kw_span.lo()
         } else if self.attrs.is_empty() {
             self.ident.span.lo()

src/formatting/types.rs

@@ -563,7 +563,12 @@ impl Rewrite for ast::GenericParam {
             _ => {}
         }
 
-        if let ast::GenericParamKind::Const { ref ty, kw_span: _ } = &self.kind {
+        if let ast::GenericParamKind::Const {
+            ref ty,
+            kw_span: _,
+            default: _,
+        } = &self.kind
+        {
             result.push_str("const ");
             result.push_str(rewrite_ident(context, self.ident));
             result.push_str(": ");

tests/target/imports_2021_edition.rs

@@ -0,0 +1,3 @@
+// rustfmt-edition: 2021
+
+use ::happy::new::year;

tests/target/macro_rules.rs

@@ -172,7 +172,7 @@ macro_rules! m [
 ];
 
 // #2470
-macro foo($type_name: ident, $docs: expr) {
+macro foo($type_name:ident, $docs:expr) {
     #[allow(non_camel_case_types)]
     #[doc=$docs]
     #[derive(Debug, Clone, Copy)]