Merge pull request #18746 from lnicola/sync-from-rust

minor: Sync from downstream

13 files changed, 97 insertions, 113 deletions

diff --git a/src/tools/rustfmt/src/expr.rs b/src/tools/rustfmt/src/expr.rs
index 77c9818b66b..16b7e7aa709 100644
--- a/src/tools/rustfmt/src/expr.rs
+++ b/src/tools/rustfmt/src/expr.rs
@@ -413,7 +413,8 @@ pub(crate) fn format_expr(
         ast::ExprKind::FormatArgs(..)
         | ast::ExprKind::Type(..)
         | ast::ExprKind::IncludedBytes(..)
-        | ast::ExprKind::OffsetOf(..) => {
+        | ast::ExprKind::OffsetOf(..)
+        | ast::ExprKind::UnsafeBinderCast(..) => {
             // These don't normally occur in the AST because macros aren't expanded. However,
             // rustfmt tries to parse macro arguments when formatting macros, so it's not totally
             // impossible for rustfmt to come across one of these nodes when formatting a file.
diff --git a/src/tools/rustfmt/src/items.rs b/src/tools/rustfmt/src/items.rs
index 18932587f1f..c3debc2f4f0 100644
--- a/src/tools/rustfmt/src/items.rs
+++ b/src/tools/rustfmt/src/items.rs
@@ -3597,7 +3597,7 @@ pub(crate) fn rewrite_extern_crate(
 pub(crate) fn is_mod_decl(item: &ast::Item) -> bool {
     !matches!(
         item.kind,
-        ast::ItemKind::Mod(_, ast::ModKind::Loaded(_, ast::Inline::Yes, _))
+        ast::ItemKind::Mod(_, ast::ModKind::Loaded(_, ast::Inline::Yes, _, _))
     )
 }
 
diff --git a/src/tools/rustfmt/src/macros.rs b/src/tools/rustfmt/src/macros.rs
index 4083d9398f6..ea8ca38cb77 100644
--- a/src/tools/rustfmt/src/macros.rs
+++ b/src/tools/rustfmt/src/macros.rs
@@ -13,7 +13,7 @@ use std::collections::HashMap;
 use std::panic::{AssertUnwindSafe, catch_unwind};
 
 use rustc_ast::token::{BinOpToken, Delimiter, Token, TokenKind};
-use rustc_ast::tokenstream::{RefTokenTreeCursor, TokenStream, TokenTree};
+use rustc_ast::tokenstream::{TokenStream, TokenStreamIter, TokenTree};
 use rustc_ast::{ast, ptr};
 use rustc_ast_pretty::pprust;
 use rustc_span::{
@@ -443,7 +443,7 @@ pub(crate) fn rewrite_macro_def(
     }
 
     let ts = def.body.tokens.clone();
-    let mut parser = MacroParser::new(ts.trees());
+    let mut parser = MacroParser::new(ts.iter());
     let parsed_def = match parser.parse() {
         Some(def) => def,
         None => return snippet,
@@ -794,7 +794,7 @@ impl MacroArgParser {
         self.buf.clear();
     }
 
-    fn add_meta_variable(&mut self, iter: &mut RefTokenTreeCursor<'_>) -> Option<()> {
+    fn add_meta_variable(&mut self, iter: &mut TokenStreamIter<'_>) -> Option<()> {
         match iter.next() {
             Some(&TokenTree::Token(
                 Token {
@@ -826,7 +826,7 @@ impl MacroArgParser {
         &mut self,
         inner: Vec<ParsedMacroArg>,
         delim: Delimiter,
-        iter: &mut RefTokenTreeCursor<'_>,
+        iter: &mut TokenStreamIter<'_>,
     ) -> Option<()> {
         let mut buffer = String::new();
         let mut first = true;
@@ -926,7 +926,7 @@ impl MacroArgParser {
 
     /// Returns a collection of parsed macro def's arguments.
     fn parse(mut self, tokens: TokenStream) -> Option<Vec<ParsedMacroArg>> {
-        let mut iter = tokens.trees();
+        let mut iter = tokens.iter();
 
         while let Some(tok) = iter.next() {
             match tok {
@@ -1063,7 +1063,7 @@ fn format_macro_args(
 }
 
 fn span_for_token_stream(token_stream: &TokenStream) -> Option<Span> {
-    token_stream.trees().next().map(|tt| tt.span())
+    token_stream.iter().next().map(|tt| tt.span())
 }
 
 // We should insert a space if the next token is a:
@@ -1179,18 +1179,18 @@ pub(crate) fn macro_style(mac: &ast::MacCall, context: &RewriteContext<'_>) -> D
 // A very simple parser that just parses a macros 2.0 definition into its branches.
 // Currently we do not attempt to parse any further than that.
 struct MacroParser<'a> {
-    toks: RefTokenTreeCursor<'a>,
+    iter: TokenStreamIter<'a>,
 }
 
 impl<'a> MacroParser<'a> {
-    const fn new(toks: RefTokenTreeCursor<'a>) -> Self {
-        Self { toks }
+    const fn new(iter: TokenStreamIter<'a>) -> Self {
+        Self { iter }
     }
 
     // (`(` ... `)` `=>` `{` ... `}`)*
     fn parse(&mut self) -> Option<Macro> {
         let mut branches = vec![];
-        while self.toks.look_ahead(1).is_some() {
+        while self.iter.peek().is_some() {
             branches.push(self.parse_branch()?);
         }
 
@@ -1199,13 +1199,13 @@ impl<'a> MacroParser<'a> {
 
     // `(` ... `)` `=>` `{` ... `}`
     fn parse_branch(&mut self) -> Option<MacroBranch> {
-        let tok = self.toks.next()?;
+        let tok = self.iter.next()?;
         let (lo, args_paren_kind) = match tok {
             TokenTree::Token(..) => return None,
             &TokenTree::Delimited(delimited_span, _, d, _) => (delimited_span.open.lo(), d),
         };
         let args = TokenStream::new(vec![tok.clone()]);
-        match self.toks.next()? {
+        match self.iter.next()? {
             TokenTree::Token(
                 Token {
                     kind: TokenKind::FatArrow,
@@ -1215,7 +1215,7 @@ impl<'a> MacroParser<'a> {
             ) => {}
             _ => return None,
         }
-        let (mut hi, body, whole_body) = match self.toks.next()? {
+        let (mut hi, body, whole_body) = match self.iter.next()? {
             TokenTree::Token(..) => return None,
             TokenTree::Delimited(delimited_span, ..) => {
                 let data = delimited_span.entire().data();
@@ -1237,10 +1237,10 @@ impl<'a> MacroParser<'a> {
                 span,
             },
             _,
-        )) = self.toks.look_ahead(0)
+        )) = self.iter.peek()
         {
             hi = span.hi();
-            self.toks.next();
+            self.iter.next();
         }
         Some(MacroBranch {
             span: mk_sp(lo, hi),
diff --git a/src/tools/rustfmt/src/modules.rs b/src/tools/rustfmt/src/modules.rs
index 493b04f16c6..a40ee7f66a9 100644
--- a/src/tools/rustfmt/src/modules.rs
+++ b/src/tools/rustfmt/src/modules.rs
@@ -316,12 +316,11 @@ impl<'ast, 'psess, 'c> ModResolver<'ast, 'psess> {
             self.directory = directory;
         }
         match (sub_mod.ast_mod_kind, sub_mod.items) {
-            (Some(Cow::Borrowed(ast::ModKind::Loaded(items, _, _))), _) => {
+            (Some(Cow::Borrowed(ast::ModKind::Loaded(items, _, _, _))), _) => {
                 self.visit_mod_from_ast(items)
             }
-            (Some(Cow::Owned(ast::ModKind::Loaded(items, _, _))), _) | (_, Cow::Owned(items)) => {
-                self.visit_mod_outside_ast(items)
-            }
+            (Some(Cow::Owned(ast::ModKind::Loaded(items, _, _, _))), _)
+            | (_, Cow::Owned(items)) => self.visit_mod_outside_ast(items),
             (_, _) => Ok(()),
         }
     }
diff --git a/src/tools/rustfmt/src/parse/macros/cfg_if.rs b/src/tools/rustfmt/src/parse/macros/cfg_if.rs
index ec771f96a3f..0b7b6c4d361 100644
--- a/src/tools/rustfmt/src/parse/macros/cfg_if.rs
+++ b/src/tools/rustfmt/src/parse/macros/cfg_if.rs
@@ -2,6 +2,7 @@ use std::panic::{AssertUnwindSafe, catch_unwind};
 
 use rustc_ast::ast;
 use rustc_ast::token::{Delimiter, TokenKind};
+use rustc_parse::exp;
 use rustc_parse::parser::ForceCollect;
 use rustc_span::symbol::kw;
 
@@ -31,7 +32,7 @@ fn parse_cfg_if_inner<'a>(
 
     while parser.token.kind != TokenKind::Eof {
         if process_if_cfg {
-            if !parser.eat_keyword(kw::If) {
+            if !parser.eat_keyword(exp!(If)) {
                 return Err("Expected `if`");
             }
 
@@ -55,7 +56,7 @@ fn parse_cfg_if_inner<'a>(
                 })?;
         }
 
-        if !parser.eat(&TokenKind::OpenDelim(Delimiter::Brace)) {
+        if !parser.eat(exp!(OpenBrace)) {
             return Err("Expected an opening brace");
         }
 
@@ -78,15 +79,15 @@ fn parse_cfg_if_inner<'a>(
             }
         }
 
-        if !parser.eat(&TokenKind::CloseDelim(Delimiter::Brace)) {
+        if !parser.eat(exp!(CloseBrace)) {
             return Err("Expected a closing brace");
         }
 
-        if parser.eat(&TokenKind::Eof) {
+        if parser.eat(exp!(Eof)) {
             break;
         }
 
-        if !parser.eat_keyword(kw::Else) {
+        if !parser.eat_keyword(exp!(Else)) {
             return Err("Expected `else`");
         }
 
diff --git a/src/tools/rustfmt/src/parse/macros/lazy_static.rs b/src/tools/rustfmt/src/parse/macros/lazy_static.rs
index b6de5f8691c..cbe81004e22 100644
--- a/src/tools/rustfmt/src/parse/macros/lazy_static.rs
+++ b/src/tools/rustfmt/src/parse/macros/lazy_static.rs
@@ -1,8 +1,9 @@
 use rustc_ast::ast;
 use rustc_ast::ptr::P;
-use rustc_ast::token::TokenKind;
+use rustc_ast::token;
 use rustc_ast::tokenstream::TokenStream;
-use rustc_span::symbol::{self, kw};
+use rustc_parse::exp;
+use rustc_span::symbol;
 
 use crate::rewrite::RewriteContext;
 
@@ -31,19 +32,19 @@ pub(crate) fn parse_lazy_static(
             }
         }
     }
-    while parser.token.kind != TokenKind::Eof {
+    while parser.token.kind != token::Eof {
         // Parse a `lazy_static!` item.
         // FIXME: These `eat_*` calls should be converted to `parse_or` to avoid
         // silently formatting malformed lazy-statics.
         let vis = parse_or!(parse_visibility, rustc_parse::parser::FollowedByType::No);
-        let _ = parser.eat_keyword(kw::Static);
-        let _ = parser.eat_keyword(kw::Ref);
+        let _ = parser.eat_keyword(exp!(Static));
+        let _ = parser.eat_keyword(exp!(Ref));
         let id = parse_or!(parse_ident);
-        let _ = parser.eat(&TokenKind::Colon);
+        let _ = parser.eat(exp!(Colon));
         let ty = parse_or!(parse_ty);
-        let _ = parser.eat(&TokenKind::Eq);
+        let _ = parser.eat(exp!(Eq));
         let expr = parse_or!(parse_expr);
-        let _ = parser.eat(&TokenKind::Semi);
+        let _ = parser.eat(exp!(Semi));
         result.push((vis, id, ty, expr));
     }
 
diff --git a/src/tools/rustfmt/src/parse/macros/mod.rs b/src/tools/rustfmt/src/parse/macros/mod.rs
index 7271e73db8d..680a35f7e03 100644
--- a/src/tools/rustfmt/src/parse/macros/mod.rs
+++ b/src/tools/rustfmt/src/parse/macros/mod.rs
@@ -4,8 +4,7 @@ use rustc_ast::{ast, ptr};
 use rustc_parse::MACRO_ARGUMENTS;
 use rustc_parse::parser::{ForceCollect, Parser, Recovery};
 use rustc_session::parse::ParseSess;
-use rustc_span::Symbol;
-use rustc_span::symbol::{self, kw};
+use rustc_span::symbol;
 
 use crate::macros::MacroArg;
 use crate::rewrite::RewriteContext;
@@ -82,18 +81,18 @@ pub(crate) struct ParsedMacroArgs {
 }
 
 fn check_keyword<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
-    for &keyword in RUST_KW.iter() {
-        if parser.token.is_keyword(keyword)
-            && parser.look_ahead(1, |t| *t == TokenKind::Eof || *t == TokenKind::Comma)
-        {
-            parser.bump();
-            return Some(MacroArg::Keyword(
-                symbol::Ident::with_dummy_span(keyword),
-                parser.prev_token.span,
-            ));
-        }
+    if parser.token.is_any_keyword()
+        && parser.look_ahead(1, |t| *t == TokenKind::Eof || *t == TokenKind::Comma)
+    {
+        let keyword = parser.token.ident().unwrap().0.name;
+        parser.bump();
+        Some(MacroArg::Keyword(
+            symbol::Ident::with_dummy_span(keyword),
+            parser.prev_token.span,
+        ))
+    } else {
+        None
     }
-    None
 }
 
 pub(crate) fn parse_macro_args(
@@ -169,65 +168,3 @@ pub(crate) fn parse_expr(
     let mut parser = build_parser(context, tokens);
     parser.parse_expr().ok()
 }
-
-const RUST_KW: [Symbol; 59] = [
-    kw::PathRoot,
-    kw::DollarCrate,
-    kw::Underscore,
-    kw::As,
-    kw::Box,
-    kw::Break,
-    kw::Const,
-    kw::Continue,
-    kw::Crate,
-    kw::Else,
-    kw::Enum,
-    kw::Extern,
-    kw::False,
-    kw::Fn,
-    kw::For,
-    kw::If,
-    kw::Impl,
-    kw::In,
-    kw::Let,
-    kw::Loop,
-    kw::Match,
-    kw::Mod,
-    kw::Move,
-    kw::Mut,
-    kw::Pub,
-    kw::Ref,
-    kw::Return,
-    kw::SelfLower,
-    kw::SelfUpper,
-    kw::Static,
-    kw::Struct,
-    kw::Super,
-    kw::Trait,
-    kw::True,
-    kw::Type,
-    kw::Unsafe,
-    kw::Use,
-    kw::Where,
-    kw::While,
-    kw::Abstract,
-    kw::Become,
-    kw::Do,
-    kw::Final,
-    kw::Macro,
-    kw::Override,
-    kw::Priv,
-    kw::Typeof,
-    kw::Unsized,
-    kw::Virtual,
-    kw::Yield,
-    kw::Dyn,
-    kw::Async,
-    kw::Try,
-    kw::UnderscoreLifetime,
-    kw::StaticLifetime,
-    kw::Auto,
-    kw::Catch,
-    kw::Default,
-    kw::Union,
-];
diff --git a/src/tools/rustfmt/src/parse/parser.rs b/src/tools/rustfmt/src/parse/parser.rs
index 28b4c2b612f..f357aed66c2 100644
--- a/src/tools/rustfmt/src/parse/parser.rs
+++ b/src/tools/rustfmt/src/parse/parser.rs
@@ -1,11 +1,10 @@
 use std::panic::{AssertUnwindSafe, catch_unwind};
 use std::path::{Path, PathBuf};
 
-use rustc_ast::token::TokenKind;
 use rustc_ast::{ast, attr, ptr};
 use rustc_errors::Diag;
 use rustc_parse::parser::Parser as RawParser;
-use rustc_parse::{new_parser_from_file, new_parser_from_source_str, unwrap_or_emit_fatal};
+use rustc_parse::{exp, new_parser_from_file, new_parser_from_source_str, unwrap_or_emit_fatal};
 use rustc_span::{Span, sym};
 use thin_vec::ThinVec;
 
@@ -107,7 +106,7 @@ impl<'a> Parser<'a> {
         let result = catch_unwind(AssertUnwindSafe(|| {
             let mut parser =
                 unwrap_or_emit_fatal(new_parser_from_file(psess.inner(), path, Some(span)));
-            match parser.parse_mod(&TokenKind::Eof) {
+            match parser.parse_mod(exp!(Eof)) {
                 Ok((a, i, spans)) => Some((a, i, spans.inner_span)),
                 Err(e) => {
                     e.emit();
diff --git a/src/tools/rustfmt/src/types.rs b/src/tools/rustfmt/src/types.rs
index dd4a788c002..f8b713117f4 100644
--- a/src/tools/rustfmt/src/types.rs
+++ b/src/tools/rustfmt/src/types.rs
@@ -1016,6 +1016,31 @@ impl Rewrite for ast::Ty {
                 let pat = pat.rewrite_result(context, shape)?;
                 Ok(format!("{ty} is {pat}"))
             }
+            ast::TyKind::UnsafeBinder(ref binder) => {
+                let mut result = String::new();
+                if let Some(ref lifetime_str) =
+                    rewrite_bound_params(context, shape, &binder.generic_params)
+                {
+                    result.push_str("unsafe<");
+                    result.push_str(lifetime_str);
+                    result.push_str("> ");
+                }
+
+                let inner_ty_shape = if context.use_block_indent() {
+                    shape
+                        .offset_left(result.len())
+                        .max_width_error(shape.width, self.span())?
+                } else {
+                    shape
+                        .visual_indent(result.len())
+                        .sub_width(result.len())
+                        .max_width_error(shape.width, self.span())?
+                };
+
+                let rewrite = binder.inner_ty.rewrite_result(context, inner_ty_shape)?;
+                result.push_str(&rewrite);
+                Ok(result)
+            }
         }
     }
 }
diff --git a/src/tools/rustfmt/src/utils.rs b/src/tools/rustfmt/src/utils.rs
index 0ca34a79491..ba4a4c045f1 100644
--- a/src/tools/rustfmt/src/utils.rs
+++ b/src/tools/rustfmt/src/utils.rs
@@ -504,6 +504,7 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::IncludedBytes(..)
         | ast::ExprKind::InlineAsm(..)
         | ast::ExprKind::OffsetOf(..)
+        | ast::ExprKind::UnsafeBinderCast(..)
         | ast::ExprKind::Let(..)
         | ast::ExprKind::Path(..)
         | ast::ExprKind::Range(..)
diff --git a/src/tools/rustfmt/src/visitor.rs b/src/tools/rustfmt/src/visitor.rs
index 9b116b620b7..805e13b7803 100644
--- a/src/tools/rustfmt/src/visitor.rs
+++ b/src/tools/rustfmt/src/visitor.rs
@@ -927,7 +927,7 @@ impl<'b, 'a: 'b> FmtVisitor<'a> {
         let ident_str = rewrite_ident(&self.get_context(), ident).to_owned();
         self.push_str(&ident_str);
 
-        if let ast::ModKind::Loaded(ref items, ast::Inline::Yes, ref spans) = mod_kind {
+        if let ast::ModKind::Loaded(ref items, ast::Inline::Yes, ref spans, _) = mod_kind {
             let ast::ModSpans {
                 inner_span,
                 inject_use_span: _,
diff --git a/src/tools/rustfmt/tests/source/unsafe-binders.rs b/src/tools/rustfmt/tests/source/unsafe-binders.rs
new file mode 100644
index 00000000000..ccf7c8bb9af
--- /dev/null
+++ b/src/tools/rustfmt/tests/source/unsafe-binders.rs
@@ -0,0 +1,11 @@
+fn foo() -> unsafe<'a>
+&'a () {}
+
+struct Foo {
+    x: unsafe<'a>
+&'a (),
+}
+
+struct Bar(unsafe<'a> &'a ());
+
+impl Trait for unsafe<'a> &'a () {}
diff --git a/src/tools/rustfmt/tests/target/unsafe-binders.rs b/src/tools/rustfmt/tests/target/unsafe-binders.rs
new file mode 100644
index 00000000000..9d308f4a894
--- /dev/null
+++ b/src/tools/rustfmt/tests/target/unsafe-binders.rs
@@ -0,0 +1,9 @@
+fn foo() -> unsafe<'a> &'a () {}
+
+struct Foo {
+    x: unsafe<'a> &'a (),
+}
+
+struct Bar(unsafe<'a> &'a ());
+
+impl Trait for unsafe<'a> &'a () {}