Add some missing support for NtIdent

src/librustc_expand/mbe/macro_parser.rs

@@ -753,6 +753,12 @@ pub(super) fn parse_tt(parser: &mut Cow<'_, Parser<'_>>, ms: &[TokenTree]) -> Na
 fn get_macro_name(token: &Token) -> Option<(Name, bool)> {
     match token.kind {
         token::Ident(name, is_raw) if name != kw::Underscore => Some((name, is_raw)),
+        token::Interpolated(ref nt) => match **nt {
+            token::NtIdent(ident, is_raw) if ident.name != kw::Underscore => {
+                Some((ident.name, is_raw))
+            }
+            _ => None,
+        },
         _ => None,
     }
 }

src/librustc_parse/parser/diagnostics.rs

@@ -13,7 +13,7 @@ use syntax::ast::{
 };
 use syntax::ast::{AttrVec, ItemKind, Mutability, Pat, PatKind, PathSegment, QSelf, Ty, TyKind};
 use syntax::ptr::P;
-use syntax::token::{self, token_can_begin_expr, TokenKind};
+use syntax::token::{self, TokenKind};
 use syntax::util::parser::AssocOp;
 
 use log::{debug, trace};
@@ -900,8 +900,7 @@ impl<'a> Parser<'a> {
         } else if !sm.is_multiline(self.prev_span.until(self.token.span)) {
             // The current token is in the same line as the prior token, not recoverable.
         } else if self.look_ahead(1, |t| {
-            t == &token::CloseDelim(token::Brace)
-                || token_can_begin_expr(t) && t.kind != token::Colon
+            t == &token::CloseDelim(token::Brace) || t.can_begin_expr() && t.kind != token::Colon
         }) && [token::Comma, token::Colon].contains(&self.token.kind)
         {
             // Likely typo: `,` → `;` or `:` → `;`. This is triggered if the current token is
@@ -919,7 +918,7 @@ impl<'a> Parser<'a> {
         } else if self.look_ahead(0, |t| {
             t == &token::CloseDelim(token::Brace)
                 || (
-                    token_can_begin_expr(t) && t != &token::Semi && t != &token::Pound
+                    t.can_begin_expr() && t != &token::Semi && t != &token::Pound
                     // Avoid triggering with too many trailing `#` in raw string.
                 )
         }) {

src/libsyntax/token.rs

@@ -147,36 +147,30 @@ impl Lit {
 
 pub fn ident_can_begin_expr(name: ast::Name, span: Span, is_raw: bool) -> bool {
     let ident_token = Token::new(Ident(name, is_raw), span);
-    token_can_begin_expr(&ident_token)
-}
 
-pub fn token_can_begin_expr(ident_token: &Token) -> bool {
     !ident_token.is_reserved_ident()
         || ident_token.is_path_segment_keyword()
-        || match ident_token.kind {
-            TokenKind::Ident(ident, _) => [
-                kw::Async,
-                kw::Do,
-                kw::Box,
-                kw::Break,
-                kw::Continue,
-                kw::False,
-                kw::For,
-                kw::If,
-                kw::Let,
-                kw::Loop,
-                kw::Match,
-                kw::Move,
-                kw::Return,
-                kw::True,
-                kw::Unsafe,
-                kw::While,
-                kw::Yield,
-                kw::Static,
-            ]
-            .contains(&ident),
-            _ => false,
-        }
+        || [
+            kw::Async,
+            kw::Do,
+            kw::Box,
+            kw::Break,
+            kw::Continue,
+            kw::False,
+            kw::For,
+            kw::If,
+            kw::Let,
+            kw::Loop,
+            kw::Match,
+            kw::Move,
+            kw::Return,
+            kw::True,
+            kw::Unsafe,
+            kw::While,
+            kw::Yield,
+            kw::Static,
+        ]
+        .contains(&name)
 }
 
 fn ident_can_begin_type(name: ast::Name, span: Span, is_raw: bool) -> bool {
@@ -369,8 +363,8 @@ impl Token {
             Lifetime(..)                      | // labeled loop
             Pound                             => true, // expression attributes
             Interpolated(ref nt) => match **nt {
+                NtIdent(ident, is_raw) => ident_can_begin_expr(ident.name, ident.span, is_raw),
                 NtLiteral(..) |
-                NtIdent(..)   |
                 NtExpr(..)    |
                 NtBlock(..)   |
                 NtPath(..)    |
@@ -397,7 +391,8 @@ impl Token {
             Lt | BinOp(Shl)             | // associated path
             ModSep                      => true, // global path
             Interpolated(ref nt) => match **nt {
-                NtIdent(..) | NtTy(..) | NtPath(..) | NtLifetime(..) => true,
+                NtIdent(ident, is_raw) => ident_can_begin_type(ident.name, ident.span, is_raw),
+                NtTy(..) | NtPath(..) | NtLifetime(..) => true,
                 _ => false,
             },
             _ => false,
@@ -442,6 +437,7 @@ impl Token {
             Literal(..) | BinOp(Minus) => true,
             Ident(name, false) if name.is_bool_lit() => true,
             Interpolated(ref nt) => match &**nt {
+                NtIdent(ident, false) if ident.name.is_bool_lit() => true,
                 NtExpr(e) | NtLiteral(e) => matches!(e.kind, ast::ExprKind::Lit(_)),
                 _ => false,
             },

src/libsyntax/util/literal.rs

@@ -197,10 +197,17 @@ impl Lit {
             }
             token::Literal(lit) => lit,
             token::Interpolated(ref nt) => {
-                if let token::NtExpr(expr) | token::NtLiteral(expr) = &**nt {
-                    if let ast::ExprKind::Lit(lit) = &expr.kind {
-                        return Ok(lit.clone());
+                match &**nt {
+                    token::NtIdent(ident, false) if ident.name.is_bool_lit() => {
+                        let lit = token::Lit::new(token::Bool, ident.name, None);
+                        return Lit::from_lit_token(lit, ident.span);
                     }
+                    token::NtExpr(expr) | token::NtLiteral(expr) => {
+                        if let ast::ExprKind::Lit(lit) = &expr.kind {
+                            return Ok(lit.clone());
+                        }
+                    }
+                    _ => {}
                 }
                 return Err(LitError::NotLiteral);
             }