Tweak more warnings.

Much like the previous commit.

I think the removal of "the token" in each message is fine here. There
are many more error messages that mention tokens without saying "the
token" than those that do say it.

Author: nnethercote

compiler/rustc_expand/src/mbe/diagnostics.rs

@@ -2,10 +2,9 @@ use std::borrow::Cow;
 
 use rustc_ast::token::{self, Token, TokenKind};
 use rustc_ast::tokenstream::TokenStream;
-use rustc_ast_pretty::pprust;
 use rustc_errors::{Applicability, Diag, DiagCtxtHandle, DiagMessage};
 use rustc_macros::Subdiagnostic;
-use rustc_parse::parser::{Parser, Recovery};
+use rustc_parse::parser::{Parser, Recovery, token_descr};
 use rustc_session::parse::ParseSess;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::Ident;
@@ -336,17 +335,11 @@ pub(super) fn annotate_doc_comment(err: &mut Diag<'_>, sm: &SourceMap, span: Spa
 /// other tokens, this is "unexpected token...".
 pub(super) fn parse_failure_msg(tok: &Token, expected_token: Option<&Token>) -> Cow<'static, str> {
     if let Some(expected_token) = expected_token {
-        Cow::from(format!(
-            "expected `{}`, found `{}`",
-            pprust::token_to_string(expected_token),
-            pprust::token_to_string(tok),
-        ))
+        Cow::from(format!("expected {}, found {}", token_descr(expected_token), token_descr(tok)))
     } else {
         match tok.kind {
             token::Eof => Cow::from("unexpected end of macro invocation"),
-            _ => {
-                Cow::from(format!("no rules expected the token `{}`", pprust::token_to_string(tok)))
-            }
+            _ => Cow::from(format!("no rules expected {}", token_descr(tok))),
         }
     }
 }

compiler/rustc_expand/src/mbe/macro_parser.rs

@@ -78,11 +78,10 @@ use std::rc::Rc;
 pub(crate) use NamedMatch::*;
 pub(crate) use ParseResult::*;
 use rustc_ast::token::{self, DocComment, NonterminalKind, Token};
-use rustc_ast_pretty::pprust;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_errors::ErrorGuaranteed;
 use rustc_lint_defs::pluralize;
-use rustc_parse::parser::{ParseNtResult, Parser};
+use rustc_parse::parser::{ParseNtResult, Parser, token_descr};
 use rustc_span::Span;
 use rustc_span::symbol::{Ident, MacroRulesNormalizedIdent};
 
@@ -150,7 +149,7 @@ impl Display for MatcherLoc {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             MatcherLoc::Token { token } | MatcherLoc::SequenceSep { separator: token } => {
-                write!(f, "`{}`", pprust::token_to_string(token))
+                write!(f, "{}", token_descr(token))
             }
             MatcherLoc::MetaVarDecl { bind, kind, .. } => {
                 write!(f, "meta-variable `${bind}")?;

tests/ui/array-slice-vec/vec-macro-with-comma-only.rs

@@ -1,3 +1,3 @@
 pub fn main() {
-    vec![,]; //~ ERROR no rules expected the token `,`
+    vec![,]; //~ ERROR no rules expected `,`
 }

tests/ui/array-slice-vec/vec-macro-with-comma-only.stderr

@@ -1,4 +1,4 @@
-error: no rules expected the token `,`
+error: no rules expected `,`
   --> $DIR/vec-macro-with-comma-only.rs:2:10
    |
 LL |     vec![,];

tests/ui/editions/edition-keywords-2015-2015-parsing.rs

@@ -13,8 +13,8 @@ pub fn check_async() {
     let mut r#async = 1; // OK
 
     r#async = consumes_async!(async); // OK
-    r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-    r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
+    r#async = consumes_async!(r#async); //~ ERROR no rules expected `r#async`
+    r#async = consumes_async_raw!(async); //~ ERROR no rules expected `async`
     r#async = consumes_async_raw!(r#async); // OK
 
     if passes_ident!(async) == 1 {} // OK

tests/ui/editions/edition-keywords-2015-2015-parsing.stderr

@@ -1,4 +1,4 @@
-error: no rules expected the token `r#async`
+error: no rules expected `r#async`
   --> $DIR/edition-keywords-2015-2015-parsing.rs:16:31
    |
 LL |     r#async = consumes_async!(r#async);
@@ -10,7 +10,7 @@ note: while trying to match `async`
 LL |     (async) => (1)
    |      ^^^^^
 
-error: no rules expected the token `async`
+error: no rules expected `async`
   --> $DIR/edition-keywords-2015-2015-parsing.rs:17:35
    |
 LL |     r#async = consumes_async_raw!(async);

tests/ui/editions/edition-keywords-2015-2018-parsing.rs

@@ -13,8 +13,8 @@ pub fn check_async() {
     let mut r#async = 1; // OK
 
     r#async = consumes_async!(async); // OK
-    r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-    r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
+    r#async = consumes_async!(r#async); //~ ERROR no rules expected `r#async`
+    r#async = consumes_async_raw!(async); //~ ERROR no rules expected `async`
     r#async = consumes_async_raw!(r#async); // OK
 
     if passes_ident!(async) == 1 {} // OK

tests/ui/editions/edition-keywords-2015-2018-parsing.stderr

@@ -1,4 +1,4 @@
-error: no rules expected the token `r#async`
+error: no rules expected `r#async`
   --> $DIR/edition-keywords-2015-2018-parsing.rs:16:31
    |
 LL |     r#async = consumes_async!(r#async);
@@ -10,7 +10,7 @@ note: while trying to match `async`
 LL |     (async) => (1)
    |      ^^^^^
 
-error: no rules expected the token `async`
+error: no rules expected `async`
   --> $DIR/edition-keywords-2015-2018-parsing.rs:17:35
    |
 LL |     r#async = consumes_async_raw!(async);

tests/ui/editions/edition-keywords-2018-2015-parsing.rs

@@ -17,8 +17,8 @@ pub fn check_async() {
     let mut r#async = 1; // OK
 
     r#async = consumes_async!(async); // OK
-    r#async = consumes_async!(r#async); //~ ERROR no rules expected the token `r#async`
-    r#async = consumes_async_raw!(async); //~ ERROR no rules expected the token `async`
+    r#async = consumes_async!(r#async); //~ ERROR no rules expected `r#async`
+    r#async = consumes_async_raw!(async); //~ ERROR no rules expected keyword `async`
     r#async = consumes_async_raw!(r#async); // OK
 
     if passes_ident!(async) == 1 {} // FIXME: Edition hygiene bug, async here is 2018 and reserved

tests/ui/editions/edition-keywords-2018-2015-parsing.stderr

@@ -20,19 +20,19 @@ help: escape `async` to use it as an identifier
 LL |     module::r#async();
    |             ++
 
-error: no rules expected the token `r#async`
+error: no rules expected `r#async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:20:31
    |
 LL |     r#async = consumes_async!(r#async);
    |                               ^^^^^^^ no rules expected this token in macro call
    |
-note: while trying to match `async`
+note: while trying to match keyword `async`
   --> $DIR/auxiliary/edition-kw-macro-2015.rs:17:6
    |
 LL |     (async) => (1)
    |      ^^^^^
 
-error: no rules expected the token `async`
+error: no rules expected keyword `async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:21:35
    |
 LL |     r#async = consumes_async_raw!(async);