Rollup merge of #69384 - petrochenkov:nounnorm, r=Centril

parser: `token` -> `normalized_token`, `nonnormalized_token` -> `token`

So, after https://github.com/rust-lang/rust/pull/69006, its follow-ups and an attempt to remove `Parser::prev_span` I came to the conclusion that the unnormalized token and its span is what you want in most cases, so it should be default.

Normalization only makes difference in few cases where we are checking against `token::Ident` or `token::Lifetime` specifically.
This PR uses `normalized_token` for those cases.

Using normalization explicitly means that people writing code should remember about `NtIdent` and `NtLifetime` in general. (That is alleviated by the fact that `token.ident()` and `fn parse_ident_*` are already written.)
Remembering about `NtIdent`, was, however, already the case, kind of, because the implicit normalization was performed only for the current/previous token, but not for things like `look_ahead`.
As a result, most of token classification methods in `token.rs` already take `NtIdent` into account (this PR fixes a few pre-existing minor mistakes though).

The next step is removing `normalized(_prev)_token` entirely and replacing it with `token.ident()` (mostly) and `token.normalize()` (occasionally).
I want to make it a separate PR for that and run it though perf.
`normalized_token` filled on every bump has both a potential to avoid repeated normalization, and to do unnecessary work in advance (it probably doesn't matter anyway, the normalization is very cheap).

r? @Centril

1 files changed, 23 insertions, 25 deletions

diff --git a/src/librustc_parse/parser/mod.rs b/src/librustc_parse/parser/mod.rs
index 7b8642b0151..58a03ee2a74 100644
--- a/src/librustc_parse/parser/mod.rs
+++ b/src/librustc_parse/parser/mod.rs
@@ -86,23 +86,22 @@ macro_rules! maybe_recover_from_interpolated_ty_qpath {
 #[derive(Clone)]
 pub struct Parser<'a> {
     pub sess: &'a ParseSess,
+    /// The current non-normalized token.
+    pub token: Token,
     /// The current normalized token.
     /// "Normalized" means that some interpolated tokens
     /// (`$i: ident` and `$l: lifetime` meta-variables) are replaced
     /// with non-interpolated identifier and lifetime tokens they refer to.
-    /// Use span from this token if you need an isolated span.
-    pub token: Token,
-    /// The current non-normalized token if it's different from `token`.
-    /// Use span from this token if you need to concatenate it with some neighbouring spans.
-    unnormalized_token: Token,
+    /// Use this if you need to check for `token::Ident` or `token::Lifetime` specifically,
+    /// this also includes edition checks for edition-specific keyword identifiers.
+    pub normalized_token: Token,
+    /// The previous non-normalized token.
+    pub prev_token: Token,
     /// The previous normalized token.
-    /// Use span from this token if you need an isolated span.
-    prev_token: Token,
-    /// The previous non-normalized token if it's different from `prev_token`.
-    /// Use span from this token if you need to concatenate it with some neighbouring spans.
-    unnormalized_prev_token: Token,
-    /// Equivalent to `unnormalized_prev_token.span`.
-    /// FIXME: Remove in favor of `(unnormalized_)prev_token.span`.
+    /// Use this if you need to check for `token::Ident` or `token::Lifetime` specifically,
+    /// this also includes edition checks for edition-specific keyword identifiers.
+    pub normalized_prev_token: Token,
+    /// FIXME: Remove in favor of the equivalent `prev_token.span`.
     pub prev_span: Span,
     restrictions: Restrictions,
     /// Used to determine the path to externally loaded source files.
@@ -375,9 +374,9 @@ impl<'a> Parser<'a> {
         let mut parser = Parser {
             sess,
             token: Token::dummy(),
-            unnormalized_token: Token::dummy(),
+            normalized_token: Token::dummy(),
             prev_token: Token::dummy(),
-            unnormalized_prev_token: Token::dummy(),
+            normalized_prev_token: Token::dummy(),
             prev_span: DUMMY_SP,
             restrictions: Restrictions::empty(),
             recurse_into_file_modules,
@@ -482,7 +481,7 @@ impl<'a> Parser<'a> {
     }
 
     fn parse_ident_common(&mut self, recover: bool) -> PResult<'a, ast::Ident> {
-        match self.token.kind {
+        match self.normalized_token.kind {
             token::Ident(name, _) => {
                 if self.token.is_reserved_ident() {
                     let mut err = self.expected_ident_found();
@@ -492,9 +491,8 @@ impl<'a> Parser<'a> {
                         return Err(err);
                     }
                 }
-                let span = self.token.span;
                 self.bump();
-                Ok(Ident::new(name, span))
+                Ok(Ident::new(name, self.normalized_prev_token.span))
             }
             _ => Err(match self.prev_token.kind {
                 TokenKind::DocComment(..) => {
@@ -824,16 +822,16 @@ impl<'a> Parser<'a> {
     // tokens are replaced with usual identifier and lifetime tokens,
     // so the former are never encountered during normal parsing.
     crate fn set_token(&mut self, token: Token) {
-        self.unnormalized_token = token;
-        self.token = match &self.unnormalized_token.kind {
+        self.token = token;
+        self.normalized_token = match &self.token.kind {
             token::Interpolated(nt) => match **nt {
                 token::NtIdent(ident, is_raw) => {
                     Token::new(token::Ident(ident.name, is_raw), ident.span)
                 }
                 token::NtLifetime(ident) => Token::new(token::Lifetime(ident.name), ident.span),
-                _ => self.unnormalized_token.clone(),
+                _ => self.token.clone(),
             },
-            _ => self.unnormalized_token.clone(),
+            _ => self.token.clone(),
         }
     }
 
@@ -847,11 +845,11 @@ impl<'a> Parser<'a> {
 
         // Update the current and previous tokens.
         self.prev_token = self.token.take();
-        self.unnormalized_prev_token = self.unnormalized_token.take();
+        self.normalized_prev_token = self.normalized_token.take();
         self.set_token(next_token);
 
         // Update fields derived from the previous token.
-        self.prev_span = self.unnormalized_prev_token.span;
+        self.prev_span = self.prev_token.span;
 
         // Diagnostics.
         self.expected_tokens.clear();
@@ -859,7 +857,7 @@ impl<'a> Parser<'a> {
 
     /// Advance the parser by one token.
     pub fn bump(&mut self) {
-        let next_token = self.next_tok(self.unnormalized_token.span);
+        let next_token = self.next_tok(self.token.span);
         self.bump_with(next_token);
     }
 
@@ -890,7 +888,7 @@ impl<'a> Parser<'a> {
     /// Parses asyncness: `async` or nothing.
     fn parse_asyncness(&mut self) -> Async {
         if self.eat_keyword(kw::Async) {
-            let span = self.prev_span;
+            let span = self.normalized_prev_token.span;
             Async::Yes { span, closure_id: DUMMY_NODE_ID, return_impl_trait_id: DUMMY_NODE_ID }
         } else {
             Async::No