Rollup merge of #140147 - xizheyin:issue-138401-1, r=compiler-errors

Clean: rename `open_braces` to `open_delimiters` in lexer and move `make_unclosed_delims_error` into `diagnostics.rs`.

Clean code prepared for resolving #138401. To avoid having too many extraneous changes in one PR, I cleaned up some of the naming and method placement in lexer in this PR.
1. For the make_unclosed_delims_error function defined in mod.rs is only used in lexer, so moved into lexer, which enhances encapsulation.
2. For open_braces in TokenTreeDiagInfo the naming is not canonical, as Brace refers to `{...} ` and this variable can store all kinds of different Delimiters. so I named it open_delimiters.

r? `@chenyukang`

5 files changed, 54 insertions, 50 deletions

diff --git a/compiler/rustc_parse/src/lexer/diagnostics.rs b/compiler/rustc_parse/src/lexer/diagnostics.rs
index e1f19beb53a..0b97d4e6993 100644
--- a/compiler/rustc_parse/src/lexer/diagnostics.rs
+++ b/compiler/rustc_parse/src/lexer/diagnostics.rs
@@ -1,14 +1,17 @@
 use rustc_ast::token::Delimiter;
 use rustc_errors::Diag;
+use rustc_session::parse::ParseSess;
 use rustc_span::Span;
 use rustc_span::source_map::SourceMap;
 
 use super::UnmatchedDelim;
+use crate::errors::MismatchedClosingDelimiter;
+use crate::pprust;
 
 #[derive(Default)]
 pub(super) struct TokenTreeDiagInfo {
     /// Stack of open delimiters and their spans. Used for error message.
-    pub open_braces: Vec<(Delimiter, Span)>,
+    pub open_delimiters: Vec<(Delimiter, Span)>,
     pub unmatched_delims: Vec<UnmatchedDelim>,
 
     /// Used only for error recovery when arriving to EOF with mismatched braces.
@@ -108,7 +111,7 @@ pub(super) fn report_suspicious_mismatch_block(
     } else {
         // If there is no suspicious span, give the last properly closed block may help
         if let Some(parent) = diag_info.matching_block_spans.last()
-            && diag_info.open_braces.last().is_none()
+            && diag_info.open_delimiters.last().is_none()
             && diag_info.empty_block_spans.iter().all(|&sp| sp != parent.0.to(parent.1))
         {
             err.span_label(parent.0, "this opening brace...");
@@ -116,3 +119,24 @@ pub(super) fn report_suspicious_mismatch_block(
         }
     }
 }
+
+pub(crate) fn make_unclosed_delims_error(
+    unmatched: UnmatchedDelim,
+    psess: &ParseSess,
+) -> Option<Diag<'_>> {
+    // `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to
+    // `unmatched_delims` only for error recovery in the `Parser`.
+    let found_delim = unmatched.found_delim?;
+    let mut spans = vec![unmatched.found_span];
+    if let Some(sp) = unmatched.unclosed_span {
+        spans.push(sp);
+    };
+    let err = psess.dcx().create_err(MismatchedClosingDelimiter {
+        spans,
+        delimiter: pprust::token_kind_to_string(&found_delim.as_close_token_kind()).to_string(),
+        unmatched: unmatched.found_span,
+        opening_candidate: unmatched.candidate_span,
+        unclosed: unmatched.unclosed_span,
+    });
+    Some(err)
+}
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index a8ec9a1e952..da4f11a3f46 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -1,5 +1,6 @@
 use std::ops::Range;
 
+use diagnostics::make_unclosed_delims_error;
 use rustc_ast::ast::{self, AttrStyle};
 use rustc_ast::token::{self, CommentKind, Delimiter, IdentIsRaw, Token, TokenKind};
 use rustc_ast::tokenstream::TokenStream;
@@ -17,9 +18,9 @@ use rustc_session::parse::ParseSess;
 use rustc_span::{BytePos, Pos, Span, Symbol};
 use tracing::debug;
 
+use crate::errors;
 use crate::lexer::diagnostics::TokenTreeDiagInfo;
 use crate::lexer::unicode_chars::UNICODE_ARRAY;
-use crate::{errors, make_unclosed_delims_error};
 
 mod diagnostics;
 mod tokentrees;
diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs
index 0ddd9a85df8..fbea958dcc5 100644
--- a/compiler/rustc_parse/src/lexer/tokentrees.rs
+++ b/compiler/rustc_parse/src/lexer/tokentrees.rs
@@ -54,8 +54,8 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         let mut err = self.dcx().struct_span_err(self.token.span, msg);
 
         let unclosed_delimiter_show_limit = 5;
-        let len = usize::min(unclosed_delimiter_show_limit, self.diag_info.open_braces.len());
-        for &(_, span) in &self.diag_info.open_braces[..len] {
+        let len = usize::min(unclosed_delimiter_show_limit, self.diag_info.open_delimiters.len());
+        for &(_, span) in &self.diag_info.open_delimiters[..len] {
             err.span_label(span, "unclosed delimiter");
             self.diag_info.unmatched_delims.push(UnmatchedDelim {
                 found_delim: None,
@@ -65,19 +65,19 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
             });
         }
 
-        if let Some((_, span)) = self.diag_info.open_braces.get(unclosed_delimiter_show_limit)
-            && self.diag_info.open_braces.len() >= unclosed_delimiter_show_limit + 2
+        if let Some((_, span)) = self.diag_info.open_delimiters.get(unclosed_delimiter_show_limit)
+            && self.diag_info.open_delimiters.len() >= unclosed_delimiter_show_limit + 2
         {
             err.span_label(
                 *span,
                 format!(
                     "another {} unclosed delimiters begin from here",
-                    self.diag_info.open_braces.len() - unclosed_delimiter_show_limit
+                    self.diag_info.open_delimiters.len() - unclosed_delimiter_show_limit
                 ),
             );
         }
 
-        if let Some((delim, _)) = self.diag_info.open_braces.last() {
+        if let Some((delim, _)) = self.diag_info.open_delimiters.last() {
             report_suspicious_mismatch_block(
                 &mut err,
                 &self.diag_info,
@@ -95,7 +95,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         // The span for beginning of the delimited section.
         let pre_span = self.token.span;
 
-        self.diag_info.open_braces.push((open_delim, self.token.span));
+        self.diag_info.open_delimiters.push((open_delim, self.token.span));
 
         // Lex the token trees within the delimiters.
         // We stop at any delimiter so we can try to recover if the user
@@ -109,11 +109,12 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         let close_spacing = if let Some(close_delim) = self.token.kind.close_delim() {
             if close_delim == open_delim {
                 // Correct delimiter.
-                let (open_brace, open_brace_span) = self.diag_info.open_braces.pop().unwrap();
-                let close_brace_span = self.token.span;
+                let (open_delimiter, open_delimiter_span) =
+                    self.diag_info.open_delimiters.pop().unwrap();
+                let close_delimiter_span = self.token.span;
 
                 if tts.is_empty() && close_delim == Delimiter::Brace {
-                    let empty_block_span = open_brace_span.to(close_brace_span);
+                    let empty_block_span = open_delimiter_span.to(close_delimiter_span);
                     if !sm.is_multiline(empty_block_span) {
                         // Only track if the block is in the form of `{}`, otherwise it is
                         // likely that it was written on purpose.
@@ -122,9 +123,11 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
                 }
 
                 // only add braces
-                if let (Delimiter::Brace, Delimiter::Brace) = (open_brace, open_delim) {
+                if let (Delimiter::Brace, Delimiter::Brace) = (open_delimiter, open_delim) {
                     // Add all the matching spans, we will sort by span later
-                    self.diag_info.matching_block_spans.push((open_brace_span, close_brace_span));
+                    self.diag_info
+                        .matching_block_spans
+                        .push((open_delimiter_span, close_delimiter_span));
                 }
 
                 // Move past the closing delimiter.
@@ -140,18 +143,18 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
                     // This is a conservative error: only report the last unclosed
                     // delimiter. The previous unclosed delimiters could actually be
                     // closed! The lexer just hasn't gotten to them yet.
-                    if let Some(&(_, sp)) = self.diag_info.open_braces.last() {
+                    if let Some(&(_, sp)) = self.diag_info.open_delimiters.last() {
                         unclosed_delimiter = Some(sp);
                     };
-                    for (brace, brace_span) in &self.diag_info.open_braces {
-                        if same_indentation_level(sm, self.token.span, *brace_span)
-                            && brace == &close_delim
+                    for (delimiter, delimiter_span) in &self.diag_info.open_delimiters {
+                        if same_indentation_level(sm, self.token.span, *delimiter_span)
+                            && delimiter == &close_delim
                         {
                             // high likelihood of these two corresponding
-                            candidate = Some(*brace_span);
+                            candidate = Some(*delimiter_span);
                         }
                     }
-                    let (_, _) = self.diag_info.open_braces.pop().unwrap();
+                    let (_, _) = self.diag_info.open_delimiters.pop().unwrap();
                     self.diag_info.unmatched_delims.push(UnmatchedDelim {
                         found_delim: Some(close_delim),
                         found_span: self.token.span,
@@ -159,7 +162,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
                         candidate_span: candidate,
                     });
                 } else {
-                    self.diag_info.open_braces.pop();
+                    self.diag_info.open_delimiters.pop();
                 }
 
                 // If the incorrect delimiter matches an earlier opening
@@ -169,7 +172,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
                 // fn foo() {
                 //     bar(baz(
                 // }  // Incorrect delimiter but matches the earlier `{`
-                if !self.diag_info.open_braces.iter().any(|&(b, _)| b == close_delim) {
+                if !self.diag_info.open_delimiters.iter().any(|&(d, _)| d == close_delim) {
                     self.bump_minimal()
                 } else {
                     // The choice of value here doesn't matter.
@@ -180,7 +183,7 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
             assert_eq!(self.token.kind, token::Eof);
             // Silently recover, the EOF token will be seen again
             // and an error emitted then. Thus we don't pop from
-            // self.open_braces here. The choice of spacing value here
+            // self.open_delimiters here. The choice of spacing value here
             // doesn't matter.
             Spacing::Alone
         };
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index 2edc8c83017..896e348a12d 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -32,7 +32,7 @@ pub const MACRO_ARGUMENTS: Option<&str> = Some("macro arguments");
 
 #[macro_use]
 pub mod parser;
-use parser::{Parser, make_unclosed_delims_error};
+use parser::Parser;
 pub mod lexer;
 pub mod validate_attr;
 
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
index d73adb39826..48df8b59d55 100644
--- a/compiler/rustc_parse/src/parser/mod.rs
+++ b/compiler/rustc_parse/src/parser/mod.rs
@@ -43,11 +43,8 @@ use token_type::TokenTypeSet;
 pub use token_type::{ExpKeywordPair, ExpTokenPair, TokenType};
 use tracing::debug;
 
-use crate::errors::{
-    self, IncorrectVisibilityRestriction, MismatchedClosingDelimiter, NonStringAbiLiteral,
-};
+use crate::errors::{self, IncorrectVisibilityRestriction, NonStringAbiLiteral};
 use crate::exp;
-use crate::lexer::UnmatchedDelim;
 
 #[cfg(test)]
 mod tests;
@@ -1745,27 +1742,6 @@ impl<'a> Parser<'a> {
     }
 }
 
-pub(crate) fn make_unclosed_delims_error(
-    unmatched: UnmatchedDelim,
-    psess: &ParseSess,
-) -> Option<Diag<'_>> {
-    // `None` here means an `Eof` was found. We already emit those errors elsewhere, we add them to
-    // `unmatched_delims` only for error recovery in the `Parser`.
-    let found_delim = unmatched.found_delim?;
-    let mut spans = vec![unmatched.found_span];
-    if let Some(sp) = unmatched.unclosed_span {
-        spans.push(sp);
-    };
-    let err = psess.dcx().create_err(MismatchedClosingDelimiter {
-        spans,
-        delimiter: pprust::token_kind_to_string(&found_delim.as_close_token_kind()).to_string(),
-        unmatched: unmatched.found_span,
-        opening_candidate: unmatched.candidate_span,
-        unclosed: unmatched.unclosed_span,
-    });
-    Some(err)
-}
-
 /// A helper struct used when building an `AttrTokenStream` from
 /// a `LazyAttrTokenStream`. Both delimiter and non-delimited tokens
 /// are stored as `FlatToken::Token`. A vector of `FlatToken`s