combine mismatched closing and missing open into one line

Signed-off-by: xizheyin <[email protected]>

Author: xizheyin

compiler/rustc_parse/messages.ftl

@@ -553,7 +553,7 @@ parse_meta_bad_delim = wrong meta list delimiters
 parse_meta_bad_delim_suggestion = the delimiters should be `(` and `)`
 
 parse_mismatched_closing_delimiter = mismatched closing delimiter: `{$delimiter}`
-    .label_unmatched = mismatched closing delimiter
+    .label_unmatched = mismatched closing delimiter{$missing_open_note}
     .label_opening_candidate = closing delimiter possibly meant for this
     .label_unclosed = unclosed delimiter
 

compiler/rustc_parse/src/errors.rs

@@ -945,6 +945,7 @@ pub(crate) struct MismatchedClosingDelimiter {
     pub delimiter: String,
     #[label(parse_label_unmatched)]
     pub unmatched: Span,
+    pub missing_open_note: String,
     #[label(parse_label_opening_candidate)]
     pub opening_candidate: Option<Span>,
     #[label(parse_label_unclosed)]

compiler/rustc_parse/src/lexer/diagnostics.rs

@@ -73,38 +73,36 @@ pub(crate) fn make_unclosed_delims_error(
     if let Some(sp) = unmatched.unclosed_span {
         spans.push(sp);
     };
-    let mut err = psess.dcx().create_err(MismatchedClosingDelimiter {
+
+    let missing_open_note = report_missing_open_delim(&unmatched)
+        .map(|s| format!(", may missing open `{s}`"))
+        .unwrap_or_default();
+
+    let err = psess.dcx().create_err(MismatchedClosingDelimiter {
         spans,
         delimiter: pprust::token_kind_to_string(&token::CloseDelim(found_delim)).to_string(),
         unmatched: unmatched.found_span,
+        missing_open_note,
         opening_candidate: unmatched.candidate_span,
         unclosed: unmatched.unclosed_span,
     });
-    report_missing_open_delim(&mut err, &[unmatched]);
     Some(err)
 }
 
 // When we get a `)` or `]` for `{`, we should emit help message here
 // it's more friendly compared to report `unmatched error` in later phase
-fn report_missing_open_delim(err: &mut Diag<'_>, unmatched_delims: &[UnmatchedDelim]) -> bool {
-    let mut reported_missing_open = false;
-    for unmatch_brace in unmatched_delims.iter() {
-        if let Some(delim) = unmatch_brace.found_delim
-            && matches!(delim, Delimiter::Parenthesis | Delimiter::Bracket)
-        {
-            let missed_open = match delim {
-                Delimiter::Parenthesis => "(",
-                Delimiter::Bracket => "[",
-                _ => unreachable!(),
-            };
-            err.span_label(
-                unmatch_brace.found_span.shrink_to_lo(),
-                format!("missing open `{missed_open}` for this delimiter"),
-            );
-            reported_missing_open = true;
-        }
+fn report_missing_open_delim(unmatched_delim: &UnmatchedDelim) -> Option<String> {
+    if let Some(delim) = unmatched_delim.found_delim
+        && matches!(delim, Delimiter::Parenthesis | Delimiter::Bracket)
+    {
+        let missed_open = match delim {
+            Delimiter::Parenthesis => "(",
+            Delimiter::Bracket => "[",
+            _ => unreachable!(),
+        };
+        return Some(missed_open.to_owned());
     }
-    reported_missing_open
+    None
 }
 
 pub(super) fn report_suspicious_mismatch_block(

tests/ui/attributes/z-crate-attr/unbalanced-paren.stderr

@@ -2,7 +2,7 @@ error: mismatched closing delimiter: `]`
   --> <crate attribute>:1:4
    |
 LL | #![(]
-   |   -^^ mismatched closing delimiter
+   |   -^^ mismatched closing delimiter, may missing open `[`
    |   ||
    |   |unclosed delimiter
    |   closing delimiter possibly meant for this

tests/ui/macros/issue-102878.stderr

@@ -2,10 +2,8 @@ error: mismatched closing delimiter: `)`
   --> $DIR/issue-102878.rs:1:35
    |
 LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
-   |                                  -^         ^
-   |                                  ||         |
-   |                                  ||         mismatched closing delimiter
-   |                                  ||         missing open `(` for this delimiter
+   |                                  -^         ^ mismatched closing delimiter, may missing open `(`
+   |                                  ||
    |                                  |unclosed delimiter
    |                                  closing delimiter possibly meant for this
 

tests/ui/parser/deli-ident-issue-2.stderr

@@ -4,10 +4,7 @@ error: mismatched closing delimiter: `]`
 LL |     if 1 < 2 {
    |              ^ unclosed delimiter
 LL |         let _a = vec!];
-   |                      ^
-   |                      |
-   |                      mismatched closing delimiter
-   |                      missing open `[` for this delimiter
+   |                      ^ mismatched closing delimiter, may missing open `[`
 
 error: aborting due to 1 previous error
 

tests/ui/parser/do-not-suggest-semicolon-before-array.stderr

@@ -2,10 +2,8 @@ error: mismatched closing delimiter: `)`
   --> $DIR/do-not-suggest-semicolon-before-array.rs:5:5
    |
 LL |     [1, 3)
-   |     ^    ^
-   |     |    |
-   |     |    mismatched closing delimiter
-   |     |    missing open `(` for this delimiter
+   |     ^    ^ mismatched closing delimiter, may missing open `(`
+   |     |
    |     unclosed delimiter
 
 error: aborting due to 1 previous error

tests/ui/parser/issues/issue-104367.stderr

@@ -2,10 +2,8 @@ error: mismatched closing delimiter: `)`
   --> $DIR/issue-104367.rs:5:15
    |
 LL |             #![w,)
-   |               ^  ^
-   |               |  |
-   |               |  mismatched closing delimiter
-   |               |  missing open `(` for this delimiter
+   |               ^  ^ mismatched closing delimiter, may missing open `(`
+   |               |
    |               unclosed delimiter
 
 error: this file contains an unclosed delimiter

tests/ui/parser/issues/issue-105209.stderr

@@ -2,10 +2,8 @@ error: mismatched closing delimiter: `)`
   --> $DIR/issue-105209.rs:2:11
    |
 LL | #![c={#![c[)x
-   |           ^^
-   |           ||
-   |           |mismatched closing delimiter
-   |           |missing open `(` for this delimiter
+   |           ^^ mismatched closing delimiter, may missing open `(`
+   |           |
    |           unclosed delimiter
 
 error: this file contains an unclosed delimiter

tests/ui/parser/issues/issue-10636-1.rs

@@ -3,7 +3,6 @@ struct Obj {
     member: usize
 )
 //~^ ERROR mismatched closing delimiter
-//~| NOTE mismatched closing delimiter
-//~| NOTE missing open `(` for this delimiter
+//~| NOTE mismatched closing delimiter, may missing open `(`
 
 fn main() {}