Remove unmatched_delims that unexpected closing delimeter error report to reduce confusion

xizheyin · xizheyin · commit 17f7f622b70e · 2025-07-07T15:27:01.000+08:00
Signed-off-by: xizheyin &lt;xizheyin@smail.nju.edu.cn&gt;
diff --git a/compiler/rustc_parse/src/lexer/diagnostics.rs b/compiler/rustc_parse/src/lexer/diagnostics.rs
@@ -34,9 +34,12 @@ pub(super) fn same_indentation_level(sm: &SourceMap, open_sp: Span, close_sp: Sp
 
 // 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 {
+fn report_missing_open_delim(
+    err: &mut Diag<'_>,
+    unmatched_delims: &mut Vec<UnmatchedDelim>,
+) -> bool {
     let mut reported_missing_open = false;
-    for unmatch_brace in unmatched_delims.iter() {
+    unmatched_delims.retain(|unmatch_brace| {
         if let Some(delim) = unmatch_brace.found_delim
             && matches!(delim, Delimiter::Parenthesis | Delimiter::Bracket)
         {
@@ -50,18 +53,21 @@ fn report_missing_open_delim(err: &mut Diag<'_>, unmatched_delims: &[UnmatchedDe
                 format!("missing open `{missed_open}` for this delimiter"),
             );
             reported_missing_open = true;
+            false
+        } else {
+            true
         }
-    }
+    });
     reported_missing_open
 }
 
 pub(super) fn report_suspicious_mismatch_block(
     err: &mut Diag<'_>,
-    diag_info: &TokenTreeDiagInfo,
+    diag_info: &mut TokenTreeDiagInfo,
     sm: &SourceMap,
     delim: Delimiter,
 ) {
-    if report_missing_open_delim(err, &diag_info.unmatched_delims) {
+    if report_missing_open_delim(err, &mut diag_info.unmatched_delims) {
         return;
     }
 
diff --git a/compiler/rustc_parse/src/lexer/tokentrees.rs b/compiler/rustc_parse/src/lexer/tokentrees.rs
@@ -77,12 +77,12 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
             );
         }
 
-        if let Some((delim, _)) = self.diag_info.open_delimiters.last() {
+        if let Some((delim, _)) = self.diag_info.open_delimiters.last().cloned() {
             report_suspicious_mismatch_block(
                 &mut err,
-                &self.diag_info,
+                &mut self.diag_info,
                 self.psess.source_map(),
-                *delim,
+                delim,
             )
         }
         err
@@ -238,13 +238,18 @@ impl<'psess, 'src> Lexer<'psess, 'src> {
         this_spacing
     }
 
-    fn close_delim_err(&mut self, delim: Delimiter) -> Diag<'psess> {
+    fn close_delim_err(&mut self, close_delim: Delimiter) -> Diag<'psess> {
         // An unexpected closing delimiter (i.e., there is no matching opening delimiter).
         let token_str = token_to_string(&self.token);
         let msg = format!("unexpected closing delimiter: `{token_str}`");
         let mut err = self.dcx().struct_span_err(self.token.span, msg);
 
-        report_suspicious_mismatch_block(&mut err, &self.diag_info, self.psess.source_map(), delim);
+        report_suspicious_mismatch_block(
+            &mut err,
+            &mut self.diag_info,
+            self.psess.source_map(),
+            close_delim,
+        );
         err.span_label(self.token.span, "unexpected closing delimiter");
         err
     }
diff --git a/tests/ui/parser/deli-ident-issue-2.rs b/tests/ui/parser/deli-ident-issue-2.rs
@@ -1,6 +1,6 @@
 fn main() {
     if 1 < 2 {
-        let _a = vec!]; //~ ERROR mismatched closing delimiter
+        let _a = vec!];
     }
 } //~ ERROR unexpected closing delimiter
 
diff --git a/tests/ui/parser/deli-ident-issue-2.stderr b/tests/ui/parser/deli-ident-issue-2.stderr
@@ -1,11 +1,3 @@
-error: mismatched closing delimiter: `]`
-  --> $DIR/deli-ident-issue-2.rs:2:14
-   |
-LL |     if 1 < 2 {
-   |              ^ unclosed delimiter
-LL |         let _a = vec!];
-   |                      ^ mismatched closing delimiter
-
 error: unexpected closing delimiter: `}`
   --> $DIR/deli-ident-issue-2.rs:5:1
    |
@@ -15,5 +7,5 @@ LL |     }
 LL | }
    | ^ unexpected closing delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-104367.rs b/tests/ui/parser/issues/issue-104367.rs
@@ -2,5 +2,5 @@
 struct S {
     d: [u32; {
         #![cfg] {
-            #![w,) //~ ERROR mismatched closing delimiter
+            #![w,)
                    //~ ERROR this file contains an unclosed delimiter
diff --git a/tests/ui/parser/issues/issue-104367.stderr b/tests/ui/parser/issues/issue-104367.stderr
@@ -1,11 +1,3 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-104367.rs:5:15
-   |
-LL |             #![w,)
-   |               ^  ^ mismatched closing delimiter
-   |               |
-   |               unclosed delimiter
-
 error: this file contains an unclosed delimiter
   --> $DIR/issue-104367.rs:6:71
    |
@@ -22,5 +14,5 @@ LL |             #![w,)
 LL |
    |                                                                      ^
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-105209.rs b/tests/ui/parser/issues/issue-105209.rs
@@ -1,3 +1,3 @@
 //@ compile-flags: -Zunpretty=ast-tree
-#![c={#![c[)x   //~ ERROR mismatched closing delimiter
+#![c={#![c[)x
                 //~ ERROR this file contains an unclosed delimiter
diff --git a/tests/ui/parser/issues/issue-105209.stderr b/tests/ui/parser/issues/issue-105209.stderr
@@ -1,11 +1,3 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-105209.rs:2:11
-   |
-LL | #![c={#![c[)x
-   |           ^^ mismatched closing delimiter
-   |           |
-   |           unclosed delimiter
-
 error: this file contains an unclosed delimiter
   --> $DIR/issue-105209.rs:3:68
    |
@@ -18,5 +10,5 @@ LL | #![c={#![c[)x
 LL |
    |                                                                   ^
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-62973.rs b/tests/ui/parser/issues/issue-62973.rs
@@ -2,8 +2,6 @@
 
 fn main() {}
 
-//~vvv ERROR mismatched closing delimiter: `)`
-//~vv ERROR mismatched closing delimiter: `)`
 //~vvv ERROR this file contains an unclosed delimiter
 fn p() { match s { v, E { [) {) }
 
diff --git a/tests/ui/parser/issues/issue-62973.stderr b/tests/ui/parser/issues/issue-62973.stderr
@@ -1,21 +1,5 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-62973.rs:8:27
-   |
-LL | fn p() { match s { v, E { [) {) }
-   |                           ^^ mismatched closing delimiter
-   |                           |
-   |                           unclosed delimiter
-
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-62973.rs:8:30
-   |
-LL | fn p() { match s { v, E { [) {) }
-   |                              ^^ mismatched closing delimiter
-   |                              |
-   |                              unclosed delimiter
-
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-62973.rs:10:2
+  --> $DIR/issue-62973.rs:8:2
    |
 LL | fn p() { match s { v, E { [) {) }
    |        -         -         -  - missing open `(` for this delimiter
@@ -27,5 +11,5 @@ LL |
 LL |
    | ^
 
-error: aborting due to 3 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-63116.rs b/tests/ui/parser/issues/issue-63116.rs
@@ -1,4 +1,3 @@
 // fixed by #66361
-//~vv ERROR mismatched closing delimiter: `]`
 //~v ERROR this file contains an unclosed delimiter
 impl W <s(f;Y(;]
diff --git a/tests/ui/parser/issues/issue-63116.stderr b/tests/ui/parser/issues/issue-63116.stderr
@@ -1,19 +1,11 @@
-error: mismatched closing delimiter: `]`
-  --> $DIR/issue-63116.rs:4:14
-   |
-LL | impl W <s(f;Y(;]
-   |              ^ ^ mismatched closing delimiter
-   |              |
-   |              unclosed delimiter
-
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-63116.rs:4:18
+  --> $DIR/issue-63116.rs:3:18
    |
 LL | impl W <s(f;Y(;]
    |          -     -^
    |          |     |
    |          |     missing open `[` for this delimiter
    |          unclosed delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.rs b/tests/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.rs
@@ -3,21 +3,18 @@ mod a {
 
     enum Bug {
         V = [PhantomData; { [ () ].len() ].len() as isize,
-        //~^ ERROR mismatched closing delimiter: `]`
     }
 }
 
 mod b {
     enum Bug {
         V = [Vec::new; { [].len()  ].len() as isize,
-        //~^ ERROR mismatched closing delimiter: `]`
     }
 }
 
 mod c {
     enum Bug {
         V = [Vec::new; { [0].len() ].len() as isize,
-        //~^ ERROR mismatched closing delimiter: `]`
 }
 
 fn main() {} //~ ERROR this file contains an unclosed delimiter
diff --git a/tests/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr b/tests/ui/parser/issues/issue-67377-invalid-syntax-in-enum-discriminant.stderr
@@ -1,32 +1,5 @@
-error: mismatched closing delimiter: `]`
-  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:5:27
-   |
-LL |         V = [PhantomData; { [ () ].len() ].len() as isize,
-   |             -             ^              ^ mismatched closing delimiter
-   |             |             |
-   |             |             unclosed delimiter
-   |             closing delimiter possibly meant for this
-
-error: mismatched closing delimiter: `]`
-  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:12:24
-   |
-LL |         V = [Vec::new; { [].len()  ].len() as isize,
-   |             -          ^           ^ mismatched closing delimiter
-   |             |          |
-   |             |          unclosed delimiter
-   |             closing delimiter possibly meant for this
-
-error: mismatched closing delimiter: `]`
-  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:19:24
-   |
-LL |         V = [Vec::new; { [0].len() ].len() as isize,
-   |             -          ^           ^ mismatched closing delimiter
-   |             |          |
-   |             |          unclosed delimiter
-   |             closing delimiter possibly meant for this
-
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:23:65
+  --> $DIR/issue-67377-invalid-syntax-in-enum-discriminant.rs:20:65
    |
 LL |         V = [PhantomData; { [ () ].len() ].len() as isize,
    |                                          - missing open `[` for this delimiter
@@ -43,5 +16,5 @@ LL |         V = [Vec::new; { [0].len() ].len() as isize,
 LL | fn main() {}
    |                                                                ^
 
-error: aborting due to 4 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-68987-unmatch-issue-2.rs b/tests/ui/parser/issues/issue-68987-unmatch-issue-2.rs
@@ -1,7 +1,7 @@
 // FIXME: this case need more work to fix
 // currently the TokenTree matching ')' with '{', which is not user friendly for diagnostics
 async fn obstest() -> Result<> {
-    let obs_connect = || -> Result<(), MyError) { //~ ERROR mismatched closing delimiter
+    let obs_connect = || -> Result<(), MyError) {
         async {
         }
     }
diff --git a/tests/ui/parser/issues/issue-68987-unmatch-issue-2.stderr b/tests/ui/parser/issues/issue-68987-unmatch-issue-2.stderr
@@ -1,11 +1,3 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-68987-unmatch-issue-2.rs:3:32
-   |
-LL | async fn obstest() -> Result<> {
-   |                                ^ unclosed delimiter
-LL |     let obs_connect = || -> Result<(), MyError) {
-   |                                               ^ mismatched closing delimiter
-
 error: unexpected closing delimiter: `}`
   --> $DIR/issue-68987-unmatch-issue-2.rs:14:1
    |
@@ -15,5 +7,5 @@ LL |     let obs_connect = || -> Result<(), MyError) {
 LL | }
    | ^ unexpected closing delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-68987-unmatch-issue-3.rs b/tests/ui/parser/issues/issue-68987-unmatch-issue-3.rs
@@ -3,6 +3,6 @@ fn f(i: u32, j: u32) {
     let res = String::new();
     let mut cnt = i;
     while cnt < j {
-        write!&mut res, " "); //~ ERROR mismatched closing delimiter
+        write!&mut res, " ");
     }
 } //~ ERROR unexpected closing delimiter
diff --git a/tests/ui/parser/issues/issue-68987-unmatch-issue-3.stderr b/tests/ui/parser/issues/issue-68987-unmatch-issue-3.stderr
@@ -1,11 +1,3 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/issue-68987-unmatch-issue-3.rs:5:19
-   |
-LL |     while cnt < j {
-   |                   ^ unclosed delimiter
-LL |         write!&mut res, " ");
-   |                            ^ mismatched closing delimiter
-
 error: unexpected closing delimiter: `}`
   --> $DIR/issue-68987-unmatch-issue-3.rs:8:1
    |
@@ -15,5 +7,5 @@ LL |     }
 LL | }
    | ^ unexpected closing delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/issue-81827.rs b/tests/ui/parser/issues/issue-81827.rs
@@ -2,6 +2,5 @@
 
 fn main() {}
 
-//~vv ERROR mismatched closing delimiter: `]`
 //~v ERROR this file contains an unclosed delimiter
 fn r()->i{0|{#[cfg(r(0{]0
diff --git a/tests/ui/parser/issues/issue-81827.stderr b/tests/ui/parser/issues/issue-81827.stderr
@@ -1,14 +1,5 @@
-error: mismatched closing delimiter: `]`
-  --> $DIR/issue-81827.rs:7:23
-   |
-LL | fn r()->i{0|{#[cfg(r(0{]0
-   |               -       ^^ mismatched closing delimiter
-   |               |       |
-   |               |       unclosed delimiter
-   |               closing delimiter possibly meant for this
-
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-81827.rs:7:27
+  --> $DIR/issue-81827.rs:6:27
    |
 LL | fn r()->i{0|{#[cfg(r(0{]0
    |          -  -          - ^
@@ -17,5 +8,5 @@ LL | fn r()->i{0|{#[cfg(r(0{]0
    |          |  unclosed delimiter
    |          unclosed delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/parser/issues/unnessary-error-issue-138401.rs b/tests/ui/parser/issues/unnessary-error-issue-138401.rs
@@ -1,6 +1,5 @@
 pub fn foo(x: i64) -> i64 {
-    x.abs) 
-    //~^ ERROR mismatched closing delimiter
+    x.abs)
 }
 //~^ ERROR unexpected closing delimiter: `}`
 
diff --git a/tests/ui/parser/issues/unnessary-error-issue-138401.stderr b/tests/ui/parser/issues/unnessary-error-issue-138401.stderr
@@ -1,19 +1,10 @@
-error: mismatched closing delimiter: `)`
-  --> $DIR/unnessary-error-issue-138401.rs:1:27
-   |
-LL | pub fn foo(x: i64) -> i64 {
-   |                           ^ unclosed delimiter
-LL |     x.abs) 
-   |          ^ mismatched closing delimiter
-
 error: unexpected closing delimiter: `}`
-  --> $DIR/unnessary-error-issue-138401.rs:4:1
+  --> $DIR/unnessary-error-issue-138401.rs:3:1
    |
-LL |     x.abs) 
+LL |     x.abs)
    |          - missing open `(` for this delimiter
-LL |
 LL | }
    | ^ unexpected closing delimiter
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
diff --git a/tests/ui/suggestions/issue-94171.rs b/tests/ui/suggestions/issue-94171.rs
diff --git a/tests/ui/suggestions/issue-94171.stderr b/tests/ui/suggestions/issue-94171.stderr
diff --git a/tests/ui/typeck/issue-91334.rs b/tests/ui/typeck/issue-91334.rs
diff --git a/tests/ui/typeck/issue-91334.stderr b/tests/ui/typeck/issue-91334.stderr

Original file line number	Diff line number	Diff line change
`@@ -1,6 +1,6 @@`
`1`	`1`	`fn main() {`
`2`	`2`	`if 1 < 2 {`
`3`		`- let _a = vec!]; //~ ERROR mismatched closing delimiter`
	`3`	`+ let _a = vec!];`
`4`	`4`	`}`
`5`	`5`	`} //~ ERROR unexpected closing delimiter`
`6`	`6`