Exit when there are unmatched delims to avoid noisy diagnostics

Author: chenyukang

compiler/rustc_parse/src/lexer/tokentrees.rs

@@ -34,7 +34,7 @@ impl<'a> TokenTreesReader<'a> {
         let mut buf = Vec::new();
         loop {
             match self.token.kind {
-                token::OpenDelim(delim) => buf.push(self.parse_token_tree_open_delim(delim)),
+                token::OpenDelim(delim) => buf.push(self.parse_token_tree_open_delim(delim)?),
                 token::CloseDelim(delim) => {
                     return if is_delimited {
                         Ok(TokenStream::new(buf))
@@ -46,7 +46,7 @@ impl<'a> TokenTreesReader<'a> {
                     if is_delimited {
                         self.eof_err().emit();
                     }
-                    return Ok(TokenStream::new(buf));
+                    return Ok(TokenStream::new(buf))
                 }
                 _ => {
                     // Get the next normal token. This might require getting multiple adjacent
@@ -98,7 +98,7 @@ impl<'a> TokenTreesReader<'a> {
         err
     }
 
-    fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> TokenTree {
+    fn parse_token_tree_open_delim(&mut self, open_delim: Delimiter) -> PResult<'a, TokenTree> {
         // The span for beginning of the delimited section
         let pre_span = self.token.span;
 
@@ -107,7 +107,7 @@ impl<'a> TokenTreesReader<'a> {
         // Parse the token trees within the delimiters.
         // We stop at any delimiter so we can try to recover if the user
         // uses an incorrect delimiter.
-        let tts = self.parse_token_trees(/* is_delimited */ true).unwrap();
+        let tts = self.parse_token_trees(/* is_delimited */ true)?;
 
         // Expand to cover the entire delimited token tree
         let delim_span = DelimSpan::from_pair(pre_span, self.token.span);
@@ -190,7 +190,7 @@ impl<'a> TokenTreesReader<'a> {
             _ => unreachable!(),
         }
 
-        TokenTree::Delimited(delim_span, open_delim, tts)
+        Ok(TokenTree::Delimited(delim_span, open_delim, tts))
     }
 
     fn close_delim_err(&mut self, delim: Delimiter) -> PErr<'a> {

compiler/rustc_parse/src/lib.rs

@@ -204,16 +204,23 @@ pub fn maybe_file_to_stream(
         lexer::parse_token_trees(sess, src.as_str(), source_file.start_pos, override_span);
 
     match token_trees {
-        Ok(stream) => Ok((stream, unmatched_braces)),
-        Err(err) => {
+        Ok(stream) if unmatched_braces.is_empty() => Ok((stream, unmatched_braces)),
+        _ => {
+            // Return error if there are unmatched delimiters or unclosng delimiters.
+            // We emit delimiter mismatch errors first, then emit the unclosing delimiter mismatch
+            // because the delimiter mismatch is more likely to be the root cause of the
+
             let mut buffer = Vec::with_capacity(1);
-            err.buffer(&mut buffer);
             // Not using `emit_unclosed_delims` to use `db.buffer`
             for unmatched in unmatched_braces {
                 if let Some(err) = make_unclosed_delims_error(unmatched, &sess) {
                     err.buffer(&mut buffer);
                 }
             }
+            if let Err(err) = token_trees {
+                // Add unclosing delimiter error
+                err.buffer(&mut buffer);
+            }
             Err(buffer)
         }
     }

src/librustdoc/doctest.rs

@@ -769,24 +769,16 @@ fn check_if_attr_is_complete(source: &str, edition: Edition) -> bool {
                 match maybe_new_parser_from_source_str(&sess, filename, source.to_owned()) {
                     Ok(p) => p,
                     Err(_) => {
-                        debug!("Cannot build a parser to check mod attr so skipping...");
-                        return true;
+                        // If there is an unclosed delimiter, an error will be returned by the tokentrees.
+                        return false;
                     }
                 };
             // If a parsing error happened, it's very likely that the attribute is incomplete.
             if let Err(e) = parser.parse_attribute(InnerAttrPolicy::Permitted) {
                 e.cancel();
                 return false;
             }
-            // We now check if there is an unclosed delimiter for the attribute. To do so, we look at
-            // the `unclosed_delims` and see if the opening square bracket was closed.
-            parser
-                .unclosed_delims()
-                .get(0)
-                .map(|unclosed| {
-                    unclosed.unclosed_span.map(|s| s.lo()).unwrap_or(BytePos(0)) != BytePos(2)
-                })
-                .unwrap_or(true)
+            true
         })
     })
     .unwrap_or(false)

tests/ui/lint/issue-104897.rs

@@ -1,6 +1,5 @@
 // error-pattern: this file contains an unclosed delimiter
 // error-pattern: this file contains an unclosed delimiter
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: format argument must be a string literal
 
 fn f(){(print!(á

tests/ui/lint/issue-104897.stderr

@@ -1,5 +1,5 @@
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-104897.rs:6:18
+  --> $DIR/issue-104897.rs:5:18
    |
 LL | fn f(){(print!(á
    |       --      -  ^
@@ -9,7 +9,7 @@ LL | fn f(){(print!(á
    |       unclosed delimiter
 
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-104897.rs:6:18
+  --> $DIR/issue-104897.rs:5:18
    |
 LL | fn f(){(print!(á
    |       --      -  ^
@@ -19,7 +19,7 @@ LL | fn f(){(print!(á
    |       unclosed delimiter
 
 error: this file contains an unclosed delimiter
-  --> $DIR/issue-104897.rs:6:18
+  --> $DIR/issue-104897.rs:5:18
    |
 LL | fn f(){(print!(á
    |       --      -  ^
@@ -28,16 +28,5 @@ LL | fn f(){(print!(á
    |       |unclosed delimiter
    |       unclosed delimiter
 
-error: format argument must be a string literal
-  --> $DIR/issue-104897.rs:6:16
-   |
-LL | fn f(){(print!(á
-   |                ^
-   |
-help: you might be missing a string literal to format with
-   |
-LL | fn f(){(print!("{}", á
-   |                +++++
-
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 

tests/ui/lint/unused_parens_multibyte_recovery.rs

@@ -3,7 +3,6 @@
 // error-pattern: this file contains an unclosed delimiter
 // error-pattern: this file contains an unclosed delimiter
 // error-pattern: this file contains an unclosed delimiter
-// error-pattern: format argument must be a string literal
 //
 // Verify that unused parens lint does not try to create a span
 // which points in the middle of a multibyte character.

tests/ui/lint/unused_parens_multibyte_recovery.stderr

@@ -1,5 +1,5 @@
 error: this file contains an unclosed delimiter
-  --> $DIR/unused_parens_multibyte_recovery.rs:11:17
+  --> $DIR/unused_parens_multibyte_recovery.rs:10:17
    |
 LL | fn f(){(print!(á
    |       --      - ^
@@ -9,7 +9,7 @@ LL | fn f(){(print!(á
    |       unclosed delimiter
 
 error: this file contains an unclosed delimiter
-  --> $DIR/unused_parens_multibyte_recovery.rs:11:17
+  --> $DIR/unused_parens_multibyte_recovery.rs:10:17
    |
 LL | fn f(){(print!(á
    |       --      - ^
@@ -19,7 +19,7 @@ LL | fn f(){(print!(á
    |       unclosed delimiter
 
 error: this file contains an unclosed delimiter
-  --> $DIR/unused_parens_multibyte_recovery.rs:11:17
+  --> $DIR/unused_parens_multibyte_recovery.rs:10:17
    |
 LL | fn f(){(print!(á
    |       --      - ^
@@ -28,16 +28,5 @@ LL | fn f(){(print!(á
    |       |unclosed delimiter
    |       unclosed delimiter
 
-error: format argument must be a string literal
-  --> $DIR/unused_parens_multibyte_recovery.rs:11:16
-   |
-LL | fn f(){(print!(á
-   |                ^
-   |
-help: you might be missing a string literal to format with
-   |
-LL | fn f(){(print!("{}", á
-   |                +++++
-
-error: aborting due to 4 previous errors
+error: aborting due to 3 previous errors
 

tests/ui/macros/issue-102878.rs

@@ -1,9 +1,5 @@
 macro_rules!test{($l:expr,$_:r)=>({const:y y)}
 //~^ ERROR mismatched closing delimiter: `)`
-//~| ERROR invalid fragment specifier `r`
-//~| ERROR expected identifier, found keyword `const`
-//~| ERROR expected identifier, found keyword `const`
-//~| ERROR expected identifier, found `:`
 
 fn s(){test!(1,i)}
 

tests/ui/macros/issue-102878.stderr

@@ -7,54 +7,5 @@ LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
    |                                  |unclosed delimiter
    |                                  closing delimiter possibly meant for this
 
-error: invalid fragment specifier `r`
-  --> $DIR/issue-102878.rs:1:27
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
-   |                           ^^^^
-   |
-   = help: valid fragment specifiers are `ident`, `block`, `stmt`, `expr`, `pat`, `ty`, `lifetime`, `literal`, `path`, `meta`, `tt`, `item` and `vis`
-
-error: expected identifier, found keyword `const`
-  --> $DIR/issue-102878.rs:1:36
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
-   |                                    ^^^^^ expected identifier, found keyword
-...
-LL | fn s(){test!(1,i)}
-   |        ---------- in this macro invocation
-   |
-   = note: this error originates in the macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: escape `const` to use it as an identifier
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({r#const:y y)}
-   |                                    ++
-
-error: expected identifier, found keyword `const`
-  --> $DIR/issue-102878.rs:1:36
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
-   |                                    ^^^^^ expected identifier, found keyword
-...
-LL | fn s(){test!(1,i)}
-   |        ---------- in this macro invocation
-   |
-   = note: this error originates in the macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: escape `const` to use it as an identifier
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({r#const:y y)}
-   |                                    ++
-
-error: expected identifier, found `:`
-  --> $DIR/issue-102878.rs:1:41
-   |
-LL | macro_rules!test{($l:expr,$_:r)=>({const:y y)}
-   |                                         ^ expected identifier
-...
-LL | fn s(){test!(1,i)}
-   |        ---------- in this macro invocation
-   |
-   = note: this error originates in the macro `test` (in Nightly builds, run with -Z macro-backtrace for more info)
-
-error: aborting due to 5 previous errors
+error: aborting due to previous error
 

tests/ui/parser/deli-ident-issue-1.rs

@@ -15,8 +15,6 @@ impl dyn Demo {
         if let Some(b) = val
         && let Some(c) = num {
         && b == c {
-            //~^ ERROR expected struct
-            //~| ERROR mismatched types
         }
     }
 }