Avoid ; -> , recovery and unclosed } recovery from being too ve…

…rbose Those two recovery attempts have a very bad interaction that causes too unnecessary output. Add a simple gate to avoid interpreting a `;` as a `,` when there are unclosed braces.
rust-lang · Apr 9, 2021 · 0d71676 · 0d71676
1 parent 8e81596
commit 0d71676
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Showing 4 changed files with 21 additions and 145 deletions.
diff --git a/compiler/rustc_parse/src/parser/mod.rs b/compiler/rustc_parse/src/parser/mod.rs
@@ -703,6 +703,8 @@ impl<'a> Parser<'a> {
         let mut recovered = false;
         let mut trailing = false;
         let mut v = vec![];
+        let unclosed_delims = !self.unclosed_delims.is_empty();
+
         while !self.expect_any_with_type(kets, expect) {
             if let token::CloseDelim(..) | token::Eof = self.token.kind {
                 break;
@@ -723,7 +725,7 @@ impl<'a> Parser<'a> {
 
                             // Attempt to keep parsing if it was a similar separator.
                             if let Some(ref tokens) = t.similar_tokens() {
-                                if tokens.contains(&self.token.kind) {
+                                if tokens.contains(&self.token.kind) && !unclosed_delims {
                                     self.bump();
                                 }
                             }

diff --git a/src/test/ui/parser/issue-63116.stderr b/src/test/ui/parser/issue-63116.stderr
@@ -12,11 +12,11 @@ error: expected one of `!`, `(`, `)`, `+`, `,`, `::`, or `<`, found `;`
 LL | impl W <s(f;Y(;]
    |            ^ expected one of 7 possible tokens
 
-error: expected one of `!`, `&&`, `&`, `(`, `)`, `*`, `+`, `,`, `->`, `...`, `::`, `:`, `<`, `=`, `>`, `?`, `[`, `_`, `async`, `const`, `dyn`, `extern`, `fn`, `for`, `impl`, `unsafe`, lifetime, or path, found `;`
-  --> $DIR/issue-63116.rs:3:15
+error: mismatched closing delimiter: `]`
+  --> $DIR/issue-63116.rs:3:16
    |
 LL | impl W <s(f;Y(;]
-   |              -^ help: `)` may belong here
+   |              - ^ mismatched closing delimiter
    |              |
    |              unclosed delimiter
 

diff --git a/src/test/ui/parser/use-unclosed-brace.rs b/src/test/ui/parser/use-unclosed-brace.rs
@@ -1,26 +1,12 @@
+// error-pattern: expected one of `,`, `::`, `as`, or `}`, found `;`
+// error-pattern: this file contains an unclosed delimiter
+// error-pattern: expected item, found `}`
 use foo::{bar, baz;
-//~^ ERROR expected one of `,`, `::`, `as`, or `}`, found `;`
 
 use std::fmt::Display;
-//~^ ERROR expected identifier, found keyword `use`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `std`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `;`
 
 mod bar { }
-//~^ ERROR expected identifier, found keyword `mod`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `bar`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `{`
 
 mod baz { }
-//~^ ERROR expected identifier, found keyword `mod`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `{`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `baz`
-//~| ERROR expected one of `,` or `}`, found keyword `mod`
 
 fn main() {}
-//~^ ERROR expected identifier, found keyword `fn`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `(`
-//~| ERROR expected one of `,` or `}`, found keyword `fn`
-//~| ERROR expected one of `,`, `::`, `as`, or `}`, found `main`
-
-//~ ERROR this file contains an unclosed delimiter
diff --git a/src/test/ui/parser/use-unclosed-brace.stderr b/src/test/ui/parser/use-unclosed-brace.stderr
@@ -1,139 +1,27 @@
 error: this file contains an unclosed delimiter
-  --> $DIR/use-unclosed-brace.rs:26:51
+  --> $DIR/use-unclosed-brace.rs:12:14
    |
 LL | use foo::{bar, baz;
    |          - unclosed delimiter
 ...
-LL |
-   |                                                   ^
-
-error: expected identifier, found keyword `use`
-  --> $DIR/use-unclosed-brace.rs:4:1
-   |
-LL | use std::fmt::Display;
-   | ^^^ expected identifier, found keyword
+LL | fn main() {}
+   |              ^
 
 error: expected one of `,`, `::`, `as`, or `}`, found `;`
-  --> $DIR/use-unclosed-brace.rs:1:19
+  --> $DIR/use-unclosed-brace.rs:4:19
    |
 LL | use foo::{bar, baz;
-   |          -        ^ expected one of `,`, `::`, `as`, or `}`
-   |          |
+   |          -        ^
+   |          |        |
+   |          |        expected one of `,`, `::`, `as`, or `}`
+   |          |        help: `}` may belong here
    |          unclosed delimiter
-   |
-help: `}` may belong here
-   |
-LL | use foo::{bar, baz};
-   |                   ^
-help: missing `,`
-   |
-LL | use foo::{bar, baz,;
-   |                   ^
-
-error: expected one of `,`, `::`, `as`, or `}`, found `std`
-  --> $DIR/use-unclosed-brace.rs:4:5
-   |
-LL | use std::fmt::Display;
-   |    -^^^ expected one of `,`, `::`, `as`, or `}`
-   |    |
-   |    help: missing `,`
-
-error: expected identifier, found keyword `mod`
-  --> $DIR/use-unclosed-brace.rs:9:1
-   |
-LL | mod bar { }
-   | ^^^ expected identifier, found keyword
-
-error: expected one of `,`, `::`, `as`, or `}`, found `;`
-  --> $DIR/use-unclosed-brace.rs:4:22
-   |
-LL | use std::fmt::Display;
-   |                      ^
-   |                      |
-   |                      expected one of `,`, `::`, `as`, or `}`
-   |                      help: missing `,`
-
-error: expected one of `,`, `::`, `as`, or `}`, found `bar`
-  --> $DIR/use-unclosed-brace.rs:9:5
-   |
-LL | mod bar { }
-   |    -^^^ expected one of `,`, `::`, `as`, or `}`
-   |    |
-   |    help: missing `,`
-
-error: expected one of `,`, `::`, `as`, or `}`, found `{`
-  --> $DIR/use-unclosed-brace.rs:9:9
-   |
-LL | mod bar { }
-   |        -^ expected one of `,`, `::`, `as`, or `}`
-   |        |
-   |        help: missing `,`
-
-error: expected identifier, found keyword `mod`
-  --> $DIR/use-unclosed-brace.rs:14:1
-   |
-LL | mod baz { }
-   | ^^^ expected identifier, found keyword
-
-error: expected one of `,` or `}`, found keyword `mod`
-  --> $DIR/use-unclosed-brace.rs:14:1
-   |
-LL | mod bar { }
-   |            -
-   |            |
-   |            expected one of `,` or `}`
-   |            help: missing `,`
-...
-LL | mod baz { }
-   | ^^^ unexpected token
-
-error: expected one of `,`, `::`, `as`, or `}`, found `baz`
-  --> $DIR/use-unclosed-brace.rs:14:5
-   |
-LL | mod baz { }
-   |    -^^^ expected one of `,`, `::`, `as`, or `}`
-   |    |
-   |    help: missing `,`
-
-error: expected one of `,`, `::`, `as`, or `}`, found `{`
-  --> $DIR/use-unclosed-brace.rs:14:9
-   |
-LL | mod baz { }
-   |        -^ expected one of `,`, `::`, `as`, or `}`
-   |        |
-   |        help: missing `,`
-
-error: expected identifier, found keyword `fn`
-  --> $DIR/use-unclosed-brace.rs:20:1
-   |
-LL | fn main() {}
-   | ^^ expected identifier, found keyword
-
-error: expected one of `,` or `}`, found keyword `fn`
-  --> $DIR/use-unclosed-brace.rs:20:1
-   |
-LL | mod baz { }
-   |            -
-   |            |
-   |            expected one of `,` or `}`
-   |            help: missing `,`
-...
-LL | fn main() {}
-   | ^^ unexpected token
-
-error: expected one of `,`, `::`, `as`, or `}`, found `main`
-  --> $DIR/use-unclosed-brace.rs:20:4
-   |
-LL | fn main() {}
-   |   -^^^^ expected one of `,`, `::`, `as`, or `}`
-   |   |
-   |   help: missing `,`
 
-error: expected one of `,`, `::`, `as`, or `}`, found `(`
-  --> $DIR/use-unclosed-brace.rs:20:8
+error: expected item, found `}`
+  --> $DIR/use-unclosed-brace.rs:12:14
    |
 LL | fn main() {}
-   |        ^ expected one of `,`, `::`, `as`, or `}`
+   |              ^ expected item
 
-error: aborting due to 16 previous errors
+error: aborting due to 3 previous errors