Improve suggestion for escaping reserved keywords

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -192,10 +192,10 @@ impl<'a> Parser<'a> {
                 if ident.is_raw_guess()
                     && self.look_ahead(1, |t| valid_follow.contains(&t.kind)) =>
             {
-                err.span_suggestion(
-                    ident.span,
-                    "you can escape reserved keywords to use them as identifiers",
-                    format!("r#{}", ident.name),
+                err.span_suggestion_verbose(
+                    ident.span.shrink_to_lo(),
+                    &format!("escape `{}` to use it as an identifier", ident.name),
+                    "r#".to_owned(),
                     Applicability::MaybeIncorrect,
                 );
             }

src/test/ui/async-await/await-keyword/2018-edition-error-in-non-macro-position.stderr

@@ -4,76 +4,76 @@ error: expected identifier, found keyword `await`
 LL |     pub mod await {
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL |     pub mod r#await {
-   |             ~~~~~~~
+   |             ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:7:20
    |
 LL |         pub struct await;
    |                    ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL |         pub struct r#await;
-   |                    ~~~~~~~
+   |                    ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:10:22
    |
 LL | use self::outer_mod::await::await;
    |                      ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | use self::outer_mod::r#await::await;
-   |                      ~~~~~~~
+   |                      ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:10:29
    |
 LL | use self::outer_mod::await::await;
    |                             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | use self::outer_mod::await::r#await;
-   |                             ~~~~~~~
+   |                             ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:13:14
    |
 LL | struct Foo { await: () }
    |              ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | struct Foo { r#await: () }
-   |              ~~~~~~~
+   |              ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:16:15
    |
 LL | impl Foo { fn await() {} }
    |               ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | impl Foo { fn r#await() {} }
-   |               ~~~~~~~
+   |               ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error-in-non-macro-position.rs:19:14
    |
 LL | macro_rules! await {
    |              ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | macro_rules! r#await {
-   |              ~~~~~~~
+   |              ++
 
 error: aborting due to 7 previous errors
 

src/test/ui/async-await/await-keyword/2018-edition-error.stderr

@@ -4,54 +4,54 @@ error: expected identifier, found keyword `await`
 LL |     pub mod await {
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL |     pub mod r#await {
-   |             ~~~~~~~
+   |             ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error.rs:6:20
    |
 LL |         pub struct await;
    |                    ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL |         pub struct r#await;
-   |                    ~~~~~~~
+   |                    ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error.rs:9:22
    |
 LL | use self::outer_mod::await::await;
    |                      ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | use self::outer_mod::r#await::await;
-   |                      ~~~~~~~
+   |                      ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error.rs:9:29
    |
 LL | use self::outer_mod::await::await;
    |                             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | use self::outer_mod::await::r#await;
-   |                             ~~~~~~~
+   |                             ++
 
 error: expected identifier, found keyword `await`
   --> $DIR/2018-edition-error.rs:12:14
    |
 LL | macro_rules! await { () => {}; }
    |              ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `await` to use it as an identifier
    |
 LL | macro_rules! r#await { () => {}; }
-   |              ~~~~~~~
+   |              ++
 
 error: expected expression, found `)`
   --> $DIR/2018-edition-error.rs:15:12

src/test/ui/editions/edition-keywords-2015-2018-expansion.stderr

@@ -5,10 +5,10 @@ LL |     produces_async! {}
    |     ^^^^^^^^^^^^^^^^^^ expected identifier, found keyword
    |
    = note: this error originates in the macro `produces_async` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     () => (pub fn r#async() {})
-   |                   ~~~~~~~
+   |                   ++
 
 error: aborting due to previous error
 

src/test/ui/editions/edition-keywords-2018-2015-parsing.stderr

@@ -4,21 +4,21 @@ error: expected identifier, found keyword `async`
 LL |     let mut async = 1;
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     let mut r#async = 1;
-   |             ~~~~~~~
+   |             ++
 
 error: expected identifier, found keyword `async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:26:13
    |
 LL |     module::async();
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     module::r#async();
-   |             ~~~~~~~
+   |             ++
 
 error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2018-2015-parsing.rs:20:31

src/test/ui/editions/edition-keywords-2018-2018-expansion.stderr

@@ -5,10 +5,10 @@ LL |     produces_async! {}
    |     ^^^^^^^^^^^^^^^^^^ expected identifier, found keyword
    |
    = note: this error originates in the macro `produces_async` (in Nightly builds, run with -Z macro-backtrace for more info)
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     () => (pub fn r#async() {})
-   |                   ~~~~~~~
+   |                   ++
 
 error: aborting due to previous error
 

src/test/ui/editions/edition-keywords-2018-2018-parsing.stderr

@@ -4,21 +4,21 @@ error: expected identifier, found keyword `async`
 LL |     let mut async = 1;
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     let mut r#async = 1;
-   |             ~~~~~~~
+   |             ++
 
 error: expected identifier, found keyword `async`
   --> $DIR/edition-keywords-2018-2018-parsing.rs:26:13
    |
 LL |     module::async();
    |             ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `async` to use it as an identifier
    |
 LL |     module::r#async();
-   |             ~~~~~~~
+   |             ++
 
 error: no rules expected the token `r#async`
   --> $DIR/edition-keywords-2018-2018-parsing.rs:20:31

src/test/ui/keyword/extern/keyword-extern-as-identifier-pat.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `extern`
 LL |     let extern = 0;
    |         ^^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `extern` to use it as an identifier
    |
 LL |     let r#extern = 0;
-   |         ~~~~~~~~
+   |         ++
 
 error: aborting due to previous error
 

src/test/ui/keyword/extern/keyword-extern-as-identifier-use.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `extern`
 LL | use extern::foo;
    |     ^^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `extern` to use it as an identifier
    |
 LL | use r#extern::foo;
-   |     ~~~~~~~~
+   |     ++
 
 error[E0432]: unresolved import `r#extern`
   --> $DIR/keyword-extern-as-identifier-use.rs:1:5

src/test/ui/parser/bad-value-ident-false.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `false`
 LL | fn false() { }
    |    ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `false` to use it as an identifier
    |
 LL | fn r#false() { }
-   |    ~~~~~~~
+   |    ++
 
 error: aborting due to previous error
 

src/test/ui/parser/bad-value-ident-true.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `true`
 LL | fn true() { }
    |    ^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `true` to use it as an identifier
    |
 LL | fn r#true() { }
-   |    ~~~~~~
+   |    ++
 
 error: aborting due to previous error
 

src/test/ui/parser/issues/issue-15980.stderr

@@ -7,10 +7,10 @@ LL |
 LL |             return
    |             ^^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `return` to use it as an identifier
    |
 LL |             r#return
-   |
+   |             ++
 
 error: expected one of `.`, `=>`, `?`, or an operator, found reserved identifier `_`
   --> $DIR/issue-15980.rs:13:9

src/test/ui/parser/issues/issue-44406.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `true`
 LL |     foo!(true);
    |          ^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `true` to use it as an identifier
    |
 LL |     foo!(r#true);
-   |          ~~~~~~
+   |          ++
 
 error: invalid `struct` delimiters or `fn` call arguments
   --> $DIR/issue-44406.rs:3:9

src/test/ui/parser/issues/issue-57198.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `for`
 LL |     m::for();
    |        ^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `for` to use it as an identifier
    |
 LL |     m::r#for();
-   |        ~~~~~
+   |        ++
 
 error: aborting due to previous error
 

src/test/ui/parser/issues/issue-81806.stderr

@@ -8,10 +8,10 @@ LL | impl
 LL | }
    | - the item list ends here
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `impl` to use it as an identifier
    |
 LL | r#impl
-   | ~~~~~~
+   | ++
 
 error: aborting due to previous error
 

src/test/ui/parser/keyword-abstract.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found reserved keyword `abstract`
 LL |     let abstract = ();
    |         ^^^^^^^^ expected identifier, found reserved keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `abstract` to use it as an identifier
    |
 LL |     let r#abstract = ();
-   |         ~~~~~~~~~~
+   |         ++
 
 error: aborting due to previous error
 

src/test/ui/parser/keyword-as-as-identifier.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `as`
 LL |     let as = "foo";
    |         ^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `as` to use it as an identifier
    |
 LL |     let r#as = "foo";
-   |         ~~~~
+   |         ++
 
 error: aborting due to previous error
 

src/test/ui/parser/keyword-break-as-identifier.stderr

@@ -4,10 +4,10 @@ error: expected identifier, found keyword `break`
 LL |     let break = "foo";
    |         ^^^^^ expected identifier, found keyword
    |
-help: you can escape reserved keywords to use them as identifiers
+help: escape `break` to use it as an identifier
    |
 LL |     let r#break = "foo";
-   |         ~~~~~~~
+   |         ++
 
 error: aborting due to previous error