Use more accurate span for : to :: suggestion

Author: estebank

compiler/rustc_parse/src/errors.rs

@@ -1562,9 +1562,11 @@ pub(crate) struct ExpectedFnPathFoundFnKeyword {
 #[diag(parse_path_single_colon)]
 pub(crate) struct PathSingleColon {
     #[primary_span]
-    #[suggestion(applicability = "machine-applicable", code = "::", style = "verbose")]
     pub span: Span,
 
+    #[suggestion(applicability = "machine-applicable", code = ":", style = "verbose")]
+    pub suggestion: Span,
+
     #[note(parse_type_ascription_removed)]
     pub type_ascription: Option<()>,
 }

compiler/rustc_parse/src/parser/path.rs

@@ -258,6 +258,7 @@ impl<'a> Parser<'a> {
                         self.bump(); // bump past the colon
                         self.dcx().emit_err(PathSingleColon {
                             span: self.prev_token.span,
+                            suggestion: self.prev_token.span.shrink_to_hi(),
                             type_ascription: self
                                 .psess
                                 .unstable_features
@@ -329,6 +330,7 @@ impl<'a> Parser<'a> {
                             err.cancel();
                             err = self.dcx().create_err(PathSingleColon {
                                 span: self.token.span,
+                                suggestion: self.prev_token.span.shrink_to_hi(),
                                 type_ascription: self
                                     .psess
                                     .unstable_features

tests/ui/generics/single-colon-path-not-const-generics.stderr

@@ -10,7 +10,7 @@ LL |   a: Vec<foo::bar:A>,
 help: use a double colon instead
    |
 LL |   a: Vec<foo::bar::A>,
-   |                  ~~
+   |                  +
 
 error: aborting due to 1 previous error
 

tests/ui/suggestions/type-ascription-instead-of-method.stderr

@@ -8,7 +8,7 @@ LL |     let _ = Box:new("foo".to_string());
 help: use a double colon instead
    |
 LL |     let _ = Box::new("foo".to_string());
-   |                ~~
+   |                 +
 
 error: aborting due to 1 previous error
 

tests/ui/suggestions/type-ascription-instead-of-path.stderr

@@ -8,7 +8,7 @@ LL |     std:io::stdin();
 help: use a double colon instead
    |
 LL |     std::io::stdin();
-   |        ~~
+   |         +
 
 error: aborting due to 1 previous error
 

tests/ui/suggestions/type-ascription-instead-of-variant.stderr

@@ -8,7 +8,7 @@ LL |     let _ = Option:Some("");
 help: use a double colon instead
    |
 LL |     let _ = Option::Some("");
-   |                   ~~
+   |                    +
 
 error: aborting due to 1 previous error
 

tests/ui/type/ascription/issue-47666.stderr

@@ -8,7 +8,7 @@ LL |     let _ = Option:Some(vec![0, 1]);
 help: use a double colon instead
    |
 LL |     let _ = Option::Some(vec![0, 1]);
-   |                   ~~
+   |                    +
 
 error: aborting due to 1 previous error
 

tests/ui/type/ascription/issue-54516.stderr

@@ -8,7 +8,7 @@ LL |     println!("{}", std::mem:size_of::<BTreeMap<u32, u32>>());
 help: use a double colon instead
    |
 LL |     println!("{}", std::mem::size_of::<BTreeMap<u32, u32>>());
-   |                            ~~
+   |                             +
 
 error: aborting due to 1 previous error
 

tests/ui/type/ascription/issue-60933.stderr

@@ -8,7 +8,7 @@ LL |     let _: usize = std::mem:size_of::<u32>();
 help: use a double colon instead
    |
 LL |     let _: usize = std::mem::size_of::<u32>();
-   |                            ~~
+   |                             +
 
 error: aborting due to 1 previous error