Add code to incorrect `pub` restriction error

src/libsyntax/diagnostic_list.rs

@@ -398,4 +398,5 @@ register_diagnostics! {
     E0693, // incorrect `repr(align)` attribute format
     E0694, // an unknown tool name found in scoped attributes
     E0697, // invalid ABI
+    E0698, // incorrect visibility restriction
 }

src/libsyntax/parse/parser.rs

@@ -5986,12 +5986,13 @@ impl<'a> Parser<'a> {
 `pub(super)`: visible only in the current module's parent
 `pub(in path::to::module)`: visible only on the specified path"##;
                 let path = self.parse_path(PathStyle::Mod)?;
-                let path_span = self.prev_span;
+                let sp = self.prev_span;
                 let help_msg = format!("make this visible only to module `{}` with `in`", path);
                 self.expect(&token::CloseDelim(token::Paren))?;  // `)`
-                let mut err = self.span_fatal_help(path_span, msg, suggestion);
+                let mut err = struct_span_err!(self.sess.span_diagnostic, sp, E0698, "{}", msg);
+                err.help(suggestion);
                 err.span_suggestion_with_applicability(
-                    path_span, &help_msg, format!("in {}", path), Applicability::MachineApplicable
+                    sp, &help_msg, format!("in {}", path), Applicability::MachineApplicable
                 );
                 err.emit();  // emit diagnostic, but continue with public visibility
             }

src/test/ui/pub/pub-restricted.stderr

@@ -1,4 +1,4 @@
-error: incorrect visibility restriction
+error[E0698]: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:15:6
    |
 LL | pub (a) fn afn() {} //~ incorrect visibility restriction
@@ -9,7 +9,7 @@ LL | pub (a) fn afn() {} //~ incorrect visibility restriction
            `pub(super)`: visible only in the current module's parent
            `pub(in path::to::module)`: visible only on the specified path
 
-error: incorrect visibility restriction
+error[E0698]: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:16:6
    |
 LL | pub (b) fn bfn() {} //~ incorrect visibility restriction
@@ -20,7 +20,7 @@ LL | pub (b) fn bfn() {} //~ incorrect visibility restriction
            `pub(super)`: visible only in the current module's parent
            `pub(in path::to::module)`: visible only on the specified path
 
-error: incorrect visibility restriction
+error[E0698]: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:32:14
    |
 LL |         pub (a) invalid: usize, //~ incorrect visibility restriction
@@ -31,7 +31,7 @@ LL |         pub (a) invalid: usize, //~ incorrect visibility restriction
            `pub(super)`: visible only in the current module's parent
            `pub(in path::to::module)`: visible only on the specified path
 
-error: incorrect visibility restriction
+error[E0698]: incorrect visibility restriction
   --> $DIR/pub-restricted.rs:41:6
    |
 LL | pub (xyz) fn xyz() {} //~ incorrect visibility restriction
@@ -50,3 +50,4 @@ LL |         pub (in x) non_parent_invalid: usize, //~ ERROR visibilities can on
 
 error: aborting due to 5 previous errors
 
+For more information about this error, try `rustc --explain E0698`.