Auto merge of rust-lang#80535 - JohnTitor:improve-use-diag, r=estebank

Add a note for `*` and `{}` usage on `use`

Closes rust-lang#80333

Author: bors

compiler/rustc_parse/src/parser/item.rs

@@ -220,7 +220,22 @@ impl<'a> Parser<'a> {
         let info = if self.eat_keyword(kw::Use) {
             // USE ITEM
             let tree = self.parse_use_tree()?;
-            self.expect_semi()?;
+
+            // If wildcard or glob-like brace syntax doesn't have `;`,
+            // the user may not know `*` or `{}` should be the last.
+            if let Err(mut e) = self.expect_semi() {
+                match tree.kind {
+                    UseTreeKind::Glob => {
+                        e.note("the wildcard token must be last on the path").emit();
+                    }
+                    UseTreeKind::Nested(..) => {
+                        e.note("glob-like brace syntax must be last on the path").emit();
+                    }
+                    _ => (),
+                }
+                return Err(e);
+            }
+
             (Ident::invalid(), ItemKind::Use(P(tree)))
         } else if self.check_fn_front_matter() {
             // FUNCTION ITEM

src/test/ui/parser/import-from-path.stderr

@@ -3,6 +3,8 @@ error: expected `;`, found `::`
    |
 LL | use foo::{bar}::baz
    |               ^^ expected `;`
+   |
+   = note: glob-like brace syntax must be last on the path
 
 error: aborting due to previous error
 

src/test/ui/parser/import-from-rename.stderr

@@ -3,6 +3,8 @@ error: expected `;`, found keyword `as`
    |
 LL | use foo::{bar} as baz;
    |                ^^ expected `;`
+   |
+   = note: glob-like brace syntax must be last on the path
 
 error: aborting due to previous error
 

src/test/ui/parser/import-glob-path.stderr

@@ -3,6 +3,8 @@ error: expected `;`, found `::`
    |
 LL | use foo::*::bar
    |           ^^ expected `;`
+   |
+   = note: the wildcard token must be last on the path
 
 error: aborting due to previous error
 

src/test/ui/parser/import-glob-rename.stderr

@@ -3,6 +3,8 @@ error: expected `;`, found keyword `as`
    |
 LL | use foo::* as baz;
    |            ^^ expected `;`
+   |
+   = note: the wildcard token must be last on the path
 
 error: aborting due to previous error