Support pretty-printing dyn* trait objects

Author: dtolnay

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -1204,8 +1204,10 @@ impl<'a> State<'a> {
             }
             ast::TyKind::Path(Some(qself), path) => self.print_qpath(path, qself, false),
             ast::TyKind::TraitObject(bounds, syntax) => {
-                if *syntax == ast::TraitObjectSyntax::Dyn {
-                    self.word_nbsp("dyn");
+                match syntax {
+                    ast::TraitObjectSyntax::Dyn => self.word_nbsp("dyn"),
+                    ast::TraitObjectSyntax::DynStar => self.word_nbsp("dyn*"),
+                    ast::TraitObjectSyntax::None => {}
                 }
                 self.print_type_bounds(bounds);
             }

compiler/rustc_hir_pretty/src/lib.rs

@@ -402,8 +402,10 @@ impl<'a> State<'a> {
             }
             hir::TyKind::Path(ref qpath) => self.print_qpath(qpath, false),
             hir::TyKind::TraitObject(bounds, lifetime, syntax) => {
-                if syntax == ast::TraitObjectSyntax::Dyn {
-                    self.word_space("dyn");
+                match syntax {
+                    ast::TraitObjectSyntax::Dyn => self.word_nbsp("dyn"),
+                    ast::TraitObjectSyntax::DynStar => self.word_nbsp("dyn*"),
+                    ast::TraitObjectSyntax::None => {}
                 }
                 let mut first = true;
                 for bound in bounds {

tests/ui-fulldeps/pprust-parenthesis-insertion.rs

@@ -129,10 +129,7 @@ static EXPRS: &[&str] = &[
     "(0.).to_string()",
     "0. .. 1.",
     */
-    /*
-    // FIXME: pretty-printer loses the dyn*. `i as Trait`
     "i as dyn* Trait",
-    */
 ];
 
 // Flatten the content of parenthesis nodes into their parent node. For example

tests/ui/suggestions/wrap-dyn-in-suggestion-issue-120223.stderr

@@ -58,14 +58,14 @@ help: consider adding an explicit lifetime bound
 LL |     executor: impl FnOnce(T) -> (dyn Future<Output = ()>) + 'static,
    |                                 +                       +++++++++++
 
-error[E0310]: the parameter type `impl FnOnce(T) -> Future<Output = ()>` may not live long enough
+error[E0310]: the parameter type `impl FnOnce(T) -> dyn* Future<Output = ()>` may not live long enough
   --> $DIR/wrap-dyn-in-suggestion-issue-120223.rs:14:5
    |
 LL |     Box::new(executor)
    |     ^^^^^^^^^^^^^^^^^^
    |     |
-   |     the parameter type `impl FnOnce(T) -> Future<Output = ()>` must be valid for the static lifetime...
-   |     ...so that the type `impl FnOnce(T) -> Future<Output = ()>` will meet its required lifetime bounds
+   |     the parameter type `impl FnOnce(T) -> dyn* Future<Output = ()>` must be valid for the static lifetime...
+   |     ...so that the type `impl FnOnce(T) -> dyn* Future<Output = ()>` will meet its required lifetime bounds
    |
 help: consider adding an explicit lifetime bound
    |