adjust how closure/generator types are printed

Author: RalfJung

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -1616,7 +1616,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     //    |     expected `()`, found closure
                     //    |
                     //    = note: expected unit type `()`
-                    //                 found closure `[closure@$DIR/issue-20862.rs:2:5: 2:14 x:_]`
+                    //                 found closure `{closure@$DIR/issue-20862.rs:2:5: 2:14 x:_}`
                     //
                     // Also ignore opaque `Future`s that come from async fns.
                     if !self.ignore_span.overlaps(span)

compiler/rustc_middle/src/mir/mod.rs

@@ -2174,11 +2174,11 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                     AggregateKind::Closure(def_id, args) => ty::tls::with(|tcx| {
                         let name = if tcx.sess.opts.unstable_opts.span_free_formats {
                             let args = tcx.lift(args).unwrap();
-                            format!("[closure@{}]", tcx.def_path_str_with_args(def_id, args),)
+                            format!("{{closure@{}}}", tcx.def_path_str_with_args(def_id, args),)
                         } else {
                             let span = tcx.def_span(def_id);
                             format!(
-                                "[closure@{}]",
+                                "{{closure@{}}}",
                                 tcx.sess.source_map().span_to_diagnostic_string(span)
                             )
                         };
@@ -2202,7 +2202,7 @@ impl<'tcx> Debug for Rvalue<'tcx> {
                     }),
 
                     AggregateKind::Generator(def_id, _, _) => ty::tls::with(|tcx| {
-                        let name = format!("[generator@{:?}]", tcx.def_span(def_id));
+                        let name = format!("{{generator@{:?}}}", tcx.def_span(def_id));
                         let mut struct_fmt = fmt.debug_struct(&name);
 
                         // FIXME(project-rfc-2229#48): This should be a list of capture names/places

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1063,7 +1063,7 @@ pub trait PrettyPrinter<'tcx>:
                     }
 
                     for (assoc_item_def_id, term) in assoc_items {
-                        // Skip printing `<[generator@] as Generator<_>>::Return` from async blocks,
+                        // Skip printing `<{generator@} as Generator<_>>::Return` from async blocks,
                         // unless we can find out what generator return type it comes from.
                         let term = if let Some(ty) = term.skip_binder().ty()
                             && let ty::Alias(ty::Projection, proj) = ty.kind()

compiler/rustc_middle/src/ty/sty.rs

@@ -2536,7 +2536,7 @@ impl<'tcx> Ty<'tcx> {
 
     /// Checks whether a type recursively contains any closure
     ///
-    /// Example: `Option<[[email protected]:4:20]>` returns true
+    /// Example: `Option<{[email protected]:4:20}>` returns true
     pub fn contains_closure(self) -> bool {
         struct ContainsClosureVisitor;
 

tests/mir-opt/inline/inline_closure.foo.Inline.after.mir

@@ -21,7 +21,7 @@ fn foo(_1: T, _2: i32) -> i32 {
 
     bb0: {
         StorageLive(_3);
-        _3 = [closure@foo::<T>::{closure#0}];
+        _3 = {closure@foo::<T>::{closure#0}};
         StorageLive(_4);
         _4 = &_3;
         StorageLive(_5);

tests/mir-opt/inline/inline_closure_borrows_arg.foo.Inline.after.mir

@@ -24,7 +24,7 @@ fn foo(_1: T, _2: &i32) -> i32 {
 
     bb0: {
         StorageLive(_3);
-        _3 = [closure@foo::<T>::{closure#0}];
+        _3 = {closure@foo::<T>::{closure#0}};
         StorageLive(_4);
         _4 = &_3;
         StorageLive(_5);

tests/mir-opt/inline/inline_closure_captures.foo.Inline.after.mir

@@ -30,7 +30,7 @@ fn foo(_1: T, _2: i32) -> (i32, T) {
         _4 = &_2;
         StorageLive(_5);
         _5 = &_1;
-        _3 = [closure@foo::<T>::{closure#0}] { q: move _4, t: move _5 };
+        _3 = {closure@foo::<T>::{closure#0}} { q: move _4, t: move _5 };
         StorageDead(_5);
         StorageDead(_4);
         StorageLive(_6);

tests/mir-opt/inline/inline_generator.main.Inline.panic-abort.diff

@@ -39,7 +39,7 @@
 -     }
 - 
 -     bb1: {
-+         _4 = [generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)];
++         _4 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
           _3 = &mut _4;
 -         _2 = Pin::<&mut [generator@$DIR/inline_generator.rs:16:5: 16:8]>::new(move _3) -> [return: bb2, unwind unreachable];
 -     }

tests/mir-opt/inline/inline_generator.main.Inline.panic-unwind.diff

@@ -39,7 +39,7 @@
 -     }
 - 
 -     bb1: {
-+         _4 = [generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)];
++         _4 = {generator@$DIR/inline_generator.rs:16:5: 16:8 (#0)};
           _3 = &mut _4;
 -         _2 = Pin::<&mut [generator@$DIR/inline_generator.rs:16:5: 16:8]>::new(move _3) -> [return: bb2, unwind: bb4];
 -     }

tests/mir-opt/inline/issue_76997_inline_scopes_parenting.main.Inline.after.mir

@@ -19,7 +19,7 @@ fn main() -> () {
 
     bb0: {
         StorageLive(_1);
-        _1 = [closure@$DIR/issue_76997_inline_scopes_parenting.rs:5:13: 5:16];
+        _1 = {closure@$DIR/issue_76997_inline_scopes_parenting.rs:5:13: 5:16};
         StorageLive(_2);
         _2 = &_1;
         StorageLive(_3);