Rollup merge of #122923 - kpreid:print-async-def, r=compiler-errors

In `pretty_print_type()`, print `async fn` futures' paths instead of spans.

This makes `-Zprint-type-sizes`'s output easier to read, because the name of an `async fn` is more immediately recognizable than its span. This change will also synergize with my other `-Zprint-type-sizes` PR #122922 which prints the type of child futures being awaited.

I also deleted the comment "FIXME(eddyb) should use `def_span`." because it appears to have already been fixed by commit 67727aa.

Author: workingjubilee

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

@@ -804,7 +804,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             }
             ty::Str => p!("str"),
             ty::Coroutine(did, args) => {
-                p!(write("{{"));
+                p!("{{");
                 let coroutine_kind = self.tcx().coroutine_kind(did).unwrap();
                 let should_print_movability = self.should_print_verbose()
                     || matches!(coroutine_kind, hir::CoroutineKind::Coroutine(_));
@@ -818,17 +818,25 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
 
                 if !self.should_print_verbose() {
                     p!(write("{}", coroutine_kind));
-                    // FIXME(eddyb) should use `def_span`.
-                    if let Some(did) = did.as_local() {
-                        let span = self.tcx().def_span(did);
+                    if coroutine_kind.is_fn_like() {
+                        // If we are printing an `async fn` coroutine type, then give the path
+                        // of the fn, instead of its span, because that will in most cases be
+                        // more helpful for the reader than just a source location.
+                        //
+                        // This will look like:
+                        //    {async fn body of some_fn()}
+                        let did_of_the_fn_item = self.tcx().parent(did);
+                        p!(" of ", print_def_path(did_of_the_fn_item, args), "()");
+                    } else if let Some(local_did) = did.as_local() {
+                        let span = self.tcx().def_span(local_did);
                         p!(write(
                             "@{}",
                             // This may end up in stderr diagnostics but it may also be emitted
                             // into MIR. Hence we use the remapped path if available
                             self.tcx().sess.source_map().span_to_embeddable_string(span)
                         ));
                     } else {
-                        p!(write("@"), print_def_path(did, args));
+                        p!("@", print_def_path(did, args));
                     }
                 } else {
                     p!(print_def_path(did, args));

tests/mir-opt/building/async_await.a-{closure#0}.coroutine_resume.0.mir

@@ -9,15 +9,15 @@
     storage_conflicts: BitMatrix(0x0) {},
 } */
 
-fn a::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>, _2: &mut Context<'_>) -> Poll<()> {
+fn a::{closure#0}(_1: Pin<&mut {async fn body of a()}>, _2: &mut Context<'_>) -> Poll<()> {
     debug _task_context => _4;
     let mut _0: std::task::Poll<()>;
     let mut _3: ();
     let mut _4: &mut std::task::Context<'_>;
     let mut _5: u32;
 
     bb0: {
-        _5 = discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16})));
+        _5 = discriminant((*(_1.0: &mut {async fn body of a()})));
         switchInt(move _5) -> [0: bb1, 1: bb4, otherwise: bb5];
     }
 
@@ -29,7 +29,7 @@ fn a::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>
 
     bb2: {
         _0 = Poll::<()>::Ready(move _3);
-        discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16}))) = 1;
+        discriminant((*(_1.0: &mut {async fn body of a()}))) = 1;
         return;
     }
 

tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir

@@ -51,34 +51,34 @@
     },
 } */
 
-fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>, _2: &mut Context<'_>) -> Poll<()> {
+fn b::{closure#0}(_1: Pin<&mut {async fn body of b()}>, _2: &mut Context<'_>) -> Poll<()> {
     debug _task_context => _38;
     let mut _0: std::task::Poll<()>;
     let _3: ();
-    let mut _4: {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _5: {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _6: {async fn body@$DIR/async_await.rs:12:14: 12:16};
+    let mut _4: {async fn body of a()};
+    let mut _5: {async fn body of a()};
+    let mut _6: {async fn body of a()};
     let mut _7: ();
     let _8: ();
     let mut _9: std::task::Poll<()>;
-    let mut _10: std::pin::Pin<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>;
-    let mut _11: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _12: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16};
+    let mut _10: std::pin::Pin<&mut {async fn body of a()}>;
+    let mut _11: &mut {async fn body of a()};
+    let mut _12: &mut {async fn body of a()};
     let mut _13: &mut std::task::Context<'_>;
     let mut _14: &mut std::task::Context<'_>;
     let mut _15: &mut std::task::Context<'_>;
     let mut _16: isize;
     let mut _18: !;
     let mut _19: &mut std::task::Context<'_>;
     let mut _20: ();
-    let mut _21: {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _22: {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _23: {async fn body@$DIR/async_await.rs:12:14: 12:16};
+    let mut _21: {async fn body of a()};
+    let mut _22: {async fn body of a()};
+    let mut _23: {async fn body of a()};
     let _24: ();
     let mut _25: std::task::Poll<()>;
-    let mut _26: std::pin::Pin<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>;
-    let mut _27: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16};
-    let mut _28: &mut {async fn body@$DIR/async_await.rs:12:14: 12:16};
+    let mut _26: std::pin::Pin<&mut {async fn body of a()}>;
+    let mut _27: &mut {async fn body of a()};
+    let mut _28: &mut {async fn body of a()};
     let mut _29: &mut std::task::Context<'_>;
     let mut _30: &mut std::task::Context<'_>;
     let mut _31: &mut std::task::Context<'_>;
@@ -90,7 +90,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     let mut _38: &mut std::task::Context<'_>;
     let mut _39: u32;
     scope 1 {
-        debug __awaitee => (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#3).0: {async fn body@$DIR/async_await.rs:12:14: 12:16});
+        debug __awaitee => (((*(_1.0: &mut {async fn body of b()})) as variant#3).0: {async fn body of a()});
         let _17: ();
         scope 2 {
         }
@@ -99,7 +99,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         }
     }
     scope 4 {
-        debug __awaitee => (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#4).0: {async fn body@$DIR/async_await.rs:12:14: 12:16});
+        debug __awaitee => (((*(_1.0: &mut {async fn body of b()})) as variant#4).0: {async fn body of a()});
         let _33: ();
         scope 5 {
         }
@@ -109,7 +109,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     }
 
     bb0: {
-        _39 = discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})));
+        _39 = discriminant((*(_1.0: &mut {async fn body of b()})));
         switchInt(move _39) -> [0: bb1, 1: bb29, 3: bb27, 4: bb28, otherwise: bb8];
     }
 
@@ -122,14 +122,14 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     }
 
     bb2: {
-        _4 = <{async fn body@$DIR/async_await.rs:12:14: 12:16} as IntoFuture>::into_future(move _5) -> [return: bb3, unwind unreachable];
+        _4 = <{async fn body of a()} as IntoFuture>::into_future(move _5) -> [return: bb3, unwind unreachable];
     }
 
     bb3: {
         StorageDead(_5);
         PlaceMention(_4);
         nop;
-        (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#3).0: {async fn body@$DIR/async_await.rs:12:14: 12:16}) = move _4;
+        (((*(_1.0: &mut {async fn body of b()})) as variant#3).0: {async fn body of a()}) = move _4;
         goto -> bb4;
     }
 
@@ -139,9 +139,9 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageLive(_10);
         StorageLive(_11);
         StorageLive(_12);
-        _12 = &mut (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#3).0: {async fn body@$DIR/async_await.rs:12:14: 12:16});
+        _12 = &mut (((*(_1.0: &mut {async fn body of b()})) as variant#3).0: {async fn body of a()});
         _11 = &mut (*_12);
-        _10 = Pin::<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>::new_unchecked(move _11) -> [return: bb5, unwind unreachable];
+        _10 = Pin::<&mut {async fn body of a()}>::new_unchecked(move _11) -> [return: bb5, unwind unreachable];
     }
 
     bb5: {
@@ -157,7 +157,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     bb6: {
         _13 = &mut (*_14);
         StorageDead(_15);
-        _9 = <{async fn body@$DIR/async_await.rs:12:14: 12:16} as Future>::poll(move _10, move _13) -> [return: bb7, unwind unreachable];
+        _9 = <{async fn body of a()} as Future>::poll(move _10, move _13) -> [return: bb7, unwind unreachable];
     }
 
     bb7: {
@@ -186,7 +186,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageDead(_4);
         StorageDead(_19);
         StorageDead(_20);
-        discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2}))) = 3;
+        discriminant((*(_1.0: &mut {async fn body of b()}))) = 3;
         return;
     }
 
@@ -199,7 +199,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageDead(_12);
         StorageDead(_9);
         StorageDead(_8);
-        drop((((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#3).0: {async fn body@$DIR/async_await.rs:12:14: 12:16})) -> [return: bb12, unwind unreachable];
+        drop((((*(_1.0: &mut {async fn body of b()})) as variant#3).0: {async fn body of a()})) -> [return: bb12, unwind unreachable];
     }
 
     bb11: {
@@ -224,14 +224,14 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     }
 
     bb14: {
-        _21 = <{async fn body@$DIR/async_await.rs:12:14: 12:16} as IntoFuture>::into_future(move _22) -> [return: bb15, unwind unreachable];
+        _21 = <{async fn body of a()} as IntoFuture>::into_future(move _22) -> [return: bb15, unwind unreachable];
     }
 
     bb15: {
         StorageDead(_22);
         PlaceMention(_21);
         nop;
-        (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#4).0: {async fn body@$DIR/async_await.rs:12:14: 12:16}) = move _21;
+        (((*(_1.0: &mut {async fn body of b()})) as variant#4).0: {async fn body of a()}) = move _21;
         goto -> bb16;
     }
 
@@ -241,9 +241,9 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageLive(_26);
         StorageLive(_27);
         StorageLive(_28);
-        _28 = &mut (((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#4).0: {async fn body@$DIR/async_await.rs:12:14: 12:16});
+        _28 = &mut (((*(_1.0: &mut {async fn body of b()})) as variant#4).0: {async fn body of a()});
         _27 = &mut (*_28);
-        _26 = Pin::<&mut {async fn body@$DIR/async_await.rs:12:14: 12:16}>::new_unchecked(move _27) -> [return: bb17, unwind unreachable];
+        _26 = Pin::<&mut {async fn body of a()}>::new_unchecked(move _27) -> [return: bb17, unwind unreachable];
     }
 
     bb17: {
@@ -259,7 +259,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
     bb18: {
         _29 = &mut (*_30);
         StorageDead(_31);
-        _25 = <{async fn body@$DIR/async_await.rs:12:14: 12:16} as Future>::poll(move _26, move _29) -> [return: bb19, unwind unreachable];
+        _25 = <{async fn body of a()} as Future>::poll(move _26, move _29) -> [return: bb19, unwind unreachable];
     }
 
     bb19: {
@@ -283,7 +283,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageDead(_21);
         StorageDead(_35);
         StorageDead(_36);
-        discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2}))) = 4;
+        discriminant((*(_1.0: &mut {async fn body of b()}))) = 4;
         return;
     }
 
@@ -296,7 +296,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
         StorageDead(_28);
         StorageDead(_25);
         StorageDead(_24);
-        drop((((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2})) as variant#4).0: {async fn body@$DIR/async_await.rs:12:14: 12:16})) -> [return: bb23, unwind unreachable];
+        drop((((*(_1.0: &mut {async fn body of b()})) as variant#4).0: {async fn body of a()})) -> [return: bb23, unwind unreachable];
     }
 
     bb22: {
@@ -319,7 +319,7 @@ fn b::{closure#0}(_1: Pin<&mut {async fn body@$DIR/async_await.rs:15:18: 18:2}>,
 
     bb25: {
         _0 = Poll::<()>::Ready(move _37);
-        discriminant((*(_1.0: &mut {async fn body@$DIR/async_await.rs:15:18: 18:2}))) = 1;
+        discriminant((*(_1.0: &mut {async fn body of b()}))) = 1;
         return;
     }