rust-lang · estebank · Jul 22, 2025
diff --git a/compiler/rustc_const_eval/src/util/type_name.rs b/compiler/rustc_const_eval/src/util/type_name.rs
@@ -1,7 +1,7 @@
 use std::fmt::Write;
 
 use rustc_data_structures::intern::Interned;
-use rustc_hir::def_id::CrateNum;
+use rustc_hir::def_id::{CrateNum, DefId};
 use rustc_hir::definitions::DisambiguatedDefPathData;
 use rustc_middle::bug;
 use rustc_middle::ty::print::{PrettyPrinter, Print, PrintError, Printer};
@@ -108,6 +108,7 @@ impl<'tcx> Printer<'tcx> for AbsolutePathPrinter<'tcx> {
 
     fn path_append(
         &mut self,
+        _def_id: DefId,
         print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<(), PrintError> {

diff --git a/compiler/rustc_lint/src/context.rs b/compiler/rustc_lint/src/context.rs
@@ -828,6 +828,7 @@ impl<'tcx> LateContext<'tcx> {
 
             fn path_append(
                 &mut self,
+                _def_id: DefId,
                 print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
                 disambiguated_data: &DisambiguatedDefPathData,
             ) -> Result<(), PrintError> {

diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -95,6 +95,7 @@ pub trait Printer<'tcx>: Sized {
 
     fn path_append(
         &mut self,
+        def_id: DefId,
         print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<(), PrintError>;
@@ -186,6 +187,7 @@ pub trait Printer<'tcx>: Sized {
                 }
 
                 self.path_append(
+                    def_id,
                     |cx: &mut Self| {
                         if trait_qualify_parent {
                             let trait_ref = ty::TraitRef::new(

diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs
@@ -660,7 +660,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
             true => {}
         }
         callers.pop();
-        self.path_append(|_| Ok(()), &DisambiguatedDefPathData { data, disambiguator: 0 })?;
+        self.path_append(def_id, |_| Ok(()), &DisambiguatedDefPathData { data, disambiguator: 0 })?;
         Ok(true)
     }
 
@@ -1352,6 +1352,7 @@ pub trait PrettyPrinter<'tcx>: Printer<'tcx> + fmt::Write {
         self.path_generic_args(
             |cx| {
                 cx.path_append(
+                    alias_ty.def_id,
                     |cx| cx.path_qualified(alias_ty.self_ty(), None),
                     &def_key.disambiguated_data,
                 )
@@ -2408,6 +2409,7 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
 
     fn path_append(
         &mut self,
+        def_id: DefId,
         print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<(), PrintError> {
@@ -2417,6 +2419,15 @@ impl<'tcx> Printer<'tcx> for FmtPrinter<'_, 'tcx> {
         if let DefPathData::ForeignMod | DefPathData::Ctor = disambiguated_data.data {
             return Ok(());
         }
+        if let DefPathData::Closure = disambiguated_data.data
+            && let Some(hir::CoroutineKind::Desugared(
+                hir::CoroutineDesugaring::Async,
+                hir::CoroutineSource::Fn,
+            )) = self.tcx.coroutine_kind(def_id)
+        {
+            // Skip the implicit closure in `async_function::{closure#0}`.
+            return Ok(());
+        }
 
         let name = disambiguated_data.data.name();
         if !self.empty_path {

diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -357,6 +357,7 @@ impl<'tcx> Printer<'tcx> for SymbolPrinter<'tcx> {
     }
     fn path_append(
         &mut self,
+        _def_id: DefId,
         print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<(), PrintError> {

diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -859,6 +859,7 @@ impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> {
 
     fn path_append(
         &mut self,
+        _def_id: DefId,
         print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
         disambiguated_data: &DisambiguatedDefPathData,
     ) -> Result<(), PrintError> {

diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/mod.rs
@@ -276,6 +276,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             }
             fn path_append(
                 &mut self,
+                _def_id: DefId,
                 print_prefix: impl FnOnce(&mut Self) -> Result<(), PrintError>,
                 disambiguated_data: &DisambiguatedDefPathData,
             ) -> Result<(), PrintError> {

diff --git a/tests/mir-opt/async_drop_live_dead.a-{closure#0}.coroutine_drop_async.0.panic-abort.mir b/tests/mir-opt/async_drop_live_dead.a-{closure#0}.coroutine_drop_async.0.panic-abort.mir
@@ -1,6 +1,6 @@
-// MIR for `a::{closure#0}` 0 coroutine_drop_async
+// MIR for `a` 0 coroutine_drop_async
 
-fn a::{closure#0}(_1: Pin<&mut {async fn body of a<T>()}>, _2: &mut Context<'_>) -> Poll<()> {
+fn a(_1: Pin<&mut {async fn body of a<T>()}>, _2: &mut Context<'_>) -> Poll<()> {
     debug _task_context => _19;
     debug x => ((*(_1.0: &mut {async fn body of a<T>()})).0: T);
     let mut _0: std::task::Poll<()>;

diff --git a/tests/mir-opt/async_drop_live_dead.a-{closure#0}.coroutine_drop_async.0.panic-unwind.mir b/tests/mir-opt/async_drop_live_dead.a-{closure#0}.coroutine_drop_async.0.panic-unwind.mir
@@ -1,6 +1,6 @@
-// MIR for `a::{closure#0}` 0 coroutine_drop_async
+// MIR for `a` 0 coroutine_drop_async
 
-fn a::{closure#0}(_1: Pin<&mut {async fn body of a<T>()}>, _2: &mut Context<'_>) -> Poll<()> {
+fn a(_1: Pin<&mut {async fn body of a<T>()}>, _2: &mut Context<'_>) -> Poll<()> {
     debug _task_context => _19;
     debug x => ((*(_1.0: &mut {async fn body of a<T>()})).0: T);
     let mut _0: std::task::Poll<()>;

diff --git a/tests/mir-opt/building/async_await.a-{closure#0}.coroutine_resume.0.mir b/tests/mir-opt/building/async_await.a-{closure#0}.coroutine_resume.0.mir
@@ -1,4 +1,4 @@
-// MIR for `a::{closure#0}` 0 coroutine_resume
+// MIR for `a` 0 coroutine_resume
 /* coroutine_layout = CoroutineLayout {
     field_tys: {},
     variant_fields: {
@@ -9,7 +9,7 @@
     storage_conflicts: BitMatrix(0x0) {},
 } */
 
-fn a::{closure#0}(_1: Pin<&mut {async fn body of a()}>, _2: &mut Context<'_>) -> Poll<()> {
+fn a(_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: ();

diff --git a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
@@ -1,4 +1,4 @@
-// MIR for `b::{closure#0}` 0 coroutine_resume
+// MIR for `b` 0 coroutine_resume
 /* coroutine_layout = CoroutineLayout {
     field_tys: {
         _0: CoroutineSavedTy {
@@ -57,7 +57,7 @@
     },
 } */
 
-fn b::{closure#0}(_1: Pin<&mut {async fn body of b()}>, _2: &mut Context<'_>) -> Poll<()> {
+fn b(_1: Pin<&mut {async fn body of b()}>, _2: &mut Context<'_>) -> Poll<()> {
     debug _task_context => _38;
     let mut _0: std::task::Poll<()>;
     let _3: ();

diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-abort.diff
@@ -20,7 +20,7 @@
               debug fut => _4;
               scope 3 {
               }
-+             scope 6 (inlined ActionPermit::<'_, T>::perform::{closure#0}) {
++             scope 6 (inlined ActionPermit::<'_, T>::perform) {
 +                 let _11: ActionPermit<'_, T>;
 +                 let mut _12: std::future::Ready<()>;
 +                 let mut _13: std::future::Ready<()>;

diff --git a/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff b/tests/mir-opt/inline_coroutine_body.run2-{closure#0}.Inline.panic-unwind.diff
@@ -20,7 +20,7 @@
               debug fut => _4;
               scope 3 {
               }
-+             scope 6 (inlined ActionPermit::<'_, T>::perform::{closure#0}) {
++             scope 6 (inlined ActionPermit::<'_, T>::perform) {
 +                 let _11: ActionPermit<'_, T>;
 +                 let mut _12: std::future::Ready<()>;
 +                 let mut _13: std::future::Ready<()>;

diff --git a/tests/ui/force-inlining/deny-async.stderr b/tests/ui/force-inlining/deny-async.stderr
@@ -20,15 +20,15 @@ LL | pub fn callee_justified() {
    |
    = note: incompatible due to: #[rustc_no_mir_inline]
 
-error: `callee` could not be inlined into `async_caller::{closure#0}` but is required to be inlined
+error: `callee` could not be inlined into `async_caller` but is required to be inlined
   --> $DIR/deny-async.rs:22:5
    |
 LL |     callee();
    |     ^^^^^^^^ ...`callee` called here
    |
    = note: could not be inlined due to: #[rustc_no_mir_inline]
 
-error: `callee_justified` could not be inlined into `async_caller::{closure#0}` but is required to be inlined
+error: `callee_justified` could not be inlined into `async_caller` but is required to be inlined
   --> $DIR/deny-async.rs:24:5
    |
 LL |     callee_justified();