Rollup merge of #139153 - compiler-errors:incr-comp-closure, r=oli-obk

Encode synthetic by-move coroutine body with a different `DefPathData`

See the included test. In the first revision rpass1, we have an async closure `{closure#0}` which has a coroutine as a child `{closure#0}::{closure#0}`. We synthesize a by-move coroutine body, which is `{closure#0}::{closure#1}` which depends on the mir_built query, which depends on the typeck query.

In the second revision rpass2, we've replaced the coroutine-closure by a closure with two children closure. Notably, the def path of the second child closure is the same as the synthetic def id from the last revision: `{closure#0}::{closure#1}`. When type-checking this closure, we end up trying to compute its def_span, which tries to fetch it from the incremental cache; this will try to force the dependencies from the last run, which ends up forcing the mir_built query, which ends up forcing the typeck query, which ends up with a query cycle.

The problem here is that we really should never have used the same `DefPathData` for the synthetic by-move coroutine body, since it's not a closure. Changing the `DefPathData` will mean that we can see that the def ids are distinct, which means we won't try to look up the closure's def span from the incremental cache, which will properly skip replaying the node's dependencies and avoid a query cycle.

Fixes #139142

17 files changed, 64 insertions, 29 deletions

diff --git a/compiler/rustc_hir/src/def.rs b/compiler/rustc_hir/src/def.rs
index 5f8941d4754..dc00b52a593 100644
--- a/compiler/rustc_hir/src/def.rs
+++ b/compiler/rustc_hir/src/def.rs
@@ -294,7 +294,7 @@ impl DefKind {
             DefKind::GlobalAsm => DefPathData::GlobalAsm,
             DefKind::Impl { .. } => DefPathData::Impl,
             DefKind::Closure => DefPathData::Closure,
-            DefKind::SyntheticCoroutineBody => DefPathData::Closure,
+            DefKind::SyntheticCoroutineBody => DefPathData::SyntheticCoroutineBody,
         }
     }
 
diff --git a/compiler/rustc_hir/src/definitions.rs b/compiler/rustc_hir/src/definitions.rs
index 61f5efd9978..c52954aa96f 100644
--- a/compiler/rustc_hir/src/definitions.rs
+++ b/compiler/rustc_hir/src/definitions.rs
@@ -291,6 +291,8 @@ pub enum DefPathData {
     /// An existential `impl Trait` type node.
     /// Argument position `impl Trait` have a `TypeNs` with their pretty-printed name.
     OpaqueTy,
+    /// A synthetic body for a coroutine's by-move body.
+    SyntheticCoroutineBody,
 }
 
 impl Definitions {
@@ -415,8 +417,16 @@ impl DefPathData {
 
             ValueNs(name) | MacroNs(name) | LifetimeNs(name) => Some(name),
 
-            Impl | ForeignMod | CrateRoot | Use | GlobalAsm | Closure | Ctor | AnonConst
-            | OpaqueTy => None,
+            Impl
+            | ForeignMod
+            | CrateRoot
+            | Use
+            | GlobalAsm
+            | Closure
+            | Ctor
+            | AnonConst
+            | OpaqueTy
+            | SyntheticCoroutineBody => None,
         }
     }
 
@@ -441,6 +451,7 @@ impl DefPathData {
             Ctor => DefPathDataName::Anon { namespace: sym::constructor },
             AnonConst => DefPathDataName::Anon { namespace: sym::constant },
             OpaqueTy => DefPathDataName::Anon { namespace: sym::opaque },
+            SyntheticCoroutineBody => DefPathDataName::Anon { namespace: sym::synthetic },
         }
     }
 }
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 08d4c1f9cf2..618a65a0186 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -1930,10 +1930,10 @@ impl<'tcx> TyCtxt<'tcx> {
         // As a consequence, this LocalDefId is always re-created before it is needed by the incr.
         // comp. engine itself.
         //
-        // This call also writes to the value of `source_span` and `expn_that_defined` queries.
+        // This call also writes to the value of the `source_span` query.
         // This is fine because:
-        // - those queries are `eval_always` so we won't miss their result changing;
-        // - this write will have happened before these queries are called.
+        // - that query is `eval_always` so we won't miss its result changing;
+        // - this write will have happened before that query is called.
         let def_id = self.untracked.definitions.write().create_def(parent, data);
 
         // This function modifies `self.definitions` using a side-effect.
diff --git a/compiler/rustc_middle/src/ty/print/mod.rs b/compiler/rustc_middle/src/ty/print/mod.rs
index dc2040aa5cf..5904deaaaad 100644
--- a/compiler/rustc_middle/src/ty/print/mod.rs
+++ b/compiler/rustc_middle/src/ty/print/mod.rs
@@ -139,8 +139,7 @@ pub trait Printer<'tcx>: Sized {
 
                     match key.disambiguated_data.data {
                         DefPathData::Closure => {
-                            // FIXME(async_closures): This is somewhat ugly.
-                            // We need to additionally print the `kind` field of a closure if
+                            // We need to additionally print the `kind` field of a coroutine if
                             // it is desugared from a coroutine-closure.
                             if let Some(hir::CoroutineKind::Desugared(
                                 _,
@@ -156,6 +155,10 @@ pub trait Printer<'tcx>: Sized {
                                 // Closures' own generics are only captures, don't print them.
                             }
                         }
+                        DefPathData::SyntheticCoroutineBody => {
+                            // Synthetic coroutine bodies have no distinct generics, since like
+                            // closures they're all just internal state of the coroutine.
+                        }
                         // This covers both `DefKind::AnonConst` and `DefKind::InlineConst`.
                         // Anon consts doesn't have their own generics, and inline consts' own
                         // generics are their inferred types, so don't print them.
diff --git a/compiler/rustc_query_system/src/dep_graph/graph.rs b/compiler/rustc_query_system/src/dep_graph/graph.rs
index 495f34733f7..127dcd825da 100644
--- a/compiler/rustc_query_system/src/dep_graph/graph.rs
+++ b/compiler/rustc_query_system/src/dep_graph/graph.rs
@@ -66,6 +66,7 @@ pub struct MarkFrame<'a> {
     parent: Option<&'a MarkFrame<'a>>,
 }
 
+#[derive(Debug)]
 pub(super) enum DepNodeColor {
     Red,
     Green(DepNodeIndex),
@@ -909,7 +910,7 @@ impl<D: Deps> DepGraphData<D> {
                 self.try_mark_previous_green(qcx, parent_dep_node_index, dep_dep_node, frame);
 
             if node_index.is_some() {
-                debug!("managed to MARK dependency {dep_dep_node:?} as green",);
+                debug!("managed to MARK dependency {dep_dep_node:?} as green");
                 return Some(());
             }
         }
@@ -930,7 +931,7 @@ impl<D: Deps> DepGraphData<D> {
                 return Some(());
             }
             Some(DepNodeColor::Red) => {
-                debug!("dependency {dep_dep_node:?} was red after forcing",);
+                debug!("dependency {dep_dep_node:?} was red after forcing");
                 return None;
             }
             None => {}
@@ -950,7 +951,7 @@ impl<D: Deps> DepGraphData<D> {
         // invalid state will not be persisted to the
         // incremental compilation cache because of
         // compilation errors being present.
-        debug!("dependency {dep_dep_node:?} resulted in compilation error",);
+        debug!("dependency {dep_dep_node:?} resulted in compilation error");
         return None;
     }
 
diff --git a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs
index e088417d72e..d56ca9c2453 100644
--- a/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs
+++ b/compiler/rustc_sanitizers/src/cfi/typeid/itanium_cxx_abi/encode.rs
@@ -716,6 +716,7 @@ fn encode_ty_name(tcx: TyCtxt<'_>, def_id: DefId) -> String {
             hir::definitions::DefPathData::Ctor => "c",
             hir::definitions::DefPathData::AnonConst => "k",
             hir::definitions::DefPathData::OpaqueTy => "i",
+            hir::definitions::DefPathData::SyntheticCoroutineBody => "s",
             hir::definitions::DefPathData::CrateRoot
             | hir::definitions::DefPathData::Use
             | hir::definitions::DefPathData::GlobalAsm
diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
index 88754f1f15b..2802e891807 100644
--- a/compiler/rustc_symbol_mangling/src/legacy.rs
+++ b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -28,7 +28,10 @@ pub(super) fn mangle<'tcx>(
     loop {
         let key = tcx.def_key(ty_def_id);
         match key.disambiguated_data.data {
-            DefPathData::TypeNs(_) | DefPathData::ValueNs(_) | DefPathData::Closure => {
+            DefPathData::TypeNs(_)
+            | DefPathData::ValueNs(_)
+            | DefPathData::Closure
+            | DefPathData::SyntheticCoroutineBody => {
                 instance_ty = tcx.type_of(ty_def_id).instantiate_identity();
                 debug!(?instance_ty);
                 break;
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index d824a23279b..99d44bcd7eb 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -850,6 +850,7 @@ impl<'tcx> Printer<'tcx> for SymbolMangler<'tcx> {
             DefPathData::Ctor => 'c',
             DefPathData::AnonConst => 'k',
             DefPathData::OpaqueTy => 'i',
+            DefPathData::SyntheticCoroutineBody => 's',
 
             // These should never show up as `path_append` arguments.
             DefPathData::CrateRoot
diff --git a/tests/coverage/async_closure.cov-map b/tests/coverage/async_closure.cov-map
index 9144a938a9e..0e1d9877830 100644
--- a/tests/coverage/async_closure.cov-map
+++ b/tests/coverage/async_closure.cov-map
@@ -38,21 +38,21 @@ Number of file 0 mappings: 1
 - Code(Counter(0)) at (prev + 11, 35) to (start + 0, 36)
 Highest counter ID seen: c0
 
-Function name: async_closure::main::{closure#0}::{closure#0}::<i16>
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
+Function name: async_closure::main::{closure#0}
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 23, 00, 24]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
+- Code(Counter(0)) at (prev + 11, 35) to (start + 0, 36)
 Highest counter ID seen: c0
 
-Function name: async_closure::main::{closure#0}::{closure#1}::<i32>
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 23, 00, 24]
+Function name: async_closure::main::{closure#0}::{closure#0}::<i16>
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
 Number of files: 1
 - file 0 => global file 1
 Number of expressions: 0
 Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 11, 35) to (start + 0, 36)
+- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
 Highest counter ID seen: c0
 
diff --git a/tests/coverage/async_closure.coverage b/tests/coverage/async_closure.coverage
index 7fbea265812..10a8ea14504 100644
--- a/tests/coverage/async_closure.coverage
+++ b/tests/coverage/async_closure.coverage
@@ -14,7 +14,7 @@
   | async_closure::main::{closure#0}:
   |   LL|      1|    let async_closure = async || {};
   ------------------
-  | async_closure::main::{closure#0}::{closure#1}::<i32>:
+  | async_closure::main::{closure#0}:
   |   LL|      1|    let async_closure = async || {};
   ------------------
    LL|      1|    executor::block_on(async_closure());
diff --git a/tests/incremental/user-written-closure-synthetic-closure-conflict.rs b/tests/incremental/user-written-closure-synthetic-closure-conflict.rs
new file mode 100644
index 00000000000..618604d06b1
--- /dev/null
+++ b/tests/incremental/user-written-closure-synthetic-closure-conflict.rs
@@ -0,0 +1,15 @@
+//@ revisions: rpass1 rpass2
+//@ edition: 2024
+
+#![allow(unused)]
+
+fn main() {
+    #[cfg(rpass1)]
+    async || {};
+
+    #[cfg(rpass2)]
+    || {
+        || ();
+        || ();
+    };
+}
diff --git a/tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#1}.built.after.mir b/tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{synthetic#0}.built.after.mir
index bd0baddb1f8..9070c95bca4 100644
--- a/tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#1}.built.after.mir
+++ b/tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{synthetic#0}.built.after.mir
@@ -1,6 +1,6 @@
-// MIR for `foo::{closure#0}::{closure#1}` after built
+// MIR for `foo::{closure#0}::{synthetic#0}` after built
 
-fn foo::{closure#0}::{closure#1}(_1: {async closure body@$DIR/async_closure_fake_read_for_by_move.rs:12:27: 15:6}, _2: ResumeTy) -> ()
+fn foo::{closure#0}::{synthetic#0}(_1: {async closure body@$DIR/async_closure_fake_read_for_by_move.rs:12:27: 15:6}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_fake_read_for_by_move.rs b/tests/mir-opt/async_closure_fake_read_for_by_move.rs
index 3c5aec94bbf..e78671f5e9d 100644
--- a/tests/mir-opt/async_closure_fake_read_for_by_move.rs
+++ b/tests/mir-opt/async_closure_fake_read_for_by_move.rs
@@ -7,7 +7,7 @@ enum Foo {
 }
 
 // EMIT_MIR async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#0}.built.after.mir
-// EMIT_MIR async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#1}.built.after.mir
+// EMIT_MIR async_closure_fake_read_for_by_move.foo-{closure#0}-{synthetic#0}.built.after.mir
 fn foo(f: &Foo) {
     let x = async move || match f {
         Foo::Bar if true => {}
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{synthetic#0}.built.after.mir
index a9e08d2e8f6..c5f538e5ecd 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#0}-{synthetic#0}.built.after.mir
@@ -1,6 +1,6 @@
-// MIR for `main::{closure#0}::{closure#0}::{closure#1}` after built
+// MIR for `main::{closure#0}::{closure#0}::{synthetic#0}` after built
 
-fn main::{closure#0}::{closure#0}::{closure#1}(_1: {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#0}::{synthetic#0}(_1: {async closure body@$DIR/async_closure_shims.rs:53:53: 56:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.mir b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{synthetic#0}.built.after.mir
index 4452ae7812e..e295f9b3cf1 100644
--- a/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.mir
+++ b/tests/mir-opt/async_closure_shims.main-{closure#0}-{closure#1}-{synthetic#0}.built.after.mir
@@ -1,6 +1,6 @@
-// MIR for `main::{closure#0}::{closure#1}::{closure#1}` after built
+// MIR for `main::{closure#0}::{closure#1}::{synthetic#0}` after built
 
-fn main::{closure#0}::{closure#1}::{closure#1}(_1: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10}, _2: ResumeTy) -> ()
+fn main::{closure#0}::{closure#1}::{synthetic#0}(_1: {async closure body@$DIR/async_closure_shims.rs:62:48: 65:10}, _2: ResumeTy) -> ()
 yields ()
  {
     debug _task_context => _2;
diff --git a/tests/mir-opt/async_closure_shims.rs b/tests/mir-opt/async_closure_shims.rs
index cd2e83e939a..93cc7834a64 100644
--- a/tests/mir-opt/async_closure_shims.rs
+++ b/tests/mir-opt/async_closure_shims.rs
@@ -42,11 +42,11 @@ async fn call_normal_mut<F: Future<Output = ()>>(f: &mut impl FnMut(i32) -> F) {
 
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}.coroutine_closure_by_move.0.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#0}.built.after.mir
-// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{closure#1}.built.after.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#0}-{synthetic#0}.built.after.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_ref.0.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}.coroutine_closure_by_move.0.mir
 // EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{closure#0}.built.after.mir
-// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{closure#1}.built.after.mir
+// EMIT_MIR async_closure_shims.main-{closure#0}-{closure#1}-{synthetic#0}.built.after.mir
 pub fn main() {
     block_on(async {
         let b = 2i32;
diff --git a/tests/ui/stable-mir-print/async-closure.stdout b/tests/ui/stable-mir-print/async-closure.stdout
index 21df1fd3954..12e7a5530ac 100644
--- a/tests/ui/stable-mir-print/async-closure.stdout
+++ b/tests/ui/stable-mir-print/async-closure.stdout
@@ -56,7 +56,7 @@ fn foo::{closure#0}::{closure#0}(_1: Pin<&mut {async closure body@$DIR/async-clo
         unreachable;
     }
 }
-fn foo::{closure#0}::{closure#1}(_1: Pin<&mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}>, _2: &mut Context<'_>) -> Poll<()> {
+fn foo::{closure#0}::{synthetic#0}(_1: Pin<&mut {async closure body@$DIR/async-closure.rs:9:22: 11:6}>, _2: &mut Context<'_>) -> Poll<()> {
     let mut _0: Poll<()>;
     let  _3: i32;
     let mut _4: &i32;