Make closure capturing have consistent and correct behaviour around patterns

compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs

@@ -1447,6 +1447,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
     pub(crate) fn try_structurally_resolve_type(&self, sp: Span, ty: Ty<'tcx>) -> Ty<'tcx> {
         let ty = self.resolve_vars_with_obligations(ty);
 
+        debug!("next_solver = {:?}", self.next_trait_solver());
         if self.next_trait_solver()
             && let ty::Alias(..) = ty.kind()
         {

compiler/rustc_hir_typeck/src/upvar.rs

@@ -18,12 +18,12 @@
 //! from there).
 //!
 //! The fact that we are inferring borrow kinds as we go results in a
-//! semi-hacky interaction with mem-categorization. In particular,
-//! mem-categorization will query the current borrow kind as it
-//! categorizes, and we'll return the *current* value, but this may get
+//! semi-hacky interaction with the way `ExprUseVisitor` is computing
+//! `Place`s. In particular, it will query the current borrow kind as it
+//! goes, and we'll return the *current* value, but this may get
 //! adjusted later. Therefore, in this module, we generally ignore the
-//! borrow kind (and derived mutabilities) that are returned from
-//! mem-categorization, since they may be inaccurate. (Another option
+//! borrow kind (and derived mutabilities) that `ExprUseVisitor` returns
+//! within `Place`s, since they may be inaccurate. (Another option
 //! would be to use a unification scheme, where instead of returning a
 //! concrete borrow kind like `ty::ImmBorrow`, we return a
 //! `ty::InferBorrow(upvar_id)` or something like that, but this would

compiler/rustc_middle/src/hir/place.rs

@@ -53,7 +53,10 @@ pub struct Projection<'tcx> {
     pub kind: ProjectionKind,
 }
 
-/// A `Place` represents how a value is located in memory.
+/// A `Place` represents how a value is located in memory. This does not
+/// always correspond to a syntactic place expression. For example, when
+/// processing a pattern, a `Place` can be used to refer to the sub-value
+/// currently being inspected.
 ///
 /// This is an HIR version of [`rustc_middle::mir::Place`].
 #[derive(Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable)]
@@ -67,7 +70,10 @@ pub struct Place<'tcx> {
     pub projections: Vec<Projection<'tcx>>,
 }
 
-/// A `PlaceWithHirId` represents how a value is located in memory.
+/// A `PlaceWithHirId` represents how a value is located in memory. This does not
+/// always correspond to a syntactic place expression. For example, when
+/// processing a pattern, a `Place` can be used to refer to the sub-value
+/// currently being inspected.
 ///
 /// This is an HIR version of [`rustc_middle::mir::Place`].
 #[derive(Clone, Debug, PartialEq, Eq, Hash, TyEncodable, TyDecodable, HashStable)]

tests/crashes/119786-2.rs

@@ -0,0 +1,15 @@
+//@ known-bug: #119786
+//@ edition:2021
+
+fn enum_upvar() {
+    type T = impl Copy;
+    let foo: T = Some((1u32, 2u32));
+    let x = move || {
+        match foo {
+            None => (),
+            Some(_) => (),
+        }
+    };
+}
+
+pub fn main() {}

tests/crashes/119786-3.rs

@@ -0,0 +1,15 @@
+//@ known-bug: #119786
+//@ edition:2021
+
+fn enum_upvar() {
+    type T = impl Copy;
+    let foo: T = Some((1u32, 2u32));
+    let x = move || {
+        match foo {
+            None => (),
+            Some((a, b)) => (),
+        }
+    };
+}
+
+pub fn main() {}

tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#0}.built.after.mir

@@ -4,18 +4,16 @@ fn foo::{closure#0}::{closure#0}(_1: {async closure body@$DIR/async_closure_fake
 yields ()
  {
     debug _task_context => _2;
-    debug f => (*(_1.0: &&Foo));
+    debug f => (*(_1.0: &Foo));
     let mut _0: ();
     let mut _3: &Foo;
     let mut _4: &&Foo;
-    let mut _5: &&&Foo;
-    let mut _6: isize;
-    let mut _7: bool;
+    let mut _5: isize;
+    let mut _6: bool;
 
     bb0: {
-        PlaceMention((*(_1.0: &&Foo)));
-        _6 = discriminant((*(*(_1.0: &&Foo))));
-        switchInt(move _6) -> [0: bb2, otherwise: bb1];
+        _5 = discriminant((*(_1.0: &Foo)));
+        switchInt(move _5) -> [0: bb2, otherwise: bb1];
     }
 
     bb1: {
@@ -32,28 +30,25 @@ yields ()
     }
 
     bb4: {
-        FakeRead(ForMatchedPlace(None), (*(_1.0: &&Foo)));
         unreachable;
     }
 
     bb5: {
-        _3 = &fake shallow (*(*(_1.0: &&Foo)));
-        _4 = &fake shallow (*(_1.0: &&Foo));
-        _5 = &fake shallow (_1.0: &&Foo);
-        StorageLive(_7);
-        _7 = const true;
-        switchInt(move _7) -> [0: bb8, otherwise: bb7];
+        _3 = &fake shallow (*(_1.0: &Foo));
+        _4 = &fake shallow (_1.0: &Foo);
+        StorageLive(_6);
+        _6 = const true;
+        switchInt(move _6) -> [0: bb8, otherwise: bb7];
     }
 
     bb6: {
         falseEdge -> [real: bb3, imaginary: bb1];
     }
 
     bb7: {
-        StorageDead(_7);
+        StorageDead(_6);
         FakeRead(ForMatchGuard, _3);
         FakeRead(ForMatchGuard, _4);
-        FakeRead(ForMatchGuard, _5);
         _0 = const ();
         goto -> bb10;
     }
@@ -63,7 +58,7 @@ yields ()
     }
 
     bb9: {
-        StorageDead(_7);
+        StorageDead(_6);
         goto -> bb6;
     }
 

tests/mir-opt/async_closure_fake_read_for_by_move.foo-{closure#0}-{closure#1}.built.after.mir

@@ -4,18 +4,16 @@ fn foo::{closure#0}::{closure#1}(_1: {async closure body@$DIR/async_closure_fake
 yields ()
  {
     debug _task_context => _2;
-    debug f => (_1.0: &Foo);
+    debug f => (*(_1.0: &Foo));
     let mut _0: ();
     let mut _3: &Foo;
     let mut _4: &&Foo;
-    let mut _5: &&&Foo;
-    let mut _6: isize;
-    let mut _7: bool;
+    let mut _5: isize;
+    let mut _6: bool;
 
     bb0: {
-        PlaceMention((_1.0: &Foo));
-        _6 = discriminant((*(_1.0: &Foo)));
-        switchInt(move _6) -> [0: bb2, otherwise: bb1];
+        _5 = discriminant((*(_1.0: &Foo)));
+        switchInt(move _5) -> [0: bb2, otherwise: bb1];
     }
 
     bb1: {
@@ -29,24 +27,22 @@ yields ()
 
     bb3: {
         _3 = &fake shallow (*(_1.0: &Foo));
-        _4 = &fake shallow (_1.0: &Foo);
         nop;
-        StorageLive(_7);
-        _7 = const true;
-        switchInt(move _7) -> [0: bb5, otherwise: bb4];
+        StorageLive(_6);
+        _6 = const true;
+        switchInt(move _6) -> [0: bb5, otherwise: bb4];
     }
 
     bb4: {
-        StorageDead(_7);
+        StorageDead(_6);
         FakeRead(ForMatchGuard, _3);
         FakeRead(ForMatchGuard, _4);
-        FakeRead(ForMatchGuard, _5);
         _0 = const ();
         goto -> bb6;
     }
 
     bb5: {
-        StorageDead(_7);
+        StorageDead(_6);
         falseEdge -> [real: bb1, imaginary: bb1];
     }
 

tests/ui/closures/2229_closure_analysis/capture-enums.rs

@@ -22,13 +22,15 @@ fn multi_variant_enum() {
     //~| Min Capture analysis includes:
         if let Info::Point(_, _, str) = point {
             //~^ NOTE: Capturing point[] -> Immutable
+            //~| NOTE: Capturing point[] -> Immutable
             //~| NOTE: Capturing point[(2, 0)] -> ByValue
             //~| NOTE: Min Capture point[] -> ByValue
             println!("{}", str);
         }
 
         if let Info::Meta(_, v) = meta {
             //~^ NOTE: Capturing meta[] -> Immutable
+            //~| NOTE: Capturing meta[] -> Immutable
             //~| NOTE: Capturing meta[(1, 1)] -> ByValue
             //~| NOTE: Min Capture meta[] -> ByValue
             println!("{:?}", v);

tests/ui/closures/2229_closure_analysis/capture-enums.stderr

@@ -9,7 +9,7 @@ LL |     let c = #[rustc_capture_analysis]
    = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/capture-enums.rs:48:13
+  --> $DIR/capture-enums.rs:50:13
    |
 LL |     let c = #[rustc_capture_analysis]
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -34,18 +34,28 @@ note: Capturing point[] -> Immutable
    |
 LL |         if let Info::Point(_, _, str) = point {
    |                                         ^^^^^
+note: Capturing point[] -> Immutable
+  --> $DIR/capture-enums.rs:23:41
+   |
+LL |         if let Info::Point(_, _, str) = point {
+   |                                         ^^^^^
 note: Capturing point[(2, 0)] -> ByValue
   --> $DIR/capture-enums.rs:23:41
    |
 LL |         if let Info::Point(_, _, str) = point {
    |                                         ^^^^^
 note: Capturing meta[] -> Immutable
-  --> $DIR/capture-enums.rs:30:35
+  --> $DIR/capture-enums.rs:31:35
+   |
+LL |         if let Info::Meta(_, v) = meta {
+   |                                   ^^^^
+note: Capturing meta[] -> Immutable
+  --> $DIR/capture-enums.rs:31:35
    |
 LL |         if let Info::Meta(_, v) = meta {
    |                                   ^^^^
 note: Capturing meta[(1, 1)] -> ByValue
-  --> $DIR/capture-enums.rs:30:35
+  --> $DIR/capture-enums.rs:31:35
    |
 LL |         if let Info::Meta(_, v) = meta {
    |                                   ^^^^
@@ -67,13 +77,13 @@ note: Min Capture point[] -> ByValue
 LL |         if let Info::Point(_, _, str) = point {
    |                                         ^^^^^
 note: Min Capture meta[] -> ByValue
-  --> $DIR/capture-enums.rs:30:35
+  --> $DIR/capture-enums.rs:31:35
    |
 LL |         if let Info::Meta(_, v) = meta {
    |                                   ^^^^
 
 error: First Pass analysis includes:
-  --> $DIR/capture-enums.rs:52:5
+  --> $DIR/capture-enums.rs:54:5
    |
 LL | /     || {
 LL | |
@@ -85,13 +95,13 @@ LL | |     };
    | |_____^
    |
 note: Capturing point[(2, 0)] -> ByValue
-  --> $DIR/capture-enums.rs:55:47
+  --> $DIR/capture-enums.rs:57:47
    |
 LL |         let SingleVariant::Point(_, _, str) = point;
    |                                               ^^^^^
 
 error: Min Capture analysis includes:
-  --> $DIR/capture-enums.rs:52:5
+  --> $DIR/capture-enums.rs:54:5
    |
 LL | /     || {
 LL | |
@@ -103,7 +113,7 @@ LL | |     };
    | |_____^
    |
 note: Min Capture point[(2, 0)] -> ByValue
-  --> $DIR/capture-enums.rs:55:47
+  --> $DIR/capture-enums.rs:57:47
    |
 LL |         let SingleVariant::Point(_, _, str) = point;
    |                                               ^^^^^

tests/ui/closures/2229_closure_analysis/match/match-edge-cases_2.stderr

@@ -4,7 +4,7 @@ error[E0505]: cannot move out of `ts` because it is borrowed
 LL |     let _b = || { match ts {
    |              --         -- borrow occurs due to use in closure
    |              |
-   |              borrow of `ts` occurs here
+   |              borrow of `ts.x` occurs here
 ...
 LL |     let mut mut_ts = ts;
    |                      ^^ move out of `ts` occurs here