From 125326e4ed6c4752cd7fdea75128379cb24847f6 Mon Sep 17 00:00:00 2001
From: Eric Holk <ericholk@microsoft.com>
Date: Tue, 10 May 2022 13:43:14 -0700
Subject: [PATCH 1/5] Add test case for the need for fake_read callbacks
---
.../generator/drop-track-addassign-yield.rs | 41 +++++++++++++++++++
1 file changed, 41 insertions(+)
create mode 100644 src/test/ui/generator/drop-track-addassign-yield.rs
diff --git a/src/test/ui/generator/drop-track-addassign-yield.rs b/src/test/ui/generator/drop-track-addassign-yield.rs
new file mode 100644
index 0000000000000..71cfb170bf6aa
--- /dev/null
+++ b/src/test/ui/generator/drop-track-addassign-yield.rs
@@ -0,0 +1,41 @@
+// run-pass
+// compile-flags: -Zdrop-tracking
+
+// Based on addassign-yield.rs, but with drop tracking enabled. Originally we did not implement
+// the fake_read callback on ExprUseVisitor which caused this case to break.
+
+#![feature(generators)]
+
+fn foo() {
+ let _y = static || {
+ let x = &mut 0;
+ *{
+ yield;
+ x
+ } += match String::new() {
+ _ => 0,
+ };
+ };
+
+ // Please don't ever actually write something like this
+ let _z = static || {
+ let x = &mut 0;
+ *{
+ let inner = &mut 1;
+ *{
+ yield ();
+ inner
+ } += match String::new() {
+ _ => 1,
+ };
+ yield;
+ x
+ } += match String::new() {
+ _ => 2,
+ };
+ };
+}
+
+fn main() {
+ foo()
+}
From 5ba2e09bde735b4a5783fc1e6439f7d3bb00ff7d Mon Sep 17 00:00:00 2001
From: Eric Holk <ericholk@microsoft.com>
Date: Thu, 5 May 2022 11:59:45 -0700
Subject: [PATCH 2/5] Fix addassign-yield.rs by implementing fake_read
---
.../drop_ranges/record_consumed_borrow.rs | 79 +++++++++++--------
compiler/rustc_typeck/src/check/upvar.rs | 11 ++-
compiler/rustc_typeck/src/expr_use_visitor.rs | 19 +++--
.../ui/generator/yielding-in-match-guards.rs | 42 +++++-----
4 files changed, 88 insertions(+), 63 deletions(-)
diff --git a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
index 928daba0a7b39..20269a67c72b6 100644
--- a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
+++ b/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
@@ -77,38 +77,8 @@ impl<'tcx> ExprUseDelegate<'tcx> {
}
self.places.consumed.get_mut(&consumer).map(|places| places.insert(target));
}
-}
-
-impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
- fn consume(
- &mut self,
- place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>,
- diag_expr_id: HirId,
- ) {
- let parent = match self.tcx.hir().find_parent_node(place_with_id.hir_id) {
- Some(parent) => parent,
- None => place_with_id.hir_id,
- };
- debug!(
- "consume {:?}; diag_expr_id={:?}, using parent {:?}",
- place_with_id, diag_expr_id, parent
- );
- place_with_id
- .try_into()
- .map_or((), |tracked_value| self.mark_consumed(parent, tracked_value));
- }
-
- fn borrow(
- &mut self,
- place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>,
- diag_expr_id: HirId,
- bk: rustc_middle::ty::BorrowKind,
- ) {
- debug!(
- "borrow: place_with_id = {place_with_id:?}, diag_expr_id={diag_expr_id:?}, \
- borrow_kind={bk:?}"
- );
+ fn borrow_place(&mut self, place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>) {
self.places
.borrowed
.insert(TrackedValue::from_place_with_projections_allowed(place_with_id));
@@ -158,6 +128,40 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
self.places.borrowed_temporaries.insert(place_with_id.hir_id);
}
}
+}
+
+impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
+ fn consume(
+ &mut self,
+ place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>,
+ diag_expr_id: HirId,
+ ) {
+ let parent = match self.tcx.hir().find_parent_node(place_with_id.hir_id) {
+ Some(parent) => parent,
+ None => place_with_id.hir_id,
+ };
+ debug!(
+ "consume {:?}; diag_expr_id={:?}, using parent {:?}",
+ place_with_id, diag_expr_id, parent
+ );
+ place_with_id
+ .try_into()
+ .map_or((), |tracked_value| self.mark_consumed(parent, tracked_value));
+ }
+
+ fn borrow(
+ &mut self,
+ place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>,
+ diag_expr_id: HirId,
+ bk: rustc_middle::ty::BorrowKind,
+ ) {
+ debug!(
+ "borrow: place_with_id = {place_with_id:?}, diag_expr_id={diag_expr_id:?}, \
+ borrow_kind={bk:?}"
+ );
+
+ self.borrow_place(place_with_id);
+ }
fn copy(
&mut self,
@@ -199,9 +203,16 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
fn fake_read(
&mut self,
- _place: expr_use_visitor::Place<'tcx>,
- _cause: rustc_middle::mir::FakeReadCause,
- _diag_expr_id: HirId,
+ place_with_id: &expr_use_visitor::PlaceWithHirId<'tcx>,
+ cause: rustc_middle::mir::FakeReadCause,
+ diag_expr_id: HirId,
) {
+ debug!(
+ "fake_read place_with_id={place_with_id:?}; cause={cause:?}; diag_expr_id={diag_expr_id:?}"
+ );
+
+ // fake reads happen in places like the scrutinee of a match expression, so we can treat
+ // these as a borrow.
+ self.borrow_place(place_with_id);
}
}
diff --git a/compiler/rustc_typeck/src/check/upvar.rs b/compiler/rustc_typeck/src/check/upvar.rs
index fee2efd5804f0..f57d576105185 100644
--- a/compiler/rustc_typeck/src/check/upvar.rs
+++ b/compiler/rustc_typeck/src/check/upvar.rs
@@ -1755,14 +1755,19 @@ struct InferBorrowKind<'a, 'tcx> {
}
impl<'a, 'tcx> euv::Delegate<'tcx> for InferBorrowKind<'a, 'tcx> {
- fn fake_read(&mut self, place: Place<'tcx>, cause: FakeReadCause, diag_expr_id: hir::HirId) {
- let PlaceBase::Upvar(_) = place.base else { return };
+ fn fake_read(
+ &mut self,
+ place: &PlaceWithHirId<'tcx>,
+ cause: FakeReadCause,
+ diag_expr_id: hir::HirId,
+ ) {
+ let PlaceBase::Upvar(_) = place.place.base else { return };
// We need to restrict Fake Read precision to avoid fake reading unsafe code,
// such as deref of a raw pointer.
let dummy_capture_kind = ty::UpvarCapture::ByRef(ty::BorrowKind::ImmBorrow);
- let (place, _) = restrict_capture_precision(place, dummy_capture_kind);
+ let (place, _) = restrict_capture_precision(place.place.clone(), dummy_capture_kind);
let (place, _) = restrict_repr_packed_field_ref_capture(
self.fcx.tcx,
diff --git a/compiler/rustc_typeck/src/expr_use_visitor.rs b/compiler/rustc_typeck/src/expr_use_visitor.rs
index e69ba99dcef42..aa902ad726220 100644
--- a/compiler/rustc_typeck/src/expr_use_visitor.rs
+++ b/compiler/rustc_typeck/src/expr_use_visitor.rs
@@ -69,7 +69,12 @@ pub trait Delegate<'tcx> {
}
/// The `place` should be a fake read because of specified `cause`.
- fn fake_read(&mut self, place: Place<'tcx>, cause: FakeReadCause, diag_expr_id: hir::HirId);
+ fn fake_read(
+ &mut self,
+ place_with_id: &PlaceWithHirId<'tcx>,
+ cause: FakeReadCause,
+ diag_expr_id: hir::HirId,
+ );
}
#[derive(Copy, Clone, PartialEq, Debug)]
@@ -327,7 +332,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
};
self.delegate.fake_read(
- discr_place.place.clone(),
+ &discr_place,
FakeReadCause::ForMatchedPlace(closure_def_id),
discr_place.hir_id,
);
@@ -617,7 +622,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
};
self.delegate.fake_read(
- discr_place.place.clone(),
+ discr_place,
FakeReadCause::ForMatchedPlace(closure_def_id),
discr_place.hir_id,
);
@@ -641,7 +646,7 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
};
self.delegate.fake_read(
- discr_place.place.clone(),
+ discr_place,
FakeReadCause::ForLet(closure_def_id),
discr_place.hir_id,
);
@@ -764,7 +769,11 @@ impl<'a, 'tcx> ExprUseVisitor<'a, 'tcx> {
);
}
};
- self.delegate.fake_read(fake_read.clone(), *cause, *hir_id);
+ self.delegate.fake_read(
+ &PlaceWithHirId { place: fake_read.clone(), hir_id: *hir_id },
+ *cause,
+ *hir_id,
+ );
}
}
diff --git a/src/test/ui/generator/yielding-in-match-guards.rs b/src/test/ui/generator/yielding-in-match-guards.rs
index 4e89fc975d04c..86481edf76b0d 100644
--- a/src/test/ui/generator/yielding-in-match-guards.rs
+++ b/src/test/ui/generator/yielding-in-match-guards.rs
@@ -15,21 +15,21 @@
async fn f() -> u8 { 1 }
async fn foo() -> [bool; 10] { [false; 10] }
-pub async fn g(x: u8) {
- match x {
- y if f().await == y => (),
- _ => (),
- }
-}
+// pub async fn g(x: u8) {
+// match x {
+// y if f().await == y => (),
+// _ => (),
+// }
+// }
// #78366: check the reference to the binding is recorded even if the binding is not autorefed
-async fn h(x: usize) {
- match x {
- y if foo().await[y] => (),
- _ => (),
- }
-}
+// async fn h(x: usize) {
+// match x {
+// y if foo().await[y] => (),
+// _ => (),
+// }
+// }
async fn i(x: u8) {
match x {
@@ -38,16 +38,16 @@ async fn i(x: u8) {
}
}
-async fn j(x: u8) {
- match x {
- y if let (1, 42) = (f().await, y) => (),
- _ => (),
- }
-}
+// async fn j(x: u8) {
+// match x {
+// y if let (1, 42) = (f().await, y) => (),
+// _ => (),
+// }
+// }
fn main() {
- let _ = g(10);
- let _ = h(9);
+ // let _ = g(10);
+ // let _ = h(9);
let _ = i(8);
- let _ = j(7);
+ // let _ = j(7);
}
From 36c4c1e366813e7c25fc2faf3a0566f267b62688 Mon Sep 17 00:00:00 2001
From: Eric Holk <ericholk@microsoft.com>
Date: Tue, 10 May 2022 14:20:34 -0700
Subject: [PATCH 3/5] Update clippy to new rake_read signature
---
src/tools/clippy/clippy_lints/src/escape.rs | 2 +-
src/tools/clippy/clippy_lints/src/loops/mut_range_bound.rs | 2 +-
src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs | 2 +-
src/tools/clippy/clippy_utils/src/sugg.rs | 2 +-
src/tools/clippy/clippy_utils/src/usage.rs | 2 +-
5 files changed, 5 insertions(+), 5 deletions(-)
diff --git a/src/tools/clippy/clippy_lints/src/escape.rs b/src/tools/clippy/clippy_lints/src/escape.rs
index af591dd71aa1d..807ecd2ddd16e 100644
--- a/src/tools/clippy/clippy_lints/src/escape.rs
+++ b/src/tools/clippy/clippy_lints/src/escape.rs
@@ -187,7 +187,7 @@ impl<'a, 'tcx> Delegate<'tcx> for EscapeDelegate<'a, 'tcx> {
}
}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
impl<'a, 'tcx> EscapeDelegate<'a, 'tcx> {
diff --git a/src/tools/clippy/clippy_lints/src/loops/mut_range_bound.rs b/src/tools/clippy/clippy_lints/src/loops/mut_range_bound.rs
index 9d8679d77c6d0..d20df83045589 100644
--- a/src/tools/clippy/clippy_lints/src/loops/mut_range_bound.rs
+++ b/src/tools/clippy/clippy_lints/src/loops/mut_range_bound.rs
@@ -114,7 +114,7 @@ impl<'tcx> Delegate<'tcx> for MutatePairDelegate<'_, 'tcx> {
}
}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
impl MutatePairDelegate<'_, '_> {
diff --git a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
index 4034079a90c0d..303ce7a5075aa 100644
--- a/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
+++ b/src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
@@ -343,5 +343,5 @@ impl<'tcx> euv::Delegate<'tcx> for MovedVariablesCtxt {
fn mutate(&mut self, _: &euv::PlaceWithHirId<'tcx>, _: HirId) {}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
diff --git a/src/tools/clippy/clippy_utils/src/sugg.rs b/src/tools/clippy/clippy_utils/src/sugg.rs
index 18915553e61c0..db5299c2c05f4 100644
--- a/src/tools/clippy/clippy_utils/src/sugg.rs
+++ b/src/tools/clippy/clippy_utils/src/sugg.rs
@@ -1033,7 +1033,7 @@ impl<'tcx> Delegate<'tcx> for DerefDelegate<'_, 'tcx> {
fn mutate(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
#[cfg(test)]
diff --git a/src/tools/clippy/clippy_utils/src/usage.rs b/src/tools/clippy/clippy_utils/src/usage.rs
index 4236e3aae2fbd..b7b9d54d0b2c1 100644
--- a/src/tools/clippy/clippy_utils/src/usage.rs
+++ b/src/tools/clippy/clippy_utils/src/usage.rs
@@ -74,7 +74,7 @@ impl<'tcx> Delegate<'tcx> for MutVarsDelegate {
self.update(cmt);
}
- fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
+ fn fake_read(&mut self, _: &rustc_typeck::expr_use_visitor::PlaceWithHirId<'tcx>, _: FakeReadCause, _: HirId) {}
}
pub struct ParamBindingIdCollector {
From 6d6be5fd8b6615dbf8b6244d777a462efda3d410 Mon Sep 17 00:00:00 2001
From: Eric Holk <ericholk@microsoft.com>
Date: Tue, 10 May 2022 14:22:03 -0700
Subject: [PATCH 4/5] Revert spurious change
---
.../ui/generator/yielding-in-match-guards.rs | 42 +++++++++----------
1 file changed, 21 insertions(+), 21 deletions(-)
diff --git a/src/test/ui/generator/yielding-in-match-guards.rs b/src/test/ui/generator/yielding-in-match-guards.rs
index 86481edf76b0d..4e89fc975d04c 100644
--- a/src/test/ui/generator/yielding-in-match-guards.rs
+++ b/src/test/ui/generator/yielding-in-match-guards.rs
@@ -15,21 +15,21 @@
async fn f() -> u8 { 1 }
async fn foo() -> [bool; 10] { [false; 10] }
-// pub async fn g(x: u8) {
-// match x {
-// y if f().await == y => (),
-// _ => (),
-// }
-// }
+pub async fn g(x: u8) {
+ match x {
+ y if f().await == y => (),
+ _ => (),
+ }
+}
// #78366: check the reference to the binding is recorded even if the binding is not autorefed
-// async fn h(x: usize) {
-// match x {
-// y if foo().await[y] => (),
-// _ => (),
-// }
-// }
+async fn h(x: usize) {
+ match x {
+ y if foo().await[y] => (),
+ _ => (),
+ }
+}
async fn i(x: u8) {
match x {
@@ -38,16 +38,16 @@ async fn i(x: u8) {
}
}
-// async fn j(x: u8) {
-// match x {
-// y if let (1, 42) = (f().await, y) => (),
-// _ => (),
-// }
-// }
+async fn j(x: u8) {
+ match x {
+ y if let (1, 42) = (f().await, y) => (),
+ _ => (),
+ }
+}
fn main() {
- // let _ = g(10);
- // let _ = h(9);
+ let _ = g(10);
+ let _ = h(9);
let _ = i(8);
- // let _ = j(7);
+ let _ = j(7);
}
From bf21a81b1541a420566fc81f8a1dde5486008387 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Fri, 20 May 2022 15:54:22 -0400
Subject: [PATCH 5/5] Update
compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
---
.../drop_ranges/record_consumed_borrow.rs | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs b/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
index 20269a67c72b6..8dcffd56b5843 100644
--- a/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
+++ b/compiler/rustc_typeck/src/check/generator_interior/drop_ranges/record_consumed_borrow.rs
@@ -211,8 +211,10 @@ impl<'tcx> expr_use_visitor::Delegate<'tcx> for ExprUseDelegate<'tcx> {
"fake_read place_with_id={place_with_id:?}; cause={cause:?}; diag_expr_id={diag_expr_id:?}"
);
- // fake reads happen in places like the scrutinee of a match expression, so we can treat
- // these as a borrow.
+ // fake reads happen in places like the scrutinee of a match expression.
+ // we treat those as a borrow, much like a copy: the idea is that we are
+ // transiently creating a `&T` ref that we can read from to observe the current
+ // value (this `&T` is immediately dropped afterwards).
self.borrow_place(place_with_id);
}
}