diff options
8 files changed, 551 insertions, 26 deletions
diff --git a/compiler/rustc_mir_transform/src/elaborate_drop.rs b/compiler/rustc_mir_transform/src/elaborate_drop.rs index de96b1f255a..df4853c1dcb 100644 --- a/compiler/rustc_mir_transform/src/elaborate_drop.rs +++ b/compiler/rustc_mir_transform/src/elaborate_drop.rs @@ -761,24 +761,37 @@ where let skip_contents = adt.is_union() || adt.is_manually_drop(); let contents_drop = if skip_contents { + if adt.has_dtor(self.tcx()) && self.elaborator.get_drop_flag(self.path).is_some() { + // the top-level drop flag is usually cleared by open_drop_for_adt_contents + // types with destructors would still need an empty drop ladder to clear it + + // however, these types are only open dropped in `DropShimElaborator` + // which does not have drop flags + // a future box-like "DerefMove" trait would allow for this case to happen + span_bug!(self.source_info.span, "open dropping partially moved union"); + } + (self.succ, self.unwind, self.dropline) } else { self.open_drop_for_adt_contents(adt, args) }; - if adt.is_box() { - // we need to drop the inside of the box before running the destructor - let succ = self.destructor_call_block_sync((contents_drop.0, contents_drop.1)); - let unwind = contents_drop - .1 - .map(|unwind| self.destructor_call_block_sync((unwind, Unwind::InCleanup))); - let dropline = contents_drop - .2 - .map(|dropline| self.destructor_call_block_sync((dropline, contents_drop.1))); - - self.open_drop_for_box_contents(adt, args, succ, unwind, dropline) - } else if adt.has_dtor(self.tcx()) { - self.destructor_call_block(contents_drop) + if adt.has_dtor(self.tcx()) { + let destructor_block = if adt.is_box() { + // we need to drop the inside of the box before running the destructor + let succ = self.destructor_call_block_sync((contents_drop.0, contents_drop.1)); + let unwind = contents_drop + .1 + .map(|unwind| self.destructor_call_block_sync((unwind, Unwind::InCleanup))); + let dropline = contents_drop + .2 + .map(|dropline| self.destructor_call_block_sync((dropline, contents_drop.1))); + self.open_drop_for_box_contents(adt, args, succ, unwind, dropline) + } else { + self.destructor_call_block(contents_drop) + }; + + self.drop_flag_test_block(destructor_block, contents_drop.0, contents_drop.1) } else { contents_drop.0 } @@ -982,12 +995,7 @@ where unwind.is_cleanup(), ); - let destructor_block = self.elaborator.patch().new_block(result); - - let block_start = Location { block: destructor_block, statement_index: 0 }; - self.elaborator.clear_drop_flag(block_start, self.path, DropFlagMode::Shallow); - - self.drop_flag_test_block(destructor_block, succ, unwind) + self.elaborator.patch().new_block(result) } fn destructor_call_block( @@ -1002,13 +1010,7 @@ where && !unwind.is_cleanup() && ty.is_async_drop(self.tcx(), self.elaborator.typing_env()) { - let destructor_block = - self.build_async_drop(self.place, ty, None, succ, unwind, dropline, true); - - let block_start = Location { block: destructor_block, statement_index: 0 }; - self.elaborator.clear_drop_flag(block_start, self.path, DropFlagMode::Shallow); - - self.drop_flag_test_block(destructor_block, succ, unwind) + self.build_async_drop(self.place, ty, None, succ, unwind, dropline, true) } else { self.destructor_call_block_sync((succ, unwind)) } diff --git a/tests/mir-opt/box_conditional_drop_allocator.main.ElaborateDrops.diff b/tests/mir-opt/box_conditional_drop_allocator.main.ElaborateDrops.diff new file mode 100644 index 00000000000..6f6c239d7c8 --- /dev/null +++ b/tests/mir-opt/box_conditional_drop_allocator.main.ElaborateDrops.diff @@ -0,0 +1,186 @@ +- // MIR for `main` before ElaborateDrops ++ // MIR for `main` after ElaborateDrops + + fn main() -> () { + let mut _0: (); + let _1: std::boxed::Box<HasDrop, DropAllocator>; + let mut _2: HasDrop; + let mut _3: DropAllocator; + let mut _4: bool; + let _5: (); + let mut _6: HasDrop; + let _7: (); + let mut _8: std::boxed::Box<HasDrop, DropAllocator>; ++ let mut _9: bool; ++ let mut _10: &mut std::boxed::Box<HasDrop, DropAllocator>; ++ let mut _11: (); ++ let mut _12: &mut std::boxed::Box<HasDrop, DropAllocator>; ++ let mut _13: (); ++ let mut _14: *const HasDrop; ++ let mut _15: &mut std::boxed::Box<HasDrop, DropAllocator>; ++ let mut _16: (); ++ let mut _17: *const HasDrop; + scope 1 { + debug b => _1; + } + + bb0: { ++ _9 = const false; + StorageLive(_1); + StorageLive(_2); + _2 = HasDrop; + StorageLive(_3); + _3 = DropAllocator; + _1 = Box::<HasDrop, DropAllocator>::new_in(move _2, move _3) -> [return: bb1, unwind: bb11]; + } + + bb1: { ++ _9 = const true; + StorageDead(_3); + StorageDead(_2); + StorageLive(_4); + _4 = const true; + switchInt(move _4) -> [0: bb4, otherwise: bb2]; + } + + bb2: { + StorageLive(_5); + StorageLive(_6); + _6 = move (*_1); + _5 = std::mem::drop::<HasDrop>(move _6) -> [return: bb3, unwind: bb9]; + } + + bb3: { + StorageDead(_6); + StorageDead(_5); + _0 = const (); + goto -> bb6; + } + + bb4: { + StorageLive(_7); + StorageLive(_8); ++ _9 = const false; + _8 = move _1; + _7 = std::mem::drop::<Box<HasDrop, DropAllocator>>(move _8) -> [return: bb5, unwind: bb8]; + } + + bb5: { + StorageDead(_8); + StorageDead(_7); + _0 = const (); + goto -> bb6; + } + + bb6: { + StorageDead(_4); +- drop(_1) -> [return: bb7, unwind continue]; ++ goto -> bb23; + } + + bb7: { ++ _9 = const false; + StorageDead(_1); + return; + } + + bb8 (cleanup): { +- drop(_8) -> [return: bb10, unwind terminate(cleanup)]; ++ goto -> bb10; + } + + bb9 (cleanup): { +- drop(_6) -> [return: bb10, unwind terminate(cleanup)]; ++ goto -> bb10; + } + + bb10 (cleanup): { +- drop(_1) -> [return: bb13, unwind terminate(cleanup)]; ++ goto -> bb29; + } + + bb11 (cleanup): { +- drop(_3) -> [return: bb12, unwind terminate(cleanup)]; ++ goto -> bb12; + } + + bb12 (cleanup): { +- drop(_2) -> [return: bb13, unwind terminate(cleanup)]; ++ goto -> bb13; + } + + bb13 (cleanup): { + resume; ++ } ++ ++ bb14: { ++ _9 = const false; ++ goto -> bb7; ++ } ++ ++ bb15 (cleanup): { ++ drop((_1.1: DropAllocator)) -> [return: bb13, unwind terminate(cleanup)]; ++ } ++ ++ bb16 (cleanup): { ++ switchInt(copy _9) -> [0: bb13, otherwise: bb15]; ++ } ++ ++ bb17: { ++ drop((_1.1: DropAllocator)) -> [return: bb14, unwind: bb13]; ++ } ++ ++ bb18: { ++ switchInt(copy _9) -> [0: bb14, otherwise: bb17]; ++ } ++ ++ bb19: { ++ _10 = &mut _1; ++ _11 = <Box<HasDrop, DropAllocator> as Drop>::drop(move _10) -> [return: bb18, unwind: bb16]; ++ } ++ ++ bb20 (cleanup): { ++ _12 = &mut _1; ++ _13 = <Box<HasDrop, DropAllocator> as Drop>::drop(move _12) -> [return: bb16, unwind terminate(cleanup)]; ++ } ++ ++ bb21: { ++ goto -> bb19; ++ } ++ ++ bb22: { ++ _14 = copy ((_1.0: std::ptr::Unique<HasDrop>).0: std::ptr::NonNull<HasDrop>) as *const HasDrop (Transmute); ++ goto -> bb21; ++ } ++ ++ bb23: { ++ switchInt(copy _9) -> [0: bb18, otherwise: bb22]; ++ } ++ ++ bb24 (cleanup): { ++ drop((_1.1: DropAllocator)) -> [return: bb13, unwind terminate(cleanup)]; ++ } ++ ++ bb25 (cleanup): { ++ switchInt(copy _9) -> [0: bb13, otherwise: bb24]; ++ } ++ ++ bb26 (cleanup): { ++ _15 = &mut _1; ++ _16 = <Box<HasDrop, DropAllocator> as Drop>::drop(move _15) -> [return: bb25, unwind terminate(cleanup)]; ++ } ++ ++ bb27 (cleanup): { ++ goto -> bb26; ++ } ++ ++ bb28 (cleanup): { ++ _17 = copy ((_1.0: std::ptr::Unique<HasDrop>).0: std::ptr::NonNull<HasDrop>) as *const HasDrop (Transmute); ++ goto -> bb27; ++ } ++ ++ bb29 (cleanup): { ++ switchInt(copy _9) -> [0: bb25, otherwise: bb28]; + } + } + diff --git a/tests/mir-opt/box_conditional_drop_allocator.rs b/tests/mir-opt/box_conditional_drop_allocator.rs new file mode 100644 index 00000000000..9471be14c87 --- /dev/null +++ b/tests/mir-opt/box_conditional_drop_allocator.rs @@ -0,0 +1,39 @@ +// skip-filecheck +//@ test-mir-pass: ElaborateDrops +//@ needs-unwind +#![feature(allocator_api)] + +// Regression test for #131082. +// Testing that the allocator of a Box is dropped in conditional drops + +use std::alloc::{AllocError, Allocator, Global, Layout}; +use std::ptr::NonNull; + +struct DropAllocator; + +unsafe impl Allocator for DropAllocator { + fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> { + Global.allocate(layout) + } + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + Global.deallocate(ptr, layout); + } +} +impl Drop for DropAllocator { + fn drop(&mut self) {} +} + +struct HasDrop; +impl Drop for HasDrop { + fn drop(&mut self) {} +} + +// EMIT_MIR box_conditional_drop_allocator.main.ElaborateDrops.diff +fn main() { + let b = Box::new_in(HasDrop, DropAllocator); + if true { + drop(*b); + } else { + drop(b); + } +} diff --git a/tests/ui/async-await/async-drop/async-drop-box-allocator.rs b/tests/ui/async-await/async-drop/async-drop-box-allocator.rs new file mode 100644 index 00000000000..86ebf8a0ffd --- /dev/null +++ b/tests/ui/async-await/async-drop/async-drop-box-allocator.rs @@ -0,0 +1,134 @@ +//@ run-pass +//@ check-run-results +// struct `Foo` has both sync and async drop. +// It's used as the allocator of a `Box` which is conditionally moved out of. +// Sync version is called in sync context, async version is called in async function. + +#![feature(async_drop, allocator_api)] +#![allow(incomplete_features)] + +use std::mem::ManuallyDrop; + +//@ edition: 2021 + +#[inline(never)] +fn myprintln(msg: &str, my_resource_handle: usize) { + println!("{} : {}", msg, my_resource_handle); +} + +use std::{ + future::{Future, async_drop_in_place, AsyncDrop}, + pin::{pin, Pin}, + sync::{mpsc, Arc}, + task::{Context, Poll, Wake, Waker}, + alloc::{AllocError, Allocator, Global, Layout}, + ptr::NonNull, +}; + +struct Foo { + my_resource_handle: usize, +} + +impl Foo { + fn new(my_resource_handle: usize) -> Self { + let out = Foo { + my_resource_handle, + }; + myprintln("Foo::new()", my_resource_handle); + out + } +} + +impl Drop for Foo { + fn drop(&mut self) { + myprintln("Foo::drop()", self.my_resource_handle); + } +} + +impl AsyncDrop for Foo { + async fn drop(self: Pin<&mut Self>) { + myprintln("Foo::async drop()", self.my_resource_handle); + } +} + +unsafe impl Allocator for Foo { + fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> { + Global.allocate(layout) + } + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + Global.deallocate(ptr, layout); + } +} + +struct HasDrop; +impl Drop for HasDrop { + fn drop(&mut self) {} +} + +fn main() { + { + let b = Box::new_in(HasDrop, Foo::new(7)); + + if true { + let _x = *b; + } else { + let _y = b; + } + } + println!("Middle"); + block_on(bar(10)); + println!("Done") +} + +async fn bar(ident_base: usize) { + let b = Box::new_in(HasDrop, Foo::new(ident_base)); + + if true { + let _x = *b; + } else { + let _y = b; + } +} + +fn block_on<F>(fut_unpin: F) -> F::Output +where + F: Future, +{ + let mut fut_pin = pin!(ManuallyDrop::new(fut_unpin)); + let mut fut: Pin<&mut F> = unsafe { + Pin::map_unchecked_mut(fut_pin.as_mut(), |x| &mut **x) + }; + let (waker, rx) = simple_waker(); + let mut context = Context::from_waker(&waker); + let rv = loop { + match fut.as_mut().poll(&mut context) { + Poll::Ready(out) => break out, + // expect wake in polls + Poll::Pending => rx.try_recv().unwrap(), + } + }; + let drop_fut_unpin = unsafe { async_drop_in_place(fut.get_unchecked_mut()) }; + let mut drop_fut: Pin<&mut _> = pin!(drop_fut_unpin); + loop { + match drop_fut.as_mut().poll(&mut context) { + Poll::Ready(()) => break, + Poll::Pending => rx.try_recv().unwrap(), + } + } + rv +} + +fn simple_waker() -> (Waker, mpsc::Receiver<()>) { + struct SimpleWaker { + tx: std::sync::mpsc::Sender<()>, + } + + impl Wake for SimpleWaker { + fn wake(self: Arc<Self>) { + self.tx.send(()).unwrap(); + } + } + + let (tx, rx) = mpsc::channel(); + (Waker::from(Arc::new(SimpleWaker { tx })), rx) +} diff --git a/tests/ui/async-await/async-drop/async-drop-box-allocator.run.stdout b/tests/ui/async-await/async-drop/async-drop-box-allocator.run.stdout new file mode 100644 index 00000000000..cb7d0b0fea5 --- /dev/null +++ b/tests/ui/async-await/async-drop/async-drop-box-allocator.run.stdout @@ -0,0 +1,6 @@ +Foo::new() : 7 +Foo::drop() : 7 +Middle +Foo::new() : 10 +Foo::async drop() : 10 +Done diff --git a/tests/ui/async-await/async-drop/async-drop-box.rs b/tests/ui/async-await/async-drop/async-drop-box.rs new file mode 100644 index 00000000000..0a6ed412863 --- /dev/null +++ b/tests/ui/async-await/async-drop/async-drop-box.rs @@ -0,0 +1,109 @@ +//@ run-pass +//@ check-run-results +// struct `Foo` has both sync and async drop. +// `Foo` is always inside `Box` +// Sync version is called in sync context, async version is called in async function. + +//@ known-bug: #143658 +// async version is never actually called + +#![feature(async_drop)] +#![allow(incomplete_features)] + +use std::mem::ManuallyDrop; + +//@ edition: 2021 + +#[inline(never)] +fn myprintln(msg: &str, my_resource_handle: usize) { + println!("{} : {}", msg, my_resource_handle); +} + +use std::{ + future::{Future, async_drop_in_place, AsyncDrop}, + pin::{pin, Pin}, + sync::{mpsc, Arc}, + task::{Context, Poll, Wake, Waker}, +}; + +struct Foo { + my_resource_handle: usize, +} + +impl Foo { + fn new(my_resource_handle: usize) -> Self { + let out = Foo { + my_resource_handle, + }; + myprintln("Foo::new()", my_resource_handle); + out + } +} + +impl Drop for Foo { + fn drop(&mut self) { + myprintln("Foo::drop()", self.my_resource_handle); + } +} + +impl AsyncDrop for Foo { + async fn drop(self: Pin<&mut Self>) { + myprintln("Foo::async drop()", self.my_resource_handle); + } +} + +fn main() { + { + let _ = Box::new(Foo::new(7)); + } + println!("Middle"); + block_on(bar(10)); + println!("Done") +} + +async fn bar(ident_base: usize) { + let _first = Box::new(Foo::new(ident_base)); +} + +fn block_on<F>(fut_unpin: F) -> F::Output +where + F: Future, +{ + let mut fut_pin = pin!(ManuallyDrop::new(fut_unpin)); + let mut fut: Pin<&mut F> = unsafe { + Pin::map_unchecked_mut(fut_pin.as_mut(), |x| &mut **x) + }; + let (waker, rx) = simple_waker(); + let mut context = Context::from_waker(&waker); + let rv = loop { + match fut.as_mut().poll(&mut context) { + Poll::Ready(out) => break out, + // expect wake in polls + Poll::Pending => rx.try_recv().unwrap(), + } + }; + let drop_fut_unpin = unsafe { async_drop_in_place(fut.get_unchecked_mut()) }; + let mut drop_fut: Pin<&mut _> = pin!(drop_fut_unpin); + loop { + match drop_fut.as_mut().poll(&mut context) { + Poll::Ready(()) => break, + Poll::Pending => rx.try_recv().unwrap(), + } + } + rv +} + +fn simple_waker() -> (Waker, mpsc::Receiver<()>) { + struct SimpleWaker { + tx: std::sync::mpsc::Sender<()>, + } + + impl Wake for SimpleWaker { + fn wake(self: Arc<Self>) { + self.tx.send(()).unwrap(); + } + } + + let (tx, rx) = mpsc::channel(); + (Waker::from(Arc::new(SimpleWaker { tx })), rx) +} diff --git a/tests/ui/async-await/async-drop/async-drop-box.run.stdout b/tests/ui/async-await/async-drop/async-drop-box.run.stdout new file mode 100644 index 00000000000..a2dab2ba992 --- /dev/null +++ b/tests/ui/async-await/async-drop/async-drop-box.run.stdout @@ -0,0 +1,6 @@ +Foo::new() : 7 +Foo::drop() : 7 +Middle +Foo::new() : 10 +Foo::drop() : 10 +Done diff --git a/tests/ui/drop/box-conditional-drop-allocator.rs b/tests/ui/drop/box-conditional-drop-allocator.rs new file mode 100644 index 00000000000..8f78da16473 --- /dev/null +++ b/tests/ui/drop/box-conditional-drop-allocator.rs @@ -0,0 +1,43 @@ +//@ run-pass +#![feature(allocator_api)] + +// Regression test for #131082. +// Testing that the allocator of a Box is dropped in conditional drops + +use std::alloc::{AllocError, Allocator, Global, Layout}; +use std::cell::Cell; +use std::ptr::NonNull; + +struct DropCheckingAllocator<'a>(&'a Cell<bool>); + +unsafe impl Allocator for DropCheckingAllocator<'_> { + fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> { + Global.allocate(layout) + } + unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) { + Global.deallocate(ptr, layout); + } +} +impl Drop for DropCheckingAllocator<'_> { + fn drop(&mut self) { + self.0.set(true); + } +} + +struct HasDrop; +impl Drop for HasDrop { + fn drop(&mut self) {} +} + +fn main() { + let dropped = Cell::new(false); + { + let b = Box::new_in(HasDrop, DropCheckingAllocator(&dropped)); + if true { + drop(*b); + } else { + drop(b); + } + } + assert!(dropped.get()); +} |