Rollup merge of rust-lang#125982 - xTachyon:fix-linked-list, r=jhpratt

workingjubilee · web-flow · commit 2c5f1acc4c19 · 2024-06-05T01:14:33.000-07:00
Make deleting on LinkedList aware of the allocator Fixed rust-lang#125950
diff --git a/alloc/src/collections/linked_list.rs b/alloc/src/collections/linked_list.rs
@@ -1705,7 +1705,7 @@ impl<'a, T, A: Allocator> CursorMut<'a, T, A> {
         unsafe {
             self.current = unlinked_node.as_ref().next;
             self.list.unlink_node(unlinked_node);
-            let unlinked_node = Box::from_raw(unlinked_node.as_ptr());
+            let unlinked_node = Box::from_raw_in(unlinked_node.as_ptr(), &self.list.alloc);
             Some(unlinked_node.element)
         }
     }
@@ -1946,7 +1946,7 @@ where
                 if (self.pred)(&mut node.as_mut().element) {
                     // `unlink_node` is okay with aliasing `element` references.
                     self.list.unlink_node(node);
-                    return Some(Box::from_raw(node.as_ptr()).element);
+                    return Some(Box::from_raw_in(node.as_ptr(), &self.list.alloc).element);
                 }
             }
         }
diff --git a/alloc/src/collections/linked_list/tests.rs b/alloc/src/collections/linked_list/tests.rs
@@ -1164,3 +1164,42 @@ fn test_drop_panic() {
 
     assert_eq!(unsafe { DROPS }, 8);
 }
+
+#[test]
+fn test_allocator() {
+    use core::alloc::AllocError;
+    use core::alloc::Allocator;
+    use core::alloc::Layout;
+    use core::cell::Cell;
+
+    struct A {
+        has_allocated: Cell<bool>,
+        has_deallocated: Cell<bool>,
+    }
+
+    unsafe impl Allocator for A {
+        fn allocate(&self, layout: Layout) -> Result<NonNull<[u8]>, AllocError> {
+            assert!(!self.has_allocated.get());
+            self.has_allocated.set(true);
+
+            Global.allocate(layout)
+        }
+
+        unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
+            assert!(!self.has_deallocated.get());
+            self.has_deallocated.set(true);
+
+            unsafe { Global.deallocate(ptr, layout) }
+        }
+    }
+
+    let alloc = &A { has_allocated: Cell::new(false), has_deallocated: Cell::new(false) };
+    {
+        let mut list = LinkedList::new_in(alloc);
+        list.push_back(5u32);
+        list.remove(0);
+    }
+
+    assert!(alloc.has_allocated.get());
+    assert!(alloc.has_deallocated.get());
+}

Original file line number	Diff line number	Diff line change
`@@ -1705,7 +1705,7 @@ impl<'a, T, A: Allocator> CursorMut<'a, T, A> {`
`1705`	`1705`	`unsafe {`
`1706`	`1706`	`self.current = unlinked_node.as_ref().next;`
`1707`	`1707`	`self.list.unlink_node(unlinked_node);`
`1708`		`- let unlinked_node = Box::from_raw(unlinked_node.as_ptr());`
	`1708`	`+ let unlinked_node = Box::from_raw_in(unlinked_node.as_ptr(), &self.list.alloc);`
`1709`	`1709`	`Some(unlinked_node.element)`
`1710`	`1710`	`}`
`1711`	`1711`	`}`
`@@ -1946,7 +1946,7 @@ where`
`1946`	`1946`	`if (self.pred)(&mut node.as_mut().element) {`
`1947`	`1947`	// `unlink_node` is okay with aliasing `element` references.
`1948`	`1948`	`self.list.unlink_node(node);`
`1949`		`- return Some(Box::from_raw(node.as_ptr()).element);`
	`1949`	`+ return Some(Box::from_raw_in(node.as_ptr(), &self.list.alloc).element);`
`1950`	`1950`	`}`
`1951`	`1951`	`}`
`1952`	`1952`	`}`