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refactor(AstNode): replace UnsafeCells with Cells #574

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wetneb merged 1 commit from ada4a/mergiraf:cell-parent into main 2025-08-27 11:41:20 +02:00
Conversation 1 Commits 1 Files changed 1 +15 -16
1 changed files with 15 additions and 16 deletions
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31
src/ast.rs
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@ -2,7 +2,7 @@
use std::iter::zip;
use std::{
borrow::Cow,
cell::UnsafeCell,
cell::Cell,
cmp::max,
fmt::Display,
hash::{Hash, Hasher},
@ -57,14 +57,14 @@ pub struct AstNode<'a> {
/// A cached number of descendants
descendant_count: usize,
/// The parent of this node, if any.
parent: UnsafeCell<Option<&'a Self>>,
parent: Cell<Option<&'a Self>>,
/// The commutative merging settings associated with this node.
commutative_parent: Option<&'a CommutativeParent>,
/// As the DFS of a child is a subslice of the DFS of its parent, we compute the entire DFS of
/// the root once and slice all child DFS into this slice.
/// This is computed right after construction and then never written to again.
/// On nodes that have been truncated (which is rare) this will be `None`.
dfs: UnsafeCell<Option<&'a [&'a Self]>>,
dfs: Cell<Option<&'a [&'a Self]>>,
/// The language this node was parsed from
pub lang_profile: &'a LangProfile,
}
@ -349,11 +349,11 @@ impl<'a> AstNode<'a> {
byte_range: start_position..start_position + trimmed.len(),
id: *next_node_id,
descendant_count: 1,
parent: UnsafeCell::new(None),
parent: Cell::new(None),
// `@virtual_line@` isn't an actual grammar type, so it cannot be present in
// the grammar and thus can't have a commutative parent defined
commutative_parent: None,
dfs: UnsafeCell::new(None),
dfs: Cell::new(None),
lang_profile,
is_extra: node.is_extra(),
}));
@ -404,9 +404,9 @@ impl<'a> AstNode<'a> {
byte_range: range,
id: *next_node_id,
descendant_count,
parent: UnsafeCell::new(None),
parent: Cell::new(None),
commutative_parent,
dfs: UnsafeCell::new(None),
dfs: Cell::new(None),
lang_profile,
is_extra: node.is_extra(),
});
@ -417,7 +417,7 @@ impl<'a> AstNode<'a> {
fn internal_set_parent_on_children(&'a self) {
for child in &self.children {
unsafe { *child.parent.get() = Some(self) }
child.parent.set(Some(self))
}
}
@ -439,7 +439,7 @@ impl<'a> AstNode<'a> {
process_node(child, result, i);
}
let end = *i;
unsafe { *node.dfs.get() = Some(&result[start..end]) };
node.dfs.set(Some(&result[start..end]));
}
let mut i = 0;
@ -518,8 +518,7 @@ impl<'a> AstNode<'a> {
/// Depth-first search iterator
pub fn dfs(&'a self) -> impl ExactSizeIterator<Item = &'a Self> + Clone {
// SAFETY: This is not written to after construction.
if let Some(dfs) = unsafe { *self.dfs.get() } {
if let Some(dfs) = self.dfs.get() {
Either::Left(dfs.iter().copied())
} else {
Either::Right(self.calculate_dfs())
@ -689,7 +688,7 @@ impl<'a> AstNode<'a> {
/// Get the parent of this node, if any
pub fn parent(&'a self) -> Option<&'a Self> {
unsafe { *self.parent.get() }
self.parent.get()
}
/// The node that comes just before this node in the list of children
@ -755,8 +754,8 @@ impl<'a> AstNode<'a> {
children,
field_to_children,
byte_range: node.byte_range.clone(),
parent: UnsafeCell::new(None),
dfs: UnsafeCell::new(None),
parent: Cell::new(None),
dfs: Cell::new(None),
..*node
});
result.internal_set_parent_on_children();
@ -1284,9 +1283,9 @@ mod tests {
let node_2 = ctx.parse("a.rs", "fn x() -> i32 { 8 - 1 }");
let fake_hash_collision = AstNode {
hash: node_1.hash,
parent: UnsafeCell::new(None),
parent: Cell::new(None),
commutative_parent: node_2.commutative_parent,
dfs: UnsafeCell::new(None),
dfs: Cell::new(None),
children: node_2.children.to_owned(),
field_to_children: FxHashMap::default(),
byte_range: node_2.byte_range.to_owned(),