bendns' repos / rust-analyzer
Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/hir/src/lib.rs')
-rw-r--r--crates/hir/src/lib.rs53
1 files changed, 53 insertions, 0 deletions
diff --git a/crates/hir/src/lib.rs b/crates/hir/src/lib.rs
index 3a91050d15..e8218cf861 100644
--- a/crates/hir/src/lib.rs
+++ b/crates/hir/src/lib.rs
@@ -5972,6 +5972,59 @@ impl Layout {
}
}
+ pub fn tail_padding(&self, field_size: &mut impl FnMut(usize) -> Option<u64>) -> Option<u64> {
+ match self.0.fields {
+ layout::FieldsShape::Primitive => None,
+ layout::FieldsShape::Union(_) => None,
+ layout::FieldsShape::Array { stride, count } => count.checked_sub(1).and_then(|tail| {
+ let tail_field_size = field_size(tail as usize)?;
+ let offset = stride.bytes() * tail;
+ self.0.size.bytes().checked_sub(offset)?.checked_sub(tail_field_size)
+ }),
+ layout::FieldsShape::Arbitrary { ref offsets, ref memory_index } => {
+ let tail = memory_index.last_index()?;
+ let tail_field_size = field_size(tail.0.into_raw().into_u32() as usize)?;
+ let offset = offsets.get(tail)?.bytes();
+ self.0.size.bytes().checked_sub(offset)?.checked_sub(tail_field_size)
+ }
+ }
+ }
+
+ pub fn largest_padding(
+ &self,
+ field_size: &mut impl FnMut(usize) -> Option<u64>,
+ ) -> Option<u64> {
+ match self.0.fields {
+ layout::FieldsShape::Primitive => None,
+ layout::FieldsShape::Union(_) => None,
+ layout::FieldsShape::Array { stride: _, count: 0 } => None,
+ layout::FieldsShape::Array { stride, .. } => {
+ let size = field_size(0)?;
+ stride.bytes().checked_sub(size)
+ }
+ layout::FieldsShape::Arbitrary { ref offsets, ref memory_index } => {
+ let mut reverse_index = vec![None; memory_index.len()];
+ for (src, (mem, offset)) in memory_index.iter().zip(offsets.iter()).enumerate() {
+ reverse_index[*mem as usize] = Some((src, offset.bytes()));
+ }
+ if reverse_index.iter().any(|it| it.is_none()) {
+ stdx::never!();
+ return None;
+ }
+ reverse_index
+ .into_iter()
+ .flatten()
+ .chain(std::iter::once((0, self.0.size.bytes())))
+ .tuple_windows()
+ .filter_map(|((i, start), (_, end))| {
+ let size = field_size(i)?;
+ end.checked_sub(start)?.checked_sub(size)
+ })
+ .max()
+ }
+ }
+ }
+
pub fn enum_tag_size(&self) -> Option<usize> {
let tag_size =
if let layout::Variants::Multiple { tag, tag_encoding, .. } = &self.0.variants {