Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 39 insertions, 0 deletions

diff --git a/third_party/rust/naga/src/proc/emitter.rs b/third_party/rust/naga/src/proc/emitter.rs
new file mode 100644
index 0000000000..0df804fff2
--- /dev/null
+++ b/third_party/rust/naga/src/proc/emitter.rs
@@ -0,0 +1,39 @@
+use crate::arena::Arena;
+
+/// Helper class to emit expressions
+#[allow(dead_code)]
+#[derive(Default, Debug)]
+pub struct Emitter {
+    start_len: Option<usize>,
+}
+
+#[allow(dead_code)]
+impl Emitter {
+    pub fn start(&mut self, arena: &Arena<crate::Expression>) {
+        if self.start_len.is_some() {
+            unreachable!("Emitting has already started!");
+        }
+        self.start_len = Some(arena.len());
+    }
+    pub const fn is_running(&self) -> bool {
+        self.start_len.is_some()
+    }
+    #[must_use]
+    pub fn finish(
+        &mut self,
+        arena: &Arena<crate::Expression>,
+    ) -> Option<(crate::Statement, crate::span::Span)> {
+        let start_len = self.start_len.take().unwrap();
+        if start_len != arena.len() {
+            #[allow(unused_mut)]
+            let mut span = crate::span::Span::default();
+            let range = arena.range_from(start_len);
+            for handle in range.clone() {
+                span.subsume(arena.get_span(handle))
+            }
+            Some((crate::Statement::Emit(range), span))
+        } else {
+            None
+        }
+    }
+}