set_f_lineno, set_f_lasti

youknowone · youknowone · commit 66a8aee7fbcb · 2026-02-24T10:18:35.000+09:00
diff --git a/crates/vm/src/builtins/frame.rs b/crates/vm/src/builtins/frame.rs
@@ -71,6 +71,46 @@ impl Frame {
         }
     }
 
+    #[pygetset(setter)]
+    fn set_f_lineno(&self, value: PySetterValue, vm: &VirtualMachine) -> PyResult<()> {
+        let target_line = match value {
+            PySetterValue::Assign(val) => {
+                let line_ref: PyIntRef = val
+                    .downcast()
+                    .map_err(|_| vm.new_value_error("lineno must be an integer".to_owned()))?;
+                line_ref
+                    .try_to_primitive::<usize>(vm)
+                    .map_err(|_| vm.new_value_error("lineno must be an integer".to_owned()))?
+            }
+            PySetterValue::Delete => {
+                return Err(vm.new_type_error("can't delete f_lineno attribute".to_owned()));
+            }
+        };
+
+        // Find the first instruction at the target line
+        let locations = &self.code.locations;
+        let mut target_idx = None;
+        for (idx, (loc, _)) in locations.iter().enumerate() {
+            if loc.line.get() == target_line {
+                target_idx = Some(idx);
+                break;
+            }
+        }
+
+        match target_idx {
+            Some(idx) => {
+                // Set lasti to point to the target instruction.
+                // The run loop reads lasti then increments, so set to idx
+                // so the next iteration executes instruction at idx.
+                self.set_lasti(idx as u32);
+                Ok(())
+            }
+            None => Err(vm.new_value_error(format!(
+                "line {target_line} comes after the current code block"
+            ))),
+        }
+    }
+
     #[pygetset]
     fn f_trace(&self) -> PyObjectRef {
         let boxed = self.trace.lock();
diff --git a/crates/vm/src/frame.rs b/crates/vm/src/frame.rs
@@ -258,6 +258,17 @@ impl Frame {
         }
     }
 
+    pub fn set_lasti(&self, val: u32) {
+        #[cfg(feature = "threading")]
+        {
+            self.lasti.store(val, atomic::Ordering::Relaxed);
+        }
+        #[cfg(not(feature = "threading"))]
+        {
+            self.lasti.set(val);
+        }
+    }
+
     /// Sync locals dict back to fastlocals. Called before generator/coroutine resume
     /// to apply any modifications made via f_locals.
     pub fn locals_to_fast(&self, vm: &VirtualMachine) -> PyResult<()> {
