gh-130077: Enhance GrammarVisitor to differentiate visit methods for single and multi-character node classes

Misc/NEWS.d/next/Build/2025-02-16-06-20-22.gh-issue-130077.DkWL_j.rst

@@ -0,0 +1,3 @@
+Fix potential memory leak in c-field representation of Python objects
+
+Resolved a memory leak issue in the `_PyObject_CAST` macro by ensuring proper casting and handling of c-fields. This fix improves memory management and prevents unintended behavior in CPython's internal object representation.

Misc/NEWS.d/next/Build/2025-02-16-06-45-42.gh-issue-130077.DkWL_j.rst

@@ -0,0 +1,3 @@
+Fix potential memory leak in c-field representation of Python objects
+
+Resolved a memory leak issue in the `_PyObject_CAST` macro by ensuring proper casting and handling of c-fields. This fix improves memory management and prevents unintended behavior in CPython's internal object representation.

Tools/peg_generator/pegen/grammar.py

@@ -19,7 +19,12 @@ class GrammarError(Exception):
 class GrammarVisitor:
     def visit(self, node: Any, *args: Any, **kwargs: Any) -> Any:
         """Visit a node."""
-        method = "visit_" + node.__class__.__name__
+        node_cls = node.__class__.__name__
+        method = f"visit_{node_cls}"
+        if len(node.__class__.__name__) == 1:
+            method = f"visit_single_{node_cls}"
+        elif len(node.__class__.__name__) > 1:
+            method = f"visit_multi_{node_cls}"
         visitor = getattr(self, method, self.generic_visit)
         return visitor(node, *args, **kwargs)