feat: Format function names with qualname for Python 3.11+ (#825)

This change will update function names to have module paths in them
which is useful for disambiguating functions when viewing a profile.

See https://docs.python.org/3/glossary.html#term-qualified-name

Author: jake-kramer

src/python_interpreters.rs

@@ -70,6 +70,12 @@ pub trait CodeObject: Copy {
     fn varnames(&self) -> *mut Self::TupleObject;
 
     fn get_line_number(&self, lasti: i32, table: &[u8]) -> i32;
+
+    /// Returns the qualified name (co_qualname) if available (Python 3.11+).
+    /// For older Python versions, returns None.
+    fn qualname(&self) -> Option<*mut Self::StringObject> {
+        None
+    }
 }
 
 pub trait BytesObject: Copy {
@@ -354,6 +360,10 @@ macro_rules! CompactCodeObjectImpl {
                 }
                 line_number
             }
+
+            fn qualname(&self) -> Option<*mut Self::StringObject> {
+                Some(self.co_qualname as *mut Self::StringObject)
+            }
         }
     };
 }
@@ -921,4 +931,24 @@ mod tests {
         ];
         assert_eq!(code.get_line_number(214, &table), 5);
     }
+
+    #[test]
+    fn test_py3_11_qualname() {
+        use crate::python_bindings::v3_11_0::PyCodeObject;
+        let code = PyCodeObject {
+            co_firstlineno: 1,
+            ..Default::default()
+        };
+        assert!(code.qualname().is_some());
+    }
+
+    #[test]
+    fn test_py3_10_qualname_not_available() {
+        use crate::python_bindings::v3_10_0::PyCodeObject;
+        let code = PyCodeObject {
+            co_firstlineno: 1,
+            ..Default::default()
+        };
+        assert!(code.qualname().is_none());
+    }
 }

src/stack_trace.rs

@@ -150,7 +150,15 @@ where
             .context("Failed to copy PyCodeObject")?;
 
         let filename = copy_string(code.filename(), process).context("Failed to copy filename");
-        let name = copy_string(code.name(), process).context("Failed to copy function name");
+
+        // Try to get qualname first (available in Python 3.11+), fall back to name
+        let name = match code.qualname() {
+            Some(qualname_ptr) => {
+                copy_string(qualname_ptr, process).or_else(|_| copy_string(code.name(), process))
+            }
+            None => copy_string(code.name(), process),
+        }
+        .context("Failed to copy function name");
 
         // just skip processing the current frame if we can't load the filename or function name.
         // this can happen in python 3.13+ since the f_executable isn't guaranteed to be