add function pointer detection warning as well as identify ctypes non recursion error

Author: varun-r-mallya

pythonbpf/vmlinux_parser/class_handler.py

@@ -99,13 +99,32 @@ def process_vmlinux_post_ast(
                 local_module_name = getattr(elem_type, "__module__", None)
                 new_dep_node.add_field(elem_name, elem_type, ready=False)
                 if local_module_name == ctypes.__name__:
-                    #TODO: need to process pointer to ctype and also CFUNCTYPES here
+                    #TODO: need to process pointer to ctype and also CFUNCTYPES here recursively.
+                    #  for now, function pointers should give an error
                     new_dep_node.set_field_bitfield_size(elem_name, elem_bitfield_size)
-                    print(elem_type)
-                    new_dep_node.set_field_ready(elem_name, is_ready=True)
-                    logger.debug(
-                        f"Field {elem_name} is direct ctypes type: {elem_type}"
-                    )
+
+                    # Process pointer to ctype
+                    if isinstance(elem_type, type) and issubclass(elem_type, ctypes._Pointer):
+                        # Get the pointed-to type
+                        pointed_type = elem_type._type_
+                        logger.debug(f"Found pointer to type: {pointed_type}")
+                        new_dep_node.set_field_containing_type(elem_name, pointed_type)
+                        new_dep_node.set_field_ctype_complex_type(elem_name, ctypes._Pointer)
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+
+                    # Process function pointers (CFUNCTYPE)
+                    elif hasattr(elem_type, '_restype_') and hasattr(elem_type, '_argtypes_'):
+                        # This is a CFUNCTYPE or similar
+                        logger.info(f"Function pointer detected for {elem_name} with return type {elem_type._restype_} and arguments {elem_type._argtypes_}")
+                        # Set the field as ready but mark it with special handling
+                        new_dep_node.set_field_ctype_complex_type(elem_name, ctypes.CFUNCTYPE)
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+                        logger.warning("Blindly processing CFUNCTYPE ctypes to ensure compilation. Unsupported")
+
+                    else:
+                        # Regular ctype
+                        new_dep_node.set_field_ready(elem_name, is_ready=True)
+                        logger.debug(f"Field {elem_name} is direct ctypes type: {elem_type}")
                 elif local_module_name == "vmlinux":
                     new_dep_node.set_field_bitfield_size(elem_name, elem_bitfield_size)
                     logger.debug(

tests/passing_tests/vmlinux/simple_struct_test.py

@@ -1,7 +1,7 @@
 from pythonbpf import bpf, section, bpfglobal, compile_to_ir, compile
 from vmlinux import TASK_COMM_LEN  # noqa: F401
 from vmlinux import struct_trace_event_raw_sys_enter  # noqa: F401
-# from vmlinux import struct_uinput_device
+from vmlinux import struct_uinput_device
 from vmlinux import struct_blk_integrity_iter
 from ctypes import c_int64