extract fields from the class

Author: varun-r-mallya

pythonbpf/vmlinux_parser/vmlinux_class_handler.py

@@ -9,15 +9,38 @@
 
 @lru_cache(maxsize=1)
 def get_module_symbols(module_name: str):
-    module = importlib.import_module(module_name)
-    return [name for name in dir(module)]
+    imported_module = importlib.import_module(module_name)
+    return [name for name in dir(imported_module)], imported_module
 
-def process_vmlinux_class(node, module, handler: DependencyHandler, parent=""):
-    symbols_in_module = get_module_symbols("vmlinux")
+def process_vmlinux_class(node, llvm_module, handler: DependencyHandler, parent=""):
+    symbols_in_module, imported_module = get_module_symbols("vmlinux")
     current_symbol_name = node.name
     if current_symbol_name not in symbols_in_module:
         raise ImportError(f"{current_symbol_name} not present in module vmlinux")
     logger.info(f"Resolving vmlinux class {current_symbol_name}")
-    # Now we find fields present in current class
-    pass
+    field_table = {}  # should contain the field and it's type.
+
+    # Get the class object from the module
+    class_obj = getattr(imported_module, current_symbol_name)
+
+    # Below, I've written a general structure that gets class-info
+    # everytime, no matter the format in which it is present
+
+    # Inspect the class fields
+    # Assuming class_obj has fields stored in some standard way
+    #If it's a ctypes-like structure with _fields_
+    if hasattr(class_obj, '_fields_'):
+        for field_name, field_type in class_obj._fields_:
+            field_table[field_name] = field_type
+
+    # If it's using __annotations__
+    elif hasattr(class_obj, '__annotations__'):
+        for field_name, field_type in class_obj.__annotations__.items():
+            field_table[field_name] = field_type
+
+    else:
+        raise TypeError("Could not get required class and definition")
+
+    logger.info(f"Extracted fields for {current_symbol_name}: {field_table}")
+    return field_table