Allow renaming of functions without stack or parameters (#13)

* Allow renaming of functions without stack or parameters
* return on failure

Author: mahaloz

varbert/__init__.py

@@ -1,4 +1,4 @@
-__version__ = "2.2.1"
+__version__ = "2.3.0"
 
 import importlib.resources
 import tarfile

varbert/api.py

@@ -47,11 +47,8 @@ def predict_variable_names(
         if function is None and decompilation_text is None:
             raise ValueError("Must provide either a Function or decompilation text.")
         if function:
-            if not function.args and not function.stack_vars:
-                self.debug(f"{function} has no arguments or stack variables to predict names for.")
-                return {}, ""
             if function.size < self._min_func_size:
-                self.debug(f"{function} is smaller than min size of {self._min_func_size} bytes.")
+                self.error(f"{function} is smaller than min size of {self._min_func_size} bytes.")
                 return {}, ""
         # can be None because of the delay init
         if self._model_interface is None:
@@ -70,6 +67,9 @@ def predict_variable_names(
         preprocessor = DecompilationTextProcessor(
             decompilation_text, func=function, decompiler=self._dec_interface if use_decompiler else None
         )
+        if preprocessor.failed:
+            return {}, ""
+
         processed_code, func_args = preprocessor.processed_code, preprocessor.func_args
         scores, score_origins = self._model_interface.process(processed_code)
         if scores is None:

varbert/text_processor.py

@@ -19,6 +19,8 @@ def __init__(self, raw_code, func: Optional[Function] = None, decompiler: Option
         self._decompiler = decompiler
         self._func = func
 
+        self.failed = False
+
         # updated in process_code
         self.processed_code = raw_code
         # TODO: this actually needs to be disabled for now because Function does not handle register variables
@@ -83,6 +85,11 @@ def _process_code_with_decompiler(self):
         # refresh the decompiled obj backend
         self._func.dec_obj = self._decompiler.get_decompilation_object(self._func)
         original_names = self._decompiler.local_variable_names(self._func)
+        if not original_names:
+            self._decompiler.error(f"No variable names (local or args) found in decompiled function {self._func} for renaming.")
+            self.failed = True
+            return
+
         og_name_to_tokenized_name = self._tokenize_names(original_names, token=tmp_token)
         tokenized_name_to_og_name = {v: k for k, v in og_name_to_tokenized_name.items()}