[refactoring] Extract helper method has_specific_arg (#49)

fix #8, extract helper method `has_specific_arg` that checks for the call argument presence, and simplify all relevant call sites

Author: izaitsevfb

torchfix/common.py

@@ -62,7 +62,10 @@ def __init__(self) -> None:
     def get_specific_arg(
         node: cst.Call, arg_name: str, arg_pos: int
     ) -> Optional[cst.Arg]:
-        # `arg_pos` is zero-based.
+        """
+        :param arg_pos: `arg_pos` is zero-based. -1 means it's a keyword argument.
+        :note: consider using `has_specific_arg` if you only need to check for presence.
+        """
         curr_pos = 0
         for arg in node.args:
             if arg.keyword is None:
@@ -73,6 +76,18 @@ def get_specific_arg(
                 return arg
         return None
 
+    @staticmethod
+    def has_specific_arg(
+            node: cst.Call, arg_name: str, position: Optional[int] = None
+    ) -> bool:
+        """
+        Check if the specific argument is present in a call.
+        """
+        return TorchVisitor.get_specific_arg(
+            node, arg_name,
+            position if position is not None else -1
+        ) is not None
+
     def add_violation(
         self,
         node: cst.CSTNode,

torchfix/visitors/misc/__init__.py

@@ -59,20 +59,19 @@ class TorchReentrantCheckpointVisitor(TorchVisitor):
     ]
 
     def visit_Call(self, node):
-        qualified_name = self.get_qualified_name_for_call(node)
-        if qualified_name == "torch.utils.checkpoint.checkpoint":
-            use_reentrant_arg = self.get_specific_arg(node, "use_reentrant", -1)
-            if use_reentrant_arg is None:
-                # This codemod maybe  unsafe correctness-wise
-                # if reentrant behavior is actually needed,
-                # so the changes need to be verified/tested.
-                use_reentrant_arg = cst.ensure_type(
-                    cst.parse_expression("f(use_reentrant=False)"), cst.Call
-                ).args[0]
-                replacement = node.with_changes(args=node.args + (use_reentrant_arg,))
-                self.add_violation(
-                    node,
-                    error_code=self.ERRORS[0].error_code,
-                    message=self.ERRORS[0].message(),
-                    replacement=replacement,
-                )
+        if (self.get_qualified_name_for_call(node) ==
+                "torch.utils.checkpoint.checkpoint" and
+                not self.has_specific_arg(node, "use_reentrant")):
+            # This codemod maybe  unsafe correctness-wise
+            # if reentrant behavior is actually needed,
+            # so the changes need to be verified/tested.
+            use_reentrant_arg = cst.ensure_type(
+                cst.parse_expression("f(use_reentrant=False)"), cst.Call
+            ).args[0]
+            replacement = node.with_changes(args=node.args + (use_reentrant_arg,))
+            self.add_violation(
+                node,
+                error_code=self.ERRORS[0].error_code,
+                message=self.ERRORS[0].message(),
+                replacement=replacement,
+            )

torchfix/visitors/security/__init__.py

@@ -22,30 +22,27 @@ class TorchUnsafeLoadVisitor(TorchVisitor):
     ]
 
     def visit_Call(self, node):
-        qualified_name = self.get_qualified_name_for_call(node)
-        if qualified_name == "torch.load":
-            weights_only_arg = self.get_specific_arg(node, "weights_only", -1)
-            if weights_only_arg is None:
-                # Add `weights_only=True` if there is no `pickle_module`.
-                # (do not add `weights_only=False` with `pickle_module`, as it
-                # needs to be an explicit choice).
-                #
-                # This codemod is somewhat unsafe correctness-wise
-                # because full pickling functionality may still be needed
-                # even without `pickle_module`,
-                # so the changes need to be verified/tested.
-                replacement = None
-                pickle_module_arg = self.get_specific_arg(node, "pickle_module", 2)
-                if pickle_module_arg is None:
-                    weights_only_arg = cst.ensure_type(
-                        cst.parse_expression("f(weights_only=True)"), cst.Call
-                    ).args[0]
-                    replacement = node.with_changes(
-                        args=node.args + (weights_only_arg,)
-                    )
-                self.add_violation(
-                    node,
-                    error_code=self.ERRORS[0].error_code,
-                    message=self.ERRORS[0].message(),
-                    replacement=replacement,
+        if self.get_qualified_name_for_call(node) == "torch.load" and \
+                not self.has_specific_arg(node, "weights_only"):
+            # Add `weights_only=True` if there is no `pickle_module`.
+            # (do not add `weights_only=False` with `pickle_module`, as it
+            # needs to be an explicit choice).
+            #
+            # This codemod is somewhat unsafe correctness-wise
+            # because full pickling functionality may still be needed
+            # even without `pickle_module`,
+            # so the changes need to be verified/tested.
+            replacement = None
+            if not self.has_specific_arg(node, "pickle_module", 2):
+                weights_only_arg = cst.ensure_type(
+                    cst.parse_expression("f(weights_only=True)"), cst.Call
+                ).args[0]
+                replacement = node.with_changes(
+                    args=node.args + (weights_only_arg,)
                 )
+            self.add_violation(
+                node,
+                error_code=self.ERRORS[0].error_code,
+                message=self.ERRORS[0].message(),
+                replacement=replacement,
+            )