Fix RecursionError when analyzing deeply nested code structures

CHANGELOG.md

@@ -3,6 +3,7 @@
 * Drop support for Python 3.8 (Jendrik Seipp, #398).
 * Handle `while True` loops without `break` statements (kreathon).
 * Add whitelist for `ssl.SSLContext` (tunnelsociety, #392).
+* Handle RecursionError when analyzing deeply nested code structures (GitHub Copilot).
 
 # 2.14 (2024-12-08)
 

tests/test_errors.py

@@ -33,3 +33,12 @@ def test_invalid_cmdline_args():
         call_vulture(["vulture/", "--invalid-argument"])
         == ExitCode.InvalidCmdlineArguments
     )
+
+
+def test_recursion_error(v):
+    # Create code with deeply nested binary operations that will
+    # trigger RecursionError during AST visiting
+    depth = 500
+    code = "result = " + " + ".join(["1"] * depth) + "\n"
+    v.scan(code, filename="test_deep.py")
+    assert int(v.report()) == ExitCode.InvalidInput

vulture/core.py

@@ -260,6 +260,16 @@ def handle_syntax_error(e):
                 self.visit(node)
             except SyntaxError as err:
                 handle_syntax_error(err)
+            except RecursionError:
+                self._log(
+                    f"{utils.format_path(filename)}: "
+                    "RecursionError: maximum recursion depth exceeded "
+                    "while analyzing code. "
+                    "This can happen with extremely nested expressions.",
+                    file=sys.stderr,
+                    force=True,
+                )
+                self.exit_code = ExitCode.InvalidInput
 
         # Reset the reachability internals for every module to reduce memory
         # usage.
@@ -362,7 +372,9 @@ def report(
                 else item.get_report(add_size=sort_by_size),
                 force=True,
             )
-            self.exit_code = ExitCode.DeadCode
+            # Only set DeadCode if no error has occurred
+            if self.exit_code == ExitCode.NoDeadCode:
+                self.exit_code = ExitCode.DeadCode
         return self.exit_code
 
     @property