[NOT FOR COMMINT] Linter for RunShellCommand calls

lint_shell_commands.py

Index: lint_shell_commands.py
diff --git a/lint_shell_commands.py b/lint_shell_commands.py
new file mode 100755
index 0000000000000000000000000000000000000000..87bc81b764541852dc4b7fb621e972cc090d8f58
--- /dev/null
+++ b/lint_shell_commands.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+import argparse
+import ast
+import logging
+import os
+import sys
+
+logging.basicConfig(format='%(levelname)s:%(message)s', stream=sys.stdout)
+
+
+def is_true(node):
+  return isinstance(node, ast.Name) and node.id == 'True'
+
+
+def node_repr(node):
+  if isinstance(node, ast.Name):
+    return node.id
+  else:
+    raise NotImplementedError(ast.dump(node))
+
+
+def lint_shell_command_calls(basename, filename):
+  with open(os.path.join(basename, filename)) as f:
+    try:
+      tree = ast.parse(f.read(), filename)
+    except Exception:
+      logging.warning('%s: Parse error, skipping.', filename)
+      return
+
+  for node in ast.walk(tree):
+    if (isinstance(node, ast.Call) and
+        isinstance(node.func, ast.Attribute) and
+        node.func.attr == 'RunShellCommand'):
+
+      if node.args and isinstance(node.args[0], ast.Str):
+        logging.warning(
+            '%s:%s: Avoid passing command as a string.', filename, node.lineno)
+
+      kwargs = {kw.arg: kw.value for kw in node.keywords}
+      check_return = kwargs.get('check_return')
+      if check_return is None:
+        logging.warning(
+            '%s:%s: Missing check_return=True.', filename, node.lineno)
+      elif not is_true(check_return):
+        logging.warning(
+            '%s:%s: Consider switching check_return=%s to True.',
+            filename, node.lineno, node_repr(check_return))
+
+
+def ignore_dir(dirname):
+  return dirname.startswith('.') or dirname == 'third_party'
+
+
+def iter_python_files(root):
+  for abs_dirpath, dirnames, filenames in os.walk(root):
+    dirpath = os.path.relpath(abs_dirpath, root)
+    for filename in filenames:
+      if filename.endswith('.py'):
+        yield os.path.join(dirpath, filename)
+    dirnames[:] = [d for d in dirnames if not ignore_dir(d)]
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('root')
+  args = parser.parse_args()
+
+  args.root = os.path.realpath(args.root)
+  for filename in iter_python_files(args.root):
+    lint_shell_command_calls(args.root, filename)
+
+
+if __name__ == '__main__':
+  sys.exit(main())