qemu-trace2txt: port to clifunction

qemu-trace2txt

@@ -1,13 +1,19 @@
 #!/usr/bin/env python3
 
 import os
-import subprocess
-import sys
 
 import common
 from shell_helpers import LF
 
-def main():
+class Main(common.LkmcCliFunction):
+    def __init__(self):
+        super().__init__(
+            description='''\
+Convert a QEMU `-trace exec_tb` to text form.
+'''
+        )
+
+    def timed_main(self):
         return self.sh.run_cmd(
             [
                 os.path.join(self.env['qemu_source_dir'], 'scripts/simpletrace.py'), LF,
@@ -20,8 +26,4 @@ def main():
         )
 
 if __name__ == '__main__':
-    parser = self.get_argparse(argparse_args={
+    Main().cli_exit()
-        'description': 'Convert a QEMU `-trace exec_tb` to text form.'
-    })
-    args = self.setup(parser)
-    sys.exit(main())

shell_helpers.py

@@ -169,6 +169,9 @@ class ShellHelpers:
 
         :param extra_env: extra environment variables to add when running the command
         :type extra_env: Dict[str,str]
+
+        :return: exit status of the command
+        :rtype: int
         '''
         if out_file is not None:
             stdout = subprocess.PIPE