tests/guest-debug: Support passing arguments to the GDB test script

This commit adds support for passing arguments to the GDB test scripts
so it's possible to parse the args in an "argparse way" in the test
scripts launched by the runner. The arguments should be preceded by --
when passed to the runner. For example, passing "--help" arg to the
GDB_TEST_SCRIPT:

run-test.py [...] --test <GDB_TEST_SCRIPT> -- --help

The test script should not use the argparse module directly but import
arg_parser from test_gdbstub module. arg_parser then can be used just
like the argparse.ArgumentParser class:

from test_gdbstub import arg_parser

p = arg_parser(prog="test-mytest.py", description="My test.")
p.add_argument("--vowel", help="Select vowel",
               required=True, choices=['a','e','i','o','u'])
[...]

The arg_parser allows a smooth and informative exit if, for instance,
the caller of the runner script passes an invalid argument or misses a
required argument by the test script.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240906143316.657436-4-gustavo.romero@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240910173900.4154726-9-alex.bennee@linaro.org>

tests/guest-debug/run-test.py

@@ -27,6 +27,10 @@ def get_args():
     parser.add_argument("--binary", help="Binary to debug",
                         required=True)
     parser.add_argument("--test", help="GDB test script")
+    parser.add_argument('test_args', nargs='*',
+                        help="Additional args for GDB test script. "
+                        "The args should be preceded by -- to avoid confusion "
+                        "with flags for runner script")
     parser.add_argument("--gdb", help="The gdb binary to use",
                         default=None)
     parser.add_argument("--gdb-args", help="Additional gdb arguments")
@@ -91,6 +95,8 @@ if __name__ == '__main__':
     gdb_cmd += " -ex 'target remote %s'" % (socket_name)
     # finally the test script itself
     if args.test:
+        if args.test_args:
+            gdb_cmd += f" -ex \"py sys.argv={args.test_args}\""
         gdb_cmd += " -x %s" % (args.test)
 
 

tests/guest-debug/test_gdbstub.py

@@ -2,6 +2,7 @@
 
 """
 from __future__ import print_function
+import argparse
 import gdb
 import os
 import sys
@@ -9,6 +10,10 @@ import traceback
 
 fail_count = 0
 
+class arg_parser(argparse.ArgumentParser):
+    def exit(self, status=None, message=""):
+        print("Wrong GDB script test argument! " + message)
+        gdb.execute("exit 1")
 
 def report(cond, msg):
     """Report success/fail of a test"""