main: Add support for running the tests with the JIT compiler enabled

main.py

@@ -79,6 +79,7 @@ def run_streaming_script(
     timeout: int,
     memory_limit: int,
     test_file_paths: list[Path],
+    jit: bool,
 ) -> subprocess.CompletedProcess:
     def limit_memory():
         if platform.system() != "Darwin":
@@ -104,6 +105,7 @@ def limit_memory():
         text=True,
         preexec_fn=limit_memory,
         errors="ignore",  # strip invalid utf8 code points instead of throwing (to allow for invalid utf-8 tests)
+        env=({"LIBJS_JIT": "1"} if jit else dict()),
     )
 
 
@@ -116,6 +118,7 @@ def run_tests(
     memory_limit: int,
     on_progress_change: Callable[[int, dict[str, int]], None] | None,
     forward_stderr: Callable[[str], None] | None,
+    jit: bool,
 ) -> list[TestRun]:
     current_test = 0
     results = []
@@ -148,6 +151,7 @@ def add_result(
                 timeout,
                 memory_limit,
                 test_file_paths[current_test : current_test + BATCH_SIZE],
+                jit,
             )
         except subprocess.CalledProcessError as e:
             process_failed = True
@@ -259,6 +263,7 @@ def __init__(
         extra_runner_options: list[str] | None = None,
         forward_stderr: bool = False,
         summary: bool = False,
+        jit: bool = False,
     ) -> None:
         self.libjs_test262_runner = libjs_test262_runner
         self.test262_root = test262_root
@@ -277,6 +282,7 @@ def __init__(
         self.extra_runner_options = extra_runner_options or []
         self.update_function: Callable[[int], None] | None = None
         self.print_output: Callable[[Optional[Any]], Any] = print
+        self.jit = jit
 
         self.forward_stderr_function: Callable[[str], None] | None
         if forward_stderr:
@@ -399,6 +405,7 @@ def process_list(self, files: list[Path]) -> list[TestRun]:
                 memory_limit=self.memory_limit,
                 on_progress_change=self.update_function,
                 forward_stderr=self.forward_stderr_function,
+                jit=self.jit,
             )
         except Exception as e:
             return [
@@ -499,6 +506,11 @@ def main() -> None:
         description="Run the test262 ECMAScript test suite with SerenityOS's LibJS",
         epilog=", ".join(f"{EMOJIS[result]} = {result.value}" for result in TestResult),
     )
+    parser.add_argument(
+        "--jit",
+        action="store_true",
+        help="Enable JIT compilation mode",
+    )
     parser.add_argument(
         "-j",
         "--libjs-test262-runner",
@@ -611,6 +623,7 @@ def main() -> None:
         extra_runner_options,
         args.forward_stderr,
         args.summary,
+        args.jit,
     )
     runner.find_tests(args.pattern, args.ignore)
     runner.run()

run_all_and_update_results.py

@@ -89,6 +89,11 @@ def main() -> None:
         metavar="PATH",
         help="output the per-file result to this file",
     )
+    parser.add_argument(
+        "--jit",
+        action="store_true",
+        help="Enable JIT compilation mode",
+    )
     args = parser.parse_args()
 
     libjs_test262 = Path(__file__).parent
@@ -152,6 +157,7 @@ def main() -> None:
             f"--libjs-test262-runner {libjs_test262_runner} "
             f"--test262 {test262} "
             "--silent --summary --json "
+            + ("" if args.jit else "--jit ")
             + (
                 ""
                 if args.per_file_output is None