tools: make js2c.py usable for other build systems

PR-URL: #46930
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: zcbenz

tools/js2c.py

@@ -209,12 +209,20 @@ def main():
 '--directory',
 default=None,
 help='input file directory')
+parser.add_argument(
+'--root',
+default=None,
+help='root directory containing the sources')
 parser.add_argument('--verbose', action='store_true', help='output file')
 parser.add_argument('sources', nargs='*', help='input files')
 options=parser.parse_args()
 globalis_verbose
 is_verbose=options.verbose
 sources=options.sources
+
+ifoptions.rootisnotNone:
+os.chdir(options.root)
+
 ifoptions.directoryisnotNone:
 js_files=utils.SearchFiles(options.directory, 'js')
 mjs_files=utils.SearchFiles(options.directory, 'mjs')
@@ -225,7 +233,8 @@ def main():
 # Should have exactly 3 types: `.js`, `.mjs` and `.gypi`
 assertlen(source_files) ==3
 # Currently config.gypi is the only `.gypi` file allowed
-assertsource_files['.gypi'] == ['config.gypi']
+assertlen(source_files['.gypi']) ==1
+assertos.path.basename(source_files['.gypi'][0]) =='config.gypi'
 source_files['config.gypi'] =source_files.pop('.gypi')[0]
 JS2C(source_files, options.target)