Fix creating __generated_config on Windows

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290853 91177308-0d34-0410-b5e6-96231b3b80d8

utils/cat_files.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+#===----------------------------------------------------------------------===##
+#
+#                     The LLVM Compiler Infrastructure
+#
+# This file is dual licensed under the MIT and the University of Illinois Open
+# Source Licenses. See LICENSE.TXT for details.
+#
+#===----------------------------------------------------------------------===##
+
+from argparse import ArgumentParser
+import sys
+
+def print_and_exit(msg):
+    sys.stderr.write(msg + '\n')
+    sys.exit(1)
+
+def main():
+    parser = ArgumentParser(
+        description="Concatenate two files into a single file")
+    parser.add_argument(
+        '-o', '--output', dest='output', required=True,
+        help='The output file. stdout is used if not given',
+        type=str, action='store')
+    parser.add_argument(
+        'files', metavar='files',  nargs='+',
+        help='The files to concatenate')
+
+    args = parser.parse_args()
+
+    if len(args.files) < 2:
+        print_and_exit('fewer than 2 inputs provided')
+    data = ''
+    for filename in args.files:
+        with open(filename, 'r') as f:
+            data += f.read()
+        if len(data) != 0 and data[-1] != '\n':
+            data += '\n'
+    assert len(data) > 0 and "cannot cat empty files"
+    with open(args.output, 'w') as f:
+        f.write(data)
+
+
+if __name__ == '__main__':
+    main()
+    sys.exit(0)