[Incremental] Add a utility for generating simple output file maps

Author: CodaFi

test/Incremental/gen-output-file-map.py

@@ -0,0 +1,64 @@
+#!/usr/bin/env python
+
+from __future__ import print_function
+
+import argparse
+import json
+import os
+import sys
+
+
+def fatal(msg):
+    print(msg, file=sys.stderr)
+    sys.exit(1)
+
+
+def find_swift_files(path):
+    for parent, dirs, files in os.walk(path, topdown=True):
+        for filename in files:
+            if not filename.endswith('.swift'):
+                continue
+            yield filename
+
+
+def main(arguments):
+    parser = argparse.ArgumentParser(
+        description='Generate an output file map for the given directory')
+    parser.add_argument('-o', dest='output_dir',
+                        help='Directory to which the file map will be emitted')
+    parser.add_argument('input_dir', help='a directory of swift files')
+    args = parser.parse_args(arguments)
+
+    if not args.output_dir:
+        fatal("output directory is required")
+
+    # Create the output directory if it doesn't already exist.
+    if not os.path.isdir(args.output_dir):
+        os.makedirs(args.output_dir)
+
+    output_path = os.path.join(args.output_dir, 'output.json')
+
+    if not os.path.isdir(args.input_dir):
+        fatal("input directory does not exist, or is not a directory")
+
+    swift_files = find_swift_files(args.input_dir)
+    if not swift_files:
+        fatal("no swift files in the given input directory")
+
+    all_records = {}
+    for swift_file in swift_files:
+        file_name = os.path.splitext(swift_file)[0]
+        all_records['./' + swift_file] = {
+            'object': './' + file_name + '.o',
+            'swift-dependencies': './' + file_name + '.swiftdeps',
+        }
+    all_records[""] = {
+        'swift-dependencies': './main-buildrecord.swiftdeps'
+    }
+
+    with open(output_path, 'w') as f:
+        json.dump(all_records, f)
+
+
+if __name__ == '__main__':
+    sys.exit(main(sys.argv[1:]))