webkitpy: Small changes to merging script

third_party/WebKit/Tools/Scripts/merge-layout-test-results

 #!/usr/bin/python
 #
 # Copyright 2017 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import argparse
+import json
 import logging
 import os
+import shutil
 import sys
 import tempfile
 
 from webkitpy.common.system.log_utils import configure_logging
 from webkitpy.layout_tests import merge_results
 
 # ------------------------------------------------------------------------
 
 
 def main(argv):
@@ skipping 22 matching lines @@
     parser.add_argument(
         '--results-json-allow-unknown-if-matching',
         action='store_true', default=False,
         help='Allow unknown values in the result.json file as long as the '
              'value match on all shards.')
 
     parser.add_argument(
         '--output-directory',
         help='Directory to create the merged results in.')
     parser.add_argument(
+        '--allow-existing-output-directory',
+        action='store_true', default=False,
+        help='Allow merging results into a directory which already exists.')
+    parser.add_argument(
+        '--remove-existing-output-directory',
+        action='store_true', default=False,
+        help='Remove merging results into a directory which already exists.')
+    parser.add_argument(
         '--input-directories', nargs='+',
         help='Directories to merge the results from.')
 
     # Swarming Isolated Merge Script API
     # script.py --build-properties /s/build.json --output-json /tmp/output.json  shard0/output.json shard1/output.json
     parser.add_argument(
         '-o', '--output-json',
         help='(Swarming Isolated Merge Script API) Output JSON file to create.')
     parser.add_argument(
         '--build-properties',
         help='(Swarming Isolated Merge Script API) Build property JSON file provided by recipes.')
+    parser.add_argument(
+        '--results-json-override-with-build-property',
+        nargs=2, metavar=('RESULT_JSON_KEY', 'BUILD_PROPERTY_KEY'), default=[],
+        action='append',
+        help='Override the value of a value in the result style JSON file '
+             '(--result-jsons-override-value layout_test_dirs /tmp/output).')
 
     # Script to run after merging the directories together. Normally used with archive_layout_test_results.py
     # scripts/slave/chromium/archive_layout_test_results.py \
     #     --results-dir /b/rr/tmpIcChUS/w/layout-test-results \
     #     --build-dir /b/rr/tmpIcChUS/w/src/out \
     #     --build-number 3665 \
     #     --builder-name 'WebKit Linux - RandomOrder' \
     #     --gs-bucket gs://chromium-layout-test-archives \
     #     --staging-dir /b/c/chrome_staging \
     #     --slave-utils-gsutil-py-path /b/rr/tmpIcChUS/rw/scripts/slave/.recipe_deps/depot_tools/gsutil.py
     # in dir /b/rr/tmpIcChUS/w
     parser.add_argument(
         '--post-merge-script',
         nargs='*',
         help='Script to call after the results have been merged.')
 
     # The position arguments depend on if we are using the isolated merge
     # script API mode or not.
     parser.add_argument(
         'positional', nargs='*',
         help='output.json from shards.')
 
     args = parser.parse_args(argv)
     if args.verbose:
         logging_level = logging.DEBUG
     else:
         logging_level = logging.INFO
     configure_logging(logging_level=logging_level)
 
+    results_json_value_overrides = {}
+
     # Map the isolate arguments back to our output / input arguments.
     if args.output_json:
+        logging.info('Running with isolated arguments')
         assert args.positional
 
+        if args.results_json_override_with_build_property:
+            if not args.build_properties:
+                parser.error(
+                    '--results-json-override-with-build-property given'
+                    ' but --build-properties was not.')
+            build_properties = json.loads(args.build_properties)
+            for result_key, build_prop_key in args.results_json_override_with_build_property:
+                results_json_value_overrides[result_key] = build_properties[build_prop_key]
+
         assert not args.output_directory
-        args.output_directory = os.path.dirname(args.output_json)
+        args.output_directory = os.getcwd()
+        args.remove_existing_output_directory = True
 
         assert not args.input_directories
         args.input_directories = [os.path.dirname(f) for f in args.positional]
         args.positional = []
 
     # Allow skipping the --input-directories bit, for example,
     #   merge-layout-test-results -o outputdir shard0 shard1 shard2
     if args.positional and not args.input_directories:
         args.input_directories = args.positional
 
     if not args.output_directory:
         args.output_directory = tempfile.mkdtemp(suffix='webkit_layout_test_results.')
 
     assert args.output_directory
     assert args.input_directories
 
-    results_json_value_overrides = {}
     for k, v in args.results_json_override_value:
         assert k not in results_json_value_overrides
         try:
             results_json_value_overrides[k] = eval(v)
         except NameError:
             results_json_value_overrides[k] = v
+    logging.debug('results_json_value_overrides: %r', results_json_value_overrides)
 
     merger = merge_results.LayoutTestDirMerger(
         results_json_value_overrides=results_json_value_overrides,
         results_json_allow_unknown_if_matching=args.results_json_allow_unknown_if_matching)
+    if os.path.exists(args.output_directory):
+        logging.warning('Output directory exists %r', args.output_directory)
+        if args.remove_existing_output_directory:
+            shutil.rmtree(args.output_directory)
+        elif not args.allow_existing_output_directory:
+            raise IOError(
+                ('Output directory %s exists!\n'
+                 'Use --allow-existing-output-directory to continue') % args.output_directory)
+
     merger.merge(args.output_directory, args.input_directories)
 
+    merged_output_json = os.path.join(args.output_directory, 'output.json')
+    if os.path.exists(merged_output_json) and args.output_json:
+        logging.debug(
+            'Copying output.json from %s to %s', merged_output_json, args.output_json)
+        shutil.copyfile(merged_output_json, args.output_json)
+
     if args.post_merge_script:
+        logging.debug('Changing directory to %s', args.output_directory)
         os.chdir(args.output_directory)
 
         post_script = list(args.post_merge_script)
         post_script.append('--result-dir', args.output_directory)
 
+        logging.info('Running post merge script %r', post_script)
         os.execlp(post_script)
 
 main(sys.argv[1:])