Ninja dependency analysis tool

The tool collects every input file for target except exempted_files.
And also, it counts input files per each project.

Bug: 238156000
Test: collect_ninja_inputs \
  -n prebuilts/build-tools/linux-x86/bin/ninja \
  -f out/combined-aosp_cf_x86_64_phone.ninja \
  -t vendorimage \
  -e exempted_files \
  -r .repo/project.list

Change-Id: I19b8b3462a1f1766babe4d437fe71bd7eb4bc7d2

tools/ninja_dependency_analysis/collect_ninja_inputs.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2022 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the 'License');
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an 'AS IS' BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import json
+import os
+import pathlib
+import subprocess
+import sys
+import xml.etree.ElementTree as ET
+from collections import OrderedDict
+from operator import itemgetter
+
+
+def build_cmd(ninja_binary, ninja_file, target, exempted_file_list):
+    cmd = [ninja_binary, '-f', ninja_file, '-t', 'inputs']
+    if exempted_file_list and exempted_file_list.exists():
+        with open(exempted_file_list) as fin:
+            for l in map(str.strip, fin.readlines()):
+                if l:
+                    cmd.extend(['-e', l])
+    cmd.append(target)
+
+    return cmd
+
+
+def count_project(projects, input_files):
+    project_count = dict()
+    for p in projects:
+        file_count = sum(f.startswith(p + os.path.sep) for f in input_files)
+        if file_count > 0:
+            project_count[p] = file_count
+
+    return dict(sorted(project_count.items(), key=itemgetter(1), reverse=True))
+
+
+parser = argparse.ArgumentParser()
+
+parser.add_argument('-n', '--ninja_binary', type=pathlib.Path, required=True)
+parser.add_argument('-f', '--ninja_file', type=pathlib.Path, required=True)
+parser.add_argument('-t', '--target', type=str, required=True)
+parser.add_argument('-e', '--exempted_file_list', type=pathlib.Path)
+group = parser.add_mutually_exclusive_group()
+group.add_argument('-r', '--repo_project_list', type=pathlib.Path)
+group.add_argument('-m', '--repo_manifest', type=pathlib.Path)
+args = parser.parse_args()
+
+input_files = sorted(
+    subprocess.check_output(
+        build_cmd(args.ninja_binary, args.ninja_file, args.target,
+                  args.exempted_file_list), text=True).strip().split('\n'))
+
+result = dict()
+result['input_files'] = input_files
+
+projects = None
+if args.repo_project_list and args.repo_project_list.exists():
+    with open(args.repo_project_list) as fin:
+        projects = list(map(str.strip, fin.readlines()))
+elif args.repo_manifest and args.repo_manifest.exists():
+    projects = [
+        p.attrib['path']
+        for p in ET.parse(args.repo_manifest).getroot().findall('project')
+    ]
+
+if projects:
+    project_to_count = count_project(projects, input_files)
+    result['project_count'] = project_to_count
+    result['total_project_count'] = len(project_to_count)
+
+result['total_input_count'] = len(input_files)
+print(json.dumps(result, indent=2))