Generate privacy manifest when creating Apple Framework

Bug: webrtc:42226059
Change-Id: I4427346b2340c6fafcaf9934ee462582dfa83fc5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/349440
Commit-Queue: Daniel.L (Byoungchan) Lee <daniel.l@hpcnt.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42198}
diff --git a/tools_webrtc/apple/generate_privacy_manifest.py b/tools_webrtc/apple/generate_privacy_manifest.py
new file mode 100644
index 0000000..8d4dad9
--- /dev/null
+++ b/tools_webrtc/apple/generate_privacy_manifest.py
@@ -0,0 +1,81 @@
+#!/usr/bin/env vpython3
+
+# Copyright (c) 2024 The WebRTC Project Authors. All rights reserved.
+#
+# Use of this source code is governed by a BSD-style license
+# that can be found in the LICENSE file in the root of the source
+# tree. An additional intellectual property rights grant can be found
+# in the file PATENTS.  All contributing project authors may
+# be found in the AUTHORS file in the root of the source tree.
+
+__doc__ = """Generate privacy manifest of WebRTC iOS framework."""
+
+import argparse
+import plistlib
+import sys
+
+
+def generate_privacy_manifest(out_file):
+    privacy_manifest = {
+        "NSPrivacyTracking":
+        False,
+        "NSPrivacyCollectedDataTypes": [],
+        "NSPrivacyTrackingDomains": [],
+        "NSPrivacyAccessedAPITypes": [
+            # For mach_absolute_time usage in rtc_base/system_time.cc
+            {
+                "NSPrivacyAccessedAPIType":
+                "NSPrivacyAccessedAPICategorySystemBootTime",
+                "NSPrivacyAccessedAPITypeReasons": [
+                    # Declare this reason to access the system boot time
+                    # in order to measure the amount of time that has elapsed
+                    # between events that occurred within the app or to perform
+                    # calculations to enable timers.
+                    "35F9.1",
+                    # Declare this reason to access the system boot time to
+                    # calculate absolute timestamps for events that occurred
+                    # within your app, such as events related to the UIKit or
+                    # AVFAudio frameworks.
+                    "8FFB.1",
+                ]
+            },
+            # For stat usage in rtc_base/file_rotating_stream.cc
+            # TODO: bugs.webrtc.org/337909152 - Make this optional since this
+            # is only used for RTCFileLogger, which is not used by default and
+            # not considered as a core feature.
+            {
+                "NSPrivacyAccessedAPIType":
+                "NSPrivacyAccessedAPICategoryFileTimestamp",
+                "NSPrivacyAccessedAPITypeReasons": [
+                    # Declare this reason to access the timestamps, size, or
+                    # other metadata of files inside the app container, app
+                    # group container, or the app’s CloudKit container.
+                    "C617.1"
+                ]
+            }
+        ]
+    }
+
+    with open(out_file, 'wb') as file:
+        plistlib.dump(privacy_manifest, file, fmt=plistlib.FMT_XML)
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("-o", "--output", type=str, help="Output file.")
+    # TODO: bugs.webrtc.org/337909152 - Add an option to not to emit privacy
+    # manifest entries for NSPrivacyAccessedAPICategoryFileTimestamp
+
+    args = parser.parse_args()
+
+    if not args.output:
+        print("Output file is required")
+        return 1
+
+    generate_privacy_manifest(args.output)
+
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())
diff --git a/webrtc.gni b/webrtc.gni
index af341d7..9afe281 100644
--- a/webrtc.gni
+++ b/webrtc.gni
@@ -1037,6 +1037,7 @@
     umbrella_header_path =
         "$target_gen_dir/$output_name.framework/WebRTC/$output_name.h"
     modulemap_path = "$target_gen_dir/Modules/module.modulemap"
+    privacy_manifest_path = "$target_gen_dir/$target_name/PrivacyInfo.xcprivacy"
 
     action_foreach("create_bracket_include_headers_$target_name") {
       script = "//tools_webrtc/apple/copy_framework_header.py"
@@ -1077,6 +1078,7 @@
         deps += [
           ":copy_framework_headers_$this_target_name",
           ":copy_modulemap_$this_target_name",
+          ":copy_privacy_manifest_$this_target_name",
           ":copy_umbrella_header_$this_target_name",
           ":create_bracket_include_headers_$this_target_name",
           ":modulemap_$this_target_name",
@@ -1099,6 +1101,7 @@
                 ":create_bracket_include_headers_$this_target_name")
 
         deps += [
+          ":copy_privacy_manifest_$this_target_name",
           ":copy_umbrella_header_$this_target_name",
           ":create_bracket_include_headers_$this_target_name",
         ]
@@ -1108,8 +1111,13 @@
     if (is_mac || target_environment == "catalyst") {
       # Catalyst frameworks use the same layout as regular Mac frameworks.
       headers_dir = "Versions/A/Headers"
+
+      # The path to the privacy manifest file differs between Mac and iOS.
+      # https://developer.apple.com/documentation/bundleresources/privacy_manifest_files/adding_a_privacy_manifest_to_your_app_or_third-party_sdk
+      privacy_manifest_out_path = "Versions/A/Resources/PrivacyInfo.xcprivacy"
     } else {
       headers_dir = "Headers"
+      privacy_manifest_out_path = "PrivacyInfo.xcprivacy"
     }
 
     bundle_data("copy_framework_headers_$this_target_name") {
@@ -1159,6 +1167,25 @@
 
       deps = [ ":umbrella_header_$target_name" ]
     }
+
+    action("create_privacy_manifest_$target_name") {
+      script = "//tools_webrtc/apple/generate_privacy_manifest.py"
+
+      args = [
+        "--output",
+        rebase_path(privacy_manifest_path),
+      ]
+
+      outputs = [ privacy_manifest_path ]
+    }
+
+    copy("copy_privacy_manifest_$target_name") {
+      sources = [ privacy_manifest_path ]
+      outputs =
+          [ "$root_out_dir/$output_name.framework/$privacy_manifest_out_path" ]
+
+      deps = [ ":create_privacy_manifest_$target_name" ]
+    }
   }
 }