Build ARM64 iPhone IPA for signing with Sideloadly

.github/workflows/ios.yml

@@ -64,3 +64,21 @@ jobs:
           name: MusicBridge-simulator
           path: build/MusicBridge-simulator.zip
           retention-days: 7
+      - name: Build iPhone IPA for local signing
+        shell: bash
+        run: bash tools/package_ipa.sh
+      - name: Save iPhone IPA
+        uses: actions/upload-artifact@v4
+        with:
+          name: MusicBridge-iPhone
+          path: build/MusicBridge-iPhone.ipa
+          if-no-files-found: error
+          retention-days: 7
+      - name: Save device build log
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: ios-device-build-log
+          path: build/device-build.log
+          if-no-files-found: ignore
+          retention-days: 7

tools/package_ipa.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+set -euo pipefail
+cd "$(dirname "$0")/.."
+mkdir -p build
+xcodebuild archive \
+  -project MusicBridge.xcodeproj \
+  -scheme MusicBridge \
+  -configuration Release \
+  -destination 'generic/platform=iOS' \
+  -derivedDataPath build/DeviceDerivedData \
+  -archivePath build/MusicBridge-iPhone.xcarchive \
+  ARCHS=arm64 \
+  CODE_SIGNING_ALLOWED=NO \
+  CODE_SIGNING_REQUIRED=NO \
+  | tee build/device-build.log
+
+# A device archive packaged for re-signing by Sideloadly on the user's PC.
+# This is not an App Store export and contains no Apple credentials or provisioning profile.
+package_dir=$(mktemp -d "${TMPDIR:-/tmp}/musicbridge-ipa.XXXXXX")
+trap 'rm -rf -- "$package_dir"' EXIT
+mkdir -p "$package_dir/Payload"
+ditto build/MusicBridge-iPhone.xcarchive/Products/Applications/MusicBridge.app "$package_dir/Payload/MusicBridge.app"
+ditto -c -k --keepParent "$package_dir/Payload" build/MusicBridge-iPhone.ipa
+python3 tools/verify_ipa.py build/MusicBridge-iPhone.ipa

tools/verify_ipa.py

@@ -0,0 +1,33 @@
+"""Verify a thin ARM64 iPhone IPA, independently of the macOS build environment."""
+import pathlib
+import plistlib
+import struct
+import sys
+import zipfile
+
+path = pathlib.Path(sys.argv[1])
+with zipfile.ZipFile(path) as archive:
+    assert archive.testzip() is None, "Corrupt ZIP member"
+    prefix = "Payload/MusicBridge.app/"
+    info = plistlib.loads(archive.read(prefix + "Info.plist"))
+    assert info["CFBundleSupportedPlatforms"] == ["iPhoneOS"], "Not an iPhone device build"
+    assert info["CFBundleIdentifier"] == "ru.yukinoki.musicbridge", "Unexpected bundle ID"
+    assert info["MinimumOSVersion"] == "17.0", "Unexpected minimum iOS version"
+    executable = info["CFBundleExecutable"]
+    assert executable == "MusicBridge", "Unexpected executable"
+    binary = archive.read(prefix + executable)
+    magic, cpu = struct.unpack_from("<II", binary)
+    assert magic == 0xFEEDFACF and cpu == 0x0100000C, "Expected ARM64 Mach-O executable"
+    # ARM64 can also be a simulator build: check LC_BUILD_VERSION's platform field.
+    command_count = struct.unpack_from("<I", binary, 16)[0]
+    offset = 32
+    platforms = []
+    for _ in range(command_count):
+        command, size = struct.unpack_from("<II", binary, offset)
+        assert size >= 8 and offset + size <= len(binary), "Invalid Mach-O load command"
+        if command == 0x32:
+            platforms.append(struct.unpack_from("<I", binary, offset + 8)[0])
+        offset += size
+    assert platforms == [2], "Mach-O is not built for iOS devices"
+print(f"PASS: {path.name}: valid IPA, iPhoneOS ARM64, iOS 17+, ru.yukinoki.musicbridge.")
+print("Requires local signing with Sideloadly before installation on an iPhone.")