Fix symbol exports for SparklePlugin native library

The C functions need to be exported with visibility("default") and
explicit linker flags for Unity P/Invoke to find them. Without this,
the bundle binary had no exported symbols.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

MODULE.bazel

@@ -130,6 +130,13 @@ bazel_dep(name = "apple_support", version = "1.21.1", repo_name = "build_bazel_a
 bazel_dep(name = "rules_apple", version = "4.3.3", repo_name = "build_bazel_rules_apple")
 bazel_dep(name = "rules_swift", version = "2.4.0", repo_name = "build_bazel_rules_swift")
 
+# Register Apple CC toolchain for Objective-C compilation
+apple_cc_configure = use_extension(
+    "@build_bazel_apple_support//crosstool:setup.bzl",
+    "apple_cc_configure_extension",
+)
+use_repo(apple_cc_configure, "local_config_apple_cc")
+
 #
 # Protocol Buffers & RPC
 #
@@ -293,6 +300,17 @@ http_archive(
     ],
 )
 
+# Sparkle framework for macOS auto-updates
+SPARKLE_VERSION = "2.6.4"
+
+http_archive(
+    name = "sparkle",
+    build_file = "@//external:BUILD.sparkle",
+    sha256 = "50612a06038abc931f16011d7903b8326a362c1074dabccb718404ce8e585f0b",
+    strip_prefix = "",
+    url = "https://github.com/sparkle-project/Sparkle/releases/download/%s/Sparkle-%s.tar.xz" % (SPARKLE_VERSION, SPARKLE_VERSION),
+)
+
 # Busybox static binary for Docker health checks (provides nc, wget, etc.)
 # Primary: DigitalOcean Spaces (public, reliable)
 # Fallback: busybox.net (can be unreliable/slow)

MODULE.bazel.lock

@@ -396,7 +396,7 @@
     "@@apple_support~//crosstool:setup.bzl%apple_cc_configure_extension": {
       "general": {
         "bzlTransitiveDigest": "Z3yAd66IJL0GAZUTSeMOjoHiE1SZPPwiIs/XQui5BvE=",
-        "usagesDigest": "tl3VVeQX3Hzh7FhM2gjnkCwEJpRMlY5S6a850WY/xvc=",
+        "usagesDigest": "DqQsfZN5lA8z+nLEEY+EpKGzQ8M73mDm/A8lofDSyus=",
         "recordedFileInputs": {},
         "recordedDirentsInputs": {},
         "envVariables": {},

external/BUILD.sparkle

@@ -0,0 +1,8 @@
+load("@build_bazel_rules_apple//apple:apple.bzl", "apple_dynamic_framework_import")
+
+# Import pre-built Sparkle framework
+apple_dynamic_framework_import(
+    name = "Sparkle",
+    framework_imports = glob(["Sparkle.framework/**"]),
+    visibility = ["//visibility:public"],
+)

scripts/build_mac_plugin.sh

@@ -8,3 +8,6 @@ ZIP_LOCATION=$(bazel cquery --config=mactools --output=files @net_eagle0_unity_g
 /usr/bin/unzip -o $ZIP_LOCATION -d src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/
 
 /usr/bin/plutil -convert xml1 src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/DarwinGodiceBundle.bundle/Contents/Info.plist
+
+/bin/echo "building sparkle plugin"
+./scripts/build_sparkle_plugin.sh

scripts/build_sparkle_plugin.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+#
+# Build the SparklePlugin native library for Unity using Bazel
+#
+# Usage: build_sparkle_plugin.sh [output_dir]
+
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
+
+OUTPUT_DIR="${1:-$PROJECT_ROOT/src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/macOS}"
+
+echo "=== Building SparklePlugin with Bazel ==="
+
+bazel build --config=mactools //src/main/objc/net/eagle0/sparkle:SparklePlugin
+
+# Get the zip path from bazel
+ZIP_PATH=$(bazel cquery --config=mactools --output=files //src/main/objc/net/eagle0/sparkle:SparklePlugin 2>/dev/null)
+
+echo "=== Extracting SparklePlugin.bundle ==="
+mkdir -p "$OUTPUT_DIR"
+rm -rf "$OUTPUT_DIR/SparklePlugin.bundle"
+unzip -o "$ZIP_PATH" -d "$OUTPUT_DIR/"
+
+echo "=== SparklePlugin built successfully ==="
+ls -la "$OUTPUT_DIR/SparklePlugin.bundle/"

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Eagle/SparkleInitializer.cs

@@ -0,0 +1,13 @@
+using UnityEngine;
+
+/// <summary>
+/// Initializes Sparkle auto-updater at app startup.
+/// Uses RuntimeInitializeOnLoadMethod to ensure early initialization.
+/// </summary>
+public static class SparkleInitializer {
+    [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterSceneLoad)]
+    private static void Initialize() {
+        Debug.Log("SparkleInitializer: Initializing Sparkle at startup");
+        SparkleUpdater.Initialize();
+    }
+}

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Eagle/SparkleInitializer.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 2b4c6d8e0f1a3b5c7d9e1f3a5b7c9d1e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: -100
+  icon: {instanceID: 0}
+  userData:
+  assetBundleName:
+  assetBundleVariant:

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Eagle/SparkleUpdater.cs

@@ -0,0 +1,120 @@
+using System.Runtime.InteropServices;
+using UnityEngine;
+
+/// <summary>
+/// C# wrapper for the native SparklePlugin on macOS.
+/// Provides auto-update functionality via the Sparkle framework.
+/// On non-macOS platforms, all methods are no-ops.
+/// </summary>
+public static class SparkleUpdater {
+#if UNITY_STANDALONE_OSX && !UNITY_EDITOR
+    private const string PluginName = "SparklePlugin";
+
+    [DllImport(PluginName)]
+    private static extern void SparklePlugin_Initialize();
+
+    [DllImport(PluginName)]
+    private static extern void SparklePlugin_CheckForUpdates();
+
+    [DllImport(PluginName)]
+    private static extern void SparklePlugin_CheckForUpdatesInBackground();
+
+    [DllImport(PluginName)]
+    private static extern int SparklePlugin_IsCheckingForUpdates();
+
+    [DllImport(PluginName)]
+    private static extern int SparklePlugin_GetAutomaticallyChecksForUpdates();
+
+    [DllImport(PluginName)]
+    private static extern void SparklePlugin_SetAutomaticallyChecksForUpdates(int enabled);
+
+    private static bool _initialized = false;
+
+    /// <summary>
+    /// Initialize the Sparkle updater. Should be called once at app startup.
+    /// This starts automatic background update checks based on Info.plist settings.
+    /// </summary>
+    public static void Initialize() {
+        if (_initialized) {
+            Debug.Log("SparkleUpdater: Already initialized");
+            return;
+        }
+
+        Debug.Log("SparkleUpdater: Initializing Sparkle");
+        try {
+            SparklePlugin_Initialize();
+            _initialized = true;
+            Debug.Log("SparkleUpdater: Initialization complete");
+        } catch (System.Exception e) {
+            Debug.LogError($"SparkleUpdater: Failed to initialize: {e.Message}");
+        }
+    }
+
+    /// <summary>
+    /// Manually check for updates. Shows the update UI to the user.
+    /// </summary>
+    public static void CheckForUpdates() {
+        if (!_initialized) {
+            Debug.LogWarning("SparkleUpdater: Not initialized");
+            return;
+        }
+        SparklePlugin_CheckForUpdates();
+    }
+
+    /// <summary>
+    /// Check for updates silently in the background.
+    /// Only shows UI if an update is found.
+    /// </summary>
+    public static void CheckForUpdatesInBackground() {
+        if (!_initialized) {
+            Debug.LogWarning("SparkleUpdater: Not initialized");
+            return;
+        }
+        SparklePlugin_CheckForUpdatesInBackground();
+    }
+
+    /// <summary>
+    /// Returns true if an update check is currently in progress.
+    /// </summary>
+    public static bool IsCheckingForUpdates {
+        get {
+            if (!_initialized) return false;
+            return SparklePlugin_IsCheckingForUpdates() != 0;
+        }
+    }
+
+    /// <summary>
+    /// Gets or sets whether automatic update checks are enabled.
+    /// </summary>
+    public static bool AutomaticallyChecksForUpdates {
+        get {
+            if (!_initialized) return false;
+            return SparklePlugin_GetAutomaticallyChecksForUpdates() != 0;
+        }
+        set {
+            if (!_initialized) return;
+            SparklePlugin_SetAutomaticallyChecksForUpdates(value? 1: 0);
+        }
+    }
+
+#else
+    // Stub implementations for non-macOS platforms and Editor
+
+    public static void Initialize() { Debug.Log("SparkleUpdater: Not available on this platform"); }
+
+    public static void CheckForUpdates() {
+        Debug.Log("SparkleUpdater: Not available on this platform");
+    }
+
+    public static void CheckForUpdatesInBackground() {
+        Debug.Log("SparkleUpdater: Not available on this platform");
+    }
+
+    public static bool IsCheckingForUpdates => false;
+
+    public static bool AutomaticallyChecksForUpdates {
+        get => false;
+        set {}
+    }
+#endif
+}

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Eagle/SparkleUpdater.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 8a3b5c7d9e1f2a3b4c5d6e7f8a9b0c1d
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData:
+  assetBundleName:
+  assetBundleVariant:

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/.gitignore

@@ -1,3 +1,6 @@
 System.Runtime.CompilerServices.Unsafe/**
 !**/*.psd
 **/*.dll
+# Native plugins built at CI time
+DarwinGodiceBundle.bundle/
+macOS/SparklePlugin.bundle/

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/macOS.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 3c5d7e9f1a2b4c6d8e0f2a4b6c8d0e2f
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData:
+  assetBundleName:
+  assetBundleVariant:

src/main/csharp/net/eagle0/clients/unity/eagle0/Assets/Plugins/macOS/SparklePlugin.bundle.meta

@@ -0,0 +1,45 @@
+fileFormatVersion: 2
+guid: 4d6e8f0a2b3c5d7e9f1a3b5c7d9e1f3a
+PluginImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  iconMap: {}
+  executionOrder: {}
+  defineConstraints: []
+  isPreloaded: 0
+  isOverridable: 0
+  isExplicitlyReferenced: 0
+  validateReferences: 1
+  platformData:
+  - first:
+      : Any
+    second:
+      enabled: 0
+      settings:
+        Exclude Editor: 1
+        Exclude Linux64: 1
+        Exclude OSXUniversal: 0
+        Exclude Win: 1
+        Exclude Win64: 1
+  - first:
+      Any:
+    second:
+      enabled: 0
+      settings: {}
+  - first:
+      Editor: Editor
+    second:
+      enabled: 0
+      settings:
+        CPU: AnyCPU
+        DefaultValueInitialized: true
+        OS: AnyOS
+  - first:
+      Standalone: OSXUniversal
+    second:
+      enabled: 1
+      settings:
+        CPU: AnyCPU
+  userData:
+  assetBundleName:
+  assetBundleVariant:

src/main/objc/net/eagle0/sparkle/BUILD.bazel

@@ -0,0 +1,40 @@
+load("@build_bazel_rules_apple//apple:macos.bzl", "macos_bundle")
+
+# Native Sparkle plugin for Unity
+# This plugin initializes Sparkle auto-updater at runtime
+objc_library(
+    name = "sparkle_plugin_lib",
+    srcs = ["SparklePlugin.m"],
+    copts = [
+        "-fmodules",
+        "-fobjc-arc",
+        "-fvisibility=default",  # Export symbols for Unity P/Invoke
+    ],
+    sdk_frameworks = ["Foundation"],
+    deps = ["@sparkle//:Sparkle"],
+)
+
+macos_bundle(
+    name = "SparklePlugin",
+    bundle_id = "net.eagle0.SparklePlugin",
+    bundle_name = "SparklePlugin",
+    infoplists = ["Info.plist"],
+    linkopts = [
+        # Export symbols for Unity P/Invoke
+        "-exported_symbol",
+        "_SparklePlugin_Initialize",
+        "-exported_symbol",
+        "_SparklePlugin_CheckForUpdates",
+        "-exported_symbol",
+        "_SparklePlugin_CheckForUpdatesInBackground",
+        "-exported_symbol",
+        "_SparklePlugin_IsCheckingForUpdates",
+        "-exported_symbol",
+        "_SparklePlugin_GetAutomaticallyChecksForUpdates",
+        "-exported_symbol",
+        "_SparklePlugin_SetAutomaticallyChecksForUpdates",
+    ],
+    minimum_os_version = "10.13",
+    visibility = ["//visibility:public"],
+    deps = [":sparkle_plugin_lib"],
+)

src/main/objc/net/eagle0/sparkle/Info.plist

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+    <key>CFBundleDevelopmentRegion</key>
+    <string>en</string>
+    <key>CFBundleExecutable</key>
+    <string>SparklePlugin</string>
+    <key>CFBundleIdentifier</key>
+    <string>net.eagle0.SparklePlugin</string>
+    <key>CFBundleInfoDictionaryVersion</key>
+    <string>6.0</string>
+    <key>CFBundleName</key>
+    <string>SparklePlugin</string>
+    <key>CFBundlePackageType</key>
+    <string>BNDL</string>
+    <key>CFBundleShortVersionString</key>
+    <string>1.0</string>
+    <key>CFBundleVersion</key>
+    <string>1</string>
+</dict>
+</plist>

src/main/objc/net/eagle0/sparkle/SparklePlugin.m

@@ -0,0 +1,86 @@
+//
+// SparklePlugin.m
+// Native macOS plugin for Unity to initialize Sparkle auto-updates
+//
+// Copyright 2026 Dan Crosby
+//
+
+#import <Foundation/Foundation.h>
+#import <Sparkle/Sparkle.h>
+
+// The updater controller - retained for the lifetime of the app
+static SPUStandardUpdaterController *updaterController = nil;
+
+// Export macro for Unity P/Invoke
+#define EXPORT __attribute__((visibility("default")))
+
+// Called from Unity to initialize Sparkle
+// This should be called once at app startup
+EXPORT void SparklePlugin_Initialize(void) {
+    if (updaterController != nil) {
+        NSLog(@"SparklePlugin: Already initialized");
+        return;
+    }
+
+    NSLog(@"SparklePlugin: Initializing Sparkle auto-updater");
+
+    // Create the updater controller with automatic update checking enabled
+    // The feed URL and public key are read from Info.plist (SUFeedURL, SUPublicEDKey)
+    updaterController = [[SPUStandardUpdaterController alloc]
+        initWithStartingUpdater:YES
+        updaterDelegate:nil
+        userDriverDelegate:nil];
+
+    if (updaterController != nil) {
+        NSLog(@"SparklePlugin: Sparkle initialized successfully");
+    } else {
+        NSLog(@"SparklePlugin: Failed to initialize Sparkle");
+    }
+}
+
+// Manually trigger an update check (shows UI)
+EXPORT void SparklePlugin_CheckForUpdates(void) {
+    if (updaterController == nil) {
+        NSLog(@"SparklePlugin: Not initialized, call Initialize first");
+        return;
+    }
+
+    NSLog(@"SparklePlugin: Checking for updates");
+    [updaterController checkForUpdates:nil];
+}
+
+// Check for updates silently in background (no UI unless update found)
+EXPORT void SparklePlugin_CheckForUpdatesInBackground(void) {
+    if (updaterController == nil) {
+        NSLog(@"SparklePlugin: Not initialized, call Initialize first");
+        return;
+    }
+
+    NSLog(@"SparklePlugin: Checking for updates in background");
+    [[updaterController updater] checkForUpdatesInBackground];
+}
+
+// Returns 1 if an update check is in progress, 0 otherwise
+EXPORT int SparklePlugin_IsCheckingForUpdates(void) {
+    if (updaterController == nil) {
+        return 0;
+    }
+    return [[updaterController updater] sessionInProgress] ? 1 : 0;
+}
+
+// Returns 1 if automatic update checks are enabled, 0 otherwise
+EXPORT int SparklePlugin_GetAutomaticallyChecksForUpdates(void) {
+    if (updaterController == nil) {
+        return 0;
+    }
+    return [[updaterController updater] automaticallyChecksForUpdates] ? 1 : 0;
+}
+
+// Enable or disable automatic update checks
+EXPORT void SparklePlugin_SetAutomaticallyChecksForUpdates(int enabled) {
+    if (updaterController == nil) {
+        NSLog(@"SparklePlugin: Not initialized");
+        return;
+    }
+    [[updaterController updater] setAutomaticallyChecksForUpdates:(enabled != 0)];
+}