From e08d022e2febdd691354028c6811986c62b75b43 Mon Sep 17 00:00:00 2001
From: Wojtek Mach <wojtek@wojtekmach.pl>
Date: Fri, 19 Aug 2022 13:43:37 +0200
Subject: [PATCH] Cross-compile MacOS launcher on x86_64 and aarch64

---
 app_bundler/lib/app_bundler/macos.ex | 40 +++++++++++++++++++---------
 1 file changed, 27 insertions(+), 13 deletions(-)

diff --git a/app_bundler/lib/app_bundler/macos.ex b/app_bundler/lib/app_bundler/macos.ex
index 7d006b957..f7dcad6cc 100644
--- a/app_bundler/lib/app_bundler/macos.ex
+++ b/app_bundler/lib/app_bundler/macos.ex
@@ -18,21 +18,45 @@ defmodule AppBundler.MacOS do
 
     launcher_eex_path = Path.expand("#{@templates_path}/macos/Launcher.swift.eex")
     launcher_src_path = "#{tmp_dir}/Launcher.swift"
+    launcher_x86_64_path = "#{tmp_dir}/#{app_name}Launcher-x86_64"
+    launcher_aarch64_path = "#{tmp_dir}/#{app_name}Launcher-aarch64"
     launcher_bin_path = "#{contents_path}/MacOS/#{app_name}Launcher"
     copy_template(launcher_eex_path, launcher_src_path, release: release, app_options: options)
 
     File.mkdir!("#{contents_path}/MacOS")
-    log(:green, :creating, Path.relative_to_cwd(launcher_bin_path))
+
+    log(:green, :creating, launcher_x86_64_path)
 
     cmd!("swiftc", [
       "-warnings-as-errors",
       "-target",
-      swiftc_target(),
+      "x86_64-apple-macosx10.15",
       "-o",
-      launcher_bin_path,
+      launcher_x86_64_path,
       launcher_src_path
     ])
 
+    log(:green, :creating, launcher_aarch64_path)
+
+    cmd!("swiftc", [
+      "-warnings-as-errors",
+      "-target",
+      "arm64-apple-macosx12",
+      "-o",
+      launcher_aarch64_path,
+      launcher_src_path
+    ])
+
+    log(:green, :creating, Path.relative_to_cwd(launcher_bin_path))
+
+    cmd!("lipo", [
+      launcher_x86_64_path,
+      launcher_aarch64_path,
+      "-create",
+      "-output",
+      launcher_bin_path
+    ])
+
     icon_path =
       Keyword.get(options, :icon_path, Application.app_dir(:wx, "examples/demo/erlang.png"))
 
@@ -167,14 +191,4 @@ defmodule AppBundler.MacOS do
       File.rm_rf!(dest_tmp_path)
     end
   end
-
-  defp swiftc_target do
-    case :erlang.system_info(:system_architecture) do
-      'x86_64' ++ _ ->
-        "x86_64-apple-macosx10.15"
-
-      'aarch64' ++ _ ->
-        "arm64-apple-macosx12"
-    end
-  end
 end