From 7da0c5421ce2374ca5cf48d259186b792d3128ea Mon Sep 17 00:00:00 2001
From: godofredoc <godofredoc@google.com>
Date: Fri, 4 Feb 2022 09:30:02 -0800
Subject: [PATCH] Archives for dart-sdk and flutter_patched_sdk.
 (flutter/engine#30888)

---
 engine/src/flutter/BUILD.gn                | 10 +------
 engine/src/flutter/build/archives/BUILD.gn | 26 +++++++++++++++---
 engine/src/flutter/common/config.gni       | 31 ++++++++++++++++++++--
 3 files changed, 53 insertions(+), 14 deletions(-)

diff --git a/engine/src/flutter/BUILD.gn b/engine/src/flutter/BUILD.gn
index 108ef8328af..65a46f1d50a 100644
--- a/engine/src/flutter/BUILD.gn
+++ b/engine/src/flutter/BUILD.gn
@@ -33,14 +33,6 @@ config("export_dynamic_symbols") {
 
 if (flutter_prebuilt_dart_sdk) {
   copy_trees("_copy_trees") {
-    # There is no prebuilt Dart SDK targeting Fuchsia, but we also don't need
-    # one, so even when the build is targeting Fuchsia, use the prebuilt
-    # Dart SDK for the host.
-    if (current_toolchain == host_toolchain || is_fuchsia) {
-      prebuilt_dart_sdk = host_prebuilt_dart_sdk
-    } else {
-      prebuilt_dart_sdk = target_prebuilt_dart_sdk
-    }
     sources = [
       {
         target = "copy_dart_sdk"
@@ -62,7 +54,7 @@ _build_engine_artifacts =
     (is_linux && !is_chromeos && current_cpu != "arm") || is_mac
 
 group("dart_sdk") {
-  if (_build_engine_artifacts) {
+  if (build_engine_artifacts) {
     if (flutter_prebuilt_dart_sdk) {
       public_deps = [ ":copy_dart_sdk" ]
     } else {
diff --git a/engine/src/flutter/build/archives/BUILD.gn b/engine/src/flutter/build/archives/BUILD.gn
index b7ffa219cdb..b5fda380180 100644
--- a/engine/src/flutter/build/archives/BUILD.gn
+++ b/engine/src/flutter/build/archives/BUILD.gn
@@ -48,17 +48,37 @@ if (host_os == "linux") {
   }
 }
 
+# Generates flutter_patched_sdk.zip for debug and profile runtime modes
+# and saves it in the zips_archive folder. For release runtime mode it
+# generates flutter_patched_sdk_product.zip and saves it to
+# zips_archive/flutter_patched_sdk_product/ folder.
 zip_bundle("flutter_patched_sdk") {
-  output = "flutter_patched_sdk.zip"
+  file_suffix = ""
+  path_prefix = ""
+  if (flutter_runtime_mode == "release") {
+    file_suffix = "_product"
+    path_prefix = "flutter_patched_sdk_product/"
+  }
+  output = "flutter_patched_sdk${file_suffix}.zip"
   deps = [ "//flutter/lib/snapshot:strong_platform" ]
   files = [
     {
       source = "$root_out_dir/flutter_patched_sdk/vm_outline_strong.dill"
-      destination = "vm_outline_strong.dill"
+      destination = "${path_prefix}vm_outline_strong.dill"
     },
     {
       source = "$root_out_dir/flutter_patched_sdk/platform_strong.dill"
-      destination = "platform_strong.dill"
+      destination = "${path_prefix}platform_strong.dill"
     },
   ]
 }
+
+# Flutter consumes the dart sdk as a prebuilt. Rather than regenerating
+# the zip file we are just copying the original file to the artifacts location.
+if (build_engine_artifacts && flutter_prebuilt_dart_sdk) {
+  copy("dart_sdk_archive") {
+    sources = [ prebuilt_dart_sdk_archive ]
+    outputs =
+        [ "$root_out_dir/zip_archives/dart-sdk-$prebuilt_dart_sdk_config" ]
+  }
+}
diff --git a/engine/src/flutter/common/config.gni b/engine/src/flutter/common/config.gni
index 57292c750d9..dd4c2a60da4 100644
--- a/engine/src/flutter/common/config.gni
+++ b/engine/src/flutter/common/config.gni
@@ -83,8 +83,35 @@ if (flutter_prebuilt_dart_sdk) {
     _host_os_name = "windows"
   }
 
+  _target_prebuilt_dart_sdk_config = "$_target_os_name-$target_cpu"
+  _host_prebuilt_dart_sdk_config = "$_host_os_name-$host_cpu"
+  _target_prebuilt_dart_sdk_archive = "//flutter/prebuilts/dartsdk-$_target_prebuilt_dart_sdk_config-release.zip"
+  _host_prebuilt_dart_sdk_archive =
+      "//flutter/prebuilts/dartsdk-$_host_prebuilt_dart_sdk_config-release.zip"
+
   target_prebuilt_dart_sdk =
-      "//flutter/prebuilts/$_target_os_name-$target_cpu/dart-sdk"
+      "//flutter/prebuilts/$_target_prebuilt_dart_sdk_config/dart-sdk"
   host_prebuilt_dart_sdk =
-      "//flutter/prebuilts/$_host_os_name-$host_cpu/dart-sdk"
+      "//flutter/prebuilts/$_host_prebuilt_dart_sdk_config/dart-sdk"
+
+  # There is no prebuilt Dart SDK targeting Fuchsia, but we also don't need
+  # one, so even when the build is targeting Fuchsia, use the prebuilt
+  # Dart SDK for the host.
+  if (current_toolchain == host_toolchain || is_fuchsia) {
+    prebuilt_dart_sdk = host_prebuilt_dart_sdk
+    prebuilt_dart_sdk_config = _host_prebuilt_dart_sdk_config
+    prebuilt_dart_sdk_archive = _host_prebuilt_dart_sdk_archive
+  } else {
+    prebuilt_dart_sdk = target_prebuilt_dart_sdk
+    prebuilt_dart_sdk_config = _target_prebuilt_dart_sdk_config
+    prebuilt_dart_sdk_archive = _target_prebuilt_dart_sdk_archive
+  }
 }
+
+# Flutter SDK artifacts should only be built when either doing host builds, or
+# for cross-compiled desktop targets.
+# TODO: We can't build the engine artifacts for arm (32-bit) right now;
+# see https://github.com/flutter/flutter/issues/74322
+build_engine_artifacts =
+    current_toolchain == host_toolchain ||
+    (is_linux && !is_chromeos && current_cpu != "arm") || is_mac