Adding missing snapshot to the fuchsia package in AOT builds (flutter/engine#29268)

The initial implementation tried to leverage the fuchsia.git approach to
adding resources via GN template, but the GN SDK does not use the same
format or approach. This PR adds the snapshot resource in the way the
GN SDK expects.

engine/src/flutter/tools/fuchsia/dist/resource.gni

@@ -1,96 +0,0 @@
-# Copyright 2013 The Flutter Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# Declare data files to be accessible at runtime on the target device.
-#
-# A resource() target looks just like a copy() target but $outputs are
-# relative target paths.  Using $data_deps to this resource() target in
-# each target whose code uses $outputs at runtime ensures that the files
-# will be present on the system.
-#
-# If the file is not in the source tree, it should be generated by another
-# target in the build listed in $deps.  If that would be a generated_file()
-# target, then use generated_resource() instead of resource().
-#
-# Parameters
-#
-#   data_deps
-#     Optional: Additional dependencies for the runtime image.  These are
-#     included in the image if this target is, but are not related to the
-#     $sources list.
-#     Type: list(label)
-#
-#   deps
-#     Optional: Targets that produce $sources.  Any files listed in
-#     $sources that are produced by the build should be produced by a
-#     target listed here.  This is the only thing that guarantees those
-#     files will have been built by the time the image is being packed.
-#     Targets reached only via this $deps list will *not* contribute their
-#     own contents to the image directly.  For that, list them in $data_deps.
-#     Targets listed here are used only to produce the $sources files.
-#     Type: list(label)
-#
-#   outputs
-#     Required: List of one runtime path.  This must be a relative path (no
-#     leading `/`).  It can use placeholders based on $sources; see copy()
-#     and `gn help source_expansion`.  When this resource() target is in
-#     the dependency graph of a zbi() target, then this is the path within
-#     the BOOTFS, which appears at /boot in the namespace of early-boot and
-#     standalone Zircon processes.
-#     Type: list(path)
-#
-#   sources
-#     Required: List of files in the source tree or build that become $outputs.
-#     See copy() for details.
-#     Type: list(file)
-#
-# See copy() for other parameters.
-template("resource") {
-  if (invoker.sources != []) {
-    _label = get_label_info(":$target_name", "label_with_toolchain")
-  }
-
-  group(target_name) {
-    forward_variables_from(invoker,
-                           "*",
-                           [
-                             "metadata",
-                             "outputs",
-                             "sources",
-                           ])
-    metadata = {
-      # Used by the distribution_manifest() template.
-      distribution_entries_barrier = []
-      distribution_entries = []
-
-      # Used by the zbi() template.
-      zbi_input_barrier = []
-
-      if (defined(invoker.metadata)) {
-        forward_variables_from(invoker.metadata, "*")
-      }
-
-      # Stop *_manifest() and zbi_test() from picking up files or
-      # zbi_input() items from the deps, but let them reach the data_deps.
-      if (defined(data_deps)) {
-        distribution_entries_barrier += data_deps
-        zbi_input_barrier += data_deps
-      }
-
-      foreach(source, invoker.sources) {
-        foreach(target, process_file_template([ source ], invoker.outputs)) {
-          assert(rebase_path(target, "foo") != target,
-                 "`outputs` in resource() cannot start with /")
-          distribution_entries += [
-            {
-              source = rebase_path(source, root_build_dir)
-              destination = target
-              label = _label
-            },
-          ]
-        }
-      }
-    }
-  }
-}

engine/src/flutter/tools/fuchsia/flutter/flutter_component.gni

@@ -22,17 +22,18 @@ import("//flutter/tools/fuchsia/flutter/internal/flutter_dart_component.gni")
 #
 # Once a library is defined a flutter component can be created which
 # depends on this package. If the component needs any other resources they may
-# be defined using the resource target and added to the components deps.
+# be defined in the `resources` variable.
 #
 # ```
-# resource("text-file") {
-#   sources = [ "text_file.txt" ]
-#   outputs = [ "data/text_file.txt" ]
-# }
-#
 # flutter_component("my-component") {
 #   manifest = "meta/my-component.cmx"
 #   main_package = "my_library"
+#   resources = [
+#     {
+#       path = "text_file.txt"
+#       dest = "data/text_file.txt"
+#     },
+#   ]
 #   deps = [
 #     ":lib",
 #     ":text-file",
@@ -133,6 +134,7 @@ template("flutter_component") {
                              "main_dart",
                              "main_package",
                              "component_name",
+                             "resources",
                            ])
     deps = _component_deps
 

engine/src/flutter/tools/fuchsia/flutter/internal/flutter_dart_component.gni

@@ -7,7 +7,6 @@ import("//flutter/tools/fuchsia/dart/config.gni")
 import("//flutter/tools/fuchsia/dart/dart.gni")
 import("//flutter/tools/fuchsia/dart/dart_package_config.gni")
 import("//flutter/tools/fuchsia/dart/kernel/dart_kernel.gni")
-import("//flutter/tools/fuchsia/dist/resource.gni")
 import("//flutter/tools/fuchsia/gn-sdk/cmc.gni")
 import("//flutter/tools/fuchsia/gn-sdk/component.gni")
 
@@ -71,6 +70,11 @@ template("flutter_dart_component") {
     _component_name = target_name
   }
 
+  _resources = []
+  if (defined(invoker.resources)) {
+    _resources = invoker.resources
+  }
+
   # Flutter and Dart components need to run inside the runner which matches how
   # they were compiled, for example, a JIT component must run in the JIT runner.
   # We need to be able to dynamically convert the manifest files to include the
@@ -231,20 +235,7 @@ template("flutter_dart_component") {
       args += [ rebase_path(_kernel_path, root_build_dir) ]
     }
 
-    # copy the snapshot as a resource
-    _snapshot_resource_target_name = "${target_name}_snapshot_resource"
-
-    # TODO(richkadel): It looks like this is the _ONLY_ place resource() is used
-    # and maybe that logic should simply be embedded here, directly?
-    resource(_snapshot_resource_target_name) {
-      sources = [ _snapshot_path ]
-      outputs = [ "data/${_component_name}/app_aot_snapshot.so" ]
-    }
-
-    _component_deps += [
-      ":$_snapshot_resource_target_name",
-      ":$_snapshot_target_name",
-    ]
+    _component_deps += [ ":$_snapshot_target_name" ]
   }
 
   fuchsia_component(_component_name) {
@@ -257,7 +248,14 @@ template("flutter_dart_component") {
     manifest = _manifest
     manifest_output_name = _manifest_output_name
 
-    if (!build_cfg.is_aot) {
+    if (build_cfg.is_aot) {
+      _resources += [
+        {
+          path = _snapshot_path
+          dest = "data/${_component_name}/app_aot_snapshot.so"
+        },
+      ]
+    } else {
       _convert_kernel_target_name =
           "${_kernel_target_name}_convert_kernel_manifest"
       _convert_kernel_manifest_file =
@@ -274,6 +272,8 @@ template("flutter_dart_component") {
       # at some point during the build/compile phase.
       resources_in_json_files = [ rebase_path(_convert_kernel_manifest_file) ]
     }
+
+    resources = _resources
   }
 
   group(target_name) {

engine/src/flutter/tools/fuchsia/gn-sdk/component.gni

@@ -33,8 +33,10 @@ declare_args() {
 #   fuchsia_component("my_component") {
 #      manifest = "meta/component-manifest.cmx"
 #      resources = [
-#        path = "testdata/use_case1.json"
-#        dest = "data/testdata/use_case1.json"
+#        {
+#          path = "testdata/use_case1.json"
+#          dest = "data/testdata/use_case1.json"
+#        },
 #      ]
 #      data_deps = [ ":hello_world_executable"]
 #   }