Introduce dart_host_toolchain argument for generate_patch_sdk.gni. This allows for Flutter build to make sure that host_toolchain used for patched_sdk generation word size matches target platform.

Flutter Dart in product configuration doesn't allow --checked option. So remove '--checked' from invocation.

R=rmacnak@google.com

BUG:https://github.com/flutter/flutter/issues/10841
Review-Url: https://codereview.chromium.org/2944103003 .

build/compiled_action.gni

@@ -66,6 +66,8 @@
 # saves unnecessarily compiling your tool for the target platform. But if you
 # need a target build of your tool as well, just leave off the if statement.
 
+import("dart_host_toolchain.gni")
+
 if (host_os == "win") {
   _host_executable_suffix = ".exe"
 } else {
@@ -97,7 +99,7 @@ template("compiled_action") {
     outputs = invoker.outputs
 
     # Constuct the host toolchain version of the tool.
-    host_tool = invoker.tool + "($host_toolchain)"
+    host_tool = invoker.tool + "($dart_host_toolchain)"
 
     # Get the path to the executable. Currently, this assumes that the tool
     # does not specify output_name so that the target name is the name to use.
@@ -150,7 +152,7 @@ template("compiled_action_foreach") {
     outputs = invoker.outputs
 
     # Constuct the host toolchain version of the tool.
-    host_tool = invoker.tool + "($host_toolchain)"
+    host_tool = invoker.tool + "($dart_host_toolchain)"
 
     # Get the path to the executable. Currently, this assumes that the tool
     # does not specify output_name so that the target name is the name to use.

build/dart_host_toolchain.gni

@@ -0,0 +1,13 @@
+# Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
+# for details. All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+declare_args() {
+  # This argument allows to override host_toolchain used to build dart artifacts.
+  # This is needed to make sure that word size of the code produced on host
+  # machine matches word size of target architecture. For example, when
+  # targeting android arm 32-bit while building on linux 64-bit machine, dart vm
+  # that is used to produce snapshots for that android arm 32, has to be built
+  # using linux 32-bit toolchain.
+  dart_host_toolchain = host_toolchain
+}

runtime/observatory/BUILD.gn

@@ -4,6 +4,7 @@
 
 import("../../build/executable_suffix.gni")
 import("../../build/prebuilt_dart_sdk.gni")
+import("../../build/dart_host_toolchain.gni")
 
 # Currently paths here are hard coded for convenience in building Mojo/Flutter.
 declare_args() {
@@ -40,10 +41,10 @@ if (dart_host_pub_exe != "") {
     dart_host_pub_exe,
   ]
 } else if (!prebuilt_dart_exe_works) {
-  pub_build_deps += [ "../bin:dart_bootstrap($host_toolchain)" ]
+  pub_build_deps += [ "../bin:dart_bootstrap($dart_host_toolchain)" ]
 
-  dart_out_dir =
-      get_label_info("../bin:dart_bootstrap($host_toolchain)", "root_out_dir")
+  dart_out_dir = get_label_info("../bin:dart_bootstrap($dart_host_toolchain)",
+                                "root_out_dir")
   dart_bootstrap = rebase_path("$dart_out_dir/dart_bootstrap$executable_suffix")
 
   pub_build_args = [

tools/patch_sdk.py

@@ -48,8 +48,7 @@ def main():
     print >> sys.stderr, 'ERROR: cannot locate dart executable'
     return -1
   dart_file = os.path.join(os.path.dirname(__file__), 'patch_sdk.dart')
-  subprocess.check_call(
-      [options.dart_executable, '--checked', dart_file] + args)
+  subprocess.check_call([options.dart_executable, dart_file] + args)
   return 0
 
 if __name__ == '__main__':

utils/generate_patch_sdk.gni

@@ -3,6 +3,7 @@
 # BSD-style license that can be found in the LICENSE file.
 
 import("../build/prebuilt_dart_sdk.gni")
+import("../build/dart_host_toolchain.gni")
 
 _dart_root = get_path_info("..", "abspath")
 
@@ -28,7 +29,7 @@ template("generate_patched_sdk") {
     }
 
     if (!prebuilt_dart_exe_works) {
-      deps += [ "$_dart_root/runtime/bin:dart_bootstrap($host_toolchain)" ]
+      deps += [ "$_dart_root/runtime/bin:dart_bootstrap_host_arch($dart_host_toolchain)" ]
     }
 
     script = "$_dart_root/tools/patch_sdk.py"
@@ -49,7 +50,7 @@ template("generate_patched_sdk") {
     args = [ "--quiet" ]
     if (!prebuilt_dart_exe_works) {
       dart_out_dir = get_label_info(
-              "$_dart_root/runtime/bin:dart_bootstrap($host_toolchain)",
+              "$_dart_root/runtime/bin:dart_bootstrap_host_arch($dart_host_toolchain)",
               "root_out_dir")
       dart_bootstrap =
           rebase_path("$dart_out_dir/dart_bootstrap$executable_suffix")

utils/kernel-service/BUILD.gn

@@ -3,11 +3,12 @@
 # BSD-style license that can be found in the LICENSE file.
 
 import("../application_snapshot.gni")
+import("../../build/dart_host_toolchain.gni")
 
 application_snapshot("kernel-service") {
   dfe_script = "kernel-service.dart"
   deps = [
-    "../../runtime/vm:patched_sdk($host_toolchain)",
+    "../../runtime/vm:patched_sdk($dart_host_toolchain)",
   ]
   main_dart = dfe_script
   training_args = [