Support script response files in GN.

components/domain_reliability/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Paths to the JSON files are kind of gross. They're stored in the gypi
 # relative to //components, since that's the working directory gyp seems
 # to use for all of the components. When we depend on them here, we need
 # to remove the leading domain_reliability, since *our* working directory
 # is one level deeper. When we call bake_in_configs.py, we need to give
 # it a properly-rebased path to //components so it can properly join the
 # paths relative to that and find the JSON files.
 
 baked_in_configs_gypi = exec_script("//build/gypi_to_gn.py",
                                     [ rebase_path("baked_in_configs.gypi") ],
                                     "scope",
                                     [ "baked_in_configs.gypi" ])
+
+# The config file names in the .gypi are relative to "//components".
 baked_in_configs =
-    rebase_path(baked_in_configs_gypi.baked_in_configs, "domain_reliability")
+    rebase_path(baked_in_configs_gypi.baked_in_configs, ".", "//components")
 
-action("bake_in_configs") {
-  visibility = [ ":*" ]
-  script = "bake_in_configs.py"
+# TODO(brettw) enable once GN supports response_file_contents for actions.
+if (false) {
+  action("bake_in_configs") {
+    visibility = [ ":*" ]
+    script = "bake_in_configs.py"
 
-  inputs = baked_in_configs
-  outputs = [
-    "$target_gen_dir/baked_in_configs.cc",
-  ]
+    inputs = baked_in_configs
+    output_file = "$target_gen_dir/baked_in_configs.cc"
+    outputs = [
+      output_file,
+    ]
 
-  # The actual list of JSON files will overflow the command line length limit
-  # on Windows, so pass the name of the .gypi file and bake_in_configs.py will
-  # read the filenames out of it manually.
-  args = [ rebase_path("//components", root_build_dir) ] +
-         [ rebase_path("baked_in_configs.gypi", root_build_dir) ] +
-         rebase_path(outputs, root_build_dir)
+    # The JSON file list is too long for the command line on Windows, so put
+    # them in a response file.
+    response_file_contents = rebase_path(inputs, root_build_dir)
+    args = [
+      "--file-list",
+      "{{response_file_name}}",
+      "--output",
+      rebase_path(output_file, root_build_dir),
+    ]
+  }
+} else {
+  action("bake_in_configs") {
+    visibility = [ ":*" ]
+    script = "bake_in_configs.py"
+
+    inputs = baked_in_configs
+    output_file = "$target_gen_dir/baked_in_configs.cc"
+    outputs = [
+      output_file,
+    ]
+
+    # The actual list of JSON files will overflow the command line length limit
+    # on Windows, so pass the name of the .gypi file and bake_in_configs.py will
+    # read the filenames out of it manually.
+    args = [
+      "--gypi-file=" + rebase_path("baked_in_configs.gypi", root_build_dir),
+      "--gypi-relative-to=" + rebase_path("//components", root_build_dir),
+      "--output=" + rebase_path(output_file, root_build_dir),
+    ]
+  }
 }
 
 component("domain_reliability") {
   sources = [
     "baked_in_configs.h",
     "beacon.cc",
     "beacon.h",
     "clear_mode.h",
     "config.cc",
     "config.h",
@@ skipping 47 matching lines @@
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   deps = [
     ":domain_reliability",
     "//base",
     "//base/test:test_support",
     "//net:test_support",
     "//testing/gtest",
   ]
 }