Strip comments and whitespace from Javascript resources

tools/grit/grit_rule.gni

Index: tools/grit/grit_rule.gni
diff --git a/tools/grit/grit_rule.gni b/tools/grit/grit_rule.gni
index 107a4bc9a0d1193546370bc9ca8d4ece78b594e0..047772f9bd34b93748ac0e165289da4cc08a2a2c 100644
--- a/tools/grit/grit_rule.gni
+++ b/tools/grit/grit_rule.gni
@@ -82,6 +82,7 @@ import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
+import("//build/util/java_action.gni")
 
 declare_args() {
   # Enables used resource whitelist generation.
@@ -89,6 +90,7 @@ declare_args() {
 }
 
 grit_defines = []
+grit_environment = []
 
 # Mac and iOS want Title Case strings.
 use_titlecase_in_grd_files = is_mac || is_ios
@@ -103,6 +105,8 @@ if (is_chrome_branded) {
   grit_defines += [
     "-D",
     "_google_chrome",
+  ]
+  grit_environment += [
     "-E",
     "CHROMIUM_BUILD=google_chrome",
   ]
@@ -110,6 +114,8 @@ if (is_chrome_branded) {
   grit_defines += [
     "-D",
     "_chromium",
+  ]
+  grit_environment += [
     "-E",
     "CHROMIUM_BUILD=chromium",
   ]
@@ -174,7 +180,7 @@ if (enable_image_loader_extension) {
 }
 
 if (is_android) {
-  grit_defines += [
+  grit_environment += [
     "-E",
     "ANDROID_JAVA_TAGGED_ONLY=true",
   ]
@@ -433,7 +439,7 @@ template("grit") {
               rebase_path(depfile, root_build_dir),
               "--write-only-new=1",
               "--depend-on-stamp",
-            ] + grit_defines
+            ] + grit_defines + grit_environment
 
     # Add extra defines with -D flags.
     if (defined(invoker.defines)) {
@@ -445,6 +451,11 @@ template("grit") {
       }
     }
 
+    if (defined(invoker.moved_file_list)) {
+      response_file_contents = invoker.moved_file_list
+      args += [ "--moved-input-file-list={{response_file_name}}" ]
+    }
+
     args += grit_flags + assert_files_flags
 
     if (defined(invoker.visibility)) {
@@ -499,3 +510,105 @@ template("grit") {
     output_name = grit_output_name
   }
 }
+
+flatten_resource_path = "//tools/grit/flatten_resource.py"
+closure_compiler_path = "//third_party/closure_compiler/compiler/compiler.jar"
+
+template("strip_js") {
+  assert(defined(invoker.sources),
+         "Need sources in $target_name listing the js files.")
+
+  _target_name = target_name
+
+  action_foreach("${_target_name}_flatten") {
+    script = flatten_resource_path
+    sources = invoker.sources
+    outputs = [
+      "{{source_gen_dir}}/{{source_name_part}}.${_target_name}_flattened_js",
+    ]
+    args = grit_defines
+    args += [
+      rebase_path("{{source}}"),
+      rebase_path(
+          "$root_out_dir/{{source_gen_dir}}/{{source_name_part}}.${_target_name}_flattened_js"),
+    ]
+  }
+
+  java_action_foreach(_target_name) {

[Dan Beam, 2016/06/29 22:20:57]

does this run in an optimized way, i.e.

https://cs.chromium.org/chromium/src/third_party/closure_compiler/compile2.py...

[aberent, 2016/07/14 15:41:36]

Now it does. See compile_js2.gni

+    script = closure_compiler_path
+    sources = get_target_outputs(":${_target_name}_flatten")
+    outputs = [
+      "{{source_gen_dir}}/{{source_name_part}}_${_target_name}.js",
+    ]
+
+    args = [
+      "--compilation_level",
+      "WHITESPACE_ONLY",
+      "--js_output_file",
+      rebase_path(
+          "$root_out_dir/{{source_gen_dir}}/{{source_name_part}}_${_target_name}.js"),

[Dan Beam, 2016/06/29 22:20:57]

what about source maps?

third_party/closure_compiler/compile{,2}.py already do this

https://cs.chromium.org/chromium/src/third_party/closure_compiler/compile2.py...

[aberent, 2016/07/14 15:41:36]

Done.

+      "--js",
+      "{{source}}",
+      "--language_out=ES5",

[Dan Beam, 2016/06/29 22:20:57]

don't you want a --language_in as well?

[aberent, 2016/07/14 15:41:36]

Done. See compile_js2.gni

+    ]
+    deps = [
+      ":${_target_name}_flatten",
+    ]
+  }
+}
+
+template("strip_and_grit") {
+  _target_name = target_name
+
+  if (strip_resource_files) {
+    strip_js("${_target_name}_stripped") {
+      sources = invoker.js_resource_files
+    }
+    grit(_target_name) {
+      forward_variables_from(invoker,
+                             [
+                               "source",
+                               "outputs",
+                               "outputs_dir",
+                               "defines",
+                               "grit_flags",
+                               "output_dir",
+                             ])
+      moved_file_list = []
+
+      foreach(js_resource_file, invoker.js_resource_files) {
+        name = get_path_info(js_resource_file, "name")
+
+        # Generating the actual paths is messy, because, to avoid name clashes both the
+        # actions in strip_js use {{source_gen_dir}}, hence adding $root_gen_dir to
+        # the front of the path twice.
+        gen_dir = get_path_info(js_resource_file, "gen_dir")
+        gen_dir_rebased = rebase_path(gen_dir, "//")
+        actual = "${root_gen_dir}/${gen_dir_rebased}/${name}_${_target_name}_stripped.js"
+        abs_orig = rebase_path(js_resource_file)
+        abs_actual = rebase_path(actual)
+        moved_file_list += [ "$abs_orig:$abs_actual" ]
+      }
+
+      deps = invoker.deps
+      deps += [ ":${_target_name}_stripped" ]
+    }
+  } else {
+    # If we can't run the closure compiler simply run grit.
+    grit(_target_name) {
+      forward_variables_from(invoker,
+                             [
+                               "source",
+                               "outputs",
+                               "outputs_dir",
+                               "defines",
+                               "grit_flags",
+                               "output_dir",
+                             ])
+
+      inputs = invoker.js_resource_files
+
+      deps = invoker.deps
+    }
+  }
+}