Reland Auto-generate v8 version based on tags.

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.
 
 # Because standalone V8 builds are not supported, assume this is part of a
 # Chromium build.
 import("//build/module_args/v8.gni")
 
 # TODO(jochen): These will need to be user-settable to support standalone V8
 # builds.
@@ skipping 296 matching lines @@
 
   if (v8_use_external_startup_data) {
     outputs += [ "$root_out_dir/snapshot_blob.bin" ]
     args += [
       "--startup_blob",
       rebase_path("$root_out_dir/snapshot_blob.bin", root_build_dir),
     ]
   }
 }
 
+action("generate_v8_version") {
+  visibility = [ ":*" ]  # Only targets in this file can depend on this.
+
+  script = "tools/push-to-trunk/generate_version.py"
+
+  sources = [
+    "src/version.cc",
+  ]
+
+  outputs = [
+    "$target_gen_dir/version.cc"
+  ]
+
+  args = [
+    rebase_path("$target_gen_dir/version.cc", root_build_dir),
+  ]
+}
+
+
 ###############################################################################
 # Source Sets (aka static libraries)
 #
 
 source_set("v8_nosnapshot") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   deps = [
     ":js2c",
     ":js2c_experimental",
@@ skipping 64 matching lines @@
       ":features",
       ":toolchain",
     ]
   }
 }
 
 source_set("v8_base") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   sources = [
+    "$target_gen_dir/version.cc",
     "src/accessors.cc",
     "src/accessors.h",
     "src/allocation.cc",
     "src/allocation.h",
     "src/allocation-site-scopes.cc",
     "src/allocation-site-scopes.h",
     "src/allocation-tracker.cc",
     "src/allocation-tracker.h",
     "src/api.cc",
     "src/api.h",
@@ skipping 515 matching lines @@
     "src/utils-inl.h",
     "src/utils.cc",
     "src/utils.h",
     "src/v8.cc",
     "src/v8.h",
     "src/v8memory.h",
     "src/v8threads.cc",
     "src/v8threads.h",
     "src/variables.cc",
     "src/variables.h",
-    "src/version.cc",
     "src/version.h",
     "src/vm-state-inl.h",
     "src/vm-state.h",
     "src/zone-inl.h",
     "src/zone.cc",
     "src/zone.h",
     "src/third_party/fdlibm/fdlibm.cc",
     "src/third_party/fdlibm/fdlibm.h",
   ]
 
@@ skipping 257 matching lines @@
   ]
 
   if (!is_debug) {
     configs -= [ "//build/config/compiler:optimize" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
 
   defines = []
   deps = [
     ":v8_libbase",
+    ":generate_v8_version",
   ]
 
   if (is_win) {
     # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
     cflags = [ "/wd4267" ]
   }
 
   if (v8_enable_i18n_support) {
     deps += [ "//third_party/icu" ]
     if (is_win) {
@@ skipping 241 matching lines @@
       assert(!v8_use_external_startup_data)
       deps = [
         ":v8_base",
         ":v8_nosnapshot",
       ]
     }
 
     direct_dependent_configs = [ ":external_config" ]
   }
 }