gn build changes for v8

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.
 v8_deprecation_warnings = false
 v8_enable_disassembler = false
 v8_enable_gdbjit = false
 v8_enable_handle_zapping = true
 v8_enable_i18n_support = true
 v8_enable_verify_heap = false
 v8_interpreted_regexp = false
 v8_object_print = false
 v8_postmortem_support = false
 v8_use_snapshot = true
 v8_target_arch = current_cpu
+if (enable_correct_v8_arch) {
+  v8_target_arch = target_cpu
+}
 v8_random_seed = "314159265"
 v8_toolset_for_d8 = "host"
 
 ###############################################################################
 # Configurations
 #
 config("internal_config") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   include_dirs = [ "." ]
@@ skipping 17 matching lines @@
 config("external_config") {
   if (is_component_build) {
     defines = [
       "V8_SHARED",
       "USING_V8_SHARED",
     ]
   }
   include_dirs = [ "include" ]
 }
 
+declare_args() {
+  host_cxx_is_biarch = 0
+  if (enable_correct_v8_arch &&
+      (host_cpu == "ia32" || host_cpu =="x64" || host_cpu=="ppc" ||
+       host_cpu=="ppc64" || is_clang)) {
+    host_cxx_is_biarch = 1
+  }
+}
+
 config("features") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   defines = []
 
   if (v8_enable_disassembler == true) {
     defines += [ "ENABLE_DISASSEMBLER" ]
   }
   if (v8_enable_gdbjit == true) {
     defines += [ "ENABLE_GDB_JIT_INTERFACE" ]
@@ skipping 19 matching lines @@
   if (v8_use_external_startup_data == true) {
     defines += [ "V8_USE_EXTERNAL_STARTUP_DATA" ]
   }
 }
 
 config("toolchain") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   defines = []
   cflags = []
+  ldflags = []
 
   # TODO(jochen): Add support for arm subarchs, mips, mipsel.
 
   if (v8_target_arch == "arm") {
     defines += [ "V8_TARGET_ARCH_ARM" ]
     if (arm_version == 7) {
       defines += [ "CAN_USE_ARMV7_INSTRUCTIONS" ]
     }
     if (arm_fpu == "vfpv3-d16") {
       defines += [ "CAN_USE_VFP3_INSTRUCTIONS" ]
@@ skipping 36 matching lines @@
     # TODO(jochen): Add support for different debug optimization levels.
     defines += [
       "ENABLE_DISASSEMBLER",
       "V8_ENABLE_CHECKS",
       "OBJECT_PRINT",
       "VERIFY_HEAP",
       "DEBUG",
       "OPTIMIZED_DEBUG",
     ]
   }
+
+  if ((current_os == "linux" || current_os == "freebsd" ||
+       current_os == "openbsd" || current_os == "solaris" ||
+       current_os == "netbsd" || current_os == "mac" ||
+       current_os == "android" || current_os == "qnx") &&
+      (v8_target_arch == "arm" || v8_target_arch == "ia32" ||
+       v8_target_arch == "x87" || v8_target_arch == "mips" ||
+       v8_target_arch == "mipsel" || v8_target_arch == "ppc")) {
+    if (current_toolchain == host_toolchain) {
+      if (host_cxx_is_biarch == 1) {
+        cflags += [ "-m32" ]
+        ldflags += [ "-m32" ]
+      }
+    }
+  }
 }
 
 ###############################################################################
 # Actions
 #
 
 action("js2c") {
   visibility = [ ":*" ]  # Only targets in this file can depend on this.
 
   script = "tools/js2c.py"
@@ skipping 1393 matching lines @@
       sources += [
         "src/d8-debug.cc",
         "$target_gen_dir/d8-js.cc",
       ]
     }
     if (v8_enable_i18n_support) {
       deps += [ "//third_party/icu" ]
     }
   }
 }