Introduce a v8::Platform class that bundles embedder callbacks

build/features.gypi

 # Copyright 2013 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 40 matching lines @@
     # Interpreted regexp engine exists as platform-independent alternative
     # based where the regular expression is compiled to a bytecode.
     'v8_interpreted_regexp%': 0,
 
     # Enable ECMAScript Internationalization API. Enabling this feature will
     # add a dependency on the ICU library.
     'v8_enable_i18n_support%': 1,
 
     # Enable compiler warnings when using V8_DEPRECATED apis.
     'v8_deprecation_warnings%': 0,
+
+    # Use the v8 provided v8::Platform implementation.
+    'v8_use_default_platform%': 1,

[Benedikt Meurer, 2013/11/18 15:34:44]

Do we really need this option here? Couldn't we just always include our default
implementation, and in V8::Initialize just check whether g_platform is NULL, and
if so, automagically use the default implementation?

[jochen (gone - plz use gerrit), 2013/11/18 16:27:56]

The default implementation will have to provide e.g. a thread pool, so it's a
non-trivial amount of code which I'd like to avoid including if possible.

Also, V8::Initialize just picking a default implementation is too much magic
IMO. It would lead to unexpected results if we e.g. add a new process in chrome
and forget to set the platform there.

[Benedikt Meurer, 2013/11/19 06:57:15]

Hm, so the default implementation is not used by Chrome? What worries me is that
we may then run into trouble with reproducing Chrome behavior in d8. We'll have
to regularily sync the default implementation with Chrome, which is certainly
not what we want. Can we do better here?

   },
   'target_defaults': {
     'conditions': [
       ['v8_enable_debugger_support==1', {
         'defines': ['ENABLE_DEBUGGER_SUPPORT',],
       }],
       ['v8_enable_disassembler==1', {
         'defines': ['ENABLE_DISASSEMBLER',],
       }],
       ['v8_enable_gdbjit==1', {
         'defines': ['ENABLE_GDB_JIT_INTERFACE',],
       }],
       ['v8_object_print==1', {
         'defines': ['OBJECT_PRINT',],
       }],
       ['v8_enable_verify_heap==1', {
         'defines': ['VERIFY_HEAP',],
       }],
       ['v8_interpreted_regexp==1', {
         'defines': ['V8_INTERPRETED_REGEXP',],
       }],
       ['v8_deprecation_warnings==1', {
         'defines': ['V8_DEPRECATION_WARNINGS',],
       }],
       ['v8_enable_i18n_support==1', {
         'defines': ['V8_I18N_SUPPORT',],
       }],
+      ['v8_use_default_platform==1', {
+        'defines': ['V8_USE_DEFAULT_PLATFORM',],
+      }],
       ['v8_compress_startup_data=="bz2"', {
         'defines': [
           'COMPRESS_STARTUP_DATA_BZ2',
         ],
       }],
     ],  # conditions
     'configurations': {
       'Debug': {
         'variables': {
           'v8_enable_extra_checks%': 1,
@@ skipping 18 matching lines @@
             'defines': ['ENABLE_EXTRA_CHECKS',],
           }],
           ['v8_enable_handle_zapping==1', {
             'defines': ['ENABLE_HANDLE_ZAPPING',],
           }],
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }