Use abstract configurations to switch between opt debug settings

build/standalone.gypi

 # Copyright 2012 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 120 matching lines @@
   },
   'target_defaults': {
     'variables': {
       'v8_code%': '<(v8_code)',
     },
     'default_configuration': 'Debug',
     'configurations': {
       'Debug': {
         'cflags': [ '-g', '-O0' ],
       },
+      'Optdebug': {
+        'inherit_from': [ 'Debug' ],
+      },
       'Release': {
         # Xcode insists on this empty entry.
       },
     },
     'target_conditions': [
       ['v8_code == 0', {
         'defines!': [
           'DEBUG',
         ],
         'conditions': [
@@ skipping 31 matching lines @@
           '-fomit-frame-pointer',
         ],
         'ldflags': [
           '-fsanitize=address',
         ],
       },
     }],
     ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
        or OS=="netbsd"', {
       'target_defaults': {
         'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',

[jochen (gone - plz use gerrit), 2014/04/03 22:21:38]

Any idea why these settings are used "twice" in the Optdebug configuration?

If you patch this into v8, and run ninja ia32.release, it'll create
out/ia32/{Release,Debug,Optdebug} and Debug and Optdebug only differ by the
settings in this section appearing twice, i.e.

cflags_cc is -Wnon-virtual-dtor -fno-rtti -Wnon-virtual-dtor -fno-rtti

                     '-pthread', '-fno-exceptions', '-pedantic' ],
         'cflags_cc': [ '-Wnon-virtual-dtor', '-fno-rtti' ],
         'ldflags': [ '-pthread', ],
         'conditions': [
           [ 'OS=="linux"', {
             'cflags': [ '-ansi' ],
           }],
           [ 'visibility=="hidden" and v8_enable_backtrace==0', {
             'cflags': [ '-fvisibility=hidden' ],
           }],
@@ skipping 149 matching lines @@
         ],
         'target_conditions': [
           ['_type!="static_library"', {
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
           }],
         ],  # target_conditions
       },  # target_defaults
     }],  # OS=="mac"
   ],
 }