Enable compilation of GDBJIT interface on Linux.

build/common.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 333 matching lines @@
             ],
           },
           'VCLinkerTool': {
             'LinkIncremental': '2',
           },
         },
         'conditions': [
           ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="netbsd"', {
             'cflags': [ '-Wall', '<(werror)', '-W', '-Wno-unused-parameter',
                         '-Wnon-virtual-dtor', '-Woverloaded-virtual' ],
+            'defines': ['ENABLE_GDB_JIT_INTERFACE',],

[caseq1, 2012/10/15 17:55:19]

This broke debugging of chrome, at least with gdb v7.5 -- gdb fails with "Unable
to read JIT descriptor from remote memory!" followed by "Error accessing memory
address 0xXXXXXXXXX: Input/output error".
Is there a reason that v8_enable_gdbjit variable is not used here? What I would
do instead of unconditionally adding the DEFINE, set the default value of
v8_enable_gdbjit to 1:

'variables': {
  'v8_enable_gdbjit%': 1
}

so that those for whom gdbjit still does not work at least have a way to turn it
off in their include.gypi.

[Michael Starzinger, 2012/10/16 08:19:13]

I'll fix that and make sure that the GDBJIT support can be turned off with a GYP
flag as you suggested.

           }],
           ['OS=="android"', {
             'variables': {
               'android_full_debug%': 1,
             },
             'conditions': [
               ['android_full_debug==0', {
                 # Disable full debug if we want a faster v8 in a debug build.
                 # TODO(2304): pass DISABLE_DEBUG_ASSERT instead of hiding DEBUG.
                 'defines!': [
@@ skipping 62 matching lines @@
                 'OptimizeReferences': '2',
                 'EnableCOMDATFolding': '2',
               },
             },
           }],  # OS=="win"
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }