gyp: allow pass v8 gyp variables to configure

[trevnorris]

As far as I know, currently it's impossible to pass, say -Dv8_enable_i18n_support=1 to ./configure so it's read in as one of the variables in common.gypi. Is there a way, or will we need to add support for this?

/cc @tjfontaine @TooTallNate

[TooTallNate]

I'm not sure if it would be possible to add a generic -D handler with the python options parser we're using in ./configure, but we should probably do like what we do for like dtrace and the other optional compile-time features.

By that I mean add a --with-i18n switch. It should be pretty trivial to add that switch and have it map to -Dv8_enable_i18n_support=1 in the generated config.gypi file. Let me know if you need help with that.

[bnoordhuis]

Is there a way, or will we need to add support for this?

os.environ['GYP_DEFINES'] = \
  os.environ.get('GYP_DEFINES', '') + ' v8_enable_i18n_support=1'

Right before calling into gyp?

[tjfontaine]

diff --git a/configure b/configure
index 4a38c70..4c49888 100755
--- a/configure
+++ b/configure
@@ -706,4 +706,6 @@ elif flavor == 'win':
 else:
   gyp_args = ['-f', 'make-' + flavor]

+gyp_args = gyp_args + args
+
 subprocess.call([sys.executable, 'tools/gyp_node.py'] + gyp_args)

then ./configure -- -Dv8_enable_i18n_support=1

if lgty I'll land

[tjfontaine]

landed in b5e1619