This CL adds support for extension in GYP.

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
diff --git a/pylib/gyp/generator/ninja.py b/pylib/gyp/generator/ninja.py
index f31068a9bf44a89b1c83e61afccc01d284e06fc8..6200ae5238cc92d9385581c79c83e37525564c5d 100644
--- a/pylib/gyp/generator/ninja.py
+++ b/pylib/gyp/generator/ninja.py
@@ -25,6 +25,8 @@ import gyp.ninja_syntax as ninja_syntax
 generator_default_variables = {
   'EXECUTABLE_PREFIX': '',
   'EXECUTABLE_SUFFIX': '',
+  'EXTENSION_PREFIX': '',
+  'EXTENSION_SUFFIX': '',
   'STATIC_LIB_PREFIX': 'lib',
   'STATIC_LIB_SUFFIX': '.a',
   'SHARED_LIB_PREFIX': 'lib',
@@ -997,6 +999,7 @@ class NinjaWriter:
     """Write out a link step. Fills out target.binary. """
     command = {
       'executable':      'link',
+      'extension':       'link',
       'loadable_module': 'solink_module',
       'shared_library':  'solink',
     }[spec['type']]
@@ -1046,7 +1049,8 @@ class NinjaWriter:
     if arch is None and not self.is_mac_bundle:
       self.AppendPostbuildVariable(extra_bindings, spec, output, output)
 
-    is_executable = spec['type'] == 'executable'
+    is_executable = (spec['type'] == 'executable' or
+        spec['type'] == 'extension')

[pkl (ping after 24h if needed), 2014/07/09 08:07:50]

how about this:
  spec['type'] in ('executable', 'extension')

[olivierrobin, 2014/07/09 12:46:27]

Done.

     # The ldflags config key is not used on mac or win. On those platforms
     # linker flags are set via xcode_settings and msvs_settings, respectively.
     env_ldflags = os.environ.get('LDFLAGS', '').split()
@@ -1340,6 +1344,7 @@ class NinjaWriter:
       'shared_library': default_variables['SHARED_LIB_PREFIX'],
       'static_library': default_variables['STATIC_LIB_PREFIX'],
       'executable': default_variables['EXECUTABLE_PREFIX'],
+      'extension': default_variables['EXTENSION_PREFIX'],
       }
     prefix = spec.get('product_prefix', DEFAULT_PREFIX.get(type, ''))
 
@@ -1350,6 +1355,7 @@ class NinjaWriter:
         'shared_library': default_variables['SHARED_LIB_SUFFIX'],
         'static_library': default_variables['STATIC_LIB_SUFFIX'],
         'executable': default_variables['EXECUTABLE_SUFFIX'],
+        'extension': default_variables['EXTENSION_SUFFIX'],
       }
     extension = spec.get('product_extension')
     if extension:
@@ -1368,7 +1374,7 @@ class NinjaWriter:
         target = StripPrefix(target, 'lib')
 
     if type in ('static_library', 'loadable_module', 'shared_library',
-                        'executable'):
+                        'executable', 'extension'):
       return '%s%s%s' % (prefix, target, extension)
     elif type == 'none':
       return '%s.stamp' % target
@@ -1386,7 +1392,11 @@ class NinjaWriter:
         return override
 
     if arch is None and self.flavor == 'mac' and type in (
-        'static_library', 'executable', 'shared_library', 'loadable_module'):
+        'static_library',
+        'executable',
+        'extension',
+        'shared_library',
+        'loadable_module'):
       filename = self.xcode_settings.GetExecutablePath()
     else:
       filename = self.ComputeOutputFileName(spec, type)
@@ -1397,7 +1407,7 @@ class NinjaWriter:
 
     # Some products go into the output root, libraries go into shared library
     # dir, and everything else goes into the normal place.
-    type_in_output_root = ['executable', 'loadable_module']
+    type_in_output_root = ['executable', 'extension', 'loadable_module']
     if self.flavor == 'mac' and self.toolset == 'target':
       type_in_output_root += ['shared_library', 'static_library']
     elif self.flavor == 'win' and self.toolset == 'target':