Attempt to define some reasonable flags for OS X linker.

--HG--
branch : setuptools
extra : convert_revision : svn%3A6015fed2-1504-0410-9fe1-9d1591cc4771/sandbox/trunk/setuptools%4042040

setuptools/command/build_ext.py

@@ -9,7 +9,7 @@ import os, sys
 from distutils.file_util import copy_file
 from setuptools.extension import Library
 from distutils.ccompiler import new_compiler
-from distutils.sysconfig import customize_compiler
+from distutils.sysconfig import customize_compiler, _config_vars
 from distutils import log
 from distutils.errors import *
 
@@ -39,7 +39,6 @@ if os.name != 'nt':
 
 
 
-
 class build_ext(_build_ext):
     def run(self):
         """Build extensions in build directory, then copy if --inplace"""
@@ -126,10 +125,19 @@ class build_ext(_build_ext):
         compiler = self.shlib_compiler = new_compiler(
             compiler=self.compiler, dry_run=self.dry_run, force=self.force
         )
-        customize_compiler(compiler)
         if sys.platform == "darwin":
-            # XXX need to fix up compiler_so:ccshared + linker_so:ldshared too
-            compiler.shared_lib_extension = ".dylib"
+            tmp = _config_vars.copy()
+            try:
+                # XXX Help!  I don't have any idea whether these are right...
+                _config_vars['LDSHARED'] = "-dynamiclib -undefined dynamic_lookup"
+                _config_vars['CCSHARED'] = " -dynamiclib"
+                _config_vars['SO'] = ".dylib"
+                customize_compiler(compiler)
+            finally:
+                _config_vars.clear()
+                _config_vars.update(tmp)
+        else:
+            customize_compiler(compiler)
 
         if self.include_dirs is not None:
             compiler.set_include_dirs(self.include_dirs)
@@ -152,17 +160,13 @@ class build_ext(_build_ext):
         # hack so distutils' build_extension() builds a library instead
         compiler.link_shared_object = link_shared_object.__get__(compiler)
 
+
+
     def get_export_symbols(self, ext):
         if isinstance(ext,Library):
             return ext.export_symbols
         return _build_ext.get_export_symbols(self,ext)
 
-
-
-
-
-
-
     def build_extension(self, ext):
         _compiler = self.compiler
         try:
@@ -199,11 +203,6 @@ class build_ext(_build_ext):
                     outputs.append(base+'.pyo')
         return outputs
 
-
-
-
-
-
     def write_stub(self, output_dir, ext, compile=False):
         log.info("writing stub loader for %s to %s",ext._full_name, output_dir)
         stub_file = os.path.join(output_dir, *ext._full_name.split('.'))+'.py'