mac: Support ARCHS with zero or one element in the make and ninja generators.

test/mac/gyptest-archs.py

Index: test/mac/gyptest-archs.py
===================================================================
--- test/mac/gyptest-archs.py	(revision 0)
+++ test/mac/gyptest-archs.py	(revision 0)
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2012 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""
+Tests things related to ARCHS.
+"""
+
+import TestGyp
+
+import subprocess
+import sys
+
+if sys.platform == 'darwin':
+  test = TestGyp.TestGyp(formats=['ninja', 'make', 'xcode'])
+
+  def CheckFileType(file, expected):
+    proc = subprocess.Popen(['file', '-b', file], stdout=subprocess.PIPE)
+    o = proc.communicate()[0].strip()
+    assert not proc.returncode
+    if o != expected:
+      print 'File: Expected %s, got %s' % (expected, o)
+      test.fail_test()
+
+  test.run_gyp('test-no-archs.gyp', chdir='archs')
+  test.build('test-no-archs.gyp', test.ALL, chdir='archs')
+  result_file = test.built_file_path('Test', chdir='archs')
+  test.must_exist(result_file)
+  CheckFileType(result_file, 'Mach-O executable i386')
+
+  test.run_gyp('test-archs-x86_64.gyp', chdir='archs')
+  test.build('test-archs-x86_64.gyp', test.ALL, chdir='archs')
+  result_file = test.built_file_path('Test64', chdir='archs')
+  test.must_exist(result_file)
+  CheckFileType(result_file, 'Mach-O 64-bit executable x86_64')