[build_support] Fixed python 3 errors

utils/swift_build_support/swift_build_support/debug.py

@@ -23,7 +23,7 @@
 def _output(args):
     try:
         out = subprocess.check_output(args, stderr=subprocess.PIPE)
-        return out.rstrip()
+        return out.rstrip().decode()
     except subprocess.CalledProcessError:
         return None
 

utils/swift_build_support/swift_build_support/toolchain.py

@@ -36,7 +36,8 @@ def __init__(self, cc=None, cxx=None, **kwargs):
         self.cc = cc
         self.cxx = cxx
         self.tools = [cc, cxx]
-        for tool, path in kwargs.iteritems():
+        for tool in kwargs:
+            path = kwargs[tool]
             self.tools.append(path)
             setattr(self, tool, path)
 
@@ -98,7 +99,8 @@ def host_toolchain(xcrun_toolchain='default', tools=None, suffixes=None):
     if platform.system() == 'Darwin':
         # Only use xcrun on Darwin
         path_map = {}
-        for name, tool in tools.iteritems():
+        for name in tools:
+            tool = tools[name]
             path = xcrun.find(xcrun_toolchain, tool)
             if not path:
                 return None

utils/swift_build_support/swift_build_support/which.py

@@ -31,6 +31,6 @@ def which(cmd):
     been backported to Python 2.7, which we support.
     """
     try:
-        return subprocess.check_output(['which', cmd]).rstrip()
+        return subprocess.check_output(['which', cmd]).rstrip().decode()
     except subprocess.CalledProcessError:
         return None

utils/swift_build_support/swift_build_support/xcrun.py

@@ -29,6 +29,6 @@ def find(toolchain, tool):
                                        '--toolchain', toolchain,
                                        '--find', tool],
                                       stderr=subprocess.PIPE)
-        return out.rstrip()
+        return out.rstrip().decode()
     except subprocess.CalledProcessError:
         return None

utils/swift_build_support/tests/test_which.py

@@ -19,7 +19,7 @@ def test_when_cmd_not_found_returns_none(self):
         self.assertIsNone(which('a-tool-that-doesnt-exist'))
 
     def test_when_cmd_found_returns_path(self):
-        self.assertEquals(os.path.split(which('ls'))[-1], 'ls')
+        self.assertEqual(os.path.split(which('ls'))[-1], 'ls')
 
 
 if __name__ == '__main__':