add PRESUBMIT for native_client_sdk.

native_client_sdk/src/tools/getos.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Native Client Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Determine OS
 
 Determine the name of the platform used to determine the correct Toolchain to
 invoke.
 """
 
 import optparse
 import os
 import re
 import subprocess
 import sys
 
 
-TOOL_PATH=os.path.dirname(os.path.abspath(__file__))
+TOOL_PATH = os.path.dirname(os.path.abspath(__file__))
 
 
 def ErrOut(text):
   sys.stderr.write(text + '\n')
   sys.exit(1)
   
 
 
 def GetSDKPath():
   return os.getenv('NACL_SDK_ROOT', os.path.dirname(TOOL_PATH))
@@ skipping 21 matching lines @@
 
 
 def GetSystemArch(platform):
   if platform == 'win':
     if UseWin64():
       return 'x86_64'
     return 'x86_32'
 
   if platform in ['mac', 'linux']:
     try:
-      pobj = subprocess.Popen(['uname', '-m'],stdout= subprocess.PIPE)
-      arch, serr = pobj.communicate()
+      pobj = subprocess.Popen(['uname', '-m'], stdout= subprocess.PIPE)
+      arch = pobj.communicate()[0]
       arch = arch.split()[0]
-    except:
+    except Exception:
       arch = None
   return arch
 
 
 def GetChromeArch(platform):
   if platform == 'win':
     if UseWin64():
       return 'x86_64'
     return 'x86_32'
 
   if platform in ['mac', 'linux']:
     chrome_path = os.getenv('CHROME_PATH', None)
     if not chrome_path:
       ErrOut('CHROME_PATH is undefined.')
 
     try:
       pobj = subprocess.Popen(['objdump', '-f', chrome_path],
                               stdout=subprocess.PIPE,
                               stderr=subprocess.PIPE)
-      arch, serr = pobj.communicate()
-      format = re.compile(r'(file format) ([a-zA-Z0-9_\-]+)')
-      arch = format.search(arch).group(2)
+      arch = pobj.communicate()[0]
+      file_format = re.compile(r'(file format) ([a-zA-Z0-9_\-]+)')
+      arch = file_format.search(arch).group(2)
       if '64' in arch:
         return 'x86_64'
       return 'x86_32'
-    except:
+    except Exception:
       print "FAILED"
       arch = None
   return arch
 
 
 def GetLoaderPath(platform):
   sdk_path = GetSDKPath()
   arch = GetChromeArch(platform)
   return os.path.join(sdk_path, 'tools', 'sel_ldr_' + arch)
 
@@ skipping 66 matching lines @@
       out = GetPluginPath(platform)
     print out
     return 0
 
   print 'Failed with args: ' + ' '.join(args)
   return 1
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv))