Add initial support for color output in the build system

lib/naclports/util.py

 # Copyright 2014 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.
 
 import fcntl
 import hashlib
 import os
 import shutil
 import subprocess
 import sys
+import termcolor
 
 from naclports import error, paths
 
 GS_URL = 'http://storage.googleapis.com/'
 GS_BUCKET = 'naclports'
 GS_MIRROR_URL = '%s%s/mirror' % (GS_URL, GS_BUCKET)
 
 arch_to_pkgarch = {
   'x86_64': 'x86-64',
   'i686': 'i686',
   'arm': 'arm',
   'pnacl': 'pnacl',
 }
 
 # Inverse of arch_to_pkgarch
 pkgarch_to_arch = {v:k for k, v in arch_to_pkgarch.items()}
 
 verbose = False
 
 
+def Color(message, color):
+  if Color.enabled:
+    return termcolor.colored(message, color)
+  else:
+    return message
+
+
+def CheckForColorSupport():
+  Color.enabled = sys.stdout.isatty()

[binji, 2015/01/09 18:24:59]

Is there a better check here? Not all ttys support color, right?

[Sam Clegg, 2015/01/09 22:14:54]

This is the same change that "ls --color=auto" does.

This is from the stackoverflow discussion that seems to back this up:
http://unix.stackexchange.com/questions/9957/how-to-check-if-bash-can-print-c...
"Terminals that don't support ANSI color-changing sequences are rare enough that
it's acceptable to make their users override the default choice. In any case,
make sure your application has an option to force colors on or off."

So, I think as long as I add an option for force it to be disabled we should be
fine.

+CheckForColorSupport()
+
+
 def Memoize(f):
   """Memoization decorator for functions taking one or more arguments."""
   class Memo(dict):
     def __init__(self, f):
       super(Memo, self).__init__()
       self.f = f
 
     def __call__(self, *args):
       return self[args]
 
     def __missing__(self, key):
       ret = self[key] = self.f(*key)
       return ret
 
   return Memo(f)
 
 
 def SetVerbose(verbosity):
   global verbose
   verbose = verbosity
 
 
 def Log(message):
   """Log a message to the console (stdout)."""
   sys.stdout.write(str(message) + '\n')
   sys.stdout.flush()
 
 
+def LogHeading(message, suffix=''):
+  """Log a colored message with optional suffix."""
+  if Color.enabled:
+    Log(Color(message, 'green') + suffix)
+  else:
+    Log('#####################################################################')
+    Log(message + suffix)
+    Log('#####################################################################')
+
+
 def Warn(message):
   Log('warning: ' + message)
 
 
 def Trace(message):
   """Log a message to the console if running in verbose mode (-v)."""
   if verbose:
     Log(message)
 
 
@@ skipping 168 matching lines @@
   This file is written at install time.
   """
   root = GetInstallStampRoot(config)
   return os.path.join(root, package_name + '.list')
 
 
 def IsInstalled(package_name, config, stamp_content=None):
   """Returns True if the given package is installed."""
   stamp = GetInstallStamp(package_name, config)
   result = CheckStamp(stamp, stamp_content)
-  Trace("IsInstalled: %s -> %s" % (package_name, result))
   return result
 
 
 def CheckSDKRoot():
   """Check validity of NACL_SDK_ROOT."""
   root = GetSDKRoot()
   if not root:
     raise error.Error('$NACL_SDK_ROOT not set')
 
   if not os.path.isdir(root):
@@ skipping 86 matching lines @@
   """Lock used when building a package (essentially a lock on OUT_DIR)"""
   def __init__(self):
     super(BuildLock, self).__init__(paths.OUT_DIR)
 
 
 class InstallLock(Lock):
   """Lock used when installing/uninstalling package"""
   def __init__(self, config):
     root = GetInstallRoot(config)
     super(InstallLock, self).__init__(root)