Improve emscripten download, install and auto-detection

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
@@ skipping 232 matching lines @@
     else:
       raise error.Error('$EMSCRIPTEN not set and %s does not exist.' %
                         local_root)
 
   if not os.path.isdir(emscripten):
     raise error.Error('$EMSCRIPTEN environment variable does not point'
                       ' to a directory: %s' % emscripten)
   return emscripten
 
 
+def SetupEmscripten():
+  if 'EMSCRIPTEN' in os.environ:
+    return
+
+  local_root = GetEmscriptenRoot()
+  os.environ['EMSCRIPTEN'] = local_root
+  os.environ['EM_CONFIG'] = os.path.join(os.path.dirname(local_root),
+                                         '.emscripten')
+  try:
+    FindInPath('node')
+  except error.Error:
+    node_bin = os.path.join(paths.OUT_DIR, 'node', 'bin')
+    if not os.path.isdir(node_bin):
+      raise error.Error('node not found in path and default path not found: %s'
+                        % node_bin)
+
+    os.environ['PATH'] += ':' + node_bin
+    FindInPath('node')
+
+
 @Memoize
 def GetSDKVersion():
   """Returns the version (as a string) of the current SDK."""
   getos = os.path.join(GetSDKRoot(), 'tools', 'getos.py')
   version = subprocess.check_output([getos, '--sdk-version']).strip()
   return version
 
 
 def CheckSDKVersion(version):
   """Returns True if the currently configured SDK is 'version' or above."""
   return int(GetSDKVersion()) >= int(version)
 
 
 @Memoize
 def GetSDKRevision():
   """Returns the revision of the currently configured Native Client SDK."""
   getos = os.path.join(GetSDKRoot(), 'tools', 'getos.py')
   version = subprocess.check_output([getos, '--sdk-revision']).strip()
   return int(version)
 
 
 @Memoize
 def GetPlatform():
   """Returns the current platform name according getos.py."""
   getos = os.path.join(GetSDKRoot(), 'tools', 'getos.py')
   platform = subprocess.check_output([getos]).strip()
   return platform
 
-
 @Memoize
 def GetToolchainRoot(config):
   """Returns the toolchain folder for a given NaCl toolchain."""
   if config.toolchain == 'emscripten':
     return GetEmscriptenRoot()
 
   platform = GetPlatform()
   if config.toolchain in ('pnacl', 'clang-newlib'):
     tc_dir = os.path.join('%s_pnacl' % platform)
   else:
@@ skipping 169 matching lines @@
 
 class InstallLock(Lock):
   """Lock used when installing/uninstalling package"""
 
   def __init__(self, config):
     root = GetInstallRoot(config)
     super(InstallLock, self).__init__(root)
 
 
 CheckStdoutForColorSupport()