Purify support:...

build/SConscript.main

 # Copyright (c) 2006-2008 The Chromium 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 os
 import shutil
 import sys
 
 
 p = ARGUMENTS.get('PROGRESS')
 if p == 'spinner':
   Progress(['/\r', '|\r', '\\\r', '-\r'], interval=5, file=open('con', 'w'))
 elif p == 'name':
   Progress('$TARGET\r', overwrite=True, file=open('con', 'w'))
 
 
 default_warnings = ['no-missing-sconscript', 'no-no-parallel-support']
 default_warnings = ['no-no-parallel-support']
 SetOption('warn', default_warnings + GetOption('warn'))
 
 
+chrome_build_type = ARGUMENTS.get('CHROME_BUILD_TYPE')
+if chrome_build_type is None:
+  chrome_build_type = os.environ.get('CHROME_BUILD_TYPE', ''),
+
+chromium_build = ARGUMENTS.get('CHROMIUM_BUILD')
+if chromium_build is None:
+  chromium_build = os.environ.get('CHROMIUM_BUILD', ''),
+
+
 root_env = Environment(
     tools = ['component_setup',
              'chromium_builders',
              'chromium_load_component'],
 
     # Requested list of system (shared) libraries, from the comma separated
     # SYSTEM_LIBS command-line argument
     req_system_libs = [],
     # All supported system libraries, for the help message
     all_system_libs = [],
 
-    CHROME_BUILD_TYPE = os.environ.get('CHROME_BUILD_TYPE', ''),
-    CHROMIUM_BUILD = os.environ.get('CHROMIUM_BUILD', ''),
+    CHROME_BUILD_TYPE = chrome_build_type,
+    CHROMIUM_BUILD = chromium_build,
 
     CHROME_SRC_DIR = '$MAIN_DIR/..',
     DESTINATION_ROOT = '$MAIN_DIR/Hammer',
 
     # Where ComponentTestProgram() will build test executables.
     TESTS_DIR = '$DESTINATION_ROOT',
 
     # Where ComponentProgram() will build program executables.
     STAGING_DIR = '$DESTINATION_ROOT',
 
@@ skipping 631 matching lines @@
         'all_libraries',
         'all_languages',
         'all_programs',
         'all_test_programs',
     ], projects = [p],
     COMPONENT_VS_PROJECT_SCRIPT_PATH=(
         'cd $$(ProjectDir)/$VS_PROJECT_TO_MAIN_DIR && hammer.bat'),
 )
 
 # -------------------------------------------------------------------------