Cygwin support

SConstruct

 # Copyright 2010 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 645 matching lines @@
   tools = Environment()['TOOLS']
   if 'gcc' in tools:
     return 'gcc'
   elif 'msvc' in tools:
     return 'msvc'
   else:
     return None
 
 
 def GuessVisibility(os, toolchain):
-  if os == 'win32' and toolchain == 'gcc':
-    # MinGW can't do it.
+  if (os == 'win32' or os == 'cygwin') and toolchain == 'gcc':
+    # MinGW / Cygwin can't do it.
     return 'default'
   elif os == 'solaris':
     return 'default'
   else:
     return 'hidden'
 
 
 OS_GUESS = utils.GuessOS()
 TOOLCHAIN_GUESS = GuessToolchain(OS_GUESS)
 ARCH_GUESS = utils.GuessArchitecture()
 VISIBILITY_GUESS = GuessVisibility(OS_GUESS, TOOLCHAIN_GUESS)
 
 
 SIMPLE_OPTIONS = {
   'toolchain': {
     'values': ['gcc', 'msvc'],
     'default': TOOLCHAIN_GUESS,
     'help': 'the toolchain to use (%s)' % TOOLCHAIN_GUESS
   },
   'os': {
-    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris'],
+    'values': ['freebsd', 'linux', 'macos', 'win32', 'android', 'openbsd', 'solaris', 'cygwin'],
     'default': OS_GUESS,
     'help': 'the os to build for (%s)' % OS_GUESS
   },
   'arch': {
     'values':['arm', 'ia32', 'x64', 'mips'],
     'default': ARCH_GUESS,
     'help': 'the architecture to build for (%s)' % ARCH_GUESS
   },
   'regexp': {
     'values': ['native', 'interpreted'],
@@ skipping 484 matching lines @@
 # version of scons.  Also, there's a bug in some revisions that
 # doesn't allow this flag to be set, so we swallow any exceptions.
 # Lovely.
 try:
   SetOption('warn', 'no-deprecated')
 except:
   pass
 
 
 Build()