Cygwin support

Patch by Bert Belder.

BUG=v8:64
BUG=v8:964
BUG=v8:1029

Review URL: http://codereview.chromium.org/6525028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6842 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

SConstruct

@@ -663,8 +663,8 @@ def GuessToolchain(os):
 
 
 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'
@@ -685,7 +685,7 @@ SIMPLE_OPTIONS = {
     '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
   },

src/SConscript

@@ -234,6 +234,7 @@ SOURCES = {
   'os:android': ['platform-linux.cc', 'platform-posix.cc'],
   'os:macos':   ['platform-macos.cc', 'platform-posix.cc'],
   'os:solaris': ['platform-solaris.cc', 'platform-posix.cc'],
+  'os:cygwin':  ['platform-cygwin.cc', 'platform-posix.cc'],
   'os:nullos':  ['platform-nullos.cc'],
   'os:win32':   ['platform-win32.cc'],
   'mode:release': [],
@@ -265,6 +266,9 @@ D8_FILES = {
   'os:solaris': [
     'd8-posix.cc'
   ],
+  'os:cygwin': [
+    'd8-posix.cc'
+  ],
   'os:win32': [
     'd8-windows.cc'
   ],

src/ia32/macro-assembler-ia32.cc

@@ -1283,7 +1283,7 @@ MaybeObject* MacroAssembler::TryTailCallRuntime(Runtime::FunctionId fid,
 // If false, it is returned as a pointer to a preallocated by caller memory
 // region. Pointer to this region should be passed to a function as an
 // implicit first argument.
-#if defined(USING_BSD_ABI) || defined(__MINGW32__)
+#if defined(USING_BSD_ABI) || defined(__MINGW32__) || defined(__CYGWIN__)
 static const bool kReturnHandlesDirectly = true;
 #else
 static const bool kReturnHandlesDirectly = false;

tools/utils.py

@@ -49,6 +49,8 @@ def GuessOS():
     return 'linux'
   elif id == 'Darwin':
     return 'macos'
+  elif id.find('CYGWIN') >= 0:
+    return 'cygwin'
   elif id == 'Windows' or id == 'Microsoft':
     # On Windows Vista platform.system() can return 'Microsoft' with some
     # versions of Python, see http://bugs.python.org/issue1082