Work around a page size issue on Cygwin.

llvm-svn: 72332

llvm/lib/System/Unix/Process.inc

@@ -42,7 +42,12 @@ using namespace sys;
 unsigned 
 Process::GetPageSize() 
 {
-#if defined(HAVE_GETPAGESIZE)
+#if defined(__CYGWIN__)
+  // On Cygwin, getpagesize() returns 64k but the page size for the purposes of
+  // memory protection and mmap() is 4k.
+  // See http://www.cygwin.com/ml/cygwin/2009-01/threads.html#00492
+  static const int page_size = 0x1000;
+#elif defined(HAVE_GETPAGESIZE)
   static const int page_size = ::getpagesize();
 #elif defined(HAVE_SYSCONF)
   static long page_size = ::sysconf(_SC_PAGE_SIZE);