build: unistd.h is manditory on unix platforms

cmake/Libraries.cmake

@@ -83,7 +83,12 @@ macro(configure_unix_libs)
   include(CheckCSourceCompiles)
 
   check_include_files(sys/socket.h HAVE_SYS_SOCKET_H)
+
+
   check_include_files(unistd.h HAVE_UNISTD_H)
+  if (NOT HAVE_UNISTD_H)
+    message(FATAL_ERROR "Missing unistd.h")
+  endif()
 
   check_function_exists(sigwait HAVE_POSIX_SIGWAIT)
   check_function_exists(inet_aton HAVE_INET_ATON)

src/lib/Config.h.in

@@ -31,9 +31,6 @@
 /* Define to 1 if you have the <sys/types.h> header file. */
 #cmakedefine HAVE_SYS_TYPES_H @HAVE_SYS_TYPES_H@
 
-/* Define to 1 if you have the <unistd.h> header file. */
-#cmakedefine HAVE_UNISTD_H @HAVE_UNISTD_H@
-
 /* Define to 1 if you have the <X11/extensions/Xrandr.h> header file. */
 #cmakedefine HAVE_X11_EXTENSIONS_XRANDR_H @HAVE_X11_EXTENSIONS_XRANDR_H@
 

src/lib/arch/unix/ArchNetworkBSD.cpp

@@ -18,10 +18,7 @@
 #include <fcntl.h>
 #include <netdb.h>
 #include <netinet/in.h>
-
-#if HAVE_UNISTD_H
 #include <unistd.h>
-#endif
 
 #if !defined(TCP_NODELAY)
 #include <netinet/tcp.h>

src/lib/platform/XWindowsEventQueueBuffer.cpp

@@ -13,11 +13,8 @@
 #include "mt/Thread.h"
 
 #include <fcntl.h>
-#if HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
 #include <poll.h>
+#include <unistd.h>
 
 //
 // EventQueueTimer