Guard includes of termios.h with #ifdef HAVE_TERMIOS_H

Guard includes of termios.h with #ifdef HAVE_TERMIOS_H.
Test for termios.h in scons, and define/undefine HAVE_TERMIOS_H accordingly.

Fixes the below error seen on cygwin, which lacks termios.h:

In file included from gpsutils.c:22:0:
gpsd.h:349:21: fatal error: termios.h: No such file or directory
  #include <termios.h>
                      ^

4 files changed, 16 insertions, 0 deletions

diff --git a/SConstruct b/SConstruct
index ea425f85..f6f85287 100644
--- a/SConstruct
+++ b/SConstruct
@@ -624,6 +624,11 @@ else:
         announce("You do not have kernel CANbus available.")
         env["nmea2000"] = False
 
+    if config.CheckHeader("termios.h"):
+        confdefs.append("#define HAVE_TERMIOS_H 1\n")
+    else:
+        confdefs.append("/* #undef HAVE_TERMIOS_H */\n")
+
     # endian.h is required for rtcm104v2 unless the compiler defines
     # __ORDER_BIG_ENDIAN__, __ORDER_LITTLE_ENDIAN__ and __BYTE_ORDER__
     if config.CheckCompilerDefines("__ORDER_BIG_ENDIAN__") \
diff --git a/gps2udp.c b/gps2udp.c
index c530275e..c1965ccf 100644
--- a/gps2udp.c
+++ b/gps2udp.c
@@ -11,6 +11,9 @@
  * BSD terms apply: see the file COPYING in the distribution root for details.
  *
  */
+
+#include "gpsd_config.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
@@ -18,7 +21,9 @@
 #include <string.h>
 #include <strings.h>
 #include <fcntl.h>
+#ifdef HAVE_TERMIOS_H
 #include <termios.h>
+#endif /* HAVE_TERMIOS_H */
 #include <time.h>
 #include <assert.h>
 #include <sys/time.h>
diff --git a/gpsd.h-tail b/gpsd.h-tail
index 63cfd69f..fd7d2a89 100644
--- a/gpsd.h-tail
+++ b/gpsd.h-tail
@@ -5,7 +5,9 @@
  */
 #endif /* GPSD_CONFIG_H */
 
+#ifdef HAVE_TERMIOS_H
 #include <termios.h>
+#endif /* HAVE_TERMIOS_H */
 #include <stdint.h>
 #include <stdarg.h>
 #include "gps.h"
diff --git a/gpspipe.c b/gpspipe.c
index 7e6a37b1..64cc39e1 100644
--- a/gpspipe.c
+++ b/gpspipe.c
@@ -23,6 +23,8 @@
  *
  */
 
+#include "gpsd_config.h"
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdbool.h>
@@ -30,7 +32,9 @@
 #include <string.h>
 #include <strings.h>
 #include <fcntl.h>
+#ifdef HAVE_TERMIOS_H
 #include <termios.h>
+#endif /* HAVE_TERMIOS_H */
 #include <time.h>
 #include <sys/time.h>
 #include <sys/types.h>