ft2232_libftdi: perform basic configure checking when cross-compiling

When cross-compiling, current configure script fully ignores libftdi
unavailability and proceeds with LIBS having -lftdi -lusb, that
results in a non-obvious failure much later.

Try to verify libftdi is available by checking if ftdi_new function is
linkable.

Change-Id: I4f593d8ada1f38f82e7f1baa1a4b37b09619e1b4
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/1473
Tested-by: jenkins
Reviewed-by: Xiaofan <xiaofanc@gmail.com>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

diff --git a/configure.ac b/configure.ac
index 6e3f9861c0ccd5659d83764231c120c20608f1e4..87f95d5dd19486d23940bdfc087e94f51d53d9eb 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1128,7 +1128,8 @@ if test $build_ft2232_libftdi = yes -o $build_usb_blaster_libftdi = yes -o \
     ], [
       AC_MSG_ERROR([Cannot build & run test program using libftdi])
     ], [
-      AC_MSG_RESULT([Skipping as we are cross-compiling])
+      AC_MSG_RESULT([Skipping as we are cross-compiling, trying build only])
+      AC_SEARCH_LIBS([ftdi_new], [], [], [AC_MSG_ERROR([Cannot link with libftdi])])
     ])
 
 AC_MSG_CHECKING([for libftdi highspeed device support])