error: impossible constraint in ‘asm’

[slj2606]

Hello,

I am trying to compile dtls-server.c in TinyDTLS and I am getting the error given below:

make dtls-server.wismote TARGET=wismote
Makefile:44: warning: overriding recipe for target 'clean'
/home/user/contiki/Makefile.include:219: warning: ignoring old recipe for target 'clean'
CC dtls-server.c
In file included from dtls-server.c:15:0:
/usr/include/signal.h:321:1: warning: ‘interrupt’ attribute ignored [-Wattributes]
In file included from /home/user/contiki/apps/tinydtls/dtls-crypto.h:29:0,
from /home/user/contiki/apps/tinydtls/dtls-peer.h:28,
from /home/user/contiki/apps/tinydtls/dtls.h:30,
from /home/user/contiki/apps/tinydtls/dtls-support.h:7,
from /home/user/contiki/apps/tinydtls/tinydtls.h:148,
from dtls-server.c:19:
/home/user/contiki/apps/tinydtls/dtls-numeric.h: In function ‘dtls_int_to_uint24’:
/home/user/contiki/apps/tinydtls/dtls-numeric.h:47:3: warning: right shift count >= width of type [enabled by default]
/home/user/contiki/apps/tinydtls/dtls-numeric.h: In function ‘dtls_int_to_uint32’:
/home/user/contiki/apps/tinydtls/dtls-numeric.h:55:3: warning: right shift count >= width of type [enabled by default]
/home/user/contiki/apps/tinydtls/dtls-numeric.h:56:3: warning: right shift count >= width of type [enabled by default]
/home/user/contiki/apps/tinydtls/dtls-numeric.h: In function ‘dtls_uint24_to_int’:
/home/user/contiki/apps/tinydtls/dtls-numeric.h:99:3: warning: left shift count >= width of type [enabled by default]
/home/user/contiki/apps/tinydtls/dtls-numeric.h: In function ‘dtls_uint32_to_int’:
/home/user/contiki/apps/tinydtls/dtls-numeric.h:106:3: warning: left shift count >= width of type [enabled by default]
/home/user/contiki/apps/tinydtls/dtls-numeric.h:107:3: warning: left shift count >= width of type [enabled by default]

dtls-server.c: In function ‘main’:
dtls-server.c:342:5: error: impossible constraint in ‘asm’
dtls-server.c:343:5: error: impossible constraint in ‘asm’
dtls-server.c:369: confused by earlier errors, bailing out

/home/user/contiki/Makefile.include:260: recipe for target 'dtls-server.co' failed
make: *** [dtls-server.co] Error 1
Process returned error code 2

---

The error in the main function points to lines 342 and 434 which has the following macros in dtls-server.c file:

FD_ZERO(&rfds);
FD_ZERO(&wfds);

I am not sure how to fix this issue.

Kindly help.

Thank You.