If I compile the socket_wrapper project [1] with clang and run the tests, they
started to fail.

My current WIP tree is at [2] for reproducing it.

For the tests, socker_wrapper implements a very simple echo server. If I run
this echo server with valgrind, I see:

==11833== Invalid write of size 8
==11833==    at 0x40211E: echo_udp (echo_srv.c:783)
==11833==    by 0x401CF4: echo (echo_srv.c:826)
==11833==    by 0x40164E: main (echo_srv.c:918)
==11833==  Address 0x1ffebff248 is on thread 1's stack
==11833==  in frame #0, created by echo_udp (echo_srv.c:782)
==11833== 
==11833== Invalid write of size 8
==11833==    at 0x4036F54: memset (in
/usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==11833==    by 0x402122: echo_udp (echo_srv.c:783)
==11833==    by 0x401CF4: echo (echo_srv.c:826)
==11833==    by 0x40164E: main (echo_srv.c:918)
==11833==  Address 0x1ffefff310 is on thread 1's stack
==11833==  in frame #1, created by echo_udp (echo_srv.c:782)

Looking at the code, this is:

781 static void echo_udp(int sock)                                              
782 {
783     struct torture_address saddr = {                                        
784         .sa_socklen = sizeof(struct sockaddr_storage),                      
785     };


So it looks like, clang has a bug initializing structures!



[1] https://cwrap.org/socket_wrapper.html
[2] https://git.cryptomilk.org/users/asn/socket_wrapper.git/log/?h=master-fix