I have the same error (also on Debian GNU/Linux 8/testing x86-64).

[ 0%] Building C object Externals/enet/CMakeFiles/enet.dir/unix.c.o
/home/rydroid/dolphin-emu/Externals/enet/unix.c:52:13: error: conflicting types for ‘socklen_t’
typedef int socklen_t;
^
In file included from /usr/include/x86_64-linux-gnu/sys/socket.h:38:0,
from /home/rydroid/dolphin-emu/Externals/enet/unix.c:8:
/usr/include/x86_64-linux-gnu/bits/socket.h:33:21: note: previous declaration of ‘socklen_t’ was here
typedef __socklen_t socklen_t;
^
/home/rydroid/dolphin-emu/Externals/enet/unix.c: In function ‘enet_socket_get_address’:
/home/rydroid/dolphin-emu/Externals/enet/unix.c:220:57: warning: pointer targets in passing argument 3 of ‘getsockname’ differ in signedness [-Wpointer-sign]
if (getsockname (socket, (struct sockaddr *) & sin, & sinLength) == -1)
^
In file included from /home/rydroid/dolphin-emu/Externals/enet/unix.c:8:0:
/usr/include/x86_64-linux-gnu/sys/socket.h:127:12: note: expected ‘socklen_t * restrict’ but argument is of type ‘socklen_t *’
extern int getsockname (int __fd, __SOCKADDR_ARG __addr,
^
/home/rydroid/dolphin-emu/Externals/enet/unix.c: In function ‘enet_socket_get_option’:
/home/rydroid/dolphin-emu/Externals/enet/unix.c:308:71: warning: pointer targets in passing argument 5 of ‘getsockopt’ differ in signedness [-Wpointer-sign]
result = getsockopt (socket, SOL_SOCKET, SO_ERROR, value, & len);
^
In file included from /home/rydroid/dolphin-emu/Externals/enet/unix.c:8:0:
/usr/include/x86_64-linux-gnu/sys/socket.h:219:12: note: expected ‘socklen_t * restrict’ but argument is of type ‘socklen_t *’
extern int getsockopt (int __fd, int __level, int __optname,
^
/home/rydroid/dolphin-emu/Externals/enet/unix.c: In function ‘enet_socket_accept’:
/home/rydroid/dolphin-emu/Externals/enet/unix.c:345:22: warning: pointer targets in passing argument 3 of ‘accept’ differ in signedness [-Wpointer-sign]
address != NULL ? & sinLength : NULL);
^
In file included from /home/rydroid/dolphin-emu/Externals/enet/unix.c:8:0:
/usr/include/x86_64-linux-gnu/sys/socket.h:243:12: note: expected ‘socklen_t * restrict’ but argument is of type ‘socklen_t *’
extern int accept (int __fd, __SOCKADDR_ARG __addr,
^
Externals/enet/CMakeFiles/enet.dir/build.make:215: recipe for target 'Externals/enet/CMakeFiles/enet.dir/unix.c.o' failed
make[2]: *** [Externals/enet/CMakeFiles/enet.dir/unix.c.o] Error 1
CMakeFiles/Makefile2:167: recipe for target 'Externals/enet/CMakeFiles/enet.dir/all' failed
make[1]: *** [Externals/enet/CMakeFiles/enet.dir/all] Error 2
Makefile:147: recipe for target 'all' failed
make: *** [all] Error 2

<sys/socket.h>

• does not define socklen_t or HAS_SOCKLEN_T
• it does include bits/socket.h

<bits/socket.h>
defines typedef __socklen_t socklen_t;
but not HAS_SOCKLEN_T

/* Type for length arguments in socket calls. */
#ifndef __socklen_t_defined
typedef __socklen_t socklen_t;

define __socklen_t_defined¶

#endif

so instead of using HAS_SOCKLEN_T use __socklen_t_defined
** note: that __socklen_t_defined will always being defined because <sys/socket.h> has been included

bits/types.h defines:
__STD_TYPE __U32_TYPE __socklen_t;
where as the following code is used (change int to unsigned int or __U32_TYPE, should fix compiler warnings as well)
#ifndef HAS_SOCKLEN_T
typedef int socklen_t;
#endif

Hi,

the attached patch fixes the problem for me. I tried not to harm the APPLE #ifdefs logic. Additionally, I kept the original "typedef int socklen_t" for APPLE since they seem not to have __socklen_t.

That patch may fix the issue, but we currently have logic in the CMakeLists file to detect socklen_t. This was not working because of a global scoping issue, which is fixed in that PR.

Ah alright. Thanks for the fix :).

I have still the problem with commit 4fd980e6d48fc15d31121878eb61e4b331c1c4bd and a fully updated Debian GNU/Linux 8/jessie (after git pull, I did a "cmake .." before make).

You may need to delete your build directory for the change to take effect.

Thanks, it works. Sorry, I thought that cmake was more intelligent.