build: Fix build and tests on macOS

This commit addresses several compatibility issues that prevented Wayland
from building and passing its test suite on macOS

Core and Compatibility changes:
- Emulate Linux behavior by explicitly setting O_NONBLOCK on connections
  (fixes blocking sendmsg issues on macOS).
- Fix compilation on platforms missing SOCK_CLOEXEC and MSG_CMSG_CLOEXEC.
- Implement wl_os_socket_peercred() using LOCAL_PEERPID for macOS.
- Ensure availability of struct itimerspec (required for POSIX Timers API).

Test suite fixes:
- Add socketpair_cloexec() wrapper to handle platforms without atomic
  SOCK_CLOEXEC support.
- Add implementation of memrchr() for platforms that do not provide it.
- Implement is_debugger_attached() for macOS to handle test timeouts.
- Fix tests to handle Mach-O binary format (instead of ELF).
- Update egl-symbols-check to support macOS *.dylib Mach-O libraries.

Build system:
- Add meson option 'xml_catalog' to allow specifying custom catalog paths.

Signed-off-by: Martin Lopatář <lopin@dataplex.cz>

src/connection.c

@@ -316,6 +316,19 @@ wl_connection_set_max_buffer_size(struct wl_connection *connection,
 	ring_buffer_ensure_space(&connection->out, 0);
 }
 
+#ifdef __APPLE__
+static int fd_setfl_nonblock(int fd)
+{
+	int flags;
+
+	flags = fcntl(fd, F_GETFL, 0);
+	if (flags < 0)
+		return flags;
+
+	return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+}
+#endif
+
 struct wl_connection *
 wl_connection_create(int fd, size_t max_buffer_size)
 {
@@ -329,6 +342,10 @@ wl_connection_create(int fd, size_t max_buffer_size)
 
 	connection->fd = fd;
 
+#ifdef __APPLE__
+	fd_setfl_nonblock(fd);
+#endif
+
 	return connection;
 }
 

src/event-loop.c

@@ -23,6 +23,8 @@
  * SOFTWARE.
  */
 
+#include "../config.h"
+
 #include <stddef.h>
 #include <stdio.h>
 #include <errno.h>
@@ -45,6 +47,13 @@
 #include "wayland-server-private.h"
 #include "wayland-os.h"
 
+#ifndef HAVE_ITIMERSPEC
+struct itimerspec {
+	struct timespec it_interval;
+	struct timespec it_value;
+};
+#endif
+
 /** \cond INTERNAL */
 
 #define TIMER_REMOVED -2

src/wayland-client.c

@@ -34,6 +34,7 @@
 #include <errno.h>
 #include <string.h>
 #include <unistd.h>
+#include <sys/signalfd.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <ctype.h>

src/wayland-os.c

@@ -75,17 +75,19 @@ wl_os_socket_cloexec(int domain, int type, int protocol)
 {
 	int fd;
 
+#ifdef SOCK_CLOEXEC
 	fd = wl_socket(domain, type | SOCK_CLOEXEC, protocol);
 	if (fd >= 0)
 		return fd;
 	if (errno != EINVAL)
 		return -1;
+#endif
 
 	fd = wl_socket(domain, type, protocol);
 	return set_cloexec_or_close(fd);
 }
 
-#if defined(__FreeBSD__)
+#if defined(LOCAL_PEERCRED)
 int
 wl_os_socket_peercred(int sockfd, uid_t *uid, gid_t *gid, pid_t *pid)
 {
@@ -101,11 +103,15 @@ wl_os_socket_peercred(int sockfd, uid_t *uid, gid_t *gid, pid_t *pid)
 #if HAVE_XUCRED_CR_PID
 	/* Since https://cgit.freebsd.org/src/commit/?id=c5afec6e895a */
 	*pid = ucred.cr_pid;
+#elif defined(LOCAL_PEERPID)
+	if (getsockopt(sockfd, SOL_LOCAL, LOCAL_PEERPID, pid, &len) < 0)
+	    *pid = 0;
 #else
 	*pid = 0;
 #endif
 	return 0;
 }
+
 #elif defined(SO_PEERCRED)
 int
 wl_os_socket_peercred(int sockfd, uid_t *uid, gid_t *gid, pid_t *pid)
@@ -125,6 +131,7 @@ wl_os_socket_peercred(int sockfd, uid_t *uid, gid_t *gid, pid_t *pid)
 	*pid = ucred.pid;
 	return 0;
 }
+
 #else
 #error "Don't know how to read ucred on this platform"
 #endif
@@ -186,7 +193,7 @@ wl_os_recvmsg_cloexec(int sockfd, struct msghdr *msg, int flags)
 	 * fix (https://cgit.freebsd.org/src/commit/?id=6ceacebdf52211).
 	 */
 #pragma message("Using fallback directly since MSG_CMSG_CLOEXEC is broken.")
-#else
+#elif defined(MSG_CMSG_CLOEXEC)
 	ssize_t len;
 
 	len = wl_recvmsg(sockfd, msg, flags | MSG_CMSG_CLOEXEC);
@@ -220,7 +227,8 @@ wl_os_accept_cloexec(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
 {
 	int fd;
 
-#ifdef HAVE_ACCEPT4
+#if defined(HAVE_ACCEPT4) && defined(SOCK_CLOEXEC)
+
 	fd = accept4(sockfd, addr, addrlen, SOCK_CLOEXEC);
 	if (fd >= 0)
 		return fd;