MDEV-20685: compile fixes for Solaris/OSX/AIX

sig_return: Solaris/OSX returns different function ptr
Move defination to my_alarm.h as its the only use.

prevents compile warnings (copied from 10.3 branch)

mysys/my_sync.c:136:19: error: 'cur_dir_name' defined but not used [-Werror=unused-const-variable=]
  136 | static const char cur_dir_name[]= {FN_CURLIB, 0};
      |                   ^~~~~~~~~~~~

fix compile error (DEPRECATED) leaked from ssl headers.

In file included from /export/home/dan/mariadb-server-10.4/sql/sys_vars.cc:37:
/export/home/dan/mariadb-server-10.4/sql/sys_vars.ic:69: error: "DEPRECATED" redefined [-Werror]
   69 | #define DEPRECATED(X) X
      |
In file included from /export/home/dan/mariadb-server-10.4/include/violite.h:150,
                 from /export/home/dan/mariadb-server-10.4/sql/sql_class.h:38,
                 from /export/home/dan/mariadb-server-10.4/sql/sys_vars.cc:36:
/usr/include/openssl/ssl.h:2356: note: this is the location of the previous definition
 2356 | # define DEPRECATED __attribute__((deprecated))
      |

Avoid Werror condition on non-Linux:

plugin/server_audit/server_audit.c:2267:7: error: variable 'db_len_off' set but not used [-Werror=unused-but-set-variable]
 2267 |   int db_len_off;
      |       ^~~~~~~~~~
plugin/server_audit/server_audit.c:2266:7: error: variable 'db_off' set but not used [-Werror=unused-but-set-variable]
 2266 |   int db_off;
      |       ^~~~~~

auth_gssapi fix include path for Solaris

Consistent with the upstream packaged patch:
https://github.com/OpenIndiana/oi-userland/blob/oi/hipster/components/database/mariadb-103/patches/06-gssapi.h.patch

compile warnings on Solaris

[ 91%] Building C object plugin/server_audit/CMakeFiles/server_audit.dir/server_audit.c.o
/plugin/server_audit/server_audit.c: In function 'auditing_v8':
/plugin/server_audit/server_audit.c:2194:20: error: unused variable 'db_len_off' [-Werror=unused-variable]
 2194 |   static const int db_len_off= 128;
      |                    ^~~~~~~~~~
/plugin/server_audit/server_audit.c:2193:20: error: unused variable 'db_off' [-Werror=unused-variable]
 2193 |   static const int db_off= 120;
      |                    ^~~~~~
/plugin/server_audit/server_audit.c:2192:20: error: unused variable 'cmd_off' [-Werror=unused-variable]
 2192 |   static const int cmd_off= 4432;
      |                    ^~~~~~~
At top level:
/plugin/server_audit/server_audit.c:2192:20: error: 'cmd_off' defined but not used [-Werror=unused-const-variable=]
/plugin/server_audit/server_audit.c:2193:20: error: 'db_off' defined but not used [-Werror=unused-const-variable=]
 2193 |   static const int db_off= 120;
      |                    ^~~~~~
/plugin/server_audit/server_audit.c:2194:20: error: 'db_len_off' defined but not used [-Werror=unused-const-variable=]
 2194 |   static const int db_len_off= 128;
      |                    ^~~~~~~~~~
cc1: all warnings being treated as errors

tested on:
$ uname -a
SunOS openindiana 5.11 illumos-b97b1727bc i86pc i386 i86pc

include/my_alarm.h

@@ -29,6 +29,13 @@ extern ulong my_time_to_wait_for_lock;
 
 #if defined(HAVE_ALARM) && !defined(NO_ALARM_LOOP)
 #include <signal.h>
+#ifdef HAVE_SIGHANDLER_T
+#define sig_return sighandler_t
+#elif defined(SOLARIS) || defined(__sun) || defined(__APPLE__)
+typedef void (*sig_return)(int); /* Returns type from signal */
+#else
+typedef void (*sig_return)(void); /* Returns type from signal */
+#endif
 #define ALARM_VARIABLES uint alarm_old=0; \
 			sig_return alarm_signal=0
 #define ALARM_INIT	my_have_got_alarm=0 ; \

include/my_global.h

@@ -531,13 +531,6 @@ typedef int	my_socket;	/* File descriptor for sockets */
 #endif
 /* Type for fuctions that handles signals */
 #define sig_handler RETSIGTYPE
-C_MODE_START
-#ifdef HAVE_SIGHANDLER_T
-#define sig_return sighandler_t
-#else
-typedef void (*sig_return)(void); /* Returns type from signal */
-#endif
-C_MODE_END
 #if defined(__GNUC__) && !defined(_lint)
 typedef char	pchar;		/* Mixed prototypes can take char */
 typedef char	puchar;		/* Mixed prototypes can take char */

include/violite.h

@@ -138,6 +138,9 @@ typedef my_socket YASSL_SOCKET_T;
 #define YASSL_SOCKET_T_DEFINED
 #include <openssl/ssl.h>
 #include <openssl/err.h>
+#ifdef DEPRECATED
+#undef DEPRECATED
+#endif
 
 enum enum_ssl_init_error
 {

mysys/my_sync.c

@@ -133,8 +133,6 @@ int my_sync(File fd, myf my_flags)
 } /* my_sync */
 
 
-static const char cur_dir_name[]= {FN_CURLIB, 0};
-
 /*
   Force directory information to disk.
 
@@ -151,6 +149,7 @@ int my_sync_dir(const char *dir_name __attribute__((unused)),
                 myf my_flags __attribute__((unused)))
 {
 #ifdef NEED_EXPLICIT_SYNC_DIR
+  static const char cur_dir_name[]= {FN_CURLIB, 0};
   File dir_fd;
   int res= 0;
   const char *correct_dir_name;

plugin/auth_gssapi/gssapi_errmsg.cc

@@ -26,7 +26,11 @@ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 */
 
+#if defined(__FreeBSD__) ||  defined(SOLARIS) || defined(__sun)
+#include <gssapi/gssapi.h>
+#else
 #include <gssapi.h>
+#endif
 #include <string.h>
 void gssapi_errmsg(OM_uint32 major, OM_uint32 minor, char *buf, size_t size)
 {

plugin/server_audit/server_audit.c

@@ -2177,6 +2177,7 @@ struct mysql_event_general_v8
 
 static void auditing_v8(MYSQL_THD thd, struct mysql_event_general_v8 *ev_v8)
 {
+#ifdef __linux__
 #ifdef DBUG_OFF
   #ifdef __x86_64__
   static const int cmd_off= 4200;
@@ -2198,6 +2199,7 @@ static void auditing_v8(MYSQL_THD thd, struct mysql_event_general_v8 *ev_v8)
   static const int db_len_off= 68;
   #endif /*x86_64*/
 #endif /*DBUG_OFF*/
+#endif /*__linux*/
 
   struct mysql_event_general event;
 
@@ -2259,6 +2261,7 @@ static void auditing_v13(MYSQL_THD thd, unsigned int *ev_v0)
 
 int get_db_mysql57(MYSQL_THD thd, char **name, int *len)
 {
+#ifdef __linux__
   int db_off;
   int db_len_off;
   if (debug_server_started)
@@ -2282,7 +2285,6 @@ int get_db_mysql57(MYSQL_THD thd, char **name, int *len)
 #endif /*x86_64*/
   }
 
-#ifdef __linux__
   *name= *(char **) (((char *) thd) + db_off);
   *len= *((int *) (((char*) thd) + db_len_off));
   if (*name && (*name)[*len] != 0)

sql/sql_parse.cc

@@ -1295,7 +1295,8 @@ bool do_command(THD *thd)
       mysql_mutex_lock(&thd->LOCK_thd_data);
       if (thd->wsrep_conflict_state == MUST_ABORT)
       {
-        DBUG_PRINT("wsrep",("aborted for wsrep rollback: %lu", thd->real_id));
+        DBUG_PRINT("wsrep",("aborted for wsrep rollback: %lu",
+                   (long unsigned int) thd->real_id));
         wsrep_client_rollback(thd);
       }
       mysql_mutex_unlock(&thd->LOCK_thd_data);