Only check for System V IPC if multiprocessing is enabled. The unix

port only uses System V IPC for shared memory and semaphores to
communicate between nodes in a multiprocessor configuration.  If you
disable multiprocessing, then this code should be unused.  Thus systems
like Cygwin which are POSIX but do not support System V IPC should
not work.

c/src/exec/score/cpu/configure.in

@@ -38,7 +38,10 @@ RTEMS_CHECK_MULTIPROCESSING(RTEMS_BSP)
 RTEMS_CHECK_POSIX_API(RTEMS_BSP)
 RTEMS_CHECK_ITRON_API(RTEMS_BSP)
 
-RTEMS_CHECK_SYSV_UNIX
+# The only use of System V IPC is the UNIX port when multiprocessing.
+if test "$HAS_MP" = "yes"; then
+  RTEMS_CHECK_SYSV_UNIX
+fi
 
 # find all the Executive Makefiles
 RTEMS_CHECK_MAKEFILE($RTEMS_CPU)

c/src/exec/score/cpu/unix/cpu.c

@@ -29,9 +29,11 @@
 #include <sys/time.h>
 #include <errno.h>
 #include <unistd.h>
+#if defined(RTEMS_MULTIPROCESSING)
 #include <sys/ipc.h>
 #include <sys/shm.h>
 #include <sys/sem.h>
+#endif
 #include <string.h>   /* memset */
 
 #ifndef SA_RESTART
@@ -922,8 +924,10 @@ void _CPU_Stop_clock( void )
   setitimer(ITIMER_REAL, &new, 0);
 }
 
+extern void fix_syscall_errno( void );
+
+#if defined(RTEMS_MULTIPROCESSING)
 int  _CPU_SHM_Semid;
-extern       void fix_syscall_errno( void );
 
 void _CPU_SHM_Init(
   unsigned32   maximum_nodes,
@@ -1015,12 +1019,14 @@ void _CPU_SHM_Init(
   *shm_length = shm_size;
 
 }
+#endif
 
 int _CPU_Get_pid( void )
 {
   return getpid();
 }
 
+#if defined(RTEMS_MULTIPROCESSING)
 /*
  * Define this to use signals for MPCI shared memory driver.
  * If undefined, the shared memory driver will poll from the
@@ -1108,3 +1114,4 @@ void _CPU_SHM_Unlock(
   }
 
 }
+#endif

c/src/exec/score/cpu/unix/rtems/score/cpu.h

@@ -1061,6 +1061,8 @@ void _CPU_Start_clock(
 
 void _CPU_Stop_clock( void );
 
+#if defined(RTEMS_MULTIPROCESSING)
+
 void _CPU_SHM_Init( 
   unsigned32   maximum_nodes,
   boolean      is_master_node,
@@ -1084,6 +1086,7 @@ void _CPU_SHM_Lock(
 void _CPU_SHM_Unlock(
   int semaphore
 );
+#endif
 
 #ifdef __cplusplus
 }

cpukit/score/cpu/unix/cpu.c

@@ -29,9 +29,11 @@
 #include <sys/time.h>
 #include <errno.h>
 #include <unistd.h>
+#if defined(RTEMS_MULTIPROCESSING)
 #include <sys/ipc.h>
 #include <sys/shm.h>
 #include <sys/sem.h>
+#endif
 #include <string.h>   /* memset */
 
 #ifndef SA_RESTART
@@ -922,8 +924,10 @@ void _CPU_Stop_clock( void )
   setitimer(ITIMER_REAL, &new, 0);
 }
 
+extern void fix_syscall_errno( void );
+
+#if defined(RTEMS_MULTIPROCESSING)
 int  _CPU_SHM_Semid;
-extern       void fix_syscall_errno( void );
 
 void _CPU_SHM_Init(
   unsigned32   maximum_nodes,
@@ -1015,12 +1019,14 @@ void _CPU_SHM_Init(
   *shm_length = shm_size;
 
 }
+#endif
 
 int _CPU_Get_pid( void )
 {
   return getpid();
 }
 
+#if defined(RTEMS_MULTIPROCESSING)
 /*
  * Define this to use signals for MPCI shared memory driver.
  * If undefined, the shared memory driver will poll from the
@@ -1108,3 +1114,4 @@ void _CPU_SHM_Unlock(
   }
 
 }
+#endif

cpukit/score/cpu/unix/rtems/score/cpu.h

@@ -1061,6 +1061,8 @@ void _CPU_Start_clock(
 
 void _CPU_Stop_clock( void );
 
+#if defined(RTEMS_MULTIPROCESSING)
+
 void _CPU_SHM_Init( 
   unsigned32   maximum_nodes,
   boolean      is_master_node,
@@ -1084,6 +1086,7 @@ void _CPU_SHM_Lock(
 void _CPU_SHM_Unlock(
   int semaphore
 );
+#endif
 
 #ifdef __cplusplus
 }