Rework symbol visibility for easier maintenance

Save in a few special cases, _X_EXPORT should not be used in C source
files. Instead, it should be used in headers, and the proper C source
include that header. Some special cases are symbols that need to be
shared between modules, but not expected to be used by external drivers,
and symbols that are accessible via LoaderSymbol/dlopen.

  This patch also adds conditionally some new sdk header files, depending
on extensions enabled. These files were added to match pattern for
other extensions/modules, that is, have the headers "deciding" symbol
visibility in the sdk. These headers are:
o Xext/panoramiXsrv.h, Xext/panoramiX.h
o fbpict.h (unconditionally)
o vidmodeproc.h
o mioverlay.h (unconditionally, used only by xaa)
o xfixes.h (unconditionally, symbols required by dri2)

  LoaderSymbol and similar functions now don't have different prototypes,
in loaderProcs.h and xf86Module.h, so that both headers can be included,
without the need of defining IN_LOADER.

  xf86NewInputDevice() device prototype readded to xf86Xinput.h, but
not exported (and with a comment about it).

os/connection.c

@@ -141,12 +141,12 @@ fd_set LastSelectMask;		/* mask returned from last select call */
 fd_set ClientsWithInput;	/* clients with FULL requests in buffer */
 fd_set ClientsWriteBlocked;	/* clients who cannot receive output */
 fd_set OutputPending;		/* clients with reply/event data ready to go */
-_X_EXPORT int MaxClients = 0;
+int MaxClients = 0;
 Bool NewOutputPending;		/* not yet attempted to write some new output */
 Bool AnyClientsWriteBlocked;	/* true if some client blocked on write */
 
 static Bool RunFromSmartParent;	/* send SIGUSR1 to parent process */
-_X_EXPORT Bool PartialNetwork;	/* continue even if unable to bind all addrs */
+Bool PartialNetwork;	/* continue even if unable to bind all addrs */
 static Pid_t ParentProcess;
 
 static Bool debug_conns = FALSE;
@@ -156,7 +156,7 @@ static fd_set GrabImperviousClients;
 static fd_set SavedAllClients;
 static fd_set SavedAllSockets;
 static fd_set SavedClientsWithInput;
-_X_EXPORT int GrabInProgress = 0;
+int GrabInProgress = 0;
 
 #if !defined(WIN32)
 int *ConnectionTranslation = NULL;
@@ -273,7 +273,7 @@ lookup_trans_conn (int fd)
 
 /* Set MaxClients and lastfdesc, and allocate ConnectionTranslation */
 
-_X_EXPORT void
+void
 InitConnectionLimits(void)
 {
     lastfdesc = -1;
@@ -358,7 +358,7 @@ InitParentProcess(void)
 #endif
 }
 
-_X_EXPORT void
+void
 NotifyParentProcess(void)
 {
 #if !defined(WIN32)
@@ -375,7 +375,7 @@ NotifyParentProcess(void)
  *    At initialization, create the sockets to listen on for new clients.
  *****************/
 
-_X_EXPORT void
+void
 CreateWellKnownSockets(void)
 {
     int		i;
@@ -442,7 +442,7 @@ CreateWellKnownSockets(void)
 #endif
 }
 
-_X_EXPORT void
+void
 ResetWellKnownSockets (void)
 {
     int i;
@@ -493,7 +493,7 @@ ResetWellKnownSockets (void)
 #endif
 }
 
-_X_EXPORT void
+void
 CloseWellKnownConnections(void)
 {
     int i;
@@ -618,7 +618,7 @@ AuthAudit (ClientPtr client, Bool letin,
 #endif	
 }
 
-_X_EXPORT XID
+XID
 AuthorizationIDOfClient(ClientPtr client)
 {
     if (client->osPrivate)
@@ -647,7 +647,7 @@ AuthorizationIDOfClient(ClientPtr client)
  *
  *****************************************************************/
 
-_X_EXPORT char * 
+char *
 ClientAuthorized(ClientPtr client, 
     unsigned int proto_n, char *auth_proto, 
     unsigned int string_n, char *auth_string)
@@ -798,7 +798,7 @@ AllocNewConnection (XtransConnInfo trans_conn, int fd, CARD32 conn_time)
  *****************/
 
 /*ARGSUSED*/
-_X_EXPORT Bool
+Bool
 EstablishNewConnections(ClientPtr clientUnused, pointer closure)
 {
     fd_set  readyconnections;     /* set of listeners that are ready */
@@ -980,7 +980,7 @@ CloseDownFileDescriptor(OsCommPtr oc)
  *    to check each and every socket individually.
  *****************/
 
-_X_EXPORT void
+void
 CheckConnections(void)
 {
 #ifndef WIN32
@@ -1040,7 +1040,7 @@ CheckConnections(void)
  *    Delete client from AllClients and free resources 
  *****************/
 
-_X_EXPORT void
+void
 CloseDownConnection(ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1058,7 +1058,7 @@ CloseDownConnection(ClientPtr client)
 	AuditF("client %d disconnected\n", client->index);
 }
 
-_X_EXPORT void
+void
 AddGeneralSocket(int fd)
 {
     FD_SET(fd, &AllSockets);
@@ -1066,14 +1066,14 @@ AddGeneralSocket(int fd)
 	FD_SET(fd, &SavedAllSockets);
 }
 
-_X_EXPORT void
+void
 AddEnabledDevice(int fd)
 {
     FD_SET(fd, &EnabledDevices);
     AddGeneralSocket(fd);
 }
 
-_X_EXPORT void
+void
 RemoveGeneralSocket(int fd)
 {
     FD_CLR(fd, &AllSockets);
@@ -1081,7 +1081,7 @@ RemoveGeneralSocket(int fd)
 	FD_CLR(fd, &SavedAllSockets);
 }
 
-_X_EXPORT void
+void
 RemoveEnabledDevice(int fd)
 {
     FD_CLR(fd, &EnabledDevices);
@@ -1098,7 +1098,7 @@ RemoveEnabledDevice(int fd)
  *    This routine is "undone" by ListenToAllClients()
  *****************/
 
-_X_EXPORT int
+int
 OnlyListenToOneClient(ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1135,7 +1135,7 @@ OnlyListenToOneClient(ClientPtr client)
  *    Undoes OnlyListentToOneClient()
  ****************/
 
-_X_EXPORT void
+void
 ListenToAllClients(void)
 {
     if (GrabInProgress)
@@ -1153,7 +1153,7 @@ ListenToAllClients(void)
  *    Must have cooresponding call to AttendClient.
  ****************/
 
-_X_EXPORT void
+void
 IgnoreClient (ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1188,7 +1188,7 @@ IgnoreClient (ClientPtr client)
  *    Adds one client back into the input masks.
  ****************/
 
-_X_EXPORT void
+void
 AttendClient (ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1213,7 +1213,7 @@ AttendClient (ClientPtr client)
 
 /* make client impervious to grabs; assume only executing client calls this */
 
-_X_EXPORT void
+void
 MakeClientGrabImpervious(ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1232,7 +1232,7 @@ MakeClientGrabImpervious(ClientPtr client)
 
 /* make client pervious to grabs; assume only executing client calls this */
 
-_X_EXPORT void
+void
 MakeClientGrabPervious(ClientPtr client)
 {
     OsCommPtr oc = (OsCommPtr)client->osPrivate;
@@ -1262,7 +1262,7 @@ MakeClientGrabPervious(ClientPtr client)
 
 #ifdef XQUARTZ
 /* Add a fd (from launchd) to our listeners */
-_X_EXPORT void ListenOnOpenFD(int fd, int noxauth) {
+void ListenOnOpenFD(int fd, int noxauth) {
     char port[256];
     XtransConnInfo ciptr;