Conditionally include header files required by select() and poll()

Feature checks are introduced to check for all the headers required by
the select() and poll() calls. Include files are then included
conditionally without the use of any OS-specific directive. The change
also fixes a couple of problems:

- Fixed compilation under FreeBSD, NetBSD and OpenBSD when forcing the
  use of select() in the poller
- Quieted a warning mixed-sign comparison warning on FreeBSD caused by
  FD_SETSIZE being declared as an unsigned constant on that OS
- Removed the obsolescent AC_HEADER_TIME macro from the configure script

Signed-off-by: Gabriele Svelto <gabriele.svelto@gmail.com>

7 files changed, 98 insertions, 42 deletions

diff --git a/src/pgm_socket.cpp b/src/pgm_socket.cpp
index 1c214a8..7747fe0 100644
--- a/src/pgm_socket.cpp
+++ b/src/pgm_socket.cpp
@@ -26,10 +26,18 @@
 
 #ifdef XS_HAVE_WINDOWS
 #include "windows.hpp"
-#endif
-
-#ifdef XS_HAVE_LINUX
-#include <poll.h>
+#else
+#   if HAVE_SYS_TYPES
+#       include <sys/types.h>
+#   endif
+#   if HAVE_SYS_SELECT_H
+#       include <sys/select.h>
+#   endif
+#   if HAVE_POLL_H
+#       include <poll.h>
+#   elif HAVE_SYS_POLL_H
+#       include <sys/poll.h>
+#   endif
 #endif
 
 #include <stdlib.h>
diff --git a/src/poll.cpp b/src/poll.cpp
index 9f901fc..048de97 100644
--- a/src/poll.cpp
+++ b/src/poll.cpp
@@ -23,12 +23,8 @@
 
 #if defined XS_USE_ASYNC_POLL
 
-#include <sys/types.h>
-#include <sys/time.h>
-#include <poll.h>
 #include <algorithm>
 
-#include "poll.hpp"
 #include "err.hpp"
 #include "config.hpp"
 
diff --git a/src/poll.hpp b/src/poll.hpp
index c192a77..879f4ee 100644
--- a/src/poll.hpp
+++ b/src/poll.hpp
@@ -26,8 +26,22 @@
 
 #if defined XS_USE_ASYNC_POLL
 
-#include <poll.h>
 #include <stddef.h>
+
+#if HAVE_SYS_TYPES
+#   include <sys/types.h>
+#endif
+
+#if HAVE_SYS_SELECT_H
+#   include <sys/select.h>
+#endif
+
+#if HAVE_POLL_H
+#   include <poll.h>
+#elif HAVE_SYS_POLL_H
+#   include <sys/poll.h>
+#endif
+
 #include <vector>
 
 #include "fd.hpp"
diff --git a/src/select.cpp b/src/select.cpp
index 72346a4..1e3a7c4 100644
--- a/src/select.cpp
+++ b/src/select.cpp
@@ -24,17 +24,9 @@
 #if defined XS_USE_ASYNC_SELECT
 
 #include "platform.hpp"
+
 #if defined XS_HAVE_WINDOWS
-#include "windows.hpp"
-#elif defined XS_HAVE_HPUX
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/time.h>
-#elif defined XS_HAVE_OPENVMS
-#include <sys/types.h>
-#include <sys/time.h>
-#else
-#include <sys/select.h>
+#   include "windows.hpp"
 #endif
 
 #include <string.h>
diff --git a/src/select.hpp b/src/select.hpp
index df188eb..23ca4d7 100644
--- a/src/select.hpp
+++ b/src/select.hpp
@@ -31,13 +31,24 @@
 #include <stddef.h>
 #include <vector>
 
-#ifdef XS_HAVE_WINDOWS
-#include "winsock2.h"
-#elif defined XS_HAVE_OPENVMS
-#include <sys/types.h>
-#include <sys/time.h>
+#if defined XS_HAVE_WINDOWS
+#   include "winsock2.h"
 #else
-#include <sys/select.h>
+#   if HAVE_SYS_TYPES_H
+#       include <sys/types.h>
+#   endif
+#   if HAVE_SYS_TIME_H
+#       include <sys/time.h>
+#   endif
+#   if HAVE_TIME_H
+#       include <time.h>
+#   endif
+#   if HAVE_UNISTD_H
+#       include <unistd.h>
+#   endif
+#   if HAVE_SYS_SELECT_H
+#       include <sys/select.h>
+#   endif
 #endif
 
 #include "fd.hpp"
diff --git a/src/signaler.hpp b/src/signaler.hpp
index a47763f..b94858f 100644
--- a/src/signaler.hpp
+++ b/src/signaler.hpp
@@ -29,20 +29,37 @@
 //  instead of 'events' and 'revents' and defines macros to map from POSIX-y
 //  names to AIX-specific names).
 #if defined XS_USE_SYNC_POLL
-#include <poll.h>
+#   if HAVE_SYS_TYPES
+#       include <sys/types.h>
+#   endif
+#   if HAVE_SYS_SELECT_H
+#       include <sys/select.h>
+#   endif
+#   if HAVE_POLL_H
+#       include <poll.h>
+#   elif HAVE_SYS_POLL_H
+#       include <sys/poll.h>
+#   endif
 #elif defined XS_USE_SYNC_SELECT
-#if defined XS_HAVE_WINDOWS
-#include "windows.hpp"
-#elif defined XS_HAVE_HPUX
-#include <sys/param.h>
-#include <sys/types.h>
-#include <sys/time.h>
-#elif defined XS_HAVE_OPENVMS
-#include <sys/types.h>
-#include <sys/time.h>
-#else
-#include <sys/select.h>
-#endif
+#   if defined XS_HAVE_WINDOWS
+#       include "windows.hpp"
+#   else
+#       if HAVE_SYS_TYPES_H
+#           include <sys/types.h>
+#       endif
+#       if HAVE_SYS_TIME_H
+#           include <sys/time.h>
+#       endif
+#       if HAVE_TIME_H
+#           include <time.h>
+#       endif
+#       if HAVE_UNISTD_H
+#           include <unistd.h>
+#       endif
+#       if HAVE_SYS_SELECT_H
+#           include <sys/select.h>
+#       endif
+#   endif
 #endif
 
 namespace xs
diff --git a/src/upoll.cpp b/src/upoll.cpp
index 089a6a5..4d61b77 100644
--- a/src/upoll.cpp
+++ b/src/upoll.cpp
@@ -33,13 +33,31 @@
 //  instead of 'events' and 'revents' and defines macros to map from POSIX-y
 //  names to AIX-specific names).
 #if defined XS_USE_SYNC_POLL
-#include <poll.h>
+#   if HAVE_SYS_TYPES
+#       include <sys/types.h>
+#   endif
+#   if HAVE_SYS_SELECT_H
+#       include <sys/select.h>
+#   endif
+#   if HAVE_POLL_H
+#       include <poll.h>
+#   elif HAVE_SYS_POLL_H
+#       include <sys/poll.h>
+#   endif
 #endif
 
 #if defined XS_HAVE_WINDOWS
-#include "windows.hpp"
+#   include "windows.hpp"
 #else
-#include <unistd.h>
+#   if HAVE_SYS_TIME_H
+#       include <sys/time.h>
+#   endif
+#   if HAVE_TIME_H
+#       include <time.h>
+#   endif
+#   if HAVE_UNISTD_H
+#      include <unistd.h>
+#   endif
 #endif
 
 int xs::upoll (xs_pollitem_t *items_, int nitems_, int timeout_)
@@ -227,7 +245,7 @@ int xs::upoll (xs_pollitem_t *items_, int nitems_, int timeout_)
 
     //  Ensure we do not attempt to select () on more than FD_SETSIZE
     //  file descriptors.
-    xs_assert (nitems_ <= FD_SETSIZE);
+    xs_assert (nitems_ <= (int)FD_SETSIZE);
 
     fd_set pollset_in;
     FD_ZERO (&pollset_in);