Make <sys/select.h> really self-contained, also on Solaris 10.

[gnulib.git] / m4 / sys_select_h.m4

diff --git a/m4/sys_select_h.m4 b/m4/sys_select_h.m4
index c48be2c..0bb097e 100644 (file)
--- a/m4/sys_select_h.m4
+++ b/m4/sys_select_h.m4
@@ -1,4 +1,4 @@
-# sys_select_h.m4 serial 7
+# sys_select_h.m4 serial 8
 dnl Copyright (C) 2006-2009 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -11,10 +11,39 @@ AC_DEFUN([gl_HEADER_SYS_SELECT],
   AC_CACHE_CHECK([whether <sys/select.h> is self-contained],
     [gl_cv_header_sys_select_h_selfcontained],
     [
+      dnl Test against two bugs:
+      dnl 1. On many platforms, <sys/select.h> assumes prior inclusion of
+      dnl    <sys/types.h>.
+      dnl 2. On OSF/1 4.0, <sys/select.h> provides only a forward declaration
+      dnl    of 'struct timeval', and no definition of this type.
       AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/select.h>]],
                                         [[struct timeval b;]])],
         [gl_cv_header_sys_select_h_selfcontained=yes],
         [gl_cv_header_sys_select_h_selfcontained=no])
+      dnl Test against another bug:
+      dnl 3. On Solaris 10, <sys/select.h> provides an FD_ZERO implementation
+      dnl    that relies on memset(), but without including <string.h>.
+      if test $gl_cv_header_sys_select_h_selfcontained = yes; then
+        AC_COMPILE_IFELSE(
+          [AC_LANG_PROGRAM([[#include <sys/select.h>]],
+                           [[int memset; int bzero;]])
+          ],
+          [AC_LINK_IFELSE(
+             [AC_LANG_PROGRAM([[#include <sys/select.h>]], [[
+                  #undef memset
+                  #define memset nonexistent_memset
+                  extern void *memset (void *, int, unsigned long);
+                  #undef bzero
+                  #define bzero nonexistent_bzero
+                  extern void bzero (void *, unsigned long);
+                  fd_set fds;
+                  FD_ZERO (&fds);
+                ]])
+             ],
+             [],
+             [gl_cv_header_sys_select_h_selfcontained=no])
+          ])
+      fi
     ])
   if test $gl_cv_header_sys_select_h_selfcontained = yes; then
     SYS_SELECT_H=''