X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fsys_select_h.m4;h=f1671186f335b474ccc590c6cd72d4f629f9d2d4;hb=8585ce2ff5698c650ba5d5e3bb99763654ad62e8;hp=865a414426eb59eece761c096eb58e12f5cda0e3;hpb=305951edfeb48e73ea5af3cd9b97e1642e439a0e;p=gnulib.git

diff --git a/m4/sys_select_h.m4 b/m4/sys_select_h.m4
index 865a41442..f1671186f 100644
--- a/m4/sys_select_h.m4
+++ b/m4/sys_select_h.m4
@@ -1,5 +1,5 @@
-# sys_select_h.m4 serial 5
-dnl Copyright (C) 2006-2008 Free Software Foundation, Inc.
+# sys_select_h.m4 serial 16
+dnl Copyright (C) 2006-2011 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
 dnl with or without modifications, as long as this notice is preserved.
@@ -7,29 +7,78 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_HEADER_SYS_SELECT],
 [
   AC_REQUIRE([gl_HEADER_SYS_SOCKET])
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
   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;]])],
+                                         [[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=''
+  dnl <sys/select.h> is always overridden, because of GNULIB_POSIXCHECK.
+  gl_CHECK_NEXT_HEADERS([sys/select.h])
+  if test $ac_cv_header_sys_select_h = yes; then
+    HAVE_SYS_SELECT_H=1
   else
-    SYS_SELECT_H='sys/select.h'
-    gl_CHECK_NEXT_HEADERS([sys/select.h])
-    if test $ac_cv_header_sys_select_h = yes; then
-      HAVE_SYS_SELECT_H=1
-    else
-      HAVE_SYS_SELECT_H=0
-    fi
-    AC_SUBST([HAVE_SYS_SELECT_H])
-    gl_PREREQ_SYS_H_WINSOCK2
-  fi
-  AC_SUBST([SYS_SELECT_H])
-  if test x$ac_cv_header_winsock2_h = xyes; then
-    AC_LIBOBJ(winsock-select)
+    HAVE_SYS_SELECT_H=0
   fi
+  AC_SUBST([HAVE_SYS_SELECT_H])
+  gl_PREREQ_SYS_H_WINSOCK2
+
+  dnl Check for declarations of anything we want to poison if the
+  dnl corresponding gnulib module is not in use.
+  gl_WARN_ON_USE_PREPARE([[
+/* Some systems require prerequisite headers.  */
+#include <sys/types.h>
+#if !(defined __GLIBC__ && !defined __UCLIBC__) && HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+#include <sys/select.h>
+    ]], [select])
+])
+
+AC_DEFUN([gl_SYS_SELECT_MODULE_INDICATOR],
+[
+  dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
+  AC_REQUIRE([gl_SYS_SELECT_H_DEFAULTS])
+  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
+  dnl Define it also as a C macro, for the benefit of the unit tests.
+  gl_MODULE_INDICATOR_FOR_TESTS([$1])
+])
+
+AC_DEFUN([gl_SYS_SELECT_H_DEFAULTS],
+[
+  GNULIB_SELECT=0; AC_SUBST([GNULIB_SELECT])
+  dnl Assume proper GNU behavior unless another module says otherwise.
+  REPLACE_SELECT=0; AC_SUBST([REPLACE_SELECT])
 ])