X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fftruncate.m4;h=c3c33426525de12c30f35da7f1d44286f562f9d6;hb=485d6733ec4255ae5679fcc495c52de81234cc69;hp=d25c17ef66e51fe0a653e2e86de102c368cc2a9e;hpb=44d7c1c1f004fa9bfb8ec3948de2671a7958cf5b;p=gnulib.git

diff --git a/m4/ftruncate.m4 b/m4/ftruncate.m4
index d25c17ef6..c3c334265 100644
--- a/m4/ftruncate.m4
+++ b/m4/ftruncate.m4
@@ -1,23 +1,46 @@
-#serial 7
+# serial 16
 
 # See if we need to emulate a missing ftruncate function using fcntl or chsize.
 
-# Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
+# Copyright (C) 2000-2001, 2003-2007, 2009-2011 Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.
 
+# FIXME: remove this macro, along with all uses of HAVE_FTRUNCATE in 2012,
+# if the check below provokes no more reports.  So far, the only report
+# arose from a test build of this gnulib module, cross-compiling to mingw:
+# <http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/9203>
+# Now (in 2010), MSVC has been raised as a possible target:
+# <http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/21394/focus=21396>
+
 AC_DEFUN([gl_FUNC_FTRUNCATE],
 [
-  AC_REPLACE_FUNCS(ftruncate)
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CHECK_FUNCS_ONCE([ftruncate])
   if test $ac_cv_func_ftruncate = no; then
-    gl_PREREQ_FTRUNCATE
+    HAVE_FTRUNCATE=0
+    case "$host_os" in
+      mingw*)
+        # Yes, we know mingw lacks ftruncate.
+        ;;
+      *)
+        # If someone lacks ftruncate, make configure fail, and request
+        # a bug report to inform us about it.
+        if test x"$SKIP_FTRUNCATE_CHECK" != xyes; then
+          AC_MSG_FAILURE([Your system lacks the ftruncate function.
+              Please report this, along with the output of "uname -a", to the
+              bug-coreutils@gnu.org mailing list.  To continue past this point,
+              rerun configure with SKIP_FTRUNCATE_CHECK=yes.
+              E.g., ./configure SKIP_FTRUNCATE_CHECK=yes])
+        fi
+    esac
   fi
 ])
 
 # Prerequisites of lib/ftruncate.c.
 AC_DEFUN([gl_PREREQ_FTRUNCATE],
 [
-  AC_CHECK_HEADERS_ONCE(unistd.h)
-  AC_CHECK_FUNCS(chsize)
+  AC_CHECK_FUNCS([chsize])
 ])