X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fftruncate.m4;h=95e371b0c04b092838618540d49bd109a8965f03;hb=f1195ccd1ee2cd56ed6b82a76fdee8de0c3d78b7;hp=0397a000c2317fad1f92f38557f96486416df28f;hpb=ee76465ad82c04707c78ff3ed723358217c9e34f;p=gnulib.git

diff --git a/m4/ftruncate.m4 b/m4/ftruncate.m4
index 0397a000c..95e371b0c 100644
--- a/m4/ftruncate.m4
+++ b/m4/ftruncate.m4
@@ -1,14 +1,46 @@
-#serial 4
+# serial 14
 
 # See if we need to emulate a missing ftruncate function using fcntl or chsize.
 
-AC_DEFUN([jm_FUNC_FTRUNCATE],
-[
-  AC_CHECK_FUNCS(ftruncate, , [ftruncate_missing=yes])
+# Copyright (C) 2000-2001, 2003-2007, 2009-2010 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 2010,
+# 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>
 
-  if test "$ftruncate_missing" = yes; then
-    AC_CHECK_HEADERS([unistd.h])
-    AC_CHECK_FUNCS([chsize])
-    AC_LIBOBJ(ftruncate)
+AC_DEFUN([gl_FUNC_FTRUNCATE],
+[
+  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+  AC_REQUIRE([AC_CANONICAL_HOST])
+  AC_CHECK_FUNCS_ONCE([ftruncate])
+  if test $ac_cv_func_ftruncate = no; then
+    HAVE_FTRUNCATE=0
+    AC_LIBOBJ([ftruncate])
+    gl_PREREQ_FTRUNCATE
+    case "$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_FUNCS([chsize])
+])