X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Fftruncate.m4;h=969eb0412dfacb71c86c624abd3220239e81c562;hb=b2234a55a9065eeb2aba8d26706c63facd34f3ef;hp=d158e25b82eaf2df81e0dcdc109c0ecb086411af;hpb=3cb664198b93b8c1119c8ba1a02c1fda2136f4ce;p=gnulib.git

diff --git a/m4/ftruncate.m4 b/m4/ftruncate.m4
index d158e25b8..969eb0412 100644
--- a/m4/ftruncate.m4
+++ b/m4/ftruncate.m4
@@ -1,14 +1,41 @@
-#serial 3
+# serial 19
 
-# See if we need to emulate a missing ftruncate function using fcntl or chsize.
+# See if we need to emulate a missing ftruncate function using chsize.
 
-AC_DEFUN(jm_FUNC_FTRUNCATE,
-[
-  AC_CHECK_FUNCS(ftruncate, , [ftruncate_missing=yes])
+# Copyright (C) 2000-2001, 2003-2007, 2009-2012 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.
 
-  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_CHECK_FUNCS_ONCE([ftruncate])
+  if test $ac_cv_func_ftruncate = yes; then
+    m4_ifdef([gl_LARGEFILE], [
+      AC_REQUIRE([AC_CANONICAL_HOST])
+      case "$host_os" in
+        mingw*)
+          dnl Native Windows, and Large File Support is requested.
+          dnl The MSVCRT _chsize() function only accepts a 32-bit file size,
+          dnl and the mingw64 ftruncate64() function is unreliable (it may
+          dnl delete the file, see
+          dnl <http://mingw-w64.sourcearchive.com/documentation/2.0-1/ftruncate64_8c_source.html>).
+          dnl Use gnulib's ftruncate() implementation instead.
+          REPLACE_FTRUNCATE=1
+          ;;
+      esac
+    ], [
+      :
+    ])
+  else
+    HAVE_FTRUNCATE=0
   fi
 ])
+
+# Prerequisites of lib/ftruncate.c.
+AC_DEFUN([gl_PREREQ_FTRUNCATE],
+[
+  AC_REQUIRE([AC_C_INLINE])
+  AC_CHECK_FUNCS([chsize])
+])