X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=m4%2Flseek.m4;h=73c40698c2f9c0d18dee0e64b460bb2109b0a1bc;hb=d48d7d9132b633a3a31a2f6f131ce7033f1faf8d;hp=075c2f42c2108415cb87a073a313e5178123f044;hpb=e461ff7387db733080824cb94b239d8d1d09c4f3;p=gnulib.git

diff --git a/m4/lseek.m4 b/m4/lseek.m4
index 075c2f42c..73c40698c 100644
--- a/m4/lseek.m4
+++ b/m4/lseek.m4
@@ -1,5 +1,5 @@
-# lseek.m4 serial 1
-dnl Copyright (C) 2007 Free Software Foundation, Inc.
+# lseek.m4 serial 8
+dnl Copyright (C) 2007, 2009-2011 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.
@@ -8,23 +8,41 @@ AC_DEFUN([gl_FUNC_LSEEK],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
   AC_REQUIRE([AC_PROG_CC])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
   AC_CACHE_CHECK([whether lseek detects pipes], [gl_cv_func_lseek_pipe],
-    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([#include <unistd.h>],
-[#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
-/* mingw mistakenly returns 0 when trying to seek on pipes.  */
+    [if test $cross_compiling = no; then
+       AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+#include <sys/types.h> /* for off_t */
+#include <stdio.h> /* for SEEK_CUR */
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#else /* on Windows with MSVC */
+# include <io.h>
+#endif
+]], [[
+  /* Exit with success only if stdin is seekable.  */
+  return lseek (0, (off_t)0, SEEK_CUR) < 0;
+]])],
+         [if test -s conftest$ac_exeext \
+             && ./conftest$ac_exeext < conftest.$ac_ext \
+             && test 1 = "`echo hi \
+               | { ./conftest$ac_exeext; echo $?; cat >/dev/null; }`"; then
+            gl_cv_func_lseek_pipe=yes
+          else
+            gl_cv_func_lseek_pipe=no
+          fi],
+         [gl_cv_func_lseek_pipe=no])
+     else
+       AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
+#if ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) || defined __BEOS__
+/* mingw and BeOS mistakenly return 0 when trying to seek on pipes.  */
   Choke me.
-#endif])],
-      [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no])])
+#endif]])],
+         [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no])
+     fi])
   if test $gl_cv_func_lseek_pipe = no; then
-    gl_REPLACE_LSEEK
+    REPLACE_LSEEK=1
+    AC_DEFINE([LSEEK_PIPE_BROKEN], [1],
+      [Define to 1 if lseek does not detect pipes.])
   fi
 ])
-
-AC_DEFUN([gl_REPLACE_LSEEK],
-[
-  AC_LIBOBJ([lseek])
-  AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
-  REPLACE_LSEEK=1
-  AC_DEFINE([LSEEK_PIPE_BROKEN], [1],
-	    [Define to 1 if lseek does not detect pipes.])
-])