Import upstream version 1.27

[debian/tar] / m4 / lseek.m4

diff --git a/m4/lseek.m4 b/m4/lseek.m4
index f6452f6f20ea7d499e127ac4650739e3abd00bc0..df9302af4074e2393ba8e9fbb30ff604030443d3 100644 (file)
--- a/m4/lseek.m4
+++ b/m4/lseek.m4
@@ -1,5 +1,5 @@
-# lseek.m4 serial 6
-dnl Copyright (C) 2007, 2009-2011 Free Software Foundation, Inc.
+# lseek.m4 serial 10
+dnl Copyright (C) 2007, 2009-2013 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.
@@ -7,43 +7,65 @@ dnl with or without modifications, as long as this notice is preserved.
 AC_DEFUN([gl_FUNC_LSEEK],
 [
   AC_REQUIRE([gl_UNISTD_H_DEFAULTS])
+
+  AC_REQUIRE([AC_CANONICAL_HOST])
   AC_REQUIRE([AC_PROG_CC])
+  AC_CHECK_HEADERS_ONCE([unistd.h])
   AC_CACHE_CHECK([whether lseek detects pipes], [gl_cv_func_lseek_pipe],
-    [if test $cross_compiling = no; then
-       AC_LINK_IFELSE([AC_LANG_PROGRAM([[
+    [case "$host_os" in
+       mingw*)
+         dnl Native Windows.
+         dnl The result of lseek (fd, (off_t)0, SEEK_CUR) or
+         dnl SetFilePointer(handle, 0, NULL, FILE_CURRENT)
+         dnl for a pipe depends on the environment: In a Cygwin 1.5
+         dnl environment it succeeds (wrong); in a Cygwin 1.7 environment
+         dnl it fails with a wrong errno value.
+         gl_cv_func_lseek_pipe=no
+         ;;
+       *)
+         if test $cross_compiling = no; then
+           AC_LINK_IFELSE([AC_LANG_PROGRAM([[
 #include <sys/types.h> /* for off_t */
 #include <stdio.h> /* for SEEK_CUR */
-#include <unistd.h>]], [[
+#if HAVE_UNISTD_H
+# include <unistd.h>
+#else /* on Windows with MSVC */
+# include <io.h>
+#endif
+]], [[
   /* Exit with success only if stdin is seekable.  */
   return lseek (0, (off_t)0, SEEK_CUR) < 0;
 ]])],
-         [if test -s conftest$ac_exeext \
-             && ./conftest$ac_exeext < conftest.$ac_ext \
-             && test 1 = "`echo hi \
-               | { ./conftest$ac_exeext; echo $?; cat >/dev/null; }`"; then
-            gl_cv_func_lseek_pipe=yes
-          else
-            gl_cv_func_lseek_pipe=no
-          fi],
-         [gl_cv_func_lseek_pipe=no])
-     else
-       AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
-#if ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) || defined __BEOS__
-/* mingw and BeOS mistakenly return 0 when trying to seek on pipes.  */
+             [if test -s conftest$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 __BEOS__
+/* 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])
-     fi])
+             [gl_cv_func_lseek_pipe=yes], [gl_cv_func_lseek_pipe=no])
+         fi
+         ;;
+     esac
+    ])
   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.])
+  AC_REQUIRE([gl_SYS_TYPES_H])
+  if test $WINDOWS_64_BIT_OFF_T = 1; then
+    REPLACE_LSEEK=1
+  fi
 ])