1 files changed, 32 insertions, 0 deletions
diff --git a/gl/m4/unistd_h.m4 b/gl/m4/unistd_h.m4
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+++ b/gl/m4/unistd_h.m4
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+# unistd_h.m4 serial 3
+dnl Copyright (C) 2006 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.
+
+dnl Written by Simon Josefsson
+
+AC_DEFUN([gl_HEADER_UNISTD],
+[
+  AC_CHECK_HEADERS([unistd.h], [
+    UNISTD_H=''
+  ], [
+    UNISTD_H='unistd.h'
+  ])
+  AC_SUBST(UNISTD_H)
+  dnl This module decides to build unistd.h if it is missing.
+  dnl The fchdir module decides to build unistd.h if fchdir() is missing.
+  dnl Therefore check for the prerequisites of lib/unistd.h always.
+  gl_PREREQ_UNISTD
+])
+
+dnl Prerequisites of lib/unistd.h.
+AC_DEFUN([gl_PREREQ_UNISTD],
+[
+  AC_CHECK_HEADERS_ONCE([unistd.h])
+  if test $ac_cv_header_unistd_h = yes; then
+    gl_ABSOLUTE_HEADER([unistd.h])
+    ABSOLUTE_UNISTD_H=\"$gl_cv_absolute_unistd_h\"
+  fi
+  AC_SUBST([ABSOLUTE_UNISTD_H])
+])