1# eoverflow.m4 serial 2
2dnl Copyright (C) 2004, 2006 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl From Bruno Haible.
8
9# The EOVERFLOW errno value ought to be defined in <errno.h>, according to
10# POSIX.  But some systems (like AIX 3) don't define it, and some systems
11# (like OSF/1) define it when _XOPEN_SOURCE_EXTENDED is defined.
12
13# Define EOVERFLOW as a C macro and as a substituted macro in such a way that
14# 1. on all systems, after inclusion of <errno.h>, EOVERFLOW is usable,
15# 2. on systems where EOVERFLOW is defined elsewhere, we use the same numeric
16#    value.
17
18AC_DEFUN([gl_EOVERFLOW],
19[
20  AC_REQUIRE([AC_PROG_CC])dnl
21
22  AC_CACHE_CHECK([for EOVERFLOW], ac_cv_decl_EOVERFLOW, [
23    AC_EGREP_CPP(yes,[
24#include <errno.h>
25#ifdef EOVERFLOW
26yes
27#endif
28      ], have_eoverflow=1)
29    if test -n "$have_eoverflow"; then
30      dnl EOVERFLOW exists in <errno.h>. Don't need to define EOVERFLOW ourselves.
31      ac_cv_decl_EOVERFLOW=yes
32    else
33      AC_EGREP_CPP(yes,[
34#define _XOPEN_SOURCE_EXTENDED 1
35#include <errno.h>
36#ifdef EOVERFLOW
37yes
38#endif
39        ], have_eoverflow=1)
40      if test -n "$have_eoverflow"; then
41        dnl EOVERFLOW exists but is hidden.
42        dnl Define it to the same value.
43        AC_COMPUTE_INT([ac_cv_decl_EOVERFLOW], [EOVERFLOW], [
44#define _XOPEN_SOURCE_EXTENDED 1
45#include <errno.h>
46/* The following two lines are a workaround against an autoconf-2.52 bug.  */
47#include <stdio.h>
48#include <stdlib.h>
49])
50      else
51        dnl EOVERFLOW isn't defined by the system. Define EOVERFLOW ourselves, but
52        dnl don't define it as EINVAL, because snprintf() callers want to
53        dnl distinguish EINVAL and EOVERFLOW.
54        ac_cv_decl_EOVERFLOW=E2BIG
55      fi
56    fi
57  ])
58  if test "$ac_cv_decl_EOVERFLOW" != yes; then
59    AC_DEFINE_UNQUOTED([EOVERFLOW], [$ac_cv_decl_EOVERFLOW],
60                       [Define as good substitute value for EOVERFLOW.])
61    EOVERFLOW="$ac_cv_decl_EOVERFLOW"
62    AC_SUBST(EOVERFLOW)
63  fi
64])
65
66dnl Autoconf >= 2.61 has AC_COMPUTE_INT built-in.
67dnl Remove this when we can assume autoconf >= 2.61.
68m4_ifdef([AC_COMPUTE_INT], [], [
69  AC_DEFUN([AC_COMPUTE_INT], [_AC_COMPUTE_INT([$2],[$1],[$3],[$4])])
70])
71