Edit: /usr/share/aclocal-1.11/cond-if.m4 (1050B)
# AM_COND_IF -*- Autoconf -*-
# Copyright (C) 2008 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.
# serial 1
# _AM_COND_IF
# _AM_COND_ELSE
# _AM_COND_ENDIF
# --------------
# These macros are only used for tracing.
m4_define([_AM_COND_IF])
m4_define([_AM_COND_ELSE])
m4_define([_AM_COND_ENDIF])
# AM_COND_IF(COND, [IF-TRUE], [IF-FALSE])
# ---------------------------------------
# If the shell condition matching COND is true, execute IF-TRUE,
# otherwise execute IF-FALSE. Allow automake to learn about conditional
# instantiating macros (the AC_CONFIG_FOOS).
AC_DEFUN([AM_COND_IF],
[m4_ifndef([_AM_COND_VALUE_$1],
[m4_fatal([$0: no such condition "$1"])])dnl
_AM_COND_IF([$1])dnl
if _AM_COND_VALUE_$1; then
m4_default([$2], [:])
m4_ifval([$3],
[_AM_COND_ELSE([$1])dnl
else
$3
])dnl
_AM_COND_ENDIF([$1])dnl
fi[]dnl
])