1# Check to see how 'make' treats includes.	            -*- Autoconf -*-
2
3# Copyright (C) 2001-2021 Free Software Foundation, Inc.
4#
5# This file is free software; the Free Software Foundation
6# gives unlimited permission to copy and/or distribute it,
7# with or without modifications, as long as this notice is preserved.
8
9# AM_MAKE_INCLUDE()
10# -----------------
11# Check whether make has an 'include' directive that can support all
12# the idioms we need for our automatic dependency tracking code.
13AC_DEFUN([AM_MAKE_INCLUDE],
14[AC_MSG_CHECKING([whether ${MAKE-make} supports the include directive])
15cat > confinc.mk << 'END'
16am__doit:
17	@echo this is the am__doit target >confinc.out
18.PHONY: am__doit
19END
20am__include="#"
21am__quote=
22# BSD make does it like this.
23echo '.include "confinc.mk" # ignored' > confmf.BSD
24# Other make implementations (GNU, Solaris 10, AIX) do it like this.
25echo 'include confinc.mk # ignored' > confmf.GNU
26_am_result=no
27for s in GNU BSD; do
28  AM_RUN_LOG([${MAKE-make} -f confmf.$s && cat confinc.out])
29  AS_CASE([$?:`cat confinc.out 2>/dev/null`],
30      ['0:this is the am__doit target'],
31      [AS_CASE([$s],
32          [BSD], [am__include='.include' am__quote='"'],
33          [am__include='include' am__quote=''])])
34  if test "$am__include" != "#"; then
35    _am_result="yes ($s style)"
36    break
37  fi
38done
39rm -f confinc.* confmf.*
40AC_MSG_RESULT([${_am_result}])
41AC_SUBST([am__include])])
42AC_SUBST([am__quote])])
43