| # =========================================================================== |
| # https://www.gnu.org/software/autoconf-archive/ax_check_gnu_make.html |
| # =========================================================================== |
| # |
| # SYNOPSIS |
| # |
| # AX_CHECK_GNU_MAKE([run-if-true],[run-if-false]) |
| # |
| # DESCRIPTION |
| # |
| # This macro searches for a GNU version of make. If a match is found: |
| # |
| # * The makefile variable `ifGNUmake' is set to the empty string, otherwise |
| # it is set to "#". This is useful for including a special features in a |
| # Makefile, which cannot be handled by other versions of make. |
| # * The makefile variable `ifnGNUmake' is set to #, otherwise |
| # it is set to the empty string. This is useful for including a special |
| # features in a Makefile, which can be handled |
| # by other versions of make or to specify else like clause. |
| # * The variable `_cv_gnu_make_command` is set to the command to invoke |
| # GNU make if it exists, the empty string otherwise. |
| # * The variable `ax_cv_gnu_make_command` is set to the command to invoke |
| # GNU make by copying `_cv_gnu_make_command`, otherwise it is unset. |
| # * If GNU Make is found, its version is extracted from the output of |
| # `make --version` as the last field of a record of space-separated |
| # columns and saved into the variable `ax_check_gnu_make_version`. |
| # * Additionally if GNU Make is found, run shell code run-if-true |
| # else run shell code run-if-false. |
| # |
| # Here is an example of its use: |
| # |
| # Makefile.in might contain: |
| # |
| # # A failsafe way of putting a dependency rule into a makefile |
| # $(DEPEND): |
| # $(CC) -MM $(srcdir)/*.c > $(DEPEND) |
| # |
| # @ifGNUmake@ ifeq ($(DEPEND),$(wildcard $(DEPEND))) |
| # @ifGNUmake@ include $(DEPEND) |
| # @ifGNUmake@ else |
| # fallback code |
| # @ifGNUmake@ endif |
| # |
| # Then configure.in would normally contain: |
| # |
| # AX_CHECK_GNU_MAKE() |
| # AC_OUTPUT(Makefile) |
| # |
| # Then perhaps to cause gnu make to override any other make, we could do |
| # something like this (note that GNU make always looks for GNUmakefile |
| # first): |
| # |
| # if ! test x$_cv_gnu_make_command = x ; then |
| # mv Makefile GNUmakefile |
| # echo .DEFAULT: > Makefile ; |
| # echo \ $_cv_gnu_make_command \$@ >> Makefile; |
| # fi |
| # |
| # Then, if any (well almost any) other make is called, and GNU make also |
| # exists, then the other make wraps the GNU make. |
| # |
| # LICENSE |
| # |
| # Copyright (c) 2008 John Darrington <j.darrington@elvis.murdoch.edu.au> |
| # Copyright (c) 2015 Enrico M. Crisostomo <enrico.m.crisostomo@gmail.com> |
| # |
| # Copying and distribution of this file, with or without modification, are |
| # permitted in any medium without royalty provided the copyright notice |
| # and this notice are preserved. This file is offered as-is, without any |
| # warranty. |
| |
| #serial 12 |
| |
| AC_DEFUN([AX_CHECK_GNU_MAKE],dnl |
| [AC_PROG_AWK |
| AC_CACHE_CHECK([for GNU make],[_cv_gnu_make_command],[dnl |
| _cv_gnu_make_command="" ; |
| dnl Search all the common names for GNU make |
| for a in "$MAKE" make gmake gnumake ; do |
| if test -z "$a" ; then continue ; fi ; |
| if "$a" --version 2> /dev/null | grep GNU 2>&1 > /dev/null ; then |
| _cv_gnu_make_command=$a ; |
| AX_CHECK_GNU_MAKE_HEADLINE=$("$a" --version 2> /dev/null | grep "GNU Make") |
| ax_check_gnu_make_version=$(echo ${AX_CHECK_GNU_MAKE_HEADLINE} | ${AWK} -F " " '{ print $(NF); }') |
| break ; |
| fi |
| done ;]) |
| dnl If there was a GNU version, then set @ifGNUmake@ to the empty string, '#' otherwise |
| AS_VAR_IF([_cv_gnu_make_command], [""], [AS_VAR_SET([ifGNUmake], ["#"])], [AS_VAR_SET([ifGNUmake], [""])]) |
| AS_VAR_IF([_cv_gnu_make_command], [""], [AS_VAR_SET([ifnGNUmake], [""])], [AS_VAR_SET([ifnGNUmake], ["#"])]) |
| AS_VAR_IF([_cv_gnu_make_command], [""], [AS_UNSET(ax_cv_gnu_make_command)], [AS_VAR_SET([ax_cv_gnu_make_command], [${_cv_gnu_make_command}])]) |
| AS_VAR_IF([_cv_gnu_make_command], [""],[$2],[$1]) |
| AC_SUBST([ifGNUmake]) |
| AC_SUBST([ifnGNUmake]) |
| ]) |