Re: Require GNU Make Somehow?

[Craig Burley <burley@gnu.org>]

>This isn't quite the same, since GNU make isn't required to
>build the fileutils, but it might be useful...

Thanks!  We're going to try a simple solution in the next g77 0.5.23 alpha
release, which is a release that will be based on gcc 2.8:

# We want to try to catch the common trap of building outside srcdir
# without GNU make.  We do that by adding a phony target to the
# all the LANGUAGES dependencies, and doing the check in the phony target.
$(LANGUAGES): gnumake-check
gnumake-check:
        @if [ $(srcdir) != . ]; then \
          case `$(MAKE) --version 2>/dev/null` in \
          *GNU*) true ;; \
          *) echo 1>&2 ''; \
             echo 1>&2 'You must use GNU make to build outside the source directory.'; \
             echo 1>&2 ''; \
             false;; \
          esac; \
        else true; \
        fi

(This goes into g77's Make-lang.in, a fragment that gets pulled into
the "master" Makefile for gcc when configuring with g77 present.
$(LANGUAGES) is the list of languages the user wants to build; I'd
thought about making this just "F77 f77" to catch the problem only
when g77 itself gets built, but then realized that happens well
into a build, so this approach, which Dave Love came up with, seems
best, because it kicks back on error quite quickly after issuing
the non-GNU `make' command.)

        tq vm, (burley)