Determine if Makefile is executed with gmake

Question

Say on FreeBSD an application needs to be compiled with GNU make (gmake), not the standard system make. Is there any directive I could put to the Makefile to stop executing it and print an error if the Makefile is not compiled with gmake?

Answer 1

This is an addon to Jack Kelly's answer.

After you have renamed your Makefile to GNUmakefile create Makefile with:

USEGNU=gmake $*
all:
    @$(USEGNU)
.DEFAULT:
    @$(USEGNU)

This will call gmake for you every time you run make.

Answer 2

Call your makefile GNUmakefile. GNU Make will find it, but not other makes.

The first name checked, GNUmakefile, is not recommended for most makefiles. You should use this name if you have a makefile that is specific to GNU make, and will not be understood by other versions of make. Other make programs look for makefile and Makefile, but not GNUmakefile.