quick makefile question

r.stiltskin · 01-06-2010, 03:45 PM

When I put a "test" target in my Makefile containing

Code:

@echo "CXX= $(CXX)"

it tells me "CXX= g++". But I have nothing in the Makefile assigning any value to CXX, and as far as I can tell I have no CXX environment variable (no "CXX" appears when I run the shell command "env", and "echo $CXX" returns a blank line. So where's the g++ value coming from. Is this just built into Gnu Make, or is there a configuration file for make somewhere?

JohnGraham · 01-06-2010, 05:09 PM

Quote:

Originally Posted by r.stiltskin

Is this just built into Gnu Make

Basically, yes - make needs a default for things like implicit rules. You can, of course, override this in makefiles or on the command line, and if you always use $(CXX), $(MAKE), $(LD) instead of g++, make and ld (etc) then users of your Makefiles will be able to easily change which compiler to use for a whole project.

r.stiltskin · 01-06-2010, 05:17 PM

Thanks, John.