Obtaining directory makefile resides in

Question

What is the correct way to get the directory where the currently executing makefile resides?

I'm currently using export ROOT=$(realpath $(dir $(lastword $(MAKEFILE_LIST)))) and am running into some problems where when running make with the exact same options will result in different values for ROOT. About 90%of the time it has the correct value, but in the remaining 10% there are a number of invalid paths.

Answer 1

realpath,abspath,lastword and a couple of more functions were only introduced in GNU Make 3.81 [See ref]. Now you can get the current filename in older versions using words and word:

THIS_MAKEFILE:=$(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST))

But I am not sure of a workaround for realpath without going to the shell. e.g. this works with make v3.80:

THIS_MAKEFILE_PATH:=$(word $(words $(MAKEFILE_LIST)),$(MAKEFILE_LIST))
THIS_DIR:=$(shell cd $(dir $(THIS_MAKEFILE_PATH));pwd)
THIS_MAKEFILE:=$(notdir $(THIS_MAKEFILE_PATH))

all:
        @echo "This makefile is $(THIS_MAKEFILE) in the $(THIS_DIR) directory"

Which gives

$ make -f ../M
This makefile is M in the /home/sandipb directory

Ref: http://cvs.savannah.gnu.org/viewvc/make/NEWS?revision=2.93&root=make&view=markup