Is it possible to create a multi-line string variable in a Makefile

Question

I want to create a makefile variable that is a multi-line string (e.g. the body of an email release announcement). something like

ANNOUNCE_BODY=\"
Version $         


        

Answer 1

With GNU Make 3.82 and above, the .ONESHELL option is your friend when it comes to multiline shell snippets. Putting together hints from other answers, I get:

VERSION = 1.2.3
PACKAGE_NAME = foo-bar
DOWNLOAD_URL = $(PACKAGE_NAME).somewhere.net

define nwln

endef

define ANNOUNCE_BODY
Version $(VERSION) of $(PACKAGE_NAME) has been released.

It can be downloaded from $(DOWNLOAD_URL).

etc, etc.
endef

.ONESHELL:

# mind the *leading*  character
version:
    @printf "$(subst $(nwln),\n,$(ANNOUNCE_BODY))"

Make sure, when copying and pasting the above example into your editor, that any characters are preserved, else the version target will break!

Note that .ONESHELL will cause all targets in the Makefile to use a single shell for all their commands.