CODEWITHSUNDEEP
makefile
user2007843
user2007843

Reputation: 609

If using specific kernel build Makefile

I'm really struggling with this Makefile. I have an application that I want to build on an old Fedora computer but also on a new CentOS computer. I want to change a variable depending on which computer I am using.

This is what I've tried but it doesn't seem to work.

UNAME := $(uname -r)
ifeq ($(UNAME),2.6.32.11-99.fc12.x86_64)
        DIRS = Control Simulator
else
        DIRS = Control
endif

My question is, how can I get this to work in some standalone Makefile to test? This gives me the "*** No targets. Stop" error currently. After that I should be able to implement it in my real Makefile.

Upvotes: 0

Views: 119

Answers (1)

MadScientist
MadScientist

Reputation: 100916

As the error says, you need to provide a target to build. A makefile that doesn't contain anything other than variable assignments won't do anything. Maybe you want to add:

all:
        @echo 'DIRS = $(DIRS)'

to see what value you obtained.

However, I can already see that this won't work as written. Makefile syntax is not shell syntax, so the statement $(uname -r) is trying to expand a make variable named uname -r (just like $(FOO) is trying to expand a make variable named FOO). That variable is not set, so UNAME will always be set to the empty string.

You probably want this instead:

UNAME := $(shell uname -r)

to invoke the make shell function to run a shell script and expand to the results.

Upvotes: 1

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