ifdef command not found (GNU make 3.81)

Question

I have the following makefile for a simple helloWorld program:

helloWorld: helloWorld.cpp
        echo "Argument entered is $(foo)"
        ifdef foo
        echo "Defined.";
        else
        echo "Not defined.";
        endif
        g++ -Wall -pedantic -g helloWorld.cpp -o h 

When I invoke make from the command line like so: make foo=bar, I get the following error:

bar
"not set"
echo "Argument entered is bar"
Argument entered is bar
ifdef foo
make: ifdef: Command not found
make: *** [helloWorld] Error 127

I have gone through some of the links here on SO regarding this error but have not yet been able to solve this issue.

Answer 1

Your syntax is wrong. You have the make directives (ifdef, else and endif) indented like shell commands.

See Example of a Conditional in the GNU make manual for how to do exactly this sort of thing.

libs_for_gcc = -lgnu
normal_libs =

foo: $(objects)
ifeq ($(CC),gcc)
        $(CC) -o foo $(objects) $(libs_for_gcc)
else
        $(CC) -o foo $(objects) $(normal_libs)
endif