Makefile Rules and If Statements -- How?

14,121

Solution 1

You're just missing some parentheses:

ifeq ($(TOOL), toolA)
...

P.S. You can make the conditional a little tighter (and remove a little redundancy):

ci:
ifeq ($(TOOL), toolA)
    [syntax for tool (A)]
else
    [syntax for tool (B)
endif

Solution 2

Usually, you do that with a macro:

  # put tool A or tool B command line here
  TOOL=...

  ci:
       $(TOOL) args

That can be extended with something like a TOOLARGS macro, so something like

  ci:
       $(TOOL) $(TOOLARGS)

Then you can modify the makefile, or put the macros on the command line

  $ make TOOL=... TOOLARGS=...

If you want to encapsulate it, you could use an if to set the arguments.

Solution 3

Try this:

TOOLARGS_toolA = -a1 -a2
TOOLARGS_toolB = -b1 -b2

ci:
        $(TOOL) $(TOOLARGS_$(TOOL))

Now if TOOL is toolA it will use the args -a1 -a2, and if TOOL is toolB then it will use the args -b1 -b2.

Share:
14,121
RaytheonLiszt
Author by

RaytheonLiszt

Updated on June 17, 2022

Comments

  • RaytheonLiszt
    RaytheonLiszt almost 2 years

    I'm new to Makefiles so please bear with me.

    I need to modify a Makefile so some rules call different utilities depending on a variable.

    Right now, a rule looks like:

    ci:
        [shell syntax for tool (A)]
    

    But now I need ci to have a different syntax depending on the variable. So I define a global variable at the top of the file:

    TOOL = toolA
    

    or

    TOOL = toolB
    

    Ideally what I'd like is something like this, but obviously it doesn't work:

    ifeq ($TOOL, toolA)
        ci:
            [syntax for tool (A)]
    else
        ci:
            [syntax for tool (B)
    endif
    

    Does anyone know the best way to implement something like this properly?

    Thanks!!

    EDIT: The tool syntax is more complicated than one line. Sometimes its multiple lines and not just "toolA args etc etc". Sorry for the confusion!

  • RaytheonLiszt
    RaytheonLiszt almost 13 years
    That is nice! But unfortunately the "tool syntax" above is more complicated than just one line...it needs several, and sometimes it's not just "toolA". I should ahve been more clear in my original post, sorry. Thanks though!
  • RaytheonLiszt
    RaytheonLiszt almost 13 years
    That would work! But like with @mark4o's answer, the "tool syntax" above is more complicated than just one line...it needs several, and sometimes it's not just "toolA". I should have been more clear in my original post. Sorry about that. Thanks though!
  • RaytheonLiszt
    RaytheonLiszt almost 13 years
    Wow thanks! I wasn't that far off! But now I'm having problems with the if statement--but I'll create a new question for that. Thanks!
  • Jonathan Leffler
    Jonathan Leffler almost 13 years
    @RaytheonLiszt: the more complex the commands, the more merit there is to using a script to cover up the complexity.
  • RaytheonLiszt
    RaytheonLiszt almost 13 years
    @Jonathan Leffler: very true. I think if I hit one more roadblock, I'm just going to go your way and use a script. =(
  • Beta
    Beta about 11 years
    @Yasky: this is comparing strings. What are you trying to do?
  • Igbanam
    Igbanam about 11 years
    I was trying to compare a string which is an output from uname. I resorted to writing a mini shell script in the Makefile though
  • Beta
    Beta about 11 years
    @Yasky: I'm not sure what you mean, but if you post it as a question I'm sure someone can help.