Re: building templates

[Martin Kleinschmidt]

On Mit, 09 Apr 2003, Paul D. Smith wrote:

>%% Martin Kleinschmidt <address@hidden> writes:
>
>  mk> I have files xaaa.F, xbbb.F, which contain C preprocessor
>  mk> directives.  From each of these files, i want to generate
>  mk> different objects by passing different variables to the C
>  mk> preprocessor.  e.g. I want to generate zaaa.o and daaa.o from
>  mk> xaaa.F, and zbbb.o and dbbb.o from xbbb.F There will be multiple
>  mk> x???.F files but from each x???.F I will need to generate at most
>  mk> 4 (probably only 2) different objects.
>
>  mk> I thought of doing something like
>
>  mk> z%.f: x%.F
>  mk>         $(CC) -E -P $(ZWHICH) $< -o $@
>
>  mk> but that would break all other z*.o (which do not depend on an x???.F)
>  mk> Okay - I could place my templates in a separate directory, but 
>  mk> a) I don't want that and 
>  mk> b) I want to learn something about makefiles :-)
>
>  mk> I tried:
>
>  mk> ZOBJS = zaaa.o zbbb.o
>  mk> $(foreach object, $(ZOBJS), $(eval \
>  mk> $(object): $(patsubst z%.o, x%.F, $(object)) \
>  mk>         $(CC) $(PREFLAG) $(ZWHICH) $< -o $@))
>
>No, this won't work.  You don't have any newlines here first of all, so
>the whole output will appear on one line.  Replace "eval" with "warning"
>to see what make sees:
>
>$(foreach object, $(ZOBJS), $(warning \
>$(object): $(patsubst z%.o, x%.F, $(object)) \
>         $(CC) $(PREFLAG) $(ZWHICH) $< -o $@))
>
>(the $(warning ...) function is handy for this).

Uh. Ok. But adding an escaped semicolon helps:

$(foreach object, $(ZOBJS), $(warning \
$(object): $(patsubst z%.o, x%.F, $(object))\;\
$(CC) -E -P $(ZWHICH) $$< -o $$@))

yields:

Makefile:74: zaaa.o:  xaaa.F; cc -E -P -DMY_Z $< -o $@

which for me looks like what I want 
(except for the incomplete build rule)
BUT: Replacing warning bey eval:

make: *** No rule to make target `zaaa.o', needed by `program'.  Stop.



>Anyway, eval is very much overkill for this: you just need static
>pattern rules.  Try:

I was hoping, someone would say this :-)

>  ZOBJS = zaaa.o zbbb.o
>
>  $(patsubst %.o,%.f,$(ZOBJS)) : %.f : %.F
>           $(CC) -E -P $(ZWHICH) $< -o $@

I don't understand this.
That's TWO ":" in one line?
And it lacks the prefix change from z* to x*

What I am using now is:

$(ZOBJS) :  $(patsubst z%.o, x%.F, $(ZOBJS)) 
        $(CC) -E -P $(ZWHICH) $(patsubst z%.o, x%.F, $@) -o $(patsubst %.o, 
%.f, $@) 
        $(FC) $(FFLAGS) -c  $(patsubst %.o, %.f, $@) -o $@

It works, but has one drawback:
each of the objects in $(ZOBJS) now depends on all source files.
That's okay for the moment but I would like a way to change it.

I tried to add the dependence:

$(foreach dummy, $(ZOBJS), $(dummy):  $(patsubst z%.o, x%.F, $(dummy)))

Result:

Makefile:96: *** multiple target patterns.  Stop.

wrapping a $(warning ) around it makes clear why:

Makefile:96:  zaaa.o:   xaaa.F  zbbb.o:   xbbb.F

Any ideas?

   ...martin