Il 26/07/2012 13:50, Markus Armbruster ha scritto:
>> > +qapi-errors.h qapi-errors.c :\
>> > +$(SRC_PATH)/qapi-schema-errors.json $(SRC_PATH)/scripts/qapi-errors.py
>> > + $(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-errors.py -o
>> > "." < $<, " GEN $@")
> I'm afraid this isn't quite what you want. It's shorthand for two
> separate rules with the same recipe[*]. Therefore, it's prone to run
> the recipe twice, with make blissfully unaware that each of the two runs
> clobbers the other file, too. Could conceivably lead to trouble with
> parallel execution.
>
> Paolo, Eric, maybe you can provide advice on how to best tell make that
> a recipe generates multiple files.
Hmm, I would just do
qapi-errors.h: qapi-errors.c
qapi-errors.c: $(SRC_PATH)/qapi-schema-errors.json
$(SRC_PATH)/scripts/qapi-errors.py
$(call quiet-command,$(PYTHON) $(SRC_PATH)/scripts/qapi-errors.py -o
"." < $<, " GEN $@")
I think that's what I usually saw for bison (which creates both .h and .c).
A perhaps cleaner alternative is to add a stamp file, and make both files
depend on it.
Paolo
