Re: [Qemu-devel] [PATCH v3 2/2] make: load only required dependency files.

[Peter Maydell]

On 9 August 2015 at 12:39, Michael S. Tsirkin <address@hidden> wrote:
> On Sun, Aug 09, 2015 at 12:39:59PM +0300, Victor Kaplansky wrote:
>> -        $(eval -include $(addsuffix *.d, $(sort $(dir $($v)))))
>> +        $(eval -include $(patsubst %.o,%.d,$(patsubst %.mo,%.d,$($v))))
>>          $(eval $v := $(filter-out %/,$($v))))
>>  endef
>
> Please add space after each comma.

(I thought we discussed this in v1 review?)

We don't seem to be completely consistent in our makefile
style, but I would say that the majority of it is written
in the same style used in the GNU Make docs, with no spaces
after commas.

In particular, $(patsubst %.o,%.d,$(THING)) and
$(patsubst %.o, %.d, $(THING)) do *not* expand to the same thing;
Make syntax for functions says the delimiter is 'comma', not
'comma followed by whitespace':

FOO=bar.o baz.o boz.o

all:
    @echo '$(patsubst %.o,%.d,$(FOO))'
    @echo '$(patsubst %.o, %.d, $(FOO))'
manooth$ make -f test.mak
bar.d baz.d boz.d
 bar.d  baz.d  boz.d

Admittedly most of the time the extra whitespace that ends
up in the output is unlikely to be problematic, but there
might be rare cases when it is, so the better style
recommendation is to not have spaces after the commas,
because that is always safe and always the behaviour
the author actually wanted.

thanks
-- PMM