Re: [Qemu-devel] [PATCH v2 2/2] make: load only required dependency files.

[Markus Armbruster]

Paolo Bonzini <address@hidden> writes:

> On 05/08/2015 19:29, Victor Kaplansky wrote:
>> The old rules.mak loads dependency .d files using include directive
>> with file glob pattern "*.d". This breaks the build when build tree has
>> remanent *.d files from another build.
>> 
>> This patch fixes this by
>>   - loading precise list of .d files made from *.o and *.mo.
>>   - specifying explicit list of required dependency info files for
>>      *.hex autogenerated sources.
>> 
>> Note that Makefile still includes some .d in rood directory by including
>> "*.d".
>> 
>> Signed-off-by: Victor Kaplansky <address@hidden>
>> ---
>>  hw/i386/Makefile.objs | 2 ++
>>  rules.mak             | 2 +-
>>  2 files changed, 3 insertions(+), 1 deletion(-)
>> 
>> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
>> index bd4f147..311d364 100644
>> --- a/hw/i386/Makefile.objs
>> +++ b/hw/i386/Makefile.objs
>> @@ -10,6 +10,8 @@ obj-y += acpi-build.o
>>  hw/i386/acpi-build.o: hw/i386/acpi-build.c \
>>      hw/i386/acpi-dsdt.hex hw/i386/q35-acpi-dsdt.hex
>>  
>> +-include hw/i386/acpi-dsdt.d hw/i386/q35-acpi-dsdt.d
>> +
>
> Having to include the files manually is ugly though.
>
> The failed builds are ugly too, but I'm not sure which is worse... :(
> Failed builds happen rarely

Not for me.

>                             and there are other cases where you should
> just "make distclean" your way out of a failure.

ccache saves.

>                                                   On the other hand,
> more complicated makefiles have to be maintained always.

Globbing in makefiles is rarely a good idea.

Including *.d is as questionable as linking *.o would be.