[RFC PATCH 1/4] common/image.c: image_decomp: put IH_COMP_XXX cases inside ifndef USE_HOSTCC

[Rasmus Villemoes]

On 17/06/2020 05.11, Simon Glass wrote:
> Hi Rasmus,
> 
> On Fri, 12 Jun 2020 at 05:02, Rasmus Villemoes
> <rasmus.villemoes at prevas.dk> wrote:
>>
>> When building host tools, the CONFIG_GZIP etc. symbols are not defined
>> anyway, so this does not (should not) change anything [1]. However,
>> since the host tools also don't include linux/kconfig.h, one cannot
>> use the CONFIG_IS_ENABLED() smartness in a preprocessor conditional,
>> which in turn prevents one from adding, say, an
>>
>>   #if CONFIG_IS_ENABLED(ZSTD)
>>
>> case.
>>
>> OTOH, with this, one can do that, and it also makes it possible to
>> convert say, "#ifdef CONFIG_GZIP" to "#if CONFIG_IS_ENABLED(GZIP)" to
>> make those other cases SPL-or-not-SPL-aware.
>>
>> [1] The gzip.h header is only included under !USE_HOSTCC, and removing
>> the CONFIG_GZIP conditional hence both gives an "no declaration of
>> gunzip" warning as well as breaks the link of the host tools, since
>> the gunzip code is indeed not linked in.
>>
>> Signed-off-by: Rasmus Villemoes <rasmus.villemoes at prevas.dk>
>> ---
>>  common/image.c | 2 ++
>>  1 file changed, 2 insertions(+)
>>
>> diff --git a/common/image.c b/common/image.c
>> index e1ca1a7905..73f6845274 100644
>> --- a/common/image.c
>> +++ b/common/image.c
>> @@ -458,6 +458,7 @@ int image_decomp(int comp, ulong load, ulong image_start, int type,
>>                 else
>>                         ret = -ENOSPC;
>>                 break;
>> +#ifndef USE_HOSTCC
> 
> In general I'm not a fan of the USE_HOSTCC stuff. I suspect HOST
> should be a Kconfig like anything else, although perhaps magically
> inserted somehow. Then we can do more things at compile-time.

Yes, as you can see in 2/4, I agree that the hostcc stuff is messy. I
imagine we can introduce a Kconfig.hosttools at some point which can
have a lot of def_bool y symbols (and of course one could eventually
allow them to be actually choosable, e.g. to allow the user to not build
some tool or functionality that he doesn't use and which requires some
external library dependency).

So for example, to make the fit_check_sign actually also check the
decompression, we'd add a

CONFIG_HOSTTOOL_GZIP
  def_bool y

move this USE_HOSTCC a bit further down, and change the #ifdef
CONFIG_GZIP to #if CONFIG_IS_ENABLED(GZIP) - all after checking all the
other places CONFIG_GZIP is tested... so not something that's just done
mechanically or over night, but I think it can be done mostly piecemeal.

Rasmus