[Buildroot] [PATCH v2] pkg-infra: add <pkg>_CONFIG_FIXUP to fix *-config files

["Stefan Fröberg" <stefan.froberg@petroprogram.com>]

11.1.2013 23:33, Arnout Vandecappelle kirjoitti:
> On 10/01/13 20:52, Stefan Fr?berg wrote:
>> This patch will add<pkg>_CONFIG_FIXUP variable to buildroot infra.
>> It's purpose is to inform buildroot that the package in question
>> contains some $(STAGING_DIR)/usr/bin/*-config files and that we
>> want to automatically fix prefixes of such files.
>>
>> It is often the case that many packages call these
>> files during their configuration step to determine 3rd party
>> library package locations and any flags needed to link against them.
>>
>> For example:
>> Some package might try to check the existense and linking flags
>> of NSPR package by calling $(STAGING_DIR)/usr/bin/nspr-config --prefix.
>> Without this fix, NSPR would return /usr/ as it's prefix which is
>> wrong when cross-compiling.
>> Correct would be $(STAGING_DIR)/usr.
>>
>> All packages that have<pkg>_INSTALL_STAGING = YES defined and
>> also install some config file(s) into $(STAGING_DIR)/usr/bin must
>> hereafter also define<pkg>_CONFIG_FIXUP with the corresponding
>> filename(s).
>>
>> For example:
>>
>> DIVINE_CONFIG_FIXUP = divine-config
>>
>> or for multiple files:
>>
>> IMAGEMAGICK_CONFIG_FIXUP = Magick-config Wand-config
>>
>> Signed-off-by: Stefan Fr?berg<stefan.froberg@petroprogram.com>
>> ---
>>   package/pkg-generic.mk |    6 ++++++
>>   1 files changed, 6 insertions(+), 0 deletions(-)
>>
>> diff --git a/package/pkg-generic.mk b/package/pkg-generic.mk
>> index a570ad7..9f6ea7b 100644
>> --- a/package/pkg-generic.mk
>> +++ b/package/pkg-generic.mk
>> @@ -121,6 +121,12 @@ $(BUILD_DIR)/%/.stamp_staging_installed:
>>       @$(call MESSAGE,"Installing to staging directory")
>>       $($(PKG)_INSTALL_STAGING_CMDS)
>>       $(foreach hook,$($(PKG)_POST_INSTALL_STAGING_HOOKS),$(call
>> $(hook))$(sep))
>> +    $(Q)if test -n "$($(PKG)_CONFIG_FIXUP)" ; then \
>> +        $(call MESSAGE,"Fixing package configuration files") ;\
>> +        $(SED) "s,^prefix=.*,prefix=$(STAGING_DIR)/usr,g" \
>> +            -e "s,^exec_prefix=.*,exec_prefix=$(STAGING_DIR)/usr,g" \
>> +            $(addprefix
>> $(STAGING_DIR)/usr/bin/,$($(PKG)_CONFIG_FIXUP)) ;\
>> +    fi
>
>  I just discovered that you can also write:
>
> ifneq ($($(PKG)_CONFIG_FIXUP),)
>     @$(call MESSAGE,"Fixing package configuration files")
>     $(Q)$(SED) "s,^prefix=.*,prefix=$(STAGING_DIR)/usr,g" \
>       -e "s,^exec_prefix=.*,exec_prefix=$(STAGING_DIR)/usr,g" \
>       $(addprefix $(STAGING_DIR)/usr/bin/,$($(PKG)_CONFIG_FIXUP))
> endif
>
>  Yes, you can use make conditions in rule definitions!
>
>  [How I love micro-optimizing Makefiles :-)]
>

Heh :-)

I have a question that has been nagging in my head two days now:

Let's suppose that command

$(STAGING_DIR)/usr/bin/somepkg-config  --prefix gives the correct prefix
$(STAGING_DIR)/usr  which is ok

And $(STAGING_DIR)/usr/bin/somepkg-config --cflags gives empty (which is
also fine)

But $(STAGING_DIR)/usr/bin/somepkg-config --libs gives -L/usr/lib

Isn't this horribly wrong ? I think it should give  -L$(STAGING_DIR)/usr/lib

I noticed that some *-config files have just prefix (and maybe
exec_prefix) but not any includedir or libdir defined inside them
and just give -I/usr/include for --cflags and -L/usr/lib for --libs

Im beginning to suspect now that this is the very reason that my
wireshark compilation borked, like you said Arnout, with that -L/usr/lib
being added somehow to the final linking of wireshark binary  ....

This or then that *.la file problem you mentioned.

Just my two cents

Regards
Stefan