[PATCH 2/6] tools/dwarves: add host package

[Stijn Tintel]

On 28/02/2022 16:16, Ansuel Smith wrote:
>> On 27/02/2022 17:20, Ansuel Smith wrote:
>>>  >
>>>> From: Tony Ambardar <itugrok at yahoo.com>
>>>>
>>>> dwarves is a set of tools that use the debugging information inserted in
>>>> ELF binaries by compilers such as GCC. Utilities in the dwarves suite
>>>> include pahole, which can be used to find alignment holes in structs and
>>>> classes, and also extracts other information such as CPU cacheline
>>>> alignment, helping pack those structures to achieve more cache hits.
>>>>
>>>> These tools are also used to encode and read the BTF type information
>>>> format used with the bpf syscall, making this a Linux build dependency
>>>> when using kernel BTF information.
>>> BTW this fails to build if libdw-dev is not installed with
>>>
>>> -- Checking availability of DWARF and ELF development libraries
>>> -- Could NOT find dwarf include dir
>>> -- Could NOT find libdw include dir
>>> -- Could NOT find libdw library
>>> CMake Error at cmake/modules/FindDWARF.cmake:93 (message):
>>>   Could NOT find some ELF and DWARF libraries, please install the missing
>>>   packages
>>> Call Stack (most recent call first):
>>>   CMakeLists.txt:60 (find_package)
>>>
>>>     ERROR: tools/dwarves failed to build.
>>>
>>> Should we add it to the build prereq?
>> Please try this instead:
>>
>> diff --git a/tools/dwarves/Makefile b/tools/dwarves/Makefile
>> index b02a2398a1..e5a55706be 100644
>> --- a/tools/dwarves/Makefile
>> +++ b/tools/dwarves/Makefile
>> @@ -12,14 +12,12 @@PKG_LICENSE:=GPL-2.0-only
>> PKG_LICENSE_FILES:=COPYING
>>
>> HOST_BUILD_PARALLEL:=1
>> +PKG_BUILD_DEPENDS:=elfutils/host
>>
>> include $(INCLUDE_DIR)/host-build.mk
>> include $(INCLUDE_DIR)/cmake.mk
>>
>> CMAKE_HOST_OPTIONS += \
>> -       -DCMAKE_FIND_ROOT_PATH_MODE_INCLUDE=BOTH \
>> -       -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=BOTH \
>> -       -DCMAKE_BUILD_TYPE=Release \
>>        -D__LIB=lib \
>>        -DCMAKE_INSTALL_RPATH="$(STAGING_DIR_HOST)/lib" \
>>        -DCMAKE_SKIP_RPATH=FALSE
>>
>> Thanks,
>> Stijn
>>
> No luck... still
>
Apparently we cannot use PKG_BUILD_DEPENDS or HOST_BUILD_DEPENDS in
tools/, as this is handled in include/package-dumpinfo.mk, which is
included from include/package.mk, which we don't include in tools/...
Could use some guidance here, as I am not familiar enough with this part
of the code.

Thanks,
Stijn