[OE-core] What is TOOLCHAIN_NEED_CONFIGSITE_CACHE for?

[Mark Hatle]

On 10/29/12 12:33 PM, Chris Larson wrote:
> On Mon, Oct 29, 2012 at 8:43 AM, Richard Purdie
> <richard.purdie at linuxfoundation.org> wrote:
>> On Mon, 2012-10-29 at 13:33 +0000, Phil Blundell wrote:
>>> This morning I happened to notice that some/all of my images had a
>>> dependency on ncurses for no obviously good reason.  (Following an
>>> earlier small crusade these are now the only remaining dependencies on
>>> ncurses in my build, so I would quite like to get rid of them.)
>>>
>>> It turns out that the dependency in question is due to the code in
>>> toolchain-scripts.bbclass (which is inherited from
>>> populate_sdk_base.bbclass, from image.bbclass) which does:
>>>
>>> TOOLCHAIN_NEED_CONFIGSITE_CACHE = "${TCLIBC} ncurses"
>>>
>>> [...]
>>>
>>> python __anonymous () {
>>>      deps = ""
>>>      for dep in (d.getVar('TOOLCHAIN_NEED_CONFIGSITE_CACHE', True) or "").split():
>>>          deps += " %s:do_populate_sysroot" % dep
>>>      d.appendVarFlag('do_configure', 'depends', deps)
>>> }
>>>
>>> The code in question was added in:
>>>
>>> commit 9e87f1347788beed181476dc4563085db14a4729
>>> Author: Lianhao Lu <lianhao.lu at intel.com>
>>> Date:   Tue Aug 16 11:15:36 2011 +0800
>>>
>>>      toolchain-script.bbclass: Collected cached site config in runtime.
>>>
>>>      [YOCTO #892]
>>>      Modify the function toolchain_create_sdk_siteconfig to collect the
>>>      cached site config files which are specified by
>>>      TOOLCHAIN_NEED_CONFIGSITE_CACHE in runtime.
>>>
>>>      Also added task dependency to ensure the cached site config files are
>>>      generated.
>>>
>>>      Signed-off-by: Lianhao Lu <lianhao.lu at intel.com>
>>>
>>> ... but I don't entirely understand from that commentary what exactly is
>>> special about ncurses that means it needs to be handled this way.  Can
>>> anybody clarify?
>>
>> We ship the "site" cache files with the toolchain. We decided to include
>> the generated cache files as well as the static ones. We currently
>> generate "site" files for libc and ncurses.
>>
>> You can almost certainly just set:
>>
>> TOOLCHAIN_NEED_CONFIGSITE_CACHE = "${TCLIBC}"
>>
>> and be happy since this just lists which generated cache site files to
>> include.
>
> Shouldn't it be pulled in via depends from the populate_sdk bits,
> rather than a task that's used both for image builds and toolchain
> builds, though?
>

Ya, this seems like a design issue.  The site cache files require the package to 
be built, but I was under the impression they were included with the dev items 
within that package.  If this isn't how it works, maybe this is a change we 
should consider.

--Mark