[OE-core] [PATCH] module.bbclass: swap AR and LD order

[Jason Wessel]

On 1/24/20 3:19 PM, Khem Raj wrote:
> On Fri, Jan 24, 2020 at 1:05 PM Jason Wessel <jason.wessel at windriver.com> wrote:
>>
>> On 1/24/20 1:13 PM, Khem Raj wrote:
>>> On 1/24/20 10:19 AM, Christopher Larson wrote:
>>>> What makefile change caused this? That behavior doesn't make much sense
>>>> given how make processes its command-line arguments.
>>>>
>>>
>>> I agree with you here, it could be a rare check where one want to define
>>> what collect progam should be used ( ld or ar )
>>>
>>> besides, recently we moved AR to be gcc-ar/llvm-ar by default in config
>>> metadata, which is not going to work out of box for compiling kernel and
>>> modules, so overriding it with KERNEL_AR in
>>> module_do_compile/install/configure tasks is good change.
>>
>> I am not actually sure which part of kbuild is parsing the LD
>> arguments.  My best guess is that it is actually all the nested
>> gnumake filter calls causing the issue.
>>
>> With some further experimentation I determined that a space at the end
>> of the LD= is what causes it to think the next argument is part of the
>> prior one.  The poky distro is defining KERNEL_LD as:
>>
>> % bitbake vboxguestdrivers -e |grep ^KERNEL_LD
>> KERNEL_LD="x86_64-poky-linux-ld.bfd "
>>
>> The kbuild really doesn't like that space at the end.  You can trash out
>> a host native kernel compile module build by adding the arguments:
>>     LD="ld " JUNK_VAR="junk"
>>
>> Attempting to debug/fix kbuild doesn't seem like the right answer.
>>
>> The next version of this patch looks like what is below.  Would that be ok?
>>
>>
>> diff --git a/meta/classes/module.bbclass b/meta/classes/module.bbclass
>> index c0dfa35061..7b0a85a06d 100644
>> --- a/meta/classes/module.bbclass
>> +++ b/meta/classes/module.bbclass
>> @@ -12,6 +12,9 @@ python __anonymous () {
>>          if dep.startswith("kernel-module-"):
>>              extra_symbols.append("${STAGING_INCDIR}/" + dep + "/Module.symvers")
>>      d.setVar('KBUILD_EXTRA_SYMBOLS', " ".join(extra_symbols))
>> +    d.setVar('KERNEL_CC', d.getVar('KERNEL_CC').rstrip())
>> +    d.setVar('KERNEL_LD', d.getVar('KERNEL_LD').rstrip())
>> +    d.setVar('KERNEL_AR', d.getVar('KERNEL_AR').rstrip())
>>  }
>>
> 
> no one else uses KERNEL_* vars, so if modules cant use it then we have
> an issue, perhaps just delete it in base class where KERNEL_* vars are set
> 


I am not sure I follow what you want to see changed.  Do you want the to try
and fix up the problem where the variables are initially set?  Example:

classes/kernel-arch.bbclass:KERNEL_LD = "${CCACHE}${HOST_PREFIX}ld.bfd ${HOST_LD_KERNEL_ARCH}"

I see there are some BSPs that append to KERNEL_LD, so this problem could happen
at a later point. 

The other possibility is adding an echo to force the trimming without using the python.

@@ -41,8 +38,8 @@ module_do_compile() {
        unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
        oe_runmake KERNEL_PATH=${STAGING_KERNEL_DIR}   \
                   KERNEL_VERSION=${KERNEL_VERSION}    \
-                  CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
-                  AR="${KERNEL_AR}" \
+                  CC="$(echo ${KERNEL_CC})" LD="$(echo ${KERNEL_LD})" \
+                  AR="$(echo ${KERNEL_AR})" \
                   O=${STAGING_KERNEL_BUILDDIR} \
                   KBUILD_EXTRA_SYMBOLS="${KBUILD_EXTRA_SYMBOLS}" \
                   ${MAKE_TARGETS}
@@ -52,7 +49,7 @@ module_do_install() {
        unset CFLAGS CPPFLAGS CXXFLAGS LDFLAGS
        oe_runmake DEPMOD=echo MODLIB="${D}${nonarch_base_libdir}/modules/${KERNEL_VERSION}" \
                   INSTALL_FW_PATH="${D}${nonarch_base_libdir}/firmware" \
-                  CC="${KERNEL_CC}" LD="${KERNEL_LD}" \
+                  CC="$(echo ${KERNEL_CC})" LD="$(echo ${KERNEL_LD})" \
                   O=${STAGING_KERNEL_BUILDDIR} \
                   ${MODULES_INSTALL_TARGET}