[Buildroot] [PATCH 2/2] xen: Remove TARGET_CONFIGURE_OPTS from make

[Alistair Francis]

On Mon, Sep 19, 2016 at 11:41 AM, Alistair Francis
<alistair.francis at xilinx.com> wrote:
> On Sat, Sep 17, 2016 at 7:09 AM, Thomas Petazzoni
> <thomas.petazzoni at free-electrons.com> wrote:
>> Hello,
>>
>> On Wed, 14 Sep 2016 01:23:32 +0200, Arnout Vandecappelle wrote:
>>> On 13-09-16 22:45, Alistair Francis wrote:
>>> > The TARGET_CONFIGURE_OPTS variable resulted in a double definition
>>> > error:
>>> > <command-line>:0:0: error: "__OBJECT_FILE__" redefined [-Werror]
>>> >
>>> > Remove the options to avoid the error.
>>>
>>>  This doesn't look right. TARGET_CONFIGURE_OPTS definitely doesn't
>>> contain -D__OBJECT_FILE__ (or you have some very weird stuff in
>>> BR2_TARGET_OPTIMIZATION).
>>
>> It doesn't look right, but it's actually what happens. When we pass our
>> TARGET_CONFIGURE_OPTS, what happens is:
>>
>> /home/thomas/projets/buildroot/output/host/usr/bin/aarch64-linux-gnu-gcc -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable
>> -Wno-unused-local-typedefs -DNDEBUG -nostdinc -fno-builtin -fno-common -Werror -Wredundant-decls -Wno-pointer-arith -pipe -g -D__XEN__ -include /home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include/xen/config.h '-D__OBJECT_FILE__="/home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/xen"' -Wa,--strip-local-absolute -MMD -MF /home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/.xen.d -mcpu=generic -mgeneral-regs-only -I/home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include -fno-stack-protector -fno-exceptions -Wnested-externs -DGCC_HAS_VISIBILITY_ATTRIBUTE -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall
>> -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -DNDEBUG -nostdinc -fno-builtin -fno-common -Werror -Wredundant-decls -Wno-pointer-arith -pipe -g -D__XEN__ -include /home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include/xen/config.h '-D__OBJECT_FILE__="asm-offsets.s"' -Wa,--strip-local-absolute -MMD -MF ./.asm-offsets.s.d -mcpu=generic -mgeneral-regs-only -I/home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include -fno-stack-protector -fno-exceptions -Wnested-externs -DGCC_HAS_VISIBILITY_ATTRIBUTE -S -o asm-offsets.s arm64/asm-offsets.c
>> <command-line>:0:0: error: "__OBJECT_FILE__" redefined [-Werror]
>> <command-line>:0:0: note: this is the location of the previous definition
>> cc1: all warnings being treated as errors
>> Makefile:103: recipe for target 'asm-offsets.s' failed
>> make[5]: *** [asm-offsets.s] Error 1
>>
>> So _OBJECT_FILE_ is really defined twice, once incorrectly, and the
>> second time correctly.
>>
>> When we stop passing $(TARGET_CONFIGURE_OPTS), the same compilation
>> step looks like this:
>>
>> /home/thomas/projets/buildroot/output/host/usr/bin/aarch64-linux-gnu-gcc -O2 -fomit-frame-pointer -DBUILD_ID -fno-strict-aliasing -std=gnu99 -Wall -Wstrict-prototypes -Wdeclaration-after-statement -Wno-unused-but-set-variable -Wno-unused-local-typedefs -DNDEBUG -nostdinc -fno-builtin -fno-common -Werror -Wredundant-decls -Wno-pointer-arith -pipe -g -D__XEN__ -include /home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include/xen/config.h '-D__OBJECT_FILE__="asm-offsets.s"' -Wa,--strip-local-absolute -MMD -MF ./.asm-offsets.s.d -mcpu=generic -mgeneral-regs-only -I/home/thomas/projets/buildroot/output/build/xen-4.7.0/xen/include -fno-stack-protector -fno-exceptions -Wnested-externs -DGCC_HAS_VISIBILITY_ATTRIBUTE -S -o asm-offsets.s arm64/asm-offsets.c
>>
>> And the build succeeds.
>>
>> So apparently, the fact that we are passing our own CFLAGS confuses the
>> Xen build system, which then adds its own CFLAGS twice for some reason.
>
> That is exactly what I see as well.
>
> It was surprising to me as well, but the only way I could figure out
> how to fix this build issue was to remove the flags.
>
> Is this an acceptable solution, or do I need to look at the Xen build
> system and patch that to not add the duplicate options?

Any opinions? I would like to fix the build issue soon.

Thanks,

Alistair

>
> Thanks,
>
> Alistair
>
>>
>> Thomas
>> --
>> Thomas Petazzoni, CTO, Free Electrons
>> Embedded Linux and Kernel engineering
>> http://free-electrons.com
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