lkml.org 
[lkml]   [2019]   [Sep]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v3 bpf-next 05/14] samples: bpf: makefile: use __LINUX_ARM_ARCH__ selector for arm
On Mon, Sep 16, 2019 at 01:44:23PM -0700, Andrii Nakryiko wrote:
>On Mon, Sep 16, 2019 at 3:59 AM Ivan Khoronzhuk
><ivan.khoronzhuk@linaro.org> wrote:
>>
>> For arm, -D__LINUX_ARM_ARCH__=X is min version used as instruction
>> set selector and is absolutely required while parsing some parts of
>> headers. It's present in KBUILD_CFLAGS but not in autoconf.h, so let's
>> retrieve it from and add to programs cflags. In another case errors
>> like "SMP is not supported" for armv7 and bunch of other errors are
>> issued resulting to incorrect final object.
>> ---
>> samples/bpf/Makefile | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
>> index 8ecc5d0c2d5b..d3c8db3df560 100644
>> --- a/samples/bpf/Makefile
>> +++ b/samples/bpf/Makefile
>> @@ -185,6 +185,16 @@ HOSTLDLIBS_map_perf_test += -lrt
>> HOSTLDLIBS_test_overhead += -lrt
>> HOSTLDLIBS_xdpsock += -pthread
>>
>> +ifeq ($(ARCH), arm)
>> +# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
>> +# headers when arm instruction set identification is requested.
>> +ARM_ARCH_SELECTOR = $(shell echo "$(KBUILD_CFLAGS) " | \
>> + sed 's/[[:blank:]]/\n/g' | sed '/^-D__LINUX_ARM_ARCH__/!d')
>
>Does the following work exactly like that without shelling out (and
>being arguably simpler)?
>
>ARM_ARCH_SELECTOR = $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
>
>> +
>> +CLANG_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
>> +KBUILD_HOSTCFLAGS := $(ARM_ARCH_SELECTOR)
>
>Isn't this clearing out previous value of KBUILD_HOSTCFLAGS? Is that
>intentional, or it was supposed to be += here?
>
>> +endif
>> +
>> # Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
>> # make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang
>> LLC ?= llc
>> --
>> 2.17.1
>>

Just left from previous version filtering all -D options.
Will update in next v., SELECTOR also.

--
Regards,
Ivan Khoronzhuk

\
 
 \ /
  Last update: 2019-09-17 00:05    [W:0.077 / U:1.184 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site