Re: [dpdk-dev] [PATCH 1/2] acl: remove use of weak functions

[Aaron Conole <aconole@redhat.com>]

Bruce Richardson <bruce.richardson@intel.com> writes:

> On Wed, Apr 10, 2019 at 09:54:02AM -0400, Aaron Conole wrote:
>> Bruce Richardson <bruce.richardson@intel.com> writes:
>> 
>> > Weak functions don't work well with static libraries and require the
>> > use of "whole-archive" flag to ensure that the correct function is used
>> > when linking. Since the weak functions are only used as placeholders
>> > within this library alone, we can replace them with non-weak functions
>> > using preprocessor ifdefs.
>> >
>> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com> ---
>> > lib/librte_acl/meson.build |  7 ++++++- lib/librte_acl/rte_acl.c   | 18
>> > ++++++++++++++---- mk/rte.app.mk              |  3 --- 3 files changed,
>> > 20 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/lib/librte_acl/meson.build b/lib/librte_acl/meson.build
>> > index 2207dbafe..98ece7d85 100644 --- a/lib/librte_acl/meson.build +++
>> > b/lib/librte_acl/meson.build @@ -6,7 +6,7 @@ sources =
>> > files('acl_bld.c', 'acl_gen.c', 'acl_run_scalar.c', 'rte_acl.c',
>> > 'tb_mem.c') headers = files('rte_acl.h', 'rte_acl_osdep.h')
>> >  
>> > -if arch_subdir == 'x86' +if dpdk_conf.has('RTE_ARCH_X86') sources +=
>> > files('acl_run_sse.c')
>> >  
>> >  	# compile AVX2 version if either: @@ -28,4 +28,9 @@ if arch_subdir
>> >  	== 'x86' cflags += '-DCC_AVX2_SUPPORT' endif
>> >  
>> > +elif dpdk_conf.has('RTE_ARCH_ARM') or dpdk_conf.has('RTE_ARCH_ARM64')
>> > +	cflags += '-flax-vector-conversions' +	sources +=
>> > files('acl_run_neon.c')
>> 
>> This will also need -Wno-uninitialized (otherwise it will generate
>> warnings about the search_neon_4 and search_neon_8 functions).
>> 
>> But I don't like papering over these conversions.  I'd prefer instead the
>> patches I posted at:
>> 
>> http://mails.dpdk.org/archives/dev/2019-April/129540.html and
>> http://mails.dpdk.org/archives/dev/2019-April/129541.html
>> 
>> Are you opposed to merging those?
>> 
> Nope, not in the least. I'm happy enough to rework this patch on top of
> those - I'd just had forgotten about them in my rush to get a potential
> solution out here.  I did these up quickly to show how easy it is to remove
> the need for the weak functions and the subsequent linker "--whole-archive"
> flag.
>
> /Bruce
>
> PS: I see your patch 2 does not include the Wno-uninitialized flag, is it
> not needed in your patch, or just an oversight?

It isn't needed, I resolved the issue with an explicit initialization.