[v3,7/7] build/pkg-config: prevent overlinking
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Commit Message
Add the --as-needed linker flag to the DPDK library list in the pkg-config
file so as to prevent overlinking. Without this flag, when linking
statically using flags from $(pkg-config --static --libs libdpdk), all DPDK
drivers and libs were statically linked in, but the binary was also
requiring all the shared versions be present to run.
The real root-cause of this issue is that the DPDK libraries need to be
duplicated in the linker command when doing static linking, due to the
behaviour of pkg-config, but since that behaviour cannot be easily changed,
this is a simple workaround to avoid problems.
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Sunil Pai G <sunil.pai.g@intel.com>
---
buildtools/pkg-config/meson.build | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Comments
30/06/2020 16:14, Bruce Richardson:
> Add the --as-needed linker flag to the DPDK library list in the pkg-config
> file so as to prevent overlinking. Without this flag, when linking
> statically using flags from $(pkg-config --static --libs libdpdk), all DPDK
> drivers and libs were statically linked in, but the binary was also
> requiring all the shared versions be present to run.
>
> The real root-cause of this issue is that the DPDK libraries need to be
> duplicated in the linker command when doing static linking, due to the
> behaviour of pkg-config, but since that behaviour cannot be easily changed,
> this is a simple workaround to avoid problems.
It deserves to give a more detailed explanation here.
On Wed, Jul 01, 2020 at 09:56:13AM +0200, Thomas Monjalon wrote:
> 30/06/2020 16:14, Bruce Richardson:
> > Add the --as-needed linker flag to the DPDK library list in the pkg-config
> > file so as to prevent overlinking. Without this flag, when linking
> > statically using flags from $(pkg-config --static --libs libdpdk), all DPDK
> > drivers and libs were statically linked in, but the binary was also
> > requiring all the shared versions be present to run.
> >
> > The real root-cause of this issue is that the DPDK libraries need to be
> > duplicated in the linker command when doing static linking, due to the
> > behaviour of pkg-config, but since that behaviour cannot be easily changed,
> > this is a simple workaround to avoid problems.
>
> It deserves to give a more detailed explanation here.
>
It's already explained in commit log for patch 5 and in the code comments
added in patch 5 also, so I didn't think it was necessary again. However
can add in a V4, if needed.
/Bruce
@@ -23,7 +23,7 @@ Use libdpdk.pc instead of this file to query DPDK compile/link arguments''',
version: meson.project_version(),
subdirs: [get_option('include_subdir_arch'), '.'],
extra_cflags: pkg_extra_cflags,
- libraries: dpdk_libraries,
+ libraries: ['-Wl,--as-needed'] + dpdk_libraries,
libraries_private: dpdk_extra_ldflags)
pkg.generate(name: 'DPDK', # main DPDK pkgconfig file