Re: [dpdk-dev] [PATCH v3] build: add pkg-config validation

[Gregory Etelson <getelson@nvidia.com>]

Hello Bruce,

Thank you for the review.
I'll update the script and post a new patch to the mailing list.

Regards,
Gregory

> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Tuesday, November 3, 2020 12:09
> To: Gregory Etelson <getelson@nvidia.com>
> Cc: dev@dpdk.org; bluca@debian.org; christian.ehrhardt@canonical.com;
> david.marchand@redhat.com; ktraynor@redhat.com; Matan Azrad
> <matan@nvidia.com>; Raslan Darawsheh <rasland@nvidia.com>; NBU-Contact-
> Thomas Monjalon <thomas@monjalon.net>
> Subject: Re: [PATCH v3] build: add pkg-config validation
> 
> External email: Use caution opening links or attachments
> 
> 
> On Mon, Nov 02, 2020 at 09:34:26PM +0200, Gregory Etelson wrote:
> > DPDK relies on pkg-config(1) to provide correct parameters for
> > compiler and linker used in application build.
> > Inaccurate build parameters, produced by pkg-config from DPDK .pc
> > files could fail application build or cause unpredicted results
> > during application runtime.
> >
> > This patch validates host pkg-config utility and notifies about
> > known issues.
> >
> > Signed-off-by: Gregory Etelson <getelson@nvidia.com>
> 
> All looks reasonably ok to me. Some suggestions inline below which might
> shorten and simplify the script a bit.
> 
> Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> 
> > ---
> >  buildtools/pkg-config/meson.build           | 11 ++++++
> >  buildtools/pkg-config/pkgconfig-validate.sh | 43 +++++++++++++++++++++
> >  doc/guides/linux_gsg/sys_reqs.rst           |  5 +++
> >  3 files changed, 59 insertions(+)
> >  create mode 100755 buildtools/pkg-config/pkgconfig-validate.sh
> >
> > diff --git a/buildtools/pkg-config/meson.build b/buildtools/pkg-
> config/meson.build
> > index 5f19304289..4f907d7638 100644
> > --- a/buildtools/pkg-config/meson.build
> > +++ b/buildtools/pkg-config/meson.build
> > @@ -53,3 +53,14 @@ This is required for a number of static inline
> functions in the public headers.'
> >  # For static linking with dependencies as shared libraries,
> >  # the internal static libraries must be flagged explicitly.
> >  run_command(py3, 'set-static-linker-flags.py', check: true)
> > +
> > +pkgconf = find_program('pkg-config', 'pkgconf', required: false)
> > +if (pkgconf.found())
> > +     cmd = run_command('./pkgconfig-validate.sh', pkgconf.path(),
> > +                        check:false)
> > +     if cmd.returncode() != 0
> > +             version = run_command(pkgconf, '--version')
> > +             warning('invalid pkg-config version @0@'.format(
> > +                     version.stdout().strip()))
> > +     endif
> > +endif
> > diff --git a/buildtools/pkg-config/pkgconfig-validate.sh
> b/buildtools/pkg-config/pkgconfig-validate.sh
> > new file mode 100755
> > index 0000000000..4b3bd2a9e3
> > --- /dev/null
> > +++ b/buildtools/pkg-config/pkgconfig-validate.sh
> > @@ -0,0 +1,43 @@
> > +#! /bin/sh
> > +# SPDX-License-Identifier: BSD-3-Clause
> > +
> > +# Statically linked private DPDK objects of form
> > +# -l:file.a must be positionned between --whole-archive … --no-whole-
> archive
> > +# linker parameters.
> > +# Old pkg-config versions misplace --no-whole-archive parameter and put
> it
> > +# next to --whole-archive.
> > +test1_static_libs_order () {
> > +     PKG_CONFIG_PATH="$PKG_CONFIG_PATH" \
> > +     "$PKGCONF" --libs --static libdpdk | \
> > +     grep -q 'whole-archive.*l:lib.*no-whole-archive'
> > +     if test "$?" -ne 0 ; then
> > +             echo "WARNING: invalid static libraries order"
> > +             ret=1
> 
> Why not just set "ret=$?" before the condition check? Save having to
> pre-init ret to 0 and having it as a global variable.
> 
> Also, since the meson.build file has the error printout, you can consider
> dropping the warning text too, in which case you can have the function
> just
> return the return-code from grep itself.
> 
> > +     fi
> > +     return $ret
> > +}
> > +
> > +if [ "$#" -ne 1 ]; then
> > +     echo "$0: no pkg-config parameter"
> > +     exit 1
> > +fi
> > +PKGCONF="$1"
> > +
> > +$PKGCONF --exists libdpdk
> > +if [ $? -ne 0 ]; then
> > +     # pkgconf could not locate libdpdk.pc from existing
> PKG_CONFIG_PATH
> > +     # check meson template instead
> 
> Why bother checking first? Since all we care about is the pkg-config
> behaviour, we can just always add on the path to PKG_CONFIG_PATH and
> guarantee that way a dpdk file will be found.
> 
> > +     pc_file=$(find "$MESON_BUILD_ROOT" -type f -name 'libdpdk.pc' -
> quit)
> > +     if [ ! -f "$pc_file" ]; then
> > +             echo "$0: cannot locate libdpdk.pc"
> > +             exit 1
> > +     fi
> > +     pc_dir=$(dirname "$pc_file")
> > +     PKG_CONFIG_PATH="${PKG_CONFIG_PATH}:$pc_dir"
> > +fi
> > +
> > +ret=0
> > +test1_static_libs_order
> > +if [ $ret -ne 0 ]; then
> > +     exit $ret
> > +fi
> 
> Rather than branching, why not just call "exit $ret"?
> 
> Given that the return code from the script will be the result of the last
> command run, and if we are ok to dropping the print of the warning, I
> think
> the test function can be dropped and the last line of the script just made
> the call to pkg-config and grep.
> 
> > diff --git a/doc/guides/linux_gsg/sys_reqs.rst
> b/doc/guides/linux_gsg/sys_reqs.rst
> > index 6ecdc04aa9..b67da05e13 100644
> > --- a/doc/guides/linux_gsg/sys_reqs.rst
> > +++ b/doc/guides/linux_gsg/sys_reqs.rst
> > @@ -60,6 +60,11 @@ Compilation of the DPDK
> >
> >  *   Linux kernel headers or sources required to build kernel modules.
> >
> > +
> > +**Known Issues:**
> > +
> > +*   pkg-config v0.27 supplied with RHEL-7 does not process correctly
> libdpdk.pc Libs.private section.
> > +
> >  .. note::
> >
> >     Please ensure that the latest patches are applied to third party
> libraries
> > --
> > 2.28.0
> >