Re: [dpdk-stable] [PATCH v2] ifpga/base/meson: fix looking for librt

["Hussin, Mohamad Noor Alim" <mohamad.noor.alim.hussin@intel.com>]

Hi Tianfei,

To reproduce this, assume using Ubuntu 20.04.
1. Install libfdt (It will include ifpga driver from drivers/raw/ifpga/base)
    $ sudo apt-get install libfdt-dev
2. configure DPDK library
    $ meson build
3. check libdpdk.pc file in build/meson-private/libdpdk.pc. It will include path to librt.so without this patch.

Regards,
Alim Hussin

-----Original Message-----
From: Zhang, Tianfei <tianfei.zhang@intel.com> 
Sent: Thursday, July 1, 2021 9:19 PM
To: Xu, Rosen <rosen.xu@intel.com>; Hussin, Mohamad Noor Alim <mohamad.noor.alim.hussin@intel.com>
Cc: dev@dpdk.org; Huang, Wei <wei.huang@intel.com>; stable@dpdk.org
Subject: RE: [PATCH v2] ifpga/base/meson: fix looking for librt



> -----Original Message-----
> From: Xu, Rosen <rosen.xu@intel.com>
> Sent: 2021年6月30日 18:03
> To: Hussin, Mohamad Noor Alim <mohamad.noor.alim.hussin@intel.com>;
> Zhang, Tianfei <tianfei.zhang@intel.com>
> Cc: dev@dpdk.org; Huang, Wei <wei.huang@intel.com>; stable@dpdk.org
> Subject: RE: [PATCH v2] ifpga/base/meson: fix looking for librt
> 
> CC Tianfei, who is maintainer.
> 
> > -----Original Message-----
> > From: Hussin, Mohamad Noor Alim
> <mohamad.noor.alim.hussin@intel.com>
> > Sent: Wednesday, June 30, 2021 17:26
> > To: Xu, Rosen <rosen.xu@intel.com>
> > Cc: dev@dpdk.org; Hussin, Mohamad Noor Alim 
> > <mohamad.noor.alim.hussin@intel.com>; Huang, Wei 
> > <wei.huang@intel.com>; stable@dpdk.org
> > Subject: [PATCH v2] ifpga/base/meson: fix looking for librt
> >
> > Finding with "librt" keyword would give the output with full path of 
> > librt such as 
> > /usr/lib/gcc/x86_64-linux-gnu/7/../../../x86_64-linux-gnu/librt.so
> > instead of -lrt in libdpdk.pc pkg-config file.
> >
> > Assume find_library() will prepend "lib", thus remove "lib" from "librt"
> > keyword. The output will shows as -lrt.
> >
> > This will cause an issue when compile DPDK app with static library 
> > as the path of librt has been hard-coded in the libdpdk.pc file.

How to reproduce this issue?

> >
> > Fixes: e41856b515ce ("raw/ifpga/base: enhance driver reliability in
> > multi-
> > process")
> > Cc: wei.huang@intel.com
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Mohamad Noor Alim Hussin 
> > <mohamad.noor.alim.hussin@intel.com>
> > ---
> >  drivers/raw/ifpga/base/meson.build | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/raw/ifpga/base/meson.build
> > b/drivers/raw/ifpga/base/meson.build
> > index 8d27c6021..ce592a13a 100644
> > --- a/drivers/raw/ifpga/base/meson.build
> > +++ b/drivers/raw/ifpga/base/meson.build
> > @@ -27,7 +27,7 @@ sources = [
> >
> >  rtdep = dependency('librt', required: false)  if not rtdep.found()
> > -    rtdep = cc.find_library('librt', required: false)
> > +    rtdep = cc.find_library('rt', required: false)
> >  endif
> >  if not rtdep.found()
> >      build = false
> > --
> > 2.17.1