Re: [oe] [meta-oe][RFC PATCH] include-what-you-use: new recipe

[Christian Eggers <ceggers@arri.de>]

Hi Khem,


On Tuesday, 16 July 2024, 15:45:54 CEST, Khem Raj wrote:
> On Tue, Jul 16, 2024 at 1:08 AM Christian Eggers <ceggers@arri.de> wrote:
> 
> > On Monday, 15 July 2024, 16:18:14 CEST, Khem Raj wrote:
> > > On Mon, Jul 15, 2024 at 5:18 AM Christian Eggers via
> > lists.openembedded.org
> > > <ceggers=arri.de@lists.openembedded.org> wrote:
> > >
> > > > Based on proposal send previously here:
> > > > https://lists.yoctoproject.org/g/yocto/topic/recipe_for/83279588
> > > >
> > > > This recipe depends on meta-clang, so should it be added to that layer?
> > > >
> > > > Unfortunately the 'include-what-you-use' (iwyu) tool doesn't work yet.
> > > > Although I have installed nativesdk-clang (via CLANGSDK = "1") and
> > > > nativesdk-include-what-you-use packages, the C++ standard headers are
> > > > not found:
> > > >
> > > > include-what-you-use
> > > >
> > --sysroot=/opt/poky/5.0.2/sysroots/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi
> > > > impl/Fdt.cpp
> > > > impl/Fdt.cpp:9:10: fatal error: 'cerrno' file not found
> > > >     9 | #include <cerrno>
> > > >       |          ^~~~~~~~
> > > >
> > > > As iwyu uses Clang and I have no experience working with it, this is
> > > > probably only a beginner mistake. Can Clang use the C++ headers
> > provided
> > > > by libstdc++, or do I need to install further packages?
> > > >
> > >
> > > It can but it seems your SDK install might be missing any c++ runtime so
> > > check a simple program that includes say <iostream> header and try
> > > compiling it
> > My SDK definitely contains std:: C++ headers for target and nativesdk. But
> > the
> > libstdc++ C++ headers are installed in GCC specific locations:
> >
> > /opt/poky/5.0.2/sysroots/x86_64-pokysdk-linux/usr/include/c++/13.3.0/
> >
> > /opt/poky/5.0.2/sysroots/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/usr/include/c++/13.3.0
> >
> > How can Clang know that the C++ headers are located in the (GCC specific)
> > c++/13.3.0
> > sub directory?
> 
> 
> Try adding -stdlib=libstdc++ on clang cmdline

The following seems to work:
include-what-you-use \
    -target arm-poky-linux-musleabi \
    --sysroot /opt/poky/5.0.2/sysroots/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi \
    -stdlib++-isystem /opt/poky/5.0.2/sysroots/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/usr/include/c++/13.3.0/arm-poky-linux-musleabi \
    -stdlib++-isystem /opt/poky/5.0.2/sysroots/cortexa7t2hf-neon-vfpv4-poky-linux-musleabi/usr/include/c++/13.3.0  \
    File.cpp

Is there a way to make this a little bit handier? I would like to avoid hard coding this into my CMake toolchain file.

regards,
Christian