Hi
On Tue, Jul 20, 2021 at 4:12 PM Jag Raman <jag.ra...@oracle.com> wrote:
>
>
> > On Jul 19, 2021, at 4:24 PM, John Levon <john.le...@nutanix.com> wrote:
> >
> > On Mon, Jul 19, 2021 at 04:00:03PM -0400, Jagannathan Raman wrote:
> >
> >> add the libvfio-user library as a submodule. build it as part of QEMU
> >>
> >> diff --git a/meson.build b/meson.build
> >> index 6e4d2d8..f2f9f86 100644
> >> --- a/meson.build
> >> +++ b/meson.build
> >> @@ -1894,6 +1894,41 @@ if get_option('cfi') and slirp_opt == 'system'
> >> + ' Please configure with --enable-slirp=git')
> >> endif
> >>
> >> +vfiouser = not_found
> >> +if have_system and multiprocess_allowed
> >> + have_internal = fs.exists(meson.current_source_dir() /
> 'libvfio-user/Makefile')
> >> +
> >> + if not have_internal
> >> + error('libvfio-user source not found - please pull git submodule')
> >> + endif
> >> +
> >> + vfiouser_files = [
> >> + 'libvfio-user/lib/dma.c',
> >> + 'libvfio-user/lib/irq.c',
> >> + 'libvfio-user/lib/libvfio-user.c',
> >> + 'libvfio-user/lib/migration.c',
> >> + 'libvfio-user/lib/pci.c',
> >> + 'libvfio-user/lib/pci_caps.c',
> >> + 'libvfio-user/lib/tran_sock.c',
> >> + ]
> >> +
> >> + vfiouser_inc = include_directories('libvfio-user/include',
> 'libvfio-user/lib')
> >> +
> >> + json_c = dependency('json-c', required: false)
> >> + if not json_c.found()
> >> + json_c = dependency('libjson-c')
> >> + endif
> >> +
> >> + libvfiouser = static_library('vfiouser',
> >> + build_by_default: false,
> >> + sources: vfiouser_files,
> >> + dependencies: json_c,
> >> + include_directories: vfiouser_inc)
> >> +
> >> + vfiouser = declare_dependency(link_with: libvfiouser,
> >> + include_directories: vfiouser_inc)
> >> +endif
> >
> > Why this way, rather than recursing into the submodule? Seems a bit
> fragile to
> > encode details of the library here.
>
> +maintainers of meson.build. I apologize for not adding them when I sent
> the
> patches out initially. I copied the email list from Elena, but Elena did
> not make
> any changes to meson.build - stupid me.
>
> John,
>
> This way appears to be present convention with QEMU - I’m also not
> very clear
> on the reason for it.
>
> For example submodules such as slirp (libslirp), capstone (libcapstone),
> dtc (libfdt) are built this way.
>
For slirp and dtc, we are eventually going to use meson subproject(). No
idea about capstone.
>
> I’m guessing it’s because QEMU doesn’t build all parts of a submodule. For
> example, QEMU only builds libfdt in the doc submodule. Similarly,
> libvfio-user only builds the core library without building the tests and
> samples.
>
>
You can give subproject options to build limited parts.
Fwiw, since libvfio-user uses cmake, we may be able to use meson
cmake.subproject() (https://mesonbuild.com/CMake-module.html).
--
Marc-André Lureau
