On Tue, Jun 11, 2024 at 02:25:39PM -0400, Stefan Hajnoczi wrote:
> On Tue, 11 Jun 2024 at 13:54, Manos Pitsidianakis
> <manos.pitsidianakis@linaro.org> wrote:
> >
> > On Tue, 11 Jun 2024 at 17:05, Stefan Hajnoczi <stefanha@redhat.com> wrote:
> > >
> > > On Mon, Jun 10, 2024 at 09:22:36PM +0300, Manos Pitsidianakis wrote:
> > > > Add options for Rust in meson_options.txt, meson.build, configure to
> > > > prepare for adding Rust code in the followup commits.
> > > >
> > > > `rust` is a reserved meson name, so we have to use an alternative.
> > > > `with_rust` was chosen.
> > > >
> > > > Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> > > > ---
> > > > The cargo wrapper script hardcodes some rust target triples. This is
> > > > just temporary.
> > > > ---
> > > >  .gitignore               |   2 +
> > > >  configure                |  12 +++
> > > >  meson.build              |  11 ++
> > > >  meson_options.txt        |   4 +
> > > >  scripts/cargo_wrapper.py | 211 +++++++++++++++++++++++++++++++++++++++
> > > >  5 files changed, 240 insertions(+)
> > > >  create mode 100644 scripts/cargo_wrapper.py

> > > > diff --git a/configure b/configure
> > > > index 38ee257701..c195630771 100755
> > > > --- a/configure
> > > > +++ b/configure

snip

> > > > +  test "$with_rust_target_triple" != "" && meson_option_add "-Dwith_rust_target_triple=$with_rust_target_triple"

So the --rust-target-triple is only needed when cross compiling,
but this is not the way we normally handle passing cross compiler
info to meson. Instead we create a meson cross compiler options
file containing the target info.

eg for ./configure --cross-prefix=x86_64-w64-mingw32-

we end up creating:

$ cat build/config-meson.cross
# Automatically generated by configure - do not modify
[properties]
[built-in options]
c_args = []
cpp_args = []
objc_args = []
c_link_args = []
cpp_link_args = []
# environment defaults, can still be overridden on
# the command line
werror = true
[project options]

[binaries]
c = ['x86_64-w64-mingw32-gcc','-m64']
cpp = ['x86_64-w64-mingw32-g++','-m64']
objc = ['x86_64-w64-mingw32-clang','-m64']
ar = ['x86_64-w64-mingw32-ar']
dlltool = ['x86_64-w64-mingw32-dlltool']
nm = ['x86_64-w64-mingw32-nm']
pkgconfig = ['x86_64-w64-mingw32-pkg-config']
pkg-config = ['x86_64-w64-mingw32-pkg-config']
ranlib = ['x86_64-w64-mingw32-ranlib']
strip = ['x86_64-w64-mingw32-strip']
widl = ['x86_64-w64-mingw32-widl']
windres = ['x86_64-w64-mingw32-windres']
windmc = ['x86_64-w64-mingw32-windmc']
[host_machine]
system = 'windows'
cpu_family = 'x86_64'
cpu = 'x86_64'
endian = 'little'


Should we not be passing the rust compiler target through
this meson options file by setting something like this

  rust = ['rustc', '--target', '$target_target_triple']

Also I don't think we should be requiring --rust-target-triple
to be passed by the user. For all the combinations we know &
test, we should have configure "do the right thing" and set a
suitable rust target triple based on the --cross-prefix argument
that is given, so there is no extra burden on users cross
compiling. Users should then only use --rust-target-triple
if our default logic is wrong for some reason.