On 12/9/25 07:01, Markus Armbruster wrote:
Markus Armbruster <[email protected]> writes:
I applied, ran make, and it didn't create qapi-types.rs and
test-qapi-types.rs for me. What am I missing?
Looks like I have to run with -B qapi.backend.QAPIRsBackend.
-B is meant for out-of-tree backends. Commit dde279925c9 explains:
qapi: pluggable backend code generators
The 'qapi.backend.QAPIBackend' class defines an API contract for code
generators. The current generator is put into a new class
'qapi.backend.QAPICBackend' and made to be the default impl.
A custom generator can be requested using the '-k' arg which takes a
fully qualified python class name
qapi-gen.py -B the.python.module.QAPIMyBackend
This allows out of tree code to use the QAPI generator infrastructure
to create new language bindings for QAPI schemas. This has the caveat
that the QAPI generator APIs are not guaranteed stable, so consumers
of this feature may have to update their code to be compatible with
future QEMU releases.
Using it for the in-tree Rust backend is fine for a prototype.
Mentioning it in a commit message or the cover letter would've saved me
some digging.
Well, it wasn't intentional - right now it does this:
test_qapi_rs_files = custom_target('QAPI Rust',
output: 'test-qapi-types.rs',
input: [ files(meson.project_source_root() +
'/tests/qapi-schema/qapi-schema-test.json') ],
command: [ qapi_gen, '-o', meson.current_build_dir(), '-b',
'@INPUT0@', '-B', 'qapi.backend.QAPIRsBackend', '-p', 'test-' ],
depend_files: [ qapi_inputs, qapi_gen_depends ])
so "make rust/tests/test-qapi-types.rs" will work, and so will "make" if
you have --enable-rust.
Let us know what you'd prefer and we'll switch. Alternatively,
retconning -B's meaning so that it applies to Rust will work too. :)
Paolo
