This includes a few fixes to the Rust build system machinery, and removes constructs that were added or stabilized after version 1.63.0:
- "let else" (by patching bilge-impl, patch 4; stable in 1.65.0) - std::sync::OnceLock (patch 6; stable in 1.70.0) - core::ffi (patch 7; stable in 1.64.0) - c"" literals (patch 9; stable in 1.77.0) - offset_of! (patch 10; stable in 1.77.0) - MaybeUninit::zeroed() (patch 11; stable in 1.75.0 in const context) It also replicates the configuration checks normally done by proc-macro2's build.rs into our Meson-based build rules, so that the crate can be made to work with an older version of rustc. As a small bonus, patch 11 removes some uses of unsafe, so that patch probably won't just be simply reverted even once we can assume version 1.75.0 of the language. And as another small bonus this series introduces the first use of Rust unit tests. On top of this, the required version of bindgen is still too new for Debian 12 and Ubuntu 22.04. This is fixed by the last four patches. This is an RFC for two reasons. First, because it would be a valid decision to delay enabling of Rust until at least some of these features are available in all supported distros. Another possibility could be to accept Rust 1.64.0 but require installing a newer bindgen (0.66.x for example) on those two distros with an older release. Second, because the series is missing the CI updates to actually ensure that these minimum versions keep working. The main purpose is to show the kind of hacks that would be needed to support older toolchains. The fixes (for example patches 1/2/3/6/8/11/13/14) can be easily extracted independent of the outcome of the discussion, and/or while the CI updates are made. Thanks, Paolo Paolo Bonzini (16): meson: import rust module into a global variable meson: remove repeated search for rust_root_crate.sh rust: pass rustc_args when building all crates rust: patch bilge-impl to allow compilation with 1.63.0 rust: fix cfgs of proc-macro2 for 1.63.0 rust: do not use OnceLock for properties rust: use std::os::raw instead of core::ffi rust: build tests for the qemu_api crate rust: introduce a c_str macro rust: introduce alternative implementation of offset_of! rust: do not use MaybeUninit::zeroed() rust: allow version 1.63.0 of rustc rust: do not use TYPE_CHARDEV unnecessarily rust: do not use --no-size_t-is-usize rust: do not use --generate-cstr rust: allow older version of bindgen meson.build | 42 ++++--- .gitattributes | 2 + rust/hw/char/pl011/src/device.rs | 117 ++++++++++-------- rust/hw/char/pl011/src/device_class.rs | 13 +- rust/hw/char/pl011/src/lib.rs | 4 +- rust/hw/char/pl011/src/memory_ops.rs | 21 ++-- rust/qemu-api-macros/meson.build | 2 +- rust/qemu-api/meson.build | 17 ++- rust/qemu-api/src/c_str.rs | 52 ++++++++ rust/qemu-api/src/definitions.rs | 10 +- rust/qemu-api/src/device_class.rs | 49 +++++--- rust/qemu-api/src/lib.rs | 14 ++- rust/qemu-api/src/offset_of.rs | 106 ++++++++++++++++ rust/qemu-api/src/tests.rs | 21 ++-- rust/qemu-api/src/zeroable.rs | 75 +++++++++++ subprojects/bilge-impl-0.2-rs.wrap | 1 + .../packagefiles/bilge-impl-1.63.0.patch | 45 +++++++ .../packagefiles/proc-macro2-1-rs/meson.build | 4 +- 18 files changed, 469 insertions(+), 126 deletions(-) create mode 100644 rust/qemu-api/src/c_str.rs create mode 100644 rust/qemu-api/src/offset_of.rs create mode 100644 rust/qemu-api/src/zeroable.rs create mode 100644 subprojects/packagefiles/bilge-impl-1.63.0.patch -- 2.46.2
