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In C version, VMSTATE_VALIDATE accepts the function pointer, which is used to check if some conditions of structure could meet, although the C version macro doesn't accept any structure as the opaque type. But it's hard to integrate VMSTATE_VALIDAE into vmstate_struct, a new macro has to be introduced to specifically handle the case corresponding to VMSTATE_VALIDATE. One of the difficulties is inferring the type of a callback by its name `test_fn`. We can't directly use `test_fn` as a parameter of test_cb_builder__() to get its type "F", because in this way, Rust compiler will be too conservative on drop check and complain "the destructor for this type cannot be evaluated in constant functions". Fortunately, PhantomData<T> could help in this case, because it is considered to never have a destructor, no matter its field type [*]. The `phantom__()` in the `call_func_with_field` macro provides a good example of using PhantomData to infer type. So copy this idea and apply it to the `vmstate_validate` macro. [*]: https://doc.rust-lang.org/std/ops/trait.Drop.html#drop-check Signed-off-by: Zhao Liu <zhao1.liu@intel.com> Link: https://lore.kernel.org/r/20250318130219.1799170-11-zhao1.liu@intel.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| qemu-api-macros | ||
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| Cargo.lock | ||
| Cargo.toml | ||
| clippy.toml | ||
| Kconfig | ||
| meson.build | ||
| rustfmt.toml | ||
| wrapper.h | ||