marcandre.lureau@redhat.com writes:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> Generate Rust #[cfg(...)] guards from QAPI 'if' conditions.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> scripts/qapi/common.py | 16 ++++++++++++++++
> scripts/qapi/schema.py | 4 ++++
> 2 files changed, 20 insertions(+)
>
> diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
> index 5f8f76e5b2..6d22c66391 100644
> --- a/scripts/qapi/common.py
> +++ b/scripts/qapi/common.py
> @@ -201,6 +201,22 @@ def guardend(name: str) -> str:
> name=c_fname(name).upper())
>
>
> +def rsgen_ifcond(ifcond: Union[str, Dict[str, Any]]) -> str:
> +
> + def cfg(ifcond: Union[str, Dict[str, Any]]):
> + if isinstance(ifcond, str):
> + return ifcond
> + if isinstance(ifcond, list):
> + return ', '.join([cfg(c) for c in ifcond])
> + oper, operands = next(iter(ifcond.items()))
> + operands = cfg(operands)
> + return f'{oper}({operands})'
> +
> + if not ifcond:
> + return ''
> + return '#[cfg(%s)]' % cfg(ifcond)
> +
> +
> def gen_ifcond(ifcond: Optional[Union[str, Dict[str, Any]]],
> cond_fmt: str, not_fmt: str,
> all_operator: str, any_operator: str) -> str:
Can we generalize gen_ifcond() to work for rsgen_ifcond(), too?
Not elegantly, I am afraid. The logic of gen_ifcond() is based around the distinct prefix vs infix handling. In contrast, Rust cfg are all infix. As you can see from the code above, it is quite straightforward. Reusing gen_ifcond() would make it quite convoluted.
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index 6455a8f425..c61f35e13f 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -26,6 +26,7 @@
> docgen_ifcond,
> gen_endif,
> gen_if,
> + rsgen_ifcond,
> )
> from .error import QAPIError, QAPISemError, QAPISourceError
> from .expr import check_exprs
> @@ -48,6 +49,9 @@ def gen_endif(self):
> def docgen(self):
> return docgen_ifcond(self.ifcond)
>
> + def rsgen(self):
> + return rsgen_ifcond(self.ifcond)
> +
> def is_present(self):
> return bool(self.ifcond)