marcandre.lureau@redhat.com writes:
> From: Marc-André Lureau <marcandre.lureau@redhat.com>
>
> The argument isn't owned by the callee, so it better be const.
> But a lot of code in QEMU rely on non-const arguments to tweak it (steal
> values etc).
>
> Since Rust types / bindings are derived from the C version, we have to
> be more accurate there to do correct ownership in the bindings.
>
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
> scripts/qapi/schema.py | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/scripts/qapi/schema.py b/scripts/qapi/schema.py
> index 3d72c7dfc9..1f6301c394 100644
> --- a/scripts/qapi/schema.py
> +++ b/scripts/qapi/schema.py
> @@ -226,8 +226,15 @@ def c_type(self):
> pass
>
> # Return the C type to be used in a parameter list.
> - def c_param_type(self):
> - return self.c_type()
> + #
> + # The argument should be considered const, since no ownership is given to
> + # the callee, but qemu C code frequently tweaks it. Set const=True for a
> + # stricter declaration.
This comment makes sense only if you're familiar with Rust, where "may
change" is actually tied to ownership.
Arguably, this semantic can also apply to C.
However, I can't see a use of .c_param_type(True). Sure you need this
patch in this series?
Indeed it looks like a leftover now. Let's drop it.
> + def c_param_type(self, const: bool = False):
> + c_type = self.c_type()
> + if const and c_type.endswith(POINTER_SUFFIX):
> + c_type = 'const ' + c_type
> + return c_type
>
> # Return the C type to be used where we suppress boxing.
> def c_unboxed_type(self):
> @@ -280,10 +287,10 @@ def c_name(self):
> def c_type(self):
> return self._c_type_name
>
> - def c_param_type(self):
> + def c_param_type(self, const: bool = False):
> if self.name == 'str':
> return 'const ' + self._c_type_name
> - return self._c_type_name
> + return super().c_param_type(const)
Would
def c_param_type(self, const: bool = False):
return super().c_param_type(const or self.name == 'str')
do?
>
> def json_type(self):
> return self._json_type_name