The typeof_strip_qual() is most useful for the atomic fetch-and-modify
operations in atomic.h, but it can be used elsewhere as well. For example,
QAPI_LIST_LENGTH() assumes that the argument is not const, which is not a
requirement.
Move the macro to compiler.h and, while at it, move it under #ifndef
__cplusplus to emphasize that it uses C-only constructs. A C++ version
of typeof_strip_qual() using type traits is possible[1], but beyond the
scope of this patch because the little C++ code that is in QEMU does not
use QAPI.
The patch was tested by changing the declaration of strv_from_str_list()
in qapi/qapi-type-helpers.c to:
char **strv_from_str_list(const strList *const list)
This is valid C code, and it fails to compile without this change.
[1] https://lore.kernel.org/qemu-devel/20240624205647.112034-1-flwu@google.com/
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Tested-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>