On 2/17/22 16:02, Serge Guelton wrote:
I took a quick look at C++20 coroutines since they are available in
compilers but the primitives look hard to use even from C++, let alone
>from C.
They're C++ only in GCC, too. I really think that QEMU should be
compilable in C++, but I'm not sure how easy a sell it is.
It's perfectly fine to have one compilation unit written in C++ with a few
symbol in `extern "C"`. No need to touch the other part of the project.
It's not just one compilation unit, it's everything that uses coroutines
so basically all of block/. But yes, good point---it means for example
that you don't have to deal as much with lack of operators in C++ enums,
which would be a huge PITA in compiling QEMU with C++. There would
still be some churn such as adding extern "C" blocks to headers, etc.
The main change with C++20 coroutines would be to introduce co_await,
co_return and std::future<> everywhere, which is also a pretty
substantial change (possibly an improvement in the case of co_await and
co_return, but still a lot of work).
That said, it's certainly valuable to try and get at least
tests/unit/test-coroutine.c to run with C++ coroutines, and see how much
work that is.
Paolo
