[C++] [Coroutines] Does GCC want to support `-fno-coroutines`?

[C++] [Coroutines] Does GCC want to support `-fno-coroutines`?

[chuanqi.xcq]

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Hi,
 We're discussing to implement `-fno-coroutines` in clang so that we can disable the coroutine feature with C++ standard higher than 20.
A full discussion can be found here: https://reviews.llvm.org/D156247. A major motivation for us to do this is to keep consistency with GCC.
However, we don't find `-fno-coroutines` in https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/C_002b_002b-Dialect-Options.html#index-fcoroutines.
Then we're not sure if GCC intends to support it. And we want to ask opinions from GCC developers for `-fno-coroutines`.
Thanks,
Chuanqi

Re: [C++] [Coroutines] Does GCC want to support `-fno-coroutines`?

[Andrew Pinski]

On Thu, Jul 27, 2023 at 7:11 PM chuanqi.xcq via Gcc <gcc@gcc.gnu.org> wrote:
>
> Hi,
>  We're discussing to implement `-fno-coroutines` in clang so that we can disable the coroutine feature with C++ standard higher than 20.
> A full discussion can be found here: https://reviews.llvm.org/D156247. A major motivation for us to do this is to keep consistency with GCC.
> However, we don't find `-fno-coroutines` in https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/C_002b_002b-Dialect-Options.html#index-fcoroutines.
> Then we're not sure if GCC intends to support it. And we want to ask opinions from GCC developers for `-fno-coroutines`.

It is already supported.
Read https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Invoking-GCC.html which says:
```
Many options have long names starting with ‘-f’ or with ‘-W’—for
example, -fmove-loop-invariants, -Wformat and so on. Most of these
have both positive and negative forms; the negative form of -ffoo is
-fno-foo. This manual documents only one of these two forms, whichever
one is not the default.
```

Thanks,
Andrew

> Thanks,
> Chuanqi