[BUG]:

Describe the bug

getting gcc error in clang-output window

Steps to reproduce

1. https://godbolt.org
2. open two compiler windows
3. select gcc-11.2 on the left, clang-13 on the right.
4. add (broken) example code below
5. add compiler options for gcc-11.2: -Wall -Wextra -fcoroutines
6. add compiler options for clang-13: -Wall -Wextra

#include <type_traits>
#include <limits>
#include <fmt/core.h>
#include <coroutine>

int gen()
{
    co_yield 42;
    co_yield 44;
    co_yield 46;
}

int main()
{
    fmt::print("{}\n", gen());
    fmt::print("{}\n", gen());
    fmt::print("{}\n", gen());
}

Expected behavior

error message: “error: unable to find the promise type for this coroutine in both” or similar in both output windows

Actual behaviour:

getting:

In file included from <source>:4:
/opt/compiler-explorer/gcc-11.2.0/lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0/coroutine:334:2: error: "the coroutine header requires -fcoroutines"
#error "the coroutine header requires -fcoroutines"

in the CLANG-13 output window, see screenshot

Reproduction link

https://godbolt.org/z/fqj5fv686

Screenshots

Operating System

Windows 11

Browser version

Chrome Version 98.0.4758.102 (Official Build) (64-bit)

[janwilmans]

The error is most likely a macro in the header file, and by default clang uses gcc’s stdlibc++

ok, so then the gcc version is fine, its clang that needs to either support -fcoroutines or not-use gcc’s stdlibc++. I think a workaround is using clang-trunk. closing.

[partouf]

I don’t think so, remember, the correct behaviour is: “error: unable to find the promise type for this coroutine”

but its the CLANG-13 output window reporting a gcc error??? that can’t right??

The error is most likely a macro in the header file, and by default clang uses gcc’s stdlibc++