Due to a recent change in mingw-w64 master [1], libgomp ceases to build:

```
../../../gcc-git/libgomp/target.c:936:21: error: unknown conversion type
character 'l' in format [-Werror=format=]
  936 |         gomp_fatal ("present clause: !acc_is_present (%p, "
      |                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```


On line 29 of 'libgomp/libgomp.h' from GCC 9 branch I found this declaration

```
extern void gomp_fatal (const char *, ...)
        __attribute__ ((noreturn, format (printf, 1, 2)));
```

, which uses the `printf` attribute, but the `PRIu64` macro from
<inttypes.h> expands to `%llu` because now GCC has `-std=gnu11` by
default, which is only valid with `gnu_printf`.

AFAICS there are three solutions:

1. Revert bfd33f6c0ec5e652cc9911857dd1492ece8d8383 in mingw-w64, or
2. Make GCC treat `format(printf)` as `format(gnu_printf)` if C11 or
   C++11 is selected, or
3. Replace `format(printf)` with `format(gnu_printf)` in libgomp source.


What do you think?


[1]
https://github.com/mingw-w64/mingw-w64/commit/bfd33f6c0ec5e652cc9911857dd1492ece8d8383


-- 
Best regards,
LH_Mouse