On Mon, Sep 07, 2026 at 10:53:04PM +0800, Jakit Liang wrote:
> Thus the `__BFLT16_DIG__`-guarded code is visible to clangd because
> CLion injects the predefined macros collected from the selected GCC
> toolchain. The same JetBrains clangd run standalone with an ordinary
Then just don't do it, if CLion (whatever it is) does that always,
ask it to be fixed, otherwise don't configure it that way.
> GCC-style compile command, without CLion's injected `-imacros` file,
> does not define `__BFLT16_DIG__` and does not reach this code.
>
> So the issue is a mismatch: clangd is given GCC's bfloat16 capability
> macros but does not recognize the corresponding `bf16` literal suffix.
>
> Separately, I understand your point that `__bf16` cannot be assumed to
> be the type of `0.0bf16` on every target. My proposed change to
> `c++config` was checked on x86_64.
>
> And maybe the previous commit is better?
No, libstdc++ shouldn't be changed to cope with bad configuration.
Whatever is predefining the macros when it actually isn't supported
is lying to the compiler.
Jakub
