clang: undefined reference to `typeinfo for half'

[jroelofs]

#include <typeinfo>
#include <cstdio>

int main() {
    printf("%s\n", typeid(__fp16).name());
}

https://clang.godbolt.org/z/9Tzaahx4q

[jroelofs]

I believe the problem is that TypeInfoIsInStandardLibrary and ItaniumCXXABI::EmitFundamentalRTTIDescriptors don't agree. Which one is correct?

[jroelofs]

cc @sjoerdmeijer @majnemer @zygoloid

[llvmbot]

@llvm/issue-subscribers-c-1

Author: Jon Roelofs (jroelofs)

``` #include <typeinfo> #include <cstdio> int main() { printf("%s\n", typeid(__fp16).name()); } ``` https://clang.godbolt.org/z/9Tzaahx4q

[zygoloid]

Oops, looks like we missed this comment when authoring / reviewing the patch.

[jroelofs]

Yep. We should probably enforce that with an assertion on both ends.