LDC PGO on Windows

[Imperatorn]

On Monday, 16 October 2023 at 17:43:21 UTC, Imperatorn wrote:
> On Monday, 16 October 2023 at 17:13:04 UTC, Imperatorn wrote:
>> On Monday, 16 October 2023 at 17:00:41 UTC, Imperatorn wrote:
>>> [...]
>>
>> With msvc I get
>> unresolved external symbol llvm_profile_instrument_target 
>> referenced in function _D4hash7keynode9xtoHashFNbNeKxSQBfQBdZm
>> unresolved external symbol llvm_profile_runtime referenced in 
>> function llvm_profile_runtime_user
>>
>> And with link-internally I get
>> lld-link: error: undefined symbol: llvm_profile_runtime
>> lld-link: error: undefined symbol: 
>> llvm_profile_instrument_target
>
> I get the same on Linux:
> undefined reference to `__llvm_profile_instrument_target'
>
> And trying a minimal example gives me:
>
> Exception Code: 0xC000001D
> 0x00007FF603511EDE, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x3201EDE byte(s)
> 0x00007FF60318F052, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x2E7F052 byte(s)
> 0x00007FF6032A01DA, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x2F901DA byte(s)
> 0x00007FF60329FE2F, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x2F8FE2F byte(s)
> 0x00007FF6032A0135, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x2F90135 byte(s)
> 0x00007FF6031884DD, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x2E784DD byte(s)
> 0x00007FF60353F4C4, C:\Program Files\LDC 
> 1.35\bin\ldc2.exe(0x00007FF600310000) + 0x322F4C4 byte(s)
> 0x00007FFF17AB7344, 
> C:\windows\System32\KERNEL32.DLL(0x00007FFF17AA0000) + 0x17344 
> byte(s), BaseThreadInitThunk() + 0x14 byte(s)
> 0x00007FFF18F426B1, 
> C:\windows\SYSTEM32\ntdll.dll(0x00007FFF18EF0000) + 0x526B1 
> byte(s), RtlUserThreadStart() + 0x21 byte(s)

After some experimentation it turned out it was working after 
all, but not with any code and dependencies.

For example in my case, if I removed asdf deserialize, it worked, 
but if I introduced it again, I got a bunch of errors like this

```
lld-link: error: undefined symbol: ClassInfo for 
asdf.asdf.AsdfSerdeException
>>> [...]

lld-link: error: undefined symbol: vtable for 
asdf.asdf.AsdfSerdeException
>>> [...]

lld-link: error: undefined symbol: initializer for 
asdf.asdf.AsdfSerdeException
```