Implementation of "extern" functions in Kaleidoscope

[inumanag]

Hi, I was trying to add support for "extern" functions from libc in Kaleidoscope (which come for free in C++ version of Kaleidoscope). However, for the following IR (trying to use sin from libc):

declare double @sin(double %f)
%calltmp = call double @sin(double 9.000000e+00)

I keep getting:

Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file /tmp/llvm-5.0.0.src/include/llvm/Support/Casting.h, line 255.
Stacktrace:
  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) LLVMSharp.LLVM.GetPointerToGlobal (LLVMSharp.LLVMExecutionEngineRef,LLVMSharp.LLVMValueRef) [0x00002] in <c6808a9c612144c69fe813302a5e9c29>:0

Will this require P/Invoke of any sort, or it is not doable from .NET framework as of now? Btw. I am using MCJIT as specified in the tutorial.

Thanks!

[ChaseLewis]

Hey inumanag I figured out how to solve this issue.

delgate double Unary(double);
LLVMValueRef sin = LLVM.GetNamedFunction(visitor.Module, "sin");
LLVM.AddGlobalMapping(engine, sin, Marshal.GetFunctionPointerForDelegate<Unary>(Math.Sin));

You need to manually map the values, I'm unsure how to map an entire lib file (still learning myself) but that should help you out hopefully.