How do I return an integer constant created via `

Question

How do I return an integer constant created via `<http IrConstImpl int|IrConstImpl int>` from a `Function0 lt Int gt ` lambda local function that i ve created

jw · Answer

I was doing ```body = DeclarationIrBuilder pluginContext symbol irExprBody replacement ``` where `replacement` is the `IrConst` but that breaks the JVM verifier and LLVM

jw · Answer

I was hoping to find something where I didn t really have to know that boxing was required

Youssef Shoaib [MOD] · Answer

Maybe try a regular irBlockBody with one statement being an irReturn myConstant If that doesn t work I would try storing the IrConst in an irTemporary and then return that irTemporary

jw · Answer

yeah i started with the block body and thought i was cool moving to an expression temporary is a good idea will try

Youssef Shoaib [MOD] · Answer

Expression probably doesn t even change much in the output binary but I do agree it really feels more right to use an expression body there I suspect that maybe even expression bodies might still need an irReturn for some reason although I m not sure easy way to check would be to compile an expression body and look at its IR I haven t worked with IR in a while though so maybe I m missing something more subtle

jw · Answer

No dice

shikasd · Answer

I d expect irReturn irConst to work here What kind of verification error did you get

jw · Answer

The stack has an int and it wants an Object Integer

jw · Answer

I can get the actual message here in a bit

jw · Answer

```java lang VerifyError Bad type on operand stack Exception Details Location com example cite LambdasKt$propertyReferenceLine$1 invoke Ljava lang Integer 2 checkcast Reason Type integer current frame stack 0 is not assignable to java lang Object Current Frame bci 2 flags locals com example cite LambdasKt$propertyReferenceLine$1 stack integer Bytecode 0000000 100e c000 13b0 ```

shikasd · Answer

Huh that s weird in my practice it was lowered after You might want to dump something like `val a = 0 ` and check what it gets compiled to on IR level

jw · Answer

Yeah That helped Because I m an idiot

jw · Answer

I was propagating the wrong type in the wrong place and it was preventing the autoboxing

shikasd · Answer

Not surprised IR is very particular about it sometimes Glad that helped

jw · Answer

But also weirdly flexible I was specifying a completely nonsensical type before and it worked for String constants just not int

shikasd · Answer

Yeah the validation doesn t check it at all most of the times it just depends if downstream lowering uses this type or not