I have library, that has function with header like `int func(const char* src...);` that I use with c...

# kotlin-native

[Matej Kormuth]

I have library, that has function with header like int func(const char* src...); that I use with cinterop. I want to pass inside CPointer<ByteVar> or CPointer<UByteVar> as a parameter (because char* is pointer to char) that a aquired from previous native call. However the function has in kotlin binding header public fun func(source: kotlin.String?... accepting kotlin string. How do I do it? Do I need to call toKString()? Doesn't toKString() involve some allocation? Does it correctly translates the CPointer<ByteVar> buffer to string (without some corruption due to encoding for example)? Isn't it useless step as the KString will have to be translated back to C char array later?

[Matej Kormuth]

I finally found the sourcecode of toKString() and indeed it does allocate stuff https://github.com/JetBrains/kotlin-native/blob/master/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt#L399.

[Matej Kormuth]

And the generated function does create .cstr (which also allocates memory) and than it takes pointer from it.

fun func(source: String?...): Int {
            memScoped {
                return kniBridge25(source?.cstr?.getPointer(memScope).rawValue ...)
            }
        }

[Matej Kormuth]

https://github.com/JetBrains/kotlin-native/blob/master/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Utils.kt#L348

[Matej Kormuth]

Is there any way to disable this behavior? Because its pretty crazy to allocate two times the same memory just to pass the buffer from one native call to another.

[msink]

noStringConversion = func in .def file

[Matej Kormuth]

Thank you so much