maybe

c.d/helloworld.c

@@ -1,5 +1,5 @@
 #include "helloworld.h"
 
-void main() {
+int foo() {
-   printf("hello world\n");
+   return 0;
 }

c.d/helloworld.def

@@ -0,0 +1,3 @@
+headers = helloworld.h
+headerFilter = helloworld.h
+package = helloworld

c.d/helloworld.h

@@ -1 +1,3 @@
 #include <stdio.h>
+
+int foo();

c.d/run.sh

@@ -4,5 +4,10 @@ set -e
 set -o pipefail
 set -u
 
-gcc ./*.{h,c}
+echo GCC
-./a.out
+echo gcc ./*.{h,c}
+
+echo CINTEROP
+cinterop -def helloworld.def -compiler-option -I. -o helloworld
+echo LS
+ls ./helloworld.klib ./helloworld-build/kotlin