babashka C?

c99.clj

(ns c99
  (:require [clojure.core :as core]
            [clojure.string :as string]))

(def e' clojure.walk/macroexpand-all)

(core/defmacro defn [var bindings & body]
  (str (:tag (meta var)) " " var "("
       (->> bindings
            (map (fn [v]
                   (let [{:keys [line column tag]} (meta v)]
                     (str tag " " v)
                     )))
            (string/join ", "))
       ")\n"
       "{\n"
       (apply str
              (map #(str "\t" %)
                   (e' body)))
       "}"))

(core/defmacro return [body]
  (str "return("
       (e' body)
       ");\n"))

(core/defmacro + [a b]
  (str "(" (e' a) "+" (e' b) ")"))

(core/defmacro * [a b]
  (str "(" (e' a) "*" (e' b) ")"))

gen.clj

#!/usr/bin/env bb

(require '[c99 :as c])

(println
 (c/defn ^int calculate [^int x ^int y ^int p ^int q]
   (c/return
    (c/*
     (c/+ x y)
     (c/+ p q)))))

gistfile1.txt

$ BABASHKA_CLASSPATH=. bb gen.clj 
int calculate(int x, int y, int p, int q)
{
	return(((x+y)*(p+q)));
}