janet/lib/metabuild.dst

# A script to help generate build files on different platforms

(def- make-cflags "-std=c99 -Wall -Wextra -O2 -shared -fpic")
(def- make-ldflags "")

(defn $
  "Do and get the value of a subshell command"
  [command]
  (def f (file.popen command))
  (def ret (file.read f :all))
  (file.close f)
  ret)

(defn- emit-rule
  "Emit a rule in a makefile"
  @[out target deps recipe]
  (default recipe "@echo '-----'")
  (file.write
    out 
    target 
    ": " 
    (if (indexed? deps) (string.join deps " ") deps) 
    "\n\t"
    (if (indexed? recipe) (string.join recipe "\n\t") recipe)
    "\n\n")
  out)

(defn generate-make
  "Generate a makefile"
  [out-path sources target]
  (def out (file.open out-path :w))
  (def csources (filter (fn [x] (= ".c" (string.slice x -2))) sources))
  (def hsources (filter (fn [x] (= ".h" (string.slice x -2))) sources))
  (file.write
    out
    "# Autogenerated Makefile, do not edit\n"
    "# Generated at " ($ `date`)
    "\nCFLAGS:=" make-cflags
    "\nLDFLAGS:=" make-ldflags
    "\nSOURCES:=" (string.join csources " ")
    "\nHEADERS:=" (string.join hsources " ")
    "\nOBJECTS:=$(patsubst %.c,%.o,${SOURCES})"
    "\nTARGET:=" target ".so"
    "\n\n")
  (emit-rule out "all" "${TARGET}")
  (emit-rule out "%.o" @["%.c" "${HEADERS}"] "${CC} ${CFLAGS} -o $@ $< ${LDFLAGS}")
  (emit-rule out "${TARGET}" "${OBJECTS}" "${CC} ${CFLAGS} -o $@ $^ ${LDFLAGS}")
  (emit-rule out "clean" "" "rm ${OBJECTS}")
  (emit-rule out "clean" "" @["rm ${OBJECTS}" "rm @{TARGET}"])
  # Phony targets
  (emit-rule out ".PHONY" @["all" "clean"])
  nil)