ocamlocamlfind

Difference in program behavior with different make files

I have this OCaml program

open Core.Std;;
open Printf;;

let all l = List.fold ~f:(&&) ~init:true l;;

let any l = List.fold ~f:(||) ~init:false l;;

let main () = let bools = [true; false; true; true; false; true] in
  printf "%b %b\n" (all bools) (any bools);;
main();;

And then two make files, the first is 

all: a.out
    @true

a.out: fold.cmx
    ocamlfind ocamlopt -g -linkpkg -package core -package core_kernel -thread -w -10 fold.cmx

fold.cmx: fold.ml fold.cmi
    ocamlfind ocamlopt -g -c fold.cmx -package core -package core_kernel -thread -w -10 fold.ml

fold.cmi: fold.mli
    ocamlfind ocamlopt -g -c -package core -package core_kernel -thread -w -10 fold.mli

fold.mli: fold.ml
    ocamlfind ocamlc -i -package core -package core_kernel -thread -w -10 fold.ml > fold.mli

clean:
    @rm *.cmx *.cmi *.o tests 2>/dev/null || true

Which produces an a.out that gives the expected output of false true. The second is

all: fold
    @true

fold: fold.cmx
    ocamlfind ocamlopt -g -o fold -linkpkg -package core -package core_kernel -thread -w -10 fold.cmx

fold.cmx: fold.ml fold.cmi
    ocamlfind ocamlopt -g -c fold.cmx -package core -package core_kernel -thread -w -10 fold.ml

fold.cmi: fold.mli
    ocamlfind ocamlopt -g -c -package core -package core_kernel -thread -w -10 fold.mli

fold.mli: fold.ml
    ocamlfind ocamlc -i -package core -package core_kernel -thread -w -10 fold.ml > fold.mli

clean:
    @rm *.cmx *.cmi *.o tests 2>/dev/null || true

which produces a fold that on my machine, hangs without output. The only difference between the two is that one of them puts its output in fold and the other puts it in a.out. The version numbers for my ocaml, ocamlc, ocamlopt, and ocamlfind are all 4.02.1 and opam show core says it's version 112.06.01. Any of you guys know what's causing the difference?

Solution

  • You are running the standard fold program. Try ./fold.