(* Step 2: reach enough of the compiler that the linker cannot drop it, and do
   real compiler work in-process so the measurement is of a working compiler
   rather than of dead code that happened to link.

   The work is the driver's own path, the one bin/main.ml takes:
   read -> Parse.program -> Load.program -> Check.program -> Emit.program. That
   is the whole front end and the whole back end short of [llc]. Check.program
   prepends the prelude itself, so the prelude is in the measurement without
   being fed in twice. *)

let compile file =
  let l = Flan.Load.program ~file (Flan.Parse.program (Flan.Reader.read_file file)) in
  let p = Flan.Check.program l.Flan.Load.decls in
  let ir = Flan.Emit.program ~dev:true p in
  (List.length l.Flan.Load.decls, String.length ir)

(* Touched only so the linker keeps the modules a merged dev build would carry.
   Nothing here is called for its effect. *)
let footprint () =
  String.concat ","
    [ Flan.Build.clang;
      string_of_int (String.length Flan.Shim.header);
      string_of_int (String.length Flan.Runtime_src.source);
      string_of_int (String.length Flan.Runtime_src.dev_source);
      string_of_int (List.length Flan.Session.externs);
      string_of_int (Flan.Render.max_span);
      string_of_int (String.length (Flan.Wire.ints [ 1; 2 ])) ]

let () =
  Callback.register "spike_compile" (fun (file : string) ->
      match compile file with
      | d, n -> Printf.sprintf "%s: %d decls, %d bytes of LLVM IR" file d n
      | exception e -> Printf.sprintf "FAILED: %s" (Printexc.to_string e));
  Callback.register "spike_footprint" footprint;
  (* Dev.start and Cimport are never run here, but naming them keeps the socket
     server and the C importer in the link -- a dev build pays for them. *)
  Callback.register "spike_unused" (fun () ->
      ignore (Flan.Dev.start : ?debug:bool -> file:string -> sock:string -> unit -> unit);
      ignore (Flan.Cimport.decl_source : Flan.Ast.decl -> string);
      "ok")