let rec apply_cmd arch prog = function
  | AnalysisAst f -> (
    match prog with
    | Ast p as p' -> f p; p'
    | _ -> failwith "need explicit translation to AST"
  )
  | AnalysisModeAst f -> (
    match prog with
    | Ast p as p' -> f (Input.get_arch arch) p; p'
    | _ -> failwith "need explicit translation to AST"
  )
  | AnalysisAstCfg f -> (
    match prog with
    | AstCfg p as p' -> f p; p'
    | _ -> failwith "need explicit translation to AST CFG"
  )
  | AnalysisModeAstCfg f -> (
    match prog with
    | AstCfg p as p' -> f (Input.get_arch arch) p; p'
    | _ -> failwith "need explicit translation to AST CFG"
  )
  | AnalysisSsa f -> (
    match prog with
    | Ssa p as p' -> f p; p'
    | _ -> failwith "need explicit translation to SSA"
  )
  | TransformAst f -> (
    match prog with
    | Ast p -> Ast(f p)
    | _ -> failwith "need explicit translation to AST"
  )
  | TransformModeAst f -> (
    match prog with
    | Ast p -> Ast(f (Input.get_arch arch) p)
    | _ -> failwith "need explicit translation to AST"
  )
  | TransformAstCfg f -> (
    match prog with
    | AstCfg p -> AstCfg(f p)
    | _ -> failwith "need explicit translation to AST CFG"
  )
  | TransformSsa f -> (
    match prog with
    | Ssa p -> Ssa(f p)
    | _ -> failwith "need explicit translation to SSA"
  )
  | ToCfg -> (
    match prog with
    | Ast p -> AstCfg(Cfg_ast.of_prog p)
    | Ssa p -> AstCfg(Cfg_ssa.to_astcfg p)
    | AstCfg _ as p -> prerr_endline "Warning: null transformation"; p
  )
  | ToAst -> (
    match prog with
    | AstCfg p -> Ast(Cfg_ast.to_prog p)
    | p -> apply_cmd arch (apply_cmd arch p ToCfg) ToAst
  )
  | ToSsa -> (
    match prog with
    | AstCfg p -> Ssa(Cfg_ssa.of_astcfg ~tac:!tac p)
    | p -> apply_cmd arch (apply_cmd arch p ToCfg) ToSsa
  );;