DllExaminer.fs

open System
open System.IO
open System.Reflection

let rec extractDll opts =
  match opts with
  | "-d"::s::t -> Some s
  | h::t -> extractDll t
  | [] -> None

let dllName = 
  match extractDll (System.Environment.GetCommandLineArgs() |> List.ofSeq) with
  | Some s -> s
  | None -> System.Console.WriteLine "must provide -d dllFileName option"; exit 0

let resolve _ (y: ResolveEventArgs) : Assembly =
  try
    Assembly.ReflectionOnlyLoad(y.Name) |> ignore
  with
    | :? System.IO.FileNotFoundException as xy -> printfn "got exception %A" xy
  null

let domain = AppDomain.CurrentDomain

domain.add_ReflectionOnlyAssemblyResolve (ResolveEventHandler resolve)

let r = Assembly.ReflectionOnlyLoadFrom dllName

let types = r.GetExportedTypes ()

let parametersToArgStrings (ps: ParameterInfo seq) =
  let fn (p: ParameterInfo) =
    match p.ParameterType.IsGenericParameter with
    | true -> p.Name + ": " + "'" + p.ParameterType.ToString()
    | false -> p.Name + ": " + p.ParameterType.ToString()
  let vals = ps |> Seq.map fn |> Seq.map (fun f -> "(" + f + ")")
  String.Join(" ", vals)

let parametersToGenerics (ps: ParameterInfo seq) =
  let fn (p: ParameterInfo) =
    match p.ParameterType.IsGenericParameter with
    | true -> Some ("'" + p.Name)
    | false -> None
  let vals = ps |> Seq.choose fn
  let result = String.Join(", ", vals)
  if String.length result > 0
  then "<" + result + ">"
  else ""

let parametersToCallStrings (ps: ParameterInfo seq) =
  String.Join(", ", ps |> Seq.map (fun p -> p.Name))

let printParameters (ps: ParameterInfo seq) t m =
  ps |> Seq.iter (fun p -> printfn "type: %A; method: %A; paramter: %A" t m p)

let printMethod t (m: MethodInfo) =
  let ps = (m.GetParameters())
  let argsParametersString = parametersToArgStrings ps
  let callParametersString = parametersToCallStrings ps
  let genericsString = parametersToGenerics ps
  match m.IsStatic with
  | false -> printfn "  let %sFn%s (obj: %A) %s = obj.%s(%s)" m.Name genericsString t argsParametersString m.Name callParametersString
  | true -> ()

let printMemberInfo t (m: MemberInfo) =
  match m with
  | :? System.Reflection.MethodInfo as mi -> printMethod t mi
  | _ -> printfn "// doing nothing with %A" m

let printMemberInfos (ms: MemberInfo seq) t =
  ms |> Seq.iter (printMemberInfo t)

let printTypes (ts: Type seq) = 
  let toModuleName (t: Type) =
    t.FullName.Replace(".", "_").Replace("`","_").Replace('+', '_')
  ts |> Seq.iter (fun t -> printfn ""; printfn "module %sFn = " (toModuleName t); printMemberInfos (t.GetMembers()) t)
  printfn "  let HackHackHackMakeSureTheresAtLeastOneFunctionHere() = ()"

printfn "namespace com.restphone"

printTypes types