(* Memory info for virtual domains.
   (C) Copyright 2008 Richard W.M. Jones, Red Hat Inc.
   http://libvirt.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*)

(* This program takes the kernel database (in kernels/ in toplevel
   directory) and generates parsing code for the various structures
   in the kernel that we are interested in.

   The output programs -- *.ml, *.mli files of generated code -- go
   into lib/ at the toplevel, eg. lib/kernel_task_struct.ml

   The stuff at the top of this file determine what structures
   and fields we try to parse.
*)

let what = [
  "task_struct", (
    "struct task_struct",
    [ "state"; "prio"; "normal_prio"; "static_prio"; "tasks"; "comm"]
  );
]

open ExtList
open ExtString
open Printf

let (//) = Filename.concat

let () =
  let args = Array.to_list Sys.argv in

  let kernelsdir, outputdir =
    match args with
    | [_;kd;od] -> kd,od
    | _ ->
	let arg0 = Filename.basename Sys.executable_name in
	eprintf "%s - Turn kernels database into code modules.

Usage:
  %s <kernelsdir> <outputdir>

Example (from toplevel of virt-mem source tree):
  %s kernels/ lib/
" arg0 arg0 arg0;
	exit 2 in

  (* Get the *.info files from the kernels database. *)
  let infos = Sys.readdir kernelsdir in
  let infos = Array.to_list infos in
  let infos = List.filter (fun name -> String.ends_with name ".info") infos in
  let infos = List.map ((//) kernelsdir) infos in

  (* Regular expressions.  We really really should use ocaml-mikmatch ... *)
  let re_oldformat = Pcre.regexp "^RPM: \\d+: \\(build \\d+\\) ([-\\w]+) ([\\w.]+) ([\\w.]+) \\(.*?\\) (\\w+)" in
  let re_keyvalue = Pcre.regexp "^(\\w+): (.*)" in

  (* Parse in the *.info files.  These have historically had a few different
   * formats that we need to support.
   *)
  let infos = List.map (
    fun filename ->
      (* Get the basename (for getting the .data file later on). *)
      let basename = Filename.chop_suffix filename ".info" in

      let chan = open_in filename in
      let line = input_line chan in

      let name, version =
	if Pcre.pmatch ~rex:re_oldformat line then (
	  (* If the file starts with "RPM: \d+: ..." then it's the original
	   * format.  Everything in one line.
	   *)
	  let subs = Pcre.exec ~rex:re_oldformat line in
	  let name = Pcre.get_substring subs 1 in
	  let version = Pcre.get_substring subs 2 in
	  let release = Pcre.get_substring subs 3 in
	  let arch = Pcre.get_substring subs 4 in
	  close_in chan;
	  name, sprintf "%s-%s.%s" version release arch
	) else (
	  (* New-style "key: value" entries, up to end of file or the first
	   * blank line.
	   *)
	  let name, version, release, arch =
	    ref "", ref "", ref "", ref "" in
	  let rec loop line =
	    try
	      let subs = Pcre.exec ~rex:re_keyvalue line in
	      let key = Pcre.get_substring subs 1 in
	      let value = Pcre.get_substring subs 2 in
	      if key = "Name" then name := value
	      else if key = "Version" then version := value
	      else if key = "Release" then release := value
	      else if key = "Architecture" then arch := value;
	      let line = input_line chan in
	      loop line
	    with
	      Not_found | End_of_file ->
		close_in chan
	  in
	  loop line;
	  let name, version, release, arch =
	    !name, !version, !release, !arch in
	  if name = "" || version = "" || release = "" || arch = "" then
	    failwith (sprintf "%s: missing Name, Version, Release or Architecture key" filename);
	  name, sprintf "%s-%s.%s" version release arch
	) in

      printf "%s -> %s, %s\n" basename name version;

      (basename, name, version)
  ) infos in

  ()