[bpt/coccinelle.git] / engine / pattern_c.ml

(*
 * Copyright 2010, INRIA, University of Copenhagen
 * Julia Lawall, Rene Rydhof Hansen, Gilles Muller, Nicolas Palix
 * Copyright 2005-2009, Ecole des Mines de Nantes, University of Copenhagen
 * Yoann Padioleau, Julia Lawall, Rene Rydhof Hansen, Henrik Stuart, Gilles Muller, Nicolas Palix
 * This file is part of Coccinelle.
 *
 * Coccinelle 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, according to version 2 of the License.
 *
 * Coccinelle 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 Coccinelle.  If not, see <http://www.gnu.org/licenses/>.
 *
 * The authors reserve the right to distribute this or future versions of
 * Coccinelle under other licenses.
 *)


open Common

module Flag_engine = Flag_matcher
(*****************************************************************************)
(* The functor argument  *)
(*****************************************************************************)

(* info passed recursively in monad in addition to binding *)
type xinfo = {
  optional_storage_iso : bool;
  optional_qualifier_iso : bool;
  value_format_iso : bool;
}

module XMATCH = struct

  (* ------------------------------------------------------------------------*)
  (* Combinators history *)
  (* ------------------------------------------------------------------------*)
  (*
   * version0:
   *   type ('a, 'b) matcher = 'a -> 'b -> bool
   *
   * version1: same but with a global variable holding the current binding
   *  BUT bug
   *   - can have multiple possibilities
   *   - globals sux
   *   - sometimes have to undo, cos if start match, then it binds,
   *     and if later it does not match, then must undo the first binds.
   *     ex: when match parameters, can  try to match, but then we found far
   *     later that the last argument of a function does not match
   *      => have to uando the binding !!!
   *      (can handle that too with a global, by saving the
   *      global, ... but sux)
   *   => better not use global
   *
   * version2:
   *    type ('a, 'b) matcher = binding -> 'a -> 'b -> binding list
   *
   * Empty list mean failure (let matchfailure = []).
   * To be able to have pretty code, have to use partial application
   * powa, and so the type is in fact
   *
   * version3:
   *    type ('a, 'b) matcher =  'a -> 'b -> binding -> binding list
   *
   * Then by defining the correct combinators, can have quite pretty code (that
   * looks like the clean code of version0).
   *
   * opti: return a lazy list of possible matchs ?
   *
   * version4: type tin = Lib_engine.metavars_binding
   *)

  (* ------------------------------------------------------------------------*)
  (* Standard type and operators  *)
  (* ------------------------------------------------------------------------*)

  type tin = {
    extra: xinfo;
    binding: Lib_engine.metavars_binding;
    binding0: Lib_engine.metavars_binding; (* inherited bindings *)
  }
  (* 'x is a ('a * 'b) but in fact dont care about 'b, we just tag the SP *)
  (* opti? use set instead of list *)
  type 'x tout = ('x * Lib_engine.metavars_binding) list

  type ('a, 'b) matcher = 'a -> 'b  -> tin -> ('a * 'b) tout

  (* was >&&> *)
  let (>>=) m1 m2 = fun tin ->
    let xs = m1 tin in
    let xxs = xs +> List.map (fun ((a,b), binding) ->
      m2 a b {tin with binding = binding}
    ) in
    List.flatten xxs

  (* Je compare les bindings retournés par les differentes branches.
   * Si la deuxieme branche amene a des bindings qui sont deja presents
   * dans la premiere branche, alors je ne les accepte pas.
   *
   * update: still useful now that julia better handle Exp directly via
   * ctl tricks using positions ?
   *)
  let (>|+|>) m1 m2 = fun tin ->
(* CHOICE
      let xs = m1 tin in
      if null xs
      then m2 tin
      else xs
*)
    let res1 = m1 tin in
    let res2 = m2 tin in
    let list_bindings_already = List.map snd res1 in
    res1 ++
      (res2 +> List.filter (fun (x, binding) ->
        not
          (list_bindings_already +> List.exists (fun already ->
            Lib_engine.equal_binding binding already))
      ))




  let (>||>) m1 m2 = fun tin ->
(* CHOICE
      let xs = m1 tin in
      if null xs
      then m2 tin
      else xs
*)
    (* opti? use set instead of list *)
    let l1 = m1 tin in
    let l2 = m2 tin in
    if l2 = [] then l1 else l1 ++ l2 (*a small benefit; avoid a trivial @*)


  let return res = fun tin ->
    [res, tin.binding]

  let fail = fun tin ->
    []

  let (>&&>) f m = fun tin ->
    if f tin
    then m tin
    else fail tin


  let mode = Cocci_vs_c.PatternMode

  (* ------------------------------------------------------------------------*)
  (* Exp  *)
  (* ------------------------------------------------------------------------*)
  let cocciExp = fun expf expa node -> fun tin ->

    let globals = ref [] in
    let bigf = {
      (* julia's style *)
      Visitor_c.default_visitor_c with
      Visitor_c.kexpr = (fun (k, bigf) expb ->
        match expf expa expb tin with
        | [] -> (* failed *) k expb
        | xs ->
            globals := xs @ !globals;
            if not !Flag_engine.disallow_nested_exps then k expb (* CHOICE *)
      );
      (* pad's style.
       * push2 expr globals;  k expr
       *  ...
       *  !globals +> List.fold_left (fun acc e -> acc >||> match_e_e expr e)
       * (return false)
       *
       *)
    }
    in
    Visitor_c.vk_node bigf node;
    !globals +> List.map (fun ((a, _exp), binding) ->
      (a, node), binding
    )

  (* same as cocciExp, but for expressions in an expression, not expressions
     in a node *)
  let cocciExpExp = fun expf expa expb -> fun tin ->

    let globals = ref [] in
    let bigf = {
      (* julia's style *)
      Visitor_c.default_visitor_c with
      Visitor_c.kexpr = (fun (k, bigf) expb ->
        match expf expa expb tin with
        | [] -> (* failed *) k expb
        | xs ->
            globals := xs @ !globals;
            if not !Flag_engine.disallow_nested_exps then k expb (* CHOICE *)
      );
      (* pad's style.
       * push2 expr globals;  k expr
       *  ...
       *  !globals +> List.fold_left (fun acc e -> acc >||> match_e_e expr e)
       * (return false)
       *
       *)
    }
    in
    Visitor_c.vk_expr bigf expb;
    !globals +> List.map (fun ((a, _exp), binding) ->
      (a, expb), binding
    )

  let cocciTy = fun expf expa node -> fun tin ->

    let globals = ref [] in
    let bigf = {
      Visitor_c.default_visitor_c with
        Visitor_c.ktype = (fun (k, bigf) expb ->
        match expf expa expb tin with
        | [] -> (* failed *) k expb
        | xs -> globals := xs @ !globals);

    }
    in
    Visitor_c.vk_node bigf node;
    !globals +> List.map (fun ((a, _exp), binding) ->
      (a, node), binding
    )

  let cocciInit = fun expf expa node -> fun tin ->

    let globals = ref [] in
    let bigf = {
      Visitor_c.default_visitor_c with
        Visitor_c.kini = (fun (k, bigf) expb ->
        match expf expa expb tin with
        | [] -> (* failed *) k expb
        | xs -> globals := xs @ !globals);

    }
    in
    Visitor_c.vk_node bigf node;
    !globals +> List.map (fun ((a, _exp), binding) ->
      (a, node), binding
    )


  (* ------------------------------------------------------------------------*)
  (* Distribute mcode *)
  (* ------------------------------------------------------------------------*)
  let tag_mck_pos mck posmck =
    match mck with
    | Ast_cocci.PLUS c -> Ast_cocci.PLUS c
    | Ast_cocci.CONTEXT (pos, xs) ->
        assert (pos =*= Ast_cocci.NoPos || pos =*= Ast_cocci.DontCarePos);
        Ast_cocci.CONTEXT (posmck, xs)
    | Ast_cocci.MINUS (pos, inst, adj, xs) ->
        assert (pos =*= Ast_cocci.NoPos || pos =*= Ast_cocci.DontCarePos);
        Ast_cocci.MINUS (posmck, inst, adj, xs)


  let tag_mck_pos_mcode (x,info,mck,pos) posmck stuff = fun tin ->
    [((x, info, tag_mck_pos mck posmck, pos),stuff), tin.binding]


  let distrf (ii_of_x_f) =
    fun mcode x -> fun tin ->
    let (max, min) = Lib_parsing_c.max_min_by_pos (ii_of_x_f x)
    in
    let posmck = Ast_cocci.FixPos (min, max) (* subtil: and not max, min !!*)
    in
    tag_mck_pos_mcode mcode posmck x tin

  let distrf_e      = distrf (Lib_parsing_c.ii_of_expr)
  let distrf_args   = distrf (Lib_parsing_c.ii_of_args)
  let distrf_type   = distrf (Lib_parsing_c.ii_of_type)
  let distrf_param  = distrf (Lib_parsing_c.ii_of_param)
  let distrf_params = distrf (Lib_parsing_c.ii_of_params)
  let distrf_ini    = distrf (Lib_parsing_c.ii_of_ini)
  let distrf_inis   = distrf (Lib_parsing_c.ii_of_inis)
  let distrf_decl   = distrf (Lib_parsing_c.ii_of_decl)
  let distrf_field  = distrf (Lib_parsing_c.ii_of_field)
  let distrf_node   = distrf (Lib_parsing_c.ii_of_node)
  let distrf_enum_fields = distrf (Lib_parsing_c.ii_of_enum_fields)
  let distrf_struct_fields = distrf (Lib_parsing_c.ii_of_struct_fields)
  let distrf_cst    = distrf (Lib_parsing_c.ii_of_cst)
  let distrf_define_params = distrf (Lib_parsing_c.ii_of_define_params)


  (* ------------------------------------------------------------------------*)
  (* Constraints on metavariable values *)
  (* ------------------------------------------------------------------------*)
  let check_idconstraint matcher c id = fun f tin ->
    if matcher c id then
      (* success *)
      f () tin
    else
      (* failure *)
      fail tin

  let check_constraints_ne matcher constraints exp = fun f tin ->
    let rec loop = function
        [] -> f () tin (* success *)
      | c::cs ->
          match matcher c exp tin with
            [] (* failure *) -> loop cs
          | _ (* success *) -> fail tin in
    loop constraints

  let check_pos_constraints constraints pvalu f tin =
    check_constraints_ne
      (fun c exp tin ->
        let success = [[]] in
        let failure = [] in
        (* relies on the fact that constraints on pos variables must refer to
           inherited variables *)
        (match Common.optionise (fun () -> tin.binding0 +> List.assoc c) with
          Some valu' ->
            if Cocci_vs_c.equal_inh_metavarval exp valu'
            then success else failure
        | None ->
            (* if the variable is not there, it puts no constraints *)
            (* not sure this is still useful *)
            failure))
      constraints pvalu f tin

  (* ------------------------------------------------------------------------*)
  (* Environment *)
  (* ------------------------------------------------------------------------*)
  (* pre: if have declared a new metavar that hide another one, then
   * must be passed with a binding that deleted this metavar
   *
   * Here we dont use the keep argument of julia. cf f(X,X), J'ai
   * besoin de garder le X en interne, meme si julia s'en fout elle du
   * X et qu'elle a mis X a DontSaved.
   *)
  let check_add_metavars_binding strip _keep inherited = fun (k, valu) tin ->
    if inherited
    then
      match Common.optionise (fun () -> tin.binding0 +> List.assoc k) with
      | Some (valu') ->
          if Cocci_vs_c.equal_inh_metavarval valu valu'
          then Some tin.binding
          else None
      | None -> None
    else
      match Common.optionise (fun () -> tin.binding +> List.assoc k) with
      | Some (valu') ->
          if Cocci_vs_c.equal_metavarval valu valu'
          then Some tin.binding
          else None

      | None ->
          let success valu' =
            Some (tin.binding +> Common.insert_assoc (k, valu')) in
          (match valu with
            Ast_c.MetaIdVal (a,c)    ->
              (* c is a negated constraint *)
              let rec loop = function
                  [] -> success(Ast_c.MetaIdVal(a,[]))
                | c::cs ->
                    let tmp =
                      Common.optionise
                        (fun () -> tin.binding0 +> List.assoc c) in
                    (match tmp with
                      Some (Ast_c.MetaIdVal(v,_)) ->
                        if a =$= v
                        then None (* failure *)
                        else success(Ast_c.MetaIdVal(a,[]))
                    | Some _ -> failwith "Not possible"
                    | None -> success(Ast_c.MetaIdVal(a,[]))) in
              loop c
          | Ast_c.MetaFuncVal a      ->
              success(Ast_c.MetaFuncVal a)
          | Ast_c.MetaLocalFuncVal a ->
              success(Ast_c.MetaLocalFuncVal a) (*more?*)
          | Ast_c.MetaExprVal (a,c) ->
              (* c in the value is only to prepare for the future in which
                 we figure out how to have subterm constraints on unbound
                 variables.  Now an environment will only contain expression
                 values with empty constraints, as all constraints are
                 resolved at binding time *)
              let stripped =
                if strip
                then Lib_parsing_c.al_expr a
                else Lib_parsing_c.semi_al_expr a in
              let inh_stripped = Lib_parsing_c.al_inh_expr a in
              let rec loop = function
                  [] -> success(Ast_c.MetaExprVal(stripped,[]))
                | c::cs ->
                    let tmp =
                      Common.optionise
                        (fun () -> tin.binding0 +> List.assoc c) in
                    (match tmp with
                      Some (Ast_c.MetaExprVal(v,_)) ->
                        if C_vs_c.subexpression_of_expression inh_stripped v
                        then loop cs (* forget satisfied constraints *)
                        else None (* failure *)
                    | Some _ -> failwith "not possible"
                      (* fail if this should be a subterm of something that
                         doesn't exist *)
                    | None -> None) in
              loop c
          | Ast_c.MetaExprListVal a ->
              success
                (Ast_c.MetaExprListVal
                   (if strip
                   then Lib_parsing_c.al_arguments a
                   else Lib_parsing_c.semi_al_arguments a))
                
          | Ast_c.MetaDeclVal a ->
              success
                (Ast_c.MetaDeclVal
                   (if strip
                   then Lib_parsing_c.al_declaration a
                   else Lib_parsing_c.semi_al_declaration a))
          | Ast_c.MetaFieldVal a ->
              success
                (Ast_c.MetaFieldVal
                   (if strip
                   then Lib_parsing_c.al_field a
                   else Lib_parsing_c.semi_al_field a))
          | Ast_c.MetaStmtVal a ->
              success
                (Ast_c.MetaStmtVal
                   (if strip
                   then Lib_parsing_c.al_statement a
                   else Lib_parsing_c.semi_al_statement a))
          | Ast_c.MetaTypeVal a ->
              success
                (Ast_c.MetaTypeVal
                   (if strip
                   then Lib_parsing_c.al_type a
                   else Lib_parsing_c.semi_al_type a))
                
          | Ast_c.MetaInitVal a ->
              success
                (Ast_c.MetaInitVal
                   (if strip
                   then Lib_parsing_c.al_init a
                   else Lib_parsing_c.semi_al_init a))
                
          | Ast_c.MetaListlenVal a -> success(Ast_c.MetaListlenVal a)
                
          | Ast_c.MetaParamVal a ->
              success
                (Ast_c.MetaParamVal
                   (if strip
                   then Lib_parsing_c.al_param a
                   else Lib_parsing_c.semi_al_param a))
          | Ast_c.MetaParamListVal a ->
              success
                (Ast_c.MetaParamListVal
                   (if strip
                   then Lib_parsing_c.al_params a
                   else Lib_parsing_c.semi_al_params a))
                
          | Ast_c.MetaPosVal (pos1,pos2) ->
              success(Ast_c.MetaPosVal (pos1,pos2))
          | Ast_c.MetaPosValList l -> success (Ast_c.MetaPosValList l))

  let envf keep inherited = fun (k, valu, get_max_min) f tin ->
    let x = Ast_cocci.unwrap_mcode k in
    match check_add_metavars_binding true keep inherited (x, valu) tin with
    | Some binding ->
        let new_tin = {tin with binding = binding} in
        (match Ast_cocci.get_pos_var k with
          Ast_cocci.MetaPos(name,constraints,per,keep,inherited) ->
            let pvalu =
              let (file,current_element,min,max) = get_max_min() in
              Ast_c.MetaPosValList[(file,current_element,min,max)] in
            (* check constraints.  success means that there is a match with
               one of the constraints, which will ultimately result in
               failure. *)
            check_pos_constraints constraints pvalu
              (function () ->
                (* constraints are satisfied, now see if we are compatible
                   with existing bindings *)
                function new_tin ->
                  let x = Ast_cocci.unwrap_mcode name in
                  (match
                    check_add_metavars_binding false keep inherited (x, pvalu)
                      new_tin with
                  | Some binding ->
                      f () {new_tin with binding = binding}
                  | None -> fail tin))
              new_tin
        | Ast_cocci.NoMetaPos -> f () new_tin)
    | None -> fail tin

  (* ------------------------------------------------------------------------*)
  (* Environment, allbounds *)
  (* ------------------------------------------------------------------------*)
  (* all referenced inherited variables have to be bound. This would
   * be naturally checked for the minus or context ones in the
   * matching process, but have to check the plus ones as well. The
   * result of get_inherited contains all of these, but the potential
   * redundant checking for the minus and context ones is probably not
   * a big deal. If it's a problem, could fix free_vars to distinguish
   * between + variables and the other ones. *)

  let (all_bound : Ast_cocci.meta_name list -> tin -> bool) = fun l tin ->
    l +> List.for_all (fun inhvar ->
      match Common.optionise (fun () -> tin.binding0 +> List.assoc inhvar) with
      | Some _ -> true
      | None -> false
    )

  let optional_storage_flag f = fun tin ->
    f (tin.extra.optional_storage_iso) tin

  let optional_qualifier_flag f = fun tin ->
    f (tin.extra.optional_qualifier_iso) tin

  let value_format_flag f = fun tin ->
    f (tin.extra.value_format_iso) tin

  (* ------------------------------------------------------------------------*)
  (* Tokens *)
  (* ------------------------------------------------------------------------*)
  let tokenf ia ib = fun tin ->
    let pos = Ast_c.info_to_fixpos ib in
    let posmck = Ast_cocci.FixPos (pos, pos) in
    let finish tin = tag_mck_pos_mcode ia posmck ib tin in
    match Ast_cocci.get_pos_var ia with
      Ast_cocci.MetaPos(name,constraints,per,keep,inherited) ->
        let mpos = Lib_parsing_c.lin_col_by_pos [ib] in
        let pvalu = Ast_c.MetaPosValList [mpos] in
        check_pos_constraints constraints pvalu
          (function () ->
            (* constraints are satisfied, now see if we are compatible
               with existing bindings *)
            function new_tin ->
              let x = Ast_cocci.unwrap_mcode name in
              (match
                check_add_metavars_binding false keep inherited (x, pvalu) tin
              with
                Some binding -> finish {tin with binding = binding}
              | None -> fail tin))
          tin
    | _ -> finish tin

  let tokenf_mck mck ib = fun tin ->
    let pos = Ast_c.info_to_fixpos ib in
    let posmck = Ast_cocci.FixPos (pos, pos) in
    [(tag_mck_pos mck posmck, ib), tin.binding]

end

(*****************************************************************************)
(* Entry point  *)
(*****************************************************************************)
module MATCH  = Cocci_vs_c.COCCI_VS_C (XMATCH)


let match_re_node2 dropped_isos a b binding0 =

  let tin = {
    XMATCH.extra = {
      optional_storage_iso   = not(List.mem "optional_storage"   dropped_isos);
      optional_qualifier_iso = not(List.mem "optional_qualifier" dropped_isos);
      value_format_iso       = not(List.mem "value_format"       dropped_isos);
    };
    XMATCH.binding = [];
    XMATCH.binding0 = binding0;
  } in

  MATCH.rule_elem_node a b tin
  (* take only the tagged-SP, the 'a' *)
  +> List.map (fun ((a,_b), binding) -> a, binding)


let match_re_node a b c d =
  Common.profile_code "Pattern3.match_re_node"
    (fun () -> match_re_node2 a b c d)