parsing_cocci/comm_assoc.ml

   1 (* searches for E op ..., for any commutative and associative binary
   2 operator.  When this satisfies the isomorphism conditions (ie all minus, or
   3 context for the op and ...), then this is converted to Nested(E,op).
   4 Nested is not used before this phase. *)
   5
   6 module Ast = Ast_cocci
   7 module Ast0 = Ast0_cocci
   8 module V0 = Visitor_ast0
   9 module VT0 = Visitor_ast0_types
  10
  11 let comm_assoc =
  12   [Ast.Arith(Ast.Plus);Ast.Arith(Ast.Mul);Ast.Arith(Ast.And);Ast.Arith(Ast.Or);
  13     Ast.Logical(Ast.AndLog);Ast.Logical(Ast.OrLog)]
  14
  15 let is_minus e =
  16   match Ast0.get_mcodekind e with Ast0.MINUS(cell) -> true | _ -> false
  17
  18 let is_context e =
  19   !Flag.sgrep_mode2 or (* everything is context for sgrep *)
  20   (match Ast0.get_mcodekind e with
  21     Ast0.CONTEXT(cell) -> true
  22   | _ -> false)
  23
  24 let nopos mc =
  25   match Ast0.get_pos mc with Ast0.MetaPos _ -> false | Ast0.NoMetaPos -> true
  26
  27 let process_binops rule_name =
  28   let expr r k e1 =
  29     let e = k e1 in
  30     match Ast0.unwrap e with
  31       Ast0.Binary(left,op,right)
  32       when List.mem (Ast0.unwrap_mcode op) comm_assoc ->
  33         (match Ast0.unwrap right with
  34           Ast0.Edots(d,None) ->
  35             if (is_minus e || (is_context e && is_context right))
  36                 && nopos op && nopos d
  37             (* keep dots to record required modif *)
  38             then Ast0.rewrap e (Ast0.Nested(left,op,right))
  39             else
  40               (Printf.printf
  41                  "%s: position variables or mixed modifs interfere with comm_assoc iso" rule_name;
  42                Unparse_ast0.expression e1;
  43                Format.print_newline();
  44                e)
  45         | Ast0.Edots(d,_) ->
  46             (Printf.printf
  47                "%s: whencode interferes with comm_assoc iso" rule_name;
  48              Unparse_ast0.expression e1;
  49              Format.print_newline();
  50              e)
  51         | _ -> e)
  52     | _ -> e in
  53   V0.rebuilder {V0.rebuilder_functions with VT0.rebuilder_exprfn = expr}
  54
  55 let comm_assoc rule rule_name dropped_isos =
  56   if List.mem "comm_assoc" dropped_isos
  57   then rule
  58   else List.map (process_binops rule_name).VT0.rebuilder_rec_top_level rule