parsing_cocci/top_level.ml

   1 (* Reorganize the top level of a rule to be a list of either top-level
   2 declarations or code dots.  A function declaration is always considered top
   3 level.  A statement is always considered code dots.  A variable declaration
   4 is ambiguous.  We use the heuristic that if there are code dots somewhere
   5 else, then the variable declaration is at top level, otherwise it applies
   6 both at top level and to all code. *)
   7
   8 (* This is assumed to be done before compute_lines, and thus the info on a
   9 complex term is assumed to be Ast0.default_info *)
  10
  11 module Ast0 = Ast0_cocci
  12
  13 let top_dots l =
  14   let circle x =
  15     match Ast0.unwrap x with Ast0.Circles(_) -> true | _ -> false in
  16   let star x =
  17     match Ast0.unwrap x with Ast0.Stars(_) -> true | _ -> false in
  18   if List.exists circle l
  19   then Ast0.wrap (Ast0.CIRCLES(l))
  20   else if List.exists star l
  21   then Ast0.wrap (Ast0.STARS(l))
  22   else Ast0.wrap (Ast0.DOTS(l))
  23
  24 let scan_code l =
  25   let statements = ref false in
  26   let rec loop = function
  27       [] -> ([],[])
  28     | (x::xs) as all ->
  29         (match Ast0.unwrap x with
  30           (Ast0.OTHER(code)) ->
  31             (match Ast0.unwrap code with
  32               Ast0.Decl(_) ->
  33                 let (front,rest) = loop xs in
  34                 (code::front,rest)
  35             | _ ->
  36                 statements := true;
  37                 let (front,rest) = loop xs in
  38                 (code::front,rest))
  39         | _ -> ([],all)) in
  40   match loop l with
  41     ([],_) as res -> res
  42   | (code,rest) ->
  43       if !statements = true
  44       then ([Ast0.wrap(Ast0.CODE(top_dots code))],rest)
  45       else
  46         (List.map
  47            (function d ->
  48              match Ast0.unwrap d with
  49                Ast0.Decl(bef,x) -> Ast0.wrap (Ast0.DECL(d))
  50              | _ -> failwith "impossible")
  51            code,
  52          rest)
  53
  54 let rec scan_top_decl = function
  55     [] -> ([],[])
  56   | ((topdecl::rest) as all) ->
  57       (match Ast0.unwrap topdecl with
  58         Ast0.OTHER(_) -> ([],all)
  59       | _ -> let (front,rest) = scan_top_decl rest in (topdecl::front,rest))
  60
  61 (* for debugging *)
  62 let l2c l =
  63   match Ast0.unwrap l with
  64     Ast0.DECL(_) -> "decl"
  65   | Ast0.CODE(_) -> "code"
  66   | Ast0.FILEINFO(_,_) -> "fileinfo"
  67   | Ast0.ERRORWORDS(_) -> "errorwords"
  68   | Ast0.OTHER(_) -> "other"
  69
  70 let rec top_level l =
  71   match scan_code l with
  72     (code,[]) -> code
  73   | (code,rest) ->
  74       (match scan_top_decl rest with
  75         (top_decls,[]) -> code@top_decls
  76       | (top_decls,rest) -> code @ top_decls @ (top_level rest))