Re: [Cocci] [PATCH 01/26] parsing_cocci: Add Function Prototype token

[Julia Lawall <julia.lawall@inria.fr>]

On Thu, 19 Mar 2020, Jaskaran Singh wrote:

> On Wed, 2020-03-18 at 18:25 +0100, Julia Lawall wrote:
> >
> > On Mon, 16 Mar 2020, Jaskaran Singh wrote:
> >
> > > To add the types ParenType and FunctionType to the SmPL AST, a
> > > reduce/reduce conflict with the funproto rule of the SmPL parser
> > > must be resolved. This requires explicitly identifying a function
> > > prototype by use of a token (TFunProto).
> > >
> > > While the correct method of identifying a function prototype would
> > > be to
> > > check if an identifier is preceded by a return type, it is
> > > challenging
> > > to implement. This is because implementing an OCaml function, to
> > > correctly determine a C type in SmPL, without the aid of Yacc,
> > > would
> > > have to handle a number of cases (disjunctions, typeof expressions,
> > > etc.).
> > >
> > > Thus, a slightly hacky approach is taken to determine a function
> > > prototype with not the best certainty but what works for most cases
> > > in SmPL. If the identifier is preceded by any token that does not
> > > seem to be part of a type, then it is not identified as a function
> > > prototype. Else, it is.
> >
> > This sacrifices the test case tests/p1p2.cocci:
> >
>
> What do you mean by sacrifice?

That it doesn't work after applying 01.

Does something that comes later make it work again?

julia

> The test case seems to work, but not with just 01 applied. Here's what
> the debugger tells me about the AST:
>
> Ast_cocci.FunProto
> ([Ast_cocci.FType
>    {Ast_cocci.node =
>      Ast_cocci.Type (false, None,
>       {Ast_cocci.node =
>         Ast_cocci.MetaType
>          ((("rule starting on line 11", "T"),
>            {Ast_cocci.line = 18; column = 1;
>             strbef = []; straft = [];
>             whitespace = " "},
>            Ast_cocci.CONTEXT (Ast_cocci.NoPos,
>             Ast_cocci.AFTER
>              ([[Ast_cocci.Directive
>                  [Ast_cocci.Space
>                    "__attribute__((nonnull(2)))"]]],
>              Ast_cocci.ONE)),
>            []),
>
> Maybe after the grammar changes, Menhir does some kind of lookahead?
> I'm not sure.
>
> Cheers,
> Jaskaran.
>
> > @@
> > typedef Error;
> > type T;
> > identifier FN;
> > parameter P1;
> > @@
> >  T
> > +__attribute__((nonnull(1)))
> >  FN(P1, Error **errp);
> >
> > @@
> > typedef Error;
> > type T;
> > identifier FN;
> > parameter P1;
> > parameter P2;
> > @@
> >  T
> > +__attribute__((nonnull(2)))
> >  FN(P1, P2, Error **errp);
> >
> > Normally, the only way that you can have a ) before a function call
> > is
> > when there is a cast.  But hopefully in that case there would not be
> > two
> > )) before the function call.  Can that get around the problem?
> >
> > julia
> >
> >
> >
> >
> > > Signed-off-by: Jaskaran Singh <jaskaransingh7654321@gmail.com>
> > > ---
> > >  parsing_cocci/parse_cocci.ml          | 72
> > > +++++++++++++++++++++++----
> > >  parsing_cocci/parser_cocci_menhir.mly |  9 ++--
> > >  2 files changed, 67 insertions(+), 14 deletions(-)
> > >
> > > diff --git a/parsing_cocci/parse_cocci.ml
> > > b/parsing_cocci/parse_cocci.ml
> > > index 679d213a..4b2cb7e4 100644
> > > --- a/parsing_cocci/parse_cocci.ml
> > > +++ b/parsing_cocci/parse_cocci.ml
> > > @@ -295,6 +295,7 @@ let token2c (tok,_) add_clt =
> > >    | PC.TLineEnd(clt) -> "line end"
> > >    | PC.TInvalid -> "invalid"
> > >    | PC.TFunDecl(clt) -> "fundecl"
> > > +  | PC.TFunProto(clt) -> "funproto"
> > >
> > >    | PC.TIso -> "<=>"
> > >    | PC.TRightIso -> "=>"
> > > @@ -480,7 +481,7 @@ let get_clt (tok,_) =
> > >
> > >    | PC.TOPar0(_,clt) | PC.TMid0(_,clt) | PC.TAnd0(_,clt) |
> > > PC.TCPar0(_,clt)
> > >    | PC.TOEllipsis(clt) | PC.TCEllipsis(clt)
> > > -  | PC.TPOEllipsis(clt) | PC.TPCEllipsis(clt)
> > > +  | PC.TPOEllipsis(clt) | PC.TPCEllipsis(clt) | PC.TFunProto(clt)
> > >    | PC.TFunDecl(clt) | PC.TDirective(_,clt) | PC.TAttr_(clt)
> > >    | PC.TLineEnd(clt) -> clt
> > >    | PC.TVAEllipsis(clt) -> clt
> > > @@ -718,6 +719,7 @@ let update_clt (tok,x) clt =
> > >
> > >    | PC.TLineEnd(_) -> (PC.TLineEnd(clt),x)
> > >    | PC.TFunDecl(_) -> (PC.TFunDecl(clt),x)
> > > +  | PC.TFunProto(_) -> (PC.TFunProto(clt),x)
> > >    | PC.TTildeExclEq(_) -> (PC.TTildeExclEq(clt),x)
> > >    | PC.TDirective(a,_) -> (PC.TDirective(a,clt),x)
> > >    | PC.TAttr_(_) -> (PC.TAttr_(clt),x)
> > > @@ -925,7 +927,7 @@ let split_token ((tok,_) as t) =
> > >    | PC.TInitialize | PC.TFinalize -> ([t],[t])
> > >    | PC.TPArob clt | PC.TMetaPos(_,_,_,clt) | PC.TMetaCom(_,_,clt)
> > > -> split t clt
> > >
> > > -  | PC.TFunDecl(clt)
> > > +  | PC.TFunDecl(clt) | PC.TFunProto(clt)
> > >    | PC.TWhen(clt) | PC.TWhenTrue(clt) | PC.TWhenFalse(clt)
> > >    | PC.TAny(clt) | PC.TStrict(clt) | PC.TLineEnd(clt)
> > >    | PC.TEllipsis(clt)
> > > @@ -1006,7 +1008,8 @@ let find_function_names l =
> > >      | _ -> false in
> > >    let rec split acc = function
> > >        [] | [_] -> raise Irrelevant
> > > -    | ((PC.TCPar(_),_) as t1) :: ((PC.TOBrace(_),_) as t2) :: rest
> > > ->
> > > +    | ((PC.TCPar(_),_) as t1) :: ((PC.TOBrace(_),_) as t2) :: rest
> > > +    | ((PC.TCPar(_),_) as t1) :: ((PC.TPtVirg(_),_) as t2) :: rest
> > > ->
> > >  	(List.rev (t1::acc),(t2::rest))
> > >      | x::xs -> split (x::acc) xs in
> > >    let rec balanced_name level = function
> > > @@ -1037,7 +1040,48 @@ let find_function_names l =
> > >      | (PC.TArobArob,_)::_ | (PC.TArob,_)::_ | (PC.EOF,_)::_ ->
> > >  	raise Irrelevant
> > >      | t::rest -> balanced_args level rest in
> > > -  let rec loop = function
> > > +  let rec is_permissible_proto = function
> > > +      [] -> false
> > > +    | (PC.TCPar0(_),_)::
> > > +      ((PC.TMid0(_),_) | (PC.TAnd0(_),_))::
> > > +      (PC.TOPar0(_),_)::_ -> false
> > > +    | (PC.TOPar0(_),_)::rest
> > > +    | (PC.TCPar0(_),_)::rest -> is_permissible_proto rest
> > > +    | x::rest when is_mid x ->
> > > +        let rec loop = function
> > > +          [] -> false
> > > +        | (PC.TOPar0(_),_)::xs -> is_permissible_proto xs
> > > +        | x::xs -> loop xs in
> > > +        loop rest
> > > +    | _::((PC.TEq(_),_) | (PC.TNotEq(_),_))::(PC.TWhen(_),_)::_
> > > +    | _::(PC.TWhen(_),_)::_
> > > +    | (PC.TComma(_),_)::_
> > > +    | (PC.TDirective(_),_)::_
> > > +    | (PC.TElse(_),_)::_
> > > +    | (PC.TReturn(_),_)::_
> > > +    | (PC.TMetaStm(_),_)::_
> > > +    | (PC.TMetaExp(_),_)::_
> > > +    | (PC.TMetaId(_),_)::_
> > > +    | (PC.TMetaLocalIdExp(_),_)::_
> > > +    | (PC.TEq(_),_)::_
> > > +    | (PC.TEllipsis(_),_)::_
> > > +    | (PC.TOEllipsis(_),_)::_
> > > +    | (PC.TCEllipsis(_),_)::_
> > > +    | (PC.TPOEllipsis(_),_)::_
> > > +    | (PC.TPCEllipsis(_),_)::_
> > > +    | (PC.TPtVirg(_),_)::_
> > > +    | (PC.TOBrace(_),_)::_
> > > +    | (PC.TCBrace(_),_)::_
> > > +    | (PC.TOPar(_),_)::_
> > > +    | (PC.TCPar(_),_)::_
> > > +    | (PC.TIdent(_),_)::_ -> false
> > > +    | _ -> true in
> > > +  let decl_or_proto clt info bef aft =
> > > +    match aft with
> > > +      (PC.TOBrace(_),_)::_ -> (((PC.TFunDecl(clt),info) :: bef),
> > > aft)
> > > +    | (PC.TPtVirg(_),_)::_ -> (((PC.TFunProto(clt),info) :: bef),
> > > aft)
> > > +    | _ -> raise Irrelevant in
> > > +  let rec loop acc = function
> > >        [] -> []
> > >      | t :: rest ->
> > >  	if is_par t || is_mid t || is_ident t
> > > @@ -1046,26 +1090,30 @@ let find_function_names l =
> > >  	    try
> > >  	      let (bef,aft) = split [] (t::rest) in
> > >  	      let rest = balanced_name 0 bef in
> > > +              (match aft with
> > > +                (PC.TPtVirg(_),_)::_
> > > +                 when not(is_permissible_proto acc) -> raise
> > > Irrelevant
> > > +              | _ ->
> > >  	      (match rest with
> > >  		(PC.TOPar(_),_)::_ ->
> > >  		  (match balanced_args 0 rest with
> > >  		    [] ->
> > >  		      let (_,info) as h = List.hd bef in
> > >  		      let clt = get_clt h in
> > > -		      (((PC.TFunDecl(clt),info) :: bef), aft)
> > > +                      decl_or_proto clt info bef aft
> > >  		  | (PC.TAttr_(_),_)::rest ->
> > >  		      (match balanced_args 0 rest with
> > >  			[] ->
> > >  			  let (_,info) as h = List.hd bef in
> > >  			  let clt = get_clt h in
> > > -			  (((PC.TFunDecl(clt),info) :: bef), aft)
> > > +                          decl_or_proto clt info bef aft
> > >  		      | _ -> raise Irrelevant)
> > >  		  | _ -> raise Irrelevant)
> > > -	      | _ -> raise Irrelevant)
> > > +	      | _ -> raise Irrelevant))
> > >  	    with Irrelevant -> ([t],rest) in
> > > -	  t @ (loop rest)
> > > -	else t :: (loop rest) in
> > > -  loop l
> > > +          t @ (loop (t @ acc) rest)
> > > +        else t :: (loop (t :: acc) rest) in
> > > +  loop [] l
> > >
> > >  (* -------------------------------------------------------------
> > > ---------- *)
> > >  (* an attribute is an identifier that precedes another identifier
> > > and
> > > @@ -1168,6 +1216,8 @@ let detect_types in_meta_decls l =
> > >  	delim::newid::id::(loop false infn (ident::type_names) rest)
> > >      | ((PC.TFunDecl(_),_) as fn)::rest ->
> > >  	fn::(loop false 1 type_names rest)
> > > +    | ((PC.TFunProto(_),_) as fn)::rest ->
> > > +	fn::(loop false 1 type_names rest)
> > >      | ((PC.TOPar(_),_) as lp)::rest when infn > 0 ->
> > >  	lp::(loop false (infn + 1) type_names rest)
> > >      | ((PC.TCPar(_),_) as rp)::rest when infn > 0 ->
> > > @@ -1252,7 +1302,7 @@ let token2line (tok,_) =
> > >    | PC.TMetaDParamList(_,_,_,_,clt) | PC.TMetaFunc(_,_,_,clt)
> > >    | PC.TMetaLocalFunc(_,_,_,clt) | PC.TMetaPos(_,_,_,clt) |
> > > PC.TMetaCom(_,_,clt)
> > >
> > > -  | PC.TFunDecl(clt)
> > > +  | PC.TFunDecl(clt) | PC.TFunProto(clt)
> > >    | PC.TWhen(clt) | PC.TWhenTrue(clt) | PC.TWhenFalse(clt)
> > >    | PC.TAny(clt) | PC.TStrict(clt) | PC.TEllipsis(clt)
> > >
> > > diff --git a/parsing_cocci/parser_cocci_menhir.mly
> > > b/parsing_cocci/parser_cocci_menhir.mly
> > > index 9e6c8a08..26958f63 100644
> > > --- a/parsing_cocci/parser_cocci_menhir.mly
> > > +++ b/parsing_cocci/parser_cocci_menhir.mly
> > > @@ -239,7 +239,8 @@ let inline_id aft = function
> > >
> > >  %token <Data.clt> TVAEllipsis
> > >  %token <Data.clt> TIf TElse TWhile TFor TDo TSwitch TCase TDefault
> > > TReturn
> > > -%token <Data.clt> TBreak TContinue TGoto TSizeof TTypeof TFunDecl
> > > Tdecimal Texec
> > > +%token <Data.clt> TBreak TContinue TGoto TSizeof TTypeof TFunDecl
> > > TFunProto
> > > +%token <Data.clt> Tdecimal Texec
> > >  %token <string * Data.clt> TIdent TTypeId TDeclarerId TIteratorId
> > > TSymId
> > >  %token <Ast_cocci.added_string * Data.clt> TDirective
> > >  %token <Data.clt> TAttr_
> > > @@ -1439,7 +1440,8 @@ reverse_separated_nonempty_llist(separator,
> > > X):
> > >
> > >  funproto:
> > >    s=ioption(storage) i=ioption(Tinline) t=ctype
> > > -  id=fn_ident lp=TOPar arglist=arg_list(name_opt_decl) rp=TCPar
> > > pt=TPtVirg
> > > +  TFunProto id=fn_ident
> > > +  lp=TOPar arglist=arg_list(name_opt_decl) rp=TCPar pt=TPtVirg
> > >        { let s = match s with None -> [] | Some s -> [Ast0.FStorage
> > > s] in
> > >          let i =
> > >  	  match i with
> > > @@ -1453,7 +1455,8 @@ funproto:
> > >  	      P.clt2mcode "(" lp, args, vararg, P.clt2mcode ")" rp,
> > >  	      P.clt2mcode ";" pt)) }
> > >  | i=Tinline s=storage t=ctype
> > > -  id=fn_ident lp=TOPar arglist=arg_list(name_opt_decl) rp=TCPar
> > > pt=TPtVirg
> > > +  TFunProto id=fn_ident
> > > +  lp=TOPar arglist=arg_list(name_opt_decl) rp=TCPar pt=TPtVirg
> > >        { let s = [Ast0.FStorage s] in
> > >          let i = [Ast0.FInline (P.clt2mcode "inline" i)] in
> > >  	let t = [Ast0.FType t] in
> > > --
> > > 2.21.1
> > >
> > >
>
>
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