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Date:   Sun, 1 Oct 2023 21:14:02 +0200 (CEST)
From:   Julia Lawall <julia.lawall@inria.fr>
To:     Kees Cook <kees@kernel.org>
cc:     Julia Lawall <julia.lawall@inria.fr>,
        Kees Cook <keescook@chromium.org>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Ian Abbott <abbotti@mev.co.uk>,
        H Hartley Sweeten <hsweeten@visionengravers.com>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org,
        kernel-janitors@vger.kernel.org, linux-hardening@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH] comedi: Annotate struct comedi_lrange with
 __counted_by
In-Reply-To: <90E2BBA5-8A2D-42DE-B36A-CD37BABBB433@kernel.org>
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References: <5c3b7459b820e22e2ac6ce892d4aadcc119cc919.1696065263.git.christophe.jaillet@wanadoo.fr> <202309301342.5B5BED40A1@keescook> <alpine.DEB.2.22.394.2310010945130.3166@hadrien> <90E2BBA5-8A2D-42DE-B36A-CD37BABBB433@kernel.org>
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Kees,

You can try the following.

julia

#spatch --all-includes

@r@
identifier i,j;
type T;
@@

struct i {
  ...
  T j[];
}

@s@
identifier r.i;
constant ini;
identifier j;
initializer list [n] is2;
position p;
identifier x;
@@

struct i@p x =
 { ...,
   .j = ini,
   ...,
   { is2 } }
  ;

@script:ocaml@
ini << s.ini;
i << r.i;
j << s.j;
n << s.n;
p << s.p;
@@

try
  let ini = int_of_string ini in
  if n = ini
  then Printf.printf "%s:%d: struct %s: field %s is the counter for the flex array\n" (List.hd p).file (List.hd p).line i j
with _-> () (* not an explicit integer *)

@s2@
identifier r.i;
constant ini;
initializer list [n] is;
initializer list [n2] is2;
position p;
identifier x;
@@

struct i@p x =
  { is,
    ini,
    ...,
    { is2 } };

@script:ocaml@
ini << s2.ini;
i << r.i;
n << s2.n;
n2 << s2.n2;
p << s2.p;
@@

try
  let ini = int_of_string ini in
  if n2 = ini
  then Printf.printf "%s:%d: struct %s: field at offset %d is the counter for the flex array\n" (List.hd p).file (List.hd p).line i n
with _-> () (* not an explicit integer *)