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(*
*
* Copyright (c) 2001-2002,
* George C. Necula <necula@cs.berkeley.edu>
* Scott McPeak <smcpeak@cs.berkeley.edu>
* Wes Weimer <weimer@cs.berkeley.edu>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. The names of the contributors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
* PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*)
open Pretty
open Cil
module E = Errormsg
module H = Hashtbl
(* David Park at Stanford points out that you cannot take the address of a
* bitfield in GCC. *)
(* Returns true if the given lvalue offset ends in a bitfield access. *)
let rec is_bitfield lo = match lo with
| NoOffset -> false
| Field(fi,NoOffset) -> not (fi.fbitfield = None)
| Field(_,lo) -> is_bitfield lo
| Index(_,lo) -> is_bitfield lo
(* Return an expression that evaluates to the address of the given lvalue.
* For most lvalues, this is merely AddrOf(lv). However, for bitfields
* we do some offset gymnastics.
*)
let addr_of_lv (lh,lo) =
if is_bitfield lo then begin
(* we figure out what the address would be without the final bitfield
* access, and then we add in the offset of the bitfield from the
* beginning of its enclosing comp *)
let rec split_offset_and_bitfield lo = match lo with
| NoOffset -> failwith "logwrites: impossible"
| Field(fi,NoOffset) -> (NoOffset,fi)
| Field(e,lo) -> let a,b = split_offset_and_bitfield lo in
((Field(e,a)),b)
| Index(e,lo) -> let a,b = split_offset_and_bitfield lo in
((Index(e,a)),b)
in
let new_lv_offset, bf = split_offset_and_bitfield lo in
let new_lv = (lh, new_lv_offset) in
let enclosing_type = TComp(bf.fcomp, []) in
let bits_offset, bits_width =
bitsOffset enclosing_type (Field(bf,NoOffset)) in
let bytes_offset = bits_offset / 8 in
let lvPtr = mkCast ~e:(mkAddrOf (new_lv)) ~newt:(charPtrType) in
(BinOp(PlusPI, lvPtr, (integer bytes_offset), ulongType))
end else (AddrOf (lh,lo))
class logWriteVisitor = object
inherit nopCilVisitor
(* Create a prototype for the logging function, but don't put it in the
* file *)
val printfFun =
let fdec = emptyFunction "syslog" in
fdec.svar.vtype <- TFun(intType,
Some [ ("prio", intType, []);
("format", charConstPtrType, []) ],
true, []);
fdec
method vinst (i: instr) : instr list visitAction =
match i with
Set(lv, e, l) -> begin
(* Check if we need to log *)
match lv with
(Var(v), off) when not v.vglob -> SkipChildren
| _ -> let str = Pretty.sprint 80
(Pretty.dprintf "Write %%p to 0x%%08x at %%s:%%d (%a)\n" d_lval lv)
in
ChangeTo
[ Call((None), (Lval(Var(printfFun.svar),NoOffset)),
[ one ;
mkString str ; e ; addr_of_lv lv;
mkString l.file;
integer l.line], locUnknown);
i]
end
| Call(Some lv, f, args, l) -> begin
(* Check if we need to log *)
match lv with
(Var(v), off) when not v.vglob -> SkipChildren
| _ -> let str = Pretty.sprint 80
(Pretty.dprintf "Write retval to 0x%%08x at %%s:%%d (%a)\n" d_lval lv)
in
ChangeTo
[ Call((None), (Lval(Var(printfFun.svar),NoOffset)),
[ one ;
mkString str ; AddrOf lv;
mkString l.file;
integer l.line], locUnknown);
i]
end
| _ -> SkipChildren
end
let feature : featureDescr =
{ fd_name = "logwrites";
fd_enabled = Cilutil.logWrites;
fd_description = "generation of code to log memory writes";
fd_extraopt = [];
fd_doit =
(function (f: file) ->
let lwVisitor = new logWriteVisitor in
visitCilFileSameGlobals lwVisitor f);
fd_post_check = true;
}
|
