Source file ir.ml
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module StrTbl = Basic_types.String.Htbl
module IntTbl = Hmap.Make (struct
type t = int
let hash = Fun.id
let compare = ( - )
end)
module IntSet = Basic_types.Integers.Int.Set
module Var = struct
module Tag = Dba.Var.Tag
include Dba_types.Var
let collect = Dba_types.Expr.collect_variables
end
type builtin = ..
type builtin += Inline of Dhunk.t | EndOfHook
let (pp_builtin, register_builtin_printer) :
(Format.formatter -> builtin -> unit)
* ((Format.formatter -> builtin -> bool) -> unit) =
let rec pp_builtin ppf x printers =
match printers with
| [] -> Format.pp_print_string ppf "unknown builtin"
| printer :: printers ->
if not (printer ppf x) then pp_builtin ppf x printers
in
let builtin_printers =
ref
[
(fun ppf builtin ->
match builtin with
| EndOfHook ->
Format.pp_print_string ppf "end of hook";
true
| _ -> false);
]
in
( (fun ppf x -> pp_builtin ppf x !builtin_printers),
fun printer -> builtin_printers := printer :: !builtin_printers )
type 'a opcode =
| Nop : [ `Fallthrough ] opcode
| Instruction : Instruction.t -> [< `Label | `Fallthrough ] opcode
| Hook : {
addr : Virtual_address.t;
info : string;
}
-> [< `Label | `Fallthrough ] opcode
| Assign : { var : Dba.Var.t; rval : Dba.Expr.t } -> [ `Fallthrough ] opcode
| Clobber : Dba.Var.t -> [ `Fallthrough ] opcode
| Forget : Dba.Var.t -> [ `Fallthrough ] opcode
| Load : {
var : Dba.Var.t;
base : string option;
dir : Machine.endianness;
addr : Dba.Expr.t;
}
-> [ `Fallthrough ] opcode
| Store : {
base : string option;
dir : Machine.endianness;
addr : Dba.Expr.t;
rval : Dba.Expr.t;
}
-> [ `Fallthrough ] opcode
| Symbolize : Dba.Var.t -> [ `Fallthrough ] opcode
| Assume : Dba.Expr.t -> [ `Fallthrough ] opcode
| Assert : Dba.Expr.t -> [ `Fallthrough ] opcode
| Builtin : builtin -> [< `Fallthrough | `Terminator ] opcode
| Goto : {
target : Virtual_address.t;
tag : Dba.tag;
}
-> [< `Fallthrough | `Terminator ] opcode
| Jump : { target : Dba.Expr.t; tag : Dba.tag } -> [ `Terminator ] opcode
| Halt : [ `Terminator ] opcode
| Cut : [ `Terminator ] opcode
| Die : string -> [ `Terminator ] opcode
and label = [ `Label ] opcode
and fallthrough = [ `Fallthrough ] opcode
and terminator = [ `Terminator ] opcode
let pp_opcode : type a. Format.formatter -> a opcode -> unit =
fun ppf fallthrough ->
match fallthrough with
| Nop -> Format.pp_print_string ppf "nop"
| Instruction inst ->
Format.fprintf ppf "%a %a" Virtual_address.pp (Instruction.address inst)
Mnemonic.pp
(Instruction.mnemonic inst)
| Hook { addr; info } ->
Format.fprintf ppf "%a %s" Virtual_address.pp addr info
| Assign { var = { name; _ }; rval } ->
Format.fprintf ppf "%s := %a" name Dba_printer.Ascii.pp_bl_term rval
| Clobber { name; _ } -> Format.fprintf ppf "%s := undef" name
| Forget { name; _ } -> Format.fprintf ppf "%s := undef" name
| Load { var = { name; size; _ }; base; dir; addr } ->
Format.fprintf ppf "%s := %s[%a%s, %d]" name
(Option.fold ~none:"@" ~some:Fun.id base)
Dba_printer.Ascii.pp_bl_term addr
(match dir with LittleEndian -> "" | BigEndian -> ", ->")
(size / 8)
| Store { base; dir; addr; rval } ->
Format.fprintf ppf "%s[%a%s, %d] := %a"
(Option.fold ~none:"@" ~some:Fun.id base)
Dba_printer.Ascii.pp_bl_term addr
(match dir with LittleEndian -> "" | BigEndian -> ", ->")
(Dba.Expr.size_of rval / 8)
Dba_printer.Ascii.pp_bl_term rval
| Symbolize { name; _ } -> Format.fprintf ppf "%s := nondet" name
| Assume test ->
Format.fprintf ppf "assume %a" Dba_printer.Ascii.pp_bl_term test
| Assert test ->
Format.fprintf ppf "assert %a" Dba_printer.Ascii.pp_bl_term test
| Goto { target; _ } ->
Format.fprintf ppf "jump at %a" Virtual_address.pp target
| Jump { target; _ } ->
Format.fprintf ppf "jump at %a" Dba_printer.Ascii.pp_bl_term target
| Halt -> Format.pp_print_string ppf "halt"
| Cut -> Format.pp_print_string ppf "cut"
| Die msg -> Format.fprintf ppf "die(%S)" msg
| Builtin x -> pp_builtin ppf x
type node =
| Fallthrough of { label : label; kind : fallthrough; succ : int }
| Branch of {
label : label;
test : Dba.Expr.t;
target : int;
fallthrough : int;
}
| Terminator of { label : label; kind : terminator }
let pp_node ppf node =
match node with
| Fallthrough { kind; _ } -> pp_opcode ppf kind
| Branch { test; target; fallthrough; _ } ->
Format.fprintf ppf "if %a then goto %d else goto %d"
Dba_printer.Ascii.pp_bl_term test target fallthrough
| Terminator { kind; _ } -> pp_opcode ppf kind
let label_of : node -> label = function
| Fallthrough { label; _ } | Branch { label; _ } | Terminator { label; _ } ->
label
type stmt =
| Nop
| Label of string (** [label]: *)
| Opcode of fallthrough
| If of Dba.Expr.t * string (** if [rval] then goto [label] *)
| Goto of string (** goto [label] *)
| End of terminator
module type GRAPH = sig
include Graph.Sig.G with type V.t = int and type E.t = int * bool * int
val node : t -> vertex -> node
val fold_entries : (vertex -> 'a -> 'a) -> t -> 'a -> 'a
val fold_exits : (vertex -> 'a -> 'a) -> t -> 'a -> 'a
val iter_entries : (vertex -> unit) -> t -> unit
val iter_exits : (vertex -> unit) -> t -> unit
end
module type INSTRUMENT = sig
type t
type vertex
val insert_before : t -> vertex -> ?label:label -> fallthrough -> unit
val insert_before_v : t -> vertex -> ?label:label -> fallthrough -> vertex
val insert_list_before :
t -> vertex -> ?label:label -> fallthrough list -> unit
val insert_list_before_v :
t -> vertex -> ?label:label -> fallthrough list -> vertex
end
module Graph = struct
type t = {
mutable n : int;
mutable nodes : node IntTbl.t;
mutable preds : int list IntTbl.t;
mutable entries : IntSet.t;
mutable exits : IntSet.t;
}
let length : t -> int = fun { n; _ } -> n
type vertex = int
let add_node : t -> vertex -> node -> unit =
fun t vertex node ->
(match IntTbl.find vertex t.nodes with
| exception Not_found -> t.n <- t.n + 1
| Fallthrough { succ; _ } ->
t.preds <-
IntTbl.add succ
(List.filter (( != ) vertex) (IntTbl.find succ t.preds))
t.preds
| Branch { target; fallthrough; _ } ->
t.preds <-
IntTbl.add target
(List.filter (( != ) vertex) (IntTbl.find target t.preds))
t.preds;
t.preds <-
IntTbl.add fallthrough
(List.filter (( != ) vertex) (IntTbl.find fallthrough t.preds))
t.preds
| Terminator _ -> t.exits <- IntSet.remove vertex t.exits);
t.nodes <- IntTbl.add vertex node t.nodes;
if not (IntTbl.mem vertex t.preds) then
t.preds <- IntTbl.add vertex [] t.preds;
match node with
| Fallthrough { succ; _ } ->
t.preds <-
IntTbl.add succ
(vertex :: (try IntTbl.find succ t.preds with Not_found -> []))
t.preds
| Branch { target; fallthrough; _ } ->
t.preds <-
IntTbl.add target
(vertex :: (try IntTbl.find target t.preds with Not_found -> []))
t.preds;
t.preds <-
IntTbl.add fallthrough
(vertex
:: (try IntTbl.find fallthrough t.preds with Not_found -> []))
t.preds
| Terminator _ -> t.exits <- IntSet.add vertex t.exits
let node { nodes; _ } vertex = IntTbl.find vertex nodes
module V : Graph.Sig.VERTEX with type t = int = struct
type t = vertex
let compare = ( - )
let equal = ( == )
let hash = Fun.id
type label = t
let create = Fun.id
let label = Fun.id
end
module E :
Graph.Sig.EDGE with type t = V.t * bool * V.t and type vertex = V.t = struct
type t = V.t * bool * V.t
let compare = compare
type vertex = V.t
let src (vertex, _, _) = vertex
let dst (_, _, vertex) = vertex
type label = bool
let create src branch dst = (src, branch, dst)
let label (_, branch, _) = branch
end
type edge = E.t
let is_directed = true
let is_empty t = length t = 0
let nb_vertex = length
let nb_edges { preds; _ } =
IntTbl.fold (fun _ preds n -> n + List.length preds) preds 0
let out_degree { nodes; _ } vertex =
match IntTbl.find vertex nodes with
| Terminator _ -> 0
| Fallthrough _ -> 1
| Branch _ -> 2
let in_degree { preds; _ } vertex = List.length (IntTbl.find vertex preds)
let mem_vertex { nodes; _ } vertex = IntTbl.mem vertex nodes
let mem_edge { nodes; _ } src dst =
match IntTbl.find src nodes with
| Fallthrough { succ; _ } -> succ = dst
| Branch { target; fallthrough; _ } -> target = dst || fallthrough = dst
| Terminator _ -> false
let mem_edge_e { nodes; _ } (src, branch, dst) =
match IntTbl.find src nodes with
| Fallthrough { succ; _ } -> succ = dst
| Branch { target; fallthrough; _ } ->
(branch && target = dst) || ((not branch) && fallthrough = dst)
| Terminator _ -> false
let find_edge { nodes; _ } src dst =
match IntTbl.find src nodes with
| (Fallthrough { succ; _ } | Branch { fallthrough = succ; _ })
when succ = dst ->
(src, false, dst)
| Branch { target; _ } when target = dst -> (src, true, dst)
| Fallthrough _ | Branch _ | Terminator _ -> raise Not_found
let find_all_edges t src dst =
try [ find_edge t src dst ] with Not_found -> []
let succ { nodes; _ } vertex =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> [ succ ]
| Branch { target; fallthrough; _ } -> [ target; fallthrough ]
| Terminator _ -> []
let pred { preds; _ } vertex = IntTbl.find vertex preds
let succ_e { nodes; _ } vertex =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> [ (vertex, false, succ) ]
| Branch { target; fallthrough; _ } ->
[ (vertex, true, target); (vertex, false, fallthrough) ]
| Terminator _ -> []
let pred_e t vertex =
List.map (fun src -> find_edge t src vertex) (pred t vertex)
let iter_vertex f t =
let last = length t - 1 in
for i = 0 to last do
f i
done
let fold_entries : (vertex -> 'a -> 'a) -> t -> 'a -> 'a =
fun f { entries; _ } a -> IntSet.fold f entries a
let fold_exits : (vertex -> 'a -> 'a) -> t -> 'a -> 'a =
fun f { exits; _ } a -> IntSet.fold f exits a
let iter_entries : (vertex -> unit) -> t -> unit =
fun f { entries; _ } -> IntSet.iter f entries
let iter_exits : (vertex -> unit) -> t -> unit =
fun f { exits; _ } -> IntSet.iter f exits
let fold_vertex f { nodes; _ } data =
IntTbl.fold (fun vertex _ -> f vertex) nodes data
let iter_edges f { nodes; _ } =
IntTbl.iter
(fun vertex node ->
match node with
| Fallthrough { succ; _ } -> f vertex succ
| Branch { target; fallthrough; _ } ->
f vertex target;
f vertex fallthrough
| Terminator _ -> ())
nodes
let fold_edges f { nodes; _ } data =
IntTbl.fold
(fun vertex node data ->
match node with
| Fallthrough { succ; _ } -> f vertex succ data
| Branch { target; fallthrough; _ } ->
f vertex target (f vertex fallthrough data)
| Terminator _ -> data)
nodes data
let iter_edges_e f { nodes; _ } =
IntTbl.iter
(fun vertex node ->
match node with
| Fallthrough { succ; _ } -> f (vertex, false, succ)
| Branch { target; fallthrough; _ } ->
f (vertex, true, target);
f (vertex, false, fallthrough)
| Terminator _ -> ())
nodes
let fold_edges_e f { nodes; _ } data =
IntTbl.fold
(fun vertex node data ->
match node with
| Fallthrough { succ; _ } -> f (vertex, false, succ) data
| Branch { target; fallthrough; _ } ->
f (vertex, true, target) (f (vertex, false, fallthrough) data)
| Terminator _ -> data)
nodes data
let shuffle f node =
match node with
| Fallthrough { label; kind; succ } ->
Fallthrough { label; kind; succ = f succ }
| Branch { label; test; target; fallthrough } ->
Branch { label; test; target = f target; fallthrough = f fallthrough }
| Terminator _ -> node
let map_vertex f r =
{
n = r.n;
nodes =
IntTbl.fold
(fun vertex node nodes ->
IntTbl.add (f vertex) (shuffle f node) nodes)
r.nodes IntTbl.empty;
preds =
IntTbl.fold
(fun vertex pred preds ->
IntTbl.add (f vertex) (List.map f pred) preds)
r.preds IntTbl.empty;
exits = IntSet.map f r.exits;
entries = IntSet.map f r.entries;
}
let iter_succ f { nodes; _ } vertex =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> f succ
| Branch { target; fallthrough; _ } ->
f target;
f fallthrough
| Terminator _ -> ()
let iter_pred f { preds; _ } vertex = List.iter f (IntTbl.find vertex preds)
let fold_succ f { nodes; _ } vertex data =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> f succ data
| Branch { target; fallthrough; _ } -> f target (f fallthrough data)
| Terminator _ -> data
let fold_pred f { preds; _ } vertex data =
List.fold_left (Fun.flip f) data (IntTbl.find vertex preds)
let iter_succ_e f { nodes; _ } vertex =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> f (vertex, false, succ)
| Branch { target; fallthrough; _ } ->
f (vertex, true, target);
f (vertex, false, fallthrough)
| Terminator _ -> ()
let iter_pred_e f t vertex =
List.iter
(fun src -> f (find_edge t src vertex))
(IntTbl.find vertex t.preds)
let fold_succ_e f { nodes; _ } vertex data =
match IntTbl.find vertex nodes with
| Fallthrough { succ; _ } -> f (vertex, false, succ) data
| Branch { target; fallthrough; _ } ->
f (vertex, true, target) (f (vertex, false, fallthrough) data)
| Terminator _ -> data
let fold_pred_e f t vertex data =
List.fold_left
(fun data src -> f (find_edge t src vertex) data)
data
(IntTbl.find vertex t.preds)
let insert_before_v : t -> vertex -> ?label:label -> fallthrough -> vertex =
fun t vertex ?label kind ->
let cur = length t
and label =
match label with None -> label_of (node t vertex) | Some label -> label
in
iter_pred
(fun pred ->
add_node t pred
(shuffle (fun i -> if i = vertex then cur else i) (node t pred)))
t vertex;
add_node t cur (Fallthrough { label; kind; succ = vertex });
cur
let insert_before : t -> vertex -> ?label:label -> fallthrough -> unit =
fun t vertex ?label kind -> ignore (insert_before_v t vertex ?label kind)
let insert_list_before_v :
t -> vertex -> ?label:label -> fallthrough list -> vertex =
fun t vertex ?label -> function
| [] -> vertex
| kind :: tl ->
let vertex' = insert_before_v t vertex ?label kind in
List.iter (fun kind -> insert_before t vertex ?label kind) tl;
vertex'
let insert_list_before :
t -> vertex -> ?label:label -> fallthrough list -> unit =
fun t vertex ?label list ->
ignore (insert_list_before_v t vertex ?label list)
let :
((vertex * Basic_types.endianness * Dba.Expr.t * string option) * Var.t)
list ->
Dba.Expr.t ->
((vertex * Basic_types.endianness * Dba.Expr.t * string option) * Var.t)
list
* Dba.Expr.t =
let rec fold :
((vertex * Basic_types.endianness * Dba.Expr.t * string option) * Var.t)
list ->
Dba.Expr.t ->
((vertex * Basic_types.endianness * Dba.Expr.t * string option) * Var.t)
list
* Dba.Expr.t =
fun m (e : Dba.Expr.t) ->
match e with
| Cst _ -> (m, e)
| Var _ -> (m, e)
| Load (sz, dir, addr, base) ->
let m', addr' = fold m addr in
let k = (sz, dir, addr', base) in
let v =
try List.assoc k m'
with Not_found ->
Dba.Var.(
create
(Printf.sprintf "$$%d" (List.length m'))
~bitsize:(Size.Bit.create (8 * sz))
~tag:Tag.Temp)
in
((k, v) :: m', Dba.Expr.v v)
| Unary (o, x) ->
let m', x' = fold m x in
let e' = if x == x' then e else Dba.Expr.unary o x' in
(m', e')
| Binary (o, x, y) ->
let m', x' = fold m x in
let m', y' = fold m' y in
let e' = if x == x' && y == y' then e else Dba.Expr.binary o x' y' in
(m', e')
| Ite (c, x, y) ->
let m', c' = fold m c in
let m', x' = fold m' x in
let m', y' = fold m' y in
let e' =
if c == c' && x == x' && y == y' then e else Dba.Expr.ite c' x' y'
in
(m', e')
in
fold
let define_loads :
[ `Fallthrough ] opcode ->
((vertex * Basic_types.endianness * Dba.Expr.t * string option) * Var.t)
list
* [ `Fallthrough ] opcode =
fun kind ->
match kind with
| Nop | Instruction _ | Hook _ | Clobber _ | Forget _ | Symbolize _
| Builtin _ | Goto _ ->
([], kind)
| Assign { var; rval = Load (_, dir, addr, base) } -> (
match extract_loads [] addr with
| [], _ -> ([], Load { var; base; dir; addr })
| loads, addr -> (loads, Load { var; base; dir; addr }))
| Assign { var; rval } -> (
match extract_loads [] rval with
| [], _ -> ([], kind)
| loads, rval -> (loads, Assign { var; rval }))
| Load { var; base; dir; addr } -> (
match extract_loads [] addr with
| [], _ -> ([], kind)
| loads, addr -> (loads, Load { var; base; dir; addr }))
| Store { base; dir; addr; rval } -> (
let loads, addr = extract_loads [] addr in
match extract_loads loads rval with
| [], _ -> ([], kind)
| loads, rval -> (loads, Store { base; dir; addr; rval }))
| Assume test -> (
match extract_loads [] test with
| [], _ -> ([], kind)
| loads, test -> (loads, Assume test))
| Assert test -> (
match extract_loads [] test with
| [], _ -> ([], kind)
| loads, test -> (loads, Assert test))
let define_load : t -> vertex -> unit =
fun t vertex ->
match node t vertex with
| Fallthrough { label; kind; succ } -> (
match define_loads kind with
| [], kind' when kind == kind' -> ()
| loads, kind ->
add_node t vertex (Fallthrough { label; kind; succ });
List.fold_right
(fun ((_, dir, addr, base), var) () ->
insert_before t vertex ~label (Load { var; base; dir; addr });
insert_before t succ ~label (Forget var))
loads ())
| Branch { label; test; target; fallthrough } -> (
match extract_loads [] test with
| [], _ -> ()
| loads, test ->
add_node t vertex (Branch { label; test; target; fallthrough });
List.fold_right
(fun ((_, dir, addr, base), var) () ->
insert_before t vertex ~label (Load { var; base; dir; addr });
insert_before t target ~label (Forget var);
insert_before t fallthrough ~label (Forget var))
loads ())
| Terminator { label; kind = Jump { target; tag } } -> (
match extract_loads [] target with
| [], _ -> ()
| loads, target ->
add_node t vertex
(Terminator { label; kind = Jump { target; tag } });
List.fold_right
(fun ((_, dir, addr, base), var) () ->
insert_before t vertex ~label (Load { var; base; dir; addr }))
loads ())
| Terminator _ -> ()
let entropy = Printf.sprintf "%%entropy%%%d"
let inline_dhunk : t -> label -> Dhunk.t -> Var.Set.t =
fun t label hunk ->
let vertex = length t in
let next = ref (vertex + Dhunk.length hunk) in
let temps = ref Var.Set.empty in
Dhunk.iteri
~f:(fun i inst ->
let cur = vertex + i in
match inst with
| Assign (Var var, rval, succ) ->
if var.info = Var.Tag.Temp then temps := Var.Set.add var !temps;
add_node t cur
(Fallthrough
{ label; kind = Assign { var; rval }; succ = vertex + succ })
| Assign (Restrict (var, { hi; lo }), rval, succ) ->
if var.info = Var.Tag.Temp then temps := Var.Set.add var !temps;
add_node t cur
(Fallthrough
{
label;
kind =
Assign
{
var;
rval = Dba_types.Expr.complement rval ~hi ~lo var;
};
succ = vertex + succ;
})
| Assign (Store (_, dir, addr, base), rval, succ) ->
add_node t cur
(Fallthrough
{
label;
kind = Store { base; dir; addr; rval };
succ = vertex + succ;
})
| Nondet (Var var, succ) | Undef (Var var, succ) ->
if var.info = Var.Tag.Temp then temps := Var.Set.add var !temps;
let kind =
match inst with Nondet _ -> Symbolize var | _ -> Clobber var
in
add_node t cur (Fallthrough { label; kind; succ = vertex + succ })
| Nondet (Restrict (var, { hi; lo }), succ)
| Undef (Restrict (var, { hi; lo }), succ) ->
if var.info = Var.Tag.Temp then temps := Var.Set.add var !temps;
let size' = hi - lo + 1 in
let name' = entropy size' in
let var' = Dba.Var.temporary name' (Size.Bit.create size') in
temps := Var.Set.add var' !temps;
let rval =
Dba_types.Expr.complement (Dba.Expr.v var') ~lo ~hi var
in
let succ' = !next in
incr next;
let kind =
match inst with Nondet _ -> Symbolize var' | _ -> Clobber var'
in
add_node t cur (Fallthrough { label; kind; succ = succ' });
add_node t succ'
(Fallthrough
{ label; kind = Assign { var; rval }; succ = vertex + succ })
| Nondet (Store (bytes, dir, addr, base), succ)
| Undef (Store (bytes, dir, addr, base), succ) ->
let size' = 8 * bytes in
let name' = entropy size' in
let var' = Dba.Var.temporary name' (Size.Bit.create size') in
let rval = Dba.Expr.v var' in
let succ' = !next in
incr next;
let kind =
match inst with Nondet _ -> Symbolize var' | _ -> Clobber var'
in
add_node t cur (Fallthrough { label; kind; succ = succ' });
add_node t succ'
(Fallthrough
{
label;
kind = Store { base; dir; addr; rval };
succ = vertex + succ;
})
| Assume (test, succ) ->
add_node t cur
(Fallthrough { label; kind = Assume test; succ = vertex + succ })
| Assert (test, succ) ->
add_node t cur
(Fallthrough { label; kind = Assert test; succ = vertex + succ })
| If (test, JInner target, fallthrough) ->
add_node t cur
(Branch
{
label;
test;
target = vertex + target;
fallthrough = vertex + fallthrough;
})
| If (test, JOuter { base = target; _ }, fallthrough) ->
let succ = !next in
incr next;
add_node t succ
(Terminator { label; kind = Goto { target; tag = Default } });
add_node t cur
(Branch
{
label;
test;
target = succ;
fallthrough = vertex + fallthrough;
})
| DJump (target, tag) ->
add_node t cur (Terminator { label; kind = Jump { target; tag } })
| SJump (JOuter { base = target; _ }, tag) ->
add_node t cur (Terminator { label; kind = Goto { target; tag } })
| SJump (JInner succ, _) ->
add_node t cur
(Fallthrough { label; kind = Nop; succ = vertex + succ })
| Stop (None | Some OK) ->
add_node t cur (Terminator { label; kind = Halt })
| Stop (Some KO) ->
add_node t cur (Terminator { label; kind = Die "KO" })
| Stop (Some (Unsupported msg)) ->
let msg =
match label with
| Instruction ins ->
Format.asprintf "%a # %s" Binstream.pp
(Instruction.opcode ins) msg
| Hook _ -> msg
in
add_node t cur (Terminator { label; kind = Die msg })
| Stop (Some (Undecoded msg)) ->
add_node t cur (Terminator { label; kind = Die msg }))
hunk;
!temps
let inline_script : t -> label -> stmt list -> Var.Set.t =
fun t label stmts ->
let labels = StrTbl.create 16
and tolink = StrTbl.create 16
and temps = ref Var.Set.empty in
List.iter
(fun ins ->
let vertex = length t in
match ins with
| Nop -> ()
| Opcode kind ->
(match kind with
| Assign { var = { info = Temp; _ } as var; _ }
| Load { var = { info = Temp; _ } as var; _ }
| Symbolize ({ info = Temp; _ } as var)
| Clobber ({ info = Temp; _ } as var) ->
temps := Var.Set.add var !temps
| _ -> ());
add_node t vertex (Fallthrough { label; kind; succ = vertex + 1 })
| Label name -> StrTbl.add labels name vertex
| If (test, target) ->
add_node t vertex (Terminator { label; kind = Halt });
StrTbl.replace tolink target
((Some test, vertex)
:: (try StrTbl.find tolink target with Not_found -> []))
| Goto target ->
add_node t vertex (Terminator { label; kind = Halt });
StrTbl.replace tolink target
((None, vertex)
:: (try StrTbl.find tolink target with Not_found -> []))
| End (Jump { target = Cst bv; tag }) ->
add_node t vertex
(Terminator
{
label;
kind = Goto { target = Virtual_address.of_bitvector bv; tag };
})
| End (Builtin (Inline hunk)) ->
temps := Var.Set.union !temps (inline_dhunk t label hunk)
| End kind -> add_node t vertex (Terminator { label; kind }))
stmts;
StrTbl.iter
(fun target preds ->
let target = StrTbl.find labels target in
List.iter
(fun (test, pred) ->
match test with
| None ->
add_node t pred
(Fallthrough { label; kind = Nop; succ = target })
| Some test ->
add_node t pred
(Branch { label; test; target; fallthrough = pred + 1 }))
preds)
tolink;
let vertex = length t in
if stmts = [] || IntTbl.mem vertex t.preds then
add_node t vertex (Terminator { label; kind = Builtin EndOfHook });
!temps
let copy : t -> t =
fun { n; nodes; preds; entries; exits } ->
IntTbl.freeze nodes;
IntTbl.freeze preds;
{ n; nodes; preds; entries; exits }
let empty : unit -> t =
fun () ->
{
n = 0;
nodes = IntTbl.empty;
preds = IntTbl.empty;
entries = IntSet.empty;
exits = IntSet.empty;
}
let init : label -> (t -> Var.Set.t) -> t =
fun label f ->
let t = empty () in
add_node t 0
(Fallthrough
{
label;
kind =
(match label with
| (Instruction _ as label) | (Hook _ as label) -> label);
succ = 1;
});
t.entries <- IntSet.add 0 t.entries;
let temps = f t in
iter_vertex (define_load t) t;
IntSet.iter
(fun vertex ->
let temps =
match node t vertex with
| Terminator { kind = Jump { target; _ }; _ } ->
Var.Set.diff temps (Var.collect target Var.Set.empty)
| _ -> temps
in
Var.Set.iter
(fun var -> insert_before t vertex ~label (Forget var))
temps)
t.exits;
t
let of_instruction : Instruction.t -> t =
fun ins ->
let label = Instruction ins in
init label (fun t -> inline_dhunk t label (Instruction.hunk ins))
let of_script :
Virtual_address.t -> string -> ?eoh:terminator -> stmt list -> t =
fun addr info ?eoh stmts ->
let label = Hook { addr; info } in
let t = init label (fun t -> inline_script t label stmts) in
match eoh with
| None -> t
| Some kind ->
iter_exits
(fun v ->
match node t v with
| Terminator { label; kind = Builtin EndOfHook } ->
add_node t v (Terminator { label; kind })
| _ -> ())
t;
t
let replace_node : t -> vertex -> node -> unit =
fun t vertex node ->
if t.n <= vertex then raise (Invalid_argument "replace_node");
add_node t vertex node
let append_node : t -> node -> vertex =
fun t node ->
let vertex = length t in
add_node t vertex node;
vertex
let append : t -> from:t -> vertex =
fun t ~from ->
let vertex = length t in
let map_vertex = ( + ) vertex in
iter_vertex
(fun i -> add_node t (map_vertex i) (shuffle map_vertex (node from i)))
from;
t.entries <-
IntSet.fold
(fun i entries -> IntSet.add (map_vertex i) entries)
from.entries t.entries;
t.exits <-
IntSet.fold
(fun i entries -> IntSet.add (map_vertex i) entries)
from.exits t.exits;
vertex
end
module View = Graph
module Killset = struct
module IntTbl = Basic_types.Integers.Int.Htbl
type t = Var.Set.t IntTbl.t
let is_deadstore : t -> Dba.Var.t -> View.vertex -> bool =
fun killset var vertex ->
try Var.Set.mem var (IntTbl.find killset vertex) with Not_found -> false
let analyze_fallthrough :
may_read:(builtin -> Var.Set.t option) ->
must_write:(builtin -> Var.Set.t) ->
fallthrough ->
Var.Set.t ->
Var.Set.t =
fun ~may_read ~must_write kind killset ->
match kind with
| Nop | Instruction _ | Hook _ | Goto _ -> killset
| Clobber var | Forget var | Symbolize var -> Var.Set.add var killset
| Assign { var; rval } ->
if Var.Set.mem var killset then killset
else
Var.Set.diff (Var.Set.add var killset)
(Var.collect rval Var.Set.empty)
| Load { var; addr; _ } ->
Var.Set.diff (Var.Set.add var killset) (Var.collect addr Var.Set.empty)
| Store { addr; rval; _ } ->
Var.Set.diff
(Var.Set.diff killset (Var.collect addr Var.Set.empty))
(Var.collect rval Var.Set.empty)
| Assume expr | Assert expr ->
Var.Set.diff killset (Var.collect expr Var.Set.empty)
| Builtin builtin -> (
match may_read builtin with
| None -> Var.Set.empty
| Some readset ->
Var.Set.diff (Var.Set.union killset (must_write builtin)) readset)
let analyze_branch :
Dba.Expr.t -> Var.Set.t option -> Var.Set.t option -> Var.Set.t =
fun test target fallthrough ->
match (target, fallthrough) with
| None, None -> assert false
| None, Some killset | Some killset, None ->
Var.Set.diff killset (Var.collect test Var.Set.empty)
| Some target, Some fallthrough ->
let killset = Var.Set.inter target fallthrough in
Var.Set.diff killset (Var.collect test Var.Set.empty)
let rec closure :
View.t ->
may_read:(builtin -> Var.Set.t option) ->
must_write:(builtin -> Var.Set.t) ->
View.vertex Queue.t ->
(View.vertex -> unit) ->
t ->
unit =
fun t ~may_read ~must_write todo push acc ->
if not (Queue.is_empty todo) then
let vertex = Queue.pop todo in
let killset =
match View.node t vertex with
| Fallthrough { kind; succ; _ } ->
analyze_fallthrough ~may_read ~must_write kind
(IntTbl.find acc succ)
| Branch { test; target; fallthrough; _ } ->
analyze_branch test
(IntTbl.find_opt acc target)
(IntTbl.find_opt acc fallthrough)
| Terminator _ -> assert false
in
match IntTbl.find acc vertex with
| old when Var.Set.equal old killset ->
closure t ~may_read ~must_write todo push acc
| (exception Not_found) | _ ->
IntTbl.replace acc vertex killset;
View.iter_pred push t vertex;
closure t ~may_read ~must_write todo push acc
let analyze :
View.t ->
may_read:(builtin -> Var.Set.t option) ->
must_write:(builtin -> Var.Set.t) ->
?sink:IntSet.t ->
t ->
unit =
fun t ~may_read ~must_write ?(sink = t.exits) killset ->
let todo = Queue.create () in
let push = Fun.flip Queue.push todo in
IntSet.iter
(fun vertex ->
View.iter_pred push t vertex;
match View.node t vertex with
| Fallthrough { kind; succ; _ } ->
IntTbl.add killset vertex
(analyze_fallthrough ~may_read ~must_write kind
(IntTbl.find killset succ))
| Branch { test; target; fallthrough; _ } ->
IntTbl.add killset vertex
(analyze_branch test
(IntTbl.find_opt killset target)
(IntTbl.find_opt killset fallthrough))
| Terminator { kind = Builtin builtin; _ } ->
IntTbl.add killset vertex
(match may_read builtin with
| None -> Var.Set.empty
| Some readset -> Var.Set.diff (must_write builtin) readset)
| Terminator _ -> IntTbl.add killset vertex Var.Set.empty)
sink;
closure t ~may_read ~must_write todo push killset
end