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-rw-r--r--src/Collections.ml24
-rw-r--r--src/Interpreter.ml16
-rw-r--r--src/Pure.ml88
-rw-r--r--src/SymbolicAst.ml12
-rw-r--r--src/SymbolicToPure.ml260
-rw-r--r--src/main.ml3
6 files changed, 344 insertions, 59 deletions
diff --git a/src/Collections.ml b/src/Collections.ml
index ee998546..ee088a9d 100644
--- a/src/Collections.ml
+++ b/src/Collections.ml
@@ -61,6 +61,10 @@ end
module type Map = sig
include Map.S
+ val add_list : (key * 'a) list -> 'a t -> 'a t
+
+ val of_list : (key * 'a) list -> 'a t
+
val to_string : string option -> ('a -> string) -> 'a t -> string
(** "Simple" pretty printing function.
@@ -80,6 +84,10 @@ module MakeMap (Ord : OrderedType) : Map with type key = Ord.t = struct
module Map = Map.Make (Ord)
include Map
+ let add_list bl m = List.fold_left (fun s (key, e) -> add key e s) m bl
+
+ let of_list bl = add_list bl empty
+
let to_string indent_opt a_to_string m =
let indent, break =
match indent_opt with Some indent -> (indent, "\n") | None -> ("", " ")
@@ -121,6 +129,10 @@ end
module type Set = sig
include Set.S
+ val add_list : elt list -> t -> t
+
+ val of_list : elt list -> t
+
val to_string : string option -> t -> string
(** "Simple" pretty printing function.
@@ -140,6 +152,10 @@ module MakeSet (Ord : OrderedType) : Set with type elt = Ord.t = struct
module Set = Set.Make (Ord)
include Set
+ let add_list bl s = List.fold_left (fun s e -> add e s) s bl
+
+ let of_list bl = add_list bl empty
+
let to_string indent_opt m =
let indent, break =
match indent_opt with Some indent -> (indent, "\n") | None -> ("", " ")
@@ -246,6 +262,10 @@ module type MapInj = sig
val add_seq : (key * elem) Seq.t -> t -> t
val of_seq : (key * elem) Seq.t -> t
+
+ val add_list : (key * elem) list -> t -> t
+
+ val of_list : (key * elem) list -> t
end
(** See [MapInj] *)
@@ -361,4 +381,8 @@ module MakeMapInj (Key : OrderedType) (Elem : OrderedType) :
add_seq s m
let of_seq s = add_seq s empty
+
+ let add_list ls m = List.fold_left (fun m (key, elem) -> add key elem m) m ls
+
+ let of_list ls = add_list ls empty
end
diff --git a/src/Interpreter.ml b/src/Interpreter.ml
index 2c4d86d2..a9a44b0f 100644
--- a/src/Interpreter.ml
+++ b/src/Interpreter.ml
@@ -2,6 +2,7 @@ module L = Logging
module T = Types
module A = CfimAst
module M = Modules
+module SA = SymbolicAst
open Cps
open InterpreterUtils
open InterpreterStatements
@@ -170,8 +171,8 @@ module Test = struct
List.iter test_unit_fun unit_funs
(** Execute the symbolic interpreter on a function. *)
- let test_function_symbolic (config : C.partial_config) (m : M.cfim_module)
- (fid : A.FunDefId.id) : unit =
+ let test_function_symbolic (config : C.partial_config) (synthesize : bool)
+ (m : M.cfim_module) (fid : A.FunDefId.id) : unit =
(* Retrieve the function declaration *)
let fdef = A.FunDefId.nth m.functions fid in
@@ -185,10 +186,11 @@ module Test = struct
(* Create the continuation to check the function's result *)
let cf_check res _ =
match res with
- | Return | Panic ->
+ | Return -> if synthesize then raise Errors.Unimplemented else None
+ | Panic ->
(* Note that as we explore all the execution branches, one of
* the executions can lead to a panic *)
- None
+ if synthesize then Some SA.Panic else None
| _ ->
failwith
("Unit test failed (symbolic execution) on: "
@@ -205,8 +207,8 @@ module Test = struct
TODO: for now we ignore the functions which contain loops, because
they are not supported by the symbolic interpreter.
*)
- let test_functions_symbolic (config : C.partial_config) (m : M.cfim_module) :
- unit =
+ let test_functions_symbolic (config : C.partial_config) (synthesize : bool)
+ (m : M.cfim_module) : unit =
let no_loop_funs =
List.filter (fun f -> not (CfimAstUtils.fun_def_has_loops f)) m.functions
in
@@ -214,7 +216,7 @@ module Test = struct
(* Execute the function - note that as the symbolic interpreter explores
* all the path, some executions are expected to "panic": we thus don't
* check the return value *)
- test_function_symbolic config m def.A.def_id
+ test_function_symbolic config synthesize m def.A.def_id
in
List.iter test_fun no_loop_funs
end
diff --git a/src/Pure.ml b/src/Pure.ml
index fcf8e6f0..6549d3fa 100644
--- a/src/Pure.ml
+++ b/src/Pure.ml
@@ -9,6 +9,7 @@ module RegionId = T.RegionId
module VariantId = T.VariantId
module FieldId = T.FieldId
module SymbolicValueId = V.SymbolicValueId
+module FunDefId = A.FunDefId
module SynthPhaseId = IdGen ()
(** We give an identifier to every phase of the synthesis (forward, backward
@@ -17,6 +18,9 @@ module SynthPhaseId = IdGen ()
module BackwardFunId = IdGen ()
(** Every backward function has its identifier *)
+module VarId = IdGen ()
+(** Pay attention to the fact that we also define a [VarId] module in Values *)
+
type ty =
| Adt of T.type_id * ty list
(** [Adt] encodes ADTs, tuples and assumed types.
@@ -26,7 +30,6 @@ type ty =
| TypeVar of TypeVarId.id
| Bool
| Char
- | Never
| Integer of T.integer_type
| Str
| Array of ty (* TODO: there should be a constant with the array *)
@@ -64,10 +67,7 @@ type symbolic_value = {
*)
}
-type value =
- | Concrete of constant_value
- | Adt of adt_value
- | Symbolic of symbolic_value
+type value = Concrete of constant_value | Adt of adt_value
and adt_value = {
variant_id : (VariantId.id option[@opaque]);
@@ -76,13 +76,27 @@ and adt_value = {
and typed_value = { value : value; ty : ty }
+type var = { id : VarId.id; ty : ty }
+(** Because we introduce a lot of temporary variables, the list of variables
+ is not fixed: we thus must carry all its information with the variable
+ itself
+ *)
+
+(** Sometimes, when introducing several variables in an assignment (because
+ deconstructing a tuple) we can ignore some of the values: in such situation
+ we introduce dummy variables (extracted to "_").
+ *)
+type var_or_dummy = Var of var | Dummy
+
type projection_elem = { pkind : E.field_proj_kind; field_id : FieldId.id }
type projection = projection_elem list
-type operand = typed_value
+type place = { var : VarId.id; projection : projection }
+
+type operand = Value of typed_value | Place of place
-type assertion = { cond : operand; expected : bool }
+(* type assertion = { cond : operand; expected : bool } *)
type fun_id =
| Local of A.FunDefId.id * BackwardFunId.id option
@@ -94,20 +108,45 @@ type fun_id =
type call = { func : fun_id; type_params : ty list; args : operand list }
-type let_bindings = { call : call; bindings : symbolic_value list }
+type left_value = unit
+(** TODO: assignment left value *)
+
+type let_bindings =
+ | Call of var_or_dummy list * call
+ (** The called function and the tuple of returned values *)
+ | Assignment of var * place
+ (** Variable assignment: the introduced variable and the place we read *)
+ | ExpandEnum of var_or_dummy list * TypeDefId.id * VariantId.id * place
+ (** When expanding an enumeration with exactly one variant, we first
+ introduce something like this (with [ExpandEnum]):
+ ```
+ let Cons x tl = ls in
+ ...
+ ```
+
+ Later, depending on the language we extract to, we can eventually
+ update it to something like this (for F*, for instance):
+ ```
+ let x = Cons?.v ls in
+ let tl = Cons?.tl ls in
+ ...
+ ```
+
+ Note that we prefer not handling this case through a match.
+ TODO: actually why not encoding it as a match internally, then
+ generating the `let Cons ... = ... in ...` if we check there
+ is exactly one variant?...
+ *)
(** **Rk.:** here, [expression] is not at all equivalent to the expressions
used in CFIM. They are lambda-calculus expressions, and are thus actually
more general than the CFIM statements, in a sense.
*)
type expression =
+ | Return of operand
+ | Panic
| Let of let_bindings * expression
(** Let bindings include the let-bindings introduced because of function calls *)
- | Assert of assertion
- | Return of typed_value
- | Panic of SynthPhaseId.id
- | Nop
- | Sequence of expression * expression
| Switch of operand * switch_body
and switch_body =
@@ -120,3 +159,26 @@ and match_branch = {
vars : symbolic_value list;
branch : expression;
}
+
+type fun_sig = {
+ type_params : type_var list;
+ inputs : ty list;
+ outputs : ty list;
+ (** The list of outputs.
+
+ In case of a forward function, the list will have length = 1.
+ However, in case of backward function, the list may have length > 1.
+ If the length is > 1, it gets extracted to a tuple type. Followingly,
+ we could not use a list because we can encode tuples, but here we
+ want to account for the fact that we immediately deconstruct the tuple
+ upon calling the backward function (because the backward function is
+ called to update a set of values in the environment).
+ *)
+}
+
+type fun_def = {
+ def_id : FunDefId.id;
+ name : name;
+ signature : fun_sig;
+ body : expression;
+}
diff --git a/src/SymbolicAst.ml b/src/SymbolicAst.ml
index fc2b2fc4..f1939802 100644
--- a/src/SymbolicAst.ml
+++ b/src/SymbolicAst.ml
@@ -23,8 +23,14 @@ type call = {
dest : V.symbolic_value;
}
+(** **Rk.:** here, [expression] is not at all equivalent to the expressions
+ used in CFIM: they are a first step towards lambda-calculus expressions.
+ *)
type expression =
- | Return
+ | Return of V.typed_value
+ (** The typed value stored in [Return] is the value contained in the return
+ variable upon returning
+ *)
| Panic
| FunCall of call * expression
| EndAbstraction of V.abs * expression
@@ -34,8 +40,8 @@ type expression =
and expansion =
| ExpandNoBranch of V.symbolic_expansion * expression
(** A symbolic expansion which doesn't generate a branching.
- Includes: expansion of borrows, structures, enumerations with one
- variants... *)
+ Includes: expansion of borrows, structures, enumerations with
+ exactly one variant... *)
| ExpandEnum of
(T.VariantId.id option * V.symbolic_value list * expression) list
(** A symbolic expansion of an ADT value which leads to branching (i.e.,
diff --git a/src/SymbolicToPure.ml b/src/SymbolicToPure.ml
index 19fa85b3..69c22b09 100644
--- a/src/SymbolicToPure.ml
+++ b/src/SymbolicToPure.ml
@@ -6,8 +6,10 @@ module E = Expressions
module A = CfimAst
module M = Modules
module S = SymbolicAst
+module TA = TypesAnalysis
open Pure
+(** TODO: move this, it is not useful for symbolic -> pure *)
type name =
| FunName of A.FunDefId.id * V.BackwardFunctionId.id option
| TypeName of T.TypeDefId.id
@@ -38,8 +40,8 @@ module NameMap = Collections.MakeMapInj (NameOrderedType) (Id.NameOrderedType)
generation with collision in mind, it is always good to have such checks.
*)
-let fun_to_name (fdef : A.fun_def) (bid : V.BackwardFunctionId.id option) :
- Id.name =
+let translate_fun_name (fdef : A.fun_def) (bid : V.BackwardFunctionId.id option)
+ : Id.name =
let sg = fdef.signature in
(* General function to generate a suffix for a region group
* (i.e., an abstraction)*)
@@ -93,22 +95,26 @@ let fun_to_name (fdef : A.fun_def) (bid : V.BackwardFunctionId.id option) :
add_to_last fdef.name
(** Generates a name for a type (simply reuses the name in the definition) *)
-let type_to_name (def : T.type_def) : Id.name = def.T.name
+let translate_type_name (def : T.type_def) : Id.name = def.T.name
type type_context = { type_defs : type_def TypeDefId.Map.t }
-type fun_context = unit
-(** TODO *)
+type fun_context = { fun_defs : fun_def FunDefId.Map.t }
+(* TODO: do we really need that actually? *)
type synth_ctx = {
names : NameMap.t;
+ (* TODO: remove? *)
type_context : type_context;
fun_context : fun_context;
declarations : M.declaration_group list;
}
-let rec translate_sty (ctx : synth_ctx) (ty : T.sty) : ty =
- let translate = translate_sty ctx in
+type bs_ctx = { types_infos : TA.type_infos }
+(** Body synthesis context *)
+
+let rec translate_sty (ty : T.sty) : ty =
+ let translate = translate_sty in
match ty with
| T.Adt (type_id, regions, tys) ->
(* Can't translate types with regions for now *)
@@ -125,52 +131,236 @@ let rec translate_sty (ctx : synth_ctx) (ty : T.sty) : ty =
| Slice ty -> Slice (translate ty)
| Ref (_, rty, _) -> translate rty
-let translate_field (ctx : synth_ctx) (f : T.field) : field =
+let translate_field (f : T.field) : field =
let field_name = f.field_name in
- let field_ty = translate_sty ctx f.field_ty in
+ let field_ty = translate_sty f.field_ty in
{ field_name; field_ty }
-let translate_fields (ctx : synth_ctx) (fl : T.field list) : field list =
- List.map (translate_field ctx) fl
+let translate_fields (fl : T.field list) : field list =
+ List.map translate_field fl
-let translate_variant (ctx : synth_ctx) (v : T.variant) : variant =
+let translate_variant (v : T.variant) : variant =
let variant_name = v.variant_name in
- let fields = translate_fields ctx v.fields in
+ let fields = translate_fields v.fields in
{ variant_name; fields }
-let translate_variants (ctx : synth_ctx) (vl : T.variant list) : variant list =
- List.map (translate_variant ctx) vl
+let translate_variants (vl : T.variant list) : variant list =
+ List.map translate_variant vl
(** Translate a type def kind to IM *)
-let translate_type_def_kind (ctx : synth_ctx) (kind : T.type_def_kind) :
- type_def_kind =
+let translate_type_def_kind (kind : T.type_def_kind) : type_def_kind =
match kind with
- | T.Struct fields -> Struct (translate_fields ctx fields)
- | T.Enum variants -> Enum (translate_variants ctx variants)
+ | T.Struct fields -> Struct (translate_fields fields)
+ | T.Enum variants -> Enum (translate_variants variants)
(** Translate a type definition from IM
TODO: this is not symbolic to pure but IM to pure. Still, I don't see the
point of moving this definition for now.
*)
-let translate_type_def (ctx : synth_ctx) (def : T.type_def) :
- synth_ctx * type_def =
+let translate_type_def (def : T.type_def) : type_def =
(* Translate *)
let def_id = def.T.def_id in
- let name = type_to_name def in
+ let name = translate_type_name def in
(* Can't translate types with regions for now *)
assert (def.region_params = []);
let type_params = def.type_params in
- let kind = translate_type_def_kind ctx def.T.kind in
- let def = { def_id; name; type_params; kind } in
- (* Insert in the context *)
- (* type context *)
- let type_context = ctx.type_context in
- let type_defs = type_context.type_defs in
- let type_defs = TypeDefId.Map.add def_id def type_defs in
- let type_context = { type_defs } in
- (* names map *)
- let names = NameMap.add (TypeName def_id) name ctx.names in
- (* update the fields *)
- let ctx = { ctx with type_context; names } in
- (ctx, def)
+ let kind = translate_type_def_kind def.T.kind in
+ { def_id; name; type_params; kind }
+
+(** Translate a type, seen as an input/output of a forward function
+ (preserve all borrows, etc.)
+*)
+
+let rec translate_fwd_ty (ctx : bs_ctx) (ty : 'r T.ty) : ty =
+ let translate = translate_fwd_ty ctx in
+ match ty with
+ | T.Adt (type_id, regions, tys) ->
+ (* Can't translate types with regions for now *)
+ assert (regions = []);
+ (* No general parametricity for now *)
+ assert (not (List.exists (TypesUtils.ty_has_borrows ctx.types_infos) tys));
+ (* Translate the type parameters *)
+ let tys = List.map translate tys in
+ Adt (type_id, tys)
+ | TypeVar vid -> TypeVar vid
+ | Bool -> Bool
+ | Char -> Char
+ | Never -> failwith "Unreachable"
+ | Integer int_ty -> Integer int_ty
+ | Str -> Str
+ | Array ty ->
+ assert (not (TypesUtils.ty_has_borrows ctx.types_infos ty));
+ Array (translate ty)
+ | Slice ty ->
+ assert (not (TypesUtils.ty_has_borrows ctx.types_infos ty));
+ Slice (translate ty)
+ | Ref (_, rty, _) -> translate rty
+
+(** Translate a type, when some regions may have ended.
+
+ We return an option, because the translated type may be empty.
+
+ [inside_mut]: are we inside a mutable borrow?
+ *)
+let rec translate_back_ty (ctx : bs_ctx) (keep_region : 'r -> bool)
+ (inside_mut : bool) (ty : 'r T.ty) : ty option =
+ let translate = translate_back_ty ctx keep_region inside_mut in
+ (* A small helper for "leave" types *)
+ let wrap ty = if inside_mut then Some ty else None in
+ match ty with
+ | T.Adt (type_id, regions, tys) -> (
+ match type_id with
+ | T.AdtId _ | Assumed _ ->
+ (* Don't accept ADTs (which are not tuples) with borrows for now *)
+ assert (not (TypesUtils.ty_has_borrows ctx.types_infos ty));
+ None
+ | T.Tuple -> (
+ (* Tuples can contain borrows (which we eliminated) *)
+ let tys_t = List.filter_map translate tys in
+ match tys_t with [] -> None | _ -> Some (Adt (T.Tuple, tys_t))))
+ | TypeVar vid -> wrap (TypeVar vid)
+ | Bool -> wrap Bool
+ | Char -> wrap Char
+ | Never -> failwith "Unreachable"
+ | Integer int_ty -> wrap (Integer int_ty)
+ | Str -> wrap Str
+ | Array ty -> (
+ assert (not (TypesUtils.ty_has_borrows ctx.types_infos ty));
+ match translate ty with None -> None | Some ty -> Some (Array ty))
+ | Slice ty -> (
+ assert (not (TypesUtils.ty_has_borrows ctx.types_infos ty));
+ match translate ty with None -> None | Some ty -> Some (Slice ty))
+ | Ref (r, rty, rkind) -> (
+ match rkind with
+ | T.Shared ->
+ (* Ignore shared references, unless we are below a mutable borrow *)
+ if inside_mut then translate rty else None
+ | T.Mut ->
+ (* Dive in, remembering the fact that we are inside a mutable borrow *)
+ let inside_mut = true in
+ if keep_region r then translate_back_ty ctx keep_region inside_mut rty
+ else None)
+
+(** Small utility: list the transitive parents of a region var group.
+ We don't do that in an efficient manner, but it doesn't matter.
+ *)
+let rec list_parent_region_groups (def : A.fun_def) (gid : T.RegionGroupId.id) :
+ T.RegionGroupId.Set.t =
+ let rg = T.RegionGroupId.nth def.signature.regions_hierarchy gid in
+ let parents =
+ List.fold_left
+ (fun s gid ->
+ (* Compute the parents *)
+ let parents = list_parent_region_groups def gid in
+ (* Parents U current region *)
+ let parents = T.RegionGroupId.Set.add gid parents in
+ (* Make the union with the accumulator *)
+ T.RegionGroupId.Set.union s parents)
+ T.RegionGroupId.Set.empty rg.parents
+ in
+ parents
+
+let translate_fun_sig (ctx : bs_ctx) (def : A.fun_def)
+ (bid : V.BackwardFunctionId.id option) : fun_sig =
+ let sg = def.signature in
+ (* Retrieve the list of parent backward functions *)
+ let gid, parents =
+ match bid with
+ | None -> (None, T.RegionGroupId.Set.empty)
+ | Some bid ->
+ let gid = T.RegionGroupId.of_int (V.BackwardFunctionId.to_int bid) in
+ let parents = list_parent_region_groups def gid in
+ (Some gid, parents)
+ in
+ (* List the inputs for:
+ * - the forward function
+ * - the parent backward functions, in proper order
+ * - the current backward function (if it is a backward function)
+ *)
+ let fwd_inputs = List.map (translate_fwd_ty ctx) sg.inputs in
+ (* For the backward functions: for now we don't supported nested borrows,
+ * so just check that there aren't parent regions *)
+ assert (T.RegionGroupId.Set.is_empty parents);
+ (* Small helper to translate types for backward functions *)
+ let translate_back_ty_for_gid (gid : T.RegionGroupId.id) : T.sty -> ty option
+ =
+ let rg = T.RegionGroupId.nth sg.regions_hierarchy gid in
+ let regions = T.RegionVarId.Set.of_list rg.regions in
+ let keep_region r =
+ match r with
+ | T.Static -> raise Unimplemented
+ | T.Var r -> T.RegionVarId.Set.mem r regions
+ in
+ let inside_mut = false in
+ translate_back_ty ctx keep_region inside_mut
+ in
+ (* Compute the additinal inputs for the current function, if it is a backward
+ * function *)
+ let back_inputs =
+ match gid with
+ | None -> []
+ | Some gid ->
+ (* For now, we don't allow nested borrows, so the additional inputs to the
+ * backward function can only come from borrows that were returned like
+ * in (for the backward function we introduce for 'a):
+ * ```
+ * fn f<'a>(...) -> &'a mut u32;
+ * ```
+ * Upon ending the abstraction for 'a, we need to get back the borrow
+ * the function returned.
+ *)
+ List.filter_map (translate_back_ty_for_gid gid) [ sg.output ]
+ in
+ let inputs = List.append fwd_inputs back_inputs in
+ (* Outputs *)
+ let outputs : ty list =
+ match gid with
+ | None ->
+ (* This is a forward function: there is one output *)
+ [ translate_fwd_ty ctx sg.output ]
+ | Some gid ->
+ (* This is a backward function: there might be several outputs.
+ * The outputs are the borrows inside the regions of the abstractions
+ * and which are present in the input values. For instance, see:
+ * ```
+ * fn f<'a>(x : 'a mut u32) -> ...;
+ * ```
+ * Upon ending the abstraction for 'a, we give back the borrow which
+ * was consumed through the `x` parameter.
+ *)
+ List.filter_map (translate_back_ty_for_gid gid) sg.inputs
+ in
+ (* Type parameters *)
+ let type_params = sg.type_params in
+ (* Return *)
+ { type_params; inputs; outputs }
+
+let translate_typed_value (v : V.typed_value) (ctx : bs_ctx) :
+ bs_ctx * typed_value =
+ raise Unimplemented
+
+let rec translate_expression (def : A.fun_def)
+ (bid : V.BackwardFunctionId.id option) (body : S.expression) (ctx : bs_ctx)
+ : expression =
+ match body with
+ | S.Return v ->
+ let _, v = translate_typed_value v ctx in
+ Return (Value v)
+ | Panic -> Panic
+ | FunCall (call, e) -> raise Unimplemented
+ | EndAbstraction (abs, e) -> raise Unimplemented
+ | Expansion (sv, exp) -> raise Unimplemented
+ | Meta (_, e) ->
+ (* We ignore the meta information *)
+ translate_expression def bid e ctx
+
+let translate_fun_def (types_infos : TA.type_infos) (def : A.fun_def)
+ (bid : V.BackwardFunctionId.id option) (body : S.expression) : fun_def =
+ let bs_ctx = { types_infos } in
+ (* Translate the function *)
+ let def_id = def.A.def_id in
+ let name = translate_fun_name def bid in
+ let signature = translate_fun_sig bs_ctx def bid in
+ let body = translate_expression def bid body bs_ctx in
+ { def_id; name; signature; body }
diff --git a/src/main.ml b/src/main.ml
index 67db362e..492470c7 100644
--- a/src/main.ml
+++ b/src/main.ml
@@ -77,4 +77,5 @@ let () =
I.Test.test_unit_functions config m;
(* Evaluate the symbolic interpreter on the functions *)
- I.Test.test_functions_symbolic config m
+ let synthesize = true in
+ I.Test.test_functions_symbolic config synthesize m