open Identifiers open Names module T = Types module V = Values module E = Expressions module A = LlbcAst module TypeDeclId = T.TypeDeclId module TypeVarId = T.TypeVarId module RegionGroupId = T.RegionGroupId module VariantId = T.VariantId module FieldId = T.FieldId module SymbolicValueId = V.SymbolicValueId module FunDeclId = A.FunDeclId module SynthPhaseId = IdGen () (** We give an identifier to every phase of the synthesis (forward, backward for group of regions 0, etc.) *) module VarId = IdGen () (** Pay attention to the fact that we also define a [VarId] module in Values *) type integer_type = T.integer_type [@@deriving show, ord] (** The assumed types for the pure AST. In comparison with LLBC: - we removed `Box` (because it is translated as the identity: `Box T == T`) - we added: - `Result`: the type used in the error monad. This allows us to have a unified treatment of expressions (especially when we have to unfold the monadic binds) - `State`: the type of the state, when using state-error monads. Note that this state is opaque to Aeneas (the user can define it, or leave it as assumed) *) type assumed_ty = State | Result | Vec | Option [@@deriving show, ord] (* TODO: we should never directly manipulate `Return` and `Fail`, but rather * the monadic functions `return` and `fail` (makes treatment of error and * state-error monads more uniform) *) let result_return_id = VariantId.of_int 0 let result_fail_id = VariantId.of_int 1 let option_some_id = T.option_some_id let option_none_id = T.option_none_id type type_id = AdtId of TypeDeclId.id | Tuple | Assumed of assumed_ty [@@deriving show, ord] (** Ancestor for iter visitor for [ty] *) class ['self] iter_ty_base = object (_self : 'self) inherit [_] VisitorsRuntime.iter method visit_id : 'env -> TypeVarId.id -> unit = fun _ _ -> () method visit_type_id : 'env -> type_id -> unit = fun _ _ -> () method visit_integer_type : 'env -> integer_type -> unit = fun _ _ -> () end (** Ancestor for map visitor for [ty] *) class ['self] map_ty_base = object (_self : 'self) inherit [_] VisitorsRuntime.map method visit_id : 'env -> TypeVarId.id -> TypeVarId.id = fun _ id -> id method visit_type_id : 'env -> type_id -> type_id = fun _ id -> id method visit_integer_type : 'env -> integer_type -> integer_type = fun _ ity -> ity end type ty = | Adt of type_id * ty list (** [Adt] encodes ADTs and tuples and assumed types. TODO: what about the ended regions? (ADTs may be parameterized with several region variables. When giving back an ADT value, we may be able to only give back part of the ADT. We need a way to encode such "partial" ADTs. *) | TypeVar of TypeVarId.id | Bool | Char | Integer of integer_type | Str | Array of ty (* TODO: this should be an assumed type?... *) | Slice of ty (* TODO: this should be an assumed type?... *) | Arrow of ty * ty [@@deriving show, visitors { name = "iter_ty"; variety = "iter"; ancestors = [ "iter_ty_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "map_ty"; variety = "map"; ancestors = [ "map_ty_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }] type field = { field_name : string option; field_ty : ty } [@@deriving show] type variant = { variant_name : string; fields : field list } [@@deriving show] type type_decl_kind = Struct of field list | Enum of variant list | Opaque [@@deriving show] type type_var = T.type_var [@@deriving show] type type_decl = { def_id : TypeDeclId.id; name : name; type_params : type_var list; kind : type_decl_kind; } [@@deriving show] type scalar_value = V.scalar_value [@@deriving show] type constant_value = V.constant_value [@@deriving show] type var = { id : VarId.id; basename : string option; (** The "basename" is used to generate a meaningful name for the variable (by potentially adding an index to uniquely identify it). *) ty : ty; } [@@deriving show] (** 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. *) (* TODO: we might want to redefine field_proj_kind here, to prevent field accesses * on enumerations. * Also: tuples... *) type projection_elem = { pkind : E.field_proj_kind; field_id : FieldId.id } [@@deriving show] type projection = projection_elem list [@@deriving show] type mplace = { var_id : V.VarId.id; name : string option; projection : projection; } [@@deriving show] (** "Meta" place. Meta-data retrieved from the symbolic execution, which gives provenance information about the values. We use this to generate names for the variables we introduce. *) (* TODO: there shouldn't be places *) type place = { var : VarId.id; projection : projection } [@@deriving show] (** Ancestor for [iter_var_or_dummy] visitor *) class ['self] iter_value_base = object (_self : 'self) inherit [_] VisitorsRuntime.iter method visit_constant_value : 'env -> constant_value -> unit = fun _ _ -> () method visit_var : 'env -> var -> unit = fun _ _ -> () method visit_place : 'env -> place -> unit = fun _ _ -> () method visit_mplace : 'env -> mplace -> unit = fun _ _ -> () method visit_ty : 'env -> ty -> unit = fun _ _ -> () end (** Ancestor for [map_typed_rvalue] visitor *) class ['self] map_value_base = object (_self : 'self) inherit [_] VisitorsRuntime.map method visit_constant_value : 'env -> constant_value -> constant_value = fun _ x -> x method visit_var : 'env -> var -> var = fun _ x -> x method visit_place : 'env -> place -> place = fun _ x -> x method visit_mplace : 'env -> mplace -> mplace = fun _ x -> x method visit_ty : 'env -> ty -> ty = fun _ x -> x end (** Ancestor for [reduce_typed_rvalue] visitor *) class virtual ['self] reduce_value_base = object (self : 'self) inherit [_] VisitorsRuntime.reduce method visit_constant_value : 'env -> constant_value -> 'a = fun _ _ -> self#zero method visit_var : 'env -> var -> 'a = fun _ _ -> self#zero method visit_place : 'env -> place -> 'a = fun _ _ -> self#zero method visit_mplace : 'env -> mplace -> 'a = fun _ _ -> self#zero method visit_ty : 'env -> ty -> 'a = fun _ _ -> self#zero end (** Ancestor for [mapreduce_typed_rvalue] visitor *) class virtual ['self] mapreduce_value_base = object (self : 'self) inherit [_] VisitorsRuntime.mapreduce method visit_constant_value : 'env -> constant_value -> constant_value * 'a = fun _ x -> (x, self#zero) method visit_var : 'env -> var -> var * 'a = fun _ x -> (x, self#zero) method visit_place : 'env -> place -> place * 'a = fun _ x -> (x, self#zero) method visit_mplace : 'env -> mplace -> mplace * 'a = fun _ x -> (x, self#zero) method visit_ty : 'env -> ty -> ty * 'a = fun _ x -> (x, self#zero) end (* TODO: merge with expressions *) type rvalue = | RvConcrete of constant_value | RvPlace of place (* TODO: field projectors should be expressions *) | RvAdt of adt_rvalue and adt_rvalue = { variant_id : (VariantId.id option[@opaque]); (* TODO: variant constructors should be expressions, treated in a manner * similar to functions *) field_values : typed_rvalue list; } and typed_rvalue = { value : rvalue; ty : ty } [@@deriving show, visitors { name = "iter_typed_rvalue"; variety = "iter"; ancestors = [ "iter_value_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "map_typed_rvalue"; variety = "map"; ancestors = [ "map_value_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "reduce_typed_rvalue"; variety = "reduce"; ancestors = [ "reduce_value_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); polymorphic = false; }, visitors { name = "mapreduce_typed_rvalue"; variety = "mapreduce"; ancestors = [ "mapreduce_value_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); polymorphic = false; }] type var_or_dummy = | Var of var * mplace option (** Rk.: the mdplace is actually always a variable (i.e.: there are no projections). We use [mplace] because it leads to a more uniform treatment of the meta information. *) | Dummy (** Ignored value: `_`. *) [@@deriving show, visitors { name = "iter_var_or_dummy"; variety = "iter"; ancestors = [ "iter_typed_rvalue" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "map_var_or_dummy"; variety = "map"; ancestors = [ "map_typed_rvalue" ]; nude = true (* Don't inherit [VisitorsRuntime.map] *); concrete = true; polymorphic = false; }, visitors { name = "reduce_var_or_dummy"; variety = "reduce"; ancestors = [ "reduce_typed_rvalue" ]; nude = true (* Don't inherit [VisitorsRuntime.reduce] *); polymorphic = false; }, visitors { name = "mapreduce_var_or_dummy"; variety = "mapreduce"; ancestors = [ "mapreduce_typed_rvalue" ]; nude = true (* Don't inherit [VisitorsRuntime.reduce] *); polymorphic = false; }] (** A left value (which appears on the left of assignments. TODO: rename to "pattern" *) type lvalue = | LvConcrete of constant_value (** [LvConcrete] is necessary because we merge the switches over integer values and the matches over enumerations *) | LvVar of var_or_dummy | LvAdt of adt_lvalue and adt_lvalue = { variant_id : (VariantId.id option[@opaque]); field_values : typed_lvalue list; } and typed_lvalue = { value : lvalue; ty : ty } [@@deriving show, visitors { name = "iter_typed_lvalue"; variety = "iter"; ancestors = [ "iter_var_or_dummy" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "map_typed_lvalue"; variety = "map"; ancestors = [ "map_var_or_dummy" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; polymorphic = false; }, visitors { name = "reduce_typed_lvalue"; variety = "reduce"; ancestors = [ "reduce_var_or_dummy" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); polymorphic = false; }, visitors { name = "mapreduce_typed_lvalue"; variety = "mapreduce"; ancestors = [ "mapreduce_var_or_dummy" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); polymorphic = false; }] type unop = Not | Neg of integer_type [@@deriving show, ord] type fun_id = | Regular of A.fun_id * T.RegionGroupId.id option (** Backward id: `Some` if the function is a backward function, `None` if it is a forward function. TODO: we need to redefine A.fun_id here, to add `fail` and `return` (important to get a unified treatment of the state-error monad). For now, when using the state-error monad: extraction works only if we unfold all the monadic let-bindings, and we then replace the content of the occurrences of `Return` to also return the state (which is really super ugly). *) | Unop of unop | Binop of E.binop * integer_type [@@deriving show, ord] (** Meta-information stored in the AST *) type meta = Assignment of mplace * typed_rvalue * mplace option [@@deriving show] type func = { func : fun_id; type_params : ty list } [@@deriving show] (** A function. Note that for now we have a clear separation between types and expressions, which explains why we have the `type_params` field: a function is always fully instantiated. *) (** Ancestor for [iter_expression] visitor *) class ['self] iter_expression_base = object (_self : 'self) inherit [_] iter_typed_lvalue method visit_meta : 'env -> meta -> unit = fun _ _ -> () method visit_integer_type : 'env -> integer_type -> unit = fun _ _ -> () method visit_scalar_value : 'env -> scalar_value -> unit = fun _ _ -> () method visit_func : 'env -> func -> unit = fun _ _ -> () end (** Ancestor for [map_expression] visitor *) class ['self] map_expression_base = object (_self : 'self) inherit [_] map_typed_lvalue method visit_meta : 'env -> meta -> meta = fun _ x -> x method visit_integer_type : 'env -> integer_type -> integer_type = fun _ x -> x method visit_scalar_value : 'env -> scalar_value -> scalar_value = fun _ x -> x method visit_func : 'env -> func -> func = fun _ x -> x end (** Ancestor for [reduce_expression] visitor *) class virtual ['self] reduce_expression_base = object (self : 'self) inherit [_] reduce_typed_lvalue method visit_meta : 'env -> meta -> 'a = fun _ _ -> self#zero method visit_integer_type : 'env -> integer_type -> 'a = fun _ _ -> self#zero method visit_scalar_value : 'env -> scalar_value -> 'a = fun _ _ -> self#zero method visit_func : 'env -> func -> 'a = fun _ _ -> self#zero end (** Ancestor for [mapreduce_expression] visitor *) class virtual ['self] mapreduce_expression_base = object (self : 'self) inherit [_] mapreduce_typed_lvalue method visit_meta : 'env -> meta -> meta * 'a = fun _ x -> (x, self#zero) method visit_integer_type : 'env -> integer_type -> integer_type * 'a = fun _ x -> (x, self#zero) method visit_scalar_value : 'env -> scalar_value -> scalar_value * 'a = fun _ x -> (x, self#zero) method visit_func : 'env -> func -> func * 'a = fun _ x -> (x, self#zero) end (** **Rk.:** here, [expression] is not at all equivalent to the expressions used in LLBC. They are lambda-calculus expressions, and are thus actually more general than the LLBC statements, in a sense. *) type expression = | Value of typed_rvalue * mplace option | App of texpression * texpression (** Application of a function to an argument. The function calls are still quite structured. Change that?... We might want to have a "normal" lambda calculus app (with head and argument): this would allow us to replace some field accesses with calls to projectors over fields (when there are clashes of field names, some provers like F* get pretty bad...) *) | Abs of typed_lvalue * texpression (** Lambda abstraction: `fun x -> e` *) | Func of func (** A function - TODO: change to Qualifier *) | Let of bool * typed_lvalue * texpression * texpression (** Let binding. TODO: the boolean should be replaced by an enum: sometimes we use the error-monad, sometimes we use the state-error monad (and we do this an a per-function basis! For instance, arithmetic functions are always in the error monad). The boolean controls whether the let is monadic or not. For instance, in F*: - non-monadic: `let x = ... in ...` - monadic: `x <-- ...; ...` Note that we are quite general for the left-value on purpose; this is used in several situations: 1. When deconstructing a tuple: ``` let (x, y) = p in ... ``` (not all languages have syntax like `p.0`, `p.1`... and it is more readable anyway). 2. When expanding an enumeration with one variant. In this case, [Deconstruct] has to be understood as: ``` let Cons x tl = ls in ... ``` Note that 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 ... ``` *) | Switch of texpression * switch_body | Meta of meta * texpression (** Meta-information *) and switch_body = If of texpression * texpression | Match of match_branch list and match_branch = { pat : typed_lvalue; branch : texpression } and texpression = { e : expression; ty : ty } [@@deriving show, visitors { name = "iter_expression"; variety = "iter"; ancestors = [ "iter_expression_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; }, visitors { name = "map_expression"; variety = "map"; ancestors = [ "map_expression_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); concrete = true; }, visitors { name = "reduce_expression"; variety = "reduce"; ancestors = [ "reduce_expression_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); }, visitors { name = "mapreduce_expression"; variety = "mapreduce"; ancestors = [ "mapreduce_expression_base" ]; nude = true (* Don't inherit [VisitorsRuntime.iter] *); }] type fun_sig = { type_params : type_var list; inputs : ty list; outputs : ty list; (** The list of outputs. Immediately after the translation from symbolic to pure we have this the following: 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). After the "to monadic" pass, the list has size exactly one (and we use the `Result` type). *) } type inst_fun_sig = { inputs : ty list; outputs : ty list } type fun_body = { inputs : var list; inputs_lvs : typed_lvalue list; (** The inputs seen as lvalues. Allows to make transformations, for example to replace unused variables by `_` *) body : texpression; } type fun_decl = { def_id : FunDeclId.id; back_id : T.RegionGroupId.id option; basename : fun_name; (** The "base" name of the function. The base name is the original name of the Rust function. We add suffixes (to identify the forward/backward functions) later. *) signature : fun_sig; body : fun_body option; }