diff options
Diffstat (limited to 'compiler/Pure.ml')
| -rw-r--r-- | compiler/Pure.ml | 176 |
1 files changed, 117 insertions, 59 deletions
diff --git a/compiler/Pure.ml b/compiler/Pure.ml index 8d39cc69..a879ba37 100644 --- a/compiler/Pure.ml +++ b/compiler/Pure.ml @@ -561,7 +561,7 @@ type fun_id_or_trait_method_ref = (** A function id for a non-assumed function *) type regular_fun_id = - fun_id_or_trait_method_ref * LoopId.id option * T.RegionGroupId.id option + fun_id_or_trait_method_ref * LoopId.id option * RegionGroupId.id option [@@deriving show, ord] (** A function identifier *) @@ -684,7 +684,7 @@ type expression = 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_pattern * texpression (** Lambda abstraction: [fun x -> e] *) + | Lambda of typed_pattern * texpression (** Lambda abstraction: [λ x => e] *) | Qualif of qualif (** A top-level qualifier *) | Let of bool * typed_pattern * texpression * texpression (** Let binding. @@ -754,9 +754,7 @@ and loop = { inputs : var list; inputs_lvs : typed_pattern list; (** The inputs seen as patterns. See {!fun_body}. *) - back_output_tys : ty list option; - (** The types of the given back values, if we ar esynthesizing a backward - function *) + output_ty : ty; (** The output type of the loop *) loop_body : texpression; } @@ -860,8 +858,8 @@ type fun_effect_info = { the set [{ forward function } U { backward functions }]. We need this because of the option {!val:Config.backward_no_state_update}: - if it is [true], then in case of a backward function {!stateful} is [false], - but we might need to know whether the corresponding forward function + if it is [true], then in case of a backward function {!stateful} might be + [false], but we might need to know whether the corresponding forward function is stateful or not. *) stateful : bool; (** [true] if the function is stateful (updates a state) *) @@ -873,22 +871,108 @@ type fun_effect_info = { } [@@deriving show] -(** Meta information about a function signature *) -type fun_sig_info = { +type inputs_info = { has_fuel : bool; - (* TODO: add [num_fwd_inputs_no_fuel_no_state] *) - num_fwd_inputs_with_fuel_no_state : int; - (** The number of input types for forward computation, with the fuel (if used) + num_inputs_no_fuel_no_state : int; + (** The number of input types ignoring the fuel (if used) + and ignoring the state (if used) *) + num_inputs_with_fuel_no_state : int; + (** The number of input types, with the fuel (if used) and ignoring the state (if used) *) - num_fwd_inputs_with_fuel_with_state : int; - (** The number of input types for forward computation, with fuel and state (if used) *) - num_back_inputs_no_state : int option; - (** The number of additional inputs for the backward computation (if pertinent), - ignoring the state (if there is one) *) - num_back_inputs_with_state : int option; - (** The number of additional inputs for the backward computation (if pertinent), - with the state (if there is one) *) + num_inputs_with_fuel_with_state : int; + (** The number of input types, with fuel and state (if used) *) +} +[@@deriving show] + +(** Meta information about a function signature *) +type fun_sig_info = { + fwd_info : inputs_info; + (** Information about the inputs of the forward function *) effect_info : fun_effect_info; + ignore_output : bool; + (** In case we merge the forward/backward functions: should we ignore + the output (happens for forward functions if the output type is + [unit] and there are non-filtered backward functions)? + *) +} +[@@deriving show] + +type back_sg_info = { + inputs : (string option * ty) list; + (** The additional inputs of the backward function *) + inputs_no_state : (string option * ty) list; + outputs : ty list; + (** The "decomposed" list of outputs. + + The list contains all the types of + all the given back values (there is at most one type per forward + input argument). + + Ex.: + {[ + fn choose<'a, T>(b : bool, x : &'a mut T, y : &'a mut T) -> &'a mut T; + ]} + Decomposed outputs: + - forward function: [[T]] + - backward function: [[T; T]] (for "x" and "y") + + Non-decomposed ouputs (if the function can fail, but is not stateful): + - [result T] + - [[result (T * T)]] + *) + output_names : string option list; + (** The optional names for the backward outputs. + We derive those from the names of the inputs of the original LLBC + function. *) + effect_info : fun_effect_info; + filter : bool; (** Should we filter this backward function? *) +} +[@@deriving show] + +(** A *decomposed* function signature. *) +type decomposed_fun_sig = { + generics : generic_params; + (** TODO: we should analyse the signature to make the type parameters implicit whenever possible *) + llbc_generics : Types.generic_params; + (** We use the LLBC generics to generate "pretty" names, for instance + for the variables we introduce for the trait clauses: we derive + those names from the types, and when doing so it is more meaningful + to derive them from the original LLBC types from before the + simplification of types like boxes and references. *) + preds : predicates; + fwd_inputs : ty list; + (** The types of the inputs of the forward function. + + Note that those input types take include the [fuel] parameter, + if the function uses fuel for termination, and the [state] parameter, + if the function is stateful. + + For instance, if we have the following Rust function: + {[ + fn f(x : int); + ]} + + If we translate it to a stateful function which uses fuel we get: + {[ + val f : nat -> int -> state -> result (state * unit); + ]} + + In particular, the list of input types is: [[nat; int; state]]. + *) + fwd_output : ty; + (** The "pure" output type of the forward function. + + Note that this type doesn't contain the "effect" of the function (i.e., + we haven't added the [state] if it is a stateful function and haven't + wrapped the type in a [result]). Also, this output type is only about + the forward function (it doesn't contain the type of the closures we + return for the backward functions, in case we merge the forward and + backward functions). + *) + back_sg : back_sg_info RegionGroupId.Map.t; + (** Information about the backward functions *) + fwd_info : fun_sig_info; + (** Additional information about the forward function *) } [@@deriving show] @@ -906,15 +990,15 @@ type fun_sig_info = { [in_ty0 -> ... -> in_tyn -> state -> back_in0 -> ... back_inm -> state -> result (state & (back_out0 & ... & back_outp))] (* state-error *) - Note that a stateful backward function may take two states as inputs: the - state received by the associated forward function, and the state at which - the backward is called. This leads to code of the following shape: + Note that a stateful backward function may take two states as inputs: the + state received by the associated forward function, and the state at which + the backward is called. This leads to code of the following shape: - {[ - (st1, y) <-- f_fwd x st0; // st0 is the state upon calling f_fwd - ... // the state may be updated - (st3, x') <-- f_back x st0 y' st2; // st2 is the state upon calling f_back - ]} + {[ + (st1, y) <-- f_fwd x st0; // st0 is the state upon calling f_fwd + ... // the state may be updated + (st3, x') <-- f_back x st0 y' st2; // st2 is the state upon calling f_back + ]} The function's type should be given by [mk_arrows sig.inputs sig.output]. We provide additional meta-information with {!fun_sig.info}: @@ -962,40 +1046,14 @@ type fun_sig = { be a tuple with a [state] if the function is stateful, and will be wrapped in a [result] if the function can fail. *) - doutputs : ty list; - (** The "decomposed" list of outputs. - - In case of a forward function, the list has length = 1, for the - type of the returned value. - - In case of backward function, the list contains all the types of - all the given back values (there is at most one type per forward - input argument). - - Ex.: - {[ - fn choose<'a, T>(b : bool, x : &'a mut T, y : &'a mut T) -> &'a mut T; - ]} - Decomposed outputs: - - forward function: [[T]] - - backward function: [[T; T]] (for "x" and "y") - - Non-decomposed ouputs (if the function can fail, but is not stateful): - - [result T] - - [[result (T * T)]] - *) - info : fun_sig_info; (** Additional information *) + fwd_info : fun_sig_info; + (** Additional information about the forward function. *) + back_effect_info : fun_effect_info RegionGroupId.Map.t; } [@@deriving show] (** An instantiated function signature. See {!fun_sig} *) -type inst_fun_sig = { - inputs : ty list; - output : ty; - doutputs : ty list; - info : fun_sig_info; -} -[@@deriving show] +type inst_fun_sig = { inputs : ty list; output : ty } [@@deriving show] type fun_body = { inputs : var list; @@ -1020,7 +1078,7 @@ type fun_decl = { *) loop_id : LoopId.id option; (** [Some] if this definition was generated for a loop *) - back_id : T.RegionGroupId.id option; + back_id : RegionGroupId.id option; llbc_name : llbc_name; (** The original LLBC name. *) name : string; (** We use the name only for printing purposes (for debugging): |