Prepare v7.1.0 release (#438)

* Add hole expressions

* Fix the issue of unreported holes

* Add tests

* New line in the end of the test file

* Update CHANGELOG

* Add hole expression to the docs

* Do not treat hole as a special type

* Update docs

* Update docs/sophia_features.md

Co-authored-by: Radosław Rowicki <35342116+radrow@users.noreply.github.com>

Co-authored-by: Radosław Rowicki <35342116+radrow@users.noreply.github.com>

.github/workflows/requirements.txt

@@ -1,5 +1,5 @@
-mkdocs==1.2.4
+mkdocs==1.4.2
 mkdocs-simple-hooks==0.1.5
-mkdocs-material==7.3.6
+mkdocs-material==9.0.9
 mike==1.1.2
-pygments==2.12.0
+pygments==2.14.0

CHANGELOG.md

@@ -10,6 +10,25 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Removed
 ### Fixed
 
+## [7.1.0]
+### Added
+- Options to enable/disable certain optimizations.
+- The ability to call a different instance of the current contract
+  ```
+  contract Main =
+    entrypoint spend(x : int) : int = x
+    entrypoint f(c : Main) : int = c.spend(10)
+  ```
+- Return a mapping from variables to FATE registers in the compilation output.
+- Hole expression.
+### Changed
+- Type definitions serialised to ACI as `typedefs` field instead of `type_defs` to increase compatibility.
+- Check contracts and entrypoints modifiers when implementing interfaces.
+- Contracts can no longer be used as namespaces.
+- Do not show unused stateful warning for functions that call other contracts with a non-zero value argument.
+### Fixed
+- Typechecker crashes if Chain.create or Chain.clone are used without arguments.
+
 ## [7.0.1]
 ### Added
 - Add CONTRIBUTING.md file.
@@ -361,7 +380,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Simplify calldata creation - instead of passing a compiled contract, simply
   pass a (stubbed) contract string.
 
-[Unreleased]: https://github.com/aeternity/aesophia/compare/v7.0.1...HEAD
+[Unreleased]: https://github.com/aeternity/aesophia/compare/v7.1.0...HEAD
+[7.1.0]: https://github.com/aeternity/aesophia/compare/v7.0.1...v7.1.0
 [7.0.1]: https://github.com/aeternity/aesophia/compare/v7.0.0...v7.0.1
 [7.0.0]: https://github.com/aeternity/aesophia/compare/v6.1.0...v7.0.0
 [6.1.0]: https://github.com/aeternity/aesophia/compare/v6.0.2...v6.1.0

CONTRIBUTING.md

@@ -10,6 +10,8 @@ The following points should be considered before creating a new PR to the Sophia
 - If a PR introduces a new feature that is relevant to the users of the language, the [Sophia Features Documentation](docs/sophia_features.md) should be updated to describe the new feature.
 - If a PR introduces new syntax (e.g. changes in [aeso_syntax.erl](src/aeso_syntax.erl), [aeso_scan.erl](src/aeso_scan.erl), or [aeso_parser.erl](src/aeso_parser.erl)), the [Sophia Syntax Documentation](docs/sophia_syntax.md) should be updated to include the new syntax.
 - If a PR introduces a new library, the public interface of the new library should be fully documented in the [Sophia Standard Library Documentation](docs/sophia_stdlib.md).
+- If a PR introduces a new compiler option, the new option should be documented in the file
+[aeso_compiler.md](docs/aeso_compiler.md).
 
 ### Tests
 

docs/aeso_aci.md

@@ -67,7 +67,7 @@ generates the following JSON structure representing the contract interface:
         }
       ]
     },
-    "type_defs": [
+    "typedefs": [
       {
         "name": "answers",
         "typedef": {
@@ -138,7 +138,7 @@ be included inside another contract.
              state =>
                  #{record =>
                        [#{name => <<"a">>,type => <<"Answers.answers">>}]},
-             type_defs =>
+             typedefs =>
                  [#{name => <<"answers">>,
                     typedef => #{<<"map">> => [<<"string">>,<<"int">>]},
                     vars => []}]}}]}

docs/aeso_compiler.md

@@ -51,6 +51,36 @@ The **pp_** options all print to standard output the following:
 
 `pp_assembler` - print the generated assembler code
 
+The option `include_child_contract_symbols` includes the symbols of child contracts functions in the generated fate code. It is turned off by default to avoid making contracts bigger on chain.
+
+The option `debug_info` includes information related to debugging in the compiler output. Currently this option only includes the mapping from variables to registers.
+
+#### Options to control which compiler optimizations should run:
+
+By default all optimizations are turned on, to disable an optimization, it should be
+explicitly set to false and passed as a compiler option.
+
+List of optimizations:
+
+- optimize_inliner
+- optimize_inline_local_functions
+- optimize_bind_subexpressions
+- optimize_let_floating
+- optimize_simplifier
+- optimize_drop_unused_lets
+- optimize_push_consume
+- optimize_one_shot_var
+- optimize_write_to_dead_var
+- optimize_inline_switch_target
+- optimize_swap_push
+- optimize_swap_pop
+- optimize_swap_write
+- optimize_constant_propagation
+- optimize_prune_impossible_branches
+- optimize_single_successful_branch
+- optimize_inline_store
+- optimize_float_switch_bod
+
 #### check_call(ContractString, Options) -> CheckRet
 
 Types

docs/sophia_features.md

@@ -191,6 +191,17 @@ contract interface X : Z =
      entrypoint z() = 1
 ```
 
+#### Adding or removing modifiers
+
+When a `contract` or a `contract interface` implements another `contract interface`, the `payable` and `stateful` modifiers can be kept or changed, both in the contract and in the entrypoints, according to the following rules:
+
+1. A `payable` contract or interface can implement a `payable` interface or a non-`payable` interface.
+2. A non-`payable` contract or interface can only implement a non-`payable` interface, and cannot implement a `payable` interface.
+3. A `payable` entrypoint can implement a `payable` entrypoint or a non-`payable` entrypoint.
+4. A non-`payable` entrypoint can only implement a non-`payable` entrypoint, and cannot implement a `payable` entrypoint.
+5. A non-`stateful` entrypoint can implement a `stateful` entrypoint or a non-`stateful` entrypoint.
+6. A `stateful` entrypoint can only implement a `stateful` entrypoint, and cannot implement a non-`stateful` entrypoint.
+
 #### Subtyping and variance
 
 Subtyping in Sophia follows common rules that take type variance into account. As described by [Wikipedia](https://en.wikipedia.org/wiki/Covariance_and_contravariance_(computer_science)), 
@@ -245,10 +256,10 @@ datatype bi('a) = Bi // bi is bivariant on 'a
 
 The following facts apply here:
 
-- `co('a)` is a subtype of `co('b) when `'a` is a subtype of `'b`
-- `ct('a)` is a subtype of `ct('b) when `'b` is a subtype of `'a`
-- `in('a)` is a subtype of `in('b) when `'a` is equal to `'b`
-- `bi('a)` is a subtype of `bi('b) always
+- `co('a)` is a subtype of `co('b)` when `'a` is a subtype of `'b`
+- `ct('a)` is a subtype of `ct('b)` when `'b` is a subtype of `'a`
+- `in('a)` is a subtype of `in('b)` when `'a` is equal to `'b`
+- `bi('a)` is a subtype of `bi('b)` always
 
 That altogether induce the following rules of subtyping in Sophia:
 
@@ -549,6 +560,19 @@ Sophia has the following types:
 | oracle_query('a, 'b) | `oq_2oRvyowJuJnEkxy58Ckkw77XfWJrmRgmGaLzhdqb67SKEL1gPY`                                                                             |
 | contract             | `ct_Ez6MyeTMm17YnTnDdHTSrzMEBKmy7Uz2sXu347bTDPgVH2ifJ`                                                                              |
 
+## Hole expression
+
+Hole expressions, written as `???`, are expressions that are used as a placeholder. During compilation, the compiler will generate a type error indication the type of the hole expression.
+
+```
+include "List.aes"
+contract C =
+    entrypoint f() =
+        List.sum(List.map(???, [1,2,3]))
+```
+
+A hole expression found in the example above will generate the error `` Found a hole of type `(int) => int` ``. This says that the compiler expects a function from `int` to `int` in place of the `???` placeholder.
+
 ## Arithmetic
 
 Sophia integers (`int`) are represented by arbitrary-sized signed words and support the following

docs/sophia_stdlib.md

@@ -483,7 +483,7 @@ The address of the account that mined the current block.
 Chain.timestamp : int
 ```
 
-The timestamp of the current block.
+The timestamp of the current block (unix time, milliseconds).
 
 
 ##### difficulty

docs/sophia_syntax.md

@@ -238,6 +238,7 @@ Expr ::= '(' LamArgs ')' '=>' Block(Stmt)   // Anonymous function    (x) => x +
        | Int | Bytes | String | Char        // Literals              123, 0xff, #00abc123, "foo", '%'
        | AccountAddress | ContractAddress   // Chain identifiers
        | OracleAddress | OracleQueryId      // Chain identifiers
+       | '???'                              // Hole expression       1 + ???
 
 Generator ::= Pattern '<-' Expr   // Generator
             | 'if' '(' Expr ')'   // Guard

rebar.config

@@ -2,7 +2,7 @@
 
 {erl_opts, [debug_info]}.
 
-{deps, [ {aebytecode, {git, "https://github.com/aeternity/aebytecode.git", {tag, "v3.1.1"}}}
+{deps, [ {aebytecode, {git, "https://github.com/aeternity/aebytecode.git", {tag, "v3.2.0"}}}
        , {getopt, "1.0.1"}
        , {eblake2, "1.0.0"}
        , {jsx, {git, "https://github.com/talentdeficit/jsx.git", {tag, "2.8.0"}}}
@@ -14,7 +14,7 @@
             {base_plt_apps, [erts, kernel, stdlib, crypto, mnesia]}
            ]}.
 
-{relx, [{release, {aesophia, "7.0.1"},
+{relx, [{release, {aesophia, "7.1.0"},
          [aesophia, aebytecode, getopt]},
 
         {dev_mode, true},

rebar.lock

@@ -1,7 +1,7 @@
 {"1.2.0",
 [{<<"aebytecode">>,
   {git,"https://github.com/aeternity/aebytecode.git",
-       {ref,"8269dbd71e9011921c60141636f1baa270a0e784"}},
+       {ref,"2a0a397afad6b45da52572170f718194018bf33c"}},
   0},
  {<<"aeserialization">>,
   {git,"https://github.com/aeternity/aeserialization.git",

src/aeso_aci.erl

@@ -91,7 +91,7 @@ encode_contract(Contract = {Head, _, {con, _, Name}, _, _}) when ?IS_CONTRACT_HE
     {Es, Tdefs1} = lists:partition(FilterT(<<"event">>), Tdefs0),
     {Ss, Tdefs}  = lists:partition(FilterT(<<"state">>), Tdefs1),
 
-    C1 = C0#{type_defs => Tdefs},
+    C1 = C0#{typedefs => Tdefs},
 
     C2 = case Es of
              []                 -> C1;
@@ -111,7 +111,7 @@ encode_contract(Contract = {Head, _, {con, _, Name}, _, _}) when ?IS_CONTRACT_HE
 encode_contract(Namespace = {namespace, _, {con, _, Name}, _}) ->
     Tdefs = [ encode_typedef(T) || T <- sort_decls(contract_types(Namespace)) ],
     #{namespace => #{name => encode_name(Name),
-                     type_defs => Tdefs}}.
+                     typedefs => Tdefs}}.
 
 %%  Encode a function definition. Currently we are only interested in
 %%  the interface and type.
@@ -234,7 +234,7 @@ do_render_aci_json(Json) ->
 decode_contract(#{contract := #{name := Name,
                                 kind := Kind,
                                 payable := Payable,
-                                type_defs := Ts0,
+                                typedefs := Ts0,
                                 functions := Fs} = C}) ->
     MkTDef = fun(N, T) -> #{name => N, vars => [], typedef => T} end,
     Ts = [ MkTDef(<<"state">>, maps:get(state, C)) || maps:is_key(state, C) ] ++
@@ -246,7 +246,7 @@ decode_contract(#{contract := #{name := Name,
                        end,
      io_lib:format("~s", [Name])," =\n",
      decode_tdefs(Ts), decode_funcs(Fs)];
-decode_contract(#{namespace := #{name := Name, type_defs := Ts}}) when Ts /= [] ->
+decode_contract(#{namespace := #{name := Name, typedefs := Ts}}) when Ts /= [] ->
     ["namespace ", io_lib:format("~s", [Name])," =\n",
      decode_tdefs(Ts)];
 decode_contract(_) -> [].

src/aeso_ast_infer_types.erl

@@ -229,7 +229,7 @@ force_bind_fun(X, Type, Env = #env{ what = What }) ->
     NoCode = get_option(no_code, false),
     Entry = if X == "init", What == contract, not NoCode ->
                     {reserved_init, Ann, Type};
-               What == contract_interface -> {contract_fun, Ann, Type};
+               What == contract; What == contract_interface -> {contract_fun, Ann, Type};
                true -> {Ann, Type}
             end,
     on_current_scope(Env, fun(Scope = #scope{ funs = Funs }) ->
@@ -270,15 +270,24 @@ bind_state(Env) ->
         false  -> Env1
     end.
 
--spec bind_field(name(), field_info(), env()) -> env().
-bind_field(X, Info, Env = #env{ fields = Fields }) ->
+-spec bind_field_append(name(), field_info(), env()) -> env().
+bind_field_append(X, Info, Env = #env{ fields = Fields }) ->
     Fields1 = maps:update_with(X, fun(Infos) -> [Info | Infos] end, [Info], Fields),
     Env#env{ fields = Fields1 }.
 
--spec bind_fields([{name(), field_info()}], env()) -> env().
-bind_fields([], Env) -> Env;
-bind_fields([{Id, Info} | Rest], Env) ->
-    bind_fields(Rest, bind_field(Id, Info, Env)).
+-spec bind_field_update(name(), field_info(), env()) -> env().
+bind_field_update(X, Info, Env = #env{ fields = Fields }) ->
+    Fields1 = maps:update_with(X, fun([_ | Infos]) -> [Info | Infos]; ([]) -> [Info] end, [Info], Fields),
+    Env#env{ fields = Fields1 }.
+
+-spec bind_fields([{name(), field_info()}], typed | untyped, env()) -> env().
+bind_fields([], _Typing, Env) -> Env;
+bind_fields([{Id, Info} | Rest], Typing, Env) ->
+    NewEnv = case Typing of
+                 untyped -> bind_field_append(Id, Info, Env);
+                 typed   -> bind_field_update(Id, Info, Env)
+             end,
+    bind_fields(Rest, Typing, NewEnv).
 
 %% Contract entrypoints take three named arguments
 %%  gas       : int  = Call.gas_left()
@@ -296,26 +305,27 @@ contract_call_type({fun_t, Ann, [], Args, Ret}) ->
                   Named("protected", Typed({bool, Ann, false}, Id("bool")))],
      Args, {if_t, Ann, Id("protected"), {app_t, Ann, {id, Ann, "option"}, [Ret]}, Ret}}.
 
--spec bind_contract(aeso_syntax:decl(), env()) -> env().
-bind_contract({Contract, Ann, Id, _Impls, Contents}, Env)
+-spec bind_contract(typed | untyped, aeso_syntax:decl(), env()) -> env().
+bind_contract(Typing, {Contract, Ann, Id, _Impls, Contents}, Env)
   when ?IS_CONTRACT_HEAD(Contract) ->
-    Key    = name(Id),
-    Sys    = [{origin, system}],
-    Fields =
+    Key         = name(Id),
+    Sys         = [{origin, system}],
+    TypeOrFresh = fun({typed, _, _, Type}) -> Type; (_) -> fresh_uvar(Sys) end,
+    Fields      =
         [ {field_t, AnnF, Entrypoint, contract_call_type(Type)}
-          || {fun_decl, AnnF, Entrypoint, Type} <- Contents ] ++
+          || {fun_decl, AnnF, Entrypoint, Type = {fun_t, _, _, _, _}} <- Contents ] ++
         [ {field_t, AnnF, Entrypoint,
            contract_call_type(
-             {fun_t, AnnF, [], [ArgT || {typed, _, _, ArgT} <- Args], RetT})
+             {fun_t, AnnF, [], [TypeOrFresh(Arg) || Arg <- Args], TypeOrFresh(Ret)})
           }
-          || {letfun, AnnF, Entrypoint = {id, _, Name}, Args, _Type, [{guarded, _, [], {typed, _, _, RetT}}]} <- Contents,
+          || {letfun, AnnF, Entrypoint = {id, _, Name}, Args, _Type, [{guarded, _, [], Ret}]} <- Contents,
              Name =/= "init"
         ] ++
         %% Predefined fields
         [ {field_t, Sys, {id, Sys, "address"}, {id, Sys, "address"}} ] ++
         [ {field_t, Sys, {id, Sys, ?CONSTRUCTOR_MOCK_NAME},
            contract_call_type(
-             case [ [ArgT || {typed, _, _, ArgT} <- Args]
+             case [ [TypeOrFresh(Arg) || Arg <- Args]
                     || {letfun, AnnF, {id, _, "init"}, Args, _, _} <- Contents,
                        aeso_syntax:get_ann(entrypoint, AnnF, false)]
                  ++ [ Args
@@ -337,7 +347,7 @@ bind_contract({Contract, Ann, Id, _Impls, Contents}, Env)
                                             record_t = Id }}
                 || {field_t, _, {id, FieldAnn, Entrypoint}, Type} <- Fields ],
     bind_type(Key, Ann, {[], {contract_t, Fields}},
-        bind_fields(FieldInfo, Env)).
+        bind_fields(FieldInfo, Typing, Env)).
 
 %% What scopes could a given name come from?
 -spec possible_scopes(env(), qname()) -> [qname()].
@@ -416,6 +426,7 @@ lookup_env(Env, Kind, Ann, Name) ->
 lookup_env1(#env{ namespace = Current, used_namespaces = UsedNamespaces, scopes = Scopes }, Kind, Ann, QName) ->
     Qual = lists:droplast(QName),
     Name = lists:last(QName),
+    QNameIsEvent = lists:suffix(["Chain", "event"], QName),
     AllowPrivate = lists:prefix(Qual, Current),
     %% Get the scope
     case maps:get(Qual, Scopes, false) of
@@ -431,6 +442,8 @@ lookup_env1(#env{ namespace = Current, used_namespaces = UsedNamespaces, scopes
                 {reserved_init, Ann1, Type} ->
                     type_error({cannot_call_init_function, Ann}),
                     {QName, {Ann1, Type}};  %% Return the type to avoid an extra not-in-scope error
+                {contract_fun, Ann1, Type} when AllowPrivate orelse QNameIsEvent ->
+                    {QName, {Ann1, Type}};
                 {contract_fun, Ann1, Type} ->
                     type_error({contract_treated_as_namespace, Ann, QName}),
                     {QName, {Ann1, Type}};
@@ -447,6 +460,9 @@ lookup_env1(#env{ namespace = Current, used_namespaces = UsedNamespaces, scopes
             end
     end.
 
+fun_arity({fun_t, _, _, Args, _}) -> length(Args);
+fun_arity(_)                      -> none.
+
 -spec lookup_record_field(env(), name()) -> [field_info()].
 lookup_record_field(Env, FieldName) ->
     maps:get(FieldName, Env#env.fields, []).
@@ -457,6 +473,11 @@ lookup_record_field(Env, FieldName, Kind) ->
     [ Fld || Fld = #field_info{ kind = K } <- lookup_record_field(Env, FieldName),
              Kind == project orelse K /= contract ].
 
+lookup_record_field_arity(Env, FieldName, Arity, Kind) ->
+    Fields = lookup_record_field(Env, FieldName, Kind),
+    [ Fld || Fld = #field_info{ field_t = FldType } <- Fields,
+             fun_arity(dereference_deep(FldType)) == Arity ].
+
 %% -- Name manipulation ------------------------------------------------------
 
 -spec qname(type_id()) -> qname().
@@ -837,6 +858,7 @@ infer(Contracts, Options) ->
         ets_new(type_vars, [set]),
         ets_new(warnings, [bag]),
         ets_new(type_vars_variance, [set]),
+        ets_new(functions_to_implement, [set]),
         %% Set the variance for builtin types
         ets_insert(type_vars_variance, {"list", [covariant]}),
         ets_insert(type_vars_variance, {"option", [covariant]}),
@@ -871,7 +893,7 @@ infer(Contracts, Options) ->
 -spec infer1(env(), [aeso_syntax:decl()], [aeso_syntax:decl()], list(option())) ->
     {env(), [aeso_syntax:decl()]}.
 infer1(Env, [], Acc, _Options) -> {Env, lists:reverse(Acc)};
-infer1(Env0, [{Contract, Ann, ConName, Impls, Code} | Rest], Acc, Options)
+infer1(Env0, [Contract0 = {Contract, Ann, ConName, Impls, Code} | Rest], Acc, Options)
   when ?IS_CONTRACT_HEAD(Contract) ->
     %% do type inference on each contract independently.
     Env = Env0#env{ contract_parents = maps:put(name(ConName),
@@ -887,12 +909,16 @@ infer1(Env0, [{Contract, Ann, ConName, Impls, Code} | Rest], Acc, Options)
         contract -> ets_insert(defined_contracts, {qname(ConName)});
         contract_interface -> ok
     end,
-    {Env1, Code1} = infer_contract_top(push_scope(contract, ConName, Env), What, Code, Options),
+    check_contract_preserved_payability(Env, ConName, Ann, Impls, Acc, What),
+    populate_functions_to_implement(Env, ConName, Impls, Acc),
+    Env1 = bind_contract(untyped, Contract0, Env),
+    {Env2, Code1} = infer_contract_top(push_scope(contract, ConName, Env1), What, Code, Options),
+    report_unimplemented_functions(Env1, ConName),
     Contract1 = {Contract, Ann, ConName, Impls, Code1},
-    check_implemented_interfaces(Env1, Contract1, Acc),
-    Env2 = pop_scope(Env1),
-    Env3 = bind_contract(Contract1, Env2),
-    infer1(Env3, Rest, [Contract1 | Acc], Options);
+    Env3 = pop_scope(Env2),
+    %% Rebinding because the qualifications of types are added during type inference. Could we do better?
+    Env4 = bind_contract(typed, Contract1, Env3),
+    infer1(Env4, Rest, [Contract1 | Acc], Options);
 infer1(Env, [{namespace, Ann, Name, Code} | Rest], Acc, Options) ->
     when_warning(warn_unused_includes,
                  fun() ->
@@ -909,54 +935,71 @@ infer1(Env, [{pragma, _, _} | Rest], Acc, Options) ->
     %% Pragmas are checked in check_modifiers
     infer1(Env, Rest, Acc, Options).
 
-check_implemented_interfaces(Env, {_Contract, _Ann, ConName, Impls, Code}, DefinedContracts) ->
+-spec check_contract_preserved_payability(env(), Con, Ann, Impls, Contracts, Kind) -> ok | no_return() when
+      Con :: aeso_syntax:con(),
+      Ann :: aeso_syntax:ann(),
+      Impls :: [Con],
+      Contracts :: [aeso_syntax:decl()],
+      Kind :: contract | contract_interface.
+check_contract_preserved_payability(Env, ContractName, ContractAnn, Impls, DefinedContracts, Kind) ->
+    Payable = proplists:get_value(payable, ContractAnn, false),
+    ImplsNames = [ name(I) || I <- Impls ],
+    Interfaces = [ Con || I = {contract_interface, _, Con, _, _} <- DefinedContracts,
+                          lists:member(name(Con), ImplsNames),
+                          aeso_syntax:get_ann(payable, I, false) ],
+
     create_type_errors(),
-    AllInterfaces = [{name(IName), I} || I = {contract_interface, _, IName, _, _} <- DefinedContracts],
-    ImplsNames = lists:map(fun name/1, Impls),
+    [ type_error({unpreserved_payablity, Kind, ContractName, I}) || I <- Interfaces, Payable == false ],
+    destroy_and_report_type_errors(Env),
 
-    %% All implemented intrefaces should already be defined
-    lists:foreach(fun(Impl) -> case proplists:get_value(name(Impl), AllInterfaces) of
-                                   undefined -> type_error({referencing_undefined_interface, Impl});
-                                   _         -> ok
-                               end
-                  end, Impls),
+    ok.
 
-    ImplementedInterfaces = [I || I <- [proplists:get_value(Name, AllInterfaces) || Name <- ImplsNames],
-                                    I /= undefined],
-    Funs = [ Fun || Fun <- Code,
-                    element(1, Fun) == letfun orelse element(1, Fun) == fun_decl ],
-    check_implemented_interfaces1(Env, ImplementedInterfaces, ConName, Funs, AllInterfaces),
+%% Report all functions that were not implemented by the contract ContractName.
+-spec report_unimplemented_functions(env(), ContractName) -> ok | no_return() when
+      ContractName :: aeso_syntax:con().
+report_unimplemented_functions(Env, ContractName) ->
+    create_type_errors(),
+    [ type_error({unimplemented_interface_function, ContractName, name(I), FunName})
+      || {FunName, I, _} <- ets_tab2list(functions_to_implement) ],
     destroy_and_report_type_errors(Env).
 
-%% Recursively check that all directly and indirectly referenced interfaces are implemented
-check_implemented_interfaces1(_, [], _, _, _) ->
-    ok;
-check_implemented_interfaces1(Env, [{contract_interface, _, IName, _, Decls} | Interfaces],
-                              ConId, Impls, AllInterfaces) ->
-    Unmatched = match_impls(Env, Decls, ConId, name(IName), Impls),
-    check_implemented_interfaces1(Env, Interfaces, ConId, Unmatched, AllInterfaces).
+%% Return a list of all function declarations to be implemented, given the list
+%% of interfaces to be implemented Impls and all the previously defined
+%% contracts DefinedContracts>
+-spec functions_to_implement(Impls, DefinedContracts) -> [{InterfaceCon, FunDecl}] when
+      Impls :: [aeso_syntax:con()],
+      DefinedContracts :: [aeso_syntax:decl()],
+      InterfaceCon :: aeso_syntax:con(),
+      FunDecl :: aeso_syntax:fundecl().
+functions_to_implement(Impls, DefinedContracts) ->
+    ImplsNames = [ name(I) || I <- Impls ],
+    Interfaces = [ I || I = {contract_interface, _, Con, _, _} <- DefinedContracts,
+                        lists:member(name(Con), ImplsNames) ],
 
-%% Match the functions of the contract with the interfaces functions, and return unmatched functions
-match_impls(_, [], _, _, Impls) ->
-    Impls;
-match_impls(Env, [{fun_decl, _, {id, _, FunName}, FunType = {fun_t, _, _, ArgsTypes, RetDecl}} | Decls], ConId, IName, Impls) ->
-    Match = fun({letfun, _, {id, _, FName}, Args, RetFun, _}) when FName == FunName ->
-                    length(ArgsTypes) == length(Args) andalso
-                    unify(Env#env{unify_throws = false}, RetDecl, RetFun, unknown) andalso
-                    lists:all(fun({T1, {typed, _, _, T2}}) -> unify(Env#env{unify_throws = false}, T1, T2, unknown) end,
-                              lists:zip(ArgsTypes, Args));
-               ({fun_decl, _, {id, _, FName}, FunT}) when FName == FunName ->
-                    unify(Env#env{unify_throws = false}, FunT, FunType, unknown);
-               (_) -> false
-            end,
-    UnmatchedImpls = case lists:search(Match, Impls) of
-                         {value, V} ->
-                             lists:delete(V, Impls);
-                         false ->
-                             type_error({unimplemented_interface_function, ConId, IName, FunName}),
-                             Impls
-                     end,
-    match_impls(Env, Decls, ConId, IName, UnmatchedImpls).
+    %% All implemented intrefaces should already be defined
+    InterfacesNames = [name(element(3, I)) || I <- Interfaces],
+    [ begin
+        Found = lists:member(name(Impl), InterfacesNames),
+        Found orelse type_error({referencing_undefined_interface, Impl})
+      end || Impl <- Impls
+    ],
+
+    lists:flatten([ [ {Con, Decl} || Decl <- Decls] || {contract_interface, _, Con, _, Decls} <- Interfaces ]).
+
+%% Fill the ets table functions_to_implement with functions from the implemented
+%% interfaces Impls.
+-spec populate_functions_to_implement(env(), ContractName, Impls, DefinedContracts) -> ok | no_return() when
+      ContractName :: aeso_syntax:con(),
+      Impls :: [aeso_syntax:con()],
+      DefinedContracts :: [aeso_syntax:decl()].
+populate_functions_to_implement(Env, ContractName, Impls, DefinedContracts) ->
+    create_type_errors(),
+    [ begin
+        Inserted = ets_insert_new(functions_to_implement, {name(Id), I, Decl}),
+        [{_, I2, _}] = ets_lookup(functions_to_implement, name(Id)),
+        Inserted orelse type_error({interface_implementation_conflict, ContractName, I, I2, Id})
+      end || {I, Decl = {fun_decl, _, Id, _}} <- functions_to_implement(Impls, DefinedContracts) ],
+    destroy_and_report_type_errors(Env).
 
 %% Asserts that the main contract is somehow defined.
 identify_main_contract(Contracts, Options) ->
@@ -1214,6 +1257,10 @@ check_usings(Env = #env{ used_namespaces = UsedNamespaces }, [{using, Ann, Con,
             create_type_errors(),
             type_error({using_undefined_namespace, Ann, qname(Con)}),
             destroy_and_report_type_errors(Env);
+        #scope{kind = contract} ->
+            create_type_errors(),
+            type_error({using_undefined_namespace, Ann, qname(Con)}),
+            destroy_and_report_type_errors(Env);
         Scope ->
             Nsp = case Parts of
                       none ->
@@ -1367,7 +1414,7 @@ check_named_arg(Env, {named_arg_t, Ann, Id, Type, Default}) ->
 -spec check_fields(env(), #{ name() => aeso_syntax:decl() }, type(), [aeso_syntax:field_t()]) -> env().
 check_fields(Env, _TypeMap, _, []) -> Env;
 check_fields(Env, TypeMap, RecTy, [{field_t, Ann, Id, Type} | Fields]) ->
-    Env1 = bind_field(name(Id), #field_info{ ann = Ann, kind = record, field_t = Type, record_t = RecTy }, Env),
+    Env1 = bind_field_append(name(Id), #field_info{ ann = Ann, kind = record, field_t = Type, record_t = RecTy }, Env),
     check_fields(Env1, TypeMap, RecTy, Fields).
 
 check_parameterizable({id, Ann, "event"}, [_ | _]) ->
@@ -1466,15 +1513,50 @@ check_reserved_entrypoints(Funs) ->
 -spec check_fundecl(env(), aeso_syntax:decl()) -> {{name(), typesig()}, aeso_syntax:decl()}.
 check_fundecl(Env, {fun_decl, Ann, Id = {id, _, Name}, Type = {fun_t, _, _, _, _}}) ->
     Type1 = {fun_t, _, Named, Args, Ret} = check_type(Env, Type),
-    {{Name, {type_sig, Ann, none, Named, Args, Ret}}, {fun_decl, Ann, Id, Type1}};
+    TypeSig = {type_sig, Ann, none, Named, Args, Ret},
+    register_implementation(Id, TypeSig),
+    {{Name, TypeSig}, {fun_decl, Ann, Id, Type1}};
 check_fundecl(Env, {fun_decl, Ann, Id = {id, _, Name}, Type}) ->
     type_error({fundecl_must_have_funtype, Ann, Id, Type}),
     {{Name, {type_sig, Ann, none, [], [], Type}}, check_type(Env, Type)}.
 
+%% Register the function FunId as implemented by deleting it from the functions
+%% to be implemented table if it is included there, or return true otherwise.
+-spec register_implementation(FunId, FunSig) -> true | no_return() when
+      FunId :: aeso_syntax:id(),
+      FunSig :: typesig().
+register_implementation(Id, Sig) ->
+    Name = name(Id),
+    case ets_lookup(functions_to_implement, Name) of
+        [{Name, Interface, Decl = {fun_decl, _, DeclId, _}}] ->
+            DeclStateful   = aeso_syntax:get_ann(stateful,   Decl, false),
+            DeclPayable    = aeso_syntax:get_ann(payable,    Decl, false),
+
+            SigEntrypoint = aeso_syntax:get_ann(entrypoint, Sig, false),
+            SigStateful   = aeso_syntax:get_ann(stateful,   Sig, false),
+            SigPayable    = aeso_syntax:get_ann(payable,    Sig, false),
+
+            [ type_error({function_should_be_entrypoint, Id, DeclId, Interface})
+                || not SigEntrypoint ],
+
+            [ type_error({entrypoint_cannot_be_stateful, Id, DeclId, Interface})
+                || SigStateful andalso not DeclStateful ],
+
+            [ type_error({entrypoint_must_be_payable, Id, DeclId, Interface})
+                || not SigPayable andalso DeclPayable ],
+
+            ets_delete(functions_to_implement, Name);
+        [] ->
+            true;
+        _ ->
+            error("Ets set has multiple keys")
+    end.
+
 infer_nonrec(Env, LetFun) ->
     create_constraints(),
-    NewLetFun = infer_letfun(Env, LetFun),
+    NewLetFun = {{_, Sig}, _} = infer_letfun(Env, LetFun),
     check_special_funs(Env, NewLetFun),
+    register_implementation(get_letfun_id(LetFun), Sig),
     solve_then_destroy_and_report_unsolved_constraints(Env),
     Result = {TypeSig, _} = instantiate(NewLetFun),
     print_typesig(TypeSig),
@@ -1503,7 +1585,8 @@ infer_letrec(Env, Defs) ->
     ExtendEnv = bind_funs(Funs, Env),
     Inferred =
         [ begin
-            Res    = {{Name, TypeSig}, _} = infer_letfun(ExtendEnv, LF),
+            Res    = {{Name, TypeSig}, LetFun} = infer_letfun(ExtendEnv, LF),
+            register_implementation(get_letfun_id(LetFun), TypeSig),
             Got    = proplists:get_value(Name, Funs),
             Expect = typesig_to_fun_t(TypeSig),
             unify(Env, Got, Expect, {check_typesig, Name, Got, Expect}),
@@ -1555,6 +1638,9 @@ infer_letfun1(Env0 = #env{ namespace = NS }, {letfun, Attrib, Fun = {id, NameAtt
     {{Name, TypeSig},
      {letfun, Attrib, {id, NameAttrib, Name}, TypedArgs, ResultType, NewGuardedBodies}}.
 
+get_letfun_id({fun_clauses, _, Id, _, _}) -> Id;
+get_letfun_id({letfun, _, Id, _, _, _})   -> Id.
+
 desugar_clauses(Ann, Fun, {type_sig, _, _, _, ArgTypes, RetType}, Clauses) ->
     NeedDesugar =
         case Clauses of
@@ -1632,10 +1718,14 @@ check_stateful(#env { current_function = Fun }, _Id, _Type) ->
 
 %% Hack: don't allow passing the 'value' named arg if not stateful. This only
 %% works since the user can't create functions with named arguments.
-check_stateful_named_arg(#env{ stateful = false, current_function = Fun }, {id, _, "value"}, Default) ->
+check_stateful_named_arg(#env{ stateful = Stateful, current_function = Fun }, {id, _, "value"}, Default) ->
     case Default of
         {int, _, 0} -> ok;
-        _           -> type_error({value_arg_not_allowed, Default, Fun})
+        _           ->
+            case Stateful of
+                true  -> when_warning(warn_unused_stateful, fun() -> used_stateful(Fun) end);
+                false -> type_error({value_arg_not_allowed, Default, Fun})
+            end
     end;
 check_stateful_named_arg(_, _, _) -> ok.
 
@@ -1753,6 +1843,10 @@ infer_expr(_Env, Body={contract_pubkey, As, _}) ->
     {typed, As, Body, Con};
 infer_expr(_Env, Body={id, As, "_"}) ->
     {typed, As, Body, fresh_uvar(As)};
+infer_expr(_Env, Body={id, As, "???"}) ->
+    T = fresh_uvar(As),
+    type_error({hole_found, As, T}),
+    {typed, As, Body, T};
 infer_expr(Env, Id = {Tag, As, _}) when Tag == id; Tag == qid ->
     {QName, Type} = lookup_name(Env, As, Id),
     {typed, As, QName, Type};
@@ -2204,7 +2298,7 @@ next_count() ->
 ets_tables() ->
     [options, type_vars, constraints, freshen_tvars, type_errors,
      defined_contracts, warnings, function_calls, all_functions,
-     type_vars_variance].
+     type_vars_variance, functions_to_implement].
 
 clean_up_ets() ->
     [ catch ets_delete(Tab) || Tab <- ets_tables() ],
@@ -2240,10 +2334,18 @@ ets_delete(Name) ->
     put(aeso_ast_infer_types, maps:remove(Name, Tabs)),
     ets:delete(TabId).
 
+ets_delete(Name, Key) ->
+    TabId = ets_tabid(Name),
+    ets:delete(TabId, Key).
+
 ets_insert(Name, Object) ->
     TabId = ets_tabid(Name),
     ets:insert(TabId, Object).
 
+ets_insert_new(Name, Object) ->
+    TabId = ets_tabid(Name),
+    ets:insert_new(TabId, Object).
+
 ets_lookup(Name, Key) ->
     TabId = ets_tabid(Name),
     ets:lookup(TabId, Key).
@@ -2310,7 +2412,12 @@ solve_constraints(Env) ->
                field_t  = FieldType,
                kind     = Kind,
                context  = When }) ->
-                case lookup_record_field(Env, FieldName, Kind) of
+                Arity = fun_arity(dereference_deep(FieldType)),
+                FieldInfos = case Arity of
+                                 none -> lookup_record_field(Env, FieldName, Kind);
+                                 _    -> lookup_record_field_arity(Env, FieldName, Arity, Kind)
+                             end,
+                case FieldInfos of
                     [] ->
                         type_error({undefined_field, Field}),
                         false;
@@ -2805,6 +2912,8 @@ unify0(Env, A, B, Variance, When) ->
 
 unify1(_Env, {uvar, _, R}, {uvar, _, R}, _Variance, _When) ->
     true;
+unify1(_Env, {uvar, _, _}, {fun_t, _, _, var_args, _}, _Variance, When) ->
+    type_error({unify_varargs, When});
 unify1(Env, {uvar, A, R}, T, _Variance, When) ->
     case occurs_check(R, T) of
         true ->
@@ -2828,6 +2937,12 @@ unify1(Env, [A|B], [C|D], Variance, When) ->
     unify0(Env, A, C, Variance, When) andalso unify0(Env, B, D, Variance, When);
 unify1(_Env, X, X, _Variance, _When) ->
     true;
+unify1(_Env, _A, {id, _, "void"}, Variance, _When)
+  when Variance == covariant orelse Variance == bivariant ->
+    true;
+unify1(_Env, {id, _, "void"}, _B, Variance, _When)
+  when Variance == contravariant orelse Variance == bivariant ->
+    true;
 unify1(_Env, {id, _, Name}, {id, _, Name}, _Variance, _When) ->
     true;
 unify1(Env, A = {con, _, NameA}, B = {con, _, NameB}, Variance, When) ->
@@ -3285,6 +3400,9 @@ mk_error({cannot_unify, A, B, Cxt, When}) ->
                         [pp(instantiate(A)), pp(instantiate(B))]),
     {Pos, Ctxt} = pp_when(When),
     mk_t_err(Pos, Msg, Ctxt);
+mk_error({hole_found, Ann, Type}) ->
+    Msg = io_lib:format("Found a hole of type `~s`", [pp(instantiate(Type))]),
+    mk_t_err(pos(Ann), Msg);
 mk_error({unbound_variable, Id}) ->
     Msg = io_lib:format("Unbound variable `~s`", [pp(Id)]),
     case Id of
@@ -3568,7 +3686,7 @@ mk_error({multiple_main_contracts, Ann}) ->
     Msg = "Only one main contract can be defined.",
     mk_t_err(pos(Ann), Msg);
 mk_error({unify_varargs, When}) ->
-    Msg = "Cannot unify variable argument list.",
+    Msg = "Cannot infer types for variable argument list.",
     {Pos, Ctxt} = pp_when(When),
     mk_t_err(Pos, Msg, Ctxt);
 mk_error({clone_no_contract, Ann}) ->
@@ -3600,7 +3718,7 @@ mk_error({empty_record_definition, Ann, Name}) ->
     Msg = io_lib:format("Empty record definitions are not allowed. Cannot define the record `~s`", [Name]),
     mk_t_err(pos(Ann), Msg);
 mk_error({unimplemented_interface_function, ConId, InterfaceName, FunName}) ->
-    Msg = io_lib:format("Unimplemented function `~s` from the interface `~s` in the contract `~s`", [FunName, InterfaceName, pp(ConId)]),
+    Msg = io_lib:format("Unimplemented entrypoint `~s` from the interface `~s` in the contract `~s`", [FunName, InterfaceName, pp(ConId)]),
     mk_t_err(pos(ConId), Msg);
 mk_error({referencing_undefined_interface, InterfaceId}) ->
     Msg = io_lib:format("Trying to implement or extend an undefined interface `~s`", [pp(InterfaceId)]),
@@ -3643,6 +3761,34 @@ mk_error({invalid_oracle_type, Why, What, Ann, Type}) ->
     Msg = io_lib:format("Invalid oracle type\n~s`", [pp_type("  `", Type)]),
     Cxt = io_lib:format("The ~s type must not be ~s", [What, WhyS]),
     mk_t_err(pos(Ann), Msg, Cxt);
+mk_error({interface_implementation_conflict, Contract, I1, I2, Fun}) ->
+    Msg = io_lib:format("Both interfaces `~s` and `~s` implemented by "
+                        "the contract `~s` have a function called `~s`",
+                        [name(I1), name(I2), name(Contract), name(Fun)]),
+    mk_t_err(pos(Contract), Msg);
+mk_error({function_should_be_entrypoint, Impl, Base, Interface}) ->
+    Msg = io_lib:format("`~s` must be declared as an entrypoint instead of a function "
+                        "in order to implement the entrypoint `~s` from the interface `~s`",
+                        [name(Impl), name(Base), name(Interface)]),
+    mk_t_err(pos(Impl), Msg);
+mk_error({entrypoint_cannot_be_stateful, Impl, Base, Interface}) ->
+    Msg = io_lib:format("`~s` cannot be stateful because the entrypoint `~s` in the "
+                        "interface `~s` is not stateful",
+                        [name(Impl), name(Base), name(Interface)]),
+    mk_t_err(pos(Impl), Msg);
+mk_error({entrypoint_must_be_payable, Impl, Base, Interface}) ->
+    Msg = io_lib:format("`~s` must be payable because the entrypoint `~s` in the "
+                        "interface `~s` is payable",
+                        [name(Impl), name(Base), name(Interface)]),
+    mk_t_err(pos(Impl), Msg);
+mk_error({unpreserved_payablity, Kind, ContractCon, InterfaceCon}) ->
+    KindStr = case Kind of
+                  contract -> "contract";
+                  contract_interface -> "interface"
+              end,
+    Msg = io_lib:format("Non-payable ~s `~s` cannot implement payable interface `~s`",
+                        [KindStr, name(ContractCon), name(InterfaceCon)]),
+    mk_t_err(pos(ContractCon), Msg);
 mk_error(Err) ->
     Msg = io_lib:format("Unknown error: ~p", [Err]),
     mk_t_err(pos(0, 0), Msg).

src/aeso_ast_to_fcode.erl

@@ -149,17 +149,18 @@
 
 -type state_layout() :: {tuple, [state_layout()]} | {reg, state_reg()}.
 
--type env() :: #{ type_env      := type_env(),
-                  fun_env       := fun_env(),
-                  con_env       := con_env(),
-                  child_con_env := child_con_env(),
-                  event_type    => aeso_syntax:typedef(),
-                  builtins      := builtins(),
-                  options       := [option()],
-                  state_layout  => state_layout(),
-                  context       => context(),
-                  vars          => [var_name()],
-                  functions     := #{ fun_name() => fun_def() }
+-type env() :: #{ type_env          := type_env(),
+                  fun_env           := fun_env(),
+                  con_env           := con_env(),
+                  child_con_env     := child_con_env(),
+                  event_type        => aeso_syntax:typedef(),
+                  builtins          := builtins(),
+                  options           := [option()],
+                  state_layout      => state_layout(),
+                  context           => context(),
+                  vars              => [var_name()],
+                  functions         := #{ fun_name() => fun_def() },
+                  saved_fresh_names => #{ var_name() => var_name() }
                }.
 
 -define(HASH_BYTES, 32).
@@ -170,7 +171,7 @@
 %% and produces Fate intermediate code.
 -spec ast_to_fcode(aeso_syntax:ast(), [option()]) -> {env(), fcode()}.
 ast_to_fcode(Code, Options) ->
-    init_fresh_names(),
+    init_fresh_names(Options),
     {Env1, FCode1} = to_fcode(init_env(Options), Code),
     FCode2 = optimize(FCode1, Options),
     Env2 = Env1#{ child_con_env :=
@@ -178,13 +179,18 @@ ast_to_fcode(Code, Options) ->
                         fun (_, FC) -> optimize(FC, Options) end,
                         maps:get(child_con_env, Env1)
                        )},
-    clear_fresh_names(),
-    {Env2, FCode2}.
+    Env3 =
+        case proplists:get_value(debug_info, Options, false) of
+            true  -> Env2#{ saved_fresh_names => get(saved_fresh_names) };
+            false -> Env2
+        end,
+    clear_fresh_names(Options),
+    {Env3, FCode2}.
 
 optimize(FCode1, Options) ->
     Verbose = lists:member(pp_fcode, Options),
     [io:format("-- Before lambda lifting --\n~s\n\n", [format_fcode(FCode1)]) || Verbose],
-    FCode2 = optimize_fcode(FCode1),
+    FCode2 = optimize_fcode(FCode1, Options),
     [ io:format("-- After optimization --\n~s\n\n", [format_fcode(FCode2)]) || Verbose, FCode2 /= FCode1 ],
     FCode3 = lambda_lift(FCode2),
     [ io:format("-- After lambda lifting --\n~s\n\n", [format_fcode(FCode3)]) || Verbose, FCode3 /= FCode2 ],
@@ -1287,20 +1293,28 @@ lambda_lift_exprs(Layout, As) -> [lambda_lift_expr(Layout, A) || A <- As].
 %% - Constant propagation
 %% - Inlining
 
--spec optimize_fcode(fcode()) -> fcode().
-optimize_fcode(Code = #{ functions := Funs }) ->
-    Code1 = Code#{ functions := maps:map(fun(Name, Def) -> optimize_fun(Code, Name, Def) end, Funs) },
+-spec optimize_fcode(fcode(), [option()]) -> fcode().
+optimize_fcode(Code = #{ functions := Funs }, Options) ->
+    Code1 = Code#{ functions := maps:map(fun(Name, Def) -> optimize_fun(Code, Name, Def, Options) end, Funs) },
     eliminate_dead_code(Code1).
 
--spec optimize_fun(fcode(), fun_name(), fun_def()) -> fun_def().
-optimize_fun(Fcode, Fun, Def = #{ body := Body }) ->
-    %% io:format("Optimizing ~p =\n~s\n", [_Fun, prettypr:format(pp_fexpr(_Body))]),
-    Def#{ body := drop_unused_lets(
-                  simplifier(
-                  let_floating(
-                  bind_subexpressions(
-                  inline_local_functions(
-                  inliner(Fcode, Fun, Body)))))) }.
+-spec optimize_fun(fcode(), fun_name(), fun_def(), [option()]) -> fun_def().
+optimize_fun(Fcode, Fun, Def = #{ body := Body0 }, Options) ->
+    Inliner              = proplists:get_value(optimize_inliner,                Options, true),
+    InlineLocalFunctions = proplists:get_value(optimize_inline_local_functions, Options, true),
+    BindSubexpressions   = proplists:get_value(optimize_bind_subexpressions,    Options, true),
+    LetFloating          = proplists:get_value(optimize_let_floating,           Options, true),
+    Simplifier           = proplists:get_value(optimize_simplifier,             Options, true),
+    DropUnusedLets       = proplists:get_value(optimize_drop_unused_lets,       Options, true),
+
+    Body1 = if Inliner              -> inliner   (Fcode, Fun, Body0); true -> Body0 end,
+    Body2 = if InlineLocalFunctions -> inline_local_functions(Body1); true -> Body1 end,
+    Body3 = if BindSubexpressions   -> bind_subexpressions   (Body2); true -> Body2 end,
+    Body4 = if LetFloating          -> let_floating          (Body3); true -> Body3 end,
+    Body5 = if Simplifier           -> simplifier            (Body4); true -> Body4 end,
+    Body6 = if DropUnusedLets       -> drop_unused_lets      (Body5); true -> Body5 end,
+
+    Def#{ body := Body6 }.
 
 %% --- Inlining ---
 
@@ -1720,12 +1734,29 @@ resolve_fun(#{ fun_env := Funs, builtins := Builtin } = Env, Q) ->
         {{Fun, Ar}, _}         -> {def_u, Fun, Ar}
     end.
 
-init_fresh_names() ->
+init_fresh_names(Options) ->
+    proplists:get_value(debug_info, Options, false) andalso init_saved_fresh_names(),
     put('%fresh', 0).
 
-clear_fresh_names() ->
+clear_fresh_names(Options) ->
+    proplists:get_value(debug_info, Options, false) andalso clear_saved_fresh_names(),
     erase('%fresh').
 
+init_saved_fresh_names() ->
+    put(saved_fresh_names, #{}).
+
+clear_saved_fresh_names() ->
+    erase(saved_fresh_names).
+
+-spec fresh_name_save(string()) -> var_name().
+fresh_name_save(Name) ->
+    Fresh = fresh_name(),
+    case get(saved_fresh_names) of
+        undefined -> ok;
+        Old       -> put(saved_fresh_names, Old#{Fresh => Name})
+    end,
+    Fresh.
+
 -spec fresh_name() -> var_name().
 fresh_name() -> fresh_name("%").
 
@@ -1854,7 +1885,7 @@ bottom_up(F, Env, Expr) ->
                                (_)            -> true end,
             case ShouldFreshen(X) of
                 true ->
-                    Z = fresh_name(),
+                    Z = fresh_name_save(X),
                     Env1 = Env#{ Z => E1 },
                     {'let', Z, E1, bottom_up(F, Env1, rename([{X, Z}], Body))};
                 false ->

src/aeso_compiler.erl

@@ -112,10 +112,12 @@ from_string(ContractString, Options) ->
 
 from_string1(ContractString, Options) ->
     #{ fcode := FCode
-     , fcode_env := #{child_con_env := ChildContracts}
+     , fcode_env := FCodeEnv
      , folded_typed_ast := FoldedTypedAst
      , warnings := Warnings } = string_to_code(ContractString, Options),
-    FateCode = aeso_fcode_to_fate:compile(ChildContracts, FCode, Options),
+    #{ child_con_env := ChildContracts } = FCodeEnv,
+    SavedFreshNames = maps:get(saved_fresh_names, FCodeEnv, #{}),
+    {FateCode, VarsRegs} = aeso_fcode_to_fate:compile(ChildContracts, FCode, SavedFreshNames, Options),
     pp_assembler(FateCode, Options),
     ByteCode = aeb_fate_code:serialize(FateCode, []),
     {ok, Version} = version(),
@@ -128,7 +130,13 @@ from_string1(ContractString, Options) ->
             payable => maps:get(payable, FCode),
             warnings => Warnings
            },
-    {ok, maybe_generate_aci(Res, FoldedTypedAst, Options)}.
+    ResDbg = Res#{variables_registers => VarsRegs},
+    FinalRes =
+        case proplists:get_value(debug_info, Options, false) of
+            true  -> ResDbg;
+            false -> Res
+        end,
+    {ok, maybe_generate_aci(FinalRes, FoldedTypedAst, Options)}.
 
 maybe_generate_aci(Result, FoldedTypedAst, Options) ->
     case proplists:get_value(aci, Options) of
@@ -185,7 +193,7 @@ check_call1(ContractString0, FunName, Args, Options) ->
         #{fcode := OrgFcode
         , fcode_env := #{child_con_env := ChildContracts}
         , ast := Ast} = string_to_code(ContractString0, Options),
-        FateCode = aeso_fcode_to_fate:compile(ChildContracts, OrgFcode, []),
+        {FateCode, _} = aeso_fcode_to_fate:compile(ChildContracts, OrgFcode, #{}, []),
         %% collect all hashes and compute the first name without hash collision to
         SymbolHashes = maps:keys(aeb_fate_code:symbols(FateCode)),
         CallName = first_none_match(?CALL_NAME, SymbolHashes,

src/aeso_fcode_to_fate.erl

@@ -9,7 +9,7 @@
 %%%-------------------------------------------------------------------
 -module(aeso_fcode_to_fate).
 
--export([compile/2, compile/3, term_to_fate/1, term_to_fate/2]).
+-export([compile/3, compile/4, term_to_fate/1, term_to_fate/2]).
 
 -ifdef(TEST).
 -export([optimize_fun/4, to_basic_blocks/1]).
@@ -45,7 +45,14 @@
 -define(s(N), {store, N}).
 -define(void, {var, 9999}).
 
--record(env, { contract, vars = [], locals = [], current_function, tailpos = true, child_contracts = #{}, options = []}).
+-record(env, { contract,
+               vars              = [],
+               locals            = [],
+               current_function,
+               tailpos           = true,
+               child_contracts   = #{},
+               saved_fresh_names = #{},
+               options           = [] }).
 
 %% -- Debugging --------------------------------------------------------------
 
@@ -71,16 +78,27 @@ code_error(Err) ->
 %% -- Main -------------------------------------------------------------------
 
 %% @doc Main entry point.
-compile(FCode, Options) ->
-    compile(#{}, FCode, Options).
-compile(ChildContracts, FCode, Options) ->
+compile(FCode, SavedFreshNames, Options) ->
+    compile(#{}, FCode, SavedFreshNames, Options).
+compile(ChildContracts, FCode, SavedFreshNames, Options) ->
+    try
+        compile1(ChildContracts, FCode, SavedFreshNames, Options)
+    after
+        put(variables_registers, undefined)
+    end.
+
+compile1(ChildContracts, FCode, SavedFreshNames, Options) ->
     #{ contract_name := ContractName,
        functions     := Functions } = FCode,
-    SFuns  = functions_to_scode(ChildContracts, ContractName, Functions, Options),
+    SFuns  = functions_to_scode(ChildContracts, ContractName, Functions, SavedFreshNames, Options),
     SFuns1 = optimize_scode(SFuns, Options),
     FateCode = to_basic_blocks(SFuns1),
     ?debug(compile, Options, "~s\n", [aeb_fate_asm:pp(FateCode)]),
-    FateCode.
+    FateCode1 = case proplists:get_value(include_child_contract_symbols, Options, false) of
+                    false -> FateCode;
+                    true -> add_child_symbols(ChildContracts, FateCode)
+                end,
+    {FateCode1, get_variables_registers()}.
 
 make_function_id(X) ->
     aeb_fate_code:symbol_identifier(make_function_name(X)).
@@ -89,22 +107,48 @@ make_function_name(event)              -> <<"Chain.event">>;
 make_function_name({entrypoint, Name}) -> Name;
 make_function_name({local_fun, Xs})    -> list_to_binary("." ++ string:join(Xs, ".")).
 
-functions_to_scode(ChildContracts, ContractName, Functions, Options) ->
+add_child_symbols(ChildContracts, FateCode) ->
+    Funs = lists:flatten([ maps:keys(ChildFuns) || {_, #{functions := ChildFuns}} <- maps:to_list(ChildContracts) ]),
+    Symbols = maps:from_list([ {make_function_id(FName), make_function_name(FName)} || FName <- Funs ]),
+    aeb_fate_code:update_symbols(FateCode, Symbols).
+
+functions_to_scode(ChildContracts, ContractName, Functions, SavedFreshNames, Options) ->
     FunNames = maps:keys(Functions),
     maps:from_list(
-        [ {make_function_name(Name), function_to_scode(ChildContracts, ContractName, FunNames, Name, Attrs, Args, Body, Type, Options)}
+        [ {make_function_name(Name), function_to_scode(ChildContracts, ContractName, FunNames, Name, Attrs, Args, Body, Type, SavedFreshNames, Options)}
         || {Name, #{args   := Args,
                     body   := Body,
                     attrs  := Attrs,
                     return := Type}} <- maps:to_list(Functions)]).
 
-function_to_scode(ChildContracts, ContractName, Functions, Name, Attrs0, Args, Body, ResType, Options) ->
+function_to_scode(ChildContracts, ContractName, Functions, Name, Attrs0, Args, Body, ResType, SavedFreshNames, Options) ->
     {ArgTypes, ResType1} = typesig_to_scode(Args, ResType),
     Attrs = Attrs0 -- [stateful], %% Only track private and payable from here.
-    Env = init_env(ChildContracts, ContractName, Functions, Name, Args, Options),
+    Env = init_env(ChildContracts, ContractName, Functions, Name, Args, SavedFreshNames, Options),
+    [ add_variables_register(Env, Arg, Register) ||
+        proplists:get_value(debug_info, Options, false),
+        {Arg, Register} <- Env#env.vars ],
     SCode = to_scode(Env, Body),
     {Attrs, {ArgTypes, ResType1}, SCode}.
 
+get_variables_registers() ->
+    case get(variables_registers) of
+        undefined -> #{};
+        Vs        -> Vs
+    end.
+
+add_variables_register(Env = #env{saved_fresh_names = SavedFreshNames}, Name, Register) ->
+    Olds = get_variables_registers(),
+    RealName = maps:get(Name, SavedFreshNames, Name),
+    FunName =
+        case Env#env.current_function of
+            event -> "Chain.event";
+            {entrypoint, BinName} -> binary_to_list(BinName);
+            {local_fun, QualName} -> lists:last(QualName)
+        end,
+    New = {Env#env.contract, FunName, RealName},
+    put(variables_registers, Olds#{New => Register}).
+
 -define(tvars, '$tvars').
 
 typesig_to_scode(Args, Res) ->
@@ -149,19 +193,21 @@ types_to_scode(Ts) -> lists:map(fun type_to_scode/1, Ts).
 
 %% -- Environment functions --
 
-init_env(ChildContracts, ContractName, FunNames, Name, Args, Options) ->
+init_env(ChildContracts, ContractName, FunNames, Name, Args, SavedFreshNames, Options) ->
     #env{ vars      = [ {X, {arg, I}} || {I, {X, _}} <- with_ixs(Args) ],
           contract  = ContractName,
           child_contracts = ChildContracts,
           locals    = FunNames,
           current_function = Name,
           options = Options,
-          tailpos   = true }.
+          tailpos   = true,
+          saved_fresh_names = SavedFreshNames }.
 
 next_var(#env{ vars = Vars }) ->
     1 + lists:max([-1 | [J || {_, {var, J}} <- Vars]]).
 
 bind_var(Name, Var, Env = #env{ vars = Vars }) ->
+    proplists:get_value(debug_info, Env#env.options, false) andalso add_variables_register(Env, Name, Var),
     Env#env{ vars = [{Name, Var} | Vars] }.
 
 bind_local(Name, Env) ->
@@ -185,9 +231,10 @@ serialize_contract_code(Env, C) ->
             end,
     case maps:get(C, Cache, none) of
         none ->
-            Options  = Env#env.options,
-            FCode    = maps:get(C, Env#env.child_contracts),
-            FateCode = compile(Env#env.child_contracts, FCode, Options),
+            Options = Env#env.options,
+            SavedFreshNames = Env#env.saved_fresh_names,
+            FCode = maps:get(C, Env#env.child_contracts),
+            {FateCode, _} = compile1(Env#env.child_contracts, FCode, SavedFreshNames, Options),
             ByteCode = aeb_fate_code:serialize(FateCode, []),
             {ok, Version} = aeso_compiler:version(),
             OriginalSourceCode = proplists:get_value(original_src, Options, ""),
@@ -709,7 +756,7 @@ tuple(N) -> aeb_fate_ops:tuple(?a, N).
 
 optimize_scode(Funs, Options) ->
     maps:map(fun(Name, Def) -> optimize_fun(Funs, Name, Def, Options) end,
-             Funs).
+            Funs).
 
 flatten(missing) -> missing;
 flatten(Code)    -> lists:map(fun flatten_s/1, lists:flatten(Code)).
@@ -1092,7 +1139,8 @@ simpl_top(I, Code, Options) ->
 simpl_top(0, I, Code, _Options) ->
     code_error({optimizer_out_of_fuel, I, Code});
 simpl_top(Fuel, I, Code, Options) ->
-    apply_rules(Fuel, rules(), I, Code, Options).
+    Rules = [R || R = {Rule, _} <- rules(), proplists:get_value(Rule, Options, true)],
+    apply_rules(Fuel, Rules, I, Code, Options).
 
 apply_rules(Fuel, Rules, I, Code, Options) ->
     Cons = fun(X, Xs) -> simpl_top(Fuel - 1, X, Xs, Options) end,
@@ -1119,29 +1167,29 @@ apply_rules_once([{RName, Rule} | Rules], I, Code) ->
 -define(RULE(Name), {Name, fun Name/2}).
 
 merge_rules() ->
-    [?RULE(r_push_consume),
-     ?RULE(r_one_shot_var),
-     ?RULE(r_write_to_dead_var),
-     ?RULE(r_inline_switch_target)
+    [?RULE(optimize_push_consume),
+     ?RULE(optimize_one_shot_var),
+     ?RULE(optimize_write_to_dead_var),
+     ?RULE(optimize_inline_switch_target)
     ].
 
 rules() ->
     merge_rules() ++
-    [?RULE(r_swap_push),
-     ?RULE(r_swap_pop),
-     ?RULE(r_swap_write),
-     ?RULE(r_constant_propagation),
-     ?RULE(r_prune_impossible_branches),
-     ?RULE(r_single_successful_branch),
-     ?RULE(r_inline_store),
-     ?RULE(r_float_switch_body)
+    [?RULE(optimize_swap_push),
+     ?RULE(optimize_swap_pop),
+     ?RULE(optimize_swap_write),
+     ?RULE(optimize_constant_propagation),
+     ?RULE(optimize_prune_impossible_branches),
+     ?RULE(optimize_single_successful_branch),
+     ?RULE(optimize_inline_store),
+     ?RULE(optimize_float_switch_body)
     ].
 
 %% Removing pushes that are immediately consumed.
-r_push_consume({i, Ann1, {'STORE', ?a, A}}, Code) ->
+optimize_push_consume({i, Ann1, {'STORE', ?a, A}}, Code) ->
     inline_push(Ann1, A, 0, Code, []);
 %% Writing directly to memory instead of going through the accumulator.
-r_push_consume({i, Ann1, I}, [{i, Ann2, {'STORE', R, ?a}} | Code]) ->
+optimize_push_consume({i, Ann1, I}, [{i, Ann2, {'STORE', R, ?a}} | Code]) ->
     IsPush =
         case op_view(I) of
             {_, ?a, _} -> true;
@@ -1153,7 +1201,7 @@ r_push_consume({i, Ann1, I}, [{i, Ann2, {'STORE', R, ?a}} | Code]) ->
         end,
     if IsPush -> {[{i, merge_ann(Ann1, Ann2), setelement(2, I, R)}], Code};
        true   -> false end;
-r_push_consume(_, _) -> false.
+optimize_push_consume(_, _) -> false.
 
 inline_push(Ann, Arg, Stack, [{i, _, switch_body} = AI | Code], Acc) ->
     {AI1, {i, Ann1, _}} = swap_instrs({i, Ann, {'STORE', ?a, Arg}}, AI),
@@ -1186,7 +1234,7 @@ split_stack_arg(N, [A | As], Acc) ->
     split_stack_arg(N1, As, [A | Acc]).
 
 %% Move PUSHes past non-stack instructions.
-r_swap_push(Push = {i, _, PushI}, [I | Code]) ->
+optimize_swap_push(Push = {i, _, PushI}, [I | Code]) ->
     case op_view(PushI) of
         {_, ?a, _} ->
             case independent(Push, I) of
@@ -1197,10 +1245,10 @@ r_swap_push(Push = {i, _, PushI}, [I | Code]) ->
             end;
         _ -> false
     end;
-r_swap_push(_, _) -> false.
+optimize_swap_push(_, _) -> false.
 
 %% Move non-stack instruction past POPs.
-r_swap_pop(IA = {i, _, I}, [JA = {i, _, J} | Code]) ->
+optimize_swap_pop(IA = {i, _, I}, [JA = {i, _, J} | Code]) ->
     case independent(IA, JA) of
         true ->
             case {op_view(I), op_view(J)} of
@@ -1208,7 +1256,7 @@ r_swap_pop(IA = {i, _, I}, [JA = {i, _, J} | Code]) ->
                 {_, false} -> false;
                 {{_, IR, IAs}, {_, RJ, JAs}} ->
                     NonStackI = not lists:member(?a, [IR | IAs]),
-                    %% RJ /= ?a to not conflict with r_swap_push
+                    %% RJ /= ?a to not conflict with optimize_swap_push
                     PopJ      = RJ /= ?a andalso lists:member(?a, JAs),
                     case NonStackI andalso PopJ of
                         false -> false;
@@ -1219,22 +1267,22 @@ r_swap_pop(IA = {i, _, I}, [JA = {i, _, J} | Code]) ->
             end;
         false -> false
     end;
-r_swap_pop(_, _) -> false.
+optimize_swap_pop(_, _) -> false.
 
 %% Match up writes to variables with instructions further down.
-r_swap_write(I = {i, _, _}, [J | Code]) ->
+optimize_swap_write(I = {i, _, _}, [J | Code]) ->
     case {var_writes(I), independent(I, J)} of
         {[_], true} ->
             {J1, I1} = swap_instrs(I, J),
-            r_swap_write([J1], I1, Code);
+            optimize_swap_write([J1], I1, Code);
         _ -> false
     end;
-r_swap_write(_, _) -> false.
+optimize_swap_write(_, _) -> false.
 
-r_swap_write(Pre, I, [{i, _, switch_body} = J | Code]) ->
+optimize_swap_write(Pre, I, [{i, _, switch_body} = J | Code]) ->
     {J1, I1} = swap_instrs(I, J),
-    r_swap_write([J1 | Pre], I1, Code);
-r_swap_write(Pre, I, Code0 = [J | Code]) ->
+    optimize_swap_write([J1 | Pre], I1, Code);
+optimize_swap_write(Pre, I, Code0 = [J | Code]) ->
     case apply_rules_once(merge_rules(), I, Code0) of
         {_Rule, New, Rest} ->
             {lists:reverse(Pre) ++ New, Rest};
@@ -1243,27 +1291,27 @@ r_swap_write(Pre, I, Code0 = [J | Code]) ->
                 false -> false;
                 true  ->
                     {J1, I1} = swap_instrs(I, J),
-                    r_swap_write([J1 | Pre], I1, Code)
+                    optimize_swap_write([J1 | Pre], I1, Code)
             end
     end;
-r_swap_write(_, _, _) -> false.
+optimize_swap_write(_, _, _) -> false.
 
 %% Precompute instructions with known values
-r_constant_propagation(Cons = {i, Ann1, {'CONS', R, X, Xs}}, [{i, Ann, {'IS_NIL', S, R}} | Code]) ->
+optimize_constant_propagation(Cons = {i, Ann1, {'CONS', R, X, Xs}}, [{i, Ann, {'IS_NIL', S, R}} | Code]) ->
     Store = {i, Ann, {'STORE', S, ?i(false)}},
     Cons1 = case R of
                 ?a -> {i, Ann1, {'CONS', ?void, X, Xs}};
                 _  -> Cons
             end,
     {[Cons1, Store], Code};
-r_constant_propagation(Nil = {i, Ann1, {'NIL', R}}, [{i, Ann, {'IS_NIL', S, R}} | Code]) ->
+optimize_constant_propagation(Nil = {i, Ann1, {'NIL', R}}, [{i, Ann, {'IS_NIL', S, R}} | Code]) ->
     Store = {i, Ann, {'STORE', S, ?i(true)}},
     Nil1 = case R of
                ?a -> {i, Ann1, {'NIL', ?void}};
                _  -> Nil
            end,
     {[Nil1, Store], Code};
-r_constant_propagation({i, Ann, I}, Code) ->
+optimize_constant_propagation({i, Ann, I}, Code) ->
     case op_view(I) of
         false -> false;
         {Op, R, As} ->
@@ -1277,7 +1325,7 @@ r_constant_propagation({i, Ann, I}, Code) ->
                     end
             end
     end;
-r_constant_propagation(_, _) -> false.
+optimize_constant_propagation(_, _) -> false.
 
 eval_op('ADD', [X, Y]) when is_integer(X), is_integer(Y) -> X + Y;
 eval_op('SUB', [X, Y]) when is_integer(X), is_integer(Y) -> X - Y;
@@ -1296,12 +1344,12 @@ eval_op('NOT', [false]) -> true;
 eval_op(_, _)           -> no_eval.   %% TODO: bits?
 
 %% Prune impossible branches from switches
-r_prune_impossible_branches({switch, ?i(V), Type, Alts, missing}, Code) ->
+optimize_prune_impossible_branches({switch, ?i(V), Type, Alts, missing}, Code) ->
     case pick_branch(Type, V, Alts) of
         false -> false;
         Alt   -> {Alt, Code}
     end;
-r_prune_impossible_branches({switch, ?i(V), boolean, [False, True] = Alts, Def}, Code) when V == true; V == false ->
+optimize_prune_impossible_branches({switch, ?i(V), boolean, [False, True] = Alts, Def}, Code) when V == true; V == false ->
     Alts1 = [if V -> missing; true -> False   end,
              if V -> True;    true -> missing end],
     case Alts == Alts1 of
@@ -1312,7 +1360,7 @@ r_prune_impossible_branches({switch, ?i(V), boolean, [False, True] = Alts, Def},
                 _                  -> {[{switch, ?i(V), boolean, Alts1, Def}], Code}
             end
     end;
-r_prune_impossible_branches(Variant = {i, _, {'VARIANT', R, ?i(_), ?i(Tag), ?i(_)}},
+optimize_prune_impossible_branches(Variant = {i, _, {'VARIANT', R, ?i(_), ?i(Tag), ?i(_)}},
                             [{switch, R, Type = {variant, _}, Alts, missing} | Code]) when is_integer(Tag) ->
     case {R, lists:nth(Tag + 1, Alts)} of
         {_, missing} ->
@@ -1328,7 +1376,7 @@ r_prune_impossible_branches(Variant = {i, _, {'VARIANT', R, ?i(_), ?i(Tag), ?i(_
                 false -> {Alt, Code}
             end
     end;
-r_prune_impossible_branches(_, _) -> false.
+optimize_prune_impossible_branches(_, _) -> false.
 
 pick_branch(boolean, V, [False, True]) when V == true; V == false ->
     Alt = if V -> True; true -> False end,
@@ -1341,7 +1389,7 @@ pick_branch(_Type, _V, _Alts) ->
 
 %% If there's a single branch that doesn't abort we can push the code for that
 %% out of the switch.
-r_single_successful_branch({switch, R, Type, Alts, Def}, Code) ->
+optimize_single_successful_branch({switch, R, Type, Alts, Def}, Code) ->
     case push_code_out_of_switch([Def | Alts]) of
         {_, none} -> false;
         {_, many} -> false;
@@ -1349,7 +1397,7 @@ r_single_successful_branch({switch, R, Type, Alts, Def}, Code) ->
         {[Def1 | Alts1], PushedOut} ->
             {[{switch, R, Type, Alts1, Def1} | PushedOut], Code}
     end;
-r_single_successful_branch(_, _) -> false.
+optimize_single_successful_branch(_, _) -> false.
 
 push_code_out_of_switch([]) -> {[], none};
 push_code_out_of_switch([Alt | Alts]) ->
@@ -1385,7 +1433,7 @@ does_abort({switch, _, _, Alts, Def}) ->
 does_abort(_) -> false.
 
 %% STORE R A, SWITCH R --> SWITCH A
-r_inline_switch_target({i, Ann, {'STORE', R, A}}, [{switch, R, Type, Alts, Def} | Code]) ->
+optimize_inline_switch_target({i, Ann, {'STORE', R, A}}, [{switch, R, Type, Alts, Def} | Code]) ->
     Ann1   =
         case is_reg(A) of
             true  -> Ann#{ live_out := ordsets:add_element(A, maps:get(live_out, Ann)) };
@@ -1404,18 +1452,18 @@ r_inline_switch_target({i, Ann, {'STORE', R, A}}, [{switch, R, Type, Alts, Def}
             end;
         _        -> false %% impossible
     end;
-r_inline_switch_target(_, _) -> false.
+optimize_inline_switch_target(_, _) -> false.
 
 %% Float switch-body to closest switch
-r_float_switch_body(I = {i, _, _}, [J = {i, _, switch_body} | Code]) ->
+optimize_float_switch_body(I = {i, _, _}, [J = {i, _, switch_body} | Code]) ->
     {J1, I1} = swap_instrs(I, J),
     {[], [J1, I1 | Code]};
-r_float_switch_body(_, _) -> false.
+optimize_float_switch_body(_, _) -> false.
 
 %% Inline stores
-r_inline_store({i, _, {'STORE', R, R}}, Code) ->
+optimize_inline_store({i, _, {'STORE', R, R}}, Code) ->
     {[], Code};
-r_inline_store(I = {i, _, {'STORE', R = {var, _}, A}}, Code) ->
+optimize_inline_store(I = {i, _, {'STORE', R = {var, _}, A}}, Code) ->
     %% Not when A is var unless updating the annotations properly.
     Inline = case A of
                  {arg, _}   -> true;
@@ -1423,13 +1471,13 @@ r_inline_store(I = {i, _, {'STORE', R = {var, _}, A}}, Code) ->
                  {store, _} -> true;
                  _          -> false
              end,
-    if Inline -> r_inline_store([I], false, R, A, Code);
+    if Inline -> optimize_inline_store([I], false, R, A, Code);
        true   -> false end;
-r_inline_store(_, _) -> false.
+optimize_inline_store(_, _) -> false.
 
-r_inline_store(Acc, Progress, R, A, [I = {i, _, switch_body} | Code]) ->
-    r_inline_store([I | Acc], Progress, R, A, Code);
-r_inline_store(Acc, Progress, R, A, [{i, Ann, I} | Code]) ->
+optimize_inline_store(Acc, Progress, R, A, [I = {i, _, switch_body} | Code]) ->
+    optimize_inline_store([I | Acc], Progress, R, A, Code);
+optimize_inline_store(Acc, Progress, R, A, [{i, Ann, I} | Code]) ->
     #{ write := W } = attributes(I),
     Inl = fun(X) when X == R -> A; (X) -> X end,
     case live_in(R, Ann) of
@@ -1449,14 +1497,14 @@ r_inline_store(Acc, Progress, R, A, [{i, Ann, I} | Code]) ->
             case lists:member(W, [R, A]) of
                 true when Progress1 -> {lists:reverse(Acc1), Code};
                 true                -> false;
-                false               -> r_inline_store(Acc1, Progress1, R, A, Code)
+                false               -> optimize_inline_store(Acc1, Progress1, R, A, Code)
             end
     end;
-r_inline_store(Acc, true, _, _, Code) -> {lists:reverse(Acc), Code};
-r_inline_store(_, false, _, _, _) -> false.
+optimize_inline_store(Acc, true, _, _, Code) -> {lists:reverse(Acc), Code};
+optimize_inline_store(_, false, _, _, _) -> false.
 
 %% Shortcut write followed by final read
-r_one_shot_var({i, Ann1, I}, [{i, Ann2, J} | Code]) ->
+optimize_one_shot_var({i, Ann1, I}, [{i, Ann2, J} | Code]) ->
     case op_view(I) of
         {Op, R = {var, _}, As} ->
             Copy = case J of
@@ -1470,11 +1518,11 @@ r_one_shot_var({i, Ann1, I}, [{i, Ann2, J} | Code]) ->
             end;
         _ -> false
     end;
-r_one_shot_var(_, _) -> false.
+optimize_one_shot_var(_, _) -> false.
 
 %% Remove writes to dead variables
-r_write_to_dead_var({i, _, {'STORE', ?void, ?a}}, _) -> false; %% Avoid looping
-r_write_to_dead_var({i, Ann, I}, Code) ->
+optimize_write_to_dead_var({i, _, {'STORE', ?void, ?a}}, _) -> false; %% Avoid looping
+optimize_write_to_dead_var({i, Ann, I}, Code) ->
     #{ pure := Pure } = attributes(I),
     case op_view(I) of
         {_Op, R, As} when R /= ?a, Pure ->
@@ -1487,7 +1535,7 @@ r_write_to_dead_var({i, Ann, I}, Code) ->
             end;
         _ -> false
     end;
-r_write_to_dead_var(_, _) -> false.
+optimize_write_to_dead_var(_, _) -> false.
 
 op_view({'ABORT', R}) -> {'ABORT', none, [R]};
 op_view({'EXIT', R}) -> {'EXIT', none, [R]};

src/aeso_parser.erl

@@ -359,9 +359,12 @@ exprAtom() ->
         , ?RULE(tok('['), Expr, binop('..'), Expr, tok(']'), _3(_2, _4))
         , ?RULE(keyword('('), comma_sep(Expr), tok(')'), tuple_e(_1, _2))
         , letpat()
+        , hole()
         ])
     end).
 
+hole() -> ?RULE(token('???'), {id, get_ann(_1), "???"}).
+
 comprehension_exp() ->
     ?LAZY_P(choice(
       [ comprehension_bind()

src/aeso_pretty.erl

@@ -261,6 +261,8 @@ type(Type, Options) ->
     with_options(Options, fun() -> type(Type) end).
 
 -spec type(aeso_syntax:type()) -> doc().
+type(F = {fun_t, _, _, var_args, _}) ->
+    type(setelement(4, F, [var_args]));
 type({fun_t, _, Named, Args, Ret}) ->
     follow(hsep(args_type(Named ++ Args), text("=>")), type(Ret));
 type({type_sig, _, Named, Args, Ret}) ->
@@ -288,7 +290,9 @@ type(T = {id, _, _})   -> name(T);
 type(T = {qid, _, _})  -> name(T);
 type(T = {con, _, _})  -> name(T);
 type(T = {qcon, _, _}) -> name(T);
-type(T = {tvar, _, _}) -> name(T).
+type(T = {tvar, _, _}) -> name(T);
+
+type(var_args) -> text("var_args").
 
 -spec args_type([aeso_syntax:type()]) -> doc().
 args_type(Args) ->

src/aeso_syntax.erl

@@ -13,7 +13,7 @@
 -export_type([ann_line/0, ann_col/0, ann_origin/0, ann_format/0, ann/0]).
 -export_type([name/0, id/0, con/0, qid/0, qcon/0, tvar/0, op/0]).
 -export_type([bin_op/0, un_op/0]).
--export_type([decl/0, letbind/0, typedef/0, pragma/0]).
+-export_type([decl/0, letbind/0, typedef/0, pragma/0, fundecl/0]).
 -export_type([arg/0, field_t/0, constructor_t/0, named_arg_t/0]).
 -export_type([type/0, constant/0, expr/0, arg_expr/0, field/1, stmt/0, alt/0, lvalue/0, elim/0, pat/0]).
 -export_type([ast/0]).

src/aesophia.app.src

@@ -1,6 +1,6 @@
 {application, aesophia,
  [{description, "Compiler for Aeternity Sophia language"},
-  {vsn, "7.0.1"},
+  {vsn, "7.1.0"},
   {registered, []},
   {applications,
    [kernel,

test/aeso_aci_tests.erl

@@ -21,7 +21,7 @@ test_cases(1) ->
 		 "  payable stateful entrypoint a(i : int) = i+1\n">>,
     MapACI = #{contract =>
 		   #{name => <<"C">>,
-		     type_defs => [],
+		     typedefs => [],
          payable => true,
          kind => contract_main,
 		     functions =>
@@ -43,7 +43,7 @@ test_cases(2) ->
     MapACI = #{contract =>
                    #{name => <<"C">>, payable => false,
                      kind => contract_main,
-                     type_defs =>
+                     typedefs =>
                          [#{name => <<"allan">>,
                             typedef => <<"int">>,
                             vars => []}],
@@ -76,7 +76,7 @@ test_cases(3) ->
 		     name => <<"C">>, payable => false, kind => contract_main,
          event => #{variant => [#{<<"SingleEventDefined">> => []}]},
          state => <<"unit">>,
-		     type_defs =>
+		     typedefs =>
              [#{name => <<"bert">>,
                 typedef =>
                     #{variant =>

test/aeso_compiler_tests.erl

@@ -203,6 +203,11 @@ compilable_contracts() ->
      "polymorphism_contract_interface_same_decl_multi_interface",
      "polymorphism_contract_interface_same_name_same_type",
      "polymorphism_variance_switching_chain_create",
+     "polymorphism_variance_switching_void_supertype",
+     "polymorphism_variance_switching_unify_with_interface_decls",
+     "polymorphism_preserve_or_add_payable_contract",
+     "polymorphism_preserve_or_add_payable_entrypoint",
+     "polymorphism_preserve_or_remove_stateful_entrypoint",
      "missing_init_fun_state_unit",
      "complex_compare_leq",
      "complex_compare",
@@ -215,6 +220,7 @@ compilable_contracts() ->
      "polymorphic_map_keys",
      "unapplied_contract_call",
      "unapplied_named_arg_builtin",
+     "resolve_field_constraint_by_arity",
      "test" % Custom general-purpose test file. Keep it last on the list.
     ].
 
@@ -731,10 +737,22 @@ failing_contracts() ->
                      "Conflicting updates for field 'foo'">>])
     , ?TYPE_ERROR(factories_type_errors,
                   [<<?Pos(10,18)
-                    "Chain.clone requires `ref` named argument of contract type.">>,
+                     "Chain.clone requires `ref` named argument of contract type.">>,
                    <<?Pos(11,18)
-                     "Cannot unify `(gas : int, value : int, protected : bool) => if(protected, option(void), void)` and `(gas : int, value : int, protected : bool, int, bool) => 'b`\n"
-                     "when checking contract construction of type\n  (gas : int, value : int, protected : bool) =>\n    if(protected, option(void), void) (at line 11, column 18)\nagainst the expected type\n  (gas : int, value : int, protected : bool, int, bool) => 'b">>,
+                     "Cannot unify `(gas : int, value : int, protected : bool) => if(protected, option(void), void)` and `(gas : int, value : int, protected : bool, int, bool) => if(protected, option(void), void)`\n"
+                     "when checking contract construction of type\n"
+                     "  (gas : int, value : int, protected : bool) =>\n"
+                     "    if(protected, option(void), void) (at line 11, column 18)\n"
+                     "against the expected type\n"
+                     "  (gas : int, value : int, protected : bool, int, bool) =>\n"
+                     "    if(protected, option(void), void)">>,
+                   <<?Pos(11,18)
+                     "Cannot unify `Bakoom` and `Kaboom`\n"
+                     "when checking that contract construction of type\n"
+                     "  Bakoom\n"
+                     "arising from resolution of variadic function `Chain.clone`\n"
+                     "matches the expected type\n"
+                     "  Kaboom">>,
                    <<?Pos(12,37)
                      "Cannot unify `int` and `bool`\n"
                      "when checking named argument `gas : int` against inferred type `bool`">>,
@@ -847,25 +865,25 @@ failing_contracts() ->
                      "Trying to implement or extend an undefined interface `Z`">>
                   ])
     , ?TYPE_ERROR(polymorphism_contract_interface_same_name_different_type,
-                  [<<?Pos(4,20)
-                     "Unimplemented function `f` from the interface `I1` in the contract `I2`">>])
+                  [<<?Pos(9,5)
+                     "Duplicate definitions of `f` at\n"
+                     "  - line 8, column 5\n"
+                     "  - line 9, column 5">>])
     , ?TYPE_ERROR(polymorphism_contract_missing_implementation,
                   [<<?Pos(4,20)
-                     "Unimplemented function `f` from the interface `I1` in the contract `I2`">>
+                     "Unimplemented entrypoint `f` from the interface `I1` in the contract `I2`">>
                   ])
     , ?TYPE_ERROR(polymorphism_contract_same_decl_multi_interface,
                   [<<?Pos(7,10)
-                     "Unimplemented function `f` from the interface `J` in the contract `C`">>
+                     "Both interfaces `I` and `J` implemented by the contract `C` have a function called `f`">>
                   ])
     , ?TYPE_ERROR(polymorphism_contract_undefined_interface,
                   [<<?Pos(1,14)
                      "Trying to implement or extend an undefined interface `I`">>
                   ])
     , ?TYPE_ERROR(polymorphism_contract_same_name_different_type_multi_interface,
-                  [<<?Pos(9,5)
-                     "Duplicate definitions of `f` at\n"
-                     "  - line 8, column 5\n"
-                     "  - line 9, column 5">>
+                  [<<?Pos(7,10)
+                     "Both interfaces `I` and `J` implemented by the contract `C` have a function called `f`">>
                   ])
     , ?TYPE_ERROR(polymorphism_contract_interface_undefined_interface,
                   [<<?Pos(1,24)
@@ -1124,6 +1142,56 @@ failing_contracts() ->
                      "  `oracle(string, (int) => int)`\n"
                      "The response type must not be higher-order (contain function types)">>
                   ])
+    , ?TYPE_ERROR(var_args_unify_let,
+                  [<<?Pos(3,9)
+                     "Cannot infer types for variable argument list.\n"
+                     "when checking the type of the pattern `x : 'a` against the expected type `(gas : int, value : int, protected : bool, ref : 'b, var_args) => 'b`">>
+                  ])
+    , ?TYPE_ERROR(var_args_unify_fun_call,
+                  [<<?Pos(6,5)
+                     "Cannot infer types for variable argument list.\n"
+                     "when checking the application of\n"
+                     "  `g : (() => 'b) => 'b`\n"
+                     "to arguments\n"
+                     "  `Chain.create : (value : int, var_args) => 'c`">>
+                  ])
+    , ?TYPE_ERROR(polymorphism_add_stateful_entrypoint,
+                  [<<?Pos(5,25)
+                     "`f` cannot be stateful because the entrypoint `f` in the interface `I` is not stateful">>
+                  ])
+    , ?TYPE_ERROR(polymorphism_change_entrypoint_to_function,
+                  [<<?Pos(6,14)
+                     "`f` must be declared as an entrypoint instead of a function in order to implement the entrypoint `f` from the interface `I`">>
+                  ])
+    , ?TYPE_ERROR(polymorphism_non_payable_contract_implement_payable,
+                  [<<?Pos(4,10)
+                     "Non-payable contract `C` cannot implement payable interface `I`">>
+                  ])
+    , ?TYPE_ERROR(polymorphism_non_payable_interface_implement_payable,
+                  [<<?Pos(4,20)
+                     "Non-payable interface `H` cannot implement payable interface `I`">>
+                  ])
+    , ?TYPE_ERROR(polymorphism_remove_payable_entrypoint,
+                  [<<?Pos(5,16)
+                     "`f` must be payable because the entrypoint `f` in the interface `I` is payable">>
+                  ])
+    , ?TYPE_ERROR(calling_child_contract_entrypoint,
+                  [<<?Pos(5,20)
+                     "Invalid call to contract entrypoint `F.g`.\n"
+                     "It must be called as `c.g` for some `c : F`.">>])
+    , ?TYPE_ERROR(using_contract_as_namespace,
+                  [<<?Pos(5,3)
+                     "Cannot use undefined namespace F">>])
+    , ?TYPE_ERROR(hole_expression,
+                  [<<?Pos(5,13)
+                     "Found a hole of type `bool`">>,
+                   <<?Pos(6,17)
+                     "Found a hole of type `string`">>,
+                   <<?Pos(9,37)
+                     "Found a hole of type `(int) => int`">>,
+                   <<?Pos(13,20)
+                     "Found a hole of type `'a`">>
+                  ])
     ].
 
 validation_test_() ->

test/contracts/calling_child_contract_entrypoint.aes

@@ -0,0 +1,5 @@
+contract F =
+  entrypoint g() = 1
+
+main contract C =
+  entrypoint f() = F.g()

test/contracts/complex_types.aes

@@ -1,16 +1,7 @@
 
-contract interface Remote =
-  entrypoint up_to       : (int)               => list(int)
-  entrypoint sum         : (list(int))         => int
-  entrypoint some_string : ()                  => string
-  entrypoint pair        : (int, string)       => int * string
-  entrypoint squares     : (int)               => list(int * int)
-  entrypoint filter_some : (list(option(int))) => list(int)
-  entrypoint all_some    : (list(option(int))) => option(list(int))
-
 contract ComplexTypes =
 
-  record state = { worker : Remote }
+  record state = { worker : ComplexTypes }
 
   entrypoint init(worker) = {worker = worker}
 

test/contracts/environment.aes

@@ -1,14 +1,9 @@
 
 // Testing primitives for accessing the block chain environment
-contract interface Interface =
-  entrypoint contract_address : () => address
-  entrypoint call_origin      : () => address
-  entrypoint call_caller      : () => address
-  entrypoint call_value       : () => int
 
 contract Environment =
 
-  record state = {remote : Interface}
+  record state = {remote : Environment}
 
   entrypoint init(remote) = {remote = remote}
 

test/contracts/hole_expression.aes

@@ -0,0 +1,13 @@
+include "List.aes"
+
+contract C =
+    entrypoint f() =
+        let ??? = true
+        let v = ???
+        let q = v == "str"
+        let xs = [1, 2, 3, 4]
+        switch (List.first(List.map(???, xs)))
+            Some(x) => x + 1
+            None    => 0
+
+    function g() = ???

test/contracts/polymorphism_add_stateful_entrypoint.aes

@@ -0,0 +1,5 @@
+contract interface I =
+    entrypoint f : () => int
+
+contract C : I =
+    stateful entrypoint f() = 1

test/contracts/polymorphism_change_entrypoint_to_function.aes

@@ -0,0 +1,6 @@
+contract interface I =
+    entrypoint f : () => int
+
+contract C : I =
+    entrypoint init() = ()
+    function f() = 1

test/contracts/polymorphism_non_payable_contract_implement_payable.aes

@@ -0,0 +1,5 @@
+payable contract interface I =
+    payable entrypoint f : () => int
+
+contract C : I =
+    entrypoint f() = 123

test/contracts/polymorphism_non_payable_interface_implement_payable.aes

@@ -0,0 +1,8 @@
+payable contract interface I =
+    payable entrypoint f : () => int
+
+contract interface H : I =
+    payable entrypoint f : () => int
+
+payable contract C : H =
+    entrypoint f() = 123

test/contracts/polymorphism_preserve_or_add_payable_contract.aes

@@ -0,0 +1,14 @@
+contract interface F =
+    entrypoint f : () => int
+
+payable contract interface G : F =
+    payable entrypoint f : () => int
+    entrypoint g : () => int
+
+payable contract interface H =
+    payable entrypoint h : () => int
+
+payable contract C : G, H =
+    payable entrypoint f() = 1
+    payable entrypoint g() = 2
+    payable entrypoint h() = 3

test/contracts/polymorphism_preserve_or_add_payable_entrypoint.aes

@@ -0,0 +1,7 @@
+contract interface I =
+    payable entrypoint f : () => int
+    entrypoint g : () => int
+
+contract C : I =
+    payable entrypoint f() = 1
+    payable entrypoint g() = 2

test/contracts/polymorphism_preserve_or_remove_stateful_entrypoint.aes

@@ -0,0 +1,7 @@
+contract interface I =
+    stateful entrypoint f : () => int
+    stateful entrypoint g : () => int
+
+contract C : I =
+    stateful entrypoint f() = 1
+    entrypoint g() = 2

test/contracts/polymorphism_remove_payable_entrypoint.aes

@@ -0,0 +1,5 @@
+contract interface I =
+    payable entrypoint f : () => int
+
+contract C : I =
+    entrypoint f() = 1

test/contracts/polymorphism_variance_switching_unify_with_interface_decls.aes

@@ -0,0 +1,5 @@
+payable contract interface SalesOffer =
+    entrypoint init : (address, address, int, int) => unit
+
+payable contract Test : SalesOffer =
+    entrypoint init(_, _, _, _) = ()

test/contracts/polymorphism_variance_switching_void_supertype.aes

@@ -0,0 +1,5 @@
+payable contract interface SalesOffer =
+    entrypoint init : (address, address, int, int) => void
+
+payable contract Test : SalesOffer =
+    entrypoint init(_ : address, _ : address, _ : int, _ : int) = ()

test/contracts/resolve_field_constraint_by_arity.aes

@@ -0,0 +1,9 @@
+contract First =
+    entrypoint print_num(x) = 1 + x
+
+contract Second =
+    entrypoint print_num() = 1
+
+main contract Test =
+    entrypoint f(c) = c.print_num(1)
+    entrypoint g(c) = c.print_num()

test/contracts/spend_test.aes

@@ -1,7 +1,4 @@
 
-contract interface SpendContract =
-  entrypoint withdraw : (int) => int
-
 contract SpendTest =
 
   stateful entrypoint spend(to, amount) =

test/contracts/using_contract_as_namespace.aes

@@ -0,0 +1,7 @@
+contract F =
+  entrypoint g() = 1
+
+main contract C =
+  using F for [g]
+
+  entrypoint f() = g()

test/contracts/var_args_unify_fun_call.aes

@@ -0,0 +1,7 @@
+contract C =
+  stateful function g(h) =
+    h()
+
+  stateful entrypoint f() =
+    g(Chain.create)
+    123

test/contracts/var_args_unify_let.aes

@@ -0,0 +1,4 @@
+main contract C =
+  stateful entrypoint f() =
+    let x = Chain.clone
+    123

test/contracts/warnings.aes

@@ -12,7 +12,7 @@ namespace UnusedNamespace =
   // Unused
   private function h() = 3
 
-contract Warnings =
+main contract Warnings =
 
   type state = int
 
@@ -58,3 +58,10 @@ namespace FunctionsAsArgs =
     private function inc(n : int) : int = n + 1
     // Never used
     private function dec(n : int) : int = n - 1
+
+contract Remote =
+  entrypoint id(_) = 0
+
+contract C = 
+  payable stateful entrypoint
+    call_missing_con() : int = (ct_1111111111111111111111111111112JF6Dz72 : Remote).id(value = 1, 0)