Hide warning when calling with non-0 value arg (#431)

* Hide warning when calling with non-0 value arg

* Update the tests

* Update CHANGELOG

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - 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.
 ### Removed
 ### Fixed
 - Typechecker crashes if Chain.create or Chain.clone are used without arguments.

src/aeso_ast_infer_types.erl

@@ -1718,10 +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.
 

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)