From 22aaeceba8210fd4ca2268c867f523806b7c2689 Mon Sep 17 00:00:00 2001
From: Hans Svensson <hans.svensson@happihacking.se>
Date: Mon, 25 Jan 2021 21:24:08 +0100
Subject: [PATCH] Properly handle type errors during desugar

---
 src/aeso_ast_infer_types.erl | 7 ++++++-
 test/aeso_compiler_tests.erl | 3 +++
 test/contracts/bad_state.aes | 5 +++++
 3 files changed, 14 insertions(+), 1 deletion(-)
 create mode 100644 test/contracts/bad_state.aes

diff --git a/src/aeso_ast_infer_types.erl b/src/aeso_ast_infer_types.erl
index e7f151e..86027bf 100644
--- a/src/aeso_ast_infer_types.erl
+++ b/src/aeso_ast_infer_types.erl
@@ -623,7 +623,9 @@ check_scope_name_clash(Env, Kind, Name) ->
 -spec infer_contract_top(env(), main_contract | contract | namespace, [aeso_syntax:decl()], list(option())) ->
     {env(), [aeso_syntax:decl()]}.
 infer_contract_top(Env, Kind, Defs0, Options) ->
+    create_type_errors(),
     Defs = desugar(Defs0),
+    destroy_and_report_type_errors(Env),
     infer_contract(Env, Kind, Defs, Options).
 
 %% infer_contract takes a proplist mapping global names to types, and
@@ -2586,6 +2588,9 @@ mk_error({mixed_record_and_map, Expr}) ->
     Msg = io_lib:format("Mixed record fields and map keys in\n~s",
                         [pp_expr("  ", Expr)]),
     mk_t_err(pos(Expr), Msg);
+mk_error({conflicting_updates_for_field, Upd, Key}) ->
+    Msg = io_lib:format("Conflicting updates for field '~s'\n", [Key]),
+    mk_t_err(pos(Upd), Msg);
 mk_error(Err) ->
     Msg = io_lib:format("Unknown error: ~p\n", [Err]),
     mk_t_err(pos(0, 0), Msg).
@@ -2808,7 +2813,7 @@ desugar_updates([Upd | Updates]) ->
     {More, Updates1}       = updates_key(Key, Updates),
     %% Check conflicts
     case length([ [] || [] <- [Rest | More] ]) of
-        N when N > 1 -> error({conflicting_updates_for_field, Upd, Key});
+        N when N > 1 -> type_error({conflicting_updates_for_field, Upd, Key});
         _ -> ok
     end,
     [MakeField(lists:append([Rest | More])) | desugar_updates(Updates1)].
diff --git a/test/aeso_compiler_tests.erl b/test/aeso_compiler_tests.erl
index a6c76a6..8fd6c53 100644
--- a/test/aeso_compiler_tests.erl
+++ b/test/aeso_compiler_tests.erl
@@ -713,6 +713,9 @@ failing_contracts() ->
                      "  g : (int, string) => 'c\nto arguments\n"
                      "  \"Litwo, ojczyzno moja\" : string">>
                   ])
+    , ?TYPE_ERROR(bad_state,
+                  [<<?Pos(4, 16)
+                     "Conflicting updates for field 'foo'">>])
     ].
 
 -define(Path(File), "code_errors/" ??File).
diff --git a/test/contracts/bad_state.aes b/test/contracts/bad_state.aes
new file mode 100644
index 0000000..e632a41
--- /dev/null
+++ b/test/contracts/bad_state.aes
@@ -0,0 +1,5 @@
+contract C =
+  record state = { foo : int }
+  entrypoint init(i : int) =
+    state{ foo = i,
+           foo = 42 }