Merge branch 'nox/maps-eval-empty-update'

* nox/maps-eval-empty-update:
  Fix evaluation of empty map patterns in erl_lint
  Fix evaluation of empty map updates in the debugger
  Fix evaluation of empty map updates in erl_eval

2 files changed, 20 insertions, 7 deletions

diff --git a/lib/stdlib/src/erl_eval.erl b/lib/stdlib/src/erl_eval.erl
index 3a4108e297..acde3ad5d6 100644
--- a/lib/stdlib/src/erl_eval.erl
+++ b/lib/stdlib/src/erl_eval.erl
@@ -18,6 +18,9 @@
 %%
 -module(erl_eval).
 
+%% Guard is_map/1 is not yet supported in HiPE.
+-compile(no_native).
+
 %% An evaluator for Erlang abstract syntax.
 
 -export([exprs/2,exprs/3,exprs/4,expr/2,expr/3,expr/4,expr/5,
@@ -243,11 +246,18 @@ expr({record,_,_,Name,_}, _Bs, _Lf, _Ef, _RBs) ->
 %% map
 expr({map,_, Binding,Es}, Bs0, Lf, Ef, RBs) ->
     {value, Map0, Bs1} = expr(Binding, Bs0, Lf, Ef, RBs),
-    {Vs,Bs} = eval_map_fields(Es, Bs1, Lf, Ef),
-    ret_expr(lists:foldl(fun
-		({map_assoc,K,V}, Mi) -> maps:put(K,V,Mi);
-		({map_exact,K,V}, Mi) -> maps:update(K,V,Mi)
-	end, Map0, Vs), Bs, RBs);
+    case Map0 of
+        #{} ->
+            {Vs,Bs} = eval_map_fields(Es, Bs1, Lf, Ef),
+            Map1 = lists:foldl(fun ({map_assoc,K,V}, Mi) ->
+                                       maps:put(K, V, Mi);
+                                   ({map_exact,K,V}, Mi) ->
+                                       maps:update(K, V, Mi)
+                               end, Map0, Vs),
+            ret_expr(Map1, Bs, RBs);
+        _ ->
+            erlang:raise(error, {badarg,Map0}, stacktrace())
+    end;
 expr({map,_,Es}, Bs0, Lf, Ef, RBs) ->
     {Vs,Bs} = eval_map_fields(Es, Bs0, Lf, Ef),
     ret_expr(lists:foldl(fun
@@ -1113,9 +1123,10 @@ match1({tuple,_,Elts}, Tuple, Bs, BBs)
     match_tuple(Elts, Tuple, 1, Bs, BBs);
 match1({tuple,_,_}, _, _Bs, _BBs) ->
     throw(nomatch);
-match1({map,_,Fs}, Map, Bs, BBs) ->
+match1({map,_,Fs}, #{}=Map, Bs, BBs) ->
     match_map(Fs, Map, Bs, BBs);
-
+match1({map,_,_}, _, _Bs, _BBs) ->
+    throw(nomatch);
 match1({bin, _, Fs}, <<_/bitstring>>=B, Bs0, BBs) ->
     eval_bits:match_bits(Fs, B, Bs0, BBs,
 			 match_fun(BBs),
diff --git a/lib/stdlib/test/erl_eval_SUITE.erl b/lib/stdlib/test/erl_eval_SUITE.erl
index e6512b7d71..b91d14b5b8 100644
--- a/lib/stdlib/test/erl_eval_SUITE.erl
+++ b/lib/stdlib/test/erl_eval_SUITE.erl
@@ -1451,6 +1451,8 @@ eep43(Config) when is_list(Config) ->
           "    {Map#{a := B},Map#{a => c},Map#{d => e}} "
           "end.",
           {#{a => b},#{a => c},#{a => b,d => e}}),
+    error_check("[camembert]#{}.", {badarg,[camembert]}),
+    error_check("#{} = 1.", {badmatch,1}),
     ok.
 
 %% Check the string in different contexts: as is; in fun; from compiled code.