Merge branch 'egil/fix-erts_debug-size/OTP-11923' into maint

* egil/fix-erts_debug-size/OTP-11923:
  erts: Update preloaded erts_internal.beam
  erts: Add spec for erts_internal:map_to_tuple_keys/1
  erts: Add testcase for erts_debug:size/1 Map terms
  kernel: Fix erts_debug:size/1 to handle Map sizes
  erts: Add erts_internal:map_to_tuple_keys/1

6 files changed, 48 insertions, 5 deletions

diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 2d888862bf..fbdddf09db 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -157,6 +157,7 @@ bif erts_internal:binary_to_term/2
 bif erts_internal:request_system_task/3
 bif erts_internal:check_process_code/2
 
+bif erts_internal:map_to_tuple_keys/1
 
 # inet_db support
 bif erlang:port_set_data/2
diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c
index fdd2d0c0f6..5e740aacdd 100644
--- a/erts/emulator/beam/erl_map.c
+++ b/erts/emulator/beam/erl_map.c
@@ -58,6 +58,8 @@
  * - maps:size/1
  * - maps:without/2
  *
+ * DEBUG: for sharing calculation
+ * - erts_internal:map_to_tuple_keys/1
  */
 
 /* erlang:map_size/1
@@ -819,3 +821,17 @@ int erts_validate_and_sort_map(map_t* mp)
     }
     return 1;
 }
+
+/*
+ * erts_internal:map_to_tuple_keys/1
+ *
+ * Used in erts_debug:size/1
+ */
+
+BIF_RETTYPE erts_internal_map_to_tuple_keys_1(BIF_ALIST_1) {
+    if (is_map(BIF_ARG_1)) {
+	map_t *mp = (map_t*)map_val(BIF_ARG_1);
+	BIF_RET(mp->keys);
+    }
+    BIF_ERROR(BIF_P, BADARG);
+}
diff --git a/erts/emulator/test/erts_debug_SUITE.erl b/erts/emulator/test/erts_debug_SUITE.erl
index 87778dd0c2..e5c904cfb9 100644
--- a/erts/emulator/test/erts_debug_SUITE.erl
+++ b/erts/emulator/test/erts_debug_SUITE.erl
@@ -67,6 +67,9 @@ test_size(Config) when is_list(Config) ->
     2 = do_test_size({[]}),
     3 = do_test_size({a,b}),
     7 = do_test_size({a,[b,c]}),
+    8 = do_test_size(#{b => 2,c => 3}),
+    4 = do_test_size(#{}),
+    32 = do_test_size(#{b => 2,c => 3,txt => "hello world"}),
 
     %% Test internal consistency of sizes, but without testing
     %% exact sizes.
@@ -97,6 +100,9 @@ test_size(Config) when is_list(Config) ->
     do_test_size({SimplestFun,SimplestFun},
 		 2*FunSz0+do_test_size({a,b}),
 		 FunSz0+do_test_size({a,b})),
+
+    M = id(#{ "atom" => first, i => 0}),
+    do_test_size([M,M#{ "atom" := other },M#{i := 42}],54,32),
     ok.
 
 do_test_size(Term) ->
diff --git a/erts/preloaded/ebin/erts_internal.beam b/erts/preloaded/ebin/erts_internal.beam
index d41c833e05..3d650aff74 100644
--- a/erts/preloaded/ebin/erts_internal.beam
+++ b/erts/preloaded/ebin/erts_internal.beam
diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl
index edcd50c77e..764d7730aa 100644
--- a/erts/preloaded/src/erts_internal.erl
+++ b/erts/preloaded/src/erts_internal.erl
@@ -31,6 +31,7 @@
 -export([await_port_send_result/3]).
 -export([binary_to_term/1, binary_to_term/2]).
 -export([cmp_term/2]).
+-export([map_to_tuple_keys/1]).
 -export([port_command/3, port_connect/2, port_close/1,
 	 port_control/3, port_call/3, port_info/1, port_info/2]).
 
@@ -181,3 +182,11 @@ binary_to_term(_Binary, _Opts) ->
 
 cmp_term(_A,_B) ->
     erlang:nif_error(undefined).
+
+%% return the internal key tuple for map keys
+-spec map_to_tuple_keys(M) -> Keys when
+    M :: map(),
+    Keys :: tuple().
+
+map_to_tuple_keys(_M) ->
+    erlang:nif_error(undefined).
diff --git a/lib/kernel/src/erts_debug.erl b/lib/kernel/src/erts_debug.erl
index f7a815882b..ef605d0bfe 100644
--- a/lib/kernel/src/erts_debug.erl
+++ b/lib/kernel/src/erts_debug.erl
@@ -182,6 +182,11 @@ size(Tuple, Seen0, Sum0) when is_tuple(Tuple) ->
 	    Sum = Sum0 + 1 + tuple_size(Tuple),
 	    tuple_size(1, tuple_size(Tuple), Tuple, Seen, Sum)
     end;
+size(Map, Seen0, Sum) when is_map(Map) ->
+    case remember_term(Map, Seen0) of
+	seen -> {Sum,Seen0};
+	Seen -> map_size(Map, Seen, Sum)
+    end;
 size(Fun, Seen0, Sum) when is_function(Fun) ->
     case remember_term(Fun, Seen0) of
 	seen -> {Sum,Seen0};
@@ -203,6 +208,12 @@ tuple_size(I, Sz, Tuple, Seen0, Sum0) ->
     {Sum,Seen} = size(element(I, Tuple), Seen0, Sum0),
     tuple_size(I+1, Sz, Tuple, Seen, Sum).
 
+map_size(Map,Seen0,Sum0) ->
+    Kt = erts_internal:map_to_tuple_keys(Map),
+    Vs = maps:values(Map),
+    {Sum1,Seen1} = size(Kt,Seen0,Sum0),
+    fold_size(Vs,Seen1,Sum1+length(Vs)+3).
+
 fun_size(Fun, Seen, Sum) ->
     case erlang:fun_info(Fun, type) of
 	{type,external} ->
@@ -210,14 +221,14 @@ fun_size(Fun, Seen, Sum) ->
 	{type,local} ->
 	    Sz = erts_debug:flat_size(fun() -> ok end),
 	    {env,Env} = erlang:fun_info(Fun, env),
-	    fun_size_1(Env, Seen, Sum+Sz+length(Env))
+	    fold_size(Env, Seen, Sum+Sz+length(Env))
     end.
 
-fun_size_1([H|T], Seen0, Sum0) ->
+fold_size([H|T], Seen0, Sum0) ->
     {Sum,Seen} = size(H, Seen0, Sum0),
-    fun_size_1(T, Seen, Sum);
-fun_size_1([], Seen, Sum) -> {Sum,Seen}.
-	    
+    fold_size(T, Seen, Sum);
+fold_size([], Seen, Sum) -> {Sum,Seen}.
+
 remember_term(Term, Seen) ->
     case gb_trees:lookup(Term, Seen) of
 	none -> gb_trees:insert(Term, [Term], Seen);