Merge branch 'map-get-bif' of git://github.com/michalmuskala/otp

* 'map-get-bif' of git://github.com/michalmuskala/otp:
  Introduce map_get guard-safe function

OTP-15037

8 files changed, 35 insertions, 5 deletions

diff --git a/lib/compiler/src/erl_bifs.erl b/lib/compiler/src/erl_bifs.erl
index 8fab2400f7..70b36f029e 100644
--- a/lib/compiler/src/erl_bifs.erl
+++ b/lib/compiler/src/erl_bifs.erl
@@ -110,6 +110,7 @@ is_pure(erlang, list_to_pid, 1) -> true;
 is_pure(erlang, list_to_tuple, 1) -> true;
 is_pure(erlang, max, 2) -> true;
 is_pure(erlang, make_fun, 3) -> true;
+is_pure(erlang, map_get, 2) -> true;
 is_pure(erlang, min, 2) -> true;
 is_pure(erlang, phash, 2) -> false;
 is_pure(erlang, pid_to_list, 1) -> true;
diff --git a/lib/compiler/src/v3_codegen.erl b/lib/compiler/src/v3_codegen.erl
index 8808c0a3b7..8e73b613a0 100644
--- a/lib/compiler/src/v3_codegen.erl
+++ b/lib/compiler/src/v3_codegen.erl
@@ -588,6 +588,7 @@ is_gc_bif(node, 1) -> false;
 is_gc_bif(element, 2) -> false;
 is_gc_bif(get, 1) -> false;
 is_gc_bif(tuple_size, 1) -> false;
+is_gc_bif(map_get, 2) -> false;
 is_gc_bif(Bif, Arity) ->
     not (erl_internal:bool_op(Bif, Arity) orelse
 	 erl_internal:new_type_test(Bif, Arity) orelse
diff --git a/lib/compiler/test/map_SUITE.erl b/lib/compiler/test/map_SUITE.erl
index 3146c31c21..e98c295da6 100644
--- a/lib/compiler/test/map_SUITE.erl
+++ b/lib/compiler/test/map_SUITE.erl
@@ -36,7 +36,7 @@
         t_guard_fun/1,
 	t_list_comprehension/1,
 	t_map_sort_literals/1,
-	t_map_size/1,
+	t_map_size/1, t_map_get/1,
 	t_build_and_match_aliasing/1,
 	t_is_map/1,
 
@@ -91,7 +91,7 @@ all() ->
 	t_guard_receive, t_guard_receive_large,
         t_guard_fun, t_list_comprehension,
 	t_map_sort_literals,
-	t_map_size,
+	t_map_size, t_map_get,
 	t_build_and_match_aliasing,
 	t_is_map,
 
@@ -691,6 +691,26 @@ t_map_size(Config) when is_list(Config) ->
 map_is_size(M,N) when map_size(M) =:= N -> true;
 map_is_size(_,_) -> false.
 
+t_map_get(Config) when is_list(Config) ->
+    1 = map_get(a, id(#{a=>1})),
+
+    {'EXIT',{{badkey,a},_}} = (catch map_get(a, #{})),
+    {'EXIT',{{badkey,a},_}} = (catch map_get(a, #{b=>1})),
+
+    M = #{"a"=>1, "b" => 2},
+    true = check_map_value(M, "a", 1),
+    false = check_map_value(M, "b", 1),
+    true = check_map_value(M#{"c"=>2}, "c", 2),
+    false = check_map_value(M#{"a"=>5}, "a", 1),
+
+    {'EXIT',{{badmap,[]},_}} = (catch map_get(a, [])),
+    {'EXIT',{{badmap,<<1,2,3>>},_}} = (catch map_get(a, <<1,2,3>>)),
+    {'EXIT',{{badmap,1},_}} = (catch map_get(a, 1)),
+    ok.
+
+check_map_value(Map, Key, Value) when map_get(Key, Map) =:= Value -> true;
+check_map_value(_, _, _) -> false.
+
 t_is_map(Config) when is_list(Config) ->
     true = is_map(#{}),
     true = is_map(#{a=>1}),
diff --git a/lib/hipe/cerl/erl_bif_types.erl b/lib/hipe/cerl/erl_bif_types.erl
index bfffb8db41..fe6ab0659c 100644
--- a/lib/hipe/cerl/erl_bif_types.erl
+++ b/lib/hipe/cerl/erl_bif_types.erl
@@ -770,6 +770,9 @@ type(erlang, length, 1, Xs, Opaques) ->
 %% Guard bif, needs to be here.
 type(erlang, map_size, 1, Xs, Opaques) ->
   type(maps, size, 1, Xs, Opaques);
+%% Guard bif, needs to be here.
+type(erlang, map_get, 2, Xs, Opaques) ->
+  type(maps, get, 2, Xs, Opaques);
 type(erlang, make_fun, 3, Xs, Opaques) ->
   strict(erlang, make_fun, 3, Xs,
          fun ([_, _, Arity]) ->
@@ -2391,6 +2394,9 @@ arg_types(erlang, length, 1) ->
 %% Guard bif, needs to be here.
 arg_types(erlang, map_size, 1) ->
   [t_map()];
+%% Guard bif, needs to be here.
+arg_types(erlang, map_get, 2) ->
+  [t_map(), t_any()];
 arg_types(erlang, make_fun, 3) ->
   [t_atom(), t_atom(), t_arity()];
 arg_types(erlang, make_tuple, 2) ->
diff --git a/lib/hipe/cerl/erl_types.erl b/lib/hipe/cerl/erl_types.erl
index 8a609ef911..a91da97f93 100644
--- a/lib/hipe/cerl/erl_types.erl
+++ b/lib/hipe/cerl/erl_types.erl
@@ -217,7 +217,7 @@
 	]).
 
 %%-define(DO_ERL_TYPES_TEST, true).
--compile({no_auto_import,[min/2,max/2]}).
+-compile({no_auto_import,[min/2,max/2,map_get/2]}).
 
 -ifdef(DO_ERL_TYPES_TEST).
 -export([test/0]).
diff --git a/lib/stdlib/src/erl_internal.erl b/lib/stdlib/src/erl_internal.erl
index 89b97b901e..6d3d5baa23 100644
--- a/lib/stdlib/src/erl_internal.erl
+++ b/lib/stdlib/src/erl_internal.erl
@@ -76,6 +76,7 @@ guard_bif(floor, 1) -> true;
 guard_bif(hd, 1) -> true;
 guard_bif(length, 1) -> true;
 guard_bif(map_size, 1) -> true;
+guard_bif(map_get, 2) -> true;
 guard_bif(node, 0) -> true;
 guard_bif(node, 1) -> true;
 guard_bif(round, 1) -> true;
@@ -337,6 +338,7 @@ bif(list_to_tuple, 1) -> true;
 bif(load_module, 2) -> true;
 bif(make_ref, 0) -> true;
 bif(map_size,1) -> true;
+bif(map_get,2) -> true;
 bif(max,2) -> true;
 bif(min,2) -> true;
 bif(module_loaded, 1) -> true;
diff --git a/lib/stdlib/src/ms_transform.erl b/lib/stdlib/src/ms_transform.erl
index 6616e957c0..ec8cfd56c2 100644
--- a/lib/stdlib/src/ms_transform.erl
+++ b/lib/stdlib/src/ms_transform.erl
@@ -944,6 +944,7 @@ real_guard_function(node,1) -> true;
 real_guard_function(round,1) -> true;
 real_guard_function(size,1) -> true;
 real_guard_function(map_size,1) -> true;
+real_guard_function(map_get,2) -> true;
 real_guard_function(tl,1) -> true;
 real_guard_function(trunc,1) -> true;
 real_guard_function(self,0) -> true;
@@ -1115,5 +1116,3 @@ normalise_list([H|T]) ->
     [normalise(H)|normalise_list(T)];
 normalise_list([]) ->
     [].
-
-
diff --git a/lib/tools/emacs/erlang.el b/lib/tools/emacs/erlang.el
index b88f368746..fd51aca861 100644
--- a/lib/tools/emacs/erlang.el
+++ b/lib/tools/emacs/erlang.el
@@ -825,6 +825,7 @@ resulting regexp is surrounded by \\_< and \\_>."
       "list_to_tuple"
       "load_module"
       "make_ref"
+      "map_get"
       "map_size"
       "max"
       "min"