beam_validator: Tighten and simplify map validation code

The assert_strict_literal_termorder/1 function is used to validate the
get_map_elements and has_map_fields instructions. In neither case is
it useful to allow an empty lists of fields, so we should no longer
allow an empty list.

The mmap/2 function is cute, but it is used in only one place, so it
is much simpler to write a special-purpose function to extract the
keys from the list of map pairs.

2 files changed, 45 insertions, 2 deletions

diff --git a/lib/compiler/test/beam_validator_SUITE.erl b/lib/compiler/test/beam_validator_SUITE.erl
index 27979647c6..8bbbcb21f2 100644
--- a/lib/compiler/test/beam_validator_SUITE.erl
+++ b/lib/compiler/test/beam_validator_SUITE.erl
@@ -30,7 +30,8 @@
 	 freg_range/1,freg_uninit/1,freg_state/1,
 	 bin_match/1,bad_bin_match/1,bin_aligned/1,bad_dsetel/1,
 	 state_after_fault_in_catch/1,no_exception_in_catch/1,
-	 undef_label/1,illegal_instruction/1,failing_gc_guard_bif/1]).
+	 undef_label/1,illegal_instruction/1,failing_gc_guard_bif/1,
+	 map_field_lists/1]).
 	 
 -include_lib("test_server/include/test_server.hrl").
 
@@ -58,7 +59,8 @@ groups() ->
        bad_catch_try,cons_guard,freg_range,freg_uninit,
        freg_state,bin_match,bad_bin_match,bin_aligned,bad_dsetel,
        state_after_fault_in_catch,no_exception_in_catch,
-       undef_label,illegal_instruction,failing_gc_guard_bif]}].
+       undef_label,illegal_instruction,failing_gc_guard_bif,
+       map_field_lists]}].
 
 init_per_suite(Config) ->
     Config.
@@ -414,6 +416,18 @@ process_request_foo(_) ->
 process_request_bar(Pid, [Response]) when is_pid(Pid) ->
     Response.
 
+map_field_lists(Config) ->
+    Errors = do_val(map_field_lists, Config),
+    [{{map_field_lists,x,1},
+      {{test,has_map_fields,{f,1},{x,0},
+	{list,[{atom,z},{atom,a}]}},
+       5,
+       not_strict_order}},
+     {{map_field_lists,y,1},
+      {{test,has_map_fields,{f,3},{x,0},{list,[]}},
+       5,
+       empty_field_list}}
+    ] = Errors.
 
 %%%-------------------------------------------------------------------------
 
diff --git a/lib/compiler/test/beam_validator_SUITE_data/map_field_lists.S b/lib/compiler/test/beam_validator_SUITE_data/map_field_lists.S
new file mode 100644
index 0000000000..9af68c82d4
--- /dev/null
+++ b/lib/compiler/test/beam_validator_SUITE_data/map_field_lists.S
@@ -0,0 +1,29 @@
+{module, map_field_lists}.  %% version = 0
+
+{exports, [{x,1},{y,1}]}.
+
+{attributes, []}.
+
+{labels, 5}.
+
+
+{function, x, 1, 2}.
+  {label,1}.
+    {line,[{location,"map_field_lists.erl",4}]}.
+    {func_info,{atom,map_field_lists},{atom,x},1}.
+  {label,2}.
+    {test,is_map,{f,1},[{x,0}]}.
+    {test,has_map_fields,{f,1},{x,0},{list,[{atom,z},{atom,a}]}}.
+    {move,{atom,ok},{x,0}}.
+    return.
+
+
+{function, y, 1, 4}.
+  {label,3}.
+    {line,[{location,"map_field_lists.erl",7}]}.
+    {func_info,{atom,map_field_lists},{atom,y},1}.
+  {label,4}.
+    {test,is_map,{f,3},[{x,0}]}.
+    {test,has_map_fields,{f,3},{x,0},{list,[]}}.
+    {move,{atom,ok},{x,0}}.
+    return.