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.

1 files changed, 29 insertions, 0 deletions

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.