Correct compile_SUITE:core_roundtrip/1

The test is supposed to compare the Core Erlang code that has been
printed and parsed back. It did compare and print any differences,
but it did not fail when there were differences.

Also fix problems with variable names and maps not comparing
equal when the inliner has been used.

1 files changed, 64 insertions, 5 deletions

diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 10740ac2b0..474c3e2ca0 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -865,9 +865,7 @@ do_core_roundtrip_2(M, Core0, Outdir) ->
     case cmp_core(Core0, Core, M) of
 	true -> ok;
 	false -> error
-    end,
-
-    ok.
+    end.
 
 undo_var_translation(Tree) ->
     F = fun(Node) ->
@@ -920,11 +918,72 @@ diff(E, E) ->
 diff([H1|T1], [H2|T2]) ->
     [diff(H1, H2)|diff(T1, T2)];
 diff(T1, T2) when tuple_size(T1) =:= tuple_size(T2) ->
-    L = diff(tuple_to_list(T1), tuple_to_list(T2)),
-    list_to_tuple(L);
+    case cerl:is_c_var(T1) andalso cerl:is_c_var(T2) of
+        true ->
+            diff_var(T1, T2);
+        false ->
+            case cerl:is_c_map(T1) andalso cerl:is_c_map(T2) of
+                true ->
+                    diff_map(T1, T2);
+                false ->
+                    diff_tuple(T1, T2)
+            end
+    end;
 diff(E1, E2) ->
     {'DIFF',E1,E2}.
 
+diff_var(V1, V2) ->
+    case {cerl:var_name(V1),cerl:var_name(V2)} of
+        {Same,Same} ->
+            V1;
+        {Name1,Name2} ->
+            %% The inliner uses integers as variable names. Such integers
+            %% are read back as atoms.
+            case is_integer(Name1) andalso
+                list_to_atom(integer_to_list(Name1)) =:= Name2 of
+                true ->
+                    V1;
+                _ ->
+                    cerl:update_c_var(V1, {'DIFF',Name1,Name2})
+            end
+    end.
+
+%% Annotations for maps are not preserved exactly, but that is not
+%% a real problem. Workaround by not comparing all annotations when
+%% comparing maps.
+
+diff_map(M, M) ->
+    M;
+diff_map(M1, M2) ->
+    case cerl:get_ann(M1) =:= cerl:get_ann(M2) of
+        false ->
+            diff_tuple(M1, M2);
+        true ->
+            case remove_compiler_gen(M1) =:= remove_compiler_gen(M2) of
+                true ->
+                    M1;
+                false ->
+                    diff_tuple(M1, M2)
+            end
+    end.
+
+diff_tuple(T1, T2) ->
+    L = diff(tuple_to_list(T1), tuple_to_list(T2)),
+    list_to_tuple(L).
+
+remove_compiler_gen(M) ->
+    Arg0 = cerl:map_arg(M),
+    Arg = cerl:set_ann(Arg0, []),
+    Es0 = cerl:map_es(M),
+    Es = [remove_compiler_gen_1(Pair) || Pair <- Es0],
+    cerl:update_c_map(M, Arg, Es).
+
+remove_compiler_gen_1(Pair) ->
+    Op0 = cerl:map_pair_op(Pair),
+    Op = cerl:set_ann(Op0, []),
+    K = cerl:map_pair_key(Pair),
+    V = cerl:map_pair_val(Pair),
+    cerl:update_c_map_pair(Pair, Op, K, V).
 
 %% Compile to Beam assembly language (.S) and then try to
 %% run .S through the compiler again.