compiler: Fix inplace tuple updates for an edge case

Fix #10367.
This reverts a30e40e.
In certain edge cases, aggregates are incorrectly marked as unique
when their contained records are not unique. This leads to unsafe
destructive updates and strange runtime behaviours.

If there is a less conservative fix that is more specific for this
edge case, we can revisit.

Author: lucioleKi

lib/compiler/src/beam_ssa_ss.erl

@@ -645,12 +645,7 @@ set_alias([], State) ->
     State.
 
 get_alias_edges(V, State) ->
-    OutEdges = [To
-                || {#b_var{},To,Kind} <- beam_digraph:out_edges(State, V),
-                   case Kind of
-                       {embed,_} -> false;
-                       _ -> true
-                   end],
+    OutEdges = [To || {#b_var{},To,_} <- beam_digraph:out_edges(State, V)],
     EmbedEdges = [Src
                   || {#b_var{}=Src,_,Lbl} <- beam_digraph:in_edges(State, V),
                      case Lbl of

lib/compiler/test/beam_ssa_check_SUITE_data/alias.erl

@@ -831,13 +831,12 @@ aliased_pair_tl_instr(Ls) ->
 aliasing_after_tuple_extract(N) ->
     aliasing_after_tuple_extract(N, {<<>>, dummy}).
 
-%% Check that the Acc tuple is unique on entry, but that the elements
-%% are aliased.
+%% Check that both the tuple (Acc) and the extracted element (X) are
+%% aliased.
 aliasing_after_tuple_extract(0, Acc) ->
 %ssa% (_,Acc) when post_ssa_opt ->
-%ssa% X = get_tuple_element(Acc, 0) {unique => [Acc]},
-%ssa% Bin = bs_create_bin(_,_,X,...) {aliased => [X]},
-%ssa% Tuple = put_tuple(Bin, Acc) {aliased => [Bin], unique => [Acc]}.
+%ssa% X = get_tuple_element(Acc, 0) {aliased => [Acc]},
+%ssa% _ = bs_create_bin(_,_,X,...) {aliased => [X]}.
     Acc;
 aliasing_after_tuple_extract(N, Acc) ->
     {X,_} = Acc,
@@ -853,9 +852,8 @@ alias_after_pair_hd(0, Acc) ->
     Acc;
 alias_after_pair_hd(N, Acc) ->
 %ssa% (_,Acc) when post_ssa_opt ->
-%ssa% X = get_hd(Acc) {unique => [Acc]},
-%ssa% Bin = bs_create_bin(_,_,X,...) {aliased => [X]},
-%ssa% Tuple = put_list(Bin, Acc) {aliased => [Bin], unique => [Acc]}.
+%ssa% X = get_hd(Acc) {aliased => [Acc]},
+%ssa% _ = bs_create_bin(_,_,X,...) {aliased => [X]}.
     [X|_] = Acc,
     alias_after_pair_hd(N - 1, [<<X/bitstring, 1>>|Acc]).
 
@@ -868,9 +866,8 @@ alias_after_pair_tl(0, Acc) ->
     Acc;
 alias_after_pair_tl(N, Acc) ->
 %ssa% (_,Acc) when post_ssa_opt ->
-%ssa% X = get_tl(Acc) {unique => [Acc]},
-%ssa% Bin = bs_create_bin(_,_,X,...) {aliased => [X]},
-%ssa% Tuple = put_list(Acc, Bin) {aliased => [Bin], unique => [Acc]}.
+%ssa% X = get_tl(Acc) {aliased => [Acc]},
+%ssa% _ = bs_create_bin(_,_,X,...) {aliased => [X]}.
     [_|X] = Acc,
     alias_after_pair_tl(N - 1, [Acc|<<X/bitstring, 1>>]).
 
@@ -1204,8 +1201,8 @@ nested_tuple_inner() ->
 
 nested_tuple() ->
 %ssa% () when post_ssa_opt ->
-%ssa% U = bs_create_bin(append, _, T, ...) { unique => [T] },
-%ssa% R = put_tuple(U, A) { aliased => [A], unique => [U] },
+%ssa% U = bs_create_bin(append, _, T, ...) { aliased => [T] },
+%ssa% R = put_tuple(U, A) { aliased => [U, A] },
 %ssa% ret(R).
     {{{{Z,X}}}} = nested_tuple_inner(),
     {<<Z/binary, 1:8>>,X}.
@@ -1228,8 +1225,8 @@ nested_mixed_inner() ->
 
 nested_mixed() ->
 %ssa% () when post_ssa_opt ->
-%ssa% U = bs_create_bin(append, _, T, ...) { unique => [T] },
-%ssa% R = put_tuple(U, A) { aliased => [A], unique => [U] },
+%ssa% U = bs_create_bin(append, _, T, ...) { aliased => [T] },
+%ssa% R = put_tuple(U, A) { aliased => [U, A] },
 %ssa% ret(R).
     [{[{Z,X}]}] = nested_mixed_inner(),
     {<<Z/binary, 1:8>>,X}.

lib/compiler/test/beam_ssa_check_SUITE_data/tuple_inplace_checks.erl

@@ -25,7 +25,8 @@
 -export([do0a/0, do0b/2, different_sizes/2, ambiguous_inits/1,
          update_record0/0, fc/0, track_update_record/1,
          gh8124_a/0, gh8124_b/0, tuple_set_a/1, tuple_set_b/0,
-         failure_to_patch_list/0, erierl1208/0, gh_9903/0]).
+         failure_to_patch_list/0, erierl1208/0, gh_9903/0,
+         gh10367/0]).
 -record(r, {a=0,b=0,c=0,tot=0}).
 -record(r1, {a}).
 -record(r2, {b}).
@@ -279,7 +280,7 @@ tuple_set_a(Something) ->
 
 tuple_set_b() ->
 %ssa% () when post_ssa_opt ->
-%ssa% _ = update_record(inplace, 2, _, ...).
+%ssa% _ = update_record(copy, 2, _, ...).
     case tuple_set_a(ex:f()) of
 	{ok, A} ->
 	    case e:f() of
@@ -315,3 +316,21 @@ ftpl(Ts0) ->
 %ssa% _ = update_record(inplace, 5, X,...).
     A = erlang:timestamp(),
     Ts0#r{a=A}.
+
+gh10367_gen() ->
+    [#r4{a = a}, #r4{a = b, b = dict:new()}].
+
+gh10367_update([_, #r4{a = b} = P2]) ->
+%ssa% (X) when post_ssa_opt ->
+%ssa% _ = update_record(copy, 3, _, ...).
+    P2#r4{a = a};
+gh10367_update([_, #r4{a = a} = P2]) ->
+    P2#r4{a = b}.
+
+gh10367() ->
+%ssa% () when post_ssa_opt ->
+%ssa% _ = update_record(reuse, 3, _, ...).
+    [P1, P2] = gh10367_gen(),
+    Expected = P2#r4{a = a},
+    timer:sleep(0),
+    Expected = gh10367_update([P1, P2]).