From a7a43c50a4b3df5f0ac1965319de04234734dd14 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 3 Oct 2018 15:34:04 +0200
Subject: beam_ssa_bsm: Fix replacement of variables in a remote call
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Co-authored-by: John Högberg <john@erlang.org>
---
 lib/compiler/src/beam_ssa_bsm.erl    | 22 +++++++++++++++++++---
 lib/compiler/test/bs_match_SUITE.erl | 26 ++++++++++++++++++++++++--
 2 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/lib/compiler/src/beam_ssa_bsm.erl b/lib/compiler/src/beam_ssa_bsm.erl
index 2efeb6b5b6..9631bf3334 100644
--- a/lib/compiler/src/beam_ssa_bsm.erl
+++ b/lib/compiler/src/beam_ssa_bsm.erl
@@ -354,6 +354,11 @@ amb_get_alias(#b_var{}=Arg, Lbl, State) ->
         error ->
             {Arg, State}
     end;
+amb_get_alias(#b_remote{mod=Mod0,name=Name0}=Arg0, Lbl, State0) ->
+    {Mod, State1} = amb_get_alias(Mod0, Lbl, State0),
+    {Name, State} = amb_get_alias(Name0, Lbl, State1),
+    Arg = Arg0#b_remote{mod=Mod,name=Name},
+    {Arg, State};
 amb_get_alias(Arg, _Lbl, State) ->
     {Arg, State}.
 
@@ -391,15 +396,22 @@ amb_insert_promotions(Blocks0, State) ->
                 Block = maps:get(Lbl, Blocks),
 
                 Alias = Promotion#b_set.dst,
-                {Before, After} = splitwith(fun(#b_set{args=Args}) ->
-                                                    not member(Alias, Args)
-                                            end, Block#b_blk.is),
+                {Before, After} = splitwith(
+                                    fun(#b_set{args=Args}) ->
+                                            not is_var_in_args(Alias, Args)
+                                    end, Block#b_blk.is),
                 Is = Before ++ [Promotion | After],
 
                 maps:put(Lbl, Block#b_blk{is=Is}, Blocks)
         end,
     maps:fold(F, Blocks0, State#amb.promotions).
 
+is_var_in_args(Var, [Var | _]) -> true;
+is_var_in_args(Var, [#b_remote{name=Var} | _]) -> true;
+is_var_in_args(Var, [#b_remote{mod=Var} | _]) -> true;
+is_var_in_args(Var, [_ | Args]) -> is_var_in_args(Var, Args);
+is_var_in_args(_Var, []) -> false.
+
 %%%
 %%% Subpasses
 %%%
@@ -732,6 +744,10 @@ aca_cs_args([Arg | Args], VRs) ->
 aca_cs_args([], _VRs) ->
     [].
 
+aca_cs_arg(#b_remote{mod=Mod0,name=Name0}=Rem, VRs) ->
+    Mod = aca_cs_arg(Mod0, VRs),
+    Name = aca_cs_arg(Name0, VRs),
+    Rem#b_remote{mod=Mod,name=Name};
 aca_cs_arg(Arg, VRs) ->
     case VRs of
         #{ Arg := New } -> New;
diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl
index f021177c61..8e105c6244 100644
--- a/lib/compiler/test/bs_match_SUITE.erl
+++ b/lib/compiler/test/bs_match_SUITE.erl
@@ -42,7 +42,8 @@
 	 parse_xml/1,get_payload/1,escape/1,num_slots_different/1,
          beam_bsm/1,guard/1,is_ascii/1,non_opt_eq/1,
          expression_before_match/1,erl_689/1,restore_on_call/1,
-         restore_after_catch/1,matches_on_parameter/1,big_positions/1]).
+         restore_after_catch/1,matches_on_parameter/1,big_positions/1,
+         matching_meets_apply/1]).
 
 -export([coverage_id/1,coverage_external_ignore/2]).
 
@@ -76,7 +77,8 @@ groups() ->
        get_payload,escape,num_slots_different,
        beam_bsm,guard,is_ascii,non_opt_eq,
        expression_before_match,erl_689,restore_on_call,
-       matches_on_parameter,big_positions]}].
+       matches_on_parameter,big_positions,
+       matching_meets_apply]}].
 
 
 init_per_suite(Config) ->
@@ -1889,4 +1891,24 @@ bp_getpos(<<_:((1 bsl 27) - 8),T/bits>>) -> bp_getpos(T);
 bp_getpos(<<A,1:1,"gurka",A>>) -> {a,A};
 bp_getpos(<<B,"hello",B>>) -> {b,B}.
 
+matching_meets_apply(_Config) ->
+    <<"abc">> = do_matching_meets_apply(<<"/abc">>, []),
+    42 = do_matching_meets_apply(<<"">>, {erlang,-42}),
+    100 = do_matching_meets_apply(no_binary, {erlang,-100}),
+    ok.
+
+do_matching_meets_apply(<<$/, Rest/binary>>, _Handler) ->
+    id(Rest);
+do_matching_meets_apply(<<_/binary>>=Name, never_matches_a) ->
+    %% Used to crash the compiler because variables in a remote
+    %% were not handled properly by beam_ssa_bsm.
+    Name:foo(gurka);
+do_matching_meets_apply(<<_/binary>>=Name, never_matches_b) ->
+    %% Another case of the above.
+    foo:Name(gurka);
+do_matching_meets_apply(_Bin, {Handler, State}) ->
+    %% Another case of the above.
+    Handler:abs(State).
+
+
 id(I) -> I.
-- 
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