From 7d9dda27337271ee8cf0d85652c2f941f8a303d0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Mon, 1 Aug 2022 12:06:34 +0200
Subject: [PATCH] Eliminate crash in beam_ssa_bool

Fixes #6184
---
 lib/compiler/src/beam_ssa_bool.erl |  6 +++++-
 lib/compiler/test/guard_SUITE.erl  | 11 +++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/compiler/src/beam_ssa_bool.erl b/lib/compiler/src/beam_ssa_bool.erl
index 7a7209e1973e..fb72a78c29b6 100644
--- a/lib/compiler/src/beam_ssa_bool.erl
+++ b/lib/compiler/src/beam_ssa_bool.erl
@@ -435,7 +435,11 @@ pre_opt_terminator(#b_switch{arg=Arg0}=Sw0, Sub, Blocks) ->
 pre_opt_sw(#b_switch{arg=Arg,fail=Fail}=Sw, False, True, Sub, Blocks) ->
     case Sub of
         #{Arg:={true_or_any,PhiL}} ->
-            #{Fail:=FailBlk,False:=FalseBlk,PhiL:=PhiBlk} = Blocks,
+            #{Fail := FailBlk,False := FalseBlk} = Blocks,
+            PhiBlk = case Blocks of
+                         #{PhiL := PhiBlk0} -> PhiBlk0;
+                         #{} -> none
+                     end,
             case {FailBlk,FalseBlk,PhiBlk} of
                 {#b_blk{is=[],last=#b_br{succ=PhiL,fail=PhiL}},
                  #b_blk{is=[],last=#b_br{succ=PhiL,fail=PhiL}},
diff --git a/lib/compiler/test/guard_SUITE.erl b/lib/compiler/test/guard_SUITE.erl
index 9664b4cbfd02..1a96fa4b6ca0 100644
--- a/lib/compiler/test/guard_SUITE.erl
+++ b/lib/compiler/test/guard_SUITE.erl
@@ -2548,6 +2548,7 @@ beam_bool_SUITE(_Config) ->
     beam_ssa_bool_coverage(),
     bad_map_in_guard(),
     gh_6164(),
+    gh_6184(),
     ok.
 
 before_and_inside_if() ->
@@ -3076,6 +3077,16 @@ do_gh_6164(V1) ->
             end
     end.
 
+gh_6184() ->
+    {'EXIT',{function_clause,_}} = catch do_gh_6184(id(true), id({a,b,c})),
+    {'EXIT',{function_clause,_}} = catch do_gh_6184(true, true),
+    {'EXIT',{function_clause,_}} = catch do_gh_6184({a,b,c}, {x,y,z}),
+
+    ok.
+
+do_gh_6184(V1, V2) when (false and is_tuple(V2)) andalso (V1 orelse V2) ->
+    V2 orelse V2.
+
 -record(bad_map_in_guard, {name}).
 bad_map_in_guard() ->
     error = bad_map_in_guard_1().