From e553fbc8d6e55773172358f75c7e83ab38f0cb4c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 29 Jul 2019 14:21:51 +0200 Subject: Fix unsafe code sharing --- lib/compiler/src/beam_ssa_share.erl | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'lib/compiler/src/beam_ssa_share.erl') diff --git a/lib/compiler/src/beam_ssa_share.erl b/lib/compiler/src/beam_ssa_share.erl index 426efa2cc9..73983bd34a 100644 --- a/lib/compiler/src/beam_ssa_share.erl +++ b/lib/compiler/src/beam_ssa_share.erl @@ -303,8 +303,12 @@ canonical_is([#b_ret{arg=Arg}], VarMap, Acc0) -> Acc0 end, {{ret,canonical_arg(Arg, VarMap),Acc1},VarMap}; -canonical_is([#b_br{bool=#b_var{},fail=Fail}], VarMap, Acc) -> - {{br,succ,Fail,Acc},VarMap}; +canonical_is([#b_br{bool=#b_var{}=Arg,fail=Fail}], VarMap, Acc) -> + %% A previous buggy version of this code omitted the canonicalized + %% argument in the return value. Unfortunately, that worked most + %% of the time, except when `br` terminator referenced a variable + %% defined in a previous block instead of in the same block. + {{br,canonical_arg(Arg, VarMap),succ,Fail,Acc},VarMap}; canonical_is([#b_br{succ=Succ}], VarMap, Acc) -> {{br,Succ,Acc},VarMap}; canonical_is([], VarMap, Acc) -> -- cgit v1.2.3