diff options
Diffstat (limited to 'lib/compiler')
| -rw-r--r-- | lib/compiler/src/beam_bsm.erl | 13 | ||||
| -rw-r--r-- | lib/compiler/test/bs_match_SUITE.erl | 33 |
2 files changed, 43 insertions, 3 deletions
diff --git a/lib/compiler/src/beam_bsm.erl b/lib/compiler/src/beam_bsm.erl index 1c8e0e9854..abc6e96c85 100644 --- a/lib/compiler/src/beam_bsm.erl +++ b/lib/compiler/src/beam_bsm.erl @@ -310,7 +310,18 @@ btb_reaches_match_2([{test,bs_start_match2,{f,F},Live,[Bin,_],Ctx}|Is], end; btb_reaches_match_2([{test,_,{f,F},Ss}=I|Is], Regs, D0) -> btb_ensure_not_used(Ss, I, Regs), - D = btb_follow_branch(F, Regs, D0), + D1 = btb_follow_branch(F, Regs, D0), + D = case Is of + [{bs_context_to_binary,_}|_] -> + %% bs_context_to_binary following a test instruction + %% probably needs the current position to be saved as + %% the new start position, but we can't be sure. + %% Therefore, conservatively disable the optimization + %% (instead of forcing a saving of the position). + D1#btb{must_save=true,must_not_save=true}; + _ -> + D1 + end, btb_reaches_match_1(Is, Regs, D); btb_reaches_match_2([{test,_,{f,F},_,Ss,_}=I|Is], Regs, D0) -> btb_ensure_not_used(Ss, I, Regs), diff --git a/lib/compiler/test/bs_match_SUITE.erl b/lib/compiler/test/bs_match_SUITE.erl index e737839575..7814738449 100644 --- a/lib/compiler/test/bs_match_SUITE.erl +++ b/lib/compiler/test/bs_match_SUITE.erl @@ -40,7 +40,7 @@ map_and_binary/1,unsafe_branch_caching/1, bad_literals/1,good_literals/1,constant_propagation/1, parse_xml/1,get_payload/1,escape/1,num_slots_different/1, - beam_bsm/1,guard/1,is_ascii/1,non_opt_eq/1]). + beam_bsm/1,guard/1,is_ascii/1,non_opt_eq/1,erl_689/1]). -export([coverage_id/1,coverage_external_ignore/2]). @@ -72,7 +72,7 @@ groups() -> map_and_binary,unsafe_branch_caching, bad_literals,good_literals,constant_propagation,parse_xml, get_payload,escape,num_slots_different, - beam_bsm,guard,is_ascii,non_opt_eq]}]. + beam_bsm,guard,is_ascii,non_opt_eq,erl_689]}]. init_per_suite(Config) -> @@ -1688,6 +1688,35 @@ non_opt_eq([_|_], <<_,_/binary>>) -> non_opt_eq([], <<>>) -> true. +%% ERL-689 + +erl_689(Config) -> + {{0, 0, 0}, <<>>} = do_erl_689_1(<<0>>, ?MODULE), + {{2018, 8, 7}, <<>>} = do_erl_689_1(<<4,2018:16/little,8,7>>, ?MODULE), + {{0, 0, 0}, <<>>} = do_erl_689_2(?MODULE, <<0>>), + {{2018, 8, 7}, <<>>} = do_erl_689_2(?MODULE, <<4,2018:16/little,8,7>>), + ok. + +do_erl_689_1(<<Length, Data/binary>>, _) -> + case {Data, Length} of + {_, 0} -> + %% bs_context_to_binary would incorrectly set Data to the original + %% binary (before matching in the function head). + {{0, 0, 0}, Data}; + {<<Y:16/little, M, D, Rest/binary>>, 4} -> + {{Y, M, D}, Rest} + end. + +do_erl_689_2(_, <<Length, Data/binary>>) -> + case {Length, Data} of + {0, _} -> + %% bs_context_to_binary would incorrectly set Data to the original + %% binary (before matching in the function head). + {{0, 0, 0}, Data}; + {4, <<Y:16/little, M, D, Rest/binary>>} -> + {{Y, M, D}, Rest} + end. + check(F, R) -> R = F(). |