From 73c5ceba1185b0be7db9acac8593e5b913dba845 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 27 May 2019 04:46:41 +0200 Subject: Fix loading of Core Erlang code for extracting a map element The following Core Erlang code could not be loaded: 'f'/1 = fun (_1) -> case <_1> of <~{'foo':='foo'}~> when 'true' -> _1 end Loading would fail with the following message: beam/beam_load.c(2314): Error loading function example:f/1: op i_get_map_element_hash p x a u x: no specific operation found https://bugs.erlang.org/browse/ERL-955 --- lib/compiler/src/beam_ssa_codegen.erl | 15 +++++++++++++-- lib/compiler/test/core_SUITE.erl | 7 +++++-- lib/compiler/test/core_SUITE_data/get_map_element.core | 18 ++++++++++++++++++ 3 files changed, 36 insertions(+), 4 deletions(-) create mode 100644 lib/compiler/test/core_SUITE_data/get_map_element.core diff --git a/lib/compiler/src/beam_ssa_codegen.erl b/lib/compiler/src/beam_ssa_codegen.erl index c2d5035b19..07f4c8b461 100644 --- a/lib/compiler/src/beam_ssa_codegen.erl +++ b/lib/compiler/src/beam_ssa_codegen.erl @@ -1016,6 +1016,14 @@ bif_fail({catch_tag,_}) -> {f,0}. next_block([]) -> none; next_block([{Next,_}|_]) -> Next. +%% Certain instructions (such as get_map_element or is_nonempty_list) +%% are only used in guards and **must** have a non-zero label; +%% otherwise, the loader will refuse to load the +%% module. ensure_label/2 replaces a zero label with the "ultimate +%% failure" label to make the module loadable. The instruction that +%% have had the zero label replaced is **not** supposed to ever fail +%% and actually jump to the label. + ensure_label(Fail0, #cg{ultimate_fail=Lbl}) -> case bif_fail(Fail0) of {f,0} -> {f,Lbl}; @@ -1160,6 +1168,11 @@ cg_block([#cg_set{op=call}=I, #cg_set{op=succeeded,dst=Bool}], {Bool,_Fail}, St) -> %% A call in try/catch block. cg_block([I], none, St); +cg_block([#cg_set{op=get_map_element,dst=Dst0,args=Args0}, + #cg_set{op=succeeded,dst=Bool}], {Bool,Fail0}, St) -> + [Dst,Map,Key] = beam_args([Dst0|Args0], St), + Fail = ensure_label(Fail0, St), + {[{get_map_elements,Fail,Map,{list,[Key,Dst]}}],St}; cg_block([#cg_set{op=Op,dst=Dst0,args=Args0}=I, #cg_set{op=succeeded,dst=Bool}], {Bool,Fail}, St) -> [Dst|Args] = beam_args([Dst0|Args0], St), @@ -1606,8 +1619,6 @@ cg_test({float,Op0}, Fail, Args, Dst, #cg_set{anno=Anno}) -> '/' -> fdiv end, [line(Anno),{bif,Op,Fail,Args,Dst}]; -cg_test(get_map_element, Fail, [Map,Key], Dst, _I) -> - [{get_map_elements,Fail,Map,{list,[Key,Dst]}}]; cg_test(peek_message, Fail, [], Dst, _I) -> [{loop_rec,Fail,{x,0}}|copy({x,0}, Dst)]; cg_test(put_map, Fail, [{atom,exact},SrcMap|Ss], Dst, Set) -> diff --git a/lib/compiler/test/core_SUITE.erl b/lib/compiler/test/core_SUITE.erl index e5611e99d1..72016c6d76 100644 --- a/lib/compiler/test/core_SUITE.erl +++ b/lib/compiler/test/core_SUITE.erl @@ -29,7 +29,8 @@ bs_shadowed_size_var/1, cover_v3_kernel_1/1,cover_v3_kernel_2/1,cover_v3_kernel_3/1, cover_v3_kernel_4/1,cover_v3_kernel_5/1, - non_variable_apply/1,name_capture/1,fun_letrec_effect/1]). + non_variable_apply/1,name_capture/1,fun_letrec_effect/1, + get_map_element/1]). -include_lib("common_test/include/ct.hrl"). @@ -57,7 +58,8 @@ groups() -> bs_shadowed_size_var, cover_v3_kernel_1,cover_v3_kernel_2,cover_v3_kernel_3, cover_v3_kernel_4,cover_v3_kernel_5, - non_variable_apply,name_capture,fun_letrec_effect + non_variable_apply,name_capture,fun_letrec_effect, + get_map_element ]}]. @@ -95,6 +97,7 @@ end_per_group(_GroupName, Config) -> ?comp(non_variable_apply). ?comp(name_capture). ?comp(fun_letrec_effect). +?comp(get_map_element). try_it(Mod, Conf) -> Src = filename:join(proplists:get_value(data_dir, Conf), diff --git a/lib/compiler/test/core_SUITE_data/get_map_element.core b/lib/compiler/test/core_SUITE_data/get_map_element.core new file mode 100644 index 0000000000..092b5e71eb --- /dev/null +++ b/lib/compiler/test/core_SUITE_data/get_map_element.core @@ -0,0 +1,18 @@ +module 'get_map_element' ['get_map_element'/0] +attributes [] + +'get_map_element'/0 = + fun () -> + apply 'match_map'/1(~{'foo'=>'bar'}~) + +'match_map'/1 = + fun (_0) -> + case _0 of + <~{'foo':='bar'}~> when 'true' -> + 'ok' + %% It will be undefined behaviour at runtime if no + %% clause of the case can be selected. That can't + %% happen for this module, because match_map/1 is + %% always called with a matching map argument. + end +end -- cgit v1.2.3