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-rw-r--r--lib/compiler/src/beam_ssa_codegen.erl15
1 files changed, 13 insertions, 2 deletions
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) ->