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-rw-r--r--lib/compiler/src/beam_except.erl7
-rw-r--r--lib/compiler/src/beam_ssa.erl28
-rw-r--r--lib/compiler/src/beam_ssa_bsm.erl6
-rw-r--r--lib/compiler/src/beam_ssa_codegen.erl15
-rw-r--r--lib/compiler/src/beam_ssa_dead.erl30
-rw-r--r--lib/compiler/src/beam_ssa_opt.erl66
-rw-r--r--lib/compiler/src/beam_ssa_pre_codegen.erl11
-rw-r--r--lib/compiler/src/beam_ssa_type.erl89
-rw-r--r--lib/compiler/src/beam_validator.erl12
-rw-r--r--lib/compiler/src/cerl.erl2
-rw-r--r--lib/compiler/src/v3_core.erl3
11 files changed, 164 insertions, 105 deletions
diff --git a/lib/compiler/src/beam_except.erl b/lib/compiler/src/beam_except.erl
index 28c89782c9..2305502800 100644
--- a/lib/compiler/src/beam_except.erl
+++ b/lib/compiler/src/beam_except.erl
@@ -140,8 +140,11 @@ fix_block_1([{set,[],[],{alloc,Live,{F1,F2,Needed0,F3}}}|Is], Words) ->
[{set,[],[],{alloc,Live,{F1,F2,Needed,F3}}}|Is]
end;
fix_block_1([I|Is], Words) ->
- [I|fix_block_1(Is, Words)].
-
+ [I|fix_block_1(Is, Words)];
+fix_block_1([], _Words) ->
+ %% Rare. The heap allocation was probably done by a binary
+ %% construction instruction.
+ [].
dig_out_fc(Arity, Is0) ->
Regs0 = maps:from_list([{{x,X},{arg,X}} || X <- seq(0, Arity-1)]),
diff --git a/lib/compiler/src/beam_ssa.erl b/lib/compiler/src/beam_ssa.erl
index a9977b0b1d..6492d1e1bf 100644
--- a/lib/compiler/src/beam_ssa.erl
+++ b/lib/compiler/src/beam_ssa.erl
@@ -96,7 +96,8 @@
%% To avoid the collapsing, change the value of SET_LIMIT to 50 in the
%% file erl_types.erl in the hipe application.
--type prim_op() :: 'bs_add' | 'bs_extract' | 'bs_init' | 'bs_init_writable' |
+-type prim_op() :: 'bs_add' | 'bs_extract' | 'bs_get_tail' |
+ 'bs_init' | 'bs_init_writable' |
'bs_match' | 'bs_put' | 'bs_start_match' | 'bs_test_tail' |
'bs_utf16_size' | 'bs_utf8_size' | 'build_stacktrace' |
'call' | 'catch_end' |
@@ -117,11 +118,12 @@
'+' | '-' | '*' | '/'.
%% Primops only used internally during code generation.
--type cg_prim_op() :: 'bs_get' | 'bs_match_string' | 'bs_restore' | 'bs_skip' |
+-type cg_prim_op() :: 'bs_get' | 'bs_get_position' | 'bs_match_string' |
+ 'bs_restore' | 'bs_save' | 'bs_set_position' | 'bs_skip' |
'copy' | 'put_tuple_arity' | 'put_tuple_element' |
- 'set_tuple_element'.
+ 'put_tuple_elements' | 'set_tuple_element'.
--import(lists, [foldl/3,keyfind/3,mapfoldl/3,member/2,reverse/1]).
+-import(lists, [foldl/3,keyfind/3,mapfoldl/3,member/2,reverse/1,umerge/1]).
-spec add_anno(Key, Value, Construct) -> Construct when
Key :: atom(),
@@ -649,12 +651,18 @@ is_commutative('=/=') -> true;
is_commutative('/=') -> true;
is_commutative(_) -> false.
-def_used_1([#b_blk{is=Is,last=Last}|Bs], Preds, Def0, Used0) ->
- {Def,Used1} = def_used_is(Is, Preds, Def0, Used0),
- Used = ordsets:union(used(Last), Used1),
- def_used_1(Bs, Preds, Def, Used);
-def_used_1([], _Preds, Def, Used) ->
- {ordsets:from_list(Def),Used}.
+def_used_1([#b_blk{is=Is,last=Last}|Bs], Preds, Def0, UsedAcc) ->
+ {Def,Used} = def_used_is(Is, Preds, Def0, used(Last)),
+ case Used of
+ [] ->
+ def_used_1(Bs, Preds, Def, UsedAcc);
+ [_|_] ->
+ def_used_1(Bs, Preds, Def, [Used|UsedAcc])
+ end;
+def_used_1([], _Preds, Def0, UsedAcc) ->
+ Def = ordsets:from_list(Def0),
+ Used = umerge(UsedAcc),
+ {Def,Used}.
def_used_is([#b_set{op=phi,dst=Dst,args=Args}|Is],
Preds, Def0, Used0) ->
diff --git a/lib/compiler/src/beam_ssa_bsm.erl b/lib/compiler/src/beam_ssa_bsm.erl
index 382e6f635e..1ac9e6a3bb 100644
--- a/lib/compiler/src/beam_ssa_bsm.erl
+++ b/lib/compiler/src/beam_ssa_bsm.erl
@@ -683,8 +683,12 @@ aca_copy_successors(Lbl0, Blocks0, Counter0) ->
Lbl = maps:get(Lbl0, BRs),
{Lbl, Blocks, Counter}.
+aca_cs_build_brs([?BADARG_BLOCK=Lbl | Path], Counter, Acc) ->
+ %% ?BADARG_BLOCK is a marker and not an actual block, so renaming it will
+ %% break exception handling.
+ aca_cs_build_brs(Path, Counter, Acc#{ Lbl => Lbl });
aca_cs_build_brs([Lbl | Path], Counter0, Acc) ->
- aca_cs_build_brs(Path, Counter0 + 1, maps:put(Lbl, Counter0, Acc));
+ aca_cs_build_brs(Path, Counter0 + 1, Acc#{ Lbl => Counter0 });
aca_cs_build_brs([], Counter, Acc) ->
{Acc, Counter}.
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/src/beam_ssa_dead.erl b/lib/compiler/src/beam_ssa_dead.erl
index bb43a550ae..64b9b3e222 100644
--- a/lib/compiler/src/beam_ssa_dead.erl
+++ b/lib/compiler/src/beam_ssa_dead.erl
@@ -436,8 +436,22 @@ get_phi_arg([{Val,From}|_], From) -> Val;
get_phi_arg([_|As], From) -> get_phi_arg(As, From).
eval_terminator(#b_br{bool=#b_var{}=Bool}=Br, Bs, _St) ->
- Val = get_value(Bool, Bs),
- beam_ssa:normalize(Br#b_br{bool=Val});
+ case get_value(Bool, Bs) of
+ #b_literal{val=Val}=Lit ->
+ case is_boolean(Val) of
+ true ->
+ beam_ssa:normalize(Br#b_br{bool=Lit});
+ false ->
+ %% Non-boolean literal. This means that this `br`
+ %% terminator will never actually be reached with
+ %% these bindings. (There must be a previous two-way
+ %% branch that branches the other way when Bool
+ %% is bound to a non-boolean literal.)
+ none
+ end;
+ #b_var{}=Var ->
+ beam_ssa:normalize(Br#b_br{bool=Var})
+ end;
eval_terminator(#b_br{bool=#b_literal{}}=Br, _Bs, _St) ->
beam_ssa:normalize(Br);
eval_terminator(#b_switch{arg=Arg,fail=Fail,list=List}=Sw, Bs, St) ->
@@ -680,11 +694,8 @@ will_succeed_test(is_list, is_nonempty_list) ->
maybe;
will_succeed_test(is_nonempty_list, is_list) ->
yes;
-will_succeed_test(T1, T2) ->
- case is_numeric_test(T1) andalso is_numeric_test(T2) of
- true -> maybe;
- false -> no
- end.
+will_succeed_test(_T1, _T2) ->
+ maybe.
will_succeed_1('=:=', A, '<', B) ->
if
@@ -769,11 +780,6 @@ will_succeed_vars('==', Val1, '/=', Val2) when Val1 == Val2 -> no;
will_succeed_vars(_, _, _, _) -> maybe.
-is_numeric_test(is_float) -> true;
-is_numeric_test(is_integer) -> true;
-is_numeric_test(is_number) -> true;
-is_numeric_test(_) -> false.
-
eval_type_test(Test, Arg) ->
case eval_type_test_1(Test, Arg) of
true -> yes;
diff --git a/lib/compiler/src/beam_ssa_opt.erl b/lib/compiler/src/beam_ssa_opt.erl
index 90c0d3cf16..229edc6a1d 100644
--- a/lib/compiler/src/beam_ssa_opt.erl
+++ b/lib/compiler/src/beam_ssa_opt.erl
@@ -904,8 +904,7 @@ cse_suitable(#b_set{}) -> false.
}).
ssa_opt_float({#st{ssa=Linear0,cnt=Count0}=St, FuncDb}) ->
- NonGuards0 = float_non_guards(Linear0),
- NonGuards = gb_sets:from_list(NonGuards0),
+ NonGuards = non_guards(Linear0),
Blocks = maps:from_list(Linear0),
Fs = #fs{non_guards=NonGuards,bs=Blocks},
{Linear,Count} = float_opt(Linear0, Count0, Fs),
@@ -916,15 +915,6 @@ float_blk_is_in_guard(#b_blk{last=#b_br{fail=F}}, #fs{non_guards=NonGuards}) ->
float_blk_is_in_guard(#b_blk{}, #fs{}) ->
false.
-float_non_guards([{L,#b_blk{is=Is}}|Bs]) ->
- case Is of
- [#b_set{op=landingpad}|_] ->
- [L|float_non_guards(Bs)];
- _ ->
- float_non_guards(Bs)
- end;
-float_non_guards([]) -> [?BADARG_BLOCK].
-
float_opt([{L,Blk}|Bs0], Count0, Fs) ->
case float_blk_is_in_guard(Blk, Fs) of
true ->
@@ -1774,35 +1764,44 @@ opt_bs_put_split_int_1(Int, L, R) ->
%%%
ssa_opt_tuple_size({#st{ssa=Linear0,cnt=Count0}=St, FuncDb}) ->
- {Linear,Count} = opt_tup_size(Linear0, Count0, []),
+ %% This optimization is only safe in guards, as prefixing tuple_size with
+ %% an is_tuple check prevents it from throwing an exception.
+ NonGuards = non_guards(Linear0),
+ {Linear,Count} = opt_tup_size(Linear0, NonGuards, Count0, []),
{St#st{ssa=Linear,cnt=Count}, FuncDb}.
-opt_tup_size([{L,#b_blk{is=Is,last=Last}=Blk}|Bs], Count0, Acc0) ->
+opt_tup_size([{L,#b_blk{is=Is,last=Last}=Blk}|Bs], NonGuards, Count0, Acc0) ->
case {Is,Last} of
{[#b_set{op={bif,'=:='},dst=Bool,args=[#b_var{}=Tup,#b_literal{val=Arity}]}],
#b_br{bool=Bool}} when is_integer(Arity), Arity >= 0 ->
- {Acc,Count} = opt_tup_size_1(Tup, L, Count0, Acc0),
- opt_tup_size(Bs, Count, [{L,Blk}|Acc]);
+ {Acc,Count} = opt_tup_size_1(Tup, L, NonGuards, Count0, Acc0),
+ opt_tup_size(Bs, NonGuards, Count, [{L,Blk}|Acc]);
{_,_} ->
- opt_tup_size(Bs, Count0, [{L,Blk}|Acc0])
+ opt_tup_size(Bs, NonGuards, Count0, [{L,Blk}|Acc0])
end;
-opt_tup_size([], Count, Acc) ->
+opt_tup_size([], _NonGuards, Count, Acc) ->
{reverse(Acc),Count}.
-opt_tup_size_1(Size, EqL, Count0, [{L,Blk0}|Acc]) ->
- case Blk0 of
- #b_blk{is=Is0,last=#b_br{bool=Bool,succ=EqL,fail=Fail}} ->
- case opt_tup_size_is(Is0, Bool, Size, []) of
- none ->
+opt_tup_size_1(Size, EqL, NonGuards, Count0, [{L,Blk0}|Acc]) ->
+ #b_blk{is=Is0,last=Last} = Blk0,
+ case Last of
+ #b_br{bool=Bool,succ=EqL,fail=Fail} ->
+ case gb_sets:is_member(Fail, NonGuards) of
+ true ->
{[{L,Blk0}|Acc],Count0};
- {PreIs,TupleSizeIs,Tuple} ->
- opt_tup_size_2(PreIs, TupleSizeIs, L, EqL,
- Tuple, Fail, Count0, Acc)
+ false ->
+ case opt_tup_size_is(Is0, Bool, Size, []) of
+ none ->
+ {[{L,Blk0}|Acc],Count0};
+ {PreIs,TupleSizeIs,Tuple} ->
+ opt_tup_size_2(PreIs, TupleSizeIs, L, EqL,
+ Tuple, Fail, Count0, Acc)
+ end
end;
- #b_blk{} ->
+ _ ->
{[{L,Blk0}|Acc],Count0}
end;
-opt_tup_size_1(_, _, Count, Acc) ->
+opt_tup_size_1(_, _, _, Count, Acc) ->
{Acc,Count}.
opt_tup_size_2(PreIs, TupleSizeIs, PreL, EqL, Tuple, Fail, Count0, Acc) ->
@@ -2241,6 +2240,19 @@ gcd(A, B) ->
X -> gcd(B, X)
end.
+non_guards(Linear) ->
+ gb_sets:from_list(non_guards_1(Linear)).
+
+non_guards_1([{L,#b_blk{is=Is}}|Bs]) ->
+ case Is of
+ [#b_set{op=landingpad}|_] ->
+ [L | non_guards_1(Bs)];
+ _ ->
+ non_guards_1(Bs)
+ end;
+non_guards_1([]) ->
+ [?BADARG_BLOCK].
+
rel2fam(S0) ->
S1 = sofs:relation(S0),
S = sofs:rel2fam(S1),
diff --git a/lib/compiler/src/beam_ssa_pre_codegen.erl b/lib/compiler/src/beam_ssa_pre_codegen.erl
index bf99e8fc26..9af72afca7 100644
--- a/lib/compiler/src/beam_ssa_pre_codegen.erl
+++ b/lib/compiler/src/beam_ssa_pre_codegen.erl
@@ -1415,12 +1415,15 @@ fix_receive([], _Defs, Blocks, Count) ->
find_loop_exit([L1,L2|_Ls], Blocks) ->
Path1 = beam_ssa:rpo([L1], Blocks),
Path2 = beam_ssa:rpo([L2], Blocks),
- find_loop_exit_1(reverse(Path1), reverse(Path2), none);
+ find_loop_exit_1(Path1, cerl_sets:from_list(Path2));
find_loop_exit(_, _) -> none.
-find_loop_exit_1([H|T1], [H|T2], _) ->
- find_loop_exit_1(T1, T2, H);
-find_loop_exit_1(_, _, Exit) -> Exit.
+find_loop_exit_1([H|T], OtherPath) ->
+ case cerl_sets:is_element(H, OtherPath) of
+ true -> H;
+ false -> find_loop_exit_1(T, OtherPath)
+ end;
+find_loop_exit_1([], _) -> none.
%% find_rm_blocks(StartLabel, Blocks) -> [Label].
%% Find all blocks that start with remove_message within the receive
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl
index 06b42f1928..68920e7dd3 100644
--- a/lib/compiler/src/beam_ssa_type.erl
+++ b/lib/compiler/src/beam_ssa_type.erl
@@ -23,8 +23,8 @@
-include("beam_ssa_opt.hrl").
-import(lists, [all/2,any/2,droplast/1,foldl/3,last/1,member/2,
- keyfind/3,partition/2,reverse/1,reverse/2,
- seq/2,sort/1,split/2]).
+ keyfind/3,reverse/1,reverse/2,
+ sort/1,split/2]).
-define(UNICODE_INT, #t_integer{elements={0,16#10FFFF}}).
@@ -840,15 +840,8 @@ type({bif,Bif}, Args, Ts, _Ds) ->
Type ->
Type
end;
-type(bs_init, [#b_literal{val=Type}|Args], _Ts, _Ds) ->
- case {Type,Args} of
- {new,[_,#b_literal{val=Unit}]} ->
- {binary,Unit};
- {append,[_,_,#b_literal{val=Unit}]} ->
- {binary,Unit};
- {private_append,[_,_,#b_literal{val=Unit}]} ->
- {binary,Unit}
- end;
+type(bs_init, _Args, _Ts, _Ds) ->
+ {binary, 1};
type(bs_extract, [Ctx], Ts, _Ds) ->
#t_bs_match{type=Type} = get_type(Ctx, Ts),
Type;
@@ -874,11 +867,11 @@ type(call, [#b_remote{mod=#b_literal{val=Mod},
true ->
none
end;
- {#t_integer{elements={Min,Max}},
+ {#t_integer{elements={Min,_}}=IntType,
#t_tuple{elements=Es0,size=Size}=T} ->
- %% We know this will land between Min and Max, so kill the
- %% types for those indexes.
- Es = maps:without(seq(Min, Max), Es0),
+ %% Remove type information for all indices that
+ %% falls into the range of the integer.
+ Es = remove_element_info(IntType, Es0),
case T#t_tuple.exact of
false ->
T#t_tuple{elements=Es,size=max(Min, Size)};
@@ -896,11 +889,15 @@ type(call, [#b_remote{mod=#b_literal{val=Mod},
{_,_} ->
#t_tuple{}
end;
- {erlang,'++',[List1,List2]} ->
- case get_type(List1, Ts) =:= cons orelse
- get_type(List2, Ts) =:= cons of
- true -> cons;
- false -> list
+ {erlang,'++',[LHS,RHS]} ->
+ LType = get_type(LHS, Ts),
+ RType = get_type(RHS, Ts),
+ case LType =:= cons orelse RType =:= cons of
+ true ->
+ cons;
+ false ->
+ %% `[] ++ RHS` yields RHS, even if RHS is not a list.
+ join(list, RType)
end;
{erlang,'--',[_,_]} ->
list;
@@ -1388,24 +1385,11 @@ get_type(#b_literal{val=Val}, _Ts) ->
%% type for L. For example, if L was known to be 'list', subtracting
%% 'cons' would give 'nil' as the only possible type. The result of the
%% subtraction for L will be added to FailTypes.
-%%
-%% Here is another example, asking about the variable Bool:
-%%
-%% Head = bif:hd L
-%% Bool = succeeded Head
-%%
-%% 'succeeded Head' will evaluate to 'true' if the instrution that
-%% defined Head succeeded. In this case, it is the 'bif:hd L'
-%% instruction, which will succeed if L is 'cons'. Thus, the meet of
-%% the previous type for L and 'cons' will be added to SuccTypes.
-%%
-%% If 'succeeded Head' evaluates to 'false', it means that 'bif:hd L'
-%% failed and that L is not 'cons'. 'cons' can be subtracted from the
-%% previously known type for L and the result put in FailTypes.
infer_types_br(#b_var{}=V, Ts, #d{ds=Ds}) ->
#{V:=#b_set{op=Op,args=Args}} = Ds,
- Types0 = infer_type(Op, Args, Ds),
+ PosTypes0 = infer_type(Op, Args, Ds),
+ NegTypes0 = infer_type_negative(Op, Args, Ds),
%% We must be careful with types inferred from '=:='.
%%
@@ -1416,13 +1400,17 @@ infer_types_br(#b_var{}=V, Ts, #d{ds=Ds}) ->
%%
%% However, it is safe to subtract a type inferred from '=:=' if
%% it is single-valued, e.g. if it is [] or the atom 'true'.
- EqTypes0 = infer_eq_type(Op, Args, Ts, Ds),
- {Types1,EqTypes} = partition(fun({_,T}) ->
- is_singleton_type(T)
- end, EqTypes0),
- Types = Types1 ++ Types0,
- {meet_types(EqTypes++Types, Ts),subtract_types(Types, Ts)}.
+ EqTypes = infer_eq_type(Op, Args, Ts, Ds),
+ NegTypes1 = [P || {_,T}=P <- EqTypes, is_singleton_type(T)],
+
+ PosTypes = EqTypes ++ PosTypes0,
+ SuccTs = meet_types(PosTypes, Ts),
+
+ NegTypes = NegTypes0 ++ NegTypes1,
+ FailTs = subtract_types(NegTypes, Ts),
+
+ {SuccTs,FailTs}.
infer_types_switch(V, Lit, Ts, #d{ds=Ds}) ->
Types = infer_eq_type({bif,'=:='}, [V, Lit], Ts, Ds),
@@ -1457,6 +1445,19 @@ infer_eq_lit(#b_set{op=get_tuple_element,
[{Tuple,#t_tuple{size=Index,elements=Es}}];
infer_eq_lit(_, _) -> [].
+infer_type_negative(Op, Args, Ds) ->
+ case is_negative_inference_safe(Op, Args) of
+ true ->
+ infer_type(Op, Args, Ds);
+ false ->
+ []
+ end.
+
+%% Conservative list of instructions for which negative
+%% inference is safe.
+is_negative_inference_safe(is_nonempty_list, _Args) -> true;
+is_negative_inference_safe(_, _) -> false.
+
infer_type({bif,element}, [#b_literal{val=Pos},#b_var{}=Tuple], _Ds) ->
if
is_integer(Pos), 1 =< Pos ->
@@ -1649,6 +1650,12 @@ get_literal_from_type(nil) ->
#b_literal{val=[]};
get_literal_from_type(_) -> none.
+remove_element_info(#t_integer{elements={Min,Max}}, Es) ->
+ foldl(fun(El, Acc) when Min =< El, El =< Max ->
+ maps:remove(El, Acc);
+ (_El, Acc) -> Acc
+ end, Es, maps:keys(Es)).
+
t_atom() ->
#t_atom{elements=any}.
diff --git a/lib/compiler/src/beam_validator.erl b/lib/compiler/src/beam_validator.erl
index 09a5a6c104..ebe9631e09 100644
--- a/lib/compiler/src/beam_validator.erl
+++ b/lib/compiler/src/beam_validator.erl
@@ -2844,10 +2844,14 @@ call_return_type_1(erlang, setelement, 3, Vst) ->
setelement(3, TupleType, #{})
end;
call_return_type_1(erlang, '++', 2, Vst) ->
- case get_term_type({x,0}, Vst) =:= cons orelse
- get_term_type({x,1}, Vst) =:= cons of
- true -> cons;
- false -> list
+ LType = get_term_type({x,0}, Vst),
+ RType = get_term_type({x,1}, Vst),
+ case LType =:= cons orelse RType =:= cons of
+ true ->
+ cons;
+ false ->
+ %% `[] ++ RHS` yields RHS, even if RHS is not a list
+ join(list, RType)
end;
call_return_type_1(erlang, '--', 2, _Vst) ->
list;
diff --git a/lib/compiler/src/cerl.erl b/lib/compiler/src/cerl.erl
index 62cd5b5120..bc28f58712 100644
--- a/lib/compiler/src/cerl.erl
+++ b/lib/compiler/src/cerl.erl
@@ -263,7 +263,7 @@
%% @see subtrees/1
%% @see meta/1
--type ctype() :: 'alias' | 'apply' | 'binary' | 'bitrst' | 'call' | 'case'
+-type ctype() :: 'alias' | 'apply' | 'binary' | 'bitstr' | 'call' | 'case'
| 'catch' | 'clause' | 'cons' | 'fun' | 'let' | 'letrec'
| 'literal' | 'map' | 'map_pair' | 'module' | 'primop'
| 'receive' | 'seq' | 'try' | 'tuple' | 'values' | 'var'.
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 3699c9d22e..007a0247f4 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1811,7 +1811,8 @@ force_safe(Ce, St0) ->
is_safe(#c_cons{}) -> true;
is_safe(#c_tuple{}) -> true;
-is_safe(#c_var{}) -> true;
+is_safe(#c_var{name={_,_}}) -> false; %Fun. Not safe.
+is_safe(#c_var{name=_}) -> true; %Ordinary variable.
is_safe(#c_literal{}) -> true;
is_safe(_) -> false.