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-rw-r--r--lib/compiler/src/beam_except.erl173
1 files changed, 130 insertions, 43 deletions
diff --git a/lib/compiler/src/beam_except.erl b/lib/compiler/src/beam_except.erl
index 05c0f4fbc7..2305502800 100644
--- a/lib/compiler/src/beam_except.erl
+++ b/lib/compiler/src/beam_except.erl
@@ -31,7 +31,7 @@
%%% erlang:error(function_clause, Args) => jump FuncInfoLabel
%%%
--import(lists, [reverse/1]).
+-import(lists, [reverse/1,reverse/2,seq/2,splitwith/2]).
-spec module(beam_utils:module_code(), [compile:option()]) ->
{'ok',beam_utils:module_code()}.
@@ -53,7 +53,7 @@ function({function,Name,Arity,CLabel,Is0}) ->
-record(st,
{lbl :: beam_asm:label(), %func_info label
loc :: [_], %location for func_info
- arity :: arity() %arity for function
+ arity :: arity() %arity for function
}).
function_1(Is0) ->
@@ -74,27 +74,33 @@ translate([I|Is], St, Acc) ->
translate([], _, Acc) ->
reverse(Acc).
-translate_1(Ar, I, Is, St, [{line,_}=Line|Acc1]=Acc0) ->
- case dig_out(Ar, Acc1) of
+translate_1(Ar, I, Is, #st{arity=Arity}=St, [{line,_}=Line|Acc1]=Acc0) ->
+ case dig_out(Ar, Arity, Acc1) of
no ->
translate(Is, St, [I|Acc0]);
- {yes,{function_clause,Arity},Acc2} ->
- case {Line,St} of
- {{line,Loc},#st{lbl=Fi,loc=Loc,arity=Arity}} ->
+ {yes,function_clause,Acc2} ->
+ case {Is,Line,St} of
+ {[return|_],{line,Loc},#st{lbl=Fi,loc=Loc}} ->
Instr = {jump,{f,Fi}},
translate(Is, St, [Instr|Acc2]);
- {_,_} ->
- %% This must be "error(function_clause, Args)" in
- %% the Erlang source code or a fun. Don't translate.
+ {_,_,_} ->
+ %% Not a call_only instruction, or not the same
+ %% location information as in in the line instruction
+ %% before the func_info instruction. Not safe
+ %% to translate to a jump.
translate(Is, St, [I|Acc0])
end;
{yes,Instr,Acc2} ->
translate(Is, St, [Instr,Line|Acc2])
end.
-dig_out(Ar, [{kill,_}|Is]) ->
- dig_out(Ar, Is);
-dig_out(1, [{block,Bl0}|Is]) ->
+dig_out(1, _Arity, Is) ->
+ dig_out(Is);
+dig_out(2, Arity, Is) ->
+ dig_out_fc(Arity, Is);
+dig_out(_, _, _) -> no.
+
+dig_out([{block,Bl0}|Is]) ->
case dig_out_block(reverse(Bl0)) of
no -> no;
{yes,What,[]} ->
@@ -102,25 +108,13 @@ dig_out(1, [{block,Bl0}|Is]) ->
{yes,What,Bl} ->
{yes,What,[{block,Bl}|Is]}
end;
-dig_out(2, [{block,Bl}|Is]) ->
- case dig_out_block_fc(Bl) of
- no -> no;
- {yes,What} -> {yes,What,Is}
- end;
-dig_out(_, _) -> no.
+dig_out(_) -> no.
dig_out_block([{set,[{x,0}],[{atom,if_clause}],move}]) ->
{yes,if_end,[]};
dig_out_block([{set,[{x,0}],[{literal,{Exc,Value}}],move}|Is]) ->
translate_exception(Exc, {literal,Value}, Is, 0);
-dig_out_block([{set,[{x,0}],[Tuple],move},
- {set,[],[Value],put},
- {set,[],[{atom,Exc}],put},
- {set,[Tuple],[],{put_tuple,2}}|Is]) ->
- translate_exception(Exc, Value, Is, 3);
-dig_out_block([{set,[],[Value],put},
- {set,[],[{atom,Exc}],put},
- {set,[{x,0}],[],{put_tuple,2}}|Is]) ->
+dig_out_block([{set,[{x,0}],[{atom,Exc},Value],put_tuple2}|Is]) ->
translate_exception(Exc, Value, Is, 3);
dig_out_block(_) -> no.
@@ -138,23 +132,116 @@ fix_block(Is, Words) ->
reverse(fix_block_1(Is, Words)).
fix_block_1([{set,[],[],{alloc,Live,{F1,F2,Needed0,F3}}}|Is], Words) ->
- Needed = Needed0 - Words,
- true = Needed >= 0, %Assertion.
- [{set,[],[],{alloc,Live,{F1,F2,Needed,F3}}}|Is];
+ case Needed0 - Words of
+ 0 ->
+ Is;
+ Needed ->
+ true = Needed >= 0, %Assertion.
+ [{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)]),
+ {Is,Acc0} = splitwith(fun({label,_}) -> false;
+ ({test,_,_,_}) -> false;
+ (_) -> true
+ end, Is0),
+ {Regs,Acc} = dig_out_fc_1(reverse(Is), Regs0, Acc0),
+ case Regs of
+ #{{x,0}:={atom,function_clause},{x,1}:=Args} ->
+ case moves_from_stack(Args, 0, []) of
+ {Moves,Arity} ->
+ {yes,function_clause,reverse(Moves, Acc)};
+ {_,_} ->
+ no
+ end;
+ #{} ->
+ no
+ end.
-dig_out_block_fc([{set,[],[],{alloc,Live,_}}|Bl]) ->
- case dig_out_fc(Bl, Live-1, nil) of
- no ->
- no;
- yes ->
- {yes,{function_clause,Live}}
+dig_out_fc_1([{block,Bl}|Is], Regs0, Acc) ->
+ Regs = dig_out_fc_block(Bl, Regs0),
+ dig_out_fc_1(Is, Regs, Acc);
+dig_out_fc_1([{bs_set_position,_,_}=I|Is], Regs, Acc) ->
+ dig_out_fc_1(Is, Regs, [I|Acc]);
+dig_out_fc_1([{bs_get_tail,Src,Dst,Live0}|Is], Regs0, Acc) ->
+ Regs = prune_xregs(Live0, Regs0),
+ Live = dig_out_stack_live(Regs, Live0),
+ I = {bs_get_tail,Src,Dst,Live},
+ dig_out_fc_1(Is, Regs, [I|Acc]);
+dig_out_fc_1([_|_], _Regs, _Acc) ->
+ {#{},[]};
+dig_out_fc_1([], Regs, Acc) ->
+ {Regs,Acc}.
+
+dig_out_fc_block([{set,[],[],{alloc,Live,_}}|Is], Regs0) ->
+ Regs = prune_xregs(Live, Regs0),
+ dig_out_fc_block(Is, Regs);
+dig_out_fc_block([{set,[Dst],[Hd,Tl],put_list}|Is], Regs0) ->
+ Regs = Regs0#{Dst=>{cons,get_reg(Hd, Regs0),get_reg(Tl, Regs0)}},
+ dig_out_fc_block(Is, Regs);
+dig_out_fc_block([{set,[Dst],[Src],move}|Is], Regs0) ->
+ Regs = Regs0#{Dst=>get_reg(Src, Regs0)},
+ dig_out_fc_block(Is, Regs);
+dig_out_fc_block([{set,_,_,_}|_], _Regs) ->
+ %% Unknown instruction. Fail.
+ #{};
+dig_out_fc_block([], Regs) -> Regs.
+
+dig_out_stack_live(Regs, Default) ->
+ Reg = {x,2},
+ case Regs of
+ #{Reg:=List} ->
+ dig_out_stack_live_1(List, Default);
+ #{} ->
+ Default
+ end.
+
+dig_out_stack_live_1({cons,{arg,N},T}, Live) ->
+ dig_out_stack_live_1(T, max(N + 1, Live));
+dig_out_stack_live_1({cons,_,T}, Live) ->
+ dig_out_stack_live_1(T, Live);
+dig_out_stack_live_1(nil, Live) ->
+ Live;
+dig_out_stack_live_1(_, Live) -> Live.
+
+prune_xregs(Live, Regs) ->
+ maps:filter(fun({x,X}, _) -> X < Live end, Regs).
+
+moves_from_stack({cons,{arg,N},_}, I, _Acc) when N =/= I ->
+ %% Wrong argument. Give up.
+ {[],-1};
+moves_from_stack({cons,H,T}, I, Acc) ->
+ case H of
+ {arg,I} ->
+ moves_from_stack(T, I+1, Acc);
+ _ ->
+ moves_from_stack(T, I+1, [{move,H,{x,I}}|Acc])
end;
-dig_out_block_fc(_) -> no.
+moves_from_stack(nil, I, Acc) ->
+ {reverse(Acc),I};
+moves_from_stack({literal,[H|T]}, I, Acc) ->
+ Cons = {cons,tag_literal(H),tag_literal(T)},
+ moves_from_stack(Cons, I, Acc);
+moves_from_stack(_, _, _) ->
+ %% Not understood. Give up.
+ {[],-1}.
+
+
+get_reg(R, Regs) ->
+ case Regs of
+ #{R:=Val} -> Val;
+ #{} -> R
+ end.
-dig_out_fc([{set,[Dst],[{x,Reg},Dst0],put_list}|Is], Reg, Dst0) ->
- dig_out_fc(Is, Reg-1, Dst);
-dig_out_fc([{set,[{x,0}],[{atom,function_clause}],move}], -1, {x,1}) ->
- yes;
-dig_out_fc(_, _, _) -> no.
+tag_literal([]) -> nil;
+tag_literal(T) when is_atom(T) -> {atom,T};
+tag_literal(T) when is_float(T) -> {float,T};
+tag_literal(T) when is_integer(T) -> {integer,T};
+tag_literal(T) -> {literal,T}.
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-31 18:04:09 +0000