From 8369dbfe5b5d70de339f9a8a84931d4ba354d6e7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 28 May 2013 14:10:13 +0200 Subject: asn1ct_imm: Break out the rule for string alignment Break out the the rules for determining whether a string should be in aligned so that it can be reused for encoding. --- lib/asn1/src/asn1ct_imm.erl | 57 ++++++++++++++++++++++++++------------------- 1 file changed, 33 insertions(+), 24 deletions(-) (limited to 'lib/asn1/src/asn1ct_imm.erl') diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl index bf362db843..a7e62e061b 100644 --- a/lib/asn1/src/asn1ct_imm.erl +++ b/lib/asn1/src/asn1ct_imm.erl @@ -115,25 +115,15 @@ per_dec_named_integer(Constraint, NamedList0, Aligned) -> per_dec_k_m_string(StringType, Constraint, Aligned) -> SzConstr = effective_constraint(bitstring, Constraint), N = string_num_bits(StringType, Constraint, Aligned), - %% X.691 (07/2002) 27.5.7 says if the upper bound times the number - %% of bits is greater than or equal to 16, then the bit field should - %% be aligned. - Imm = dec_string(SzConstr, N, Aligned, fun(_, Ub) -> Ub >= 16 end), + Imm = dec_string(SzConstr, N, Aligned, k_m_string), Chars = char_tab(Constraint, StringType, N), convert_string(N, Chars, Imm). per_dec_octet_string(Constraint, Aligned) -> - dec_string(Constraint, 8, Aligned, - %% Aligned unless the size is fixed and =< 16. - fun(Sv, Sv) -> Sv > 16; - (_, _) -> true - end). + dec_string(Constraint, 8, Aligned, 'OCTET STRING'). per_dec_raw_bitstring(Constraint, Aligned) -> - dec_string(Constraint, 1, Aligned, - fun(Sv, Sv) -> Sv > 16; - (_, _) -> true - end). + dec_string(Constraint, 1, Aligned, 'BIT STRING'). per_dec_open_type(Aligned) -> {get_bits,decode_unconstrained_length(true, Aligned), @@ -157,21 +147,40 @@ per_dec_restricted_string(Aligned) -> %%% Local functions. %%% -dec_string(Sv, U, Aligned0, AF) when is_integer(Sv) -> +%% is_aligned(StringType, LowerBound, UpperBound) -> boolean() +%% StringType = 'OCTET STRING' | 'BIT STRING' | k_m_string +%% LowerBound = UpperBound = number of bits +%% Determine whether a string should be aligned in PER. + +is_aligned(T, Lb, Ub) when T =:= 'OCTET STRING'; T =:= 'BIT STRING' -> + %% OCTET STRINGs and BIT STRINGs are aligned to a byte boundary + %% unless the size is fixed and less than or equal to 16 bits. + Lb =/= Ub orelse Lb > 16; +is_aligned(k_m_string, _Lb, Ub) -> + %% X.691 (07/2002) 27.5.7 says if the upper bound times the number + %% of bits is greater than or equal to 16, then the bit field should + %% be aligned. + Ub >= 16. + +%%% +%%% Generating the intermediate format format for decoding. +%%% + +dec_string(Sv, U, Aligned0, T) when is_integer(Sv) -> Bits = U*Sv, - Aligned = Aligned0 andalso AF(Bits, Bits), + Aligned = Aligned0 andalso is_aligned(T, Bits, Bits), {get_bits,Sv,[U,binary,{align,Aligned}]}; -dec_string({{Sv,Sv},[]}, U, Aligned, AF) -> - bit_case(dec_string(Sv, U, Aligned, AF), - dec_string(no, U, Aligned, AF)); -dec_string({{_,_}=C,[]}, U, Aligned, AF) -> - bit_case(dec_string(C, U, Aligned, AF), - dec_string(no, U, Aligned, AF)); -dec_string({Lb,Ub}, U, Aligned0, AF) -> +dec_string({{Sv,Sv},[]}, U, Aligned, T) -> + bit_case(dec_string(Sv, U, Aligned, T), + dec_string(no, U, Aligned, T)); +dec_string({{_,_}=C,[]}, U, Aligned, T) -> + bit_case(dec_string(C, U, Aligned, T), + dec_string(no, U, Aligned, T)); +dec_string({Lb,Ub}, U, Aligned0, T) -> Len = per_dec_constrained(Lb, Ub, Aligned0), - Aligned = Aligned0 andalso AF(Lb*U, Ub*U), + Aligned = Aligned0 andalso is_aligned(T, Lb*U, Ub*U), {get_bits,Len,[U,binary,{align,Aligned}]}; -dec_string(_, U, Aligned, _AF) -> +dec_string(_, U, Aligned, _T) -> Al = [{align,Aligned}], DecRest = fun(V, Buf) -> asn1ct_func:call(per_common, -- cgit v1.2.3 From eb49ee71f0751cf54bc39f9971f389c92525b0a4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 15 Apr 2013 18:02:45 +0200 Subject: PER, UPER: Optimize encoding using an intermediate format There are some minor incompatibilities for BIT STRING: {bit,Position} is now only only supported for a named BIT STRING type. Values longer than the maximum size for the BIT STRING type would be truncated silently - they now cause an exception. --- lib/asn1/src/asn1ct_imm.erl | 1411 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1411 insertions(+) (limited to 'lib/asn1/src/asn1ct_imm.erl') diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl index a7e62e061b..44282b4b55 100644 --- a/lib/asn1/src/asn1ct_imm.erl +++ b/lib/asn1/src/asn1ct_imm.erl @@ -26,6 +26,18 @@ per_dec_octet_string/2,per_dec_open_type/1,per_dec_real/1, per_dec_restricted_string/1]). -export([per_dec_constrained/3,per_dec_normally_small_number/1]). +-export([per_enc_bit_string/4,per_enc_boolean/2, + per_enc_choice/3,per_enc_enumerated/3, + per_enc_integer/3,per_enc_integer/4, + per_enc_null/2, + per_enc_k_m_string/4,per_enc_octet_string/3, + per_enc_open_type/2, + per_enc_restricted_string/3, + per_enc_small_number/2]). +-export([per_enc_extension_bit/2,per_enc_extensions/4,per_enc_optional/3]). +-export([per_enc_sof/5]). +-export([enc_absent/3,enc_append/1,enc_bind_var/1]). +-export([enc_cg/2]). -export([optimize_alignment/1,optimize_alignment/2, dec_slim_cg/2,dec_code_gen/2]). -export([effective_constraint/2]). @@ -142,6 +154,246 @@ per_dec_restricted_string(Aligned) -> DecLen = decode_unconstrained_length(true, Aligned), {get_bits,DecLen,[8,binary]}. +%%% +%%% Encoding. +%%% + +per_enc_bit_string(Val0, [], Constraint0, Aligned) -> + {B,[Val,Bs,Bits]} = mk_vars(Val0, [bs,bits]), + Constraint = effective_constraint(bitstring, Constraint0), + ExtraArgs = case constr_min_size(Constraint) of + no -> []; + Lb -> [Lb] + end, + B ++ [{call,per_common,to_bitstring,[Val|ExtraArgs],Bs}, + {call,erlang,bit_size,[Bs],Bits}| + per_enc_length(Bs, 1, Bits, Constraint, Aligned, 'BIT STRING')]; +per_enc_bit_string(Val0, NNL0, Constraint0, Aligned) -> + {B,[Val,Bs,Bits,Positions]} = mk_vars(Val0, [bs,bits,positions]), + NNL = lists:keysort(2, NNL0), + Constraint = effective_constraint(bitstring, Constraint0), + ExtraArgs = case constr_min_size(Constraint) of + no -> []; + Lb -> [Lb] + end, + B ++ [{'try', + [bit_string_name2pos_fun(NNL, Val)], + {Positions, + [{call,per_common,bitstring_from_positions, + [Positions|ExtraArgs]}]}, + [{call,per_common,to_named_bitstring,[Val|ExtraArgs]}],Bs}, + {call,erlang,bit_size,[Bs],Bits}| + per_enc_length(Bs, 1, Bits, Constraint, Aligned, 'BIT STRING')]. + +per_enc_boolean(Val0, _Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + B++build_cond([[{eq,Val,false},{put_bits,0,1,[1]}], + [{eq,Val,true},{put_bits,1,1,[1]}]]). + +per_enc_choice(Val0, Cs0, _Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + Cs = [[{eq,Val,Tag}|opt_choice(Imm)] || {Tag,Imm} <- Cs0], + B++build_cond(Cs). + +per_enc_enumerated(Val0, {Root,Ext}, Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + Constr = enumerated_constraint(Root), + RootCs = per_enc_enumerated_root(Root, [{put_bits,0,1,[1]}], + Val, Constr, Aligned), + ExtCs = per_enc_enumerated_ext(Ext, Val, Aligned), + B++[{'cond',RootCs++ExtCs++enumerated_error(Val)}]; +per_enc_enumerated(Val0, Root, Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + Constr = enumerated_constraint(Root), + Cs = per_enc_enumerated_root(Root, [], Val, Constr, Aligned), + B++[{'cond',Cs++enumerated_error(Val)}]. + +enumerated_error(Val) -> + [['_',{error,Val}]]. + +per_enc_integer(Val0, Constraint0, Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + Constraint = effective_constraint(integer, Constraint0), + B ++ per_enc_integer_1(Val, Constraint, Aligned). + +per_enc_integer(Val0, NNL, Constraint0, Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + Constraint = effective_constraint(integer, Constraint0), + Cs = [[{eq,Val,N}|per_enc_integer_1(V, Constraint, Aligned)] || + {N,V} <- NNL], + case per_enc_integer_1(Val, Constraint, Aligned) of + [{'cond',IntCs}] -> + B ++ [{'cond',Cs++IntCs}]; + Other -> + B ++ [{'cond',Cs++[['_'|Other]]}] + end. + +per_enc_null(_Val, _Aligned) -> + []. + +per_enc_k_m_string(Val0, StringType, Constraint, Aligned) -> + {B,[Val,Bin,Len]} = mk_vars(Val0, [bin,len]), + SzConstraint = effective_constraint(bitstring, Constraint), + Unit = string_num_bits(StringType, Constraint, Aligned), + Chars0 = char_tab(Constraint, StringType, Unit), + Args = case enc_char_tab(Chars0) of + notab -> [Val,Unit]; + Chars -> [Val,Unit,Chars] + end, + Enc = case Unit of + 16 -> + {call,per_common,encode_chars_16bit,[Val],Bin}; + 32 -> + {call,per_common,encode_big_chars,[Val],Bin}; + 8 -> + {call,erlang,list_to_binary,[Val],Bin}; + _ -> + {call,per_common,encode_chars,Args,Bin} + end, + case Unit of + 8 -> + B ++ [Enc,{call,erlang,byte_size,[Bin],Len}]; + _ -> + B ++ [{call,erlang,length,[Val],Len},Enc] + end ++ per_enc_length(Bin, Unit, Len, SzConstraint, Aligned, k_m_string). + +per_enc_open_type([], Aligned) -> + [{put_bits,1,8,unit(1, Aligned)},{put_bits,0,8,[1]}]; +per_enc_open_type([{'cond', + [['_', + {put_bits,0,0,_}, + {call,per_common,encode_unconstrained_number,_}=Call]]}], + Aligned) -> + %% We KNOW that encode_unconstrained_number/1 will return an IO list; + %% therefore the call to complete/1 can be replaced with a cheaper + %% call to iolist_to_binary/1. + {Dst,Imm} = per_enc_open_type_output([Call], []), + ToBin = {erlang,iolist_to_binary}, + Imm ++ per_enc_open_type(Dst, ToBin, Aligned); +per_enc_open_type([{call,erlang,iolist_to_binary,Args}], Aligned) -> + {_,[_,Bin,Len]} = mk_vars('dummy', [bin,len]), + [{call,erlang,iolist_to_binary,Args,Bin}, + {call,erlang,byte_size,[Bin],Len}|per_enc_length(Bin, 8, Len, Aligned)]; +per_enc_open_type(Imm0, Aligned) -> + try + {Prefix,Imm1} = split_off_nonbuilding(Imm0), + Prefix ++ enc_open_type(Imm1, Aligned) + catch + throw:impossible -> + {Dst,Imm} = per_enc_open_type_output(Imm0, []), + ToBin = {enc_mod(Aligned),complete}, + Imm ++ per_enc_open_type(Dst, ToBin, Aligned) + end. + +per_enc_octet_string(Val0, Constraint0, Aligned) -> + {B,[Val,Bin,Len]} = mk_vars(Val0, [bin,len]), + Constraint = effective_constraint(bitstring, Constraint0), + B ++ [{call,erlang,iolist_to_binary,[Val],Bin}, + {call,erlang,byte_size,[Bin],Len}| + per_enc_length(Bin, 8, Len, Constraint, Aligned, 'OCTET STRING')]. + +per_enc_restricted_string(Val0, {M,F}, Aligned) -> + {B,[Val,Bin,Len]} = mk_vars(Val0, [bin,len]), + B ++ [{call,M,F,[Val],Bin}, + {call,erlang,byte_size,[Bin],Len}| + per_enc_length(Bin, 8, Len, Aligned)]. + +per_enc_small_number(Val, Aligned) -> + build_cond([[{lt,Val,64},{put_bits,Val,7,[1]}], + ['_',{put_bits,1,1,[1]}| + per_enc_unsigned(Val, Aligned)]]). + +per_enc_extension_bit(Val0, _Aligned) -> + {B,[Val]} = mk_vars(Val0, []), + B++build_cond([[{eq,Val,[]},{put_bits,0,1,[1]}], + ['_',{put_bits,1,1,[1]}]]). + +per_enc_extensions(Val0, Pos0, NumBits, Aligned) when NumBits > 0 -> + Pos = Pos0 + 1, + {B,[Val,Bitmap]} = mk_vars(Val0, [bitmap]), + Length = per_enc_small_length(NumBits, Aligned), + PutBits = case NumBits of + 1 -> [{put_bits,1,1,[1]}]; + _ -> [{put_bits,Bitmap,NumBits,[1]}] + end, + B++[{call,per_common,extension_bitmap,[Val,Pos,Pos+NumBits],Bitmap}, + {'cond',[[{eq,Bitmap,0}], + ['_'|Length ++ PutBits]],{var,"Extensions"}}]. + +per_enc_optional(Val0, {Pos,Def}, _Aligned) when is_integer(Pos) -> + Val1 = lists:concat(["element(",Pos,", ",Val0,")"]), + {B,[Val]} = mk_vars(Val1, []), + Zero = {put_bits,0,1,[1]}, + One = {put_bits,1,1,[1]}, + B++[{'cond',[[{eq,Val,asn1_DEFAULT},Zero], + [{eq,Val,Def},Zero], + ['_',One]]}]; +per_enc_optional(Val0, Pos, _Aligned) when is_integer(Pos) -> + Val1 = lists:concat(["element(",Pos,", ",Val0,")"]), + {B,[Val]} = mk_vars(Val1, []), + Zero = {put_bits,0,1,[1]}, + One = {put_bits,1,1,[1]}, + B++[{'cond',[[{eq,Val,asn1_NOVALUE},Zero], + ['_',One]]}]. + +per_enc_sof(Val0, Constraint, ElementVar, ElementImm, Aligned) -> + {B,[Val,Len]} = mk_vars(Val0, [len]), + SzConstraint = effective_constraint(bitstring, Constraint), + LenImm = enc_length(Len, SzConstraint, Aligned), + Lc0 = [{lc,ElementImm,{var,atom_to_list(ElementVar)},Val}], + Lc = opt_lc(Lc0, LenImm), + PreBlock = B ++ [{call,erlang,length,[Val],Len}], + case LenImm of + [{'cond',[[C|Action]]}] -> + PreBlock ++ [{'cond',[[C|Action++Lc]]}]; + [{sub,_,_,_}=Sub,{'cond',[[C|Action]]}] -> + PreBlock ++ + [Sub,{'cond',[[C|Action++Lc]]}]; + EncLen -> + PreBlock ++ EncLen ++ Lc + end. + +enc_absent(Val0, AbsVals, Body) -> + {B,[Var]} = mk_vars(Val0, []), + Cs = [[{eq,Var,Aval}] || Aval <- AbsVals] ++ [['_'|Body]], + B++build_cond(Cs). + +enc_append([[]|T]) -> + enc_append(T); +enc_append([[{put_bits,_,_,_}|_]=Pb|[Imm|T]=T0]) -> + case opt_choice(Pb++Imm) of + [{put_bits,_,_,_}|_] -> + [{block,Pb}|enc_append(T0)]; + Opt -> + enc_append([Opt|T]) + end; +enc_append([Imm0|[Imm1|T]=T0]) -> + try combine_imms(Imm0, Imm1) of + Imm -> + enc_append([Imm|T]) + catch + throw:impossible -> + [{block,Imm0}|enc_append(T0)] + end; +enc_append([H|T]) -> + [{block,H}|enc_append(T)]; +enc_append([]) -> []. + +enc_bind_var(Val) -> + {B,[{var,Var}]} = mk_vars(Val, []), + {B,list_to_atom(Var)}. + +enc_cg(Imm0, false) -> + Imm1 = enc_cse(Imm0), + Imm = enc_pre_cg(Imm1), + enc_cg(Imm); +enc_cg(Imm0, true) -> + Imm1 = enc_cse(Imm0), + Imm2 = enc_hoist_align(Imm1), + Imm3 = enc_opt_al(Imm2), + Imm4 = per_fixup(Imm3), + Imm = enc_pre_cg(Imm4), + enc_cg(Imm). %%% %%% Local functions. @@ -701,6 +953,1165 @@ mk_dest(I) when is_integer(I) -> integer_to_list(I); mk_dest(S) -> S. +%%% +%%% Constructing the intermediate format for encoding. +%%% + +split_off_nonbuilding(Imm) -> + lists:splitwith(fun is_nonbuilding/1, Imm). + +is_nonbuilding({apply,_,_,_}) -> true; +is_nonbuilding({assign,_,_}) -> true; +is_nonbuilding({call,_,_,_,_}) -> true; +is_nonbuilding({'cond',_,_}) -> true; +is_nonbuilding({lc,_,_,_,_}) -> true; +is_nonbuilding({sub,_,_,_}) -> true; +is_nonbuilding({'try',_,_,_,_}) -> true; +is_nonbuilding(_) -> false. + +mk_vars(Input0, Temps) -> + asn1ct_name:new(enc), + Curr = asn1ct_name:curr(enc), + [H|T] = atom_to_list(Curr), + Base = [H - ($a - $A)|T ++ "@"], + if + is_atom(Input0) -> + Input = {var,atom_to_list(Input0)}, + {[],[Input|mk_vars_1(Base, Temps)]}; + is_integer(Input0) -> + {[],[Input0|mk_vars_1(Base, Temps)]}; + Input0 =:= [] -> + {[],[Input0|mk_vars_1(Base, Temps)]}; + true -> + Input = mk_var(Base, input), + {[{assign,Input,Input0}],[Input|mk_vars_1(Base, Temps)]} + end. + +mk_vars_1(Base, Vars) -> + [mk_var(Base, V) || V <- Vars]. + +mk_var(Base, V) -> + {var,Base ++ atom_to_list(V)}. + +per_enc_integer_1(Val, [], Aligned) -> + [{'cond',[['_'|per_enc_unconstrained(Val, Aligned)]]}]; +per_enc_integer_1(Val0, [{{_,_}=Constr,[]}], Aligned) -> + {Prefix,Check,Action} = per_enc_integer_2(Val0, Constr, Aligned), + Prefix++build_cond([[Check,{put_bits,0,1,[1]}|Action], + ['_',{put_bits,1,1,[1]}| + per_enc_unconstrained(Val0, Aligned)]]); +per_enc_integer_1(Val0, [Constr], Aligned) -> + {Prefix,Check,Action} = per_enc_integer_2(Val0, Constr, Aligned), + Prefix++build_cond([[Check|Action], + ['_',{error,Val0}]]). + +per_enc_integer_2(Val, {'SingleValue',Sv}, Aligned) -> + per_enc_constrained(Val, Sv, Sv, Aligned); +per_enc_integer_2(Val0, {'ValueRange',{Lb,'MAX'}}, Aligned) + when is_integer(Lb) -> + {Prefix,Val} = sub_lb(Val0, Lb), + {Prefix,{ge,Val,0},per_enc_unsigned(Val, Aligned)}; +per_enc_integer_2(Val, {'ValueRange',{Lb,Ub}}, Aligned) + when is_integer(Lb), is_integer(Ub) -> + per_enc_constrained(Val, Lb, Ub, Aligned). + +per_enc_constrained(Val, Sv, Sv, _Aligned) -> + {[],{eq,Val,Sv},[]}; +per_enc_constrained(Val0, Lb, Ub, false) -> + {Prefix,Val} = sub_lb(Val0, Lb), + Range = Ub - Lb + 1, + NumBits = uper_num_bits(Range), + Check = {ult,Val,Range}, + Put = [{put_bits,Val,NumBits,[1]}], + {Prefix,Check,Put}; +per_enc_constrained(Val0, Lb, Ub, true) -> + {Prefix,Val} = sub_lb(Val0, Lb), + Range = Ub - Lb + 1, + if + Range < 256 -> + NumBits = per_num_bits(Range), + Check = {ult,Val,Range}, + Put = [{put_bits,Val,NumBits,[1]}], + {Prefix,Check,Put}; + Range =:= 256 -> + NumBits = 8, + Check = {ult,Val,Range}, + Put = [{put_bits,Val,NumBits,[1,align]}], + {Prefix,Check,Put}; + Range =< 65536 -> + Check = {ult,Val,Range}, + Put = [{put_bits,Val,16,[1,align]}], + {Prefix,Check,Put}; + true -> + {var,VarBase} = Val, + Bin = {var,VarBase++"@bin"}, + BinSize0 = {var,VarBase++"@bin_size0"}, + BinSize = {var,VarBase++"@bin_size"}, + Check = {ult,Val,Range}, + RangeOctsLen = byte_size(binary:encode_unsigned(Range - 1)), + BitsNeeded = per_num_bits(RangeOctsLen), + Enc = [{call,binary,encode_unsigned,[Val],Bin}, + {call,erlang,byte_size,[Bin],BinSize0}, + {sub,BinSize0,1,BinSize}, + {'cond',[['_', + {put_bits,BinSize,BitsNeeded,[1]}, + {put_bits,Bin,binary,[8,align]}]]}], + {Prefix,Check,Enc} + end. + +per_enc_unconstrained(Val, Aligned) -> + case Aligned of + false -> []; + true -> [{put_bits,0,0,[1,align]}] + end ++ [{call,per_common,encode_unconstrained_number,[Val]}]. + +per_enc_unsigned(Val, Aligned) -> + case is_integer(Val) of + false -> + {var,VarBase} = Val, + Bin = {var,VarBase++"@bin"}, + BinSize = {var,VarBase++"@bin_size"}, + [{call,binary,encode_unsigned,[Val],Bin}, + {call,erlang,byte_size,[Bin],BinSize}| + per_enc_length(Bin, 8, BinSize, Aligned)]; + true -> + Bin = binary:encode_unsigned(Val), + Len = byte_size(Bin), + per_enc_length(Bin, 8, Len, Aligned) + end. + +%% Encode a length field without any constraint. +per_enc_length(Bin, Unit, Len, Aligned) -> + U = unit(1, Aligned), + PutBits = put_bits_binary(Bin, Unit, Aligned), + EncFragmented = {call,per_common,encode_fragmented,[Bin,Unit]}, + Al = case Aligned of + false -> []; + true -> [{put_bits,0,0,[1,align]}] + end, + build_cond([[{lt,Len,128}, + {put_bits,Len,8,U},PutBits], + [{lt,Len,16384}, + {put_bits,2,2,U},{put_bits,Len,14,[1]},PutBits], + ['_'|Al++[EncFragmented]]]). + +per_enc_length(Bin, Unit, Len, no, Aligned, _Type) -> + per_enc_length(Bin, Unit, Len, Aligned); +per_enc_length(Bin, Unit, Len, {{Lb,Ub},[]}, Aligned, Type) -> + {Prefix,Check,PutLen} = per_enc_constrained(Len, Lb, Ub, Aligned), + NoExt = {put_bits,0,1,[1]}, + U = unit(Unit, Aligned, Type, Lb*Unit, Ub*Unit), + PutBits = [{put_bits,Bin,binary,U}], + [{'cond',ExtConds0}] = per_enc_length(Bin, Unit, Len, Aligned), + Ext = {put_bits,1,1,[1]}, + ExtConds = prepend_to_cond(ExtConds0, Ext), + build_length_cond(Prefix, [[Check,NoExt|PutLen++PutBits]|ExtConds]); +per_enc_length(Bin, Unit, Len, {Lb,Ub}, Aligned, Type) + when is_integer(Lb) -> + {Prefix,Check,PutLen} = per_enc_constrained(Len, Lb, Ub, Aligned), + U = unit(Unit, Aligned, Type, Lb*Unit, Ub*Unit), + PutBits = [{put_bits,Bin,binary,U}], + build_length_cond(Prefix, [[Check|PutLen++PutBits]]); +per_enc_length(Bin, Unit, Len, Sv, Aligned, Type) when is_integer(Sv) -> + NumBits = Sv*Unit, + U = unit(Unit, Aligned, Type, NumBits, NumBits), + Pb = {put_bits,Bin,binary,U}, + [{'cond',[[{eq,Len,Sv},Pb]]}]. + +enc_length(Len, no, Aligned) -> + U = unit(1, Aligned), + build_cond([[{lt,Len,128}, + {put_bits,Len,8,U}], + [{lt,Len,16384}, + {put_bits,2,2,U},{put_bits,Len,14,[1]}]]); +enc_length(Len, {{Lb,Ub},[]}, Aligned) -> + {Prefix,Check,PutLen} = per_enc_constrained(Len, Lb, Ub, Aligned), + NoExt = {put_bits,0,1,[1]}, + [{'cond',ExtConds0}] = enc_length(Len, no, Aligned), + Ext = {put_bits,1,1,[1]}, + ExtConds = prepend_to_cond(ExtConds0, Ext), + build_length_cond(Prefix, [[Check,NoExt|PutLen]|ExtConds]); +enc_length(Len, {Lb,Ub}, Aligned) when is_integer(Lb) -> + {Prefix,Check,PutLen} = per_enc_constrained(Len, Lb, Ub, Aligned), + build_length_cond(Prefix, [[Check|PutLen]]); +enc_length(Len, Sv, _Aligned) when is_integer(Sv) -> + [{'cond',[[{eq,Len,Sv}]]}]. + +put_bits_binary(Bin, _Unit, Aligned) when is_binary(Bin) -> + Sz = byte_size(Bin), + <> = Bin, + {put_bits,Int,8*Sz,unit(1, Aligned)}; +put_bits_binary(Bin, Unit, Aligned) -> + {put_bits,Bin,binary,unit(Unit, Aligned)}. + +sub_lb(Val, 0) -> + {[],Val}; +sub_lb({var,Var}=Val0, Lb) -> + Val = {var,Var++"@sub"}, + {[{sub,Val0,Lb,Val}],Val}; +sub_lb(Val, Lb) when is_integer(Val) -> + {[],Val-Lb}. + +build_length_cond([{sub,Var0,Base,Var}]=Prefix, Cs) -> + %% Non-zero lower bound, such as: SIZE (50..200, ...) + Prefix++[{'cond',opt_length_nzlb(Cs, {Var0,Var,Base}, 0)}]; +build_length_cond([], Cs) -> + %% Zero lower bound, such as: SIZE (0..200, ...) + [{'cond',opt_length_zlb(Cs, 0)}]. + +opt_length_zlb([[{ult,Var,Val}|Actions]|T], Ub) -> + %% Since the SIZE constraint is zero-based, Var + %% must be greater than zero, and we can use + %% the slightly cheaper signed less than operator. + opt_length_zlb([[{lt,Var,Val}|Actions]|T], Ub); +opt_length_zlb([[{lt,_,Val}|_]=H|T], Ub) -> + if + Val =< Ub -> + %% A previous test has already matched. + opt_length_zlb(T, Ub); + true -> + [H|opt_length_zlb(T, max(Ub, Val))] + end; +opt_length_zlb([H|T], Ub) -> + [H|opt_length_zlb(T, Ub)]; +opt_length_zlb([], _) -> []. + +opt_length_nzlb([[{ult,Var,Val}|_]=H|T], {_,Var,Base}=St, _Ub) -> + [H|opt_length_nzlb(T, St, Base+Val)]; +opt_length_nzlb([[{lt,Var0,Val}|_]=H|T], {Var0,_,_}=St, Ub) -> + if + Val =< Ub -> + %% A previous test has already matched. + opt_length_nzlb(T, St, Ub); + true -> + [H|opt_length_nzlb(T, St, Val)] + end; +opt_length_nzlb([H|T], St, Ub) -> + [H|opt_length_nzlb(T, St, Ub)]; +opt_length_nzlb([], _, _) -> []. + +build_cond(Conds0) -> + case eval_cond(Conds0, gb_sets:empty()) of + [['_'|Actions]] -> + Actions; + Conds -> + [{'cond',Conds}] + end. + +eval_cond([['_',{'cond',Cs}]], Seen) -> + eval_cond(Cs, Seen); +eval_cond([[Cond|Actions]=H|T], Seen0) -> + case gb_sets:is_element(Cond, Seen0) of + false -> + Seen = gb_sets:insert(Cond, Seen0), + case eval_cond_1(Cond) of + false -> + eval_cond(T, Seen); + true -> + [['_'|Actions]]; + maybe -> + [H|eval_cond(T, Seen)] + end; + true -> + eval_cond(T, Seen0) + end; +eval_cond([], _) -> []. + +eval_cond_1({ult,I,N}) when is_integer(I), is_integer(N) -> + 0 =< I andalso I < N; +eval_cond_1({eq,[],[]}) -> + true; +eval_cond_1({eq,I,N}) when is_integer(I), is_integer(N) -> + I =:= N; +eval_cond_1({lt,I,N}) when is_integer(I), is_integer(N) -> + I < N; +eval_cond_1(_) -> maybe. + +prepend_to_cond([H|T], Code) -> + [prepend_to_cond_1(H, Code)|prepend_to_cond(T, Code)]; +prepend_to_cond([], _) -> []. + +prepend_to_cond_1([Check|T], Code) -> + [Check,Code|T]. + +enc_char_tab(notab) -> + notab; +enc_char_tab(Tab0) -> + Tab = tuple_to_list(Tab0), + First = hd(Tab), + {First-1,list_to_tuple(enc_char_tab_1(Tab, First, 0))}. + +enc_char_tab_1([H|T], H, I) -> + [I|enc_char_tab_1(T, H+1, I+1)]; +enc_char_tab_1([_|_]=T, H, I) -> + [ill|enc_char_tab_1(T, H+1, I)]; +enc_char_tab_1([], _, _) -> []. + +enumerated_constraint([_]) -> + [{'SingleValue',0}]; +enumerated_constraint(Root) -> + [{'ValueRange',{0,length(Root)-1}}]. + +per_enc_enumerated_root(NNL, Prefix, Val, Constr, Aligned) -> + per_enc_enumerated_root_1(NNL, Prefix, Val, Constr, Aligned, 0). + +per_enc_enumerated_root_1([{H,_}|T], Prefix, Val, Constr, Aligned, N) -> + [[{eq,Val,H}|Prefix++per_enc_integer_1(N, Constr, Aligned)]| + per_enc_enumerated_root_1(T, Prefix, Val, Constr, Aligned, N+1)]; +per_enc_enumerated_root_1([], _, _, _, _, _) -> []. + +per_enc_enumerated_ext(NNL, Val, Aligned) -> + per_enc_enumerated_ext_1(NNL, Val, Aligned, 0). + +per_enc_enumerated_ext_1([{H,_}|T], Val, Aligned, N) -> + [[{eq,Val,H},{put_bits,1,1,[1]}|per_enc_small_number(N, Aligned)]| + per_enc_enumerated_ext_1(T, Val, Aligned, N+1)]; +per_enc_enumerated_ext_1([], _, _, _) -> []. + +per_enc_small_length(Val0, Aligned) -> + {Sub,Val} = sub_lb(Val0, 1), + U = unit(1, Aligned), + Sub ++ build_cond([[{lt,Val,64},{put_bits,Val,7,[1]}], + [{lt,Val0,128},{put_bits,1,1,[1]}, + {put_bits,Val0,8,U}], + ['_',{put_bits,1,1,[1]}, + {put_bits,2,2,U},{put_bits,Val0,14,[1]}]]). + +constr_min_size(no) -> no; +constr_min_size({{Lb,_},[]}) when is_integer(Lb) -> Lb; +constr_min_size({Lb,_}) when is_integer(Lb) -> Lb; +constr_min_size(Sv) when is_integer(Sv) -> Sv. + +enc_mod(false) -> uper; +enc_mod(true) -> per. + +unit(U, false) -> [U]; +unit(U, true) -> [U,align]. + +unit(U, Aligned, Type, Lb, Ub) -> + case Aligned andalso is_aligned(Type, Lb, Ub) of + true -> [U,align]; + false -> [U] + end. + +opt_choice(Imm) -> + {Pb,T0} = lists:splitwith(fun({put_bits,V,_,_}) when is_integer(V) -> + true; + (_) -> + false + end, Imm), + try + {Prefix,T} = split_off_nonbuilding(T0), + Prefix ++ opt_choice_1(T, Pb) + catch + throw:impossible -> + Imm + end. + +opt_choice_1([{'cond',Cs0}], Pb) -> + case Cs0 of + [[C|Act]] -> + [{'cond',[[C|Pb++Act]]}]; + [[C|Act],['_',{error,_}]=Error] -> + [{'cond',[[C|Pb++Act],Error]}]; + _ -> + [{'cond',opt_choice_2(Cs0, Pb)}] + end; +opt_choice_1(_, _) -> throw(impossible). + +opt_choice_2([[C|[{put_bits,_,_,_}|_]=Act]|T], Pb) -> + [[C|Pb++Act]|opt_choice_2(T, Pb)]; +opt_choice_2([[_,{error,_}]=H|T], Pb) -> + [H|opt_choice_2(T, Pb)]; +opt_choice_2([_|_], _) -> + throw(impossible); +opt_choice_2([], _) -> []. + + +%%% +%%% Helper functions for code generation of open types. +%%% + +per_enc_open_type(Val0, {ToBinMod,ToBinFunc}, Aligned) -> + {B,[Val,Len,Bin]} = mk_vars(Val0, [len,bin]), + B ++ [{call,ToBinMod,ToBinFunc,[Val],Bin}, + {call,erlang,byte_size,[Bin],Len}| + per_enc_length(Bin, 8, Len, Aligned)]. + +enc_open_type([{'cond',Cs}], Aligned) -> + [{'cond',[[C|enc_open_type_1(Act, Aligned)] || [C|Act] <- Cs]}]; +enc_open_type(_, _) -> + throw(impossible). + +enc_open_type_1([{error,_}]=Imm, _) -> + Imm; +enc_open_type_1(Imm, Aligned) -> + NumBits = num_bits(Imm, 0), + Pad = case 8 - (NumBits rem 8) of + 8 -> []; + Pad0 -> [{put_bits,0,Pad0,[1]}] + end, + NumBytes = (NumBits+7) div 8, + enc_length(NumBytes, no, Aligned) ++ Imm ++ Pad. + +num_bits([{put_bits,_,N,[U|_]}|T], Sum) when is_integer(N) -> + num_bits(T, Sum+N*U); +num_bits([_|_], _) -> + throw(impossible); +num_bits([], Sum) -> Sum. + +per_enc_open_type_output([{apply,F,A}], Acc) -> + Dst = output_var(), + {Dst,lists:reverse(Acc, [{apply,F,A,{var,atom_to_list(Dst)}}])}; +per_enc_open_type_output([{call,M,F,A}], Acc) -> + Dst = output_var(), + {Dst,lists:reverse(Acc, [{call,M,F,A,{var,atom_to_list(Dst)}}])}; +per_enc_open_type_output([{'cond',Cs}], Acc) -> + Dst = output_var(), + {Dst,lists:reverse(Acc, [{'cond',Cs,{var,atom_to_list(Dst)}}])}; +per_enc_open_type_output([H|T], Acc) -> + per_enc_open_type_output(T, [H|Acc]). + +output_var() -> + asn1ct_name:new(enc), + Curr = asn1ct_name:curr(enc), + [H|T] = atom_to_list(Curr), + list_to_atom([H - ($a - $A)|T ++ "@output"]). + + +%%% +%%% Optimize list comprehensions (SEQUENCE OF/SET OF). +%%% + +opt_lc([{lc,[{call,erlang,iolist_to_binary,[Var],Bin}, + {call,erlang,byte_size,[Bin],LenVar}, + {'cond',[[{eq,LenVar,Len},{put_bits,Bin,_,[_|Align]}]]}], + Var,Val}]=Lc, LenImm) -> + %% Given a sequence of a fixed length string, such as + %% SEQUENCE OF OCTET STRING (SIZE (4)), attempt to rewrite to + %% a list comprehension that just checks the size, followed by + %% a conversion to binary: + %% + %% _ = [if length(Comp) =:= 4; byte_size(Comp) =:= 4 -> [] end || + %% Comp <- Sof], + %% [align|iolist_to_binary(Sof)] + + CheckImm = [{'cond',[[{eq,{expr,"length("++mk_val(Var)++")"},Len}], + [{eq,{expr,"byte_size("++mk_val(Var)++")"},Len}]]}], + Al = case Align of + [] -> + []; + [align] -> + [{put_bits,0,0,[1|Align]}] + end, + case Al =:= [] orelse + is_end_aligned(LenImm) orelse + lb_is_nonzero(LenImm) of + false -> + %% Not possible because an empty SEQUENCE OF would be + %% improperly aligned. Example: + %% + %% SEQUENCE (SIZE (0..3)) OF ... + + Lc; + true -> + %% Examples: + %% + %% SEQUENCE (SIZE (1..4)) OF ... + %% (OK because there must be at least one element) + %% + %% SEQUENCE OF ... + %% (OK because the length field will force alignment) + %% + Al ++ [{lc,CheckImm,Var,Val,{var,"_"}}, + {call,erlang,iolist_to_binary,[Val]}] + end; +opt_lc([{lc,ElementImm0,V,L}]=Lc, LenImm) -> + %% Attempt to hoist the alignment, putting after the length + %% and before the list comprehension: + %% + %% [Length, + %% align, + %% [Encode(Comp) || Comp <- Sof]] + %% + + case enc_opt_al_1(ElementImm0, 0) of + {ElementImm,0} -> + case is_end_aligned(LenImm) orelse + (is_beginning_aligned(ElementImm0) andalso + lb_is_nonzero(LenImm)) of + false -> + %% Examples: + %% + %% SEQUENCE (SIZE (0..3)) OF OCTET STRING + %% (An empty SEQUENCE OF would be improperly aligned) + %% + %% SEQUENCE (SIZE (1..3)) OF OCTET STRING (SIZE (0..4)) + %% (There would be an improper alignment before the + %% first element) + + Lc; + true -> + %% Examples: + %% + %% SEQUENCE OF INTEGER + %% SEQUENCE (SIZE (1..4)) OF INTEGER + %% SEQUENCE (SIZE (1..4)) OF INTEGER (0..256) + + [{put_bits,0,0,[1,align]},{lc,ElementImm,V,L}] + end; + _ -> + %% Unknown alignment, no alignment, or not aligned at the end. + %% Examples: + %% + %% SEQUENCE OF SomeConstructedType + %% SEQUENCE OF INTEGER (0..15) + + Lc + end. + +is_beginning_aligned([{'cond',Cs}]) -> + lists:all(fun([_|Act]) -> is_beginning_aligned(Act) end, Cs); +is_beginning_aligned([{error,_}|_]) -> true; +is_beginning_aligned([{put_bits,_,_,U}|_]) -> + case U of + [_,align] -> true; + [_] -> false + end; +is_beginning_aligned(Imm0) -> + case split_off_nonbuilding(Imm0) of + {[],_} -> false; + {[_|_],Imm} -> is_beginning_aligned(Imm) + end. + +is_end_aligned(Imm) -> + case enc_opt_al_1(Imm, unknown) of + {_,0} -> true; + {_,_} -> false + end. + +lb_is_nonzero([{sub,_,_,_}|_]) -> true; +lb_is_nonzero(_) -> false. + +%%% +%%% Attempt to combine two chunks of intermediate code. +%%% + +combine_imms(ImmA0, ImmB0) -> + {Prefix0,ImmA} = split_off_nonbuilding(ImmA0), + {Prefix1,ImmB} = split_off_nonbuilding(ImmB0), + Prefix = Prefix0 ++ Prefix1, + Combined = do_combine(ImmA ++ ImmB, 3.0), + Prefix ++ Combined. + +do_combine([{error,_}=Imm|_], _Budget) -> + [Imm]; +do_combine([{'cond',Cs0}|T], Budget0) -> + Budget = debit(Budget0, num_clauses(Cs0, 0)), + Cs = [[C|do_combine(Act++T, Budget)] || [C|Act] <- Cs0], + [{'cond',Cs}]; +do_combine([{put_bits,V,_,_}|_]=L, Budget) when is_integer(V) -> + {Pb,T} = collect_put_bits(L), + do_combine_put_bits(Pb, T,Budget); +do_combine(_, _) -> + throw(impossible). + +do_combine_put_bits(Pb, [], _Budget) -> + Pb; +do_combine_put_bits(Pb, [{'cond',Cs0}|T], Budget) -> + Cs = [case Act of + [{error,_}] -> + [C|Act]; + _ -> + [C|do_combine(Pb++Act, Budget)] + end || [C|Act] <- Cs0], + do_combine([{'cond',Cs}|T], Budget); +do_combine_put_bits(_, _, _) -> + throw(impossible). + +debit(Budget0, Alternatives) -> + case Budget0 - log2(Alternatives) of + Budget when Budget > 0.0 -> + Budget; + _ -> + throw(impossible) + end. + +num_clauses([[_,{error,_}]|T], N) -> + num_clauses(T, N); +num_clauses([_|T], N) -> + num_clauses(T, N+1); +num_clauses([], N) -> N. + +log2(N) -> + math:log(N) / math:log(2.0). + +collect_put_bits(Imm) -> + lists:splitwith(fun({put_bits,V,_,_}) when is_integer(V) -> true; + (_) -> false + end, Imm). + +%%% +%%% Simple common subexpression elimination to avoid fetching +%%% the same element twice. +%%% + +enc_cse([{assign,{var,V},E}=H|T]) -> + [H|enc_cse_1(T, E, V)]; +enc_cse(Imm) -> Imm. + +enc_cse_1([{assign,Dst,E}|T], E, V) -> + [{assign,Dst,V}|enc_cse_1(T, E, V)]; +enc_cse_1([{block,Bl}|T], E, V) -> + [{block,enc_cse_1(Bl, E, V)}|enc_cse_1(T, E, V)]; +enc_cse_1([H|T], E, V) -> + [H|enc_cse_1(T, E, V)]; +enc_cse_1([], _, _) -> []. + + +%%% +%%% Pre-process the intermediate code to simplify code generation. +%%% + +enc_pre_cg(Imm) -> + enc_pre_cg_1(Imm, outside_list, in_seq). + +enc_pre_cg_1([], _StL, _StB) -> + nil; +enc_pre_cg_1([H], StL, StB) -> + enc_pre_cg_2(H, StL, StB); +enc_pre_cg_1([H0|T0], StL, StB) -> + case is_nonbuilding(H0) of + true -> + H = enc_pre_cg_nonbuilding(H0, StL), + Seq = {seq,H,enc_pre_cg_1(T0, StL, in_seq)}, + case StB of + outside_seq -> {block,Seq}; + in_seq -> Seq + end; + false -> + H = enc_pre_cg_2(H0, in_head, outside_seq), + T = enc_pre_cg_1(T0, in_tail, outside_seq), + enc_make_cons(H, T) + end. + +enc_pre_cg_2(align, StL, _StB) -> + case StL of + in_head -> align; + in_tail -> {cons,align,nil} + end; +enc_pre_cg_2({apply,_,_}=Imm, _, _) -> + Imm; +enc_pre_cg_2({block,Bl0}, StL, StB) -> + enc_pre_cg_1(Bl0, StL, StB); +enc_pre_cg_2({call,_,_,_}=Imm, _, _) -> + Imm; +enc_pre_cg_2({call_gen,_,_,_,_}=Imm, _, _) -> + Imm; +enc_pre_cg_2({'cond',Cs0}, StL, _StB) -> + Cs = [{C,enc_pre_cg_1(Act, StL, outside_seq)} || [C|Act] <- Cs0], + {'cond',Cs}; +enc_pre_cg_2({error,_}=E, _, _) -> + E; +enc_pre_cg_2({lc,B0,V,L}, StL, _StB) -> + B = enc_pre_cg_1(B0, StL, outside_seq), + {lc,B,V,L}; +enc_pre_cg_2({put_bits,V,8,[1]}, StL, _StB) -> + case StL of + in_head -> {integer,V}; + in_tail -> {cons,{integer,V},nil}; + outside_list -> {cons,{integer,V},nil} + end; +enc_pre_cg_2({put_bits,V,binary,_}, _StL, _StB) -> + V; +enc_pre_cg_2({put_bits,_,_,[_]}=PutBits, _StL, _StB) -> + {binary,[PutBits]}; +enc_pre_cg_2({var,_}=Imm, _, _) -> Imm. + +enc_make_cons({binary,H}, {binary,T}) -> + {binary,H++T}; +enc_make_cons({binary,H0}, {cons,{binary,H1},T}) -> + {cons,{binary,H0++H1},T}; +enc_make_cons({integer,Int}, {binary,T}) -> + {binary,[{put_bits,Int,8,[1]}|T]}; +enc_make_cons(H, T) -> + {cons,H,T}. + +enc_pre_cg_nonbuilding({'cond',Cs0,Dst}, StL) -> + Cs = [{C,enc_pre_cg_1(Act, StL, outside_seq)} || [C|Act] <- Cs0], + {'cond',Cs,Dst}; +enc_pre_cg_nonbuilding({lc,B0,Var,List,Dst}, StL) -> + B = enc_pre_cg_1(B0, StL, outside_seq), + {lc,B,Var,List,Dst}; +enc_pre_cg_nonbuilding({'try',Try0,{P,Succ0},Else0,Dst}, StL) -> + Try = enc_pre_cg_1(Try0, StL, outside_seq), + Succ = enc_pre_cg_1(Succ0, StL, outside_seq), + Else = enc_pre_cg_1(Else0, StL, outside_seq), + {'try',Try,{P,Succ},Else,Dst}; +enc_pre_cg_nonbuilding(Imm, _) -> Imm. + + +%%% +%%% Code generation for encoding. +%%% + +enc_cg({cons,_,_}=Cons) -> + enc_cg_cons(Cons); +enc_cg({block,Imm}) -> + emit(["begin",nl]), + enc_cg(Imm), + emit([nl, + "end"]); +enc_cg({seq,First,Then}) -> + enc_cg(First), + emit([com,nl]), + enc_cg(Then); +enc_cg(align) -> + emit(align); +enc_cg({apply,F0,As0}) -> + As = enc_call_args(As0, ""), + case F0 of + {M,F} -> + emit([{asis,M},":",{asis,F},"(",As,")"]); + F when is_atom(F) -> + emit([{asis,F},"(",As,")"]) + end; +enc_cg({apply,F0,As0,Dst}) -> + As = enc_call_args(As0, ""), + emit([mk_val(Dst)," = "]), + case F0 of + {var,F} -> + emit([F,"(",As,")"]); + {M,F} -> + emit([{asis,M},":",{asis,F},"(",As,")"]); + F when is_atom(F) -> + emit([{asis,F},"(",As,")"]) + end; +enc_cg({assign,Dst0,Expr}) -> + Dst = mk_val(Dst0), + emit([Dst," = ",Expr]); +enc_cg({binary,PutBits}) -> + emit(["<<",enc_cg_put_bits(PutBits, ""),">>"]); +enc_cg({call,M,F,As0}) -> + As = [mk_val(A) || A <- As0], + asn1ct_func:call(M, F, As); +enc_cg({call,M,F,As0,Dst}) -> + As = [mk_val(A) || A <- As0], + emit([mk_val(Dst)," = "]), + asn1ct_func:call(M, F, As); +enc_cg({call_gen,Prefix,Key,Gen,As0}) -> + As = [mk_val(A) || A <- As0], + asn1ct_func:call_gen(Prefix, Key, Gen, As); +enc_cg({'cond',Cs}) -> + enc_cg_cond(Cs); +enc_cg({'cond',Cs,Dst0}) -> + Dst = mk_val(Dst0), + emit([Dst," = "]), + enc_cg_cond(Cs); +enc_cg({error,Error}) when is_function(Error, 0) -> + Error(); +enc_cg({error,Var0}) -> + Var = mk_val(Var0), + emit(["exit({error,{asn1,{illegal_value,",Var,"}}})"]); +enc_cg({integer,Int}) -> + emit(mk_val(Int)); +enc_cg({lc,Body,Var,List}) -> + emit("["), + enc_cg(Body), + emit([" || ",mk_val(Var)," <- ",mk_val(List),"]"]); +enc_cg({lc,Body,Var,List,Dst}) -> + emit([mk_val(Dst)," = ["]), + enc_cg(Body), + emit([" || ",mk_val(Var)," <- ",mk_val(List),"]"]); +enc_cg(nil) -> + emit("[]"); +enc_cg({sub,Src0,Int,Dst0}) -> + Src = mk_val(Src0), + Dst = mk_val(Dst0), + emit([Dst," = ",Src," - ",Int]); +enc_cg({'try',Try,{P,Succ},Else,Dst}) -> + emit([mk_val(Dst)," = try "]), + enc_cg(Try), + emit([" of",nl, + mk_val(P)," ->",nl]), + enc_cg(Succ), + emit([nl, + "catch throw:invalid ->",nl]), + enc_cg(Else), + emit([nl, + "end"]); +enc_cg({var,V}) -> + emit(V). + +enc_cg_cons(Cons) -> + emit("["), + enc_cg_cons_1(Cons), + emit("]"). + +enc_cg_cons_1({cons,H,{cons,_,_}=T}) -> + enc_cg(H), + emit([com,nl]), + enc_cg_cons_1(T); +enc_cg_cons_1({cons,H,nil}) -> + enc_cg(H); +enc_cg_cons_1({cons,H,T}) -> + enc_cg(H), + emit("|"), + enc_cg(T). + +enc_call_args([A|As], Sep) -> + [Sep,mk_val(A)|enc_call_args(As, ", ")]; +enc_call_args([], _) -> []. + +enc_cg_cond([{'_',Action}]) -> + enc_cg(Action); +enc_cg_cond(Cs) -> + emit("if "), + enc_cg_cond(Cs, ""), + emit([nl, + "end"]). + +enc_cg_cond([C|Cs], Sep) -> + emit(Sep), + enc_cg_cond_1(C), + enc_cg_cond(Cs, [";",nl]); +enc_cg_cond([], _) -> ok. + +enc_cg_cond_1({Cond,Action}) -> + enc_cond_term(Cond), + emit([" ->",nl]), + enc_cg(Action). + +enc_cond_term('_') -> + emit("true"); +enc_cond_term({ult,Var0,Int}) -> + Var = mk_val(Var0), + N = uper_num_bits(Int), + case 1 bsl N of + Int -> + emit([Var," bsr ",N," =:= 0"]); + _ -> + emit(["0 =< ",Var,", ",Var," < ",Int]) + end; +enc_cond_term({eq,Var0,Term}) -> + Var = mk_val(Var0), + emit([Var," =:= ",{asis,Term}]); +enc_cond_term({ge,Var0,Int}) -> + Var = mk_val(Var0), + emit([Var," >= ",Int]); +enc_cond_term({lt,Var0,Int}) -> + Var = mk_val(Var0), + emit([Var," < ",Int]). + +enc_cg_put_bits([{put_bits,Val0,N,[1]}|T], Sep) -> + Val = mk_val(Val0), + [[Sep,Val,":",integer_to_list(N)]|enc_cg_put_bits(T, ",")]; +enc_cg_put_bits([], _) -> []. + +mk_val({var,Str}) -> Str; +mk_val({expr,Str}) -> Str; +mk_val(Int) when is_integer(Int) -> integer_to_list(Int); +mk_val(Other) -> {asis,Other}. + +%%% +%%% Generate a function that maps a name of a bit position +%%% to the bit position. +%%% + +bit_string_name2pos_fun(NNL, Src) -> + {call_gen,"bit_string_name2pos_",NNL, + fun(Fd, Name) -> gen_name2pos(Fd, Name, NNL) end,[Src]}. + +gen_name2pos(Fd, Name, Names) -> + Cs0 = gen_name2pos_cs(Names, Name), + Cs = Cs0 ++ [bit_clause(Name),nil_clause(),invalid_clause()], + F = {function,1,Name,1,Cs}, + file:write(Fd, [erl_pp:function(F)]). + +gen_name2pos_cs([{K,V}|T], Name) -> + P = [{cons,0,{atom,0,K},{var,0,'T'}}], + B = [{cons,0,{integer,0,V},{call,0,{atom,0,Name},[{var,0,'T'}]}}], + [{clause,0,P,[],B}|gen_name2pos_cs(T, Name)]; +gen_name2pos_cs([], _) -> []. + +bit_clause(Name) -> + VarT = {var,0,'T'}, + VarPos = {var,0,'Pos'}, + P = [{cons,0,{tuple,0,[{atom,0,bit},VarPos]},VarT}], + G = [[{call,0,{atom,0,is_integer},[VarPos]}]], + B = [{cons,0,VarPos,{call,0,{atom,0,Name},[VarT]}}], + {clause,0,P,G,B}. + +nil_clause() -> + P = B = [{nil,0}], + {clause,0,P,[],B}. + +invalid_clause() -> + P = [{var,0,'_'}], + B = [{call,0,{atom,0,throw},[{atom,0,invalid}]}], + {clause,0,P,[],B}. + +%%% +%%% Hoist alignment to reduce the number of list elements in +%%% encode. Fewer lists elements means faster traversal in +%%% complete/{2,3}. +%%% +%%% For example, the following data sequence: +%%% +%%% [align,<<1:1,0:1>>,[align,<>|Data]] +%%% +%%% can be rewritten to: +%%% +%%% [align,<<1:1,0:1,0:6>>,[<>|Data]] +%%% +%%% The change from the literal <<1:1,0:1>> to <<1:1,0:1,0:6>> +%%% comes for free, and we have eliminated one element of the +%%% sub list. +%%% +%%% We must be careful not to rewrite: +%%% +%%% [<<1:1,0:1>>,[align,<>|Data]] +%%% +%%% to: +%%% +%%% [[<<1:1,0:1>>,align],[<>|Data]] +%%% +%%% because even though [<<1:0,0:1>>,align] is a literal and does +%%% not add any additional construction cost, there is one more +%%% sub list that needs to be traversed. +%%% + +enc_hoist_align(Imm0) -> + Imm = enc_hoist_align_reverse(Imm0, []), + enc_hoist_align(Imm, false, []). + +enc_hoist_align_reverse([H|T], Acc) -> + case enc_opt_al_1([H], 0) of + {[H],_} -> + enc_hoist_align_reverse(T, [H|Acc]); + {_,_} -> + lists:reverse(T, [H,stop|Acc]) + end; +enc_hoist_align_reverse([], Acc) -> Acc. + +enc_hoist_align([stop|T], _Aligned, Acc) -> + lists:reverse(T, Acc); +enc_hoist_align([{block,Bl0}|T], Aligned, Acc) -> + Bl = case Aligned of + false -> Bl0; + true -> enc_hoist_block(Bl0) + end, + case is_beginning_aligned(Bl) of + false -> + enc_hoist_align(T, false, [{block,Bl}|Acc]); + true -> + enc_hoist_align(T, true, [{put_bits,0,0,[1,align]}, + {block,Bl}|Acc]) + end; +enc_hoist_align([H|T], _, Acc) -> + enc_hoist_align(T, false, [H|Acc]); +enc_hoist_align([], _, Acc) -> Acc. + +enc_hoist_block(Bl) -> + try + enc_hoist_block_1(lists:reverse(Bl)) + catch + throw:impossible -> + Bl + end. + +enc_hoist_block_1([{'cond',Cs0}|T]) -> + Cs = [[C|enc_hoist_block_2(Act)] || [C|Act] <- Cs0], + H = {'cond',Cs}, + lists:reverse(T, [H]); +enc_hoist_block_1(_) -> + throw(impossible). + +enc_hoist_block_2([{'cond',_}|_]=L) -> + enc_hoist_block(L); +enc_hoist_block_2([{error,_}]=L) -> + L; +enc_hoist_block_2([]) -> + [{put_bits,0,0,[1,align]}]; +enc_hoist_block_2(L) -> + case lists:last(L) of + {put_bits,_,_,_} -> + L ++ [{put_bits,0,0,[1,align]}]; + _ -> + throw(impossible) + end. + +%%% +%%% Optimize alignment for encoding. +%%% + +enc_opt_al(Imm0) -> + {Imm,_} = enc_opt_al_1(Imm0, unknown), + Imm. + +enc_opt_al_1([{'cond',Cs0,Dst},{call,per,complete,[Dst],Bin}|T0], Al0) -> + {Cs1,{M,F}} = enc_opt_al_prepare_cond(Cs0), + {Cs,_} = enc_opt_al_cond(Cs1, 0), + {T,Al} = enc_opt_al_1([{call,M,F,[Dst],Bin}|T0], Al0), + {[{'cond',Cs,Dst}|T],Al}; +enc_opt_al_1([H0|T0], Al0) -> + {H,Al1} = enc_opt_al(H0, Al0), + {T,Al} = enc_opt_al_1(T0, Al1), + {H++T,Al}; +enc_opt_al_1([], Al) -> {[],Al}. + +enc_opt_al({apply,_,_,_}=Imm, Al) -> + {[Imm],Al}; +enc_opt_al({assign,_,_}=Imm, Al) -> + {[Imm],Al}; +enc_opt_al({block,Bl0}, Al0) -> + {Bl,Al} = enc_opt_al_1(Bl0, Al0), + {[{block,Bl}],Al}; +enc_opt_al({call,erlang,iolist_to_binary,[_]}=Imm, Al) -> + {[Imm],Al}; +enc_opt_al({call,per_common,encode_fragmented,[_,U]}=Call, Al) -> + case U rem 8 of + 0 -> {[Call],Al}; + _ -> {[Call],unknown} + end; +enc_opt_al({call,per_common,encode_unconstrained_number,[_]}=Call, _) -> + {[Call],0}; +enc_opt_al({call,_,_,_,_}=Call, Al) -> + {[Call],Al}; +enc_opt_al({'cond',Cs0}, Al0) -> + {Cs,Al} = enc_opt_al_cond(Cs0, Al0), + {[{'cond',Cs}],Al}; +enc_opt_al({error,_}=Imm, Al) -> + {[Imm],Al}; +enc_opt_al({put_bits,V,N,[U,align]}, Al0) when Al0 rem 8 =:= 0 -> + Al = if + is_integer(N) -> N*U; + N =:= binary, U rem 8 =:= 0 -> 0; + true -> unknown + end, + {[{put_bits,V,N,[U]}],Al}; +enc_opt_al({put_bits,V,binary,[U,align]}, Al0) when is_integer(Al0) -> + N = 8 - (Al0 rem 8), + Al = case U rem 8 of + 0 -> 0; + _ -> unknown + end, + {[{put_bits,0,N,[1]},{put_bits,V,binary,[U]}],Al}; +enc_opt_al({put_bits,V,N0,[U,align]}, Al0) when is_integer(N0), is_integer(Al0) -> + N = N0 + (8 - Al0 rem 8), + Al = N0*U, + {[{put_bits,V,N,[1]}],Al}; +enc_opt_al({put_bits,_,N,[U,align]}=PutBits, _) when is_integer(N) -> + {[PutBits],N*U}; +enc_opt_al({put_bits,_,binary,[U,align]}=PutBits, _) when U rem 8 =:= 0 -> + {[PutBits],0}; +enc_opt_al({put_bits,_,N,[U]}=PutBits, Al) when is_integer(N), is_integer(Al) -> + {[PutBits],Al+N*U}; +enc_opt_al({put_bits,_,binary,[U]}=PutBits, Al) when U rem 8 =:= 0 -> + {[PutBits],Al}; +enc_opt_al({sub,_,_,_}=Imm, Al) -> + {[Imm],Al}; +enc_opt_al(Imm, _) -> + {[Imm],unknown}. + +enc_opt_al_cond(Cs0, Al0) -> + enc_opt_al_cond_1(Cs0, Al0, [], []). + +enc_opt_al_cond_1([['_',{error,_}]=C|Cs], Al, CAcc, AAcc) -> + enc_opt_al_cond_1(Cs, Al, [C|CAcc], AAcc); +enc_opt_al_cond_1([[C|Act0]|Cs0], Al0, CAcc, AAcc) -> + {Act,Al1} = enc_opt_al_1(Act0, Al0), + Al = if + Al1 =:= unknown -> Al1; + true -> Al1 rem 8 + end, + enc_opt_al_cond_1(Cs0, Al0, [[C|Act]|CAcc], [Al|AAcc]); +enc_opt_al_cond_1([], _, CAcc, AAcc) -> + Al = case lists:usort(AAcc) of + [Al0] -> Al0; + [_|_] -> unknown + end, + {lists:reverse(CAcc),Al}. + +enc_opt_al_prepare_cond(Cs0) -> + try enc_opt_al_prepare_cond_1(Cs0) of + Cs -> + {Cs,{erlang,iolist_to_binary}} + catch + throw:impossible -> + {Cs0,{per,complete}} + end. + +enc_opt_al_prepare_cond_1(Cs) -> + [[C|enc_opt_al_prepare_cond_2(Act)] || [C|Act] <- Cs]. + +enc_opt_al_prepare_cond_2([{put_bits,_,binary,[U|_]}|_]) when U rem 8 =/= 0 -> + throw(impossible); +enc_opt_al_prepare_cond_2([{put_bits,_,_,_}=H|T]) -> + [H|enc_opt_al_prepare_cond_2(T)]; +enc_opt_al_prepare_cond_2([{call,per_common,encode_fragmented,_}=H|T]) -> + [H|enc_opt_al_prepare_cond_2(T)]; +enc_opt_al_prepare_cond_2([_|_]) -> + throw(impossible); +enc_opt_al_prepare_cond_2([]) -> + [{put_bits,0,0,[1,align]}]. + + +%%% +%%% For the aligned PER format, fix up the intermediate format +%%% before code generation. Code generation will be somewhat +%%% easier if 'align' appear as a separate instruction. +%%% + +per_fixup([{apply,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{apply,_,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{block,Block}|T]) -> + [{block,per_fixup(Block)}|per_fixup(T)]; +per_fixup([{'assign',_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{'cond',Cs0}|T]) -> + Cs = [[C|per_fixup(Act)] || [C|Act] <- Cs0], + [{'cond',Cs}|per_fixup(T)]; +per_fixup([{'cond',Cs0,Dst}|T]) -> + Cs = [[C|per_fixup(Act)] || [C|Act] <- Cs0], + [{'cond',Cs,Dst}|per_fixup(T)]; +per_fixup([{call,_,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{call,_,_,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{call_gen,_,_,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{error,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{lc,B,V,L}|T]) -> + [{lc,per_fixup(B),V,L}|per_fixup(T)]; +per_fixup([{lc,B,V,L,Dst}|T]) -> + [{lc,per_fixup(B),V,L,Dst}|per_fixup(T)]; +per_fixup([{sub,_,_,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([{'try',Try0,{P,Succ0},Else0,Dst}|T]) -> + Try = per_fixup(Try0), + Succ = per_fixup(Succ0), + Else = per_fixup(Else0), + [{'try',Try,{P,Succ},Else,Dst}|per_fixup(T)]; +per_fixup([{put_bits,_,_,_}|_]=L) -> + fixup_put_bits(L); +per_fixup([{var,_}=H|T]) -> + [H|per_fixup(T)]; +per_fixup([]) -> []. + +fixup_put_bits([{put_bits,0,0,[_,align]}|T]) -> + [align|fixup_put_bits(T)]; +fixup_put_bits([{put_bits,0,0,_}|T]) -> + fixup_put_bits(T); +fixup_put_bits([{put_bits,V,N,[U,align]}|T]) -> + [align,{put_bits,V,N,[U]}|fixup_put_bits(T)]; +fixup_put_bits([{put_bits,_,_,_}=H|T]) -> + [H|fixup_put_bits(T)]; +fixup_put_bits(Other) -> per_fixup(Other). + %% effective_constraint(Type,C) %% Type = atom() %% C = [C1,...] -- cgit v1.2.3 From df7bb30fd0e8161e5146705fd117aa0bb115fbe7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Mon, 1 Jul 2013 09:05:37 +0200 Subject: PER, UPER: Optimize table constraints The generated code for table constraints has several problems: * For each object set, a function for getting an encoding or decoding fun is generated, regardless of whether it is actually used. In many specifications, the object set actually used is the union of several other object sets. That means that the code can become a lot bulkier than it would need to be. * The funs are not necessary. The funs just add to the code bloat and generate more unnecessary garbage at run-time. Also, one of the arguments of the fun is the name of the field in the class which is known at compile-time, and the fun for decoding has unused arguments. How to fix the problems: At each call site where an open type should be encoded/decoded, call a specific generated function specialized for the actual object set and the name of the field in the class. When generating the specialized functions, make sure that we re-use a previously generated function if possible. --- lib/asn1/src/asn1ct_imm.erl | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'lib/asn1/src/asn1ct_imm.erl') diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl index 44282b4b55..7994889a38 100644 --- a/lib/asn1/src/asn1ct_imm.erl +++ b/lib/asn1/src/asn1ct_imm.erl @@ -1680,8 +1680,6 @@ enc_cg({apply,F0,As0,Dst}) -> As = enc_call_args(As0, ""), emit([mk_val(Dst)," = "]), case F0 of - {var,F} -> - emit([F,"(",As,")"]); {M,F} -> emit([{asis,M},":",{asis,F},"(",As,")"]); F when is_atom(F) -> @@ -2028,6 +2026,7 @@ enc_opt_al_cond_1([[C|Act0]|Cs0], Al0, CAcc, AAcc) -> enc_opt_al_cond_1(Cs0, Al0, [[C|Act]|CAcc], [Al|AAcc]); enc_opt_al_cond_1([], _, CAcc, AAcc) -> Al = case lists:usort(AAcc) of + [] -> unknown; [Al0] -> Al0; [_|_] -> unknown end, -- cgit v1.2.3 From c28e00b24d4d67a8aac55415c36dcab2537db2cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Thu, 8 Aug 2013 11:58:58 +0200 Subject: PER, UPER: Fix encoding/decoding of open types greater than 16K --- lib/asn1/src/asn1ct_imm.erl | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'lib/asn1/src/asn1ct_imm.erl') diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl index 7994889a38..892178f61b 100644 --- a/lib/asn1/src/asn1ct_imm.erl +++ b/lib/asn1/src/asn1ct_imm.erl @@ -138,8 +138,7 @@ per_dec_raw_bitstring(Constraint, Aligned) -> dec_string(Constraint, 1, Aligned, 'BIT STRING'). per_dec_open_type(Aligned) -> - {get_bits,decode_unconstrained_length(true, Aligned), - [8,binary,{align,Aligned}]}. + dec_string(no, 8, Aligned, open_type). per_dec_real(Aligned) -> Dec = fun(V, Buf) -> -- cgit v1.2.3