diff options
Diffstat (limited to 'lib/asn1/src/asn1ct_imm.erl')
| -rw-r--r-- | lib/asn1/src/asn1ct_imm.erl | 1470 |
1 files changed, 1444 insertions, 26 deletions
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl index bf362db843..892178f61b 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]). @@ -115,29 +127,18 @@ 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), - [8,binary,{align,Aligned}]}. + dec_string(no, 8, Aligned, open_type). per_dec_real(Aligned) -> Dec = fun(V, Buf) -> @@ -152,26 +153,285 @@ 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. %%% -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, @@ -692,6 +952,1164 @@ 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), + <<Int:Sz/unit:8>> = 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 + {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,<<Len:16>>|Data]] +%%% +%%% can be rewritten to: +%%% +%%% [align,<<1:1,0:1,0:6>>,[<<Len:16>>|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,<<Len:16>>|Data]] +%%% +%%% to: +%%% +%%% [[<<1:1,0:1>>,align],[<<Len:16>>|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 + [] -> unknown; + [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,...] |