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authorBjörn Gustavsson <bjorn@erlang.org>2012-11-25 10:46:20 +0100
committerBjörn Gustavsson <bjorn@erlang.org>2012-12-06 14:22:36 +0100
commita14c59482e5823b4a056b9ca7bb80a9ac65de726 (patch)
treeb453e305e215d0297dd5403fa090b58897988b15 /lib/asn1/src
parenteec4313f7c8785734b432c4a3771838c88bb2495 (diff)
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Add the asn1ct_imm module
Diffstat (limited to 'lib/asn1/src')
-rw-r--r--lib/asn1/src/Makefile1
-rw-r--r--lib/asn1/src/asn1ct_imm.erl462
2 files changed, 463 insertions, 0 deletions
diff --git a/lib/asn1/src/Makefile b/lib/asn1/src/Makefile
index c18db7a8fd..8d9422144e 100644
--- a/lib/asn1/src/Makefile
+++ b/lib/asn1/src/Makefile
@@ -54,6 +54,7 @@ CT_MODULES= \
asn1ct_constructed_per \
asn1ct_constructed_ber_bin_v2 \
asn1ct_gen_ber_bin_v2 \
+ asn1ct_imm \
asn1ct_value \
asn1ct_tok \
asn1ct_parser2 \
diff --git a/lib/asn1/src/asn1ct_imm.erl b/lib/asn1/src/asn1ct_imm.erl
new file mode 100644
index 0000000000..9cb4677ce3
--- /dev/null
+++ b/lib/asn1/src/asn1ct_imm.erl
@@ -0,0 +1,462 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2012. All Rights Reserved.
+%%
+%% The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved online at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% %CopyrightEnd%
+%%
+%%
+-module(asn1ct_imm).
+-export([per_dec_boolean/0,per_dec_enumerated/2,per_dec_enumerated/3,
+ per_dec_integer/2,per_dec_length/3,per_dec_named_integer/3,
+ dec_slim_cg/2,dec_code_gen/2]).
+-export([effective_constraint/2]).
+-import(asn1ct_gen, [emit/1]).
+
+-record(st, {var,
+ base}).
+
+dec_slim_cg(Imm, BytesVar) ->
+ asn1ct_name:new(v),
+ [H|T] = atom_to_list(asn1ct_name:curr(v)) ++ "@",
+ VarBase = [H-($a-$A)|T],
+ St0 = #st{var=0,base=VarBase},
+ {Res,Pre,_} = flatten(Imm, BytesVar, St0),
+ dcg_list_outside(Pre),
+ Res.
+
+dec_code_gen(Imm, BytesVar) ->
+ emit(["begin",nl]),
+ {Dst,DstBuf} = dec_slim_cg(Imm, BytesVar),
+ emit([",",nl,
+ "{",Dst,",",DstBuf,"}",nl,
+ "end"]),
+ ok.
+
+per_dec_boolean() ->
+ {map,{get_bits,1,[1]},[{0,false},{1,true}]}.
+
+per_dec_enumerated(NamedList0, Aligned) ->
+ Constraint = [{'ValueRange',{0,length(NamedList0)-1}}],
+ NamedList = per_dec_enumerated_fix_list(NamedList0, [enum_error], 0),
+ Int = per_dec_integer(Constraint, Aligned),
+ {map,Int,NamedList}.
+
+per_dec_enumerated(BaseNamedList, NamedListExt0, Aligned) ->
+ Base = per_dec_enumerated(BaseNamedList, Aligned),
+ NamedListExt = per_dec_enumerated_fix_list(NamedListExt0,
+ [enum_default], 0),
+ Ext = {map,per_dec_normally_small_number(Aligned),NamedListExt},
+ bit_case(Base, Ext).
+
+per_dec_integer(Constraint0, Aligned) ->
+ Constraint = effective_constraint(integer, Constraint0),
+ per_dec_integer_1(Constraint, Aligned).
+
+per_dec_length(SingleValue, _, _Aligned) when is_integer(SingleValue) ->
+ {value,SingleValue};
+per_dec_length({S,S}, _, _Aligned) when is_integer(S) ->
+ {value,S};
+per_dec_length({{_,_}=Constr,_}, AllowZero, Aligned) ->
+ bit_case(per_dec_length(Constr, AllowZero, Aligned),
+ per_dec_length(undefined, AllowZero, Aligned));
+per_dec_length({Lb,Ub}, _AllowZero, Aligned) when is_integer(Lb),
+ is_integer(Lb),
+ Ub =< 65535 ->
+ per_dec_constrained(Lb, Ub, Aligned);
+per_dec_length({_,_}, AllowZero, Aligned) ->
+ decode_unconstrained_length(AllowZero, Aligned);
+per_dec_length(undefined, AllowZero, Aligned) ->
+ decode_unconstrained_length(AllowZero, Aligned).
+
+per_dec_named_integer(Constraint, NamedList0, Aligned) ->
+ Int = per_dec_integer(Constraint, Aligned),
+ NamedList = [{K,V} || {V,K} <- NamedList0] ++ [integer_default],
+ {map,Int,NamedList}.
+
+%%%
+%%% Local functions.
+%%%
+
+per_dec_enumerated_fix_list([{V,_}|T], Tail, N) ->
+ [{N,V}|per_dec_enumerated_fix_list(T, Tail, N+1)];
+per_dec_enumerated_fix_list([], Tail, _) -> Tail.
+
+per_dec_integer_1([{'SingleValue',Value}], _Aligned) ->
+ {value,Value};
+per_dec_integer_1([{'ValueRange',{Lb,'MAX'}}], Aligned) when is_integer(Lb) ->
+ per_dec_unconstrained(Aligned);
+per_dec_integer_1([{'ValueRange',{Lb,Ub}}], Aligned) when is_integer(Lb),
+ is_integer(Ub) ->
+ per_dec_constrained(Lb, Ub, Aligned);
+per_dec_integer_1([{{_,_}=Constr0,_}], Aligned) ->
+ Constr = effective_constraint(integer, [Constr0]),
+ bit_case(per_dec_integer(Constr, Aligned),
+ per_dec_unconstrained(Aligned));
+per_dec_integer_1([], Aligned) ->
+ per_dec_unconstrained(Aligned).
+
+per_dec_unconstrained(Aligned) ->
+ {get_bits,decode_unconstrained_length(false, Aligned),[8,signed]}.
+
+per_dec_constrained(Lb, Ub, false) ->
+ Range = Ub - Lb + 1,
+ Get = {get_bits,uper_num_bits(Range),[1]},
+ add_lb(Lb, Get);
+per_dec_constrained(Lb, Ub, true) ->
+ Range = Ub - Lb + 1,
+ Get = if
+ Range =< 255 ->
+ {get_bits,per_num_bits(Range),[1,unsigned]};
+ Range == 256 ->
+ {get_bits,1,[8,unsigned,{align,true}]};
+ Range =< 65536 ->
+ {get_bits,2,[8,unsigned,{align,true}]};
+ true ->
+ RangeOctLen = byte_size(binary:encode_unsigned(Range - 1)),
+ {get_bits,per_dec_length({1,RangeOctLen}, false, true),
+ [8,unsigned,{align,true}]}
+ end,
+ add_lb(Lb, Get).
+
+add_lb(0, Get) -> Get;
+add_lb(Lb, Get) -> {add,Get,Lb}.
+
+per_dec_normally_small_number(Aligned) ->
+ Small = {get_bits,6,[1]},
+ Unlimited = per_decode_semi_constrained(0, Aligned),
+ bit_case(Small, Unlimited).
+
+per_decode_semi_constrained(Lb, Aligned) ->
+ add_lb(Lb, {get_bits,decode_unconstrained_length(false, Aligned),[8]}).
+
+bit_case(Base, Ext) ->
+ {'case',[{test,{get_bits,1,[1]},0,Base},
+ {test,{get_bits,1,[1]},1,Ext}]}.
+
+decode_unconstrained_length(AllowZero, Aligned) ->
+ Al = [{align,Aligned}],
+ Zero = case AllowZero of
+ false -> [non_zero];
+ true -> []
+ end,
+ {'case',[{test,{get_bits,1,[1|Al]},0,
+ {value,{get_bits,7,[1|Zero]}}},
+ {test,{get_bits,1,[1|Al]},1,
+ {test,{get_bits,1,[1]},0,
+ {value,{get_bits,14,[1|Zero]}}}}]}.
+
+uper_num_bits(N) ->
+ uper_num_bits(N, 1, 0).
+
+uper_num_bits(N, T, B) when N =< T -> B;
+uper_num_bits(N, T, B) -> uper_num_bits(N, T bsl 1, B+1).
+
+per_num_bits(2) -> 1;
+per_num_bits(N) when N =< 4 -> 2;
+per_num_bits(N) when N =< 8 -> 3;
+per_num_bits(N) when N =< 16 -> 4;
+per_num_bits(N) when N =< 32 -> 5;
+per_num_bits(N) when N =< 64 -> 6;
+per_num_bits(N) when N =< 128 -> 7;
+per_num_bits(N) when N =< 255 -> 8.
+
+%%%
+%%% Flatten the intermediate format and assign temporaries.
+%%%
+
+flatten({get_bits,I,U}, Buf0, St0) when is_integer(I) ->
+ {Dst,St} = new_var_pair(St0),
+ Gb = {get_bits,{I,Buf0},U,Dst},
+ flatten_align(Gb, [], St);
+flatten({get_bits,E0,U}, Buf0, St0) ->
+ {E,Pre,St1} = flatten(E0, Buf0, St0),
+ {Dst,St2} = new_var_pair(St1),
+ Gb = {get_bits,E,U,Dst},
+ flatten_align(Gb, Pre, St2);
+flatten({test,{get_bits,I,U},V,E0}, Buf0, St0) when is_integer(I) ->
+ {DstBuf0,St1} = new_var("Buf", St0),
+ Gb = {get_bits,{I,Buf0},U,{V,DstBuf0}},
+ {{_Dst,DstBuf},Pre0,St2} = flatten_align(Gb, [], St1),
+ {E,Pre1,St3} = flatten(E0, DstBuf, St2),
+ {E,Pre0++Pre1,St3};
+flatten({add,E0,I}, Buf0, St0) ->
+ {{Src,Buf},Pre,St1} = flatten(E0, Buf0, St0),
+ {Dst,St} = new_var("Add", St1),
+ {{Dst,Buf},Pre++[{add,Src,I,Dst}],St};
+flatten({'case',Cs0}, Buf0, St0) ->
+ {Dst,St1} = new_var_pair(St0),
+ {Cs1,St} = flatten_cs(Cs0, Buf0, St1),
+ {Al,Cs2} = flatten_hoist_align(Cs1),
+ {Dst,Al++[{'case',Buf0,Cs2,Dst}],St};
+flatten({map,E0,Cs0}, Buf0, St0) ->
+ {{E,DstBuf},Pre,St1} = flatten(E0, Buf0, St0),
+ {Dst,St2} = new_var("Int", St1),
+ Cs = flatten_map_cs(Cs0, E),
+ {{Dst,DstBuf},Pre++[{'map',E,Cs,{Dst,DstBuf}}],St2};
+flatten({value,V0}, Buf0, St0) when is_integer(V0) ->
+ {{V0,Buf0},[],St0};
+flatten({value,V0}, Buf0, St0) ->
+ flatten(V0, Buf0, St0).
+
+flatten_cs([C0|Cs0], Buf, St0) ->
+ {C,Pre,St1} = flatten(C0, Buf, St0),
+ {Cs,St2} = flatten_cs(Cs0, Buf, St0),
+ St3 = St2#st{var=max(St1#st.var, St2#st.var)},
+ {[Pre++[{return,C}]|Cs],St3};
+flatten_cs([], _, St) -> {[],St}.
+
+flatten_map_cs(Cs, Var) ->
+ flatten_map_cs_1(Cs, {Var,Cs}).
+
+flatten_map_cs_1([{K,V}|Cs], DefData) ->
+ [{{asis,K},{asis,V}}|flatten_map_cs_1(Cs, DefData)];
+flatten_map_cs_1([integer_default], {Int,_}) ->
+ [{'_',Int}];
+flatten_map_cs_1([enum_default], {Int,_}) ->
+ [{'_',["{asn1_enum,",Int,"}"]}];
+flatten_map_cs_1([enum_error], {Var,Cs}) ->
+ Vs = [V || {_,V} <- Cs],
+ [{'_',["exit({error,{asn1,{decode_enumerated,{",Var,",",
+ {asis,Vs},"}}}})"]}];
+flatten_map_cs_1([], _) -> [].
+
+flatten_hoist_align([[{align_bits,_,_}=Ab|T]|Cs]) ->
+ flatten_hoist_align_1(Cs, Ab, [T]);
+flatten_hoist_align(Cs) -> {[],Cs}.
+
+flatten_hoist_align_1([[Ab|T]|Cs], Ab, Acc) ->
+ flatten_hoist_align_1(Cs, Ab, [T|Acc]);
+flatten_hoist_align_1([], Ab, Acc) ->
+ {[Ab],lists:reverse(Acc)}.
+
+flatten_align({get_bits,{SrcBits,SrcBuf},U,Dst}=Gb0, Pre, St0) ->
+ case is_aligned(U) of
+ false ->
+ flatten_align_1(U, Dst, Pre++[Gb0], St0);
+ true ->
+ {PadBits,St1} = new_var("Pad", St0),
+ {DstBuf,St2} = new_var("Buf", St1),
+ Ab = {align_bits,SrcBuf,PadBits},
+ Agb = {get_bits,{PadBits,SrcBuf},[1],{'_',DstBuf}},
+ Gb = {get_bits,{SrcBits,DstBuf},U,Dst},
+ flatten_align_1(U, Dst, Pre++[Ab,Agb,Gb], St2)
+ end.
+
+flatten_align_1(U, {D,_}=Dst, Pre, St) ->
+ case is_non_zero(U) of
+ false ->
+ {Dst,Pre,St};
+ true ->
+ {Dst,Pre++[{non_zero,D}],St}
+ end.
+
+new_var_pair(St0) ->
+ {Var,St1} = new_var("V", St0),
+ {Buf,St2} = new_var("Buf", St1),
+ {{Var,Buf},St2}.
+
+new_var(Tag, #st{base=VarBase,var=N}=St) ->
+ {VarBase++Tag++integer_to_list(N),St#st{var=N+1}}.
+
+is_aligned(Fl) ->
+ proplists:get_bool(align, Fl).
+
+is_non_zero(Fl) ->
+ lists:member(non_zero, Fl).
+
+%%%
+%%% Generate Erlang code from the flattened intermediate format.
+%%%
+
+dcg_list_outside([{align_bits,Buf,SzVar}|T]) ->
+ emit([SzVar," = bit_size(",Buf,") band 7"]),
+ iter_dcg_list_outside(T);
+dcg_list_outside([{'case',Buf,Cs,Dst}|T]) ->
+ dcg_case(Buf, Cs, Dst),
+ iter_dcg_list_outside(T);
+dcg_list_outside([{'map',Val,Cs,Dst}|T]) ->
+ dcg_map(Val, Cs, Dst),
+ iter_dcg_list_outside(T);
+dcg_list_outside([{add,S1,S2,Dst}|T]) ->
+ emit([Dst," = ",S1," + ",S2]),
+ iter_dcg_list_outside(T);
+dcg_list_outside([{return,{V,Buf}}|T]) ->
+ emit(["{",V,",",Buf,"}"]),
+ iter_dcg_list_outside(T);
+dcg_list_outside([{get_bits,{_,Buf0},_,_}|_]=L0) ->
+ emit("<<"),
+ {L,Buf} = dcg_list_inside(L0, buf),
+ emit([Buf,"/bitstring>> = ",Buf0]),
+ iter_dcg_list_outside(L);
+dcg_list_outside([]) ->
+ emit("ignore"),
+ ok.
+
+iter_dcg_list_outside([_|_]=T) ->
+ emit([",",nl]),
+ dcg_list_outside(T);
+iter_dcg_list_outside([]) -> ok.
+
+dcg_case(Buf, Cs, {Dst,DstBuf}) ->
+ emit(["{",Dst,",",DstBuf,"} = case ",Buf," of",nl]),
+ dcg_case_cs(Cs),
+ emit("end").
+
+dcg_case_cs([C|Cs]) ->
+ emit("<<"),
+ {T0,DstBuf} = dcg_list_inside(C, buf),
+ emit([DstBuf,"/bitstring>>"]),
+ T1 = dcg_guard(T0),
+ dcg_list_outside(T1),
+ case Cs of
+ [] -> emit([nl]);
+ [_|_] -> emit([";",nl])
+ end,
+ dcg_case_cs(Cs);
+dcg_case_cs([]) -> ok.
+
+dcg_guard([{non_zero,Src}|T]) ->
+ emit([" when ",Src," =/= 0 ->",nl]),
+ T;
+dcg_guard(T) ->
+ emit([" ->",nl]),
+ T.
+
+dcg_map(Val, Cs, {Dst,_}) ->
+ emit([Dst," = case ",Val," of",nl]),
+ dcg_map_cs(Cs),
+ emit("end").
+
+dcg_map_cs([{K,V}]) ->
+ emit([K," -> ",V,nl]);
+dcg_map_cs([{K,V}|Cs]) ->
+ emit([K," -> ",V,";",nl]),
+ dcg_map_cs(Cs).
+
+dcg_list_inside([{get_bits,{Sz,_},Fl0,{Dst,DstBuf}}|T], _) ->
+ Fl = bit_flags(Fl0, []),
+ emit([mk_dest(Dst),":",Sz,Fl,","]),
+ dcg_list_inside(T, DstBuf);
+dcg_list_inside(L, Dst) -> {L,Dst}.
+
+bit_flags([1|T], Acc) ->
+ bit_flags(T, Acc);
+bit_flags([{align,_}|T], Acc) ->
+ bit_flags(T, Acc);
+bit_flags([non_zero|T], Acc) ->
+ bit_flags(T, Acc);
+bit_flags([U|T], Acc) when is_integer(U) ->
+ bit_flags(T, ["unit:"++integer_to_list(U)|Acc]);
+bit_flags([H|T], Acc) ->
+ bit_flags(T, [atom_to_list(H)|Acc]);
+bit_flags([], []) ->
+ "";
+bit_flags([], Acc) ->
+ "/" ++ bit_flags_1(Acc, "").
+
+bit_flags_1([H|T], Sep) ->
+ Sep ++ H ++ bit_flags_1(T, "-");
+bit_flags_1([], _) -> [].
+
+mk_dest(I) when is_integer(I) ->
+ integer_to_list(I);
+mk_dest(S) -> S.
+
+%% effective_constraint(Type,C)
+%% Type = atom()
+%% C = [C1,...]
+%% C1 = {'SingleValue',SV} | {'ValueRange',VR} | {atom(),term()}
+%% SV = integer() | [integer(),...]
+%% VR = {Lb,Ub}
+%% Lb = 'MIN' | integer()
+%% Ub = 'MAX' | integer()
+%% Returns a single value if C only has a single value constraint, and no
+%% value range constraints, that constrains to a single value, otherwise
+%% returns a value range that has the lower bound set to the lowest value
+%% of all single values and lower bound values in C and the upper bound to
+%% the greatest value.
+effective_constraint(integer,[C={{_,_},_}|_Rest]) -> % extension
+ [C];
+effective_constraint(integer, C) ->
+ SVs = get_constraints(C, 'SingleValue'),
+ SV = effective_constr('SingleValue', SVs),
+ VRs = get_constraints(C, 'ValueRange'),
+ VR = effective_constr('ValueRange', VRs),
+ greatest_common_range(SV, VR);
+effective_constraint(bitstring, C) ->
+ get_constraint(C, 'SizeConstraint').
+
+effective_constr(_, []) -> [];
+effective_constr('SingleValue', List) ->
+ SVList = lists:flatten(lists:map(fun(X) -> element(2, X) end, List)),
+ %% Sort and remove duplicates before generating SingleValue or ValueRange
+ %% In case of ValueRange, also check for 'MIN and 'MAX'
+ case lists:usort(SVList) of
+ [N] ->
+ [{'SingleValue',N}];
+ [_|_]=L ->
+ [{'ValueRange',{least_Lb(L),greatest_Ub(L)}}]
+ end;
+effective_constr('ValueRange', List) ->
+ LBs = lists:map(fun({_,{Lb,_}}) -> Lb end, List),
+ UBs = lists:map(fun({_,{_,Ub}}) -> Ub end, List),
+ Lb = least_Lb(LBs),
+ [{'ValueRange',{Lb,lists:max(UBs)}}].
+
+greatest_common_range([], VR) ->
+ VR;
+greatest_common_range(SV, []) ->
+ SV;
+greatest_common_range([{_,Int}], [{_,{'MIN',Ub}}])
+ when is_integer(Int), Int > Ub ->
+ [{'ValueRange',{'MIN',Int}}];
+greatest_common_range([{_,Int}],[{_,{Lb,Ub}}])
+ when is_integer(Int), Int < Lb ->
+ [{'ValueRange',{Int,Ub}}];
+greatest_common_range([{_,Int}],VR=[{_,{_Lb,_Ub}}]) when is_integer(Int) ->
+ VR;
+greatest_common_range([{_,L}],[{_,{Lb,Ub}}]) when is_list(L) ->
+ Min = least_Lb([Lb|L]),
+ Max = greatest_Ub([Ub|L]),
+ [{'ValueRange',{Min,Max}}];
+greatest_common_range([{_,{Lb1,Ub1}}], [{_,{Lb2,Ub2}}]) ->
+ Min = least_Lb([Lb1,Lb2]),
+ Max = greatest_Ub([Ub1,Ub2]),
+ [{'ValueRange',{Min,Max}}].
+
+
+least_Lb(L) ->
+ case lists:member('MIN', L) of
+ true -> 'MIN';
+ false -> lists:min(L)
+ end.
+
+greatest_Ub(L) ->
+ case lists:member('MAX', L) of
+ true -> 'MAX';
+ false -> lists:max(L)
+ end.
+
+get_constraint(C, Key) ->
+ case lists:keyfind(Key, 1, C) of
+ false -> no;
+ {_,V} -> V
+ end.
+
+get_constraints([{Key,_}=Pair|T], Key) ->
+ [Pair|get_constraints(T, Key)];
+get_constraints([_|T], Key) ->
+ get_constraints(T, Key);
+get_constraints([], _) -> [].