%% %% %CopyrightBegin% %% %% Copyright Ericsson AB 2000-2012. 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(bs_construct_SUITE). %% Copied from bs_construct_SUITE in the emulator test suite. %% The following test cases have been omitted since they don't %% make much sense for the debugger: %% bs_add %% kostis -export([all/0, suite/0,groups/0,init_per_group/2,end_per_group/2, init_per_testcase/2,end_per_testcase/2, init_per_suite/1,end_per_suite/1, test1/1, test2/1, test3/1, test4/1, test5/1, testf/1, not_used/1, in_guard/1, mem_leak/1, coerce_to_float/1, bjorn/1, huge_float_field/1, huge_binary/1, system_limit/1, badarg/1, copy_writable_binary/1, dynamic/1, otp_7422/1, zero_width/1]). -include_lib("test_server/include/test_server.hrl"). suite() -> [{ct_hooks,[ts_install_cth]}]. all() -> [test1, test2, test3, test4, test5, testf, not_used, in_guard, mem_leak, coerce_to_float, bjorn, huge_float_field, huge_binary, system_limit, badarg, copy_writable_binary, dynamic, otp_7422, zero_width]. groups() -> []. init_per_group(_GroupName, Config) -> Config. end_per_group(_GroupName, Config) -> Config. init_per_testcase(_Case, Config) -> test_lib:interpret(?MODULE), Dog = test_server:timetrap(?t:minutes(15)), [{watchdog,Dog}|Config]. end_per_testcase(_Case, Config) -> Dog = ?config(watchdog, Config), ?t:timetrap_cancel(Dog), ok. init_per_suite(Config) when is_list(Config) -> ?line test_lib:interpret(?MODULE), ?line true = lists:member(?MODULE, int:interpreted()), Config. end_per_suite(Config) when is_list(Config) -> ok. big(1) -> 57285702734876389752897683. i(X) -> X. r(L) -> lists:reverse(L). -define(T(B, L), {B, ??B, L}). -define(N(B), {B, ??B, unknown}). -define(FAIL(Expr), ?line fail_check(catch Expr, ??Expr, [])). -define(FAIL_VARS(Expr, Vars), ?line fail_check(catch Expr, ??Expr, Vars)). l(I_13, I_big1) -> [ ?T(<<-43>>, [256-43]), ?T(<<56>>, [56]), ?T(<<1,2>>, [1, 2]), ?T(<<4:4, 7:4>>, [4*16+7]), ?T(<<777:16/big>>, [3, 9]), ?T(<<777:16/little>>, [9, 3]), ?T(<<0.0:32/float>>, [0,0,0,0]), ?T(<<0.125:32/float>>, [62,0,0,0]), ?T(<<0.125:32/little-float>>, [0,0,0,62]), ?T(<<I_big1:32>>, [138, 99, 0, 147]), ?T(<<57285702734876389752897684:32>>, [138, 99, 0, 148]), ?T(<<I_big1:32/little>>, r([138, 99, 0, 147])), ?T(<<-1:17/unit:8>>, lists:duplicate(17, 255)), ?T(<<I_13>>, [13]), ?T(<<4:8/unit:2,5:2/unit:8>>, [0, 4, 0, 5]), ?T(<<1:1, 0:6, 1:1>>, [129]), ?T(<<1:1/little, 0:6/little, 1:1/little>>, [129]), ?T(<<<<1,2>>/binary>>, [1, 2]), ?T(<<<<1,2>>:1/binary>>, [1]), ?T(<<4,3,<<1,2>>:1/binary>>, [4,3,1]), ?T(<<(256*45+47)>>, [47]), ?T(<<57:0>>, []), ?T(<<"apa">>, "apa"), ?T(<<1:3,"string",9:5>>, [46,110,142,77,45,204,233]), ?T(<<>>, []), ?T(<<37.98:64/native-float>>, native_3798()), ?T(<<32978297842987249827298387697777669766334937:128/native-integer>>, native_bignum()), %% Unit tests. ?T(<<<<5:3>>/bitstring>>, <<5:3>>), ?T(<<42,<<7:4>>/binary-unit:4>>, <<42,7:4>>), ?T(<<<<344:17>>/binary-unit:17>>, <<344:17>>), ?T(<<<<42,3,7656:16>>/binary-unit:16>>, <<42,3,7656:16>>) ]. native_3798() -> case <<1:16/native>> of <<0,1>> -> [64,66,253,112,163,215,10,61]; <<1,0>> -> [61,10,215,163,112,253,66,64] end. native_bignum() -> case <<1:16/native>> of <<0,1>> -> [129,205,18,177,1,213,170,101,39,231,109,128,176,11,73,217]; <<1,0>> -> [217,73,11,176,128,109,231,39,101,170,213,1,177,18,205,129] end. evaluate(Str, Vars) -> {ok,Tokens,_} = erl_scan:string(Str ++ " . "), {ok, [Expr]} = erl_parse:parse_exprs(Tokens), case erl_eval:expr(Expr, Vars) of {value, Result, _} -> Result end. eval_list([], _Vars) -> []; eval_list([{C_bin, Str, Bytes} | Rest], Vars) -> case catch evaluate(Str, Vars) of {'EXIT', Error} -> io:format("Evaluation error: ~p, ~p, ~p~n", [Str, Vars, Error]), exit(Error); E_bin -> [{C_bin, E_bin, Str, Bytes} | eval_list(Rest, Vars)] end. one_test({C_bin, E_bin, Str, Bytes}) when is_list(Bytes) -> io:format(" ~s, ~p~n", [Str, Bytes]), Bin = list_to_binary(Bytes), if C_bin == Bin -> ok; true -> io:format("ERROR: Compiled: ~p. Expected ~p. Got ~p.~n", [Str, Bytes, binary_to_list(C_bin)]), test_server:fail(comp) end, if E_bin == Bin -> ok; true -> io:format("ERROR: Interpreted: ~p. Expected ~p. Got ~p.~n", [Str, Bytes, binary_to_list(E_bin)]), test_server:fail(comp) end; one_test({C_bin, E_bin, Str, Result}) -> io:format(" ~s ~p~n", [Str, C_bin]), if C_bin == E_bin -> ok; true -> Arbitrary = case Result of unknown -> size(C_bin); _ -> Result end, case equal_lists(binary_to_list(C_bin), binary_to_list(E_bin), Arbitrary) of false -> io:format("ERROR: Compiled not equal to interpreted:" "~n ~p, ~p.~n", [binary_to_list(C_bin), binary_to_list(E_bin)]), test_server:fail(comp); 0 -> ok; %% For situations where the final bits may not matter, like %% for floats: N when is_integer(N) -> io:format("Info: compiled and interpreted differ in the" " last bytes:~n ~p, ~p.~n", [binary_to_list(C_bin), binary_to_list(E_bin)]), ok end end. equal_lists([], [], _) -> 0; equal_lists([], _, _) -> false; equal_lists(_, [], _) -> false; equal_lists([A|AR], [A|BR], R) -> equal_lists(AR, BR, R); equal_lists(A, B, R) -> if length(A) /= length(B) -> false; length(A) =< R -> R; true -> false end. fail_check({'EXIT',{badarg,_}}, Str, Vars) -> try evaluate(Str, Vars) of Res -> io:format("Interpreted result: ~p", [Res]), ?t:fail(did_not_fail_in_intepreted_code) catch error:badarg -> ok end; fail_check(Res, _, _) -> io:format("Compiled result: ~p", [Res]), ?t:fail(did_not_fail_in_compiled_code). %%% Simple working cases test1(suite) -> []; test1(Config) when is_list(Config) -> ?line I_13 = i(13), ?line I_big1 = big(1), ?line Vars = [{'I_13', I_13}, {'I_big1', I_big1}], ?line lists:foreach(fun one_test/1, eval_list(l(I_13, I_big1), Vars)). %%% Misc %%% <<A:S, A:(N-S)>> comp(N, A, S) -> M1 = (1 bsl S) - 1, M2 = (1 bsl (N-S)) - 1, [((A band M1) bsl (N-S)) bor (A band M2)]. gen(N, S, A) -> [?T(<<A:S, A:(N-S)>>, comp(N, A, S))]. gen_l(N, S, A) -> [?T(<<A:S/little, A:(N-S)/little>>, comp(N, A, S))]. test2(suite) -> []; test2(Config) when is_list(Config) -> ?line test2(0, 8, 2#10101010101010101), ?line test2(0, 8, 2#1111111111). test2(End, End, _) -> ok; test2(I, End, A) -> test2(I, A), test2(I+1, End, A). test2(S, A) -> N = 8, Vars = [{'A',A}, {'N',N}, {'S',S}], io:format("Vars: ~p\n", [Vars]), lists:foreach(fun one_test/1, eval_list(gen(N, S, A), Vars)), lists:foreach(fun one_test/1, eval_list(gen_l(N, S, A), Vars)). %%% Tests without facit t3() -> [?N(<<4711:13, 9876:13, 3:6>>), ?N(<<4.57:64/float>>), ?N(<<4.57:32/float>>), ?N(<<>>) ]. test3(suite) -> []; test3(Config) when is_list(Config) -> ?line Vars = [], ?line lists:foreach(fun one_test/1, eval_list(t3(), Vars)). gen_u(N, S, A) -> [?N(<<A:S, A:(N-S)>>)]. gen_u_l(N, S, A) -> [?N(<<A:S/little, A:(N-S)/little>>)]. test4(suite) -> []; test4(Config) when is_list(Config) -> ?line test4(0, 16, 2#10101010101010101), ?line test4(0, 16, 2#1111111111). test4(End, End, _) -> ok; test4(I, End, A) -> test4(I, A), test4(I+1, End, A). test4(S, A) -> N = 16, Vars = [{'A', A}, {'N', 16}, {'S', S}], lists:foreach(fun one_test/1, eval_list(gen_u(N, S, A), Vars)), lists:foreach(fun one_test/1, eval_list(gen_u_l(N, S, A), Vars)). gen_b(N, S, A) -> [?T(<<A:S/binary-unit:1, A:(N-S)/binary-unit:1>>, binary_to_list(<<A:S/binary-unit:1, A:(N-S)/binary-unit:1>>))]. test5(suite) -> []; test5(doc) -> ["OTP-3995"]; test5(Config) when is_list(Config) -> ?line test5(0, 8, <<73>>), ?line test5(0, 8, <<68>>). test5(End, End, _) -> ok; test5(I, End, A) -> test5(I, A), test5(I+1, End, A). test5(S, A) -> N = 8, Vars = [{'A', A}, {'N', 8}, {'S', S}], lists:foreach(fun one_test/1, eval_list(gen_b(N, S, A), Vars)). %%% Failure cases testf(suite) -> []; testf(Config) when is_list(Config) -> ?line ?FAIL(<<3.14>>), ?line ?FAIL(<<<<1,2>>>>), ?line ?FAIL(<<2.71/binary>>), ?line ?FAIL(<<24334/binary>>), ?line ?FAIL(<<24334344294788947129487129487219847/binary>>), BigInt = id(24334344294788947129487129487219847), ?line ?FAIL_VARS(<<BigInt/binary>>, [{'BigInt',BigInt}]), ?line ?FAIL_VARS(<<42,BigInt/binary>>, [{'BigInt',BigInt}]), ?line ?FAIL_VARS(<<BigInt:2/binary>>, [{'BigInt',BigInt}]), %% One negative field size, but the sum of field sizes will be 1 byte. %% Make sure that we reject that properly. I_minus_777 = id(-777), I_minus_2047 = id(-2047), ?line ?FAIL_VARS(<<I_minus_777:2048/unit:8,57:I_minus_2047/unit:8>>, ordsets:from_list([{'I_minus_777',I_minus_777}, {'I_minus_2047',I_minus_2047}])), ?line ?FAIL(<<<<1,2,3>>/float>>), %% Negative field widths. ?line testf_1(-8, <<1,2,3,4,5>>), ?line ?FAIL(<<0:(-(1 bsl 100))>>), ?line ?FAIL(<<42:(-16)>>), ?line ?FAIL(<<3.14:(-8)/float>>), ?line ?FAIL(<<<<23,56,0,2>>:(-16)/binary>>), ?line ?FAIL(<<<<23,56,0,2>>:(2.5)/binary>>), ?line ?FAIL(<<<<23,56,0,2>>:(anka)>>), ?line ?FAIL(<<<<23,56,0,2>>:(anka)>>), %% Unit failures. ?line ?FAIL(<<<<1:1>>/binary>>), Sz = id(1), ?line ?FAIL_VARS(<<<<1:Sz>>/binary>>, [{'Sz',Sz}]), ?line {'EXIT',{badarg,_}} = (catch <<<<1:(id(1))>>/binary>>), ?line ?FAIL(<<<<7,8,9>>/binary-unit:16>>), ?line ?FAIL(<<<<7,8,9,3:7>>/binary-unit:16>>), ?line ?FAIL(<<<<7,8,9,3:7>>/binary-unit:17>>), ok. testf_1(W, B) -> Vars = [{'W',W}], ?FAIL_VARS(<<42:W>>, Vars), ?FAIL_VARS(<<3.14:W/float>>, Vars), ?FAIL_VARS(<<B:W/binary>>, [{'B',B}|Vars]). not_used(doc) -> "Test that constructed binaries that are not used will still give an exception."; not_used(Config) when is_list(Config) -> ?line ok = not_used1(3, <<"dum">>), ?line {'EXIT',{badarg,_}} = (catch not_used1(3, "dum")), ?line {'EXIT',{badarg,_}} = (catch not_used2(444, -2)), ?line {'EXIT',{badarg,_}} = (catch not_used2(444, anka)), ?line {'EXIT',{badarg,_}} = (catch not_used3(444)), ok. not_used1(I, BinString) -> <<I:32,BinString/binary>>, ok. not_used2(I, Sz) -> <<I:Sz>>, ok. not_used3(I) -> <<I:(-8)>>, ok. in_guard(Config) when is_list(Config) -> ?line 1 = in_guard(<<16#74ad:16>>, 16#e95, 5), ?line 2 = in_guard(<<16#3A,16#F7,"hello">>, 16#3AF7, <<"hello">>), ?line 3 = in_guard(<<16#FBCD:14,3.1415/float,3:2>>, 16#FBCD, 3.1415), nope = in_guard(<<1>>, 42, b), nope = in_guard(<<1>>, a, b), nope = in_guard(<<1,2>>, 1, 1), nope = in_guard(<<4,5>>, 1, 2.71), nope = in_guard(<<4,5>>, 1, <<12,13>>), ok. in_guard(Bin, A, B) when <<A:13,B:3>> == Bin -> 1; in_guard(Bin, A, B) when <<A:16,B/binary>> == Bin -> 2; in_guard(Bin, A, B) when <<A:14,B/float,3:2>> == Bin -> 3; in_guard(Bin, A, B) when {a,b,<<A:14,B/float,3:2>>} == Bin -> cant_happen; in_guard(_, _, _) -> nope. mem_leak(doc) -> "Make sure that construction has no memory leak"; mem_leak(Config) when is_list(Config) -> ?line B = make_bin(16, <<0>>), ?line mem_leak(1024, B), ok. mem_leak(0, _) -> ok; mem_leak(N, B) -> ?line big_bin(B, <<23>>), ?line {'EXIT',{badarg,_}} = (catch big_bin(B, bad)), mem_leak(N-1, B). big_bin(B1, B2) -> <<B1/binary,B1/binary,B1/binary,B1/binary, B1/binary,B1/binary,B1/binary,B1/binary, B1/binary,B1/binary,B1/binary,B1/binary, B1/binary,B1/binary,B1/binary,B1/binary, B2/binary>>. make_bin(0, Acc) -> Acc; make_bin(N, Acc) -> make_bin(N-1, <<Acc/binary,Acc/binary>>). -define(COF(Int0), ?line (fun(Int) -> true = <<Int:32/float>> =:= <<(float(Int)):32/float>>, true = <<Int:64/float>> =:= <<(float(Int)):64/float>> end)(nonliteral(Int0)), ?line true = <<Int0:32/float>> =:= <<(float(Int0)):32/float>>, ?line true = <<Int0:64/float>> =:= <<(float(Int0)):64/float>>). -define(COF64(Int0), ?line (fun(Int) -> true = <<Int:64/float>> =:= <<(float(Int)):64/float>> end)(nonliteral(Int0)), ?line true = <<Int0:64/float>> =:= <<(float(Int0)):64/float>>). nonliteral(X) -> X. coerce_to_float(Config) when is_list(Config) -> ?COF(0), ?COF(-1), ?COF(1), ?COF(42), ?COF(255), ?COF(-255), ?COF(38474), ?COF(387498738948729893849444444443), ?COF(-37489378937773899999999999999993), ?COF64(298748888888888888888888888883478264866528467367364766666666666666663), ?COF64(-367546729879999999999947826486652846736736476555566666663), ok. bjorn(Config) when is_list(Config) -> ?line error = bjorn_1(), ok. bjorn_1() -> Bitstr = <<7:13>>, try do_something() catch throw:blurf -> ignore end, do_more(Bitstr, 13). do_more(Bin, Sz) -> %% Previous bug in the bs_bits_to_bytes instruction: The exeption code %% was not set - the previous exception (throw:blurf) would be used, %% causing the catch to slip. try <<Bin:Sz/binary>> of _V -> ok catch error:_ -> error end. do_something() -> throw(blurf). huge_float_field(Config) when is_list(Config) -> ?line {'EXIT',{badarg,_}} = (catch <<0.0:9/float-unit:8>>), ?line huge_float_check(catch <<0.0:67108865/float-unit:64>>), ?line huge_float_check(catch <<0.0:((1 bsl 26)+1)/float-unit:64>>), ?line huge_float_check(catch <<0.0:(id(67108865))/float-unit:64>>), %% ?line huge_float_check(catch <<0.0:((1 bsl 60)+1)/float-unit:64>>), ?line huge_float_check(catch <<3839739387439387383739387987347983:((1 bsl 26)+1)/float-unit:64>>), %% ?line huge_float_check(catch <<3839739387439387383739387987347983:((1 bsl 60)+1)/float-unit:64>>), ok. huge_float_check({'EXIT',{system_limit,_}}) -> ok; huge_float_check({'EXIT',{badarg,_}}) -> ok. huge_binary(Config) when is_list(Config) -> ?line 16777216 = size(<<0:(id(1 bsl 26)),(-1):(id(1 bsl 26))>>), ok. system_limit(Config) when is_list(Config) -> WordSize = erlang:system_info(wordsize), BitsPerWord = WordSize * 8, ?line {'EXIT',{system_limit,_}} = (catch <<0:(id(0)),42:(id(1 bsl BitsPerWord))>>), ?line {'EXIT',{system_limit,_}} = (catch <<42:(id(1 bsl BitsPerWord)),0:(id(0))>>), ?line {'EXIT',{system_limit,_}} = (catch <<(id(<<>>))/binary,0:(id(1 bsl 100))>>), case WordSize of 4 -> system_limit_32(); 8 -> ok end. system_limit_32() -> ?line {'EXIT',{badarg,_}} = (catch <<42:(-1)>>), ?line {'EXIT',{badarg,_}} = (catch <<42:(id(-1))>>), ?line {'EXIT',{badarg,_}} = (catch <<42:(id(-389739873536870912))/unit:8>>), ?line {'EXIT',{system_limit,_}} = (catch <<42:536870912/unit:8>>), ?line {'EXIT',{system_limit,_}} = (catch <<42:(id(536870912))/unit:8>>), ?line {'EXIT',{system_limit,_}} = (catch <<0:(id(8)),42:536870912/unit:8>>), ?line {'EXIT',{system_limit,_}} = (catch <<0:(id(8)),42:(id(536870912))/unit:8>>), ok. badarg(Config) when is_list(Config) -> %% BEAM will generate a badarg exception for: %% <<0:(id(1 bsl 100)),0:(id(-1))>> %% but the debugger will generate a system_limit exception. %% It does not seems worthwhile to fix the debugger. ?line {'EXIT',{badarg,_}} = (catch <<(id(<<>>))/binary,0:(id(-(1 bsl 100)))>>), ok. copy_writable_binary(Config) when is_list(Config) -> ?line [copy_writable_binary_1(I) || I <- lists:seq(0, 256)], ok. copy_writable_binary_1(_) -> ?line Bin0 = <<(id(<<>>))/binary,0,1,2,3,4,5,6,7>>, ?line SubBin = make_sub_bin(Bin0), ?line id(<<42,34,55,Bin0/binary>>), %Make reallocation likelier. ?line Pid = spawn(fun() -> copy_writable_binary_holder(Bin0, SubBin) end), ?line Tab = ets:new(holder, []), ?line ets:insert(Tab, {17,Bin0}), ?line ets:insert(Tab, {42,SubBin}), ?line id(<<Bin0/binary,0:(64*1024*8)>>), ?line Pid ! self(), ?line [{17,Bin0}] = ets:lookup(Tab, 17), ?line [{42,Bin0}] = ets:lookup(Tab, 42), receive {Pid,Bin0,Bin0} -> ok; Other -> io:format("Unexpected message: ~p", [Other]), ?line ?t:fail() end, ok. copy_writable_binary_holder(Bin, SubBin) -> receive Pid -> Pid ! {self(),Bin,SubBin} end. make_sub_bin(Bin0) -> N = bit_size(Bin0), <<_:17,Bin:N/bitstring,_:5>> = <<(-1):17,Bin0/bitstring,(-1):5>>, Bin = Bin0, %Assertion. Bin. %% Test that different ways of using bit syntax instructions %% give the same result. dynamic(Config) when is_list(Config) -> ?line dynamic_1(fun dynamic_big/5), ?line dynamic_1(fun dynamic_little/5), ok. dynamic_1(Dynamic) -> <<Lpad:128>> = erlang:md5([0]), <<Rpad:128>> = erlang:md5([1]), <<Int:128>> = erlang:md5([2]), 8385 = dynamic_2(0, {Int,Lpad,Rpad,Dynamic}, 0). dynamic_2(129, _, Count) -> Count; dynamic_2(Bef, Data, Count0) -> Count = dynamic_3(Bef, 128-Bef, Data, Count0), dynamic_2(Bef+1, Data, Count). dynamic_3(_, -1, _, Count) -> Count; dynamic_3(Bef, N, {Int0,Lpad,Rpad,Dynamic}=Data, Count) -> Int1 = Int0 band ((1 bsl (N+3))-1), Dynamic(Bef, N, Int1, Lpad, Rpad), Dynamic(Bef, N, -Int1, Lpad, Rpad), %% OTP-7085: Test a small number in a wide field. Int2 = Int0 band 16#FFFFFF, Dynamic(Bef, N, Int2, Lpad, Rpad), Dynamic(Bef, N, -Int2, Lpad, Rpad), dynamic_3(Bef, N-1, Data, Count+1). dynamic_big(Bef, N, Int, Lpad, Rpad) -> NumBin = id(<<Int:N>>), MaskedInt = Int band ((1 bsl N) - 1), <<MaskedInt:N>> = NumBin, %% Construct the binary in two different ways. Bin = id(<<Lpad:Bef,NumBin/bitstring,Rpad:(128-Bef-N)>>), Bin = <<Lpad:Bef,Int:N,Rpad:(128-Bef-N)>>, %% Further verify the result by matching. LpadMasked = Lpad band ((1 bsl Bef) - 1), RpadMasked = Rpad band ((1 bsl (128-Bef-N)) - 1), Rbits = (128-Bef-N), <<LpadMasked:Bef,MaskedInt:N,RpadMasked:Rbits>> = id(Bin), ok. dynamic_little(Bef, N, Int, Lpad, Rpad) -> NumBin = id(<<Int:N/little>>), MaskedInt = Int band ((1 bsl N) - 1), <<MaskedInt:N/little>> = NumBin, %% Construct the binary in two different ways. Bin = id(<<Lpad:Bef/little,NumBin/bitstring,Rpad:(128-Bef-N)/little>>), Bin = <<Lpad:Bef/little,Int:N/little,Rpad:(128-Bef-N)/little>>, %% Further verify the result by matching. LpadMasked = Lpad band ((1 bsl Bef) - 1), RpadMasked = Rpad band ((1 bsl (128-Bef-N)) - 1), Rbits = (128-Bef-N), <<LpadMasked:Bef/little,MaskedInt:N/little,RpadMasked:Rbits/little>> = id(Bin), ok. otp_7422(Config) when is_list(Config) -> otp_7422_int(0), otp_7422_bin(0). otp_7422_int(N) when N < 512 -> T = erlang:make_tuple(N, []), spawn_link(fun() -> id(T), %% A size of field 0 would write one byte beyond %% the current position in the binary. It could %% overwrite the continuation pointer stored on %% the stack if HTOP was equal to E (the stack pointer). id(<<0:(id(0))>>) end), otp_7422_int(N+1); otp_7422_int(_) -> ok. otp_7422_bin(N) when N < 512 -> T = erlang:make_tuple(N, []), Z = id(<<>>), spawn_link(fun() -> id(T), id(<<Z:(id(0))/bits>>) end), otp_7422_bin(N+1); otp_7422_bin(_) -> ok. zero_width(Config) when is_list(Config) -> ?line Z = id(0), Small = id(42), Big = id(1 bsl 128), ?line <<>> = <<Small:Z>>, ?line <<>> = <<Small:0>>, ?line <<>> = <<Big:Z>>, ?line <<>> = <<Big:0>>, ?line {'EXIT',{badarg,_}} = (catch <<not_a_number:0>>), ?line {'EXIT',{badarg,_}} = (catch <<(id(not_a_number)):Z>>), ?line {'EXIT',{badarg,_}} = (catch <<(id(not_a_number)):0>>), ok. id(I) -> I.