%% -*- erlang-indent-level: 2 -*-
%%--------------------------------------------------------------------
%% Contains three cases of bugs that were reported for R12B
%%--------------------------------------------------------------------
-module(bs_bugs_R12).
-export([test/0]).
test() ->
ok = test_beam_bug(),
ok = test_v3_codegen(),
ok = test_hipe_bug(),
ok.
%%--------------------------------
%% First test case: a bug in BEAM
%%--------------------------------
test_beam_bug() ->
lists:foreach(fun (_) -> ok = run(100) end, [1,2,3,4]).
%% For testing - runs scanner N number of times with same input
run(N) ->
lists:foreach(fun(_) -> scan(<<"region:whatever">>, []) end, lists:seq(1, N)).
scan(<<>>, TokAcc) ->
lists:reverse(['$thats_all_folks$' | TokAcc]);
scan(<<D, Z, Rest/binary>>, TokAcc)
when (D =:= $D orelse D =:= $d) and
((Z =:= $\s) or (Z =:= $() or (Z =:= $))) ->
scan(<<Z, Rest/binary>>, ['AND' | TokAcc]);
scan(<<D>>, TokAcc) when (D =:= $D) or (D =:= $d) ->
scan(<<>>, ['AND' | TokAcc]);
scan(<<N, Z, Rest/binary>>, TokAcc)
when (N =:= $N orelse N =:= $n) and
((Z =:= $\s) or (Z =:= $() or (Z =:= $))) ->
scan(<<Z, Rest/binary>>, ['NOT' | TokAcc]);
scan(<<C, Rest/binary>>, TokAcc) when (C >= $A) and (C =< $Z);
(C >= $a) and (C =< $z);
(C >= $0) and (C =< $9) ->
case Rest of
<<$:, R/binary>> ->
scan(R, [{'FIELD', C} | TokAcc]);
_ ->
scan(Rest, [{'KEYWORD', C} | TokAcc])
end.
%%---------------------------------------------------
%% Second test case: an internal error in v3_codegen
%% Reported by Mateusz Berezecki on 19/1/2008
%%---------------------------------------------------
-define(S, {42, 4242, 4711}).
-define(R, <<90,164,116>>).
test_v3_codegen() ->
_ = random:seed(?S),
B0 = gen_bit(120, <<>>),
B1 = set_bit(B0, 5),
B2 = clr_bit(B1, 5),
?R = set_bit(B2, 5),
ok.
gen_bit(0, Acc) -> Acc;
gen_bit(N, Acc) when is_integer(N), N > 0 ->
gen_bit(N-1, <<Acc/bits, (random:uniform(2)-1):1>>).
%% sets bit K in the Bitmap
set_bit(<<_Start:32/unsigned-little-integer, Bitmap/bits>>, K)
when is_integer(K), 0 < K, K =< bit_size(Bitmap) ->
Before = K-1,
After = bit_size(Bitmap) - K,
<<BeforeBits:Before/bits, _:1, AfterBits:After/bits>> = Bitmap,
<<BeforeBits/bits, 1:1, AfterBits/bits>>.
%% clears bit K in the Bitmap
clr_bit(<<_Start:32/unsigned-little-integer, Bitmap/bits>>, K)
when is_integer(K), 0 < K, K =< bit_size(Bitmap) ->
Before = K-1,
After = bit_size(Bitmap) - K,
<<BeforeBits:Before/bits, _:1, AfterBits:After/bits>> = Bitmap,
<<BeforeBits/bits, 0:1, AfterBits/bits>>.
%%--------------------------------------------------------------------
%% Third test case: a bug in HiPE
%% Reported by Steve Vinoski on 1/3/2008
%%
%% Below find the results of compiling and running the example code at
%% the bottom of this message. Using "c" to compile gives the right
%% answer; using "hipe:c" gives the wrong answer. This is with R12B-1.
%%
%% Within the code, on the second instance of function check/2 you'll
%% find a commented-out guard. If you uncomment the guard, then the
%% code works correctly with both "c" and "hipe:c".
%%---------------------------------------------------------------------
test_hipe_bug() ->
String = "2006/10/02/Linux-Journal",
Binary = list_to_binary(String),
StringToMatch = "200x/" ++ String ++ " ",
BinaryToMatch = list_to_binary(StringToMatch),
{ok, Binary} = match(BinaryToMatch),
ok.
match(<<>>) ->
nomatch;
match(Bin) ->
<<Front:16/binary, Tail/binary>> = Bin,
case Front of
<<_:3/binary,"x/",Y:4/binary,$/,M:2/binary,$/,D:2/binary,$/>> ->
case check(Tail) of
{ok, Match} ->
{ok, <<Y/binary,$/,M/binary,$/,D/binary,$/,Match/binary>>};
{nomatch, Skip} ->
{skip, Skip+size(Front)};
_ ->
wrong_answer
end;
_ ->
nomatch
end.
check(Bin) ->
check(Bin, 0).
check(<<$ , _/binary>>, 0) ->
{nomatch, 0};
check(Bin, Len) -> %when Len < size(Bin) ->
case Bin of
<<Front:Len/binary, $ , _/binary>> ->
{ok, Front};
<<_:Len/binary, $., _/binary>> ->
{nomatch, Len};
_ ->
check(Bin, Len+1)
end.
