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authorAnthony Ramine <[email protected]>2013-03-28 08:52:43 +0100
committerFredrik Gustafsson <[email protected]>2013-06-05 12:08:39 +0200
commit90efeaf21147505b1e8207822e606027f94183cc (patch)
treea8f4709a1625aa7ac96e67b08a43119943aae34a /lib/stdlib/src
parent872987787b0d95b89c45920c8b5453a86580d201 (diff)
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Forbid unsized fields in patterns of binary generators
It makes no sense to be able to do `<<...,Rest/binary>> <= ...` in a comprehension. The related Dialyzer test is removed.
Diffstat (limited to 'lib/stdlib/src')
-rw-r--r--lib/stdlib/src/erl_lint.erl21
-rw-r--r--lib/stdlib/src/eval_bits.erl19
2 files changed, 32 insertions, 8 deletions
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 08b8541014..573b05e4e2 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -281,6 +281,8 @@ format_error(utf_bittype_size_or_unit) ->
"neither size nor unit must be given for segments of type utf8/utf16/utf32";
format_error({bad_bitsize,Type}) ->
io_lib:format("bad ~s bit size", [Type]);
+format_error(unsized_binary_in_bin_gen_pattern) ->
+ "binary fields without size are not allowed in patterns of bit string generators";
%% --- behaviours ---
format_error({conflicting_behaviours,{Name,Arity},B,FirstL,FirstB}) ->
io_lib:format("conflicting behaviours - callback ~w/~w required by both '~p' "
@@ -2878,7 +2880,8 @@ lc_quals([{generate,_Line,P,E} | Qs], Vt0, Uvt0, St0) ->
{Vt,Uvt,St} = handle_generator(P,E,Vt0,Uvt0,St0),
lc_quals(Qs, Vt, Uvt, St);
lc_quals([{b_generate,_Line,P,E} | Qs], Vt0, Uvt0, St0) ->
- {Vt,Uvt,St} = handle_generator(P,E,Vt0,Uvt0,St0),
+ St1 = handle_bitstring_gen_pat(P,St0),
+ {Vt,Uvt,St} = handle_generator(P,E,Vt0,Uvt0,St1),
lc_quals(Qs, Vt, Uvt, St);
lc_quals([F|Qs], Vt, Uvt, St0) ->
{Fvt,St1} = case is_guard_test2(F, St0#lint.records) of
@@ -2906,6 +2909,22 @@ handle_generator(P,E,Vt,Uvt,St0) ->
Vt3 = vtupdate(vtsubtract(Vt2, Binvt), Binvt),
{Vt3,NUvt,St5}.
+handle_bitstring_gen_pat({bin,_,Segments=[_|_]},St) ->
+ case lists:last(Segments) of
+ {bin_element,Line,{var,_,_},default,Flags} when is_list(Flags) ->
+ case member(binary, Flags) orelse member(bits, Flags)
+ orelse member(bitstring, Flags) of
+ true ->
+ add_error(Line, unsized_binary_in_bin_gen_pattern, St);
+ false ->
+ St
+ end;
+ _ ->
+ St
+ end;
+handle_bitstring_gen_pat(_,St) ->
+ St.
+
%% fun_clauses(Clauses, ImportVarTable, State) ->
%% {UsedVars, State}.
%% Fun's cannot export any variables.
diff --git a/lib/stdlib/src/eval_bits.erl b/lib/stdlib/src/eval_bits.erl
index e49cbc1fd1..75fe2c00c7 100644
--- a/lib/stdlib/src/eval_bits.erl
+++ b/lib/stdlib/src/eval_bits.erl
@@ -192,7 +192,7 @@ bin_gen_field({bin_element,Line,VE,Size0,Options0},
make_bit_type(Line, Size0, Options0),
V = erl_eval:partial_eval(VE),
NewV = coerce_to_float(V, Type),
- match_check_size(Mfun, Size1, BBs0),
+ match_check_size(Mfun, Size1, BBs0, false),
{value, Size, _BBs} = Efun(Size1, BBs0),
bin_gen_field1(Bin, Type, Size, Unit, Sign, Endian, NewV, Bs0, BBs0, Mfun).
@@ -380,20 +380,25 @@ make_bit_type(_Line, Size, Type0) -> %Size evaluates to an integer or 'all'
{error,Reason} -> error(Reason)
end.
-match_check_size(Mfun, {var,_,V}, Bs) ->
+match_check_size(Mfun, Size, Bs) ->
+ match_check_size(Mfun, Size, Bs, true).
+
+match_check_size(Mfun, {var,_,V}, Bs, _AllowAll) ->
case Mfun(binding, {V,Bs}) of
{value,_} -> ok;
unbound -> throw(invalid) % or, rather, error({unbound,V})
end;
-match_check_size(_, {atom,_,all}, _Bs) ->
+match_check_size(_, {atom,_,all}, _Bs, true) ->
ok;
-match_check_size(_, {atom,_,undefined}, _Bs) ->
+match_check_size(_, {atom,_,all}, _Bs, false) ->
+ throw(invalid);
+match_check_size(_, {atom,_,undefined}, _Bs, _AllowAll) ->
ok;
-match_check_size(_, {integer,_,_}, _Bs) ->
+match_check_size(_, {integer,_,_}, _Bs, _AllowAll) ->
ok;
-match_check_size(_, {value,_,_}, _Bs) ->
+match_check_size(_, {value,_,_}, _Bs, _AllowAll) ->
ok; %From the debugger.
-match_check_size(_, _, _Bs) ->
+match_check_size(_, _, _Bs, _AllowAll) ->
throw(invalid).
%% error(Reason) -> exception thrown