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authorBjörn-Egil Dahlberg <[email protected]>2014-03-12 22:08:13 +0100
committerBjörn-Egil Dahlberg <[email protected]>2014-03-17 17:47:36 +0100
commitc57ac1a6e02ae0fc9b85b204052596ab74cde45e (patch)
treeb582dab237ab5131203e517238916d68928d793f /lib/stdlib/src
parentfb3ffad98fb1b35d096eaa3ce941b8390395ae8c (diff)
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stdlib: Properly lint map key expressions
Only values are valid key expressions.
Diffstat (limited to 'lib/stdlib/src')
-rw-r--r--lib/stdlib/src/erl_lint.erl70
1 files changed, 52 insertions, 18 deletions
diff --git a/lib/stdlib/src/erl_lint.erl b/lib/stdlib/src/erl_lint.erl
index 269e4b34cf..dc20a18485 100644
--- a/lib/stdlib/src/erl_lint.erl
+++ b/lib/stdlib/src/erl_lint.erl
@@ -225,6 +225,8 @@ format_error({too_many_arguments,Arity}) ->
"maximum allowed is ~w", [Arity,?MAX_ARGUMENTS]);
%% --- patterns and guards ---
format_error(illegal_pattern) -> "illegal pattern";
+format_error(illegal_map_key) ->
+ "illegal map key";
format_error({illegal_map_key_variable,K}) ->
io_lib:format("illegal use of variable ~w in map",[K]);
format_error(illegal_bin_pattern) ->
@@ -1385,19 +1387,20 @@ pattern({cons,_Line,H,T}, Vt, Old, Bvt, St0) ->
pattern({tuple,_Line,Ps}, Vt, Old, Bvt, St) ->
pattern_list(Ps, Vt, Old, Bvt, St);
pattern({map,_Line,Ps}, Vt, Old, Bvt, St) ->
- foldl(fun ({map_field_assoc,L,_,_}, {Psvt,Bvt0,St0}) ->
- {Psvt,Bvt0,add_error(L, illegal_pattern, St0)};
- ({map_field_exact,L,KP,VP}, {Psvt,Bvt0,St0}) ->
- case expr(KP, [], St0) of
- {[],_} ->
- {Pvt,Bvt1,St1} = pattern(VP, Vt, Old, Bvt, St0),
- {vtmerge_pat(Pvt, Psvt),vtmerge_pat(Bvt0, Bvt1),
- St1};
- {[Var|_],_} ->
- Error = {illegal_map_key_variable,element(1, Var)},
- {Psvt,Bvt0,add_error(L, Error, St0)}
- end
- end, {[],[],St}, Ps);
+ foldl(fun
+ ({map_field_assoc,L,_,_}, {Psvt,Bvt0,St0}) ->
+ {Psvt,Bvt0,add_error(L, illegal_pattern, St0)};
+ ({map_field_exact,L,KP,VP}, {Psvt,Bvt0,St0}) ->
+ case is_valid_map_key(KP, St0) of
+ true ->
+ {Pvt,Bvt1,St1} = pattern(VP, Vt, Old, Bvt, St0),
+ {vtmerge_pat(Pvt, Psvt),vtmerge_pat(Bvt0, Bvt1), St1};
+ false ->
+ {Psvt,Bvt0,add_error(L, illegal_map_key, St0)};
+ {false,variable,Var} ->
+ {Psvt,Bvt0,add_error(L, {illegal_map_key_variable,Var}, St0)}
+ end
+ end, {[],[],St}, Ps);
%%pattern({struct,_Line,_Tag,Ps}, Vt, Old, Bvt, St) ->
%% pattern_list(Ps, Vt, Old, Bvt, St);
pattern({record_index,Line,Name,Field}, _Vt, _Old, _Bvt, St) ->
@@ -2237,9 +2240,10 @@ check_assoc_fields([], St) ->
map_fields([{Tag,Line,K,V}|Fs], Vt, St, F) when Tag =:= map_field_assoc;
Tag =:= map_field_exact ->
St1 = case is_valid_map_key(K, St) of
- true -> St;
- {false,Var} -> add_error(Line, {illegal_map_key_variable,Var}, St)
- end,
+ true -> St;
+ false -> add_error(Line, illegal_map_key, St);
+ {false,variable,Var} -> add_error(Line, {illegal_map_key_variable,Var}, St)
+ end,
{Pvt,St2} = F([K,V], Vt, St1),
{Vts,St3} = map_fields(Fs, Vt, St2, F),
{vtupdate(Pvt, Vts),St3};
@@ -2298,11 +2302,41 @@ is_valid_call(Call) ->
_ -> true
end.
+%% is_valid_map_key(K,St) -> true | false | {false, Var::atom()}
+%% check for value expression without variables
+
is_valid_map_key(K,St) ->
case expr(K,[],St) of
- {[],_} -> true;
+ {[],_} ->
+ is_valid_map_key_value(K);
{[Var|_],_} ->
- {false,element(1,Var)}
+ {false,variable,element(1,Var)}
+ end.
+
+is_valid_map_key_value(K) ->
+ case K of
+ {char,_,_} -> true;
+ {integer,_,_} -> true;
+ {float,_,_} -> true;
+ {string,_,_} -> true;
+ {nil,_} -> true;
+ {atom,_,_} -> true;
+ {cons,_,H,T} ->
+ is_valid_map_key_value(H) andalso
+ is_valid_map_key_value(T);
+ {tuple,_,Es} ->
+ foldl(fun(E,B) ->
+ B andalso is_valid_map_key_value(E)
+ end,true,Es);
+ {bin,_,Es} ->
+ % only check for value expressions to be valid
+ % invalid binary expressions are later checked in
+ % core and kernel
+ foldl(fun
+ ({bin_element,_,E,_,_},B) ->
+ B andalso is_valid_map_key_value(E)
+ end,true,Es);
+ _ -> false
end.
%% record_def(Line, RecordName, [RecField], State) -> State.