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authorPatrik Nyblom <[email protected]>2010-06-04 10:16:32 +0200
committerPatrik Nyblom <[email protected]>2010-06-23 14:43:38 +0200
commit7493d97d7f8211cb60d52a5cb6af9fb9983b84fa (patch)
tree8f7b813f0ec4c21320de20220f9ac2cd540737ea /lib/stdlib/src/ms_transform.erl
parentc1e94fa9a6fe4ae717d35dfbd1b628dc2e06d26a (diff)
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Add warnings for shadowed variables in ms_transform funs
Also changed compiler to allow for warnings in parse_transforms.
Diffstat (limited to 'lib/stdlib/src/ms_transform.erl')
-rw-r--r--lib/stdlib/src/ms_transform.erl168
1 files changed, 111 insertions, 57 deletions
diff --git a/lib/stdlib/src/ms_transform.erl b/lib/stdlib/src/ms_transform.erl
index 78b1de6e16..1a571fc607 100644
--- a/lib/stdlib/src/ms_transform.erl
+++ b/lib/stdlib/src/ms_transform.erl
@@ -43,6 +43,7 @@
-define(ERR_GENREMOTECALL,22).
-define(ERR_GENBINCONSTRUCT,23).
-define(ERR_GENDISALLOWEDOP,24).
+-define(WARN_SHADOW_VAR,50).
-define(ERR_GUARDMATCH,?ERR_GENMATCH+?ERROR_BASE_GUARD).
-define(ERR_BODYMATCH,?ERR_GENMATCH+?ERROR_BASE_BODY).
-define(ERR_GUARDLOCALCALL,?ERR_GENLOCALCALL+?ERROR_BASE_GUARD).
@@ -63,8 +64,13 @@
-define(ERR_BODYDISALLOWEDOP,?ERR_GENDISALLOWEDOP+?ERROR_BASE_BODY).
%%
-%% Called by compiler or ets/dbg:fun2ms when errors occur
+%% Called by compiler or ets/dbg:fun2ms when errors/warnings occur
%%
+format_error({?WARN_SHADOW_VAR,Name}) ->
+ lists:flatten(
+ io_lib:format("variable ~p shadowed in ms_transform fun head",
+ [Name]));
+
format_error(?ERR_NOFUN) ->
"Parameter of ets/dbg:fun2ms/1 is not a literal fun";
format_error(?ERR_ETS_HEAD) ->
@@ -182,7 +188,7 @@ format_error(Else) ->
%%
transform_from_shell(Dialect, Clauses, BoundEnvironment) ->
SaveFilename = setup_filename(),
- case catch ms_clause_list(1,Clauses,Dialect) of
+ case catch ms_clause_list(1,Clauses,Dialect,gb_sets:new()) of
{'EXIT',Reason} ->
cleanup_filename(SaveFilename),
exit(Reason);
@@ -207,6 +213,7 @@ transform_from_shell(Dialect, Clauses, BoundEnvironment) ->
%%
parse_transform(Forms, _Options) ->
SaveFilename = setup_filename(),
+ %io:format("~p~n",[Forms]),
case catch forms(Forms) of
{'EXIT',Reason} ->
cleanup_filename(SaveFilename),
@@ -215,12 +222,31 @@ parse_transform(Forms, _Options) ->
{error, [{cleanup_filename(SaveFilename),
[{Line, ?MODULE, R}]}], []};
Else ->
- cleanup_filename(SaveFilename),
+ %io:format("Transformed into: ~p~n",[Else]),
+ case get_warnings() of
+ [] ->
+ cleanup_filename(SaveFilename),
+ Else;
+ WL ->
+ FName = cleanup_filename(SaveFilename) ,
+ WList = [ {FName, [{L, ?MODULE, R}]} || {L,R} <- WL ],
+ {warning, Else, WList}
+ end
+ end.
+
+get_warnings() ->
+ case get(warnings) of
+ undefined ->
+ [];
+ Else ->
Else
end.
+add_warning(Line,R) ->
+ put(warnings,[{Line,R}| get_warnings()]).
+
setup_filename() ->
- {erase(filename),erase(records)}.
+ {erase(filename),erase(records),erase(warnings)}.
put_filename(Name) ->
put(filename,Name).
@@ -235,7 +261,7 @@ get_records() ->
Else ->
Else
end.
-cleanup_filename({Old,OldRec}) ->
+cleanup_filename({Old,OldRec,OldWarnings}) ->
Ret = case erase(filename) of
undefined ->
"TOP_LEVEL";
@@ -248,6 +274,12 @@ cleanup_filename({Old,OldRec}) ->
Rec ->
put(records,Rec)
end,
+ case OldWarnings of
+ undefined ->
+ erase(warnings);
+ Warn ->
+ put(warnings,Warn)
+ end,
case Old of
undefined ->
Ret;
@@ -285,42 +317,52 @@ form({function,Line,Name0,Arity0,Clauses0}) ->
form(AnyOther) ->
AnyOther.
function(Name, Arity, Clauses0) ->
- Clauses1 = clauses(Clauses0),
+ {Clauses1,_} = clauses(Clauses0,gb_sets:new()),
{Name,Arity,Clauses1}.
-clauses([C0|Cs]) ->
- C1 = clause(C0),
- [C1|clauses(Cs)];
-clauses([]) -> [].
-clause({clause,Line,H0,G0,B0}) ->
- B1 = copy(B0),
- {clause,Line,H0,G0,B1}.
+clauses([C0|Cs],Bound) ->
+ {C1,Bound1} = clause(C0,Bound),
+ {C2,Bound2} = clauses(Cs,Bound1),
+ {[C1|C2],Bound2};
+clauses([],Bound) -> {[],Bound}.
+clause({clause,Line,H0,G0,B0},Bound) ->
+ {H1,Bound1} = copy(H0,Bound),
+ {B1,Bound2} = copy(B0,Bound1),
+ {{clause,Line,H1,G0,B1},Bound2}.
copy({call,Line,{remote,_Line2,{atom,_Line3,ets},{atom,_Line4,fun2ms}},
- As0}) ->
- transform_call(ets,Line,As0);
+ As0},Bound) ->
+ {transform_call(ets,Line,As0,Bound),Bound};
copy({call,Line,{remote,_Line2,{record_field,_Line3,
{atom,_Line4,''},{atom,_Line5,ets}},
- {atom,_Line6,fun2ms}}, As0}) ->
+ {atom,_Line6,fun2ms}}, As0},Bound) ->
%% Packages...
- transform_call(ets,Line,As0);
+ {transform_call(ets,Line,As0,Bound),Bound};
copy({call,Line,{remote,_Line2,{atom,_Line3,dbg},{atom,_Line4,fun2ms}},
- As0}) ->
- transform_call(dbg,Line,As0);
-copy(T) when is_tuple(T) ->
- list_to_tuple(copy_list(tuple_to_list(T)));
-copy(L) when is_list(L) ->
- copy_list(L);
-copy(AnyOther) ->
- AnyOther.
+ As0},Bound) ->
+ {transform_call(dbg,Line,As0,Bound),Bound};
+copy({var,_Line,'_'} = VarDef,Bound) ->
+ {VarDef,Bound};
+copy({var,_Line,Name} = VarDef,Bound) ->
+ Bound1 = gb_sets:add(Name,Bound),
+ {VarDef,Bound1};
+copy(T,Bound) when is_tuple(T) ->
+ {L,Bound1} = copy_list(tuple_to_list(T),Bound),
+ {list_to_tuple(L),Bound1};
+copy(L,Bound) when is_list(L) ->
+ copy_list(L,Bound);
+copy(AnyOther,Bound) ->
+ {AnyOther,Bound}.
-copy_list([H|T]) ->
- [copy(H)|copy_list(T)];
-copy_list([]) ->
- [].
+copy_list([H|T],Bound) ->
+ {C1,Bound1} = copy(H,Bound),
+ {C2,Bound2} = copy_list(T,Bound1),
+ {[C1|C2],Bound2};
+copy_list([],Bound) ->
+ {[],Bound}.
-transform_call(Type,_Line,[{'fun',Line2,{clauses, ClauseList}}]) ->
- ms_clause_list(Line2, ClauseList,Type);
-transform_call(_Type,Line,_NoAbstractFun) ->
+transform_call(Type,_Line,[{'fun',Line2,{clauses, ClauseList}}],Bound) ->
+ ms_clause_list(Line2, ClauseList,Type,Bound);
+transform_call(_Type,Line,_NoAbstractFun,_) ->
throw({error,Line,?ERR_NOFUN}).
% Fixup semicolons in guards
@@ -329,18 +371,19 @@ ms_clause_expand({clause, Line, Parameters, Guard = [_,_|_], Body}) ->
ms_clause_expand(_Other) ->
false.
-ms_clause_list(Line,[H|T],Type) ->
+ms_clause_list(Line,[H|T],Type,Bound) ->
case ms_clause_expand(H) of
NewHead when is_list(NewHead) ->
- ms_clause_list(Line,NewHead ++ T, Type);
+ ms_clause_list(Line,NewHead ++ T, Type, Bound);
false ->
- {cons, Line, ms_clause(H,Type), ms_clause_list(Line, T,Type)}
+ {cons, Line, ms_clause(H, Type, Bound),
+ ms_clause_list(Line, T, Type, Bound)}
end;
-ms_clause_list(Line,[],_) ->
+ms_clause_list(Line,[],_,_) ->
{nil,Line}.
-ms_clause({clause, Line, Parameters, Guards, Body},Type) ->
+ms_clause({clause, Line, Parameters, Guards, Body},Type,Bound) ->
check_type(Line,Parameters,Type),
- {MSHead,Bindings} = transform_head(Parameters),
+ {MSHead,Bindings} = transform_head(Parameters,Bound),
MSGuards = transform_guards(Line, Guards, Bindings),
MSBody = transform_body(Line,Body,Bindings),
{tuple, Line, [MSHead,MSGuards,MSBody]}.
@@ -627,29 +670,31 @@ tg(Other,B) ->
Element = io_lib:format("unknown element ~w", [Other]),
throw({error,unknown,{?ERR_GENELEMENT+B#tgd.eb,Element}}).
-transform_head([V]) ->
+transform_head([V],OuterBound) ->
Bind = cre_bind(),
- {NewV,NewBind} = toplevel_head_match(V,Bind),
- th(NewV,NewBind).
+ {NewV,NewBind} = toplevel_head_match(V,Bind,OuterBound),
+ th(NewV,NewBind,OuterBound).
-toplevel_head_match({match,_,{var,_,VName},Expr},B) ->
+toplevel_head_match({match,Line,{var,_,VName},Expr},B,OB) ->
+ warn_var_clash(Line,VName,OB),
{Expr,new_bind({VName,'$_'},B)};
-toplevel_head_match({match,_,Expr,{var,_,VName}},B) ->
+toplevel_head_match({match,Line,Expr,{var,_,VName}},B,OB) ->
+ warn_var_clash(Line,VName,OB),
{Expr,new_bind({VName,'$_'},B)};
-toplevel_head_match(Other,B) ->
+toplevel_head_match(Other,B,_OB) ->
{Other,B}.
-th({record,Line,RName,RFields},B) ->
+th({record,Line,RName,RFields},B,OB) ->
% youch...
RDefs = get_records(),
{KeyList0,NewB} = lists:foldl(fun({record_field,_,{atom,_,Key},Value},
{L,B0}) ->
- {NV,B1} = th(Value,B0),
+ {NV,B1} = th(Value,B0,OB),
{[{Key,NV}|L],B1};
({record_field,_,{var,_,'_'},Value},
{L,B0}) ->
- {NV,B1} = th(Value,B0),
+ {NV,B1} = th(Value,B0,OB),
{[{{default},NV}|L],B1};
(_,_) ->
throw({error,Line,{?ERR_HEADBADREC,
@@ -692,9 +737,9 @@ th({record,Line,RName,RFields},B) ->
_ ->
throw({error,Line,{?ERR_HEADBADREC,RName}})
end;
-th({match,Line,_,_},_) ->
+th({match,Line,_,_},_,_) ->
throw({error,Line,?ERR_HEADMATCH});
-th({atom,Line,A},B) ->
+th({atom,Line,A},B,_OB) ->
case atom_to_list(A) of
[$$|NL] ->
case (catch list_to_integer(NL)) of
@@ -706,10 +751,11 @@ th({atom,Line,A},B) ->
_ ->
{{atom,Line,A},B}
end;
-th({bin_element,_Line0,{var, Line, A},_,_},_) ->
+th({bin_element,_Line0,{var, Line, A},_,_},_,_) ->
throw({error,Line,{?ERR_HEADBINMATCH,A}});
-th({var,Line,Name},B) ->
+th({var,Line,Name},B,OB) ->
+ warn_var_clash(Line,Name,OB),
case lkup_bind(Name,B) of
undefined ->
NewB = new_bind(Name,B),
@@ -717,16 +763,24 @@ th({var,Line,Name},B) ->
Trans ->
{{atom,Line,Trans},B}
end;
-th([H|T],B) ->
- {NH,NB} = th(H,B),
- {NT,NNB} = th(T,NB),
+th([H|T],B,OB) ->
+ {NH,NB} = th(H,B,OB),
+ {NT,NNB} = th(T,NB,OB),
{[NH|NT],NNB};
-th(T,B) when is_tuple(T) ->
- {L,NB} = th(tuple_to_list(T),B),
+th(T,B,OB) when is_tuple(T) ->
+ {L,NB} = th(tuple_to_list(T),B,OB),
{list_to_tuple(L),NB};
-th(Nonstruct,B) ->
+th(Nonstruct,B,_OB) ->
{Nonstruct,B}.
+warn_var_clash(Line,Name,OuterBound) ->
+ case gb_sets:is_member(Name,OuterBound) of
+ true ->
+ add_warning(Line,{?WARN_SHADOW_VAR,Name});
+ _ ->
+ ok
+ end.
+
%% Could be more efficient...
check_multi_field(_, _, [], _) ->
ok;