From 31ffea630ffd73d39970c3def796b00dd782373d Mon Sep 17 00:00:00 2001
From: Stavros Aronis <aronisstav@gmail.com>
Date: Sun, 6 Mar 2011 00:01:59 +0200
Subject: Generate better warnings for failing guards
---
lib/dialyzer/src/dialyzer.erl | 3 +++
lib/dialyzer/src/dialyzer_dataflow.erl | 42 +++++++++++++++++++++++-----------
2 files changed, 32 insertions(+), 13 deletions(-)
(limited to 'lib')
diff --git a/lib/dialyzer/src/dialyzer.erl b/lib/dialyzer/src/dialyzer.erl
index dde0c17c39..3e7680f4bb 100644
--- a/lib/dialyzer/src/dialyzer.erl
+++ b/lib/dialyzer/src/dialyzer.erl
@@ -334,6 +334,9 @@ message_to_string({guard_fail, []}) ->
"Clause guard cannot succeed.\n";
message_to_string({guard_fail, [Arg1, Infix, Arg2]}) ->
io_lib:format("Guard test ~s ~s ~s can never succeed\n", [Arg1, Infix, Arg2]);
+message_to_string({neg_guard_fail, [Arg1, Infix, Arg2]}) ->
+ io_lib:format("Guard test not(~s ~s ~s) can never succeed\n",
+ [Arg1, Infix, Arg2]);
message_to_string({guard_fail, [Guard, Args]}) ->
io_lib:format("Guard test ~w~s can never succeed\n", [Guard, Args]);
message_to_string({neg_guard_fail, [Guard, Args]}) ->
diff --git a/lib/dialyzer/src/dialyzer_dataflow.erl b/lib/dialyzer/src/dialyzer_dataflow.erl
index f4e429e6fd..b01e7a4b05 100644
--- a/lib/dialyzer/src/dialyzer_dataflow.erl
+++ b/lib/dialyzer/src/dialyzer_dataflow.erl
@@ -2087,7 +2087,10 @@ handle_guard_eq(Guard, Map, Env, Eval, State) ->
true ->
if
Eval =:= pos -> {Map, t_atom(true)};
- Eval =:= neg -> throw({fail, none});
+ Eval =:= neg ->
+ ArgTypes = [t_from_term(cerl:concrete(Arg1)),
+ t_from_term(cerl:concrete(Arg2))],
+ signal_guard_fail(Eval, Guard, ArgTypes, State);
Eval =:= dont_know -> {Map, t_atom(true)}
end;
false ->
@@ -2142,7 +2145,10 @@ handle_guard_eqeq(Guard, Map, Env, Eval, State) ->
{literal, literal} ->
case cerl:concrete(Arg1) =:= cerl:concrete(Arg2) of
true ->
- if Eval =:= neg -> throw({fail, none});
+ if Eval =:= neg ->
+ ArgTypes = [t_from_term(cerl:concrete(Arg1)),
+ t_from_term(cerl:concrete(Arg2))],
+ signal_guard_fail(Eval, Guard, ArgTypes, State);
Eval =:= pos -> {Map, t_atom(true)};
Eval =:= dont_know -> {Map, t_atom(true)}
end;
@@ -2238,11 +2244,11 @@ handle_guard_and(Guard, Map, Env, Eval, State) ->
pos ->
{Map1, Type1} = bind_guard(Arg1, Map, Env, Eval, State),
case t_is_atom(true, Type1) of
- false -> throw({fail, none});
+ false -> signal_guard_fail(Eval, Guard, [Type1, t_any()], State);
true ->
{Map2, Type2} = bind_guard(Arg2, Map1, Env, Eval, State),
case t_is_atom(true, Type2) of
- false -> throw({fail, none});
+ false -> signal_guard_fail(Eval, Guard, [Type1, Type2], State);
true -> {Map2, t_atom(true)}
end
end;
@@ -2257,7 +2263,7 @@ handle_guard_and(Guard, Map, Env, Eval, State) ->
end,
case t_is_atom(false, Type1) orelse t_is_atom(false, Type2) of
true -> {join_maps([Map1, Map2], Map), t_atom(false)};
- false -> throw({fail, none})
+ false -> signal_guard_fail(Eval, Guard, [Type1, Type2], State)
end;
dont_know ->
{Map1, Type1} = bind_guard(Arg1, Map, Env, dont_know, State),
@@ -2297,16 +2303,16 @@ handle_guard_or(Guard, Map, Env, Eval, State) ->
orelse
(t_is_atom(true, Bool2) andalso t_is_boolean(Bool1))) of
true -> {join_maps([Map1, Map2], Map), t_atom(true)};
- false -> throw({fail, none})
+ false -> signal_guard_fail(Eval, Guard, [Bool1, Bool2], State)
end;
neg ->
{Map1, Type1} = bind_guard(Arg1, Map, Env, neg, State),
case t_is_atom(false, Type1) of
- false -> throw({fail, none});
+ false -> signal_guard_fail(Eval, Guard, [Type1, t_any()], State);
true ->
{Map2, Type2} = bind_guard(Arg2, Map1, Env, neg, State),
case t_is_atom(false, Type2) of
- false -> throw({fail, none});
+ false -> signal_guard_fail(Eval, Guard, [Type1, Type2], State);
true -> {Map2, t_atom(false)}
end
end;
@@ -2337,13 +2343,17 @@ handle_guard_not(Guard, Map, Env, Eval, State) ->
{Map1, Type} = bind_guard(Arg, Map, Env, pos, State),
case t_is_atom(true, Type) of
true -> {Map1, t_atom(false)};
- false -> throw({fail, none})
+ false ->
+ {_, Type0} = bind_guard(Arg, Map, Env, Eval, State),
+ signal_guard_fail(Eval, Guard, [Type0], State)
end;
pos ->
{Map1, Type} = bind_guard(Arg, Map, Env, neg, State),
case t_is_atom(false, Type) of
true -> {Map1, t_atom(true)};
- false -> throw({fail, none})
+ false ->
+ {_, Type0} = bind_guard(Arg, Map, Env, Eval, State),
+ signal_guard_fail(Eval, Guard, [Type0], State)
end;
dont_know ->
{Map1, Type} = bind_guard(Arg, Map, Env, dont_know, State),
@@ -2382,9 +2392,15 @@ signal_guard_fail(Eval, Guard, ArgTypes, State) ->
true ->
[ArgType1, ArgType2] = ArgTypes,
[Arg1, Arg2] = Args,
- {guard_fail, [format_args_1([Arg1], [ArgType1], State),
- atom_to_list(F),
- format_args_1([Arg2], [ArgType2], State)]};
+ Kind =
+ case Eval of
+ neg -> neg_guard_fail;
+ pos -> guard_fail;
+ dont_know -> guard_fail
+ end,
+ {Kind, [format_args_1([Arg1], [ArgType1], State),
+ atom_to_list(F),
+ format_args_1([Arg2], [ArgType2], State)]};
false ->
mk_guard_msg(Eval, F, Args, ArgTypes, State)
end,
--
cgit v1.2.3