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author | Magnus Lång <[email protected]> | 2016-04-18 19:01:54 +0200 |
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committer | Hans Bolinder <[email protected]> | 2016-04-28 16:16:10 +0200 |
commit | 81234c978d1ff1295d20158ed83b296b1f5b1c9f (patch) | |
tree | 8cc1e9d6c608f76aa5b3330d410c9c483aedb78f /lib/dialyzer/src/dialyzer_typesig.erl | |
parent | 80bda0beb9c45a016414009d3a84c502301bece8 (diff) | |
download | otp-81234c978d1ff1295d20158ed83b296b1f5b1c9f.tar.gz otp-81234c978d1ff1295d20158ed83b296b1f5b1c9f.tar.bz2 otp-81234c978d1ff1295d20158ed83b296b1f5b1c9f.zip |
dialyzer: Fix another pattern literal bug
dialyzer_typesig:traverse/3 would perform an unsafe optimisation when
given a cons pattern that contained a map and could be folded into a
literal with cerl:fold_literal/1. In this case, when traversing the map
a type variable would be generated, but this variable would be dropped
by the erl_types:t_cons/2 constructor by in turn calling t_sup(),
producing the overapproximation any(). However, in this particular case,
dialyzer_typesig:traverse/3 is not allowed to overapproximate, since its
result is used in an EQ-constraint.
Although erl_types:t_tuple/1 does not overapproximate like t_cons/2,
which makes the bug unlikely to affect tuples too, the fix was
nevertheless applied defensively to the case of tuples as well.
Also, fix a bug where dialyzer_utils:refold_pattern/1 would generate
syntax nodes with two {label, _} attributes.
Diffstat (limited to 'lib/dialyzer/src/dialyzer_typesig.erl')
-rw-r--r-- | lib/dialyzer/src/dialyzer_typesig.erl | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/lib/dialyzer/src/dialyzer_typesig.erl b/lib/dialyzer/src/dialyzer_typesig.erl index 5b40376352..ae8b195345 100644 --- a/lib/dialyzer/src/dialyzer_typesig.erl +++ b/lib/dialyzer/src/dialyzer_typesig.erl @@ -127,6 +127,8 @@ solvers = [] :: [solver()] }). +-type state() :: #state{}. + %%----------------------------------------------------------------------------- -define(TYPE_LIMIT, 4). @@ -312,7 +314,7 @@ traverse(Tree, DefinedVars, State) -> Hd = cerl:cons_hd(Tree), Tl = cerl:cons_tl(Tree), {State1, [HdVar, TlVar]} = traverse_list([Hd, Tl], DefinedVars, State), - case cerl:is_literal(cerl:fold_literal(Tree)) of + case cerl:is_literal(fold_literal_maybe_match(Tree, State)) of true -> %% We do not need to do anything more here. {State, t_cons(HdVar, TlVar)}; @@ -448,7 +450,7 @@ traverse(Tree, DefinedVars, State) -> Elements = cerl:tuple_es(Tree), {State1, EVars} = traverse_list(Elements, DefinedVars, State), {State2, TupleType} = - case cerl:is_literal(cerl:fold_literal(Tree)) of + case cerl:is_literal(fold_literal_maybe_match(Tree, State1)) of true -> %% We do not need to do anything more here. {State, t_tuple(EVars)}; @@ -2056,7 +2058,7 @@ sane_maps(Map1, Map2, Keys, _S1, _S2) -> %% Solver v2 -record(v2_state, {constr_data = dict:new() :: dict:dict(), - state :: #state{}}). + state :: state()}). v2_solve_ref(Fun, Map, State) -> V2State = #v2_state{state = State}, @@ -3430,6 +3432,15 @@ find_constraint(Tuple, [#constraint_list{list = List}|Cs]) -> find_constraint(Tuple, [_|Cs]) -> find_constraint(Tuple, Cs). +-spec fold_literal_maybe_match(cerl:tree(), state()) -> cerl:tree(). + +fold_literal_maybe_match(Tree0, State) -> + Tree1 = cerl:fold_literal(Tree0), + case state__is_in_match(State) of + false -> Tree1; + true -> dialyzer_utils:refold_pattern(Tree1) + end. + lookup_record(Records, Tag, Arity) -> case erl_types:lookup_record(Tag, Arity, Records) of {ok, Fields} -> |