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authorStavros Aronis <[email protected]>2012-12-07 18:53:18 +0100
committerStavros Aronis <[email protected]>2012-12-20 14:09:33 +0100
commit0e37e993c477dfab0e7218b8246bf94b7a9b97a1 (patch)
treefd5cc0c5a532fac57d367f9cbd0f66830f921c83 /lib/dialyzer/src
parentaf68f5a22f995284b07ece178c42e630ecf94d54 (diff)
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Report spec discrepancy on mismatching lists
This patch enables Dialyzer to detect cases where a function has a specification for a return type containing some list with elements different than the ones Dialyzer's own algorithm can infer e.g. a function specified to return [atom()] when actually [[atom()]] is returned. Previously Dialyzer remained silent, under normal operation, seeing that these two types have the empty list as a common element, so they were not 'completely irrelevant'.
Diffstat (limited to 'lib/dialyzer/src')
-rw-r--r--lib/dialyzer/src/dialyzer_contracts.erl27
1 files changed, 24 insertions, 3 deletions
diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl
index 0b932d5a1f..157c951f77 100644
--- a/lib/dialyzer/src/dialyzer_contracts.erl
+++ b/lib/dialyzer/src/dialyzer_contracts.erl
@@ -254,14 +254,35 @@ check_extraneous([C|Cs], SuccType) ->
end.
check_extraneous_1(Contract, SuccType) ->
- CRngs = erl_types:t_elements(erl_types:t_fun_range(Contract)),
+ CRng = erl_types:t_fun_range(Contract),
+ CRngs = erl_types:t_elements(CRng),
STRng = erl_types:t_fun_range(SuccType),
?debug("CR = ~p\nSR = ~p\n", [CRngs, STRng]),
- case [CR || CR <- CRngs, erl_types:t_is_none(erl_types:t_inf(CR, STRng, opaque))] of
- [] -> ok;
+ case [CR || CR <- CRngs,
+ erl_types:t_is_none(erl_types:t_inf(CR, STRng, opaque))] of
+ [] ->
+ CRngList = list_part(CRng),
+ STRngList = list_part(STRng),
+ case is_not_nil_list(CRngList) andalso is_not_nil_list(STRngList) of
+ false -> ok;
+ true ->
+ CRngElements = erl_types:t_list_elements(CRngList),
+ STRngElements = erl_types:t_list_elements(STRngList),
+ Inf = erl_types:t_inf(CRngElements, STRngElements, opaque),
+ case erl_types:t_is_none(Inf) of
+ true -> {error, invalid_contract};
+ false -> ok
+ end
+ end;
CRs -> {error, {extra_range, erl_types:t_sup(CRs), STRng}}
end.
+list_part(Type) ->
+ erl_types:t_inf(erl_types:t_list(), Type, opaque).
+
+is_not_nil_list(Type) ->
+ erl_types:t_is_list(Type) andalso not erl_types:t_is_nil(Type).
+
%% This is the heart of the "range function"
-spec process_contracts([contract_pair()], [erl_types:erl_type()]) -> erl_types:erl_type().