From 9883f9714bd4a56ae9d68b3b0e7958461918946e Mon Sep 17 00:00:00 2001 From: Richard Carlsson Date: Tue, 20 Feb 2018 13:47:25 +0100 Subject: Dialyzer should not throw away spec information because of overspec --- lib/dialyzer/src/dialyzer_contracts.erl | 4 ++ lib/dialyzer/test/small_SUITE_data/results/chars | 6 +-- .../test/small_SUITE_data/results/extra_range | 4 ++ lib/dialyzer/test/small_SUITE_data/src/chars.erl | 18 +++++-- .../test/small_SUITE_data/src/extra_range.erl | 59 ++++++++++++++++++++++ 5 files changed, 83 insertions(+), 8 deletions(-) create mode 100644 lib/dialyzer/test/small_SUITE_data/results/extra_range create mode 100644 lib/dialyzer/test/small_SUITE_data/src/extra_range.erl (limited to 'lib/dialyzer') diff --git a/lib/dialyzer/src/dialyzer_contracts.erl b/lib/dialyzer/src/dialyzer_contracts.erl index e72c1aecfc..0df15e55f9 100644 --- a/lib/dialyzer/src/dialyzer_contracts.erl +++ b/lib/dialyzer/src/dialyzer_contracts.erl @@ -197,6 +197,10 @@ check_contracts(Contracts, Callgraph, FunTypes, ModOpaques) -> false -> [{MFA, Contract}|NewContracts] end; + {error, {extra_range, _, _}} -> + %% do not treat extra range as an error in this check + %% since that prevents discovering other actual errors + [{MFA, Contract}|NewContracts]; {error, _Error} -> NewContracts end; error -> NewContracts diff --git a/lib/dialyzer/test/small_SUITE_data/results/chars b/lib/dialyzer/test/small_SUITE_data/results/chars index 2c1f8f8d17..72fbdb4528 100644 --- a/lib/dialyzer/test/small_SUITE_data/results/chars +++ b/lib/dialyzer/test/small_SUITE_data/results/chars @@ -1,4 +1,4 @@ -chars.erl:29: Invalid type specification for function chars:f/1. The success typing is (#{'b':=50}) -> 'ok' -chars.erl:32: Function t1/0 has no local return -chars.erl:32: The call chars:f(#{'b':=50}) breaks the contract (#{'a':=49,'b'=>50,'c'=>51}) -> 'ok' +chars.erl:37: Invalid type specification for function chars:f/1. The success typing is (#{'b':=50}) -> 'ok' +chars.erl:40: Function t1/0 has no local return +chars.erl:40: The call chars:f(#{'b':=50}) breaks the contract (#{'a':=49,'b'=>50,'c'=>51}) -> 'ok' diff --git a/lib/dialyzer/test/small_SUITE_data/results/extra_range b/lib/dialyzer/test/small_SUITE_data/results/extra_range new file mode 100644 index 0000000000..ec50c95c4e --- /dev/null +++ b/lib/dialyzer/test/small_SUITE_data/results/extra_range @@ -0,0 +1,4 @@ + +extra_range.erl:29: The pattern 'ok' can never match the type 'error' +extra_range.erl:43: The pattern 'no' can never match the type 'maybe' | 'yes' +extra_range.erl:58: The pattern 'maybe' can never match the type 'no' | 'yes' diff --git a/lib/dialyzer/test/small_SUITE_data/src/chars.erl b/lib/dialyzer/test/small_SUITE_data/src/chars.erl index 1e9c8ab6b9..62b90cf54d 100644 --- a/lib/dialyzer/test/small_SUITE_data/src/chars.erl +++ b/lib/dialyzer/test/small_SUITE_data/src/chars.erl @@ -12,17 +12,25 @@ -spec t() -> $0-$0..$9-$0| $?. t() -> - c(#r{f = $z - 3}), + r(#r{f = $z - 3}), + r(#r{f = 97}), + c($/), c($z - 3), c($B). -spec c(cs()) -> $3-$0..$9-$0. - -c($A + 1) -> 2; +c($A + 1) -> $9-$0; c(C) -> case C of - $z - 3 -> 3; - #r{f = $z - 3} -> 7 + $z - 3 -> $3-$0; + _ -> $7-$0 + end. + +-spec r(#r{f :: $a..$z}) -> ok | error. +r(R) -> + case R of + #r{f = $z - 3} -> error; + _ -> ok end. %% Display contract with character in warning: diff --git a/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl b/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl new file mode 100644 index 0000000000..9d6ba89c95 --- /dev/null +++ b/lib/dialyzer/test/small_SUITE_data/src/extra_range.erl @@ -0,0 +1,59 @@ +%% Test that a spec containing more items than actually returned +%% (whether by accident or by benign overspeccing) does not prevent +%% detection of impossible matches. + +-module(extra_range). + +-export([t1/2, t2/2, t3/2, t4/2]). + +-dialyzer([no_return]). + +%% this spec matches the behaviour of the code +-spec normal(integer()) -> ok | error. +normal(1) -> ok; +normal(2) -> error. + +t1(X, Y) when is_integer(X), is_integer(Y) -> + ok = normal(X), + error = normal(Y), + ok. + + +%% this spec has a typo, which should cause anyone trying to match on +%% `ok = typo(X)' to get a warning, because `ok' is not in the spec +-spec typo(integer()) -> ook | error. +typo(1) -> ok; +typo(2) -> error. + +t2(X, Y) when is_integer(X), is_integer(Y) -> + ok = typo(X), % warning expected - not allowed according to spec + error = typo(Y), + ok. + + +%% this is overspecified, and should cause a warning for trying +%% to match on `no = over(X)', because it cannot succeed and either +%% the spec should be updated or the code should be extended +-spec over(integer()) -> yes | no | maybe. +over(1) -> yes; +over(_) -> maybe. + +t3(X, Y) when is_integer(X), is_integer(Y) -> + yes = over(X), + no = over(Y), % warning expected - spec or code needs fixing + maybe = over(X + Y), + ok. + + +%% this is underspecified, which should cause anyone trying to match on +%% `maybe = under(X)' to get a warning, because `maybe' is not in the spec +-spec under(integer()) -> yes | no. +under(1) -> yes; +under(2) -> no; +under(_) -> maybe. + +t4(X, Y) when is_integer(X), is_integer(Y) -> + yes = under(X), + no = under(Y), + maybe = under(X + Y), % warning expected - not in spec + ok. -- cgit v1.2.3