dialyzer: Introduce module local suppression of warnings

The -dialyzer() attribute can be used for suppressing warnings in a
module by specifying functions or warning options. It can also be used
for requesting warnings in a module.

1 files changed, 50 insertions, 0 deletions

diff --git a/lib/dialyzer/test/small_SUITE_data/src/suppress_request.erl b/lib/dialyzer/test/small_SUITE_data/src/suppress_request.erl
new file mode 100644
index 0000000000..c4275fa110
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/suppress_request.erl
@@ -0,0 +1,50 @@
+-module(suppress_request).
+
+-export([test1/1, test1_b/1, test2/0, test2_b/0,
+         test3/0, test3_b/0, test4/0, test4_b/0]).
+
+-dialyzer({[specdiffs], test1/1}).
+-spec test1(a | b) -> ok. % spec is subtype
+test1(A) ->
+    ok = test1_1(A).
+
+-spec test1_b(a | b) -> ok. % spec is subtype (suppressed by default)
+test1_b(A) ->
+    ok = test1_1(A).
+
+-spec test1_1(a | b | c) -> ok.
+test1_1(_) ->
+    ok.
+
+-dialyzer(unmatched_returns).
+test2() ->
+    tuple(), % unmatched
+    ok.
+
+test2_b() ->
+    tuple(), % unmatched
+    ok.
+
+-dialyzer({[no_return, no_match], [test3/0]}).
+test3() -> % no local return (suppressed)
+    A = fun(_) ->
+                1
+        end,
+    A = 2. % can never succeed (suppressed)
+
+test3_b() -> % no local return (requested by default)
+    A = fun(_) ->
+                1
+        end,
+    A = 2. % can never succeed (requested by default)
+
+-dialyzer(no_improper_lists).
+test4() ->
+    [1 | 2]. % improper list (suppressed)
+
+-dialyzer({no_improper_lists, test4_b/0}).
+test4_b() ->
+    [1 | 2]. % improper list (suppressed)
+
+tuple() ->
+    {a, b}.