Teach Dialyzer arity of funs with literal arity

Re-insert logic for `erlang:make_fun/3` in `erl_bif_types`. It had
been removed in bd941f5 while type spec-ing `erlang.erl`. Type spec in
`erlang.erl` cannot express arity of returned fun based on value of
argument hence re-introducing logic in `erl_bif_types`.

Re-definition of logic in `erl_bif_types` follows approach in 9d870a0.

4 files changed, 177 insertions, 0 deletions

diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 291356c7b1..b4c9de9e1e 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -1974,6 +1974,7 @@ localtime_to_universaltime(_Localtime, _IsDst) ->
 %% CHECK! Why the strange very thorough specification of the error
 %% condition with disallowed arity in erl_bif_types?
 %% Not documented
+%% Shadowed by erl_bif_types: erlang:make_fun/3
 -spec erlang:make_fun(Module, Function, Arity) -> function() when
       Module :: atom(),
       Function :: atom(),
diff --git a/lib/dialyzer/test/small_SUITE_data/results/fun_arity b/lib/dialyzer/test/small_SUITE_data/results/fun_arity
new file mode 100644
index 0000000000..280f5490d0
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/results/fun_arity
@@ -0,0 +1,35 @@
+
+fun_arity.erl:100: Fun application will fail since _cor1 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:100: Function 'Mfa_0_ko'/1 has no local return
+fun_arity.erl:104: Fun application will fail since _cor1 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:104: Function 'Mfa_1_ko'/1 has no local return
+fun_arity.erl:111: Fun application will fail since _cor1 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:111: Function mFa_0_ko/1 has no local return
+fun_arity.erl:115: Fun application will fail since _cor1 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:115: Function mFa_1_ko/1 has no local return
+fun_arity.erl:122: Fun application will fail since _cor2 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:122: Function 'MFa_0_ko'/2 has no local return
+fun_arity.erl:126: Fun application will fail since _cor2 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:126: Function 'MFa_1_ko'/2 has no local return
+fun_arity.erl:35: Fun application will fail since _cor0 :: fun(() -> 'ok') is not a function of arity 1
+fun_arity.erl:35: Function f_0_ko/0 has no local return
+fun_arity.erl:39: Fun application will fail since _cor0 :: fun((_) -> 'ok') is not a function of arity 0
+fun_arity.erl:39: Function f_1_ko/0 has no local return
+fun_arity.erl:48: Fun application will fail since _cor0 :: fun(() -> 'ok') is not a function of arity 1
+fun_arity.erl:48: Function fa_0_ko/0 has no local return
+fun_arity.erl:53: Fun application will fail since _cor0 :: fun((_) -> 'ok') is not a function of arity 0
+fun_arity.erl:53: Function fa_1_ko/0 has no local return
+fun_arity.erl:63: Fun application will fail since _cor0 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:63: Function mfa_0_ko/0 has no local return
+fun_arity.erl:68: Fun application will fail since _cor0 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:68: Function mfa_1_ko/0 has no local return
+fun_arity.erl:76: Fun application will fail since _cor0 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:76: Function mfa_ne_0_ko/0 has no local return
+fun_arity.erl:78: Function mf_ne/0 will never be called
+fun_arity.erl:81: Fun application will fail since _cor0 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:81: Function mfa_ne_1_ko/0 has no local return
+fun_arity.erl:83: Function mf_ne/1 will never be called
+fun_arity.erl:89: Fun application will fail since _cor0 :: fun(() -> any()) is not a function of arity 1
+fun_arity.erl:89: Function mfa_nd_0_ko/0 has no local return
+fun_arity.erl:93: Fun application will fail since _cor0 :: fun((_) -> any()) is not a function of arity 0
+fun_arity.erl:93: Function mfa_nd_1_ko/0 has no local return
diff --git a/lib/dialyzer/test/small_SUITE_data/src/fun_arity.erl b/lib/dialyzer/test/small_SUITE_data/src/fun_arity.erl
new file mode 100644
index 0000000000..850d2fd331
--- /dev/null
+++ b/lib/dialyzer/test/small_SUITE_data/src/fun_arity.erl
@@ -0,0 +1,127 @@
+%%--------------------------------------------------------------------------
+%% Module which contains calls to funs of different arity.
+%%--------------------------------------------------------------------------
+-module(fun_arity).
+
+-export([f_0_ok/0, f_0_ko/0]).
+-export([f_1_ok/0, f_1_ko/0]).
+
+-export([fa_0_ok/0, fa_0_ko/0]).
+-export([fa_1_ok/0, fa_1_ko/0]).
+
+-export([mfa_0_ok/0, mfa_0_ko/0, mf/0]).
+-export([mfa_1_ok/0, mfa_1_ko/0, mf/1]).
+
+-export([mfa_ne_0_ok/0, mfa_ne_0_ko/0]).
+-export([mfa_ne_1_ok/0, mfa_ne_1_ko/0]).
+
+-export([mfa_nd_0_ok/0, mfa_nd_0_ko/0]).
+-export([mfa_nd_1_ok/0, mfa_nd_1_ko/0]).
+
+-export(['Mfa_0_ok'/1, 'Mfa_0_ko'/1]).
+-export(['Mfa_1_ok'/1, 'Mfa_1_ko'/1]).
+
+-export(['mFa_0_ok'/1, 'mFa_0_ko'/1]).
+-export(['mFa_1_ok'/1, 'mFa_1_ko'/1]).
+
+-export(['MFa_0_ok'/2, 'MFa_0_ko'/2]).
+-export(['MFa_1_ok'/2, 'MFa_1_ko'/2]).
+
+%%--------------------------------------------------------------------------
+
+%% Funs like "fun(...) -> ... end".
+
+f_0_ok() -> (fun_f_0())().
+f_0_ko() -> (fun_f_0())(1).
+fun_f_0() -> fun() -> ok end.
+
+f_1_ok() -> (fun_f_1())(1).
+f_1_ko() -> (fun_f_1())().
+fun_f_1() -> fun(_) -> ok end .
+
+%%--------------------------------------------------------------------------
+
+%% Funs like "fun F/A" when F is literal atom and A is literal
+%% non-negative integer.
+
+fa_0_ok() -> (fun_fa_0())().
+fa_0_ko() -> (fun_fa_0())(1).
+fun_fa_0() -> fun f/0.
+f() -> ok.
+
+fa_1_ok() -> (fun_fa_1())(1).
+fa_1_ko() -> (fun_fa_1())().
+fun_fa_1() -> fun f/1.
+f(_) -> ok.
+
+%%--------------------------------------------------------------------------
+
+%% Funs like "fun M:F/A" when M and F are literal atoms, A is literal
+%% non-negative integer and function is (defined and) exported.
+
+mfa_0_ok() -> (fun_mfa_0())().
+mfa_0_ko() -> (fun_mfa_0())(1).
+fun_mfa_0() -> fun ?MODULE:mf/0.
+mf() -> ok.
+
+mfa_1_ok() -> (fun_mfa_1())(1).
+mfa_1_ko() -> (fun_mfa_1())().
+fun_mfa_1() -> fun ?MODULE:mf/1.
+mf(_) -> ok.
+
+%% Funs like "fun M:F/A" when M and F are literal atoms, A is literal
+%% non-negative integer and function is defined but not exported.
+
+mfa_ne_0_ok() -> (fun_mfa_ne_0())().
+mfa_ne_0_ko() -> (fun_mfa_ne_0())(1).
+fun_mfa_ne_0() -> fun ?MODULE:mf_ne/0.
+mf_ne() -> ok.
+
+mfa_ne_1_ok() -> (fun_mfa_ne_1())(1).
+mfa_ne_1_ko() -> (fun_mfa_ne_1())().
+fun_mfa_ne_1() -> fun ?MODULE:mf_ne/1.
+mf_ne(_) -> ok.
+
+%% Funs like "fun M:F/A" when M and F are literal atoms, A is literal
+%% non-negative integer and function is not defined.
+
+mfa_nd_0_ok() -> (fun_mfa_nd_0())().
+mfa_nd_0_ko() -> (fun_mfa_nd_0())(1).
+fun_mfa_nd_0() -> fun ?MODULE:mf_nd/0.
+
+mfa_nd_1_ok() -> (fun_mfa_nd_1())(1).
+mfa_nd_1_ko() -> (fun_mfa_nd_1())().
+fun_mfa_nd_1() -> fun ?MODULE:mf_nd/1.
+
+%% Funs like "fun M:F/A" when M is variable, F is literal atoms and A
+%% is literal non-negative integer.
+
+'Mfa_0_ok'(M) -> ('fun_Mfa_0'(M))().
+'Mfa_0_ko'(M) -> ('fun_Mfa_0'(M))(1).
+'fun_Mfa_0'(M) -> fun M:f/0.
+
+'Mfa_1_ok'(M) -> ('fun_Mfa_1'(M))(1).
+'Mfa_1_ko'(M) -> ('fun_Mfa_1'(M))().
+'fun_Mfa_1'(M) -> fun M:f/1.
+
+%% Funs like "fun M:F/A" when M is literal atom, F is variable and A
+%% is literal non-negative integer.
+
+'mFa_0_ok'(F) -> ('fun_mFa_0'(F))().
+'mFa_0_ko'(F) -> ('fun_mFa_0'(F))(1).
+'fun_mFa_0'(F) -> fun ?MODULE:F/0.
+
+'mFa_1_ok'(F) -> ('fun_mFa_1'(F))(1).
+'mFa_1_ko'(F) -> ('fun_mFa_1'(F))().
+'fun_mFa_1'(F) -> fun ?MODULE:F/1.
+
+%% Funs like "fun M:F/A" when M and F are variables and A is literal
+%% non-negative integer.
+
+'MFa_0_ok'(M, F) -> ('fun_MFa_0'(M, F))().
+'MFa_0_ko'(M, F) -> ('fun_MFa_0'(M, F))(1).
+'fun_MFa_0'(M, F) -> fun M:F/0.
+
+'MFa_1_ok'(M, F) -> ('fun_MFa_1'(M, F))(1).
+'MFa_1_ko'(M, F) -> ('fun_MFa_1'(M, F))().
+'fun_MFa_1'(M, F) -> fun M:F/1.
diff --git a/lib/hipe/cerl/erl_bif_types.erl b/lib/hipe/cerl/erl_bif_types.erl
index 41a6c731c9..9c3bd0a284 100644
--- a/lib/hipe/cerl/erl_bif_types.erl
+++ b/lib/hipe/cerl/erl_bif_types.erl
@@ -767,6 +767,18 @@ type(erlang, length, 1, Xs, Opaques) ->
 %% Guard bif, needs to be here.
 type(erlang, map_size, 1, Xs, Opaques) ->
   strict(erlang, map_size, 1, Xs, fun (_) -> t_non_neg_integer() end, Opaques);
+type(erlang, make_fun, 3, Xs, Opaques) ->
+  strict(erlang, make_fun, 3, Xs,
+         fun ([_, _, Arity]) ->
+             case t_number_vals(Arity, Opaques) of
+               [N] ->
+                 case is_integer(N) andalso 0 =< N andalso N =< 255 of
+                   true -> t_fun(N, t_any());
+                   false -> t_none()
+                 end;
+               _Other -> t_fun()
+             end
+         end, Opaques);
 type(erlang, make_tuple, 2, Xs, Opaques) ->
   strict(erlang, make_tuple, 2, Xs,
 	 fun ([Int, _]) ->
@@ -2338,6 +2350,8 @@ arg_types(erlang, length, 1) ->
 %% Guard bif, needs to be here.
 arg_types(erlang, map_size, 1) ->
   [t_map()];
+arg_types(erlang, make_fun, 3) ->
+  [t_atom(), t_atom(), t_arity()];
 arg_types(erlang, make_tuple, 2) ->
   [t_non_neg_fixnum(), t_any()];  % the value 0 is OK as first argument
 arg_types(erlang, make_tuple, 3) ->