Merge branch 'bjorn/external-funs/OTP-9643'

* bjorn/external-funs/OTP-9643:
  EEP-23: Allow variables in fun M:F/A
  Reference manual: Improve the documentation for external funs
  Test calling a parameterized module within a fun
  beam_loader: Support external funs in the literal pool

4 files changed, 118 insertions, 12 deletions

diff --git a/lib/tools/src/xref_reader.erl b/lib/tools/src/xref_reader.erl
index d22f0df164..92f0c45c7b 100644
--- a/lib/tools/src/xref_reader.erl
+++ b/lib/tools/src/xref_reader.erl
@@ -158,15 +158,20 @@ expr({'try',_Line,Es,Scs,Ccs,As}, S) ->
     S2 = clauses(Scs, S1),
     S3 = clauses(Ccs, S2),
     expr(As, S3);
-expr({call, Line,
-      {remote, _, {atom,_,erlang}, {atom,_,make_fun}},
-      [{atom,_,Mod}, {atom,_,Fun}, {integer,_,Arity}]}, S) ->
-    %% Added in R10B-6. M:F/A.
-    expr({'fun', Line, {function, Mod, Fun, Arity}}, S);
-expr({'fun', Line, {function, Mod, Name, Arity}}, S) ->
-    %% Added in R10B-6. M:F/A.
+expr({'fun', Line, {function, {atom,_,Mod},
+		    {atom,_,Name},
+		    {integer,_,Arity}}}, S) ->
+    %% New format in R15. M:F/A (literals).
     As = lists:duplicate(Arity, {atom, Line, foo}),
     external_call(Mod, Name, As, Line, false, S);
+expr({'fun', Line, {function, Mod, Name, {integer,_,Arity}}}, S) ->
+    %% New format in R15. M:F/A (one or more variables).
+    As = lists:duplicate(Arity, {atom, Line, foo}),
+    external_call(erlang, apply, [Mod, Name, list2term(As)], Line, true, S);
+expr({'fun', Line, {function, Mod, Name, _Arity}}, S) ->
+    %% New format in R15. M:F/A (one or more variables).
+    As = {var, Line, '_'},
+    external_call(erlang, apply, [Mod, Name, As], Line, true, S);
 expr({'fun', Line, {function, Name, Arity}, _Extra}, S) ->
     %% Added in R8.
     handle_call(local, S#xrefr.module, Name, Arity, Line, S);
@@ -286,10 +291,10 @@ check_funarg(W, ArgsList, Line, S) ->
     expr(ArgsList, S1).
 
 funarg({'fun', _, _Clauses, _Extra}, _S) -> true;
-funarg({var, _, Var}, S) -> member(Var, S#xrefr.funvars);
-funarg({call,_,{remote,_,{atom,_,erlang},{atom,_,make_fun}},_MFA}, _S) ->
-    %% R10B-6. M:F/A.
+funarg({'fun', _, {function,_,_,_}}, _S) ->
+    %% New abstract format for fun M:F/A in R15.
     true;
+funarg({var, _, Var}, S) -> member(Var, S#xrefr.funvars);
 funarg(_, _S) -> false.
 
 fun_args(apply2, [FunArg, Args]) -> {FunArg, Args};
diff --git a/lib/tools/test/xref_SUITE.erl b/lib/tools/test/xref_SUITE.erl
index 2f83ab4995..e0876381ca 100644
--- a/lib/tools/test/xref_SUITE.erl
+++ b/lib/tools/test/xref_SUITE.erl
@@ -46,7 +46,8 @@
 -export([
 	 add/1, default/1, info/1, lib/1, read/1, read2/1, remove/1,
 	 replace/1, update/1, deprecated/1, trycatch/1,
-         abstract_modules/1, fun_mfa/1, qlc/1]).
+         abstract_modules/1, fun_mfa/1, fun_mfa_r14/1,
+	 fun_mfa_vars/1, qlc/1]).
 
 -export([
 	 analyze/1, basic/1, md/1, q/1, variables/1, unused_locals/1]).
@@ -82,7 +83,7 @@ groups() ->
      {files, [],
       [add, default, info, lib, read, read2, remove, replace,
        update, deprecated, trycatch, abstract_modules, fun_mfa,
-       qlc]},
+       fun_mfa_r14, fun_mfa_vars, qlc]},
      {analyses, [],
       [analyze, basic, md, q, variables, unused_locals]},
      {misc, [], [format_error, otp_7423, otp_7831]}].
@@ -1771,6 +1772,88 @@ fun_mfa(Conf) when is_list(Conf) ->
     ?line ok = file:delete(Beam),
     ok.
 
+%% Same as the previous test case, except that we use a BEAM file
+%% that was compiled by an R14 compiler to test backward compatibility.
+fun_mfa_r14(Conf) when is_list(Conf) ->
+    Dir = ?config(data_dir, Conf),
+    MFile = fname(Dir, "fun_mfa_r14"),
+
+    A = fun_mfa_r14,
+    {ok, _} = xref:start(s),
+    {ok, A} = xref:add_module(s, MFile, {warnings,false}),
+    {ok, [{{{A,t,0},{'$M_EXPR','$F_EXPR',0}},[7]},
+	  {{{A,t,0},{A,t,0}},[6]},
+	  {{{A,t1,0},{'$M_EXPR','$F_EXPR',0}},[11]},
+	  {{{A,t1,0},{A,t,0}},[10]},
+	  {{{A,t2,0},{A,t,0}},[14]},
+	  {{{A,t3,0},{A,t3,0}},[17]}]} =
+        xref:q(s, "(Lin) E"),
+
+    ok = check_state(s),
+    xref:stop(s),
+
+    ok.
+
+%% fun M:F/A with varibles.
+fun_mfa_vars(Conf) when is_list(Conf) ->
+    Dir = ?copydir,
+    File = fname(Dir, "fun_mfa_vars.erl"),
+    MFile = fname(Dir, "fun_mfa_vars"),
+    Beam = fname(Dir, "fun_mfa_vars.beam"),
+    Test = <<"-module(fun_mfa_vars).
+
+              -export([t/1, t1/1, t2/3]).
+
+              t(Mod) ->
+                  F = fun Mod:bar/2,
+                  (F)(a, b).
+
+              t1(Name) ->
+                  F = fun ?MODULE:Name/1,
+                  (F)(a).
+
+              t2(Mod, Name, Arity) ->
+                  F = fun Mod:Name/Arity,
+                  (F)(a).
+
+              t3(Arity) ->
+                  F = fun ?MODULE:t/Arity,
+                  (F)(1, 2, 3).
+
+              t4(Mod, Name) ->
+                  F = fun Mod:Name/3,
+                  (F)(a, b, c).
+
+              t5(Mod, Arity) ->
+                  F = fun Mod:t/Arity,
+                  (F)().
+             ">>,
+
+    ok = file:write_file(File, Test),
+    A = fun_mfa_vars,
+    {ok, A} = compile:file(File, [report,debug_info,{outdir,Dir}]),
+    {ok, _} = xref:start(s),
+    {ok, A} = xref:add_module(s, MFile, {warnings,false}),
+    {ok, [{{{A,t,1},{'$M_EXPR','$F_EXPR',2}},[7]},
+	  {{{A,t,1},{'$M_EXPR',bar,2}},[6]},
+	  {{{A,t1,1},{'$M_EXPR','$F_EXPR',1}},[11]},
+	  {{{A,t1,1},{A,'$F_EXPR',1}},[10]},
+	  {{{A,t2,3},{'$M_EXPR','$F_EXPR',-1}},[14]},
+	  {{{A,t2,3},{'$M_EXPR','$F_EXPR',1}},[15]},
+	  {{{A,t3,1},{'$M_EXPR','$F_EXPR',3}},[19]},
+	  {{{A,t3,1},{fun_mfa_vars,t,-1}},[18]},
+	  {{{A,t4,2},{'$M_EXPR','$F_EXPR',3}},[22,23]},
+	  {{{A,t5,2},{'$M_EXPR','$F_EXPR',0}},[27]},
+	  {{{A,t5,2},{'$M_EXPR',t,-1}},[26]}]} =
+	xref:q(s, "(Lin) E"),
+
+    ok = check_state(s),
+    xref:stop(s),
+
+    ok = file:delete(File),
+    ok = file:delete(Beam),
+    ok.
+
 qlc(suite) -> [];
 qlc(doc) -> ["OTP-5195: A bug fix when using qlc:q/1,2."];
 qlc(Conf) when is_list(Conf) ->
diff --git a/lib/tools/test/xref_SUITE_data/fun_mfa_r14.beam b/lib/tools/test/xref_SUITE_data/fun_mfa_r14.beam
new file mode 100644
index 0000000000..4645525690
--- /dev/null
+++ b/lib/tools/test/xref_SUITE_data/fun_mfa_r14.beam
diff --git a/lib/tools/test/xref_SUITE_data/fun_mfa_r14.erl b/lib/tools/test/xref_SUITE_data/fun_mfa_r14.erl
new file mode 100644
index 0000000000..293bd83a8b
--- /dev/null
+++ b/lib/tools/test/xref_SUITE_data/fun_mfa_r14.erl
@@ -0,0 +1,18 @@
+-module(fun_mfa_r14).
+
+-export([t/0, t1/0, t2/0, t3/0]).
+
+t() ->
+    F = fun ?MODULE:t/0,
+    (F)().
+
+t1() ->
+    F = fun t/0,
+    (F)().
+
+t2() ->
+    fun ?MODULE:t/0().
+
+t3() ->
+    fun t3/0().
+