Merge pull request #1725 from michalmuskala/fun-literals

Compile external fun expressions to literals

OTP-15003

4 files changed, 57 insertions, 21 deletions

diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index af620d7432..e61199a8fd 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -4522,6 +4522,19 @@ is_empty_map(LoaderState* stp, GenOpArg Lit)
 }
 
 /*
+ * Predicate to test whether the given literal is an export.
+ */
+static int
+literal_is_export(LoaderState* stp, GenOpArg Lit)
+{
+    Eterm term;
+
+    ASSERT(Lit.type == TAG_q);
+    term = stp->literals[Lit.val].term;
+    return is_export(term);
+}
+
+/*
  * Pseudo predicate map_key_sort that will sort the Rest operand for
  * map instructions as a side effect.
  */
diff --git a/erts/emulator/beam/erl_printf_term.c b/erts/emulator/beam/erl_printf_term.c
index e6f8460164..910f241a3a 100644
--- a/erts/emulator/beam/erl_printf_term.c
+++ b/erts/emulator/beam/erl_printf_term.c
@@ -532,14 +532,13 @@ print_term(fmtfn_t fn, void* arg, Eterm obj, long *dcount) {
 		Atom* module = atom_tab(atom_val(ep->info.mfa.module));
 		Atom* name = atom_tab(atom_val(ep->info.mfa.function));
 
-		PRINT_STRING(res, fn, arg, "#Fun<");
+		PRINT_STRING(res, fn, arg, "fun ");
 		PRINT_BUF(res, fn, arg, module->name, module->len);
-		PRINT_CHAR(res, fn, arg, '.');
+		PRINT_CHAR(res, fn, arg, ':');
 		PRINT_BUF(res, fn, arg, name->name, name->len);
-		PRINT_CHAR(res, fn, arg, '.');
+		PRINT_CHAR(res, fn, arg, '/');
 		PRINT_SWORD(res, fn, arg, 'd', 0, 1,
 			    (ErlPfSWord) ep->info.mfa.arity);
-		PRINT_CHAR(res, fn, arg, '>');
 	    }
 	    break;
 	case FUN_DEF:
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index bc765a8c94..8b2d9098a8 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -710,7 +710,8 @@ is_boolean Fail=f ac => jump Fail
 is_boolean f? xy
 %hot
 
-is_function2 Fail=f acq Arity => jump Fail
+is_function2 Fail=f Literal=q Arity | literal_is_export(Literal) =>
+is_function2 Fail=f c Arity => jump Fail
 is_function2 Fail=f Fun a => jump Fail
 
 is_function2 f? S s
diff --git a/erts/emulator/test/beam_literals_SUITE.erl b/erts/emulator/test/beam_literals_SUITE.erl
index 09761263e2..b447ca0210 100644
--- a/erts/emulator/test/beam_literals_SUITE.erl
+++ b/erts/emulator/test/beam_literals_SUITE.erl
@@ -248,35 +248,58 @@ literal_type_tests(Config) when is_list(Config) ->
     ok.
 
 make_test([{is_function=T,L}|Ts]) ->
-    [test(T, L),test(T, 0, L)|make_test(Ts)];
+    [guard_test(T, L),guard_test(T, 0, L),body_test(T, L),body_test(T, 0, L)|make_test(Ts)];
 make_test([{T,L}|Ts]) ->
-    [test(T, L)|make_test(Ts)];
+    [guard_test(T, L),body_test(T, L)|make_test(Ts)];
 make_test([]) -> [].
 
-test(T, L) ->
-    S = lists:flatten(io_lib:format("begin io:format(\"~~p~n\", [{~p,~p}]), if ~w(~w) -> true; true -> false end end. ", [T, L, T, L])),
-    {ok,Toks,_Line} = erl_scan:string(S),
-    {ok,E} = erl_parse:parse_exprs(Toks),
-    {value,Val,_Bs} = erl_eval:exprs(E, []),
+guard_test(_, L) when is_function(L) ->
+    %% Skip guard tests with exports - they are not literals
+    {atom,erl_anno:new(0),true};
+guard_test(T, L) ->
+    S = io_lib:format("begin io:format(\"~~p~n\", [{~p,~p}]), if ~w(~w) -> true; true -> false end end. ", [T, L, T, L]),
+    {Val,Expr} = eval_string(S),
+    Anno = erl_anno:new(0),
+    {match,Anno,{atom,Anno,Val},Expr}.
+
+guard_test(_, _, L) when is_function(L) ->
+    %% Skip guard tests with exports - they are not literals
+    {atom,erl_anno:new(0),true};
+guard_test(T, A, L) ->
+    S = io_lib:format("begin io:format(\"~~p~n\", [{~p,~p,~p}]), if ~w(~w, ~w) -> true; true -> false end end. ", [T,L,A,T,L,A]),
+    {Val,Expr} = eval_string(S),
+    Anno = erl_anno:new(0),
+    {match,Anno,{atom,Anno,Val},Expr}.
+
+body_test(T, L) ->
+    S = io_lib:format("begin io:format(\"~~p~n\", [{~p,~p}]), ~w(~w) end. ", [T,L,T,L]),
+    {Val,Expr} = eval_string(S),
     Anno = erl_anno:new(0),
-    {match,Anno,{atom,Anno,Val},hd(E)}.
+    {match,Anno,{atom,Anno,Val},Expr}.
 
-test(T, A, L) ->
-    S = lists:flatten(io_lib:format("begin io:format(\"~~p~n\", [{~p,~p,~p}]), if ~w(~w, ~w) -> true; true -> false end end. ",
-				    [T,L,A,T,L,A])),
-    {ok,Toks,_Line} = erl_scan:string(S),
+body_test(T, A, L) ->
+    S = io_lib:format("begin io:format(\"~~p~n\", [{~p,~p,~p}]), ~w(~w,~w) end. ", [T,L,A,T,L,A]),
+    {Val,Expr} = eval_string(S),
+    Anno = erl_anno:new(0),
+    {match,Anno,{atom,Anno,Val},Expr}.
+
+eval_string(S) ->
+    {ok,Toks,_Line} = erl_scan:string(lists:flatten(S)),
     {ok,E} = erl_parse:parse_exprs(Toks),
     {value,Val,_Bs} = erl_eval:exprs(E, []),
-    Anno = erl_anno:new(0),
-    {match,Anno,{atom,Anno,Val},hd(E)}.
-    
+    {Val,hd(E)}.
+
 literals() ->
     [42,
      3.14,
      -3,
      32982724987789283473473838474,
      [],
-     xxxx].
+     "abc",
+     <<"abc">>,
+     {},
+     xxxx,
+     fun erlang:erase/0].
 
 type_tests() ->
     [is_boolean,