Add enif_raise_exception

Add enif_raise_exception function to allow NIFs to raise error
exceptions holding any Erlang terms. This does not replace or
deprecate the enif_make_badarg function, though, because raising
badarg errors is so idiomatic in NIFs. Reimplement enif_make_badarg on
top of enif_raise_exception. Add new tests for enif_raise_exception
for both normal and dirty NIFs. Add documentation for
enif_raise_exception.

2 files changed, 61 insertions, 24 deletions

diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index 434d1c38d0..778f6fd087 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -39,8 +39,9 @@
 	 get_length/1, make_atom/1, make_string/1, reverse_list_test/1,
 	 otp_9828/1,
 	 otp_9668/1, consume_timeslice/1, dirty_nif/1, dirty_nif_send/1,
-	 dirty_nif_exception/1, nif_schedule/1,
-	 nif_exception/1, nif_nan_and_inf/1, nif_atom_too_long/1
+	 dirty_nif_exception/1, call_dirty_nif_exception/1, nif_schedule/1,
+	 nif_exception/1, call_nif_exception/1,
+	 nif_nan_and_inf/1, nif_atom_too_long/1
 	]).
 
 -export([many_args_100/100]).
@@ -1621,7 +1622,10 @@ dirty_nif_exception(Config) when is_list(Config) ->
 		    [{?MODULE,call_dirty_nif_exception,[0],_}|_] =
 			erlang:get_stacktrace(),
 		    ok
-	    end
+	    end,
+	    %% this checks that a dirty NIF can raise various terms as
+	    %% exceptions
+	    ok = nif_raise_exceptions(call_dirty_nif_exception)
     catch
 	error:badarg ->
 	    {skipped,"No dirty scheduler support"}
@@ -1633,12 +1637,15 @@ nif_exception(Config) when is_list(Config) ->
 	%% this checks that the expected exception occurs when the NIF
 	%% calls enif_make_badarg at some point but then tries to return a
 	%% value that isn't an exception
-	call_nif_exception(),
+	call_nif_exception(0),
 	?t:fail(expected_badarg)
     catch
 	error:badarg ->
 	    ok
-    end.
+    end,
+    %% this checks that a NIF can raise various terms as exceptions
+    ok = nif_raise_exceptions(call_nif_exception),
+    ok.
 
 nif_nan_and_inf(Config) when is_list(Config) ->
     ensure_lib_loaded(Config),
@@ -1760,7 +1767,20 @@ check(Exp,Got,Line) ->
   	    io:format("CHECK at ~p: Expected ~p but got ~p\n",[Line,Exp,Got]),
  	    Got
     end.
-	    
+
+nif_raise_exceptions(NifFunc) ->
+    ExcTerms = [{error, test}, "a string", <<"a binary">>,
+		42, [1,2,3,4,5], [{p,1},{p,2},{p,3}]],
+    lists:foldl(fun(Term, ok) ->
+			try
+			    erlang:apply(?MODULE,NifFunc,[Term]),
+			    ?t:fail({expected,Term})
+			catch
+			    error:Term ->
+				[{?MODULE,NifFunc,[Term],_}|_] = erlang:get_stacktrace(),
+				ok
+			end
+		end, ok, ExcTerms).
 
 %% The NIFs:
 lib_version() -> undefined.
@@ -1816,7 +1836,7 @@ call_dirty_nif(_,_,_) -> ?nif_stub.
 send_from_dirty_nif(_) -> ?nif_stub.
 call_dirty_nif_exception(_) -> ?nif_stub.
 call_dirty_nif_zero_args() -> ?nif_stub.
-call_nif_exception() -> ?nif_stub.
+call_nif_exception(_) -> ?nif_stub.
 call_nif_nan_or_inf(_) -> ?nif_stub.
 call_nif_atom_too_long(_) -> ?nif_stub.
 
diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
index 95e361690f..0191e098db 100644
--- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
+++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
@@ -1618,13 +1618,18 @@ static ERL_NIF_TERM call_dirty_nif_exception(ErlNifEnv* env, int argc, const ERL
 {
     switch (argc) {
     case 1: {
-	ERL_NIF_TERM args[255];
-	int i;
-	args[0] = argv[0];
-	for (i = 1; i < 255; i++)
-	    args[i] = enif_make_int(env, i);
-	return enif_schedule_nif(env, "call_dirty_nif_exception", ERL_NIF_DIRTY_JOB_CPU_BOUND,
-				 call_dirty_nif_exception, 255, args);
+	int arg;
+	if (enif_get_int(env, argv[0], &arg) && arg < 2) {
+	    ERL_NIF_TERM args[255];
+	    int i;
+	    args[0] = argv[0];
+	    for (i = 1; i < 255; i++)
+		args[i] = enif_make_int(env, i);
+	    return enif_schedule_nif(env, "call_dirty_nif_exception", ERL_NIF_DIRTY_JOB_CPU_BOUND,
+				     call_dirty_nif_exception, 255, args);
+	} else {
+	    return enif_raise_exception(env, argv[0]);
+	}
     }
     case 2: {
         int return_badarg_directly;
@@ -1657,20 +1662,32 @@ static ERL_NIF_TERM call_dirty_nif_zero_args(ErlNifEnv* env, int argc, const ERL
 #endif
 
 /*
- * Call enif_make_badarg, but don't return its return value. Instead,
- * return ok.  Result should still be a badarg exception for the erlang
- * caller.
+ * If argv[0] is the integer 0, call enif_make_badarg, but don't return its
+ * return value. Instead, return ok.  Result should still be a badarg
+ * exception for the erlang caller.
+ *
+ * For any other value of argv[0], use it as an exception term and return
+ * the exception.
  */
 static ERL_NIF_TERM call_nif_exception(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     ERL_NIF_TERM exc_term;
     ERL_NIF_TERM badarg_atom = enif_make_atom(env, "badarg");
-
-    /* ignore return value */ enif_make_badarg(env);
-    assert(enif_has_pending_exception(env, NULL));
-    assert(enif_has_pending_exception(env, &exc_term));
-    assert(enif_is_identical(badarg_atom, exc_term));
-    return enif_make_atom(env, "ok");
+    int arg;
+
+    if (enif_get_int(env, argv[0], &arg) && arg == 0) {
+	/* ignore return value */ enif_make_badarg(env);
+	assert(enif_has_pending_exception(env, NULL));
+	assert(enif_has_pending_exception(env, &exc_term));
+	assert(enif_is_identical(badarg_atom, exc_term));
+	return enif_make_atom(env, "ok");
+    } else {
+	ERL_NIF_TERM exc_retval = enif_raise_exception(env, argv[0]);
+	assert(enif_has_pending_exception(env, NULL));
+	assert(enif_has_pending_exception(env, &exc_term));
+	assert(enif_is_identical(argv[0], exc_term));
+	return exc_retval;
+    }
 }
 
 #if !defined(NAN) || !defined(INFINITY)
@@ -1925,7 +1942,7 @@ static ErlNifFunc nif_funcs[] =
     {"call_dirty_nif_exception", 1, call_dirty_nif_exception, ERL_NIF_DIRTY_JOB_IO_BOUND},
     {"call_dirty_nif_zero_args", 0, call_dirty_nif_zero_args, ERL_NIF_DIRTY_JOB_CPU_BOUND},
 #endif
-    {"call_nif_exception", 0, call_nif_exception},
+    {"call_nif_exception", 1, call_nif_exception},
     {"call_nif_nan_or_inf", 1, call_nif_nan_or_inf},
     {"call_nif_atom_too_long", 1, call_nif_atom_too_long},
     {"is_map_nif", 1, is_map_nif},