From 41c0850f237934bef429560bf76dc22c368127bb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= <egil@erlang.org>
Date: Thu, 12 Jan 2012 19:25:18 +0100
Subject: [PATCH] erts: Add some erlang:process_flag/2 functionality

---
 erts/emulator/beam/bif.c | 51 ++++++++++++++++++++++++++++++++++------
 1 file changed, 44 insertions(+), 7 deletions(-)

diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 4d8347a9094d..cff903512c3b 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -868,7 +868,7 @@ BIF_RETTYPE spawn_opt_1(BIF_ALIST_1)
 		    if (is_tuple(limit)) {
 			tpl = tuple_val(limit);
 
-			if (*tp2 != make_arityval(2))
+			if (*tpl != make_arityval(2))
 			    goto error;
 
 			/* reuse vars */
@@ -1636,6 +1636,9 @@ BIF_RETTYPE process_flag_2(BIF_ALIST_2)
        BIF_RET(old_value);
    }
    else if (BIF_ARG_1 == am_limits) {
+       /* lots here can be refactored with spawn_opt
+	* this should be broken out
+	*/
        if (is_tuple(BIF_ARG_2)) {
 	   Eterm *tp = tuple_val(BIF_ARG_2);
 	   if (arityval(tp[0]) == 2) {
@@ -1644,16 +1647,50 @@ BIF_RETTYPE process_flag_2(BIF_ALIST_2)
 		   old_value = make_small(LIMIT_HEAP_SIZE(BIF_P));
 		   LIMIT_HEAP_SIZE(BIF_P) = i;
 		   BIF_RET(old_value);
-	       } else {
-		   goto error;
 	       }
 	   }
        } else if (is_list(BIF_ARG_2)) {
-	   /* will this be the real one? */
-	   goto error;
-       } else {
-	   goto error;
+
+	   Eterm limits = BIF_ARG_2;
+	   Eterm limit, arg, limitval;
+	   Eterm *tpl;
+
+	   while (is_list(limits)) {
+	       limit = CAR(list_val(limits));
+	       if (is_tuple(limit)) {
+		   tpl = tuple_val(limit);
+
+		   if (*tpl != make_arityval(2))
+		       goto error;
+
+		   arg = tpl[1];
+		   limitval = tpl[2];
+
+		   if (arg == am_heap_size && is_small(limitval)) {
+		       Sint heap_size = signed_val(limitval);
+
+		       if (heap_size < 0) {
+			   goto error;
+		       } else {
+			   old_value = make_small(LIMIT_HEAP_SIZE(BIF_P));
+			   LIMIT_HEAP_SIZE(BIF_P) = heap_size;
+			   BIF_RET(old_value);
+		       }
+		   } else /* not heap_size */
+		       goto error;
+	       } else /* not a is_tuple */
+		   goto error;
+
+	       limits = CDR(list_val(limits));
+	   }
+
+	   /* is proper list
+	   if (is_not_nil(limits)) {
+	       goto error;
+	   }
+	   */
        }
+       goto error;
    } else if (BIF_ARG_1 == am_min_bin_vheap_size) {
        Sint i;
        if (!is_small(BIF_ARG_2)) {