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-rw-r--r--erts/emulator/beam/erl_db_util.c52
1 files changed, 28 insertions, 24 deletions
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index b9fd3b208e..7eb80e3bb1 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -3254,34 +3254,38 @@ int db_is_variable(Eterm obj)
/* return 1 if obj contains a variable or underscore */
/* return 0 if obj is fully ground */
-int db_has_variable(Eterm obj)
-{
- switch(obj & _TAG_PRIMARY_MASK) {
- case TAG_PRIMARY_LIST: {
- while (is_list(obj)) {
- if (db_has_variable(CAR(list_val(obj))))
+int db_has_variable(Eterm node) {
+ DECLARE_ESTACK(s);
+
+ ESTACK_PUSH(s,node);
+ while (!ESTACK_ISEMPTY(s)) {
+ node = ESTACK_POP(s);
+ switch(node & _TAG_PRIMARY_MASK) {
+ case TAG_PRIMARY_LIST:
+ while (is_list(node)) {
+ ESTACK_PUSH(s,CAR(list_val(node)));
+ node = CDR(list_val(node));
+ }
+ ESTACK_PUSH(s,node); /* Non wellformed list or [] */
+ break;
+ case TAG_PRIMARY_BOXED:
+ if (is_tuple(node)) {
+ Eterm *tuple = tuple_val(node);
+ int arity = arityval(*tuple);
+ while(arity--) {
+ ESTACK_PUSH(s,*(++tuple));
+ }
+ }
+ break;
+ case TAG_PRIMARY_IMMED1:
+ if (node == am_Underscore || db_is_variable(node) >= 0) {
+ DESTROY_ESTACK(s);
return 1;
- obj = CDR(list_val(obj));
- }
- return(db_has_variable(obj)); /* Non wellformed list or [] */
- }
- case TAG_PRIMARY_BOXED:
- if (!is_tuple(obj)) {
- return 0;
- } else {
- Eterm *tuple = tuple_val(obj);
- int arity = arityval(*tuple++);
- while(arity--) {
- if (db_has_variable(*tuple))
- return 1;
- tuple++;
}
- return(0);
+ break;
}
- case TAG_PRIMARY_IMMED1:
- if (obj == am_Underscore || db_is_variable(obj) >= 0)
- return 1;
}
+ DESTROY_ESTACK(s);
return 0;
}