add set_empty_repeat_node_trav()

diff --git a/src/regcomp.c b/src/regcomp.c
index a08b254ccd9900b0d8820a79c1e55c080906c5be..80ca23868caa5a74d9f1df36b9139444ca650de3 100644 (file)
--- a/src/regcomp.c
+++ b/src/regcomp.c
@@ -3193,6 +3193,81 @@ check_backrefs(Node* node, ScanEnv* env)
   return r;
 }
 
+static int
+set_empty_repeat_node_trav(Node* node, Node* empty, ScanEnv* env)
+{
+  int r;
+
+  switch (NODE_TYPE(node)) {
+  case NODE_LIST:
+  case NODE_ALT:
+    do {
+      r = set_empty_repeat_node_trav(NODE_CAR(node), empty, env);
+    } while (r == 0 && IS_NOT_NULL(node = NODE_CDR(node)));
+    break;
+
+  case NODE_ANCHOR:
+    {
+      AnchorNode* an = ANCHOR_(node);
+
+      if (! ANCHOR_HAS_BODY(an)) {
+       r = 0;
+       break;
+      }
+
+      switch (an->type) {
+      case ANCR_PREC_READ:
+      case ANCR_LOOK_BEHIND:
+       empty = NULL_NODE;
+       break;
+      default:
+       break;
+      }
+      r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+    }
+    break;
+
+  case NODE_QUANT:
+    {
+      QuantNode* qn = QUANT_(node);
+
+      if (qn->emptiness != BODY_IS_NOT_EMPTY) empty = node;
+      r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+    }
+    break;
+
+  case NODE_BAG:
+    r = set_empty_repeat_node_trav(NODE_BODY(node), empty, env);
+    {
+      BagNode* en = BAG_(node);
+
+      if (en->type == BAG_MEMORY) {
+       if (NODE_IS_BACKREF(node)) {
+         if (IS_NOT_NULL(empty))
+           SCANENV_MEMENV(env)[en->m.regnum].empty_repeat_node = empty;
+       }
+      }
+      else if (en->type == BAG_IF_ELSE) {
+        if (r != 0) return r;
+        if (IS_NOT_NULL(en->te.Then)) {
+         r = set_empty_repeat_node_trav(en->te.Then, empty, env);
+          if (r != 0) return r;
+        }
+        if (IS_NOT_NULL(en->te.Else)) {
+         r = set_empty_repeat_node_trav(en->te.Else, empty, env);
+        }
+      }
+    }
+    break;
+
+  default:
+    r = 0;
+    break;
+  }
+
+  return r;
+}
+
 
 #ifdef USE_CALL