From b32eed9a849381172a5d3208cc7798a8a11c4c9b Mon Sep 17 00:00:00 2001
From: James Cherry <cherry@parallaxsw.com>
Date: Thu, 15 May 2025 17:21:39 -0700
Subject: [PATCH] Fix levelize crash when vertices enqueued in arrival/required
 iterators

Signed-off-by: James Cherry <cherry@parallaxsw.com>
---
 include/sta/Search.hh |  1 +
 search/Levelize.cc    | 27 ++++++++++++++++++++++-----
 search/Levelize.hh    |  3 +++
 search/Search.cc      | 20 ++++++++++++++++++--
 search/Sta.cc         |  9 ++++++++-
 5 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/include/sta/Search.hh b/include/sta/Search.hh
index cd2dd9e7..780ef60a 100644
--- a/include/sta/Search.hh
+++ b/include/sta/Search.hh
@@ -359,6 +359,7 @@ public:
   void reportArrivals(Vertex *vertex) const;
   Slack wnsSlack(Vertex *vertex,
 		 PathAPIndex path_ap_index);
+  void levelsChangedBefore();
   void levelChangedBefore(Vertex *vertex);
   void seedInputArrival(const Pin *pin,
  			Vertex *vertex,
diff --git a/search/Levelize.cc b/search/Levelize.cc
index 9bfdacde..79f54066 100644
--- a/search/Levelize.cc
+++ b/search/Levelize.cc
@@ -122,6 +122,8 @@ Levelize::levelize()
   Stats stats(debug_, report_);
   debugPrint(debug_, "levelize", 1, "levelize");
   clear();
+  if (observer_)
+    observer_->levelsChangedBefore();
 
   VertexIterator vertex_iter(graph_);
   while (vertex_iter.hasNext()) {
@@ -545,6 +547,19 @@ Levelize::ensureLatchLevels()
   latch_d_to_q_edges_.clear();
 }
 
+void
+Levelize::setLevel(Vertex  *vertex,
+		   Level level)
+{
+  debugPrint(debug_, "levelize", 2, "set level %s %d",
+             vertex->to_string(this).c_str(),
+             level);
+  vertex->setLevel(level);
+  max_level_ = max(level, max_level_);
+  if (level >= Graph::vertex_level_max)
+    criticalError(616, "maximum logic level exceeded");
+}
+
 void
 Levelize::invalid()
 {
@@ -597,6 +612,8 @@ Levelize::deleteEdgeBefore(Edge *edge)
 {
   if (levelized_
       && loop_edges_.hasKey(edge)) {
+    debugPrint(debug_, "levelize", 2, "delete loop edge %s",
+               edge->to_string(this).c_str());
     disabled_loop_edges_.erase(edge);
     // Relevelize if a loop edge is removed. Incremental levelization
     // fails because the DFS path will be missing.
@@ -621,7 +638,7 @@ Levelize::relevelize()
                vertex->to_string(this).c_str());
     if (search_pred_.searchFrom(vertex)) {
       if (isRoot(vertex)) {
-	setLevel(vertex, 0);
+	setLevelIncr(vertex, 0);
 	roots_->insert(vertex);
       }
       VertexSet visited(graph_);
@@ -645,7 +662,7 @@ Levelize::visit(Vertex *vertex,
 		EdgeSeq &path)
 {
   Pin *from_pin = vertex->pin();
-  setLevel(vertex, level);
+  setLevelIncr(vertex, level);
   level += level_space;
   visited.insert(vertex);
   path_vertices.insert(vertex);
@@ -691,8 +708,8 @@ Levelize::isDisabledLoop(Edge *edge) const
 }
 
 void
-Levelize::setLevel(Vertex  *vertex,
-		   Level level)
+Levelize::setLevelIncr(Vertex  *vertex,
+                       Level level)
 {
   debugPrint(debug_, "levelize", 2, "set level %s %d",
              vertex->to_string(this).c_str(),
@@ -704,7 +721,7 @@ Levelize::setLevel(Vertex  *vertex,
   }
   max_level_ = max(level, max_level_);
   if (level >= Graph::vertex_level_max)
-    criticalError(616, "maximum logic level exceeded");
+    criticalError(617, "maximum logic level exceeded");
 }
 
 ////////////////////////////////////////////////////////////////
diff --git a/search/Levelize.hh b/search/Levelize.hh
index a1a9a383..28a34603 100644
--- a/search/Levelize.hh
+++ b/search/Levelize.hh
@@ -96,6 +96,8 @@ protected:
              EdgeSeq &path);
   void setLevel(Vertex  *vertex,
 		Level level);
+  void setLevelIncr(Vertex  *vertex,
+                    Level level);
   void clearLoopEdges();
   void deleteLoops();
   void reportPath(EdgeSeq &path) const;
@@ -135,6 +137,7 @@ class LevelizeObserver
 public:
   LevelizeObserver() {}
   virtual ~LevelizeObserver() {}
+  virtual void levelsChangedBefore() = 0;
   virtual void levelChangedBefore(Vertex *vertex) = 0;
 };
 
diff --git a/search/Search.cc b/search/Search.cc
index 85370049..a18e436f 100644
--- a/search/Search.cc
+++ b/search/Search.cc
@@ -795,14 +795,30 @@ Search::arrivalInvalid(Vertex *vertex)
   }
 }
 
+// Move any pending arrival/requireds to invalid before relevelization.
+void
+Search::levelsChangedBefore()
+{
+  if (arrivals_exist_) {
+    while (arrival_iter_->hasNext()) {
+      Vertex *vertex = arrival_iter_->next();
+      arrivalInvalid(vertex);
+    }
+    while (required_iter_->hasNext()) {
+      Vertex *vertex = required_iter_->next();
+      requiredInvalid(vertex);
+    }
+  }
+}
+
 void
 Search::levelChangedBefore(Vertex *vertex)
 {
   if (arrivals_exist_) {
     arrival_iter_->remove(vertex);
     required_iter_->remove(vertex);
-    search_->arrivalInvalid(vertex);
-    search_->requiredInvalid(vertex);
+    arrivalInvalid(vertex);
+    requiredInvalid(vertex);
   }
 }
 
diff --git a/search/Sta.cc b/search/Sta.cc
index 4bf71fca..4a42db38 100644
--- a/search/Sta.cc
+++ b/search/Sta.cc
@@ -210,7 +210,8 @@ class StaLevelizeObserver : public LevelizeObserver
 {
 public:
   StaLevelizeObserver(Search *search);
-  virtual void levelChangedBefore(Vertex *vertex);
+  void levelsChangedBefore() override;
+  void levelChangedBefore(Vertex *vertex) override;
 
 private:
   Search *search_;
@@ -221,6 +222,12 @@ StaLevelizeObserver::StaLevelizeObserver(Search *search) :
 {
 }
 
+void
+StaLevelizeObserver::levelsChangedBefore()
+{
+  search_->levelsChangedBefore();
+}
+
 void
 StaLevelizeObserver::levelChangedBefore(Vertex *vertex)
 {