From a07d742bee3ee50de74f65b0ac11806b5516e0e5 Mon Sep 17 00:00:00 2001
From: Matthias Koefferlein <matthias@klayout.de>
Date: Sun, 18 May 2025 00:48:10 +0200
Subject: [PATCH] Fixed a problem with via uniquification - via definitions may
 be DEF local, so we need to clean them between different DEF reads.

---
 .../lefdef/db_plugin/dbDEFImporter.cc         |  2 ++
 .../lefdef/db_plugin/dbLEFDEFImporter.cc      | 20 +++++++++++++++++++
 .../lefdef/db_plugin/dbLEFDEFImporter.h       |  4 +++-
 3 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
index 3aa4d79c7..a47f99d32 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/dbDEFImporter.cc
@@ -1182,8 +1182,10 @@ DEFImporter::read_vias (db::Layout &layout, db::Cell & /*design*/, double scale)
     if (rule_based_vg.get () && geo_based_vg.get ()) {
       error (tl::to_string (tr ("A via can only be defined through a VIARULE or geometry, not both ways")));
     } else if (rule_based_vg.get ()) {
+      rule_based_vg->def_local = true;
       reader_state ()->register_via_cell (n, std::string (), rule_based_vg.release ());
     } else if (geo_based_vg.get ()) {
+      geo_based_vg->def_local = true;
       reader_state ()->register_via_cell (n, std::string (), geo_based_vg.release ());
     } else {
       error (tl::to_string (tr ("Too little information to generate a via")));
diff --git a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
index 3059105da..4d1ecba24 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
+++ b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.cc
@@ -1810,9 +1810,29 @@ std::set<unsigned int> LEFDEFReaderState::open_layer_uncached(db::Layout &layout
 void
 LEFDEFReaderState::start ()
 {
+  //  Start over for a new DEF file - this function is used in LEF context mode
+  //  i.e. when LEFs are cached during multiple DEF reads. It is called when a new DEF is read.
+
   CommonReaderBase::start ();
 
   m_foreign_cells.clear ();
+
+  //  Remove the via generators that were added by DEF
+  //  TODO: there is no concept for "local LEFs" currently. Even LEFs stored along
+  //  with DEFs are considered "global".
+  for (auto vg = m_via_generators.begin (); vg != m_via_generators.end (); ) {
+    auto vg_here = vg;
+    ++vg;
+    if (vg_here->second->def_local) {
+      delete vg_here->second;
+      m_via_generators.erase (vg_here);
+    }
+  }
+
+  //  We always create fresh via cells for different DEFs to avoid potential
+  //  content conflicts. Problem is: vias can be generated by both LEF (global)
+  //  and DEF (local)
+  m_via_cells.clear ();
 }
 
 void
diff --git a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
index ddb90415e..5c2a2a346 100644
--- a/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
+++ b/src/plugins/streamers/lefdef/db_plugin/dbLEFDEFImporter.h
@@ -1141,12 +1141,14 @@ public:
 class DB_PLUGIN_PUBLIC LEFDEFLayoutGenerator
 {
 public:
-  LEFDEFLayoutGenerator () { }
+  LEFDEFLayoutGenerator () : def_local (false) { }
   virtual ~LEFDEFLayoutGenerator () { }
 
   virtual void create_cell (LEFDEFReaderState &reader, db::Layout &layout, db::Cell &cell, const std::vector<std::string> *maskshift_layers, const std::vector<unsigned int> &masks, const LEFDEFNumberOfMasks *nm) = 0;
   virtual std::vector<std::string> maskshift_layers () const = 0;
   virtual bool is_fixedmask () const = 0;
+
+  bool def_local;
 };
 
 /**