Handling of ghost cells in strm2x merge

Ghost cells act as anchors for top cells of the other
layout in "," merges. Unlike other cells which are
renamed.

src/buddies/src/bd/bdReaderOptions.cc

@@ -892,16 +892,42 @@ void read_files (db::Layout &layout, const std::string &infile, const db::LoadLa
 
       std::vector<db::cell_index_type> cells_target;
       std::vector<db::cell_index_type> cells_source;
+
       for (auto c = tmp.begin_top_down (); c != tmp.end_top_cells (); ++c) {
+
         cells_source.push_back (*c);
+
+        //  as a special rule, join ghost cells if the source top cell fits into
+        //  a ghost cell of the target.
+        auto cell_target = layout.cell_by_name (tmp.cell_name (*c));
+        if (cell_target.first && layout.cell (cell_target.second).is_ghost_cell ()) {
+          cells_target.push_back (cell_target.second);
+        } else {
           cells_target.push_back (layout.add_cell (tmp.cell_name (*c)));
         }
 
-      db::LayerMapping lm;
-      lm.create_full (layout, tmp);
+      }
+
+      //  ghost cell joining also works the other way around: a top cell of destination
+      //  can match a ghost cell of the source
+      for (auto c = tmp.end_top_cells (); c != tmp.end_top_down (); ++c) {
+
+        const db::Cell &cell_source = tmp.cell (*c);
+        auto cell_target = layout.cell_by_name (tmp.cell_name (*c));
+
+        if (cell_source.is_ghost_cell () && cell_target.first) {
+          cells_source.push_back (*c);
+          cells_target.push_back (cell_target.second);
+        }
+
+      }
+
       db::CellMapping cm;
       cm.create_multi_mapping_full (layout, cells_target, tmp, cells_source);
 
+      db::LayerMapping lm;
+      lm.create_full (layout, tmp);
+
       layout.move_tree_shapes (tmp, cm, lm);
 
     }

src/buddies/unit_tests/bdConverterTests.cc

@@ -592,3 +592,119 @@ TEST(11_3)
 
   db::compare_layouts (this, layout, input_au, db::WriteOAS);
 }
+
+//  Merging with + and , under the presence of ghost cells: test+test,top->(test)
+TEST(12_1)
+{
+  std::string input_dir = tl::testdata ();
+  input_dir += "/bd";
+
+  std::string input_au = input_dir + "/strm2oas_au_12_1.oas";
+  std::string input = input_dir + "/strm2oas_a.oas+" + input_dir + "/strm2oas_b.oas," + input_dir + "/strm2oas_c.oas";
+
+  std::string output = this->tmp_file ("strm2oas_12_1.oas");
+  const char *argv[] = { "x",
+                         "--blend-mode=0",
+                         input.c_str (),
+                         output.c_str ()
+                       };
+
+  EXPECT_EQ (bd::converter_main (sizeof (argv) / sizeof (argv[0]), (char **) argv, bd::GenericWriterOptions::oasis_format_name), 0);
+
+  db::Layout layout;
+  {
+    tl::InputStream stream (output);
+    db::LoadLayoutOptions options;
+    db::Reader reader (stream);
+    reader.read (layout, options);
+  }
+
+  db::compare_layouts (this, layout, input_au, db::WriteOAS);
+}
+
+//  Merging with + and , under the presence of ghost cells: top->(test),test+test
+TEST(12_2)
+{
+  std::string input_dir = tl::testdata ();
+  input_dir += "/bd";
+
+  std::string input_au = input_dir + "/strm2oas_au_12_2.oas";
+  std::string input = input_dir + "/strm2oas_c.oas," + input_dir + "/strm2oas_a.oas+" + input_dir + "/strm2oas_b.oas";
+
+  std::string output = this->tmp_file ("strm2oas_12_2.oas");
+  const char *argv[] = { "x",
+                         "--blend-mode=0",
+                         input.c_str (),
+                         output.c_str ()
+                       };
+
+  EXPECT_EQ (bd::converter_main (sizeof (argv) / sizeof (argv[0]), (char **) argv, bd::GenericWriterOptions::oasis_format_name), 0);
+
+  db::Layout layout;
+  {
+    tl::InputStream stream (output);
+    db::LoadLayoutOptions options;
+    db::Reader reader (stream);
+    reader.read (layout, options);
+  }
+
+  db::compare_layouts (this, layout, input_au, db::WriteOAS);
+}
+
+//  Merging with + and , under the presence of ghost cells: test+test,toptop->top->(test)
+TEST(12_3)
+{
+  std::string input_dir = tl::testdata ();
+  input_dir += "/bd";
+
+  std::string input_au = input_dir + "/strm2oas_au_12_3.oas";
+  std::string input = input_dir + "/strm2oas_a.oas+" + input_dir + "/strm2oas_b.oas," + input_dir + "/strm2oas_cc.oas";
+
+  std::string output = this->tmp_file ("strm2oas_12_3.oas");
+  const char *argv[] = { "x",
+                         "--blend-mode=0",
+                         input.c_str (),
+                         output.c_str ()
+                       };
+
+  EXPECT_EQ (bd::converter_main (sizeof (argv) / sizeof (argv[0]), (char **) argv, bd::GenericWriterOptions::oasis_format_name), 0);
+
+  db::Layout layout;
+  {
+    tl::InputStream stream (output);
+    db::LoadLayoutOptions options;
+    db::Reader reader (stream);
+    reader.read (layout, options);
+  }
+
+  db::compare_layouts (this, layout, input_au, db::WriteOAS);
+}
+
+//  Merging with + and , under the presence of ghost cells: toptop->top->(test),test+test
+TEST(12_4)
+{
+  std::string input_dir = tl::testdata ();
+  input_dir += "/bd";
+
+  std::string input_au = input_dir + "/strm2oas_au_12_4.oas";
+  std::string input = input_dir + "/strm2oas_cc.oas," + input_dir + "/strm2oas_a.oas+" + input_dir + "/strm2oas_b.oas";
+
+  std::string output = this->tmp_file ("strm2oas_12_4.oas");
+  const char *argv[] = { "x",
+                         "--blend-mode=0",
+                         input.c_str (),
+                         output.c_str ()
+                       };
+
+  EXPECT_EQ (bd::converter_main (sizeof (argv) / sizeof (argv[0]), (char **) argv, bd::GenericWriterOptions::oasis_format_name), 0);
+
+  db::Layout layout;
+  {
+    tl::InputStream stream (output);
+    db::LoadLayoutOptions options;
+    db::Reader reader (stream);
+    reader.read (layout, options);
+  }
+
+  db::compare_layouts (this, layout, input_au, db::WriteOAS);
+}