Implemented a dummy arrangement of cells when the MAG output file isn't corresponding to a existing cell - useful for obtaining a cell overview

src/plugins/streamers/magic/db_plugin/dbMAGWriter.cc

@@ -63,7 +63,7 @@ MAGWriter::write (db::Layout &layout, tl::OutputStream &stream, const db::SaveLa
   std::string basename = tl::basename (src.path ());
   std::pair<bool, db::cell_index_type> ci = layout.cell_by_name (basename.c_str ());
   if (! ci.first || cell_set.find (ci.second) == cell_set.end ()) {
-    tl::warn << tl::to_string (tr ("Magic file names should be valid cell names - otherwise no such file is written. This is not a valid name: ")) << basename;
+    tl::warn << tl::to_string (tr ("The output file is not corresponding to an existing cell name. The content of this cell will not be a real layout: ")) << basename;
   }
 
   m_options = options.get_options<MAGWriterOptions> ();
@@ -91,6 +91,11 @@ MAGWriter::write (db::Layout &layout, tl::OutputStream &stream, const db::SaveLa
 
   m_sf = layout.dbu () / lambda;
 
+  //  As a favor, write a dummy top level file before closing the stream. If the file name corresponds to a real cell,
+  //  this file is overwritten by the true cell.
+  write_dummmy_top (cell_set, layout, stream);
+  stream.close ();
+
   for (std::set<db::cell_index_type>::const_iterator c = cell_set.begin (); c != cell_set.end (); ++c) {
     tl::OutputStream os (filename_for_cell (*c, layout), tl::OutputStream::OM_Auto, true);
     write_cell (*c, layers, layout, os);
@@ -109,6 +114,50 @@ MAGWriter::filename_for_cell (db::cell_index_type ci, db::Layout &layout)
   return uri.to_string ();
 }
 
+void
+MAGWriter::write_dummmy_top (const std::set<db::cell_index_type> &cell_set, const db::Layout &layout, tl::OutputStream &os)
+{
+  os.set_as_text (true);
+  os << "magic\n";
+
+  std::string tech = m_options.tech;
+  if (tech.empty ()) {
+    tech = layout.meta_info_value ("technology");
+  }
+  if (! tech.empty ()) {
+    os << "tech " << make_string (tl::to_lower_case (tech)) << "\n";
+  }
+
+  os << "timestamp " << m_timestamp << "\n";
+
+  std::map<std::string, db::cell_index_type> cells_by_name;
+  for (std::set<db::cell_index_type>::const_iterator c = cell_set.begin (); c != cell_set.end (); ++c) {
+    cells_by_name.insert (std::make_pair (std::string (layout.cell_name (*c)), *c));
+  }
+
+  db::Coord y = 0;
+  db::Coord w = 0;
+  std::vector<db::CellInstArray> cell_instances;
+  cell_instances.reserve (cells_by_name.size ());
+  for (std::map<std::string, db::cell_index_type>::const_iterator c = cells_by_name.begin (); c != cells_by_name.end (); ++c) {
+    //  instances are arrayed as stack
+    db::Box bx = layout.cell (c->second).bbox ();
+    cell_instances.push_back (db::CellInstArray (db::CellInst (c->second), db::Trans (db::Vector (0, y) + (db::Point () - bx.p1 ()))));
+    y += bx.height ();
+    w = std::max (w, db::Coord (bx.width ()));
+  }
+
+  os << "<< checkpaint >>\n";
+  write_polygon (db::Polygon (db::Box (0, 0, w, y)), layout, os);
+
+  m_cell_id.clear ();
+  for (std::vector<db::CellInstArray>::const_iterator i = cell_instances.begin (); i != cell_instances.end (); ++i) {
+    write_instance (*i, layout, os);
+  }
+
+  os << "<< end >>\n";
+}
+
 void
 MAGWriter::write_cell (db::cell_index_type ci, const std::vector <std::pair <unsigned int, db::LayerProperties> > &layers, db::Layout &layout, tl::OutputStream &os)
 {
@@ -403,6 +452,4 @@ MAGWriter::make_string (const std::string &s)
   return res;
 }
 
-
 }
-

src/plugins/streamers/magic/db_plugin/dbMAGWriter.h

@@ -99,6 +99,7 @@ private:
 
   std::string filename_for_cell (db::cell_index_type ci, db::Layout &layout);
   void write_cell (db::cell_index_type ci, const std::vector <std::pair <unsigned int, db::LayerProperties> > &layers, db::Layout &layout, tl::OutputStream &os);
+  void write_dummmy_top (const std::set<db::cell_index_type> &cell_set, const db::Layout &layout, tl::OutputStream &os);
   void do_write_cell (db::cell_index_type ci, const std::vector <std::pair <unsigned int, db::LayerProperties> > &layers, db::Layout &layout, tl::OutputStream &os);
   void write_polygon (const db::Polygon &poly, const db::Layout &layout, tl::OutputStream &os);
   void write_label (const std::string &layer, const db::Text &text, const Layout &layout, tl::OutputStream &os);

src/tl/tl/tlStream.cc

@@ -715,6 +715,12 @@ OutputStream::OutputStream (const std::string &abstract_path, OutputStreamMode o
 }
 
 OutputStream::~OutputStream ()
+{
+  close ();
+}
+
+void
+OutputStream::close ()
 {
   flush ();
 
@@ -759,7 +765,7 @@ inline void fast_copy (char *t, const char *s, size_t n)
 void
 OutputStream::flush ()
 {
-  if (m_buffer_pos > 0) {
+  if (m_buffer_pos > 0 && mp_delegate) {
     mp_delegate->write (mp_buffer, m_buffer_pos);
     m_buffer_pos = 0;
   }
@@ -768,6 +774,10 @@ OutputStream::flush ()
 void
 OutputStream::put (const char *b, size_t n)
 {
+  if (! mp_delegate) {
+    return;
+  }
+
   if (m_as_text) {
     //  skip CR, but replace LF by CRLF -> this will normalize the line terminators to CRLF
     while (n > 0) {
@@ -825,7 +835,9 @@ OutputStream::seek (size_t pos)
 {
   flush ();
 
-  mp_delegate->seek (pos);
+  if (mp_delegate) {
+    mp_delegate->seek (pos);
+  }
   m_pos = pos;
 }
 

src/tl/tl/tlStream.h

@@ -1033,6 +1033,11 @@ public:
    */
   virtual ~OutputStream ();
 
+  /**
+   *  @brief Closes the stream - after closing, the stream can't be accessed anymore
+   */
+  void close ();
+
   /** 
    *  @brief This is the outer write method to call
    *  
@@ -1108,7 +1113,7 @@ public:
    */
   bool supports_seek () const
   {
-    return mp_delegate->supports_seek ();
+    return mp_delegate != 0 && mp_delegate->supports_seek ();
   }
 
   /**