refactoring: replaced manual plugin registration with link-time plugin binding

pcbnew/eagle_plugin.cpp

@@ -2254,3 +2254,7 @@ bool EAGLE_PLUGIN::IsFootprintLibWritable( const wxString& aLibraryPath )
 }
 
 */
+
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::EAGLE, wxT("Eagle"), []() -> PLUGIN* { return new EAGLE_PLUGIN; } );
+};

pcbnew/github/github_plugin.cpp

@@ -594,6 +594,10 @@ void GITHUB_PLUGIN::remoteGetZip( const wxString& aRepoURL )
     }
 }
 
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::GITHUB, wxT("Github"), []() -> PLUGIN* { return new GITHUB_PLUGIN; } );
+};
+
 #if 0 && defined(STANDALONE)
 
 int main( int argc, char** argv )

pcbnew/gpcb_plugin.cpp

@@ -1141,3 +1141,7 @@ bool GPCB_PLUGIN::IsFootprintLibWritable( const wxString& aLibraryPath )
 
     return m_cache->IsWritable();
 }
+
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::GEDA_PCB, wxT("GEDA/Pcb"), []() -> PLUGIN* { return new GPCB_PLUGIN; } );
+};

pcbnew/io_mgr.cpp

@@ -60,35 +60,7 @@ PLUGIN* IO_MGR::PluginFind( PCB_FILE_T aFileType )
     // This implementation is subject to change, any magic is allowed here.
     // The public IO_MGR API is the only pertinent public information.
 
-    switch( aFileType )
+    return PLUGIN_REGISTRY::Instance()->Create( aFileType );
-    {
-    case LEGACY:
-        return new LEGACY_PLUGIN();
-
-    case KICAD_SEXP:
-        return new PCB_IO();
-
-    case EAGLE:
-        return new EAGLE_PLUGIN();
-
-    case PCAD:
-        return new PCAD_PLUGIN();
-
-    case GEDA_PCB:
-        return new GPCB_PLUGIN();
-
-    case GITHUB:
-#if defined(BUILD_GITHUB_PLUGIN)
-        return new GITHUB_PLUGIN();
-#else
-        THROW_IO_ERROR( "BUILD_GITHUB_PLUGIN not enabled in cmake build environment" );
-#endif
-
-    case FILE_TYPE_NONE:
-        return NULL;
-    }
-
-    return NULL;
 }
 
 
@@ -108,29 +80,17 @@ const wxString IO_MGR::ShowType( PCB_FILE_T aType )
     // text spellings.  If you change the spellings, you will obsolete
     // library tables, so don't do change, only additions are ok.
 
-    switch( aType )
+    const auto& plugins = PLUGIN_REGISTRY::Instance()->AllPlugins();
+
+    for( const auto& plugin : plugins )
     {
-    default:
+        if ( plugin.m_type == aType )
-        return wxString::Format( _( "Unknown PCB_FILE_T value: %d" ), aType );
+        {
-
+            return plugin.m_name;
-    case LEGACY:
-        return wxString( wxT( "Legacy" ) );
-
-    case KICAD_SEXP:
-        return wxString( wxT( "KiCad" ) );
-
-    case EAGLE:
-        return wxString( wxT( "Eagle" ) );
-
-    case PCAD:
-        return wxString( wxT( "P-Cad" ) );
-
-    case GEDA_PCB:
-        return wxString( wxT( "Geda-PCB" ) );
-
-    case GITHUB:
-        return wxString( wxT( "Github" ) );
         }
+    }
+
+    return wxString::Format( _( "Unknown PCB_FILE_T value: %d" ), aType );
 }
 
 
@@ -140,25 +100,15 @@ IO_MGR::PCB_FILE_T IO_MGR::EnumFromStr( const wxString& aType )
     // text spellings.  If you change the spellings, you will obsolete
     // library tables, so don't do change, only additions are ok.
 
-    if( aType == wxT( "KiCad" ) )
+    const auto& plugins = PLUGIN_REGISTRY::Instance()->AllPlugins();
-        return KICAD_SEXP;
 
-    if( aType == wxT( "Legacy" ) )
+    for( const auto& plugin : plugins )
-        return LEGACY;
+    {
-
+        if ( plugin.m_name == aType )
-    if( aType == wxT( "Eagle" ) )
+        {
-        return EAGLE;
+            return plugin.m_type;
-
+        }
-    if( aType == wxT( "P-Cad" ) )
+    }
-        return PCAD;
-
-    if( aType == wxT( "Geda-PCB" ) )
-        return GEDA_PCB;
-
-    if( aType == wxT( "Github" ) )
-        return GITHUB;
-
-    // wxASSERT( blow up here )
 
     return PCB_FILE_T( -1 );
 }

pcbnew/io_mgr.h

@@ -27,7 +27,7 @@
 
 #include <richio.h>
 #include <map>
-
+#include <functional>
 
 class BOARD;
 class PLUGIN;
@@ -65,6 +65,78 @@ public:
         FILE_TYPE_NONE
     };
 
+    /**
+     * Class PLUGIN_REGISTRY
+     * Holds a list of available plugins, created using a singleton REGISTER_PLUGIN object.
+     * This way, plugins can be added link-time.
+     */
+    class PLUGIN_REGISTRY
+    {
+        public:
+            struct ENTRY
+            {
+                PCB_FILE_T m_type;
+                std::function<PLUGIN*(void)> m_createFunc;
+                wxString m_name;
+            };
+
+            static PLUGIN_REGISTRY *Instance()
+            {
+                static PLUGIN_REGISTRY *self = nullptr;
+
+                if( !self )
+                {
+                    self = new PLUGIN_REGISTRY;
+                }
+                return self;
+            }
+
+            void Register( PCB_FILE_T aType, const wxString& aName, std::function<PLUGIN*(void)> aCreateFunc )
+            {
+                ENTRY ent;
+                ent.m_type = aType;
+                ent.m_createFunc = aCreateFunc;
+                ent.m_name = aName;
+                m_plugins.push_back( ent );
+            }
+
+            PLUGIN* Create( PCB_FILE_T aFileType ) const
+            {
+                for( auto& ent : m_plugins )
+                {
+                    if ( ent.m_type == aFileType )
+                    {
+                        return ent.m_createFunc();
+                    }
+                }
+                return nullptr;
+            }
+
+            const std::vector<ENTRY>& AllPlugins() const
+            {
+                return m_plugins;
+            }
+
+        private:
+            std::vector<ENTRY> m_plugins;
+    };
+
+    /**
+     * Class REGISTER_PLUGIN
+     * Registers a plugin. Declare as a static variable in an anonymous namespace.
+     * @param aType: type of the plugin
+     * @param aName: name of the file format
+     * @param aCreateFunc: function that creates a new object for the plugin.
+     */
+    struct REGISTER_PLUGIN
+    {
+         REGISTER_PLUGIN( PCB_FILE_T aType, const wxString& aName, std::function<PLUGIN*(void)> aCreateFunc )
+         {
+             PLUGIN_REGISTRY::Instance()->Register( aType, aName, aCreateFunc );
+         }
+    };
+
+
     /**
      * Function PluginFind
      * returns a PLUGIN which the caller can use to import, export, save, or load

pcbnew/kicad_plugin.cpp

@@ -2214,3 +2214,7 @@ bool PCB_IO::IsFootprintLibWritable( const wxString& aLibraryPath )
 
     return m_cache->IsWritable();
 }
+
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::KICAD_SEXP, wxT("KiCad"), []() -> PLUGIN* { return new PCB_IO; } );
+};

pcbnew/legacy_plugin.cpp

@@ -3505,3 +3505,7 @@ LEGACY_PLUGIN::~LEGACY_PLUGIN()
     delete m_cache;
     delete m_mapping;
 }
+
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::LEGACY, wxT("Legacy"), []() -> PLUGIN* { return new LEGACY_PLUGIN; } );
+};

pcbnew/pcad2kicadpcb_plugin/pcad_plugin.cpp

@@ -89,3 +89,7 @@ BOARD* PCAD_PLUGIN::Load( const wxString& aFileName, BOARD* aAppendToMe, const P
 
     return m_board;
 }
+
+namespace {
+    static IO_MGR::REGISTER_PLUGIN registerSelf( IO_MGR::PCAD, wxT("P-Cad"), []() -> PLUGIN* { return new PCAD_PLUGIN; } );
+};