Hash symbol libraries per library rather than statically per cache type.

eeschema/sch_plugins/kicad/sch_sexpr_plugin.cpp

@@ -2230,11 +2230,6 @@ void SCH_SEXPR_PLUGIN::cacheLib( const wxString& aLibraryFileName, const PROPERT
         delete m_cache;
         m_cache = new SCH_SEXPR_PLUGIN_CACHE( aLibraryFileName );
 
-        // Because m_cache is rebuilt, increment SYMBOL_LIBS::s_modify_generation
-        // to modify the hash value that indicate symbol to symbol links
-        // must be updated.
-        SYMBOL_LIBS::IncrementModifyGeneration();
-
         if( !isBuffering( aProperties ) )
             m_cache->Load();
     }

eeschema/sch_plugins/legacy/sch_legacy_plugin.cpp

@@ -1963,11 +1963,6 @@ void SCH_LEGACY_PLUGIN::cacheLib( const wxString& aLibraryFileName, const PROPER
         delete m_cache;
         m_cache = new SCH_LEGACY_PLUGIN_CACHE( aLibraryFileName );
 
-        // Because m_cache is rebuilt, increment SYMBOL_LIBS::s_modify_generation
-        // to modify the hash value that indicate symbol to symbol links
-        // must be updated.
-        SYMBOL_LIBS::IncrementModifyGeneration();
-
         if( !isBuffering( aProperties ) )
             m_cache->Load();
     }
@@ -1994,7 +1989,7 @@ bool SCH_LEGACY_PLUGIN::isBuffering( const PROPERTIES* aProperties )
 int SCH_LEGACY_PLUGIN::GetModifyHash() const
 {
     if( m_cache )
-        return SCH_LEGACY_PLUGIN_CACHE::GetModifyHash();
+        return m_cache->GetModifyHash();
 
     // If the cache hasn't been loaded, it hasn't been modified.
     return 0;

eeschema/sch_plugins/sch_lib_plugin_cache.cpp

@@ -25,11 +25,8 @@
 #include <wx_filename.h>
 
 
-int SCH_LIB_PLUGIN_CACHE::m_modHash = 1;          // starts at 1 and goes up
-std::mutex SCH_LIB_PLUGIN_CACHE::m_modHashMutex;
-
-
 SCH_LIB_PLUGIN_CACHE::SCH_LIB_PLUGIN_CACHE( const wxString& aFullPathAndFileName ) :
+    m_modHash( 1 ),
     m_fileName( aFullPathAndFileName ),
     m_libFileName( aFullPathAndFileName ),
     m_isWritable( true ),
@@ -154,7 +151,7 @@ LIB_SYMBOL* SCH_LIB_PLUGIN_CACHE::removeSymbol( LIB_SYMBOL* aSymbol )
     m_symbols.erase( it );
     delete aSymbol;
     m_isModified = true;
-    SCH_LIB_PLUGIN_CACHE::IncrementModifyHash();
+    IncrementModifyHash();
     return firstChild;
 }
 
@@ -172,5 +169,5 @@ void SCH_LIB_PLUGIN_CACHE::AddSymbol( const LIB_SYMBOL* aSymbol )
 
     m_symbols[ name ] = const_cast< LIB_SYMBOL* >( aSymbol );
     m_isModified = true;
-    SCH_LIB_PLUGIN_CACHE::IncrementModifyHash();
+    IncrementModifyHash();
 }

eeschema/sch_plugins/sch_lib_plugin_cache.h

@@ -43,16 +43,16 @@ public:
     SCH_LIB_PLUGIN_CACHE( const wxString& aLibraryPath );
     virtual ~SCH_LIB_PLUGIN_CACHE();
 
-    static void IncrementModifyHash()
+    void IncrementModifyHash()
     {
-        std::lock_guard<std::mutex> mut( SCH_LIB_PLUGIN_CACHE::m_modHashMutex );
+        std::lock_guard<std::mutex> mut( m_modHashMutex );
-        SCH_LIB_PLUGIN_CACHE::m_modHash++;
+        m_modHash++;
     }
 
-    static int GetModifyHash()
+    int GetModifyHash()
     {
-        std::lock_guard<std::mutex> mut( SCH_LIB_PLUGIN_CACHE::m_modHashMutex );
+        std::lock_guard<std::mutex> mut( m_modHashMutex );
-        return SCH_LIB_PLUGIN_CACHE::m_modHash;
+        return m_modHash;
     }
 
     // Most all functions in this class throw IO_ERROR exceptions.  There are no
@@ -88,8 +88,8 @@ public:
 protected:
     LIB_SYMBOL* removeSymbol( LIB_SYMBOL* aAlias );
 
-    static int        m_modHash;      // Keep track of the modification status of the library.
+    int               m_modHash;      // Keep track of the modification status of the library.
-    static std::mutex m_modHashMutex;
+    std::mutex        m_modHashMutex;
 
     wxString          m_fileName;     // Absolute path and file name.
     wxFileName        m_libFileName;  // Absolute path and file name is required here.

eeschema/symbol_library.cpp

@@ -3,7 +3,7 @@
  *
  * Copyright (C) 2004-2016 Jean-Pierre Charras, jp.charras at wanadoo.fr
  * Copyright (C) 2008 Wayne Stambaugh <stambaughw@gmail.com>
- * Copyright (C) 2004-2021 KiCad Developers, see AUTHORS.txt for contributors.
+ * Copyright (C) 2004-2022 KiCad Developers, see AUTHORS.txt for contributors.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -45,10 +45,7 @@
 #include <wx/tokenzr.h>
 
 SYMBOL_LIB::SYMBOL_LIB( SCH_LIB_TYPE aType, const wxString& aFileName,
-                    SCH_IO_MGR::SCH_FILE_T aPluginType ) :
+                        SCH_IO_MGR::SCH_FILE_T aPluginType ) :
-    // start @ != 0 so each additional library added
-    // is immediately detectable, zero would not be.
-    m_mod_hash( SYMBOL_LIBS::GetModifyGeneration() ),
     m_pluginType( aPluginType )
 {
     type = aType;
@@ -75,8 +72,9 @@ SYMBOL_LIB::~SYMBOL_LIB()
 
 void SYMBOL_LIB::Save( bool aSaveDocFile )
 {
-    wxCHECK_RET( m_plugin != nullptr, wxString::Format( "no plugin defined for library `%s`.",
+    wxCHECK_RET( m_plugin != nullptr,
-                                                        fileName.GetFullPath() ) );
+                 wxString::Format( wxT( "no plugin defined for library `%s`." ),
+                                   fileName.GetFullPath() ) );
 
     PROPERTIES props;
 
@@ -409,28 +407,6 @@ void SYMBOL_LIBS::FindLibraryNearEntries( std::vector<LIB_SYMBOL*>& aCandidates,
 }
 
 
-int        SYMBOL_LIBS::s_modify_generation = 1;     // starts at 1 and goes up
-std::mutex SYMBOL_LIBS::s_generationMutex;
-
-
-int SYMBOL_LIBS::GetModifyHash()
-{
-    int hash = 0;
-
-    for( SYMBOL_LIBS::const_iterator it = begin();  it != end();  ++it )
-    {
-        hash += it->GetModHash();
-    }
-
-    // Rebuilding the cache (m_cache) does not change the GetModHash() value,
-    // but changes SYMBOL_LIBS::s_modify_generation.
-    // Take this change in account:
-    hash += SYMBOL_LIBS::GetModifyGeneration();
-
-    return hash;
-}
-
-
 void SYMBOL_LIBS::LibNamesAndPaths( PROJECT* aProject, bool doSave,
                                     wxString* aPaths, wxArrayString* aNames )
 {

eeschema/symbol_library.h

@@ -64,26 +64,7 @@ class SYMBOL_LIBS : public SYMBOL_LIBS_BASE, public PROJECT::_ELEM
 public:
     KICAD_T Type() override { return SYMBOL_LIBS_T; }
 
-    SYMBOL_LIBS()
+    SYMBOL_LIBS() {}
-    {
-        IncrementModifyGeneration();
-    }
-
-    static void IncrementModifyGeneration()
-    {
-        std::lock_guard<std::mutex> mut( SYMBOL_LIBS::s_generationMutex );
-        ++SYMBOL_LIBS::s_modify_generation;
-    }
-
-    static int GetModifyGeneration()
-    {
-        std::lock_guard<std::mutex> mut( SYMBOL_LIBS::s_generationMutex );
-        return SYMBOL_LIBS::s_modify_generation;
-    }
-
-    /// Return the modification hash for all libraries.  The value returned
-    /// changes on every library modification.
-    int GetModifyHash();
 
     /**
      * Allocate and adds a symbol library to the library list.
@@ -175,9 +156,6 @@ public:
                                  const wxString& aLibraryName = wxEmptyString );
 
     int GetLibraryCount() { return size(); }
-
-    static int        s_modify_generation;         ///< helper for GetModifyHash()
-    static std::mutex s_generationMutex;
 };