Another attempt trying to fix the DLL load issue for pya on Windows - force-load all DLL that are needed by pyacore into the app before importing the module

src/klayout_main/klayout_main/klayout.cc

@@ -65,6 +65,8 @@
 # include "gsiQtDesignerExternals.h"
 # include "gsiQtUiToolsExternals.h"
 
+//  pulls in the Qt GSI binding modules - need to be force loaded so they are available
+//  the pya Python module (Python >= 3.8 does not recognize DLL paths on Windows)
 FORCE_LINK_GSI_QTCORE
 FORCE_LINK_GSI_QTGUI
 FORCE_LINK_GSI_QTWIDGETS

src/klayout_main/klayout_main/klayout_main.pro

@@ -25,52 +25,3 @@ INCLUDEPATH += $$DOC_INC $$ICONS_INC $$QTBASIC_INC
 DEPENDPATH += $$DOC_INC $$ICONS_INC $$QTBASIC_INC
 
 LIBS += -lklayout_doc -lklayout_icons
-
-equals(HAVE_QTBINDINGS, "1") {
-
-  LIBS += -lklayout_qtbasic -lklayout_QtGui
-
-  !equals(HAVE_QT_XML, "0") {
-    LIBS += -lklayout_QtXml
-  }
-  !equals(HAVE_QT_NETWORK, "0") {
-    LIBS += -lklayout_QtNetwork
-  }
-  !equals(HAVE_QT_SQL, "0") {
-    LIBS += -lklayout_QtSql
-  }
-  !equals(HAVE_QT_DESIGNER, "0") {
-    LIBS += -lklayout_QtDesigner
-  }
-  !equals(HAVE_QT_UITOOLS, "0") {
-    LIBS += -lklayout_QtUiTools
-  }
-
-  greaterThan(QT_MAJOR_VERSION, 4) {
-
-    LIBS += -lklayout_QtWidgets
-
-    !equals(HAVE_QT_MULTIMEDIA, "0") {
-      LIBS += -lklayout_QtMultimedia
-    }
-    !equals(HAVE_QT_PRINTSUPPORT, "0") {
-      LIBS += -lklayout_QtPrintSupport
-    }
-    !equals(HAVE_QT_SVG, "0") {
-      LIBS += -lklayout_QtSvg
-    }
-    !equals(HAVE_QT_XML, "0") {
-      LIBS += -lklayout_QtXmlPatterns
-    }
-
-  }
-
-  greaterThan(QT_MAJOR_VERSION, 5) {
-
-    LIBS += -lklayout_QtCore5Compat
-    LIBS -= -lklayout_QtXmlPatterns
-    LIBS -= -lklayout_QtDesigner
-
-  }
-
-}

src/pya/pya/pya.cc

@@ -326,18 +326,6 @@ PythonInterpreter::PythonInterpreter (bool embedded)
     tl::warn << tl::to_string (tr ("Unable to find built-in Python module library path"));
   }
 
-  //  Supply a DLL load path for certain Python versions and on Windows
-  define_variable ("__klayout_dll_path", tl::dirname (app_path));
-  //  NOTE: there is no API I know of ...
-  eval_string (
-    "import os\n"
-    "try:\n"
-    "  global __klayout_dll_path\n"
-    "  os.add_dll_directory(__klayout_dll_path)\n"
-    "except:\n"
-    "  pass\n"    //  on Windows or older versions of Python
-  );
-
   //  Import the pya module
   PyObject *pya_module = PyImport_ImportModule (pya_module_name);
   if (pya_module == NULL) {

src/unit_tests/unit_test_main.cc

@@ -80,6 +80,40 @@
 #  include "lvsForceLink.h"
 #endif
 
+#if defined(HAVE_QTBINDINGS)
+
+//  pulls in the Qt GSI binding modules - need to be force loaded so they are available
+//  the pya Python module (Python >= 3.8 does not recognize DLL paths on Windows)
+# include "gsiQtGuiExternals.h"
+# include "gsiQtWidgetsExternals.h"
+# include "gsiQtCoreExternals.h"
+# include "gsiQtMultimediaExternals.h"
+# include "gsiQtPrintSupportExternals.h"
+# include "gsiQtXmlExternals.h"
+# include "gsiQtXmlPatternsExternals.h"
+# include "gsiQtSqlExternals.h"
+# include "gsiQtSvgExternals.h"
+# include "gsiQtNetworkExternals.h"
+# include "gsiQtDesignerExternals.h"
+# include "gsiQtUiToolsExternals.h"
+
+FORCE_LINK_GSI_QTCORE
+FORCE_LINK_GSI_QTGUI
+FORCE_LINK_GSI_QTWIDGETS
+FORCE_LINK_GSI_QTMULTIMEDIA
+FORCE_LINK_GSI_QTPRINTSUPPORT
+FORCE_LINK_GSI_QTXML
+FORCE_LINK_GSI_QTXMLPATTERNS
+FORCE_LINK_GSI_QTDESIGNER
+FORCE_LINK_GSI_QTNETWORK
+FORCE_LINK_GSI_QTSQL
+FORCE_LINK_GSI_QTSVG
+FORCE_LINK_GSI_QTUITOOLS
+
+#else
+# define QT_EXTERNAL_BASE(x)
+#endif
+
 static int main_cont (int &argc, char **argv);
 
 #ifdef _WIN32 // for VC++

src/with_all_libs.pri

@@ -29,6 +29,55 @@ equals(HAVE_PYTHON, "1") {
   LIBS += -lklayout_pyastub
 }
 
+equals(HAVE_QTBINDINGS, "1") {
+
+  LIBS += -lklayout_qtbasic -lklayout_QtGui
+
+  !equals(HAVE_QT_XML, "0") {
+    LIBS += -lklayout_QtXml
+  }
+  !equals(HAVE_QT_NETWORK, "0") {
+    LIBS += -lklayout_QtNetwork
+  }
+  !equals(HAVE_QT_SQL, "0") {
+    LIBS += -lklayout_QtSql
+  }
+  !equals(HAVE_QT_DESIGNER, "0") {
+    LIBS += -lklayout_QtDesigner
+  }
+  !equals(HAVE_QT_UITOOLS, "0") {
+    LIBS += -lklayout_QtUiTools
+  }
+
+  greaterThan(QT_MAJOR_VERSION, 4) {
+
+    LIBS += -lklayout_QtWidgets
+
+    !equals(HAVE_QT_MULTIMEDIA, "0") {
+      LIBS += -lklayout_QtMultimedia
+    }
+    !equals(HAVE_QT_PRINTSUPPORT, "0") {
+      LIBS += -lklayout_QtPrintSupport
+    }
+    !equals(HAVE_QT_SVG, "0") {
+      LIBS += -lklayout_QtSvg
+    }
+    !equals(HAVE_QT_XML, "0") {
+      LIBS += -lklayout_QtXmlPatterns
+    }
+
+  }
+
+  greaterThan(QT_MAJOR_VERSION, 5) {
+
+    LIBS += -lklayout_QtCore5Compat
+    LIBS -= -lklayout_QtXmlPatterns
+    LIBS -= -lklayout_QtDesigner
+
+  }
+
+}
+
 equals(HAVE_RUBY, "1") {
   # DRC is only available with Ruby
   INCLUDEPATH += $$DRC_INC $$LVS_INC