Fix qt_import_plugins compatibility with Qt 5

Handle versionless plugin names passed to qt_import_plugins.

Task-number: QTBUG-74137
Task-number: QTBUG-80477
Change-Id: Ic7fb6e54d2822c7eb58a7874b4a1c137f0c101d9
Reviewed-by: Qt CMake Build Bot
Reviewed-by: Cristian Adam <cristian.adam@qt.io>

2 files changed, 48 insertions, 5 deletions

diff --git a/cmake/QtPlugins.cmake.in b/cmake/QtPlugins.cmake.in
index 5e2352d6c1..91884302c6 100644
--- a/cmake/QtPlugins.cmake.in
+++ b/cmake/QtPlugins.cmake.in
@@ -34,6 +34,7 @@ if(NOT @BUILD_SHARED_LIBS@)
     # The code in here uses the properties defined in qt_import_plugins (Qt6CoreMacros.cmake)
     foreach(target @qt_plugins@)
         set(_plugin_target "@INSTALL_CMAKE_NAMESPACE@::${target}")
+        set(_plugin_target_versionless "Qt::${target}")
         get_target_property(_classname "${_plugin_target}" QT_PLUGIN_CLASS_NAME)
         if(NOT _classname)
           message("Warning: plugin ${_plugin_target} has no class name, skipping.")
@@ -52,6 +53,8 @@ if(NOT @BUILD_SHARED_LIBS@)
 
         # INCLUDE
         set(_plugin_is_whitelisted "$<IN_LIST:${_plugin_target},${_manual_plugins_genex}>")
+        set(_plugin_versionless_is_whitelisted
+            "$<IN_LIST:${_plugin_target_versionless},${_manual_plugins_genex}>")
 
         # Note: qt_import_plugins sets the QT_PLUGINS_${_plugin_type} to "-"
         # when excluding it with EXCLUDE_BY_TYPE,
@@ -61,7 +64,11 @@ if(NOT @BUILD_SHARED_LIBS@)
                 "$<NOT:" # EXCLUDE
                     "$<IN_LIST:${_plugin_target},${_no_plugins_genex}>"
                 ">,"
-                # excludes both plugins targeted by EXCLUDE_BY_TYPE and not included in INCLUDE_BY_TYPE
+                "$<NOT:"
+                    "$<IN_LIST:${_plugin_target_versionless},${_no_plugins_genex}>"
+                ">,"
+                # Excludes both plugins targeted by EXCLUDE_BY_TYPE and not included in
+                # INCLUDE_BY_TYPE.
                 "$<STREQUAL:,$<GENEX_EVAL:$<TARGET_PROPERTY:QT_PLUGINS_${_plugin_type}>>>"
             ">"
         )
@@ -75,6 +82,14 @@ if(NOT @BUILD_SHARED_LIBS@)
                 ">"
             ">"
         )
+        string(CONCAT _plugin_versionless_is_in_type_whitelist
+            "$<IN_LIST:"
+                "${_plugin_target_versionless},"
+                "$<GENEX_EVAL:"
+                    "$<TARGET_PROPERTY:QT_PLUGINS_${_plugin_type}>"
+                ">"
+            ">"
+        )
 
         # Complete condition that defines whether a static plugin is linked
         string(CONCAT _plugin_condition
@@ -82,7 +97,9 @@ if(NOT @BUILD_SHARED_LIBS@)
                 "${_build_allow_plugin_link_rules_genex},"
                 "$<OR:"
                     "${_plugin_is_whitelisted},"
+                    "${_plugin_versionless_is_whitelisted},"
                     "${_plugin_is_in_type_whitelist},"
+                    "${_plugin_versionless_is_in_type_whitelist},"
                     "$<AND:"
                         "${_default_plugins_are_enabled_wrapped},"
                         "${_plugin_is_default},"
diff --git a/src/corelib/Qt6CoreMacros.cmake b/src/corelib/Qt6CoreMacros.cmake
index ff1e1d1910..03be9488c6 100644
--- a/src/corelib/Qt6CoreMacros.cmake
+++ b/src/corelib/Qt6CoreMacros.cmake
@@ -478,10 +478,33 @@ function(add_qt_gui_executable target)
     endif()
 endfunction()
 
+function(_qt_get_plugin_name_with_version target out_var)
+    string(REGEX REPLACE "^Qt::(.+)" "Qt${QT_DEFAULT_MAJOR_VERSION}::\\1"
+           qt_plugin_with_version "${target}")
+    if(TARGET "${qt_plugin_with_version}")
+        set("${out_var}" "${qt_plugin_with_version}" PARENT_SCOPE)
+    else()
+        set("${out_var}" "" PARENT_SCOPE)
+    endif()
+endfunction()
+
 macro(_qt_import_plugin target plugin)
-    get_target_property(plugin_class_name "${plugin}" QT_PLUGIN_CLASS_NAME)
-    if(plugin_class_name)
-        set_property(TARGET "${target}" APPEND PROPERTY QT_PLUGINS "${plugin}")
+    set(_final_plugin_name "${plugin}")
+    if(NOT TARGET "${plugin}")
+        _qt_get_plugin_name_with_version("${plugin}" _qt_plugin_with_version_name)
+        if(TARGET "${_qt_plugin_with_version_name}")
+            set(_final_plugin_name "${_qt_plugin_with_version_name}")
+        endif()
+    endif()
+
+    if(NOT TARGET "${_final_plugin_name}")
+        message(
+            "Warning: plug-in ${_final_plugin_name} is not known to the current Qt installation.")
+    else()
+        get_target_property(_plugin_class_name "${_final_plugin_name}" QT_PLUGIN_CLASS_NAME)
+        if(_plugin_class_name)
+            set_property(TARGET "${target}" APPEND PROPERTY QT_PLUGINS "${plugin}")
+        endif()
     endif()
 endmacro()
 
@@ -535,7 +558,10 @@ function(qt6_import_plugins target)
                 message(FATAL_ERROR "qt_import_plugins: invalid syntax for INCLUDE_BY_TYPE")
             endif()
 
-            if(TARGET "${_arg}")
+            # Check if passed plugin target name is a version-less one, and make a version-full
+            # one.
+            _qt_get_plugin_name_with_version("${_arg}" qt_plugin_with_version)
+            if(TARGET "${_arg}" OR TARGET "${qt_plugin_with_version}")
                 set_property(TARGET "${target}" APPEND PROPERTY "QT_PLUGINS_${_current_type}" "${_arg}")
             else()
                 message("Warning: plug-in ${_arg} is not known to the current Qt installation.")