CMake: Add support for auto-importing plugins in CMake

This commit adds transitive dependencies to the plugins, so that a
sane set of default plugins get auto-imported when linking against a
module. It also provides a new function, qt5_import_plugins(), which
allows you to override the set of plugins that get imported. The decision
of whether or not to import a specific plugin is based on several custom
target properties and a very clever generator expression.

Note that this change only imports plugins on static Qt builds. It
does nothing on shared Qt builds, as the shared libraries already have
their own plugin import mechanism.

[ChangeLog][CMake] Added ability to auto-import non-qml plugins on
CMake builds

Task-number: QTBUG-38913
Task-number: QTBUG-76562
Change-Id: I2d6c8908b521cf6ba1ebbbc33a87cb7ddd9935cf
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

1 files changed, 34 insertions, 1 deletions

diff --git a/mkspecs/features/data/cmake/Qt5BasicConfig.cmake.in b/mkspecs/features/data/cmake/Qt5BasicConfig.cmake.in
index 2b7c1d28c4..7a599d30d5 100644
--- a/mkspecs/features/data/cmake/Qt5BasicConfig.cmake.in
+++ b/mkspecs/features/data/cmake/Qt5BasicConfig.cmake.in
@@ -397,6 +397,8 @@ if (NOT TARGET Qt5::$${CMAKE_MODULE_NAME})
     set_property(TARGET Qt5::$${CMAKE_MODULE_NAME} PROPERTY INTERFACE_QT_ENABLED_FEATURES $$join(QT.$${MODULE}.enabled_features, ";"))
     set_property(TARGET Qt5::$${CMAKE_MODULE_NAME} PROPERTY INTERFACE_QT_DISABLED_FEATURES $$join(QT.$${MODULE}.disabled_features, ";"))
 
+    set_property(TARGET Qt5::$${CMAKE_MODULE_NAME} PROPERTY QT_PLUGIN_TYPES \"$${CMAKE_MODULE_PLUGIN_TYPES}\")
+
     set(_Qt5$${CMAKE_MODULE_NAME}_PRIVATE_DIRS_EXIST TRUE)
     foreach (_Qt5$${CMAKE_MODULE_NAME}_PRIVATE_DIR ${Qt5$${CMAKE_MODULE_NAME}_OWN_PRIVATE_INCLUDE_DIRS})
         if (NOT EXISTS ${_Qt5$${CMAKE_MODULE_NAME}_PRIVATE_DIR})
@@ -504,7 +506,8 @@ if (NOT TARGET Qt5::$${CMAKE_MODULE_NAME})
 
     file(GLOB pluginTargets \"${CMAKE_CURRENT_LIST_DIR}/Qt5$${CMAKE_MODULE_NAME}_*Plugin.cmake\")
 
-    macro(_populate_$${CMAKE_MODULE_NAME}_plugin_properties Plugin Configuration PLUGIN_LOCATION)
+    macro(_populate_$${CMAKE_MODULE_NAME}_plugin_properties Plugin Configuration PLUGIN_LOCATION
+          IsDebugAndRelease)
         set_property(TARGET Qt5::${Plugin} APPEND PROPERTY IMPORTED_CONFIGURATIONS ${Configuration})
 
 !!IF isEmpty(CMAKE_PLUGIN_DIR_IS_ABSOLUTE)
@@ -516,6 +519,36 @@ if (NOT TARGET Qt5::$${CMAKE_MODULE_NAME})
         set_target_properties(Qt5::${Plugin} PROPERTIES
             \"IMPORTED_LOCATION_${Configuration}\" ${imported_location}
         )
+
+!!IF !isEmpty(CMAKE_STATIC_TYPE)
+        set(_static_deps
+            ${_Qt5${Plugin}_STATIC_${Configuration}_LIB_DEPENDENCIES}
+        )
+
+        if(NOT "${IsDebugAndRelease}")
+            set(_genex_condition \"1\")
+        else()
+            if("${Configuration}" STREQUAL "DEBUG")
+                set(_genex_condition \"$<CONFIG:Debug>\")
+            else()
+                set(_genex_condition \"$<NOT:$<CONFIG:Debug>>\")
+            endif()
+        endif()
+        if(_static_deps)
+            set(_static_deps_genex \"$<${_genex_condition}:${_static_deps}>\")
+            set_property(TARGET Qt5::${Plugin} APPEND PROPERTY INTERFACE_LINK_LIBRARIES
+                         \"${_static_deps_genex}\"
+            )
+        endif()
+
+        set(_static_link_flags \"${_Qt5${Plugin}_STATIC_${Configuration}_LINK_FLAGS}\")
+        if(NOT CMAKE_VERSION VERSION_LESS \"3.13\" AND _static_link_flags)
+            set(_static_link_flags_genex \"$<${_genex_condition}:${_static_link_flags}>\")
+            set_property(TARGET Qt5::${Plugin} APPEND PROPERTY INTERFACE_LINK_OPTIONS
+                \"${_static_link_flags_genex}\"
+            )
+        endif()
+!!ENDIF
     endmacro()
 
     if (pluginTargets)