qt5base-lts/cmake/QtPlugins.cmake.in
Craig Scott 5807e1ae81 Add plugins to Qt tools and executables for static builds
In static builds, we cannot allow any part of the main build to make a
call to find_package(Qt6...) where such a call may load a
Qt6*Plugins.cmake file. That would add additional dependencies to the
main module targets, setting up a circular dependency in the set of
*Config.cmake files which cannot be resolved. This scenario would be
triggered by per-repo builds or user projects.

But Qt's tools and other executables still need to load some plugins
in static builds. Sometimes a platform plugin may be enough, other
times we may want all supportable plugins (e.g. Qt Designer).
Therefore, add all plugins we can identify as relevant for an
executable that is part of the Qt build, but add them directly to the
executable without affecting the linking relationships between the
main module libraries.

Also remove the now unnecessary check for QT_BUILD_PROJECT_NAME in
top level builds because there should be no difference between per-repo
and top level builds any more (as far as linking static plugins is
concerned).

Examples that build as part of the main build will still build
successfully after this change, but they will not run if they require
a platform plugin. Examples need to be moved out to a separate build
where they can call find_package(Qt6) without QT_NO_CREATE_TARGETS
set to TRUE to be runnable (see QTBUG-90820).

Fixes: QTBUG-91915
Pick-to: 6.1
Change-Id: I8088baddb54e394ca111b103313596d6743570ba
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
2021-03-23 11:15:33 +11:00

154 lines
6.5 KiB
CMake

include_guard(DIRECTORY)
@QT_MODULE_PLUGIN_INCLUDES@
# Use a function to hide all the temporary variables we use so they don't leak
# out into the consuming scope
function(__qt_internal_add_static_plugins_once)
set(_module_target "@INSTALL_CMAKE_NAMESPACE@::@QT_MODULE@")
set(_qt_plugins "")
# Properties can't be set on aliased targets, so make sure to unalias the target. This is needed
# when Qt examples are built as part of the Qt build itself.
get_target_property(_aliased_target ${_module_target} ALIASED_TARGET)
if(_aliased_target)
set(_module_target ${_aliased_target})
endif()
# Include all PluginConfig.cmake files and update the QT_PLUGINS property of the module.
file(GLOB _qt_plugin_config_files "${CMAKE_CURRENT_LIST_DIR}/@INSTALL_CMAKE_NAMESPACE@*PluginConfig.cmake")
foreach(_config_file ${_qt_plugin_config_files})
string(REGEX REPLACE "^.*/@INSTALL_CMAKE_NAMESPACE@(.*Plugin)Config.cmake$" "\\1" _qt_plugin "${_config_file}")
include("${_config_file}")
list(APPEND _qt_plugins ${_qt_plugin})
endforeach()
set_property(TARGET ${_module_target} PROPERTY QT_PLUGINS ${_qt_plugins})
get_target_property(_have_added_plugins_already ${_module_target} __qt_internal_plugins_added)
if(_have_added_plugins_already)
return()
endif()
set(_default_plugins_are_enabled "$<NOT:$<STREQUAL:$<GENEX_EVAL:$<TARGET_PROPERTY:QT_DEFAULT_PLUGINS>>,0>>")
set(_manual_plugins_genex "$<GENEX_EVAL:$<TARGET_PROPERTY:QT_PLUGINS>>")
set(_no_plugins_genex "$<GENEX_EVAL:$<TARGET_PROPERTY:QT_NO_PLUGINS>>")
# Plugin genex marker for prl processing.
set(_is_plugin_marker_genex "$<BOOL:QT_IS_PLUGIN_GENEX>")
# 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 ${_plugin_target} has no class name, skipping.")
continue()
endif()
get_target_property(_plugin_type "${_plugin_target}" QT_PLUGIN_TYPE)
if(NOT _plugin_type)
message("Warning: plugin ${_plugin_target} has no type ('${_plugin_type}'), skipping.")
continue()
endif()
list(APPEND "QT_ALL_PLUGINS_FOUND_BY_FIND_PACKAGE_${_plugin_type}" "${target}")
set("QT_ALL_PLUGINS_FOUND_BY_FIND_PACKAGE_${_plugin_type}"
"${QT_ALL_PLUGINS_FOUND_BY_FIND_PACKAGE_${_plugin_type}}"
PARENT_SCOPE
)
set(_plugin_is_default "$<TARGET_PROPERTY:${_plugin_target},QT_DEFAULT_PLUGIN>")
# INCLUDE
set(_plugin_is_whitelisted "$<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,
# which ensures that no plug-in will be supported unless explicitly re-added afterwards.
string(CONCAT _plugin_is_not_blacklisted
"$<AND:"
"$<NOT:" # EXCLUDE
"$<IN_LIST:${_plugin_target},${_no_plugins_genex}>"
">,"
"$<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_${_plugin_type}>>>"
">"
)
# Support INCLUDE_BY_TYPE
string(CONCAT _plugin_is_in_type_whitelist
"$<IN_LIST:"
"${_plugin_target},"
"$<GENEX_EVAL:"
"$<TARGET_PROPERTY:QT_PLUGINS_${_plugin_type}>"
">"
">"
)
string(CONCAT _plugin_versionless_is_in_type_whitelist
"$<IN_LIST:"
"${_plugin_target_versionless},"
"$<GENEX_EVAL:"
"$<TARGET_PROPERTY:QT_PLUGINS_${_plugin_type}>"
">"
">"
)
# Complete condition that defines whether a static plugin is linked
string(CONCAT _plugin_condition
"$<BOOL:$<AND:"
"${_is_plugin_marker_genex},"
"$<OR:"
"${_plugin_is_whitelisted},"
"${_plugin_versionless_is_whitelisted},"
"${_plugin_is_in_type_whitelist},"
"${_plugin_versionless_is_in_type_whitelist},"
"$<AND:"
"${_default_plugins_are_enabled},"
"${_plugin_is_default},"
"${_plugin_is_not_blacklisted}"
">"
">"
">>"
)
# If this condition is true, we link against the plug-in
set(_plugin_genex "$<${_plugin_condition}:${_plugin_target}>")
target_link_libraries(${_module_target} INTERFACE "${_plugin_genex}")
set(_generated_qt_plugin_file_name
"${CMAKE_CURRENT_BINARY_DIR}/qt_@QT_MODULE@_${target}.cpp")
set(_generated_qt_plugin_file_content "#include <QtPlugin>\nQ_IMPORT_PLUGIN(${_classname})")
# Generate a source file to import that plug-in. Be careful not to
# update the timestamp of the generated file if we are not going to
# change anything. Otherwise we will trigger CMake's autogen to re-run
# and executables will then need to at least relink.
set(need_write TRUE)
if(EXISTS ${_generated_qt_plugin_file_name})
file(READ ${_generated_qt_plugin_file_name} old_contents)
if(old_contents STREQUAL "${_generated_qt_plugin_file_content}")
set(need_write FALSE)
endif()
endif()
if(need_write)
file(WRITE "${_generated_qt_plugin_file_name}"
"${_generated_qt_plugin_file_content}")
endif()
target_sources(${_module_target} INTERFACE
"$<${_plugin_condition}:${_generated_qt_plugin_file_name}>")
endforeach()
set_target_properties(${_module_target} PROPERTIES __qt_internal_plugins_added TRUE)
endfunction()
if(NOT @BUILD_SHARED_LIBS@ AND NOT QT_NO_CREATE_TARGETS)
__qt_internal_add_static_plugins_once()
endif()