CMake: Provide way to register extra tool package dependencies

This is needed for qtwayland, where QtWaylandCompositor package should
call find_package(QtWaylandScanner) in the 'Tools' section of the
ModuleDependencies.cmake file, rather than the regular 'Qt' section.

This takes care of handling host path prefixes, to ensure that a host
package is found even when tools have also been cross-compiled via the
QT_BUILD_TOOLS_WHEN_CROSSCOMPILING option.

Task-number: QTBUG-83968
Change-Id: I4725a630214d053105fb6d2a0f7c5ff6128d13f9
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

2 files changed, 50 insertions, 2 deletions

diff --git a/cmake/QtFindPackageHelpers.cmake b/cmake/QtFindPackageHelpers.cmake
index 204222f58b..0ca585d1d4 100644
--- a/cmake/QtFindPackageHelpers.cmake
+++ b/cmake/QtFindPackageHelpers.cmake
@@ -165,7 +165,7 @@ macro(qt_find_package)
     endif()
 endmacro()
 
-# This function records a dependency between ${target_name} and ${dep_package_name}.
+# This function records a dependency between ${main_target_name} and ${dep_package_name}.
 # at the CMake package level.
 # E.g. The Tools package that provides the qtwaylandscanner target
 # needs to call find_package(WaylandScanner) (non-qt-package).
@@ -202,6 +202,44 @@ function(qt_record_extra_qt_package_dependency main_target_name dep_target_name
                                                              "${dep_package_version}")
 endfunction()
 
+# This function records a 'QtFooTools' package dependency for the ${main_target_name} target
+# onto the ${dep_package_name} tools package.
+# E.g. The QtWaylandCompositor package needs to call find_package(QtWaylandScannerTools).
+# main_target_name = WaylandCompositor
+# dep_package_name = Qt6WaylandScannerTools
+function(qt_record_extra_main_tools_package_dependency
+         main_target_name dep_package_name dep_package_version)
+    if(NOT TARGET "${main_target_name}")
+        qt_get_tool_target_name(main_target_name "${main_target_name}")
+    endif()
+    if (TARGET "${main_target_name}")
+        get_target_property(extra_packages "${main_target_name}"
+                            QT_EXTRA_TOOLS_PACKAGE_DEPENDENCIES)
+        if(NOT extra_packages)
+            set(extra_packages "")
+        endif()
+
+        list(APPEND extra_packages "${dep_package_name}\;${dep_package_version}")
+        set_target_properties("${main_target_name}" PROPERTIES QT_EXTRA_TOOLS_PACKAGE_DEPENDENCIES
+                                                               "${extra_packages}")
+    endif()
+endfunction()
+
+# This function records a 'QtFooTools' package dependency for the ${main_target_name} target
+# onto the ${dep_non_versioned_package_name} Tools package.
+# main_target_name = WaylandCompositor
+# dep_non_versioned_package_name = WaylandScannerTools
+# This is just a convenience function to avoid hardcoding the qtified version in the dep package
+# name.
+function(qt_record_extra_qt_main_tools_package_dependency main_target_name
+                                                          dep_non_versioned_package_name
+                                                          dep_package_version)
+    # WaylandScannerTools -> Qt6WaylandScannerTools.
+    qt_internal_module_info(qtfied_package_name "${dep_non_versioned_package_name}")
+    qt_record_extra_main_tools_package_dependency(
+        "${main_target_name}" "${qtfied_package_name_versioned}" "${dep_package_version}")
+endfunction()
+
 # This function stores the list of Qt modules a library depend on,
 # along with their version info, for usage in ${target}Depends.cmake file
 function(qt_register_target_dependencies target public_libs private_libs)
diff --git a/cmake/QtPostProcessHelpers.cmake b/cmake/QtPostProcessHelpers.cmake
index 42ad39ee5e..0da6d9e4c3 100644
--- a/cmake/QtPostProcessHelpers.cmake
+++ b/cmake/QtPostProcessHelpers.cmake
@@ -105,6 +105,16 @@ function(qt_internal_create_module_depends_file target)
     # ModuleDependencies.cmake.
     set(main_module_tool_deps "")
 
+    # Extra QtFooModuleTools packages to be added as dependencies to
+    # QtModuleDependencies.cmake. Needed for QtWaylandCompositor / QtWaylandClient.
+    if(NOT arg_HEADER_MODULE)
+        get_target_property(extra_tools_package_dependencies "${target}"
+                            QT_EXTRA_TOOLS_PACKAGE_DEPENDENCIES)
+        if(extra_tools_package_dependencies)
+            list(APPEND main_module_tool_deps "${extra_tools_package_dependencies}")
+        endif()
+    endif()
+
     qt_internal_get_qt_all_known_modules(known_modules)
 
     set(all_depends ${depends} ${public_depends})
@@ -144,7 +154,7 @@ function(qt_internal_create_module_depends_file target)
 
     # Add dependency to the main ModuleTool package to ModuleDependencies file.
     if(${target} IN_LIST QT_KNOWN_MODULES_WITH_TOOLS)
-        set(main_module_tool_deps
+        list(APPEND main_module_tool_deps
             "${INSTALL_CMAKE_NAMESPACE}${target}Tools\;${PROJECT_VERSION}")
     endif()