CMake: Harden construction of QML import paths for qmlimportscanner

In certain cases where QT6_INSTALL_PREFIX/qml might not exist, we
wouldn't add the -importPath argument itself, but would still try to
add import paths, which would then confuse qmlimportscanner and
trigger an error.
 qmlimportscanner: Invalid argument: ...

Make sure to prepend -importPath for each passed import path.

Task-number: QTBUG-96232
Task-number: QTBUG-106431
Change-Id: Iae2b02a0b50e75a297df8fbaf0427df2b6b30c93
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
(cherry picked from commit 300074edaacdad3f2ffacb87c3e718db620c564a)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 12 insertions, 10 deletions

diff --git a/src/qml/Qt6QmlMacros.cmake b/src/qml/Qt6QmlMacros.cmake
index dcf6478399..79d13bc6f8 100644
--- a/src/qml/Qt6QmlMacros.cmake
+++ b/src/qml/Qt6QmlMacros.cmake
@@ -2399,7 +2399,7 @@ but this file does not exist.  Possible reasons include:
 ")
     endif()
 
-    # Find QML import paths.
+    # Find Qt provided QML import paths.
     if("${_qt_additional_packages_prefix_paths}" STREQUAL "")
         # We have one installation prefix for all Qt modules. Add the "<prefix>/qml" directory.
         set(qml_import_paths "${QT6_INSTALL_PREFIX}/${QT6_INSTALL_QML}")
@@ -2415,11 +2415,6 @@ but this file does not exist.  Possible reasons include:
         endforeach()
     endif()
 
-    # Construct the -importPath arguments.
-    set(import_path_arguments)
-    foreach(path IN LISTS qml_import_paths)
-        list(APPEND import_path_arguments -importPath ${path})
-    endforeach()
 
     # Run qmlimportscanner to generate the cmake file that records the import entries
     get_target_property(target_source_dir ${target} SOURCE_DIR)
@@ -2433,7 +2428,6 @@ but this file does not exist.  Possible reasons include:
         -rootPath "${target_source_dir}"
         -cmake-output
         -output-file "${imports_file}"
-        ${import_path_arguments}
     )
     get_target_property(qml_import_path ${target} QT_QML_IMPORT_PATH)
 
@@ -2444,18 +2438,26 @@ but this file does not exist.  Possible reasons include:
     # Facilitate self-import so we can find the qmldir file
     get_target_property(module_out_dir ${target} QT_QML_MODULE_OUTPUT_DIRECTORY)
     if(module_out_dir)
-        list(APPEND cmd_args "${module_out_dir}")
+        list(APPEND qml_import_paths "${module_out_dir}")
     endif()
 
     # Find qmldir files we copied to the build directory
     if(NOT "${QT_QML_OUTPUT_DIRECTORY}" STREQUAL "")
         if(EXISTS "${QT_QML_OUTPUT_DIRECTORY}")
-            list(APPEND cmd_args "${QT_QML_OUTPUT_DIRECTORY}")
+            list(APPEND qml_import_paths "${QT_QML_OUTPUT_DIRECTORY}")
         endif()
     else()
-        list(APPEND cmd_args "${CMAKE_CURRENT_BINARY_DIR}")
+        list(APPEND qml_import_paths "${CMAKE_CURRENT_BINARY_DIR}")
     endif()
 
+    # Construct the -importPath arguments.
+    set(import_path_arguments)
+    foreach(path IN LISTS qml_import_paths)
+        list(APPEND import_path_arguments -importPath ${path})
+    endforeach()
+
+    list(APPEND cmd_args ${import_path_arguments})
+
     # All of the module's .qml files will be listed in one of the generated
     # .qrc files, so there's no need to list the files individually. We provide
     # the .qrc files instead because they have the additional information for