CMake: Add optional propagation argument to qt_add_win_app_sdk

This propagation is used for including header files and linking to
the Windows App SDK library.

Pick-to: 6.10
Task-number: QTBUG-124800
Change-Id: Ib5132de3bd673a57f55dda92381315070b6ecb99
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtPublicWindowsHelpers.cmake

@@ -8,6 +8,23 @@ function(qt6_add_win_app_sdk target)
         return()
     endif()
 
+    set(no_value_options INTERFACE PUBLIC PRIVATE)
+    set(single_value_options "")
+    set(multi_value_options "")
+    cmake_parse_arguments(PARSE_ARGV 1 arg
+        "${no_value_options}" "${single_value_options}" "${multi_value_options}"
+    )
+    if(arg_UNPARSED_ARGUMENTS)
+        message(FATAL_ERROR "Unexpected arguments: ${arg_UNPARSED_ARGUMENTS}")
+    endif()
+
+    set(propagation PRIVATE)
+    if(arg_PUBLIC)
+        set(propagation PUBLIC)
+    elseif(arg_INTERFACE)
+        set(propagation INTERFACE)
+    endif()
+
     if(CMAKE_SYSTEM_PROCESSOR STREQUAL "arm64" OR
        CMAKE_SYSTEM_PROCESSOR STREQUAL "ARM64")
         set(win_app_sdk_arch "arm64")
@@ -87,15 +104,15 @@ function(qt6_add_win_app_sdk target)
         endif()
     endif()
 
-    target_include_directories(${target} PRIVATE "${win_app_sdk_root}/include")
+    target_include_directories(${target} ${propagation} "${win_app_sdk_root}/include")
     target_include_directories(${target}
-                               PRIVATE "${generated_headers_path}")
+                               ${propagation} "${generated_headers_path}")
     target_link_directories(${target}
-                            PRIVATE "${win_app_sdk_root}/lib/win10-${win_app_sdk_arch}")
+                            ${propagation} "${win_app_sdk_root}/lib/win10-${win_app_sdk_arch}")
     target_link_directories(${target}
-                        PRIVATE "${win_app_sdk_root}/runtimes/win-${win_app_sdk_arch}/native")
+                        ${propagation} "${win_app_sdk_root}/runtimes/win-${win_app_sdk_arch}/native")
     target_link_libraries(${target}
-        PRIVATE Microsoft.WindowsAppRuntime.lib Microsoft.WindowsAppRuntime.Bootstrap.lib)
+        ${propagation} Microsoft.WindowsAppRuntime.lib Microsoft.WindowsAppRuntime.Bootstrap.lib)
 endfunction()
 
 if(NOT QT_NO_CREATE_VERSIONLESS_FUNCTIONS)

src/corelib/doc/src/cmake/qt_add_win_app_sdk.qdoc

@@ -16,7 +16,13 @@
 \section1 Synopsis
 
 \badcode
-qt_add_win_app_sdk(target)
+qt_add_win_app_sdk(<TARGET>)
+\endcode
+
+Since 6.10:
+
+\badcode
+qt_add_win_app_sdk(<TARGET> [<PROPAGATION>])
 \endcode
 
 \versionlessCMakeCommandsNote qt6_add_win_app_sdk()
@@ -24,7 +30,8 @@ qt_add_win_app_sdk(target)
 \section1 Description
 
 Adds Windows App SDK include files to the project, and links the necessary
-libraries to the given CMake target. Windows App SDK is provided as a \l{https://learn.microsoft.com/en-us/nuget/what-is-nuget}{NuGet}
+libraries to the given CMake target. Windows App SDK is provided as
+a \l{https://learn.microsoft.com/en-us/nuget/what-is-nuget}{NuGet}
 package so it can be easily used in managed apps. However, for unmanaged
 C++ applications we need header files.
 The function takes the following steps:
@@ -34,5 +41,43 @@ The function takes the following steps:
        \li Includes those header files and links the library to the given CMake target
 \endlist
 
+\section1 Arguments
+
+\c PROPAGATION
+
+Specifies the propagation visibility of include directories, link directories, and linked libraries
+for the target.
+This argument is passed directly to the following CMake commands:
+\list 1
+       \li target_include_directories()
+       \li target_link_directories()
+       \li target_link_libraries()
+\endlist
+
+It determines how these properties are applied to the target itself and whether they are propagated
+to other targets that link against it.
+\section2 Accepted values:
+\list 1
+       \li PRIVATE:
+        The settings (include directories, link directories, and linked libraries) are applied only
+        to the current target. They are not visible to targets that link against this one.
+        \li PUBLIC:
+        The settings are applied to the current target and are also propagated to any target that
+        links against it. Use this when the dependency is required both for building the target and
+        for its consumers.
+        \li INTERFACE:
+        The settings are not used when building the current target, but are propagated to targets
+        that link against it. This is typically used for header-only libraries or interface targets
+        that expose usage requirements without needing them for their own build.
+\endlist
+
+\section2 Notes
+\list 1
+       \li This argument is optional.
+       \li If omitted, the default behavior is equivalent to PRIVATE (or specify your actual default).
+       \li Use the appropriate propagation scope to accurately describe your target’s dependencies
+        and usage requirements.
+\endlist
+
 \warning This command is not supported on non-MSVC platforms.
 */