CMake: Deprecate some android public APIs

Deprecate usage of:
 - qt_android_add_apk_target
 - qt_android_apply_arch_suffix
 - qt_android_generate_deployment_settings

when used by user projects directly. Instead, projects should use
qt_add_executable / qt_add_library.

Show a deprecation warning when the commands are used directly.
The deprecation warnings can be silenced using cmake's
-Wno-deprecated command line option.

To detect non-direct usage from inside our own function
implementations, we set some target properties which are then read to
decide whether to show the message.

Pick-to: 6.5
Fixes: QTBUG-108508
Change-Id: Ib039cc5f3a01c2276173abb1e43f4eed216d0170
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>

src/corelib/Qt6AndroidMacros.cmake

@@ -73,6 +73,17 @@ function(qt6_android_generate_deployment_settings target)
         _qt_is_android_generate_deployment_settings_called TRUE
     )
 
+    get_target_property(android_executable_finalizer_called
+        ${target} _qt_android_executable_finalizer_called)
+
+    if(android_executable_finalizer_called)
+        # Don't show deprecation when called by our own function implementations.
+    else()
+        message(DEPRECATION
+            "Calling qt_android_generate_deployment_settings directly is deprecated since Qt 6.5. "
+            "Use qt_add_executable instead.")
+    endif()
+
     get_target_property(target_type ${target} TYPE)
 
     if (NOT "${target_type}" STREQUAL "MODULE_LIBRARY")
@@ -327,6 +338,16 @@ if(NOT QT_NO_CREATE_VERSIONLESS_FUNCTIONS)
 endif()
 
 function(qt6_android_apply_arch_suffix target)
+    get_target_property(called_from_qt_impl
+        ${target} _qt_android_apply_arch_suffix_called_from_qt_impl)
+    if(called_from_qt_impl)
+        # Don't show deprecation when called by our own function implementations.
+    else()
+        message(DEPRECATION
+            "Calling qt_android_apply_arch_suffix directly is deprecated since Qt 6.5. "
+            "Use qt_add_executable or qt_add_library instead.")
+    endif()
+
     get_target_property(target_type ${target} TYPE)
     if (target_type STREQUAL "SHARED_LIBRARY" OR target_type STREQUAL "MODULE_LIBRARY")
         set_property(TARGET "${target}" PROPERTY SUFFIX "_${CMAKE_ANDROID_ARCH_ABI}.so")
@@ -349,6 +370,17 @@ function(qt6_android_add_apk_target target)
         return()
     endif()
 
+    get_target_property(android_executable_finalizer_called
+        ${target} _qt_android_executable_finalizer_called)
+
+    if(android_executable_finalizer_called)
+        # Don't show deprecation when called by our own function implementations.
+    else()
+        message(DEPRECATION
+            "Calling qt_android_add_apk_target directly is deprecated since Qt 6.5. "
+            "Use qt_add_executable instead.")
+    endif()
+
     get_target_property(deployment_file ${target} QT_ANDROID_DEPLOYMENT_SETTINGS_FILE)
     if (NOT deployment_file)
         message(FATAL_ERROR "Target ${target} is not a valid android executable target\n")
@@ -1198,6 +1230,8 @@ endfunction()
 # package for the executable 'target'. The function is added to the finalizer list of the Core
 # module and is executed implicitly when configuring user projects.
 function(_qt_internal_android_executable_finalizer target)
+    set_property(TARGET ${target} PROPERTY _qt_android_executable_finalizer_called TRUE)
+
     _qt_internal_configure_android_multiabi_target("${target}")
     qt6_android_generate_deployment_settings("${target}")
     qt6_android_add_apk_target("${target}")

src/corelib/Qt6CoreMacros.cmake

@@ -580,6 +580,8 @@ function(_qt_internal_create_executable target)
         set_property(TARGET "${target}" PROPERTY CXX_VISIBILITY_PRESET default)
         set_property(TARGET "${target}" PROPERTY OBJC_VISIBILITY_PRESET default)
         set_property(TARGET "${target}" PROPERTY OBJCXX_VISIBILITY_PRESET default)
+        set_property(TARGET "${target}"
+                     PROPERTY _qt_android_apply_arch_suffix_called_from_qt_impl TRUE)
         qt6_android_apply_arch_suffix("${target}")
         set_property(TARGET "${target}" PROPERTY _qt_is_android_executable TRUE)
     else()
@@ -2282,6 +2284,8 @@ function(_qt_internal_add_library target)
     endif()
 
     if(ANDROID)
+        set_property(TARGET "${target}"
+                     PROPERTY _qt_android_apply_arch_suffix_called_from_qt_impl TRUE)
         qt6_android_apply_arch_suffix("${target}")
     endif()
 endfunction()

src/corelib/doc/src/cmake/qt_android_add_apk_target.qdoc

@@ -13,7 +13,7 @@
 \include cmake-find-package-core.qdocinc
 
 \cmakecommandsince 6.0
-\preliminarycmakecommand
+\warning This command is deprecated since Qt 6.5. Use \l qt_add_executable instead.
 \cmakecommandandroidonly
 
 \section1 Synopsis

src/corelib/doc/src/cmake/qt_android_apply_arch_suffix.qdoc

@@ -13,7 +13,8 @@
 \include cmake-find-package-core.qdocinc
 
 \cmakecommandsince 6.0
-\preliminarycmakecommand
+\warning This command is deprecated since Qt 6.5. Use \l qt_add_executable
+or \l qt_add_library instead.
 \cmakecommandandroidonly
 
 \section1 Synopsis

src/corelib/doc/src/cmake/qt_android_generate_deployment_settings.qdoc

@@ -13,7 +13,7 @@
 \include cmake-find-package-core.qdocinc
 
 \cmakecommandsince 6.0
-\preliminarycmakecommand
+\warning This command is deprecated since Qt 6.5. Use \l qt_add_executable instead.
 \cmakecommandandroidonly
 
 \section1 Synopsis