xT: clean up Windows and Mac deployment

xT/CMakeLists.txt

@@ -1,4 +1,5 @@
 # As per Qt 6.8 documentation, at least 3.16 is necessary
+# CMake 3.21 has RUNTIME_DEPENDENCY_SET.
 cmake_minimum_required (VERSION 3.21.1)
 
 file (READ ../xK-version project_version)
@@ -68,8 +69,9 @@ else ()
 
 		set (resource_file "${PROJECT_BINARY_DIR}/xT.rc")
 		list (APPEND project_sources "${resource_file}")
+		# Qt specifically looks up IDI_ICON1 and nothing else.
 		add_custom_command (OUTPUT "${resource_file}"
-			COMMAND ${CMAKE_COMMAND} -E echo "1 ICON \"xT.ico\""
+			COMMAND ${CMAKE_COMMAND} -E echo "IDI_ICON1 ICON \"xT.ico\""
 				> ${resource_file} VERBATIM)
 		set_property (SOURCE "${resource_file}"
 			APPEND PROPERTY OBJECT_DEPENDS ${icon_ico})
@@ -110,13 +112,24 @@ if (ANDROID)
 	install (TARGETS xT DESTINATION .)
 elseif (APPLE OR WIN32)
 	install (TARGETS xT
+		RUNTIME_DEPENDENCY_SET dependencies_xT
 		BUNDLE DESTINATION .
 		RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
-	# XXX: QTBUG-127075, which can be circumvented by manually running
-	# macdeployqt on xT.app before the install.
+	if (WIN32)
+		install (RUNTIME_DEPENDENCY_SET dependencies_xT DIRECTORIES $ENV{PATH}
+			PRE_EXCLUDE_REGEXES "api-ms-win-.*"
+			POST_EXCLUDE_REGEXES ".*[/\\]system32[/\\].*")
+	endif ()
+
 	qt_generate_deploy_app_script (TARGET xT OUTPUT_SCRIPT deploy_xT)
 	install (SCRIPT "${deploy_xT}")
+
+	# At least with Homebrew Qt, you will get QTBUG-127075,
+	# which can be circumvented by running macdeployqt twice.
+	if (APPLE)
+		install (SCRIPT "${deploy_xT}")
+	endif ()
 else ()
 	install (TARGETS xT DESTINATION ${CMAKE_INSTALL_BINDIR})
 	install (FILES ../LICENSE DESTINATION ${CMAKE_INSTALL_DOCDIR})
@@ -129,26 +142,6 @@ else ()
 		DESTINATION ${CMAKE_INSTALL_DATADIR}/applications)
 endif ()
 
-# Within MSYS2, windeployqt doesn't copy the compiler runtime,
-# which is always linked dynamically by the Qt binaries.
-# TODO(p): Consider whether or not to use MSYS2 to cross-compile, and how.
-if (WIN32)
-	install (CODE [=[
-	set (bindir "${CMAKE_INSTALL_PREFIX}/bin")
-	execute_process (COMMAND cygpath -m /
-		OUTPUT_VARIABLE cygroot OUTPUT_STRIP_TRAILING_WHITESPACE)
-	if (cygroot)
-		execute_process (COMMAND ldd "${bindir}/xT.exe"
-			OUTPUT_VARIABLE ldd_output OUTPUT_STRIP_TRAILING_WHITESPACE)
-		string (REGEX MATCHALL " /mingw64/bin/[^ ]+ " libs "${ldd_output}")
-		foreach (lib ${libs})
-			string (STRIP "${lib}" lib)
-			file (COPY "${cygroot}${lib}" DESTINATION "${bindir}")
-		endforeach()
-	endif ()
-	]=])
-endif ()
-
 # CPack
 set (CPACK_PACKAGE_VENDOR "Premysl Eric Janouch")
 set (CPACK_PACKAGE_CONTACT "Přemysl Eric Janouch <p@janouch.name>")