DVT VHDL IDE User Guide
Rev. 19.1.39, 7 November 2019
The Eclipse platform provides a similar to autosaved backup files functionality (<name>.bak in win, <name>~ in emacs etc.). It is more elaborated, quite similar with revision control systems in capabilities (compare, multiple versions across time etc.)
To quote from the platform manual: "A local edit history of a file is maintained when you create or modify a file. Each time you edit and save the file, a copy is saved so that you can replace the current file with a previous edit or even restore a deleted file. You can also compare the contents of all the local edits. Each edit in the local history is uniquely represented by the date and time the file was saved. Only files have local history; projects and folders do not."
Some quick access hints:
Right click in the editor and chose Compare With/Replace With > Local History....