This set of scripts permits you to add autowall (autotile) features to your game at runtime and is exclusive to GMS2. For GM:S 1.4, please see the original asset here.
All tilesets are based off of the built in GMS2 autotile configuration and so you can create maps in the room editor, and then use these scripts to change them at run time while maintaining the autowall features (destructible terrain, anyone?).
The asset also comes with a couple of template files for the autowall layout, which can be found in the "Included Files" section.