“Spoofax Configuration Warning” also appears if someone has a deployed Spoofax plugin installed (without having Spoofax itself installed).

Submitted by Oskar van Rest on 17 February 2013 at 00:47

Isn’t that intentional? Deployed Spoofax plugins probably also need those settings to run correctly. Having a way to turn the message off if the language developer really does not want it would be good though.

My experience so far is that deployed plugins work fine if they are based on a ctree, but need the extra settings if they are based on a jar.
However, I have only tried this with very small languages so I’m not sure if this always holds.

Fixed with https://github.com/metaborg/spoofax/pull/10

Add jvm opts: -Xmx512m to your editor/yourlang.main.esv.

This sets the maximum heap size required for your language to 512m. If there are no other languages loaded that require a higher maximum heap size, the configuration warning won’t appear since Eclipse by default starts up with -Xmx512m or -Xmx1024m (>= -Xmx512m).

Also, there is the -Xss option to set the stack size. By default, eclipse.ini does not specify a stack size. A default stack size is chosen, which is platform specific: https://docs.oracle.com/cd/E13150_01/jrockit_jvm/jrockit/jrdocs/refman/optionX.html#wp1024112
Leaving away the -Xss option in editor/yourlang.main.esv means that your language does not require more than the default stack size. The configuration warning will therefore only appear if at least one of the loaded languages has the -Xss option enabled, in which case eclipse.ini should be configured with the highest required stack size among the languages. The configuration warning will tell what the highest value is.