When using Antlr plugin and Idea plugin, generated sources are not seen by Idea, so “Make” menu option won’t work. The reason is that .java files are generated in build/generated-src/, but Idea plugin excludes the whole build/ directory. Idea does not see files inside it.
A good solution has been suggested on StackOverflow, where build/ directory is not excluded, instead all of its subdirectories except generated-src/ are. Maybe Idea plugin should detect Antlr plugin is loaded and do this by default?
I would suggest that additionally build/generated-src/antlr/main/ directory may be removed from Idea sourceDirs and added to generatedSourceDirs.