Antlr-mode can be found at the following url: http://antlr-mode.sourceforge.net/ . It is also packaged in the latest antlr release. Look in the extras directory.
It provides (taken from the website):
- Consistent Indentation. You do not have to insert or delete the correct amount of spaces or tabs manually to indent a line according to ANTLR’s coding style: just press TAB. It is even done automatically if you insert an ANTLR syntax symbol (one of :;|&(){}). Use the menu to indent all lines in a selected region. Syntax Highlighting. When enabled, this mode highlights grammar symbols (syntax symbols and keywords: bold black, rule references: dark blue, token references: dark orange, rule/token definition: bold blue) and the code in actions. See example.
- Code Browsing. Find the definition of a rule, token, or grammar class by using the Index menu, a keyboard command or selecting an entry in the speedbar frame. Fast Navigation. Move to the next or previous rule definition or to the beginning or end of the rule body by one or two key strokes.
- Action Visibility. Control the visibility of less important code like actions.
- Option Support. Insert or change one of ANTLR’s options by a using the menu or a keyboard command. This mode knows the options supported by ANTLR, their allowed values and the correct position where to insert the option (and the surrounding options{} if necessary).
- Tool Invocation. Run ANTLR from within Emacs and find the error position by selecting the error message via the mouse or a keyboard command.
- Makefile Creation. Show the makefile dependencies for all grammar and generated files in the current directory. For it, this mode considers the value of ANTLR’s language option, import/export vocabularies and grammar inheritance. See example.