antlr4 + gradle

[Tim Spriggs]

Hello!

  I'm attempting to create a somewhat complex grammar which uses lexical modes. I'm having a heck of a time getting gradle+antlr4 to build the following structure:

Foo.g4 (parser grammar)

FooLexer.g4 (lexer grammar with modes)

FooTokens.g4 (support grammar which is imported by FooLexer)

I've looked over many bug reports and possible work-arounds but haven't found anything that ultimately fixes my issue, thus I created a minimal repository [1] and created a corresponding issue [2]. It was suggested that I post here for support help so, here I am :)

  If anyone has any suggestions, I would appreciate them!

Thanks,

-Tim

[1] https://github.com/imoverclocked/antlr_bug

[2] https://github.com/antlr/antlr4/issues/2335

[Gerald Rosenberg]

Likely the errors -- or some of the errors -- stem from the Antlr tool treating (as it should) `Foo.g4` as a composite grammar.

To instead have it treated as a split grammar, need to rename `Foo.g4` to `FooParser.g4` and change the first line of the grammar to `parser grammar Foo ;`

[Tim Spriggs]

Hi Gerald,

I tried that but the difference between the parser name and the filename seems to be problematic:

  error(8): FooParser.g4:1:15: grammar name Foo and file name FooParser.g4 differ

However, using "parser grammar FooParser;" brings me back to the same set of issues and may obfuscate the results (eg: FooParserParser).

It seems the problem is understood in the bug report I filed but will not be accepted as a bug to the antlr tool so I'm going to just live with an obtuse work-around locally.

Thanks for the help!

-Tim