[Gradle 4.0.1][AntlrTask]Failed to generate grammar source when g4 files is placed at packages

[daniellansun]

When g4 files is placed at packages(e.g. package parrot whose path is src\main\antlr\parrot), generating grammar source fails because of tokens file not found.( The tokens file is generated to build\generated-src\antlr\main\parrot, but antlr4 will try to find the tokens file at build\generated-src\antlr\main\ )

D:\_APPS\git_apps\test-antlr-task>gradlew generateGrammarSource

> Task :generateGrammarSource
error(160): parrot\GroovyParser.g4:37:17: cannot find tokens file 'D:\_APPS\git_apps\test-antlr-task\build\generated-src\antlr\main\GroovyLexer.tokens'

Expected Behavior

Generate grammar source successfully.

Current Behavior

Fails to generate grammar source.

Context

Fails to generate grammar source.

Steps to Reproduce (for bugs)

1. check out https://github.com/danielsun1106/test-antlr-task/releases/tag/0.0.2
2. gradlew generateGrammarSource

Your Environment

Gradle 4.0.1

[big-guy]

@breskeby is this something that's configurable or look familiar?

[bot-plugin-portal]

I think this is a known limitation in the antlr4 support in gradle. @danielsun1106 can you try to add the package declaration to the grammar header via

@header {
    package parrot;
}

and check if that workaround is working for you?

[breskeby]

👆🏽 that was me

[daniellansun]

@gradlewaregitbot I gave it a try, but still failed.

[svanteschubert]

Unfortunately, I only got a workaround for Windows. There it works if you explicitly address the lexer and the parser in the command line arguments:

generateGrammarSource {
arguments += ["-no-listener", "-package", "parrot", "parrot/GroovyLexer.g4", "parrot/GroovyParser.g4"]
}

The generated sources will be created beyond
test-antlr-task-0.0.2\build\generated-src\antlr\main
without package name, BUT if you would compile them, they would be placed right where they belong under
build\classes\java\main\parrot
Therefore it is possible to add for instance an own Listener with the package.

It works with Java classes for the repo I am working on:
https://github.com/svanteschubert/gumtree/tree/develop/gen.antlr4-xml

But it fails under Linux (tested with Ubuntu with gradle 2, 3 and 4.01 and 4.02).

[jest]

As antlr/antlr4#638 is closed, would changes according to antlr/antlr4#2065 (comment) solve this issue?

[daniellansun]

Here is the workaround used by apache/groovy

https://github.com/apache/groovy/blob/master/subprojects/parser-antlr4/build.gradle#L34

[jest]

Thanks, works; with ANTLR 4.7.1 -Xexact-output-dir option has to be specified:

arguments += [ "-package", PARSER_PACKAGE_NAME, "-Xexact-output-dir" ]

[paflopes]

Solution mentioned by @danielsun1106 works great! Thanks!

[stale]

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[stale]

This issue has been automatically closed due to inactivity. If you can reproduce this on a recent version of Gradle or if you have a good use case for this feature, please feel free to reopen the issue with steps to reproduce, a quick explanation of your use case or a high-quality pull request.