Compiling 3.2 Antlr grammar with gradle

Question

I'm trying to compile my antlr grammar with gradle. I'm very new to gradle, so am having trouble working out how to fix the issue. I think it's trying to use the 2.7 antlr to compile (as I've seen a few other people reporting similar errors when using wrong version), and hence throwing errors. How can I: - Show what version of Antlr gradle is trying to use? - Get gradle to compile properly? Here's my grammar: ``` grammar Test; options { language = Java; } rule: ; ``` Here's my gradle script: ``` apply plugin: 'java' apply plugin: 'antlr' repositories { mavenCentral() } dependencies { antlr 'org.antlr:antlr:3.2' testCompile group: 'junit', name: 'junit', version: '4.+' } ``` Here's the output trying to compile: ``` $ gradle compileJava :generateGrammarSource /home/admin/workspace/BuildTools/src/main/antlr/Test.g:1:1: unexpected token: grammar :compileJava UP-TO-DATE BUILD SUCCESSFUL Total time: 2.458 secs ``` EDIT: Seems Antlr3 isn't supported directly in gradle yet. There's a pull req…

Accepted Answer

Not very knowledgeable with Gradle myself, but `generateGrammarSource` uses ANTLR 2.7.x (not sure which exact version) because if I use it on a 2.7 grammar, the .java files are properly generated.

You can always do something like this to use ANTLR 3 and Gradle:

```
task generateWithANTLR3(type:Exec) { 
  commandLine = ['java', '-cp', 'antlr-3.2.jar', 'org.antlr.Tool', 'T.g']  
}
```

(assuming the ANTLR jar and the grammar file are in the same dir as your Gradle build file)

EDIT

And you can also let the `Tool` output the generated source files in a particular directory. The following task:

```
task generateWithANTLR3(type:Exec) { 
  commandLine = ['java', '-cp', 'antlr-3.2.jar', 'org.antlr.Tool', '-o', 'src/x/y/generated/', 'T.g']  
} 
```

will put the generated files in `src/x/y/generated/`.

Compiling 3.2 Antlr grammar with gradle

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